Abstract: A pipe joint comprises a cylindrical main body 1 with both ends open, at least one of which is to be a pipe insertion port 10, a slender slidable cylinder 2 coaxially installed in the main body 1 so as to slide therein freely to and fro in a certain range, its free end facing the pipe insertion port 10, and a holding cylinder 3 inserted between the main body 1 and the slidable cylinder 2 in a manner to move freely back and forth. The main body 1 has a taper 11 diminishing toward the pipe insertion port 10 on its inner circumference near the port 10. The holding cylinder 3 has a slit 30 open to the pipe insertion port 10 and its outside diameter is slightly larger than the inside diameter of the pipe insertion port 10. In a state where a pipe is forcibly fitted on the slidable cylinder 2 externally, the holding cylinder 3 moves toward the pipe insertion port 10 along with the pipe being pulled back.

Abstract: A connector used in connecting a resin tube and a metallic pipe of comparatively small diameter comprises a connector body and a plurality of elastic pawl members. The connector body is formed with a large-diameter chamber. The peripheral wall of the chamber has a plurality of lock holes distributed in the circumferential direction thereof. Each elastic pawl member is assembled such that its rear end portion is passed through a corresponding one of the lock holes, bent and secured in place, and its front end portion resiliently retains and secures an expanded portion of the pipe inserted in the chamber.

Abstract: There is disclosed a connector for connecting a small diameter pipe. The connector includes: a connector body provided with an enlarge diameter chamber provided with a stepped portion; a pipe having an annular collar wall and engaging with the stepped portion; a sealing member fitted to the annular collar wall; and a sleeve member having a collar wall. An end peripheral portion of a cylindrical wall defining the enlarged diameter chamber into which the pipe connecting end is incorporated is welded to the sleeve member collar wall.There is also disclosed a connecting method comprising the steps of: fitting the sealing and sleeve members to the pipe collar wall; incorporating the connecting end of the pipe fitted with the sealing and sleeve members into the enlarged diameter chamber; and welding the sleeve member collar wall to the cylindrical wall in a state where the pipe collar wall engages with the stepped portion.

Abstract: A fitting for externally grooved and ribbed end portions of pipes, tubes, hoses and like tubular bodies has a tubular section and one or more circumferentially extending prongs each having one end integral with but pivotable relative to the section and a free second end. The inner side of each prong has one or more one-piece or composite circumferentially extending protuberances. In order to couple the fitting to the end portion of a tubular body, the free end of each prong is pulled radially outwardly to extract the protuberance or protuberances from the interior of the tubular section. The end portion of a tubular body is thereupon inserted into the section, and the prong or prongs are released to introduce their protuberances into the adjacent external groove or grooves of the inserted end portion. Each prong is surrounded by a substantially U-shaped slot of the tubular section to permit slight axial movements of the free end portion of the respective prong.

Abstract: A quick disconnect coupling having a socket and a plug. In one embodiment, the plug has an outwardly projecting ring at its end that is captured behind a plurality of pins of an inwardly stepped shoulder formed in the socket in order to prevent the plug from being withdrawn from the socket. The plug is releasably retained in the socket by a variety of means, including a resilient ring surrounding the plug that tightly fits into a stepped shoulder formed in the socket or circumferentially spaced ball bearings mounted on either the plug or the socket and biased into a groove formed on the socket or plug, respectively. In another embodiment of the invention, the plug is formed by a cylindrical sleeve on which retaining fingers are pivotally mounted. The retaining fingers each terminate in a respective retaining tab that is captured behind an inwardly stepped shoulder formed in the socket.

Abstract: The present invention comprises couplings which require no adhesives or cold welding or similar techniques for joining lengths of pipe of any known composition. The couplings, in their various shapes, are molded from Ultra High Molecular Weight Polyethylene (UHMWP). Within each end of each coupling form there are a plurality of spaced apart inwardly extending flexible rings, each ring terminating in an angular tip portion which is deformed in the direction of the inserted pipe end and forms a plurality of locking annular seals around the inserted pipe end portion. UHMWP has an inherent self-lubricity which facilitates the insertion of the pipe end portion. UHMWP is chemically inert.

Abstract: A device is suggested for the interchangeable connection of a projecting arm section (1) to an arm (2) of an internal treatment station for can bodies. The device comprises a locking member (8), by means of which the arm section (1), such as a spray arm, for example, is detachably mounted to the arm (2).

