US3655012A - Universal folding ladder - Google Patents

Universal folding ladder Download PDF

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Publication number
US3655012A
US3655012A US59505A US3655012DA US3655012A US 3655012 A US3655012 A US 3655012A US 59505 A US59505 A US 59505A US 3655012D A US3655012D A US 3655012DA US 3655012 A US3655012 A US 3655012A
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US
United States
Prior art keywords
releasing lever
stop member
joint
recesses
ladder
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.)
Expired - Lifetime
Application number
US59505A
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English (en)
Inventor
Helmut Hoffman
Walter Hoffman
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Individual
Original Assignee
Individual
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Filing date
Publication date
Priority claimed from DE19691938696 external-priority patent/DE1938696A1/de
Priority claimed from DE19702006846 external-priority patent/DE2006846C3/de
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3655012A publication Critical patent/US3655012A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06C—LADDERS
    • E06C1/00—Ladders in general
    • E06C1/02—Ladders in general with rigid longitudinal member or members
    • E06C1/32—Ladders with a strut which is formed as a ladder and can be secured in line with the ladder

Definitions

  • ABSTRACT A folding ladder is formed of several pairs of ladder sections connected by a joint.
  • the joint includes on one section a circular locking disc concentric with the joint axis and with recesses about its periphery corresponding to the different positions of the ladder sections, and a stop member on the other section engageable in the recesses.
  • a releasing lever is provided which lift the locking member out of the recesses.
  • An arresting device associated with the releasing lever locks the releasing lever in its releasing position during movement of the ladder sections with respect to each other in one direction and disengages the releasing lever at the end of such movement.
  • the present invention relates to a universal-folding ladder serving for multiple use and more especially to a ladder comprising several pairs of ladder sections or beams or stringes which are interconnected by joints or fittings and which can be locked in the flat or straightly extended position and in at least one preferred service position, each of said joints connecting two ladder sections and comprising a first joint member connected to either of the said two ladder sections and having at least one circular locking disk arranged concentrically with the joints axis, with recesses provided preferably at equal distances about its periphery which are associated to the flat or straightly extended position and to the different preferred service positions, respectively, and further comprising an other joint member which is rigidly connected to the other one of the said two ladder sections and further connected with the locking disk of the said first joint member so as to be pivotable about a joint pin, a stop member being provided and guided on the said second joint member which snugly fits into the different individual recesses, respectively, when the said ladder sections are in any of
  • an arresting or locking device engaging with and, thus, locking, the releasing lever in its operative position and disengaging from, and releasing, the releasing lever again when the joint members perform a subsequent relative rotation.
  • the universal folding ladder with multiple use according to the invention which may be employed for instance as working platform, single and double ladder and the like, offers the special advantage that the joints can be adjusted without any difficulty and with ease virtually with one hand, and that it warrants at the same time absolute service reliability.
  • the joint parts can be locked just as with ladders of the conventional type in each of the preferred positions when the ladder is being unfolded, it being impossible to bring the joint parts into the next position unless the arresting device has been released first, while contrary to most of the known arrangements no locking of the ladder parts will place between the initial and the end position when folding the ladder together, so that it is not necessary to operate the releasing lever at any time during the folding process.
  • FIG. 1 is a side elevation of a ladder joint or fitting according to the invention with the outer part of the one joint member partly removed, the joint being locked in one service position and the releasing lever being in one first position,
  • FIG. 2 is a side elevation of the joint or fitting according to FIG. 1 shown in the same position but with the joint unlocked and with the releasing lever in a second position allotted thereto,
  • FIG. 3 is a cross-section taken along the line III-III in FIG. 1
  • FIG. 4 is a cross-section taken along the line IVIV in FIG.
  • FIG. 5 is a front elevation of a detail of another embodiment of the invention shown in an intermediate stage during the manufacture thereof
  • FIG. 6 is a cross-section similar to that shown in FIG. 3 of the embodiment according to FIG. 5,
  • FIG. 7 is a side elevation of the releasing lever of another embodiment of the invention with the associated spring member
  • FIG. 8 is a side elevation of the joint or fitting member associated with the releasing lever in its disengaged or inoperative position
  • FIG. 9 is a side elevation of the joint or fitting member carrying the cams with the releasing lever in its disengaged or inoperative position
  • FIG. 10 is also a side elevation of the arrangement according to FIG. 9, but with the releasing lever in its engaged or operative position, and
  • FIG. 11 is a diagrammatic side elevation of an embodiment of the ladder rungs to be used together with the novel joint or fitting.
  • the novel ladder comprises several pairs of ladder sections which are interconnected by joints or fittings 9 and which can be locked in the respective service position, each of the said fittings or joints comprising one first joint member 11 connected to one ladder stringer or beam or section 10 and comprising at least one circular locking disk 12 of cup-shaped cross-section with preferably rectangular, for instance squareshaped recesses distributed about its periphery in correspondence with or according to the different individual service positions of the ladder or, rather, ladder members.
  • the number of such recesses may be for instance three (13, l4, 15) corresponding to a flat position, an obtuse-angled and an acute-angled position of the joint or fitting, i.e., to a service position of the ladder known as single ladder, double ladder or working platform, etc., or else there may be provided only two recesses.
