US2853037A - Integral pin forming machine - Google Patents

Description

Sept. 23, 1958 R. s. DICK 2,853,037

INTEGRAL PIN FORMING MACHINE Inventor; Roscoe S. DICK,

His Attorney Sept. 23, 1958 R. s. DICK 2,853,037

INTEGRAL PIN FORMING MACHINE Filed 0G11. 28. 1955 3 Sheets-Sheet 2 lrwenton:

Roscoe S. DioK,

byM/V-yfm His Attorney Sept. 23, 1958 R. s. DlcK 2,853,037

`INTEGRAL PIN FORMING MACHINE Filed Oct. 28, 1953 3 Sheets-Sheet 3 lrwenoor: Roscoe S. DoKI His Attorney arent tice Patented Sept. 23, 195% INTEGRAL PIN FORMING MACHINE Roscoe S. Dick, Conneaut, Ohio, assigner to General Electric Company, a corporation of New York Application October 28, 1953, Serial No. 388,834

7 Claims. (Cl. 113-1) This invention relates to a machine for forming integral pins in the side wall of` a metal shell. lt may be used to produce drawn-extruded pins by simple extrusion into a forming die, and also to produce spun-extruded pins by extrusion and spinning. It finds particular application in the manufacture of bayonet bases for electric lamps.

The bayonet bases of electric lamps comprise a cylindrical metal shell having one or more end contacts and small radial pins or protuberances for locking into a socket. Up to the present time, the pins of commercial bayonet bases have generally consisted of short lengths of wire staked into holes in the wall of the shell. It has been necessary that the pins be tightly inserted and accurately aligned in all directions with respectto the shell, and that the pin diameters and lengths be held to very close tolerances.

In an integral pin bayonet base, the pins are formed directly out of the wall of the shell by extruding and also, if desired, by spinning. It will be appreciated that inte gral pin bases require less material than cut wire pin bases and are therefore essentially more economical.

The general object of the invention is to provide a new and improved machine for forming protuberances in the wall of thin metal shells, either by simple extrusion or by combined extrusion and spinning.

A more` specic object of the invention is to provide a machine for extruding and spinning integral pins in the wall of a thin metal shell to make a bayonet base for electric lamps.

In a preferred embodiment of the invention, the machine comprises a hollow stationary stud which is transversely slotted at its lower end. Within this slot there is mounted a pair of lever punches which are pivoted at an intermediate point and have hardened bosses which press out the metal of the shell when the lower ends of the levers are swung out. The levers are actuated by a double acting wedge which is provided at the end of a spindle mounted for reciprocal movement within the stud. On the downward movement of the spindle, the lower portion of the wedge acts on the levers to forcibly swing them out against a lamp base, whereas on the upward movement, the upper wedge portion coacts with the pivotcd levers to positively swing them in, and out of engagement with the lamp base. As part of the same operation, spinning dies are indexed laterally against the shell in order to square up the extrusion, that is, to sharpen the contours of the extrusion whereby to give it a substantially cylindrical shape, more like that of a cut wire pin. The shells are lifted onto the stud in collet type holders which are indexed below the stud in a turret rotating intermittently.

For a fuller understanding of my invention and of `its features and advantages, attention is now directed to the following description and accompanying drawings. The

features of the invention believed to be novel will be more particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a plan view of a pin forming machine embodying my invention.

Fig. 2 is a pictorial illustration of a bayonet base shell with integral pins of the spun-extruded type.

Fig. 3 is a detailed cross section of a spun-extruded pin.

Fig. 4 is a side elevation of the machine taken partly in section along the line IV-IV of Fig. l.

Fig. S is a detail of the extruding punches and spinning dies.

Referring to Fig. 2 there is shown a thin-walled metal shell 1 forming the principal element of a bayonet base. It is open at its upper end into which the bulb of an electric lamp will be cemented, and partially closed at its lower end. The insulating web on which the end contact of the base will he mounted is molded through the aperture 2. The radial pins 3, 3' in the side wall of the shell are formed integrally therewith by extrusion and spinning. As shown in Fig. 3, the pin is substantially cylindrical in shape except for the corners 4 which are somewhat rounded off. Such pins, as made by the present machine, are polished by spinning dies at the end 5 and at the sides 6, so that the product has a very neat appearance.

