Technical Field of the Invention

The present invention relates to a device for marking pipes, more particularly to a device for marking the depth of which various pipe diameters should optimally be inserted into connectors.

Background to the Invention

It is known to use a tool to provide a depth mark towards the end of a pipe, where the depth mark indicates how far the pipe needs to be inserted into a connector in order to achieve a good seal. In addition to being good practice, in some instances those installing pipes are required to depth mark pipes before insertion into connectors. Checking for such depth marks provides a supervisor with a relatively straightforward reassurance that the pipes have been fitted correctly to the connectors. In some instances, the absences of such marks provide grounds for supervisors to dismiss installers. Pipe depth marking tools which are adapted to enable marking of pipes with multiple different diameters at the correct depths are known. For example, the S110 Depth Gauge by Pegler Yorkshire comprises a series of semi-cylindrical channels each having a diameter corresponding to a standard diameter of pipe. In the S110, each channel is provided with a pipe-stop at a distance from the edge of the channel that is equal to the depth the pipe of matching diameter should be inserted into a connector. The user can thus place the pipe into the channel, push the end of the pipe against the pipe-stop, and make a depth mark using a pen held against the end of the channel. Such a device does provide for accurate marking but can be awkward for a single individual to use. Additionally, relying on depth marks made by pen for review purposes is not ideal as it is possible for such marks to be applied after the pipe has been inserted into the connector.

Other marking tools are known which have a series of bores sized to receive standard diameters of pipes, each bore ending in a pipe stop. The pipe-stops are provided at a distance from the bore end that is equal to the depth a pipe of matching diameter should be inserted into a connector. At the end of each bore is provided a scribing element, which can be pressed against the exterior of a pipe inserted into the bore. The user inserts a pipe into the correct bore and pushes the pipe end against the pipe stop. Subsequently, the user can press the scribing element against the pipe and rotate the pipe within the bore to scribe a depth mark on the pipe.

Whilst such a tool is easier to use than one requiring pen marks, it can still be a little awkward. Additionally, the scribing element may remain pressed against the pipe during withdrawal of the pipe from the bore following completion of the desired line. This can result in a line being scribed along the outside of the pipe parallel to the pipe axis. This risks creating a leak path once the pipe is inserted into the connector.

It is an object of the present invention to provide a tool which at least partially overcomes or alleviates at least one or more of the shortcomings of the known pipe depth marking tools. Summary of the Invention

According to a first aspect of the present invention, there is provided a pipe marking tool comprising a channel for receiving pipes of different diameters, the channel provided at one end with a pipe stop to abut an end of a pipe received in the channel; and a limb provided with multiple marking elements, the limb movable relative to the channel such that one or more marking elements can come into contact with a pipe received in the channel, wherein the marking elements are positioned on the limb such that which marking elements come into contact with a pipe received in the channel are dependent upon the diameter of the pipe.

The above tool enables different markings, including depth marks, to be made on pipes of different diameters using a single tool. This can be readily achieved by inserting a pipe to the pipe stop, moving the limb towards the inserted pipe until the pipe is contacted by one or more marking elements and then rotating the tool relative to the pipe. In such a manner the above tool facilitates accurate use by an individual user and provides for simple removal of the pipe with minimised risk of unwanted marks.

The channel may comprise an open top edge. The channel may comprise a closed bottom edge with side walls projecting up from the bottom edge. The channel may comprise an open top edge and a closed bottom edge with side walls projecting up from the bottom edge. The side walls may have corresponding shapes. Where the walls have corresponding shapes, pipes received in the channel are retained in the centre of the channel. In particular, the side walls may be sloped, preferably narrowing the channel towards the bottom edge. This helps retain received pipes towards the bottom edge of the channel. The slopes of the side walls may be substantially constant or may vary from bottom to top. This can enable the channel to provide for secure retention of different sized pipes. The channel may comprise a wider section and a narrower section, the narrower section provided adjacent to the pipe stop. The transition between the sections may be defined by a step. The narrower section allows the pipe to be retained in the correct position within channel during marking operation whilst the wider section prevents direct contact between the channel and the pipe in the region where depth marks are formed. This can prevent additional marks being formed during marking operation by surface irregularities or loose debris.

Each marking element preferably comprises a scribing element. Such scribing elements may be adapted to scribe a line on a pipe surface when in contact with a pipe surface. In one embodiment, a suitable scribing element comprises a stylus or the like. In other embodiments, each marking element may comprise a nib or similar operable to dispense ink or similar when in contact with a pipe surface.

