US2786217A - Rivet forming machine having opposed punches and an indexible blank carrier - Google Patents

Description

H. L. JOHNSON March 26, 1957 RIVET FORMING MACHINE HAVING OPPOSED PUNCHES AND AN INDEXIBLE BLANK CARRIER '7 Sheets-Sheet 1 Filed May 14, 1955 INVENTOR.

H. L. JOHNSON March 26, 1957 RIVET FORMING MACHINE HAVING OPPOSED PUNCHES AND AN INDEXIBLE BLANK CARRIER 7 Sheets-Sheet 2 Filed May 14, 1953 II. II

iffd/f/YEK March 26, 1957 H. JOHNSON 2,786,217

RIVET FORMING MACHINE HAVING OPPOSED PUNCHES AND AN INDEXIBLE BLANK CARRIER 7 Shuts-Sheet 3 Filed May 14, 1953 INVENTOR. JZJ/asd/z mar/yfg March 5 H. JOHNSON 2,786,217

RIVET FORMING MACHINE HAVING OPPOSED PUNCHES AND AN INDEXIBLE BLANK CARRIER Filed May 14, 1953 7 Sheets-Sheet 4 IN VEN TOR. wrzce Jzin :22

March 26, 1957 H. JOHNSON 2,786,217

RIVET FORMING MACH E HAVING 0 ED PUNCHES D AN INDE AN LE BLANK IER Filed May 14, 1953 7 She ets-Sheet 6 March 26, 1957 H. L. JOHNSON 2,786,217

RIVET FORMING MACHINE HAVING OPPOSED PUNCHES L AND AN INDEXIBLE BLANK CARRIER Filed May 14, 1953 '7 Sheets-Sheet 7 INVENTOR. garaae J. Iii/r64,

EKMWM United States Patent RIVET FORMING MACHINE HAVING OPPOSED PUNCHES AND AN INDEXIBLE BLANK CAR- RIER Horace Johnson, Plymoi 1th, Mich.-, assignor to Townsend Company, New Brighton, Pa., a corporation of Pennsylvania Application May 14, 1953, Serial No. 355,001 5 Claims; (Cl. iii-13) This invention relates to a means and method for making tubular rivets, it being an object of the invention to provide a method and means for transforming rivet stock in the form of wire rod into a finished tubular rivet, the transformation to be accomplished by a sequence of progressive heading and forming operations carried on entirely within the mechanism of the machine embodying the invention.

At present tubular rivets are generally manufactured by a process requiring at least two machines. The first machine forms the wire rivet stock into a solid headed rivet blank and the second machine drills the hole to make the rivet tubular. From an efiiciency standpoint the present general method of producing rivets is' un'sat isfactory in that it requires excessive handling of the rivet blank. The rivet blanks must be carried from the first machine to the second and they must be rearranged and fed into a drill jig for the drilling operation. Whether or not the transporting and feeding are done manually or mechanically, the additional handling'is time consuming. Also, it is readily apparent that the present method requires multiple machine installations and. gen erally each machine requires a machine operator. All of these multiply the cost of producing the rivets.

Further, the removal of material by the drilling operation to make the rivet hollow or tubular structurally weakens the rivet and thus results in an inferior product.

The present invention has as one of its objects the elimination of all unnecessary handling of the rivet stock and the rivet blanks. The'production of tubular rivets in accordance with the process embodied in the present invention requires material handling only twice, once when the reel containing the wire rivet stock is initially positioned relative to the machine and fed into' the machine wire feeding mechanism and once again when the tray containing completed tubular rivets is removed from the discharge chute of the machine. There is no intermediate handling required during the manufacturing process.

A further object of the present invention is the production of a tubular rivet having superior structural qualities. Substantially all of the stock in the rivet blank is utilized in making the finished rivet. The hole in the rivet is not drilled but iscold formed and substantially all of the material in the rivet blank is utilized in the production of the rivet. As is well known, the cold forming or working of the'metal increases the structural strength to a highly desirable degree.

More particularly, the method embodied in the present invention of making a tubular rivet from wire stock" of solid cross-section comprises feeding wire stock into a cut-off die, shearing the stock to form a blank and thereafter feeding said blank into a cylindrical recess in a carrying die, piercing one end of said blank while maintaining the opposite end against deformation, forming said pierced end of the blank into a tubular portion' while upsetting the opposite end of the blank to provide a headed portion, and ejecting said blank out of the carice rying die. Briefly, the machine embodied in the pfe invention comprises a Wirefee'ding means, a eat-on means correlated with a means for feeding the cut-offwire or rivet blank into a carrying the, means for per ormin series of piercing, forming and heading" op rati ns on v rive't blank, and means for iridexing the rivet through the sequence of operations to be performed Other objects, features and advantag'sof this j tion will be apparent from the following description appended claims, reference being had to acompany ing drawings forming a part of this specification like reference numerals designate coriespondihg parts in the several views. I v;

Figs. 1 and 2 when placed end to end are a front ele; vation in part fragmentary and sectional of a tubular rivet forming machine embodying the present invention.

Fig. 3 is an end view of the machine taken from the right end as viewed in Fig. 2. p A

Fig. 4 is a schematic diagram of the various drive' mechanisms embodied in the presentinvention.

