JPH0429910B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention (1) Industrial Application Field This invention relates to pneumatic valve technology, and more particularly, to a pneumatic valve technology, in which each body is equipped with a common electrical conduit and an exhaust flow control device projecting from a cover. Concerning an excellent four-way air valve. The four-way air valve can be stacked with other valves having a common pressurized air inlet passage and a common exhaust outlet passage. Each exhaust passage between the common exhaust outlet passage and each exhaust chamber in the main valve spool bore is then provided with a respective flow control valve mounted on the valve body. The four-way air valve of the present invention is suitable for use in an air flow line to control the flow rate of pressurized air to both ends of an air cylinder.

(2) Prior art and its problems It is well known in the pneumatic valve technology to provide valves that can be stacked. In the past, suitable air valves have been provided with a flow control valve at the exhaust port. However, until now, a stacking body with a respective flow control valve for each exhaust passage between a common exhaust outlet passage and each exhaust chamber in the main valve spool bore, and a solenoid at each valve in the valve stack has been used. It has not been possible to provide a stacking body capable of providing stacking four-way valves with a common electrical conduit for electrical connection to the air valves. Flow control valve is US Patent No. 2912007
2993511 and has been used in front of the exhaust port.

(3) Purpose of the invention The present invention has been made in view of the above,
Stacking valves with respective flow control valves for each exhaust passage between a common exhaust outlet passage and each exhaust chamber in the main valve spool bore, and electrical connection of the solenoid to the air valve at each valve in the valve stack. It is an object of the present invention to provide a four-way air valve having a simple construction with a common electrical conduit for connection.

[] Structure of the Invention (1) Means for Solving the Problems According to the present invention, a valve body including a pressurized air supply chamber, a pair of cylinder chambers, and a pair of exhaust chambers, and a valve body that includes a pressurized air supply chamber to the cylinder. between two actuating positions within the valve spool bore within the valve body to control the flow of pressurized air into one of the chambers and at the same time control the exhaust from another cylinder chamber to one of said exhaust chambers. A four-way air valve including an axially movable main valve spool, a valve body cover removably attached to the valve body, and means for moving the main valve spool between the two operating positions, (a) The pressurized air supply chamber is centrally located along the valve spool bore, the cylinder chamber is located along the valve spool bore adjacent to both sides of the air supply chamber, and the exhaust chamber is centrally located along the valve spool bore. (b) the valve body is arranged along a bore and adjacent one of the cylinder chambers on the side opposite to the side adjacent the air supply chamber; (c) said valve body comprises two cylinder ports each connected to one of said cylinder chambers by respective passage means; (d) said valve body comprises a single exhaust port connected by passage means to a common exhaust passage within said valve body, and each of said exhaust chambers is connected to a common exhaust passage by a respective exhaust passage; (e) each of said respective exhaust passages between each exhaust chamber and the common exhaust passage communicates with a common exhaust passage;
(f) an adjustable flow control valve with a valve body protruding from the valve body cover adjacent each of the respective exhaust passageway bores and mounted on the valve body; , said valve body is movable into and out of each adjacent passageway bore for controlling the flow of air from each exhaust chamber into a common exhaust passageway and out of a single exhaust port; (g) said valve body; a body having a common wire passage extending longitudinally therethrough; and (h) said valve body having a wire tuck chamber on each side of said common wire passage for receiving a lead wire from said common wire passage. A four-way air valve is provided.

(2) Operation The valve 10 of the present invention has two cylinder ports 6.
6, 67 and a pressurized air inlet port 64. The main valve spool 48 is movable between two operating positions and directs pressurized air from the pressurized air inlet port 64 to the cylinder ports 66,6.
an adjustable exhaust flow control valve 85 or 8 to alternately direct the air to any one of the cylinder ports 7 and to control the flow rate of air exhausted from the other cylinder port;
6 through which the other cylinder ports can exhaust fluid. One of the applications of the four-way air valve of the present invention relates to the operation of air cylinders, with free flowing air in one direction at one end of the air cylinder and said exhaust flow control from the other end of the air cylinder. The air cylinder is operated at a desired speed by providing a controlled flow rate of air through one of the valves, and then directing the free flowing air to the other end of the air cylinder.
It is used where it is necessary to reverse the speed control action by controlling the air exhausted from the opposite end of the cylinder.

