Patent GB-986386-A (GB)
Title: Apparatus for controlling an operation in a sequential manner
IPC: G01R27/02
Filed: 1961-04-19
Abstract: 986, 386. Sequential testing of resistors; measuring bridges. WESTERN ELECTRIC CO. Inc. April 19, 1961 [April 26, 1960], No. 14139/61. Heading G1U. Carbon-deposited resistors are automatically tested and sorted into a range of resistance categories, the testing and sorting being controlled by a chain of control delay-operated relays 110, 111, 112, 113 Fig. 4A, which are energized successively to insert additional resistors 70-73, respectively, into the arm J-M of a measuring bridge JKLM (resistor 30 under test is connected in arm J-K). When the bridge passes through balance, cycling of the control relays is stopped, and, dependent on the number of control relays operated, the resistor is sorted into its appropriate category tray during a subsequent cycle of the control relays. A contact # is closed automatically to initiate each cycle. It energizes a relay 116 and thereover the first control relay 110. Each control relay operates, after its delay period, locks, and energizes (except for the last relay 113) the succeeding control relay. Relays 80-83 are operated respectively by the control relays 110-113 to insert the corresponding resistors 70-73 in the bridge arm J-M. When the bridge passes through balance a thyraton 84 fires to energize a relay 109, prevent operation of any subsequent control relay in the chain, and it energizes the one of directing relays 130-133, Fig.4B, corresponding to the last control relay to operate. The operative directing relay energizes a corresponding selector relay in one of two groups of selector relays 140-143, Fig.4A or 150-153, Fig. 4B, which groups operate alternately. During the next cycle (during which the next resistor is being tested) the operative selector relay energizes the corresponding one of solenoids 46-49 to operate mechanism for directing the resistor into the correct category tray. The operated control relays 110-113, relays 80-83, and the operative directing relay 130-133, are returned to normal at the end of each cycle (to be ready for the next resistor test) and since the actual sorting is not effected until the next subsequent cycle two groups of selector relays are necessary in order to "store" a selection made during one cycle until the next cycle when the actual sorting is effected, the other group of selector relays operating during the said next cycle to "store" the category selection for the next resistor tested in the said next cycle and so on. The actual sorting could be effected n cycles after the measuring cycle in which case (n + 1) groups of selector relays would be necessary. Holding relays 160-163 maintain their respective solenoids 46-49 operated whenever consecutive resistors under test fall in the same category. Modification. In another embodiment, Fig. 7 (not shown), there is a "coarse" sorting followed by a "fine" sorting. Constructional features, Fig. 2. The contact f is operated by a cam F, driven by a motor 28 to give one cycle during each rotation thereof. The motor, through a Geneva mechanism 57, also steps an index wheel 26 between cycles through 30 degrees. A vibratory feed unit, Fig. 1 (not shown) advances the resistors through a sizing gauge, (which rejects undersized or broken resistors) to a Venturi feed unit, see Specification 969,511, which feeds the resistors one by one to the index wheel 26 at the X (load) position. Here the resistors 30 are housed in holes 29 in the wheel 26 between a pair of insulating backing plates, and when the test position is reached the resistor ends are gripped resolvently at 60 to connect them in the test circuit. The resistors are then advanced to the unload position Z where a jet of compressed air ejects the resistor from the wheel into its appropriate category tray selected by the operative solenoid 46-49.