GB2248665A

GB2248665A - Tube clamping device

Info

Publication number: GB2248665A
Application number: GB9022244A
Authority: GB
Inventors: Didier Bergougnoux
Original assignee: Draftex Industries Ltd
Current assignee: Laird Holdings Ltd
Priority date: 1990-10-12
Filing date: 1990-10-12
Publication date: 1992-04-15
Also published as: GB9022244D0

Abstract

A clamping device for clamping a hose 1 to a pipe (2) comprises a ring-like member 11 made from a deformable thermoplastics or elastomeric material housed in a cavity 18 defined by the walls 14, 15, 16, 17 of a pair of axially displaceable clamping elements (12, 13). The clamping elements deform member 11 axially causing it to exert a radial clamping force on the hose. <IMAGE>

Description

CLAMPING DEVICE The invention relates to a clamping device for clamping a tube to a shaft, and the invention relates particularly, though not exclusively, to a clamping device for clamping a hose to a pipe, to provide a conduit for a fluid.

The invention also relates to a method of clamping a tube to a shaft.

Clamping devices are used extensively in the automobile industry. For example, they are used to attach hoses to the radiators and/or engines of vehicles and they are also used to fix in place protective bellows provided around the universal joints in the transmission systems of vehicles.

It has been customary to clamp a hose to a pipe by tightening a clamping collar, in the form of a metal wire or band, around the hose. The extent to which the collar needs to be tightened to ensure a reliable, fluid-tight seal during the service life of the clamped parts depends on the degree to which the material of the hose will deform due to ageing, and this may be difficult to assess.

Clamping collars of this kind have a number of short-comings.

In practice, the metal band or wire does not conform to a perfect circle and so it is difficult to apply a uniform clamping pressure around the entire circumference of the hose, and this can result in a defective seal.

Furthermore, the collar must be fitted manually and this is a serious drawback, especially in the automobile industry where there is a need to carry out as many assembly operations as possible in automated assembly lines, using robots or automated handlers.

Also, collars that are fitted manually may be positioned incorrectly from time-to-time. Such defects would normally be discovered during the final assembly stages and the necessary adjustments are both time consuming and expensive.

A clamping collar of the kind described can only be secured to a hose after the hose has been fitted to a pipe. The collars and hoses must, therefore, be stored as separate items and so careful stock control is needed, and this can be problematical.

According to the invention there is provided a clamping device for clamping a tube to a shaft, comprising a body of deformable material disposed, in use, around the tube fitted to the shaft, and means for so deforming the body of deformable material as to cause the body to exert a radial clamping force on the tube.

A clamping device as defined is capable of applying a more uniform clamping force than has hitherto been possible, giving a more reliable seal between the clamped parts.

A clamping device in accordance with the invention is now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a longitudinal, sectional view through the clamping device; Figure 2 shows part of the clamping device of Figure 1 on an enlarged scale; Figure 3 shows a side view of a clamping element of the clamping device; and Figure 4 shows an end view of the clamping element.

Referring to Figure 1, the clamping device is shown generally at 10.

The clamping device is positioned around one end of a hose 1, fitted to a pipe 2, and serves to clamp the hose against the pipe to form a fluid-tight seal.

The clamping device comprises a ring-like member 11 made from a deformable material, such as an elastomeric or a thermoplastics material, and a pair of inter-fitting clamping elements 12,13.

The clamping elements 12,13 are arranged coaxially and each element has a cylindrical side wall 14,15 and an end wall 16,17. In the assembled condition, the clamping elements define an annular cavity 18 in which the ring-like member 11 is housed.

Wall 15 is a close fit within wall 14 and the relative axial positions of the clamping elements can be so adjusted as to deform the ring-like member 11 by compressing the member in the longitudinal, axial direction (as indicated by arrows A in Figure 1) causing the member to exert a radial clamping force on the hose (as indicated by arrows R in Figure 1).

As is shown more clearly in Figure 2, the inner surface of wall 14 and the outer surface of wall 15 have interengageable formations that enable the clamping elements to be locked together in desired axial positions.

In the illustrated embodiment, the inter-engageable formations comprise a plurality of barbs 19 which project from the inner surface of wall 14 and slope towards the end wall 16 and a plurality of complimentarily-shaped recesses 20 formed in the outer surface of wall 15.

