US1964988A

US1964988A - Nail machine

Info

Publication number: US1964988A
Application number: US526584A
Authority: US
Inventors: Charles K Hill
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-03-31
Filing date: 1931-03-31
Publication date: 1934-07-03
Anticipated expiration: 1951-07-03

Description

July 3, 1934-. C 1,964,988

NAIL MACHINE Filed March 31, 1931 2 Sheets-Sheet l I NV EN TOR.

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Patented July 3, 1934 UNITED STATES NAIL MACHINE Charles K. Hill,

Application March 31,

3 Claims.

The present invention relates to a machine for making nails from twisted wire stock, the machine being particularly adapted to handle this stock and to make nails therefrom having a twisted shank.

In the making of nails of the type known as drive screws, i. e., those having a threaded shank, it has been necessary heretofore, first to form the nail and then to thread the shank of each individual nail after manufacture. It is obvious that such a method is costly and slow and the use of such nails, while desirable due to their great holding power, has been limited by the cost of manufacture. Also, it has been impossible to use certain hard and tough steels for these nails because the dies used to impart the thread to the nail are quickly worn out on the hard steel. For these reasons it is highly desirable to prepare nails of the type of drive screws from a twisted stock rather than from straight stock which must be rolled after the nail is formed. However, wire of appreciable length, such as a roll of wire, has not heretofore been successfully twisted since such a wiretends to untwist as formed in methods so far attempted.

In my copending application Serial No. 513,262, filed February 4, 1931, there has been described an apparatus and method for twisting wire of appreciable length and placing it in condition suitable for forming nails therefrom. In

the present application, there is described a machine adapted to take this twisted wire and make a finished nail therefrom, the nail having a threaded shank. It is, accordingly, an object of this invention to provide a machine for forming nails automatically and continuously from twisted wire. Another object of the invention is to provide a machine which may be adjusted to produce nails of different lengths as desired, the

nails produced being accurately formed of uniform length.

To the accomplishment of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims. The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings:

Fig. 1 is a plan view of the nail machine; Fig. 2 is a front elevation of a portion of the machine; Fig. 3 is an enlarged longitudinal section through a wire feeder forming Part of the nail Cleveland, Ohio 1931, Serial No. 526,584 (01. 10-46) machine; Fig. 4 is a transverse section through the wire feeder taken along the line 4-4 of Fig.

1; Fig. 5 is a perspective view of a piece of twisted wire; Fig. 6 is a perspective of the wire with rounded sections; Fig. 7 is a section showing a nail cut-01f; and Fig. '8 is a perspective. View of a nail formed by the nail machine.

Referring to Fig. 1 of the drawings, a twisted wire from a roll such as is formed in my copending application above referred to, is passed through wire straighteners 9 and 11, one of these being vertically placed and the other horizontally placed. Each of these straighteners has a plurality of rollers 12 connected by straps 13 between which the wire passes and is straightened. The wire next goes to a sliding plate 14 which is caused to reciprocate by the bell crank 15 through the link 16. The bell crank is operated by a shaft 17 connected to a wheel 18.

The sliding plate 14, as shown in Figs. 3 and 4, consists of the plate 19 having a longitudinal passage 21 through which the wire 22 passes, entering the plate through the bushing 23. A strip of metal 24 lies alongside the wire and rollers 25 contact with this strip. Each roller lies in an orifice having a lateral wall 10 which slopes toward the strip 24 thus narrowing the orifice in the direction from which the wire is being fed, the rollers being normally held in the narrow end of the orifice by plungers 26 acted upon by the springs 2'7. The rollers are otherwise unattached and the strip 24 is also unattached, being free to move laterally a limited distance with respect to the plate 14, that is, radially to the axis of the wire which is fed through this plate. As the plate 14 is drawn back by the bell crank 15 and the link 16, the rollers 25 are forced rearwardy against the springs into the wider part of the orifice where they do not bear on the strip and the plate travels back freely. On the other hand, when the reciprocating plate begins its forward stroke, the friction of the twisted wire on the strip 24 causes the latter to lag behind the sliding plate and to draw the rollers down into the narrow part of the orifices where they exert pressure on the strip which is transmitted to the wire. In fact, the wire is firmly gripped by the sliding plate and is drawn forward the length of one stroke. In practice a very small clearance exists between the ends of the strip 24 and the plate 19, so as to permit sufficient movement of the strip longitudinally of the plate to permit the limited radial movement which has been described. The strip 24 need move radially but two or three thousandths of an inch to release the wire, so that the necessary end clearance for the strip 24 need be of the order of only a few thousandths of an inch.

