GB394252A - Improvements in saliva suction devices - Google Patents

Abstract

394,252. Saliva ejectors. BJÍRKLUND, K. C., Norrk÷ping, Sweden. Dec. 15, 1932, No. 35549. Convention date, Dec. 22, 1931. [Class 81 (ii).] In saliva suction devices, a valve inter posed in the suction conduit, is adapted to open automatically to admit air when the vacuum exceeds a pre determined amount In the form shown ir Fig. 1 a spring-pressed ball valve 6, adjustable bv means of the screw 9 or the seat 7, is mounted on the casing 4 which connects the mouthpiece 26 to the tubular connection 2 from the pump. The mouthpiece 26 is removably held in a rubber plug 3 resting against the flange 16 of a pipe 12 opening into the tubular connector 1. In modifications the spring-pressed valve may be replaced by a simple weighted valve member, or, as shown in Fig. 3, a mercury-filled U-tube 19 communicates with the vacuum pump, shown in this instance as a water-jet ejector pump, so as to allow air to bubble through if too high a vacuum is produced.