GB982016A - Valves for pneumatic logic apparatus - Google Patents

Abstract

982,016. Valves. BECKMAN INSTRUMENTS Inc. Oct. 9, 1962 [Nov. 9, 1961], No. 38107/62. Heading F2V. [Also in Division G4] Logical operations are performed pneumatically by an assembly of valves of which a single example is shown in Fig. 1 and comprises a slidable valve member 16 having a restricted passage 24 communicating with an outlet 15, a central 0-ring seal 26, and O-rings &c. 20, 21 at each reduced end of the valve member or in end faces 22, 23 of the chamber in which the valve member slides. Alternatively, needle valves may be used in place of the 0-rings. A first pneumatic signal appears at the outlet 15 if it is applied simultaneously to the two inlets 13, 14 whereas a second signal appears at the outlet if it is applied to either or both of the inlets. For example, the second signal may be pressurization and the first signal lack of pressurization or venting. In this case, if 13 is vented and 14 pressurized the valve member will be urged upwardly to cut off 13 and to connect 15 directly with 14, whilst if 13 is pressurized and 14 vented the valve member will move downwardly to isolate 14 and connect 15 with 13 through the restricted passage 24. If 13 and 14 are both vented or both pressurized, 15 will be vented or pressurized, respectively whatever the position of the valve member. According to the invention a unitary structure houses a number of such valves of which each has one individual inlet and one inlet that is common to all of the valves. A " cross-bar " switch may be composed of a matrix of rows and columns of these valves in which each row has a common inlet 13, each column has a common inlet 14 and each valve has its own outlet 15 so that a single outlet may be selected by the application of a signal to one row and one column by manually operated selector valves. Fig. 2 shows a modified valve which operates in the reverse sense, i.e. it will pressurize the outlet 35 in response to pressurization of both inlets 33, 34 but will vent the outlet in response to venting of one or both of the inlets. This valve has a valve member 36 with a reduced intermediate portion provided with an O-ring seal 38 and an unrestricted bore 48. 0-rings 41, 46 coact with the end faces of the valve chamber and restricted passages are formed around the periphery of the enlarged head portions 39, 44 or by small bores (not shown) in the head portions spaced radially outwardly of the O- rings. The modification shown in Fig. 3 operates in the same sense as that of Fig. 2 but has the valving surfaces constituted by inwardly facing parts of the head portions of the valve member. The bore 57 which communicates with the outlet 52 and with the space between the head portions may be extended upwardly to a neck portion (not shown) slidable in a blind bore and corresponding with the neck portion 56 which slides in the outlet 52. " Crossbar " switches may also be formed by assemblies of valves as in Figs. 2, 3.