US 2991805 A
Description (OCR text may contain errors)
July 11, 1961 P. F. PAGE 2,991,805
PNEUMATIC VALVES Filed Jan. '7, 1958 Fig. I
INVENTOR PAUL F. PAGE ATT'oRNEYs United States Patent 2,991,805 PNEUMATIC VALVES Paul. F. Page, Newington, Conn assignor to Royal McBee Corporation, Port Chester, N.Y., a corporation of New York Filed Jan. 7,1958, Ser. No. 707,566 4 Claims. (Cl. 137-625.27)
This invention relates to a pneumatic valve which may be used to store information and more particularly relates to an improved construction for bistable pneumatic valves.
The use of conventional types of pneumatic on-off valves as a means for storing binary coded information has heretofore been unreliable in that a termination in the operation of the associated pneumatic pumping equipment always causes this type of valve to assume a given normal condition. This may result in the loss of information which has previously been stored in said valves. This difficulty can not always be rectified by merely restoring the pumping means to normal operation; rather a resetting of the valve may be additionally required in order to restore the lost information to the memory unit.
If the valve is to be properly reset then the condition thereof at the time of the termination of operation of said pump means must be known and such may be indeterminate where said pump failure has occurred unexpectedly. It will be apparent that an information storing unit which uses conventional type pneumatic on-ofi valves will have a volatile memory.
The present invention overcomes these difliculties by providing a means whereby the memory of a pneumatic information storage unit may be made non-volatile.
The primary object of the instant invention is to provide a novel construction for a pneumatic valve whereby the movable valve member may be retained in either of its two operative positions when the sub-atmospheric pressure supply to the valve is cut off.
Other objects of the invention will become apparent as the disclosure progresses.
In the drawing:
FIG. 1 is a diametral sectional view of the instant valve structure.
The construction and operation of the conventional portions of the valve of FIG. 1 will be reviewed first. The valve comprises a body member having two internal spaced partition walls 11 and 12 which are provided with centrally disposed apertures 13 and 14 respectively. A valve member 15 is operatively disposed in said apertures, said member having a headed upper end 16, a flange portion 17 and a stem portion 18. The space enclosed above the partition wall 11 is divided into two chambers 20 and 21 by means of the flexible diaphragm 22 which is centrally secured to the upper stem portion of valve member 15. The space enclosed below said partition wall 12 is divided into two chambers 23 and 24 by means of the flexible diaphragm 25. The space between the two partition walls 11 and 12 defines a chamber 26. Chambers 20 and 26 are pneumatically interconnected by the restricted bleed passage 27. Pressure conduit lines 28, 29, 30, 31 and 32 communicate with said chambers 20, 21, 26, 23 and 24 respectively. The chamber 24 is pneumatically connected to line 32 and to chamber 23 through the bleed passage 33. The lines 28 and 32 constitute the valve input or control lines, while line 30 constitutes the valve output line. Line 31 is connected to a sub-atmospheric pressure source; whereas line 29 is open to the atmosphere whereby the pressure in chamber 21 is always substantially atmospheric.
In operation the valve is adapted to be actuated to an on or an off condition wherein the valve member 15 is in an upper or a lower operative position re- 2,991,805 Patented July 11, 1961 ice spectively. When the valve member 15 is in the lower or off position as shown in FIG. 1, the flange portion 17 overlies and pneumatically blocks the aperture 14. Under these conditions it will be seen that a sub-atmospheric pressure exists in the chambers 23 and 24 and control line 32, and that an atmospheric pressure exists in the chambers 20, 21 and 26. Thus the differential pressure acting on the opposite sides of said valve flange portion 17 will hold said valve member in the off position. In this condition of the valve the pressure in the valve output line 30 will be atmospheric. To switch the valve to the on condition, an atmospheric pressure impulse is initiated in the control line 32 thereby increasing the pressure in chamber 24. Before the pressure in chambers 23 and 24 can be equalized by air flow through the restricted passage 33 the differential pressure acting on opposite sides of the diaphragm 25 will cause said diaphragm to be flexed upwardly thereby engaging and lifting the valve member 15 to an upper or on position wherein the flange portion 17 overlies and pneumatically blocks said aperture 13. In this condition of the valve the chambers 20, 26, 23 and 24 will be subjected to the said sub-atmospheric source acting through line 31 and hence the pressure in the valve output line 30 Will be lowered to a sub-atmospheric level. When the valve member 15 is moved to said upper position it will be retained there by a differential pressure acting on opposite sides of the diaphragm 22, said valve member 15 being connected to diaphragm 22 as above described. This difierential pressure acting on opposite sides of the diaphragm 22 and retaining the valve member 15 in the upper or on position will exist after the said pressure impulse in control line 32 has been terminated and will remain unchanged until a subsequent pressure impulse is initiated in the other control line 28 to thereby reset the valve to the off condition. It will be noted that when the valve is in the on condition the pressure in chamber 20 and in control line 28 will become subatmospheric due to their interconnection with chamber 26 through said passage 27.
