WO2026027983A1 - Dispositif de freinage configuré pour présenter un filtrage mécanique passe-bas - Google Patents

Dispositif de freinage configuré pour présenter un filtrage mécanique passe-bas

Info

Publication number
WO2026027983A1
WO2026027983A1 PCT/IB2025/056965 IB2025056965W WO2026027983A1 WO 2026027983 A1 WO2026027983 A1 WO 2026027983A1 IB 2025056965 W IB2025056965 W IB 2025056965W WO 2026027983 A1 WO2026027983 A1 WO 2026027983A1
Authority
WO
WIPO (PCT)
Prior art keywords
pawl
inertia
inertia disk
support plate
disk
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/IB2025/056965
Other languages
English (en)
Inventor
Greg E. Schrank
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
3M Innovative Properties Co
Original Assignee
3M Innovative Properties Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 3M Innovative Properties Co filed Critical 3M Innovative Properties Co
Publication of WO2026027983A1 publication Critical patent/WO2026027983A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B35/00—Safety belts or body harnesses; Similar equipment for limiting displacement of the human body, especially in case of sudden changes of motion
    • A62B35/0093—Fall arrest reel devices
    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B35/00—Safety belts or body harnesses; Similar equipment for limiting displacement of the human body, especially in case of sudden changes of motion
    • A62B35/04—Safety belts or body harnesses; Similar equipment for limiting displacement of the human body, especially in case of sudden changes of motion incorporating energy absorbing means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D59/00—Self-acting brakes, e.g. coming into operation at a predetermined speed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D63/00—Brakes not otherwise provided for; Brakes combining more than one of the types of groups F16D49/00 - F16D61/00
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2127/00—Auxiliary mechanisms

Definitions

  • Fall-protection apparatus such as self-retracting lifelines have often found use in applications such as building construction and the like.
  • braking devices such as for use in a fall-protection apparatus such as a self-retracting lifeline.
  • a braking device may comprise at least one velocity-actuated pawl that is on a pawl-support plate and that can be actuated between a disengaged position and an engaged position, with the pawl being biased toward the disengaged position.
  • a braking device may comprise an inertia disk that is rotatable with respect to the pawl-support plate through a predetermined range between a home position and an activated position, with the inertia disk being biased toward the home position.
  • the inertia disk and the at least one pawl can be configured so that when the inertia disk is in the activated position, the velocity -actuated pawl can be actuated toward the engaged position by a rotational velocity that is lower than a rotational velocity required to actuate the pawl when the inertia disk is in the home position.
  • the at least one velocity -actuated pawl may be configured so that the pawl is a high- moment-of-inertia pawl; in one particular aspect, this may be facilitated by equipping the pawl with a ballast element.
  • the inertia disk may be a damped inertia disk; in one particular aspect, the inertia disk may be an actively damped inertia disk.
  • the at least one velocity -actuated pawl may be biased toward its disengaged position, and the inertia disk may be biased toward its home position, by way of a co-biasing arrangement using the same biasing element.
  • Fig. 5 is a partially exploded perspective view of the exemplary components shown in Fig. 4.
  • Fig. 6 is a plan view of the exemplary components shown in Fig. 4, with an exemplary inertia disk shown in a home position and with exemplary velocity -actuated pawls shown in disengaged positions.
  • Fig. 7 is a plan view of the exemplary components shown in Fig. 6, with the exemplary inertia disk shown as having moved to an activated position and with the exemplary velocity -actuated pawls remaining in disengaged positions.
  • the direction of rotation of various components is denoted as an unwinding direction, signifying that rotation in this direction will cause a safety line 115 to unwind from drum 90.
  • An opposite rotational direction is designated as a winding direction.
  • the unwinding and winding directions are indicated (by arrows “U” and “W”) in various Figures herein.
  • the term “leading” is also used herein and refers to a direction along the unwind direction of rotation; the term “trailing” refers to an opposite direction.
  • the leading and trailing directions are indicated (by arrows as “L” and “T”) in various Figures herein.
  • the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring a high degree of approximation (e.g., within +/- 20 % for quantifiable properties).
  • the term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within +/- 10% for quantifiable properties).
  • the term “essentially” means to a very high degree of approximation (e.g., within plus or minus 2 % for quantifiable properties; it will be understood that the phrase “at least essentially” subsumes the specific case of an “exact” match.
  • a braking device that may be used e.g. in a fall-protection apparatus, by which is meant an apparatus that acts to controllably decelerate a human user of the apparatus in the event of a user fall.
  • a fall-protection apparatus and a braking device thereof, is non-motorized.
  • a safety line of the apparatus is not moved (i.e., extended or retracted from a housing of the apparatus) by way of an electrically powered motor; in other words, the apparatus is not used as part of a system (e.g., an elevator, a hoist, etc.) that uses one or more motors to raise or lower a load.
  • such a fall-protection apparatus may be a self-retracting lifeline (SRL); i.e., a deceleration apparatus comprising a housing that at least partially contains a drum-wound safety line that can be extended from the housing and retracted into the housing during normal movement of a human user of the apparatus, and which, upon the onset of a user fall, automatically arrests (i.e., slows to a controlled rate, e.g., completely stops) the fall of the user.
  • SRL self-retracting lifeline
  • An exemplary fall-protection apparatus (a self-retracting lifeline) 1 is depicted in Fig. 1.
  • Various components of another exemplary self-retracting lifeline 1 are shown in partially exploded view in Fig. 2.
  • Any such apparatus may comprise a housing 111 that is provided e.g. from a first housing piece 112 and second housing piece 113 that are assembled and fastened together to form the housing.
  • Fig. 2 depicts an exemplary prototype apparatus whose housing 111 differs somewhat from the housing 111 of the exemplary apparatus of Fig. 1.
  • Housing pieces 112 and 113 may be fastened together e.g. by bolts or by any other suitable fasteners.
  • Various ancillary components such as e.g.
  • a drum 90 comprising a spool 92 and sidewalls 93 and 94.
  • Sidewalls 93 and 94 are axially spaced apart and define a receiving space 95 into which is wound (e.g., spiral-wound) a length of safety line 115 (with the term line broadly encompassing any elongate, windable load-bearing member, including e.g. webbing, cable, rope, etc., made of any suitable metal, synthetic or natural polymeric material, etc., and having any cross-sectional shape).
  • a proximal end of line 115 is connected, directly or indirectly, to drum 90 (such a connection encompasses configurations in which the proximal end of line 115 is connected to a shaft 97 on which dmm 90 is mounted).
  • Drum 90 is rotatably mounted within housing 111, e.g. by being rotatably mounted on a shaft 97 that is fixed to housing 111 (as in the exemplary design shown in Fig. 2) or by being fixed on a shaft that is rotatable relative to the housing.
  • a drum-biasing member 96 (not visible in Fig. 2 but indicated in generic representation in Fig. 1, and which may be e.g.
