US3177506A - Punch and die for upsetting and socketing screw head - Google Patents

Description

April 13, 1965 w. A. DE VELLIER 3,177,506

PUNCH AND DIE FOR UPSETTING AND SOCKETING SCREW HEAD Filed April 13. 1961 WILLIAM A. DE VELLIER INVENTOR.

United States Patent 3,177,506 PUNCH AND DIE FOR UPSETTlNG AND SOCKETING SCREW HEAD William A. De Vellier, Hollywood, Calif., assignor to American Fastener Corporation, Hollywood, Cal1f., a

corporation of Nevada Filed Apr. 13, 1961, Ser. No. 102,857 Claims. (Cl. 7)

This invention relates to the manufacture of screws. More specifically the invention is concerned with a particular form of punch or hammer for use in forming a combination slot and a generally cruciform recess in the heads of screws and to the method employed in connection therewith.

An object of the invention is to provide a novel form of punch or hammer for forming a combination slot and recess, as aforesaid, for the reception of a generally cruciform driver combined with a blade driver and which will present a much greater area than heretofore for the positive engagement thereof with the slot and recess in optimum forcible turning moment and hence the achievement of maximum torque capacity, and wherein especially good results are also obtained in respect to the relation between end thrust and torque when either a conventional cruciform driver or a conventional blade driver is used independently.

Another object of the invention is the provision of a punch of the character described adapted for use with a conventional die to produce the combination slot and recess and wherein the slot extends entirely across the head and converges toward the axis of the screw shank.

A further object is the provision of a punch by means of which the combination slot and recess can be produced rapidly and economically from a continuous length of wire and with a minimum number of operations, which will avoid the operation of shaving the screw head or removing burrs from the end of the slot after it is formed and which will produce blanks having shanks of accurate and uniform cylindrical diameter and the exterior surface of which will be smooth and uniform so that such blanks can be easily made into satisfactory screws.

A still further object of my invention is to provide a punch which will produce recessed head screws of the character described which will have substantially increased strength in the portion of the same heretofore considered to be the inherently weak portion of conventional recessed head screws.

The foregoing and other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawing forming a part hereof and in which:

FIGURE 1 is an end elevational view of a punch made in accordance with my invention.

FIGURE 2 is an elevational view partially in section approximately along the line 2-2 of FIGURE 1 and including a sectional view of a screw-head.

FIGURE 3 is a view of FIGURE 2 rotated through 90 degrees and with the screw indicated by broken lines.

FIGURE 4 is an enlarged fragmentary detail view on an enlarged scale showing cooperation of the punch with a conventional die in producing the combination slot and recess.

FIGURE 5 shows the punch operatively mounted in a fragment of the header in a heading machine (not shown) for cooperation with a conventional die as illustrated in FIGURE 6.

With continuing reference to the drawing wherein like references of character designate like parts, and particu larly FIGURE 6 thereof, reference numeral 1 indicates generally a die mounted within a stationary part or anvil 3,177,506 Patented Apr. 13, 1965 of a conventional cold-heading machine (not shown) opposing a reciprocating gate or cross-head 2 adapted to move toward and from the anvil 1. The die 1 has a longitudinal aperture 3 therethrough to closely fit the wire W from which the screw shank and head are formed. The forward end of the aperture is counter-sunk as at 4 to form a so called fiat head screw as shown in FIGURE 2. In a two-blow heading machine the first blow upsets the protruding end of the wire W to substantially the extent and shape shown and indicated at 5 to partially form the screw head.

The punch of my invention comprises a hammer hav-, ing a cylindrical main body 6 adapted for securement in the cross-heads 2 of a heading machine as aforesaid and machined or formed at its outer end to form the punch proper, indicated generally at 8. This end of the hammer is formed with a circular recess 9 defined by an annular wall 10 and a fiat inside wall 11 at right angles to each other. The circular recess 9 is coextensive in size to the forward countersunk end of longitudinal aperture 3.

The punch proper comprises a diametrically disposed vane 12 extending entirely across the recess 9 and having side walls 13, 14 and a flat uniformly tapering outer wall 15 of diminishing axial magnitude which merges with a truncated or transverse flat portion 16. As best illustrated in FIGURE 4 the outer ends of the vane 12 originate at a point 17 substantially midway between the outer edge of the annular wall 10 and the flat inner wall 11 of the recess 9. Four wings 18, 19, 20 and 21 diverge upwardly from a substantially convex outer end 23 in cruciform disposition with the top ends of the wings 19 and 21 intersecting the fiat bottom portion 16 of the vane 12 while the top ends of the wings 18 and 20 intersect the flat inner wall 11 of the recess 9.