  • the locking disk 12 has a bottom surface 23 with bead-like or fin-type reinforcements forming the joint outside and a circular flange 24 forming the lateral extension of such bottom surface, with the radial recesses 13, 14, 15 being provided in the transition zone 25.
  • the locking disk of the middle joint 9 or fitting may have only recesses 13, 15 spaced approximately by a central angle of l20-l40 in the direction opposite to the sense of rotation, while the locking disks of the two outer joints may have each recesses I3, 14 spaced by approximately 6080.
  • the joint or fitting 9 comprises a second joint member 17 arranged essentially in parallel relation to the locking disk 12 and pivoted on the latter by means of a joint pin 16, the said second joint member 17 being connected to the other ladder beam or section 18 and comprising a disk 26, the said joint member 17 carrying a stop member 20 which snugly fits into the recesses l3, 14 or 15 when the ladder assumes any of the individual service positions and which is loaded by a spring, for instance, a spiral spring 19 bearing with its one end against the bottom of the hole 31.
  • a spring for instance, a spiral spring 19 bearing with its one end against the bottom of the hole 31.
  • the said stop member has associated to it a releasing lever 21 pivoted on the second joint member 17 and to be operated from the outside, by means of which the stop member 20 is lifted off the recesses 13, 14 or 15 when it is rotated in the direction indicated by the arrow 28.
  • the disk 26 which rests against the circular flange 24 of the associated locking disk 12 may have the form of a single or or a double disk, its wall being provided, respectively with a guide slot 27, 27a within which the stop member 20 is held so as to be positively connected or to have a form fit in the circumferential direction and as to be slidable in the radial direction, said stop member being held between the locking disk 12 and the disk 26 of the second joint member 17, the associated spring 19 arranged between the stop member 20 and the abutment 30, pressing the said stop member outwardly in the radial direction and into the associated recess 13 or 13a,
  • Each joint or fitting may consist of only one locking disk and only one disk of the other joint member co-operating therewith.
  • the first joint member 11 may also comprise two parallel locking disks 12, 12a interconnected in the form of a fork and connected to a ladder beam or section 10, with their circular flanges 24, 24a and recesses l3, l4 and 15 arranged opposite to and in register with each other, while the second joint member 17 may comprise two circular disks 26, 26a interconnected to form a drum-type box and connected to the other ladder beam or section, the said circular disks 26, 260 being embraced by the locking disks 12, 12a and pivoted on the latter by means of the central journal pin 16.
  • the drum-shaped box encases the stop member 20, which is guided there-within to slide in the radial direction in the guide slots 27, 27a of the circular disks 26, 26a allotted to one another, and encases also the pivoting releasing lever 21 which consists of two symmetrical parts made essentially of spring steel which are rigidly interconnected on one side.
  • drum-enclosed portions of the releasing lever which bear against the stop member and which are resiliently interconnected by means of the spring 59 are provided in the region of their end zone with a journal pin 56', 57' engaging a bore provided at the periphery of the associated disk of the second joint member.
  • the movement of any drum-enclosed portion of the releasing lever 21 or the journal pin rigidly connected therewith, which movement is essentially rectangular in relation to the associated disk 26, 26a, can be controlled by means of cams or recesses 60, 60'a provided in the circular flange 24, 24a of the locking disk 12, 12a, and acting upon the journal pins in dependence on the relative rotary movement of the two joint members.
  • the drum-enclosed portions of the releasing lever are provided in the region of their journal pins with one recess 61' each co-operating with an associated stop member consisting essentially of a cam 63, 63a (FIGS. 1, 2 and 4) or a pin 64, 64a (FIG.
  • the releasing lever 80 which is subjected to the action of the spring 81, comprises two arms 82, 83 arranged at an angle of approximately 90 to one another. It is rotatably connected at a point 84 situated approximately midway between its ends to the associated joint member, the arm 82 of the said angular lever, which constitutes the operating end thereof, taking a position approximately parallel to the longitudinal center axis of the joint member associated thereto when the angular lever is in the inoperative position, i.e., when the stop member is in the engaged or locked position.
  • the bores 85 in the releasing lever which serve to receive the pin take the form of oblong holes arranged essentially at a right angle in relation to the longitudinal center axis of the associated joint member, so as to allow the releasing lever slight deflections or evasive motions in the radial direction during its rotating movement.
  • the wedgeshaped stop member 86 passes through opposite recesses 88 in the releasing lever and 87 in the corresponding joint member and can be moved on the one hand along a straight line between the engaged or locked and the unlocked or disengaged position and, on the other hand, perform a relative movement in the direction of the lever movement between the stop member and the releasing lever when the latter is shifted between its two end positions.
  • the recesses 87 have a length equalling essentially the sum of the height of the stop member and the path travelled by the stop member between the engaged or locked and the unlocked or disengaged position, while the recesses 88 have a width considerably greater than the width of the stop member.
  • the releasing lever carries at its end which faces the spring member a bearing support 89 for the spiral-type spring member, which bearing support can be rotated on the releasing lever about an axis parallel to the axis of rotation of the releasing lever and is provided with a hole whose bottom serves as an abutment for one end of the spring member, with the other end of the spring member acting against an intermediate member, which comprises a shaft guided within the spiral spring and which carries on its upper end a cross-bar 90 seated in a depression 91 provided in the wall opposite the operating end of the releasing lever and which can be pivoted about an axis approximately parallel to the axis of rotation of the releasing lever.
