초록 ▼

A variable tread vehicle includes first and second parallel horizontal rails which are connected to a frame and extend in a direction which is transverse to the direction of movement of the vehicle. First and second movable carriages are movable on sections of the track formed by the rails. A first

A variable tread vehicle includes first and second parallel horizontal rails which are connected to a frame and extend in a direction which is transverse to the direction of movement of the vehicle. First and second movable carriages are movable on sections of the track formed by the rails. A first drop axle is connected to and extends downward from the first movable carriage, and a second drop axle is connected to and extends downward from the second movable carriage. Connected near the lower ends of the first and second drop axles are first and second wheels of the vehicle. The first and second movable carriages are moved on the track by first and second threaded drive shafts, which are driven by hydraulic motors. By controlling the hydraulic motors, the operator can drive the first and second movable carriages outward to increase the spacing between the first and second wheels, or can drive the first and second movable carriages inward to decrease the spacing between the first and second wheels. The adjustment of wheel spacing may be accomplished while driving the vehicle, thus permitting a rapid and simple changeover when different wheel spacing is required.

대표청구항 ▼

A variable tread vehicle comprising: a frame; first and second parallel horizontal rails connected to the frame and extending transverse to a direction of movement of the vehicle to define a track; wherein the first and second rails comprise hollow tubes having generally rectangular cross-sections;

A variable tread vehicle comprising: a frame; first and second parallel horizontal rails connected to the frame and extending transverse to a direction of movement of the vehicle to define a track; wherein the first and second rails comprise hollow tubes having generally rectangular cross-sections; first movable carriage means movable on a first section of the track; the first movable carriage means comprising: first and second slides of C-shaped cross-section for partially surrounding the first and second rails, respectively, for slidable movement thereon; first brace means attached to and extending between the first and second slides, the first brace means having a substantially vertical portion; first internally threaded means carried by the substantially vertical portion of the first brace means wherein the first internally threaded means is a first shaft nut attached to the vertical portion of the first brace means and an edge of the first plate means is in abutment with the first shaft nut; and first generally horizontal plate means attached to and extending between the first and second slides; second movable carriage means movable on a second section of the track; the second movable carriage means comprising: third and fourth slides of C-shaped cross-section for partially surrounding the first and second rails, respectively, for slidable movement thereon; second brace means attached to and extending between the third and fourth slides, the second brace means having a substantially vertical portion; second internally threaded means carried by the substantially vertical portion of the second brace means wherein the second internally threaded means is a second shaft nut attached to the vertical portion of the second brace means and an edge of the second plate means is in abutment with the second shaft nut; and second generally horizontal plate means attached to and extending between the third and fourth slides; first drop axle means attached to the first and second slides and the first plate means of the first movable carriage means proximate its upper end and extending downward; first gusset means attached to and extending between the first drop axle means and the first plate means; second drop axle means attached to the third and fourth slides and the second plate means of the second movable carriage means proximate its upper end and extending downward; second gusset means attached to and extending between the second drop axle means and the second plate means; a first wheel connected to the first drop axle means proximate its lower end; a second wheel connected to the second drop axle means proximate its lower end; first internally threaded means for driving the first movable carriage means on the first section of the track; a first threaded drive shaft extending through the internally threaded means for driving the first movable carriage means on the first section of the track; a second threaded drive shaft extending through the second internally threaded means for driving the second movable carriage means on the second section of the track; motor means for rotating the first and second shafts to move the first and second movable carriage means on the first and second sections of the track, and thereby vary the spacing between the first and second wheels; and first and second arch braces attached to and extending between the first and second rails at positions along the first and second sections of the track for maintaining the first and second rails in fixed relationship with respect to one another while permitting movement of the first and second carriage means on the first and second sections of track, respectively, without interference from the first and second arch braces.