When it is desired to reset the valve to the off condition, an atmospheric pressure is initiated in the control line 28. This will serve to reduce the differences in pressure acting on diaphragm 22 so that the diaphragm and the valve member 15 may be lowered by the differential pressure now acting on said flange portion 17. Once this occurs the valve member 15 moves to and is again held in the off position shown in FIG. 1. The valve member 15 will be so held in the off position after the termination of the said pressure impulse in said control line 28 until an atmospheric pressure impulse is again initiated in the now evacuated control line 32. After the valve member 15 has been reset to the lower operative position of FIG. 1, the pressure in the valve output line 30 will be restored to an atmospheric level.
The valve shown in FIG. 1 is operationally bistable and hence groups of this type of valve may be used to store bits of information which are coded in binary form. If the said sub-atmospheric pressure source acting through the conduit 31 is cut off then the pressure in the various chambers of the valve will soon come to an atmospheric level and gravity will cause the valve member 15 to assume its lower operative position shown in FIG. 1. When said sub-atmospheric pressure source is again operatively connected to the valve, said valve member will remain in its said lower position at least until a pressure impulse is received through the control line 32. Under these conditions if valve member 15 was in its upper position before the said sub-atmospheric pressure source was cut off, it will be apparent that the information represented by such a condition of the valve would have been lost as soon as said pressure source was cut off. This difiiculty makes the operation of a pneumatic memory unit entirely dependent on the continued and uninterrupted operation of the pneumatic pumping means associated with said memory unit. This situation is obviously undesirable as any inadvertent misoperation of the power supply switches or the malfunction of any of the elements in said supply means could destroy the in formation which has been computed and/ or stored in the system. 7
The valve shown in FIG. 1 is constructed so as to overcome the above noted difliculty. Here independent and separably operable means are provided for yieldably retaining the valve in each of its two stable conditions. Said means includes a permanent magnet 40 which is fixedly secured to the upper wall 39 of the valve body member 10 and which is adapted to coact with the pad 41 of magnetizable material that is fixedly secured to the top of valve member 15. Said magnet is operatively disposed so that when the valve member 15 is in its upper position there will be a slight gap between the upper surfaces of pad 41 and the lower edges 42 of the magnet. Operatively disposed between the magnet 40 and the valve member 15 is a compression spring 43,. The strength or the operational effect of the spring 43 is such that when the member 15 is in its lower position the downward force exerted on member 15 by the spring is greater than any upward attractive force exerted on said member by the magnet; and when said valve memher is in its upper position, the upward attractive force exerted on the member by the magnet is greater than the downward force exerted by the spring. In other words when the member 15 is moved from its lower to its upper operative position the increase in the upward attractive force of the magnet 40 is much greater than the increase in the repelling force of the spring 43. Under these conditions it may be readily seen that if the member 15 is in its lower position and the sub-atmospheric pressure supply to the valve is cut off, then the spring 43 will yieldably retain member 15 in said lower position. On the other hand if the member 15 is in its upper position when said pressure supply is cut off then the attractive force of the magnet 40 will yieldably retain member 15 in said upper position. In this manner the valve of FIG. 1 will retain its bistable operational characteristics regardless of the operating conditions of the sub-atmospheric pressure source associated therewith; hence the memory system may be turned E and then on without losing any of the information previously stored therein.
While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration only and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.
The invention claimed is:
l. A bistable pneumatic valve; comprising a valve body formed with a central chamber and an upper and a lower chamber respectively communicating with said central chamber, a first flexible diaphragm operatively disposed in said valve body so as to divide said upper chamber into outer and inner portions, a second flexible diaphragm operatively disposed in said valve body so as to divide said lower chamber into outer and inner portions, an output line communicating with said central chamber, an atmospheric pressure line communicating with the lower portion of said upper chamber, a sub-atmospheric pressure line communicating with the upper portion of said lower chamber and adapted to be connected to a' subatmospheric source,a valve member operatively disposed in said central chamber and being movable to upper-and lower valving positions wherein said atmospheric pressure line and said sub-atmospheric pressure line are alternately pneumatically disconnected from and connected to said output line, a first control line communicating with the upper portion of said upper chamber, a second control line communicating with the lower portion of said lower chamber, said control lines being adapted to alternately transmit control pressure impulses which respectively flex said diaphragms which in turn alternately move said valve member to its said upper and lower valving positions, and means for yieldably retaining said valve member in its last held position when said subatmospheric pressure line is pneumatically cut oii from said sub-atmospheric source.
2. Apparatus as defined by claim 1 wherein said yieldable retaining means includes at least one spring.
3. Apparatus as defined by claim 1 wherein said yieldable retaining means includes at least one magnet.
4. Apparatus as defined by claim 1 wherein said yieldable retaining means includes a permanent magnet which is secured to said valve body and which is magnetically cooperable with said valve member, and a compression spring operatively disposed between said magnet and said valve member.
References Cited in the file of this patent UNITED STATES PATENTS Davies Nov. 18, 1958