  • a suitable motor spring such as a spiral-coiled torsion spring
  • a suitable motor spring such as a spiral-coiled torsion spring
  • Various types and arrangements of drum-biasing motor springs are described e.g. inU.S. Patents 9925400, 10556138 and 10792523 and inU.S. Provisional Patent Application 63/527997, all of which, including any PCT patent application and/or any U.S. patent application resulting from U.S. Provisional Patent Application 63/527997, are incorporated by reference herein in their entirety.
  • a distal end of safety line 115 may comprise a gated connector 116 (which terminology broadly encompasses e.g. gated hooks, carabiners, and similar items) that allows the distal end of the safety line to be attached e.g. to a harness of a human user, to a secure anchorage, etc.
  • Apparatus 1 comprises a rotationally-activated braking device 10 as indicated in exemplary embodiment in Fig. 2. Such a braking device relies on one or more velocity-actuated pawls 20.
  • the at least one pawl 20 is fixedly co-rotatable with drum 90.
  • co-rotatable is meant that such a pawl “rotates” along with drum 90; that is, the pawl(s) moves in an orbital (circumferential) path about a center of orbital motion that coincides with the axis of rotation R a of the drum.
  • fixedly co-rotatable By fixedly co-rotatable is meant that the pawl(s) are fixed in position relative to the drum so that they will always “rotate” (or remain stationary) along with the drum.
  • such an arrangement is achieved by mounting pawls 20 on a pawl-support plate 70 that is fixedly mounted on the same shaft 97 on which drum 90 is fixedly mounted (i.e., so that pawl-support plate 70 is axially co-mounted with drum 90) and that is thus likewise fixedly co-rotatable with drum 90.
  • pawlsupport plate 70 and the pawl(s) 20 mounted thereon will rotate in lockstep with drum 90.
  • pawl-support plate 70 may be directly attached to (or, may be an integral axial extension of) sidewall 94 of drum 90; such attachment may be in addition to, or may be a substitute for, an arrangement in which the pawl-support plate and the drum are both keyed to a common shaft.
  • an arrangement in which pawl-support plate 70 and drum 90 are fixedly co- rotatable can be achieved by axially co-mounting pawl-support plate 70 and drum 90 on a shaft that is non- rotatable (relative to the housing of the apparatus) so that pawl-support plate 70 and drum 90 are both rotatable with respect to the shaft but are nevertheless in a fixed position relative to each other (e.g. are attached to each other); that is, they cannot rotate relative to each other. Any such relationship, however achieved (e.g. regardless of whether a rotatable shaft or a non-rotatable shaft is used), will be termed as pawl-support plate 70 being in fixed rotational relation with drum 90, and vice-versa.
  • drum 90 and/or pawl-support plate 70 may be rotatably mounted on a non-rotatable shaft by way of any suitable bearing (whether a plain bearing, e.g. a bushing, a roller bearing, etc.), made of any suitable material(s).
  • a plain bearing e.g. a bushing, a roller bearing, etc.
  • the one or more pawls 20 are configured (e.g. are pivotably mounted on a pawl-support plate 70) so that each pawl can pivotably move between a disengaged position and an engaged position. Such movement takes the form of pivoting about a pawl axis of pivoting (P ap , as indicated in Figs. 4 and 10b), and is different from the above-described “rotation” of pawl 20 along an orbital path around the overall axis of rotation R a of the pawl-support plate, drum, etc.
  • Each pawl 20 comprises an engaging end 22 that is configured to engage with a tooth 121 of a ratchet 120 when the pawl is in an engaged position.
  • Each pawl 20 is biased so that in ordinary use of the fall-protection apparatus, the engaging end 22 of pawl 20 is urged (e.g. radially inwardly) into a disengaged position in which it does not engage with any component (e.g. a ratchet tooth) that would limit the rotation of the pawl-support plate 70 and thus drum 90.
  • the two pawls 20 of Figs. 4 are both in a disengaged position; in this document, terminology such as a pawl moving into an engaged position will be understood to mean that the pawl pivotably moves so that an engaging end of the pawl moves into an engaged position.
  • the biasing of a pawl 20 toward its disengaged position is performed by use of a biasing element (e.g. a magnet) 54 as indicated in Figs. 4 and 5 and as discussed in detail later herein.
  • a biasing element e.g. a magnet
  • the biasing of the pawl(s) into the disengaged position allows pawl-support plate 70 and thus drum 90 to rotate freely thus allowing extension and retraction of safety line 115 in response to movements of a human user of the fall-protection apparatus as the user goes about their workplace activities.
  • At least one pawl 20 will be motivated (overcoming the biasing force of biasing element 54) toward and into an engaged position in which the engaging end 22 of the pawl is able to physically contact a tooth of a ratchet to slow and/or stop the rotation of the drum.
  • An exemplary ratchet 120 and teeth 121 thereof are depicted in exemplary embodiment in Fig. 2; however, many ratchet arrangements are possible, as discussed in detail later herein.
  • the engaging of at least one pawl with a tooth of a ratchet will at least slow, e.g. will stop, the rotation of the drum.
  • Some such braking devices may bring the dmm to a “hard stop” in which the rotation of the drum ceases nearly instantaneously when the pawl engages the tooth.
  • the safety line of such an apparatus may include a so-called shock absorber (e.g. a tear web or tear strip) to minimize the force experienced by a human user as the user is brought to a halt.
  • Some braking devices may comprise a friction brake that, rather than bringing the drum nearly -instantly to a “hard stop”, brings the drum to a halt in a more gradual manner as discussed in detail later herein. This can minimize the force experienced by a human user as a fall is being arrested, e.g. without necessarily requiring the presence of a shock absorber in the safety line.
  • an upper, anchorage end 108 of the apparatus may be connected (e.g. by way of connection feature 114) to a secure anchorage of a workplace structure (e.g., a girder, beam or the like).
  • the distal end of line 115 may then be attached (e.g., by way of gated connector 116) to a harness worn by a worker.
  • drum 90 rotates in an unwinding direction so that line 115 is extended from within housing 111.
  • drum 90 rotates in an opposing, winding direction (e.g. as urged by motor spring 96) so that line 115 is automatically retracted into housing 111 and wound upon drum 90.
  • pawl(s) 20 are biased (e.g. by biasing elements 54) so that the engaging end 22 of a pawl 20 does not engage a tooth 121 of a ratchet 120 of the rotationally -activated braking device.
  • pawl 20 is actuated, meaning that an engaging end 22 of a pawl 20 is caused to move to an engaged position in which it engages with a ratchet tooth, whereupon the rotation of drum 90 is slowed, e.g. halted, and the falling of the worker is thereby arrested.
  • Fall-protection apparatus 1 comprises at least one pawl 20 that is a velocity -actuated pawl, mounted on a pawl-support plate 70.
  • the at least one velocity-actuated pawl 20 may take the form of a pair of pawls 20.
  • the pawls 20 of such a pair may be located in circumferentially -opposing positions from each other (i.e. , on opposite sides of the axis of rotation R a of drum 90 and pawl-support plate 70, when viewed along axis of rotation R a ) as evident e.g. in Figs. 3-6.
