Abstract: A mobile crane having a telescopic jib 15 which is mounted on an upper chassis 8 has a cantilever counterweight 14 and an additional removable counterweight 27. The additional counterweight 27 is carried on a holder 28 which is mounted on a strut 21 which is directly pivotally connected to the jib 15. The strut 21 can be pivoted to raise and lower the holder 28 to enable the additional counterweight 27, which is removable, to be picked up and deposited. The additional counterweight 27 is deposited and removed to lighten the crane for road travel, but when operative, increases the lifting capacity of the crane.

Abstract: A crane of the type having a slewing upper chassis 5 carrying a jib, the lowermost component of which is shown at 10, and an erection column 12 for raising the jib from a horizontal assembly position into an upright operating position, has a hydraulic cylinder 11 connected to the component 10 and a cable 13 connecting the component 10 to the column 12. The column 12 is raised from the lowered position shown to an upright position, in which subsequently a tackle 14 swings the column 12 rearwards and raises the jib to its upright operating position, by means of the cylinder 11. A better purchase can be obtained by the cylinder 11 acting on the component 10 than by a cylinder acting directly on the column 12 which is usual, and therefore a smaller cylinder can be used.

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.