Fluid handling – Systems – Flow path with serial valves and/or closures
Reexamination Certificate
2001-02-14
2001-09-04
Chambers, A. Michael (Department: 3753)
Fluid handling
Systems
Flow path with serial valves and/or closures
C137S614000, C137S614050, C137S614060
Reexamination Certificate
active
06283151
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates generally to fluid couplings, particularly for coupling a fluid line from an apparatus such as an agricultural tractor, to a farm implement.
BACKGROUND OF THE INVENTION
Couplings for connecting fluid lines are well known and include a coupler socket (female half) and a nipple (male half). In some types of couplings, when the male half is inserted into the female half, a valve assembly in the female half opens to provide a flow path through the coupling. At the same time, a catch or coupling mechanism automatically engages the male half to retain the male half within the female half. Typically, the coupling mechanism can be manually released to disconnect the male half from the female half, at which point the valve assembly closes the flow path. Such a coupling is conventionally referred to as a “push-to-connect” coupling.
The male half of a coupling typically includes tubular valving or plug circumscribing a central passage, and a threaded fitting portion at its rear end which enables the male half to be connected to the pipe or tube. A valve assembly may also be provided in the male half. The valving of the male half narrows down at its forward end and includes an outwardly-facing circumferential groove or channel. When the male half is inserted into the female half, the coupling mechanism on the female half engages the groove on the valving to retain the male half within the female half.
One particularly useful type of push-to-connect coupling is referred to as a “flush face” coupling. In a flush face coupling, the front of the male half has a complimentary surface with the front of the female half such that the engaging surfaces of the male and female half are all flush with one another when connected. This flush face assembly is intended to prevent contaminants entering the coupler during connection and disconnection.
A number of different types of coupler sockets have been developed for receiving a male half. One known type of socket includes a cylindrical body with an internal, spring-biased poppet valve. The body of the female half has a series of tapered openings in a circumferential arrangement near the forward end, and a series of locking balls are received in the openings. A spring-biased locking collar is slidably disposed around the coupler body, and when the male valving is inserted into the socket, the locking collar forces the locking balls radially inward into the groove in the male half to lock the male half to the female half. At the same time, the poppet valve in the female half engages with a valve assembly in the male half to open a flow passage through the coupling.
To uncouple the male half from the female half, the locking collar is moved rearwardly, which allows the locking balls to move outwardly from engagement with the groove in the male half, and thereby allow the male half to be removed from the female half. As the male half is removed, the poppet valve in the female half and the valve assembly in the male half are moved to closed positions to prevent fluid flow through the respective halves of the coupling. French Patent Reference No. 1.577.931 shows such a flush-face, push-to-connect coupling.
In some applications, such as agricultural tractor applications, it can be necessary or desirable to have the coupling automatically disconnect under certain conditions, such as if an operator fails to disconnect the coupling before the tractor is driven away from an attached implement. To accomplish this breakaway feature, the locking collar of the female half of the coupling has been rigidly mounted to the tractor. When the male half is pulled away from the female half, the female body moves inside the locking collar and the coupling halves automatically disconnect.
While this solution may be appropriate for certain applications, it requires additional hose or tube to connect the female coupling body to the tractor. This increases the material, assembly and repair costs. In addition, this coupling does not allow for automatic disconnect when the pressure within the coupling increases above a predetermined amount. It can be useful or desirable to have the coupling automatically disconnect when a maximum pressure in the fluid system is reached. Still further, the male half can only be removed from the female half by pulling on the male half. This does not allow for conventional disconnect, where the operator manually moves the locking collar rearward on the coupling body to allow the male half to be disconnected.
It is therefore believed there is a demand for a further improved push-to-connect coupling which overcomes the above-described drawbacks.
SUMMARY OF THE PRESENT INVENTION
The present invention provides a new and unique push-to-connect coupling, particularly for agricultural tractor applications, where the male half of the coupling automatically disconnects from the female coupling when the male half is pulled out from the female half. The male half also automatically disconnects when a predetermined pressure is reached in the fluid system, and can be disconnected by manually moving a locking collar.
According to the present invention, the female half includes a fitting that is securely fixed directly to the tractor. There is no additional plumbing necessary between the female half and the tractor. An internal valve assembly, locking balls and a locking collar are provided within the female half. The valve assembly, locking balls and locking collar cooperate with the male half to couple the male half to the female half and to open a flow path through the coupling when connected.
The female half further includes a cylindrical coupler body which includes openings for the locking balls, as well as an annular, radially-outward projecting flange at its inner or rear end which serves as a spring stop. A centering spring urges the coupler body rearward within the fitting. When the male half is pulled out from the female half, such as if the tractor is inadvertently driven away from the farm implement, the coupler body moves against the spring until the locking balls become aligned with a ball groove in the locking collar. This allows the locking balls to move radially outward, out of engagement with the male half, such that the male half can be removed from the female half.
A further advantage is that the pressure in the coupling is applied to the female valving. This valving is pushed outwards (towards the face of the coupler) due to the pressure against an internal seal. The force created by the pressure acts against the centering spring through the valve assembly. When the pressure increases above the spring force of the centering spring, the pressure forces the coupler body forwardly in the fitting, again until the locking balls become aligned with the ball groove in the locking collar such that the male half can be removed from the female half. Thus, the male half will also automatically disconnect when the pressure within the female half increases above a predetermined amount.
The centering spring in the female half determines the breakaway and overpressure release force of the coupling. The breakaway and overpressure release force can thereby be determined by the selection of an appropriate centering spring.
A still further advantage of the present invention is that the locking collar is not fixed to the tractor. This allows the collar to be manually manipulated by the operator to disconnect the male half from the female half.
The valve assembly for the female half of the coupling includes an axiallymoveable and spring-biased cylindrical face sleeve with an annular flat front face which engages flush against the annular flat front face of the male valving; a cylindrical retainer sleeve received within the moveable face sleeve and fixed to the fitting; an axially movable and spring-biased cylindrical sealing sleeve received within the retainer sleeve; and a cylindrical valve body located centrally within the sealing sleeve and also fixed to the fitting. When the male coupling half is inserted in
Countryman Kevin E.
Hiser Nicholas R.
Magnuson Ruel D.
Chambers A. Michael
Hunter Christopher H.
Parker-Hannifin Corp.
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