Abstract: An apparatus for clamping a body to a support in which the body is provided with a slot through which the clamping member can extend includes a clamping member having a shaft with threads at one end and a T-head at the other end, a support having a recess in one face to receive the T-head and an opening through which the clamping member shaft extends and a threaded member coupled to the threaded end of the clamping member, the threaded member being rotatable to axially move the clamping member. A first drive motor is provided to rotate the threaded member to extend the clamping T-head beyond the surface of the support. A second drive motor is provided to rotate the clamping member to a clamping position and to a releasing position. A source of power such as fluid under pressure is provided, the motors being hydraulic.