As the wire comes to rest after being drawn forward this amount, it is stamped by jaws 28 which, as may be seen in Fig. 2, have each a half round indentation which rounds the twisted wire correspondingly at intervals measured by the length of stroke at which the sliding plate 14 is operated. The jaws are mounted in holders 29 and are held therein by the pieces 31 and the bolts 32. The jaw holders are mounted in

guides

33 and 34, the lower jaw being slidably mounted.

Intermittent motion is imparted to the lower jaw through the link 35 which connects the jaw holder to a lever 36. This lever has a roller 37 which contacts with a cam 38. A spring 39 retracts the jaw after the latter has stamped the wire.

To secure synchronized operation of the slide plate 14 and the jaws 28, both of these elements are operated from the same source. The arm 17 which rocks the bell crank 15 is connected, as above mentioned, to the wheel 18 by means of a fork 41 connected to a key 42 which fits in a keyway 43. To regulate-the length of stroke of the slide plate 14, the key may be set at any desired distance from the center of the wheel 18 in the keyway 43 which is cut in the wheel. As this wheel imparts a reciprocating motion to the slide plate, it also revolves the cam 38 which periodically forces the roller 37 outward and presses the jaws 28 together. The wheel 18 and appurtenant parts are supported from the frame of the nail machine by means of the hanger 44.

The twisted wire now leaves the jaws 28 and proceeds through the machine with accurately spaced rounded portions 45 as best seen in Fig. 6. As each rounded portion reaches the grip jaws 46, the wire is cut off at these rounded portions by the knives 47 and is headed by the hammer 48. This completes the formation of the nail.

The operation of the nail machine in making nails having threaded shanks from twisted stock is as follows: The wire passes through the straighteners 9 and 11 where it has any bends or kinks taken out, the straightened wire proceeding to the sliding plate 14 where it is periodically gripped by the rollers 25 and forced through the machine. The slide plate repeatedly moves freely toward the incoming stock, grips it, and draws it forward an amount approximately equal to the length of a finished nail. Due to the firm grip with which the sliding plate holds the wire, there is no slip and the stock is accurately measured for the finished nail. As before mentioned, the sliding plate releases its grip on the stock while performing the return stroke and, during this interval, the stock remains at rest to be stamped between the jaws 28 and given a rounded contour thereby. Since the jaws and the sliding plate are driven from the same means, they may be synchronized so that the stamping operation takes place while the stock is at rest, an obvious requirement since the moving stock cannot be stamped.

The twisted wire now has a series of equally spaced rounded sections along its length and proceeds in that form to the gripping jaws 46 which hold the wire while beveled knives 47 cut the stock at one of the rounded sections. This places the point on one nail which is thus finished and drops into a receiver while, at the same time, providing an end on the succeeding nail which is immediately headed up by the hammer 48. These nail-finishing means are of conventional construction and operation, being timed to form the stock at the rounded portions 45.

Fig. 5 illustrates a piece of the uniformly twisted wire stock from which the nails are made, this stock being originally square in cross section or of any section other than round. In Fig. 6 is illustrated a piece of stock after rounded sections have been placed thereon at regular intervals by the jaws 28, obliterating the twist at these points in order that thenail pointing and heading operations may be performed on the stock. A finished nail having a threaded shank, as produced in my apparatus, is shown in Fig. 8. Such a nail is as readily and cheaply manufactured by the present method and apparatus as a nail with a straight shank and yet has all the advantages resulting from a threaded shank. Such a nail has great holding power and will break before it can be withdrawn by a direct pull. This method of making nails permits hard and tough steels to be used since there are no dies to wear out rapidly, the nail formed from such steels, for example manganese steels, being very strong and capable of being driven through very hard materials without bending.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. An apparatus for making nails having threaded shanks, which comprises a reciprocably mounted feed member, a passage therethrough for a twisted wire, a flat-faced gripper lying alongside said passage and capable of limited movement relative to the feed member, inclined surfaces spaced from said gripper, and wedging means coacting with said surfaces to force the gripper into holding relation with the twisted wire when moving in one direction and releasing on the other direction.

2. An apparatus for making nails having threaded shanks, which comprises a reciprocably mounted feed member, a passage therethrough for a twisted wire, a flat-faced gripper lying alongside said passage and capable of limited movement relative to the feed member, inclined surfaces at the back of said gripper, and multiple rollers coacting with said surfaces to force the gripper into holding relation with the twisted wire when moving in one direction and releasing on the other direction.

3. An apparatus for making nails having threaded shanks which comprises a reciprocably mounted plate, a pasage therethrough for a twisted wire, a flat strip lying alongside said passage, and capable of limited lateral move- 0 ment relative to said plate, multiple rollers positioned in said plate and bearing against said strip, and inclined surfaces in said plate adapted to force said rollers against said strip to cause the latter to grip a wire when the plate is mov- 5 ing in a certain direction.

CHARLES K. HILL.