Abstract: In a backhoe of the type having an outreach boom horizontally pivotally mounted relative to a vehicle and an hydraulic cylinder therebetween, a downreach boom horizontally pivotally mounted on the free end of the outreach boom and an hydraulic cylinder therebetween, and a digging bucket horizontally pivotally mounted on the free end of the downreach boom and an hydraulic cylinder therebetween, apparatus is provided for respectively generating signals proportional to the angle between the outreach boom and the horizontal, the angle between the outreach boom and the downreach boom, the angle between the downreach boom and a line drawn to the digging teeth of the bucket, and an angle equal to the desired slope of the bottom of the excavation relative to the true horizontal.

Abstract: The invention relates to a digging bucket for a backhoe or similar excavating machine, wherein the effective forward digging edge of the bucket may selectively comprise a transverse row of digging teeth for use in the primary phases of an excavation or a blade-type edge used for smoothing the bottom of the excavation. The backhoe bucket structure permitting this instantaneous choice by the operator comprises a conventional bucket having digging teeth secured thereto to the forward edge of the bottom but the medial portion of the bottom of the bucket is movably mounted relative to the remainder of the bucket so that the forward edge of the movable bottom portion can be dropped to a position below the digging teeth to function as a smoothing blade.

Abstract: The cutting depth of an endless chain type trencher is normally determined by the angle of the frame carrying the endless chain relative to the horizontal. In accordance with this invention, the angular position of the digging frame, hence the depth of the trench is controlled by the angular relationship of a trailing shoe carried by the digging frame relative to the digging frame. The trailing shoe has an elongated horizontal bottom surface that normally rides along the bottom of the formed trench. An upstanding mast is secured to the shoe at a point forwardly of the bottom surface and means on the top of the mast are utilized to indicate and control the depth of the trench.

Abstract: The cutting depth of an endless chain type trencher is normally determined by the angle of the frame carrying the endless chain relative to the horizontal. In accordance with this invention, the angular position of the digging frame is controlled by one or more hydraulic cylinders which, in turn, are controlled by signals derived from sensors carried by an upstanding vertical mast mounted to the frame which detects a reference plane defined by a rotating laser beam. A trigonometric correction factor to compensate for the mast mounting is included.

Abstract: The invention relates to a mechanism permitting the manual control of an trencher which is normally carried in trailing relationship to a vehicle and is pivotally mounted to the vehicle. The effective cutting depth of this type trencher is determined by the angle of the frame carrying the endless chain relative to the horizontal. An upstanding sighting bar is pivotally mounted to the frame of the trencher and means are provided for maintaining the sighting bar in a true vertical position irrespective of the angle of the frame relative to the horizontal. Additionally, the effective vertical height of the sighting bar is varied as a trigonometric function of the angle of the digging frame relative to the horizontal.

Abstract: In a backhoe of the type having an outreach boom horizontally pivotally mounted relative to a vehicle, a downreach boom horizontally pivotally mounted to the free end of the outreach boom, and a digging bucket horizontally pivotally mounted to the free end of the downreach boom, apparatus is provided for respectively generating signals proportional to the angle between the outreach boom and the horizontal, the angle between the outreach boom and the downreach boom, and the angle between the downreach boom and a line drawn to the digging teeth of the bucket. Such signals are combined according to a trigonometric equation to provide a continuous signal and visual indication proportional to the depth of the digging teeth of the bucket relative to the horizontal pivotal mounting axis of the outreach boom on the vehicle.

Abstract: Apparatus for controlling the elevation of the working tool of an earthworking machine, or the pavement distributor head of a mobile road-paving machine, in predetermined relationship to a fixed horizontal plane, as set by a laser beam which is periodically swept across the working area, such apparatus comprising a tape-dispensing device carried by the machine and arranged to intermittently advance the tape past a tape reader; the tape carrying two sets of indicia, one set indicating whenever a change in the height of the tool is required at a particular point in the travel of the machine, and the second set of indicia indicating the distance between such points, there being a ground-engaging wheel measuring the travel of the machine and connected to the tape-dispensing device to advance the tape to the next set of indicia whenever the machine arrives at the next one of said predetermined points.