  • a pawl 20 may be pivotably mounted on a pawl-support plate 70 by way of an aperture 28 of pawl 20 being seated onto a pawl-support post 74 of pawl-support plate 70. Pawl-support post 74 and aperture 28 thus define the above-mentioned pivot axis P ap of pawl 20.
  • aperture 28 of pawl 20 may be provided with a bushing (i.e., in the form of a hollow sleeve) 29 as shown in Fig. 4. The inner surface of pawl-bushing 29 will be in contact with the outer surface of pawl-support post 74.
  • Pawl-bushing 29 may be comprised of a suitable material, e.g.
  • a bushing 29 may be made of a material that exhibits a Shore Hardness (D scale) of from at least 20, 40, or 60 to at most 90, 80 or 70.
  • D scale Shore Hardness
  • a variety of bushings that may be suitable e.g., bushings whose bearing surface exhibits a low coefficient of friction
  • IGLIDE trade designation for IGLIDE.
  • the above-described arrangements may be reversed, i.e. the pawl may comprise a post with the pawl-support plate comprising an aperture to receive the pawl-post. In some embodiments no bushing may be present; rather, metal-to- metal contact between an aperture and a post may exist.
  • the at least one pawl 20 is configured so that upon rotation of pawl-support plate 70 around the axis of rotation R a , pawl(s) 20 will follow a generally circumferential orbital path around axis of rotation R a .
  • pawl(s) 20 will remain in a disengaged position.
  • All such pawls 20 will typically remain in their fully disengaged position (meaning that they are moved as far in their disengaging direction as possible, by the force of their biasing element(s) 54) when drum 90 and pawl-support plate 70 are stationary or rotating slowly as a user of the fall-protection apparatus goes about work activities.
  • Each of the pawls 20 of Fig. 6 is shown in such a (fully) disengaged position, held in this position by a biasing element (magnet) 54.
  • biasing force that biasing element 54 exerts on pawl 20 is generally indicated by the arrow marked Pbf, and is achieved by way of biasing magnet 54 exerting an attractive force on leading section 24 of pawl 20.
  • leading section 24 of pawl 20 can be considered to have an effective center of mass (barycenter) 35, with the attractive force that is imposed by biasing magnet 54 on leading section 24 of pawl 20 being considered as being exerted generally on the center of mass 35 of leading section 24 of pawl 20.
  • This center of mass 35 of leading section 24 of pawl 20 will necessarily be positioned forward (i. e.
  • biasing magnet 54 and pawl 20 will be configured so that when pawl 20 is in its (fully) disengaged position (and when the inertia disk 40 on which biasing magnet 54 is mounted is in its home position as discussed in detail later herein), biasing magnet 54 will be positioned generally radially inwardly from, and closely abutting, the center of mass 35 of leading section 24 of pawl 20.
  • biasing magnet 54 will be radially -oriented so that its zone of maximum magnetic force extends generally radially (e.g., the magnet will be oriented so that its north and south poles are generally radially aligned with each other), as in the exemplary arrangement depicted in Fig. 6.
  • a velocity-actuated pawl 20 is a pawl that is actuated (i.e., caused to pivotably move from a disengaged position, toward, and into, an engaged position) when the velocity of the pawl 20 along its orbital path exceeds a predetermined threshold value.
  • rotational velocity the velocity of the pawl will be referred to herein as rotational velocity. This will be understood to refer to the velocity of a pawl along its orbital path as dictated by the rotation of the pawl-support plate; this should not be confused with pivotable movement of the pawl about pawl pivot axis P ap .
  • a velocity -actuated pawl 20 may not be not significantly actuated by any acceleration that the pawl may be experiencing; however, the acceleration of some other item (e.g. an inertia disk) may modulate the velocity-response of the pawl, as discussed in detail later herein.
  • some other item e.g. an inertia disk
  • a velocity-actuated pawl 20 can be biased toward a disengaged position by way of a biasing element 54 in the form of a magnet (e.g., a permanent magnet) that is mounted on some component of the braking device 10.
  • a biasing element 54 in the form of a magnet (e.g., a permanent magnet) that is mounted on some component of the braking device 10.
  • a magnet that performs this function will be referred to herein as a biasing magnet and will be distinguished from a magnet that serves as a damping magnet, as discussed in detail later herein.
  • biasing magnets 54 are mounted in an inertia disk 40 of braking device 10, for reasons discussed in detail later herein.
  • Pawl(s) 20 may be made of any suitable ferromagnetic material; for example, a metal or metal alloy such as stainless steel (in particular, martensitic stainless steel) or galvanized steel, nickel, etc., that renders the pawl susceptible to a magnetic force.
  • a metal or metal alloy such as stainless steel (in particular, martensitic stainless steel) or galvanized steel, nickel, etc., that renders the pawl susceptible to a magnetic force.
  • any such material of which pawl 20 is made may exhibit a Relative Magnetic Permeability of greater than 100, 500, 1000, 5000, or 10000.
  • a pawl will be considered to be in an engaged position upon the pawl having been actuated so that its engaging end is in a position (e.g. having moved radially outward) in which it will contact a ratchet tooth upon continued motion of the pawl along its orbital path.)
  • Pawl 20 comprises a pivot axis P ap that is aligned with (and defined by) a pivotable connection of pawl 20 with pawl-support plate 70 as discussed above.
  • the pivot axis of pawl 20 is generally in the midsection of pawl 20.
  • pawl 20 comprises a leading section 24 that is positioned forward (that is, in a leading direction) of the pivot axis, and a trailing section 37 that is positioned rearward (that is, in a trailing direction) of the pivot axis.
  • Exemplary pawl 20 as depicted herein has a “rocker” configuration in which, when the pawl moves from its disengaged position to its engaged position, the leading section 24 of pawl 20 (which includes the engaging end 22 of the pawl) move radially outward and the trailing section 37 of the pawl moves radially inward.
  • a “rocker” pawl will comprise a trailing/leading ratio of at least 33 %. By this is meant the ratio of the linear distance from the pawl’s pivot axis to the trailing terminus of the pawl, to the linear distance from the pawl’s pivot axis P ap to the leading terminus of the pawl.
  • a rocker pawl may exhibit a trailing/leading ratio of at least 40, 50, 60, or 70 %.
  • pawls 20 as depicted e.g. in Fig. 6 exhibit a trailing/leading ratio of approximately 73 %.
  • a “rocker” pawl can be contrasted to a pawl that has a relatively short trailing section, e.g. the pawls depicted in Fig. 10 of U.S. Patent 11779783 (which exhibit a trailing/leading ratio of approximately 25 %).
  • the trailing end of a rocker pawl can be configured to have one or more surfaces that (e.g.
  • Pawl 20 comprises an overall center of mass (indicated generally by reference number 34 in various Figures) that likewise follows an orbital path as the dmm and the pawl-support plate rotate about the axis of rotation.
  • a spacer disk (not shown in any Figure) may be positioned axially between inertia disk 40 and pawl-support plate 70, to establish and maintain a desired axial spacing (e.g. of from 0.2 mm to 1.0 mm) between major axial face 44 of inertia disk and major axial face 73 of pawl-support plate 70.