Referring to Fig. l, the shells 1 are loaded into collet type chucks 11 which are mounted in the rim of an indexing turret 12 keyed to a central supporting shaft 13. The turret indexes in a clockwise direction, as indicated by the curved arrow 14, rotating through the angle between adjacent chucks at each index. The operations of extruding and spinning the pins are performed on the` shells while indexed into station A. The construction of the turret 12 and the gearing for achieving the intermittent rotation thereof is fully described in copending application Ser. No. 351,092 of Ernest M. Schiller et al., filed April 27, 1953, entitled Pinning Machine and assigned to the same assignee as the present invention. Reference may also be made to that application for a description of devices for automatically loading and unloading the shells into the chucks 11.

As best seen in Fig. 4, the shell 1 indexed into station A is firmly held in a well within the upper end of the chuck 11. The chuck comprises an outer sleeve 15 within which is mounted a segmented spindle 16. The mating surfaces of the sleeve and spindle are ilared outwardly at the upper end of the chuck, whereby when the spindle is pulled down into the sleeve by the spring 17, the segments are pressed inward and grip the shell.

At station A, chuck 11 is located in registry with stationary stud 18 seized in block 19. The block overhangs the station and is bolted at 21 to plate 22 which is in turn fastened to table 23 of the machine. The shell is lifted up onto the lower end of the stud by raising the chuck relative to the turret. This is accomplished by a reciprocable slide rod 24 which carries at its upper end a block 25 engaging in sleeve 15 of the chuck, and at its lower end a block 26 supporting a roller 27. The roller rides in cam track 28 cut in the side of a drum cam wheel 29. The drum wheel may be mounted coaxially with turret 12 and geared to make one complete revolution for each index of the turret. Such gearing may be eiected in known manner and, if desired, reference may be made tothe previously mentioned Schiller et al. application for a preferred arrangement thereof. The cam track 28 is shaped to effect an upward movement of rod 24 whereby to lift the shell onto stud 18, to hold it there stationary for a time, and then to lower the chuck back int-o place in the turret, all within the dwell interval of the chuck at station A. f

Stud 18 has a slot 31 milled in its lower end in a plane tangential to the turret 12 which forms a lateral aperture on` each side. Within the slot there is mounted a pair of levers 32 on pivot pins 33. The ends of the levers are offset inwardly on both sides of the pivot points. The

3 levers are provided with hardened bosses 34 near their lower ends, which bosses press out and extrude the metal of the shell 1 when the levers are swung out. The levers are actuated by a double-acting wedge member 35 provided at the lower end of spindle 36 vertically reciprocable within the bore of stud 18. As the spindle moves dow-n, the wedge coacts with the lower offset portions of levers 32 to forcibly move the bosses against the shell wall to form the protuberances. When the spindle moves up in a reverse direction, wedge 35 coacts with the upper offset portions of levers 32 which were accommodated by necked portion 37 of the spindle and positively swings the levers back in. The bosses 34 are thereby disengaged from the shell, as sh-own in dotted lines in Fig. 5.

The feature of a double-acting wedge is `important to the successful operation of the machine, because the bosses 34 have a natural vtendency to bind in the pro-tuberances as a result of the extrusion and spinning. lf such binding were to happen, the shell would be ruined in stripping it off the stud. In accordance with the invention, the double-acting wedge positively disengages the lever punches from the shell so that possibility of binding is eliminated,

The reciprocal movement of spindle 36 is effected through rocker arm 38 (Fig. 4) pivoting at 39 on standard 40 fastened to plate 22. The forward end of the rocker arm is formed into a yoke portion 41 carrying a pair of rollers 42 which engage in a grooved collar 43 fast to the upper end of the spindle. The rear end of the rocker arm carries a roller 44 which engages in a cam track 45 formed in the wall of an auxiliary drum cam 46. The drum cam is keyed at 47 to an auxiliary shaft 48 supported in a bearing 49. Shaft 48 is geared to make one revolution during each index of the main turret 12, and cam track 45 is shaped to provide a complete reciprocation of spindle 36 during the time when collet chuck 11 is raised onto stud 18.

