US2537662A

US2537662A - Sheet metal spring clip

Info

Publication number: US2537662A
Application number: US54722A
Authority: US
Inventors: Laurence H Flora; Richard A Hartman
Original assignee: Tinnerman Products Inc
Current assignee: Tinnerman Products Inc
Priority date: 1948-10-15
Filing date: 1948-10-15
Publication date: 1951-01-09
Anticipated expiration: 1968-01-09

Description

Jan. 9, 1951 l.. H. FLORA ErAL SHEET METAL SPRING CLIP Filed Oct. 15, 1948 ATTOR N EY Patented Jan. 9, 1951 UNITED STATES PATENT FFICE SHEET METAL SPRING CLIP Application October 15, 1948, Serial No. 54,722

4 Claims. l

This invention relates to spring fastening clips which are used in the fabrication of various cabinet constructions andthe like for mounting or attaching trim and finishing objects and similar articles in the form of elongate plates or strips commonly known as breaker strips, molding strips, sealing strips, etc.

The improved fastening clip of the invention is of the general type comprising a sheet metal body defining laterally spaced head sections and an intermediate integral strip between said head sections providing a fastener shank in which the free end of the strip is reinforced and supported in connected relation to said head sections.

The present application, in this regard, is a continuation in part of copending application Serial Number 732,774 filed March 6, 1947 and since issued as United States Patent Number 2,451,591, October'19, 1948.

In the fabrication of refrigerator door structures, refrigerator casings and similar types of cabinet structures, it is usually necessary or desirable that a trim strip, breaker strip, molding, or other finishing object be secured in desired position in the completed structure by an operation taking place entirely from the outer or readily accessible side of the assembly inasmuch as the rearward or reverse side thereof seldom is conveniently or readily accessible for the application of fastening means for this purpose.

The trim or finishing objects preferably are relatively simple designs which may be economically provided in the form of elongate plate-like articles of relatively thin cross-section and made of molded plastic materials in a simple molding operation or in the manner of simple sheet metal stampings, castings, or the like. Breaker strips are advantageously provided in this manner in that there are no projecting parts thereon subject to damage and the' same otherwise may be compactly packaged to reduce the cost of shipping and handling to a minimum. Such trim or finishing objects are provided with a suitable connecting means for easy and quick attachment thereto of spring clip fastening devices designed for mounting the same in an assembly by substantial snap fastening action or otherwise adapted to provide the desired interlock between the finishing object and the supporting structure. A widely used arrangement of such connecting means involves the use of spaced parellel connecting ribs, flanges, or the like, which are provided either as integral portions of the trim or nishing object or as separate elements secured to the underside thereof in any suitable (Cl. 2li-73) 2 way as by an adhesive, welding or other 'securing means which is not visible on the outer'or exposed surface of the trim or finishing object.

Many trim and finishing objects provided by mass production methods, particularly 4those made of plastic materials, frequently are not uniform throughout their lengths in the space between the connecting ribs or inturned co'nnecting flanges and these irregularities often vary to a relatively wide degree. Consequently in the use of clips designed only for a specific size and spacing of the connecting ribs or flanges, there are usually several clips in an installation which do not secure the trim or finishing object properly with complete effectiveness in the ananner intended.

A primary object of the invention, therefore, is to provide an improved spring clip or fastener which is adapted to be attached effectively to such a trim or finishing object despite manufacturing variations and inconsistencies in the space between the spaced connecting ribs or flanges and in the spacing thereof from the body of the trim object so that each clip is attached firmly and rigidly to the object to be mounted in such a way as to insure a completed installation which is strong and durable throughout.

A further object of the invention is to provide a clip fastener of this characterin which the fastener head is composed of spaced head portions which are interlocked with the connecting ribs or flanges on the trim or finishing object together with lateral spring elements carried by said head portions which exert resilient spring pressure on the edges of such ribs or fianges in a manner whereby the clips are adapted to seat rigidly in varying size spaces between the connecting ribs or flanges and thereby compensate for manufacturing irregularities and variations in the size and thickness of the connecting ribs to insure a firm and rigid connection of the clips to the trim object at all points in the mounting thereof.

In conjunction with a fastener head of this character, the spring clip of the invention comprises an improved shank construction formed by an integral return bent strip which is anchored to the head in a manner to resist axial and lateral distortion of the shank in the applied position of the fastener. Heretofore, in the general construction of clip fasteners of this character in which the fastener blank defines the head of the clip and the spring stud type of shank is formed by a strip carried by the head in projecting relation thereto, the end of the strip usually extends freely and 'unsupported relative to the head of the fastener. When such a clip is applied to an installation, the free end of the strip forming the clip shank is necessarily subject to spreading apart from the head of the fastener under ordinary tensile loads and axial forces which develop in the use of the installation, with the result that the secured parts are not tightly fastened in the manner intended, and the clips frequently work loose and often become completely removed from effective fastening position.

