Wheel lift apparatus for towing vehicles

Claim 1

A wheel lift towing apparatus for the rear end of a tow truck or other towing vehicle for engaging the wheels of a vehicle to be towed, comprising: means for mounting the apparatus at the rear end of the tow truck; boom means extending rearwardly of the mounting means; carriage means on the rear end of the boom means for engaging the wheels of the vehicle to be towed and for lifting the vehicle; and complementary interengaging means between the mounting means and the front end of the boom means for guiding upward lifting movement of the boom means relative to the mounting means and for effecting angular upward movement of the rear end of the boom means and the carriage means greater than the upward movement of the forward end of the boom means, said complementary interengaging means including forwardly inclined, upwardly extending ramp means on said mounting means, the ramp means being of generally uniform cross section along the length thereof and being defined by a pair of inwardly opening parallel slots, a generally vertical post member of generally uniform cross section disposed at the front end of the boom means, a pair of follower rollers mounted directly to the upper end of the post member, one of said roller members being engageable within each of said inwardly opening slots for riding upwardly therealong and said rollers defining the pivot axis of the post member, and fixed fulcrum means on the mounting means at the base of the inclined ramp means for bearing against the front side of said vertical post member of the boom means, whereby angular upward tilting movement of the boom means is effected in response to said relative upward lifting movement of the boom means with said rollers defining both the upward guide means for the boom and the pivot point for the boom.