Technical field

[0001] The present invention relates push-on connectors for connecting pipes without the need of a tool.

Background art

[0002] It is known within the art to use so-called push-on connectors or push-fit connectors to connect pipes of metal or plastic. Prior art solutions of this type are normally not used at applications with high pressure since most push-on connectors cannot manage high pressures depending on their design. For high- pressure applications, welding or compression joints normally is used. The latter may be done by using special compression tools and joints that is tightened with adjustable spanners or the like.

[0003] Another disadvantage with prior art solutions for high-pressure applications is that the joint, when welded or compressed, gives a fixed connection where the connector is not rotatable. This means, when using connectors at manufacturing of for example heat pumps and the like, that a very low flexibility is achieved while using fixed joints/connectors. At heat pump manufacturing, the use of push-on connectors therefore often is preferred, but prior art solutions do not cope with high pressures. Therefore, applications with high pressure normally must use welded or compression joints to join pipes, which is time consuming and tricky. One problem with prior art push-on connectors is also to provide a possibility to disconnect the connector from the pipe, especially without the need of a tool, since the grip between the connector and the pipe is hard when the connector once is mounted on the pipe end. Prior art solutions do not provide a design which makes it possible to disconnect the connector from the pipe in an easy way.

Summary of the invention

[0004] It is an object of the invention to address at least some of the problems and issues outlined above. It is possible to achieve these objects and others by a push-on connector as defined in the attached independent claims, which by its design is able to cope with high pressure without risk of leakage, and which precisely guides the pipe during assembly of the connector to the pipe.

[0005] According to an aspect of the invention, a push-on connector for connecting cylindrical pipes is disclosed. The connector comprises a body, which is arranged with a cavity which extends through the body between a first end and at least a second end of the connector. At least the first end of the connector is arranged to receive an end of a cylindrical pipe, which means that the connector may be of different kinds like a 2-way straight, a 3-way T-shaped, a 2-way L- shaped, a 4-way connector, or the like. Or the connector may be one or more ends of a valve. The latter may be any kind of valve like for example a control valve, throttle valve, balancing valve, check-valve, 1-way, 2-way, 3-way, 4-way-valve, or the like. The valves may be of manual type or Wi-Fi-controlled etc. Further, the cavity of the push-on connector comprises a first cylindrical portion distal from the first end of the connector, which first portion has a first inner diameter smaller than an outside diameter of a pipe which is to be inserted into the first end of the connector. The first portion of the cavity is in direction towards the first end of the connector followed by a cylindrical second portion with a second inner diameter which is greater than the first inner diameter and which substantially corresponds to an outside diameter of a pipe which are to be inserted into the first end of the connector. The second portion is followed by a cylindrical third portion with a third inner diameter which is greater than the second inner diameter. The third portion is followed by a tapered fourth portion, which tapers radially inwardly in direction towards the first end of the connector and ends in a neck portion. The neck portion has a fourth inner diameter, which is smaller than the third inner diameter of the third portion. The neck portion is followed by a tapered fifth portion which tapers radially outwardly in direction towards the first end of the connector. The push-on connector further comprises a locking sleeve which is axially movably and rotatably arranged at the first end of the connector. This means that the locking sleeve is loosely arranged at the first end such as it is possible rotate (swivel) around a center axis of the first end and further may be moved a distance along the center axis. The locking sleeve comprises an outer collar and a circumferential portion, from which a number of flexible arms extend into the cavity. Each flexible arm ends with a radially inwardly inclined grip portion and the end of each arm further comprises a thick end portion arranged opposite the grip portion. The connector further comprises two sealing rings, which are arranged spaced apart into the third portion of the cavity, and further the connector further comprises at least one support ring, which is arranged into the third portion of the cavity between the sealing rings. The sealing rings and the support ring are arranged as package into the third portion. A transition between the third portion and the second portion of the cavity is arranged as a radially inwardly protruding heel, which functions a stop for the innermost lying sealing ring, wherein a width of the support ring in an axial direction is adapted such as the two sealing rings and the support ring fits between the heel and the tapered fourth portion of the cavity without the sealing rings being compressed radially inwards, transverse the axial direction when not subjected to fluid pressure, wherein an inner diameter of the two sealing rings substantially corresponds with the cylindrical second portion of the cavity. This means that the width of the sealing rings and the width of the support ring in an axial direction makes the package fit precisely between the heel and the tapered fourth portion of the cavity. If the pressure increases, the only way for the sealing rings to expand is inwards, towards the pipe fitted into the connector.