The limb may comprise a pipe marking face. The marking elements may each be provided upon the pipe marking face. The pipe marking face may be substantially planar or may be substantially convex. The planar form of the marking face is relatively simple to manufacture and fit correctly. The convex form of the marking face provides for greater spacing between marking elements intended to contact different diameter pipes. This allows a larger variety of pipe diameters to be marked using a single tool without danger of the pipe contacting the wrong marking site. The pipe marking face may be replaceable. This enables a pipe marking face which is worn or damaged or comprises worn or damaged marking elements to be replaced. Additionally or alternatively, a different pipe marking face can be fitted where different pipe sizes or connectors are used or where standards have changed for one or more pipe sizes.

The limb may comprise a single marking element positioned to contact each of a predetermined set of different diameter pipes received in the channel. In such instances, each marking element may be positioned so as to provide a depth mark on the pipe with the corresponding diameter. In such instances, the single marking element may be positioned at a distance from the pipe stop that is equal to the depth the pipe of the corresponding diameter should be inserted into a connector.

The limb may comprise a plurality of marking elements positioned to contact each of a predetermined set of different diameter pipes received in the channel. In such embodiments one marking element may be positioned so as to provide a check mark. A check mark may comprise a mark provided adjacent to the end of the pipe. In such instances, the check marking element may be positioned adjacent to the pipe stop. Such a mark would not be possible to add to the pipe after fitting and thus can provide (on removal of a pipe from a connection) further evidence as to whether an installer followed correct procedure.

In such embodiments, a plurality of marking elements may be positioned so as to provide depth marks. Such elements may work together to provide a single depth mark or may provide separate depth marks. In a preferred embodiment, two elements are provided at a close separation so as to provide twin depth marks. The twin depth marks may comprise a maximum insertion depth mark and a minimum insertion depth mark. This can enable an installer to ensure correct installation of a pipe where there is a range of acceptable insertion depths. Alternatively, the twin depth marks may comprise depth marks appropriate for different connectors or for pipes with different end cuts.

The pipe stop may comprise a substantially flat wall. In some embodiments, the pipe stop may comprise one or more pipe guides. Each pipe guide may comprise a curved projection from the pipe stop. The pipe guides may substantially correspond to particular pipe diameters expected to be received in the channel. The pipe guide or guides can help locate the received pipe in position for marking.

The pipe stop may be replaceable. This enables a worn or damaged pipe stop to be replaced. Additionally or alternatively, a different pipe stop can be fitted where different pipe sizes or connectors are used or where standards have changed for one or more pipe sizes.

The limb may be biased to remain in an open position away from the channel. This prevents a pipe being marked upon initial insertion into the channel. As such accidental marking of the pipe may be avoided. The limb may be pivotable relative to the channel. The limb may be pivotally connected to the channel.

The limb may be connected to a top edge of one of the side walls of the channel. The connection may be operable to allow the limb to rotate relative to the channel. In such embodiments, the connection may enable the limb to move between a closed position where the limb projects into the channel and an open position where the limb projects away from the channel. The connection may comprise prongs rotatable within corresponding sockets. The prongs may be provided on the limb and the sockets may be provided in the top edge of the side wall.

The connection may be biased to maintain the limb in an open position relative to the channel. The biasing means may comprise one or more springs. In particular, the biasing means may comprise a torsion spring.

The connection may comprise a locking mechanism. In some embodiments, the locking mechanism may be operable to inhibit or prevent relative motion of the limb and the channel when engaged. In other embodiments, the locking mechanism may be operable to retain the limb in the open position and/or in the closed position. Retaining the limb in an open position relative to the channel can help avoiding accidental marking when a pipe is introduced into the channel whilst retaining the limb in a closed position relative to the channel can provide for relatively compact storage of the marking tool when not in use. The locking mechanism may be disengaged by pressing the pipe stop against a bias. In such cases, the locking mechanism may be biased to retain the limb in an open position. In such cases, the locking mechanism may comprise a shaped lug, operable to be urged into and engage with a correspondingly shaped recess.

In other embodiments, the locking mechanism may be engaged by sliding the limb along the axis of rotation. In such cases, the locking mechanism may be biased to remain locked. The biasing means may comprise one or more springs. In particular, the biasing means may comprise a compression spring. In embodiments where the connection comprises prongs rotatable within sockets, the locking mechanism may comprise opposing faces on at least one of the prongs and the corresponding socket.

The limb may be provided with a raised tab. Such a tab can help a user to grip the limb for sliding along the rotation axis when engaging or disengaging the locking mechanism.