Abstract: A water meter service coupling facilitates removal and/or replacement of a water meter by allowing for expansion of the water service line upon disconnection of the water meter. One embodiment of the water meter service coupling includes a housing having first and second ends, an expansion piston having one end thereof slidably inserted into the first end of said housing for being slidably moved into and out of said housing, a retaining insert disposed at the outer end of said expansion piston, and a nut disposed about said retaining insert for coupling said expansion piston to a water meter, wherein the second end of said housing is coupled to a water service line and the water meter service coupling is installed in an expanded state so that upon disconnection from the water meter, the water meter service coupling may be retracted so as to allow for easy removal of the water meter.

Abstract: A device for jointing or closing pipe ends and comprising a single or double-ended rigid or semi-rigid tubular body (10) adapted to retain and protect a single or double-ended elastomeric sleeve (12) with a resilient annular collar (13) protruding from the body at the or each end. The sleeve (12) surrounds the pipe to be joined or closed, and a clamping ring consisting of a pair of semi-circular segments (14) is closed around the collar (13) with bolts (15) and diametrically opposed wedge-like members (18) which are in sliding engagement with the internal surfaces of the clamping ring segments (14) thus to be forced inwardly together with the latter when the bolts (15) are tightened. This ensures a substantially unform radial compression of the collar (13) around the pipe wall.

Abstract: A coupling device for fluid conduits comprising a tubular male member and female sleeve member, each having a hose end and a coupling end, the coupling ends being adapted to couple the members to form a fluid-tight joint, a shoulder on the male member intermediate its ends, the members having aurbaces for positioning the same with the bores thereof in communication and substantial axial alignment, latching members on the sleeve member comprising a plurality of flexible fingers having radially inwardly directed lips, and cam lock comprising a lock ring positioned around the outer surface of the latching member and moveable rotationally and axially thereof through rotational force applied thereto into and out of a position wherein said lips are forced and maintained in position for a locking relationship with said shoulder, said cam lock further comprising cooperating helical cams on said latching member and said lock ring.

Abstract: A conduit coupling member for use with a second coupling member, comprising: a generally tubular body having a bore along its longitudinal axis; an integral and portion of the body having a nose portion and an annular groove in the bore juxtaposed the nose portion which together define a cantilever lip deflectable at least partially in a direction of the longitudinal axis; and the nose portion having an outer surface, a portion of which effects a seal when the lip is longitudinally deflected.

Abstract: A preformed coupler for connecting plastic pipe to metal pipe comprises a convoluted tubular metal sleeve, a plastic tube extending part way into the metal sleeve, an annular gasket, and a retention means. The annular gasket, which encircles a portion of the plastic pipe, is compressed against the plastic pipe by the metal sleeve to form a fluid-tight seal. The retention means resists any effort to withdraw the tube from the sleeve. The free end of the metal sleeve can be telescoped over the end of the steel pipe to be joined, then the outer end of the plastic tube can be butt welded to the plastic pipe to be connected, and then the telescoped end of the sleeve can be welded to the metal pipe.

Abstract: The end of the uncooled pipe (1) is forked in cross-section, creating an inner and an outer section (5 and 6). The outer section is secure to a cooled pipe (2) and the inner section extends into the cooled pipe with radial and axial play. The annular gap (13) between the inner and outer sections is occupied by a heat-insulating material.

Abstract: There is disclosed a connector for connecting a small diameter pipe, having a connector body and a socket member. The connector body formed with a small diameter chamber accommodating sealing members and a bush and an enlarged-diameter chamber provided with a retaining wall. The socket member has oppositely protruded pawl walls. The pawl walls engage with retaining holes formed in the enlarged-diameter chamber, thus incorporating the socket member thereinto. The socket member also has a notch to assume a C-shape in section and at least one pair of protruded walls engaging with the retaining holes.

Abstract: Fitted coupling device, formed by two components, for connection to a flexible tube, having a female component and a male component on which said flexible tube is attached by thermal contraction of an external ring. The coupling device has an elastomer O-ring which is gradually compressed between two facing surfaces, one of which is essentially cylindrical and the other of which is a small-angle cone. The compression takes place during an axial manoeuver causing the rolling without sliding of said O-ring, which executes one or more complete turns on itself.

Abstract: An improved connector has a flexible braided metal hose assembly with a compression fitting or pipe fitting at one end and a special composite fitting assembly with an electrically insulating insert in a metal male outer fitting at the other end for connection to the water line of an appliance, such as a hot water heater.

