Hydraulically operated tripod head

Claim 1

A tripod head including: a head body comprising a stem and an arm projecting laterally from said stem; a socket, one end of which is rotatably connected to one end of said stem and other end of which is provided with an inwardly extending flange; a support means comprising a ball disposed in said socket so as to make a ball-socket joint with said flange, and a neck connected at one end to said ball; a slot formed in the lateral side of said socket for receiving said neck when said head body is turned vertically with respect to said support; a hydraulic mechanism comprising a main cylinder provided in said one end of the stem, a ball rest member slidably inserted in said main cylinder and having a concave surface engageable with said ball, a first cylinder provided in the other end of the stem, a second cylinder located between said main and first cylinders and having a diameter smaller than those of said main and first cylinders, said second cylinder communicating with said main and first cylinders, a piston block comprised of a first piston inserted into said first cylinder and a second piston inserted into said second cylinder, urging means for biasing said piston block toward said main cylinder to cause fluid filled in said main and second cylinders to normally press said ball rest member against said ball for firmly fixing said head body to said head support, a third cylinder formed in said arm of said head body and communicating with a space within said first cylinder adjacent to said second cylinder, and a plunger inserted into said third cylinder to move, when said plunger is forced into said third cylinder, said piston block against the biasing force of said urging means to permit movement of said head body relative to said support; and a fixing attachment mounted on said head body for fixing a load body to said tripod head.