Abstract: An air wrench, with a compressed air motor, a wrench head and a gearing for transferring the power of the motor to the head, as well as a control mechanism, which comprises at least one adjustable pressure reducer for limiting the torque and which permits the wrench to be switched on and off manually by opening and closing a main air valve in the compressed air line to the motor of the wrench.

Abstract: A needle selection device for use in a knitting machine having revolving needle carriers and including pivotable selectors that operate to bring one end of each selector into actuating relation with a respective needle. A jack is coupled to the needle and, depending upon the pivot position of the selector, moves between an active position to cause that needle to be selected for operation and an inactive preset position by which that needle is not selected. A spring is associated with the jack to bias the jack to its active position. The pivot position of the selector is electromagnetically controlled.

Abstract: A mobile crane intended for carrying heavy loads has a slewable upper chassis which is rotatably mounted on a carriage by a conventional rotatable connection and in order to transmit loads greater than the connection can withstand, there is an additional rotary mounting. The additional mounting comprises an inner frame with cantilever arms between the upper chassis and the carriage. The upper chassis is detachably bolted to the arms and the arms have rollers which run in a circular rail fixed to the carriage. The rail has a greater diameter than the width of the carriage to enable it to transmit the heavy loads and moments, but to keep the crane within the statutory width limits for transport by road from site to site, the parts of the circular rail which project beyond the sides of the carriage are detachable. When these parts are detached for transport, the rollers on the cantilevers engage with the remaining parts of the rail at the front and back of the carriage.

Abstract: A tool balancing apparatus comprises a spring arrangement for balancing the weight of a tool such as an assembly tool. The spring arrangement is a hydro-pneumatic piston-cylinder unit whose one end is connected to a suitable mounting means and whose other end, being extensible, carries the tool. The apparatus further includes a bracing means such as a tube or a torsion bar assembly to form a rigid connection between the tool and the mounting means, thereby to carry any forces produced by the tool during operation thereof and to transmit such forces to the mounting means.