US1221555A - Nail-making machine. - Google Patents

Description

D. H. McCLELLAND.

NAIL MAKING MACHINE.

APPLICATION FILED FEB. 28, I916.

Patented Apr. 3, 1917.

of the nail.

TlhlfED @Tdd NAIL-MAKING- MACHINE.

Specification of Letters Patent.

Patented Apr. 3, 191?.

Application filed February 28, 1916. Serial N 0. 80,766.

To all whom it may concern.

Be it known that I, DAVID H. MCCLEL- LAND, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Nail-Making Machines, of which the following is a specification, reference being had -to the accompanying drawings, forming a part thereof.

This application is in part a continuation of my application filed May 27, 1912, Ser. No. 700,069. The invention relates to mechanism designed for manufacturing a nail having two heads longitudinally separated by a short section on the shank, one of the heads being formed as the terminal portion Such a nail has many uses, but is particularly valuable as a fastening means for temporarily scaffolding or for molds and forms used in concrete construction work, since the head nearer the point of the nail prevents the terminal head from being driven in flush with the surface of the wood, and thus leaves it easily accessible when it is desired to take down the scaffolding or forms by removing the nails with an ordinary claw hammer. The present mechanism is designed to produce such a nail from ordinary wire stock and practically in a single operation, and the invention consists in the features and elements of construction which cooperate to this end, together with their combinations as described and shown in the drawings and asindicated by the claims.

In the drawings Figure 1 may be considered as a plan view of nail-making mechanism embodying this invention.

Fig. 2 is a plan view of the same mechanism with the parts shown in operative relation to the wire stock, and with some parts broken away and shown in section to reveal features of construction.

Fig. 3 is a detail view of a modified construction ofthe movable gripper jaws.

Fig. 4 is a detail view of another modification of the movable gripper jaws.

Fig. 5 is a detail section at the line 55 on Fig. 4.

In the drawings no attempt is made to show a complete machine but only those parts of a nail-making machine to which the present invention relates. Referring first to Fig. 1, the areas, A -X, may be understood to represent the surface of a table or other suitable supporting frame for the moving parts, provided with a slot or guide-way, B, in which there is mounted for reciprocation a cross bead, C, to which there is shown pivotally connected a pitman or thrust link, D. It may be understood that the pitman, D, may be operated by any desired and convenient means to cause reciprocation 0n the cross head, C, in the guide-way, D. The wire stock which is to be made into nails is represented at E, and is to be fed to the machine by any suitable feeding mechanism and through any suitable guide, not shown. At opposite sides of the guide-way, B, there are mounted the arms, F, pivoted at F to the table, A, and carrying the gripper jaws. G, which are suitably channeled at G to engage the wire stock, E, and to hold it against longitudinal movement during the heading operation. The arms, F, also carry the cutters, H, which form the point of the nail and cut off from the rest of the stock the portion which is being made into a finished nail. Both the grippers, G, and the cutters, H. may be rigidly associated with the arms, F, though provided with adjusting means shown at G and H respectively.

By means of suitable springs, J, the arms, F, are normally held apart in the position shown in Fig. 1, so that the stock, E, may be freely advanced to a position between the grippers. G, G, by means of a feeding mechanism not shown. Actuating levers. K, are provided, however, pivotally mounted at K on the table, A. with their rounded ends, K in contact with the arms, F, at the end portions, F of said arms which are farthest removed from their pivotal mountings at F The opposite ends, K of the levers, K. at the other side of their fulcrum pivots, K are formed with cam surfaces, K", positioned to cooperate with rollers, L, carried by the cross head, C, in such a manner that as the cross'head approaches the end of the wire stock, E, positioned between the grippers, G, the ends, K of the levers, K, will be forced apart, thus rocking the rounded ends, K toward each other, and

swinging the arms, F, F, together so as to close the grippers, G, upon the stock, E, to hold it firmly for the heading operation.