At the same time as the pins are being extruded in the shell or immediately thereafter, the spinning dies 51, 51 are indexed laterally against the walls of the shell on either side so as to spin the extruded metal to the desired configuration for the radial pins. Each die comprises a yoke 52 in which are pivotably mounted a pair of outer rollers S3 and an inner roller 54 of lesser diameter, on an axis transverse to the axis of spin of the yoke. The outer rollers form the side wall 6 of the pin whereas the inner roller forms the end face 5. The rollers are preferably made of hardened steel, and their high speed rotation imparts, to the portions of the pin which they engageLa high finish as previously mentioned.

The yoke 52 is fastened to the end of a shaft 5,5 journaled in a vbearing 56 and connected by a toothed coupling 57 to shaft 58. Shaft 58 is journaled in bearings 59 and 61 and is driven by an electric rnotor 62 through pulleys 63, 64 and flexible belt '65. As regards the spinning dies and the actuating means therefor, the apparatus on the right-hand side oftable 23 duplicates substantially that on the left-hand side and is indicated by like reference numerals characterized by a prime mark.

The dies 51, 51 are rotated continuously by they motors 62, 62' as indicated by curved arrows 66, 66 (Fig. Normally the dies are retracted from the shell, as indicated in the drawing. As the bosses ,34 are extruding the pins, or immediately thereafter and while the levers are still .swung out, dies 51, `51' arein-l dexed laterally inward against the shell, as indicatedby the arrows 67, 67. The lateral displacement of the dies is effected through levers 68, 68', toothed couplings 57,

57' allowing shafts 55, 55' to slide in and out t0 the required extent. Lever 68 is pivoted at 69 on plateZZ and carries at its forward end a roller '71 which engagesy in a grooved collar 72 faston shaft 55. The rearward end of the lever carries a roller 73 which engages in.

a cam track 74 cut in the lower face of cam disk 75 keyed to shaft 48. The right-hand lever 68', as seen in Fig. l, is provided at its rearward end with a. roller 73 which engages in cam track 76 and which is cut 4in the upper face of inferior cam disk 77, likewise keyed to shaft 48. Cam tracks 74 and 76 are shaped to cause the spinning dies 51, 51 to be pressed against the side of the shell 1 while the lever punches 32 are swung out. The dies reach the sides of the shell through the cut-out areas or windows 78 in the sides of collet chuck 11, these windows being cut through both the outer sleeve 15 and the inner spindle 16 of the chuck.

Whereas the embodiment of the invention which has been described herein uses spinning dies so that the pins formed in the base shell are both extruded and spun, `it will be appreciated that the invention may be applied to simple extrusion. In such case, dies 51, 51' are merely replaced by mating dies suitable for shaping the protuberances formed in the shell wall by bosses 34, and these mating dies are indexed laterally inward in `the manner that has been described, but without the spinning. In such case the motors 62, 62 and their couplings to the shafts 55, 55 are omitted from the machine. This modification may be used to extrude the pins described in my copending application, Serial No. 388,862, filed concurrently herewith, entitled Extruded Pin Base, and assigned to the same assignee as the present `invention and now abandoned.

After the extrusion and spinning of the pins has taken place, the lever punches 32 are swung in and the spinning dies 51, v51' are retracted. Thereafter collet chuck l11 is lowered back into the turret 12 and the turret indexes to present a succeeding chuck at the pin forming station for a repetition of the sequence of operations kthat has been described. To guard against a tendency of the shells to stick occasionally on stud 18 after the pins have been formed, there is provided a stripping plate 79 having an aperture at 81 which makes a sliding fit with stud 18. The plate is normally located in the raised position in which it is illustrated in Fig. 4. It is supported by a pair of connecting rods 82 which pass through the block 19l and are bolted at their upper ends to an upper plate 83. Plate 83 depends by bolt 84 from bracket 85, being normally spaced the full length of the bolt from the bracket by reason of spring 86. Bracket 85 is fastened to the upper end of slide rod 87 which passes through table 23 and bushing 88 fastened to the underside thereof. The slide rod is actuated by drum cam wheel 29,v through block 89 supporting roller 91 which engages in cam track 92 in the drum cam.

Normally, stripping plate 79 is raised above the end' ofstud 18 a distance sufficient to clear the upper edge of shell 1 when lifted up onto the stud. After the pin forming operation, the stripping plate is lowered and presses the shell off the end of the stud to insure that it remains properly seated within the collet chuck 11 as the chuck is being lowered back into place in turret 12. Spring 86 allows the stripping plate to remain in its raised position in case a shell should become crushed on the end of the stud such that it could not be removed Without damage to the operating parts.

