MXPA96005969A - Tube coupling assembly - Google Patents

Abstract

The present invention relates to a coupling assembly for joining two separate tube ends, comprising: an elongated sleeve adapted to receive two opposite tube ends to be connected, the sleeve having truncated cone ends that open outwardly a pair of annular elastomeric gaskets having truncated cone end portions, adapted to fit within the truncated cone ends of the sleeve, in sliding engagement around the pipe ends to be connected; a retaining ring member; separated, positioned axially outwardly from each end of the sleeve and to surround the tube ends to be connected, each retaining ring member having an internal truncated cone wall that orients the sleeve, to define a clamping ring chamber a separate, separate clamping ring member placed in each clamping ring chamber; or separate, placed at each end of the sleeve, at a location between the elastomeric packing and the clamping ring, at that respective end; clamping means for selectively moving the retaining ring members axially towards each other, to radially compress the respective clamping ring members, and cooperating stop surfaces placed on the retaining ring members and capable of engaging with the abutment surfaces on the associated sleeve and coupling ring, to provide a fixed stop to limit the movement of the retaining ring members towards each other, to provide positive limit to the compression applied to the gaskets and the ring members

Description

PIPE COUPLING ASSEMBLY BACKGROUND OF THE INVENTION The present invention is directed toward the technique of pipe couplings, and more particularly, to a coupling assembly for joining pipe or pipe of relatively large diameter. The invention is especially suitable for joining plastic pipe used in gas distribution systems and will be described with reference to the same; however, as will be apparent, the invention is capable of wider application and could be used to join other types of tubes and in a variety of different environmental environments. In the gas distribution industry, it is often necessary to join aligned ends of plastic pipe, as well as uni: plastic pipe to metal pipe. The couplings used for this purpose must be capable of being quickly assembled to provide a permetatically sealed connection capable of withstanding substantial axial tensile loads. In addition, the assembly must be able to maintain a leak-proof seal even if axial cracking occurs. In addition to the foregoing, it is highly desirable that the coupling assembly be capable of operating in extremely corrosive environments.

SUMMARY OF THE INVENTION The present invention provides a tube fitting assembly that meets the above needs and provides an extremely effective joint. The set is relativly simple to make and can easily be disarmed if required. In particular and in accordance with one aspect of the invention, sf? provides a conjun of coupling to join two coaxial tube ends, spaced apart. The assembly includes an elongated sleeve adapted to receive two opposite coaxial tube ends to be connected. The sleeve has truncated cone ends that open axially outwards. A pair of annular elastomeric gaskets having truncated cone end portions are fitted within the truncated cone ends of the coupling sleeve by sliding around the tube ends: they are to be connected. A separate retainer ring member is positioned axially out from each end of the sleeve to encircle the pipe ends to be connected. An internal truncated cone wall within each member of the retainer ring is oriented to the sleeve end and defines a clamping ring chamber. Positioned within each retaining ring arm is a separate, radially compressible clamping ring member.A separate coupling ring member is positioned at each end of the sleeve at a location between the elastomeric packing and the suction ring. At the respective end, tightening elements are provided for selectively moving the retraction ring members axially towards each other to compress the packages to their respective truncated cone chambers of the sleeve and to radially compress the ring members of the sleeve. In addition, cooperative stop surfaces are provided to limit the movement of the retaining ring members toward each other to provide positive limits to the compression applied to the clamping members. packaging «and the fastening ring members Preferably, the top surfaces are provided on the coupling ring on opposite sides thereof for engagement by the respective sleeve end and the associated retaining ring member. This ensures that during the process, the proper compression drop is applied to both the gaskets and the clamping rings. The presence of the coupling ring member and its relation to the sleeve ends and the retaining ring members ensures that the packing and the clamping rings are fully and properly compressed and none is excessively compressed and missing. . Preferably, and in accordance with a more