Patent GB-678111-A (GB)
Title: Improvements in base assembling apparatus for electric lamps
IPC: H01J9/30
Filed: 1950-04-17
Abstract: 678,111. Riveting. BRITISH THOMSONHOUSTON CO., Ltd. April 17, 1950 [April 21, 1949], No. 9382/50. Classes 83 (ii) and 83 (iv). [Also in Group VII] In a machine for automatically riveting a number of contacts 1, Fig. 2, to an insulating button 13 on a lamp base 2 the contacts 1 are automatically placed in position for riveting on the base by a means movable toward and away from the base and operating in timed relation with a plunger for feeding and riveting tubular rivets 8 and an indexing means for successively bringing rivet sets and rivet apertures in the bases located thereon into alignment with the plunger. Lamp bases 2 are supported at four work stations A, B, C, D, Fig. 4, at 90 degree intervals on a turret 4, each station comprising a rotatable head 3 carrying rivet sets 14 which support and locate the buttons 13 at each rivet aperture. The heads 3 are brought in turn to each station by an indexing movement of the turret 4, the operator placing bases over the heads at idle stations A or B. At station C the head 3 is rotated by a second indexing means to three positions, at each of which a contact 1 is fed and aligned with a rivet aperture in the button 13 and riveted thereto. At station D the lamp base is ejected and the head 3 is rotated through further indexing movements so that it is correctly positioned for the next riveting operation. Operation of riveting plunger.-The riveting plunger 85, Fig. 4, is operated in timed relation with the machine drive by a toggle mechanism and compressed air ram (not shown) which are operated by the opening of a valve 74 by a cam 99 on a drive shaft 21. Indexing of turret 4.-The turret 4 is mounted on a shaft 20 which is intermittently rotated by a Geneva mechanism comprising a pin 34 on a driving wheel 19 attached to a drive shaft 22 driven from the shaft 21 and engaging a Geneva wheel 18 mounted on the shaft 20. Positive location of the turret between the indexing movements is provided by the engagement of a cylindrical face 29 on the driving wheel 19 with one of four concave positions on the Geneva wheel 18. Further semi-positive location is obtained by means of spring-pressed balls mounted in the turret and engaging holes in. a ring 40 mounted in the base 25 of the machine frame. Indexing of heads 3.-The heads 3 are rotatable in bearings 17 supported in the turret 4 but are normally rotatably fixed relative to the turret 4 by tongues 38 integral with the base of each head 3 and projecting into a groove in the ring 40 on the bed 25 of the machine. At the riveting station C the tongue 38 passes into a groove 41 in the end of a shaft 42 which is intermittently rotated by the second indexing means comprising a gear wheel 146 with interrupted teeth mounted on the drive shaft 22 and engaging a gear wheel 143 driving a gear wheel 142 mounted on the shaft 42. Positive location of the head 3 is obtained by the engagement of one of a number of concave faces on a disc 148 with the cylindrical face of a disc 147 on the drive shaft 22. The disc 147 is cut away in the vicinity of each interrupted set of teeth on the driving gear-wheel 146 to permit relative rotation between the discs 146, 147 only when the teeth are in engagement. Indexing movement of the head 3 at the ejection station D is similarly obtained through the engagement of the tongue 38 in a groove 41<SP>1</SP> on a shaft 1421 geared to the wheel 143. Contact placing means.-The means for positioning a contact 1 in alignment with the riveting plunger 85, Fig. 4, and each rivet aperture in the button 13 at station C comprises one of a series of plungers 9 each carrying a contact 1 between spring-loaded fingers 79. The plungers 9 are movable to and away from the head 3 at station C by an arm 57 engaging a projection 56 on the plunger and mounted on a shaft 59 which is reciprocated through a crank arm 62 by a compressed air ram 60 operated in timed relation with the machine drive by the opening of an air valve 63 by a cam 67 on a drive shaft 21. The contacts are held by the engagement of projections on the spring pressed fingers in grooves on the contacts and on being fed forward to the position for riveting are clamped by the riveting plunger 85 in recesses in the end button so that fingers are disengaged on subsequent withdrawal of of the plunger 9. Contact feeding means.-Contacts 1 are fed in ordered relation to a slide 5 and transferred to the spring-pressed fingers of each of the plungers 9 in turn. The plungers 9 are mounted round the edge of a turret 44 which is intermittently rotated in timed relation with the machine drive by a ratchet mechanism operated through a push-rod 158, Fig. 3, from a second cam 153, Fig. 4, on the drive shaft 21. The turret is located at each stationary position by a spring-loaded ball 50 which engages one of a series of holes 52 in the turret. In each position of the turret the lowermost plunger 9 feeds a contact to the head 3 at station C while a contact is transferred from the slide 5 to the uppermost plunger 9 by a slidable means (not shown) operated by a further compressed air ram on the opening of the air valve 63. After engagement by the fingers 79 the contacts 1 are positioned therein by a wheel 1301 which engages a face of the contacts as the turret 44 rotates. Ejection of riveted lamp base.-As the head 3 from which the next lamp base is to be ejected reaches the station D a hinged plate 162 on the turret 4 with an aperture through which the head 3 projects rides up over a fixed wheel 176 and partially raises the lamp base. The indexing movements of the head 3 at this station further serves to ease the lamp base upwards by engagement of other parts of its periphery with the plate 162. The base is finally ejected into a discharge tube (not shown) by compressed air which enters the head 3 through an aperture 167 therein from a pipe 168 to which air is supplied in timed relation with the machine drive by a further valve 171 operated from a cam 172 on the drive shaft 21.