US3720968A - Machine for the production of half-punched rivets - Google Patents

Abstract

A machine is disclosed for the formation of half-punched rivets as a continuous operation, using an endless wire as the starting material. The rivet-forming wire sections are sequentially severed from the endless wire, pushed through a die, punched and headed, means being provided to withdraw the finished rivets from the die, and means being provided to permit the size of the produced rivets to be easily and readily varied.

Description

Q United States Patent 1191 1111 3,720,968 Garlaschi lMarch 20, 1973 [541 MACHINE FOR THE PRODUCTION OF 2,042,375 5/l936 Abel ..lO/27 PH L NC E RIVETS 2,261,067 10/1941 Lovisek ..l/ll R 2,786,217 3/1957 Johnson ..1o/27 PH 1 1 lnvemori Elffemla Garlaschl, V13 Mengonh 4 3,200,424 8/1965 McClellan.... ..10/12.5 M1111, Italy 3,471,879 10/1969 Kolec ..10/24 22 Fned: Jan. 8 1971 3,477,075 11/1969 Putetti ..l0/12 R p N04 105,050 Primary Examiner-Charles W. Lanham Related Application Data Assistant Examiner-Gene P. Crosby Attorney-Stevens, Davis, Miller & Mosher [63] Continuation-impart of Ser. No. 812,715, April 2,

1969, abandoned. [57] ABSTRACT [30] Foreign Application Priority Data A machine is disclosed for the formation of halfpunched rivets as a continuous operation, using an Apnl 6, 1968 Italy 14924 A/68 endless wire as the Starting materiaL e e or g 52 US. Cl. ..10 11 A, 10 27 PH Wire seams are sequentially Severed the endless i511 Int. Cl. ..B21 k 1/60 wire Pushed thmugh a Pwmhed and headed 5 Field of Search 10/11 R, 11 A, 11 E, 11 M means being provided {0 withdraw the finished rivets 10/1 1 G 1 1 T, 2 R, 5 2 T 2 26, 27 from the die, and means being provided to permit the R, 27 5 27 P 72 403 452 size of the produced rivets to be easily and readily varied. [56] References Cited 2 Claims, 15 Drawing Figures UNITED STATES PATENTS 2,396,995 3/1946 Friedman ..lO/27 PH PATENTEUHARZO m5 SHEET 1 UF 9 E. Maw/w INVENTOR.

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MAIIINIE FUR THE PRODUCTION OF HALF- PUNCIIED RIVETS This is a continuation -inpart of my application, Ser. No. 812,715, filed Apr. 2, i969, now abandoned.

This invention relates to a machine for producing half-punched rivets starting from sections of metal wire, and more particularly from sections of a cylindrical wire severed from a continuously fed wire.

Machines of this kind are well known in the art and, generally, provide the operations of introducing a wire section in a corresponding inner cavity of a die in which a pin, having a cross-sectional area smaller than that of the wire, is inserted, forwarding and introducing in said cavity of the die a first punch adapted to thrust said wire section against said pin so as to form a substantially axial opening at the end of the wire section confronting said pin, withdrawing said first punch, effecting a first advance movement of the'pin so as to cause the non punched end of the wire section to protrude outside the die, advancing a second punch having an enlarged head to push the unpunched end of the wire section against the outer surface of the die so as to obtain an enlarged head for the wire section, withdrawing the second punch, effecting a second advancing movement of the pin to push from die further the thusly formed rivet, causing the rivet to be grasped by means adapted to prevent any movement thereof towards the die, and finally withdrawing the pin towards its initial rearmost position.

These machines are basically classified into two classes, namely those having a fixed die, wherein the active movements are performed by the several punch means, and those having a mobile die, wherein the die itself is translated with respect to the several punch means.

The fixed die machines, among which the machine according to the present invention must be considered, have a very complicated structure and the control members particularly as regards the predetermined displacements of the several active elements, are replaceable with difficulty unless the most of the machine is dismounted. n the other hand, the sizes of the half-punched rivets usually utilized in the art range from at least few millimeters (about millimeters) up to 60 millimetersand higher.

