Trailing wheel structure for vehicle-drawn implement

Claim 2

A vehicle-drawn implement comprising an implement frame structure and a trailing wheel structure including a wheel carriage, at least one wheel rotatably journaled on said wheel carriage on a rotational axis, said wheel carriage being pivotally mounted on a support member about a pivotal axis, link means interconnecting said implement frame structure and said support member for maintaining said pivotal axis substantially perpendicular to a ground reference plane throughout the range of movement of said wheel carriage, said link means including a first link and a second link, each of said links being pivotally connected to said implement frame structure and to said support member at spaced apart first and second link axes, respectively the distance between the first and second link axes of said first link being equal to the distance between said first and second link axes of said second link, and said first and second link axes of said second link being closer to the said ground reference plane than said first and second link axes of said first link, respectively, and power means for moving said wheel carriage between a raised position and a lowered position relative to said implement frame structure to vary the distance between said implement frame structure and said ground reference plane, said power means including an expansible chamber fluid motor pivotally connected to said implement frame structure and to said support member at spaced apart fluid motor axes, one pivot point of said fluid motor being located between the spaced apart link axes at one end of said links, and the other pivot point of said fluid motor being located outside the spaced apart link axes at the other end of said links.

Claim 3

A vehicle-drawn implement as set forth in claim 1 wherein said carriage pivotal axis is arranged forwardly of and in nonintersecting relation to said wheel rotational axis.

Claim 4

A vehicle-drawn implement as set forth in claim 1 including a second link means identical to said first-mentioned link means, said first-mentioned link means being on one side of said fluid motor and said second link means being on the other side of said fluid motor.

Claim 5

In combination, a motor vehicle, an implement for being pulled by said motor vehicle along a center line of travel, a lift hitch for attaching a front portion of said implement to said motor vehicle for selectively raising and lowering said front portion relative to a ground reference plane, and a trailing wheel structure means disposed on a rear portion of said implement at said center line of travel for selectively raising and lowering said rear portion relative to said ground reference plane substantially independently of the height of said front portion relative to said ground reference plane, said trailing wheel structure including a wheel carriage, at least one wheel rotatably journaled on said wheel carriage on a rotAtional axis, said wheel carriage being pivotally mounted on a support member about a pivotal axis, link means interconnecting said implement frame structure and said support member for maintaining said pivotal axis substantially perpendicular to a ground reference plane throughout the range of movement of said wheel carriage, said link means including a first link and a second link, each of said links being pivotally connected to said implement frame structure and to said support member at spaced apart first and second link axes, respectively, the distance between the first and second link axes of said first link being equal to the distance between said link axes of said second link, and said first and second link axes of said second link being closer to the said ground reference plane than said first and second link axes of said first link, respectively, and power means for moving said wheel carriage between a raised position and a lowered position relative to said implement frame structure to vary the distance between said implement frame structure and said ground reference plane, said power means including an expansible chamber fluid motor pivotally connected to said implement frame structure and to said support member at spaced apart fluid motor axes, one pivot point of said fluid motor being located between the spaced apart link axes at one end of said links, and the other pivot point of said fluid motor being located outside the spaced apart link axes at the other end of said links.

Claim 6

In combination, a motor vehicle, an implement for being pulled by said motor vehicle along a center line of travel, a lift hitch for attaching a front portion of said implement to said motor vehicle for selectively raising and lowering said front portion relative to a ground reference plane, and a trailing wheel structure means disposed on a rear portion of said implement at said center line of travel for selectively raising and lowering said rear portion relative to said ground reference plane substantially independently of the height of said front portion relative to said ground reference plane, said trailing wheel structure including a wheel carriage, at least one wheel rotatably journaled on said wheel carriage on a rotAtional axis, said wheel carriage being pivotally mounted on a support member about a pivotal axis, link means interconnecting said implement frame structure and said support member for maintaining said pivotal axis substantially perpendicular to a ground reference plane throughout the range of movement of said wheel carriage, said link means including a first link and a second link, each of said links being pivotally connected to said implement frame structure and to said support member at spaced apart first and second link axes, respectively, the distance between the first and second link axes of said first link being equal to the distance between said link axes of said second link, and said first and second link axes of said second link being closer to the said ground reference plane than said first and second link axes of said first link, respectively, and power means for moving said wheel carriage between a raised position and a lowered position relative to said implement frame structure to vary the distance between said implement frame structure and said ground reference plane, said power means including an expansible chamber fluid motor pivotally connected to said implement frame structure and to said support member at spaced apart fluid motor axes, one pivot point of said fluid motor being located between the spaced apart link axes at one end of said links, and the other pivot point of said fluid motor being located outside the spaced apart link axes at the other end of said links.

Claim 7

The combination as set forth in claim 4, including a second link means identical to said first-mentioned link means, said first-mentioned link means being on one side of said fluid motor and said second link means being on the other side of said fluid motor.