  • a spacer disk may be made of any suitable material (e.g. an organic polymeric material) and may have any suitable radial size. (In particular, such a spacer disk may be much smaller in radial size than inertia disk 40 and pawl-support plate 70, as long as the spacer disk is able to maintain the desired spacing.)
  • Inertia disk 40 will thus remain in its home position unless it is subjected to a force that overcomes the biasing force on inertia disk 40 and causes inertia disk 40 to rotate, relative to pawl-support plate 70, in a trailing direction toward, e.g. into, an activated position.
  • the previously -described biasing element (magnet) 54 that biases pawl 20 toward its home position is mounted on inertia disk 40.
  • inertia disk 40 When inertia disk 40 is in its home position, rotation of dmm 90 and pawl-support plate 70 above a predetermined first threshold value of rotational velocity can overcome the pawl-biasing force applied by biasing magnet 54 and cause the engaging end of the pawl to be urged by centrifugal force into an engaged position in which it can engage a tooth of the ratchet.
  • inertia disk 40 When inertia disk 40 is rotated away from its home position, toward (e.g., into) its activated position, magnet 54 will be moved generally circumferentially away from center of mass 35 of leading section 24 of pawl 20 thus reducing the biasing force that magnet 54 applies to leading section 24 of pawl 20.
  • rotation of drum 90 and pawl-support plate 70 above a predetermined second threshold value of rotational velocity can overcome the pawl-biasing force and cause the engaging end of the pawl to be urged by centrifugal force into an engaged position in which it engages a tooth of the ratchet.
  • inertia disk 40 is in a home position and each pawl 20 is in a disengaged position.
  • Biasing magnet 54 of inertia disk 40 closely abuts the previously-described center of mass 35 of leading section 24 of pawl 20.
  • the close abutment of biasing magnet 54 to center of mass 35 of leading section 24 of pawl 20 means that a relatively high rotational velocity of pawl-support plate 70 would be needed in order for the centrifugal force on pawl 20 to overcome the biasing imposed by magnet 54 so as to cause pawl 20 to pivotably move to an engaged position.
  • buttress 80 does not participate in establishing the disengaged position of pawl 20. Rather, a first pawl-contacting surface 76 is provided in a cavity 75 of pawl-support plate 70, as most easily seen in Fig. 3. Cavity 75 (described in more detail later herein) is axially recessed relative to major surface 73 of pawl-support plate 70, and is axially -open-ended as evident from Fig. 3. (The exemplary cavity 75 as depicted in Fig. 3 is also radially-outwardly-open-ended, but it does not necessarily have to be.) Pawl 20 comprises a first contact surface 31 that is on a leading section 24 of pawl 20, as most easily seen in Fig. 5.
  • the disengaged position of pawl 20 is dictated by first pawl-contacting surface 76 of the pawl-support plate 70 rather than by any surface of buttress 80.
  • any suitable arrangement may be used.
  • an extension of buttress 80 (or an additional, separate buttress) that interacts with the trailing portion of pawl 20, may be used to establish the disengaged position of pawl 20.
  • a buttress 80 of pawl-support plate 70 can participate at least to an extent in limiting the rotational travel of an inertia disk and/or in limiting the pivotable motion of a pawl, and/or can participate at least to an extent in providing a loadbearing pathway that bears the load that develops when the pawl is engaged with a ratchet.
  • a pawl 20 and/or a buttress 80 of a pawl-support plate 70 are located within a notch 45 of an inertia disk in the general manner described above can advantageously provide a compact arrangement.
  • a pawl and/or a buttress can reside within a notch of an inertia disk.
  • a notch means to lie radially inside of an imaginary circle that coincides with the radially -outward perimeter 56 of the inertia disk (a portion of such an imaginary circle is shown in the form of dashed line 57 in Fig. 6). It is noted in passing that when inertia disk 40 is in its home position and pawl 20 is in its disengaged position, surface 47 of inertia disk 40 (as seen e.g. in Figs. 4 and 5) that is located generally toward the leading end 46 of notch 45 of inertia disk 40, is not in contact with any portion of pawl 20, as evident from inspection of Fig. 7.
  • a pawl-support post may be e.g. integral with pawl-support plate 70; or, it may be a separately-made item that is attached to pawl-support plate 70, e.g. on a pawl-support pedestal 77.
  • the above-discussed collection of components of pawl-support plate 70 e.g. buttress 80, pawl-support post 74, pawl-support pedestal 77 if present, and cavity 75 if present
  • pawl-support infrastructure may be integral with pawl-support plate 70, which in turn may be integral with drum 90.
  • drum 90, pawl-support plate 70, and so on may be made of any material that exhibits properties commensurate with the desired strength.
  • dmm 90 may be made of a molded polymer such as e.g. glass-fiber-reinforced nylon; or, drum 90 may be made of a metal such as e.g. cast or machined aluminum.
  • pawl-support plate 70 (or, in particular, pawl-support post 74) is a separately -made item from drum 90, it may be made of any material with suitable properties, e.g. steel (noting that the presence of a ferromagnetic, e.g. steel, pawl-support post 74 may necessitate that the design of pawl 20 and/or biasing magnet 54 be adjusted to take into account the presence of the ferromagnetic post).
  • the value of acceleration that modulates the velocity-response of a pawl 20 can be set as desired. It might seem that such a threshold should be set at 1.0 g (i.e., the nominal acceleration to which a falling user would be subjected). However, various factors (e.g. the presence of a motor spring that exerts a retracting force on the safety line, inertial and/or frictional effects of the various system components, the fact that an initial stage of a user fall might be at least slightly hindered by some object or structure, etc.) are such that it has usually been found appropriate to set the acceleration threshold at least slightly below 1.0 g.
  • such an acceleration threshold may be set to any suitable value, e.g. less than 0.95, 0.9, 0.8, 0.7, or 0.6 g. In further embodiments, such a threshold may be at least 0.5, 0.6, 0.7 or 0.8 g.
  • the above-described acceleration threshold is described in terms of the linear acceleration experienced by the extended portion of safety line 115 (and thus to a user connected thereto). This can be converted to an actual value of the threshold of rotational acceleration of pawl-support plate 70, in view of the specific design of the fall-protection apparatus. This can be used to set particular parameters (e.g. mass and mass distribution of the inertia disk, the strength, position and orientation of biasing magnet(s) 54, and so on, to ensure that inertia disk 40 rotates relative to pawl-support plate 70 (in order to modulate the velocity-response of pawl 20) at a predetermined rotational acceleration that corresponds to the desired threshold of acceleration experienced by the user.
  • parameters e.g. mass and mass distribution of the inertia disk, the strength, position and orientation of biasing magnet(s) 54, and so on, to ensure that inertia disk 40 rotates relative to pawl-support plate 70 (in order to modulate the velocity-re
  • a rotationally-actuated braking device may be configured so that the one or more pawls of the device is/are actuated at a nominal user-falling velocity in the range of e.g. 8, 10, or 12 feet per second if the acceleration is relatively low (e.g., less than 0.7, 0.6 or 0.5 g) so that inertia disk 40 remains in its home position; and, so that the one or more pawls is/are actuated at a nominal user-falling velocity in the range of e.g. 4, 5, or 6 feet per second if the acceleration is sufficient (e.g., is at least 0.5, 0.6, 0.7, or 0.8 g or more) so that inertia disk 40 is rotated to its activated position.
