Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L37/00—Couplings of the quick-acting type
  • F16L37/08—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L37/00—Couplings of the quick-acting type
  • F16L37/08—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members
  • F16L37/084—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking
  • F16L37/092—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking by means of elements wedged between the pipe and the frusto-conical surface of the body of the connector
  • F16L37/0925—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking by means of elements wedged between the pipe and the frusto-conical surface of the body of the connector with rings which bite into the wall of the pipe
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L37/00—Couplings of the quick-acting type
  • F16L37/08—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members
  • F16L37/084—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking
  • F16L37/091—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking by means of a ring provided with teeth or fingers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L37/00—Couplings of the quick-acting type
  • F16L37/08—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members
  • F16L37/084—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking
  • F16L37/092—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking by means of elements wedged between the pipe and the frusto-conical surface of the body of the connector
  • F16L37/0927—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members combined with automatic locking by means of elements wedged between the pipe and the frusto-conical surface of the body of the connector the wedge element being axially displaceable for releasing the coupling
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L37/00—Couplings of the quick-acting type
  • F16L37/08—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members
  • F16L37/10—Couplings of the quick-acting type in which the connection between abutting or axially overlapping ends is maintained by locking members using a rotary external sleeve or ring on one part
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/4459—Ducts; Conduits; Hollow tubes for air blown fibres
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/46—Processes or apparatus adapted for installing or repairing optical fibres or optical cables
  • G02B6/50—Underground or underwater installation; Installation through tubing, conduits or ducts
  • G02B6/52—Underground or underwater installation; Installation through tubing, conduits or ducts using fluid, e.g. air

