US2008274A - Lock nut, bolt, and the like - Google Patents

Description

y 1935. s. c. DlCKE RHOFF, .JR 7 2,008,274

LOCK NUT, BOLT AND THE LIKE Filed Aug. 1., 1952 /IIIIIIIII.

NM ll 5 A TTORNEYS.

Patented July 16, 1935 PATENT OFFICE LOCK NUT, BOLT, AND THE LIKE Samuel C. Dickerhofi, Jiz, New York, N. Y., as-

signor, by mesne assignments, to Automatic Nut Company, Inc., a corporation of New York Application August 1,

Claims.

vide an improved lock nut, bolt or the like of the type indicated.

More specifically, a certain tolerance is permitted in nuts and bolts sold on the market; that is to say, some of the nuts and bolts sold as of a certain size and cut of thread, depart noticeably from the rated size and thread cut. The departure may amount to some thousandths of an inch in diameter alone. A more specific object of my invention is to provide lock nuts, bolts and the like, of the type indicated, that are well adapted to perform their locking functions in a uniform manner despite these permitted tolerances.

The invention can be best explained with reference to the accompanying drawing, in which:

Figs. 1 and 2 are respectively a transverse section and an end view of a lock nut embodying the preferred form of, and manufactured in accordance with my invention. Fig. 3 illustrates another form of locking wire and its relation to a bolt or nut thread. Fig. 4, partly in elevation and partly in section, shows a seated threaded bolt with looking wire seated in the bolt rather than in the nut. Figs. 5 to 8 and 10 are transverse sections of one corner of a nut with a locking wire therein, say about on the line marked V of Fig. 1. Figs. 9 and 11 are sections substantially at right angles to the sections of Figs. 8 and 10 respectively.

Referring first to the lock nut of Figs. 1 and 2: In a hole provided (usually drilled) in the body I of the nut is seated one leg 2 of a resilient bent wire 23, circular in cross section and usually made of a steel considerably harder than the metal composing the nut. The seat hole extends substantially parallel to the axis of the nut, and also (at least in ordinary hexagonal nuts) is usually located in one corner of the nut as here illustrated. The hole or seat is made suificiently large to permit the leg 2 of the wire to tumor oscillate in the hole except as the wire is restrained as hereinafter described. The exposed or free leg 3 of the wire is bent nearly or quite to right angles to the seated leg 2, and lies near to '(in fact substantially against) the face of the nut and substantially in a plane parallel to that face; in length, this leg 3 is somewhat greater than the distance from the wire seat to the threaded hole 1932, Serial No. 627,208

in the nut, so that it extends across the nut threads and, when thenut is screwed onto a bolt the leg turns to one side and its free end assumes a position against or between the bolt threads. The free end of this leg 3 is provided with a sufficiently wide path of movement across the face of the nut, a path extending to both sides of that radial plane 9 of the nut (Fig. 2) which'passes through the leg 2, to permit this free end to make such an engagement with the bolt at both sides of the latter. To look the wire in its seat, the seated leg 2 is provided with a noncircular portion which is more or less embraced by some locking means or looking metal. The arrangement most frequently employed heretofore, at least for steel nuts, and an arrangement peculiarly "well suited for my invention, is that illustrated inFig. 1; in this formthe leg 2 of the wire is indented or somewhat widely kerfed at 6 and a'small part of the corner of the nut adjacent this depression is pressed or driven down, more or less into the depression in the wire, as indicated at 1. Other types of anchoring the wire to the body in which it is seated are disclosed in the Batchelor patent mentioned above however, and still others are more or less readily derivable. The present invention applies to them all. ,This looking or anchoring of the wire serves not only to hold the wire in its seat, but also to restrain rotation of the seated leg 2 and thus to impose atorsional stress on the seated leg, as the leg 3 is thrust to one side or the other by a bolt, whereby the free end of the wire makes a biting engagement with the bolt threads when the nut'or bolt moves in the reverse direction. Thus the wire locks the nut in place against accidental movement.

