Advancing mechanism for a dispensing tool

Claim 1

A tool for dispensing a single component or a multi-component mass within a cartridge or foil bag (3) by pressing the mass out of the cartridge or foil bag (3), comprising: at least one axially extending piston rod (7) and at least one advancing mechanism (6) for moving the piston rod (7) in a dispensing direction, said advancing mechanism including first and second clamping levers (12, 13) mounted on the piston rod (7) and being displaceable in the axial direction of said piston rod and being pivotable about an axis extending transversely of the piston rod, wherein said first clamping lever (12) is for moving said piston rod (7) in the dispensing direction and the second clamping lever (13) is for locking said piston rod (7) in the axially displaced position; at least two springs (14, 15) in biasing contact each with a different one of said first and second clamping levers (12, 13), a triggering lever (11) for operating said first clamping lever (12) and an unlocking lever (17), which when pivoted, moves a transmission element (18) for substantially simultaneously disengaging said first clamping lever (12) from the piston rod (7) and unlocking said second clamping lever (13), said transmission element (18) being at least in part, located between said first and second clamping levers (12, 13), whereby the locking lever (17) moves the transmission element (18), thereby pivoting the first and second clamping levers such that the piston rod (7) can be freely displaced relative to the clamping levers (12, 13), wherein an axial stop (11a) for said first clamping lever (12) is located on said triggering lever (11), and said triggering lever is pivotally mounted for pivotal movement between two spaced end stops (5b, 5c).