It is thus manifest that the actually used machines lack of flexibility, since the conversion from manufacturing half punched rivets having a given size to another size requires the almost complete dismounting of the machine and the substitution of a relevant member of parts.

Obviously, since a commercially feasible production requires a range of rivet sizes to be manufactured, up to date a considerable number of machines was necessary, thus adding to the investment and operating costs.

The main purpose of the present invention is that of providing, in a machine of the aforesaid type, means permiting the ready conversion from manufacturing half punched rivets of a given size to manufacturing rivets of a different size by the simple replacement of a control member, such a replacement rendering unnecessary the dismounting of other parts of the machine, except the control member itself. More particularly, the present invention provides a removable control cam for controlling the operating positions of the perforating and extracting pin, said cam being removably mounted to the actuating shaft and being easily and readily replaceable.

Furthermore, as it will appear from the following description of the machine, the flexibility of the present machine involves not only the possibility of manufacturing half punched rivets of several sizes, but also, by keeping unchanged their length, the possibility of varying at will the length of the axial inner bore of the rivet itself. 1

The embodiment of the inventive machine will be now described in detail, by way of example and without limitation, in order that the essential features of the invention may be better understood. The detailed description will be given in connection with the accompanying drawings, wherein FIG. 1 is a simplified showing, in perspective exploded view, of the principal parts of the machine illustrated by way of example.

FIGS. 2-7 show the several steps of the processing of a rivet from its raw stage, where it is severed from a feeding wire, to the final stage where it is dumped into an underlying receptacle.

FIGS. 8-10 show a cross-sectional close-up of the pin actuating mechanism, said pin sliding in the inner cavity of the die to form the perforation of the rivet, said mechanism being shown inthree different positions, each corresponding to a different processing stage of the rivet.

FIG. 11 shows a cross-sectional close-up of the mechanism for actuating the lock which is adapted to prevent'a backward movement of the pin as the latter, while being fed forward, lies in a preselected intermediate position relating to the formation of the rivet head.

FIG. 12 is a side elevational view of the lockactuating mechanism.

FIGS. 13, 14 and 15, are respectively a partially exploded view, an elevation view and a cross-section view, which show the mounting of the control cam for the perforating and extracting pin according to the 7 present invention.

Having now particular reference to FIG. 1, it can be seen that the exemplary machine shown therein comprises a main crankshaft 25, a driven shaft 30, and a tertiary shaft 33. These three shafts, which are connected to one another by means of bevel gears (FIG. 1 shows the gears connecting the driven shaft to the tertiary shaft, gears 34 and 35), actuate, as they are rotated, several members which are moved relatively to a fixed die 8 to achieve the desired processing of the rivets.

The fixed die has an inner streight cylindrical through-bore in which a pin 6 is inserted; the latter is integral with a rod 7 having a variable cross-sectional outline, the rod being affixed, in turn, to either end of a lever 37 pivotally connected at 38 to a fixed part (not shown) of the machine. The other end of the lever 37 has a follower 13 running on a cam 12 keyed to the tertiary shaft 33.

Due to its connection with the tertiary shaft 33, the rod 7 is thus moved with a substantially longitudinal rectilinear motion in the direction shown by the arrows A and B, between two positions, viz. a position of maximum stroke forward and of maximum stroke rearward of the pin 6 in the die 8. An adjustable abutment 59 limits the maximum stroke rearward of the pin,

whereas the lock 11, which can he slipped between the free end of the rod 7 and the abutment 59, acts like a spreader to prevent a possible rearward motion of the pin, when the latter is in a position between the two end positions. As viewable in FIG. 8, the abutment 59 is formed by the end of a bolt screwable and unscrewable with respect to a threaded hole formed in the machine casing. The lock 11 is thrust by one end ofa hammer 22 pivoted at 39 to a fixed part (not shown) of the machine the opposite end of the hammer 22 being pivoted to either end of a rod 21: the other end of 21 is pivoted to one end of a lever 20. The opposite end of the lever 20 is pivoted, at 41, to a fixed part (not shown) of the machine. In addition, the lever 20 has a follower 40 which engaged a-cam 19 keyed to the tertiary shaft 33. Thus, on account of the interlinking described above, the lock 11 is moved straightforward in the direction shown by the arrows C and D, so as to be reciprocably inserted into, and withdrawn from, between the rod 7 and the abutment 59.

