Patent GB-214270-A (GB)
Title: Improvements in and relating to apparatus for making incandescent lamps and similar articles
IPC: H01J9/38
Filed: 1924-04-12
Abstract: 214,270. British Thomson-Houston Co., Ltd., (Assignees of Blake, H. D., and Geiger, W. J.i. April 12, 1923, [Convention date]. Regulating switches pneumatic actuation.- An exhausting machine for electric lamp bulbs &c. is combined with a sealing-in machine adjacent to it, the two being operated by one person; the various operations are effected automatically by electropneumatic means controlled by the operator; and the connection of the bulbs with the vacuum is effected without the use of rubber tubes, and through stop-valves actuated by solenoids. The commutator through which the operations are controlled comprises a cylinder formed of insulating blocks 90, Fig. 17. with peripheral metallic blocks 91 all connected by conducting pins and strips and adapted to engage brushes 93, Fig. 14, connected to terminals outside a box 87 containing oil within which the cylinder is mounted on bearings. The commutator shaft carries also a rotating disc 94, Fig. 16, coacting with a stationary disc 95, Fig. 15, having ports connected to the clamping cylinders, spider lifting cylinder, heating lifting cylinder and trough vacuum line. The commutator is rotated through a ratchet and a pawl operated by an arm 99 pivoted to a piston working in a vacuum.cylinder 101, the return of the arm being effected by a spring 102. Fig. 18 shows the electric circuit system, in which direct current leads 104, 106 are provided, the lead 104 being connected to a terminal R of the commutator, the other terminals S .. X. Z being respectively spare and corresponding with the rough pump, a leak detector, a dry air line, final pump and sealing and severing means. Circuit is first made through the solenoid of valve 77 of the rough pump, next, this circuit is broken and current supplied through one of the terminals U to a leak detector circuit comprising a pair of terminals 107 in a mercury U-tube connected to the vacuum manifold, the circuit being completed through these terminals only when a leaky lamp impairs the vacuum and causes the mercury to rise. A warning lamp 109 is then lit and a solenoid 110 energized to break the return circuit through the valves &c. across terminals 113 and close an alternative return circuit across terminals 114. At the same time, the commutator is speeded up. The vacuum for driving the commutator is derived from the line leading to the clamping cylinders, through a pipe 115 connected to a central port in a stationary disc 117 against which a ported disc 118 is rotated by gearing from the sealing-in machine drive. The stationary disc is formed with two peripheral ports which are connected with the central port intermittently by passages in the rotating disc. One of these two ports leads always through a pipe 124 to a valve 126 controlling the lead to the commutator vacuum cylinder 101, while the other port leads to this valve through a pipe 135 controlled by a solenoidal valve which is closed so long as the circuit through the valves 77, 78, 79, 83 is closed, and open otherwise. In the open position vacuum followed by relief of vacuum is transmitted to the valve 126 six times as frequently as in the closed position so that the leaky lamp may be quickly removed. The raising of the clamp plate 43 separates a connector 136 from terminals 137, de-energizing the solenoid 111 and allowing the terminals 113 to be again connected. In the absence of leaky lamps, rough vacuum and dry air are applied several times, after which a solenoid 138 is energized to complete an alternating current heating circuit through mercury contacts 32 and the tray heating coils in one position of the lamps, and a solenoid 142 subsequently energized to supply alternating current to the coils in a second position. Rotation of the disc 128 by depressing a pedal when the lamps are in the first position connects the main vacuum line 147 with the cylinder 101 and rotates the commutator and the disc 94 one notch. This opens the spider lift cylinder to air and allows the lamp trap to be lowered. Release and pressure of the pedal causes a further rotation, operating the clamping plate and lowering the heater cover. The release of the pedal connects the cylinder 101 with the clamping cylinder vacuum line until the end of the exhaust cycle, when air is admitted to the clamping lift cylinders and vacuum to the spider lift cylinder. The sealing-in machine shown is described in Specifications 8351/09 and 151.682, [both in Class 39 (ii), Electric lamps, Incandescent].