US2431664A - Cotter pin spreader - Google Patents

Description

Patented Nov. 25, 1947 CUTTER PIN SPREADER Sven J. Strd, Chicago, Ill., assignor.- to T.V & S,V Corporation, Chicago.. Ill... a corporation. ot..

Illinois Application December 22, 1945;.Seriail No. 636,837.

6 Claims. l;

My invention relates to cotter pins, withspecial reference tocotter pin assemblies constructed for self-spreading.A action, and is directed specificallytoimprovements in the spreader member employed Vin such assemblies.

In a cotter pin of thepresent type the assembly comprises aecotter-pin-member or cotter pin proper, hayngthe usual two arms in combination with a spreader member extending between the two arms. Duringshipment and handling of the assembly prior to use,y the-Cotter pin member'and the wedge member are inlretracted positions relative to eachother. When; the cotter; pinis ulti,- mately driven into .place -for service as a retaining means, the spreader member is immobilized ata certain pointso that the-subsequent: relative longitudinal movement of the Cotter pin member causes the arms of the cotter pin membertol be wedged apart at theirinner ends by the spreader member.

TheA generalconstruction of such a spreader' memberin a-cotter=pin-assembly as taught by the prior artis to betoundin the Taylor Patent No. 1,768,721, andv theA Strid Patents Nos. 2,153,440, 2,166,614, 2,373,983, and 2,490,960.; Such a spreader member is fabricated by steps including cutting a blank of suitable-conguration out of sheet metal andY bending.; the blank to form two side flanges. .ci tapering configuration to serve-as wedge means-in the spreading of the cotter pin.

Iny all of these-prior disclosures the configuration of the. blank.l relativeto the lines along which the metalis bent to'formv the flanges is suchas to oppose the bending action unduly, and is such as toresult. in. distortion and weakening of the material adjacentv the-inner ends-of the flanges. In consequence'theblankis Yso diicult to form that theforming cost is relatively high.. Often the metal yieldsto the forming forces unevenlyso that one sideiiangeishigher than the other. Close .inspection is required and not all of the re.- jectedpiecescan be salvaged by further process-- ing.

The object.. of the present invention is tonnaprovee the constructiony and the-.method of construction. of .sucha spreader member by eliminate ing. undue.; resistanceY to tbey bending of they spreaderflanges:andbyavoiding weakeningof the. material by strainand distortion.. 1n general, ,thisl object is. attained by changing the initialv conb guration ofthe spreader blank to a congnration permitting .both ends-of the bend lines `for the side flanges to extend to the edges of the blank. When.

the bend. lines.. arethusk arranged to, extend. from edge. to.l edge. of; the. blank. the metal may be bent.

2` inz a clean-cut manner in a single formingfonerationwithoutadversely affecting the metal of the. blanlradjacent to the inner ends of the bend lines. The` new procedure in construction saves labor, lightens the. burden of inspection, and

greatly reduces the number of rejections. l have discovered' that a certain pinching. action in the older. practicerwas the cause of the uneven form ing of the side anges, andi now avoid such. pinching action.

The above andotherv objects and advantages :of my invention will be apparent in the following detailed description taken with the accompanying drawings.

Inthe drawingawhich are to be regarded as merely illustrative;

Fig; 1 is a side elevation of a typical cotter pin assemblyincluding my improved spreader mem--l ber;

Fig. 2 is afragmentary planviewon an enlarged scale of a-spreader blank according/to one practice of ,my invention.;

Fig, 3 is a fragmentary. plan view of the spreader fabricated from the blank oi.4 Fig. 2;

Fig. 4 isa fragmentary side elevation ofk the nished spreader;

Fig,v 5 is atransverse section :taken as indicated by the 1ine755 lof Fig. 4;

Figs. 6, '7 and 8 are views corresponding to Figs. 2, 3 and 4, but showing the preferred. practice of my invention;

Fig. 9 is-a fragmentary plan View similar to Eig. 7eXemp1ifying. athird practice of my invention; and

Figs. 10, l1 and 142 are-views correspondingl to Figs. 6, .7 and 8, indicating-.how such a spreader member has been vfabricated heretofore.

In the-Cotter: pin assembly shown in Fig, 1, the Cotter pin. member, generally designated 2G, is. formed from a. single piece of suitable half round stock, and comprises the usual twoarms 2l interconnected by aloopZZ, theA arms being sprung together. Inserted between the. arms 2| is a spreader. member 23.y having. two side flanges 25 atene endlofy theusllal tapered conguration to serve aslwedgeimeans for. spreading the arms .21.

