US3658107A

US3658107A - Self-locking system

Info

Publication number: US3658107A
Application number: US130229A
Authority: US
Inventors: Joseph Perina
Original assignee: American Velcro Inc
Current assignee: Velcro Industries BV; American Velcro Inc
Priority date: 1971-04-01
Filing date: 1971-04-01
Publication date: 1972-04-25
Anticipated expiration: 1989-04-25

Abstract

The self-locking system applies to two rigid members which are connected together by internally and externally threaded elements and have engaging surfaces which are flat. The self-locking arrangement is in the form of hooking elements bonded to the respective engaging surfaces.

Description

United States Patent Perina 1 Apr. 25, 1972 [541 SELF-LOCKING SYSTEM 3,176,364 4/1965 Dritz ..24/2o4 [72] inventor: Joseph Perina, Huntington, N.Y. FOREIGN PATENTS 0R APPLICATIONS [731 Assign: America" Mmheser, 1,125,236 3/1962 Gennany ..151/34 [22] Filed: Apr. 1, 1971 Primary Examiner-Marion Parsons, Jr.

[21 Appl. No.: 130,229 Attorney-Pennie, Edmonds, Morton, Taylor & Adams [52] US. CL... ..15l/34, 24/204 ABSTRACT [51] Int. Cl ..Fl6b 39/282 The self lockin g system applles to two rigid members which [58] FleldofSearch ..24/204, DIG. l8, l5l/34,4l.7 are connected together by imemany and externally threaded elements and have engaging surfaces which are flat. The self- [56] Rem-anus Cited locking arrangement is in the form of hooking elements Nn- STATES PATENTS bonded to the respective engaging surfaces.

3,135,820 6/1964 Hallett et al. ..24/204 4 Claims, 4 Drawing Figures PATEMTEDAPR 25 m2 FIG. 4

FIG. 3

INVENTOR Joseph Perin l I l J ATTORNEYS SELF-LOCKING SYSTEM SUMMARY OF THE INVENTION By providing the flat surfaces with booking elements which engage one another when the threaded elements, such as a nut and bolt, are screwed one onto the other, as the two flat surfaces approach one another the hooking elements become engaged and fonn what amounts to a lock-washer. One important difference however is that with the usual form of lockwasher the interlocking elements do not engage one another until the connecting elements have been turned substantially to their final tight position, whereas with the self-locking system of the present invention the two rigid members become locked together by the engagement of the hooking elements before the final clamping together of the two rigid members. Thus a range of adjustability is provided throughout which the two rigid members are firmly locked together against loosenmg.

The locking force of the self-locking system can be varied in a number of ways, such for example, as by providing the flat interengaging surfaces with different numbers of hooking elements per square inch, or by using different types of hooking elements on the respective surfaces. For example, the cooperating hooking elements may be of the hook type and of the loop type respectively, or hook type elements may be used on both surfaces, or hook type on one surface and a pile type or loop type, or some other type, on the other surface. The intention however is to use a hooking element fabric or tape mounted on the cooperating flat surfaces of the two rigid members. Such a tape or fabric is manufactured as a fastener and sold under the tradename Velcro" by Velcro Corporation of 681 Fifth Avenue, New York, NY. 10022 This fabric contains many heat-set, semi-rigid nylon hooks per square inch. These hooks when pressed into a cooperating fabric capable of engaging with these hooks produce a strong fastener which can be attached and detached thousands of times by merely pressing the parts together and pulling them apart.

According to the present invention each of the flat surfaces of the two rigid members has a layer of fabric bonded thereto, one of these fabric layers having hook members and the other layer having either hook members or some other appropriate element, such as loops, projecting therefrom. Also the hook members and loop members may be bonded directly to the respective fiat surfaces of the two rigid members.

When the interengaging surfaces of the two rigid members are provided with the usual form of hooking fabric the hook members will be arranged in parallel rows. The invention provides however for placing these hooks in a generally circular arrangement so that the hooks face all in the direction in which the sheer forces are exerted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in central section showing two rigid members provided with the self-locking system of the invention.