Abstract: A multi-passage tube coupling for coupling a plurality of parallel or concentric tubes or tube passages of a multi-passage tube for supplying a fluid to actuators. The coupling comprises a body and a coupling member, the body having as many passages or holes as the number of the tubes or tube passages of the multi-passage tube. At least one of the tubes or tube passages is coupled to the corresponding actuator through a passage defined in the coupling member.

Abstract: A quick disconnect coupling having a socket and a plug. In one embodiment, the plug has an outwardly projecting ring at its end that is captured behind a plurality of pins or an inwardly stepped shoulder formed in the socket in order to prevent the plug from being withdrawn from the socket. The plug is releasably retained in the socket by a variety of means, including a resilient ring surrounding the plug that tightly fits into a stepped shoulder formed in the socket or circumferentially spaced ball bearings mounted on either the plug or the socket and biased into a groove formed on the socket or plug, respectively. In another embodiment of the invention, the plug is formed by a cylindrical sleeve on which retaining fingers are pivotally mounted. The retaining fingers each terminate in a respective retaining tab that is captured behind an inwardly stepped shoulder formed in the socket.

Abstract: Improvement to reduction bushings (10, 30, 30), along with particulars of the use thereof, and to systems for sealing to the casing (15, 42), that are considerably different from those so far in use. Instead of O-rings, the seal between the bushing (10, 20, 30) and the casing (15, 42) is achieved by arc-welding (16) done at the tips thereof or by threading the bushing into the top of the casing.

Abstract: A faucet adapter for flushing paint from portable painting equipment tubing has a first end formed of an elastomer with an internal conical recess for coupling to one of a plurality of faaucet nozzles having varying diameters and a second end having a pair of hollow external conical projections of differing diameters, each for coupling to one of a pair of matching diameter lumens in portable painting equipment tubing with the hollow projections communicating with the internal conical recess for permitting the flow of liquid therethrough.

Abstract: A thread coupling includes at least one male thread and one female tread. The male thread is arranged upon a spigot that constitutes an integral part of one drill string element. The one drill string element is provided with a contact surface spaced from the free end of the spigot. The female thread is a part of a coupling sleeve that is connected to another drill string element. The coupling sleeve is provided with an internal stop surface. The contact surface of the one drill string element contacts a free end of the sleeve, but the free end of the spigot is spaced slightly from the stop surface by a gap which is eventually eliminated after the threads have become worn-in. The gap is greater than zero, but no greater than 1 mm.

Abstract: A conduit fitting for use in conduit systems having attachment structure at each end which is galvanically isolated from each other to prevent galvanic corrosion and deterioration. The fitting components are assembled to constitute a unit to facilitate handling and inventory.

Abstract: In a vibro-isolating joint including two rigid flanges, a flexible cylindrical member such as bellows interposed between the flanges and a plurality of limiting bolts extended through opposed through holes in the flanges, a cylindrical elastomer body is retained in each of through holes in at least one of the flanges and a hollow sleeve is concentrically integrated with the elastomer body so as to protrude one end of the hollow sleeve from an outer surface of the flange so that lock nuts on the limiting bolts engage the protruded ends of the hollow sleeves resiliently supported in the through holes, respectively to thereby provide a high axial thrust together with a vibration isolating property.

Abstract: In a hose fitting fixing construction according to this invention, an engagement member having restoring force of gravity or elastic force is disposed in an engagement space of a bracket. The engagement member engages with an engagement dent of a hose fitting flange inserted into the engagement space, thereby engaging the hose fitting flange with the bracket. A detachment hole may be provided on the bracket to enable easy detachment of the hose fitting flange from the bracket. A detachment jig is inserted into the detachment hole to deform the engagement member against the restoring force and disengage the engagement member from the engagement dent of the hose fitting flange, thereby enabling to detach the hose fitting flange from the engagement space. Accordingly, the hose fitting flange can be installed to the bracket by snap-action even in a limited work space, and detached with ease.

Abstract: The invention relates to a releasable coupling between a male element and a female element. The coupling comprises a split clamp ring that is ranged to be received in corresponding annular recesses in the male element and female element, whereby the ring shall have one wedge surface to engage with a support surface in one recess on the male element and another wedge surface obliquely, disposed from the first wedge surface to engage with a support surface in the other recess in the female element. By applying a circumferentially directed force to the end portions of the split ring, it will be possible to achieve a locking engagement between the ring and its matching recesses, thus assembling the male and female elements to each other.

