Dispenser including a translatable piston

A dispenser for a product including a cylindrical reservoir for the product, said reservoir having a dispensing opening at one end thereof and a movable piston disposed therein for translation in said reservoir, drive means including a rod having one end connected to said piston, said drive means being actuatable by a user upon actuation of a maneuvering device to incrementally displace said rod, said maneuvering device being carried on a support element assocated with said drive means, said drive means including one end portion that is fixed relative to said reservoir and another end portion that is movable relative to said reservoir, said and portions being connected by an elastic zone, said maneuvering device by the user from an initial position of repose with said elastic zone returning said another end portion and maneuvering device to the initial position, means for restraining said rod against rotation relative to said support element, said rod and drive means having interengaging rack means including latching means for transmitting movement from said drive means to said rod, said latching means engaging said rod when in one position of rotation and disengaged from said rod when in another position of rotation relative to said latching means, wherein said reservoir is detachable from the support element onto which it is assembled, said support element being a tubular body, one end of which includes a means for attachment to the reservoir said reservoir including one and which surrounds said means for attachment, said body being closed at its end opposite the reservoir by a maneuvering device, said maneuvering device being a pushbutton capable of sliding in the tubular body, said drive means comprising a cage cast by molding of a relatively flexible plastic material, and comprising two lateral branches, said elastic zone comprises a median zone which is corrugated, in the plane of said branches.