While a certain specific embodiment of the invention has been shown and described, it will, of course, be understood that various modification may be made without departing from the spirit of the invention. The appended claims are therefore intended to cover any such modifications coming within the proper scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1.V A machine for forming lateral protuberances in thin-walled shells comprising a support, a hollow stud mounted on said support and having one end proportioned to enter a shell slipped over said end and having a transverse slot in said end, a pair of lever punches pivotally mounted in said slot on opposite sides thereof,

each of said levers having inwardly offset portions on either side of the pivot point, a boss on the outer face of. eachlever near one extremity, a spindle reciprocable through saidstud and having at its lower end a necked portion followed by an expanded wedge portion, the wedge portion being adapted to engage the offset portions at one end of said levers while the offset portions at the other end are accommodated in said necked portion, means for reciprocating said spindle to` move the wedge portion thereof past said pivot points on each forward and backward movement of said spindle whereby to positively swing the embossed extremity of each of said levers out when said wedge portion engages one pair of offset portions and to positively swing the said embossed extremities of said levers in when said wedge portion engages the other pair of offset portions, said machine comprising also mounted on said support a pair of dies, means for advancing said dies into a work shaping position in registry with the bosses on the embossed extremities of said levers in the swung-out position of said lever extremities and for retracting said dies from said position, and means connecting said levers and said dies to bring said dies to said work shaping position when said embossed lever extremities are in swung-out position.

2. A machine for forming lateral protuberances in thin-walled shells comprising a support, a hollow stud mounted on said support and having one end proportioned to enter a shell slipped over said end and having a transverse slot in said end, a pair of lever punches pivotally mounted in said slot on opposite sides thereof, each of said levers having inwardly offset portions on either side of the pivot point, a boss on the outer face of each lever near one extremity, a spindle reciprocable through said stud and having at its lower end a necked portion followed by an expanded wedge portion, the wedge portion being adapted to engage the offset portions at one end of said levers while the offset portions at the other end are accommodated in said necked portion, means for reciprocating said spindle to move the wedge portion thereof past said pivot points on each forward and backward movement of said spindle whereby to positively swing the embossed extremity of each of said levers out when said wedge portio-n engages one pair of offset portions and to positively swing the said embossed extremities of said levers in when said wedge portion engages the other pair of offset portions, said machine comprising also mounted on said support a pair of spinning dies each comprising a plurality of rollers and a yoke mounting said rollers on an axis transverse to the axis ofspin, said rollers being proportioned to impart a desired configuration to the protuberances formed in the shell wall by said bosses, means for advancing said dies into a work shaping position in registry with the bosses on the embossed extremities of said levers in the swungout position of said lever extremities and for retracting said dies from said position, and means connecting said levers and said dies to bring said dies to said work shaping position when said embossed lever extremities are in swungout position.

3. Apparatus for forming lateral protuberances in thinwalled metal shells comprising means for presenting said shells at a work station, a protuberance forming unit lo cated at said station and and comprising a hollow stud having one end positioned and proportioned to enter a shell presented at said station by said means and having a lateral aperture in said end, a lever punch pivotally suspended in said aperture and having a boss on its outer face near one extremity, a spindle reciprocal through said stud and having at its end in said stud a wedge portion engaging a portion of said lever punch, means fo-r reciprocating said spindle to cause said lever punch to pivot and forcibly move said boss through said aperture to a protuberance forming position, said unit comprising also a die and actuating means for advancing said die into a work shaping position in registry with the boss on said punch in the protuberance forming position of said boss and for retracting saiddie from said position, and means for actuating said spindle and said die to bring said diev to said work shaping position when said boss is in its protuberance forming position.