In the vicinity of the inlet of the inner cavity of the die which is opposite to the one through which the pin 6 is inserted, there is a lock 27 which is movable in the direction shown by the arrows G and H and carries a first punch having a head whose cross-section is substantially equal to that of the inner cavity of the die 8, and a second punch 14 having an enlarged head, namely of greater cross-section than that of the inner cavity. The rectilinear motion of the block 27 is obtained by connecting the block to the shaft25 by the agency of a plate 26 hingably connected to the block 27 and to either end of a crank 43 pivoted to a crank 44 of the crankshaft 25, the end of the plate 26 which is hinged to the crank 43 being also pivoted to either end of a plate 45 hinged to a fixed part of the machine.

The rotary reciprocation of the punch-carrying head 42 is originated, conversely, by the driven shaft 30, which has a cam 29 engaging by the agency of followers 52, a rocking body 47: this body has, hinged thereto, a plate 28 which is movable in the direction shown by the arrows I and L and has a slot 48 which received a stud 49 protruding from an arm 50: the latter is pivoted to a cam 51, keyed to the shaft 70 intended to transfer the drive to the head 42.

The driven shaft 30 also controls the actuation of a cutter acting on a continuous cylindrical wire 3 passed through a fixed block 1. The cutter comprises a blade 2 affixed to an arm 31 with a cylindrical portion and prismatic portion, an end of which is hingably connected to a body 53, the latter engages, by the agency of followers 54, a cam 32 keyed to the shaft 30. Due to the connection between the arm 31 and the shaft 30, the arm 31, and thus the blade 2, are reciprocated in the direction shown by the arrows M and N, so that the blade is enabled to server from the continuous wire 3 a number of sections 4 of the wire, each of which is intended to produce a rivet. The cutter, in addition to providing to sever the individual wire sections, also provides to forward them to the inlet of the die 8. To this purpose, a tong-like member 55, adapted to hold the severed wire section, is affixed to the arm 31.

The machine shown in FIG. 1 comprises, in addition, a forked member 9 affixed, in turn, to either end of an arm the latter is affixed to one end of a non-slidable shaft l8-whose opposite end has an arm 56 pivoted to either end of a rod 17. The opposite end of 17 is pivoted to either end of a lever 23, pivoted at 57 to a fixed part (not shown) of the machine and having a follower 58 in engagement with the peripheral surface of a cam 16 keyed to the tertiary shaft 33. Due to the connection between the shaft 33 and the shaft 18, the latter is rotatably reciprocated in the direction indicated by the arrows O and P, so that the forked member 9 is moved on a vertical plane in the directions shown by the arrows Q and R. This plane is perpendicular to the axis of the inner cavity of the die 8 is positioned in the vicinity of the inlet of the die 8 which is away of the one through which the pin 6 is inserted. A fixed block 10, eventually, is arranged in such a way as to cause the overturning and dumping of the finished rivet as the latter has been removed from the die and grasped by the forked member.

In the example shown in FIG. 1, the inventive machine has been shown in an extremely simplified manner. Further detailes will be given hereinafter, with reference to FIGS. 8-12. However, the disclosure of 2 to be fed forward and thus a wire section 4 is severed from the continuously fed wire 3 which is passed through the fixed block 1 and is fed forward on the direction of the arrow M, towards the inlet of the die 8.

