US3518865A

US3518865A - Machine for making tubular rivets from a band and installing the rivets

Info

Publication number: US3518865A
Application number: US644711A
Authority: US
Inventors: Konstantin Alexee Konstantinov
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-06-08
Filing date: 1967-06-08
Publication date: 1970-07-07
Anticipated expiration: 1987-07-07

Description

y 1970 K. A. KONSTANTINOV 3,518,

MACHINE FOR MAKING TUBULAR RIVETS FROM A BAND AND INSTALLING THE RIVETS Filed June 8. 1967 United States Patent 3,518,865 MACHINE FOR MAKING TUBULAR RIVETS FROM A BAND AND INSTALLING THE RIVETS Konstantin Alexeevich Konstantinov, Scherbakovslraya ul. 32-7, kv. 291, Moscow, U. S.S.R.

Filed June 8, 1967, Ser. No. 644,711

Int. Cl. B21k 1 60; B21d 28/00, 53/00 US. Cl. 72-338 Claims ABSTRACT OF THE DISCLOSURE A machine for making and installing tubular rivets in a plate comprises a device engaging a continuous band of metal to preform the band to V-shape and intermittently feed the preformed band to a forming and cutting device which cuts successive workpieces from the band and shapes the workpieces, as tubular rivets, on a pin which is slidably carried by a punch cooperating with a die. The punch is reciprocally moved towards and away from the die to successively install the rivets in openings in a plate of an electronic printed circuit and to upset the rivets.

The present invention relates to machines for making and installing tubular rivets from a band, primarily contact rivets to be employed in electronic printed circuits.

One of the main operations in the production of printed circuits consists in soldering leads of radio components to the ends of flat or printed wires.

In the course of soldering, the ends of printed wires may become heated to such an extent that exfoliation from the insulation base of the printed circuit will occur, resulting in the destruction of the entire circuit.

For the elimination of this undesirable effect, mechanical fastening of flat or printed wire endings to the insulation base of the printed circuit has been envisaged by means of contact rivets, the latter being obtained by upsetting tubular rivets in respective rivet holes provided in the printed circuit.

Tubular rivets upset in the rivet holes of printed circuits serve as electrical contact elements to which leads of radio components are fixed, as well as for mechanical fastening of fiat or printed wire endings in order to prevent exfoliation of the latter in the process of heating while soldering.

Known in the art are machines for making tubular rivets of a band. A machine of this type is disclosed in Authors Certificate of the U.S.S.R. No. 168,256, class 7c, 26. The machine is provided with a roller device for step-bystep feeding of the band and with a cutting device adapted to cut off a workpiece which is then imparted a U-shaped form in a bending device. The U-shaped piece is pushed through a forming device of a draw-plate type with a tapered forming and a cylindrical calibrating surface, whereupon a tubular rivet is ready to be installed in the appropriate hole of the printed radio circuit.

The machine known heretofore is capable of producing tubular rivets of a definite length, the latter being determined by the band width. Tube shaping is accomplished by means of a draw-plate and requires lubrication. Therefore a ready tubular rivet should be degreased prior to being installed into a hole of the printed circuit, this being prerequisiteior soldering component leads and fastening flat wire endings thereto.

Tubular rivets installed in rivet holes of a printed circuit are upset either manually or by means of motordriven tools which generally comprise a punch and a riveting die. The upsetting of tubular rivets by means of such tools, however, is inefficient, and therefore attempts were made to rnechanize the process.

As a result of one of such attempts a machine was de- 3,51%,d55 Patented July 7, 1970 ice veloped for upsetting contact rivets in module assemblies, as disclosed in Authors Certificate of the U.S.S.R. No. 155,758, class 87a, 22. This machine is provided with a punch and a die, a perforated plate being installed therebetween for tubular rivets to be upset, said rivets being fed from a magazine by means of a chute. This machine may be used only for upsetting tubular rivets in plates with coordinate location of the openings, since the alignment of the punch and the die is effected by means of a catch pin entering the neighboring opening of the plate, said opening being located at a strictly preset distance from the opening in which the tubular rivet is to be upset. Therefore the aforesaid machine cannot be used for as sembling printed circuits, in which, as is known, rivet holes may be located arbitrarily.

In this case tubes of only one predetermined length and a plate of only one thickness may be used. If tubes of a different length are to be used, the installation of a different appropriate chute is required. Jamming of tubular rivets in the chute in the process of feeding them into the openings of the plate is also possible.

