Short-body plug for fluid couplings

A short-body connector for fluid couplings made of a sleeve-shaped body. In the sleeve-shaped body an internal thread is provided, by which the connector can be screwed onto a threaded connection. Relative to axial extension, the locking groove and locking rib serving to hold the connector in the coupler are located at the height of the thread. That is, the locking rib and locking groove located ahead of the thread in the state of the art have moved to the region of the thread in the arrangement according to the invention.

BACKGROUND OF THE INVENTION

The present invention relates broadly to fluid couplings having a female member or coupler and a male member or plug, and more particularly to a short-body plug for such couplings.

Detachable fluid couplings are used to connect fluid lines. The fluid coupling includes a coupler and a plug that can be plugged into the coupler. Within the coupler, there are locking elements that hold the plug in the coupler, so that it is not pushed out by the hydraulic force of the fluid. In addition, capturing means can also be contained in the coupler, that hold the plug in an intermediate position, so that fluid under pressure can escape into the atmosphere without a backward force appearing that would push the plug out.

The plug used for this consists of a tube-shaped male end and a threaded end. The male end is inserted in the socket, while the threaded end is provided to attach the plug to a hose or a tube line. The plug is made correspondingly long, which is especially problematic when the plug is attached to a stiff, immovable part, for example a cylinder valve.

It is believed that a short-body plug would be desirable.

BROAD STATEMENT OF THE INVENTION

The present invention is directed to a short-body plug for a fluid coupling.

The short-body plug has a sleeve or tube-shaped body, in which an inner thread is provided to connect the plug to a cylinder valve or a tube line. The outside of the tube-shaped or sleeve-shaped body carries the locking means, which works together with the locking means in the bushing body. The locking means are situated, with respect to the axial direction of the body, at the height of the thread. Thus in the solution according to the invention, the attachment means and the thread are no longer one after the other in the axial direction, but arranged next to each other in the radial direction. The required construction length of the plug is shortened.

Moreover, means of sealing are provided, in order to seal the plug against the bushing.

At least the body, preferably the entire plug can be made with rotation symmetry.

The locking means on the outside can be designed as circumferential ribs, and a circumferential groove, or as a combination of groove and ribs. Which variant is more favorable in each case depends on the other requirements and the dimensions.

For assembling the plug, it can have a tool-setting surface, for example a hexagon.

The sealing means that seal the plug with respect to the gushing can be formed from a cylinder surface, for example an outer cylinder surface, when the bushing has a corresponding O-ring seated on the inside, as is encountered very frequently.

Another possibility for the sealing surface consists of a cylindrical hole in the body. Depending on the design of the complementary bushing, it can be situated in the O-ring in an inner groove of the plug or it can be designed to be flush with the hole.

Favorable assembly relationships are achieved when the plug arrangement contains an insert piece with a sealing surface to seal a thread support, onto which the plug arrangement is screwed. It is thereby also possible to achieve a deep seated sealing surface of the thread support, as is sometimes encountered in valves of pressure-gas containers.

The sealing surface can by designed in the shape of a segment of a sphere, which opens the possibility of a metallic seal.

For a simple connection of the insert piece to the body, the insert piece can carry a radially projecting flange or band that works together with a corresponding shoulder surface in the hole of the body.

When the plug arrangement is such that the O-ring sealing is formed in the insert piece, the connection between the insert piece and body does not have to be fluid-tight.

The assembly can be simplified when the insert piece is provided with a spring ring groove with the radial flange that secures the insert piece in the body in the axial direction. After being screwed to the thread support, the spring ring has no function.

The present invention, accordingly, comprises the construction, combination of elements, and/or arrangement of parts and steps which are exemplified in the detailed disclosure to follow.

The drawings will be described further in connection with the following Detailed Description of the Invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a fluid-coupling arrangement1in the uncoupled state. The coupling arrangement1includes a coupler2and a plug3according to the invention that can be plugged into the coupler2.

The plug3has a sleeve-like body4, which is provided with an inner thread5. With the aid of the inner thread5, the body4can be screwed onto an outer thread6of a cylinder valve, of which only the thread support7can be recognized. The outside of the body4has rotation symmetry and carries at its back end, i.e., at the end away from the coupler2, a hexagon8as a tool-gripping surface. Directly adjacent to the hexagon8, a circumferential groove9with a trapezoidal cross-section is present, which goes over to the insertion end of the plug3into a rib11. When connected to the rib11, the outer circumferential surface of the body4is at first a cylindrical surface12in design, which goes over into a beveled milled surface13at its free end.

At the height of the milled surface13, a circumferential rib14projects into the interior of the sleeve-shape base body4.

As can be recognized from the diagram, rib11and the groove9are situated at the height of the inner thread5. In other words, the connecting means for the line to be connected are pushed into the mouthpiece of the plug2equally. A very short construction form arises thereby, compared to that of the state of the art, in which the mouthpiece and the thread are arranged one after the other.