In the specific form of such devices shown in the Batchelor patent the nuts and bolts are reversible; thatis to say, while the wire serves to securely lock the nut to the bolt against accidental displacement, the nut (or bolt) can be removed by, say, using a wrench to forcibly turn the nut or bolt a part of a turn against the thrust of the wire. This serves to throw the leg 3 to the opposite side of the bolt and the two can then be unscrewed, one from the other, as readily as they were screwed together. This throwing over of the leg 3 from one side of the wire, so that this leg 2 might yield laterally somewhat in a direction generally to and from the bolt during the movement of the wire from one side of the bolt to the other; this helped to relieve the stresses on the wire during reversal. Furthermore, to relieve the wire of undue torsional stresses due to the long swing the leg 3 makes in passing from one side of the bolt to the other, the wire was permitted to have a free and unimpeded movement, i. e. a movement unaccompanied by torsion on the seated leg, throughout a limited are near its center of movement. To this end for example, the metal at l was not struck down far enough to completely fill the depression 6, so that the wire might turn freely and unimpeded throughout say, the arc i ll of Fig. 2; at the same time however, the metal 6 was struck down far enough to impose a torsional stress on the seated leg 2 as the leg 3 moved beyond, these limits and into, the arcs H and it. of Fig. 2. Still further, the bottom of the depression 6 in the leg 2 was given a convex shape in these devices made under the Batchelor' patent prior to my invention, something as shown in the sectional view of Fig. '7; this further tended to permit a free and unimpeded movement of the wire throughout a certain limited range as mentioned. As a result, a nut or bolt employing the Batchelor form of locking device can readily-be reversed and unscrewed at will, no damage is done to the locking wire even by many reversals of its nut or bolt, and little damage' is done to the threads against which the wire end bears; both nut and bolt can be used repeatedly.

While devices so made under the Batchelor patent prior to my invention are quite satisfactory when the nut and cooperating bolt are reasonably well mated, difiiculties are sometimes encountered in making a device as described, under factory conditions, that will act uniformly throughout the range of tolerances permitted in nuts and bolts as now marketed; if, for example, the metal at l is struck down deep enough in all instances to secure adequate looking between an oversize nut and an undersize bolt, large stresses aredeveloped in the wire and an unnecessarily deep biting into the bolt occurs, when the nut happens to be an undersize one and the bolt cooperating with it is oversize; on the other hand, if the metal at l is struck down in all instances only suificiently to satisfy the condition of an undersize nut screwed onto an oversize bolt, then the locking may be insecure where the nut happens to sea sufficiently oversize one and the bolt sufiiciently undersize. In other words it is difiicult, with the method of manufacture indicated, to secure such lockings of the wires as will meet all conditions uniformly. I have discovered a mode of manufacture however, and an arrangement of parts, whereby the advantages of the locking described are retained but the disadvantages are eliminated.