  • the releasing lever and the spring member co-operate in the manner of a snap acting member, which means that the lever, once it is removed from its one end position and shifted beyond its dead-center position, will snap into its other end position, and vice versa.
  • the releasing lever can be moved only by hand into the position corresponding to the disengaged or unlocked position of the stop member, and against the action of the arresting or locking device.
  • cams 95, 96, 97 are provided which are formed by projections on that side of the locking disk which faces the lever, each of said cams being associated to one of the stop notches.
  • the said cams co-operate with a counterface 98 provided on that side of the releasing lever which faces away from the joint member, the shape and arrangement of the said cams being such that they will come into effect only when the ladder members are being unfolded, while they will remain ineffective during the folding process.
  • the cams When viewed from above or from the side, the cams have the shape of a quadrant with its are 101 directed to the periphery of the disk.
  • the cams may also be part of one cam plate.
  • the counterface of the releasing lever, which co-operate with the earns 95, 96, 97, is provided at about the center of its length with a tooth-shaped projection directed towards the cams and having, when viewed from the operating end towards the other end one flank 98 uniformly and slightly curved right to the tooth tip and one flank 99 dropping abruptly from the tooth tip to the basis of the releasing lever, with the portion adjacent the spring member ending in a flat curve 100.
  • the releasing lever When the ladder members are folded, the releasing lever is not actuated by the cams, because when the associated right joint member is pivoted in the clockwise direction and the other joint member is pivoted in the counterclockwise direction always viewed in the same direction as when regarding the drawings the curved portion 98 of the releasing lever will travel along the arc-shaped portion 101 of the periphery of the cam.
  • the releasing lever when unfolding the ladder into the flat or any of the preferred positions, the releasing lever is each time operated by the cam corresponding to the position in question in order to release the stop for engagement with the recess.
  • FIGS. 9 and 10 show how the releasing member and the cams of the other joint part co-operate during the two movements described above.
  • FIGS. 11 give the rungs the cross-section of a polygon, for instance a trapezoid or, preferably equalsided, triangle with two sides inclined in relation to each other, one 111 of which corresponding the respective tread surface and the other 1 12 corresponding to the opposite surface, the arrangement of the rungs in relation to the beams or sections 113 being such that the conveniently corrugated tread surface, which is comprised within one horizontal or essentially horizontal plane, forms a certain angle with the longitudinal edges of the mating beam or section and extends preferably over the entire width of the beam or section. In this manner, one obtains a horizontal tread surface even when the stringers or stringer parts are inclined, and due to the typical shape any desired surface may be used as tread surface.
  • a universal folding ladder comprising several pairs of ladder sections which are interconnected by joints and which can be locked in the straightly extended position and in at least one service position, each of said joints connecting two ladder sections and comprising a first joint member connected to either of the said two ladder sections and having at least one circular locking disk arranged concentrically with the joint axis, with recesses provided about its periphery which are associated to the straightly extended position and to different service positions, respectively, and further comprising another joint member which is rigidly connected to the other one of the said two ladder sections and further connected with the locking disk of the said first joint member so as to be pivotable about a joint pin, a stop member provided and guided on the said second joint member which snugly fits into the different individual recesses, respectively, when the said ladder sections are in any of the pre-determined positions and which is released from its engaged position and secured in its disengaged position by a single releasing lever which is pivoted on the said second joint member and is to be operated from the outside and which can be pivoted to and fro at will between an
  • cams which are provided at approximately equal intervals along the circumference consist each of a projection provided on that side of the locking disk carrying the recesses which faces the releasing lever, the said projections having when viewed from above, the form of a quadrant with the are facing the periphery of the locking disk, while one of the two straight boundary lines are directed radially to the center of the locking disk and the other one of the straight boundary lines on the corresponding point extends parallely to the tangent to the circumference of the locking disk, the counterface of the releasing lever cooperating with the cams being, when viewed from the operating end, curved towards the cams and interrupted at about the middle of its length by a step facing the other side and ending towards the spring member in a fiat curve.
  • the releasing lever comprises two portions which can be flexibly moved towards and away from each other, while maintaining the rotatable support provided by the journal pin mounted to each of the portions, the said two portions of the said releasing lever having one recess each essentially in the region of the journal pin, the said recess cooperating with an associated stop member provided on the inner surface of the associated circular disk, such cooperation taking place in such a manner that rotating of the releasing lever and displacing of the stop member into the or disengaged position, when the stop member of the joint is engaged in any of the service positions, will cause the stop member of each circular disk to engage into the associated recess in the releasing lever and thereby arrest and lock the latter in this position, while in the case of any subsequent relative movement of the joint the journal pins will be moved away from the inner surface of the associated circular disk, through the recesses provided in the locking disk, so that the recess of the releasing lever will disenthe one end of the said releasing lever is the operating end and gag
  • cross-section of the rungs has the shape of a polygon with two sides inclined in relation to each other, one of them corresponding to the opposite surface and wherein,