Abstract: A connector connected with a tube having a relatively small diameter, say about less than 20 mm, for supplying oil, air, or the like. The body of the connector has a connecting tubular wall, a communication hole formed in the tubular wall, and a large stepped chamber formed along the axis of the body. A jaw wall protrudes outwardly from the rear end of the chamber. One or more seal rings are mounted in the chamber. A bush member is inserted in the rear portion of the chamber. A socket member has a base wall from which resilient claw walls protrude. The front ends of the claw walls extend into the chamber and are in resilient contact with the outwardly swelling annular portion of the tube.

Abstract: A connector for connecting end-to-end two spiral-wound sheet metal air ducts. The connector is an annular structure with opposite end segments, each of which presents an annular recess or groove which is open at its outer end and closed at its inner end and filled with sealing mastic there. The dimension of each recess or groove transverse to the longitudinal axis of the ducts and the connector is substantially equal to the maximum thickness of the corresponding duct (i.e., where its spiral rib is located) so that each duct has a snug sliding fit in the corresponding recess.

Abstract: A flexible winding hose coupling apparatus is provided which allows for the rapid coupling of a flexible hose thereinto. The coupling can then be attached to another hose or to a pipe fitting or tap. The coupling has first and second coupling members with the first coupling member having a hollow tapered bore therein and the second coupling member loosely fitting or floating in the bore of the first coupling member. The first coupling member has an annular ledge formed in the bore to act as a stop for the second coupling member and has a plurality of annular barbs formed along the bore walls. The second coupling member is located in the first and has an external taper thereon with a plurality of external annular barbs therearound so that sliding a flexible hose over the second coupling member expands the end of the hose along the taper and over the barbs, driving the end of the hose towards the inside of the first coupling member bore walls.

Abstract: Ring collar for use in connecting a side branch line to a main header air duct, the ring collar having a tubular sheet metal body with an inlet, an outlet end which is tapered for easy insertion into a tubular member, and a U-shaped channel ring around the body with the open side of the channel facing the outlet end of the body; and a process for connecting the ring collar to the main header.

Abstract: A coupling device for connecting an end of a hose to an end of a pipe having a circumferentially extending collar includes a tubular coupling element with axially spaced ends. A first end of the coupling element is received in the end of the pipe and the coupling element is provided with elastic hooks which engage the collar in order to fix the coupling element. The device further includes a sleeve having a first section which is received in the coupling element and defines therewith an annular space of width approximately equal to the wall thickness of the hose. The sleeve also has a second section which projects from the annular space into the end of the pipe so as to define an annular gap with the latter. The second section of the sleeve is of greater diameter than the first section and abuts the first end of the coupling element.

Abstract: A double-walled pipeline system for flow media with an inner pipeline conduit including fittings, such as, T-pieces, angles, or bends, and instruments, such as, valves, stopcocks, etc., and with an outer pipeline conduit arranged concentrically to the inner pipeline conduit. The outer pipeline conduit includes two-part fittings and instrument casings, so that continuously connected outer annular space is formed in the pipeline system.

Abstract: A pressure cylinder, such as a master cylinder or wheel cylinder for an hydraulic vehicle braking system has a plastic molded body within which a threaded insert is engaged and restrained rotationally and axially. A seal is positioned within the body between surfaces of the insert and body. The insert provides a seat against which is clamped, in use, a corresponding seat on a flared end of a pipe, the letter being retained within the body by a pipe nut threadedly engaged with the insert. Long-term thread torque and clamping force are sustained by the insert rather than by the plastic body which can be subject to "creep".

Abstract: A structure comprising two interconnected metal tubes used for supplying oil or air. The first tube inserted in the second tube has a tubular wall at its one end and an outwardly swelling circumferential wall formed inside the tubular wall. The second tube has plural slots arranged circumferentially. A seal member is sandwiched between both tubes. A binding band is wound around the slots to compress the portion having the slots, for fastening the tubes together.

Abstract: A coupling assembly for hoses, fabricated of plastic and comprising one-piece male and multi-piece snap together female coupling sections. The male section includes an externally threaded fitting and an integral hub adapted to fit over the end of a hose section, the hub having internal circumferential ribs or barbs. A ferrule inserted into the hose expands the hose wall into engagement with the barbs for securing the section to the hose. The female section includes an annular collar likewise fitted over and secured to the end of a hose section. An annular flange is formed on the collar, and an internally threaded connector is provided, including an inwardly turned annular lip adapted to snap over and engage behind the flange for rotatably mounting the connector on the collar. The barbs are specially configured to bite into the hose material and resist separation of the coupling section from the hose in response to axial forces tending to pull them apart.