Due to the rotation of shaft 25, the block 27 is thus fed forward (arrow B) and brings the first punch 5 before the inner cavity of the die 8. By being further advanced, the punch 5 pushes the wire section 4 into the die 8 and it also enters the die until the pin 6 is caused to penetrate, wholly or in part, the wire section (FIG. 3). At this stage, the pin 6 is at its rearmost position, and the abutment of the rod 7 against the stop 59 enables the pin to withstand the shock imparted thereto by the punch 5 through the intermediary of the wire section itself, thus producing the expected axial perforation.

The punch 5 is then thrust rearward due to the effect of the subsequent rotation of the shaft 25, whereas, on account of the rotation of the shaft 33, the pin 6 is advanced in the direction of the arrow A, causing a portion of the wire section to protrude from the die (FIG.

4). Due to its forwardmovement, the free end of the rod 7 has been brought far from the stop 59. Then, the lock 11 is also advanced and becomes positioned between said end of the rod 7 and the stop 59, so as to prevent any subsequent rearward movement of the rod and thus also of the pin 6.

The subsequent rotation of the shaft 25 and the conby th. presence of the lock 11 between the rod 7 and the stop 59. In point of fact, should the lock be not there, the thrust of the punch 14 would cause the rod 7 to come back until contacting the stop 59 once more: if so, the wire section 4 would totally enter the die again and no formation of the head could take place. The presence of the lock, conversely, maintains the pin in position and allows the wire section to protrude, so that the intervention of the punch 14 enables the rivet head to be formed.

Now, the rivet is already formed and need only to be withdrawn from the die, To do so, the punch 14 is brought back whereas, due to the effect of the shape of cam 12, the pin 6 is further advanced (arrow A) thus causing the rivet to be wholly driven out of the die, the rivet being still threaded to the pin 6 (FIG. 6).

The forked member 9 now grasps the rivet and maintains same in position, while the pin 6 is brought back (arrow B) to be restored to its starting rearmost position. In the meanwhile, the lock 11 has come back. The reaction of the drive of the forked member against the action of the pin causes the rivet to be driven off and to remain resting against the member 9 in the position shown in phantom in FIG. 7.

Finally, the forked member is shifted in the direction shown by the arrow R and causes either end of the rivet (the head in the case of FIG. 7) to bump into the fixed block 10, so that the rivet is upturned and dumped within a receiving vessel in the direction shown by the arrow S. The positions of the forked member and the rivet in this last processing stage are shown in solid lines in FIG. 7.

It should be understood that the several above described connection parts and members can be easily varied. It is sufficient that the possibility of motion as shown by the arrows A-S of FIGS. 1 to 7 remain substantially unaltered, thus substantially defining the several operations comprising the processing sequence described above.

In FIGS. 8, 9 and 10, the enlarged detail of the driving mechanism for the pin 6 has been shown in three different processing stages. These Figures alsoshow, for convenience of illustration, also the punches 5 and 14, the die 8 and the wire section 4 contained therein during processing. As can be seen in these Figures, the rod 7 is threaded into a cavity 60 of the machine framing, and also into the inner cavity of the die 8, and is thrust to the position of FIGS by a spring .61 and by another spring 62 acting upon a plunger 65. The plunger thrust towards the position of FIG. 8 the lever 37, whose top end is affixed to the rod 7, whereas the bottom end engages, by the agency of the follower 13, the cam 12 keyed to the tertiary shaft 33, said cam having two lobes 63 and 64. The lobe 63 has a lifting incline only. The pivot of lever 37 is at the point 38 where the lever is pivoted to the supporting frame of the machine.

Due to the effect of the bias of the springs 61 and 62 and to the shape of the cam 12, the rod 7 tends to stay, at the beginning of the cycle, in the position of FIG. 8, which shows the rearmost position of the pin 6 integral with the rod 7 and threaded in the inner cavity of the die. In this position, the free end of the rod 7 rests against the stop 59 which prevents any further rearward movement of the pin 6 as the latter receives the is rotated about the pivot 38 and causes both the rod 7 and the pin 6 to be fed forward against the bias of the springs 61 and 62. The mechanism is thus brought to the position of FIG. 9, with the pin 6 pushed into the die so as to cause the unpunched end of the rivet to project therefrom: stated another way, the pin 6 and the rivet lie in the position of FIG. 4.

