Manipulator arm having co-ordinated extend/retract motion

Claim 2

A manipulator arm assembly comprising; (a) a first arm member having a proximal end and a distal end, (b) a second arm member having a proximal end and a distal end, (c) a wrist member having a proximal end and a distal end, (d) a shoulder shaft at said proximal end of said first arm member supporting said first arm member for extend/retract rotation relative thereto about a first axis, (e) an elbow shaft connecting the distal end of said first arm member to the proximal end of said second arm member, said elbow shaft being fixed against rotation relative to said second arm member and being rotatable relative to said first arm member to permit extend/retract rotation of said second arm member relative to said first arm member about a second axis which extends parallel to said first axis, (f) a wrist shaft connecting the distal end of said second arm member to the proximal end of said wrist member, said wrist shaft being rotatable relative to said second arm during extend/retract rotation about a third axis at the distal end of said second arm member and means for releasably securing the wrist member against rotation relative to said wrist shaft, said first and third axes being equally spaced from the second axis, said wrist member projecting outwardly from said third axis in a first radial direction with respect to said third axis, (g) extend/retract actuator means mounted on said first arm member and drivingly connected to said shoulder shaft for rotatably driving said first arm member relative to said shoulder shaft for rotation about said first axis at a first angular velocity, (h) integrated first and second power transmission means for effecting extension and retraction of said arms in response to operation of said extend/retract actuator means, (i) said first power transmission means extending from said shoulder shaft and drivingly connecting said shoulder shaft and said elbow shaft to rotatably drive said second arm member about said second axis, at a second angular velocity which is twice said first angular velocity but in the opposite direction to that in which said first arm member is driven about said first axis, as said actuator means drives said first arm member about said first axis, (j) said second power transmission means drivingly connecting said elbow shaft and said wrist shaft to rotatably drive said wrist member about said third axis at an angular velocity equal to said first angular velocity but in the same angular direction as said first power transmission means drives said second arm member about said second axis whereby the wrist joint at the distal end of said second arm member is driven in a straight path which extends radially from said first axis during both extension and retraction of said arm assembly and said wrist member is driven relative to said second arm member so as to be retained in a position extending in said first radial direction relative to said third axis as said arm assembly is extended and retracted in use, (k) shoulder pitch means mounted on said shoulder support and drivingly engaging said shoulder shaft in advance of said first power transmission means whereby said shoulder shaft may be rotated to adjust the pitch of said first arm member without effecting movement of said first transmission means relative to said shoulder shaft, and (l) wrist pitch drive means mounted on said wrist member and drivingly engaging said wrist shaft, said wrist pitch drive means being operable to drive said wrist member about said wrist shaft to effect adjustment of the angular disposition of the wrist member with respect to said second arm member,

Claim 3

Claim 2. A manipular arm assembly comprising; (a) a first arm member having a proximal end and a distal end, (b) a second arm member having a proximal end and a distal end, (c) a wrist member having a proximal end and a distal end, (d) a shoulder shaft at said proximal end of said first arm member supporting said first arm member for extend/retract rotation relative thereto about a first axis, (e) a compound elbow shaft connecting the distal end of said first arm member to the proximal end of said second arm member for extend/retract rotation about a second axis which extends parallel to said first axis, said compound elbow shaft comprising a first section and a second section which are axially aligned and independently rotatable about said second axis, said first section being rotatable relative to said first arm member and secured against rotation relative to said second arm member, (f) wrist pitch drive means mounted on said first arm member and normally securing said second section of said elbow shaft against rotation relative to said first arm member, said wrist pitch drive means being operable to rotatably drive said second section relative to said first arm member and said second arm member, (g) a wrist shaft connecting the distal end of said second arm member to the proximal end of said wrist member, said wrist shaft being rotatable relative to said second arm member for rotation about a third axis at the distal end of said second arm member, said first and third axes being equally spaced from said second axis, said wrist member projecting outwardly from said third axis in a first radial direction with respect to said third axis, (h) extend/retract actuator means mounted on said first arm member and drivingly connected to said shoulder shaft for rotatably driving said first arm member relative to said shoulder shaft for rotation about said first axis at a first angular velocity, (i) integrated first and second power transmission means for effecting extension and retraction of said first and second arm members in response to operation of said extend/retract actuator means, (i) said first power transmission means extending from said shoulder shaft and drivingly connecting said shoulder shaft and said first section of said elbow shaft to rotatably drive said second arm member about said second axis at a second angular velocity which is twice said first angular velocity but in the opposite direction to that in which said first arm member is driven about said first axis, as said extend/retract actuator means drives said first arm member about said first axis, (k) said second power transmission means drivingly connecting said second section of said elbow shaft and said wrist shaft to rotatably drive said wrist member about said third axis at an angle of velocity equal to said first angular velocity but in the same angular direction as said first power transmission means drive said second arm member about said second axis whereby the wrist joint at the distal end of said second arm member is driven in a straight path which extends radially from said first axis during both extension and retraction of said arm assembly and said wrist member is driven relative to said second arm member so as to be retained in a position extending in said first radial direction relative to said third axis as said arm assembly is extended and retracted in use, (l) shoulder pitch drive means mounted on said shoulder support and drivingly engaging said shoulder shaft in advance of said wrist powered transmission means whereby said shoulder shaft may be rotated to adjust the pitch of the first arm without effecting movement of the first transmission means relative to said shoulder shaft, (m) said wrist pitch drive means being operably connected to said wrist shaft by said second power transmission means whereby said wrist pitch drive means is operable to rotatably drive the wrist pitch shaft about said third axis to effect adjustment of the angular disposition of the wrist member with respect to said second arm member.