Patent ID: 7210361

Claim:
A device for measuring the tightness of a transmission belt, comprising: a hilt provided with a handle extended vertically to an axis of said hilt, a sleeve, and a retractable axle whose upper portion is further provided with a screw thread; an insertion tube, connected to said retractable axle by screwing, whose inner space defining a passage, said passage having an upper screw-thread section to be engaged with said screw thread on said retractable axle, said passage being further provided with a lower screw-thread section, said insertion tube further including surface graduations for inspection; a frame, attached to a bottom surface of said insertion tube, having a central through hole and two belt-passing slots respectively on two side arms of said frame, a rotatable shaft being connected to each of said belt-passing slots; a retaining piece having an uprightly erected screw-thread projection for connecting said insertion tube and a through hole for passing said retractable axle; and an engaging piece attached to a bottom terminal of said retractable axle; whereby a belt will be inserted through said belt-passing slots of said frame and brought into contact with said engaging piece by rotating said hilt and therefore driving said retractable axle downwardly till said engaging piece touches a top surface of said belt when a first graduation is registered, whereby said retractable axle will be moved downward continuously by rotating said hilt till said belt attains a predetermined state tightness when a second graduation is registered, and whereby said first and second graduations will be used to determine the tightness of said belt for a future adjustment.