The analysis given above makes it clear that several different devices are necessary for making, installing, and upsetting tubular rivets in rivet holes. Therefore the entire process, starting from making tubes and finishing with upset tubular rivets in rivet holes of printed circuits proves to be extremely ineificient and not always ensures satisfactory quality of printed circuits.

It is, therefore, an object of the present invention to provide an improved machine for making tubular rivets from a band with simultaneous upsetting of said rivets in rivet holes of printed circuits.

Disclosed in the present invention is a machine for making tubular rivets from a band, preferably contact rivets, to be installed in printed circuits, the machine comprising devices for feeding the band and for cutting it into workpieces, and also a mechanism adapted for shaping a tubular rivet from a workpiece.

According to the invention, the forming mechanism comprises a pin, the band being fed parallel thereto, and two forming heads, of which one is located at the side of the band being fed and the other is located at the side of the pin so, that in the course of travel of the heads perpendicular to the pin a workpiece is cut off from the band by simultaneously passing through the cutting device, and formed into a tubular rivet on said pin by means of said forming heads.

For subsequent installation and upsetting of a ready tubular rivet located on the pin in a rivet hole, the pin is connected with a drive ensuring its reciprocating motion and is associated with a punch, the latter being arranged so that a ready tubular rivet is located on the pin beneath it, the die being arranged behind the plate opposite the hole or opening in which the tubular rivet is upset. The pin travelling and the punch moving relative thereto, the tubular rivet is removed from the pin into the rivet hole and upset by the punch.

In the process of upsetting a tubular rivet, the punch and the die are aligned due to the provision of a tapered recess on the face of the free end of the punch, the appropriate projection of the die rod entering said recess, the die rod passing through the rivet hole underneath. being installed in the die and operatively connected with the machine drive.

It is expedient to provide a crown under said projection on the die rod, serving to align the rivet hole in the process of upsetting.

A specific feature of the machine of the present invention is that its forming heads are provided with V- shaped jaws having rounded-off bottoms, one of said heads being made with parallel slots and another with respective projections (or vice versa), said projections entering said slots.

The cross-section of the band being fed should correspond to the shape of the jaws of the forming heads, for which reason the feeding device is essentially a die whose members are adapted to impart a V-shaped rounded-off bottom form to the hand, both operating members of the die being connected with a drive ensuring their forward travel together with the band and their backward movement with respect thereto.

Another novel feature of the present invention resides in the provision of a plate mounted between the forming heads and the feeding device, said plate having one opening for passing the upsetting punch and a second V- shaped opening with a rounded-off projection for passing the shaped band. Said rounded-off projection serves as a stationary cutting blade for cutting off a workpiece by means of the forming head mounted at the side of the band.

It is expedient that a pair of levers should be used for moving the punch and the die of the feeding device, one of said levers having a rockshaft movably installed in a slot thereof, the displacement of said rockshaft serving to adjust the length of a workpiece.

To adjust the machine as to the thickness of the plate with rivet holes in which tubular rivets are to be upset, the rocking lever determining the length of the pin stroke is connected with a stationary support by means of connecting rods, the length thereof being adjusted by a cam or eccentric disposed in the stationary support opening, the rotation of said cam resulting in an appropriate variation of the distance between the punch and the riveting die.

The movement of the forming heads should be preferably effected by means of two cylindrical cams provided with two profiled grooves, said cams rotating on a common shaft and the grooves of said cams accommodating the ends of levers connected with the forming heads.

The compression imparted to the workpiece on the pin by the forming heads may be adjusted by mutual axial displacement of said cylindrical cams, this being effected by means of adjusting screws.

An advantage of the present invention resides primarily in that it makes possible to combine the operations of making tubular rivets, installing them into rivet holes and upsetting them during one working cycle.

Another advantage of the present invention resides in speeding up the entire manufacturing process and in a more economical utilization of production areas.

Still another advantage of the present invention consists in the simplicity with which it can be effected and operated, the provision of a tapered rod in the riveting die operatively connected with the machine drive and serving to align the rivet hole making the participation of a skilled worker in this operation unnecessary.

Yet another advantage of the present invention is the simplification of the manufacturing process, this being due to the possibility of adjusting the machine for making tubular rivets of different length, depending on the plate thickness and type of upsetting.

A further advantage of the present invention lies in improving the quality of making and upsetting tubular rivets.

Moreover, the machine of the present invention may be used for automatically making tubes employed as tubular rivets in most diverse branches of industry.

