GB2361451A

GB2361451A - Tube preparation device

Info

Publication number: GB2361451A
Application number: GB0105897A
Authority: GB
Inventors: Peter Graham; Steven W Mather
Original assignee: IMI Yorkshire Fittings Ltd
Current assignee: Aalberts Integrated Piping Systems Ltd
Priority date: 2000-03-11
Filing date: 2001-03-09
Publication date: 2001-10-24
Anticipated expiration: 2021-03-09
Also published as: GB2361451B; GB0105897D0; GB0005782D0

Abstract

A device for forming a circumferential groove (9) in the external surface of a tube (4) at a pre-determined distance A from an end thereof comprises a body (1) having a blind bore (2) formed in it for snugly receiving the end of the tube (4). The base (3) of the bore (2) limits the extent of insertion of the tube (4) into the bore (2). The body (1) holds captive a scribing tool (6) which is radially movable relative to the axis of the bore between a retracted position and a manually depressed position in which it is urged into contact with the external surface of the inserted tube (4). With the tool (6) in its depressed position, rotation of the tube (6) relative to the device causes the groove (9) to be formed. The groove (9) provides a positive location for the grab-ring of a push-in fitting to which the tube (4) is subsequently coupled. The device may additionally comprise a deburring tool (7) that protrudes into the periphery of the bore (2) adjacent to the base (3) whereby the end of the tube (4) is simultaneously deburred upon rotation thereof.

Description

2361451 Tube proaration device This invention relates to a device for

preparing the end portion of a tube made, for example, of a relatively hard material or having a slippery surface prior to connection thereof to a push-in tube fitting.

More particularly, the device is intended to form a circumferential groove in the external surface of the tube at a pre-determined distance from its end,, the groove providing a positive location for the grab-ring or collet teeth of the fitting. One example of such a fitting, which we sell under our Registered Trade Mark 'TECTITE', is described in our UK patent application No 2299838A to which the reader is referred.

According to the present invention, there is provided a device comprising a body having a bore therein for snugly receiving an end portion of a tube, stop means to limit the extent of insertion of the tube into the bore, and scribing means retained by the body in axially spaced relationship to the stop means and movable radially relative to the bore between a first, retracted position in which it is substantially free of the bore thereby permitting insertion of the tube into the bore until it abuts said stop means, and a second, depressed position in which it is urged into contact with an inserted tube and will, upon relative rotation between the body and a tube inserted fully into the bore, form a circumferential groove in the external surface of the tube at a predetermined distance from the inserted tube end.

A device of the invention preferably further comprises deburring means located adjacent to the stop means and adapted, during relative rotation between the tube and the body, to remove any burrs on the external leading end of the tube. Preferably, the deburring means serves during the deburring step also to form an external chanifer on the 2 inserted tube end and comprises a knife-edged member that protrudes, through a slot in the body, into the bore adjacent to the stop means.

As will be apparent, the bore in the body of the device will have a diameter very slightly in excess of the external diameter of the tube to be prepared and accordingly corresponding bore diameters will be required to prepare differently sized tubes. Conveniently, a device of the invention may comprise a unitary body, for example moulded in a plastics material, having a number of differently sized bores. For example, a device suitable for preparing tubes of I Omm., 12mm and 15mm OD (as are commonly used in plumbing applications) may comprise a unitary body formed with three appropriately sized bores, each being associated with respective stop means, scribing means and, optionally, deburring means as aforesaid. The relative axial positions of the stop means and the scribing means will depend on the design of the fitting being used.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings in which:

Figure I is a sectional side elevation of a device constructed in accordance with the invention for preparing a tube shown inserted into the device; Figure 2 is a plan view, on a scale of 1: 1, of a device very similar to that shown in Fig I but adapted to deburr/scribe tubes having ODs of 103 12 and 15mm. respectively; Figure 3 is an end view of the device shown in Figure 2; and Figure 4 is a perspective view of another device constructed in accordance with the invention.

3 Referring first to Fig I of the drawings, the device comprises a cylindrical body I having a blind bore 2 formed axially in it. The base 3 of the bore 2 defines a stop means which limits the extent of insertion of a tube 4 into the device. The tube 4 is a snug fit in the bore 2.

Typically, the tube 4 will be made of stainless steel or chrome-plated copper but it could, for example, be made of a plastics material having a hard and/or slippery surface.

The body I has a radial bore 5 formed in it at a pre-determined axial distance from the base 3 of the bore 2. A scribing tool 6 is held captive in the bore 5 and is movable axially therein between a retracted position in which the tube 4 can be fully inserted into the bore 2 up to the base 3 and, as described below, a depressed position in which it is urged into contact with the external surface of the tube 4.

The body 1 has fixedly mounted in it a deburring tool 7, such as a disc, having a sharp edge that radially protrudes, through a slot in the body 1, slightly into the bore 2 adjacent to its base 3.