The cross head, C, carries a heading die, M, whose impact against the end, E of the wire stock, E, occurring after the grippers, G, have closed upon the stock, may first serve to upset the end, E, forming the terminal head of the nail. This is further insured by the provision of auxiliary grippers, O, O, which are slidably carried upon the arms, F, F, in position to engage the wire, E, just back of its end, E and which are formed to furnish a recess at O dimensioned to accommodate the nail head formed at E, by the blow of the heading die M. The auxiliary grippers, O, are spaced away from the grippers, G, and are yieldingly held in such position by the compression springs, P. This leaves at E a section of the wire stock, E, which contains enough metal for the second head which is to be formed upon the nail. Therefore, when the terminal head has been formed at E and driven, by the heading die, M, into the recess, the further advance of the cross head, C, and. the die, M, forces back the auxiliary grippers, O, carrying with them the headed end portion of the nail and upsetting the portion, E to form the second head in a shape substantially as shown in Fig. 2.

' It will be understood that the stroke of the pitman, D, and the cross head, 0, connected to it is only such as to carry the grippers, 0, close enough to the grippers, G, to form the second head of, the desired thickness, after which the heading die will begin to recede and there will be no further distortion of the nail stock. As the cross head, C, reaches its original position illustrated in Fig. 1, the springs, J, will react to return the arms, F, to their original separated position, and the resulting separation of the grippers, O and G, will release the finished nail, permitting it to fall by gravity through the guide slot, B, into any convenient form of receptacle or conveyer, not shown.

It will be observed that in the foregoing description it has been assumed that the end of the stock will be upset by the initial impact of the heading die, M, so that the head at E is formed before the grippers, .O, are forced to recede toward the grippers, This, however, is not essential, for since the grippers, O, are firmly engaged with the wire stock, E, back of the terminal, E it is evident that if the'end portion, E does not readily upset into a head to occupy the recess, O, tf-e wire, E, itself will transmit the advancing movement of the heading die, M, to the grippers, O, and the section of the wire held between the grippers, 0, will be moved bodily toward the grippers, G, thus causing the upsetting of the wire which is unconfined between either pair of grippers at E forming the flange or secondary head at this point; obviously after the head has been formed at E the grippers, 0, will have reached their limit of movement, being stopped by contact with the faces of the grippers, C, and the terminal, E of the wire, E, must therefore yield to distortion and take the form of the terminal head occupying the recess, to permit the completion of the working stroke of the cutting die, M. It is therefore immaterial in which order the two heads are formed; the positive engagement of the wire stock, E, at the two portions of the nail shank which are to retain their original diameter, insures that the unrestrained portions of the wire at E and E will both be moved or upset by the longitudinal pressure of the heading die, M, before the latter has completed its working stroke, and the finished nails will therefore be'of a substantially predetermined form, regardless of the order in which their tw heads are produced. a

In Figs. 1 and 2 the auxiliary grippers, O, are shown as slidably carriedon the arms, {F, by being mounted between guide plates, 0 to which they are rigidly connected and which extend above and below the gripper dies or jaws, G, G, and beyond them to a connecting yoke, 0 which occupies a notch, F in the arm, F. It may be understood that the vertical thickness of each of the arms, F, is sufficient to provide supporting surfaces at F, upon which the plates, 0 are slidable, while the yoke, O, has a range of travel in the slot, F The compression spring, P, is pocketed in the end of this slot so as to react against the yoke, 0 for returning the grippers, O, to their normal position separated from the grippers, G, G. As a modification of this construction, to reduce the friction of the sliding parts associated with the grippers, O, and the arms, F, in which they are carried, Fig. 3 shows an anti-friction roller, Q, positioned between the gripper block, 0, and the guide-way of the arm, F. To keep this roller, Q, in proper relation to the surfaces upon which it rolls there is provided a flange, Q rigidly associated with the roller and formed with ear teeth, Q", whose pitch circle is coinci ent with the circular outline of the roller, Q, and which mesh with racks, F" and 0", carried by the parts, F and 0, respectively.

Another modified form of the grippers, O, which is also designed to reduce the friction between said members and the arms, F, is shown in Figs. 4 and 5. In this form the gripper members, 0, are pivotally carried in the arms, F, being formed with end portions, 0, which are more than semi-circular in outline and are pocketed in correspondingly shaped recesses, F, in the arms, F, thus providing ample bearing surface. In this form instead of sliding from norhill mal position to approach the gripper jaws, (-r, the members, 0", will swing through short arcs to such position in opposition to the pressure of the springs. I shown as pocketed directly in the gripper jaws, G. This movement requires that the cooperating faces of the grippers, be slightly curved about the centers of the bearings, 0, so as to roll together in the swinging movement of the members, 0-, about said bearing centers. In their initial position, therefore, the grippers, O, will form a recess at somewhat wider than such recess is when the members are moved to their final position, and to prevent the formation of a fin on the portion of the nail which occupies this recess the faces of the jaw members, 0*, O, are made to interlock with each other, as indicated in the sectional view of Fig. 5, so that while the distance between their reacting faces may vary as they move from one? position to another, the material of the nail will at all times be completely confined and will merely be compressed by the diminishing of this transverse dimension.

