The present invention is a forklift attachment device which automatically secures to the tongs of a forklift when the tongs are raised. The present invention functions to prevent a forklift load from becoming dislodged prematurely. The operative portion of the present invention is a pair of elastomer locking brakes which are positioned along the tongs of the forklift. The forks are inserted into the device. As the load is moved upwardly, levers attached to the locking brakes fall downwardly causing the locking brakes to move into operative engagement with the forks. When the load is returned to a position on the floor, the levers are returned to the starting position causing the locking brakes to release the attachment from the forks.

A tilt control valve controls the flow of hydraulic oil to actuate the tilt cylinders of a forklift mast. The tilt control valve is switched between two positions by the forklift operator by means of a tilt lever. When at one position, the tilt control valve stops flow of oil to the tilt cylinders, thereby prohibiting tilting of the mast. When at the other position, the tilt control valve permits oil flow to the tilt cylinders, thereby allowing tilting of the mast. A control valve is located between the tilt cylinders and the tilt control valve. A seat switch detects whether or not the operator is sitting on the seat. A CPU permits the operator to continue to operate the tilt cylinders to tilt the mast when out of the seat for a brief period. However, after the brief period, the CPU closes the control valve to prevent movement of the mast unless the operator has returned to the seat. When the mast reaches a predetermined maximum acceptable tilt angle, the CPU also closes the control valve, thereby prohibiting motion of the tilt cylinders.

A rotatable load-handling clamp assembly has a rotation-stopping triggering assembly for automatically stopping clamp rotation at one or more predetermined stop positions. A hydraulic motor rotates a rotatable frame having clamp arms thereon with respect to a base. A hydraulic motor control system includes a switch and a set of triggering devices mounted in mutual opposition on the frame and base. The triggering devices are positioned to actuate the switch at the predetermined stop positions, and thereby automatically stop rotation of the hydraulic motor at such positions.

A tiltable attachment is provided for a Skid Steer Loader. The tiltable attachment is secured to the loader arms of the Skid Steer Loader and receives and fastens the utility attachment of the Skid Steer Loader. The tiltable attachment including a mounting base member and a pivotal attachment member. These members being rotated by a power cylinder. The pivotal attachment member has a demountable cover plate. The pivotal attachment member will receive the commonly known utility attachments. The tiltable attachment maintains the ability of the Skid Steer Loader to move the utility attachments in the vertical and horizontal plains while further providing the ability to rotate the utility attachment around the longitudinal axis of the Skid Steer Loader.

A quick coupler for coupling an implement to a work machine is provided with a control system that substantially prevents inadvertent and unintended release of the implement from the machine. Inadvertent and unintended release of the implement is prevented by requiring two separate switches to be actuated to release the implement. Actuation of one switch supplies pressurized fluid to a fluid circuit connected to an actuator operable to release the implement from the machine. However, the pressurized fluid supplied in response to actuation of the one switch is not sufficient to activate the actuator. Concurrent actuation of a second switch raises the pressure of the fluid supplied to the actuator fluid circuit to a level sufficient to activate the actuator, thus releasing the implement.