I have discovered, first, that it is not necessary that the wire be permitted to bend laterally, and that such lateral bending is one of the causes of insecure locking in some instances with these devices as heretofore made. Therefore I preferably give the wire a push fit in its seat; that is to say, I make the seat hole only just about enough larger than the wire to permit the wire to be pushed into the hole by hand. This is sufi'i ciently large to permit the seated leg to twist or oscillate in its seat between the anchoring point (6!) and the free leg 3, so that advantags can be taken or torsional stresses developed in the seated leg as before, but at the same time the sides of the hole support the leg 2 and substantially prevent it bending when the nut or bolt is forcibly turned backwards and the leg 3 thereby thrown to the opposite side of the bolt. Secondly, I do not attempt to provide each wire with some certain fixed and predetermined amount of free movement in the intermediate portion of the range of travel of the leg 3 (within the are ill), but rather I permit each individual wire to fix for itself such an amount of free and unimpeded movement as may best suit the particular nut and particular bolt with which that nut cooperates, in so far" as may be necessary. To this end, I generally arrange to make the attachment (e. g., 6l) of the leg 2 to the nut (or bolt) at a point on this leg that is removed from the juncture of this leg 2 with the other leg 3 a distance greater than one-half the thickness of the nut in which the wire is seated or a standard size nut with which it may be expected to cooperate; this provides a rather long reach of leg 2 subject to the torsional stresses, and accordingly, without increasing the torsional stresses per unit length of seated leg, permits the use of a lesser degree of free and unimpeded movement than does an anchoring made nearer the junction point between 2 and 3. Further, I anchor the seated leg 2 to the nut firmly, without allowing for any initial free movement of the wire, and I make the anchorage in such a manner that the leg 3 tends to stand in the radial plane 9. For example, I may make the anchoring or attachment of the seated leg 2 to the nut while the ,leg 3 is held in the radial plane 9 and the leg 2 is allowed to assume any angular position it wishes within the seat. In effect then, I so anchor the wire initially as to hold the leg 3 substantially in the medial, radial, plane 9 when this leg is out of engagement with a bolt threaded into the nut, and the leg tends to return to this plane if and. when displaced somewhat therefrom, with the result that the stresses imposed on the wire when later the leg 3 is thrust to one side of a bolt, are substantially equal to the stresses imposed on the wire when subsequently'the leg 3 is reversed over to the other side of the bolt. In anchoring the wire firmly in the nut however, and particularly in the larger nuts where larger and heavier wires are used, while I anchor it firmly as described I do not anchor it so firmly but what the connection or anchorage can yield somewhat with small use, if and as excessive or dangerous stresses tend to develop in the wire; by wearing therefore, with use, as by the first few turns of the nut on and on the bolt again, a small limited amount of free movement as described above with reference to the arc Ill of Fig. 2, is allowed to develop, if necessary, and before any wire is stressed and fatigued to the breaking point, the wire is allowed to fix for itself a free and unimpeded movement suflicient to relieve it of dangerous stresses and a free movement best suiting the particular nut and particular bolt to which the wire is applied. Where the anchoring is of the kind shown at 6'l, bringing the metal 1 of the nut right down against the wire to secure this firm attachment serves a second purpose also; it permits the wire itself to act somewhat as a stop to assist in limiting the deformation of the nut to the proper degree. In not all instances however, will the free and unimpeded movement in the mid-range develop; in some nuts the stresses developed may not be sufficient to require a free andunimpeded movementto" relieve thempin such casesno'free and unimpeded movement may I develop. In the smaller nuts (andbolts) particularly, where Wires of smaller diameters and shorter legs .3 are used, there is not somuch need for .a free mid-range movement as there'isin the. case of the larger nuts therein large diameter wires'and rather long locking legs 3 are needed. With such nuts and bolts the free movement may never appear. On the other hand, it may be desirable at times to work'the wires of the larger sized nuts back and forth until some degree of free movement'is developed for them beforesale of the nuts to users or before the nuts are applied to the bolts with which they are to work. Certain. formations of the non-circular portions 6 of the wire may be employeol to help maintain the proper degree of pressure of the free end of leg 3 against the threads, once the properpressurehas been attained. To this end, for example,XI- prefer to give the depression 6 a non-convex (i..e., a

concave or flat) bottom as represented in Fig.

5, rather'than' the convex bottom of the sort shown in Fig. 7 previously employed; apparently the non-convex surface tendsto give the wire more definite limiting positions than is possible to secure with an initially convex bottom; quite possibly too the somewhat sharp edges assist in wearing the cooperating locking'metal to the degree permitting some free and unimpeded movement in the mid-range of the movement of the leg 3. It will be understood however that the non-convex form for the non-circular or anchoring portion of the seated leg 2 is preferred for those nuts wherein no development of a freeand unimpeded movement is anticipated, as well as for those in which such'afree movement is intended. Also this non-convex formis preferable to the convex form even in those cases where a free and unimpeded movement in the mid-range of the leg 3 is provided for initially, as in the Batchelor patent. Finally, I'have found'it preferable to reduce the free end of the leg 3, so that this end can enter deeper between adjacent turns of the thread than a straight out across, the wire would permit. This reducing (i. epmore or less sharpening) of, the end of the wire, permits reducingthe torsionalstresses imposed on the seated leg; it does this both by permitting the leg 3 to operate closer to the axis of the bolt-and by enabling a lesser pressure of. the leg ,3 against the thread to produce a biting'engagement with the thread when the nut r bolt starts to move in the reverse direction. In some instances too it may permit the effective length of theleg 3 to be reduced .and'thus result in the development 'of lesser stresses in the wire whenthe leg3 -is forcibly thrown over from one side to the other. Preferably this reduction of the free or biting end of the leg 3 is provided by bevelling the free end at the side thereof adjacent to or remote from the face of the nut (or bolt) from which thewire projects, 4 in Fig.1, or by bevelling at both these sides, 5 in Fig. 3. Preferably the bevel (or bevels) substantially parallels a face of the thread to be engaged, so that the point ofthe wire reaches, or nearly reaches, the bottom 8 of the valley between adjacent turns of the thread. Fig.8.