limited aspect of the invention, each retaining ring member has an end portion that overlaps and slidably receives the adjacent coupling ring member. In addition, it is preferred that the retaining rings are received around the end flanges formed circumferentially of the ends of the sleeve. In this way, when the coupling is formed completely, the gaskets, the coupling ring members and the clamping ring members are completely enclosed by the sleeve and the associated retaining rings. It is preferred that all the main components of the assembly, except for the packages that are formed from relatively rigid plastic materials, of high strength. This allows the assembly to work in relatively corrosive environments. In its preferred form, the preferential clamping elements comprise elongate retention rod bolts extending axially from the assembly between the retaining ring members. As can be seen from the foregoing, a primary object of the invention is the provision of a tube coupling assembly which ensures proper compression and coupling of the packing and clamping rings providing positive limit stop. during processing. A further object of the invention is the provision of a coupling assembly of the type described, wherein all the principal components of the coupling assembly are provided. and.-. They can be formed from plastics and resinous materials reinforced with fiber. An object . Still further is the provision of a joint with the general type described in which the package and the clamping ring are totally enclosed when the assembly is in working condition. Yet another object is the provision of a tube-coupling assembly of the type described, wherein the formation of the assembly is relatively simple and the external visual inspection allows the determination as to whether the coupling is fully made or not. Still other advantages and benefits of the invention will become apparent to those skilled in the art after a reading and understanding of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may take physical form in certain parts and arrangements of parts, a preferred embodiment and method - of which it will be described in detail in this specification and illustrated in the accompanying drawings, which form part of the invention. -presente, and wherein: Figure 1 is a longitudinal cross-sectional view through a coupling assembly formed to conform? with the present invention, installed at the ends of a pair of tubes coaxially arranged; Figure 2 is a rear view? amplified from the area surrounded by figure 1; Figure 4 is a cross-sectional view through the securing ring member of the embodiment of Figure 1; Figure 5 is an enlarged view of the enclosed area -from Figure 4 to better show the engagement diameters of the clamping ring; Figure 6 is a cross-sectional view through one of the packages of the assembly of Figure 1; Figure 7 is an end view of one of the retaining ring members of the coupling assembly of Figure 1; Figure 8 is a cross-sectional view taken on line 8-8 of Figure 7; Figure 9 is a view similar to Figure 4, but showing a modified form of clamping ring; and, Figure 10 is an enlarged view showing the portion surrounded by Figure 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in which the drawings are for purposes of illustrating the preferred embodiment of the invention only and not for purposes of limiting the same, Figures 1-3 best illustrate the arrangement of a coupling assembly 10 shown assembled to two coaxial tube ends 12 and 14. The tubes 12, 14 are relatively large diameter plastic tubes and the assembly 10 is partly suitable for use with said tubes. Preferably, in the present embodiment, the tubes are relatively large diameter polyethylene tubes, of the tube used in gas distribution systems. It should be noted, however, that the joint 10 could be used to join plastic pipes to metal pipes and / or to join other types of plastic pipes. In the illustration of Figure 1, each of the tube ends 12, 14 are of cylindrical configuration and are provided with a metal stiffening sleeve 16 which is sized and arranged so as to be received closely within the tube end. respective and to collocate therein in view of a radially extending end flange 16a which engages the end wall of the associated tube end 12 or 14. Many different materials could be used for stiffness sleeves, but typically, they are formed of zinc-coated steel. Its primary function is to make the end tubes rigid enough to allow them to withstand the significant radial clamping forces applied by the coupling assembly 10. The assembly 10 further comprises a relatively rigid sleeve member 18 which is cylindrical in shape and is dimensioned to be received closely around the tube ends 12, 14 as illustrated in Figure 1. The opposite ends of the sleeve have configurations of the same. of truncated cone open axially outward extending inwardly and forming in combination with the outer surface