Title of Invention | AN IMPROVED LOCKED COUPLING BETWEEN TWO TUBLAR ELEMENTS |
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Abstract | This invention relates to an improved locked coupling between two tubular elements (1, 1A) one of said elements having a spigot end (2) and the other being a socket (4) said coupling comprising a set of withdrawable bolts (6, 6') capable of being fixed to said socket (4) by operating said bolts (6, 6') from outside. Said bolts (6, 6') are capable of being tightened by screws to an extent, so that the free ends of the bolts (6,6') remain within a cavity (7, 7') provided on the outer surface of said socket (4). |
Full Text | The present invention relates to pipe coup lings for joints and more particularly to couplings for pipes having joints of sockets and spigots. The invention particularly relates to an elastomeric sealing element and a locking device for preventing a relative longitudinal displacement of the two-coupled pipes. The invention is applicable to pipes made of metals, ceramic concrete, plastics or other compositions. It is well known in the art to which the invention relates that the internal pressure in a pipeline will exert forces tending to separate or break the joints in the line wherever there is a change of direction, a branch, or a dead end in the pipeline. It would be desirable if the joints themselves would provide the necessary resistance to separation or breakage; however, the slip on or push-on joints in common use today for the joining of pipe do not provide any appreciable resistance to separation. For example, Indian Patent No, 60,440 dated March 17, 1958. Accordingly, it has been necessary to provide external means such as concrete blocking or clamp and tie rods along a pipeline in order to prevent relative movement of pipe sections, which would result in separation of the joints. such commonly used meant accomplish the desired purpose, but are very expensive and time consuming. An object of the present invention is to mitigate the foresaid drawbacks of the conventional jointing of pipes. A further object of the present invention is to provide anchoring or securing of flexible pipe joints and safe guarding them against relative longitudinal displacement of two coupled pipes. Another object of the invention is to provide couplings and fittings when they require fluid tight separation resistant joint between socket and spigot elements. Accordingly there is provided an improved locked coupling between two tubular elements. One of said elements having a spigot end and the other being a socket . The coupling comprising a set of withdrawable bolts capable of being fixed to said socket by operating the bolts from outside. The bolts are capable of being tightened by screws to an extent so that the free ends of the bolts remain within a cavity provided on the outer surface of said socket . Thus, a fluid tight joint similar to pipe joints and gaskets of the kind disclosed for socket and spigot type pipe couplings and fittings, comprising a spigot member having a generally cylindrical end portion, a socket member receiving said spigot member and having an axially elongated gasket groove therein radially opposite the cylindrical end portion of the spigot member, said gasket groove being defined by the internal wall of a lip with said lip extending toward the spigot member and a generally axially extending wall, the diameter of said lip at its inner extremity being slightly greater than the external diameter of the spigot member, an........................................ axially elongated annular gasket having a portion thereof in engagement with the axially extending wall of the gasket groove and the general cylindrical end portion of the spigot member under radial compressive force whereby seal is effected between the socket and spigot members. It is known that the coupling of pipes having a socket end and a spigot end is liable to be disconnected under the action of an internal pressure and/or external forces. The present invention provides an improved locked coupling between two tubular elements, one of said elements having a spigot end and the other being a socket, said coupling comprising a set of withdrawable bolts capable of being fixed to said socket by operating said bolts from outside, said bolts being capable of tightened by screws to an extent, so that the free ends of the bolts remain well within a cavity or slot provided on the outer surface of said spigot. In the above improved locked coupling, the set of bolts is fitted from within said spigot onto said socket so that free end of said bolts remain well within a cavity provided in said spigot. The bolts are preferably made of stainless steel. The socket of the improved locked coupling is provided with a inner rim and the spigot is provided with a set of holes so that when said socket and spigot are assembled for coupling , the holes are located between said rim and the rear end of said socket for the entry of said