Quick coupling for connecting during fluid flow in a hydraulic circuit

#This invention relates to quick couplings. More specifically, this invention relates to quick couplings for connecting during fluid flow in a hydraulic circuit.

#Quick couplings, including coaxial quick couplings, are widely used to connect and disconnect hydraulic components in numerous applications. For example, several such applications involve hydraulic circuits in which one hydraulic hose receives supply or higher pressure hydraulic fluid from a pressure source such as a hydraulic pump and conveys the supply pressure hydraulic fluid from the pump to a tool or equipment that uses the supply pressure hydraulic fluid to perform work. A second hydraulic hose, which may be separate from the first hose or may be coaxially arranged about the first hose to provide a coaxial hose arrangement, receives return or lower pressure hydraulic fluid from the equipment and conveys the return pressure hydraulic fluid from the equipment to a fluid reservoir that is connected back to the hydraulic pump. In these described exemplary applications, a coaxial quick coupling or other type of quick coupling may be used to connect the hoses to the equipment, and/or to connect the hoses to the pump, and/or to connect hoses to one another in order to extend the distance between the pump and the equipment.

#In these examples involving coaxial quick couplings, the coaxial quick coupling includes first and second coupling members or coupling halves that are quickly connected to and disconnected from one another. Each of the coupling halves includes a supply pressure passage that conveys higher pressure fluid from the pump to the equipment and a return pressure passage that conveys lower pressure fluid from the equipment back to the pump. Valves are provided that close to prevent flow or leakage from the passages when the coupling members are disconnected from one another. The valves open to allow fluid flow between the supply passages of the first and second coupling halves, and between the return passages of the first and second coupling halves, when the coupling halves are connected to one another.

#Embodiments of this invention will now be described in further detail with reference to the accompanying drawings, in which:

#FIG. 1 is a longitudinal cross sectional view of a coaxial coupling according to a preferred embodiment of the present invention, showing first and second members or halves of the coupling in a disconnected configuration;

#FIG. 2 is a longitudinal cross sectional view similar to FIG. 1, but showing the first and second halves of the coupling in a connection initiation configuration;

#Referring now to the drawings in greater detail, FIG. 1 illustrates a first preferred embodiment of a quick coupling 10 according to the present invention. The first preferred embodiment of the present invention is described in the context of an improvement in the above referenced Maldavs coaxial coupling, and the drawings and description of the above referenced Maldavs patents are incorporated herein by reference. For clarity and brevity, the description herein uses many of the reference numbers used in the Maldavs patents and uses some but not all of the description from the Maldavs patents. The Maldavs patents may be referenced for a more complete understanding of the structure and function and method of the Maldavs coupling. It is to be understood that the present invention may be used in a coupling of the type disclosed and claimed in the Maldavs patents, or may alternatively be used in other coaxial and non-coaxial coupling types.

#As explained in the Maldavs patents, coaxial coupling 10 includes a female half 50 and a male half 130. The female half 50 may also be called a first coupling member or female coupling member 50, and the male half 130 may also be called a second coupling member or male coupling member 130. Male coupling member 130 is attached to both a first high pressure hose fitting or connector 138 and a first low pressure hose fitting or connector (not shown in FIG. 1 but adapted to be threaded onto the left end of the male coupling exterior body 146 in the manner shown in the Maldavs patents), which are coaxial with each other. Female coupling member 50 is attached to both a second high pressure hose fitting or connector 58 and a second low pressure hose fitting or connector 63, again coaxial with each other.

#In the coupling illustrated in FIG. 1, a spacer or C-clip 65 is added to retain fitting 58, and the spacer 65 includes at least one longitudinal passage to allow for fluid flow between fittings 58 and 63. An inner high pressure fluid supply chamber or flow passage (indicated by flow arrow 47) through coupling 10 and high pressure hose fittings 58, 138 serves as the high pressure fluid supply line leading from a pump to a tool or equipment further described below. The coaxial outer low pressure return or reservoir fluid chamber or outer flow passage (indicated by flow arrow 96) through coupling 10 and low pressure hose fitting 63 serves as the low pressure return line leading from the tool or equipment back to the pump further described below.