Fig. 5 is an enlarged fragmentary sectional view taken substantially along the line 55 of Fig. 3 but showing the parts immediately before they reach the position shown in Fig. 3. I I e Fig. 6 is an enlarged fragmentary sectional view take Ir along the line 5-5 of Fig. 3 and showing the parts in the same position as shown in Fig. 3'. k e 1 Fig. 7 is an enlarged view looking inthe direction of the arrows 7-7 in Fig. 2. I

Pig. 8 is an enlarged View looking in the direction of the arrows 88 in Fig. 2. p

Fig. 9 is an enlarged partial section taken substantially along line 9'-9 of Fig. 3 looking in the direction of the arrows. V

Fig. 10 is a view illustrating the progressive steps embodied in manufacturing a rivet in accordancewith the present invention.

Before explaining in detail the present invention it is to be understood that the invention is not limitedin its application to the details of construction and arrangements of parts illustrated in the accompanyingdrawings' since the invention is capable of other ernbod-iments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not" or limitation.

In the drawings there is illustrated an embodiment of a' machine for cold headingand forming tubular; rivets' in accordance with the objects of the present invention The illustrative machine comprises a base or frame 20 supporting the various sub-mechanisms which enable the machine to accomplish its function of turning-rivet wire stock into a completedtubular rivet. Briefly, the sub-' mechanisms include a non-rotatable reciprocating header or ram carrying at selected station-s tools-adapted to per? form external operations on rivet blanks, a fixed headmounting at selected stations tools adapted to'perform'in ternal operations on the rivet blanks, an indexable die plate or rivet blank carrying member interposed between-- said ram and fixed head'and movable by andwith the ra-rn for a part of the stroke o'fthe latter toward the fixed head,;

Motive power for driving the various subemechanisnis" ofthe present machine is supplied by a single electric motor of which only a fragmentary portion of the base 21 is shown. The base 21 of the motor is bolted to a motor mounting plate 22 which is mounted on the base of the machine to extend in a vertical direction. At its lower end the motor mounting plate 22 is swingably journalled on pins or a shaft 23 carried by a motor mounting bracket 24, the bracket 24 being directly bolted to the base. At its upper end the motor mounting plate carries a threaded stud 25 which projects through a slot 26 in a link 27. The link 27 is journalled at its inner end on a pin 28 carried by a motor plate adjusting bracket 29, the bracket 29 being vertically spaced from the bracket 24 and suitably bolted to the side of the base 20. A nut 30 is threaded on the stud 25 for locking the mounting plate 22 in any position of adjustment. The stud and slot connection between the upper end of the motor mounting plate 22 and the base 20 is a conventional manner of providing for adjustment of the tension of the belt drive 31 between the drive pulley (not shown) on the motor shaft and the driven pulley 32 on the crankshaft 33 of the machine.

The pulley 32 is construe-ted and arranged to act as a friction clutch in the even that some part of the machine jams during the operation thereof. Referring particularly to Fig. 3, there is shown an outer pulley hub plate 34 and an inner pulley hub plate 35 which are keyed to the crank shaft 33 in the conventional manner. It will be noted that the disk portions 36 and 37 of the two hub plates 34 and 35 respectively are spaced apart by a cylindrical portion 38 of the inner hub plate 35. The hub 39 of the driven pulley 32 fits over the cylindrical portion 38 and between the disk portions 36 and 37. The space between the disk portions 36 and 37 and the hub 39 is taken up by friction disks 40 of suitable material. Bolt means 41 are utilized to maintain the disk portions 36 and 37, the friction disks 40 and the hub 39 in tight frictional engagement. It will be readily understood that if rotary motion of the crankshaft 33 is prevented by an internal jamming of some of the mechanism of the machine, the pulley 32 will be permitted by the friction disks 40 to slip relative to the pulley hub plates 34 and 35 until the power to the machine may be shut 01f.

Intermediate its ends the crankshaft 33 is provided with a single crankpin 42 on which is journalled a generally horizontally extending connecting rod 43. The free end of the connecting rod 43, the right end as viewed in Fig. 2, is connected by a wrist pin 44 to a horizontally slidable crosshead 45. The crosshead 45 is slidably guided for reciprocating motion between machined surfaces 46 on the base 20 and gib plates 47 rigidly secured to the machine base 20 by bolts 48. Securely bolted to the right end of the crosshead 45 is the ram member 49. This ram member 49 will be more fully explained in detail hereinafter.

Returning to the crankshaft 33, it will be noted that a crankshaft gear 50 is mounted on the right end of the crankshaft 33, see Fig. 3. Crankshaft gear 50 is in mesh with a similar gear 51, hereinafter called the camshaft gear. Camshaft gear 51 is keyed to one end of a shaft 52, hereinafter called the camshaft. Camshaft 52 extends laterally across the machine as viewed in Figs. 1 and 2. That is, the longitudinal axis of camshaft 52 is spaced below and is parallel with the longitudinal axis of the crankshaft 33. The rotation of camshaft 52 supplies the actuating power for the wire feed mechanism, the wire cut-off mechanism, the indexing mechanism and the spindle return mechanism. These mechanisms are shown in schematic outline in Fig. 4 and reference to that view is suggested in following the description.