bolts. Furthermore, a sealing element of resilient material is placed in the space located between the spigot and the socket. The said sealing element is preferably made of rubber or like material. The improved locked coupling of the present invention may further comprise a set of holes fitted to said socket so that free end of said holts remain will within a cavity or slot provided on the outer side of the spigot. The present invention further comprises a process of locking axial displacement between two tubular elements one of which elements has a spigot end and the other has a socket. The locking device comprising of withdrawable bolts radially placed screwed through the spigot and passes through the cavity provided in the socket. The arrangement being such that the bolts are capable of preventing the spigot end to withdraw from the socket when the spigot end is subjected to an axial thrust in a direction to tend to separate the two tubular elements, wherein the spigot end is; pushed cut of the socket after the bolts are radially placed around the spigot, Several embodiments of this invention will be described below by way of example with reference to the accompanying drawings, wherein- Fig, 1 is a longitudina1 axial radial sectiona1 view of a coupling according to the invention with bolts in position from outside the socket through the hole in the spigot. Fig. 2 is another longitudinal axial radial sectional view of a coupling when the set of bolts are screwed from outside the socket through the slot in the spigot. Fig, 3 is. another longitudinal axial radial sectional view of a coupling when the set of bolts are screwed from inside the pipe through the spigot to the hole in the socket such that it passes through the spigot and passes through the hole provided on the socket and places itself inside the hole of the socket. Fig.4 is another longitudinal axial radial sectional view of a coupling when the set of bolts are screwed from inside the pipe through the spigot to the cavity provided in the socket adjacent to the cavity where the gasket is fixed. Fig.l to Fig.4 describe several embodiments of this invention related to joints, which are known as Push-on-joint in the trade. Fig,5 illustrates another longitudinal axial radial sectional view of a couplng when the set of bolts are screwed from outside through the outside of socket of the type well known as common mechanical joint, such that it passes through the mechanical joint socket and passes through the hole provided on the spigot and places itself inside the hole of the spigot. These and other objects of the invention will appear more fully upon consideration of the detailed description of the illustrated embodiments of the invention, which follows. In this connection, although several different embodiments of the invention ere illustrated and described, it is to he explicitly understood that these embodiments are intended merely for the purpose of illustration and are not to construe as defining the limits of the invention. It will also be understood that, while the drawings show joints between sections of socket and spigot type pipe, the invention is equally applicable to couplings and fittings when they require a fluid tight separation resistant joint between socket and spigot elements. In the above drawings., Figs 1 and 2, a restrained jont (5) comprises a first tubular element (1) having a spigot end (2) and a second tubular element (1A) provided with a socket (4). A rubber gasket (3) is placed in an annular space between the first tubular element (1) and the socket (4) which when assembled seals the joint (5) against leaking. A first coupling comprises a set of withdrawable bolts (6,6') capable of being fixed to said socket (4), the arrangement being such that the bolts (6,6') can be turned from outside the socket (4) and passes into a hole (7,7') in the first tubular element (1). The bolts (6,6') are of such length that they do not protrude inside the tubular spigot element (1) and there is no obstruction of fluid from inside. When the set of bolts (6,6') are screwed from outside the socket into the hole (7,7') provided in the spigot (2) in an assembled positions When the spigot (2) is subjected to an axial thrust in a direction tending to separate the two tubular elements (1,1A), the bolts (6,6') come in the way of pushing out the spigot (2). The entire thrust force to separate th» two tubular elements (1,1A) is taken by the shear strength of the set of bolts (6,6' radially placed in the socket (4) from outside. In figures 3 and 4, the bolts (6,6') are turned from inside when the diameter of the tubular spigot element (1) is such that a man can enter into it after the joint is assembled. The bolts (6,6') are tightened to such an extent that they do not protrude inside the tubular element (1) and there is no obstruction of fluid flow from inside. The other ends (8,8') of the sets of bolts (6,6') protrude on the other side of the spigot (2)» which remain in the cavity (7,7') provided in