Hydraulically-operated mechanical tongs, e.g. cutting, stamping, or riveting tongs, has spring-loaded distance piece at rear of movable jaw cooperating with operating piston under control of operating element

摘要

The invention relates to an apparatus for the mechanical machining of workpieces, having two tong members in the form of two-armed levers which are mounted rotatably with respect to each other and to whose working ends tool instruments can be fastened, the one tong lever having a fixed tong handle and accommodating a driving piston whose ram can be moved over a selectable advancing stroke path towards a driving end of the other tong member, as a result of which the working end of the other tong member can be moved onto the working end of the one tong member counter to a restoring spring in order to execute a working stroke, the other tong member having, as the driving end, a pivotably coupled spacer which can be orientated towards the ram with a tension spring, which holds the spacer outside an advancing stroke path of the ram, acting on the free end of the said spacer, and on which spacer at least one driver element is provided which is engaged with a pivotable actuating element which pivots the spacer counter to the tension spring force and, supporting it with respect to the one tong member, into the advancing stroke path of the ram keeping the driving ends spaced apart and converging the working ends until they reach a closed position, and which actuating element has a projection which, when the closed position is reached, can be moved against a switch in order to trigger the working stroke.