The device may be hand-held and is used as follows. Once the tube 4 has been fully inserted, it is first gently pushed forward and rotated,, say two or three times, by the user's other hand whereupon the periphery of the leading end of the tube 4 is deburred by the deburring tool 7. Simultaneously, the tool 7 forms an external chamfer 8 on the end of the tube 4. The scribing tool 6 is then firmly depressed by the user"s thumb and the tube 4 is fully rotated at least one further turn. During the latter operation, a shallow circumferential groove 9 is formed in the external surface of the tube 4. The tube 4 is then withdrawn from the device and is ready to be connected to a push-in fitting.

4 As will be appreciated, the groove 9 will be located at a predetermined distance A, as shown, from the end of the tube 4. The distance will depend on the design of push-in fitting to which the tube 4 is to be connected and, more particularly, will be such that, when the tube 4 is properly connected, the grab-ring or collet teeth of the fitting will engage in the groove 9.

Referring now to Figs 2 and 3, in which the same or similar parts to those in Fig I bear the same reference numerals, there is depicted to actual size a device for preparing a tube of 10, 12 or 15 nim OD. The device comprises a one-piece body I moulded in, for example, glass-filled nylon 6 and defining three bores 2, 2' and 2". The bore 2 has a diameter slightly greater than l0mm, bore 2' a diameter slightly greater than 12mm and bore 2" a diameter slightly greater than 15mm. The bores 2, 2' and 2" are defined by respective cylindrical wall portions of the body I which are moulded integrally with web sections 10 and 11.

The bores 2, 2' and 2" are provided with respective, identical scribing tools 6, 6' and 6" and debuming discs 7, 7' and 7". The former are as shown in Fig 1. Each of the latter, which is of tapering cross- section as can be seen from Fig 3, is recessed into the web section I I and secured therein by a screw, just one of which is designated 13. The upper periphery of each disc 7, 7,7" protrudes into its respective bore 2 etc, adjacent to its base 3 etc, through a slot 12 formed in its cylindrical wall portion (as can clearly be seen in Fig 3) and provides a sharp edge which, when the tube to be prepared is rotated clockwise, deburrs, the tube and forms the aforesaid chamfer on it.

The device illustrated in Fig 4 is very similar to that shown in Figs 2 and 3 but is designed to prepare tubes having an OD of 10, 12, 15, 18, 22 or 28mm. As such, the unitary body I comprises two "back to-back" sets of three cylindrical wall portions, designated respectively 14 to 19, which are joined together by integral transverse web sections 20. As in the device shown in Figs 2 and 3, the wall portions 14 to 19 define differently-sized tube-receiving bores, three of which are visible and are designated 2, 2' and 2".

As can be seen, the axes of one set of tube-receiving bores are off set from those of the other set, whereby only three deburring discs (not shown) need be provided, each disc being associated with a pair of bores. In Fig 4, the slots designated 12, 12', 12" formed in the wall portions 17, 18 and 19 respectively through which the deburring discs protrude can be clearly seen.

The six scribing tools have been omitted from Fig 4 so as to reveal pips which serve to hold the scribing tools captive as shown in Fig 1. Two of the pips are designated 21, 2 1'.

The mode of use of the devices shown in Figs 2, 3 and 4 is identical to that of the device shown in Fig 1.

The devices depicted may be made of any suitable materials.

However, as noted above, the body I preferably comprises a plastics moulding. The scribing tools 6, 6' and 6" and the deburring -discs 7, 7' and 7" are preferably made of hardened tool steel.

6

Claims

CLAIMS: 1. A device for forming a circumferential groove in the external

surface of a tube adjacent to an end thereof, the device comprising a body have a bore therein for snugly receiving an end portion of the tube, stop means to limit the extent of insertion of the tube into the bore, and scribing means retained by the body in axially spaced relationship to the stop means and movable radially relative to the bore between a first, retracted position in which it is substantially free of the bore thereby permitting insertion of the tube into the bore until it abuts said stop means, and a second, depressed position in which it is urged into contact with an inserted tube and will, upon relative rotation between the body and a tube inserted fully into the bore, form a circumferential groove in the external surface of the tube at a pre-determined distance from the inserted tube end.

2. A device according to claim I further comprising deburring means located adjacent to the stop means and adapted, during relative rotation between the tube and the body, to remove any burrs on the external leading end of the tube. 3. A device according to claim 2 wherein the deburring means serves during the deburring step also to forin an external chamfer on the inserted tube end. 4. A device according to claim 2 or claim 3 wherein the deburring means comprises a member having a knife-edged portion that protrudes, through a slot in the body, into the bore adjacent to the stop means.

5. A device according to claim 4 wherein the member comprises a knife-edged disc part of the edge of which protrudes into the bore as aforesaid.

7 6. A device according to claim 1 for preparing the ends of the differently sized tubes comprising a unitary body having a plurality of differently sized tube-receiving bores therein, each bore having an aforesaid stop means and scribing means associated therewith.

7. A device according to claim 6 additionally comprising deburring means as defined in any one of claims 2 to 5 associated with each bore. 8. A device according to any one of claims I to 7 wherein said body comprises a plastics moulding. 9. A tube preparation device substantially as hereinbefore described with reference to, and as illustrated in, Fig 1, Figs 2 and 3 or Fig 4 of the accompanying drawings.