GB444933A - Improvements in and relating to machines for testing stems for electric incandescent lamps and similar tubular articles - Google Patents

Abstract

444,933. Testing valves before putting into service. BRITISH THOMSONHOUSTON CO., Ltd., Crown House, Aldwych, London. June 11, 1935, No. 16813. Convention date, June 12, 1934. [Class 135] [See also Group XI] A device for detecting the absence of an inlet or exhausting-aperture in a stem for an electric lamp, or similar tubular article such as the stem of a valve for a cycle tyre, comprises an air line which is adapted to engage the exhausting-tube of the stem so that air under pressure can be forced through the line and escape normally through the exhausting- aperture, the absence of an aperture in a stem causing an increase of pressure which produces the expansion of bellows operating controlling- mechanism for indicating the presence of the defective stem. A pipe 31 connected to a source of air under pressure is connected through a T-joint 30 to a bellows 32 and pipe 28 which is connected by a flexible hose-29 to a tubular plunger 12 provided with a rubber tip or nozzle 11 adapted to be lowered into engagement with the exhausting-tube 13 of a lamp stem 10. The plunger 12 is slidably mounted in a horizontal bracket 14 and is lowered in two movements on to the exhaust tube 13, first by a lever 18 which engages a pin 15 on a clamp 16 on the plunger 12 and lowers the pin into contact with a latch 17, the lever 18 being turned by a rod 20 operated by mechanism not shown ; the latch 17 being subsequently withdrawn by a rod 24 operated by a rocking- lever 23 to allow the plunger 12 to drop until the tip 11 engages the exhaust tube. The lever 23, through an arm 37 projecting laterally therefrom, controls the movement of a pendulum 36 provided with an upper extension arm 38, the lower end of the pendulum forming a latch 40 adapted, in the vertical position of the pendulum, to arrest the vertical movement of a cam-operated rod 41 and disengage a coupling between a driving wheel 42 and driven wheel 43 connected to a cam-shaft 47. The pendulum is brought into its vertical position by a sliding rod 35 which is moved by the expansion of the bellows 32 and engages the pendulum arm when a defective stem is beneath the tip 11 of the air pipe 12.