In the interior of the body4, an insert piece15. The insert piece15is likewise tube-shaped, and it contains a stepped hole16.

Starting from the end of the plug, the insert piece15forms a cylindrical section17with a channel18for an outer spring ring19. When connected to the cylindrical section17, the insert piece forms 1 band or flange21that projects radially outward.

The band or flange21works together, as shown, with rib14, which projects inward.

Next, on the flange or band21, the insert piece15goes over into a cylindrical part22, which is closed by an end in the shape of spherical segment23.

As shown, the cylindrical part22projects into the cylindrical hole in the screw connection7, and the assembled state, it strikes a conical surface24. There, the insert piece forms a metal seal with the metallic screw connection7.

In the stepped hole, a ring groove25is pushed into the opening region, in which an equalizing ring26and an O-ring seal27are placed.

Since the busing part2is not the object of the invention, it is sufficient to explain only the parts of it that are important for understanding the way in which the plug3works.

The coupler2has a body30, into which a base-body sleeve31is screwed. The body sleeve31contains radial holes32for a wreath of locking balls33. The position of the locking balls33will be controlled on the one hand by an outer control sleeve34, which is designed to slide axially on the outside of the base-body sleeve31, and on the other hand by an inner control sleeve35, which is likewise designed to slide axially in the interior of the base-body sleeve31. By means of prestressed springs36and37, the two control sleeves34and35are prestressed in the position shown inFIG. 1.

From the body30, a mouthpiece38projects in the axial direction, which is arranged to be coaxial to the hole in the base-body sleeve31. The mouthpiece forms a cylindrical outer circumferential surface39, which it designed to work together with the O-ring27to form a seal. A fluid hole41runs through the mouthpiece38.

The plug3is assembled by the insert piece15being first introduced in a pre-assembly step from the back side of the body4, until the flange21reaches the inner rib14. Then the spring ring19is placed in the spring-ring groove18, whereby the insert piece15is secured in the body4in the axial direction. The body4and the insert piece15thereby form a component group consisting of two main components, which are attached immovably to each other with the aid of the spring ring19of the flange21and the inner rib14.

Then, the O-ring27is placed in groove25and then the equalizing ring26. Its task consists of reducing the effective slit that the O-ring27sees on the mouthpiece38. Ring26floats in groove25.

The unit obtained in this way is now screwed on the thread support7and pulled tight. During the tightening, the surface of the spherical segment23lies on the conical surface24of the thread support7and forms a metallic seal that is fluid-tight even at high pressures.

With this, assembly of the plug is complete. As can be seen, the components that cause the locking of the plug3are situated at the height of the inner thread5with respect to the axial extent of the plug3.

The unit obtained in this way can now be coupled with the coupler3in that the plug3is pushed with the cone surface13forward, into the inner space of the base-body sleeve31. With this, through the pushing movement, the inner control sleeve3is pressed against the effect of the spring36and releases the mouthpiece38. With further pushing movement, the O-ring27slides along the outer circumferential surface39of the mouthpiece38. The pushing movement ends as soon as the rib11passes the locking balls33, which are arranged in a wreath, and the locking groove9receives the wreath of locking balls33. Now the other spring37pushes the other control sleeve34forward in the direction of the plug3and the wreath of locking balls33is held by corresponding control surfaces in the radially inward position, in which the balls33are meshed in the locking groove9. The plug3is thus locked in the coupler2in the axial direction in a form-tight manner. At the same time, the coupled arrangement is fluid-tight, since the insert piece15is sealed with the aid of the O-ring27on the mouthpiece38. A fluid-tight connection is thus created between the hole41of the mouthpiece38with the stepped hole16in the insert piece15. The insert piece15is in turn sealed by the metal sealing on surfaces23and24and held in the thread support7.

The plug3according to the invention is very short, since the locking means are situated at the height of the inner thread15in the design of the ribs11and the groove11, and not, as in the state of the art, at a distance in the axial direction. The mouthpiece of the plug3contains the connecting thread.

The sealing between the coupler2and the plug3is locked in the insert piece15in the embodiment example shown. with this, the O-ring27is protected as well as possible against outside influences. But a possibility also exists of moving the O-ring27on the outer cylinder surface12and sealing it against a corresponding surface in the base-body sleeve31. In such a case, the insert piece15can also be omitted, in that, for example, the inner rib14is designed in such a way that it can seal the front end of the thread support7.

Another possibility consists of the front part of the insert piece15, which contains groove25, being made in one piece with the body4and using the shoulder surface, which is part of a single piece with the body4, at the right end of the flange21as a sealing surface. The flange21would no longer be a separate component in the one-piece embodiment. Rather, the flange21is included in the body4.

As it is anticipated that certain changes may be made in the present invention without departing from the precepts herein involved, it is intended that all matter contained in the foregoing description shall be interpreted in as illustrative rather than in a limiting sense. All references including any priority documents cited herein are expressly incorporated by reference.