According to a second aspect of the present invention, there is provided a method of marking a pipe, the method comprising the steps of: providing a pipe marking tool according to the first aspect of the present invention; inserting a pipe into the channel of the pipe marking tool; moving the limb towards the inserted pipe until the pipe is contacted by one or more marking elements and then rotating the tool relative to the pipe.

The method of the second aspect of the present invention may include features of the tool of the first aspect of the present invention, as required or as desired.

Detailed Description of the Invention In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

Figures la-c shows a pipe marking tool according to the present invention;

Figures 2a-f illustrate use of the pipe marking tool according to the present invention to mark pipes with different external diameters;

Figures 3a-d show partly exploded detail views of the pipe marking tool of figure 1, illustrating the operation of the locking mechanism; Figure 4 illustrates an alternative embodiment of a pipe marking tool according to the present invention;

Figures 5a-b show partly exploded views illustrating how the limb is connected to the channel in the pipe marking tool of figure 4; Figure 6 comprises (a) top and (b) cross-sectional views of the pipe marking tool of figure 4, in the fully open position; and

Figure 7 comprises (a) top and (b) cross-sectional views of the pipe marking tool of figure 4, in the fully closed position.

Turning now to figure 1, a pipe depth marking tool 1 according to the present invention comprises a channel 10 and a limb 20 moveable relative to the channel 10.

The channel 10 is defined by an open top 11 and a closed bottom 13 with side walls 14, 15 projecting up from the bottom 13. The side walls 14, 15 have matching slopes such that any pipe received in the channel 10 is retained in the centre of the channel 10. The exterior surface 19 of the channel 10 may be at least partially adapted for gripping by a user. Such adaptations may include gripping formations and/or elastomeric covering.

At one end of the channel is a pipe stop 16, in the form of an end wall 12. The pipe stop additionally comprises pipe guides 17 in the form of curved projection from the pipe stop 16. The pipe guides 17 substantially correspond to particular pipe diameters expected to be received in the channel 10 and thus help locate the received pipe in position for marking. Optionally, the pipe stop 16 is replaceable. This can allow replacement of the pipe stop 16 in the case of wear or damage. Advantageously, it can also allow replacement of the pipe stop 16 if needed to accommodate different pipe sizes.

In the specific example shown, the other end of channel 10 is capped by end piece 18. This aids construction of a movable connection between the channel 10 and the limb 20.

The limb 20 is connected to the top of side wall 5 such that it can rotate between an open position away from the channel 10 (as shown in figure 1) and a closed position where the limb 20 projects over or into the channel 10. As will be discussed further below, the limb 20 can be biased to remain in the open position. The exterior surface 29 of the limb 20 may be at least partially adapted for griping by a user. Such adaptations may include gripping formations and/or elastomeric covering.

The limb 20 is provided with a planar marking face 21. On the marking face 21 are provided a plurality of marking elements 22, 23. The marking elements 22, 23 comprise scribing elements operable to scribe a mark on a pipe surface when pressed against said surface. Each of the elements 23 is positioned so as to correspond to a particular pipe external diameter.

The elements 22, 23 include a check element 22 for making check marks and depth elements 23 for making depth marks. The check marks are normally hidden when pipes are fitted. They can thus provide an indication that the tool 1 has been used to mark pipes before fitting. The depth elements 23 are positioned at a separation from the pipe stop 16 related to the desired insertion depth for a particular pipe size. The skilled man will appreciate that the provision of a check element is optional only.

In use, a pipe 2 is introduced into the channel 10 such that the pipe 2 is received abutting both side walls 14, 15 and with the end of the pipe 2 abutting the pipe stop 16 as is shown in figure lb. The limb 20 is then rotated as far towards the closed position as possible as is shown in figure lc. For pipes 2 of standard sizes, the check element 22 and a single depth element 23 will then be in contact with the external surface of the pipe 2. The user can then rotate the pipe 2 within the tool 1 or the tool 1 around the pipe 2 to mark the pipe surface. As is illustrated in figure 1, the channel 10 has a wider section 9 towards the open end and a narrower section 8 adjacent to the pipe stop 16. The transition between the two sections 8, 9 is defined by a step 7. The narrower neck section 8 allows the pipe 2 to be retained in the correct position within channel 10 during marking operation. The wider section 9 ensures that in the region of the marking elements 23, there is no direct contact between the walls 14, 15 and the pipe 2. This can prevent additional marks being formed during marking operation by irregularities on the surface of the side walls and also reduces the chance that such marks may be formed by loose debris trapped between the pipe 2 and the side walls 13, 14.

