Patent GB-1432154-A (GB)
Title: Tensile testing apparatus and method
IPC: G01N3/08
Filed: 1973-05-22
Abstract: 1432154 Tensile testing machine; thickness gauges UNIROYAL Inc 22 May 1973 24246/73 Headings G1M and G1S An intermittently driven chain conveyer 18, Fig. 7, carries cradles 34 holding rubber samples 42 having reduced middle portions 44, Fig. 20 and end gripped shoulders 42a, 42b adapted to be held by tensile test jaws 46, 48, Fig. 21. These samples move beneath a marking apparatus 20, see also Figs. 12-15 (not shown) having black and white ink fed stripe marking wheels 74, 76. After the samples have been so datum marked, (Fig. 15) they are measured by a thickness gauge 22, see also Fig. 16 which comprises an anvil 110 vertically movable through a hole in each cradle 34 by pivoting a cross-bar 116 by means of air cylinders 122, 124 supplied by airlines 130, 132 controlled by a cam mechanism (134) Fig. 10 (not shown) operated by the conveyer drive motor (50) and actuating a lever (138) and valve (140). The gauge also includes a sensor 142 which is connected to a gauge 144 connected to a potentiometer 146 and an analogue circuit and computer (30). The testing is initiated in the proper timed sequence by the actuating of the air valve (140). After thickness testing the sample is conveyed beneath carriage mounted photo-cell scanners. Each such carriage 148a, 150a, Figs. 4, 6, 7, mounts a measuring scanner 24 comprising a light 152 and a photo-cell 154 which is reciprocated by a chain 156. When the photo-cell 154 detects a dark stripe on a sample, a solenoid 174, Fig. 6, is energized to engage a pivoted lever 173 with a friction wheel 172 driven by a chain 182, Fig. 4, and a sprocket 180 from a motor 178. Rotation of the shaft 190 of the respective friction wheels driving the scanner carriages is permitted only during a test when the respective lever 173 is set to engage a wheel by a solenoid 174. The sprocket 164 rotates shaft 192 which drives with lost motion an encoder disc 200 with holes therein Fig. 18, which move progressively past a photoscanner 218, 219 feeding information to the computer (30). During the time the scanner 24 is moving in operative association with the datum marks of the specimen, the sample is gripped and tensile tested by a fixed jaw (48), Fig. 20 and a movable jaw 46. Each jaw comprises a base part 216, Fig. 21, and an upper pivoted lever part 220 clamped together by gas pressure through line 222 acting on a piston 224. The jaws are driven apart on a screw by motors, Figs. 5, 6. Conduits 230, 232 apply a cleaning gas blast in the vicinity of the jaws and the lower jaw carried a conduit for air blasting the sample from the grip, the conduits leading to an external timed air-pressure source. The moveable jaw abuts the scanner carriage and returns it to a starting position so that as a pull proceeds and the black and white stripes move apart the scanners follow the left and right stripes respectively and the holes in the disc 200 each equalling 0.1 of an inch are passed successively in front of the photocell which sends a stream of pulses to a strain register in the computer (30) which produces a punch card read-out of stress, strain, modulus and so on. When the last digit is punched out a switch starts a timer which rapidly returns the puller jaw to a zero position and air blasts out the jaws. The machine then either stops if under manual control or tests the next sample if automatically controlled. An electrical control circuit is shown and described for the apparatus.