US2323999A - Fastener - Google Patents

Description

y 1943. K L. JoHfisoN 2,323,999

FASTENER Filed Feb. 23, 1940 I VENTOR 1,4,4? TTORNEY Patented July 13, 1943 UNITED STATES PATENT OFFICE FASTENER Kenneth L. Johnson, Sewickley, Pa.

Application February 23, 1940, Serial No. 320,240

4 Claims.

This invention relates generally to fastenings and more particularly to fastenings designed to be driven into one member by repeated blows and having a spring head or clamp arranged to engage and secure another member thereto.

This invention may be conveniently applied for securing railroad rails, plates and track castings on supporting members such as crossties. Again these fastenings may be used in fabricating wood. or metal structures as substitutes for nails, bolts, and the like, The fasteners may be employed in machines for holding a slidable member against movement until after a predetermined pressure has been applied thereto.

Resilient fasteners of this character in the present art consist of a shank portion and an integral head portion with a leg extending substantially horizontally from the shank and arranged to engage the member to be fastened.

The so-called resilient rail fasteners or spikes have two general types of heads, the first type is formed by merely bending over the upper portion of the material producing an outwardly extending leg. The bends forming these heads may be fiat or arcuate and there may be more than one bend in the same or different planes. However the distinct characteristic of this type of head is that the bend or bends tend to open when the leg engages the member to be fastened.

The second type of head is formed by bending over the 'upper portion of the material and bringing the free end back past the shank portion to produce a leg portion. This head is made into a complete loop which is formed substantially on one side of the shank while the leg at the free end of the loop extends beyond the other side of the shank. This loop may be started on the leg side of the shank, but it is preferable not to have portions of the loop on both sides of the shank because it produces a spring reaction when struck with a hammer. The distinctive characteristic of the second or loop type of head is that the loop tends to close when the leg engages the member to be fas tened.

One object of this invention is the provision of a novel type of head for resil ent fasteners. This head is formed by bending the upper per tion of the material over and downwardly and then twisting the material and bending it up until the leg is at an angle of substantially ninety degrees to the first bend. The under or engaging face of the leg is the same surface that forms the top or impact surface of the head.

That part of the material which forms the head and leg progressively diverges from the vicinity of the shank and thus no loop is formed.

Another object of this invention is the provision of a fastener made of strip metal wherein the leg or holding element is disposed substantially parallel with the plane of the broad dimension of the shank.

Another object is the provision of a fastener made of strip material, the broad dimension of the leg being arranged to engage the member to be fastened and being disposed normally to the broad dimension of the plane of the shank.

Another object is the provision of a fastener having a head. formed by the twisting of the material and placing the impact receiving surface closely adjacent the axis of the shank.

Other objects and advantages appear in the following description and claims.

In the accompanying drawing a practical embodiment illustrating the principles of this invention is shown wherein: i

Fig. l is a front elevation of the fastener comprising the invention,

Fig. 2 is a plan View showing the fasteners applied to a rail with the shank of each fastener disposed diagonally in the square hold in the tie plate, parts being broken away.

Fig. 3 is a side elevation of a fastener driven through a tie plate into a tie for holding a rail, which members are shown in sections with parts broken away, the plane of the broad dimension of the shank being disposed normally to the run of the rails.

Fig. 4 is a modified form of the fastener comprising this invention.

Referring principally to Figs. 1, 2 and 3 of the drawing, the fastener shown therein is made from a strip of metal which is materially wider than it is thick. The dimensions of the strip metal may be varied to suit different applications. The fasteners illustrated were made from a strip of steel stock three-fourths of an inch wide and three sixteenths of an inch thick. By constructing a fastener of this character from strip material its weight and cost of manufacture is materially reduced as compared to the weight and cost of manufacture of a fastener made from material having a square cross section.

The fastener consists of a substantially straight shank portion Ill, the lower end of which is pointed as indicated at H. The shank may vary in length depending upon the application of the fastener. Thus when used as a rail spike the proportions indicated on the drawing may be found suitable. If it is to be employed in fabricating a structure wherein the member to be fastened is materially thicker than a rail flange, the shank would be longer.

The shank It may be provided with a rib or similarly stiffened, as indicated at l2, to guard against buckling when the fastener is driven in place. This rib is preferably centered in the material and extends longitudinally of the shank. It is formed by pressing or rolling a flute 13 in one side of the strip, causing the rib l2 to raise beyond the surface of the other side of the strip. The cross section of the rib is preferably arcuate and it may be that of a semi-circle or the segment of a circle. The depth of the flute is determined by the dimensions of the stock and th use to which the fastener is to be applied.