[0006] By that, the push-on connector provides a quick, easy and safe assembly where the locking sleeve grips the pipe, for example a copper pipe, automatically when the connector is mounted onto the pipe. Because the cavity of the coupling body is conically tapered towards the open end, the flexible locking arms can flex radially outwards when the pipe is pressed into the coupling. The grip edge at the end of respective flexible arm that protrudes radially from the end of the flexible arms, slightly grippes the surface of the pipe and secures the locking sleeve to the pipe in at least a first “attaching state”, when the pipe reaches a final position. When the pipe is subjected to liquid pressure or traction, the grip edges are further fixed to (cut into) the surface material of the pipe by the narrowing of the cavity at the neck portion. This means, that the grip edges of the locking arms grip harder in the surface of the pipe the more traction or higher liquid pressure, the connector is exposed to at the same time as the sealings expand inwards, towards the pipe, with increased sealing effect.

[0007] Because the width of the support ring is adapted such as the two sealing rings fits between the heel and the tapered fourth portion of the cavity without the sealing rings being compressed radially inwards, the sealing rings may not expand too much in the axial direction of the cavity/the axial “pipe direction”, since the innermost sealing is more or less clamped between the heel and the support ring, and the outermost sealing is clamped between the support ring and the tapered fourth portion. When a pipe is inserted in the connector, and is subjected to a pressure, the sealings may expand but are controlled to expand primarily in the radial direction, by the adaption of the distance between the tapered fourth portion, the heel and the support ring. Prior art solutions do not control the expansion of a sealing in such a controlled way. This is an advantage especially concerning high- pressure applications, which prior art solutions do not provide.

[0008] As mentioned, the inner diameter of the two sealing rings substantially corresponds with the cylindrical second portion of the cavity. This provides a tight fit around the pipe to which the connector is to be connected to, since both the cylindrical second portion and the sealings of a size of the connector is adapted to the pipe diameter.

[0009] The push-on connector may further be disassembled by pushing the locking sleeve into the front edge, whereby the grip edges of the flexible arms are detached from the pipe.

[00010] According to an embodiment, a transition between the first portion and the second portion of the cavity is arranged as a stop, arranged to stop an axial movement of a pipe when inserted into the connector. By that, a distinct support for an end position of the pipe in the connector is achieved at the same time as the heel functions as a stop for the innermost sealing of the two sealings.

[00011] According to an embodiment, the fifth portion of the cavity is followed by a sixth portion with a fifth inner diameter which is greater than the fourth inner diameter of the neck portion. A length of the sixth portion substantially corresponds to a length of the circumferential portion of the locking sleeve. This allows a controlled axial movement of the locking sleeve in axial direction, inwards into the cavity, from the first end of the connector. The axial movement may continue until the locking sleeve is stopped when the collar abuts the surface of the first end of the connector, before the end of the circumferential portion of the locking sleeve hits the tapered fifth portion. By the design of the sixth portion, the locking sleeve is guided relative the sixth portion which is very important during mounting of the connector to a pipe.

[00012] According to an embodiment, an outer diameter of the circumferential portion of the locking sleeve substantially corresponds with the fifth inner diameter of the sixth portion of the cavity. This is also very important during mounting of the connector to the pipe, for precisely control and guide the connector during the mounting. It is crucial to prevent leakage, why the fitting of the connector to the pipe end must be precise. It is also crucial that the connector is precisely fitted to the pipe if the connector is subjected to outer forces.

[00013] According to an embodiment, an inner diameter of the circumferential portion and an inner diameter between opposite flexible arms substantially corresponds with the cylindrical second portion of the cavity. Altogether, these dimensions for a particular size of the connector correlates with the pipe dimension of which is to be inserted into the connector.