When the punch 8 is forced into the upset cold end 4 of the screw blank the metal in the head will not only be forced inwardly in advance of the punch, but will also flow freely with a lateral component in its flow in such manner as, during the initial inward movement of the punch, to cause the metal to fill and fully occupy the countersunk end 4 of the die 1 and thereafter continue to flow freely to fill out and fully occupy the recess 9 between the sides of the vane 12 and the annular wall 10 of the recess.

A combination slotted and recessed screw-head is thus formed wherein grooves formed by the one pair of wings (19 and 21) intersect the flat downwardly converging bottom walls of the slot formed by the vane 12 and the top end of the grooves formed by the wings (18 and 20) intersect the top flat surface 24 of the screw-head, and wherein a vertical edge 25 will be formed about the periphery of the screw-head by the annular wall 10 of the recess 9 in the end of the hammer 6.

While I have shown a particular form of embodiment of my invention, I am aware that many minor changes therein will readily suggest themselves to others skilled in the art without departing from the spirit and scope of the invention. Having thus described my invention what I claim as new and desire to protect by Letters Patent is:

1. A screw forming means comprising die means having a longitudinal extending aperture adapted to closely fit a wire from which a screw is to be formed and having its forward end countersunk, a hammer having a work surface at one end thereof adapted to act on a screw blank to upset a head and simultaneously form a slot in the head, said work surface comprising a circular recess coextensive in size to the forward countersunk end of the aperture of said die means, said circular recess of said work surface further comprising a flat inner wall inset from said end of the hammer with an annular wall at right angles to said inner wall, and a punch extending axially from said inner wall of said working surface and comprising a vane extending entirely across said circular recess and intersecting said annular wall intermediate the,

2. The screw forming means of claim 1 wherein said vane has a flat tapering outer wall of diminishing axial length from said inner wall as said vane approaches said annular wall.

3. The screw forming means of claim 1 wherein said punch further comprises two pairs of axially outwardly. converging wings in cruciform disposition to form a cruciform recess in the head in combination with the slot.

4. The screw forming means of claim 2 wherein said punch further comprises two pairs of axially outwardly converging wings in cruciform disposition, the axially inner ends of one pair of wings intersecting said flat inner wallytheaxially inner ends of the other pair of wings intersecting said vane, and the axially outer ends of all of said wings merging into a central blunt end, to 7 form a corresponding cruciform recess in the head in 5 combination with the slot.

5. The screw forming means of claim 4' wherein said one pair of wings extends from said central blunt end radially with, greater radial magnitude thansaid other pair of. wings.

References Cited by the Examiner UNITED STATES PATENTS 389,166 9/88 Rogers 10 7 2,125,272 8/38 Erdman 10-7 2,359,898 10/44 c1ark- 85-45 2,400,684 5/46 Clark 8545 2,673,359 3/54 Stellin 8545 2,9 6,752 6 61 Lovisek 10 7 20 ANDREW R. JUHASZ, Primary Examiner.

CARL W. TOMLIN, Examiner.

Claims (1)

1. A SCREW FORMING MEANS COMPRISING DIE MEAN HAVING A LONGITUDINAL EXTENDING APERTURE ADAPTED TO CLOSELY FIT A WIRE FROM WHICH A SCREW IS TO BE FORMED AND HAVING ITS FORWARD END COUNTERSUNK, A HAMMER HAVING A WORK SURFACE AT ONE END THEREOF ADAPTED TO ACT ON A SCREW BLANK TO UPSET A HEAD AND SIMULTANEOUSLY FROM A SLOT IN THE HEAD, SAID WORK SURFACE COMPRISING A CIRCULAR RECESS COEXTENSIVE IN SIZE TO THE FORWARD COUNTERSUNK END OF THE APERTURE OF SAID DIE MEANS, SAID CIRCULAR RECESS OF SAID WORK SURFACE FURTHER COMPRISING A FLAT INNER WALL INSET FROM SAID END OF THE HAMMER WITH AN ANNULAR WALL AT RIGHT ANGLES TO SAID INNER WALL, AND A PUNCH EXTENDING AXIALLY FROM SAID INNER WALL OF SAID WORKING SURFACE AND COMPRISING A VANE EXTENDING ENTIRELY ACROSS SAID CIRCULAR RECESS AND INTERSECTING SAID ANNULAR WALL INTERMEDIATE THE OUTER AND INNER EDGES THEREOF, SAID HAMMER FORCING THE METAL OF THE WIRE INWARDLY IN ADVANCE OF SAID PUNCH TO FLOW AND FILL THE COUNTERSUNK END PORTION OF SAID DIE MEANS AND THEREAFTER FORCING THE METAL TO FLOW AND FILL SAID CIRCULAR RECESS IN SAID HAMMER BETWEEN THE SIDES OF SAID VANE AND AGAINST SAID ANNULAR AND INNER WALLS, TO THEREBY FORM A FLAT HEAD WITH A SLOT FORMED THEREIN ACROSS THE ENTIRE WIDTH OF THE HEAD AND FREE OF BURRS OR FINS.

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