Technical field

The_pxesent invention relates to quick release coupling which is used to connect the equipments that are used in agricultural tractors and in similar agricultural machinery, in heavy equipment and in industrial applications to the hydraulic system.

Prior Art

Presently, couplings are used in order to connect the equipments that are used in agricultural tractors and in similar agricultural machinery, in heavy equipment and in industrial applications to the hydraulic system.

Coupling is used in machinery to transmit a motion to other equipment. If care is not taken during their selection and assembly, couplings become the most costly member of manufacturing which have an important function in safe motion transmission and which is perhaps the simplest and which appear to be the cheapest member in the system depending on the machine onto which it is mounted. Current improvements are available in relation with couplings.

In the United States Patent document number 4598896 which comprises one of these improvements, the piston and the poppet are designed as separate parts. The pressurised fluid gets to the rear side of the piston by passing through a borehole in the poppet. Thus, by pushing the poppet forwards due to the difference in the piston surface area, it makes the flow pass through by opening the check-valve poppet or the ball of the male coupling. Furthermore, this coupling has a sealing element on its rear side which relieves the pressure. Obstruction problems are encountered due to obscuring by springs of the poppet borehole which is used to pass the oil to the rear side of the piston. Furthermore, the pressure transmitted to the rear side of the piston depends on the system pressure. For that reason, problems are encountered like failing of the female coupling to open the check valve of the male coupling and thus becoming unable to stop the flow when the system pressure is reduced or when a high pressure develops on the rear side of the male coupling and when the flow is from the male coupling towards the female-coupling-.

The United States Patent document number 6016835 as another one of these improvements has similar characteristics with the US patent number 4598896. Further to the previous patent, the bores transferring the pressurised fluid to the rear side of the piston are relocated onto the piston from the poppet in the US patent number 6016835 and a sealing element is used to retain the pressure on the rear side of the piston. However, problems may occur during long operational periods as the system used to retain the fluid trapped at the rear side of the piston is not able to provide hundred per cent sealing. In the US patent number 6016835, the obstruction problem arising from the springs is avoided by relocating the bores onto the piston. Occurrence of pressure disequilibrium on the rear side of the piston is not prevented by using a sealing element on the check valve body in order to assure pressure equilibrium on the rear side of the piston. However, pressure cannot be retained during intermediate strokes since the sealing element cannot perform its function until the piston reaches to its maximum stroke.

Summary of the invention

Object of this invention is to provide a quick release coupling where it is envisaged to avoid obstruction of flow by removing the springs from the flow path while assuring oil passage through the poppet to the rear side of the piston by means of the internal form of the poppet.

Another object of this invention is to provide a quick release coupling where an equal pressure is always assured to exist by providing an uninterrupted connection between the front and rear sides of the poppet by relocating the bore onto the poppet and therefore the forces resulting from the pressure acting on it become equal.

Another object of this invention is to provide a quick release coupling where connection with the tank line is established without encountering any disruptions by using ball chain instead of the spring that is used for securing in the prior art.

Another object of this invention is that special sealing elements are used so that the pressure trapped on the rear side of the piston, during long operational periods (particularly in applications where flow is always towards the female coupling from the male coupling like it is in hydraulic motors rather than in cylinders), shall trap the pressure on the rear side of the female coupling and shall make the piston push the poppet by assuring hundred per cent sealing. Purpose of these sealing elements is also to provide a quick release coupling aiming to avoid occurring of problems when mounting the male coupling during the next process by relieving the pressure trapped on the rear side of the piston when dismounting the male coupling after it has completed its function.

Detailed description of the invention The quick release coupling realised to attain the object of this invention is illustrated in the attached figures, where these figures are;

FIGURE- 1 Is a schematic view of the quick release coupling.

FIGURE-2 Is another schematic view of the quick release coupling. FIGURE-3 Is another schematic view of the quick release coupling.

FIGURE-4 Is the side-sectional view of the quick release coupling.