Given below is a description of an exemplary embodiment of the present invention in conjunction with the accompanying drawing, wherein:

FIG. 1 is a diagrammatic illustration partly in section of the machine according to the invention; and

FIG. 2 is a View taken along arrow A of FIG. 1.

Now referring to FIG. 1, electric motor 1 of the machine is connected by means of gear trains 2 with a pair of cranks 4 mounted parallel on a common shaft 3.

4 tRods 5 of the cranks 4 by means of shaft 7 are connected with rocking lever 6.

On the free end of the rocking lever 6 tubular rod 8 is articulated, said tubular rod 8 having a longitudinal through slot 9 to accommodate slider 10' travelling therealong, said slider being disposed inside the tubular rod 8.

The slider 10, in turn, accommodates punch 11 and die 12 adapted to impart a V-shaped form with a roundedoif bottom to band 13 passed through the hollow rod 8.

The punch 11 is connected with screw 14 passing through the slot 9 of the rod -8 and bushing '15 freely set outside the rod 8 to direct the travel of the slider 10 with respect to the tubular rod 8. Said punch and die not only initially shape the band 13, but also transport it by a feeding distance, the protruding end of the screw 14 being connected for the purpose with a pair of

levers

16 and 17 actuated by cam 18 mounted on the shaft 3.

The lever 16 is provided with rockshaft 19 displaceable in slot 20 thereof, said lever serving for a stepwise movement of the slider 10 together with the band 13 when the latter is in engagement with the punch and the die, and for the return travel of the slider with respect to the band -13 when the punch 11 and the die 12 are out of engagement therewith. By shifting the rockshaft 19 within the slot 20 of the lever 16 the length of the lever arm may be varied and thus the length of the band 13 fed during one step properly adjusted.

The lever 17 is connected with the screw 14 by means of member 21 in such a manner that the forward travel of said lever causes the screw 14 to turn in the slider 10, moving the punch 11 towards the die -12 for bending the band 13.

The punch 11 with the die 12 in combination with the

levers

16 and 17 thus constitute the device for feeding the band 13.

Coaxially with the rod 8 is an upsetting punch 22 which is connected with pin 23 movably installed therein, on which pin the workpiece cut from the band 13 is shaped into a tube. The band 13 is passed through V- shaped opening 25 with rounded-off projection 24 (FIG. 2) in plate 26 which is also provided with opening 27 to pass the punch 22 with the pin 23 during the reciprocation of the rod 8. The

openings

25 and 27 are so located in the plate 26 that the band 13 is fed parallel to the pin 23.

Two forming

heads

28 and 29 are intended for forming a tube on the pin 23 from the V-shaped workpiece cut from the band, the head 28 being mounted at the side of the pin 23 and the head 29 at the side of the band 13, respectively.

The device for cutting the band into workpieces is constituted by the projection 24 in the opening 25 of the plate 26 and by the head 29, the projection 24 serving as a stationary cutting blade.

Each forming

head

28 and 29 is provided with a V- shaped jaw 30 with a rounded-off bottom (FIG. 2) and parallel-disposed (comb-shaped) slots 31 and projections 32 which interengage in the process of forming a tube on the pin 23 by means of the

heads

28 and 29 The forming heads 28 and 29 are fixed on

pivotal levers

33 and 34, one of the ends of said levers being placed in profiled grooves 35 of

cylindrical cams

36 and 37 mounted on common shaft 38, gear 39 thereof being in mesh with the gear of one of the cranks 4. The

cylindrical cams

36 and 37 may be shifted along the shaft 38 by means of adjusting screws 40 for varying the compression effort exerted on the workpiece when the latter is being shaped into a tube on the pin 23.

The machine of the invention for making tubular rivets of a band may operate automatically.

In order to employ the machine of the present invention for simultaneous upsetting of tubular rivets being made in rivet holes of printed circuits, a riveting die 43 is provided which in combination with different shaped punches 22 and pins 23, may form various shaped tubular rivets, I, II, III, in plate 44, as shown in FIG. 1.

The die 43 is movably mounted in the casing 41 and electrically connected with a starting switch 45 of the electric motor 1 of the machine.

Movably mounted in the riveting die 43 is rod 46 which serves as a blocking breaker and is connected with the switch 45.

The rod 46 is provided with a cone-shaped projection 47 protruding into the opening or rivet hole in the plate 44 and entering a recess 48 on the face end of the pin 23, crown 49 being provided on the rod 46 beneath the cone-shaped projection 47, the diameter of said crown being equal to that of the opening in the plate 44.

