EP0276286A1 - Ecrou a blocage automatique - Google Patents

Ecrou a blocage automatique

Info

Publication number
EP0276286A1
EP0276286A1 EP87905141A EP87905141A EP0276286A1 EP 0276286 A1 EP0276286 A1 EP 0276286A1 EP 87905141 A EP87905141 A EP 87905141A EP 87905141 A EP87905141 A EP 87905141A EP 0276286 A1 EP0276286 A1 EP 0276286A1
Authority
EP
European Patent Office
Prior art keywords
nut
bolt
interior passage
slit
annular body
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.)
Withdrawn
Application number
EP87905141A
Other languages
German (de)
English (en)
Inventor
Patrick Yelverton Williams
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.)
YELVERTON WILLIAMS PATRICK
Original Assignee
YELVERTON WILLIAMS PATRICK
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 YELVERTON WILLIAMS PATRICK filed Critical YELVERTON WILLIAMS PATRICK
Publication of EP0276286A1 publication Critical patent/EP0276286A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B37/00—Nuts or like thread-engaging members
    • F16B37/08—Quickly-detachable or mountable nuts, e.g. consisting of two or more parts; Nuts movable along the bolt after tilting the nut
    • F16B37/0807—Nuts engaged from the end of the bolt, e.g. axially slidable nuts
    • F16B37/0828—Nuts engaged from the end of the bolt, e.g. axially slidable nuts with a longitudinal slit through the annular wall of the nut for enabling expansion of the nut, e.g. for easy removal
    • 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
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B39/00—Locking of screws, bolts or nuts
    • F16B39/22—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening
    • F16B39/28—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by special members on, or shape of, the nut or bolt
    • F16B39/36—Locking of screws, bolts or nuts in which the locking takes place during screwing down or tightening by special members on, or shape of, the nut or bolt with conical locking parts, which may be split, including use of separate rings co-operating therewith
    • 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
    • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
    • F16B43/00—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts
    • F16B43/004—Washers or equivalent devices; Other devices for supporting bolt-heads or nuts with a radial cut in order to improve elasticity of the washer

