GB1439105A - Dental handpiece - Google Patents

Abstract

1439105 Valves KALTENBACH & VOIGT 15 Feb 1974 [8 March 1973] 7136/74 Heading F2V [Also in Divisions A5 and G3] A dental hand piece having an internal line 8, Fig. 2, for the passage of a fluid medium comprises a holding sleeve, an adjustable throttle in line 8 and an actuating ring 2 slidable on the hand piece for adjusting the throttle, the throttle being constituted by at least one groove 10 on the inner surface of ring 2, communicating between an upstream line portion 8a and a downstream line portion 8b. The ring 2 is sealed to an inner member 1 by packing rings 16, 17, and axial movement is prevented by guideways 18, 19 and a screw 29, Fig. 3, which is engaged with a groove 26 in the member 1. A latching ball 23, resiliently biased by a compression spring 24, may engage with recesses 20, 21 or 20a as the ring 2 is rotated, so that either groove 10 or another groove 11 is carrying the flow, or, in position 20a, no groove connects the two parts of the line 8. In this case flow occurs only through a connecting duet 25. In another embodiment, Fig. 1 (not shown), a cooling water line (5) is throttled before joining a cooling air line (6). In this case the actuating ring (2) engages the inner member (1) at a screw thread (12) so that rotation of the ring causes it to move axially along the member (1). The ring (2) contains a single groove (10) the area of which intercepted by the inlet line (5a) varies continuously as the ring (2) is moved axially, reaching zero when the ring (2) meets a packing ring (15) and an end stop (14). In a third embodiment, Fig. 4 (not shown), the throttle and its associated actuating ring (2) are integral with a connecting member (3) by means of which the holding sleeve (3a) is connected to a hose coupling sleeve (4).