US2303662A - Method and apparatus for producing rivets - Google Patents

Description

Dec. 1, 1942. A. A. SCHWARTZ ETAL ,3

METHOD AND APPARATUS FOR PRODUCING RIVETS Filed Nbv. 19, 1940 5 Sheets-Sheet 1 F7614. FIG/5 F/(i/6. FIG/7.

m fi fi A/PTHVRAJCf/WARTZ GEORGE CARSON Dec. 1, 1942. A. A. SCHWARTZ EI'AL 2,303,662

METHOD AND-APPARATUS FOR PRODUCING RIVETS Filed Nov. 19, 1940 v 5 Sheets-Sheet 2 ARTHUR 4. SC'f/WJFTZ I GEORGE CARSv/V 4 I W\ r Dec. 1942- A. A. SCHWARTZ EIAL 2,303,662

METHOD AND APPARATUS FOR PRODUCING RIVETS Filed Nov. 19, 1940 5 sheet s-sheet 3 FIG. Z FIG. 8. Am

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a .13 g 32 0' v0 k a V 5 gmwms A/PI'fi/UEA. scwmwrz GEORGE CARSON Dec. 1, 1942. A. A. SCHWARTZ arm.

METHOD AND APPARATUS FOR PRODUCING RIVETS Filed Nov. 19, 19 40 Sheets-Sheet 4 FIG ll.

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Dec. 1942. A. A. SCHWARTZ ETAL 2,303,662

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Swan W018 ARTHUR 4. SCHWAXIZ GEORGE CARSON 92w) M, filfnh wow s Patented Dec. 1, 1942 METHOD AND APPARATUS roa PRODUCING RIVETS Arthur A. Schwartz and George Carson, Buflalo,

N. Y., assignors Buflalo, N. Y., a corpo Application November 19, 1940,

18 Claims.

method and appaand more especially for producing coined This invention relates to a ratus for producing rivets, to a method and apparatus rivets.

One of the objects of this invention is to provide a method and apparatus for producing rivets.

Another object of this invention is to provide a method and apparatus for producing rivets with heads of accurate shape and of similar size and concentric with the body portion.

A further object of this invention is to provide a method and apparatus for producing rivets without flash edges.

With these and other objects in view, this invention embraces broadly the concept of providing a rivet to facilitate riveting requiring rivet heads that fit and fill countersinks or dimples. To fit properly, the heads of rivets of this type must be accurate in shape, substantially identical in size, and must be concentric with the body portion of the rivet. These rivet heads must also be made without a flash edge. Ordinarily the top surfaces of these rivet heads are flat so as to be flush with the surface of the joined member, but other shaped heads could be made without departing from the spirit of this invention. This type of rivet is customarily used in the construction of airplanes, and it is especially important in airplane construction to obtain rivets having the specifications mentioned above.

In the drawings:

Figure 1 is a face view of the reciprocating header and holder which forms a part of the invention.

Figure 2 is a face view of the matrix and blank cut-oil which compose the other half of the die.

Figure 3 is a side elevational view of the header and matrix disclosed in Figures 1 and 2.

Figure 4 is a view taken along line 4-4 of Figure 2, looking in the direction of the arrows.

Figure 5 is a view taken along line 5-5 of Figure 3, looking in the direction of the arrows.

Figure 6 is a view taken along line 6-6 of Figure 3, looking in the direction of the arrows.

Figure 7 is a view taken along line |--1 of Figure 2, looking in the direction of thearrows, showing the blank cutofi in retarded position.

Figure 8 is similar to Figure 7 showing the blank cutofi in advanced position.

Figure 9 is a view taken along line 9-9 of Figure 1, looking in the direction of the arrows.

Figure 10 is a view taken along line lit-I0 of Figure 2, looking in the direction of the arrows.

Figure 11 is a view to Bell Aircraft Corporation, ration of New York Serial No. 366,310

taken along line ll--l I 'of through an arc of Figure 2, looking in the direction of the arrows. Figure 12 is a view taken along line |2--l2 of Figures 1 and 2, looking in the direction of the arrows.

Figure 13 is similar to Figure 12 but showing the header in advanced position.

