GB2526672A

GB2526672A - Screw clamp retainer

Info

Publication number: GB2526672A
Application number: GB1505545.2A
Authority: GB
Inventors: Paul Trevor Felstead
Original assignee: Avon Automotive UK Holdings Ltd
Current assignee: Akwel Chippenham UK Ltd
Priority date: 2014-04-02
Filing date: 2015-03-31
Publication date: 2015-12-02
Anticipated expiration: 2035-03-31
Also published as: GB201505545D0; GB201405945D0; GB2526672B

Abstract

A screw clamp 15 is used to secure the end of a tube 6 onto an outlet fitting or nozzle. The screw clamp 15 has a band 5 extending around the tube and a drive 16 for tightening the loop to clamp the tube 6 onto the nozzle. In order to prevent relative movement of the screw clamp 16 and tube 6, a retainer 1a engages the screw clamp 15. The retainer 1a and tube 6 inter-engage by means of a retaining structure having a projection 3 and at least one corresponding opening 4. The opening 4 may be in the tube and the projection 3 on the retainer. Alternatively, the retainer and the tube may have openings, held together by a projection or a further element. A loop 8 may retain the screw clamp 15 in the correct location relative to the retainer 1a prior to tightening. The projection and opening arrangement ensures that the screw clamp remains correctly located on the tube both

Description

SCREW CLAMP RETAINER

The present invention relates to a retainer for a screw clamp.

Screw clamps are typically used to secure the end of a tube around an outlet fitting or nozzle. For example, a tube can be clamped onto a nozzle present within it by tightening a screw clamp around the tube/nozzle assembly. The screw clamp has a band that can extend in a loop around the tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube. The drive unit typically contains a captive screw.

Usually, one end of the band is fixed to the drive unit and the other end of the band is pulled through the drive unit by turning the captive screw, which acts as a worm drive F pulling the band through the drive unit to tighten the band.

Screw clamps are preferable to other compression fittings such as crimp fittings because the tightness of a screw clamp is readily adjustable after it is fitted, and because, unlike crimp fittings, screw clamps do not usually damage the tube in normal use. Hence, screw clamps are often used in automotive and industrial settings where a tube carries toxic fluids, and where a hose fitting must be secure for many years, but must be readily removable for service, maintenance and repair.

Corrmonly, however, the screw clamp will move during application because the force that the user applies to turn the captive screw tends to rotate the screw clamp around the tube in a circumferential direction. When working in a confined environment, e.g. within the engine compartment of a car, this rotational displacement of the screw clamp makes it difficult to access the drive unit to attain the desired tension.

Screw clamps are also prone to lateral movement, i.e. axially along the length of the tube. This can occur if the nozzle or outlet fitting has a tapered profile. Again, this is problematic during application, but a creeping' lateral movement is a serious problem if it occurs after application and during use, e.g. during a car's normal lifetime, because axial (longitudinal) slippage tends to move the screw clamp away from the region of tubing that contains the nozzle, potentially causing leaks or leading to a disconnection of the tubing.

Current means for retaining the screw clamp in a desired position rely on friction, adhesives, or retention teeth that pinch the end of a tube. For example, US patent 5234233 describes a rubber band that acts through friction to hold the screw clamp in place during tightening. The rubber band has an aperture, which must be positioned to allow the drive unit to project through it for access to the captive screw. However, correctly positioning the rubber band, screw clamp and tube is not straightforward and the band's effectiveness is diminished after use and reuse.

Glue, adhesive pads or tape are also used to stick the screw clamp in place before tightening. Alternatively, some screw clamps are provided with retention teeth on the band, as illustrated in US patent application 2007/0018063. The teeth engage the end of the tube to act against rotational and lateral movement of the band.

However, the above methods primarily act to retain the band, and not the drive unit, which is the part of the screw clamp that is most prone to move during tightening. None of these methods prevent rotational movement when a large force is applied, and none effectively prevent axial creep of the drive unit during extended use. Furthermore, none of these methods assist in orienting the drive unit to position the screw to be easily accessible.

At its most general, the present invention provides a retainer for retaining a screw clamp on a tube, the tube and retainer having a retaining structure comprising a projection and a corresponding opening, to resist movement of the retention means relative to the tube. This provides a means for orienting and anchoring the screw clamp on the tube.