  • the acceleration is relatively low (e.g., less than 0.7, 0.6 or 0.5 g) so that inertia disk 40 remains in its home position
  • the acceleration is sufficient (e.g., is at least 0.5, 0.6, 0.7
  • the effective radius of the rotating item (the remaining portion of cable that has not yet unwound from the dmm) will experience occasional, small perturbations due to the slight winding inhomogeneities. (The cable-wrapped drum will of course also undergo an overall reduction in effective radius as the unwinding of the cable progresses.)
  • the rotational velocity of the drum may not necessarily increase in a smooth manner as dictated by the gravitationally -induced acceleration; rather, it may exhibit high-frequency noise e.g. in the form of short-duration spikes and/or valleys that are superimposed on the overall acceleration curve.
  • the present investigations have thus revealed a problem in the form of occasional inconsistency in the behavior of acceleration-modulated braking devices when performing a fall-arrest. While the problem does not necessarily preclude acceleration-modulated braking devices from being successfully used, the present investigations have indicated that solving the problem can significantly enhance the performance of at least some acceleration-modulated braking devices.
  • the source of the problem is that in an acceleration-modulated braking device, the effects of small inhomogeneities in cable-wrapping are amplified: the rotational velocity is proportional to the effective radius of a rotating item, and the rotational acceleration of an item is the derivative of the rotational velocity of the item.
  • acceleration-modulated braking devices exhibit this problem (e.g. in the form of inconsistency in braking performance), nor the source of this problem, appear to have been disclosed or even recognized in the art.
  • an acceleration-modulated braking device is very sensitive to perturbations in the rotational velocity of a drum caused by fluctuations in how the cable unwinds from the drum (which, in turn, arises from inhomogeneities in how the cable was wound upon the drum).
  • perturbations are typically manifested as high-frequency noise.
  • each such perturbation typically occurs over a very short time scale (e.g., less than 0.02 seconds; in comparison, a fall/arrest typically occurs over a relatively long time scale of e.g. 0.2 seconds or more).
  • an acceleration-modulated braking device configured to exhibit the characteristics of a low-pass mechanical filter can allow the sensitivity of the braking device to such high-frequency noise to be substantially reduced.
  • the term “low-pass” is with respect to the frequency domain, and denotes an item, assembly, mechanism, device, arrangement, etc. that is relatively insensitive to events of short time duration, e.g. of less than 0.02 seconds in length.
  • an acceleration-modulated braking device can be formulated that still achieves the previously- discussed advantages of such braking devices (e.g., more rapid onset of braking, with commensurate reduction in fall-arrest distance), but with the braking device exhibiting enhanced consistency in fall-arrest performance.
  • moment of inertia mass moment of inertia (also known as rotational inertia, and not to be confused with area moment of inertia), which is a scalar quantity obtained for a point mass by multiplying the mass by the square of the distance to the axis of rotation.
  • the moment of inertia can be obtained as the sum of the moments of inertia of the component masses of the pawl (as can be calculated e.g. by CAD software). In the present usage, this moment of inertia will be with respect to pivotable movement of a pawl 20 around its pivot axis P ap .
  • a fall-protection apparatus such as a selfretracting lifeline of a configuration as commonly used, for example, with a drum with a spool diameter of e.g. 2-6 inches, and with a safety line (e.g. a steel cable) of e.g. 3/16 to 7/32 inch in diameter (or equivalent diameter in the case of a non-circular-cross-section lifeline) and with a length of e.g.
  • a pawl that exhibits a moment of inertia of at least 130 g-cm 2 can provide significant benefits in addressing and overcoming the above-discussed problem.
  • a pawl that exhibits a moment of inertia of at least 130 g-cm 2 is thus defined herein as a high-moment-of-inertia pawl.
  • the exemplary prototype pawls as shown in the Figures herein were made of (martensitic) stainless steel and exhibited a mass of approximately 75 grams, and exhibited a moment of inertia of approximately 237 g-cm 2 .
  • This moment of inertia is compared to those of pawls of braking devices of representative self-retracting lifelines in the art, in Table 1.
  • Comparative Example (CE) 1 is the pawl used in the NANO-LOK self-retracting lifeline available from 3M Fall Protection; pawls of this type are also disclosed in U.S. Patent 9488235.
  • Comparative Example CE-2 is the pawl used in the TALON self-retracting lifeline available from 3M Fall Protection.
  • Comparative Example CE-3 is the pawl used in the SEALED-BLOK self-retracting lifeline available from 3M Fall Protection; pawls of this type are also disclosed in U.S. Patents 8567562 and 9925400.
  • Comparative Example CE-4 is the pawl used in the SMART-LOCK and ULTRA-LOK self-retracting lifelines available from 3M Fall Protection; pawls of this type are also disclosed in U.S. Patents 9764172 and 11504557.
  • Comparative Example CE-5 is the pawl used in the PROTECTA (REBEL) self-retracting lifeline available from 3M Fall Protection; pawls of this type are also disclosed in U.S. Patent 11779783.
  • the exemplary high-moment-of-inertia pawls disclosed herein comprise a moment of inertia that is significantly larger than that of representative pawls heretofore disclosed in the art. It is noted that none of the above-cited patents, and indeed no prior art document of which the applicant is currently aware, actually disclosed the moments of inertia of any prior art pawls (the moments of inertia of these representative prior art pawls were calculated by the applicant.) Nor has any known source disclosed that the moment of inertia of a pawl has been found to be a result-effective design parameter, whether in the general case of a conventional velocity -actuated pawl, or in the particular case of a pawl that is configured so that its velocity -actuation can be modulated based on acceleration experienced by some other item of the braking device that the pawl is used in.
  • a high-moment-of-inertia pawl of the general type disclosed herein may exhibit a moment of inertia of at least 150, 170, 190, 210, or 230 g-cm 2 ; in further embodiments, such a pawl may exhibit a moment of inertia of at most 400, 350, 300, or 250 gm-cm 2 .
  • a presently preferred range is from 200 to 250 g-cm 2 ; however, it will be understood that an optimum range of moment of inertia may depend on the design of any particular braking device.
  • pawl 20 comprises a main body 21 that comprises a leading portion 25 and a trailing section 37.
  • Pawl 20 comprises a ballast element 26 that extends at least generally axially (that is, along the axial direction “a” of the braking device) from leading portion 25 of pawl 20.
  • Leading portion 25 and ballast element 26 thus constitute leading section 24 of pawl 20, with the demarcation between ballast element 26 and leading portion 25 being indicated by dashed line 27.
  • pawl 20 is comprised of main body 21 (comprising leading portion 25 and trailing section 37) along with ballast element 26 that extends axially from leading portion 25 of main body 21.
