Abstract: A gripper is disclosed. The gripper has a frame which is connected to a mobile subassembly including a fixed end and a mobile end respectively secured to a fixed arm and a mobile arm, and an actuator supported on the fixed arm for moving the mobile arm and end relative to the fixed arm and end, along a first degree of freedom, in translation or rotation, and a balancing module introducing an additional degree of freedom, in translation or rotation, which is offset outwards of the assembly formed by the mobile subassembly and the frame.

Abstract: The invention concerns a gripper comprising a frame to which is connected a mobile subassembly including a fixed end and a mobile end respectively secured to a fixed arm and a mobile arm, and an actuator supported on the fixed arm for moving the mobile arm and end relative to the fixed arm and end, along a first degree of freedom, in translation or rotation, and a balancing module introducing an additional degree of freedom, in translation or rotation, which is offset outwards of the assembly formed by the mobile subassembly and the frame.

Abstract: The invention concerns an actuator (21) comprising a pre-stroke rod (29) which can be fixed to the tool body, for example soldering pliers. Thus by pressurising the pre-stroke chamber (27) the working rod (34) for closing the pliers can be brought into an intermediate small opening position, the working piston (31) and the amplifying pistons (36 and 37) remaining retracted in the actuator. Since the rod (29) can then be locked relative to the actuator body (21), pressurisation of the working chamber (32) and the amplifying chambers (38 and 40) will then cause the working rod to be extracted (34) and the soldering pliers to be closed without any recoil from the actuator body.

Abstract: This welding electrode is one wherein the welding cap 3 of the electrode body 1 carries a contact tip 4 which is securely fastened to it by brazing. Thus, the replacement of this contact tip can be carried out very easily by stopping the circulation of the cooling water in the electrodes, by applying them to a resistive metal sheet and by passing through them a current of sufficient intensity to cause the brazing ring 5 which securely fastens the contact tip 4 to the welding cap 3 to melt. The removal of a worn tip 4 and the replacement of a new tip 4 are carried out in the same manner. The welding electrode also has a contact tip 4 provided with a brazing ring 5, as well as to an automatically operating machine for replacing the tips 4 away from the line for welding the metal sheets T.

Abstract: The welding operation performed by the clamp 12 is under the control of a welding cabinet 15 including a servo-control unit 16' and an electronic switch 17. The clamp is moved from one weld spot to another by a robot 13 under the control of a control unit 14 provided with a servo-control unit 16. The switch 17 is controlled in such a manner that the welding operation and the beginning of the clamp opening operation and the end of the clamp closing operation are under the control of the welding cabinet 15 (with the robot then remaining stationary), while displacement of the clamp synchronizing with wide opening and closing thereof are under the control of the control unit 14.

Abstract: A tool comprising tongs with two pivoted arms and a release system. The two arms each bear, at their respective ends, pressure members. A drive motor causes the arms to pivot with respect to one another, either to close them and thus permit the pressure members to grip the part to be treated, or to open them and permit the release of the part with respect to the tongs after treatment. This tool in addition includes a release system which insures that the two pressure members are well separated from the part after actuation of the opening of the arms. The release system includes a coupling device adapted to actively control the opening and closing of the arms using a fraction of the power of the drive motor. Preferably, this coupling device is an electrically controlled clutch.

Abstract: For improving the quality of welding operations, in a process for alternating current welding, in which during a period the actual r.m.s., welding current is measured and the phase displacement of the use of current flow during the next period of the a.c. current is regulated. Variations of the actual r.m.s. welding current during all the welding periods already performed are taken into account and compared with a desired r.m.s. current during the welding period to be performed. A welding apparatus for alternating current welding using two welding electrodes, a power supply for the same and a device for regulating the r.m.s. welding current during each a.c. voltage period has a computer for taking into account variations of the actual r.m.s. welding current during preceding welding periods of a welding operation compared with a desired r.m.s. welding current flow during the further welding periods to be performed of the particular welding operation.