In a first aspect, an assembly may be provided, comprising a tube, a screw clamp having a band extending in a loop around the tube and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube, and a retainer engaged with the screw clamp to retain the screw clamp on the tube. The tube and retainer are engaged by a retaining structure having at least one projection and at least one corresponding opening into which the at least one projection is received, to resist relative movement of the retainer on the tube.

Preferably, the drive unit of the screw clamp is held by the retainer. Preferably the or each projection is on the retainer and the or each opening is in the tube. The or each opening may be a notch at the end of the tube. Preferably, the or each projection is upstanding on a surface of the retainer that is in contact with the tube.

However, it is also possible for both the retainer and tubes to have openings, and for there to be further element, having the or each projection thereon. The further element then links together the tube and retainer.

That further element may be an assembly fixture, which is used when the tube, screw clamp and retainer are fitted together, in order to hold the retainer accurately in place during such fitting. The assembly fixture may then be removed. With such an arrangement, the assembly fixture acts to provide accurate location of the tube, screw clamp and retainer during fitting, to ensure that the retainer is positioned correctly, by resisting relative movement of the retainer on the tube during such an fitting. After fitting, the screw clamp is retained on the tube by its own clamping force.

Note that in such an arrangement, the retainer may be symmetric, with openings on either side, to permit left-handed or right-handed assembly.

In some embodiments, the retaining struoture comprises more than one projection and more than one corresponding opening. In other embodiments, the retaining structure comprises more than one projection and a single opening receiving the multiple projections.

In some embodiments, the retainer has at least one projection as well as at least one opening, and the tube has at least one corresponding opening and at least one corresponding projection. A first and a second projection may each be upstanding on the surface of the retainer that is in contact with the tube.

The retainer may have an arch that extends in the opposite direction from the or each projection, wherein the arch engages the drive unit. Optionally the arch has a thumb that engages a recess in the drive unit. The arch may be elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit. Preferably, the retainer has a locating member which holds the drive unit against the arch. The locating member may be a looped strap. In some embodiments, the retainer has a tail that extends from the arch to engage the screw clamp at an additional location, e.g. the tail engages the screw clamp band. In other embodiments, the tail, which engages the screw clamp at an additional location, e.g. the screw clamp band, extends from another part of the retainer, e.g. from the base of the retainer. In some embodiments, the tail supports a part of the retaining structure, i.e. it comprises at least one projection or at least one opening that engages at least one corresponding projection or opening in the tube.

Moreover, it is possible for the retainer to have a further arch, connected to the first arch by a flexible linkage such as a strip of suitable material. In such an arrangement, the first arch is normally adjacent the drive unit and the further arch is further away. The flexible linkage may then act as a handle, when the retainer is mounted onto the screw clamp.

In some embodiments, the at least one projection comprises a plurality of projections.

In some embodiments, the tube, the retainer and the screw clamp are provided disassembled, as a kit of parts. In other embodiments, the tube and the retainer are provided as an assembly. A screw clamp may be provided separately. Alternatively, the retainer and the screw clamp may be provided as an assembly and a tube may be provided separately.

Thus, in a second aspect, a kit of parts may be provided, comprising a tube, and a screw clamp having a band for extending in a loop around the tube and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube, the kit of parts also having a retainer for engaging the screw clamp to retain the screw clamp on the tube, wherein the tube and retainer are engageable by a retaining structure having at least one projection and at least one corresponding opening into which the at least one projection can be received, to resist relative movement of the retainer on the tube. Preferably, the or each projection is on the retainer and the or each opening is in the tube. The opening may be a notch at the end of the tube. Alternatively, as discussed above, there may be openings in both the retainer and the tube connected by a projection on a further element of the assembly.

Preferably, the or each projection is upstanding on a surface of the retainer that is for contacting the tube. The retainer may have an arch for engaging the drive unit, the arch extending in the opposite direction from the or each projection. Preferably, the arch has a thumb for engaging a recess in the drive unit. The arch may be elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit, in use. Preferably, the retainer has a locating member for holding the drive unit against the arch. The locating member may be a looped strap. As in the first aspect, there may also be a further arch connected to the first arch by a flexible linkage.

In a third aspect, the kit of parts may comprise a tube, and a retainer for engaging a screw clamp having a band for extending in a loop around the tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube, to retain the screw clamp on the tube, wherein the tube and retainer are ençjageable by a retaining structure having at least one projection and at least one corresponding opening into which the at least one projection can be received, to resist relative movement of the retainer on the tube. Preferably, the or each projection is on the retainer and the or each opening is in the tube. The opening may be a notch at the end of the tbe. Once again, however, it is possible for there to be openings in the retainer and tube, connected by a projection on a further element forming part of the kit of parts.