(3) Embodiment Referring to the drawings, and in particular to FIGS. 1-3, the numeral 10 designates each four-way valve in the valve stack.
As shown in FIG. 4, each end of the valve stack seats in an end plate designated generally by the numeral 11. As shown in FIGS. 2 and 4, a plurality of valves 1 in the stack
0 are connected by a plurality of suitable tie rods, collectively designated by the numeral 14, each having a body 13 extending through the bore 16 of one end plate 11 and the bore 12 of each valve 10. Each tie rod 14
has a conventional tie rod head 15 at one end and a reduced diameter threaded end (see FIG. 4) which screws into a suitable threaded bore in the other end plate 11 at the other end. As shown in FIG. 4, a suitable seal member 30 is operatively mounted between each valve 10 and end plate 11 in the stack.

As shown in FIGS. 1 and 3, each end plate 11 includes a pair of suitable mounting legs or projections 22 on its lower outer side. Each mounting leg 22 has a U-shaped opening 23 between the pair of end plates 11 for receiving a suitable mounting screw or the like or for securing the stack of valves 10 to a suitable support table or the like.

As shown in FIGS. 1 and 3, the end plate 11 has a longitudinal end plate 11 that holds electrical wires connected to a suitable power source and receives energized electrical conduits for energizing the solenoids that actuate each valve 10. It includes a body 26 with a threaded pipe bore 27 at its upper end. Threaded pipe/
The inner end of the bore 27 opens into a bore 28 on the rear side of the end plate body 26 to complete the wire passage through the end plate 11. As shown in FIG. 4, the wire passages 28 are connected to a common wire passage 29 that vertically passes through the upper ends of adjacent valves 10. The other valves in the valve stack each have a similar common wire passageway 29, which are all aligned with the wire passageways 27, 28 in the two end plates 11 supporting the stack of valves 10.

As shown in FIG. 2, each of the valves 10 includes a valve body that is substantially T-shaped in cross-section and has an upper portion 33 and a lower portion 34. As shown in FIG. As shown in FIG. 2, each of the wire passageways 29 of each valve 10 is defined by a pair of laterally spaced internal integral walls 36 having openings formed through each of the upper ends. The upper end of each wall 36 is therefore provided with a top edge portion 37 located downwardly from the top of the valve body upper portion 33. Wires entering the stack of valve 10 through end plate wire passages 27, 28 into valve passage 29 are formed on each of the wire passage inner walls 36 and on the outside of each of the inner walls 36 in the upper part of the valve body. It can be seen that the electric wire storage chamber 40 (see FIGS. 1 and 2) is located within the electric wire storage chamber 40 (see FIGS. 1 and 2).

As shown in FIG. 2, the uppermost end of the wire storage chamber 40 and the uppermost end of the common wire path 29 of each valve 10 are surrounded by a valve body cover 41. As shown in FIG. Valve body cover 41
A suitable gasket 44 is installed between the inner surface of the valve body and the uppermost end of the upper valve body 33. Valve body cover 41
includes a plurality of suitable machine screws 42 extending through the cover 41 and into suitable threaded holes 43 in the valve body upper part 33.
It is removably fixed to the upper part 33 of the valve body. The numeral 46 in FIGS. 1 and 2 is an optional designation that is operatively mounted through the valve body cover 41 and operatively connected to electrical wiring to operate the respective valve 10. Therefore, the power lines extend into the common path. Therefore, when the solenoid is activated, this indicator light 46 lights up to indicate that the solenoid is activated.

