Patent GB-913958-A (GB)
Title: Testing and sorting apparatus
IPC: B07C5/344
Filed: 1960-04-20
Abstract: 913,958. Valve multi-stable switching circuits. SYLVANIA ELECTRIC PRODUCTS Inc. April 20, 1960 [April 20, 1959], No. 13873/60. Class 40 (6). [Also in Groups XXX and XXXVI] In an apparatus for subjecting elements (semi-conductor diodes) to a succession of tests and classifying them in accordance with the results, the element is carried mechanically to each test position and the result of each test is stored in a memory, the stored results of an element which has been submitted to all the tests being compared with a set of test references to determine its classification and open the appropriate bin. Diodes 20, Fig. 2, are dropped on to an insulated V-block 11 through a feeder 12 which is fed from a hopper and includes an escapement 33, and are conveyed to test positions 1-4, Fig. 1, by a conveyer chain 22 of a conveyer 10, the diode connecting wires traversing ramps 49, 50, Fig. 3, at the test position, to make contact with metallic connecting surfaces 51, 52. Automatically acted hold-down members 53, 54 are provided. The different respective tests on the diodes on the four positions are initiated by the application of a pulse t 1  from master timer 61 to the test circuits A-D and the results are applied to a memory 66, current on a respective one of the output lines I 1 -I 4  of an input and output selector 64 positioning the information in the store and reading out the results of the tests on the diode in the last test position. The memory, Fig. 6, comprises a block of sixteen bi-stable circuits 92, and the information is positioned in the store by a group of sixteen " and " gates. A further group of sixteen " and " gates 93 is provided to facilitate read-out of the tests on a single diode over lines TD a4 - TD d4 , and an " or " gate is provided in each line to isolate the " and " gates from each other. The outputs are each applied to six parallel " and " gates 100, Fig. 7, which are sequentially opened by pulses from a comparator scanner 73 in response to a pulse t 3  from the master timer 61, and the group of outputs are sequentially compared with desired test results set into the comparator by opening or closing contacts A-D in switches 101, the closed contacts also determining the number of inputs required to open its associated and gate. The most desired set of conditions is set in position 1, and when the bi-stable circuit D1, 103 is triggered to its 1 condition by a diode having met these requirements " or " gate 105 passes an output to all the " unless " circuits 104 associated with the rest of the output lines D2-D6 so that an output appears on one only of the lines. This output is applied via a cathode follower to an appropriate thyratron having a bin-opening solenoid in its anode circuit, and the diode is dropped into the appropriate bin after being lifted by a ramp from its V-block carrier 11. In an alternative arrangement described with reference to Figs. 11-14 (not shown), the test results are fed into a shaft register and the memory read out is applied directly to the programming switches. An output on any of the lines D 1 -D 6  in this arrangement is caused to switch the remaining bi-stable circuits to their O condition. Arrangements for using 10 cathode, two-guide counting glow transfer tubes for producing the successive outputs on leads I 1-4  and S 1-6  are described with reference to Figs. 9 and 10 (not shown).