Sensor and interlock on an industrial vehicle
View Patent ↗A skid steer loader has an interlock system that is responsive to sensor input to lock out such as operation of lift and tilt cylinders of the skid steer loader when the input indicates a condition has not been met. The loader is provided with a cab that has an operator entrance and egress door, and a door latch and a latch striker on the cab are provided with a sensor that senses when the cab door is closed and latched. The lockout prevents carrying out the functions when the door is not closed and latched.
1. A loader having a frame, a drive to move the frame, a lift arm on the frame, a lift actuator for raising and lowering an outer end of the lift arm, a cab structure on the frame, an operator door for permitting entrance and egress from the cab, said door being hingedly mounted on the cab, a door latch, and a latch striker for the latch, said latch engaging the latch striker to hold the door closed, wherein the improvement comprises a two component sensor arrangement between the door and a portion of the cab adjacent the door opening positioned to sense whether the latch is in engagement with the latch striker to hold the door closed, wherein the latch striker comprises the portion of the cab, and a lockout for enabling and disabling operating functions, said sensor arrangement being connected to the lockout to disable the functions when the sensor arrangement indicates the door is not held closed, wherein the sensor arrangement comprises a switch carried on the door latch, and a switch actuator carried on the striker, said switch being a normally closed switch connected in a circuit for the lockout, the switch being opened when the door is closed and the latch is engaging the striker, a circuit connector from the switch to the lockout, the lockout being carried on the loader frame, the connector being separable to leave the circuit open when the door is removed from the loader frame and the circuit, the lockout being operable to enable the operating functions when the circuit is open.
2. The loader of claim 1 , wherein said lockout comprises a lockout valve for hydraulic functions.
3. The loader of claim 1 , wherein said lockout comprises a lockout valve that is normally open, and a controller for the lockout valve to receive the signals from the sensor arrangement.
4. An interlock arrangement for controlling operation of power components on a powered vehicle, said vehicle having an operator access opening, and a removable door for closing the access opening, the door having a closed position wherein the door is positioned out of a zone of movement of power components, a latch having first and second latch components, the first latch component being mounted on the door, and the second latch component being mounted on the vehicle, the first and second latch components mating to hold the door in its closed and latched position, a sensor having a first sensor element mounted adjacent the first latch component, and a second sensor element mounted adjacent the second latch component, an interlock controller with a sensor input configured to receive a signal from the sensor indicative of the position of the door, the interlock controller being configured to provide an output to enable operation of at least one power component when the door is in the closed position and wherein the interlock controller is configured to enable the at least one power component when the door and the first sensor element are removed from the vehicle.
5. The interlock system of claim 4 , wherein the first sensor element comprises a switch, and the second sensor element comprises a switch actuator.
6. The interlock system of claim 5 , wherein the first sensor element is a magnetic field sensitive switch, and the second sensor element is a magnetic field producing element.
7. The interlock system of claim 6 , wherein said magnetic field sensitive element is mounted on the door latch, and the magnetic field producing element is mounted on the vehicle.
8. The interlock system of claim 6 , wherein said second latch component on the vehicle comprises a latch striker.
9. The interlock system of claim 8 , wherein said first sensor element is a magnetic field sensitive switch and the second sensor element is mounted on the striker and is a permanent magnet.