Pin retractor for semi-trailer tandems
OwnerBobbie M. Hartinventor
Life of this patent
Estimating the term…
Abstract
A pneumatically powered pin retractor is disclosed. Semi-trailers comprise tandems which can be slid forward and backward when a set of pins are retracted. In conventional semi-trailers, manually pulling a pin release lever located on the side of the tandem rotates the pin control shaft, thereby retracting the pins. The disclosed pin retractor comprises a lever arm attached to the pin control shaft, a pneumatic ram to push the lever arm thereby rotating the pin control shaft and retracting the pins, and a means for activating the pneumatic ram. The source of air pressure to power the pneumatic ram is normally the service air tank on the tandem.
Claims20
In a tandem which comprises a pin control shaft, wherein the rotation of said pin control shaft retracts pins on the tandem, the improvement comprising:
- a lever arm attached to said pin control shaft by means of gripping the exterior of said pin control shaft at a point where there is no shaft extension, wherein said gripping means comprise two U bolts, an upper pipe segment and a lower pipe segment;
- and
- a pneumatic ram pivotally attached both to the end of said lever arm and to said tandem;
- and
- means for activating said ram.
In a tandem which comprises a pin control shaft, wherein the rotation of said pin control shaft retracts pins on the tandem, the improvement comprising:
- a lever arm attached to said pin control shaft by means of gripping the exterior of said pin control shaft at a point where there is no shaft extension, wherein said gripping means comprise two U bolts, an upper pipe segment and a lower pipe segment;
- and
- a pneumatic ram pivotally attached both to the end of said lever arm and to said tandem;
- and
- means for activating said ram;
- wherein said ram activating means comprises an electric valve allowing selective communication between the interior of said ram and a source of air pressure;
- wherein said tandem is attached to the cargo surface of a semi-trailer, said semi-trailer is attached to a tractor, and said electric valve is activated by an electric switch in the cab of the tractor;
- wherein said electric switch is spring-loaded, and further comprising a warning device in said cab which is activated whenever said electric valve is activated.
A retrofit kit for a tandem comprising:
- a lever arm, wherein the top of said lever arm is adapted to grip the exterior of a pin control shaft;
- and
- a pneumatic ram, wherein one end of said ram is adapted to be pivotally attached to said lever arm, and the other end of said ram is adapted to be pivotally attached to said tandem;
- and
- a means for selectively activating said ram.
In a tandem which comprises a pin control shaft, wherein the rotation of said pin control shaft retracts pins on the tandem, the improvement comprising:
- a lever arm attached to said pin control shaft at a point where there is no shaft extension;
- and
- a pneumatic ram pivotally attached both to the end of said lever arm and to said tandem;
- and
- means for activating said ram.
In a tandem which comprises a pin control shaft, wherein the rotation of said pin control shaft retracts pins on the tandem, the improvement comprising:
- a lever arm attached to said pin control shaft at a point where there is no shaft extension;
- and
- a pneumatic ram pivotally attached both to the end of said lever arm and to said tandem, and said tandem is attached to the cargo surface of a semi-trailer, and said semi-trailer is attached to a tractor;
- and
- electrical means for activating said ram, wherein said activating means are controlled by an electric switch in the tractor;
- and
- means for connecting said electrical switch to said activating means, wherein said connecting means utilizes the center electrical line of a seven wire harness that connects the tractor and the semi-trailer.
Dependencies are inferred from the claim text.