Patent ID: 6050365
Filing Date: 2000-04-18
Classification: B66F

Abstract:
A scissors work platform lift machine, comprising:(a) a chassis;(b) a scissors lift mechanism having an upper end and a lower end mounted on said chassis;(c) a work platform mounted on said upper end of said lift mechanism; and(d) an electro-mechanical actuation arrangement for operating said lift mechanism between retracted and expanded conditions so as to move said work platform between lowered and raised positions, said electro-mechanical actuation arrangement being mounted to and extending between said chassis and said lower end of said lift mechanism and including a ballscrew shaft operable to rotate in a first angular direction and cause movement of said lift mechanism vertically toward said retracted condition and thereby movement of said work platform toward said lowered position and to rotate in a second angular direction opposite to said first angular direction and cause movement of said lift mechanism vertically toward said expanded condition and thereby movement of said work platform toward said raised position, said actuation arrangement further including a lower joint coupling a lower portion of said ballscrew shaft to said chassis for undergoing limited universal pivotal movement of said ballscrew shaft relative to said chassis as said lift mechanism is moved between said expanded and retracted conditions, said lower joint including(i) a ball support block having a pair of support pins mounted to and extending outwardly from and on opposite sides thereof for rotatable connection with a respective pair of collars mounted to said chassis; and(ii) a ball bearing block overlying said ball support block in forming a ball joint;(iii) said lower portion of said ballscrew shaft extending through said ball joint formed by said ball bearing block and said ball support block and adapted to move in a universal direction.