Abstract: An improved flexible pipe connector for interconnecting in sealing relationship two pipe or tube sections comprising a deformable resilient hollow connector portion having a first tubular end portion sealingly engageable with an end of a first pipe or tube section, a second tubular end portion connectable to a second pipe or tube section and an intermediate portion having a plurality of annular strengthening ribs, a short length rigid reinforcing collar surrounding the first end portion and a coupling slip nut slidably located on the collar for both rotational and axial movement relative thereto, the slip nut being adapted for connection to the end of a first pipe or tube section.

Abstract: Split fittings for use in the installation of a semi-rigid secondary pipe over a primary pipe comprise a pair of housing halves which, when mated, form a housing enclosure, sealing means and clamping means capable of holding the secondary pipe and housing halves as a sealed enclosure. A method of fitting a rigid pipeline system with secondary containment system with a secondary semi-rigid pipe uses the split fittings.

Abstract: A two-part type cable insert nozzle has spherical seats formed on a female die and a male die. An automatic restoring member restores the female die to coaxial alignment with the male die. The automatic restoring member may include a pressing element surrounding the male die between a nozzle holder for coupling together the female die and the male die and a flange portion fixedly secured to the outer circumference of a tubular portion of the male die and spaced from and opposed to the nozzle holder. Alternatively, the member may be a spring provided within cable insert holes extending through the male die and the female die.

Abstract: A pipe joint for connecting two pipes to each other has a joint member to which one of the pipes is fixed and provided with a bore formed therein, a socket member fixed to the outer peripheral surface of the joint member and provided at its one end with a flange having an opening and also with an annular space defined by the flange, a retainer ring composed of a plurality of segments each having a tapered surface confronting the opening, the segments being arranged in the circumferential direction and held by an elastic band fitting on the outer peripheral surfaces thereof such that the retainer ring composed of the segments can expand and contract radially, and a male member constituted by the other of the pipes and having a bead portion protruding radially outwardly from the outer peripheral surface of the male member at a position near the end of the male member.

Abstract: The invention relates to a connecting piece for connecting tubular members such as hoses, pipes, or other structural parts, carrying fluids with each other. A clamping part is available which has two half shell-shaped clamping halves with one clamping surface curved in accordance with the outer circumference of the end of the tubular member to be inserted. In their plug-in position the clamping halves are arranged at a distance to each other which permits insertion of the plug-in end of a tubular member. In their clamping position they enclose non-displaceably the plug-in end of the pipe, the hose or similar and they are simultaneously fixed on a contact part of the connecting piece.

Abstract: A connector for connecting a tube such as a coil tubing, or the like, to well tools, pipe, or another tube. The connector will withstand high pressures and is capable of transmitting high tensile and torque loads, and can be applied to tubes by crimping through use of conventional swaging devices.

Abstract: Described herein are composite devices comprising two members. The first member is a heat recoverable driving member and the second is a metallic member associated with the first in such a way that upon heat recovery of the driver, the second member is dimensionally altered to engage a substrate. In one embodiment, useful for example as a composite coupling for joining cylindrical substrates, the driver comprises a tubular heat recoverable compression sleeve having a generally uniform interior surface. In this embodiment, the second member comprises a tubular insert snugly, and concentrically disposed within the sleeve. Although both its interior and exterior surfaces may be uniform, preferably one or both surfaces has a weakened portion to facilitate its deformation or bears integral radial teeth or a combination thereof. Upon heat recovery of the compression sleeve, the insert is compressed about the substrate.In another embodiment, the driver is positioned internally of the second member.

Abstract: A flange for connecting two air ducts to one another has a pair of spaced, generally parallel walls and a pair of spaced, generally parallel legs fast with, and extending perpendicular to, the walls. The flange legs are designed to embrace and grip a wall of an air duct while the flange walls define a chamber adapted to receive one leg of an angle serving to connect the flange to a neighboring flange. One of the flange legs is plastically deformed so as to define a cavity and has a surface facing the other flange leg. The cavity is open to this surface and accommodates an elastomeric seal which projects from the cavity to a location beyond the surface. The seal is elastically compressed in the cavity to retain the seal therein and such compression may be achieved by plastically deforming the respective flange leg after the seal has been positioned on the same.