  • Ballast element 26 may be a separately -made item that is attached to leading portion 25; or, in many convenient embodiments, ballast element 26 may be integral with leading portion 25 and with the entirety of pawl 20.
  • Ballast element 26 advantageously allows the inclusion of a large amount of mass in the leading section 24 of pawl 20 so that the desired high moment of inertia of pawl 20 may be achieved.
  • This substantial amount of mass in the leading section 24 of pawl 20 also advantageously provides a large amount of ferromagnetic material for biasing magnet 54 to exert an attractive magnetic force on, so that the desired biasing force on pawl 20 (as well as on inertia disk 40) can be achieved. All this can be done while preserving an overall center of mass 34 of the pawl that is suitable for velocity -actuation of the pawl, and without unacceptably increasing the total footprint of the pawl.
  • ballast element 26 does require additional empty volume to be present to accommodate ballast element 26, in the axial direction.
  • this is achieved by providing pawl-support plate 70 with a cavity 75 (most easily seen in Figs. 3 and 5).
  • Cavity 75 is axially recessed relative to major surface 73 of pawl-support plate 70, and is axially -open-ended, both as evident from Fig. 3.
  • Cavity 75 is configured to accommodate ballast element 26 of pawl 20 therein, and to allow pawl 20 to move between the disengaged position and engaged position without hindrance from the presence of ballast element 26.
  • cavity 75 is partially defined by a surface 76 (indicated in Fig.
  • inertia disk 40 can be damped.
  • inertia disk 40 can be arranged so that motion of inertia disk 40 towards its activated position; and, motion of inertia disk 40 towards its home position, are opposed by a damping force.
  • the damping of an item e.g. an inertia disk 40, is thus distinguished from the previously-described biasing, which is specifically limited to providing a force that opposes the movement of an item in one direction, but not in a second, opposing direction.
  • a damping magnet 55 can be positioned at any suitable distance from major axial surface 73 of pawl-support plate 70 that allows the above-described magnetic damping to operate. Such a distance will be the distance of closest approach between damping magnet 55 and any point on major axial surface 73. In various embodiments, such a distance may be less than 6.0, 4.0, or 2.0 mm. In further embodiments, such a distance may be greater than 0.5, 1.0, or 1.5 mm.
  • damping mechanisms may be envisioned, subject to the limitation that any such damping must act to oppose motion of an inertia disk (or whatever item is to be damped) in a first direction and in a second, opposing direction, as discussed above.
  • One possible arrangement is frictional damping, as achieved e.g. by the presence of a frictional-damping entity that has a suitable frictional surface that will oppose the motion of inertia disk 40.
  • a frictional surface of a frictional-damping entity may be e.g. in axial contact with a major axial face of inertia disk 40 (e.g.
  • An arrangement in which an inertia disk is bidirectionally frictionally damped will be distinguished from, e.g., the use of unidirectional friction brakes that bring a rotating dmm (and/or its associated pawl-support plate, etc.) to a stop in the manner described later herein.
  • a biasing magnet and/or a damping magnet may be a permanent magnet chosen e.g. from rare-earth materials and alloys thereof, such as e.g. neodymium (typically alloyed with iron and boron), samarium-cobalt, and so on. Any such magnet may be used e.g. in a “button” geometry (as with magnets 55 as visible in Fig. 9), or in an elongate “cylinder” or “bar” format (magnets 54 are of this type, noting that only the radially outward faces of magnets 54 are visible in the Figures herein).
  • rare-earth materials and alloys thereof such as e.g. neodymium (typically alloyed with iron and boron), samarium-cobalt, and so on. Any such magnet may be used e.g. in a “button” geometry (as with magnets 55 as visible in Fig. 9), or in an elongate “cylinder”
  • a biasing magnet 54 may be radially -oriented so that its zone of maximum magnetic force extends generally radially outward toward leading section 24 of pawl 20; and, a damping magnet 55 may be axially -oriented so that its zone of maximum electromagnetic field extends generally axially, toward pawl-support plate 70.
  • inertia disk 40 could be biased by way of one or more mechanical springs (e.g.
  • inertia disk 40 includes an aperture (numbered 59 in inertia disk 40 in Fig. 5) to allow, if desired, a coil spring to be seated in shoulder 51 of inertia disk 40.
  • a coil spring acting in compression (e.g. with its opposing end abutted against surface 84 of buttress 80) would act to bias inertia disk 40 towards its home position.
  • a biasing magnet might be mounted on a pawl, whether in addition to, or in place of, a previously -described biasing magnet that is mounted on inertia disk 40.
  • at least a local area of an entity e.g., an inertia disk or a pawl-support plate
  • a complementary biasing magnet may be mounted in such a local area, e.g.
  • any damping magnets may be varied.
  • one or more damping magnets could be mounted on axial side 43 of inertia disk 40 rather than being mounted on the pawl-support-plate-facing axial side 44 of inertia disk 40 as described earlier herein.
  • Such damping magnets could be used in combination with, e.g., a dedicated damping disk that is made of a suitably conductive material and is positioned so that the damping magnets on axial face 43 of the inertia disk will cause eddy currents in the damping disk upon movement of the damping magnets relative to the damping disk.
  • the damping disk can be configured so that it is in fixed rotational relation with the pawlsupport plate (e.g.
  • an inertia disk 40 and pawl(s) 20 may be biased separately and independently, e.g. by separate biasing magnets, by separate biasing springs, or by any combination of magnet(s) and spring(s), rather than being co-biased in the manner described earlier herein.
  • any of the herein-disclosed concepts may be used in braking devices that are arranged at least somewhat differently from the exemplary devices disclosed herein.
  • U.S. Patent 11779783 discloses a braking device in which one or more pawls is mounted on a pawl-support plate that is rotatable relative to a drum, but is biased into a first position.
  • Each pawl is biased by a biasing spring whose other end is connected to the drum rather than to the pawl-support disk. Sufficient rotational acceleration will overcome the biasing of the pawl-support plate and cause the pawl-support plate to lag-rotate relative to the drum. This will change the length of the pawl-biasing spring thus modulating the response of the pawl to velocity as discussed in detail in the ‘783 patent.
  • Various of the herein-disclosed approaches may be incorporated into a braking device of the general type described in the ‘783 patent.
  • any such pawls may be equipped with a ballast element, and so on.
  • Another possibility is to include one or more damping magnets in the pawl-support plate of the ‘783 braking device to cause eddy currents in the drum (in such a case, the drum would need to be made of, or include, a sufficient amount of an electrically- conductive material) so as to damp motion of the pawl-support plate relative to the drum.
  • one or more damping magnets could be mounted e.g.
  • a braking device as disclosed herein may be self-unlocking.
  • the zone of highest magnetic force of the biasing magnet 54 is circumferentially offset from the leading section 24 of pawl 20. That is, in such circumstances the biasing magnet 54 will be located e.g. generally radially inward of the pivot axis P ap of the pawl (as in Fig.
