Patent GB-594420-A (GB)
Title: Improvements in or relating to machines for inspecting work-pieces
IPC: B07C5/08
Filed: 1945-03-15
Abstract: 594,420. Gauging - -apparatus; counting apparatus. SIGMA INSTRUMENT CO., Ltd., and LOXHAM, J. March 15, 1945, No. 6589. [Classes 106 (i) and 106 (ii)] A sorting - machine comprises measuring devices disposed upon a bed to measure several dimensions of a workpiece and a workpiece holder arranged to receive a workpiece and to displace it to, and withdraw it from, a gauging position, electrical circuits. being associated with each measuring device so as to control electromagnetically-operated deflecting means according to whether the corresponding dimension is over- or under-size or nominally correct. In the machine shown, feeding mechanism (see below) contained in the built-up front portion 32A of the bed feeds workpieces from a hopper H to a position in which three of their dimensions are measured by the measuring devices 6, 6, 7 which are adjustably mounted on vertical pillars 2. The measuring devices may be of the type described in Specification 594,450 and each comprises a reference anvil 11 and a primary gauging anvil 12. A lever operated by the anvil 12 engages either or neither of a pair of adjustable contacts arranged within the device according to whether the dimension measured is over- or under-size or nominally correct. The contacts of each device are associated with " plus " and " minus " relays, a starting winding of either relay being operated by closure of the corresponding contact. The starting winding operates to bring a main winding into circuit which advances a counter by one step and illuminates an indicating lamp. " Plus " and " minus " counters (e.g.) 28, 29, associated with each measuring device, and corresponding indicating lamps (e.g.) 26, 27 are carried by a panel 10 which is mounted on the vertical pillars 2 and has engraved upon it an explanatory diagram W of a workpiece. A master switch operated by a cam, driven by an electric motor synchronously with the feeding mechanism, prevents the closing of the relay circuits until the contacts of the measuring devices have been set by the workpiece, so that sparking is prevented while the workpiece is being positioned. The operation of the main winding of any " plus " or " minus relay results also in the deflection of a " plus or '' minus " electromvgneticallycontrolled shutter. The " minus " shutter is arranged in front of the " plus " shutter in a shoot 35 into which the workpiece is dropped on withdrawal from the measuring devices so that, if any dimension of a workpiece is undersize, the workpiece will be deflected into a shoot 34 while, if no dimension is under-size, but one or more are over-size, the workpiece will be deflected into a second shoot 33. If neither shutter operates, the workpiece is acceptable and passes through the shoot 35. When a workpiece is. in the measuring position, a light pointer 36 is displaced to close a switch with which is associated a relay which operates a counter 32 carried by the panel 10. Moreover, unless this switch is closed the circuits associated with the other relays remain open so that the relays are not operated if the machine is run without a supply of workpieces. The master switch ensures that the measuring device contacts are electrically disconnected as a workpiece is being withdrawn from the measuring devices, so that there is no indication of an under-size workpiece during this process. A further counter 31 and lamp 30 are carried by the panel 10 to indicate the acceptance of a workpiece and are associated with a relay, the circuit of which is opened if either deflecting" shutter is operated. All relay circuits are opened by the master switch before another workpiece is placed between the measuring devices. A switch (e.g.) 175 is provided on the panel 10 adjacent to each " plus " or " minus " lamp and, since these switches are in the circuit of the corresponding deflecting shutters; the effect of over- or under-size in any dimension may be cancelled by opening the corresponding switch. The feeding mechanism (Fig. 3, notshown) comprises a reciprocating plate having an aperture adapted to receive one workpiece from the hopper at each stroke and to feed it onto a pair of supporting ridges formed one on each of a pair of slidably-mounted plates. These plates are controlled individually by cams driven by the electric motor so that they carry the workpiece to the gauging position and then, when returning, separate to drop the workpiece into the shoot to be sorted. According to the Provisional Specification, which refers to Specification 555,364, the sorting may be done by hand as indicated by lamps on the panel 10 and also counters may be provided to register the numbers of workpieces to be rectified and rejected respectively.