Wire feed mechanism As stated before, the camshaft 52 carries on one end thereof the camshaft gear 51 through which the camshaft is rotated. On its other or forward end as viewed in Fig. 1, the camshaft 52 has keyed to it wire feed cam 53. Wire feed cam 53 is designed to periodically engage feed cam. roller 54 which is journalled on pin 55 carried intermediate the ends of feed cam lever 56. The lower end of feed cam lever 56 is swingably mounted on pivot stud 57 mounted in a boss on the base 23. The feed cam lever 56 is pivotally connected at its upper end to the left end of a longitudinally and upwardly extending feed link 58. The feed link 58 is pivotally connected at its right end to feed roll operating lever 59.

The feed roll operating lever 59 extends in a substantially vertical direction and is swingably mounted at its lower end on a pivot stud 60 securely mounted in a boss on the base The feed roll operating lever 59 is provided with a vertically extending guideway 61 in which a T-slot bolt 62 is mounted. The T-slot bolt 62 is vertically adjustable by stroke adjusting screw 63. The stroke adjusting screw is rotatable in either direction by means of a manually operable stroke adjusting knob 64. The T- slot bolt 62 has mounted thereon the left end, as viewed in Figs. 2 and 4, of stroke adjusting link 65. The stroke adjusting link 65 extends substantially horizontally lengthwise of the machine to a point at which its right end makes a pin and slot connection with a pin 66 carried in a boss 67 on friction feed plate 68, the link 65 having a slot 69 at said right end. To prevent lost motion movement of the slotted end of the link 65 relative to the pin 66, a feed locking lever 70 is pivotally mounted on a shoulder stud 71 secured to the link 65. When the feed locking lever 76 is interposed between the shoulder stud 71 and the pin 66 the relationship of the link 65 to the friction feed plate 68 is such that the friction feed plate 68 is responsive to any movement of the link 65. When the locking lever 70 is lifted out of contact with the pin 66, that is, when it is tilted in a position of rest against the stop 72 on the link 65, the slot 69 permits longitudinal movement of the link 65 relative to the pin 66 and no movement of the friction feed plate 68 occurs.

The friction feed plate 68 is journalled on the end of lower feed roll shaft 73. Shaft 73 extends laterally across the machine base extension 20a. The friction feed plate 68 has bolted thereto feed friction spider 74 which in turn is seated within a counterbore 75 in the hub of feed clutch gear 76. Feed clutch gear 76 is keyed to the lower feed roll shaft 73 whereas friction feed plate 68 and friction feed spider 74 are movable independently of the gear 76 and the shaft 73. However, the feed friction spider 75 and the feed clutch gear 76 when assembled with friction clutch rolls 77 and friction clutch springs 78 make up a one-way clutch mechanism for intermittently transmitting movement of feed link 58 to the lower feed roll shaft 73. In addition, the feed clutch gear 76 is in mesh with upper feed roll shaft gear 79 which is keyed to the upper feed roll shaft 80.

The upper feed roll shaft 80 is journalled in an upper feed roll shaft retainer 81. The retainer 81 comprises a laterally extending member pivotally mounted at its left end, as viewed in Fig. 3 on a pin 82 secured to base extension 26a. The retainer 81 is provided on its upper surface near the end away from the pivotal mounting with a boss 83 adapted to act as a seat for one end of a compression spring 84.

At their ends opposite the ends carrying the gears 76 and 79, the lower and upper feed roll shafts 73 and 80 respectively have mounted thereon feed rolls 85. Each feed roll is provided with a peripheral groove 36 adapted to retain and guide the wire stock W from which the tubular rivets are to be manufactured.

The aforementioned compression spring 84 is adapted to control the pressure exerted by the upper roll 85 in holding the wire stock W between the two rolls. The compression spring 84 acts in a vertical direction between the upper right end of the shaft retainer 31 and a bridge 37 on the upper side of the base extension 20a. The spring 84 carries on its upper end a collar or spring block 38. The bridge 87 is tapped to receive a pressure adjusting screw 89, the lower end of which bears against the upper surface of the collar or spring b10914 88, Thus, by selectively turning the adjusting screw 89 the pressure of. the spring 84 may be adjusted to set the pressure of the feed rolls 85 on the wire stock at any desired amount or to compensate for a change of wire stock from one diameter to another.

The feed clutch gear 76 is provided with a hub portion 90 on the inner end thereof, the left end as viewed in Fig. 3. The hub portion 90 is adapted to be engaged by a lower feed roll brake shoe 91 and an upper feed roll brake shoe 92, each brake shoe being suitably lined with a brake lining material. As best seen in Fig. 2, the lower and upper brake shoes 91 and 92 respectively are hinged at their left ends on a pin 93 securely mounted in the base extension 20a. The upper brake shoe 92 is also held fixed to the base extension 2011 by'a' stud 94; The frictional drag of the brake shoes on the feed clutch gear 76 may be selectively varied by means of an adjusting screw 95 connecting the two brake shoes at the ends thereof opposite their hinged connection. The foregoing braking device acts at all times as a drag brake and ensures that the action of the feed rolls 85 will be slow enough to feed the wire stock firmly and steadily.

Wire-cutofl' mechanism Although the wire feed mechanism is designed to feed a predetermined length of wire stock W for each revolution of the wire feed cam 53, the accuracy of measurement obtainable is doubtful. Accordingly, provision is made for the accurate measurement and severance of the rivet blank from the wire stock.

