Patent ID: 7096651

Claim:
A thermo shrinkable film machine comprising: a base with first and second sidewalls on the base, two rails connected between the first and second sidewalls and a first block and a second block movably mounted to the two rails, each of the first and second blocks having a wheel which is adapted to contact a thermo shrinkable film on a shaft, a first rotatable rod rotatably extending through the first sidewall and having a first threaded section which threadedly extends through the first block, an end of the first rotatable rod connected to an end of a rotating piece rotatably received in a case located between the first and second blocks, a second rotatable rod rotatably extending from the second sidewall and having a second threaded section which threadedly extends through the second block, an end of the second rotatable rod connected to the other end of the rotating piece in the case, a driving wheel located at an outside of the first sidewall and connected to the other end of the first rotatable rod such that the first and second blocks are moved in opposite directions when rotating the driving wheel, wherein the rotating piece is a cylindrical member and has a groove defined radially in an outer periphery thereof, the case having a positioning member which is biased by a spring, the positioning member having a tip engaged with the groove.