The parts in the figures are numbered individually and their meanings are given below; 1. Quick release coupling

2. Body

3... Eemale_coupJ ing_

4. Seal ring

5. Female coupling body

6. Female coupling poppet

7. Poppet seal ring

8. Fluid inlet port

9. Poppet oil passage bore

10. Poppet groove

11. Shuttle valve body groove

12. Shuttle valve body oil passage bore

13. Shuttle valve orifice oil passage notch

14. External seal ring

15. Locking ball

16. Ball locking socket

17. External sealing element

18. Male coupling body

19. Male coupling spring

20. Male coupling poppet

21. Male coupling

22. Female coupling poppet spring

23. Equipment connection point

24. Shuttle valve ball

25. Shuttle valve orifice

26. Shuttle valve seal ring

27. Piston rear surface

28. Seal ring

29. Seal ring

30. Restricted seal ring 31. Piston

32. Dismounting surface

33. Working surface

34. Mounting surface

35. Extractor rod

36. Pressure relieve port

37. Securing ball chain

38. Ball chain mounting bolt The female coupling (3) is in the neutral position, namely, the male coupling (21) is not mounted yet. When in this position, the fluid remains in the female coupling (3) by means of the female coupling poppet (6) and the sealing element (7) even when oil arrives to the female coupling (3) from the inlet line (8). In order the fluid pass to the rear side of the piston (27) it first has to enter through the inlet port (8) and then it has to pass through, in respective order, the poppet oil passage bore (9), the poppet groove (10), the shuttle valve body groove (1 1), the shuttle valve orifice oil passage notch (13) and the shuttle valve body oil passage bore (12) and then it is transferred to the rear side of the piston (27).

The operational condition of the quick release coupling (1), namely, the entirely mounted condition of the male coupling (21) is illustrated. Under this condition, fluid enters through the inlet port (8) and arrives to the equipment connection point (23) bay passing through the female coupling poppet (6), the female coupling body (5), the male coupling poppet (20) and between the male coupling body (18). Meanwhile, the shuttle valve ball (24) shifts from its position in Figure 1 to its position in Figure 2, namely, it interrupts the connection between the poppet side and the rear side of the piston (27) by resting against the shuttle valve seal ring (26). By that way the maximum pressure value pushes the piston (31) leftwards by remaining between the shuttle valve seal ring (26), the rubber rings (28, 29), and the restricted seal ring (30). By means of this pushing force, the female coupling poppet (6) opens the passage of flow by pushing the male coupling poppet (20).

Flow cannot be assured if pressure is not trapped on the rear side of th Tpiston (27) as the male coupling poppet (20) will not come out since the male coupling spring (19) is stiffer than the female coupling poppet spring (22). In another position, when there is trapped fluid at the equipment connection point (23), this pressure will make the male coupling poppet (20) difficult to open by pressing against it. However, by means of the pushing force resulting from the pressurised fluid on the rear side of the piston (27), flow is initiated by making the male coupling poppet (20) open by pushing the female coupling poppet (6). Under this condition, the shuttle valve ball (24) maintains the pressure on the rear side of the piston (27) by travelling on the shuttle valve seal ring (26) in order to ensure pressure equilibrium.

Dismounting condition of the male coupling (21) is illustrated in Figure-3. The balls (15) allow the male coupling (21 ) to smoothly detach from the female coupling (3) by engaging the dismounting surface (32) of the ball locking socket (16). Meanwhile the restricted seal ring (30) assure that the pressure entrapped on the rear surface of the piston (27) would not influence the mounting/dismounting forces during the next usage by relieving the pressure entrapped on the rear surface of the piston (27) through the relief ports (36) by travelling on the extractor rod (35).

In Figure-4, a securing ball chain (37) is illustrated which retains the whole system during the course of all the processes shown in the previous figures. The securing ball chain (37) is mounted by means of the ball chain mounting bolt (38) after mounting the female coupling (3) and it retains its position during the whole process. Thus, the quick release coupling system (1) is assured to operate always at the same position.