the socket (4). Due to formation of a compartment (9,9') in the socket (4), the set of bolts (6,6') do not interfere with the joining of tbe push- on joint and leak tightness of the joint. But as the (6,6) bolts protrude inside the socket (4) in the event the spigot (20) is subjected to an axial thrust tending to separate said two tubular elements (1, 1A), the bolts (6,6') come in the way of pushing out the spigot (2) from the socket (4). The entire thrust force to separte the two tubular elements (1, 1A) is taken by the shear strenght of the setoff bolts (6,6') radially present in the spigot (2). In Figure 3 of the arrangement, when the sets of bolts (6,6') are screwed into the socket (4) through the holes (2) of the spigot end (2) but do not protrude inside the spigot end (2), there is no obstruction of the fluid from the inside. In the avent, the spigot (2) is subjected to an axial thrust in a direction tending to separate the two tubular elements (1, 1A), the bolts (6,6) come in the way of pushing out the spigot (2). The entire thrust force to separate two tubular elements (1, 1A) is taken by the shear strength of the set of bolts (6.6') positioned radially in the socket (4). As shown in Figure 5, the set of bolts (6,6') are screwed from outside through the outside of a socket (4,4') and a bolt (10) with a worm (11) fastened from outside of the socket (4) and passes through the hole provided on the spigot (2) and places itself inside the hole of the spigot (2). When the bolts (6,6) are properly fastened, the socket (4') will occupy the blank space (12) of the socket (4). I CLAIM: 1. An improved locked coupling between two tubular elements (l, 1A),one of said elements having a spigot end (2) and the other being a sockat (4),said coupling comprising a sat of withdrawable bolts (6,6') capable of being fixed to said socket (4) by operating said bolts (6, 6') from outside, characterized in that said bolts (6, 6') are capable of being tightened by screws to an extent, so that the free ends of the bolts (6, 6') remain within a cavity (7, 7') provided on the outer surface of said socket (4). 2. An improved locked coupling as claimed in claim 1 wherein said set of bolts (6, 6') is fitted from within said spigot (2) onto said socket (4) so that free ends of said bolts (6,6') remain within the cavity (7, 7') provided in said socket (4). 3. An improved locked coupling as claimed in claim 1 wherein said bolts (6, 6') are made of stainless steel. 4. An improved locked coupling as claimed in claim 2 wherein said socket (4) is provided with an inner rim (13) and said spigot (2) is provided with a set of holes so that when said socket (4) and the spigot (21) are assembled, the holes are located between said rim (13) and the rear end of said socket (4) for the entry of said bolts. 5. An improved locked coupling as claimed in any of the preceding claims, wherein a sealing element (3) of resilient material is placed in the space located between said spigot (2) and said socket (4). 6. An improved locked coupling as claimed in claim 3, wherein said sealing element (3) is made of rubber or like materials. 7. An improved locked coupling as claimed in any of the preceding claims, wherein said joint further comprises a set of bolts (8, 8') fitted to said socket (4) so that free ends of said bolts (8, 8') remain within a cavity (7, 7') or slot provided on the outer side of said spigot (2). 8. An improved locked coupling substantially as herein described with reference to the drawings accompanying this specification. This invention relates to an improved locked coupling between two tubular elements (1, 1A) one of said elements having a spigot end (2) and the other being a socket (4) said coupling comprising a set of withdrawable bolts (6, 6') capable of being fixed to said socket (4) by operating said bolts (6, 6') from outside. Said bolts (6, 6') are capable of being tightened by screws to an extent, so that the free ends of the bolts (6,6') remain within a cavity (7, 7') provided on the outer surface of said socket (4). |
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332-kol-2004-correspondence.pdf
332-kol-2004-description (complete).pdf
332-kol-2004-examination report.pdf
332-kol-2004-reply to examination report.pdf
332-kol-2004-specification.pdf
Patent Number | 237808 | ||||||||
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Indian Patent Application Number | 332/KOL/2004 | ||||||||
PG Journal Number | 02/2010 | ||||||||
Publication Date | 08-Jan-2010 | ||||||||
Grant Date | 07-Jan-2010 | ||||||||
Date of Filing | 18-Jun-2004 | ||||||||
Name of Patentee | CHATTERJEE ARABINDA | ||||||||
Applicant Address | EC-65, SECTOR-1, SALT LAKE CITY, CALCUTTA | ||||||||
Inventors:
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PCT International Classification Number | F16L | ||||||||
PCT International Application Number | N/A | ||||||||
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PCT Conventions:
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