GB2248664A

GB2248664A - Quick-assembly hose clamping device

Info

Publication number: GB2248664A
Application number: GB9022243A
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: GB9022243D0

Abstract

A device is described for clamping a tubular member (14) to a connector (10) in which the tubular member (14) is held between a first inclined surface (22) provided by the connector (10) and a second inclined surface (32) provided by a collar (26), the inclined surfaces (22, 32) being urged against each other by resilient means (38) thereby clamping the tubular member (14) to the connector (10). <IMAGE>

Description

OUICK-ASSEMBLY CLAMPING DEVICE The present invention relates to a clamping device for securing a tubular member to a connector and to a method of assembly that ensures that the connection is rapidly and reliably achieved. In particular the clamping device and method of assembly of the present invention may be used in the automobile industry for securing the appropriate hoses to the connectors of an engine housing or radiator of a vehicle for the passage of fluids.

Devices are already known for securing a vehicle hose to a connector in which the sealing between the hose and the connector is ensured by means of a clamping collar. The clamping collar is generally provided with a metal strip or wire attached to the hose after the hose has been positioned on the connector, which is then tightened in such a manner as to take into account the subsequent deformation of the material of the hose as a result of ageing so as to provide a residual pressure sufficient to ensure the necessary seal during the service life of the hose.

The clamping collars of the prior art, however, suffer from problems such as their inability to provide a uniform pressure on the hose which occasionally leads to insufficient sealing. Another drawback to the vehicle manufacturer is the requirement for a method of stock control which must take into account not only the individual hoses but also the associated collars and their constituent parts. Furthermore, since each of the prior art constructions necessitates manual assembly, the possibility exists of a poor seal being caused as a result of the defective positioning of the collar. Indeed when checks are made at the end of the assembly line poor seals are sometimes discovered for this reason which then require lengthy and costly adjustment to repair the fault.The situation is no better for those manufacturers who seek to automate the assembly line wherever possible as the clamping collars of the prior art are not designed for fitting with the aid of robots.

The present invention seeks to overcome these problems.

According to a first aspect of the present invention, there is provided a device for clamping a tubular member of at least slightly flexible material to a relatively rigid surface inserted in and engaged by the material of the tubular member wherein the tubular member is held between a first inclined surface portion provided by the relatively rigid surface and a second inclined surface portion provided by a collar, said inclined surface portions being urged towards each other by resilient means thereby clamping the tubular member to the relatively rigid surface.

According to a second aspect of the present invention there is provided a device for clamping a vehicle hose to a connector provided on an engine housing or a radiator of a vehicle wherein said connector is provided with a projection of substantially circular cross-section for insertion within a bore of the vehicle hose, said vehicle hose being clamped between said external surface portion of the projection and a surface portion of a collar coaxial with the projection and urged thereagainst by means of a similarly coaxial spring.

According to a third aspect of the present invention, there is provided a method of clamping a tubular member of slightly flexible material to a relatively rigid surface inserted in and engaged by the material of the tubular member, comprising the steps of squeezing the flexible material between a first inclined surface portion of the relatively rigid surface and a second inclined surface portion on a collar which is coaxial with the relatively rigid surface and slidable over the outside of the tubular member under the bias of resilient means.

Two clamping devices embodying the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of one of the clamping devices; and Figure 2 is a cross-sectional view of the second clamping device.

Figure 1 shows a connector 10, such as that found on an engine housing or radiator of a vehicle, having a tubular projection 12 of circular cross-section to which may be connected a hose 14 by inserting the tubular projection 12 into the bore 16 of the hose 14. The tubular projection 12 has a central bore 18 therethrough for communication with the interior of the engine housing or radiator thereby permitting the passage of fluids into and from the hose 14.

The tubular projection 12 is also provided with a swelling 20 on the external surface of the projection at the end remote from the engine housing or radiator comprising oppositely inclined surfaces 22 and 24. The surface 22, facing the engine housing or radiator, is of frusto-conical section having a conic angle of between 100 and 500 and a length of between 5mm and 10mum depending on the hose to be connected. Surface 24, facing away from the engine housing or radiator, is smoothly tapered and is designed to facilitate the insertion of the tubular projection 12 within the bore 16 of the hose 14.

