Patent ID: 6092976
Filing Date: 2000-07-25
Classification: B66F

Abstract:
A tilt cylinder controlling apparatus for an industrial vehicle, wherein the industrial vehicle includes a mast tiltally supported on a body frame, a carrier supported by the mast for carrying a load, a tilt cylinder for tilting the mast and a cab for an operator, the apparatus comprising:a tilt valve that controls a supply of fluid to the tilt cylinder to actuate the tilt cylinder, wherein the tilt valve is switched between a first position for preventing fluid from entering the tilt cylinder to prohibit tilting of the mast and a second position for permitting fluid to enter the tilt cylinder to cause tilting of the mast;a handle for manually controlling the tilt valve;a fluid passage located between the tilt cylinder and the tilt valve;a control valve located in the fluid passage, wherein the control valve controls the flow of fluid in the fluid passage and thus selectively prohibits tilting motion of the mast;a first detector that detects whether an operator is at a predetermined operating position in the cab;a second detector that detects whether the tilt valve is moved to the second position by the handle; anda controller for actuating the control valve, wherein the controller judges whether to close the control valve to prohibit movement of the tilt cylinder, and the controller closes the control valve if the state of the first detector indicates that the operator has not occupied the predetermined operating position for a predetermined time period, wherein the predetermined time period is selected so that the operator may briefly move from the predetermined operating position without affecting the control valve.