Abstract: A tree shear head includes a frame which supports a pair of parallel crank shafts which are respectively linked to a pair of shear blades for moving the latter together into the trunk of a tree being sheared. The crank shafts are rotated by means of an actuator including a cylinder in which a pair of piston and piston rod units are mounted with the rods projecting oppositely and being respectively pivotally connected to a pair of crank arms respectively formed integrally with the pair of crank shafts. To prevent the cylinder of the actuator from shifting axially along the piston rods, a pair of links are connected between the cylinder and the frame, and for preventing the cylinder from rotating about the piston rods, a pair of rollers are mounted on the cylinder and engage the frame.

Abstract: A control linkage for controlling operation of a control valve of a remote hydraulically operated device is mounted in a vehicle cab and includes a control lever located between the vehicle seat and a door to the cab so as to be within easy reach of a seated operator. When in a normal working position, the lever is located such that it may present an obstacle to operator entry and exit and may be accidently bumped so as to effect actuation of the control valve.

Abstract: A vehicle is provided with a control lever which is mounted in a vehicle cab so as to be incorporated in a housing supporting the left arm rest of the operator seat. The control lever is of a type movable among various positions for actuating hydraulic valves for controlling equipment attached to the vehicle and a normal neutral position for neutralizing the control valves. Fixed to the control lever is a pin which projects vertically when the lever is in its neutral position and a vertically swingable latch member is biased towards a latched position wherein it receives the vertical pin and holds the control lever in its neutral position. The latch member includes a pin which extends crosswise to the axis of and below the pivot of the latch member at a location whereat it is engageable by a bumper carried by the door when the door is closed so as to move the latch member upwardly to a deactivated position permitting the control lever to be operated when the vehicle door is closed.