Suspension for mobile ramp structure

Claim 1

A mobile ramp capable of being towed comprising in combination: a. an elongated ambulatory structure having a substantially planar and rectangular top surface, b. a pair of vertically adjustable first wheel means disposed on axle means at a substantially intermediate longitudinal portion of said elongated structure, c. self aligning second wheel means disposed substantially intermediate said first wheel means and the trailing end of said ramp, d. releasable shock absorbing means including pre-loaded spring means pivotally connected to said axle means and pivotally connected to the underside of said structure forwardly of said axle means, to facilitate transport of said ramp over towed distances, e. arm means pivotally connected at one end to said axle means and means pivotally connecting the opposite end of said arm means to the underside of said structure rearwardly of said axle means, f. fluid motor means pivotally connected at one end to an intermediate point of said arm means and the opposite end of said motor means being pivotally connected to the underside of said structure intermediate the underside connections of said shock absorbing means and said arm means, g. fluid reservoir means communicating with said fluid motor means, whereby said arm means, said shock absorbing means, and said fluid motor means in the open position with said reservoir means, coact together to provide suspension and shock absorbing means for said ramp when it is being towed, and whereby, when said shock absorbing means is released from said combination, said arm means and said fluid motor means provide suspension for said ramp along with means for vertically adjusting the forward end of said ramp by either raising or lowering the intermediate portion of said ramp.