Meanwhile, the lock 11 has advanced and has been inserted between the rod 7 and the stop 59. Thus, the stroke imparted by the second punch 14 does not cause the pin 6 to be broughtrearwards, so that the formation of the rivet head can be accomplished.

Upon completion of the head, the punch 14 is brought back and the pin 6 is advanced since the lobe 64 of the cam 12 contacts the follower 13 of the lever 37. The mechanism is then brought to the position of FIG. 10 (pin 6 and rivet in the position of FIG. 6) and there stays during the time which is necessary for the forked member 9 to grasp the finished rivet.

At this stage, the follower 13 of lever 37 has gone past the lobe 64, so that the springs 61 and 62 push the rod 7 and the lever 37 back to the positions of FIG. 8, since the lock 11 has been brought back meanwhile. Said rearward motion of the rod 7 and thus of the pin 6 causes, as outlined above with reference to FIG. 7, the disengagement of the rivet from the pin. The mechanism is now in readiness to start a novel processing cycle again.

FIGS. 11 and 12, instead, show in two different views the actuating mechanism for the lock 11. As can be seen in these figures, the lock 11 is slidably in a cavity 66 of the supporting structure of the machines and is pushed back by a spring 67. Upon the lock is active the hammer 22 pivoted at 39 to the supporting structure of the machine and hinged to either end of the rod 21..

The other end of this rod is pivoted to an end of lever 20. The lever 20, as outlined above in connection with FIG. 1, is pivoted at 41 to a pivot affixed to the supporting structure of the machine and has a follower 40: the latter engages the peripheral surface of a cam 19 keyed to the shaft 33 and having a lobe 68.

So long as the follower 40 runs over the planar portion of the peripheral surface of cam 19, the mechanism is in its at rest position with the lock 1 1 disengaged from the rod 7 and the stop 59. However, as the follower reaches the lobe 68, the lock 11 is urged forward against the bias of the spring 67 and becomes inserted between the rod 7 and the stop 59 in the space which has now become available by the advance of the rod7 upon the formation of the rivet hole and prior to the formation of the rivet head. FIG. 11 shows just the lock in its stage of insertion and disengagement between the rod 7 and the stop 59.

Upon formation of the rivet head, the follower 40 has already gone past the lobe 68,so that the lever 20, the rod 21 and the hammer 22 do not urge forward any longer the lock 11. The latter is thus enabled to come back under the bias of the spring 67 and leaves free the space between the rod 7 and the stop-59 for the subsequent rearward motion of the rod 7 to withdraw the completed rivet. 7

As outlined above, there have been shown in FIGS. 8-10 and 11-12, and described with reference thereto, the actuating mechanisms for the pin 6 and the lock 11 which prevents the backward movement thereof during the formation of the rivet head. The actuating mechanisms for the punches, the cutter, and the forked member. have not been shown and described in detail, since they can be of any kind and their particular structure is not a feature of the invention.

Referring now to the FIGS. 13, 14 and 15, assembling details of the control cam 12 for the pin 6 are shown. Particularly the peripheral contour of the cam 12 is interrupted by an opening 76, the width and the deepness of which correspond to the outer diameter of the shaft 33, a length of the latter bearing a screw thread 78, which in turn is engaged by a sleeve 77 having an inner screw thread (not shown). A stop collar 79 is integrally formed with the shaft 33, and serves as an abutment for the control cam 12. An axially protruding lip 80, having conical section, is formed on one side surface of the cam 12, and is adapted to fit inside a correspondingly shaped recess 81 formed in the end head 82 of the sleeve 77. ,The other end 83 of the sleeve 77 is formed as a hexagonal nutto permit the same to be engaged by a suitable tool-upon tightening or unscrewing the sleeve 77 with respect to the screw threaded length 78 of the shaft 33. Another nut 84, which is also screwable and unscrewable along the screw threaded length of the shaft 33 is provided for locking the sleeve 77 in the position in which the cam 12 is firmly secured to the shaft 33. It is to be noted that the planar part 85 protruding from the outer surface of the shaft 33 is provided in order to fitv with the inner surface of the open ing 76 of the cam 12 to permit the latter to be properly positioned and centered upon mounting to the shaft 33.

