REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Application No. 62/195,400 filed July 22, 2015.

BACKGROUND OF THE INVENTION

[0002] A prior valve assembly includes a solenoid. Air flows through an inlet and then through either an outlet and an exhaust. It is beneficial to control the air flowing through the inlet. Prior valves employ a check valve and steel balls (pneumatic logic elements). However, this can be a complex arrangement.

SUMMARY OF THE INVENTION

[0003] In a featured embodiment, a valve assembly includes a first spool valve that directs fluid to a working object. A second spool valve directs fluid to the exhaust.

[0004] In another embodiment according to the previous embodiment, the first spool valve includes a first spool valve first port, a first spool valve second port, a first spool valve third port, a first spool valve fourth port, and a first spool valve fifth port. The second spool valve includes a second spool valve first port, a second spool valve second port, a second spool valve third port, a second spool valve fourth port, and a second spool valve fifth port. The first spool valve first port and the second spool valve first port define a port A. The first spool valve second port and the second spool valve second port define a port B. The first spool valve third port and the second spool valve third port define a port C. The first spool valve fourth port and the second spool valve fourth port define a port D. The first spool valve fifth port and the second spool valve fifth port define a port E.

[0005] In another embodiment according to any of the previous embodiments, the first spool valve and the second spool valve are activated simultaneously by a first pneumatic control cylinder and a second pneumatic control cylinder, respectively that each supply a first supply of pilot air and a second supply of pilot air, respectively.

[0006] In another embodiment according to any of the previous embodiments, the first pneumatic control cylinder includes a first spool valve wall. A first spool valve first piston is located in a first spool valve first compartment on one side of the first spool valve wall. A first spool valve second piston is located in a first spool valve second compartment on an opposing side of the first spool valve wall. The second pneumatic control cylinder includes a second spool valve wall. A second spool valve first piston is located in a second spool valve first compartment on one side of the second spool valve wall and a second spool valve second piston is located in a second spool valve second compartment on an opposing side of the second spool valve wall.

[0007] In another embodiment according to any of the previous embodiments, the first check valve controls a first flow of pilot air to the first cylinder, and a second check valve controls the second flow of pilot air to the second cylinder.

[0008] In another embodiment according to any of the previous embodiments, the first pneumatic control cylinder and the second pneumatic control cylinder includes a first resilient member and a second resilient member, respectively. When the valve assembly is not operating, the first resilient member and the second resilient member and extra air in the system return the first cylinder and the second cylinder to a first position.

[0009] In another embodiment according to any of the previous embodiments, each of the first pneumatic control cylinder and the second pneumatic control cylinder has 2 positions.

[0010] In another embodiment according to any of the previous embodiments, the valve assembly has 10 ports and 4 positions.

[0011] In another embodiment according to any of the previous embodiments, when the valve assembly is in a first position, a first flow of pilot air is not supplied to the first spool valve first compartment of the first spool valve first piston and the first spool valve second compartment of the first spool valve first piston of the first pneumatic control cylinder. A second flow of pilot air is not supplied to the second spool valve first compartment of the second spool valve first piston and the second spool valve second compartment of the second spool valve first piston of the second pneumatic control cylinder.

[0012] In another embodiment according to any of the previous embodiments, the first flow of pilot air and the second flow of pilot air flows through the first spool valve and the second spool valve and flows through the port A, the port B, the port C, the port D and the port E to exhaust through a silencer/muffler.

[0013] In another embodiment according to any of the previous embodiments, when the valve assembly is in a second position, a first flow of pilot air is supplied to the first spool valve first compartment of the first spool valve first piston and the first spool valve second compartment of the first spool valve first piston of the first pneumatic control cylinder. A second flow of pilot air is not supplied to the second spool valve first compartment of the second spool valve first piston and the second spool valve second compartment of the second spool valve first piston of the second pneumatic control cylinder. The first pistons are in a first position and the first pistons are in a second position, and the second pistons are in a first position.

[0014] In another embodiment according to any of the previous embodiments, the first flow of pilot air and the second flow of pilot air flows through the first spool valve and the second spool valve and flows through the port A and the port B and exhausts through the port C, the port D and the port E to exhaust through a silencer/muffler.

[0015] In another embodiment according to any of the previous embodiments, when the valve assembly is in a third position, a first flow of pilot air is not supplied to the first spool valve first compartment of the first spool valve first piston and the first spool valve second compartment of the first spool valve first piston of the first pneumatic control cylinder. A second flow of pilot air is not supplied to the second spool valve first compartment of the second spool valve first piston and the second spool valve second compartment of the second spool valve first piston of the second pneumatic control cylinder.

