Patent GB-1236006-A (GB)
Title: Improvements in or relating to wrist joints for remote control master-slave manipulators
IPC: G21F7/06
Filed: 1969-11-03
Abstract: 1,236,006. Manipulators. CENTRAL RESEARCH LABORATORIES Inc. 3 Nov., 1969 [8 Nov., 1968; 8 April, 1969; 4 June, 1969], No. 53865/69. Heading B8H. [Also in Division F2] A wrist joint for a remote control masterslave manipulator includes a housing comprising first and second portions 11/12 and 13/14, take-up drums 42-44 for motion transmitting tapes being supported in the first housing portion 11/12 for rotation independently of one another, each drum having a pair of circumferential channels on which respective tapes of pairs of the tapes are wound in opposite directions, and a gear 45 connected to each drum, each gear 45 being operatively connected to a respective gear train in the second housing portion 13/14, the housing portions being separable together with the gearing contained therein. Each drum consists of two portions 42, 44 angularly adjustable one relative to the other to tension the pair of tapes associated therewith, the gear 45, being integral with the drum portion 42. A yoke 24 supported in the lower part of the second housing portion by trunnions 23 carries a shaft 26 which rotatably supports a tubular shaft 18 adapted to carry a handle or tong means (not shown). A bevel gear 19 on the shaft 18 meshes bevel gears 29 rotatable about the trunnions 23 and secured to gears 32. Pins 62 in the gears 29 limit rotation thereof. In Fig. 2, the gears 45 are connected to the gears 32 by respective trains 37, 35, 34 in the second housing portion. Rotation of the two drums in unison pivots the shafts 18, 26 about the trunnions 23. Rotation in opposite directions at the same speed rotates the shaft 18 about its own axis. Other motions of the drums produce combined twisting and elevation of the shaft 18. A pulley 63 and two pulleys 65 guide a tong cable (not shown). A tongue 66 aligns the first and second housing portions. In Figs. 7-9, an intermediate housing portion 70 separates the first and second housing portions to provide a seal between them. Each gear 45 is connected to a respective gear 32 by gears 37A, 75, 74, a shaft 72, and gears 71, 35A, all in the portion 70 (Fig. 8). In the first housing portion a further drum 95/96 for a pair of tong control tapes is bolted to a gear 97. In the second housing portion, a gear 105 (Fig. 9) is connected to a tong control gear 120 by gears 106, 109, 112, 113, 115 and a shaft 116 rotatable in the shaft 26. Gears 100, 101, 74, a shaft 72, and a gear 71, all in the portion 70 connect the gears 97, 105. Each shaft 72 runs in two sealing rings 80 housed in retainer rings (81), (Fig. 14, not shown), the space (88) between the rings being supplied with oil from a reservoir (85) pressurized by spring-loaded bellows (91). A corrugated tubular sealing boot is secured to the portion 70 (Fig. 15, not shown) or connected thereto by a rotary joint incorporating sealing rings (134), (Fig. 16, not shown). The embodiment of Figs. 18-20 allows continuous rotation of the shaft 18 independently of the transmission tapes by an electric motor (205), (Fig. 21, not shown) mounted on an intermediate housing portion 170. Each gear 45 is connected to its respective gear 32 by gears 172, 179, 180, bevel gears 183 on radial shafts 185 in a ring gear 186, and gears 188, 189, 171, all in the housing portion 170, and gears 38B, 37B, 35B, 34B in the second housing portion. A gear 195 drivable by the motor (205) meshes both the gears 186 and carries a ratchet wheel 196. Pawls (197, 198), (Fig. 19, not shown) either both act on the ratchet wheel to hold it against rotation, or one is held clear to allow rotation in one direction. With the gear 195 locked, the gearing connects the tape drums to the shafts 18, 26 normally. With the tape drums stationary, the gear 195 is rotated to rotate the shaft 26 in a selected direction.