Definitions

  • the present invention relates to a self-locking nut, by which is meant a nut which is inherently highly resistant to loosening under vibration forces. Nuts of this type are sometimes known as "stiffnuts”.
  • Stiffnuts have certain conveniences over positive locking devices but do have certain limitations and disadvantages.
  • stiffnut is a nut having a conventional body but with the addition of a nylon insert which is engaged in an interference fit with the bolt on first application of the nut on a bolt whereby a high resistance to rotation is created to resist removal of the nut under vibration when in use.
  • a high application torque is needed and after the nut has been removed after a period of service it has a significantly reduced resistance to rotation if re-used, and it may be necessry to discard the nut.
  • this type of nut is relatively expensive.
  • Another known approach is to use a spring device such as a spring washer but in the event that the nut is sufficiently loosened so as not to be compressing the washer, the spring washer has no effect whatsoever and no further resistance to rotation is provided.
  • Examples of specifications in the field of nuts, fasteners and locking devices include the following: GB-A-372209 (S.A. DES ATELIERS GAMAIN) AU-B-53657/65 (294766) (R.K.E. GOTZ)
  • CH-A-153562 (AMEZ-DROZ and KEHRER) AU-A-60943/80 (AJAX) describes a nut with a longitudinal slit with a conical end to engage with a corresponding work piece to prevent the nut slit opening when in use.
  • the nut is of conventional dimensions and rotates freely on a bolt.
  • the disclosure is concerned with removal of the nut from a corroded thread by the opening up slit. The disclosure does not address the question of locknuts or stiffnuts.
  • a nut comprising an annular body extending around an axis with a screw-threaded interior passage extending along said axis and having first and second ends, a slit extending through the annular body and extending axially from the first end to the second end so as to provide a longitudinal slit, the nut being of resiliently expandable form and, compared with a conventional nut for application to an intended bolt, the interior passage has a reduced diameter, the resilience of the nut and its dimensions being such that the nut has a high resistance to rotation on the intended bolt.
  • any one or more and preferably most of the following features are included in a preferred embodiment of the invention: (a) Preferably one end (and possibly both of the ends) of the nut is provided with a lead-in on the screw-threading to permit easy starting of the nut or bolt with similar ease of rotation as that which applies to a conventional nut on a bolt; this features can be achieved by appropriate cutting back of the screw-threaded interior passage adjacent the end of the nut thereby leaving the remaining portion of the screw threaded interior passage to provide the gripping region for firm engagement with a bolt.
  • At least one end of the nut has a ramp-like profile such as a conical shaped or part-spherical shaped surface and adapted for co-operation with a corresponding seat on a washer or work piece.
  • a ramp-like profile such as a conical shaped or part-spherical shaped surface and adapted for co-operation with a corresponding seat on a washer or work piece.
  • the longitudinal slit is the order of 5% of the diameter of the interior passage and preferably is formed in a manufacturing process in which initially the slit is approximately 10% of the diameter of the interior passage, cold pressing occurs to close the slit substantially, and the pressure is removed thereby resulting in partial recovery of the nut to leave the slit with the width being about half of that initially provided.
  • the nut is preferably of a high tensile steel which is heat treated to provide and maintain the necessary resilient qualities.
  • a high tensile steel which is heat treated to provide and maintain the necessary resilient qualities.
  • One convenient material is that known as a Grade 8 nut having high carbon, magnesium, chromium and molybdenum contents.
  • nuts according to the present invention can be made generally to substitute for conventional nuts according to various standards. While most usually the nuts will have a conventional hexagonal profile, the invention is not limited to such a shape as any suitable form of exterior profile could be provided.
  • the nut can be used many times as it has been found that its necessary characteristics can be preserved despite periods of use, substantial vibration during periods of service, removal and reapplication.
  • the nut cannot safely be used again if it has been damaged or stressed during removal, e.g. due to an excessively corroded exposed bolt.
  • the nut can be opened up by a chisel hammered into the longitudinal slit thereby premitting the nut to be rotated further and removed from the offending corroded thread. The nut should then be discarded, (iii) If the nut is not fully tightened against a washer or work-piece e.g. due to user error, it appears that a bedding-in effect occurs when the nut is subjected to vibration, whereby the initial torque subsequently needed to commence slackening of the nut is of the order of twice the torque actually applied.