In the process of upsetting, the plate 44 is placed with its opening onto the rod 46 and by slightly pressing the die 43 the switch 45 is closed, thus actuating the motor 1.

The pin 23 with a ready tubular rivet by means of the recess 48 is aligned with the projection 47 of the rod 46 and pushes it from the opening in the plate 44 as the hollow rod 8 moves, whereby an accurate positioning of the tubular rivet into the opening or rivet hole in the plate 44 is effected. The switch 45 opens and cam contact 50 closes so that the electric motor 1 continues its operation moving the punch 22 for upsetting the tubular rivet.

The tubular rivet having been upset in the opening of the plate 44, the crown 49 of the rod 46 cannot pass through the same opening, and therefore the motor 1 can be actuated again only with the crown 49 of the rod 46 entering into a subsequent opening provided in the plate 44.

Depending on the thickness of plates 44 in whose openings tubular rivets are to be upset, the distance between the punch 22 and the riveting die 43 should be adjusted accordingly, for which purpose the rocking lever 6 is pivotally connected by means of connecting rods 51 with stationary support 52, in whose opening cam or eccentric 53 is disposed, said cam or eccentric 53 being mounted on shaft 54 of the connecting rods 51.

The amplitude of rocking of the lever 6 and also the distance between the punch 22 and the riveting die 43 is adjusted by setting the cam or eccentric 53 into a required position.

The length of tubular rivets being made should correspond to various possible thickness of the plate 44, this being effected, as pointed out hereinabove, by varying the length of the arm of the lever 16.

The machine of the invention is adjusted by means of handles 55 and 56 mounted outside its casing. Adjusting

scales

57 and 58 are provided for the same purpose. Handle 59 serves for setting up the machine.

The present invention may be used to advantage in automatic transfer lines as well as for other purposes, such as joining sheet materials by means of hollow tubular rivets.

Though the present invention has been described in connection with a particular embodiment thereof, various modifications and alterations may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. A machine for making and installing tubular rivets from a band, said machine comprising: means for feeding a band; forming means for shaping said band into a tube; cutting means for cutting workpieces from the shaped band, said forming means including a pin, said band being fed parallel thereto, and two opposed forming heads mounted externally of the band being fed and adjacent said pin; means for moving said forming heads in a direction perpendicular to said pin for shaping said band on said pin and for causing a cutting of a workpiece from said band which passes through said cutting means; drive means to impart reciprocating motion to said pin; a punch movably connected with said pin above said forming heads, to upset tubular rivets in openings in a plate; and a riveting die mounted coaxially to said punch beneath an opening in the plate where a tubular rivet is upset.

2. A machine as claimed in claim 1, wherein said pin is provided with a cone-shaped recess on the face of the free end thereof, said machine further comprising a rod including a congruent projection for entering said recess, said rod being installed in said die and passed through the opening in the plate for being driven in synchronization with said pin.

3. A machine as claimed in claim 2, wherein said rod includes a crown located behind a tapered projection thereof and serving to align the opening in the plate in said die.

4. A machine as claimed in claim 1, wherein said forming heads include interengaging V-shaped jaws.

5. A machine as claimed in claim 1, wherein said means for feeding the band comprises a punch means including a punch and die adapted to impart an initial V-shaped form to the band, and means for intermittently advancing said punch and said die together with the band.

6. A machine as claimed in claim 2, comprising a plate between said forming heads and said means for feeding the band, said plate being provided with an opening to pass said punch therethrough and with a V-shaped opening with a rounded projection therein to pass the V-shaped band, said cutting means being constituted in part by said projection serving as a stationary cutting member.

7. A machine as claimed in claim 5, wherein said means for feeding the band comprises a pair of levers for driving said punch and die, one of said levers having a slot and a fulcrum pin movably arranged in said slot to adjust the length of the band being fed.

8. A machine as claimed in claim 1, wherein said drive means for imparting reciprocating movement to the pin comprises a rocking lever, connecting rods connecting said rocking lever and means for adjusting the length of said connecting rods in accordance with the plate thickness.

9. A machine as claimed in claim 1, wherein said means for moving said forming heads comprises two rotating cylindrical cams, a common shaft supporting said cams, said cams being provided with profiled grooves, and levers engaged in said grooves and connected with said forming heads.

10. A machine as claimed in claim 9, wherein said cylindrical cams are slidably mounted on said shaft for adjustment thereon to preset the compression force imparted by said forming heads to a workpiece on said CHARLES W. LANHAM, Primary Examiner E. M. COMBS, Assistant Examiner US. Cl. X.R. 10-11; 227-92