Articulated support

An articulated support arrangement for carrying a tool, comprising a support member, a turret pivotally attached to said support member, means to rotate said turret with respect to said support member, an elongate, non-telescopic boom, elongate link means connected between a pivot on said turret and a pivot on said boom, at least one ram pivotally connected to said turret at a position spaced from said link connection on said turret and to said boom at a position spaced from said link connection on said boom, said ram being capable of producing with said link means a parallelogram linkage, whereby said boom may be advanced or retracted with respect to said turret in a vertical plane in which the angular disposition of the longitudinal axis of said boom remains unchanged, means mounted on said turret to rotate the link means about said pivotal connection thereof at said turret, said boom comprising a rear portion having a part capable of rotation about the longitudinal axis of said boom, means to effect such rotation, and a front portion attached at one end to that part and at the other end pivotally attachable to a tool means, with a ram pivotally attached at one end to said front portion of said boom and the other end being operable on said tool means.