GB654873A - Improvements in or relating to apparatus for delivering measured quantities of substances - Google Patents

Abstract

654,873. Pumps. BECKER, F. W. Oct. 13, 1949, No. 21266/50. Divided out of 654,861. [Class 102(i)] [Also in Group XVIII] Apparatus for delivering measured quantities of a liquid or semi-liquid substance comprises a cylinder 101, a head 102 closing one end of the cylinder, a member 103 closing the other end of the cylinder, a piston 105 movable within the cylinder and dividing the interior thereof into an operating chamber 119 and a displacement chamber 118, supply and delivery passages 131, 125 respectively, for the substance leading through the cylinder head and communicating with the delivery chamber 118, and compressed air inlet and outlet passages 133, 141 leading through the cylinder head and communicating with the operating chamber 119, through a pipe 129, is characterized in that the cylinder head 102 is formed with two bores one of which, 121, is connected with the said supply and delivery passages 131, 125 and the other of which. 122, is connected with the said air inlet and outlet passages 133, and in that each of the bores contains a slide valve member 123, 124 respectively; controlling the flow through the corresponding passages, which valve member is so formed that when it is moved in one direction it connects the appropriate chamber in the cylinder with the source of supply of the substance or with the compressed air supply, as the case may be, whereas when it is moved in the opposite direction it allows the discharge of the substance or of the air from the chamber to the place of use of the substance or to atmosphere respectively. The valve member 123 is formed with bores 140 and 139 adapted to connect the displacement chamber 118 either to the supply passage 131 or to the discharge passage 125 according to the longitudinal position of the valve member. The compressed air valve member 124 in its innermost position allows the flow of air from the inlet 133 through an axial bore 142 and a port 145 in said member to a space 128 and thence by the pipe 129 to the operating chamber 119, while in its outermost position a ball 147 shuts off the supply of compressed air and air from the chamber 119 is allowed to vent through the pipe 129, the space 128, a port 144 in the member 124, the bore 142 and the port 145 to the atmosphere. A lever 160 pivoted at 161 to an extension 162 on the cylinder head 102 moves the valve members 123, 124 simultaneously in the same direction, the lever normally holding the valves in their inner position. An adjustable screwed stop sleeve 115 is adapted to vary the stroke of the piston 105. This lever may be manually or cam operated.