As a result, when the hose 14 is connected to the connector 10 the tubular projection 12 may penetrate fully into the bore 16, thereby forming the basis of a fluid-tight seal.

This fluid-tight seal between the connector 10 and hose 14 is ensured by means of a clamping collar 26 of metallic or thermoplastics material coaxial with both the tubular projection 12 and the hose 14. The inner diameter of the collar 26 at an end 28 remote from the engine housing or radiator is such as to be slightly greater than the outer diameter of the hose 14 in the plane of the maximum diameter of the swelling 20. At a second point 30 along the length of the collar 26, the inner diameter of the collar 26 is slightly greater than the diameter of the hose 14 when connected to the connector 10. Between this second point 30 and the end 28, the inner diameter of the collar 26 varies in such a way as to provide an inner surface 32 of frusto-conical section having the same conic angle and length as that of surface 22.Beyond point 30 toward the end of the collar 26 facing the engine housing or radiator, the collar 26 has a much larger inner diameter of constant value forming an annular space 34 coaxial with the tubular projection 12 and hose 14 and ending at point 30 in a shoulder 36 perpendicular to the axis of bores 16 and 18.

Within the annular space 34 is housed a spring 38 one end of which abuts shoulder 36 and the other end of which abuts a surface 40 parallel to shoulder 36 provided on the connector 10. Spring 38 biases the collar 26 away from the engine housing or radiator. The spring 38 provides a constant and uniform force and has the effect of urging the frusto-conical surface 32 of the collar 26 toward the frustro-conical surface 22 of the cylindrical projection 12 clamping the hose 14 therebetween and ensuring the integrity of the seal between the connector 10 and the hose 14 and preventing accidental disconnection.

Since the spring 38 provides a constant axial force which is converted at the frusto-conical surfaces 32 and 22 to a constant radial clamping force irrespective of the hardness of the hose, it will be appreciated that the device provides a clamping action which is continually and automatically modified in use to compensate for creep of the elastomeric or thermoplastics material from which the hose 14 is formed as a result of, for example, the heating of the connector 10 and hose 14 due to the passage of hot fluid through bores 16 and 18. Such creep or other changes in the material of the hose 14 do not therefore significantly affect the clamping efficiency.

Furthermore, the device provides an efficient means of sealing which neither damages the hose 14 nor deteriorates with time even if the hose 14 itself should deform as a result of ageing. Should the hose 14 need replacing, for this or any other reason, the device permits the removal of the worn hose and the connection of a fresh hose without requiring the replacement of the clamping device itself.

In addition the illustrated embodiment is able to absorb defects in the eccentricity of the hose 14 and permits the use of hoses having dimensions with wider tolerances than would be possible with the clamping devices of the prior art.

In use the clamping device shown in Figuure 1 may be employed to connect a hose 14 to a connector 10 by either manual assembly or as part of an automated sequence performed by a robot. In either case the collar 26 is initially moved toward the engine housing or radiator against the compression of the spring 38. The end of a hose 14 is presented to the cylindrical projection 12 in such a way that the projection 12 penetrates the bore 16 of the hose 14 to a depth substantially equal to its length assisted by the smoothly tapering surface 24.

Thereafter the collar 26 is released and the action of spring 38 ensures that the hose 14 is clamped between the frusto-conical surfaces 32 and 22 of the collar 26 and the projection 12 respectively.

In the device of Figure 2, parts similar to those in Figure 1 have the same references. In Figure 2, the collar 26 is premounted and associated with the hose 14.

In this device, the collar 26 is provided with a concentric multi-element locking arrangement 42 slidable between end stops 44 and 46 for respectively locking and releasing the collar 26 for movement along the hose 14.

When the locking arrangement 42 is slid towards the end stop 44, it presses the corresponding end of the collar 26 into tight locking contact with the hose 14, such locking contact being released when the arrangement 42 is slid in the opposite direction. In other respects this device is similar to the device of Figure 1, except that it is desirable that an end of spring 38 is rigidly secured to shoulder 36 of the collar 26 by either clamping, glueing or screwing, or by moulding if the collar 26 is of thermoplastics material, in order to facilitate assembly.