Figure 14 disclosesa rivet blank.

Figure 15 discloses the blank with a centered head.

Figure 16 discloses a blank with abrazier head.

Figure 17 discloses the finished rivet.

Figure 18 discloses diagrammatically the steps ofproducing the rivet.

Referring to Figure 3 of the drawings, the numeral i represents in dot and dash lines a portion of a rivet forming press, the bed of which is indicated by the numeral 2 and the reciprocating ram by 3. Attached to the bed 2 is a die holder 4 in which is rotatably mounted an annular die 5. An annular header 5 is rigidly fastened to a header holder 1 which is in turn adjustably mounted by bolts 8 and adjusting screws 9 to the ram 3. The header is adjusted to be in coaxial alignment with the die 5.

The face of the die holder 4 is bored to form a recess II! for the die and a communicating stepped aperture II which is concentric with the recess l0 and extends through to the rear face of the holder 4. The aperture l l is for the reception of a ratchet assembly indicated generally by the numeral 12 and comprising a flanged disc l3 provided with a radial arm l4 and a central shaft l5. The arm l4 moves within a recess IS in the rear face of the holder, its movement being limited to 90 by the side walls ll of the recess.

Mounted to move with the disc I3 by means of pins l8 and positioned between the disc and the rear face of the die 5 is a circular pawl member l9 provided with spring fingers 20 which are adapted to engage apertures 2| in the rear face of the die. The periphery of the die 5 is provided with a plurality of sockets 22 which are adapted to receive spring loaded ball detents 23 provided in the die holder 4.

A linkage (not shown but operated by movement of the ram 3) engages the arm M to move it Upon its movement clockwise, looking at Figure 6 the die is also rotated a quarter turn by the fingers 20 of the pawl l9. On its return movement, however, the die 5 is held stationary by the ball detents 23. Thus the die is rotated by quarter turns, one for every stroke of the ram.

The die 5 is centrally bored as at 24 to rotate about the shaft l5 and is held within the recess ll flush with the face of the die holder 4 by means of a headed screw 25 which is threaded into the end of the shaft |5. The face of the' die 5 is also provided with two pairs of diametrically opposed sockets adapted to receive locating pins or dowels 2'I projecting ifrom the face of the header 3. g

A series of apertures 23, 2'5, 33 and 3| arranged 90" apart are drilled completely through from the front to the rear face of the die and are countersunk on the front face to conform with the underlurface of the rivet head to be coined.

An aperture 32 is drilled through the die holder 4 in a line horizontally tangent with the ring of die apertures 28 through 3| and is fitted with a quill 33 through which is fed the wire from which rivets are to be formed. The wire is frictionally fed through the quill, in a manner common to rivet heading'machines, against an ad- Justable stop indicated by the screw 34 which determines the length of wire required for each rivet. The screw 34 is supported in any suitable manner as by the press I.

Mounted to move across the end of the quill 33 and up to a point adjacent one of the die aper tures 28 through 3| is a cutoff knife 35 provided with spring fingers 36. The mechanism for moving the knife 35 is not shown but is also a part of rivet forming machinery, the reciprocating movement of the knife being synchronized with the movement of the ram.

Arranged in the face of the header 6 to be in perfect coaxial alignment with the die apertures 23 through 3| are four rivet forming stations 31, 33, 39 and 40, the function of each of which will be described later.

At the station 31 is a plunger 4| projecting through an aperture 42 in a cutaway portion 43 of the header 5. A compression spring 44 retained within a socket 45 in the header holder I normally forces the plunger outward. A head 46 on the plunger limits the outward movement of th plunger by engaging the rear face of the header as shown in Figure 12.

At the station 38, as shown in Figure 10, is a conical depression 41 while at station 39 is an oval depression 48. The station 40 is plane and flush with the face of the header.

Provided for each of the die apertures 28 through 3| is a backing pin -5|l. These pins are made in sets of four, each set of different length to correspond to the different length of rivet desired to be made. As seen in Figures 7 through 13 these pins 50 fit closely within the die apertures and are provided with a plane outer end -5| and a rounded inner end 52 which engagesthe bottom shoulder 53 of the recess It. The conventional knockout pin 54 is also shown in Figures 12 and 13 projecting through an aperture 55 provided in the die holder in line with the ring of die apertures 28 through 3|.