of the associated tube end 12, 14, receiving chambers 20a of generally triangular cross-sectional packing. Placed within the two packing chambers 20a are separate packages 22 having the shape and configuration best illustrated in Figure 6. In particular, the packages 22 are formed of an appropriate elastomer such as a bunanitrile having a truncated cone configuration generally as illustrated in Figure 6. Even though the actual shape and angular relationships may vary, in the preferred embodiment, the smaller internal diameter of the package is dimensioned so as to be closely similar to the external diameter of the associated tube with which it is to be used and in its natural, uncompressed state, it is abutted towards a 10 ° angle as shown. The outer surface which is adapted to be received within the packing chamber and coupled with the truncated cone surface 20 of the sleeve 18 is preferably inclined on the scale of 33. As noted above, however, these angles particulate Resins are merely preferred when the bu nitrile material is used and when the surface 20 is inclined, for example, at an angle of 309. Referring again to Figure 1, it will be seen that the packages 22 in position, there is a member 24 of coupling ring associated with each. The coupling rings each have a generally rectangular cross-section as best seen in FIGS. 1 and 3. The outer peripheral portion of a side face of the rings 24, however, is recessed as shown in FIG. of engaging on the radial external side of the associated package 22. In the preferred embodiment, the rings 24 are formed of a polypropylene reinforced with glass fiber, even though other materials could be used, provided. and when they have appropriate strength and are compatible with the other materials used. Axially and radially positioned afuer of each of the coupling ring members 24 is a fixing bead member 30 having the best overall shape and configuration shown in Figures 2, 4 and 5. As illustrated , each retaining ring member 30 has a conical shape, somewhat truncated, with an internal diameter so as to be narrowly receivable at the tube ends in the manner illustrated in Figure 1. As seen in Figures 4 and 5, The interior surface 32 of each ring 30 is provided with a plurality of relatively sharp clamping teeth 34 more clearly illustrated in Figure 5. The teeth are inclined in the manner shown and have sharp end edges. In the preferred fashion, three of the teeth 34 are found and have a flat face that is inclined at an angle on the scale of about 20-1 / 29. The external face 36 of each prefence ring 30 is inclined at an angle in the scale of approximately 20Q to correspond to the angle of the associated retaining ring 40 which will be described subsequently. At present, however, it should be seen that each clamping ring 30 is configured and positioned so as to be capable of closely engaging around the associated tube end in the manner shown in Figure 1. In the preferred embodiment, the fastening rings 30 are formed of a relatively hard plastic, such as an acetal copolymer. Additionally, as best seen in Figure 2, the rings 30 are divided as shown in 42 to be able to undergo radial forward compression to firmly hold the associated tube end. Adapted to be received circumferentially around the sleeve 18, the gasket 20, the coupling ring 24 and the clamping ring 30 is the aforementioned retainer ring member. Preferably, the retaining ring is polypropylene reinforced with molded glass fiber to have a generally cylindrical configuration that is seen more in Figures 2, 7 and 8. The retaining ring has a first surface 42 of cylindrical internal diameter that is d in order to receive tightly the actuating ring 24. The ends of the sleeve 18 are provided with ribs 18a (see Figure 1) which are also of an outer diameter so as to be received closely within the cylindrical wall 4. Placed axially inwardly of the wall 42, there is a truncated cone wall 44 which is joined to the wall 42 by a radially extending shoulder 46., co9rto. In this preferred form, the wall 44 makes an angle of approximately 20 ° relative to the axial centerline as shown in Figure 8. This corresponds to the angle of the external surface 36 of the retaining ring member 30. In its preferred form, the retaining ring 40, as mentioned above, is injection molded from glass fiber reinforced polypropylene. In order to reduce the roll and provide a lighter weight weight, the ring 11o provides with a plurality of axially extending inwardly extending chambers 50 arranged symmetrically around the outer portion of the ring. Extending through the annulus in the axial direction and placed 90s apart there are four through openings 52. The openings 52 provide means for applying axially directed forces to move the rings 40 towards each other for the formed condition shown in Fig. 1. In the preferred embodiment, the rings 40 are urged toward each other by the use of bolts. suitable fasteners 