As is illustrated in figure 2, depth elements 23 at different positions contact pipes of different external diameters. The depth element 23 closest to the distal end of the limb 20 is positioned to make depth marks on a pipe of the largest external diameter suitable for marking with the tool 1 as is shown in figure 2a. The depth element 23 closest to the channel 10 is positioned to make depth marks on a pipe 2 of the smallest external diameter suitable for marking with the tool 1 as is shown in figure 2f. The remaining depth elements 23 are positioned to make depth marks on pipes of successively smaller diameters as shown in the corresponding figures 2b-2e.

Optionally, the tool 1 may be constructed such that the marking face 21 is replaceable. This can allow replacement of the marking face 21 in the case of wear or damage. Advantageously, it can also allow replacement of marking face 21 if needed to accommodate different pipe sizes or if different markings are required.

The limb 20 and the channel 10 are connected such that the limb 20 can be rotated relative to the channel 10 about an axis in the top of sidewall 15. The connection is typically biased to urge the limb 20 toward the open position shown in figure la.

In preferred embodiments, a locking mechanism is provided operable to prevent rotation of the limb 20 either by a user or in response to the bias. The locking mechanism is released by the action of pressing the pipe stop 16 into the end wall 12 against a bias. As can be seen when comparing figure la to figures lb & lc the pipe stop 16 has a range of movement toward the end wall 12 against said bias. Once the pipe stop 16 is a close to the end wall 12 as it is free to move, the locking mechanism is released and the limb 20 is able to rotate.

Turning now to figure 3, the operation of the locking mechanism is explained in more detail. The limb 20 is rotatably connected to the channel 10 by means of an axle (not shown) which is threaded through the base of the limb. The ends of the axle are received in end wall 12 and end piece 19. The axle is also threaded through a locking arm 31 of the spring biased pipe stop 16. The locking arm 31 is provided with a semi-circular lug 32. A corresponding semi-circular recess 33 is provided at the base of the limb 20. When the limb 20 is in the open position lug 32 and recess 33 align. The spring bias on the pipe stop 16 forces the lug 32 into the recess 33. As a result, the limb 20 is prevented from rotating. When a pipe 2 is pressed against the pipe stop 16 sufficiently strongly to overcome the spring bias, the pipe stop 16 moves away from the limb 20, pulling the lug 32 out of the recess 33. Once the lug 32 is clear of the recess 33, the limb 20 is free to rotate. When the pressure is removed from the pipe stop 16 and the limb 20 returns to the fully open position, the lug 32 and the recess 33 are once again aligned and the spring bias will urge the lug 32 to re-engage in the recess 33, locking the position of the limb 20.

Turning now to figures 4-7, an alternative embodiment of a pipe depth marking tool 101 according to the present invention is shown. As with the earlier embodiment 1, the later embodiment 101 comprises a channel 110 and a limb 120 moveable relative to the channel 110.

The channel 110 is defined by an open top 111 and a closed bottom 113 with side walls 114, 115 projecting up from the bottom 113. The side walls 114, 115 have matching slopes such that any pipe received in the channel 110 is retained in the centre of the channel 110. The exterior surface 119 of the channel 110 may be at least partially adapted for gripping by a user. Such adaptations may include gripping formations and/or elastomeric covering.

At one end of the channel is a pipe stop 116, in the form of an end wall 112. The pipe stop additionally comprises pipe guides 117 in the form of curved projection from the pipe stop 116. The pipe guides 117 substantially correspond to particular pipe diameters expected to be received in the channel 110 and thus help locate the received pipe in position for marking. Optionally, the pipe stop 116 is replaceable. This can allow replacement of the pipe stop 116 in the case of wear or damage. Advantageously, it can also allow replacement of the pipe stop 116 if needed to accommodate different pipe sizes.

In the specific example shown, the other end of channel 110 is capped by end piece 118. This aids construction of a movable connection between the channel 110 and the limb 120. The limb 120 is connected to the top of side wall 115 such that it can rotate between an open position away from the channel 110 (as shown in figure 3) and a closed position where the limb 120 projects over or into the channel 110. As will be discussed further below, the limb 120 can be biased to remain in the open position.

The exterior surface 129 of the limb 120 may be at least partially adapted for griping by a user. Such adaptations may include gripping formations and/or elastomeric covering.

The limb 120 is provided with a marking face 121. On the marking face 121 are provided a plurality of marking elements 122, 123. The marking elements 122, 123 comprise scribing elements comprise scribing elements operable to scribe a mark on a pipe surface when pressed against said surface. Each of the elements 122, 123 is positioned on a particular row a-f, the row a-f corresponding to a particular pipe external diameter. Unlike the previous embodiment, the marking face 121 is convex which provides for greater spacing between different rows a-f of marking elements 122,123 thus facilitating use of the tool 101 to mark a wider variety of different pipe sizes.

In this embodiment of the tool 101, the elements 122, 123 include single check elements 122 for making check marks and pairs of depth elements 123 for making depth marks. The check marks are normally hidden when pipes are fitted. They can thus provide an indication that the tool 101 has been used to mark pipes before fitting. The depth elements 123 are positioned at a separation from the pipe stop 116 related to the desired insertion depth for a particular pipe size. Where a pair of depth elements 123 are provided, these may correspond to maximum and minimum insertion depths or different insertion depth for pipes with different styles of end cut.

In use, as with the previous embodiment 1, a pipe 2 is introduced into the channel 110 such that the pipe 2 is received abutting both side walls 114, 115 and with the end of the pipe 2 abutting the pipe stop 116. The limb 120 is then rotated as far towards the closed position as possible. For pipes 2 of standard sizes, a single row a-f of marking elements 122, 123 will then be in contact with the external surface of the pipe 2. The user can then rotate the pipe 2 within the tool 101 or the tool 101 around the pipe 2 to mark the pipe surface.

Optionally, the tool 101 may be constructed such that the marking face 121 is replaceable. This can allow replacement of the marking face 121 in the case of wear or damage. Advantageously, it can also allow replacement of marking face 121 if needed to accommodate different pipe sizes or if different markings are required.

Turning now to figures 5 to 7, the moveable connection between the limb 120 and channel 110 in tool 101 is discussed in greater detail. The limb 120 is provided with prongs 131, 141 adapted to be received in corresponding sockets 132, 142 and to rotate within these sockets 132, 142. In addition to being rotatable relative to the channel 110 the limb 120 can be slid laterally along the rotation axis.

Socket 132 is provided in end wall 112 and in combination with prong 131 provides a locking mechanism. The locking mechanism is engaged when the limb 120 is slid towards socket 132. Socket 142 is provided in end piece 118.

Prong 141 is provided with a central passage 143 into which a spring l44is received. The spring 44 is operable both as a torsion spring to urge the limb 120 towards the open position and as a compression spring to urge the limb 20 to slide towards socket 132, thus engaging the locking mechanism.

Turning now to the operation of the locking mechanism, when the limb 120 is partly open, the spring 144 urges the prong 131 into socket 132. When the limb 120 reaches the fully open position (as illustrated in figure 6), faces 139 and 134 are parallel to one another. Accordingly, face 139 of the prong 131 can slide past face 134 of the socket 132 until face 138 of the prong 131 abuts face 133 of the socket.

This therefore locks the limb 120 in the fully open position.

To ready the tool for marking operation, a user applies force to slide the limb 120 towards socket 142 against the biasing force of the spring 144. This moves face 138 of the prong 131 away from face 133 of the socket 132. Once the limb 120 has moved far enough that face 139 clears face 134, the limb 120 can be rotated towards the closed position against the biasing force of the spring 144. Once rotation has begun face 138 of the prong 131 abuts face 135 of the socket 132 and thus prevents the limb 120 from moving back along the axis when partially open. The user can now continue to apply rotational force to the limb 120 until the marking elements 123 contact the pipe 2.

If the user releases the rotational force on the limb 120 then the bias provided by the spring 144 will rotate the limb 120 back to the fully open position. At this point, face 139 of the prong 131 can slide past face 134 of the socket 132 until face 138 of the prong 131 abuts face 133 of the socket and the compression spring pushes the limb 120 axially back into the locked open position.

For storage, the limb 120 may be unlocked as described above and then rotated to the fully closed position (as shown in figure 7) but with no pipe 2 inserted into the channel 110. At this point face 137 of prong 131 and face 134 of socket 132 are parallel. Accordingly, the biasing force provided by the spring 144 pushes the limb 120 towards socket 132. Eventually, this results in face 138 of prong 131 abutting face 133 of socket 132. In such a position, the interaction of face 134 of the socket and face 137 of the prong 131 prevent rotation of the limb 120. Accordingly, the limb 120 is locked in the fully closed position. In order to release the limb 120, the user must slide the limb 120 towards socket 142 until face 137 of prong 131 clears face 133 of socket 132. At that point, the limb 120 can once again be rotated open.

In order to facilitate sliding the limb 120 along the rotation axis, one edge can be provided with a raised tab 125. A user can readily grip the limb 120 by tab 125 in order to apply a sliding force against the compression spring.

The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.