In the shoulder 53 in line with the station 40 of the header is a sunken cam surface 55 into which is adapted to ride the rounded end of the backing pins 50 during the coining stage of the heading operation as will be described in more detail.

The operation of the device may be understood by reference to the diagram of the cycle of operation, Figure 18, and to Figure 7 through 13 which show the several steps of cutting off and inserting the rivet blanks and forming heads thereon.

During the first part of the forward movement of the rain 2 the knife 35 moves across the face the conical depression asoaaoa ofthequill33 andcutsoflthelengthofwire I. which projects through the quill. This length of wire or blank is carried by the spring fingers to a position over the aperture 23 where movement of the knife stops. Further forward movement of the ram causes the plunger 4| to engage the blank and force it into the aperture 23 against the plane end 5 l'of the backing pin 53.

The ram 2 then makes its return stroke and the knife moves back to its normal position. During a portion of the return stroke of the ram the die is rotated 90 by means of the ratchet assembly l2 and its operating linkage. This brings the die aperture 23 in alignment with the conical recess 41 at station 33 of the header while the aperture 25 is moved in alignment with the plunger 4 at station 31. The die remains held in this position by the ball detents 23 during the remainder of the return stroke of the ram and all of the rams forward stroke.

The next forward stroke of the ram causes 41 to engage the projecting end of the blank and slightly upset this end to form a preliminary head exactly centered with respect to the countersunk end of the die aperture. While this centering operation is taking place, a second blank has been cut oil and inserted in the aperture 29. In this and the next heading operation the pin 50 backs up the blank by being held against movement by the shoulder 53.

The ram then returns and the die is moved another 90 which brings centered rivet blank in line with the oval depression 43 at station 33 of the header, the blank lust inserted in aperture 25 in line with the centering depression 41 and the aperture 30 in line with the plunger 4|. On the next forward stroke of the ram the centered blank in aperture 23 is further upset by the oval depression 48 to form a brazier head, that is, a head having partial shoulders which are necessary to support the head for the subsequent coining operation. At the same time the blank in aperture 25 is centered and a new blank is cut oil and inserted in aperture 33.

The third return stroke moves the die through a third 90 placing the brazier head rivet in aperture 28 in line with the plane station 43 of the header. The second and third blanks are also moved forward in line with the centering and braziering station on the header. In this position of the die the backing pin under the brazier head rivet moves over the cam depression 55.

On the fourth forward stroke of the ram, the plane station 40 of the header engages the face of the die flattening the brazier head of the rivet which is now supported by the partial shoulders formed on the head during the second forward stroke of the ram, and since the backing pin has been removed from its shank any metal in excess of that required to form the head of the rivet will flow into the shank aperture rather than into flash formations at the head. Thus a perfoot head is coined on the rivet which is concentric with the shank and without burr or flash edge. The second and third blanks have a brazier head formed and are centered respectively, and a fourth blank is cut off and inserted in the remaining aperture 3|.

During the fourth return stroke, the die is rotated a fourth to bring the finished rivet to the first position, i. e., station 31. As the die completes its movement, the knockout pin 54 moves forward to elect the finished rivet. The

aperture 28 is now cleared for reception of a new blank and repeating the cycle of operations.

. While for purposes of illustration a four station revolving die has been described, it is obvious that any progressive type of die may be employed. For example, the die can readily be adjusted to travel through an arc of more or less than 90 for each stage or the die may be stationary and the ram adapted to rotate. Moreover, various mechanical changes may be made in the rivet forming and positioning mechanism without departing from the spirit of this invention.

It is therefore to be understood that this invention is only to be limited by the prior art and the scope of the appended claims.

We claim:

1. A method of producing a rivet comprising the successive steps of inserting a rivet blank in a die aperture, forming a head on the rivet, the centers of the head and shank of the rivet being concentric, braziering the head, coining the head by forcing the excess metal into the rivet shank, and then removing the newly formed rivet from the die.