Figures 5 to 11 illustrate my conception of the action of;the-firm yet yielding-with-wear anchorage of the wireof my invention. Itisto beobserved however that it is difficult to determine exactly whatoocurs at the anchorage, for nomatter, how thenut is cut open, the act of cuttingseems to modify theinternal structure, or at least I fear it does so, and thereforeit may be that none of the following is entirely accurate. It will serve however to elaborate the foregoing description of this feature. 1 With the foregoing reservation:

Fig. 5 shows a transverse section of a seated wire. adjacent the depression 6, and the adjacent part of thenut before. the wire is anchored in place. As theindentation is struck down inthe corner of the-nut, conceivably the indented locking metal I may substantially fill the depression'fi in the'wire as indicated in Fig. 6. Then as the wire 2 is forced to turn a few turns, both the wire and the metal of the nut may beforcedto wear in the manner that will. appear by contrasting Fig. 7 with Fig. 6. Usually however I employ ,a ,wiremuch harder than the metal of the nuts; therefore I doubt if the wire usually wears very much, except possibly at the extreme edges of the'depression 6 in it.

conceivably therefore Fig. 7 should be modified accordingly. Furthermore, I doubt if the metal of the nut can be sunk as deeply into and as completely around the non-circular portion of the wire as is indicated in Fig. 6, for the full length in Fig. 9 that is, I believe the point of a small, more or less elongated-conical, nob 20 of nut metal is extended down into the wire depression 6. By

pressing or striking. down such a nob 20until the L end; of the nob (perhaps somewhatfiattened)- engages against the bottom of the wire depression 6, the wire may be anchored firmly initially,

While a few violent twists. of the Wire back and .forth, assuming it to be harder. than the metal .of the nut, will wear orre-mold the tip of the nob to something like the shape indicated in Fig. 10 in transverse cross section and in Fig. 11 in longitudinal crossesection. It willbe observedthat the .wire 2 in Figs. 10 and 11 is quite free to oscillate I through a small arc, but that the .main body of the nob or looking metal strongly restrains oscillation of the wire beyond the limits of such small arc. Preferably, with the larger nuts at least, I

endeavorto strike, down such a nob, 20 until it bears against the bottom of the depression 6, but with such a small tip bearing against thisbottom that a torsional stress on the seated leg 2 a little less than the elastic limit of the leg, will wear or remold the nob in the manner (although not necessarily to the degree) shown inFigs. 10 and 11. In all instances the stresses on the wire are kept belowathe elastic limit. As an alternative, it is possible .that in endeavoring to protrude the nob -20 into the depression-Suntil the. bottom begins to materially resistfurther protrusion of the nut metal,-the nut metal is never actually protruded into the depres sion 6 any farther than is indicated (in substances, not necessarily in degree) in Figs. 10 and 11. It is evident that even driving the nutmetal initiallyonly asfar as shown (in substance) in Figs. 10 and 11, causes the nut metal to bear strongly against the ends 2| of, the de- .pression 6. .It may. be that the tightness here gives the; eflect o f the nob Ill-seeming to strike the bottom of thedepressiomand is the only preventative of .free-movement-of the wire initially; and thatthe wire is freed (when a wire is freed) by these end edges 2i sawing (as it were) their ,wayintothe nutmetal slightly.

"By way of example, I may mention that I usually make the depth of the depression 6 in the wire about equal to one-third the diameter of the wire; and usually I make the-length of the depression about equal to the diameter of the wire. It will be understood however that my invention is not limited to these dimensions,

but that these figures serve simply to indicate 7 the order-of thedimensions I usually employ; they are subject to variation; for example, I have used depressions 6 equal to one-half the diameter of the wire, although this permitted (ultimately) somewhat more free movement of the wire than I thought best at the time.