56 having threaded ends 58 that receive the appropriate nuts 60. The washers 62 are positioned below the nuts and the head 56a of each of the fastening bolts 56. Preferably, the fastening bolts 56 are made of stainless steel or other corrosion resistant material. With the various components assembled towards the relation of Figure 1, the tightening of the clamping bolts attracts the components together causing radial compression of the packs 22 and the clamping rings 30. The precise amount of co-pressure of these elements is ensured by the relationship between the coupling rings 2¿, the sleeve 18 and the retaining rings 40. Note that the coupling rings are dimmed and collocated so that during proper processing, they couple the end of the associated sleeve 18 and the shoulder 46 of the associated retaining ring 40. This provides a fixed stop so that overcompression of the gaskets 22 or the clamping rings 30 is not possible. Additionally, there is a third abutment surface associated with each retaining ring 40 in the shape of the coupling occurring between the inner end of each retaining ring 40 and the end wall of the associated recess -18a in the sleeve 18. This coupling of The surface allows a visible external indication of proper processing and, when this coupling occurs, the installer is sure that simultaneous coupling has occurred on both sides of the coupling ring 24, thus ensuring that the complete coupling assembly is properly installed. and completely done. This relationship as described above also encloses the gaskets and retaining rings in such a way that they are not significantly exposed to the surrounding environment. The fastening ring 30 of Figures 4 and 5 is the preferred foil for use in the plastic pipe joint and fastener as illustrated in Figures 1-3. If necessary-joining steel pipe sections or joining a section of a steel pipe to a section of plastic pipe, an alternative fastening ring construction is preferred as shown in Figures 9 and 10. In particular, the alternative construction comprises a bearing ring 68 having a configuration external dial of the ring 30 discussed above. The carrier ring 68 can be formed from a plastic such as acetal copolymer. Air from inside the ring 68 a continuous recess 70 is formed. Collocated within the recess 70 is a metal ring 72 of generally rectangular cross section provided with a toothed internal surface 74. The ring 72 is preferably formed of steel and has teeth 76 formed formed as best seen in Figure 10. Each tooth preferably has its internal surface inclined at an angle alpha on the scale of 109-1 and encounters an end face that extends radially in a sharp corner. The ring 72 can be linked or adjusted by interference within the carrier ring 68. further, both, the ring 72, the indigo 68 carrier are divided as shown with respect to the ring 30 so that when the ring assembly is axially compressed within the retaining ring 40, radial clamping occurs inwardly. The invention has been described with reference to preferred mode. Obviously, modifications and altitudes will occur to others after a reading and understanding of this specification. It is intended to include all these changes alterations as long as they are within the scope of the attached clauses or their equivalents.

Claims (1)

CLAIMS:

1 - A coupling assembly for joining two spaced tube ends, comprising: an elongated sleeve adapted to receive two opposite tube ends to be connected, the sleeve having truncated cone ends that open outwardly; a pair of annular elastomeric gaskets having truncated cone end portions adapted to fit toward the truncated cone ends of the sleeve in sliding engagement about the end tubes to be connected; a separate retaining ring member, axially positioned outwardly from each end of the sleeve and for rounding the pipe ends to be connected4, each retaining ring member having an inner truncated cone wall oriented to the sleeve to define a clamping ring chamber; a radially compressible, separate clamping ring member positioned in each clamping ring chamber; separate coupling ring members positioned at each end of the sleeve at a location between the elastomeric packing and the retaining ring at that respective end; tightening elements for selectively moving the retaining ring members axially towards each other to compress the packages towards their truncated cone chambers of the larger unit and to radially compress the respective clamping ring members; and, cooperating stop surfaces to provide a stop for limiting the movement of the retainer ring members towards each other to provide positive limit to the compression applied to the gaskets and the ring members of the ring. 2. The coupling assembly as defined in claim 1, wherein each retaining ring member has an end portion that remains on the adjacent coupling ring member and slidably receives the adjacent end of the sleeve. 3.- The coupling set as defined in the -rei vind icaci? 