Preferably, the or each projection is upstanding on a surface of the retainer that is for contacting the tube. The retainer may have an arch for engaging the drive unit, the arch extending in the opposite direction from the or each projection. Preferably, the arch has a thumb for engaging a recess in the drive unit. The arch may be elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit, in use. Preftrably, the retainer has & locating member for holding the drive unit against the arch. The locating menter may be a looped strap. In a similar way to the previous aspects, there may be a further arch connected to the first by a flexible linkage.

In a fourth aspect, the invention may provide a retainer for engaging & screw clamp having a band for extending in a loop around a tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube, the retainer comprising a base having a first surface for contacting an outer surface of the tube; and a retaining structure comprising at least one projection and/or at least one opening situated on the first surface, wherein the retaining structure is arranged to engage a tube having a corresponding projection or opening to resist relative movement of the retainer on the tube. Preferably, the retaining structure comprises at least one projection. The or each projection may be upstanding on the first surface of the retainer.

However, as previously, the retaining structure may be an opening on the retainer. Preferably, the retainer has an arch for engaging the drive unit, the arch extending in the opposite direction from the projection. The base may comprise a first section and a second section and a separation therebetween, the first and second sections being connected by the arch. Optionally, the arch has a thumb for engaging a recess in the drive unit. In some embodiments, the arch is elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit, in use. The retainer may have a locating member for holding the drive unit against the arch. The locating member may be a looped strap.

Preferably, the looped strap has one end that is attached to the first section of the base, and another end attached to the second section of the base. The looped strap may have opposing flexible corners that can be pressed towards each other to increase the extension of the looped strap from the base. In this fourth aspect, as in the first to third aspects, there may be a further arch connected to the first arch by a flexible linkage.

In some embodiments, the retainer has a projection, e.g. an anchor, which is engaged with a complementary opening in the tube. Usually, the opening is made in the structure of the tube before the retainer is mounted upon the tube, e.g. during manufacture of the tube. The cross-sectional dimensions of the opening preferably correspond to the cross-sectional dimensions of the projection so that relative movement is resisted when these retaining structures are engaged.

The opening may be a notch at the end of the tube. The projection may extend perpendicularly from the surface of the retainer that contacts the tube. The skilled person will understand that, when provided as a kit of parts, the projection and complementary opening will be disengaged, but engagable.

Where the retainer is provided separately from the tube and screw clamp, or when provided as a kit of parts including a tube and/or a screw clamp, the at least one projection may comprise a plurality of projections. In some errUDodiments, the retainer has at least one projection as well as at least one opening, for engaging at least one corresponding opening in, and at least one corresponding projection on, the tube.

In some embodiments, the retaining structure comprises more than one projection and more than one corresponding opening. In other embodiments, the retaining structure comprises more than one projection and a single opening receiving the multiple projections.

A first and a second projection may each be upstanding on the surface of the retainer that is for contacting the tube.

In some embodiments, the retainer has a tail that extends from the arch for engaging the screw clamp at an additional location, e.g., the tail is engageable with the screw clamp band. In other embodiments, the tail, which is for engaging the screw clamp at an additional location, e.g. the screw clamp band, extends from another part of the retainer, e.g. from the base of the retainer. In some embodiments, the tail supports a part of the retaining structure, i.e. it comprises at least one projection or at least one opening for engaging at least one corresponding projection or opening in the tube.

The tube may have an opening that extends all the way through the tube wall. Alternatively the opening may extend into the tube wall, but not all the way through it. In yet further embodiments, the tube has a projection and the retainer has a notch or aperture, complementary to the tube's projection, for anchoring the retainer onto the tube. The projection or opening may be located near the end of the tube. When an opening is located at the end of the tube, it is termed a notch. In some embodiments, the projection or opening may be located distal from the end of the tube.

In most embodiments, the retainer is engaged with the screw clamp via an arch that engages the drive unit of the screw clamp.

Typically, a retainer having an arch also has an anchor or projection extending from the surface of the retainer that makes contact with the outside of the tube. The arch may extend in an opposite direction to the anchor or projection.