While for the most part I have above described my invention'in connection with looking wires seated in the nuts, to which it is most readily applicable perhaps, and rather peculiarly applicable, it is to be understood, as I have before indicated, that my invention is not entirely limited to this form; the wires may be seated in the bolts, leaving the free or exposed legs 3 to engagethe threads of the cooperating nuts. It is to be understood also that within the terms nuts and bolts as used above, I include all internally and externally threaded devices cooperating, generally, in the same manner as true nuts and bolts. By way of example, Fig. 4 illustrates a locking wire seated in a bolt and the latter screwed into a large block of metal. When seated in a bolt 15, the wire may project from one end of the bolt, the leg 2 of the wire being inserted axially of the bolt, but not at the center or axial line or the bolt. The free or exposed leg of the wire then extends toward and efiects biting engagement with the threads of the cooperating thread 16 in the manner generally indioated in this figure; The 'wire may be locked within the bolt in substantially the same way as previously describedwith respect to nuts, and in general the free end .of. the leg 3 cooperates with the thread of a nut in the same manner as described above with respect to bolts.

In general, my invention is not limited to the details, nor to the embodiments of it, described above, except as appears hereinafter in the claims. The term threaded member in the claims includes'nuts, threadedbolts, and other threaded devices onto which a nut can be screwed or into which a threadedbolt can be screwed.

I claim:

1. The combination with a threaded member, of a'resilient angular element having 'two' legs substantially at right angles to each other, one of said legs being seated in said threaded member and extending away from the other leg substantially parallel to the axis of the threaded member, and said other leg initially lying in the radial plane passing through the seat of said element and extending across the threads of said threaded member'to make locking engagement with athreaded member cooperating with the threaded member in which said element is seated and its free end being provided with a sufficiently wide path of movement extending to both sides of that radial plane of the first'mentioned threaded member which passes through the leg seated therein, to permitthe free end of said other leg to make locking engagement with the threads of a cooperating threaded member at both sides of said plane, and means coacting with the seated leg to initially hold said other leg substantially in said radial plane when said other leg is out of engagement with a cooperating threaded member and to impose a torsional stress said means and seated leg coact so weakly that their connection yields with use to permit the said other leg to have asmall limitedamount of free movement, adjacent said radial plane, suiting the requirements of the particular threaded members.- I

2. The subject matter of claim 1 further characterized by the fact that said seated leg has a push fit with its seatin the first mentioned threaded member. i

3. The combination with a threaded member, of a resilient angular element having two legs substantially at right angles to each other, one of said legs being seated insaid threaded member and extending away from the other leg substantially parallel to the axis of the threaded member, and said other leg initially lying in the radial plane passing through the seat of said element and extending across the threads of said threaded member tomake locking engagement with a threaded member cooperating with the threaded member in which said element is seated and its free end. being provided with a sufliciently wide path of movement, extending to both sides of thatradial plane of the first mentioned threaded member which passes through the leg seated therein, to permit the free end of said other leg to make locking engagement with the threads of a cooperating threaded member at both sides of said plane, said seated leg being provided with a non-circular portion remote from its juncture with said other leg, and means coacting between said non-circular portion of said' seated leg and the main body of the threaded member in which said leg is seated to hold said other leg substantially in said radial plane when said other leg is out of engagement with a cooperating threaded member and to impose a torsionalstress on said seated leg to cause the free end of said other leg to make a biting engagement with the-threads of a cooperating threaded member with which it may engage, said seated leg having a push fit with its seat in the first mentioned member from by the fact that said non-circular portion of the.

seated leg is provided by an indentation therein having a non-convex bottom.

5. For locking nut and bolt members or the like, the combination of one of such members, a resilient angular element having two legs disposed substantially at right angles to each other, said one member being provided with a seat extending substantially parallel to the axis of itself adapted to'oscillatably receive one of said legs and the other of said legs initially lying in 10 biting engagement with the thread on said other member, characterized by the fact that said means, as initially coacted with said seated leg,

further restricts the swing of said other leg, but

so weakly restricts the said swing that with use the said means and/or seated leg yield, to permit the said free leg to pass substantially unimpeded through said predetermined are of movement,

suiting the requirements of the particular threaded members.

SAMUEL C. DICKERHOFF, JR. 10

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