Lift bed tandem axle trailer

Claim 2

A lift bed, tandem axle, trailer, comprising: a bed having a load supporting floor structure with opposite sides and front and rear ends; a pair of wheel support arms mounted for pivotal movement about a pair of longitudinally spaced apart transverse axes on each side of said bed for raising and lowering the bed with respect to the ground; an axle and wheel mounted at the outer end of each support arm for rolling support of said bed; a tongue extending forwardly of the front end of said bed having an outer end adapted to be hitched to a pulling vehicle for towing said trailer; load equalizing linkage means between each pair of said wheel support arms on each side of said bed comprising a first link pivotally connected at one end to the rear support arm eccentric of the mounting axis thereof and a second link pivotally interconnected to an opposite end of said first link and pivotally connected to the front support arm eccentric of the mounting axis thereof; lift means on each side of said bed for pivoting said support arms to raise and lower said bed, said lift means including a longitudinally extensible thrust member having one end pivotally connected to said second link at a point between the pivotal connections of said first link and said front support arm therewith, said thrust member having an opposite end interconnected with said bed; and shock absorber means for interconnecting the opposite ends of said thrust member and said bed permitting limited travel of said ends in opposite directions longitudinally of said thrust member, said shock absorber means including a bracket fixed to said bed and a pair of resilient cushion members on opposite faces of said bracket, and pressure pad means connected with said thrust member for compressive engagement with said cushion members permitting limited travel of said opposite end of said thrust member in response to pivotal movement of a wheel support arm on said bed during travel.

Claim 3

The trailer of claim 1 wherein said pressure pad means include a pair of pressure pads disposed against respective oppositely facing outer surfaces of said resilient cushion members for alternately compressing the same toward said bracket in response to forces executed by said thrust member in opposite directions on said pressure pad means.

Claim 4

The trailer of claims 1 wherein said thrust member comprises a fluid cylinder having a piston and rod slideably disposed therein, said ends of said thrust member formed by opposite end portions of said cylinder and said rod.

Claim 5

The trailer of claim 3 including removable travel lock means for mechanically fixing the relative position of said rod and said cylinder during travel of said trailer.

Claim 6

The trailer of claim 2 wherein said resilient cushion members are formed with a central bore aligned on a common thrust axis extending through openings framed in said bracket and said pressure pads, and including a rod extending through said bore of said cushion members, and said openings in bracket and pressure pads and means acting on said rod element for biasing said pressure pads toward said bracket.

Claim 7

The trailer of claim 5 including a connector assembly for interconnecting a rearward end portion of said rod element and said thrust member.

Claim 8

A lift bed, tandem axle, trailer, comprising: a bed having a load supporting floor structure with opposite sides and front and rear ends; a pair of wheel support arms mounted for pivotal movement about a pair of longitudinally spaced apart transverse axes on each side of said bed for raising and lowering the bed with respect to the ground; an axle and wheel mounted at the outer end of each support arm for rolling support of said bed; a tongue extending forwardly of the front end of said bed having an outer end adapted to be hitched to a pulling vehicle for towing said trailer; means for supporting said tongue for pivotal movement about a transverse pivot axis adjacent said front end of said bed, and tongue linkage means for interconnecting said wheel support arms and said tongue for maintaining said outer end of said tongue at a relatively constant level when said bed is raised or lowered; said tongue support means including a shaft aligned on said pivot axis and interconnected with an inner end portion of said tongue intermediate the ends of said shaft and said tongue linkage means includes a pair of tongue linkages on opposite sides of said bed interconnected between outer ends of said shaft and said lift means; load equalizing linkage means between each pair of said wheel support arms on each side of said bed comprising a first link pivotally connected at one end to the rear support arm eccentric of the mounting axis thereof and a second link pivotally interconnected to an opposite end of said first link and pivotally connected to the front support arm eccentric of the mounting axis thereof; and lift means on each side of said bed for pivoting said support arms to raise and lower said bed, said lift means including a longitudinally extensible thrust member having one end pivotally connected to said second link at a point between the pivotal connections of said first link and said front support arm therewith, said thrust member having an opposite end interconnected with said bed.

Claim 9

A lift bed, tandem axle, trailer, comprising: a bed having a load supporting floor structure with opposite sides and front and rear ends; a pair of wheel support arms mounted for pivotal movement about a pair of longitudinally spaced apart transverse axes on each side of said bed for raising and lowering the bed with respect to the ground; an axle and wheel mounted at the outer end of each support arm for rolling support of said bed; a tongue extending forwardly of the front end of said bed having an outer end adapted to be hitched to a pulling vehicle for towing said trailer; means for supporting said tongue for pivotal movement about a transverse pivot axis adjacent said front end of said bed, and tongue linkage means for interconnecting said wheel support arms and said tongue for maintaining said outer end of said tongue at a relatively constant level when said bed is raised or lowered; said tongue support means including a shaft aligned on said pivot axis and interconnected with an inner end portion of said tongue intermediate the ends of said shaft and said tongue linkage means includes a pair of tongue linkages on opposite sides of said bed interconnected between outer ends of said shaft and said lift means; load equalizing linkage means between each pair of said wheel support arms on each side of said bed comprising a first link pivotally connected at one end to the rear support arm eccentric of the mounting axis thereof and a second link pivotally interconnected to an opposite end of said first link and pivotally connected to the front support arm eccentric of the mounting axis thereof; and lift means on each side of said bed for pivoting said support arms to raise and lower said bed, said lift means including a longitudinally extensible thrust member having one end pivotally connected to said second link at a point between the pivotal connections of said first link and said front support arm therewith, said thrust member having an opposite end interconnected with said bed.

Claim 10

The trailer of claim 7 wherein each of said tongue linkages includes a first leg on said shaft pivotally connected at an outer end portion with of forward end of a link member, said link member having a rearward end pivotally connected to a second leg mounted for pivotal movement about the transverse pivot axis of said front wheel support arms, said second leg being pivotally interconnected with said second link of said load equalizing linkage means.

Claim 11

The trailer of claim 8 wherein said second leg and said second link of said load equalizing linkage means are interconnected with a pin and slot connector.

Claim 12

The trailer of claim 9 wherein said pin and slot connection includes a pin mounted on said second link engaged to slide in an elongated slot formed in said second leg.

Claim 13

The trailer of claim 7 wherein said tongue linkage means maintains said bed in general parallelism with respect to said ground when said bed is raised or lowered.