MATERIALS HANDLING VEHICLE ESTIMATING A SPEED OF A MOVABLE ASSEMBLY FROM A LIFT MOTOR SPEED
First Claim
1. A materials handling vehicle comprising:
- a support structure including a first member;
a movable assembly coupled to said support structure;
said support structure further comprising lift apparatus to effect movement of said movable assembly relative to said support structure first member, said lift apparatus including at least one ram/cylinder assembly;
a hydraulic system including a motor, a pump coupled to said motor to supply a pressurized fluid to said at least one ram/cylinder assembly, and at least one electronically controlled valve associated with said at least one ram/cylinder assembly; and
control structure to estimate a speed of said movable assembly from a speed of said motor and to control the operation of said at least one valve using a comparison involving the estimated movable assembly speed and a determined speed.
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Accused Products
Abstract
A materials handling vehicle is provided comprising: a support structure including a first member; a movable assembly coupled to the support structure; a hydraulic system; and a control system. The support structure further comprises lift apparatus to effect movement of the movable assembly relative to the support structure first member. The lift apparatus includes at least one ram/cylinder assembly. The hydraulic system includes a motor, a pump coupled to the motor to supply a pressurized fluid to the at least one ram/cylinder assembly, and at least one electronically controlled valve associated with the ram/cylinder assembly. The control structure may estimate a speed of the movable assembly from a speed of the motor and may control the operation of the at least one valve using a comparison involving the estimated movable assembly speed and a determined speed, and the comparison may not involve use of an operator commanded speed.
11 Citations
26 Claims
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1. A materials handling vehicle comprising:
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a support structure including a first member; a movable assembly coupled to said support structure; said support structure further comprising lift apparatus to effect movement of said movable assembly relative to said support structure first member, said lift apparatus including at least one ram/cylinder assembly; a hydraulic system including a motor, a pump coupled to said motor to supply a pressurized fluid to said at least one ram/cylinder assembly, and at least one electronically controlled valve associated with said at least one ram/cylinder assembly; and control structure to estimate a speed of said movable assembly from a speed of said motor and to control the operation of said at least one valve using a comparison involving the estimated movable assembly speed and a determined speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A materials handling vehicle comprising:
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a first mast weldment; at least one movable mast weldment coupled to said first mast weldment; a fork carriage apparatus movably coupled to said at least one movable mast weldment; at least one first ram/cylinder assembly coupled to said first mast weldment and said at least one movable mast weldment to effect movement of said at least one movable mast weldment relative to said first mast weldment; a second ram/cylinder assembly coupled to said fork carriage apparatus and said at least one movable mast weldment to effect movement of said fork carriage apparatus relative to said at least one movable mast weldment; a hydraulic system including a motor, a pump coupled to said motor to supply a pressurized fluid to said first and second ram/cylinder assemblies, and at least one first electronically controlled valve and a second electronically controlled valve associated with said at least one first ram cylinder assembly and said second ram/cylinder assembly; and control structure to estimate a speed of said fork carriage assembly relative to said first mast weldment from a speed of said motor and to control the operation of said first and second valves using a comparison involving the estimated fork carriage assembly speed and a determined speed. - View Dependent Claims (25, 26)
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Specification