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  • Ladders (AREA)
US59505A 1969-07-30 1970-07-30 Universal folding ladder Expired - Lifetime US3655012A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19691938696 DE1938696A1 (de) 1969-07-30 1969-07-30 Zusammenklappbare Mehrzweckleiter
DE19702006846 DE2006846C3 (de) 1970-02-14 1970-02-14 Zusammenklappbare Mehrzweckleiter

Publications (1)

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US3655012A true US3655012A (en) 1972-04-11

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Family Applications (1)

Application Number Title Priority Date Filing Date
US59505A Expired - Lifetime US3655012A (en) 1969-07-30 1970-07-30 Universal folding ladder

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Country Link
US (1) US3655012A (de)
CH (1) CH528006A (de)
FR (1) FR2053308B1 (de)
GB (1) GB1323741A (de)
NL (1) NL7011282A (de)
SE (1) SE390323B (de)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3955240A (en) * 1975-04-05 1976-05-11 Firma Wilhelm Bahmuller, Maschinen- Und Apparatebau Multi-position safety lock joint, particularly for folding ladders
US4152810A (en) * 1977-08-26 1979-05-08 Salanon S.A. Automatically interlockable hinge
US4448283A (en) * 1982-09-13 1984-05-15 Andral Corporation Portable fold-up ladder
US4457391A (en) * 1981-01-26 1984-07-03 Andral Corporation Fold-up ladder
US4474264A (en) * 1982-03-26 1984-10-02 Krause Guenther Collapsible multi-purpose ladder
US4493392A (en) * 1981-01-26 1985-01-15 Andral Corp Convertible fold-up ladder
US4540306A (en) * 1983-10-19 1985-09-10 Wang Chien Yuan Positioning joint for folding ladders
US4543006A (en) * 1984-11-16 1985-09-24 Wang Chien Yuan Foldable multi-position ladder joint
US4773503A (en) * 1987-09-11 1988-09-27 Robert L. Pease Ladder hinge
US4926967A (en) * 1988-07-27 1990-05-22 Baker Mervyn R Folding ladders
US4934485A (en) * 1988-02-08 1990-06-19 Robert Pease Combination ladder and hand truck
AU723701B2 (en) * 1996-08-01 2000-09-07 Ig Corporation Company Ltd. Foldable ladder with high strength
US6161679A (en) * 1997-02-24 2000-12-19 Graham; S. Neal Vibratory drive unit and associated parts feeder bowl
US20040200667A1 (en) * 2003-04-11 2004-10-14 Babkes Mitchell H. Hinge system for combination hand truck, step ladder and dolly device
US20040201186A1 (en) * 2003-04-11 2004-10-14 Dean Tornabene Combination hand truck, step ladder and dolly
US20050028320A1 (en) * 2003-08-07 2005-02-10 Latimer Brett A. Locking hinge for folding ladder
USD541433S1 (en) 2005-12-14 2007-04-24 Robert Wise Top tray and a flip down tray combination for a ladder
US20070227819A1 (en) * 2006-03-28 2007-10-04 Layfield L D Window cleaning ladder
RU2392975C2 (ru) * 2004-09-20 2010-06-27 Медела Холдинг Аг Мембранный насос с воздушным клапаном
US20170356244A1 (en) * 2016-06-14 2017-12-14 Wing Enterprises, Incorporated Ladders, ladder hinges and related methods