[00014] According to an embodiment, an outer diameter between opposite flexible arms substantially corresponds with the fourth inner diameter of neck portion. The outer diameter between opposite arms, i.e., the outer diameter of the “arms portion”, the thickness of the arms and the inner diameter of the neck portion are adapted to allow the arms to fit between the pipe and the neck and also to prevent that the locking sleeve may loosen from the connector.

[00015] According to an embodiment, the neck portion comprises an edge which faces the tapered fourth portion. The edge has a sharp design towards the tapered fourth portion which sharp edge is arranged to cooperate with the outer ends of respective flexible arm, which outer end comprises a corresponding sharp protrusion, for interaction with the edge. By that, the locking sleeve is more secured, and may not loosen from the connector.

[00016] According to an embodiment, the body and the locking sleeve is made of metal, preferably brass or stainless steel. By using metal, the material of the connector together with the design the same can stand high pressure.

[00017] According to an aspect of the invention, a valve comprising a connector according to any of the preceding claims is disclosed. As mentioned above, the connector may be one or more ends of a valve. The valve may be any kind of valve like for example a control valve, throttle valve, balancing valve, check-valve, 1-way, 2-way, 3-way, 4-way-valve, or the like. The valves may be of manual type or Wi-Fi-controlled etc.

[00018] Further possible features and benefits of this solution will become apparent from the detailed description below.

Brief description of drawings

[00019] The solution will now be described in more detail by means of exemplary embodiments and with reference to the accompanying drawings, in which:

[00020] Fig. 1 is an exploded view of a push-on connector according to the invention.

[00021] Fig. 2 is a section view of the inventive push-on according to the invention.

[00022] Fig. 3a-c shows the inventive push-on connector when connected to a pipe, starting from Fig. 3a, where the connector is about to be connected to the pipe. Fig. 3b shows the position where the pipe reaches an end position during the connection and Fig. 3c shows the pipe and connector in a using position, where the connection is subjected to an interior fluid pressure. Detailed description

[00023] Briefly described, a push-on connector especially designed for high- pressure applications, is disclosed. The inventive design provides a solution which guides a pipe to a precise and perfect end position in the connector. When a fluid system in which the connection between the pipe and the connector is pressurized, a using position is reached in which the risk of leakage is very low, even at high pressurized systems.

[00024] Fig. 1 shows an exploded view of a preferred embodiment of a push-on connector 1 according to the invention. The connector 1 comprises a body 2, made of metal, preferably of brass or stainless steel, and the body 2 is arranged with a cavity 3 which extends through the body 2 between a first end 1a and a second end 1b. Fig. 1 shows one of several possible types of connectors - an angled pipe-connector with two ends, the first and second ends 1a, 1b, but is understood that the inventive design may be used at any type of connector or valve using at least one end for connection between a pipe and the connector 1. For example, the connector may be a 2-way straight connector, a 3-way T-shaped connector, a 2-way L-shaped connector, a 4-way connector or any kind of valve like for example a control valve, throttle valve, balancing valve, check-valve, 1- way, 2-way, 3-way, 4-way-valve, or the like.

[00025] Fig. 2 shows a section through the push-on connector 1. The connector 1 comprises the body 2, with the cavity 3 extending through the body 2, between the first end 1a and the second end 1b of the connector 1. In the example, both the first and the second end 1a, 1b are arranged to receive an end of a cylindrical pipe (not shown in Fig.2, see Figs. 3a-c). In the following description, the connector 1 is described in relation to the first end 1a, but in the exemplified L-shaped 2-way connector 1 , both ends 1 a, 1 b are similar with each other and comprise similar details and design. The cavity 3 comprises a first cylindrical portion 3a, which is distal from the first end 1 a of the connector 1. The first portion 3a has a first inner diameter da which is smaller than an outside diameter of a pipe which is to be inserted into the first end 1a of the connector 1. The first portion 3a of the cavity 3 is in direction towards the first end 1a followed by a cylindrical second portion 3b, with a second inner diameter db which is greater than the first inner diameter da and which substantially corresponds to an outside diameter of a pipe which are to be inserted into the first end 1a of the connector 1. A transition between the first portion 3a and the second portion 3b is arranged as a stop 9, arranged to stop the axial movement of the pipe when inserted into the connector 1. The second portion 3b is followed by a cylindrical third portion 3c with a third inner diameter dc which is greater than the second inner diameter db, and the third portion 3c is followed by a tapered fourth portion 3d, which tapers radially inwardly in direction towards the first end 1a of the connector 1 and ends in a neck portion 4. The neck portion 4 has a fourth inner diameter d4 which is smaller than the third inner diameter dc of the third portion 3c. In turn, the neck portion 4 is followed by a tapered fifth portion 3e, which tapers radially outwardly in direction towards the first end 1a of the connector 1. After the tapered fifth portion 3e is a sixth portion 3f arranged. The sixth portion 3f has a fifth inner diameter df which is greater than the fourth inner diameter d4 of the neck portion 4.