The wire stock W after being fed between the wire feed rolls 85 is passed through a wire guide 96 which is a tubular member mounted in the machine base. From the guide 96- the wire next passes through a cut-off quill 97, the cut-off quill being of hardened steel and having a sharp edge 98 at the exit end of the bore thereof; Figs. and 6 in particular show the structure being described. After passing through the cut-off quill 97 the wire stock W passes into a cut-off die 99.

Cut-off die 99 is mounted in the right end,'as viewed in Fig. 5, of'a cylindrical tubular member 100. The tubular member 100 is carried in a bushing 101 which in turn is mounted in an aperture in the upper end 102 of a swinging arm, hereinafter designated cut-off arm 103. The tubular member 100 which is a relatively elongated member carries an elongated pin 104 within its bore. The pin 104' has a reduced portion 105- at its right end as viewed in the drawings, which reduced portion is adapted to have asliding fit within the bore 106 of the cut-off die. in axial alignment with the Wire guide 96', the cut-off quill 97, the cut-off die 99 and the elongated pin 104 is an adjustable stock stop screw 107'. As the wire stock is fed throughthe wire guide 96, through the cut-off quill 97 and then into the bore 106 of the cut-off die 99, the free end of the Wire abuts the end of the elongated pin 104 and moves the pin longitudinally to the left as viewed in Fig. 5. This movement continues until the pin 104 abuts the stock stop screw 107. It will be apparent that the length of wire fed into the cut-off die 99 may be selectively varied by adjustment of the stock stop screw 107.

A rivetblank B is severed from the wire rod by being sheared between the adjacent faces of the cut-off quill 97 and the cut-off die 99. The shearing action takes place as. the cutoff arm 103 is swung in a counterclockwise direction, as viewed in Fig. 3, from the position shown in Fig. 5 to the position shown in Fig. 6.

It will be noted that the cut-off arm 103 is pivoted intermediate its ends on a pin 108 journalled in the main base 20.

A positivemeans is provided for swinging the arm103 from its loading station, i. e., its position in Fig. 5, to its unloading station, i. e., its positionin Fig. 6; The cyclical movements of the arm 193 originate at the camshaft 5 2. A camshaft drive mitre gear 109 is mounted on the shaft 52- inboard of the forward end of the shaft. Gear 109 is in meshwith camshaft driven mitre gear 110 which is keyed to the left end of a longitudinally extending shaft 11 1, the axis of rotation of shaft 111 being substantially at a right angle to the axis of rotation of shaft 52 Intermediate its ends the shaft 111 has keyed thereto two cams, cut-01f cam 112 and cut-offreturn cam 1 13. The cams 1 12 and 113 are spaced so as to permit cut-off cam yoke 114' to be positioned between them, each cam being in engagement with a roller or follower 115. One follower 115 is mounted at the left end of the yoke 114 asviewed in Figure 4 and the other is mounted on the yoke intermediate the ends thereof, each follower 115 beingon opposite sides of the yoke so as to be engaged by only one'of the cams. The yoke 114 is guided and supported for sliding movement between the followers 115 on a cut-off cam yoke slide block 116. The shaft 111 passes through the center of the slide block 116 and the yoke 114 slides to and fro relatively to the shaft 111 and slide block as the cams 112'and- 113 rotatably engage the followers 115.

At its right end 114a the yoke 114 is pivotally connected to the lower end 117 of the cut-off arm 103 by a cut-off arm eccentric pin 118. The purpose of connecting the yoke 114 and cut-off arm 103 by means of an eccentric pin 118 is to permit the arm 103 to be adjusted relatively to the yoke so that adjustment of the alignment of the bore 106 of the cut-off die 99 with the bore of the cut-off quill 97 may be made when required.

The upper end 102 of the cut-off arm 103 is guided and supported during swinging movement of the cut-off arm by a cut-off arm support 119. The support 119 is bolted to the top of the base 20 and is provided with guide surfaces 120 which are engaged by corresponding guide surfaces 121 on the upper end of the cut-off arm 103.

Indexing mechanism The cyclical movements of the indexing mechanism embodied in the present machine also originate at the camshaft 52. As has been described in connection with the Wire cut-off mechanism, camshaft drive mitre gear 109 is mounted on the shaft 52 inboard of the forward end of the shaft. Gear 109 is in mesh with camshaft driven mitre gear 110 which-is keyed to the left end ofthe longitudinally extending shaft 111. At its right end shaft 111 has keyedthereon spiral gear 122' which gear is in mesh with index-idler gear 123 journalled on index idler gear stud 124. The index idler gear 123 is in mesh with gear 125 which-is keyed to a laterally extending die index cam shaft 126. The cam shaft 126'is journa-lled on suitable bearings inthe base extension 20a. Intermediate its ends the die index cam shaft 126 has keyed thereto die index-cam 127. Die indexcam 127 is acylindrical cam having the cam follower grooves 128 out into the cylindrical surface. As the cam 127 is rotated the grooves 128 are successively engaged by cam followers 129 on a rotatable index plate 130; In the present embodiment, the index plate130 carries eight cam followers 106 indicating that there are 8 indexing movements for each com-' plete revolution of the index plate 130.

Index plate: 130 is bolted to index spline bushing 131 and the latter encompasses and is splined to the right end of the longitudinally extending index spindle 132-. The foregoing. splined mounting of the index plate 130 on the index spindle 132 is necessary since the spindle moves longitudinally relative to the index plate during the rivet forming operations as willbe more fully explained.

