Abstract: A handle assembly is provided for a pump jack having a shackle assembly with a rotatable pole-gripping rod for engaging and rolling along a pole surface. The handle assembly includes an extension of the pole-gripping rod, a coil spring disposed on the rod extension, a sleeve disposed around the rod extension and coil spring, and a bar fixed to the sleeve. A crank arm extends transversely of the rod extension which is pivotally connected to the arm at a first pivot location. The bar is pivotally connected to the arm at a second pivot location. The coil spring urges the sleeve into engagement with a locking member on the shackle assembly, such that the sleeve is prevented from rotating and the rod is unable to roll along the surface of the pole. A handle is mounted on the free end of the crank arm.

Abstract: Novel motorized scaffold hoisting units are provided that are intended to be used in pairs with two jack poles. Each unit comprises a carriage that is adapted to be slidably disposed on a jack pole and has guide means that restrain the carriage from moving laterally while allowing it to be raised or lowered along the length of the pole. Each unit also comprises a hoist or winch that is mounted on a platform carried by the carriage and comprises a cable-carrying drum and a power transmission for rotating the drum in response to rotative power supplied by an auxiliary electrically powered driver. The outer end of the cable carried by the drum is adapted to be releasably attached to the upper end of a jack pole on which the unit is mounted. Each carriage also carries at least two fail-safe brake means for releasably gripping the pole on which the carriage is mounted, and means in the form of a laterally-projecting arm for supporting a scaffold, e.g., a wooden or aluminum plank.

Abstract: A pump jack pole assembly includes a rigid elongated tubular member having a planar front wall surface, an elongated elastomeric strip having a flat rear surface disposed adjacent the tubular member front wall surface and a front surface having grooves therein extending lengthwise of the strip, a retainer plate in each of the grooves, each of the plates having a thickness less than the depth said grooves so that the front surfaces of the plates are recessed in the strip front surface, and screws for releasably fixing the plates in the grooves and the elastomeric strip to the tubular member front wall, the heads of the screws being recessed in the plates.

Abstract: An improved pump jack of the type comprising a metal frame that has two parallel spaced frame members carrying upper and lower shackle assemblies arranged to grip a supporting pole, and a pump arm coupled to the frame and the upper shackle assembly for raising the jack. An improved releasing mechanism is provided comprising a U-shaped release member disposed between the two frame members. The U-shaped release member has two opposed struts each provided with an elongate hole adjacent one end to slidably and rotatably receive a pivot shaft that is anchored in the two frame members. The elongate holes in the opposite ends of the release member's side struts are aligned with holes in the forward ends of the side arms of the shackle member of the lower shackle assembly. The holes in the side arm of the lower shackle member are sized and shaped to non-rotatably accommodate the front clamping bar, with the latter acting to pivotally interconnect the U-shaped release member's side struts and the lower shackle.