Preferably, the retainer has a base comprising a surface for contacting the outside of a tube, the retainer also having an arch upstanding from the base. Typically, the retaining structure is present on the tube-contacting surface of the base. Preferably, the retaining structure is a projection. The projection may extend radially in towards the centre of the tube, in use. Hence, the projection is not substantially coplanar with the tube-contacting surface. Preferably, the projection is upstanding on (i.e. substantially perpendicular to) the tube-contacting surface. In some embodiments, the projection is perpendicular to the tube-contacting surface. The projection is adapted to engage an opening in the tube, allowing the retainer to assume a fixed position on the tube.

In most embodiments, the arch is adapted to abut the drive unit of a screw clamp. In some embodiments, the arch has a protrusion, or protruding thumb, for engaging the screw clamp drive unit.

Optionally, the protrusion or protruding thumb fits into a recess in the drive unit e.g., in its casing. In some embodiments, the arch has more than one protrusion for abutting the screw clamp drive unit.

In most embodiments, the screw clamp band is able to pass through (e.g. under) the arch. This allows the end of the band that is not fixed to the drive unit to loop around a tube and feed through the arch and into the drive unit, allowing the size of the loop to be varied to tighten or loosen the band around the tube.

In some embodiments, the base has two sections, with a space between them, which are connected by the arch. The two sections of the base may each have a separate tube-contacting surface. Preferably the end of the screw clamp band that is not fixed to the drive unit is able to pass between the two sections of the base. Optionally, the two sections of the base are elongate. Elongate base sections provide a large tube-contacting surface. In some embodiments, adhesive, e.g. isocyonate glue, is applied to the tube-contacting surface of the base. In some embodiments, only one base section has a projection extending from its tube-contacting surface. In other embodiments, both base sections have projections. Typically, where multiple projections are present, the tube will have multiple corresponding openings.

In some embodiments, the arch has a back-plate for abutting the screw clamp drive unit. The back-plate may have a protrusion, or protruding thumb, for abutting the screw clamp drive unit. In some embodiments, the arch is elongate, extending orthogonally to the arch cross-section. This enables the arch to substantially cover the screw clamp drive unit held by the retainer, in use. The end of the elongate arch, distal to the back-plate, may comprise a second protrusion, or protruding finger, for engaging the screw clamp drive unit. For example, the second protrusion or protruding finger may be used to hook onto the casing of the drive unit. Preferably, the thumb and finger hold the screw clamp drive unit in place.

Typically, the screw clamp drive unit can be snapped' into place between the protruding thumb and finger. Preferably, the protruding thumb and finger are adapted to allow the screw clamp drive unit to be rotated to disengage the drive unit from the thumb and finger to remove the drive unit from their grip.

In some embodiments, the retainer has a locating strap, for holding the screw clamp drive unit against the arch of the retainer.

Tension in the strap maintains contact between the screw clamp drive unit and the arch. Preferably, the locating strap forms a loop, extending from the base. One end of the locating strap loop may be attached to one section of the base, with the other end of the locating strap loop being attached to a second section of the base.

The locating strap may be made of resilient plastics. The plastics strap may have flexible corners that can be pushed towards each other to extend the distance between the retainer base and the distal end of the strap. Allowing the corners to return to their neutral position tends to move the distal end of the strap back towards the base of the retainer. When a screw clamp drive unit is placed on the strap in its extended configuration, the drive unit is then pressed and held against the arch of the retainer by the returning distal end of the strap when the flexible corners are released.

The retainer can be made of metal or plastic, e.g. colour polymer.

A tube having an opening for receiving the anchor may be provided with the retainer. In some embodiments, the tube is provided with the retainer is mounted on the tube, with the tube and retainer engaged by a retaining structure having a projection and a corresponding opening. The opening may extend all the way through the tube wall. Alternatively, the opening may extend only part way from the outside of the tube into the tube wall. In some embodiments of the invention, complete apparatus are provided, including a retainer as described herein, a tube with a notch, and a screw clamp. The apparatus can be provided separately as a kit of parts or, alternatively engaged as an assembly.

Examples of the present invention will now bedescribed, by way of example only, with reference to the accompanying drawings, in which: Fig. 1A shows a retainer, which is an embodiment of the invention, anchored on a tube having a notch. The retainer is holding the drive unit of a screw clamp; Fig. 13 shows the retainer shown in Fig. 1A, with the tube and screw clamp removed; Fig. 2A shows a second retainer, which is an embodiment of the invention, anchored on a tube with a notch, and holding the drive unit of a screw clamp; Fig. 23 shows the retainer shown in Fig. 2A, with the tube and screw clamp removed; Fig. SA shows an axial end-view of a tube with the retainer shown in Fig. íA, anchored on a tube with a notch. The retainer is shown holding the drive unit of a screw clamp; Fig. 33 shows a side-view, a front-view, a plan-view and a perspective-view of the retainer shown in Fig. 1A;

II

Fig. 4 shows an axial end-view of a tube with a retainer similar to that shown in Fig. 1A and Fig. 3A, anchored on a notch in the tube.

