Patent ID: 9211606
Filing Date: 2015-12-15
Classification: B23K

Abstract:
1. A clamp for gripping sheet metal and used in association with a manipulating arm, called a robot, and including: a rigid frame; a balancing actuator mounted on the rigid frame; a screw having a longitudinal axis extending from the balancing actuator and being driven in rotation in both directions about the longitudinal axis by the balancing actuator; a mobile subassembly, comprising: a main actuator having an actuator body, a stationary arm connected to the actuator body so as to remain stationary relative to the actuator body, and a mobile arm operatively connected to the actuator body with the main actuator being operable to move the mobile arm relative to the actuator body and the stationary arm between a closed clamp position and an open clamp position in order, respectively, to grip a sheet metal assembly between the stationary and mobile arms and to release the sheet metal assembly; a balancing module comprising: a cassette body secured to the actuator body so, as to remain stationary relative to the body of the actuator, and operatively connected to the rigid frame for axial translation of the cassette body and the mobile subassembly relative to the rigid frame and parallel to the longitudinal axis of the screw, a nut threaded onto the screw and placed into the cassette body to permit axial translation of the nut parallel to the longitudinal axis of the screw relative to the cassette body and the mobile subassembly, and to prevent rotation of the nut about the longitudinal axis so that the nut moves axially along the screw when the balancing actuator rotates the screw, a first balancing spring coupled between the upper side of the nut and the cassette body, placed into the cassette body, to urge the cassette body and the mobile subassembly in a first direction of axial translation parallel to the longitudinal axis, and a second balancing spring opposing the first balancing spring and coupled between a lower side of the nut and the cassette body, placed into the cassette body, to urge the cassette body and the mobile subassembly in the opposite direction of axial translation parallel to the longitudinal axis, and pre-stressed in opposition to the first balancing spring so as to urge the nut in opposition to the first balancing spring, and at least one position detector, capable of detecting a movement in said balancing module of a load formed by said mobile subassembly and members that are secured thereto in movement with respect to said support, wherein said position detector being also capable of controlling said balancing actuator in order to bring said load into a balanced position, said at least one position detector being a continuous position sensor, including at least one element secured to said rigid frame and connected to an electronic control circuit of said balancing actuator, and cooperating with a second element, secured to said mobile subassembly in the movements thereof.