Spindle return mechanism In the description of theindexing mechanism, brief mention was made of the fact that the index spindle 132 moves longitudinally during the rivet forming operations. As viewed in Fig. 2, the index spindle 132 has on its right end a member which will hereinafter be designated die plate 133. The structure of die plate 133 will be'more" fully described later. As the ram 49 movesto the right as viewed. in 2, parts thereof abutthe die plate 133 and carry the same tothe right also. Thus" the spindle 132 must also move longitudinally to the right. Accordingly, the spindle is journalled for axial and rotative movement in spindle bushing 134 which is mounted in the machine base 29. The spindle bushing 134 supports a substantial part of the left end of the index shaft or spindle 132. The index shaft 132 is supported inwardly of the right end in a bushing 135 carried in a bore in a rib 136 of the base extension 20a.

Mounted on the spindle 132 in abutting relation to a boss on the left side of the rib 136 is a thrust bearing 137. Immediately to the left of the thrust bearing 137 is a spring collar 138 and to the left of this is a coil spring 139. Threaded on the spindle 132 and in abutting relation to the left end of the spring 139 are an index shaft spring adjusting nut 140 and index shaft spring adjusting lock nut 141. The function of the spring 139 is to buffer the shock of the ram 49 striking the die plate 133 and also to return the die plate 133 and the spindle 132 to their normal position upon retraction of the ram. The pre-load on the spring may be varied by the manipulation of the adjusting nuts, as will be readily understood.

Although the spring 139 will function to restore the die plate 133 and spindle 132 toward their normal or initial position upon retraction of the ram it is deemed desirable to ensure a positive return of the die plate and spindle. This is accomplished through mechanism actuated by a cam carried on cam shaft 52. A spindle return cam 142 is keyed to cam shaft 52 inboard of the camshaft gear 51. As the cam 142 rotates it engages a cam follower or roller 143 which is journalled on return cam yoke 144. The return cam yoke 144 is guided and supported for sliding movement on its left end on return cam slide block 145. As most clearly seen in Fig. 4, cam shaft 52 passes through the slide block 145 and the yoke 144 slides to and fro relatively to the shaft 52 on the slide block 145 as the cam 142 rotates and engages the roller 143. To the right end of return cam yoke 144 there is fastened return bar 146. The return bar 146 passes through an aperture in the machine base 20, being guided by a return arm guide 147 fastened to the side wall of the base. The return arm guide 147 is capped by return arm guide plate 148. Thus, the return bar 146 is guided on all four sides.

At its right end the return bar 146 has a pin and clevis connection with the left end of return arm link (left hand) 149. The latter is connected by return arm adjusting nut 150 to return arm link (right hand) 151, the return arm links 149 and 151 and the adjusting nut 150 forming a toggle bolt assembly to permit the effective length of the return arm 146 to be varied when needed to adjust the stroke. The return arm link 151 has a pin and clevis connection with the lower end of a downwardly extending bell crank lever 152. The bell crank lever 152 is keyed to one end of a shaft 153 which is journalled on a bracket 154 mounted on the end of the base extension 2011.

Keyed to shaft 153 is an upwardly extending bell crank lever 155. At its upper end this bell crank lever is provided with a U-shaped portion 156 adapted to straddle the left end of the spindle 132. The legs of the U-shaped portion 156 abut a collar 157 carried on the left end of the spindle 132.

As the cam 142 rotates the bell crank levers 152 and 155 will be rocked at appropriate intervals causing a positive movement of the spindle to the left as viewed in the drawings. Thus, no reliance need be placed on the effectiveness of the spring 139 to accomplish the complete restoration of the die plate 133 and spindle 132 to their normal position upon retraction of the ram 49.

Rivet forming Referring now to Fig. 9 therein is shown an enlarged fragmentary side elevational of the part of the machine at which the rivet forming operation occurs. Visible in this view are some parts which have been previously identified but not described in too great detail. These parts include the ram 49, the cut-off arm 103 and the die plate 133. One other part prominently shown in Fig. 9 but not heretofore identified is the punch plate 158. The plate 158 which is made of shock-resistant tool steel is fastened to the machine base 20 and is centrally bored to accommodate the spindle bushing 134 and the index spindle 132.

The shape of the face 159 of the ram 49 is best seen in Fig. 7. The face 159 of the ram is substantially circular except for two diametrically opposed ears 160 which project beyond the main perimeter of the ram 49. Each ear 1613 is bored to receive an elongated guide pin 161. The guide pin 161 has an end portion 162 adapted to be held in the bore of the car 160 of the ram, a center portion 163 of larger cylindrical cross-section and another end portion 164 having a tapered or rounded leading edge and adapted to fit into appropriate pilot holes in the die plate 133, as shown in Fig. 2.

As best viewed in Fig. 8, the die plate 133 is provided with 8 equally spaced pilot holes 165, each hole being lined with appropriate wear bushings 166.