The retainer is shown holding the drive unit of a screw clamp; Fig. 5A shows another embodiment of a retainer, mounted on a tube, with both the retainer and the tube having notches; Fig. SB is another view of the arrangement of Fig. 5A; Fig. SC shows the embodiment of Figs. 5A and SB, together with an assembly fixture; and Fig. SD corresponds to Fig. 5, but with part of the assembly fixture removed; Fig. SE shows a detail views of the retainer of the embodiment of Figs. 5A to SC.

In the drawings, like parts are denoted by like reference numerals.

Fig. 1A shows a retainer la, which is an embodiment of the invention, anchored on a tube 6. The retainer la has a base 2, an upstanding arch 7 and an anchor 3. The base 2 has a lower surface that is in contact with the outer surface of the tube 6. The arch is upstanding from the top of the base. The anchor 3 extends from the lower surface 20 of the base. The anchor 3 stands perpendicular to the lower surface 20 of the base, extending radially in towards the central axis of the tube. The tube has a notch 4, which accommodates the anchor 3. The retainer can be positioned on the tube by placing the anchor 3 into the notch 4.

The cross-sectional dimensions of the anchor and the notch are closely matched so that the anchor 3 sits flush in the notch 4.

By placing the anchor 3 in the notch 4, the retainer is prevented from moving circumferentially with respect to the tube 6 and movement of the retainer axially along the tube is resisted. Fig. 1A shows the screw clamp 15 assembled with the retainer so the screw clamp is thus also prevented from moving circumferentially or laterally with respect to the tube 6 during tightening and subsequently during normal use.

The retainer la retains the screw clamp 15 by holding the drive unit 11. The band 5 of the screw clamp 15 is tightened around the tube 6 by rotating the captive screw 16. The drive unit 11 can be placed in the retainer la before the retainer is positioned on the tube.

Alternatively, the drive unit 11 can be placed in the retainer la after the retainer is positioned on the tube.

Fig. lB shows the retainer la before it is assembled with the tube and screw clamp. Fig. lB shows that the base comprises two sections 2a and 2b, which are joined by the arch 7. In this embodiment, the retainer ía has a single anchor only, extending from the lower surface 20 of one base section (2a) . In other embodiments, each base section may have one (or more) anchors, although this would necessitate multiple openings to be present in the tube.

A space 17 exists below the arch 7 and between base sections 2a and 2b. The band of the screw clamp passes through this space 17 when assembled.

The retainer la has a locating strap 8 and a thumb 13 protruding from the arch 7, for holding a screw clamp in the retainer la.

Engagement of the drive unit with the retainer is described in more detail below, with reference to Fig. 3.

Fig. 2A shows another retainer ib, which is an embodiment of the invention, assembled with a tube 6 and screw clamp 15, before the band 5 is tightened. Like the retainer la shown in Fig. 1 and Fig. 3, the retainer lb in Fig. 2A has an anchor 3, which protrudes into a notch 4 of the tube 6, anchoring it in place. The retainer-screw clamp assembly is thus prevented from moving circumferentially or axially along the tube 6 during tightening and subsequently during normal use.

The arch 7 of the retainer lb substantially covers the top of the screw clamp 15.

Fig. 23 shows the under-side of the retainer lb, without a tube or screw clamp present. Like the retainer la shown in Fig. 1 and Fig. 3, the base of the retainer lb is split into two sections, 2a and 2b, which each have a lower surface 20. The anchor 3 extends perpendicularly from the lower surface 20 of base section 2a.

Base sections 2a and 2b are joined by the arch 7, which has a back-plate 19. Like retainer la, a space 17 exists below the back-plate 19 and between base sections 2a and 2b. The band of the screw clamp passes through this space 17 when assembled.

A thumb 13 is mounted on the back-plate 19 of the retainer lb. Retainer lb also has a finger 18 extending down from the front of the arch 7. A screw clamp drive unit is secured into retainer lb by firstly locating a recess in rear part of the drive unit's casing onto the thumb 13. secondly, the finger 18 is hooked onto a front part of the drive unit's casing. This ensures that the drive unit remains correctly located before and during tightening of the screw clamp.