Another primary object of the invention, therefore, is to provide an improved construction of a clip fastener of the kind described in which the strip forming the shank is interconnected with the clip at its free end between the spaced head portions thereof in a manner which develops greatly increased strength in the clip, and which otherwise adds to the effectiveness of the securing action of the fastener in applied fastening position in an installation.

An additional object of the invention is to provide such a clip fastener construction which is adapted to withstand any tendency of the shank to separate from the head member either in the application of the fastener or in applied fastening position incidental to the use of the completed installation.

Further objects and advantages, and other new and useful features in the construction, arrangement and general combination of parts of the invention will be readily apparent as the following description proceeds with reference to the accompanying drawings, for purposes of illustration but not of limitation, in which like reference characters designate like parts throughout, and in which:

Fig. l is a perspective view of a trim or finishing object as seen from the underside thereof and showing a clip or fastener in accordance with the invention as attached thereto and another clip in position to be similarly attached;

Fig. 2 is a sectional view of the trim object and attached fastener of Fig. l as seen along line 2 2, looking in the direction of the arrows, and showing the attached fastener in position to be applied to a fastener receiving opening in the supporting part;

Fig. 3 is a sectional view of a completed assembly taken on a section line through the longitudinal center of the fastener;

Fig. 4 is a perspective view of the clip or fastener per se;

Fig. 5 is a sectional view, as seen along line 5-5 of Fig. 3 showing the fastener as attached to the underside of the trim or finishing object;

Fig. 6`is an edge elevational view of the clip or fastener;

Fig. 'l is a sectional view of the fastener through the longitudinal center thereof; and,

Fig. 8 is an end view of the fastener as seen from the right of Figs. 6 and 7.

Referring now, more particularly, to the drawings, Fig. l illustrates a trim or finishing object of the general character described which is provided in the form of an elongate plate, molding, or the like, A, having spaced parallel connecting ribs I on the underside thereof for the attachment thereto of the required number of spring clips I for securing the object to a supporting part B. The part B is provided with a series of holes or fastener receiving openings in a predetermined spacing along the path which the trim or finishing object A extends in mounted position and the required spring clips Ill are attached to the object with a corresponding spacing so as to be received in such openings in the manner of snap studs to secure the object in mounted position.

The trim or finishing object A preferably is provided in a relatively simple design in the form of an elongate plate-like article made of molded plastic material, or. composition or fibre board, or' as a simple sheet metal stamping, casting, or the like. Such plastic finishing objects preferl ably are provided in this manner inasmuch as there are no projecting parts thereon subject to breakage and the same otherwise may be compactly packaged to reduce the cost of shipping and handling to a minimum. The connecting ribs l are provided either as integral elements on the underface of the trim or nishing object, as shown, or on a separate block secured to the underside of said object in any suitable way as by adhesive, Welding or other means which is not visible on the outer or exposed surface of the object.

In this relation, a further advantage is obtained in that it is often necessary or desirable for a saving in material that the trim or finishing object be of comparatively thin cross-section and usually of insuicient thickness to conceal a metallic insert or threaded screw fastening. In the instant construction, the use of threaded fastenings is avoided and by employing the improved spring clips in combination with the connecting ribs or iianges provided on the underside of the object A, as aforesaid, the object may be provided in any selected decorative configuration and of relatively thin cross-section, and yet v rigidly and securely mounted on to the supportspring-like characteristics.

ing panel B or other supporting structure and by completely concealed fastening means'which do not mar or detract from the appearance of the trim or finishing object in mounted position. In the present example, the connecting ribs I include inturned fianges 2 which are spaced from the body of the object A to define spaced grooves or channels 3 with the longitudinal edge surfaces 4 of said flanges extending in opposing generally parallel and spaced relation to each other.

The clip fastener designated generally lil, is a simple, inexpensive article of manufacture which may be constructed from any suitable sheet metal material, preferably spring metal such as spring steel or cold rolled steel having The devices may be formed from blanks of various outlines, but from a quantity production standpoint, are most advantageously provided from a comparatively small, generally rectangular blank which may be obtained from ordinary sheet metal strip stock with little loss or waste of material.