  • Nuts can be manufactured economically and manufacture can be based on conventional nut production techniques; essentially conventional coned nuts are formed and then subjected to additional processing steps to provide the requisite slit, the pressing step can be effected and the preferred heat treatment applied.
  • Use of the present invention can be advantageous in applying frictional forces over most if not virtually all the portion of the bolt thread within the envelope of the nut body and this is in contrast to known stiff nuts.
  • nuts embodying the present invention may be acceptably effective on bolts which are either slightly oversize or slightly under the nominal design size.
  • Yet another feature which embodiments of the invention can provide is a nut which does not function in a manner which damages or deforms the thread on either the nut or the bolt.
  • nuts embodying the present* invention can be designed to be substantially of conventional shape and dimension but having a slightly inwardly compressed normal position, ordinarily conventional spanners may be used with the nuts.
  • Preferred embodiments of the invention are used with a workpiece or washer having a ramp-like profile e.g. domed or conical corresponding to the end of the nut; the surface of the washer or work piece may be provided with a serrated finish or a saw-tooth profile with the serrations or teeth angled so that when the nut engages the surface of the washer or workpiece it has much less resistance to motion in the direction in which the nut is tightened up as opposed to the direction in which the nut is loosened.
  • the invention also extends to the combination of the nut and a suitable washer and the washer for some applications advantageously may be formed as a spring washer, the spring washer having a ramp-like surface for co-operation with the end of the nut and being adapted to be displaced from an initial position until a portion of the radially innermost part engages the workpiece .
  • Figure 1 is an elevation of a nut embodying the invention
  • Figure 2 is an inverted plan of the nut of Figure
  • Figure 3 is a cross-sectional view through a first embodiment of washer for use with a nut of Figure 1; and Figure 4 is a cross-sectional view through an alternative embodiment of washer to that Figure 3 and prior to engagement with a nut.
  • the nut is of substantially conventional shape and dimension and has a hexagonal body 1, an axial screw-threaded passage 2 extending between a plane upper end 3 and a lower end 4 having" a frusto-conical surface 5 having an angle X to the end plane typically in the range 3G to 40°.
  • a longitudinal slit 6 extends radially through one- side of the nut.
  • the screw-threaded passage 2 has a lead-in 2A formed by setting back the end portion of the threading so as to turn freely on a bolt upon initially engagement.
  • the width of the slit is about 1 mm in the final product, the nut being of a high tensile steel such as a Grade 8 steel which is believed typically to include 0.4% carbon, 0.8% magnesium, 0.9% chromium and 0.2% molybdenum.
  • the nut is formed basically by conventional nut-making technology including the domed end but without the slit 6, and with the threaded bore being of conventional dimensions and configuration.
  • the lower end 4 has the screw-thread formed to be of slightly larger diameter at the end of the nut to provide an easy lead-in onto a bolt after the nut has been pressed down to a reduced diamter as described below.
  • the slit 6 is formed by any convenient cutting technique and transverse pressure applied to close the slit from an initial width of about 2 mm so that the radial faces substantially come together. This is conducted as a cold pressing operation and it has been found that after pressure has been removed the nut only partially recovers and the slit has a final width of about 1 mm. Heat treatment is then effected typically by a hardening operation from 850°C with an oil quench followed by a tempering operation to about 450°C followed by an air cool or oil cooling technique. The resultant nut has a degree of resilience suitable for the present purposes.
  • a solid washer 7 is illustrated and has a frusto-conical bore 8 of corresponding angle X to the conical face 5 on the nut.
  • a spring washer 10 is illustrated, the washer being of spring steel and having a cylindrical skirt 11 and a resilient frusto-conical funnel portion 12 having initially a smaller angle Y to the transverse plane than the angle X.
  • the radially interior part of the funnel terminates in an axially extending throat portion 13 with a flat transverse annular end face 14 which normally is set back from the plane 15 of the end face of the skirt 11.
  • the outer annular skirt 11 may have a thickened base portion for engagement on the work piece for example as shown in the embodiment of Figure 4 where feet 16 are provided.
  • the conical face may be provided with serrations or saw tooth projections preferentially orientated to resist rotation in the direction in which a nut is turned to loosen it and a similar profiling may be provided to the surfaces of the washer adapted to engage the work piece.
  • the present nut can have a clamping effect around the bolt thereby spreading the load over a considerable length of screw-threading on the bolt.
  • dilation tends to occur thereby tending to increase the clearance between the threads on the nut and bolt.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Bolts, Nuts, And Washers (AREA)
  • Dowels (AREA)