The precise location and orientation of finger 18 and thumb 13 are chosen to optimally grip a specific screw clamp model.

The retainers depicted in the figures are illustrative, non-limiting embodiments of the invention only. The skilled person will understand that other means for holding the drive unit of a screw clamp, e.g. with clips or pegs, could also be used.

Fig. 3A shows a retainer la, anchored on a tube 6 and holding a screw clamp 15, viewed axially along the tube. The retainer la has a base 2 with a lower surface 20, which makes contact with the outside of the tube 6. The retainer la has an arch 7, which is upstanding from the base 2. The anchor 3 extends into the notch 4 of the tube 6, from the lower surface of the base 20.

The retainer la also has a locating strap 8, extending in a loop from the base. The locating strap 8 is substantially coplanar with the lower surface of the base 20. The locating strap S can also be seen in Fig. 3B. The locating strap S supports the drive unit 11 of the screw clamp 15, and tension in the locating strap 8 pulls the drive unit 11 towards the arch 7, holding the drive unit 11 in place. This ensures that the drive unit remains correctly located on the retainer la before and during tightening of the band 5. The end 9 of the band 5 sits upon the locating strap 8 after screw clamp tightening.

Fig. 3B shows the retainer la, also depicted in Fig. 1 and Fig. 3A, from different angles, with the tube and screw clamp removed.

The locating strap 8 is made of resilient plastic and it is has two flexible corners 12, which can be pressed towards each other by the user. Pressing the flexible corners 12 towards each other causes the distal end 10 of the locating strap S to move away from the arch 7. This causes the space 14 within the loop of the locating strap S to extend to encompass a larger area 14a. The drive unit of the screw clamp is placed into the larger area 14a within the extended locating strap 8, and then the flexible corners 12 are released, allowing the distal end 10 of the locating strap S to return towards the arch 7. However, the distal end 10 of the locating strap 8 engages the casing of the drive unit, pressing it into the thumb 13, holding the drive unit in place.

The base of the retainer la is split into sections 2a and 2b, which extend out from the arch 7, providing an extended surface upon which, optionally, adhesive can be applied to provide yet further stability of the retainer la on a tube.

Fig. 4 shows a retainer la, having the same parts as the retainer shown in Fig. 1A, 1B, 3A and 3E, mounted on a notch 4 in a tube 6.

Additionally, the retainer la of Fig. 4 has a tail 21, which extends from the arch 7 to engage the band 5. In other embodiments, the tail 21 also has an anchor for engaging an opening in the tube.

A further embodiment of the present invention will now be described with reference to Figs. 5A to SE. This embodiment is similar to the ones described previously, and corresponding parts will be indicated by the same reference numerals. However, this embodiment differs from those described previously in that both the retainer and the tube have notches therein, and there is a further element, in the form of an assembly fixture which links together the retainer and the tube during assembly.

Thus, in Fig. 5A, which is an axial view similar to that of Fig. 3A, the retainer lA has a notch 24 therein, which is aligned with notch 4 in tube 6. The linking together of those notches 4, 24 will be described in detail later.

Fig. 5A and also the orthogonal view of Fig. SB, shows that the retainer la has a second arch 23 connected to the first arch 7 by a linkage formed by a flexible strip of material 21. That strip of material 21 can be used as a handle to stretch the locating strap 8 of the retainer la onto the screw clamp 15. The second arch 23 bridges the strap of the screw clamp 5 at base 22, e.g. by the use of an adhesive. This prevents the screw clamp 15 from moving circumferentially or laterally with respect to the tube 6 during tightening and subsequently during normal use. Note that, during such normal use, the retainer la and hence the screw clamp 5 are in the correct position, due to the earlier alignment of the notches 4 and 24.

As mentioned previously, the notches 4 and 24 in the tube 6 and retainer la respectively are connected together by a projection. As illustrated in Fig. SC, this projection is on an assembly fixture which has a back plate 25 and a spigot 26 which fits into the tube 6. The back plate 25 and spigot 26 prevent the tube 6 from deforming when the screw clamp is fitted on the tube 6.