Electric wires for operating the solenoids 58 for each valve 10 are connected to the valve body portion 33,
34 to each of the solenoids 58 below.
As shown in FIGS. 2 and 5, the left side of each valve 10 is provided with a wire passageway 50 that communicates with the lower end of the left wire storage chamber 40 at the lower end of the valve body upper portion 33. As shown in FIGS. The lower end of the wire passage 50 opens into a passage or outlet opening 51 extending to the outer side of the main valve body lower part 34 . If a second solenoid is used, as shown in FIGS. 2 and 5, the second solenoid at the right end of valve 10
The right wire compartment 40 also has a suitable wire passageway 5 for guiding the wire to a solenoid 58 (not shown).
0 to a wire outlet opening or passageway 51.

As shown in FIGS. 2 and 4, each valve 10 includes a main valve spool bore 47 in which a conventional valve spool 48 is operatively mounted. The illustrated main valve spool 48 is spring actuated in one direction and pilot air actuated in the opposite direction, and the flow of pilot air is controlled by a solenoid actuated pilot valve 57. As shown in FIG. 2, one end of the lower valve body 34 having the return spring 74 of the main valve spool 48 mounted therein is surrounded by a suitable cover 52 and gasket 54. The cover 52 is secured to the lower valve body 34 by suitable machine screws 53.

As shown in FIG. 2, numeral 56 indicates the pilot valve adapter housing and 58 indicates the pilot valve adapter housing by means of suitable machine screws (not shown).
A conventional solenoid is shown operatively attached to housing 56. A pilot valve adapter housing 56 is removably secured to the left side of the lower valve body 34 by suitable machine screws (not shown).
As shown in FIG. 2, a solenoid wire 60 for operating the illustrated solenoid 58 is connected to a wire passage 59.
and 61 to the housings of pilot valve adapter housing 56 and solenoid 58, respectively. The solenoid wire 60 is then routed through the adjacent opening 51 (see FIGS. 2 and 5) to the lower valve body 34, and from there through the upper adjacent wire passageway 50 to the left side as shown in FIG. Enter the wire tack room 40.

As shown in FIG. 4, the illustrated end plate 11 has a longitudinally threaded inlet 6 for connection to a suitable source of pressurized air.
4. The inner end of the inlet 64 is connected to one end of a longitudinal air inlet passage 65 passing through the adjacent valve 10. Other valves 10 in the stack of valves are provided with similar air inlet passages 65 extending therethrough.

As shown in FIG. 2, each valve 10 includes a pair of cylinder or work ports 66 and 67 extending inwardly from the bottom end of the lower valve body end 34. As shown in FIG. Cylinder ports 66 and 67 are respectively connected to cylinder chambers 68 and 69, respectively, of main valve spool bore 47. As shown in FIG. 2, a pair of exhaust chambers 70 are formed in the lower valve body 34 at opposite ends of the main valve spool bore 47. As shown in FIG. Exhaust chamber 7 on the left
0 are connected by exhaust passages 75, 76, 77 extending upwardly and communicating with a vertical exhaust bore passage 78 in the valve body upper portion 33.

As shown in FIGS. 2 and 5, the exhaust bore passage 7
The outer end of 8 opens into a vertical bore 92 of increasing diameter opening to the exterior of the valve body upper portion 33 . Exhaust flow control valves, designated generally by the numeral 85, are operatively mounted through the cover 41 and their inner ends are operatively mounted in the bores 78 and 92. Flow control valve 85 includes a valve body 88 operatively mounted in a vertical bore 78 connecting valve bodies 33 and 34 with a common exhaust outlet passage 80 extending longitudinally through exhaust passage 79 . Exhaust flow control valve body 88 is shown in the closed position, but as shown in FIG.
It can be seen that depending on the position of the valve body 88 with respect to the upper end of the valve body 6, the exhaust flow rate entering the common exhaust passage 80 via the bore 78 can be adjusted upwardly to select it. As shown in FIG. 4, the common exhaust passage 80 of the valve 10 adjacent to the end plate 11 is connected to a threaded common exhaust port 82.
leads to the inner edge of