The sheet metal blank is slit longitudinally and bent to define a pair of spaced head sections I2 on either side of a central head section I5 in the body of the fastener at one end of the blank. An integral strip 20 joined to the central head section i5, extends lengthwise between the spaced head sections I2 and is bent to form the snap stud shank of the fastener as presently to be described.

The spaced head sections I2 are so provided that the outer longitudinal edge portions thereof are readily slidable in the grooves defined by the inturned flanges 2 of the connecting ribs. The corners of the leading ends of the head sections preferably are bevelled as at I3 to facilitate the entrance of said head sections into the grooves l while the longitudinal edges thereof preferably are bent downwardly therefrom for a snug fit in said grooves.

The central section or body I5 is depressed between the head sections I2 so as to define opposing wall portions I6 adjoining the head sections I2. The wall portions at one end are partially severed from the head sections I2 to define a pair of cooperating spring ngers I8 having their free ends bent laterally outwardly to a spacing greater than the space between the longitudinal edges 4 on the inturned flanges of the connecting ribs I.

The central strip 20 is bent into a generally V-shaped shank projecting from the head of the fastener defined by the spaced head sections I2. The inner end of the strip 20 is integral with the central body portion I5 and defines a relatively rigid arm 2I extending from the fastener body for the desired length of the shank as determined by a return bend providing a cooperating spring arm 22. These arms 2|, 22, defining the shank of the fastener, are substantially similar and comprise inclined guide surfaces 23 diverging outwardly from the leading end of the shank and merging into inwardly extending cam shoulders 25 designed for snap fastening engagement vin the fastener receiving opening 5 in the supportlng part B.

The free end of the strip 20 is bent into an inwardly extending projection or supporting hook 21 which is designed for overlapping bearing engagement with the central head section or body portion I5 in the space between the adjoining wall portions I6. The projection 21 is adapted to bear upon said central head section I5 and to abut the adjoining spaced walls I6, as shown in Figs. 2 and 8, to support and rigidify the spring arm 22 both axially and laterally with respect to the head of the fastener, thereby increasing the overall strength and holding ability of the fastener shank. As seen-in Fig. '1, the projection 21 is disposed in overlapping bearing engagement with a portion of the central head section I5 in the normal untensioned condition of the spring armv 22. When the arms 2|, 22 are compressed toward each other in the applied fastening position of the clip, the spring arm 22 moves to the position illustrated in broken lines in Fig. 7 where theprojection 21 y; is in substantially full bearing engagement with said central head section I5, substantially as shown in Fig. 3. v

The fastener Ill as thus provided is easily and quickly attached to the finishing object or trim object A, Fig. 1, by inserting the head vsections I2 of the fastener into interlocked relation vwith the inturned flanges 2 of the connecting ribs I from an open end thereof. The bevels I3 on the leading ends of the head sections I2 facilitate the initial insertion of said head sections into the grooves 3 in connected relation with said flanges 2, whereupon the clip is slid along said flanges to the predetermined position in registry with the associated opening 5 in the supportingpart B.

The arrangement is such that the head sections I2 of the fastener slide readily in the grooves 3 defined by the inturned flanges 2 and the depressed central head section v"I5 passes freely between the opposing edges 4 of saidA inturned flanges 2. 'Howeven the spring fingersv I8 carried by the head sections have their free ends bent outwardly to a spacing greater than the space between the opposing edges 4 of said flanges. as aforesaid. and consequently said free ends ofthe spring fingers I8 must be compressed inwardly toward each other to pass between said opposing flange edges 4 which provides for a pronounced frictionai gripping action of said spring fingers I8 with said opposing ange edges 4. 'I'he spring fingers I8 are sufficiently yieldable to permit the fastener to slide readily to the necessary attached location along the connecting ribs I but as a result of such frictional gripping action with the ange edges 4,'said spring fingers I8 serve to retain the fastener firmly and rigidly in any attached location while the head sections l2 positively connect the fastener to the object, as aforesaid.

From the foregoing, it will be understood that in the procedure for mounting a trim object or finishing object A on the supporting part B. as many spring clips or fasteners I0 as are necessary are attached to the connecting ribs I, in the manner described and in spaced relation corresponding to the spacing of the fastener receiving openings 5 provided in the supporting part B along the path with which the object A extends in mounted position. In the mounting operation, the projecting shank of each clip defined by the cooperating arms 2|, 22, is readily entered into the associated panel opening 5inasmuch as said spring arms have a spacing at the leading end of .the shank less than the size of the panel opening. Axial pressure is then applied to the outer surface of the object A in the area of the head of a fastener to move the shank of the fastener axially into the panel opening whereupon they inclined guide surfaces 23 cam against the marginal edges of the panel opening to cause a gradual contraction of the arms 2|, 22 as necessary for the cam shoulders 25 thereon to pass through the panel opening and ride on the lower corner edge of said opening at the reverse side of said part to the point v'of most effective fastening engagement.