As can be seen in Fig. SC, a pin 27 projects from the spigot 26, which pin 27 extends through both the notch 4 and the notch 24, thereby securing those notches together and preventing relative movement of the retainer la on the tube 6. The pin 27 can be seen in more detail in Fig. 3D, in which figure part of the back plate 25 is removed for clarity. It may also be noted that axial ends of the arches 7, 23 may abut against the back plate 25, to further resist relative movement of the retainer la and the tube 6.

Note that the assembly fixture will be removed when the screw clamp is correctly fitted. The screw clamp may then be held in place by adhesive.

Fig. SF shows in more detail the retainer of Figs. 5A to 5C. It can be seen from that figure that the first arch 7 terminates in two base sections 2a and 2b of the base 2, each of which may be connected to a surface on the tube by use of adhesive. Each base element 2a and 2b contains a notch 24a and 24b. In the orientation shown in Figs. 5A and SB, it is the notch 24a which is linked to the notch 4 by a projection. However, if it is desirable to fit the screw clamp 15 in the opposite orientation, so that the captive screw 16 is on the right-hand end of the drive unit 11, reversely the orientation shown in Fig. 5A, then the notch 24b can be positioned to align with the notch 4. Thus, the retainer la of Fig. 3D can be used in a left-handed or right-handed orientation.

It can be seen that notches 24a and 24b are not centrally based on elements 2a and 2b, which allows for a larger continuous area for adhesive application.

Fig. SE also shows that the base 22 of the second arch 23 is divided into base parts 22a and 22b which are attached to the tube e.g. by a adhesive.

The embodiment of Figs. 5A to SE has been described for an assembly in which there are notches on both the retainer and the tube, held together by a projection on a further element during fitting. It can readily be seen that the retainer of Fig SE may be used in an embodiment in which there is a projection on the tube, which engages notches 24a or 24b, so that the retainer will be held in place by the engagement of the notch and the projection even after fitting has been completed.