As shown in FIGS. 2 and 5, the exhaust flow control valve 85 further includes a valve stem 89 integrally constructed with the flow control valve body 88. As shown in FIGS. The valve stem 89 is attached to a group formed around its outer circumference.
- a ring seal 95 and slidably mounted in a bore 90 formed axially in the upper end of the flow control valve cylinder retainer 91; The lower end or inner end of the flow control valve retainer 91 has a bore 92
can be attached to. An O-ring seal 93 and a releasable retainer ring 94 are attached to the bore 9.
The valve retainer 91 is attached to a group around the lower end of the outer periphery of the valve retainer 91 in the valve retainer 2. The valve retainer 91 has a shoulder portion 96
Equipped with. The retainer ring 94 is the retainer 91
is placed within the bore 92. Valve retainer 91 includes a threaded axial bore 102 at its outer or upper end that communicates with retainer bore 90 . An integral part of the valve stem 89,
Threaded outer end 99 is threaded into threaded bore 102 . The upper or outer head end 96 of the valve retainer 91 is enlarged to accommodate the opening 9 in the cover 41.
7 and extends outward. Appropriate O-ring 9
8 are seated in groups around the enlarged head 96 in sealing engagement with the inner periphery of the cover opening 97. The valve body 88 has a slot 10 at the outer end of the valve stem 89.
0 and rotate the valve stem 89 to the desired position in bore 78 with a screwdriver. Valve stem 89 can be secured in the desired adjusted position by a suitable locking nut 101.

As shown in Figure 2, main valve spool bore 47
The exhaust chamber 70 at the right end of the exhaust chamber 70 is also connected by passages 75, 76 and 77 to an exhaust bore 78 having a second exhaust control valve, generally designated 86, operatively mounted therein. As shown in FIG. 1, exhaust flow control valves 85, 86 are disposed symmetrically on either side of each valve 10. As shown in FIG. Exhaust flow control valves 85 and 86 regulate the exhaust from one end of an air cylinder, etc. to control the operating speed of the cylinder, and also take advantage of stacking and provide a common electrical conduit for the electrical wires for the solenoids that operate the valves 10 in the stack. The connection of each solenoid to the power supply can therefore be made at the respective solenoid stand.

As shown in FIG. 2, each of the lower valve body ends 34 includes a pair of longitudinally extending common pilot air passages 105 located on opposite sides of the air inlet passage 65. As shown in FIG. A common pilot air passage 105 is aligned with mating pilot air passages 105 in adjacent valves 10 in the valve stack. As shown in FIG. 3, each common pilot air passage 105 of the valve 10 adjacent the end plate 11 communicates with a mating longitudinal passage 103 of the end plate 11. Each of the passageways 103 is connected to the pressurized air inlet 10 of the end plate 11 by a transversely threaded bore 104.
9, thus connected to the inlet 64. It can be seen that the common pilot air passage 105 is internally supplied with pilot air from the air inlet 64. If an internal supply of pressurized pilot air is required, each of the passageways 104 can be closed by a plug 108 threaded onto the outer end of each of the threaded bores 104. Passage 10 in end plate 11
3 are supplied with pressurized pilot air from a suitable external source via passageways 106 in end plate 11. A plug 107 threaded onto the outer end of each passageway 106 is removed to connect the passageway 106 to the source of external pilot air when internal pilot air is used. It will be seen that both end plates 11 are provided with said internal and external connection means and passage means for supplying pilot air to a common pilot air passage 105.

As shown in FIG.
The vertical passageway 112 in the adapter housing 56 of the adapter housing 56 of FIG. The longitudinal passage 112 opens into a lateral pilot air passage 113 which is surrounded at its outer end by a threaded plug 114. If internal pilot air is not supplied from the common pilot air passage 105, pressurized air can be supplied to the pilot valve 57 by removing the plug 114 and connecting the passage 113 to an external source of pressurized pilot air. I understand.