At .tbe innerY end oftbe spreader. member 23 is a pair of laterally extending wings/28 to serve two-purposes- One of the purposes is to Vprovide an.v enlargement. to limit.. the movement. ofthe spreader member. inton abore Vwhen the Cotter pin assembly isbeinginstalled, thereby to hold the spreader member` stationary during the nal movement `oi thecotter pinmember into Ithe bore; v'Ibostbe relative movement between the spreader;

member and the cotter pin member is provided as required for the spreading action. The second purpose of the two wings 26 is to limit lateral movement of the spreader member relative to the cotter pin member prior to installation of the device, and for this purpose the two wings are sufliciently bent to engage the opposite sides of the Cotter pin member 2U.

The particular spreader member 23 shown in Fig. 1 is also provided with small tabs or flanges 21 on its opposite side that fit snugly against the cotter pin member 20 to prevent lateral movement between the spreader member and the cotter pin member at a second point. Other expedients may be employed to serve the purpose of the tabs 2l, as shown in the Strid Patents Nos. 2,166,614 and 2,400,960. None of these expedients conflict with the improvement disclosed herein.

The present invention is primarily concerned with the construction of the side anges 25 that provide the wedging action for spreading the cotter pin member 20. In all five of the prior disclosures mentioned above the leading end of the spreader member, including the wedging side flanges 2'5, is formed in the manner indicated by Figs. 10, 11 and 12.

Fig. shows a flat sheet metal blank having a body portion 28 with parallel side edges 33 and having an enlargement 3l at one end with diverging side edges 32. It is to be noted that the inner ends of the diverging side edges 32 meet the parallel side edges 30.

Since the width of the body portion 28 of the usual blank is approximately the diameter of the cotter pin assembly, and therefore close to the diameter of the bore into which the cotter pin is to be installed, it is obvious that the overall width of the finished spreader member across the two wedging side flanges must be appreciably less than the width of the body portion 28. Otherwise the upstanding side anges would not lie entirely within the circle defined by the bore and would prevent the leading end of the spreader member from entering the bore. It is apparent, then, that to form the finished spreader member from the blank shown in Fig. 10 it is necessary not only to bend the metal of the blank 90 to form the two wedging side flanges, but also to pinch the metal.

The necessity for pinching action is apparent from the position of the dotted lines 23 in Fig. l0, representing the lines on which the metal is bent to form the side flanges. Note that these lines terminate at their inner ends inward from the side edges of the blank.

Fig. 11 indicates how the metal is pinched to form the two wedging side flanges 33, the pinching action being concentrated in the regions designated 34 adjacent the inner ends of the side flanges. In practice the wedging side flanges 33 of Fig. l1 are best formed in two steps, and often additional hand work is required to permit the finished pieces to pass inspection. Even with two forming steps the metal is distorted or mutilated at the regions 34 to such a degree that the metal across the spreader member between the two regions 34 tends to be weakened either by crystallization or by the formation of small ssures. It is to be borne in mind that the wedging action for spreading the ends of the cotter pin member involves high longitudinal stress in tension at this particular part of the spreader member.

In one practice of the present invention illustrated by Figs. 2 to 4, I employ a sheet metal blank, generally designated 35, having the usual body portion 28 and end enlargement 3 l, the body portion having parallel side edges 30 and the enlargement having the usual diverging side edges 32. The blank 35 differs from the blank shown in Fig. 10 in having marginal notches or recesses 38 at the inner ends of the diverging side edges 32. Thus the diverging side edges 32 terminate in the recesses 36 instead of joining the parallel side edges 3U. f

The recesses 35 are deep enough to meet, or at least come very close to, the longitudinal lines along which the metal is to be bent to form the two wedging side flanges of the finished spreader member. These bend lines are indicated by the dotted lines 3'! in Fig. 2. In other words, it is desirable that both ends of these lines of bend extend to the edges of the blank, and the recesses 35 are provided to bring the side edges inward to the bend lines.

Fig, 3 shows the wedging side flanges 38 that are formed by bending the sheet metal upward along the dotted lines 3l. It is clearly apparent that while the bending of the flanges 38 reduces the width of the wedging member at its leading end to less than the width of the body portion 2S, nevertheless no pinching action is involved in the reduction in width. The metal is bent upward along the lines 31 in a clean-cut manner and without causing any strain on the metal between the two marginal recesses 35.