1, wherein the clamping elements comprise clamping rod members extending between the retaining ring members. 4. The coupling assembly as defined in claim 2, which further includes a stop surface at c of the retaining ring member and cooperating stop surfaces in the sleeve. 5. The coupling assembly as defined in claim 1, wherein the coupling ring members and the retaining rings are formed of a resinous material. 6. The coupling assembly as defined in claim 1, wherein the sleeve is formed of a resinous material. 1. - The coupling assembly as defined in the claim? 1, wherein the sleeve has circumferential recesses formed around the ends radially outwardly of the elastomeric gaskets, the ring members of retention received on the recesses and slidable therein. 8. The coupling assembly as defined in claim 1, wherein the recesses define a portion of the abutment surfaces to limit the movement of the retaining ring members toward each other. 9. The coupling assembly as defined in claim 1, wherein each coupling ring is coupled on axially opposite sides by the respective retaining ring member and the end of the sleeve associated therewith. 10. A coupling assembly for joining two spaced coaxial tube ends, comprising: one elongate plastic sleeve adapted to receive two opposite tube ends, coaxial to be connected, the sleeve having truncated cone ends that they open out; a pair of annular elastomeric gaskets having truncated cone end portions placed on the truncated cone ends of the sleeve for sliding coupling around the pipe ends to be connected; a separate retaining ring member positioned axially and radially outwardly from each end of the sleeve to surround the tube ends to be connected, each retaining ring member having an inner truncated cone wall oriented to the sleeve to define a clamping ring camera; a radially compressible, separate clamping ring member positioned in each clamping ring chamber; separate coupling ring members positioned at each end of the sleeve, each coupling ring member having oppositely oriented end surfaces, respectively coupled with the elastomeric packing and the clamping ring at that respective end; and, clamping elements for selectively moving the retaining ring members axially towards each other to close the packages towards their respective truncated cone chambers of the sleeve and to radially compress the respective clamping members. 11. The coupling assembly as defined in claim 10, wherein each retaining ring member has an end portion that remains on the adjacent coupling ring member and slidably receives the lying end of the sleeve. 12. The coupling assembly as defined in claim 10, wherein the opposite end surfaces oriented on the coupling ring members are flattened with the cooperating stop surfaces, the associated retaining ring member. , and the sleeve when the coupling assembly d is connected to opposite tube ends. 13. The coupling assembly as defined in claim 10, wherein the coupling ring members and the retaining rings are formed of a resinous material. 14. The coupling assembly as defined in claim 10, wherein the sleeve has circumferential recesses formed around the ends radially outward of the elastomeric gaskets, the ring-retention members received on the recesses and slides. in them. 15. The coupling assembly as defined in claim 10, wherein at least one of the clamping ring members includes metal clamping teeth. 16. The coupling assembly as defined in claim 15, wherein the at least one of the clamping ring members comprises a toothed metal ring in a plastic carrier ring. SUMMARY OF THE INVENTION A coupling assembly for joining two spaced, coaxial tube ends comprises an elongated sleeve, adapted to coaxially receive two opposite tube ends to be connected. The sleeve has truncated cone ends that open outwardly and receive an elastomeric annular unpacked pair adapted to fit toward the tapered cone ends of the sleeve in sliding engagement around the ends of the tube to be connected. A separate ring-tension member is positioned axially outward from each end of. sleeve to surround the tube ends to be connected. Each retaining ring member has an annular truncated cone wall oriented to the sleeve to define a clamping ring chamber. Positioned in each clamping ring chamber is a radially compressible, spaced clamping ring member. The separate coupling ring members are positioned at each end of the sleeve in a location between the elastomeric gasket and the clamping ring at that respective end. Rod members are provided to selectively move the retaining ring members axially toward each other to compress the gaskets to their respective truncated cone chambers of the sleeve and to radially compress the respective clamping ring members, and , the cooperating stop surfaces act to limit the movement of the retainer ring members toward each other to provide positive compression limit applied to the gaskets and the clamping ring members.