The pilot air valve 57 includes a pilot air valve body 118, which includes a pilot air valve body 118.
18 from the passage 112 to the piston cylinder 11
2 to move the pilot piston 116 to the right and move the main valve spool 48 to the right against the pressure of the valve return spring 74. It is normally biased to the left by a return spring 117.
Details of the construction and operation of pilot valve 57 will not be described here as they do not form part of the present invention. Details of the construction and operation of pilot valve 57 are disclosed in the inventor's U.S. patent application Ser. No. 352,023 (U.S. Pat. No. 4,485,846).

When solenoid 58 is charged, solenoid plunger 119 moves pilot valve body 118 to the right as shown in FIG. 2, allowing pilot air to flow into piston cylinder 115 and causing pilot piston 116 to move to the right. and moves the main valve spool 48 to the right against the pressure of the return valve spring 74. When the solenoid 58 is de-energized, the pilot air valve body 118 releases the return spring 117.
2 to the position shown in FIG. 2, and the pilot air in the cylinder 115 to the rear or left side of the pilot air piston 116 exits the forward end of the piston cylinder 115 through the pilot valve structure and into the longitudinal common Pilot air exhaust passage 12
It is passed through a lateral exhaust passage 120 connected to 2. Main valve spool 48 is then returned by return spring 74 to the position shown in FIG. The pilot air exhaust passages 122 in the stack of valves 10 are aligned with each other, and the valves 10 adjacent to the end plate 11
It has a pilot air passage 122 connected to one vertical passage 122 (see FIG. 3). The pilot air passage 122 in the end plate is a transverse passage 12 extending outside the end plate 11 and discharging pilot air to the atmosphere.
3. Also, a muffler can be connected to the pilot air exhaust line 123, or a suitable conduit can be connected thereto to direct the exhausted pilot air to a point where it is removed from the valve stack.

The main valve spool 48 thereby connects the inlet passage 6
5. Cylinder ports 66, 67 and exhaust port 8
It is schematically shown with a return spring 74 to illustrate controlling the flow rate of pressurized air between the two.

In use, adjustable flow control valves 85 and 8
6 is a bore 78 and a valve body 88 of each flow control valve to adjust the operating speed of the air cylinder to a desired speed.
is adjusted to provide the desired opening between the two.

When main valve spool 48 is in the position shown in FIG.
connected to port 67, while cylinder port 6
6 is connected to the left exhaust passage 70 by a passage 68. When the solenoid 58 is charged, the main valve spool 48 has an air inlet passage 65 supplying pressurized air to a cylinder port 66 and another cylinder port 67 to the exhaust port at the right end of the valve, as shown in FIG. Move to the right to reverse the flow conditions described above to vent into passageway 70.

The operation of the four-way air valve 10 of the present invention will now be described with reference to the drawings and FIG. 6, which shows the flow path symbols.

Main valve spool 48 is moved to the position shown in FIG. 2 by the action of return spring 74 and the deenergization of solenoid 58 which actuates pilot valve 57. When main valve spool 48 is in the position shown in FIG.
7 and an internal chamber 69 to a cylinder or work port 67 to provide a free flow of pressurized air to the cylinder or work port 67 and to one end of the device to be controlled, such as an air cylinder. At the same time, pressurized air exhausted from the other end of the device, such as an air cylinder, enters another cylinder or work port 62 and is routed through passage 68 to valve bore 47 and from there to passages 70, 75-- 77
It is then sent to the exhaust passage 80 via the flow rate control valve 85, the controlled bore 78, and the passage 79.

