Patent GB-604531-A (GB)
Title: Improvements in or relating to the testing of electrical components in bulk
IPC: G01R31/01
Filed: 1945-11-26
Abstract: 604,531. Resistance, inductance and capacitance measurements; detecting faults. SPORING, P. A., PURSE, J. W., and TELEGRAPH CONDENSER CO., Ltd. Nov. 26, 1945, No. 31818. [Class 37] An electrical component to be tested is automatically moved from station to station in a series and at each or certain of such stations is temporarily connected in a circuit for the purpose of performing the required electrical operation at that station. An apparatus is shown in Fig. 1 for testing capacitors of the type enclosed within tubular containers from the ends of which leading-in wires protrude. An endless belt 1 has along its entire length a series of transverse angle members 2 and runs round a toothed driving wheel 3 and an idler pulley 4 which are mounted in bearings 5 on a framework 6. A motor 7 drives a sprocket 25 through reduction gearing and Geneva mechanism. The sprocket 25 drives the belt 1 intermittently by means of a chain 27 and gear-wheel 28, the amount of each movement being equal to the spacing between the angle members 2. The capacitors 30, Fig. 5, to be tested are fed to the righthand side of the belt 1, a single component being supported by each of the angles 2. The belt 1 travels over and rests on a pair of supports 31 and at the first station at which it is halted each of the leading-in wires 32 of the capacitor 30 is located between a fixed contact 33 and a movable spring contact 34, which is initially in a lower position than that shown so that neither of the contacts 33, 34 bears on the leading-in wires. Each of the spring contacts 34 is carried by a lever 35 which is rocked by means of a cam 42, cam roller 41, lever 39, link 38 and lever 37. The cams 42 are mounted on shafts 43, which are continuously driven through bevel gear from a shaft 18 driven from the motor 7 through a chain 16 and sprockets 14, 19. Rocking of the arms 35 lifts the spring contacts 34 so that the capacitor 30 is lifted from the belt and the leading-in wires 32 are gripped between the contacts 33, 34 and thereby connected in a testing circuit by which a test voltage of two or three times the working voltage is applied. The capacitor 30 is then lowered on to the belt 1 and carried forward to the second station where it is in position to be dealt with in accordance with the result of the test. At this station an ejector mechanism is provided comprising a lever 48 biassed by a spring 50 so that a roller 52 rests on a cam 51. This cam is loosely mounted on the spindle 43 to which it is connected by a slipping clutch. Rotation of the cam is normally prevented by a pin 56 on a detent lever 54 engaging a notch 58 in a disc 59 integral with the cam 51, the capacitor then passing to the next station for a further test. If, however, the capacitor breaks down under the flash test at the first station, a solenoid 60 is excited and attracts an armature 61 so that the pin 56 is lifted out of the notch 58 and the cam 51 is rotated. This cam is circular over most of its periphery, but has a depressed portion which engages the roller 52 at the same time as the capacitor 30 arrives at the second station. The ejector lever 48 is then actuated and the capacitor is ejected and falls down a shoot 47. The capacitors that remain on the belt pass through a series of stations 62 to 63, at each of which a charging voltage is applied so that the capacitor remains charged in spite of leakage. The charged capacitors arrive successively at station 64, where each is connected in a circuit for insulation testing, and then pass to an ejection station 65 where those that are below the permitted minimum value are ejected down a shoot 66. The remaining capacitors are then passed to testing and ejecting stations 67, 68, 70, 71, &c. at which they are subjected to capacitance tests and those falling within specified tolerances are segregated and ejected down separate shoots. The apparatus is applicable for the testing of other components, such as resistors or inductors. Specification 603,697 is referred to. Reference has been directed by the Comptroller to Specification 619,524.