Abstract: A controlling apparatus for bulldozer blade in which the control is carried out automatically or manually.The apparatus comprises an electromagnetic valve for controlling a cylinder of the bulldozer blade, a switch for changing the control of the bulldozer blade automatically or manually, a safety relay connected with said switch, the safety relay being adapted to be actuated only when the switch is maintained in a manual operating position, and a load reading relay adapted to be actuated by a signal fed from a load detecting circuit for supplying a signal to one of the solenoids of the electromagnetic valve.

Abstract: A sprocket device is provided in a track type tractor for driving endless tracks thereof. The device has a plurality of brackets fixedly secured to both side of the sprocket body along the periphery thereof at predetermined intervals, a plurality of buffer members, each being replaceably secured to each of the brackets, and plurality of frame members, each being secured to each of the brackets and including walls extending from the brackets parallel to and spaced from the side of the buffer members for preventing the buffer members from falling sideways. The frame member is coextensive with a portion of the sides of the buffer members. Thus, the endurability of the buffer members is much improved.

Abstract: An idler for use in a bulldozer, etc., comprising an idler proper having an annular groove on its peripheral surface and a shock-absorbing member fitted in said annular groove. Thus the shock-absorbing member can be made sufficiently thick to minimize impulsive noises during operation.