The main valve spool 48 is moved to a second operating position to the left of the position shown in FIG. 2 to reverse the air flow through the valve 10. solenoid 58
is a conventional solenoid which, when energized, operates pilot valve 57. The pilot valve has a pilot piston 1 which is moved to the right as shown in FIG. 2 by pilot air pressure.
16, which engages the main valve spool 48 to move it to the right in order to reverse the direction of flow through the valve 10.

When main valve spool 48 is moved from the position shown in FIG. It is connected to a passageway 68 and thus directly to a cylinder or work port 66 to provide free flow of pressurized air from port 66 to the equipment to be controlled. At the same time, another cylinder or work port 67 is connected to the device to be controlled with respect to the other end of the air cylinder, and pressurized air from the cylinder entering work port 67 passes through passage 69 and then into exhaust passage 70. , 75-77, through a flow control valve 86, and thence through bore 78, which is controlled by the exhaust flow rate controlled by flow control valve 86, and thence to passage 79 and exhaust passage 80.

When the solenoid 58 is deenergized, the return spring 7
4 returns the main valve spool 48 to the first operating position shown in FIG. 2, resulting in flow through the first described valve 10.

(3) Effects of the invention The four-way air valve of the invention has an extremely simple structure. It has the advantage that only one common electrical conduit is sufficient for the electrical wiring required for the stack of valves, and that each valve in the stack can be connected individually as required. Additionally, the valve 10 of the present invention can selectively provide flow control functionality to the exhaust system of each valve and direct exhaust air to one or both of the end plates 11, from where it is routed to a muffler. It has the advantage of being able to be directed to a remote location or discharged into the atmosphere. A further advantage of the valve 10 of the present invention is that the valve 10
0 means that pressurized pilot air can be selectively supplied internally or externally.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional and plan view of a four-way stacked valve made in accordance with the principles of the present invention. FIG. 2 is a partial cross-sectional front view of the valve structure taken along the straight line 2--2 shown in FIG. FIG. 3 is a left side, front view of the valve structure regarding straight line 3-3. 4 is a cross-sectional front view of the valve structure taken along line 4--4 shown in FIG. 3. FIG. Figure 5 shows the straight line 5- shown in Figure 1.
FIG. 5 is a cross-sectional front view of two valves for FIG. 6th
The figure is a symbolic representation of the flow path of a four-way air valve according to the invention. Explanation of symbols, 10...Four-way air valve, 11...End plate, 13...Tie rod, 20...Mounting leg,
26... Common electric wire passage, 33... Upper part of valve body, 3
4...Lower part of the valve body, 41...Valve body cover, 47
... Main valve spool bore, 48 ... Main valve spool, 57 ... Pilot valve, 58 ... Solenoid, 64 ... Pressurized air inlet, 65 ... Air inlet passage, 66, 67 ... Cylinder port, 68,6
9... Cylinder chamber or passage, 70... Exhaust chamber, 7
4... Main valve spool return spring, 85, 86... Exhaust flow rate control valve, 80... Exhaust outlet passage, 117...
...Pilot valve return spring, 118...Pilot valve body.

Claims (1)

