Abstract: A digger derrick truck for installing poles into the ground. The digger derrick truck includes a boom on which a pole guide assembly is slidably mounted. The pole guide assembly is operatively associated with a latching mechanism which releasably couples the pole guide assembly and the boom in an operative position and an inoperative position. The latching mechanism includes a latch arm and a release mechanism such that, when the boom is retracted, the release mechanism allows the latch arm to pivot and couple the pole guide assembly and the boom.

Abstract: A boom latch system for a boom movable between use and stowage positions. The boom latch includes a latch member that is operatively connected to the power supply which moves the boom, so that the boom is automatically unlatched when moved from its storage position. The boom latch includes a latch body which pivots to align with the boom latch receiving element, thereby aligning the latch members even under varying load conditions. The latch body also provides a length adjustment so that the latch system can be used with various sizes of booms and hydraulic cylinders.

Abstract: Boom latch system for a boom movable between use and stowage positions. The boom latch includes a latch member that is operatively connected to the power supply which moves the boom, so that that the boom is automatically latched when moved to its stowage position, and automatically unlatched when moved from its stowage position.

Abstract: Tensiometer placed on the free end of an aerially articulable boom such that the tensiometer's load indicator is visible from the bucket. A cable extending from the boom's free end may be attached to a working object such as a transformer. When the boom is raised, the working object is lifted off the ground. The tension placed on the cable causes a readout on the tensiometer indicating the load on the cable. Thus, a worker in the bucket can immediately determine whether the load on the cable exceeds the allowable limits.

Abstract: A wheel lifting unit for mounting to a tow truck has a base that is carried by the truck under the bed. An extending device will retract and extend the base. A telescoping member, which also retracts and extends, is mounted to the base. The telescoping member includes a neck member that pivotally connects to arms mounted to the base. The neck member will also move between retracted and extended positions. Lateral extension members are located at the end of the telescoping member assembly. Wheel supports on the lateral extension members incline outwardly to accommodate different wheel sizes.