GB915859A - Improvements in or relating to hydraulic positioning mechanisms - Google Patents

Abstract

915,859. Selecting record cards. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 13, 1961 [March 11, 1960], No. 9151/61. Class 106 (1). [Also in Group XXX] An hydraulic positioning mechanism for moving a bin 10, Fig. 2, containing record members along a straight path to a selected position comprises a cylinder 12 attached to the bin and a fixed piston 18 inside the cylinder having tubes 20a, 20b to supply liquid under pressure to the side and release it from the other when a control valve 70 is in a first position, the valve 70 having a second position in which the pressure to the piston is cut off to stop the motion of the bin, the setting of the control valve being controlled by a pump 48 operated by a cam surface 40 as the bin moves adapted to close the valve 70 when the bin is in the selected position. Valve 60 determines whether the movement is to be towards the left or the right by applying fluid pressure from supply 56 to either of pipes 55a or 55b and connecting the other via the outlet 58 to a sump. There are a number of bins and each has a selecting valve 72 which is operable to the lower position as shown in Fig. 3 by a solenoid-operated valve 78. This connects the bottom of the cylinder to the outlet 58 so as to allow the fluid pressure applied to a reduced piston portion 74 at the top of the cylinder, to move the piston to the lowermost position. This selects the bin 10 for movement by connecting the pipes 54a, 54b to the pipes 55a<SP>1</SP>, 55b<SP>1</SP>. It also lowers a locking detent 34 from engagement with a toothed rack 28. Movement commences when valve 70 is operated by energization of solenoid 96 to move the piston 91 of valve 94 so as to release the pressure below piston 89 via pipe 90. This piston then falls under the influence of spring 95 and allows a through passage for the pressure fluid and the return fluid. Connected to pipe 90 is the pump 48, the piston 46 of which is spring loaded and has a roller 44 running on cam surface 40 as the bin moves. The fluid displaced by the pump is passed through the valve 94, when open, to an elastic reservoir 100. However, when the valve 94 is closed by deenergization of solenoid 96 the next high part of the cam 40 encountered by the roller 44 causes the pump 48 to force fluid into the cylinder of valve 70, thereby lifting the piston and cutting off the supply to the slave cylinder 12 so that the bin stops. The cam 40 is formed so that the bin comes to rest in one of the positions where a record strip may be withdrawn from one of the seven magazines carried by the bin. The bin is more accurately indexed upon de-energization of solenoid 86 which allows valve 78 to pass fluid under pressure to the lower side of the piston of valve 72 so that it lifts to engage the detent 34 with the aligned notch of the rack 28. In simple operation therefore the valve 94 is operated first before the bin reaches the desired position and the selecting valve 78 is operated when the desired position is reached. To increase the speed of operation the second valve 71 is provided in parallel with valve 70. If the desired displacement of the bin exceeds three steps this second valve is operated by valve 114 to allow more fluid to pass to the slave cylinder than can pass through valve 70 alone. When the bin reaches a point three steps from its destination the valve 114 operates to re-apply the pressure below piston 110. The closing operation of valve 71 is slow because the pipe 118 has a restriction 120. This slows down the speed of the bin gradually to prepare it for final stopping at the desired place. A one-way valve 124 allows the valve 71 to open quickly when the pressure below the piston is released by valve 114.