Abstract: A pipe connection in which pipe ends are provided with flared ends within the area of the joint edges, and in which a clamping ring with a U-shaped internal profile in a cross section is adapted to be tightened radially inwardly; the inner end faces of the clamping ring and the flared end faces are inclined toward the pipe axis so that the joining edges are urged toward one another in the tightened condition of the clamping ring; the clamping ring is provided with at least one plastically deformable, lug-shaped ear adapted to be tightened by contraction thereof to thereby establish a permanent connection which can be reopened only by destruction of the clamping ring; the surfaces of the clamping ring which engage with the end faces of the flarings may be further provided with means, e.g., in the form of notches, teeth, serrations or embossments to prevent rotation of the ring relative to the joint edges.

Abstract: A pipe and flange assembly including a flange having a front surface and a rear surface, the flange having a substantially cylindrical aperture therethrough, the front surface of the flange being substantially planar, the rear surface of the flange having a cylindrical recessed portion therein for receipt of a pipe, the recessed portion having a chamfer extending around the circumference thereof between the recessed portion and the rear surface of the flange, a substantially cylindrical pipe seated in the recessed portion, and an interface portion connecting the pipe to the flange, the interface portion including the chamfer and weld material disposed between the pipe and the flange at said chamfer.

Abstract: A connector for heatable hoses and a heatable hose assembly for transporting fluids.

Abstract: Disclosed is a sealing ring comprising a molded elastomer ring having an inner ring contained therein which forms a pipe joint between two abutted pipe ends. Each of the pipe ends includes a recessed part, a flange or the like, which can be clamped together, for example, by means of a screw, and each of which has a sealing cavity into which the two axial ends of the sealing ring sealing the joint project. The axial ends of the sealing ring are deformed by the clamping together of the two recessed parts or the like and conform to the contour of the interior of the corresponding sealing cavity. To facilitate assembly and improve sealing properties, the two outer annular edges of the molded elastomer ring which rest against the surface of the two pipe ends are rounded and thus provided with a radius (R1).

Abstract: An improved coupling for connecting a pipe joint and a metal pipe which has a relatively small diameter not exceeding about 30 mm and a wall thickness not exceeding about 2 mm is offered. The coupling is often used to form a pipeline for supplying oil, air, etc. to an automobile, machine or apparatus, or collecting exhaust gas, etc. The coupling is to connect a metal pipe to a pipe joint having a bore defining a fluid passageway, wherein the joint includes a cylindrical wall portion extending from an annular shoulder, and the pipe extends into the cylindrical wall portion and has an end provided with a radially outwardly projecting flange. An elastic seal ring is provided adjacent to the shoulder and the flange. A cylindrical member is disposed between the cylindrical wall portion and the pipe for holding the flange and the seal ring against the shoulder, the cylindrical wall portion having a radially inwardly bent end holding the cylindrical member.

Abstract: A telescopic swivel pipe joint for coupling a pair of axially spaced pipes each having a connection end comprising a pair of joint connectors each connected to the connection end of a corresponding pipe and having a spherical bearing surface, a pair of main joint tubes each having a cylindrical portion and provided at one end thereof with an integral spherical portion for slidable contact with the bearing surface of a corresponding joint connector, and an auxiliary joint tube removably connected at both ends thereof to the respective cylindrical portions of the main joint tubes, wherein the auxiliary joint tube is telescopic in itself or telescopically fitted at one end thereof to the cylindrical portion of a corresponding main joint tube.

Abstract: Rings of shape memory metal are deformed to be insertable between coaxial and overlapping surfaces of a conduit and a coupler so that upon heating above their transition temperature, the rings attempt to return to their undeformed shape and seal the opening between the two surfaces; the sealing rings being concave-convex with the convex surface directed toward the adjacent end of the conduit whereby interval pressure in the conduit tends to further expand the metal and increase the seal. Retainer rings in the general form of the section of a conic may be employed to provide additional strength against separation.

Abstract: An electroweld fitting or electroweld collar for synthetic resin pipes comprising a body of a thermoplastic and/or weldable synthetic resin, on the inner surface of which a heating coil is arranged. In order to weld an electric current is conducted to the heating coil, whereby the material of the body is strongly heated and becomes plastic. The invention solves the problem of reliably applying the contact pressure in the welding zone while using a reduced amount of material. To achieve this it is proposed that a reinforcement in the form of a winding or a tube be arranged on the outer surface of the body and that the thermal coefficient of expansion of the reinforcement be smaller than that of the body.