Automatic semi-trailer landing gear extension and retraction apparatus
First Claim
1. In a tractor trailer rig of the type which includes a conventional tractor having an operator'"'"'s cab, a source of electrical power, and a fifth wheel hitch member;
- a semi-trailer having hitch pin means on the forward end portion for engaging the fifth wheel hitch member, road wheels journaled on the rear end portion and an alternately extendable and retractable landing gear mounted intermediate the hitch pin means and the road wheels;
the landing gear having gear drive means operatively engaged therewith which gear drive means includes an input drive shaft adapted to be engaged by a crank handle for manual rotation thereof in a first direction to extend the landing gear to engage the ground and support the semi-trailer independently of the tractor and, alternately, in a second direction to retract the landing gear from the ground engaging position to allow the forward end portion of the semi-trailer to be supported by the tractor with the hitch pin means engaging the fifth wheel hitch member;
an improved automatic landing gear extension and retraction apparatus comprising;
an electric drive motor mounted on the forward end portion of the semi-trailer and having a power output shaft;
means for drivingly connecting the power output shaft to the input drive shaft of the gear drive means of the landing gear;
position sensing means operatively connected to the landing gear for providing a first signal output when the landing gear is retracted and, alternately, for providing a second signal output when the landing gear is extended; and
control circuit means mutually interconnecting the source of electrical power, the electric drive motor and the position sensing means, and responsive to external control thereof, for providing electrical power to the electric drive motor to rotate the input drive shaft in the first direction to extend the landing gear and, alternately, for providing electrical power to the electric drive motor to rotate the input drive shaft in the second direction to retract the landing gear.
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Accused Products
Abstract
An improved apparatus for automatically extending and retracting the landing gear of a semi-trailer. The apparatus includes a reversible electric motor and speed reducer removably drivingly securable to an existing manually operated mechanism for extending and retracting a landing gear. Electric circuitry is provided for permitting an operator to control the extension and retraction of the landing gear from within the cab of a tractor and, alternately, from the exterior of the semi-trailer. The electrical circuitry provides both audible and visual indication of the position status of the landing gear and automatic cutoff of the electric motor when the landing gear is fully extended, and alternately, when the landing gear is fully retracted.
55 Citations
29 Claims
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1. In a tractor trailer rig of the type which includes a conventional tractor having an operator'"'"'s cab, a source of electrical power, and a fifth wheel hitch member;
- a semi-trailer having hitch pin means on the forward end portion for engaging the fifth wheel hitch member, road wheels journaled on the rear end portion and an alternately extendable and retractable landing gear mounted intermediate the hitch pin means and the road wheels;
the landing gear having gear drive means operatively engaged therewith which gear drive means includes an input drive shaft adapted to be engaged by a crank handle for manual rotation thereof in a first direction to extend the landing gear to engage the ground and support the semi-trailer independently of the tractor and, alternately, in a second direction to retract the landing gear from the ground engaging position to allow the forward end portion of the semi-trailer to be supported by the tractor with the hitch pin means engaging the fifth wheel hitch member;
an improved automatic landing gear extension and retraction apparatus comprising;an electric drive motor mounted on the forward end portion of the semi-trailer and having a power output shaft; means for drivingly connecting the power output shaft to the input drive shaft of the gear drive means of the landing gear; position sensing means operatively connected to the landing gear for providing a first signal output when the landing gear is retracted and, alternately, for providing a second signal output when the landing gear is extended; and control circuit means mutually interconnecting the source of electrical power, the electric drive motor and the position sensing means, and responsive to external control thereof, for providing electrical power to the electric drive motor to rotate the input drive shaft in the first direction to extend the landing gear and, alternately, for providing electrical power to the electric drive motor to rotate the input drive shaft in the second direction to retract the landing gear. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
- a semi-trailer having hitch pin means on the forward end portion for engaging the fifth wheel hitch member, road wheels journaled on the rear end portion and an alternately extendable and retractable landing gear mounted intermediate the hitch pin means and the road wheels;
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21. An improved automatic landing gear extension and retraction apparatus for use with a tractor having an operator'"'"'s cab and a source of electrical power, and with a semi-trailer having hitch means on the forward end portion and road wheels journaled on the rear end portion thereof, comprising:
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an alternately extendable and retractable landing gear mounted on the forward end portion of the semi-trailer intermediate the hitch means and the road wheels; a gear drive mechanism operatively engaged with said landing gear and having an input drive shaft constructed and arranged such that rotation thereof in a first direction causes a corresponding extension of the landing gear and, alternately, rotation thereof in a second direction causes retraction of the landing gear; an electric drive motor mounted on the forward end portion of the semi-trailer and having a power output shaft; means for drivingly connecting the power output shaft to the input drive shaft of said gear drive mechanism; position sensing means operatively connected to said landing gear for providing a first signal output when said landing gear is retracted, and alternately, for providing a second signal output when said landing gear is extended; and control circuit means mutually interconnecting the source of electrical power, said electric drive motor and said position sensing means, and responsive to external control thereof, for providing electrical power to said electric drive motor to rotate the input drive shaft in the first direction to extend said landing gear and, alternately, for providing electrical power to said electric drive motor to rotate the input drive shaft in the second direction to retract said landing gear. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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Specification