As the ram 49 moves to the right from the position shown in Fig. 9, the end portions 164 of the guide pins enter a pair of diametrically opposite holes 165 in the die plate 133 thus ensuring that the die plate is securely held in alignment with the ram 49. As will be explained more fully, upon the end portions 164 of the guide pins 161 entering the guide holes 165 for a substantial part of the length thereof the die plate 133 is carried by the ram 49 to the right toward the punch plate 158. It is during this movement of the ram 49 and the die plate 133 toward the punch plate 158 that each rivet blank undergoes a forming operation. As illustrated, 8 such cyclical movements are required to form a completed tubular rivet.

In Fig. 5 the wire stock W is shown with the free end thereof fed from the cut-off quill 97 into the cut-off die 99. The length of wire received by the cut-off die 99 is predetermined by the setting of the stock stop screw 197 which limits longitudinal movement of the pin 104. As described, the pin 164 has a portion which pro jects into the bore of the cut-off die 99 from the side opposite the side into which the wire W is fed.

The description of the sequence of movements will be commenced with the parts in the position shown in Fig. 5, that is, with the wire feed complete but just prior to the cut-off swing of the cut-off arm 103. The ram 49 is at this point in its fully retracted position, or stating this in another way, the crank pin 42 has reached the end of the crank back stroke and is just about to begin its forward movement. The sequence of movements will be described in terms of degrees of movement of the crank pin 42 from the zero position, the position at which the forward movement commences.

During the first 90 of crank forward movement, the cut-off arm 103 is swung from the position shown in Fig. 5 to the position shown in Fig. 6. The initial lateral movement of the cut-01f die 99 relative to the cutoff quill 97 results in the wire stock being sheared otf forming a rivet blank B. The cut-off arm 103 completes its swing toward its unloading position immediately before the ram 49 reaches the halfway mark in its forward travel. Means is provided on the ram 49 to cooperate with pin 104 to eject the rivet blank B from the cut-off die 99 and to insert the blank in a carrying or heading die 167. This means will be explained in greater detail hereinafter. The cut-off arm remains in the position shown in Fig. 6 for approximately the next 135 of crank travel. During this time the crank completes its forward stroke and travels one-fourth of the way back on its return stroke. After this the cut-off arm begins its swing back to the position shown in Fig. 5, that is, the position in which the cut-off die 99 is in alignment with the cut-ofi quill 97. This return swinging movement of the cut-off arm 103 occurs during the next 90 degrees of movement of the crank. To this point the crank has rotated 315 degrees of its travel. During the remaining 45 degrees of travel the cut-off. arm is in a dwell during which time the wire is again being fed into the cut-off die 99. As the crank reaches the Zero position the'wire feed is completed and the next cycle is ready to be commenced.

Referring to Fig. 7, it will be noted that the ram 49 is provided with a series of equally spaced holes 168 which are adapted to receive in some instances various punches or rivet head forming tools. The index or die plate 133, as shown in Fig. 8, is provided with. a corresponding series of equally spaced holes 169 adapted to receive the heading dies 167. The punch plate 158 is also provided with a similar series of holes 170 adapted to receive the various punch tools which form the hollow portion of the rivet.

The location of the aligned holes 168 in the ram and the holes 170 in the punch plate 158 will be referred to as stations. In the illustrated embodiment of the invention there are eight pairs of aligned holes in the ram 49 and punch plate 158. The die plate 133 has eight heading or carrying dies 167 mounted therein. And it has been previously mentioned that the index plate 130 which is mounted on the same spindle 132 as the die plate 133 has eight followers 129 adapted to engage the grooves 128. in the index cam 127. The foregoing indicates that there are therefore. eight stations at which an operation could be performed on the rivet blank B.

The first station is illustrated in detail in Fig. 6 and diagrammatically in Fig. 10. Referring to Fig. 6, a portion of the ram 49 is shown. At this station in the ram 49 there is mounted a bumper pin 171. The bumper pin 171 is adapted on the forward movement of the. ram 49 to abut pin 104 carried in-the tubular member 100 and to drive the pin 104 to the right as viewed in Fig. 6. The portion 105 of the. pin 104 thus is caused to enter the hereof the cut-off die 99 and to drive the rivet blank out of the cut-off die 99 into the heading or carrying die 167. As the transfer of the rivet blank B is being accomplished, the guide pins 161 on the ram and other tools thereon have abutted the die plate 133 and'are carrying the same toward the punch plate 158. The tubular member 100 in which the. pin 104 and cut-ofi' die 99 are mounted has previously been described as being mounted in the end 102 of the swinging arm 103 in a bushing 101; This construction permits the tubular member 100 to bodily move. relative to the swinging. arm 103 carrying the pin 104 and. cut-off die. 99 along with it so as to-maintain the cut-off die in contact with the face of the'heading or carrying die. 167 and the end of the portion 105 of the pin 104 in contact with the end of the rivet blank even after the. latter has been transferred to the carrying die 167.

The punch plate 158 at its first station is provided with a backpunch holder 172= adapted to receive and guide upset pin 173.

As the upset. pin 173- enters the bore of the carrying die 167, the rivet blank B thereby becomes trapped between the. end of the pin 104 and theend of the pin 173. The metal blank is thus compressed longitudinally'but expands diametrically filling up the bore of the carrying die 167 and thereby being. brought up to sizev as far as the desired outside diameter is concerned.