[00026] A locking sleeve 5 is axially movably and rotatably arranged at the first end 1a of the connector 1. The locking sleeve 5 is made of metal, preferably brass or stainless steel and comprises an outer collar 5a and a circumferential portion 5b which extends in direction towards the cavity 3 and from which a number of flexible arms 5c extend in direction into the cavity 3. Each flexible arm 5c ends with a radially inwardly inclined grip portion 5d, which is arranged to engage with the surface of the pipe in a using position of the connector 1 (see Figs. 3a-c). Each flexible arm 5c is thinner compared to the circumferential portion 5b of the locking sleeve and the end of each arm 5c further comprises a thicker end portion arranged opposite the grip portion 5d. This thicker end portion is arranged to cooperate with the neck portion 4 for preventing the locking sleeve 5 from leaving the cavity 3 and for making the grip portion 5d to engage with the surface of the pipe, when the pipe and connector 1 is subjected to pressure. The length of the sixth portion 3f of the cavity 3 substantially corresponds to a length of the circumferential portion 5b of the locking sleeve 5. By that, the locking sleeve 5 is moveable in the axial direction between positions limited by the outer collar 5a and by the thick end portions of the flexible arms 5c. The locking sleeve 5 is as mentioned above also rotatable in the cavity 3 relative the body 2.

[00027] The connector 1 further comprises two sealing rings 6, which are arranged spaced apart into the third portion 3c of the cavity 3, and which sealing rings 6 are spaced apart by a support ring 7, which also is arranged into the third portion 3c of the cavity 3, between the sealing rings 6. A transition between the third portion 3c and the second portion 3b of the cavity 3 is arranged as a radially inwardly protruding heel 8 which functions as a stop for the innermost lying sealing ring 6. Further, the width of the support ring 7 in the axial direction is adapted such as the two sealing rings 6 and the support ring 7 fits between the heel 8 and the tapered fourth portion 3d of the cavity 3, without that the sealing rings 6 are compressed radially inwards (transverse the axial direction) when not subjected to fluid pressure. The “package” of sealing rings 6 and support ring 7 is as mentioned above positioned in the third portion 3c of the cavity 3, and the possible axial motion of the locking sleeve 5 is further limited by that the flexible arms 5c abuts the outermost sealing ring 6 about simultaneously as the outer collar 5a abuts the gable of the first end 1 a of the connector 1.

[00028] An inner diameter of the circumferential portion 5b of the locking sleeve 5 and an inner diameter between opposite flexible arms 5c substantially corresponds with the cylindrical second portion 3b of the cavity 3. Further, an inner diameter of the two sealing rings 6 substantially corresponds with the cylindrical second portion 3b of the cavity 3. Pipe connectors are normally adapted by size for different standard sizes of pipes. By having a high-end precision in the design of the interior of the connector 1 , with the inner diameter of the circumferential portion 5b and the flexible arms portion of the locking sleeve 5 as well as the inner diameter of the sealings in correlation with the second portion 3b of the cavity 3, the pipe is very precise and well fitted into the connector 1. This minimizes the risk of leakage especially at high-pressure applications.