In forming the rib along the axial center of the strip, parallel marginal faces I4 are left adjacent the edges of the strip. These faces are wider on the flute side than they are on the rib side because of the thickness of the material. However in working the metal these marginal faces may become slightly inclined toward therib and the flute, not remaining in their original plane. In other words, the marginal surfaces not being tightly held are drawn toward the flute when the work is being performed thereon. This is of course more prominent on the flute side than it is on the rib side because of the difference in the radii of the two arcuate surfaces.

The end of the rib and flute taper gradually into the original surface of the stock as indicated at [5. as not to produce an immediate change in the cross section of the strip for the full width of the rib and flute. The rounding of the taper permits the formation of the rib and flute-gradually, which is important in the process of making them.

As stated above the rib maybe formed by passing a long strip between rolls having an inter rupted rotary die in the perimetral surface thereof. The flute is thus rolled into the stock at spaced intervals along its length and afterwards cut into sections of proper length for producing the fasteners. The ribbed shank may also be formed by feeding a long strip to a die in a forging machine which presses the flute to form the rib and cuts it to length. The die may also be arranged to produce the head and leg.

The head N5 of the fastener is formed by bending the upper portion of the strip over to one side and down, with the crest of the bend along a transverse lin and across the broad dimension of the stock. The depending portion is then twisted toward the shank as at I! and bent upwardly and outwardly to one side so that the free end or leg portion I8 is preferably disposed approximately thirty degrees to th horizontal. The axis of the leg I8 is substantially parallel to the plane of the broad dimension of the shank and the underface of the leg is a portion of the same side surface which forms the top of the head and the opposite or rib side of the shank.

In making the twist in the stock the edges of the material extend above the middle portion, forming a slightly concave surface terminating at both ends of the twist or adjacent the upper end of the shank and the inner end of the leg portion.

The crest of the first bend or the top of the head is the impact receiving surface of the fastener. This surface is closely adjacent to the These tapered ends are also rounded so axial center of the shank which permits the fastener to be readily driven into the anchored member.

The outer end of the leg may be turned upwardly as shown at 19 to produce a toe which prevents the end of the leg from gouging into the member being fastened. On the other hand it may be desirable to permit the end of the leg to gouge into the member being fastened, in which case the end is not bent upwardly as illustrated in Fig. 2. In this view the fasteners are driven into the tie 20 through the square holes 2| of the tie plate 22 for fastening the foot flange 23 of a rail. For convenience the holes 2| in the tie plate are shown opposite each other and the fastener 24 is termed a right hand fastener which is similar to that shown in Fig. 1, whereas the fastener 25 is called a left hand fastener because the twist I! is made in the opposite direction to that shown in Fig. 1. By providing right and left hand fasteners the head, which lies wholly on one side of the shank, may be positioned on the side away from the rail thereby permitting a longer leg than if the head was adjacent the rail. The application of brakes on a train moving to the left in Fig. 2 causes the rail to creep in the same direction. When the fasteners are properly set the ends of the legs gouge into the foot flange and resist the movement of the rail. Thus a fastener of this character may be used as a rail anchor.

The action of the forces resisting the movement of the rail have the tendency to turn or rotate the fasteners as well as pushing it back over. The holes 2| in the tie plate are squared with the run of the rail and owing to the width of the shank, the fastener must be driven through this hole when diagonal. The hole in the tie plate thus prevents the fastener from rotating when it resists the longitudinal movement of the rail.

In Fig. 3 the hole 21 in the tie plate 22 is sufficiently large to permit the plane of the broad dimension of the shank to be placed normal to the run of the rail. The up turned toe I9 011 the end of the leg prevents it from gouging into the upper surface of the foot flange of the rail when it is driven in place.

A lead hole 26 of one quarter of an inch in diameter is provided for guiding a fastener made from a strip approximately three fourths of an inch wide when anchored member is of hard wood. If the fastener is to be driven into concrete or a fabricated steel structure a lead slot or socket should be provided which is tight enough to allow a driving pit for the shank. The shank will hold when driven between spaced steel members such as two channels secured back to back.

The fastener illustrated in Fig. 4 is different in construction than the fastener described above in that the head 28 is formed by first twisting the strip at the upper end of the shank ID, as indicated at 29, and then forming the loop 30 by bending the strip rearwardly and downwardly and then forwardly past the shank to produce the leg 3!. The loop 30 may be circular with the leg 3| continuing therefrom as a tangent or it may be formed spirally with a relatively small bend at the top and gradually increasing in its radius to the point of tangency where the leg may be said to begin. The spirally formed head positions the impact receiving surface closer to the axial center of the shank than the circular loop which makes it easier to drive. However the diameter of the loop may be chosen to produce the desired driving qualities.