The upset pin 173 is backed up by a spring 174, a backing pin 1'75, and an adjusting screw 176. As seen, by a comparison of Figs. and 6, the spring 174 permits the upset pin 173 to move to the right until the head 177 thereon abuts the end of the portion 178 of the backing pin 175. It will be readily apparent that by moving the adjusting screw 176 inwardly or outwardly the distance the upset pin 173 is permitted to travel to the right against the spring 174 may be varied to suit the length. of rivet to be manufactured.

The rivet blank B having been loaded and fitted into the carrying die 167 at the first station, it is now ready to be carried. or indexed to the next station.

In, terms. of crank arm 42 travel, the die plate. 133 has been'in: a'dwell or non-rotatingposition fromv the- 45' de greeposition of the crank, that is, the crank has travelled one-fourth of its forward travel. It will berecalled that the cut-off arm 183 did not reach the first station or the position shown in Fig. 6 until the crank arm and therefore the ram 49 had travelled a distance equal to half their forward travel. Thus, the die plate 133 had completed its last indexing movement well before the ram 49 and cut-off arm 103 were in position to transfer the rivet blank from the cut-off. die'99 to the carrying die 167. The die plate 133 remains in its dwell or nonrotatable condition for the next 225 degrees of crank travel or until the crank has completed one-half of its return travel. However, due to the action of the spindle return mechanism, as soon as the ram 49'begins its back stroke the spindle 132 and therefore the die plate 133 are bodily shifted to the left from the position shown in Fig. 6 to their original position shown in Fig. 5. This return movement is completed by the time the crank arm 42 has completed one-ha1f of its return travel. Thus, the end of the dwell or non-rotating period of the die plate 133 and the end of the spindle return occurs simultaneously. The die plate 133 is then indexed to carry the newly'loaded carrying die 167 to the next station, the die plate being rotated in a counterclockwise direction as viewed in Fig. 8. The indexing movement of the die plate 133 in the illustrated embodiment of the inventionbegins at the 270 degrees point in the movement of the crankarm 4-2. and continues as the crank arm completes its'one cycle and until the crank arm has travelled 45 degrees of its uext cycle.

At its secondv station the ram 49- is provided with a ram punch 179 having a cylindrical recess 180' therein. The punch plate 158 has mounted therein at its correspending or second station a flaring punch 181, that is a punchhavinga conical point. As the ram 49 is moved forward by the crank 42 and abuts the die plate 133 and carries the same toward the punch plate 158, the flaring punch. 181 penetrates the rivet blank B and begins the piercing thereof. The cylindrical recess 180 in the ram punch 179 is equal in diameter to'the rivet blank diameter. and therefore permits the displacement of a portion of the rivet blank out of the carrying die 167. This displaced portion of the rivet blank will provide the material for the upsetting of the rivet head. The flaring operationhaving been completed the rivet blank B is then carried by the die. plate 133 to thenext or third station.

Atthe third station the ram 49 is provided with a rampunch. 1 82 having a semi-spherical seat 183 in the the. end thereof, the seat 1'83'having the shape of the rivethead to be. formed. The punch plate 158 at this station is providedwith a punch 184 having an elongated cylindrical portion 185' tipped with a radius. Thus, as the ram punch 184 is upsetting a head onthe rivet blank B the punch 182 is lengthening the hollow within the rivet blank begun by the flaring punch 181.

At. the fourth station, the ram punch 182 is the same as used at the third station. The punch plate 158 is provided at this station with merely a back-up punch 186. The operation at this station, as illustrated is only a repeat of the head upsetting operation as performed at station 3. It will be readily apparent however that if desired some additional operation could be performed at this station by providing the appropriate ram punch and back-up punch.

At the fifth station the ram may have mounted therein a ram punch 187 as shown. The ram punch 187 has an enlarged" cylindrical recess 188 in the end thereof adapted not to engage. the formed rivethead. It will be noted that the bore of'each carrying die 167 is tapered on the end thereof at which the punches mounted in the punch plate 158 are adapted'to enter. In the case of a long rivet blank some. of the rivet metal will flow toward thetapered end of the carrying die boreand according- 11 ly the rivet will be flared at the bottom. The fifth station has for its function the straightening of the outer wall of the semi-formed rivet R. The punch 189 carried in the punch plate 158 has an elongated cylindrical portion 190 of sufiicient length to bodily push the rivet R partially out of the carrying die 167 on the ram side thereof. As shown the rivet head extends well into the recess 188 within the ram punch 187 and all of the rivet body is within the true cylindrical portion of the bore of the carrying die 167.

At the sixth station the ram 49 has mounted therein piercing die 191. The die 191 has a semi-spherical seat 192 in the end thereof contoured to fit the rivet head. The contoured seat 192 leads to a cylindrical bore 193 of a diameter sufficient to receive with a slip fit in the elongated cylindrical end portion 194 of the piercing punch 195. With reference, to the shape of the rivet at the fifth station, it will be noted that only a thin section of metal prevents the rivet from being totally hollow. At the sixth station this small slug of rivet stock is pushed out and the rivet R is made completely hollow. Except for the little slug of metal lost in this piercing operation all of the original mass of metal in the rivet blank remains in the body of the rivet thereby forming a sturdy and high quality rivet.

Upon arrival at the seventh station the rivet is substantially complete. The ram punch 196 used at this station has a semi-spherical seat 197 having a small button 198 at the base thereof. This button 198 is adapted to press a chamfer on the upper end of the bore in the rivet R thereby removing any burrs or sharp edges re sulting from the final piercing operation.

