Extendable ramp assembly for detecting an obstruction and responding thereto
First Claim
1. An extendible ramp assembly for use with a vehicle comprising:
- i) a cassette attachable to a vehicle and provided with a closable access slot;
ii) a first ramp contained by the cassette, the first ramp being slidably movable relative to the cassette and hingably connected to the cassette;
iii) a second ramp contained within the first ramp and movable relative to the cassette and the first ramp;
iv) electric motor means for extending and retracting the first ramp through the access slot and relative to the cassette;
v) means for extending and retracting the second ramp relative to the first ramp and the cassette;
vi) a control unit for controlling the operation of the electric motor means and the means for extending and retracting the second ramp;
vii) means for detecting the current drawn by the electric motor means to ascertain when the current drawn exceeds a predetermined value indicative of a condition in which the first and second ramps encounter an obstruction when being extended;
viii) means responsive to the current detecting means for causing the control unit to stop the extension of the first and second ramps when the detecting means detects said excess current;
ix) means for further detecting when the first and second ramps are fully extended and operational and;
x) means responsive to the further detecting means for stopping the extension of the first and second ramps when the further detecting means detects the ramps are fully extended.
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Accused Products
Abstract
An extendable ramp assembly includes a chassis, a first ramp slidably movable relative to the chassis and hingably connected to the chassis, and a second ramp carried by the first ramp and movable relative to the chassis and the first ramp. Separate structure is provided for extending and retracting both the first and second ramps. A first mechanism is provided for detecting whether either or both of the first and second ramps abuts an obstruction when at least one of the ramps is being extended. A second mechanism is provided for stopping the extension of at least one of the ramps or for retracting at least one of the ramps in the event of the detecting mechanism detecting the obstruction.
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Citations
12 Claims
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1. An extendible ramp assembly for use with a vehicle comprising:
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i) a cassette attachable to a vehicle and provided with a closable access slot;
ii) a first ramp contained by the cassette, the first ramp being slidably movable relative to the cassette and hingably connected to the cassette;
iii) a second ramp contained within the first ramp and movable relative to the cassette and the first ramp;
iv) electric motor means for extending and retracting the first ramp through the access slot and relative to the cassette;
v) means for extending and retracting the second ramp relative to the first ramp and the cassette;
vi) a control unit for controlling the operation of the electric motor means and the means for extending and retracting the second ramp;
vii) means for detecting the current drawn by the electric motor means to ascertain when the current drawn exceeds a predetermined value indicative of a condition in which the first and second ramps encounter an obstruction when being extended;
viii) means responsive to the current detecting means for causing the control unit to stop the extension of the first and second ramps when the detecting means detects said excess current;
ix) means for further detecting when the first and second ramps are fully extended and operational and;
x) means responsive to the further detecting means for stopping the extension of the first and second ramps when the further detecting means detects the ramps are fully extended. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification