The present invention relates to a connector.

In particular, it relates to a connector with a screw thread which will engage with a second part having a complimentary screw thread to hold the two together.

Such connectors may, for example, be a nut and bolt connection or a tubular connection with a male screw thread for engagement with a complementary component with a female screw thread for example in pipe work used in plumbing,

With any such screw threaded connection of this type, the intention is commonly to screw the two components together, usually with the application of a tool such as a wrench or spanner, in order to engage the components as tightly as possible so that the friction between the engaging threads is sufficient to prevent relative rotation of the components in a sense which will tend to undo the threaded connection.

Washers of various configurations are known which will distribute the load across the threaded connection over a wider area such that a higher clamping force can be achieved.

Various types of spring washer are known. W02009/045165 discloses two-part washer with a complimentary saw tooth configuration between the two parts which will ride up one another upon relative rotation of the two parts in one direction in order to increase the distance between the parts. Similar washers are disclosed in JP H0738733U, US 5190423, US2007/128003, US2002/039522 and US2014/348609. The outer faces of the parts are provided with teeth which will bite into the opposing components that they face, such that any relative rotation between the two components will separate the two parts and will cause the teeth to bite more deeply into the two components thereby preventing the components from being undone.

The present invention is aimed at providing a connector which will provide a secure threaded connection, and which is particularly suited to a connector for a tubular connection used in plumbing.

According to the present invention there is provided a connector according to claim 1. The combination of the first ramp on the first connector with the complimentary second ramps and the friction face on the locking ring configured in this way provides a connector which will resist the first and second connector bodies being uncoupled even when they have not been coupled to one another with the use of a tool.

The locking ring also fulfils a sealing function which is particularly useful when the connector is for a tube coupling.

Without using a tool, the first and second connector bodies can be screwed onto one another such that the second shoulder bears against the friction face and causes the complimentary ramps to engage one another. There is no need for the level of pressure applied by a tool as the ramps begin to engage one another even before the bodies are fully engaged. Once in this position, any attempt to unscrew the second connector body from the first connector body will rotate the locking ring, because of the engagement of the friction face on the second shoulder, causing the first and second ramps to ride up one another. This has the effect of urging the complimentary screw threads in an axial direction such that there will be a progressive increase in the frictional force between the screw threads which quickly becomes large enough that no further rotation of the screw threads is possible. The present invention therefore provides a connector which can reliably and easily both connect and seal threaded components to together in a manner which provides protection against over tightening. This is therefore particularly suited to an application in plumbing where the connectors are made of plastic and can therefore be vulnerable to damage caused by over tightening.

As compared to the above washer of W02009/045165, the present invention removes one of the toothed interfaces on the outer face of the washer. Such a face represents a potential point of failure for the washer. This also limits the materials with which the washer is applicable as this type of toothed connection is generally only suitable for metal connectors and not, for example, a hard plastic which lacks the ductility for the teeth to grip.

The locking ring may be moulded from a single material. However, preferably, the locking ring is formed of a locking component with the locking face and a friction component with the friction face. This allows the locking face to be made of a harder material and the friction face to be made of a material with improved frictional properties such that both components can operate more effectively. In this case, the friction component can also be the seal.

The locking component and friction component may be configured such that frictional engagement between the two components prevents them rotating relatively to one another in use. Alternatively they may be bonded together. However, preferably, a keying arrangement is provided between the locking component and friction component to prevent relative rotation between the two components.

In order to assist the frictional engagement between the friction face and the second shoulder, preferably a part of the locking ring is resilient and is configured so that it is compressed in the fully engaged configuration to provide a biasing force to urge the first and second ramps axially together. This biasing force helps to ensure that the ramps remain engaged and any relative movement between the first and second ramps tending to increase the axial distance between the first shoulder and the friction face also serves to compress the resilient part of the locking ring thereby further increasing the force between the complimentary screw threads.

The resilient part of the locking ring may be provided by the frictional component being an elastomeric component as this provides an effective seal. The elastomeric component preferably has one or more axial projections which are resiliently deformable to provide the biasing force. These axial projections are relatively easy to deform when the user makes up the connection, but still provide the necessary biasing force. The elastomeric component preferably comprises a plurality of compressible annular projections extending in an axial direction away from the first shoulder, wherein the compressible annular projections are spaced from each other in the radial direction and wherein each

compressible annular projection is configured, in use, to be compressed by the second shoulder as the first connector body and second connector body are screwed together into the fully engaged configuration. Such a seal provides an effective seal in the case where the second connector body is not perfectly formed (for example because it includes split lines or other recesses/imperfections). In this case, even if one of the annular projections does not form the seal, the presence of the additional projections will help ensure that the seal is maintained. The annular projections not only provides the seal, but also provides the resilient biasing force as set out above. The use of the annular projections to provide an effective seal is the subject of our earlier application GB1721437.0.

The connector can be applied to a conventional nut and bolt connection in which the nut and bolt have a hexagonal configuration providing opposing flat surfaces or other features to which a tool can be applied. However, in other cases, overtightening of the two components is actively discouraged as it can damage the connection. For example, in the case of a tube coupling, an installer will often apply a tool to the joints and overtighten the threaded connection between the screw threaded components. Particularly if these are plastic components, this can apply an undue stress to the screw thread. This will not be apparent to the installer as it will not immediately manifest itself. However, over time, the stress applied to the threads will cause premature and potentially catastrophic failure of the connection.

Preferably, therefore, the first connector body is devoid of opposing flat surfaces on its outer wall. Instead, it can be provided with features which are suitable as finger grips.

There may, for example, be three such features spaced equiangularally around the first body such that they are not in opposable positions which can be engaged by a tool. It is impossible to prevent a user completely from attempting to apply a tool to the first body and, indeed, they may even gain some purchase in doing so. However, by configuring the first connector body in this way, it should be readily apparent to the user that it is not intended to be used with a tool and, even if a tool is used, it should not be possible to obtain anything like the same level of torque as will be the case if it were provided with opposing flat surfaces.

The intention may be to connect the first and second bodies in a manner in which they do not need to be undone. If, however, the first and second bodies are required to be undone, the locking ring is preferably provided with a release feature in the form of at least one projection. This allows the locking ring to be gripped by a user such that, upon rotation of the second body with respect to the connector, the gripping engagement of the locking ring is sufficient for rotation of the second body to overcome the frictional engagement between the friction face and the second shoulder thereby preventing the complimentary ramps from riding up one another and hence allowing the unscrewing of the complimentary screw threads. The connector can be provided with a single first ramp and a single complementary second ramp. Preferably, however, there are a plurality of complimentary first and second ramps arranged around the connector.

The ramp may have any suitable slope, such as having a symmetrical up slope and down slope. Preferably, however, the ramp has a saw tooth configuration with one long sloped surface terminating in a steep opposing surface which effectively represents the end face of each ramp.

The present invention does not require the second body to have any special features. For example, the second body may be in the form of a conventional nut in which case the bolt forms the first connector body provided with the first ramp. Alternatively the second connector body may be a conventional bolt in which case the nut forms the first connector body provided with the first ramp.

In the case of a tubular connector, the second connector body may be any conventional connector component with a conventional female screw thread.

As such, in the broadest sense, the second connector body is not part of the present invention as it may be an existing or conventional component with which the connector of the present invention is connected in situ. This is an advantage of the invention as it can be designed to fit with a conventional component.

On the other hand, the first and second connector bodies may be supplied as a pair in which case the connector further comprises the second connector body.

Examples of connectors will now be described with reference to the accompanying drawings, in which:

Fig. 1 is an exploded perspective view of a first example;

Fig. 1 A is a perspective view of the sealing ring shown in Fig. 1 from the opposite side.

Fig. 2 is an assembled perspective view of the first example; Figs. 3 and 4 are side views of the first example illustrating the connector in two different configuration and including the second connector body;

Fig. 5 is an exploded perspective view of a second example including the second connector body;

Fig. 6A is a side view of a third example in a first configuration;

Fig. 6B is a side view of the third example in a second configuration;

Fig 6C is an exploded perspective of the third example; and

Figs. 7 A to 7C are views similar to Figs. 6A to 6C of a fourth example.

The connectors shown in the examples are intended to be formed primarily of plastic components as it is these components which would suffer most from the problems of stress related overtightening. Further, in relation to the tubular connector, the components to which the connector is connected are also plastic components. The principles described will, however, apply to other materials such as metal, particularly in relation to the later examples showing the nut and bolt.

The first example shown in Figs. 1 to 4 is a tubular connector intended for use in plumbing applications and the like.

The connector comprises a first connector body 1 which has a generally tubular construction and is open at both ends.

As shown in the example, the connection according to the present invention is at one end only of the connector body as described below. There may, however, be a second connection of this type at the opposite end of connector body. On the other hand, this may be a conventional connection such as a conventional screw threaded connection or a quick release connection with a collet assembly such as the John Guest Speedfit (RTM) connection. This allows the connector body to be connected at one end in the manner described below while a pipe can be connected via the quick release connector at the opposite end. The connector body 1 has no flat faces as it is not designed to be gripped by a tool.

Instead, the central portion of the connector body 1 is provided with a number of finger grips 2. Ideally, there are three such finger grips 2 spaced equiangularally around the first connector body 1 . This allows for manual rotation of the first connector body 1 and discourages the use of a tool.

The connector shown in Fig. 1 consists of three main components namely the above mentioned first connector body 1 , a locking ring 3 and a seal 4. The locking ring 3 and the seal 4 may be integrated into a single component.

The locking ring 3 and seal 4 have complimentary annular shapes and are placed together shown in Figs. 2 to 4. The locking ring 3 is provided with a plurality of slots 5 while the seal 4 is provided with a plurality of complimentary projections 6 such that the components are keyed to one another to prevent relative rotation. The keying arrangement can be reversed such that the projections are provided on the locking ring and the grooves are provided on the seal.

The locking ring 3 and seal 4 are placed together over the end of the first connector body 1 to surround a male screw thread 10. Surrounding the male screw thread 10 are a plurality of first saw teeth 1 1. The face of the locking ring 3 which faces these saw teeth 1 1 is provided with complimentary second saw teeth 12.

The connector is shown in the assembled configuration in Fig. 2. In this configuration, the seal 4 has a pair of concentric annular projections 15 which seal against a face 16 on the connector body 1 which surrounds the male screw thread 10. The seal 4 is provided with a second pair of concentric annular projections 17 which seal against a second connector body 20 as shown in Figs. 3 and 4. The seal 4 has a third set of axial projections in the form of projections 18 which extend intermittently in a circumferential direction and are positioned between the projections 6. These projections 18 do not provide a sealing function but are compressed against the adjacent face of the locking ring 3 as described below. A second connector body 20 has a female screw thread 21 which is complimentary to the male screw thread 10 allowing the two to be screwed together into the position shown in Fig. 3 and 4.

In order to do this, the user holds the first connector body 1 by the finger grips 2 and rotates either body 1 , 20 to engage the screw threads. This also advances the locking ring 3 and seal 4 together with the first connector 1. At this time the complimentary saw teeth 1 1 , 12 are not necessary engaged with one another however, once the first connector body 1 approaches close to the fully engaged position, the saw teeth engage one another and the long faces 22 will ride along one another until end faces 23 meet one another at which point the components are fully engaged. At this point, the projections 15, 17 and 18 are compressed such that the projections 15 and 17 fulfil a sealing function, while all three sets of projections 15, 17 and 18 provide an axial biasing force in a direction to resist separation of the saw teeth 1 1 , 12. The arrangement shown in the drawings shows a conventional right-handed thread. The design can be reversed for a left-handed thread, if the direction of the saw teeth is reversed.

This fully engaged position is intended to be reached using only hand pressure from the user. The use of a tool is not required. Once in this position, the unwanted loosening of the component is prevented as will now be described.

As shown in Fig. 4, if the first connector body 1 is rotated in an uncoupling direction (i.e. a direction which tends to disengage the complimentary threads 10, 21 ), the complimentary saw teeth 1 1 , 12 will ride up one another as shown in Fig. 4. This increases the axial separation between the first connector body 1 and the second connector body 20 which puts axial pressure on the complimentary screw threads 10, 21. The more the connector bodies are rotated in this sense, the greater the axial pressure causing the two components to be clamped together, so that the axial pressure becomes so great that further rotation is impossible. This greater clamping force is in part caused by the additional frictional engagement between the saw teeth 1 1 , 12 and in part by the additional biasing force exerted by the resilience of the seal 4 and its projections 15, 17 and 18 which provide increasing resistance against further compression. From the position shown in Fig. 4, the first connector body 1 can move back to the position shown in Fig. 3, but this is a very limited range of movement as it will stop once the end faces 23 of the complimentary ramps meet one another and this movement is in a direction which will tighten the screw threaded engagement.

The only way to disengage the first connector body 1 and second connector body 20 requires manual intervention. In particular, it is necessary for a user to hold the locking ring 3. For this purpose, a pair of radial lugs 24 are provided to assist the user in gripping the locking ring 3. By holding the locking ring 3 in place, the relative rotation between the body 1 and locking ring 3 which would otherwise move the components into the locked position in Fig. 4 is avoided. The first connector body 1 and locking ring 3 are therefore maintained in the position shown in Fig. 3 while there are unscrewed together from the second connector body 20.