Definitions

• the present invention relates to a tube coupling. It has a particular application as fibre optic cable connector for use above or below ground. However, the concept can be applied more broadly to other types of connector.
• Such fibre optic connectors are used in the laying of fibre optic cables.
• the cables are used, for example, to provide a fibre optic cable connection from a junction box to a building such as an office or residence in order to provide a connection for internet data.
• the fibre optic cables are provided in bundles of individual fibres which can be up to several kilometres long.
• the fibre bundles are fed through tubes (often referred to as microducts) which are typically 100 metres long, but can be as long as 500 metres. A number of tubes therefore need to be connected together in order to support the full run of the fibre bundle.
• the connectors also need to be highly impact resistant. Cables are usually buried in the ground and, for maintenance, they need to be dug up. This is generally done by a labourer with a spade, and the first that the labourer will know if the presence of the cable is when it is struck by the spade.
• the connectors therefore need to be sufficiently robust to resist such an impact. In practice, they need to pass a ⁇ 5J impact test’.
• the connectors have a connection at either end which attaches to and retains the tube within the connector. This is done using a collet or grab ring. This grips on the outer wall of the tube and any movement which tends to pull the tube out the connector causes the collet to tighten its grip on the tube in a well-known manner. In order to release the tube, the collet can be manually displaced inwardly of the connector. This prevents the collet from gripping the tube allowing the tube to be withdrawn from the connector. It is a requirement of the fibre optic cable connectors that the collet must be locked in place to prevent accidental release of the tube.
• This connector is not designed for use with a fibre optic cable connector and, indeed, it would be unsuited to such a purpose.
• the locking ring fits over the external surface of the body. This adds to the bulk connector which is against the requirement in a fibre optic cable connector for the outer diameter to be as small as possible.
• the locking ring is exposed to dirt such that, in use, dirt particles could get into the locking ring and jam it in the locking position. Further, the locking ring is also exposed to damage during installation and the maintenance operations which can either cause the locking ring to fail, or become stuck in the locked position.
• a tube coupling according to claim 1 .
• the locking of the collet is now achieved solely by interaction between the body and the collet. This eliminates the locking clip of the prior art. It also eliminates the locking ring of EP2131089.
• the invention is motivated by the need to provide an improved fibre optic cable connector, because it provides improvements over EP2131089 in terms of the low profile nature of the connector, and the reduction in the number of components (as it does not require a locking ring) it can also be used in any of the contexts for which EP2131089 was designed. In particular, it is suitable for a wide range of plumbing applications which provide fluid communication.
• the locking mechanism can effectively be internal to the body. This can provide a low profile design and also protect the locking mechanism from impact damage and from the ingress of dirt.
• the cam surface can be provided either on the body or the collet, but is preferably on the body.
• the cam surface can be moulded directly into the body as part of the body moulding process.
• the body includes a cap retained by a main body portion, the cap being provided with the cam surface.
• the cap may be fitted over or within the main body portion. It may be retained by teeth which grip the main body portion, ultrasonic welding, a snap fit, a screw fit, or in any other way.
• the collet With the prior art fibre optic cable connectors, it is necessary for the collet to protrude beyond the body to allow an annular gap in which the locking clip is inserted. This is not necessary in the present invention.
• the collet ring can still protrude axially beyond the body, but, preferably, in the locked position, the collet ring does not protrude axially beyond the body. It may be flush with the body, but is more preferably recessed into the body. This protects the collet ring from impact damage and from dirt.
• the collet ring may be a conventional annular collet ring that the user grips in order to rotate the collet between the locking and unlocked positions.
• an unlocking feature is preferably provided in the collet ring. This make take the form of one or more openings in the axial end face of the collet ring. However, these require the use of a tool and can become clogged with dirt.
• At least one lug projects from the collet ring axially away from the open end of the through way. This provides a point at which the collet can be readily gripped for rotation.
• the or each lug may not project axially beyond the body. However, the or each lug preferably projects axially beyond the end of the body. This makes them easier to grip. Also, these lugs can provide a burr removing function. They can be shaped, for example to have an abrupt edge, such that a lug can be inserted in to the cut end of a tube and scraped around the inner edge to remove any burrs left from the tufting process. These can create snagging hazards, in use, so for an operator to have a tool readily at hand to remove these will be very useful in practice.
• the collet ring does not protrude axially beyond the body.
• the or each lug preferably protrudes beyond the axial end of the body so that it can readily be gripped.
• At least one of the body and/or collet is preferably provided with a visual indication of the locked and/or unlocked positions.
• the cam surface is preferably provided with a bump over which the cam follower rides. This serves to ensure the cam follower remains in the locked position and also provides a tactile indication to the user that the locked position has been reached.
• the connector body is made of a non-opaque plastic.
• the body preferably comprises an outer sleeve and in inner sleeve, the inner sleeve being configured to receive a distal end of a respective tube, the outer wall of the inner sleeve being generally spaced from an inner wall of the outer sleeve to define a gap, the inner sleeve being supported on the outer sleeve by a discrete web of material which supports the inner sleeve and maintains the gap between the inner and outer sleeves.