  • inertia disk 40 will begin to rotate away from its activated position toward its home position, and/or pawl 20 will begin to pivot away from its engaged position toward its disengaged position, as urged by biasing magnet 54.
  • the force that the motor spring exerts on the drum can cause the drum, and thus the pawl-support plate, to begin to rotate in the winding direction. This will cause the pawls to move orbitally in the winding direction.
  • the pawls, and the ratchet of the braking device can be configured so that this retrograde orbital movement of the pawls causes a secondary contact surface 38 (indicated in Fig. 8) of a pawl 20 to contact a secondary pawl-contact surface 122 of the ratchet. As indicated in Fig.
  • a secondary pawl-contact surface 122 will be the gently-sloped “backside” of a ratchet tooth 121. This glancing-angle contact between surfaces 38 and 122 will urge the leading section 24 of the pawl 20 at least slightly radially inward. At this point, the force of biasing magnet 54 can take over and cause the pawl to continue to pivotably move into its disengaged position and cause the inertia disk to rotate into its home position in the general manner described above.
  • the arrangements herein cause at least one pawl to engage with a tooth 121 of a ratchet 120.
  • This can either stop the rotation of drum 90 directly (and e.g. near-instantaneously, in the case of a “hard-stop” arrangement as mentioned earlier herein), or can activate a friction brake that brings the rotation of drum 90 to a halt.
  • ratchets and the manner in which one or more pawls engage with a tooth of the ratchet, are possible.
  • the pawls are configured so that the engaging end 22 of a pawl 20 will travel from a disengaged position to an engaged position by moving generally radially outward.
  • Such arrangements are typically used with a radially -inward-facing ratchet (meaning a ratchet with radially inward-facing teeth; e.g. a ratchet ring of the general type exemplified by ratchet 120 of Fig. 2 herein).
  • a velocity -actuated pawl 20 may be configured so that the engaging end of the pawl travels from a disengaged position to an engaged position by moving generally radially inward rather than outward, as noted above.
  • a ratchet e.g. a ratchet ring or disc
  • a ratchet rather than being provided e.g. as a toothed disk or ring that is made separately and inserted into a housing of a fall-protection apparatus, may be provided e.g. as an integral (e.g. molded, cast, or machined) feature of the housing of the apparatus.
  • the PROTECTA REBEL fall-protection apparatus available from 3M Fall Protection, Red Wing, MN, is an example of a product that uses this type of ratchet. Another possible variation in ratchet design is presented in U.S.
  • a ratchet takes the form of a single tooth (“stop member”) that is provided as an integral part of a bracket (e.g., a load-bearing bracket) of a fall-protection apparatus.
  • stop member e.g., a load-bearing bracket
  • a ratchet of a rotationally -activated braking device can be any component (e.g. a toothed disk or ring or partial disk or partial ring, or a portion of a fallprotection bracket or housing) that includes at least one tooth that can be engaged by an engaging end of a pawl to initiate a braking operation of the rotationally -activated braking device.
  • ratchet is used for convenience of description; use of this term does not require that the ratchet and pawl(s) must necessarily be arranged e.g. so that relative rotation of these components is permitted in one direction but is precluded in the opposite direction. (However, the ratchet and pawl(s) can be arranged so that such functionality is provided if desired.)
  • a rotationally -activated braking device as disclosed herein can bring a drum to a “hard stop” (e.g. the braking device may rely on a ratchet that is non-rotatably fixed to the housing of the apparatus), as mentioned earlier herein.
  • a rotationally-activated braking device as disclosed herein may comprise a friction brake.
  • a friction brake will comprise at least one layer of friction material and at least one rotatable member, with a friction-braking surface of the layer of friction material being in contact (typically, at all times during ordinary use of the fall-protection apparatus) with a contact surface of the rotatable member.
  • a rotatable member an item (e.g., a disk, ring, rotor, or the like) that is configured so that the member and the layer of friction material can be set into rotating motion relative to each other upon sufficient differential torque being applied to the layer of friction material and the rotatable member as the result of the engaging of a pawl with a ratchet of the rotationally-activated braking device.
  • the friction-braking surface of the layer of friction-braking material and the contact surface of the rotatable member are constantly pressed together to provide sufficient static frictional force that, as a human user moves about a workplace in ordinary use of the apparatus, there is no relative motion between the two surfaces.
  • a rotationally -activated braking device may comprise a friction brake of the general type disclosed in the isolated exploded view of Fig. 3 of the above-mentioned U.S. Patent 11504557.
  • a friction brake of the general type disclosed in the isolated exploded view of Fig. 3 of the above-mentioned U.S. Patent 11504557.
  • FIG. 3 of the ‘557 patent is merely one example of a friction brake, in which two friction layers axially sandwich the rotatable member (which, in the ‘557 design, is the ratchet itself).
  • Another exemplary friction brake is depicted in Fig. 4 of U.S. Patent 8430206; in the ‘206 friction brake, there is only a single friction layer.
  • Another exemplary friction brake is depicted in Fig. 3 of U.S. Patent 9925400; in the ‘400 friction brake, there are two rotatable members, each rotatable member being axially sandwiched between a pair of friction layers.
  • a friction layer may use any suitable friction material, e.g. cork, rubber, and so on. Some friction materials that may be particularly useful are described in the above-referenced U.S. Patent 11504557.
  • any compatible type, design or arrangement of ratchet, rotatable member, friction material, and so on may be used in combination with the herein-disclosed high-moment-of-inertia pawls, damped inertia disk, etc.
  • a shaft 97 (most easily seen in Fig. 2) that is rotatably mounted in the housing 111 of the apparatus, with drum 90 and pawl-support plate 70 being fixed to shaft 97 so that they cannot rotate relative to shaft 97 (rather, shaft 97, drum 90, and pawlsupport plate 70 will all rotate in unison).
  • any one, any subset, or all of the concepts disclosed herein may be used with an arrangement in which a shaft is fixed to a housing so that the shaft cannot rotate relative to the housing.
  • drum 90 and pawl-support plate 70 may be rotatably mounted on the shaft so that both can rotate relative to the shaft; however, they may be configured so that they cannot rotate relative to each other. In some embodiments, this may be achieved by making pawl-support plate 70 an integral part of drum 90; however, in other embodiments, pawl-support plate 70 may be a separately-made item that is then attached to dmm 90 or is otherwise connected to drum 90, directly or indirectly, in such manner as to ensure that pawl-support plate 70 cannot rotate relative to drum 90. In such an arrangement, drum 90 and pawl-support plate 70 will rotate in unison while the shaft remains stationary.
  • a fall-protection apparatus comprising any or all of the concepts disclosed herein, may comprise a housing 111, e.g. as formed by the assembling together of two major housing pieces 112 and 113, that is load-bearing.
  • a housing 111 e.g. as formed by the assembling together of two major housing pieces 112 and 113, that is load-bearing.
  • an item being load-bearing is meant that the item is configured so that in the event of a user fall, the item bears the static load of the user’ s weight as well as bearing any temporary , dynamic forces that arise from arresting the user’s fall.