The rivet leaves the seventh station in completed form and it is only necessary to eject the same from the carrying die 167. This ejection takes place at the eighth station. At this station the ram 49 is provided with a ram punch 199 which consists merely of a tube having an opening 290 in the bottom thereof. The punch plate 158 has mounted therein an ejector punch 201 which is adapted to completely push the rivet out of the carrying die 167 so that it will fall through the opening 200 in the ram punch 199 and drop into the machine discharge chute 202. The carrying die 167 thus becomes available for reloading.

If the die plate 133 carried only one carrying die 167 with a rivet blank therein,it is apparent that eight revolutions of the crank arm 42 would be required before a single rivet were produced. But it will be understood that normally each time the die plate is indexed one station, a completed rivet is ejected on the next forward movement of the ram and a new rivet blank is loaded into a carrying die 167. Thus, normally each revolution of the crank arm 42 results in the completion of another tubular rivet.

Although the foregoing description of a rivet forming process has dealt with the forming of a completely hollow or tubular rivet, it will be readily apparent that the present machine may be utilized for manufacturing rivets which have only a hollow stem portion. To manufacture partially hollow rivets it would be necessary only to shorten the punch 184, also the punch 189 and eliminate the piercing operation at the sixth station.

Thus, the present machine is readily adaptible to the production of completely hollow or partially hollow rivets and long or short ones. Once the dies and punches are in place, the only attention required by the machine is a sufficient supply of wire rod and a periodic removal of the tray of completed rivets. The conversion of the wire rod into completed rivets is completely mechanically controlled and therefore the quality of the rivet is independent of the manual dexterity of the machine attendant.

As a safety feature the machine is provided with a foot operated braking means. This consists of a brake peddle 203 pivotally mounted near the bottom of the machine base 20 on a pin or shaft 204 journalled in a bracket or boss 205 cast into the base. Pivoted to the base 20 in position to engage the inner rim 206 of the pulley 32 is a brake shoe 2537. The brake shoe 207 is pivoted on brake shoe pivot pin 208 mounted in the machine base 20. Pressure is transmitted from the brake peddle 203 to the brake shoe 207 by means of a toggle bolt arrangement consisting of upper brake operating link 209, lower brake operating link 210 and brake link adjusting nut 211. The upper brake operating link 209 is pivotally connected to the brake shoe 207 by a pivot pin 212. The lower brake operating link 211 has a pin 213 and clevis connection with the brake peddle.

I claim:

1. In a tubular rivet forming machine, a first set of annularly arranged stationary punches, a second set of annularly arranged reciprocable punches, a blank holder interposed between said sets of punches and having openings to receive a set of rivet forming blanks, said blank holder having an indexing position in which it is spaced from said sets of punches, means for indexing said blank holder when disposed in its indexing position thereby to align the blanks with said punches, reciprocating ram means for shifting said second set of punches in unison during a portion of the travel thereof toward and relatively to said blank holder and thereafter shifting said blank holder with said second set of punches during the remainder of the travel of the latter in one direction into operative relation to said first set of punches to cause said sets of punches to operate on said blanks at opposite sides thereof, means for reciprocating the ram means, a reciprocating spindle connected to said blank holder, reciprocable drive means for said spindle, cam operated means controlled by said drive means for shifting said spindle and thereby said blank holder away from said first set of punches into indexing position and in unison with said second set of punches during a portion of the return travel thereof.

2. A tubular rivet forming machine according to claim 1 wherein said ram means is provided with guide members adapted to enter guide apertures in said blank holder for holding said ram means and blank holder in predetermined circumferential relation.

3. In a tubular rivet forming machine, a first set of annularly arranged stationary punches, a second set of annularly arranged reciprocable punches, a blank holder interposed between said sets of punches and having openings to receive a set of rivet forming blanks, said blank holder having an indexing position in which it is spaced from said sets of punches, means including a reciprocable and rotatable spindle connected to said blank holder for indexing said blank holder when disposed in its indexing position thereby to align the blanks with said punches, reciprocating rarn means for shifting said second set of punches in unison during a portion of the travel thereof toward and relatively to said blank holder and thereafter shifting said blank holder with said second set of punches during the remainder of the travel of the latter in one direction into operative relation to said first set of punches to cause said sets of punches to operate on said blanks at opposite sides thereof, means for reciprocating the ram means, drive means for imparting rotatable movement to said spindle thereby to index said blank holder, and cam operated means controlled by said drive means for axially shifting said spindle and thereby shifting said blank holder away from said first set of punches into indexing position and in unison with said second set of punches during a portion of the return travel thereof.

4. A tubular rivet forming machine according to claim 3 wherein said drive means includes an index member having a splined mounting on the spindle to provide for axial shifting of the spindle relatively thereto.

5. A tubular rivet forming machine according to claim 3 wherein said ram means is provided with guide members adapted to enter guide apertures in said blank holder References Cited in the file of this patent UNITED STATES PATENTS White June 20, 1911 Svenson Sept. 18, 1923 14 Kaufman Feb. 8, 1927 Smith Nov. 3, 1931 Wilcox Mar. 23, 1937 Freter Apr. 19, 1938 Schwayder Mar. 25, 1941 Ernst Aug. 14, 1945 Buchet Feb. 26, 1946 Friedman Mar. 19, 1946

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