2. A method of producing a rivet comprising the successive steps of inserting a rivet blank in a die aperture, revolving the die through a predetermined arc, forming a head on the blank, the centers of the head and shank of the rivet being concentric, revolving the die through a second predetermined arc, braziering the newly formed head, revolving the die through a third predetermined arc, coining the head by forcing the excess metal into the shank, returning the rivet to its first position, and then removing the newly formed rivet from the die.

3. A rivet forming device comprising a header and a die, said members being in coaxial alignment with each other and one of said members being capable of a reciprocating movement in respect to the other, apertures in said die, said apertures being separated by predetermined arcs, means on said header to force a rivet blank into one of said apertures, a conical depression on said header to form a head on the blank, the center of the head and shank being concentric, an oval depression in said header adapted to braz-ier the newly formed head, a station on the header, said station of the header and adapted to flatten the rivet head, and means associated with the die to permit the excess metal to be forced into the rivet shank during said coining operation.

4. A rivet forming device comprising a header and a rotatable die, said members being in coaxial alignment with each other and one of said members being capable of a reciprocating movement in respect to the other, apertures in said die, said apertures being separated from each other by predetermined arcs, stations on said header, said stations being separated from each other by predetermined arcs, means at one station on said header to force a rivet blank into one of said apertures, a conical depression at the next station on said header to form a head on the blank after it has been rotated through a predetermined arc, the center of the head and shank being concentric, a third station comprising an oval depression in said header adapted to brazier the newly formed head after it has been rotated through a predetermined arc, and a fourth station on the header, said station being flush with the surface of the header and adapted to flatten the newly formed rivet head after it has been being flush with the surface iii) rotated through a predetermined arc, and means associated with the die to permit the excess metal to be forced into the rivet shank during said coining operation.

5. A rivet forming device comprising a header and a rotatable die, said members being in coaxial alignment with each other, means to reciprocate the header in respect to the die, apertures in said die, said apertures being separated from each other by arcs of stations on said header, said stations being separated from each other by arcs of 90, means at one station on said header to force a rivet blank into one of said apertures, a conical depression at the next station on said header to form a head on the blank after it has been rotated through an arc of 90, the center of the head and shank being concentric, a third station comprising an oval depression in said header adapted to brazier the newly formed head after it has been rotated through an arc of 90, and a fourth station on the header, said station being flush with the surface of the header and adapted to flatten the newly formed rivet head after it has been rotated through an arc of 90, and means associated with the die to permit the excess metal to be forced into the rivet shank during said coining operation.

6. A rivet forming device comprising a header holder, a header mounted on said holder, a die holder and a die rotatably mounted in said holder, said members being in coaxial alignment with each other, means to reciprocate the header in respect to the die, an aperture in the die holder, means to feed wire through the aperture, apertures in said die, said apertures being separated from each other by arcs of 90, means to rotate the die in the die holder, stations on said header, said stations being separated from each other by arcs of 90, cutting means adapted to reciprocate across a portion of the die face simultaneously with the header to cut the outer extremity of the said wire into a rivet blank, means at one station on the said header to force the newly cut rivet blank into one of the said apertures, a conical depression at the next station on the said header to form a head on the blank after the die has been rotated through an arc of 90, the center of the head and shank being concentric, a third station comprising an oval depression in said header adapted to brazier the newly formed head after the die has again been rotated through an arc of 90, and a fourth station on the header, said station being flush with the surface of the header and adapted to flatten the newly formed rivet head after the die has again been rotated through an arc of 90, and means associated'with the die to permit the excess metal to be forced into the rivet shank during said coining operation.