Such tapering cam shoulders 25 adapt the clip fastener for effective application to panel supports of. diiferentrthicknesses, within limits, and otherwiseprovide a suitable axial drawing action on the clip shank to secure the object A tightly against Athe'supporting part B in mounted position. Inasmuch as the spaced head sections I2 are interlockedwith the inturned flanges 2 together with the spring ngers I8 in frictional engagementl withy the opposing edges of said anges, as aforesaid, zthere is no tendency for vthe .clipsvto become displaced or removed from attachedposition with the trim or nishing object A during the operation of forcing the clip shanks through the panel openings.

It will be understood that the arms 2|. 22 of the clip shank are disposed in normal untensioned relation substantially as shown in Fig. 'I

and when compressed toward each other in ap- 1 bearing engagement with the central head secv 1f tion or'body portionv I5 and is thereby interconnected therewith lin a manner which prevents `any movement ofthe spring arm in an axial direction'toward separation'from the head or body of the fastener. Thus the free end of the spring arm 22 is fixedly retained by the projection 21 to strengthen and reinforce said spring arm 22 in its securing action in a manner which resists any axial force which might tend to cause a separation of the free end of the spring-.K- arm from interlocked relation with the head or body of the clip. At the same time, the side edges of said projection 21 are disposed in substantially abutting relation with the kspaced walls I6, as shown in Fig. 8. to resist any lateral force which might tend to distort the spring arm 22 laterally from its proper position in opposing relation to the arm 2| and generally normal to the head of the fastener. The projection 21, laccordingly, serves to anchor the free end ofthe spring arm against both axial and lateral rdistortion thereby increasing the overall strength of the fastener shank and maintaining the arms of the shank at all times in their proper rela.

The fastener in any form preferably is con-` structed of relatively thin sheet metal the thick,- ness of which is selected according to service r'equirements and the predetermined size ofthe parts secured. The fasteners areamost effective when provided of spring metal suitably spring' tempered and otherwise treated to give the de-` tween andin abutting relation to said wall portions.

2. Ai'astener comprising a piece of sheet metal providing a pair of spaced head sections having plane surfaces in substantially the same plane and extending in the same general direction adjacent an intermediate body portion below the plane oi' said head sections, wall portions adjoini'ng said head sections, cooperating spring elements extending outwardly from said wall portions, and a shank comprising a strip united 'to said body portion and bent to project therefrom.

3. A fastener comprising a piece of sheet metal providing a pair of spaced head sections having plane surfaces in substantially the same plane and extending in the same general direction, wall l portions adjoining said head sections and an in- 'to provide a shank comprising an arm dependent from said body portion and a return bent arm having `a `projection supported in bearing ensired toughness and hardness;particularly'in'.the'VVA case of devices which are used in installations.

where extreme vibratory motion takes place.'v A

cheap and highly effective fastener may be pro` vided from cold rolled metal, anchas-cold rolled steel,v which is untemper'ed but of a' spring metal nature and capable of providing an eiectiveand reliable fastening means.` y, n l

While the invention has been described in detail with a specic example, such example is intended as an illustration only inasmuch as changes in the construction and arrangement of the clip or fastener within the broadscope ofthe instant disclosure are fully contemplated. What is claimed is: 1 l. A fastener comprising a piece of sheet metal providing a pair of spaced head sections extending in the same general direction and wall portions adjoining said head sections and an intermediate body portion, a strip united to said body portion between said spaced head sections and bent to provide a-shank comprising an arm dependent irom said body portion and a return bent arm having a projection extending inwardly toward said dependent arm and supported in bearing engagement with said body portion begagement with said body portion between said wall portions.

V4. A fastener comprising a piece of sheet metal providing a pair of spaced head sections having plane surfaces in substantially the same plane and extending in the same general direction, wall portions adjoining said head sections and an intermediate body portion below the plane of said l head sections, a spring element extending outwardiy from at least one of said Wall portions, and a strip united to said body portion and bent to provide a shank comprising an arm dependent from said body portion and a return bent arm having a projection extending inwardly toward LAURENCE H. FLORA. RICHARD A. HARTMAN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,133,837 Wiley Oct. 18, i938 2,451,591 Tinnerman et al. Oct. 19, 1948