Drive device for travel assembly

Claim 2

A drive device comprising: (a) a travel assembly which, in use, reciprocates along guide shafts; (b) a reversible motor; (c) a drive pulley operatively connected to said reversible motor; (d) a first pulley; (e) a second pulley disposed at a predetermined position such that said second pulley and said first pulley are disposed on opposite sides of said travel assembly; (f) a wire-like member extending around said first pulley, said second pulley, and said drive pulley successively; and (g) an operating means provided on said travel assembly at a position between said first pulley and said second pulley, said operating means being resiliently connected to one end of said wire-like member to exert an absorbing force on said wire-like member when said travel assembly is moved to cause slack side tension of said wire-like member and to exert a blocking force on said wire-like member when said travel assembly is moved to cause tight side tension of said wire-like member.

Claim 3

A drive device according to claim 1 wherein: (a) said operating means comprises: (i) a third pulley rotatably supported by a one-way clutch on a portion of said travel assembly; (ii) a first wire terminal fixably supported by a fixing member on said travel assembly; and (iii) a second wire terminal connected to a resilient means for absorbing the elongation or sagging of said wire-like member and (b) said one-way clutch is arranged such that, when said third pulley is rotated to cause the slack side tension of said wire-like member, said third pulley is driven in response thereto under the resilience of said resilient means, thereby exerting an absorbing force on said wire-like member, but, when said third pulley is rotated to cause the tight side tension of said wire-like member, said third pulley is held by said one-way clutch against said tight side tension, thereby exerting a blocking force on said wire-like member.

Claim 4

A drive device according to claim 2 wherein: (a) said first wire terminal is fixably supported to allow the length of said wire-like member to be adjustable; (b) said resilient means is detachably engaged between said second wire terminal and a fixed portion on said travel assembly; and (c) said device further comprises a detachably fixing means for fixing said second wire terminal to said travel assembly.

Claim 5

A drive device according to claim 3 wherein: (a) said device comprises a pair of parallel wire-like members and a pair of operating means and (b) each one of said pair of wire-like members is trained over said first pulley and is connected to said travel assembly by a corresponding one of said pair of operating means.

Claim 6

A drive device according to claim 1 wherein said first pulley serves as a driving pulley.

Claim 7

A drive device according to claim 5 wherein: (a) said device comprises a pair of parallel wire-like members and a pair of operating means and (b) each one of said pair of wire-like members is trained over said first pulley and is connected to said travel assembly by a corresponding one of said pair of operating means.

Claim 8

A drive device according to claim 1 wherein said second pulley serves as a driving pulley.

Claim 9

A drive device according to claim 7 wherein: (a) said device comprises a pair of parallel wire-like members and a pair of operating means and (b) each one of said pair of wire-like members is trained over said first pulley and is connected to said travel assembly by a corresponding one of said pair of operating means.

Claim 10

A drive device according to claim 1 wherein: (a) said device comprises a pair of parallel wire-like members and a pair of operating means and (b) each one of said pair of wire-like members is trained over said first pulley and is connected to said travel assembly by a corresponding one of said pair of operating means.

Claim 11

A drive device according to claim 1 wherein: (a) said first pulley is positioned beyond the end point of movement of where said travel assembly is connected to said wire-like member in a direction towards said second pulley and (b) said second pulley is positioned beyond the end point of movement where said travel assembly is connected to said wire-like member in a direction toward said first pulley.

Claim 12

A drive device according to claim 1 wherein: (a) said operating means comprises: (i) a pair of pulleys; (ii) a pair of one-way clutches arranged on said travel assembly, each one of said pair of one-way clutches being associated with a corresponding one of said pair of pulleys; and (iii) a wire terminal connected to each end of a resilient means for absorbing the elongation or sagging of said wire-like member and (b) said pair of one-way clutches are arranged such that, when one of said pair of pulleys is rotated to cause the slack side tension of said wire-like member, said one of said pair of pulleys is driven in response thereto under the resilience of said resilient means, thereby exerting an absorbing force on said wire-like member, but, when said one of said pair of pulleys is rotated to cause the tight side tension of said wire-like member, said one of said pair of pulleys is held by one of said pair of one-way clutches against said tight side tension, thereby exerting a blocking force on said wire-like member.