In movable arm assemblies such as robot arms it is just as important to be able to lock the different elements making up the arm assembly as it is to provide for relative movement therebetween. It will be appreciated that if an arm is having to perform a particular task and the outboard end of the arm is not locked rigidly in position, the work which the arm is being asked to be undertaken may suffer.
In many robot arms, such as in spot welding robots, considerable forces have to be transmitted through the arms, and across articulated arm joints to the arm ends. In order to be able to transmit these force, the components making up the articulated joints have to be much more substantial than is required merely to provide an articulation function. Furthermore, the necessity to transmit these forces exposes the articulated joints to possible damage.
It is an object of the present invention to provide a locking device for use in such arms.