I claim 1. In a nail-making machine, a frame or table, a cross head carrying a heading die and mounted to reciprocate thereon, levers pivoted one at each side of the axis of reciprocation, cutters normally separated and disposed at opposite sides of said axis, one end of each lever being operatively connected to one of said cutters, and the opposite ends of the levers being formed to be wedged apart by the advance of the cross head, whereby the stock between the cutters is severed as the cross head advances for forming a head thereon.

2. In a nail-making machine, a frame or table, a cross head carrying a heading die and mounted to reciprocate thereon, levers pivoted one at each side of the axis of reciprocation, grippers normally separated and disposed at opposite sides of said axis, cutters associated with said grippers, respectively, one end of each of the said levers being operatively connected to one of said grippers with itsassociated cutter, and the opposite ends of the levers being formed to be wedged apart by the advance of the cross head. whereby the grippers are closed upon the stock and the cutters cooperate to sever the same as the heading die approaches the end of said stock for forming a head thereon.

3. In a nail-making machine, a frame or table, a cross head carrying a heading die and mounted to reciprocate thereon, a pair of gripping jaws disposed at opposite sides of the axis of reciprocation for holding the stock which is to be headed by the heading die, a swinging support upon which each of the gripping jaws is rigidly mounted, said supports being pivoted on the frame at respectively opposite sides of said axis. of reciprocation at points such that lines from the gripping jaws to the pivots of their respective supports diverge oppositely from the axis of cross head reciprocation and be yond the limit of movement of the cross head toward the grippers, and means where by said movement of the cross head effects an initial engagement of the grippers with the stock.

4. In a nail-making machine, a frame or table, a cross head carrying a heading die and mounted to reciprocate thereon, a pair of gripping jaws for holding the stock to be headed and disposed at opposite sides of the axis of reciprocation of the heading die, a pair of swinging arms by which said jaws are carried respectively, said arms being pivoted at opposite sides of the axis of reciprocation and at points beyond the limit of such movement of the cross head, said pivots being widely separated from each other so that lines from the gripping jaws to the pivots respectively diverge symmetrically about the axis of reciprocation whereby the grip of the jaws is increased by the impact of the heading die.

In a nail-making machine, a frame or table, a cross head carrying a heading die and mounted to reciprocate thereon, two pair of gripping dies normally separated along the axis of cross head movement and one of each pair normally disposed at either side of said axis, each pair being formed to completely encompass the stock when closed upon it, swinging supports each carrying one gripper of each pair, one gripper on each support being movable toward the other, said supports being pivoted on the frame at respectively opposite sides of the axis of cross head movement, so that lines from the gripping jaws to the pivots of their respective supports diverge oppositely from said axis and beyond the limit of said movement whereby the heading impact increases the gripping force, and means for moving the grippers into initial engagement 'with the stock.

6. I11 a nail-making machine, a f'ame or table, a cross head carrying a heading die and mounted to reciprocate thereon, two pair of-gripping dies normally separated along the axis of cross head movement and one of each pair normally disposed at either side of said axis,.each pair being formed to completely encompass the stock when closed upon it, swinging supports each carrying one gripper of each pair, one gripper on each support being movable toward the other, said supports being pivoted on the frame at respectively opposite sides of the axis of cross head movement, so that lilies from the gripping jaws to the pivots of their respective supports diverge oppositely from said axis and beyond the limit of said & 1,221,555

movement whereby the heading impact inset my hand at Pittsburgh, Pennsylvania, ii-eases the gripplng force, the grippers thls l-L day of February, 1916. nearestthe heading the being formed with 1 DAVID H. MCCLELLAND. a recess in then surface facing sniddie to 5 receive a terminal head formed on the Witnesses:

stock thereby. ALICE A. TRILL,

In testimony whereof I have hereunto En. J. EvANs.

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