Zarley, McKee, Thomte, Voorhees & Sease
Two-masted lifting apparatus
 A two-masted lifting apparatus particularly adapted to lift a weighty object such as a vehicle or the like to a desired height and then incline it at a desired angle in either direction. The two-masted lifting apparatus comprises two opposing upright masts on each of which a carriage for supporting the object is slidably mounted and a height-difference detecting means. Both carriages are independently hoisted up or down along the respective masts by separate driving means, and the height-difference detecting means is adapted to detect the height-difference between the two carriages and restrict the further ascent or descent of one of the two carriages when the height difference between them has reached a predetermined limit. 
Yasui Sangyo Col. Ltd.
B B
B66F B66F
inventional inventional
Matsuo
Nishimura