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106677695B (zh) * 2017-01-15 2018-07-06 黄崇华 梯关节

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1531014A (fr) * 1967-07-11 1968-06-28 Echelle pliante à usage multiple

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1531014A (fr) * 1967-07-11 1968-06-28 Echelle pliante à usage multiple

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3955240A (en) * 1975-04-05 1976-05-11 Firma Wilhelm Bahmuller, Maschinen- Und Apparatebau Multi-position safety lock joint, particularly for folding ladders
US4152810A (en) * 1977-08-26 1979-05-08 Salanon S.A. Automatically interlockable hinge
US4457391A (en) * 1981-01-26 1984-07-03 Andral Corporation Fold-up ladder
US4493392A (en) * 1981-01-26 1985-01-15 Andral Corp Convertible fold-up ladder
US4474264A (en) * 1982-03-26 1984-10-02 Krause Guenther Collapsible multi-purpose ladder
US4448283A (en) * 1982-09-13 1984-05-15 Andral Corporation Portable fold-up ladder
US4540306A (en) * 1983-10-19 1985-09-10 Wang Chien Yuan Positioning joint for folding ladders
US4543006A (en) * 1984-11-16 1985-09-24 Wang Chien Yuan Foldable multi-position ladder joint
US4773503A (en) * 1987-09-11 1988-09-27 Robert L. Pease Ladder hinge
US4934485A (en) * 1988-02-08 1990-06-19 Robert Pease Combination ladder and hand truck
US4926967A (en) * 1988-07-27 1990-05-22 Baker Mervyn R Folding ladders
AU723701B2 (en) * 1996-08-01 2000-09-07 Ig Corporation Company Ltd. Foldable ladder with high strength
US6161679A (en) * 1997-02-24 2000-12-19 Graham; S. Neal Vibratory drive unit and associated parts feeder bowl
US20040201186A1 (en) * 2003-04-11 2004-10-14 Dean Tornabene Combination hand truck, step ladder and dolly
US6877586B2 (en) 2003-04-11 2005-04-12 Sylmark Holdings Limited Hinge system for combination hand truck, step ladder and dolly device
US6880835B2 (en) 2003-04-11 2005-04-19 Sylmark Holdings Limited Combination hand truck, step ladder and dolly
US20050087943A1 (en) * 2003-04-11 2005-04-28 Babkes Mitchell H. Hinge system for combination hand truck, step ladder and dolly device
US20040200667A1 (en) * 2003-04-11 2004-10-14 Babkes Mitchell H. Hinge system for combination hand truck, step ladder and dolly device
US7234203B2 (en) * 2003-08-07 2007-06-26 Werner Co. Locking hinge for folding ladder
US20050028320A1 (en) * 2003-08-07 2005-02-10 Latimer Brett A. Locking hinge for folding ladder
RU2392975C2 (ru) * 2004-09-20 2010-06-27 Медела Холдинг Аг Мембранный насос с воздушным клапаном
USD541433S1 (en) 2005-12-14 2007-04-24 Robert Wise Top tray and a flip down tray combination for a ladder
US20070227819A1 (en) * 2006-03-28 2007-10-04 Layfield L D Window cleaning ladder
US20170356244A1 (en) * 2016-06-14 2017-12-14 Wing Enterprises, Incorporated Ladders, ladder hinges and related methods
US10801261B2 (en) * 2016-06-14 2020-10-13 Wing Enterprises, Incorporated Ladders, ladder hinges and related methods
US20210025230A1 (en) * 2016-06-14 2021-01-28 Wing Enterprises, Incorporated Ladders, ladder hinges and related methods
US11988043B2 (en) * 2016-06-14 2024-05-21 Little Giant Ladder Systems, Llc Ladders, ladder hinges and related methods

Also Published As

Publication number Publication date
CH528006A (de) 1972-09-15
SE390323B (sv) 1976-12-13
FR2053308B1 (de) 1973-04-27
NL7011282A (de) 1971-02-02
FR2053308A1 (de) 1971-04-16
GB1323741A (en) 1973-07-18

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