| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a simple and low-cost jack capable of being used under a severe working environment and of confirming the displacement of a piston rod of the jack during work at any time. <P>SOLUTION: This jack is provided with; a jack body; a piston rod fitted in the jack body to freely reciprocate; a protection cover having an inner circumference lager than an outer circumference of the jack body, fixed on a vicinity of a tip part of the piston rod at one end thereof, and covering at least one part of an outer circumference side surface of the open jack body by another end; and a calibration part provided on an outer circumference side surface of the jack body. The reciprocating displacement of the piston rod can be indicated by another end of the protection cover and the division part. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