The manner by which the control cam 12 influences the operation of the machine has been. previously discussed. Therefore, it is clear that, by substituting for the cam 12 as shown in the drawings another cam wherein the lobes 63 and 64 have different contour and height, the length of the half punched rivet and/or the length of the axial inner hole of the rivet may be varied at will.

ty and having a according to the invention will be pointed out, at any rate, in the appended claims.

What is'claimed is:

1. A machine for the production of half-punched rivets comprising a casing, a fixed die having an opena pin inserted in said inner cavingitudmal between two end positions of maximum advance and ing and an inner cavity,

' maximum withdrawal of the die with an intermediate rest position, means to limit the maximum withdrawal of the pin, and releasable means for preventing the rearward movement of the pin when the latter is in its intermediate rest position, two punches acting at the die opening which is opposite with respect to the opening through which the pin is introduced, a first punch having a head whose cross-section is substantially equal to that of the die opening and adapted to be introduced thereinto, the second punch having a head with a crosssection larger than that of the cavity, and a fork member movable on a plane which is substantially perpendicular to the die cavity and is located in the vicinity of said inlet of the die opposite to the one through which said pin is inserted, a lever pivoted to the casing of the machine and having one end engaged with the rear end of the said pin, a control cam engaged with the other .end of said lever, said control cam being removably mounted to a rotatable shaft and having a contour interrupted by an opening, the width and the deepness of said opening corresponding to the outer Obviously, as it will be appreciated by a skilled in the diameter of said rotatable shaft, the cam being blocked between an abutment collar integral with said rotatable shaft and a sleeve axially movable between a first position, wherein'the control cam is blocked in the operative position, and another position, wherein the said cam is removable from the rotatable shaft.

2. Machine according to claim 1, wherein said control cam isprovided with a conical cross-section lip protruding from one side surface thereof, said sleeve being provided with a correspondingly shaped recess, whereby said protruding lip fits into said recess when said sleeveis in said firstposition. i

translation motion

Claims (2)

1. A machine for the production of half-punched rivets comprising a casing, a fixed die having an opening and an inner cavity, a pin inserted in said inner cavity and having a longitudinal translation motion between two end positions of maximum advance and maximum withdrawal of the die with an intermediate rest position, means to limit the maximum withdrawal of the pin, and releasable means for preventing the rearward movement of the pin when the latter is in its intermediate rest position, two punches acting at the die opening which is opposite with respect to the opening through which the pin is introduced, a first punch having a head whose cross-section is substantially equal to that of the die opening and adapted to be introduced thereinto, the second punch having a head with a cross-section larger than that of the cavity, and a fork member movable on a plane which is substantially perpendicular to the die cavity and is located in the vicinity of said inlet of the die opposite to the one through which said pin is inserted, a lever pivoted to the casing of the machine and having one end engaged with the rear end of the said pin, a control cam engaged with the other end of said lever, said control cam being removably mounted to a rotatable shaft and having a contour interrupted by an opening, the width and the deepness of said opening corresponding to the outer diameter of said rotatable shaft, the cam being blocked between an abutment collar integral with said rotatable shaft and a sleeve axially movable between a first position, wherein the control cam is blocked in the operative position, and another position, wherein the said cam is removable from the rotatable shaft.

2. Machine according to claim 1, wherein said control cam is provided with a conical cross-section lip protruding from one side surface thereof, said sleeve being provided with a correspondingly shaped recess, whereby said protruding lip fits into said recess when said sleeve is in said first position.

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