The head being formed in this manner does not produce an abrupt change in the formation of the head such as would occur if the stock was bent over to an angle of approximately ninety degrees. When pressure is applied at the toe l9 the leg and loop of the head will flex in each increment along there. The bending forces are thus distributed over the entire length of these resilient sections.

With this type of head a smaller load per unit deflection may be obtained as compared to the twist head because of the added length to the resilient portion of the fastener and it may be driven to various depths without exceeding the yield point of the metal. The loop of the head closes, rather than stressing the fibers beyond their elastic limit which would produce a new permanent set in the material.

The load characteristic of both of these fasteners may be varied to suit different applications without impairing their design. Thus the cross sectional area may be increased to provide greater clamping pressure, and the length and relative angular position of the leg may be changed to produce a different load per unit of deflection. The diameter of the loop of the fastener shown in Fig. 4 may be varied to produce a different load per unit deflection. Obviously the ultimate load of any one fastener is determined by driving it to different depths in the anchoring member.

The load characteristics of the fasteners are not dependent upon the tightness of the shank when driven in the lead hole or socket because a relatively few pounds gripping pressure on the shank is ample for applying several thousand pounds pressure at the outer end of the leg.

The principal reason for this result is the fact that the load application, being at the end of the leg, is sufficiently remote of the shank that it bends the leg upwardly and tends to bend or rotate the shank in a vertical plane about a horizontal axis adjacent to the point where it enters the anchored member,

These forces are thus attempting to bend the shank in the plane of its broadest dimension, which represents the section of maximum bending resistance, because the plane of the broad dimension of the strip is substantially the same as that in which the load is applied. This is a paramount advantage of this fastener.

These forces having the tendency of rotating the shank about a horizontal axis normal to the broad dimension thereof thus increase the frictional engagement between the shank and the anchor member, thereby increasing the initial gripping force on the shank proportionally to the increased load.

Thus the load application does not tend to lift the shank out of the hole or from its socket and only a few pounds is all that is required initially to hold the shank in place as the fastener is being driven into the anchored member. Vibration will not loosen the shank after it has been set. The rib I2 is used to prevent the shank from buckling under the driving force. This rib may be placed on either face of the shank. It is not known whether there is any difference in the resistance to bending in the plane of the broad dimension of a strip with or without the rib. It is believed that this resistance would be approximately the same so the object of this invention need not be dependent upon the rib formed in the shank.

After the fastener has been formed it is heat treated. The physical dimensions and the shape of the fastener together with the heat treatment permits full advantage of the properties of the steel with minimum amount of metal and maximum results. The thinness of the strip permits accurate control with strict uniformity in the heat treating process which is not obtainable with square cross sections of steel of equivalent areas.

By the making the fastener from strip material it is comparatively light weight and is economical to manufacture. The stresses created by fastening one object to another are resisted by uniform flexure in the correctly constructed resilient section and stress concentration at any one point is avoided thereby producing a small load per unit of deflection while applying a relatively high static pressure. The fastener is readily removed by inserting a j aw puller under the impact receiving surface of the head and prying it from the anchored member yet it will not pull out due to vibration when in service.

I claim:

1. A fastener for the purposes described formed of a flat strip of spring steel and comprising a shank arranged to be inserted as by driving into a support, the material of the strip at the upper end of the shank bent across the broad side of the strip providing an impact head and twisted along the axis of the bent portion of the strip providing a leg extended downwardly and sideways parallel to the broad side of the shank to engage from above a member to be fastened to the support, the side of the strip which forms the under side of the free end of the leg being the same side which forms the impact sur face of the head at the upper end of the shank.

2. A resilient spike formed of a flat metal strip, one end portion of the strip providing a straight shank for driving into a support, the strip at the upper end of the shank having a bend across the broad side of the strip to provide an impact head and then a twist toward the shank disposing the bent portion of the strip downwardly and sideways parallel to the broad. side of the shank providing a leg to engage from above a member to be fastened to the support.

3. A resilient spike formed of a flat metal strip having greater width than thickness, consisting of a bend across the broad side of the strip providing a straight shank and a downwardly extending leg, a twist along the axis of the leg disposing it sideways with one edge closely adjacent to and substantially parallel with the broad side of the shank, the top of the bend serving as a head for driving the shank into a support.

4. A resilient spike formed of a fiat metal strip having greater width than thickness, consisting of a bend across the broad side of the strip producing a straight shank and a downwardly extending leg, a twist adjacent the bend disposing the leg sideways with one edge closely adjacent the shank and the broad side of the free end of the leg substantially normal to the plane of the broad side of the shank, the top of the bend serving as a head for driving the shank into a support.

KENNETH L. JOHNSON.

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