While the particular blank configurations shown in Fig. 2 is practical, it does result in the formation of a distinct and somewhat abrupt shoulder lill at the inner end of each side liange 33, as may be seen in Fig. 4. It is desirable, therefore, to bevel the leading end of the corresponding arm 2l of the Cotter pin 2l] to ride easily over the shoulder 40.

The preferred practice of my invention illustrated by Figs. 6, 7 and 8 has the advantage of eliminating the shoulder G0, as will now be eX- plained. The blank, generally designated il in Fig. 6, has a body portion 42 with parallel side edges i3, and has an end enlargement 45 with diverging side edges 4B. I-Iere again the blank configuration includes marginal recesses il at the inner ends of the diverging side edges 43. In this instance, however, the recesses il are formed in part simply by extending the diverging side edges it well inside the longitudinal zone defined by the parallel side edges 43. Bending the blank 4| as indicated by the two longitudinal dotted lines 48 results in the formation of the two wedging side flanges 53 of Figs. '7 and 8. Fig, 8 clearly brings out the fact that the described method of fabrication results in smoothly functioning wedging surfaces, free of any abrupt shoulder.

Fig. 9 illustrates a third practice of my invention wherein, strictly speaking, no recesses are employed. In this instance I make the body portion 5l of the spreader relatively narrow to accomplish the same purpose as recesses, viz: to permit the previously described bend lines to extend at their opposite ends to the edge of the sheet metal material. As is apparent in Fig. 9, the side edges 52 are spaced apart not more than the distance between the side flanges 53. In this specific instance the parallel side edges 52 are substantially equal to the spacing between the side flanges 53 so that the lines along which the blank is bent to form the side edges are substantially continuations of the parallel side edges 52.

The crux of the matter is that the side edges of the body portion of the blank extend inwardly,

at least inside the planes of the outer faces of the side flanges and preferably at least to the planes defined by the inner faces of the side anges. This relationship may be achieved either by cutting marginal recesses in a blank having a body portion of conventional width, or may be achieved by simply narrowing the width of the body portion,

It will be apparent to those skilled in the art that various changes and substitutions departing from the described constructions and procedures may be made within the scope of my appended claims.

I claim as my invention:

1. A spreader member for use in a cotter pin of the character described, comprising a sheet metal strip provided with laterally extending projections bent substantially at right angles to said strip to form two side flanges at one end thereof of tapering configuration to serve as Wedge means for the cotter pin, said strip having marginal recesses in its side edges at the inner ends of said iianges.

2. A spreader member for use in a cotter pin of the character described, comprising a sheet metal strip provided with laterally extending projections bent substantially at right angles to said strip to form two side flanges at one end thereof of tapering configuration to serve as wedge means for the cotter pin, said strip having marginal recesses in -its side edges at the inner ends of said lianges, said recesses extending inward at least to the planes of the inner surfaces of said fianges.

3. A spreader member for use in a cotter pin of the character described, comprising a sheet metal strip forming a flat longitudinal body provided with laterally extending projections bent substantially at right angles to said strip to form two side anges at one end thereof of tapering configuration to serve as wedge means for the cotter pin, the side edges of said body at the inner ends of said iianges lying inside the planes of the outer faces of the flanges.

4. A spreader member for use in a cotter pin of the character described, comprising a sheet metal strip forming a at longitudinal body provided with laterally extending projections bent substantially at right angles to said strip to form two side flanges at one end thereof of tapering configuration to serve as wedge means for the cotter pin, the inner faces of each of said side flanges extending from one edge of said strip to another edge of the strip.

5. A spreader member for use in a cotter pin of the character described comprising, a generally thin fiat strip of plastically deformable material provided with laterally extending projections bent substantially at right angles to said strip to form at least two side anges adjacent one end thereof of tapering configuration to serve as wedge means for the cotter pin, said strip having marginal recesses in its side edges adjacent the inner ends of said flanges and extending respectively inward to substantially the bases of said iianges.

6. A spreader member for use in a cotter pin of the character described comprising, a strip of plastically deformable material provided with laterally extending projections bent substantially at a right angle to said strip to form a side ange adjacent one end thereof of tapering configuration to serve as wedge means for the cotter pin, said strip having a marginal recess in its side edge adjacent the inner endof said fiange and extending inward to substantially the base of said flange.

SVEN J. STRID.

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

UNITED STATES PATENTS Number Name Date 1,925,804 Hiering Sept. 5, 1933 2,166,614 Strid July 18, 1939 2,386,887 Eckel Oct. 16, 1945 FOREIGN PATENTS Number Country Date 125,547 Great Britain Apr. 24, 1919

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