4. Apparatus for forming lateral protuberances in thinwalled metal shells comprising an indexing turret for presenting said shells in a lifted position at a work station, a protuberance forming unit located at said station and comprising a hollow stud having one end positioned and proportioned to enter a lifted shell and having a lateral aperture in said end, a lever punch pivotally suspended in said aperture and having a boss on its outer face near one extremity, a spindle reciprocable through said stud and havingatits lower end a wedge portion engaging a portion of said lever punch, means for reciprocating said spindle to cause said lever punch to pivot and forcibly move said'boss through said aperture to a protuberance forming position, said unit comprising also a spinning die, means for advancing said die into` a Work shaping position in registry with the boss on said punch in the protuberance forming position of said boss and for..

retracting said die from said position, and means for actuating said spindle and said die to bring said die to said work shaping position when said boss is in its protuberance forming position.

r5. Apparatus for fo-rming lateral protuberances in thinwalled metal shells comprising an indexing turret for presenting said shells in a lifted position at a work station, a protuberance forming unit located at said station and comprising a hollow stud having one end positioned and proportioned to enter a lifted shell and having a transverse slot in said end, a pair of lever punches suspended in said slot on opposite sides thereof and each having a boss on its outer face near one extremity, a spindle reciprocable through said stud and having at its lower end a wedge portion engaging a portion of each of said lever punches, means for reciprocating said spindle to cause said lever punches to swing out and forcibly move said bosses through said slot to protuberance forming positions on opposite sides of said stud, said unit comprising also a pair of spinning dies, means for advancing said dies into work shaping positions in registry with the said bosses in the protuberance forming positions of said bosses and for retracting said dies from said positions, and means for actuating said spindle and said dies to bring said dies to said work shaping positions when said bosses are in their protuberance forming positions.

6. Apparatus for forming lateral protuberances in thin-walled metal shells comprising an indexing turret for presenting said shells in a lifted position at a work station, a protuberance forming unit located at said station and comprising a hollow stud having one end positioned and proportioned to enter a lifted shell and having a transverse slot in said end, a pair of lever punches suspended in said slot on opposite sides thereof and each having a boss on its outer face near one extremity, a spindle reciprocable through said stud and having at its lower end a wedge portion engaging a portion of each of said lever punches, means for reciprocating said spindle to cause said lever punches to swing out and forcibly move said bosses through said slot to protuberance forming positions on opposite sides of said stud, said unit comprising also a pair of spinning dies each comprising a plurality of pivotally mounted rollers proportioned to impart a pin-like configuration to the protuberances formed by said bosses, means for advancing said dies into work shaping positions in registry with the said bosses in the protuberance forming positions of said bosses and for retracting said dies from said positions, and means for actuating said spindle and said dies to bring said dies to said work shaping positions when said bosses are in their protuberance forming positions.

7. Apparatus for forming lateral protuberances in thin-walled metal shells comprising an indexing turret for presenting said shells at a work station, means on said ,.7 turret `for kraising said :shells above said turret at said work station, a hollow stud at ,said station having an end positioned and proportioned to enter a lifted shell and having a transverse slot in said rend, a pair of lever punches pivotally mounted ,in said slot on opposite sides thereof, each ofsaid levers having :inwardly oiset portions oneither side ofthe pivot point, a boss on the outer face of `each lever ynear one extremity, a spindle reciprocable through said lstud and having at ,its lower end a necked portion `followed by an expanded Wedge portion, the wedge portion :being adapted to engage the offset portions `at one end of said levers 4while the offset portions at Athe other end `are accommodated in said necked portion, means :at said station for reciprocating said spindle to move the wedge portion thereof past said pivot points on .eachforward and 'backward movement of said spindle whereby to kpositively swing the embossed extremities of said levers out when sa-id wedge lportion engages one pair of `offset lever portions and to positively swing the said embossed lever extremities yin when said wedge portion engages the other pair of said offset lever portions, a

pair of `spinning .dies at said station, means ,at said station for advancing said :dies into a Work shaping position in registry with the bosses `on the embossed extremities ofv said levers in the swungout position of said ylever tremities and for retracting said :dies from said position',` and means at said station for connecting said levers and said dies `to bring said dies to said work shaping position when said embossed lever extremities are in swung-outl position.

References Cited 4in the le of this patent UNITED STATES ,PATENTS 800,764 Rigby Oct'. 3, 19.05 1,060,663 Bauroth .May `6,. 1913 1,478,692 Baranoi '.V Dec. 25, 1923` 1,744,487 Miller Jan. 21, 19,310. 1,823,047 Hothersall Sept. 15, 19131 1,836,921 Harrison Dec. 15, 1931. '1,854,424 Peellef Apr. 19, 1932` 2,254,275 Dove Sept. 2, 1941

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