Claims

Claims 1. An assembly comprising a tube; a screw clamp having a band extending in a locp around the tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube; and a retainer engaging the screw clamp to retain the screw clamp on the tube, wherein the tube and retainer are engaged by a retaining structure having at least one projection and at least one corresponding opening into which the at least one projection is received, to resist relative movement of the retainer on the tube.
2. An assembly according to claim 1, wherein the or each projection is on the retainer and the or each opening is in the tube.
3. An assembly according to claim 2, wherein the or each opening is a notch at the end of the tube.
4. An assembly according to claim 2 or claim 3, wherein the or each projection is upstanding on a surface of the retainer that is in contact with the tube.
5. An assembly acccrding to claim 1, having two of said corresponding openings, one in the tube and one in the retainer, wherein the assembly comprises a further element having said at least one projection thereon.
6. An assembly according to claim 5, wherein said further element is an assembly fixture.
7. An assembly according to any one of claims 1-6, wherein the retainer has an arch that extends in the opposite direction from the or each projection, wherein the arch engages the drive unit.
8. An assembly according to claim 7, wherein the arch has a thumb that engages a recess in the drive unit.
9. An assembly according to claim 6 or claim 7, wherein the as each arch is elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit.
10. An assembly according to any one of claims 7 to 9, wherein the arch is adjacent the drive unit.
11. An assemble according to claim 10, wherein the retainer has a further arch connected to said arch by a flexible linkage.
12. An assembly according to any one of claims 7 to 11, wherein the retainer has a tail that extends from the arch, wherein the tail engages the screw clamp band.
13. An assembly according to claim 8, wherein the tail supports a part of the retaining structure.
14. An assembly according to any one of the previous claims, wherein said at least one projection comprises a plurality of projections.
15. Mi assembly according to any one of the preceding claims, wherein the retainer has a locating member which holds the drive unit against the arch.
16. Mi assembly according to claim 15, wherein the locating member is a looped strap.
17. A kit of parts comprising a tube; a screw clamp having a band for extending in a loop around the tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube; and a retainer for engaging the screw clamp to retain the screw clamp on the tube, wherein the tube and retainer are engageable by a retaining structure having at least one projection and at least one corresponding opening into which the at least one projection can be received, to resist relative movement of the retainer on the tube.
18. A kit of parts comprising a tube; and a retainer for engaging a screw clamp having a band for extending in a loop around the tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube, to retain the screw clamp on the tube, wherein the tube and retainer are engageable by a retaining structure having at least one projection and at least one corresponding opening into which the at least one projection can be received, to resist relative movement of the retainer on the tube.
19. A kit of parts according to claim 17 or claim 18, wherein the or eaoh projection is on the retainer and the or each opening is in the tube.
20. A kit of parts acoording to claim 19, wherein the or each opening is a notch at the end of the tube.
21. A kit of parts according to claim 19 or claim 20, wherein the or each projection is upstanding on a surface of the retainer that is for contacting the tube.
22. A kit of parts according to claim 17 and claim 18, further comprising a further element having said at least one projection thereon, and there are two of said corresponding openings, one in the tube and one in the retainer.
23. A kit of parts according to claim 22, wherein said further element is an assembly fixture.
24. A kit of parts according to any one of claims 17 to 23, wherein the retainer has an arch for engaging the drive unit, the arch extending in the opposite direction from the or each proj ection.
25. A kit of parts according to claim 24, wherein the arch has a thumb for engaging a recess in the drive unit.
26. A kit of parts according to claim 25 or claim 19, wherein the arch is elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit, in use.
27. A kit of parts according to any one of claims 24 to 26, wherein the arch is adjacent the drive unit.
28. A kit of parts according to claim 27, wherein the retainer has a further arch connected to said arch by a flexible linkage.
29. A kit of parts according to any one of claims 24 to 28, wherein the retainer has a locating member for holding the drive unit against the arch.
30. A kit of parts according claim 29, wherein the locating member is a looped strap.
31. A retainer for engaging a screw clamp having a band for extending in a loop around a tube, and a drive unit for varying the size of the loop so as to cause the tube to be clamped to a nozzle within the tube, the retainer comprising a base having a first surface for contacting an outer surface of the tube; and a retaining structure comprising at least one projection or at least one opening, wherein the or each projection or opening is situated on the first surface, wherein the retaining structure is arranged to engage a tube having a corresponding projection or opening to resist relative movement of the retainer on the tube.
32. A retainer according to claim 31, wherein the retaining structure comprises at least one projection.
33. A retainer according to claim 24, wherein the or each projection is upstanding on the first surface of the retainer.
34. A retainer for engaging a screw clamp having a band for extending in a ioop around a tube, and a drive unit for varying the size of the ioop so as to cause the tube to be clamped to a nozzle within the tube, the retainer comprising a base having a first surface for contacting an outer surface of the tube; and a retaining structure comprising at least one opening, wherein the opening is situated in the first surface, wherein the retaining structure is arranged to engage a projection which is also arranged to engage a corresponding opening on the tube to resist relative movement of the retainer and the tube.
35. A retainer according to any one of claims 31 to 34, wherein the retainer has an arch for engaging the drive unit, the arch extending in the opposite direction from the proj ection.
36. A retainer according to claim 35, wherein the base comprises a first section and a second section and a separation therebetween, the first and second sections being connected by the arch.
37. A retainer according to claim 36, wherein the arch has a thumb for engaging a recess in the drive unit.
38. A retainer according to claim 30 or claim 37, wherein the arch is elongate orthogonal to a cross-section of an opening beneath the arch, such that the arch substantially covers the drive unit, in use.
39. A retainer according to any one of claims 35 to 38, wherein the arch is adjacent the drive unit.
40. A retainer according to claim 39, wherein the retainer has a further arch connected to said arch by a flexible linkage.
41. A retainer according to any one of claims 35 to 40, wherein the retainer has a locating member for holding the drive unit against the arch.
42. A retainer according to claim 41, wherein the locating member is a looped strap.
43. A retainer according to claim 42, wherein the looped strap has one end that is attached to the first section of the base, and another end that is attached to the second section of the base.
44. A retainer according to claim 42 or 43, wherein the looped strap has opposing flexible corners that can be pressed towards each other to increase the extension of the looped strap from the base.
45. A kit of parts according to any one of claims 24 to 30, or a retainer according to any one of claims 35 to 44, wherein the retainer has a tail that extends from the arch, wherein the tail is engageable with the screw clamp band.
46. A kit of parts or a retainer according to claim 45, wherein the tail supports a part of the retaining structure.
47. An assembly substantially as herein described with reference to and as illustrated in Fig. 1 or Figs. 2 and 3 or Fig. 4 or Fig. 5 of the accompanying drawings.
48. A kit of parts substantially as herein described with reference to and as illustrated in Fig. 1 or Figs. 2 and 3 or Fig. 4 or Fig. 5 of the accompanying drawings.
49. A retainer substantially as herein described with reference to and as illustrated in Fig. 1 or Figs. 2 and 3 or Fig. 4 or Fig. 5 of the accompanying drawings.