Patent GB-691459-A (GB)
Title: Improvements in and relating to filament mount testing apparatus
IPC: H01J9/42
Filed: 1952-02-19
Abstract: 691,459. Making electric incandescent lamps. BRITISH THOMSON-HOUSTON CO., Ltd. Feb. 19, 1952 [Feb. 23, 1951], No. 4385/52, Class 39(ii) The filament mounts of electric flash lamps, incandescent lamps, and similar devices are tested mechanically for continuity and strength of joint between filament 7 and leading-in wires 5, 6 by one or more movable fingers arranged to be inserted between the leading-in wires and then'moved laterally against the side of one or both of the latter by magnetic means which operates with progressively increasing force to bend the leading-in wires out of position should the filament be ruptured or defectively connected. The apparatus may also embody an indicating lamp in a circuit which is closed in the event of a rupture of the filament or filament joint, and a solenoid may be energized simultaneously to effect the opening of the jaws holding the faulty mount in a lamp-making machine, As shown in Fig. 2, a pair of fingers 3, 4 are mounted at the outer ends of a pair of levers 8, 9 pivoted on vertical studs 12, 13 on the upper surface of a slide 10 which is movable forwardly and rearwardly within guideways in a bracket 11 mounted on the machine frame. Operation of the slide 10 is effected through a push rod 17 which is linked by a lever 21 to a connecting rod 23, the inner end of the push rod being in abutment with a compression spring 20. Fig. 3, within the guiding recess for the push rod within the slide. The push rod 17 carries a vertical shank 18 mounting a wedge 14 which is arranged to bear upon rollers 15, 16 mounted on the rearward or inner parts of' the levers 8, 9, thereby holding the fingers 3, 4 close together. this position being maintained while the push rod is moving the slide 10 outwardly to place the fingers 3, 4 between the leading- in wires 5. 6 of a mount located between the jaws,43, 45, Fig. 1, of an adjacent work holder. Further movement of the slide 10 is arrested by a stop-screw 24 thereon meeting a stop 26 on the supporting bracket 11, but the connecting rod 23 continues to move the push rod within the slide 10 and against the pressure of the spring 20, thereby withdrawing the wedge 14 from between the rear portions of the levers 8, 9, so that those portions can be moved towards .one another by the mutual attraction of permanent magnets 27, 28 adjustably mounted therein. The fingers 3, 4 at the other end of the respective levers are thus moved apart and exert lateral pressure upon the adjacent leading- in wires 5, 6. A defective mount is indicated by the fingers 3, 4 moving so far apart that contacts 32, 33 on the rearward parts of the levers 8, 9 are brought together and close the circuit of an alarm bell or lamp. At the same time a solenoid 35, Fig. 1, is energized to effect the release of the faulty mount. The armature 36 of the solenoid is pivoted to a bell-crank lever 37 provided with a roller 39 arranged to engage the end of a lever 40 which is secured to a vertical spindle 49 extending down through the work-holding head, the movement of the lever 40 being opposed by the end of a torsion spring 41 engaging a post 42 extending downwardly from the lever 40. When the solenoid 35 is energized, a movable jaw 43 secured on the lower end of the spindle 49 is swung outwardly from a fixed jaw 45 and at the same time, the vertical post 42 is moved around in an arcuate slot 51 until it meets and opens a movable jaw 44 holding the exhausting tube 48 against a fixed jaw 46. The apparatus may be located at a work-station of the mountmaking machine described in Specification 390,807.