• This provides an impact protection feature as the gap allows any impact on the outer sleeve to deform the outer sleeve which will deform into the gap before it deformed the inner sleeve.
• the connector is devoid of outer ribs and has a continuous outer surface of constant radius.
• an annular flange extends radially into the through way, each end face of the annular flange providing a stop surface for a respective tube end, wherein the annular flange is undercut such that its end faces are inclined such that the axial dimension of the flanges increases towards the axis. This uncut ensures that the inner edge of the tube is able to get closer to, and preferably abut, the annular flange. This eliminates or minimises the possibility of a fibre, which is subsequently passed through the connector once the tubes are in place, becoming snagged on the tube or the annular flange.
• a plurality of annular splines are provided in the vicinity of the annular flange to deflect the outer wall of the tube as it approaches the flange.
• tubes are supplied on coils and have often been flattened into an oval cross-section. In the regions where the oval is at its widest, the inner diameter is larger than it should be and this exposes part of the annular flange in this region. This provides a snagging hazard for the fibre which is significantly reduced by the use of the splines.
• the invention also extends to a collet for the coupling as defined in claim 17.
• the collet may have any of the preferred features defined above.
• Figs. 1 A-1 C are cut-away perspective views of the connector showing the progressive insertion of a tube
• Fig. 2A is a cross-sectional view of the connector body in a plane perpendicular to the main access of the connector body through line A-A in Fig. 2B;
• Fig. 2B is a cross-sectional view of the connector body in plane through the main axis of the body through line B-B in Fig. 2A;
• Fig. 2C is a view in the same plane as Fig 2A showing a second example of a connector;
• Fig. 2D is a view in the same plane as Fig. 2B showing the second example
• Fig. 3 is a cross-section in the plane of Fig. 2B of the connector with tubes connected and a fibre bundle passing through;
• Fig. 3A shows the central portion of Fig. 3 in greater detail
• Fig. 3B shows a view similar to Fig. 3A, with a different configuration of tubing and without the fibre passing through;
• Figs. 4A and 4B correspond to Figs. 3A and 3B illustrating a prior art arrangement
• Fig. 5 is an exploded perspective view of the connector from one end of the connector body
• Fig. 6A is the equivalent to Fig. 5 in non-exploded form, showing the cartridge and collet in a first angular configuration
• Fig. 6B is a cross-section through a plane in Fig. 6A through the locking tabs;
• Figs. 7A and 7B are views corresponding to Figs. 6A and 6B respectively showing the cartridge and collet in a second angular configuration
• Figs. 8A and 8B correspond to Figs. 7A and 7B but show the tube in situ.
• the connector comprises a connector body 1 having a generally hollow cylindrical configuration centred on a main axis X.
• a connector 2 (described in greater detail below) is provided at either end to receive and grip a tube T at each end which is sealed by an O ring 3.
• the body 1 is moulded from a non-opaque plastic.
• the plastic must be such that it is clear enough that a visual inspection externally of the connector allows an operator to determine whether a fibre or fibre bundle F is present in the centre of the connector.
• the body should be as close to transparent as possible. However, practical considerations mean that the body will not be truly transparent. Instead, the body is likely to translucent to a sufficient extent that the fibre is visible. Suitable materials are polycarbonate, polystyrene, polyester, acrylic and nylon.
• the body 1 is formed in a moulding process and can optionally be polished to improve the clarity of the body.
• the outer profile of the body is a smooth configuration which is devoid of external ribs thereby eliminating any stress concentrations and orifices for the accumulation of dirt.
• the body 1 is made up of an outer sleeve 5 and an inner sleeve 6 which are connected by at least one web 7 as described below.
• the outer sleeve 5 has an axial bore 8 which is opened at the distal end 8 and which has a first step 10 and second step 1 1 which receive the connector 2 as described below.
• the inner sleeve 6 is retained by the web 7 so as to form a gap 12 of generally uniform thickness as best seen in Fig. 2A.
• the web 7 extends across only a very small part of the inner sleeve 6 so that the gap 12 is present for most of the length and circumference of the inner sleeve 6.
• the or each web 15 may extend tangentially as shown in Fig. 2C, or in any other direction across the gap 12. As shown in Fig. 2D, the webs 15 are axially offset from an annular flange 20 so that they do not impair the visibility into this region.
• FIG. 3 shows the connector body 1 with a tube T fixed and sealed in either end. Once connected in this way, the fibre F is blown from one end through the tube T, across the interface between the tubes and into the adjacent tube.
• the tubes T abut against the annular flange 20 at a midpoint of the inner sleeve 6.
• the connectors 2 and O-rings 3 broadly have the same inner diameter as the inner diameter of the inner sleeve 6 so that, when the tube T is pushed into the body 1 , it is guided into the inner sleeve 6. The end of the tube T then abuts the annular flange 20.
• the annular flange 20 is provided undercut portion 21 such that the thickness of the annular flange 20 in the axial direction increases towards the axis X.
• the innermost corner 22 of the tube T is the first part of the tube T to abut the annular flange 20. This means that there is no gap between the inner face 23 of the tube T and the annual flange 20.
• the undercut portion 21 is radiused as shown in Figs. 3A and 3B.
• the radially innermost corners 24 of the annular flange are radiused to present a smooth surface to the fibre.
• Fig. 3B depicts the situation where the left hand tube has been cut at an angle which is slightly oblique to a plane perpendicular to the axis X. As a result of this, the uppermost edge 25 of the tube T enters into the undercut region 21 and seats on the annular flange 20
• a further feature which prevents snagging of the tube is the splined arrangement listed as best illustrated in Figs. 1 and 2.
• six axially extending splines 30 are equally spaced around the circumference of the inner sleeve 6. These are shown having a constant cross- section in a plane perpendicular to the axis. However, they may have a thickness which increases towards the annular flange 20.
