Patent ID: 8020842
Filing Date: 2011-09-20
Classification: B23K,B25B,Y10T

Abstract:
1. Clamping tool comprising a first member ( 18 ) and a second member ( 20 ) displaced relative to each other under the action of a drive device, this device comprising a screw ( 10 ) of a given pitch (P 1 ) capable of being rotatably driven about an axis (XX) in one direction or in the opposite direction under the action of a motor (M), a nut ( 12 ) cooperating with the screw ( 10 ) and capable of being translationally displaced in the direction of the axis (XX) of the screw, the said nut moving translationally as one with the first member ( 18 ), first guide means ( 34 L) defining a linear guidance parallel to the axis (XX) of the screw ( 10 ) in order to prevent the rotation of the nut ( 12 ) in a first displacement phase (Dl) of the nut, and second guide means ( 34 H) defining a helical guidance that extends along the axis (XX) of the screw ( 10 ) and which has a pitch (P 2 ) that is opposite to the pitch (P 1 ) of the screw in order to permit the rotation of the nut ( 12 ) in the same direction of rotation as the screw ( 10 ) in a second displacement phase (D 2 ) of the nut ( 12 ), as well as a compensation system ( 46 ) arranged between the first member ( 18 ) and a mobile support ( 14 ) integral with the nut ( 12 ) in order to reset the position of this first member ( 18 ) with respect to the second member ( 20 ), so that the first and second displacement phases produced by the first and second guide means ( 34 L) and ( 34 H) remain synchronous with the phases necessary for an optimisation of the displacement of the first member, characterised in that the compensation system comprises a compensating disc ( 68 ) rotating as one with a hub ( 50 ) screwed about the mobile support ( 14 ), a measurement disc ( 80 ) mounted on the mobile support ( 14 ) by means of a freewheel mechanism ( 76 ), and at least one energy-storing spring ( 74 ) arranged between the compensating disc ( 68 ) and the measurement disc ( 80 ), so that the memorising of the degree of wear of the parts is specified by the relative angular position of the measurement disc ( 80 ) and of the mobile support ( 14 ), and in that, during the second displacement phase (D 2 ) of the nut ( 12 ), the need to carry out a wear compensation is established by the abutment of the measurement disc ( 80 ) against the mobile member ( 18 ), the compensating disc ( 68 ) being rotatably driven by the hub ( 50 ) then compressing the spring or springs ( 74 ) until the mobile support ( 14 ) no longer moves.