[0016] In another embodiment according to any of the previous embodiments, the first flow of pilot air and the second flow of pilot air flows through the port A, the port C and the port D and exhausts through the port B and the port E to exhaust through a silencer/muffler.

[0017] In another embodiment according to any of the previous embodiments, when the valve assembly is in a fourth position, a first flow of pilot air is not supplied to the first spool valve first compartment of the first spool valve first piston and the first spool valve second compartment of the first spool valve first piston of the first pneumatic control cylinder. A second flow of pilot air is supplied to the second spool valve first compartment of the second spool valve first piston and the second spool valve second compartment of the second spool valve first piston of the second pneumatic control cylinder such that the first pistons are in a first position. The first pistons are in a second position, and the second pistons are in a second position.

[0018] In another embodiment according to any of the previous embodiments, the first flow of pilot air and the second flow of pilot air flows through the port A, the port C and the port E and exhausts through the port B and the port E to exhaust through a silencer/muffler.

[0019] In another embodiment according to any of the previous embodiments, the first spool and the second spool are received in a body, and the port A, the port B, the port C, the port D and the port E are formed in the body between the first spool and the second spool. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The various features and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompanies the detailed description can be briefly described as follows:

[0021] Figure 1 illustrates a perspective view of a valve assembly;

[0022] Figure 2 illustrates a cross-sectional top view of the valve assembly;

[0023] Figure 3 illustrates a cross-sectional side view of the valve assembly in a first position;

[0024] Figure 4 illustrates a schematic diagram of the valve assembly in the first position;

[0025] Figure 5 illustrates a cross-sectional top view of the valve assembly in the first position;

[0026] Figure 6 illustrates a cross-sectional side view of the valve assembly in a second position;

[0027] Figure 7 illustrates a schematic diagram of the valve assembly in the second position;

[0028] Figure 8 illustrates a cross-sectional top view of the valve assembly in the second position;

[0029] Figure 9 illustrates a cross-sectional side view of the valve assembly in a third position;

[0030] Figure 10 illustrates a schematic diagram of the valve assembly in the third position;

[0031] Figure 11 illustrates a cross-sectional top view of the valve assembly in the third position;

[0032] Figure 12 illustrates a cross-sectional side view of the valve assembly in a fourth position;

[0033] Figure 13 illustrates a schematic diagram of the valve assembly in the fourth position; and

[0034] Figure 14 illustrates a cross-sectional top view of the valve assembly in the fourth position. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0035] Figure 1 illustrates a perspective view of a valve assembly 10, and Figure 2 illustrates a cross-sectional top view of the valve assembly 10. The valve assembly 10 includes two spool valves 12 and 14. In one example, the first spool valve 12 functions as a working valve, and the second spool valve 14 functions as an exhaust valve. The first spool valve 12 directs fluid through different ports and to different working objects. In the example described, the valve assembly 10 is a 10/4 valve assembly 10. That is, the valve assembly 10 has 10 ports and 4 positions. However, the valve assembly 10 could have any number of ports. For example, the valve assembly 10 could have 16 ports.

[0036] In the example shown, the first spool valve 12 includes ports 30, 32, 34, 36 and 38, and the second spool valve 14 includes ports 40, 42, 44, 46 and 48. Ports 30 and 40 define port A, ports 32 and 42 define port B, ports 34 and 44 define port C, ports 36 and 46 define port D, and ports 38 and 48 define port E.

[0037] The first spool and the second spool are received in a body 80, and the port A, the port B, the port C, the port D and the port E are formed in the body 80 between the first spool and the second spool.

[0038] As shown in Figures 4, 7, 10 and 13 described below, the first spool valve 12 and the second spool valve 14 are each activated simultaneously by a first pneumatic control cylinder 16 and a second pneumatic control cylinder 18, respectively, that supplies pilot air SI and S2, respectively. As shown in the following figures, each of the first pneumatic control cylinder 16 and the second pneumatic control cylinder includes a wall 50 and 52, respectively, with a first piston 54 and 56, respectively, on one side of the wall 50 and 52, respectively and a second piston 58 and 60, respectively, on the opposing side of the wall 50 and 52, respectively.