[Claims] 1. A valve body having a pressurized air supply chamber, a pair of cylinder chambers, and a pair of exhaust chambers, and controlling the flow rate of pressurized air from the pressurized air supply chamber to one of the cylinder chambers. and a main valve spool movable axially between two operating positions within a valve spool bore within the valve body to simultaneously control exhaust from another cylinder chamber to one of the exhaust chambers; A four-way air valve including a valve body cover removably attached to the body and means for moving the main valve spool between said two operating positions, wherein: (a) said pressurized air supply chamber is disposed along a valve spool bore; one of the exhaust chambers is centrally disposed along a valve spool bore, the cylinder chamber is disposed adjacent to both sides of the air supply chamber along a valve spool bore; (b) a pressurized air inlet adjacent one of the cylinder chambers on the opposite side to the side adjacent the air supply chamber; (b) said valve body being connected to said air supply chamber by passage means within said valve body; (c) said valve body comprises two cylinder ports each connected to one of said cylinder chambers by a respective passage means; (d) said valve body comprises two cylinder ports each connected to one of said cylinder chambers by a respective passage means; a single exhaust port connected to a common exhaust passage within the valve body, each of said exhaust chambers being connected to the common exhaust passage by a respective exhaust passage; (e) each exhaust chamber and a common exhaust each of said respective exhaust passages between the passages communicates with a common exhaust passage;
(f) an adjustable flow control valve with a valve body protruding from the valve body cover adjacent each of the respective exhaust passageway bores and mounted on the valve body; , said valve body is movable into and out of each adjacent passageway bore for controlling the flow of air from each exhaust chamber into a common exhaust passageway and out of a single exhaust port; (g) said valve body; a body having a common wire passage extending longitudinally therethrough; and (h) said valve body having a wire tuck chamber on each side of said common wire passage for receiving a lead wire from said common wire passage. A four-way air valve comprising: 2. The four-way air valve of claim 1, wherein each of the adjustable flow control valves is vertically arranged and extends upwardly from the valve body through both corners of the valve body cover. 3. The four-way air valve according to claim 2, wherein the longitudinal axes of the adjustable flow control valves are laterally offset from each other. 4. Each of the adjustable flow control valves includes a valve stem having an outer end supporting a valve body and extending outside the valve body cover, and adjusting the valve stem and the valve body in each exhaust passage bore. The four-way air valve according to claim 3, wherein the four-way air valve controls the exhaust flow rate to the common exhaust passage. 5. The four-way air valve of claim 1, wherein said means for moving the main valve spool to at least one operative position comprises a solenoid operated pilot air valve. 6. The four-way air valve of claim 5, wherein the valve body includes a wire passageway for conducting wire to a solenoid-operated pilot air valve and thus to a solenoid that operates the pilot air valve. 7. The valve body is T-shaped in end front view and has an upper end wider than a lower end, and a common wire passageway, a wire tuck chamber and an adjustable flow control valve are disposed in the wide upper end, and the valve body is solenoid actuated. 7. The four-way air valve according to claim 6, wherein the pilot air valve is fixed to the lower end of the valve body. 8 (a) a plurality of stacked valves are adjacent and aligned between a pair of end plates; and (b) each valve body has pressurized air communicating with the air supply chamber and the pressurized air inlet passage of an adjacent valve in the valve stack. (c) a pressurized air inlet passage in each valve body adjacent to the end plate communicates with a pressurized air inlet passage and a port in the adjacent end plate; and (d) each of the common exhaust passages in each valve body. (e) each of the common exhaust passages of each valve body adjacent to the end plate communicates with an exhaust passage and a port in the adjacent end plate; and (f) A plurality of stacked four-way air valves as claimed in claim 1, characterized in that loosely connecting means secure the stacked valve bodies together to the end plate. 9. A plurality of stacked four-way air valves according to claim 8, wherein said means for moving the main valve spool to at least one operative position comprises a solenoid operated pilot air valve. 10 (a) each of the valve bodies includes a pair of common pilot air passages respectively extending therethrough, at least one of said common pilot air passages communicating with a solenoid operated pilot air valve via a passage within the valve body; (b) (c) each of said end plates communicates with a pair of common pilot air passages in each valve body adjacent to said end plate; 10. The four-way air valve of claim 9 including means for selectively connecting to an external source of pressurized air or to a pressurized air inlet passageway in the end plate. 11 (a) each of the valve bodies includes a common pilot exhaust passage; (b) each of the common pilot exhaust passages in each valve body communicates with the common pilot exhaust passage of adjacent valves in the valve stack; (c) ) each of the common pilot exhaust passages in each valve body is connected by an exhaust passage to at least one solenoid-operated pilot air valve; and (d) each of the common pilot exhaust passages in each valve body adjacent to the end plate is 11. The four-way air valve of claim 10, which communicates with a pilot exhaust passage and port in the end plate.