Abstract

Un écrou (1), dont la forme est expansible de façon résiliente, comporte une fente longitudinale (6) ménagée dans sa paroi annulaire. Au moins une partie principale de l'alésage à filet de vis interne de l'écrou (1) présente une forme et une dimension lui permettant d'être rigide c'est-à-dire de présenter une résistance sensible à la rotation lorsqu'il est appliqué à un boulon traditionnel. L'une des extrémités de l'écrou (1) présente de préférence unprofil à section décroissante (5) (c'est-à-dire conique) conçu pour coopérer avec une rondelle correspondante, empêchant ainsi la dilatation de l'écrou (1) lorsqu'il est serré et lorsqu'il est soumis à une charge. Une partie traversante à diamètre supérieur est en outre de préférence disposée sur le filetage de vis à l'extrémité de l'alésage fileté, afin de permettre une rotation initiale libre de l'écrou (1) sur un boulon.
EP87905141A 1986-07-31 1987-07-30 Ecrou a blocage automatique Withdrawn EP0276286A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
AUPH720186 1986-07-31
AU7201/86 1986-07-31
AU8144/86 1986-09-23
AUPH814486 1986-09-23

Publications (1)

Publication Number Publication Date
EP0276286A1 true EP0276286A1 (fr) 1988-08-03

Family

ID=25643135

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87905141A Withdrawn EP0276286A1 (fr) 1986-07-31 1987-07-30 Ecrou a blocage automatique

Country Status (6)

Country Link
EP (1) EP0276286A1 (fr)
ES (1) ES2008152A6 (fr)
IL (1) IL83396A0 (fr)
NZ (1) NZ221244A (fr)
PT (1) PT85446A (fr)
WO (1) WO1988001024A1 (fr)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0347830Y2 (fr) * 1986-09-17 1991-10-11
US6089807A (en) * 1992-08-31 2000-07-18 Arrow Plastic Ab Bolt-and-nut joint
SE501902C2 (sv) * 1992-08-31 1995-06-19 Arrow Plastic Ab Skruv-mutter-förband
US5872242A (en) * 1992-10-05 1999-02-16 Isis Pharmaceuticals, Inc. Antisense oligonucleotide inhibition of ras
AU680449B2 (en) * 1992-10-05 1997-07-31 Isis Pharmaceuticals, Inc. Antisense oligonucleotide inhibition of the ras gene
DE102005019199B4 (de) * 2005-04-25 2012-05-24 Gkn Driveline Deutschland Gmbh Verbindungsanordnung
CN102163777A (zh) * 2010-11-22 2011-08-24 苏州华旃航天电器有限公司 一种连接器o型密封圈锁紧螺钉
MX2021001913A (es) 2020-02-18 2021-08-19 Bemis Mfg Co Conjunto de fijacion para bisagra de asiento de inodoro.
USD984881S1 (en) 2020-02-18 2023-05-02 Bemis Manufacturing Company Fastening nut
USD972403S1 (en) 2021-01-15 2022-12-13 Bemis Manufacturing Company Fastening nut
USD972404S1 (en) 2021-01-15 2022-12-13 Bemis Manufacturing Company Fastening nut
WO2022174758A1 (fr) * 2021-02-17 2022-08-25 许松林 Élément de fixation pour empêcher un mouvement de rotation automatique dans une direction de desserrage
CN115306809A (zh) * 2022-08-16 2022-11-08 嘉兴紫云精密科技股份有限公司 一种车床抗震锁紧螺母及其强化处理工艺

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR503969A (fr) * 1919-09-18 1920-06-22 Joseph Scherrer écrou indesserrable
FR509791A (fr) * 1920-02-11 1920-11-19 Baptiste Vaurs Système perfectionné d'écrou indesserrable
CH141119A (de) * 1929-10-02 1930-07-15 Edmond Hugli Leon Schraubensicherung.
BE375051A (fr) * 1930-03-13
CH153562A (fr) * 1931-03-09 1932-03-31 Amez Droz Albert Ecrou de sûreté.
US2333290A (en) * 1943-02-23 1943-11-02 Clare L Brackett Nut and method of making same
GB554555A (en) * 1943-03-17 1943-07-08 Kenneth Blondin Cater A self-locking nut
AU6094380A (en) * 1979-08-01 1981-02-05 Ajax Nettlefolds Ltd. Slit nut

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8801024A1 *

Also Published As

Publication number Publication date
PT85446A (pt) 1988-07-29
WO1988001024A1 (fr) 1988-02-11
IL83396A0 (en) 1987-12-31
NZ221244A (en) 1990-01-29
ES2008152A6 (es) 1989-07-16

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