The clamping elements 12,13 are conveniently made from a plastics material allowing the barbs and recesses to be formed directly by moulding.

The barbs and recesses may be distributed uniformly over the respective surfaces of walls 14 and 15.

Alternatively, the barbs and recesses may be provided at discrete intervals around the circumference of the walls, as illustrated in Figure 3. This arrangement enables the clamping elements to be released from their inter-locked condition. This is achieved by rotating one of the clamping elements with respect to the other until the barbs 19 disengage the recesses 20.

The clamping elements can then be moved apart axially allowing the ring-like member 11 to adopt its original, undeformed shape and so removing the radial clamping force from the hose. The hose can then be detached from the pipe.

If desired, the clamping device could be used again.

As illustrated in Figure 4, the clamping elements are formed with flat surfaces 21 at their respective ends.

These surfaces enable the clamping elements to be gripped by a suitable tool in order to facilitate their relative rotation.

In use, the ring-like member 11 is initially located in the annular recess 18 defined by the side and end walls of clamping elements 12,13. The clamping device, thus assembled, may then be placed around one end of a hose.

The ring-like member 11 exerts a small clamping force on the hose which serves to retain the clamping device on the hose. The hose and the attached clamping device may, therefore, be stored, as a single item, until they are needed on the assembly line. The hose is then fitted to a pipe, as required, and the clamping elements 12,13 are drawn together, using a suitable clamping tool, to exert a desired radial clamping force on the hose.

Because the hose and the clamping device can be stored in an assembled condition, as a single item, stock control is made easier.

It will be apparent that a clamping device, as described, enables a radial clamping force to be applied to and, if desired, removed from, a hose more quickly then has hitherto been possible, and is well suited for use in automated assembly lines using robots and/or automated handlers. Furthermore, the clamping device applies a more uniform clamping pressure giving a more reliable seal between the clamped parts.

It will be understood that the clamping device can be used to clamp other component parts. For example, the clamping device may be used to clamp the mounting tube of a protective bellows, used in the transmission system of a vehicle, to an anchorage post.

Claims

1. A clamping device for clamping a tube to a shaft, comprising a body of deformable material disposed, in use, around the tube fitted to the shaft, and means for so deforming the body of deformable material as to cause the body to exert a radial clamping force on the tube.

2. A clamping device as claimed in claim 1, wherein the deformable material is a thermoplastics or an elastomeric material.

3. A clamping device as claimed in claim 1 or claim 2, wherein the deforming means produces an axial deformation of the body.

4. A clamping device as claimed in claim 3, wherein the deforming means comprises first and second clamping elements arranged to define an annular cavity around the tube in which the body of deformable material is housed, and the first and second clamping elements can undergo relative axial displacement to produce said axial deformation of the body.

5. A clamping device as claimed in claim 3, wherein respective surfaces of the clamping elements have inter engageable formations enabling the clamping elements to be locked together in selected axial positions.

6. A clamping device as claimed in claim 5, wherein the first and second clamping elements have coaxial cylindrical walls and the inter-engageable formations are provided on opposed surfaces of the cylindrical walls.

7. A clamping device as claimed in claim 6, wherein the inter-enageable formations comprise a plurality of barbs on the surface of one of the cylindrical walls and a plurality of complementarily-shaped recesses provided on the surface of the other of the cylindrical walls.

8. A clamping device as claimed in claim 6 or claim 7, wherein the first and second clamping elements are releasable from the inter-locked condition.

9. A clamping device as claimed in claim 8, wherein the inter-enageable formations are provided at discrete intervals around the circumference of the walls whereby the clamping elements can undergo relative rotation to cause their release from the inter-locked condition.

10. A clamping device as claimed in claim 9, wherein the first and second clamping elements are formed with flat surfaces enabling the elements to be gripped by a tool to facilitate their relative rotation.

11. A method of clamping a tube to a shaft comprising positioning a body of deformable material around the tube and so deforming the body of deformable material as to cause the body to exert a radial clamping force on the tube.

12. A method as claimed in claim 11, wherein the body of deformable material is deformed axially.

13. A method as claimed in claim 11 or claim 12, wherein the body of deformable material is attached to the tube before the tube is fitted to the shaft.

14. A clamping device substantially as herein described with reference to the accompanying drawings.

15. A method of clamping a tube to a shaft substantially as herein described with reference to the accompanying drawings.