'7. A rivet forming device comprising a header holder, a header mounted on said holder, 2. die holder, a recess in said die holder, a die rotatably mounted in the recess, means to reciprocate the header in respect to the die, an aperture in the die holder, means to feed wire through the aperture, a cam surface in the recess, apertures in said die, said apertures being separated from each other by arcs of 90, a backing pin in each aperture, means to rotate the die in the die holder, stations on said header, said stations being separated from each other by arcs of 90, cutting means adapted to reciprocate across a portion of the die face simultaneously with the header to cut the outer extremity of the said wire into a rivet blank, means at one station on the said header to force the newly cut rivet blank into one of the said apertures, a conical depression at the next station on the said apertures to force a head on the blank after the die has been rotated through an arc of 90, the center of the head and shank being concentric, a third station comprising an oval depression in said header adapted to brazier the said newly formed head after the die has again been rotated through an arc of 90, and a fourth station on the die, said station being flush with the surface of the header and being adapted to flatten the newly formed rivet head after the die has again been rotated through an arc of 90", said operation forcing the outer extremity of the backing pin into the cam surface of the die holder during this coining operation to permit the excess metal to be forced into the rivet shank, an aperture in the die holder adjacent the cam surface, and a throw-out pin mounted in the aperture and adapted to force the rivet out of the die after it has again been rotated through an arc of 90.

8. A rivet forming device comprising a header holder, a header mounted on said holder, a die holder, a recess in said die holder, a die rotatably mounted in the recess, means to reciprocate the header in respect to the die, an aperture in the die holder, means to feed wire through the aperture, a cam surface in the recess, apertures in said die, said apertures being separated from each other by arcs of 90, a backing pin in each aperture, means to rotate the die in the die holder, stations on said header, said stations being separated from each other by arcs of 90, cutting means adapted to reciprocate across a portion of the die face simultaneously with the header to cut the outer extremity of the: said wire into a rivet blank, a spring actuated plunger at one station in said header to force the newly cut rivet blank into the said aperture against the backing pin, a conical depression at the next station on said apertures to force a head on the blank after the die has been rotated through an arc of 90, the center of the head and shank being concentric, a third station comprising an oval depression in said header adapted to brazier the said newly formed head after the die has again been rotated through an arc of 90, and a fourth station on the die, said station being flush with the surface of the header and being adapted to flatten the newly formed rivet head after the die has again been rotated through an arc of 90, said operation forcing the outer extremity of the backing pin into the cam surface of the die holder during this coining operation to permit the excess metal to be forced into the rivet shank, an aperture in the die holder adjacent the cam surface, and throw-out pin mounted in the aperture and adapted to force the rivet out of the die after it has again been rotated through an arc of 90.

9. A rivet forming device comprising a header holder, a header mountedon said holder, a die holder, a recess in said die holder, a die rotatably mounted in the recess, means to reciprocate the header in respect to the die, an aperture in the die holder, means to feed wire through the aperture, a cam surface in the recess, apertures in said die, said apertures being separated from each other by arcs of 90, a backing pin in each aperture, a lever attached to the die, means to force the lever to rotate the die through an arc of 90 with each movement of the lever, stations on said header, said stations being separated from each other by arcs of 90, cutting means adapted to reciprocate across a portion of the die face asoaoea simultaneously with the header to cut the outer extremity of the said wire into a rivet blank, said cutting means being provided with means to position the newly cut blank in alignment with one of the said apertures in the said die, a plunger at one station on said header to force the newly .cut rivet blank into the said aperture against the backing pin, 'a conical depression at the next station on the said apertures to force a head on the blank after the die has been rotated through an arc of the center of the head and shank being concentric, a third station comprising an oval depression in said header adapted to brazier the said newly formed head after the die has again been rotated through an arc of 90. and a fourth station on the die, said station being flush with the surface of the header and being adapted to flatten the newly formed rivet head after the die has again been rotated through an arc of 90, said operation forcing the outer extremity of the backing pin into the cam surface of the die holder during this coining operation to permit the excess metal to be forced into the rivet shank, an aperture in the die holder adjacent the cam surface, and a throw-out pin mounted in the aperture and adapted to force the rivet out of the die after it has again been rotated through an arc of 90.

