Abstract: A valve assembly of the type, wherein a first end of a movable plunger is adapted to collapse or compress a first tube length against an opposite tube backing or support structure in order to regulate or vary the flow conditions of a fluid in this first tube length, is equipped with a control assembly comprising a second interiorly pressurized tube length and a second or opposite end of the plunger engages this second tube length. Thus, by appropriately proportioning the sizes of the contact faces between the respective plunger ends and the tube length associated therewith it will be possible to control the flow conditions in one of the tube lengths responsive to the fluid pressure in the other tube length whereby various valve or regulating functions may be performed by the valve. The two tube lengths may be parts of one and the same tube whereby additional valve or regulating functions may be performed.

Abstract: A rod-shaped, manually operable or controllable handpiece is disclosed which e.g., comprises an annular actuating member positioned in a rod-shaped handle portion having actuatable means and a casing for enclosing the actuatable means with which the actuating member is in operative connection. The actuating member comprises at least one ring or disc movable between two positions substantially perpendicularly to the longitudinal axis of the casing, the largest diameter or corresponding external dimensions of said ring or disc being larger than the height or thickness hereof, the axis thereof in said central position being parallel to the longitudinal axis of the casing, and the external side thereof in the central position flushing with or extending equally outside the surface of the casing and whereby the axis of the ring in the outer position is displaced parallel to or forms an acute angle with the axis of the casing.