  • housing 111 being load-bearing is meant that in the event of a user fall, a load that is developed in arresting the fall travels through a force-transmitting pathway that substantially passes through housing 111.
  • the housing pieces that collectively provide a loadbearing housing 111 may be formed of any suitable material(s), e.g. steel or aluminum. In some embodiments, such housing pieces may be made of organic polymeric materials, e.g. reinforced with fillers such as glass fiber, carbon fiber and the like. Load-bearing housings and materials that may be suitable for use in such housings are described in U.S. Patent 8430206, which is incorporated by reference herein in its entirety.
  • a fall-protection apparatus comprising any or all of the concepts disclosed herein may comprise a housing 111 that is not load-bearing.
  • a load-bearing member (which may be variously referred to e.g. as a bracket, clevis, or stirrup) that is generally U-shaped with a drum-bearing shaft being installed in the gap between the “arms” of the U-shaped member.
  • a fall-protection apparatus as disclosed herein may comprise a housing configured so that an interior compartment of the apparatus is at least partially sealed (such as in the product line available from 3M Fall Protection under the trade designation (SEALED-BLOK) e.g. for use in harsh or marine environments.
  • SEALED-BLOK 3M Fall Protection under the trade designation
  • such a fall-protection apparatus may be configured in the general manner of those disclosed e.g. in U.S. Patents 9925400 and 10556138, which are incorporated by reference in their entirety herein. In general, such arrangements may involve configuring a housing to have two (or more) compartments separated by one or more seals, gaskets, partitions, or the like.
  • a first compartment may contain items that are desired to be isolated from the outside environment (e.g., any or all of a pawl-support plate, one or more pawls, an inertia disk, a ratchet, and a friction brake assembly if present), and may be shielded, e.g. by the one or more seals, gaskets or partitions, from the second compartment and from the outside environment.
  • a second compartment may include e.g. a drum with a safety line attached, along with any other items that do not necessarily need extra shielding from the outside environment; this second compartment will be open to the outside environment (e.g. by way of a through- aperture) at least to an extent necessary to allow the safety line to extend out of the second compartment.
  • the arrangements disclosed herein may be advantageously used in any fall-protection apparatus; in particular, in a self-retracting lifeline.
  • fall-protection apparatus such as e.g. self-retracting lifelines in which the arrangements disclosed herein may be advantageously utilized, are described in U.S. Patents 8181744, 8256574, 8430206, 8430207, 8511434, 9488235, and 10556138.
  • the arrangements disclosed herein may be used in any fall-protection apparatus, e.g. self-retracting lifeline, in which there is a desire to enhance the performance of the apparatus in the general manner discussed herein.
  • such an apparatus may be a self-retracting lifeline that meets the requirements of ANSI Z359.14-2021 (as updated August 2023).
  • a selfretracting lifeline may be an ANSI Z359.14 Class 1 device e.g. for use with an anchor point above the dorsal D-ring of the safety harness of a user; or, an ANSI Z359.14 Class 2 device e.g. for use with an anchor point above, at, or as much as five feet below the dorsal D-ring of the safety harness of a user (e.g., a “leading edge” rated apparatus).
  • such a self-retracting lifeline may comprise a housing that is e.g.
  • such a selfretracting lifeline may be a so-called “personal” self-retracting lifeline (e.g., that falls within ANSI Z359.14 category SRL-P), that comprises a housing that is attachable to a harness of a human user and that comprises a safety line with a distal end (comprising e.g. a gated connector) that can be attached e.g. to an anchorage.
  • a selfretracting lifeline may be a so-called “personal” self-retracting lifeline (e.g., that falls within ANSI Z359.14 category SRL-P), that comprises a housing that is attachable to a harness of a human user and that comprises a safety line with a distal end (comprising e.g. a gated connector) that can be attached e.g. to an anchorage.
  • a fall-protection apparatus as described herein may comprise a housing, dmm, rotationally-activated braking device, etc., of any desired size.
  • the size of the rotationally -activated braking device may be characterized e.g. in terms of the diameter of the orbital path that is followed by the pivot axis (P ap ) of the velocity -actuated pawl(s) 20, when viewed along the axial direction “a” of the braking device.
  • the diameter of such an orbital path may be at least 20, 30, 40, or 50 mm; in further embodiments, the diameter of such an orbital path may be at most 150, 120, 90, or 60 mm.
  • a fall-protection apparatus as described herein may be used in concert with, or as part of, any suitable fall-protection system such as e.g. a horizontal lifeline or retractable horizontal lifeline, a positioning lanyard, a shock-absorbing lanyard, a rope adjuster or rope grab, a vertical safety system (such as e.g. a flexible cable, rigid rail, climb assist, or fixed ladder safety system), a confined- space rescue system, davit system or hoist system, and so on.
  • a fall-protection apparatus may be installed on an aerial lift (e.g., an order picker, scissor lift, and so on).
  • any such fall-protection apparatus may include, or be used with, various ancillary items which are not described in detail herein.
  • Such items may include, but are not limited to, one or more of lanyards, shock absorbers, tear strips, harnesses, belts, straps, paddings, tool holsters or pouches, impact indicators, carabiners, D-rings, anchorage connectors, and the like.
  • Many such apparatus, products, and components are described in detail e.g. in the 3M DBI-SALA Full-Line Catalog (2022).
  • the safety line of the apparatus may comprise an in-line shock absorber e.g.
  • a fall-protection apparatus that is “non-motorized” as defined and described earlier herein, may still include such items as one or more electrically -powered sensors, monitors, communication units, actuators, and the like.
  • a fallprotection apparatus as described herein may serve merely to slow the fall of a user, and/or to allow the user to descend at a controlled rate.

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  • Emergency Lowering Means (AREA)

Abstract

La présente invention concerne un dispositif de freinage tel que destiné à être utilisé dans un appareil de protection contre les chutes tel qu'une ligne de vie auto-rétractable. Le dispositif de freinage peut comprendre un cliquet actionné par la vitesse qui est conçu pour être un cliquet à moment d'inertie élevé, par exemple en équipant le cliquet d'un élément de ballast. Le dispositif peut comprendre un disque d'inertie qui est amorti, par exemple un disque d'inertie amorti activement. Le cliquet actionné par la vitesse peut être sollicité vers une position désengagée, et le disque d'inertie peut être sollicité vers une position de repos, au moyen d'un agencement de co-sollicitation utilisant le même élément de sollicitation.
PCT/IB2025/056965 2024-07-29 2025-07-09 Dispositif de freinage configuré pour présenter un filtrage mécanique passe-bas Pending WO2026027983A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US202463676551P 2024-07-29 2024-07-29
US63/676,551 2024-07-29

Publications (1)

Publication Number Publication Date
WO2026027983A1 true WO2026027983A1 (fr) 2026-02-05

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2025/056965 Pending WO2026027983A1 (fr) 2024-07-29 2025-07-09 Dispositif de freinage configuré pour présenter un filtrage mécanique passe-bas

Country Status (1)

Country Link
WO (1) WO2026027983A1 (fr)

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