Thus, any relative movement between the first connector body 1 and second connector body 20 that will occur over time through movement caused, for example, by thermal expansion, vibration or accidental knocking of the connector will cause the connector to move between the two positions shown in Figs. 3 and 4. The connector cannot be undone without the manual intervention described above.

The connection is simple to engage requiring the two components to be threaded together with hand tight pressure as described above. The presence of the seal also causes the junction between the first and second components to be sealed during this simple assembly process, this resulting in a simple sealed connection which, once engaged cannot be accidentally be undone.

The use of a separate locking ring 3 and seal 4 is advantageous as it allows the locking ring 3 to be made of a rigid material thereby ensuring a strong engagement between the complimentary saw teeth 1 1 , 12. The seal 4 can be of an elastomeric material with good sealing properties. Alternatively, the locking ring 3 and seal 4 may be combined into a single component which may be made of an intermediate material.

Alternatively, there may be a single component where the friction face of the locking ring is provided with a surface treatment, features or coating in order to increase the frictional engagement with the second connector body. The radially extending lugs 24 assist the user in gripping the locking ring 3 in order to undo the connector. The lugs could, however, be absent such that the user simply engages with the cylindrical outer face of the locking ring 3.

Alternatively, the lugs may extend axially rather than radially as shown in the second example of Fig. 5. In Fig. 5, the principle of operation is the same as described above in relation to the first example and the same reference numerals have been used to designate the same components.

In this example, the locking ring 3’ is provided with a pair of axially extending lugs 25.

There could be any number of these. As will be appreciated with a comparison of Fig. 5 with the first example, the lugs 25 are significantly larger and therefore easier to grip. The second example has some further features such as a slot 26 in the end face of the first connector body 1 which receives the lug 25 in order to limit relative rotation between the connector ring 3’ and the first connector body 1. The first connector body 1 is also provided with a clip 27 for each lug 25 which engages with a complimentary feature on the respective lug 25 in order to clip the end of the lug 25 opposite to locking ring 3’ in place. Otherwise, the operation of the connector is as described in relation to the first example.

A third example is shown in Figs. 6A to 6C. In this case, the first connector body is a bolt 30 and the second connector body is a nut 31. The nut 31 has a conventional construction. The nut and bolt fasten to a plate P which signifies any component or group of components which require a bolted connection. The only modification to the bolt 31 is the presence of a saw tooth configuration 1 1 A on an annular face facing the male screw thread 10A. The locking ring 3 is provided with a complimentary saw tooth configuration 12A and is provided with slots 5A on the opposite face which faces the seal 4A. This has complimentary projections 6A to engage with the locking ring 3A. The locking ring 3A and seal 4A are placed together over the bolt 30 before it is assembled onto the plate P. The nut 31 is then screwed in place into the engaged configuration shown in Fig. 6A.

As described in relation to the first example, any movement caused by vibration, thermal movement or the like that creates a force on the seal 4A that tends to undo the screw threaded connection causes the saw teeth 1 1 , 12 to move to the position shown in Fig. 6C, thereby tending to increase the separation between the head of the bolt and the nut 31 causing axial pressure on the screw thread to lock the components in place as before. In this case, the seal 4A seals with the plate P, although, at this case, it may only need to fulfil the function of providing frictional engagement with the plate P. There may be no necessity for it to create a seal.

In order to undo the connection, the user simply unscrews the nut 31 which they can readily do provided that they hold the bolt to prevent it from moving to the locked position shown in Fig. 6B.

A fourth example is shown in Fig. 7A. This shows a nut and bolt configuration similar to that shown in Figs. 6A to 6C. In this case, the bolt 40 is a conventional bolt with the nut 41 forming the first connector body provided with the saw tooth arrangement 1 1 B. The locking ring 3B and the seal 4B are reversed such that the saw tooth arrangement 12B on the locking ring 3B faces the saw tooth arrangement 1 1 B on the nut 41. The locking ring 3B and seal 4B have the same keying arrangement of grooves 5B and projections 6B as previously described.

In the fully engaged position shown in Fig. 7A, any relative rotation of the nut 40 and bolt 41 in the disengaging direction causes the nut 41 to back off causing the saw teeth 1 1 B, 12B to ride up one another to the position shown in Fig. 7B where the axial force generated between the nut and bolt causes sufficient axial pressure on the screw threads that they are locked in place. To undo the connection the user has to hold the nut 41 in the position shown in Fig. 7 A while they unscrew the bolt 40.