[0039] The first pneumatic control cylinder 16 and the second pneumatic control cylinder 18 each independently have 2 positions. Together, the first pneumatic control cylinder 16 and the second pneumatic control cylinder 18 define 4 positions. A first check valve 64 controls a first flow of pilot air SI to the first pneumatic control cylinder 16, and a second check valve 66 controls a second flow of pilot air S2 to the second pneumatic control cylinder 18. Based on the supply of pilot air SI and S2, the first pneumatic control cylinder 16 and the second pneumatic control cylinder 18 define 4 positions of the valve assembly 10. The first pneumatic control cylinder 16 and the second pneumatic control cylinder 18 together define a 4 position cylinder. [0040] Figures 3, 4 and 5 illustrate the valve assembly 10 in a first position. In the first position, the stroke is 0 mm. In the first position, pilot air S 1 and S2 is not provided to the compartments that contain the first piston 54 and the second piston 58 of the first pneumatic control cylinder 16 and the compartments that contain the first piston 56 and the second piston 60 of the second pneumatic control cylinder 18. That is, there is no pilot air supply from the first flow of pilot air SI and the second flow of pilot air S2. The first pistons 54 and 56 are in a first position, and the second pistons 58 and 60 are in a first position. As no pilot air SI and S2 is provided to either the first pneumatic control cylinder 16 or the second pneumatic control cylinder 18, air flows through the first spool valve 12 (the working valve) and the second spool valve 14 (the exhaust valve) and exhausts through ports A, B, C, D and E through the silencer/muffler 62.

[0041] Figures 6, 7 and 8 illustrate the valve assembly 10 in a second position. In the second position, the stroke is 10 mm. The flow of working air is shown with dotted lines, and the flow of exhausted air is shown as diagonal lines. In the second position, the pilot air SI is provided to the compartments that contain the first piston 54 of the first pneumatic control cylinder 16 and the first piston 56 of the second pneumatic control cylinder 18, and the pilot air S2 is not provided to the compartments that contain the second piston 58 of the first pneumatic control cylinder 16 and the second piston 60 of the second pneumatic control cylinder 18. In one example, the pressure of the pilot air SI is 6 bar. The first pistons 54 and 56 are in the second position, and the second pistons 58 and 60 are in the first position. When the valve assembly 10 is the second position, air flows through the first spool valve 12 and the second spool valve 14 and flows to the working ports A and B and exhausts through exhaust ports C, D and E through the silencer/muffler 62.

[0042] Figures 9, 10 and 11 illustrate the valve assembly 10 in a third position. In the third position, the stroke is 20 mm. The flow of working air is shown with dotted lines, and the flow of exhausted air is shown as diagonal lines. In the third position, the pilot air SI is not provided to the compartments that contain the first piston 54 of the first pneumatic control cylinder 16 and the first piston 56 of the second pneumatic control cylinder 18, and the pilot air S2 is provided to the compartments that contain the second piston 58 of the first pneumatic control cylinder 16 and the second piston 60 of the second pneumatic control cylinder 18. In one example, the pressure of the pilot air S2 is 6 bar. The first pistons 54 and 56 are in the first position, and the second pistons 58 and 60 are in the second position. When the valve assembly 10 is the third position, air flows through the first spool valve 12 and the second spool valve 14 and flows to the working ports A, C and D and exhausts through exhaust ports B and E through the silencer/muffler 62.

[0043] Figures 12, 13 and 14 illustrate the valve assembly 10 in a fourth position. In the fourth position, the stroke is 30 mm. The flow of working air is shown with dotted lines, and the flow of exhausted air is shown as diagonal lines. In the fourth position, the pilot air SI is provided to the compartments that contain the first piston 54 of the first pneumatic control cylinder 16 and the first piston 56 of the second pneumatic control cylinder 18, and the pilot air S2 is provided to the compartments that contain the second piston 58 of the first pneumatic control cylinder 16 and the second piston 60 of the second pneumatic control cylinder 18. In one example, the pressure of the pilot air SI and S2 is 6 bar. The first pistons 54 and 56 are in the second position, and the second pistons 58 and 60 are in the second position. When the valve assembly 10 is the fourth position, air flows through the first spool valve 12 and the second spool valve 14 and flows to the working ports A, C and E and exhausts through exhaust ports B and E through the silencer/muffler 62.

[0044] The valve assembly 10 includes a first resilient member mechanism 68 and a second first resilient member mechanism 70. When the valve assembly 10 is not operating, the first resilient member mechanism 68 and the second resilient member mechanism 70, along with the extra air remaining in the system, return the first piston 54 of the first pneumatic control cylinder 16 and the second piston 58 of the first pneumatic control cylinder 16, and the first piston 56 of the second pneumatic control cylinder 18 and the second piston 60 of the second pneumatic control cylinder 18, respectively, to the first position.

[0045] The valve assembly 10 includes the first spool valve 12 that directs fluid to a working object and the second spool valve 14 that directs fluid to the exhaust. The valve assembly 10 can direct the working air through different ports to allow for different working objects to be actuated.

[0046] The foregoing description is only exemplary of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention.