Patent GB-848865-A (GB)
Title: Improvements relating to the insertion of leads in glass stems
IPC: H01J9/32
Filed: 1958-12-08
Abstract: 848,865. Assembling leads in glass stems; making electron tubes. SYLVANIA ELECTRIC PRODUCTS Inc. Dec. 8, 1958 [Dec. 6, 1957], No. 39552/58. Class 39(2). [Also in Group XXX] In a machine for feeding leads and/or dummy pins into a rotatable press head on an indexable turret, the head subsequently moving downwards to insert the leads into a glass stem held in a lower rotating mould mounted on the turret, means are provided for stopping the rotation of the head in a raised position, for feeding leads into the heads from below when in the raised position and for ensuring rotation of the head and lower mould in unison during approach movement of the head to the lower mould. The machine described has provision for feeding dummy pins to a head in which leads have already been inserted. Pin feeding arrangement. The pins 30, Fig. 4, are inserted by hand into a pin dispenser having spring urged bars 50 arranged on opposite sides of a sliding member 54 of channel shape having slots 62 which in one position of the slide register with slots 68 in a fixed bar 66 into which pins are therefore fed. The sliding member 54 has holes 74 in the base which in another position register with the slots 68 so that the pins therein drop into channels 86 below the holes. Pin feed checking means. The channels 86 lead to an apertured plate 164, Fig. 8, below which is a tapered platform mounted for reciprocating movement, in one position of which it closes the apertures 184 in the plate 164. In this position spring pressed sensing fingers 186 each associated with a micro-switch contact the pins. All the spring fingers are controlled by a common air manifold 204, application of fluid pressure to which causes withdrawal of the finger against the action of springs 190. If all the pins are present, they will be held by the fingers 186 until an apertured plate 159 arrives below the channel 86. Fluid pressure is then applied to the manifold withdrawing the sensing fingers and releasing the pins which pass down chanels 218. In the absence of a pin in any of the channels, the corresponding micro-switch is closed applying fluid pressure to the manifold so that the pins fall from the channels as the platform moves away from the opening. The pins pass via the channels 218 to apertures 212 partly by the action of compressed air fed into the channels 218 and partly by suction from the press head 29, Fig. 14. Operation of the press head. The press head 29 comprises an outer sleeve 262 mounted on roller bearings 260 on a supporting casting 256 and carrying the upper mould 28, and an inner reciprocable sleeve 294 carrying ejection plungers 254 which operate to eject the pins from the upper mould. In the position shown, the press head is in position to receive pins from the dispenser channels 212. Thereafter the dispenser is withdrawn and the press lowered towards a rotating spindle 22 for the lower mould which carries the heated glass wafer 26 into which lead pins have already been inserted. Downward movement of the head 29 brings a finger 264 thereon into contact with a projection 266 on the spindle 22, so that the pins, head and spindle will rotate in unison during the pressing of the dummy pins into the glass 26. Withdrawal of the head brings a projection 274 on the finger 264 into contact with a retractable stop plunger .276 on the casting 256. Thereafter the plunger 254 is operated again to clear the openings in the upper mould for the reception of fresh pins.