FIG. 2 is an isometric view of a standard form of hooking fabric ready to be applied to the engaging surface of one of the rigid members.

FIG. 3 is a view similar to FIG. 2 of a modification, and

FIG. 4 is a vertical sectional view drawn to a larger scale.

DETAILED DESCRIPTION The rigid element shown in FIG. 1 will be referred to as a nut element and has a circular projection 11 with a central aperture 12 having internal threads 13. The second rigid member, indicated by numeral 14, in this case also has a cylindrical projection 15 and the same diameter as projection 11. Extending outwardly from the center of projection 15 is an externally threaded or bolt element 16 of appropriate diameter to fit the aperture 12. Also the internal threads 13 are of the same pitch and form to cooperate with the external threads of bolt element 16.

The

cooperating faces

17 and 18 of the

elements

10 and 14 are circular and are shown as having approximately the same diameter, although this is not necessary, the only essential requirement being that both surfaces should be flat. Appropriately secured to the face 17, as by bonding, there is a fabric washer 19, from the surface of which a multiplicity of hook members 20 project. On face 18 of member 14 there is a similar fabric washer 21 having a multiplicity of loops 22 projecting from its outer surface. As indicated, there are many more loops than hooks. It will be understood that although a loop type of hooking member on washer 21 is advantageous, other hooking elements as indicated above, and many others, may be used.

When the internal threads 13 and external threads 16 are engaged and the nut member 10 is screwed onto the bolt member, the surfaces of the two fabric washers l9 and 21 will be brought sufficiently close together that some of the hook elements 20 will engage some of the loop elements 22. Such engagement is shown in FIG. 4. Due to the fact that contact between the hook and loop elements occurs during a turning movement of the nut member 10 with respect to the second rigid or bolt member 14 the hook members 20 are apt to be shifted to a somewhat inclined position. Any loosening of the nut member with respect to the bolt member will tend to shift the hook members 20 to an oppositely inclined position. However even with the hook members barely entering the mass of loop members 22 a sufficient resistance to relative turning movement between the nut and bolt members exists to prevent the loosening of the nut member.

The tightening of nut member 10 with respect to the bolt member may continue until the hook members 20 have entered a considerable distance into the mass of loop members and a considerable range of adjustability is therefore provided. However, throughout this range a positive lock washer effect is produced. In other words, the parts are not only self-locking with respect to each other but selective positioning of the nut member with respect to the bolt member is available.

Referring to FIG. 2 there is here shown a washer 19 which is made from standard Velcro material with the hooks 20 facing in different directions, but with the hooks arranged in parallel rows. Under certain circumstances it may be desirable to provide an extraordinarily large locking force or sheer force between the hooking elements on the nut member and the cooperating elements on the bolt member. This can be accomplished by arranging the hook members so that they face generally in the same direction, the direction in which the locking forces are exerted. Such a construction is illustrated in FIG. 3 in which the washer 19b is made in wedge shaped sections 23 and the hooks 20b are arranged in either parallel or concentric rows with all of the hooks directed either counterclockwise (as shown) or clockwise.

Iclaim:

1. In a self-locking system for two rigid members having cooperating internally and externally threaded connecting elements and having flat engaging surfaces, the improvement in combination therewith which comprises a plurality of hooking elements bonded to each of said surfaces, said hooking elements on the respective surfaces engaging one another when said threaded elements are rotated with respect to each other to secure said rigid members together.

2. A self-locking system according to claim 1 in which the hooking elements on one of said surfaces are in the form of hooks, and those on the cooperating surfaces are in the form of loops.

3. A self-locking system according to claim 1 in which the engaging surfaces are circular in shape and the hooking elements project from fabrics bonded thereto, the improvement in combination therewith wherein the hooking elements on at least one of said engaging surfaces project from wedge-shaped sections of said fabric and the hooks thereon all face in the direction in which the locking forces are exerted.

4. A self-locking system according to claim 3 in which the hooking elements on both of said surfaces project from wedge-shaped sections of fabric, and the said elements all face in generally the same direction.