GB1277102A - Apparatus for delivering a predetermined volume of a liquid - Google Patents

Abstract

1277102 Sample dosing device E ENGELBRECHT 23 July 1969 [24 July 1968] 36974/ 69 Heading B1X [Also in Divisions B8 and F1] The apparatus of Fig. 1 comprises a pipe 8 held wthin a first container 5 with an open end of the pipe at a determined level, the pipe being in communication with the interior of a second container 3 via a closure member 2 which is such as to seal the second container when the mouth of the latter is applied thereto, and means for reducing the pressure in the second container relative to that in the first instance. Actuation of the means which includes pipe 1 causes the volume of liquid above the open end of pipe 8 to be delivered to the second container. The pipe 8 may be supported by means permitting adjustment of the level of the open end within the first container (Figs. 1A, 1B not shown). In the apparatus of Fig. 2 suction applied via pipe 48 will cause liquid above the open end of pipe 44 in container 39 to be delivered to container 47, and displacement to the right of piston 34 against bias of spring 50. The container 47 is initially held against closure member 46. During the rightward displacement of the piston communication between the pipes 44, 45 is broken. At the end of the displacement a variable volume defined by piston portion 35 and the cylinder wall (Fig. 2A) is in communication with the container 39 via pipe 42, and the suction pipe 48 is in communication with the container 39 via pipes 45, and 51, so that suction will cause transfer of the liquid in the volume into the container 39. Upon breaking the suction, e.g. by removing the container 47 from the closure member the piston will return to its illustrated position. Application of the container 47 to the closure member will initiate another such cycle. In a modification of the Fig. 2 embodiment reservoir 31 is flexible and suction is not applied via pipe 48 which instead has a one way valve. In this modification port 41 is connected with a space above the liquid in the reservoir. Upon squeezing the reservoir the piston will be moved to the right. During this movement only liquid in the volume 35 will be delivered to the container 39. Upon release of the reservoir the piston will be biassed by spring 50 to its illustrated position and the suction induced in container 47 by the piston will effect delivery of liquid from the container 39 into the container 47 upon the pipes 44, 45 being in communication.