GB691912A - Improvements in systems for supplying fluid to components sequentially - Google Patents

Abstract

691,912. Pneumatic single-stroke apparatus. DAVY & UNITED ENGINEERING CO., Ltd., and BEARD, J. H. Dec. 11, 1950 [Dec. 12, 1949], No. 31852/49. Class 8 (ii) [Also in Group XXIX] In a fluid flow sequence system for two fluidoperated components requiring sequential operation, the system being provided with a flow sequence valve having a piston and means for supplying fluid under pressure to a space at one end of the piston while a separate volume of fluid in a space in communication with one of the components at the opposite end of the piston is forced in a direction such as to operate that component and means for putting the two spaces into communication with one another after the piston has moved a certain distance so that continued operation of the said component is effected as a result of fluid flowing from one of the said spaces to the other, when such flow between the two spaces is arrested, the piston returns to its initial position and thereby initiates the operation of the second component. A two-position hand operated control valve 102 controls an inlet port 169 from a fluid supply system 167, exhaust ports 197, 217, a port 171 connected to one end of a two-position valve 156, and a port 189 connected to the other end of valve 156 and to a port 192 in a valve block 109. The valve block 109 is bored to accommodate two pistons 111, 110 biased upwardly by springs 145, 131 respectively. The piston 111 comprises an end cap 135 secured to the upper part and forming a seat for a spring- loaded valve 140 slidably fitted within the piston. The piston 111 and cap 135 are hollow and the interior of the upper part of piston 111 communicates through ports 141 in the valve 140 and ports 137 with a chamber 138 in the body 109 and the open end of the cap 135 communicates with a chamber 149 which is connected to a cylinder 160 containing a piston 158 which is to be actuated. The other end of the cylinder 160 is connected to the valve 156. A port 121a in the body is connected to another cylinder 161 containing a piston 159, the opposite end being connected to the fluid supply system 167. The valve 156 is connected to the supply 167 at 177 and to a port 200 in the chamber 138 at 198 and to exhaust at 219, 207. In the lower position of the valve 102 the supply 167 is connected by ports 169, 189 to the right hand end of valve 156 the piston of which is moved to the left thereby connecting the right hand side of cylinder 160 to exhaust at 207 and the supply 167 through 177, 198 to port 200 and to the interior of piston 111 which is forced down, thereby connecting chambers 138, 149 and supplying pressure to cylinder 160 to move the piston 158, the dimensions of which are so determined that the net power is appreciably greater than the pressure which it is required to exert. The piston 111 uncovers a port 112 and fluid is supplied to the top of piston 110 which is forced down. At the end of the stroke of piston 158 pressures in chambers 138, 149 equalise and piston 111 moves up under the influence of the spring 145, fluid above the valve 140 exhausting through a restricted opening 209. The piston 110 is held down by fluid entering the port 192 and when the piston 111 reaches the upper position this port is connected by a duct 115 to the port 121a to supply fluid to the cylinder 161. To return the pistons the valve 102 is moved to the upper position whereby the piston of the valve 156 is moved to the right connecting the right hand side of the cylinder 160 to the supply 167 and chamber 138 to exhaust 219. Valve 102 connects port 192 to exhaust and piston 110 returns to the upper position exhausting through port 112 and pipe 124 to an exhaust chamber 120. The cylinder 160 exhausts through valve 140 to chamber 138. The cylinder 161 exhausts through port 121a port 115 through the piston 110 to chamber 120, both pistons returning simultaneously. The pistons 110, 111 may be accommodated in separate blocks. The valve 102 may be actuated bv remote control means.