• a tube T has been fed from a coil and has taken on a flattened oval shape. As this enters the inner sleeve 6 the tube T engages with the enlarged portions of the tube T and tend to push this back to a more circular shape as shown in Fig. 1 C.
• any number of splines may be used. However six has been found to be a reasonable number. This allows engagement with a flattened tube which is inserted in any orientation. A smaller number of flanges risks the possibility that the enlarged part of the tube enters between adjacent splines. On the other hand, adding more splines increases the insertion resistance for the tube T into the connector 1.
• the splines 30 are dimensioned such that where the splines are present is slightly smaller than the outer diameter of the tube. The splines 30 will therefore bite into the material of the tube T in these regions. This ensures a secure and robust fit of the tube T and also provides the maximum opportunity for the splines to reduce the eccentricity of the tube.
• the connectors 2 (one at each end of the body 1 ) will now be described in greater detail with reference to Figs. 5 to 8.
• the connectors 2 are formed of two components, namely a cartridge 40 and a collet 41 .
• the cartridge 40 has a generally annular configuration.
• the outer surface is provided with a plurality of flexible metal teeth 42.
• the cartridge 40 is inserted into an end of the body 1 until it seats against the second step 1 1 .
• the teeth 42 grip the wall of the body 1 to ensure that the cartridge 40 is permanent retained in the body 1 .
• At the end of the cartridge 40 adjacent to the second step 1 1 there is a tapered cam surface 43 which cooperates with the collet as described below.
• the end face of the cartridge 40 is provided with a pair of ramped surfaces 44. Although two such surfaces are shown, there may be a single surface or there may be more than two.
• Each ramp surface has a low point 45 corresponding to an unlocked configuration and a high point 46 corresponding to a locked configuration within an inclined face 47 in between.
• a bump 48 is provided at the interface between the high point 46 and the inclined face 47.
• a similar bump may be provided interface between the incline face 47 and the low point 45.
• the low point 45 terminates at the first end stop 49 and the high point 46 terminates at a second end stop 50.
• collet 41 has a collet ring 52 from which a plurality of flexible arms 53 extend. Each arm has a head 54 at its distal end as is provided with an inwardly projected metal tooth 55.
• the adaptation provided by the present invention is the presence of a pair of cam followers
• the cam arrangement may be inverted such that the ramped surface(s) is/are on the collet and the follower(s) is/are on the cartridge
• the collet ring 52 is also provided with a pair of tabs 57 which extend from the collet ring 52 the opposite direction to the followers 56. As shown in the drawings, the position of the tabs
• Figs. 6A and 6B The position shown in Figs. 6A and 6B is an unlocked position. In this position, the collet 41 has been rotated such that cam followers 56 abut the first end stops 49 such that the cam followers are at the low point 45. As will be apparent from Fig. 6B (particularly when compared with Fig.
• the collet 41 has a relatively large degree of axial freedom as it can move from the position in which the heads 54 engage with the tapered cam surface 43 all the way to the left (with reference to Fig. 6B) in the position shown in that figure. If held in that position by a user, the tube T can be withdrawn because the heads 54 are kept away from the tapered inclined surface 43 such that the collet cannot grip the tube. The collet 41 is then rotated in the direction of arrow 60 into the locked position shown in Fig. 7A. In doing so, the followers 56 moves up the inclined faces 57, over the bumps 48, providing a tactile feel to the user that a position has been reached, and onto the high point 46.
• the only way to remove the tube T in this locked configuration is for the user to grasp the tabs 57, rotate the collet 41 in the direction of arrow 61 in Figs. 6A to the unlocked position, and manually hold the collet in the position shown in Fig 6B while pulling the tube out of the body 1 .
• the tube T will usually be inserted with the collet 41 in the unlocked position shown in Figs. 6A and 6B as this allows for more scope for the arms 53 to be deflected upon insertion of the tube.
• Fig. 7B even in the locked position, there is a small clearance between the head 54 and the tapered cam surface 43.
• the collet ring 52 is axially set back inside the body 1 .
• the tabs 57 extend beyond the end of the body 1 .
• the collet 41 is protected from external impacts by the body 1 .
• it is recessed within body 1 , it is, to some extent, shielded from the soil in which the cables are buried.
• the only points where dirt can potentially enter internal workings of the connector are between the collet ring 52 and the tube T and between the collet ring 52 and the body 1 .
• the rotary action required to unlock the collet even if some dirt does enter into these gaps, this is unlikely to jam the collet 41 in place as a rotary motion can readily generate sufficient torque to overcome any such sticking.
• the tabs 57 have right angled corners. This allows them to be inserted into the cut end of a tube T and scraped around the inner edge of the tube to remove any burrs which are formed during the cutting operation and which might otherwise create a snagging hazard for the fibre F.
• the edge may be shaped in a different way to provide more effective burr removal.
• the connectors 2 described above are in the combination with an unconventional arrangement of the outer sleeve 5 and inner sleeve 6 supported by a web 7 and the annular flange 20 and the splines 30.
• the connectors can equally be used in a coupling which has a conventional interior without these features.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Quick-Acting Or Multi-Walled Pipe Joints (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=67623246

Family Applications (1)

Country Status (6)

Families Citing this family (6)

Family Cites Families (12)

• 2019
  • 2019-07-10 GB GB1909906.8A patent/GB2585668B/en active Active
  • 2019-12-18 EP EP19832174.7A patent/EP3997374A1/en active Pending
  • 2019-12-18 WO PCT/GB2019/053602 patent/WO2021005319A1/en unknown
  • 2019-12-18 CN CN201980100227.4A patent/CN114630982A/zh active Pending
  • 2019-12-18 AU AU2019456730A patent/AU2019456730A1/en active Pending
• 2020
  • 2020-02-19 KR KR1020227004304A patent/KR20220088406A/ko not_active Application Discontinuation

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