| 摘要 |
The jointed stand comprises two joint or swivel heads coupled to each other and two arms each extending from a related one of the joint heads and terminating in a respective ball-and-socket joint. Each ball-and-socket joint is operatively associated with a push or thrust rod which slidably extends through the related arm and cooperates with a related transmission or transfer member in the associated joint or swivel head. Each transfer or displacement member has two oppositely inclined surfaces on opposite sides thereof which are supported at an associated end of the related push rod and at the joint head, respectively, by means of roller bodies. A hinge pin extends through the transmission members with clearance. A tightening element coacts with the hinge pin in order to be able to cam the transmission members at the roller bodies, so as to be able to selectively positively lock in place the arms and ball-and-socket joints and, when desired, to quickly release such locking action.
|