10. A rivet forming device comprising a header holder, a header mounted on said holder, a die holder, a recess in said die holder, a die rotatably mounted in the recess, the upper surface of said die being flush with the surface of the die holder, means to reciprocate the header in respect to the die, an aperture in the die holder, means to feed wire through the aperture, a camsurface in the recess, apertures in said die, said apertures being separated from each other by arcs of 90, a backing pin in each aperture, a lever attached to the die means to force the lever to rotate the die through an arc of 90 with each movement of the lever, stations on said header, said stations being separated from each other by arcs of 90, cutting means adapted to reciprocate across a portion of the die face simultaneously with the header to cut the outer extremity of the said wire into a rivet blank, said cutting means being provided with means to position the newly cut blank in alignment with one of the said apertures in the said die, a spring actuated plunger at one station in said header to force the newly cut rivet blank into the said aperture against the backing pin, a conical depression at the next station on the said apertures to force a head on the blank after the die has been rotated through an arc of 90, the center of the head and shank being concentric, a third station comprising an oval. depression in said header adapted to brazier the said newly formed head after the die has again been rotated through an arc of 90, and a fourth station on the die, said station being flush with the surface of the header and being adapted to flatten the newly formed rivet head after the die has again been rotated through an arc of 90, said operation forcing the outer extremity of the backing pin into the cam surface of the die holder during this coining operation to permit the excess metal to be forced into the rivet shank, an aperture in the die holder adjacent the cam surface, and a throw-out pin mounted in the aperture and adapted to force the rivet out of the die after it has again been rotated through an arc of 90.

11. A method of producing a rivet from a rivet means associated with the die to permit the exblank comprising forming a head on the blank, the centers of the head and shank of the rivet being concentric, and partly flattening the head, the blank being supported by a backing during said steps, and then removing the backing and coining the head by forcing the excess metal into the rivet shank.

12. A method of producing a rivet from a rivet blank comprising the successive steps of forming a head on the blank, the centers of the head and shank of the rivet being concentric, and braziering the head, the blank being supported by a backing during said steps, and then removing the bacbng and coining the head by forcing the excess metal into the rivet shank.

13. A method of producing a rivet froma rivet blank comprising forming a head on the blank, the centers of the head and shank of the rivet being concentric, braziering the head, coining the head by forcing the excess metal into the rivet shank, and then removing the newly formed rivet.

14. A rivet forming device comprising a header and a die, at least one of said members being capable of a reciprocating movement in respect to the other, apertures in said die, means to force a rivet blank into one of said apertures, means on said header to form a head on the blank, the centers of the head and shank of the rivet being concentric, a second means on said head adapted to partly flatten the newly formed head, a third means on said header adapted to coin the rivet head, and means associated with the die to permit the excess metal to be forced into the rivet shank during said coining operation, said heading, flattening and coining operations being performed in successive steps.

15. A rivet forming device comprising a header and a die, at least one of said members being capable of a reciprocating movement in respect to the other, apertures in the said die, means to force the rivet blank into one of said apertures, means on said header to form a head on the blank, a depression in said header adapted to brazier the newly formed head, a station on said header designed to flatten the rivet head, and

cess metal to be forced into the rivet shank during said coining operation, said head forming. braziering and coining operations being performed in successive steps.

16. A rivet forming device comprising a header and a die, at least one of said members being capable of a reciprocating movement in respect to the other, and one of said members being rotatably mounted, apertures in said die, means to force the rivet blank into one of said apertures, a depression on said header to form a head on the blank, the centers of the head and shank being concentric, a depression in said header adapted to brazier the newly formedhead, a station on the header, said station being designed to coin the rivet head, and means associated with the die to permit the excess metal to be forced into the rivet shank during said coining operatio 1'1. A rivet forming device comprising a header and a die, at least one of said members being capable of a reciprocating movement in respect to the other, and one of said members being rotatably mounted, stations on saiddie and said header, means at one station on said header to force the rivet blank into one of the said stations on the die, a depression at the next station on said header to form a head on the blank, the centers of the head and shank being concentric, a third station comprising a depression on said head adapted to brazier the newly formed head, and a fourth station on the header, said station being flush with the'surface of the header and adapted to flatten the newly formed rivet head, and means associated with the die to permit the excess metal to be forced into the rivet shank during said coining operation.

18. A method of producing a rivet from a rivet blank comprising forming a head on the blank, the centers of the head and shank of the rivet being concentric, partly flattening the head and then coining the head by forcing the excess metal into the rivet shank.

ARTHUR A. SCHWARTZ. GEORGE CARBON.

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