[00029] An outer diameter of the circumferential portion 5b of the locking sleeve 5 substantially corresponds with the fifth inner diameter df of the sixth portion 3f of the cavity 3. By having a tight fit between the circumferential portion 5b of the locking sleeve 5 and the surrounding walls of the body 2 at the sixth portion 3f of the cavity 3, a precise and good guided control of the locking sleeve 5 along the axial motion is achieved, which enables that the connector 1 is precisely fitted on the pipe and the risk for leakage due to a skew assembly to the pipe is avoided.

[00030] Fig. 3a-c shows the push-on connector 1 when connected to a pipe 100. Starting from Fig. 3a, the connector is about to be connected to the pipe. The locking sleeve 5 is loosely fitted at the first end 1a of the connector and is possible to rotate and move axially between the end positions, wherein the axial movement is limited in the right direction (relating to the figure) by the sealing rings 6 and/or the outer collar 5a and in the opposite direction by the thicker end portion arranged at the outer ends of the flexible arms 5c.

[00031] Fig. 3b shows the position where the pipe 100 reaches an end position during the connection of the pipe and the connector, wherein the end of the pipe abuts the stop 9. When introducing the pipe into the connector 1, the grip portions 5d of the flexible arms 5c of the locking sleeve 5, engages with the surface of the pipe 100 and the locking sleeve 5 follows the pipe until the outer collar 5a reaches the first end 1 a of the connector. At the same time, the ends of the flexible arms 5c abuts the outermost sealing ring 6. Of course, this must not happen at the same time, but it is preferred. Due to the precise fit between the circumferential portion 5b of the locking sleeve 5 and the surrounding walls of the body 2 at the sixth portion 3f of the cavity 3, and the precise fit of the pipe 100 into the locking sleeve 5 and in the second portion 3b of the cavity 3, the connector 1 is connected to the pipe 100 in a complete straight connection, which is crucial at high-pressure applications. Further, the two sealing rings 6 supported by the precisely adapted support ring 7 guides the pipe 100 and controls that the pipe 100 continues to follow the precise direction to the end position. The interior design is crucial to achieve a high-pressure application.

[00032] Fig. 3c shows the pipe 100 and connector 1 in a using position, where the connection 1 is subjected to an interior fluid pressure in the cavity 3. The fluid pressure causes the pipe to be pushed out from the connector. When this happens, the locking sleeve 5 moves together with the pipe 100 in direction towards the first end 1a of the connector 1 , by that the grip portion 5d of each flexible arm 5c earlier has engaged with the surface of the pipe 100. When the locking sleeve 5 moves outwards (to the left in the figure), the thick portion of respective flexible arm 5c gets more and more clamped between the tapered fourth portion 3d and the pipe 100, wherein the grip between the grip portion 5d of each flexible arm 5c and the pipe 100 gets stronger and stronger, and the pipe 100 and locking sleeve 5 are prevented to leave the connector, since due to the strengthen grip and the neck portion 4. At the same time, the sealing rings 6 are subjected to the pressure and are caused to expand in any possible direction. Because of the inventive design, where the material of the sealing rings and the support ring 7 are tested and designed to cope with high pressure, and the arrangement of the sealing rings 6 and the support ring 7 with its width between the heel 8 and the tapered fourth portion 3d, the expansion of the sealing rings 6 is controlled. This means that they more or less are controlled to expand radially towards the pipe 100, wherein a very high sealing effect is achieved.

[00033] To disconnect the connector 1 from the pipe 100, the locking sleeve 5 is pushed inwards in direction towards the first end 1a of the connector 1 , wherein the grip portions 5d may leave the surface of the pipe while the flexible arms 5c may flex radially outwards. By the material in the locking sleeve 5 and the flexibility of the arms 5c, no tool is needed to disconnect the connector 1 from the pipe 100.

[00034] Although the description above contains a plurality of specificities, these should not be construed as limiting the scope of the concept described herein but as merely providing illustrations of some exemplifying embodiments of the described concept. It will be appreciated that the scope of the presently described concept fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the presently described concept is accordingly not to be limited. Reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." All structural and functional equivalents to the elements of the above- described embodiments that are known to those of ordinary skill in the art are expressly incorporated herein and are intended to be encompassed hereby.