In use the device of Figure 2 may again be assembled either manually or with the aid of a robot in the following sequence. Firstly, the hose 14 and collar 26 are offered to the cylindrical projection 12 of the connector 10. The multi-element locking arrangement 42 is then slid toward end stop 46 to release the collar 26 on the hose 14 and the collar 26 moved so as to compress spring 38 against surface 40 provided on the connector 10. The hose 14 may then be pushed over the cylindrical projection 12 so that the projection 12 penetrates the bore 16 of the hose 14 to a depth substantially equal to its length whereafter the collar 26 is released and spring 38 ensures the clamping of the hose 14 between the frusto-conical surfaces 32 and 22 of the collar 26 and projection 12 respectively.

It will be appreciated that, although the devices illustrated have been described with reference to hoses and connectors of an engine housing or radiator of a vehicle, they are not restricted to use within the automobile industry but may find use wherever a tubular member requires connection to a connector. Furthermore, although there are advantages in providing a tubular projection of circular cross-section, the devices may also be used in connection with projections of differing cross-sections provided that the collar is of corresponding shape and the clamping surfaces 32 and 22 are no longer frusto-conical but generally and similarly inclined.

It will also be apparent that the devices can use any other resilient means instead of the spring illustrated.

Claims

1. A device for clamping a tubular member of at least slightly flexible material to a relatively rigid surface inserted in and engaged by the material of the tubular member wherein the tubular member is held between a first inclined surface portion provided by the relatively rigid surface and a second inclined surface portion provided by a collar, said inclined surface portions being urged towards each other by resilient means thereby clamping the tubular member to the relatively rigid surface.

2. A device in accordance with claim 1, wherein the resilient means provides a constant axial force that is converted to a radial clamping force at the inclined surface portions.

3. A device in accordance with claim 1 or claim 2, wherein said first inclined surface portion is located on a projection constituting said relatively rigid surface and being for insertion into a bore in the tubular member, said collar in use being coaxial with said projection.

4. A device in accordance with claim 3, wherein said projection is of substantially circular cross-section.

5. A device in accordance with claim 4, wherein said first inclined surface portion is of substantially frusto-conical cross-section having a conic angle of between 100 and 500.

6. A device in accordance with any of claims 3 to 5, wherein the projection is hollow.

7. A device in accordance with any of claims 3 to 6, wherein said resilient means comprises a spring which in use is coaxial with said projection.

8. A device in accordance with claim 7, wherein an end of said spring is rigidly secured to said collar.

9. A device in accordance with any preceding claim, wherein said collar is associated with said relatively rigid surface and is provided as part of a connector assembly.

10. A device in accordance with any of claims 1 to 8, wherein said collar is associated with said tubular member and is provided with releasable locking means to prevent the collar from moving along the length of the said tubular member.

11. A device in accordance with any preceding claim, wherein said relatively rigid surface constitutes a connector provided on an engine housing or a radiator of a vehicle and said tubular member is a vehicle hose.

12. A device in accordance with any preceding claim, wherein said collar is of metallic or thermoplastics material.

13. A device for clamping a vehicle hose to a connector provided on an engine housing or a radiator of a vehicle wherein said socket is provided with a projection of substantially circular cross-section for insertion within a bore of the vehicle hose, said vehicle hose being clamped between said external surface portion of the projection and a surface portion of a collar coaxial with the projection and urged thereagainst by means of a similarly coaxial spring.

14. A device in accordance with claim 13, wherein the collar is provided on the vehicle hose prior to the insertion of the projection within the said bore.

15. A method of clamping a tubular member of slightly flexible material to a relatively rigid surface inserted in and engaged by the material of the tubular member, comprising the steps of squeezing the flexible material between a first inclined surface portion of the relatively rigid surface and a second inclined surface portion on a collar which is coaxial with the relatively rigid surface and slidable over the outside of the tubular member under the bias of resilient means.

16. A device for clamping a tubular member of slightly flexible material to a relatively rigid surface substantially as herein described with reference to the accompanying drawing.

17. A method of clamping a tubular member of slightly flexible material to a relatively rigid surface substantially as herein described with reference to the accompanying drawing.