Patent GB-880152-A (GB)
Title: Remote control manipulators
IPC: B25J19/00
Filed: 1959-09-08
Abstract: 880,152. Toothed gearing. GENERAL MILLS Inc. Sept. 8, 1959 [Sept. 19, 1958], No. 30680/59. Class 80 (1). [Also in Group XL (a)] In a remote controlled manipulator in which movements of the human arm and hand are simulated the several members, e.g. upper arm, lower arm and wrist are connected to one another for relative pivotal or rotational movement and a driving mechanism is provided for each connection, the driving mechanism comprising a differential planetary gear speed reducer having a planetary gear assembly and input and output ring gears mounted for relative rotation coaxially of the axis of relative movement situated at the said connection, said planetary gear assembly being rotatable within the ring gears and the input and output ring gears being respectively secured to the two manipulator members having relative movement at the said connection, and a drive motor mounted on one of said members for rotating the planetary gear assembly thereby causing relative movement of the said two members. The arrangement enables a motor rotating at e.g. 6,000 r.p.m. to cause relative movement of two connected members of the manipulator at speeds as low as 1 r.p.m. As shown in Fig. 1, a manipulator 10 has a hand member 12 with grip members 14, 16, the member 12 being mounted for coaxial rotation on the longitudinal axis of a wrist member 18, 19. Member 19 is pivoted at 20 to a forearm member 22 which is pivoted at 24 to an upper arm member 26. Upper arm 26 is pivoted at 28 to a shoulder member 30 and member 30 is mounted for coaxial relative rotation on a support 32 carried by a vertically extensible support including telescoping members 34, 36. The support 34, 36 is carried by a carriage 38 supported for lateral translation on rail members 40, and the rails may be part of a travelling crane to provide translating movement at right angles to the rails. The various movements of the manipulator are performed by motors connected by a cable 42 to a remote control console 44. The driving mechanism between shoulder 30 and support 32 comprises, Fig. 2, a motor 100 secured to the support 32 and having a pinion 104 driving a gear 106 on a shaft 108 supported in bearings 110. Members 112, 114 of a planetary gear cage are rotatably supported on the shaft 108 and have three equi-angularly spaced shafts 116 (only one shown) each supporting a planetary gear unit 118. Each unit 118 comprises an input gear portion 120 and an output gear portion 124. The portion 120 engages the internal teeth of an input ring gear 122 secured to the support 32 whilst the portion 124 engages the internal teeth of an output ring gear 126 secured at 128 to the shoulder 30, a bearing 130 supporting the shoulder on the support. The ring gear 122 is normally stationary so that on rotation of the shaft 108 a sun-gear 136 on the shaft rotates the planetary gear units 118 by engagement with the input portions 120 and the cage 112, 114 rotates. The effective driving ratios between gears 120 and 122 and between 124 and 126 are slightly different by the use of a slightly different number of teeth or by differences in diameter of the respective gears. As shown, the output gears have slightly smaller diameters, and on account of this difference the shoulder 30 is rotated at a much slower speed than the shaft 108. An overload slipping clutch is provided and to this end the ring gear 122 is mounted for limited rotational movement on a bearing 134 and a plate 138 having a clutch facing 140 is secured to the gear 122. A fixed clutch plate 142 is held against the facing 140 by a cooperating surface 144 on a plate 146, the various clutch parts being held in axial engagement with one another by bolts 148 and springs 150. A somewhat similar driving mechanism for effecting movement about a longitudinal axis of the hand member 12 within the wrist member 18 is described with reference to Fig. 4 (not shown), whilst with reference to Fig. 5 (not shown) there is described the two driving mechanisms for effecting rotational movement about the axes 20, 24 of the forearm member 22 and wrist member 19. Both driving mechanisms are situated on the axis 24, rotation of the member 19 about axis 20 being through a chain 335 and sprocket 302. Specification 880,153 is referred to.