GB2201845A - Torque-relieving collar of cable or hose clamp - Google Patents

Abstract

A collar assembly for use in fastening a component to a structure comprises a collar having a longitudinal axis (12) and comprising a flanged hollow inner member 19 having a first circumferentially extending abutment surface (21) for clamping engagement with the nut and a second circumferentially extending abutment surface (22) at an opposite end thereof for clamping engagement with the component (32). A hollow outer member (28) is attached to the inner member and is provided with two longitudinal lateral facing abutment faces (24, 26) for engagement with corresponding abutment faces (40, 42) which in use are fixed relative to the structure (36) to prevent relative rotation between the collar and the structure, and two inclined surfaces (25) adapted for sliding engagement with corresponding inclined surfaces which in use are fixed relative to the structure, to guide the collar into position. <IMAGE>

Description

COLLAR ASSEMBLY This invention relates to a collar assembly for use in fastening a component-to a structure.

When a nut is used to fasten a component to a structure such as a housing or casing there is often a twisting force exerted on the component by the nut during tightening. The component may then be damaged, or where an electrical cable or pneumatic or hydraulic hose extends from the component, there may be undesirable twisting of the hose or cable.

This problem can be somewhat alleviated by using splines machined on the component and housing.

However splines can be expensive to machine and intricate tooling may be required.

The p#asent vcntion overcomes the problem by us ,:g a relatively simple collar assembly to resist twisting.

According to one aspect of the invention there is provided a collar assembly for use in fastening a component to a structure, comprising a tubular collar having a longitudinal axis and provided with at least one generally longitudinal abutment surface which faces a generally lateral direction, for engagement with a corresponding abutment surface which in use is fixed relative to the structure, said engagement thereby preventing relative rotation between the collar and the structure.

Preferably the collar assembly further comprises a circumferentially extending abutment surface for clamping engagement with the component.

The collar may be further provided with at least one peripheral surface which is inclined with respect to the longitudinal axis and adapted for sliding engagement with a corresponding surface which in use is fixed relative to the structure.

The collar may have two generally longitudinal abutment surfaces with two inclined peripheral surfaces extending between the longitudinal abutment surfaces.

Preferably the two longitudinal abutment surfaces are of approximately equal length and are disposed as substantially 1800 apart about the longitudinaJ axis.

Preferably the collar assembly further comprises a second circumferentially extending abutment surface adopted to engage a nut or washer.

Preferably the collar has tubular inner and outer members.

The collar assembly may further comprise a second tubular collar on which the or each corresponding longitudinal abutment surface is formed and wherein the second hollow member is adapted to in use be attached to the structure.

The invention will now be described in detail by way of example with reference to the accompanying drawings in which: Figure 1 shows an isometric view of an outer member of a collar assembly according to one aspect of the invention; Figure 2 depicts an isometric view of an inner member for use with the outer member shown in figure 1; Figure 3 is a view of a preferred form of outer member for use with the inner member illustrated in figure 2; Figure 4 is a side view of a collar assembly according to one aspect of the invention; Figures 5 and 6 illustrate the collar assembly in use; Figure 7 shows a second collar for use with the collar of figure 4 according to another aspect of the invention.

Referring to figure 1, a collar assembly comprises a tubular collar having an outer member 10 of tubular shape about a longitudinal axis 12. The outer member is provided with two lateral facing longitudinal abutment surfaces 14, 16 and a peripheral surface 18 which is inclined with respect to the longitudinal axis 12 and extends between the two abutment surfaces. Figure 2 shows the inner member 19 of the collar assembly. The inner member is tubular with a flange 20 upon which in use a nut of washer bears on an abutment surface 21 of the flange. A circumferentially extending abutment surface 22 at the other end from the flange is provided for clamping engagement with the component to be fastened.The inner member 19 is thereby responsible for transmitting the clamping load from a nut to the component while the function of the outer member is to prevent the tightening torque on the nut being transmitted to the component.

Figure 3 shows the preferred form of outer member 28 in which abutment surfaces 24, 26 are of approximately equal length and 1800 apart and inclined peripheral surfaces 25 extend between the abutment surfaces on both sides.

Figure 4 shows an assembled collar assembly 30 in which the inner and outer members 19, 28 are attached to each other. This may be by any suitable method such as brazing or even heat shrinking the outer member onto the inner member. Alternatively, the inner and outer members can be formed integrally by casting fcr example.

Referring to figures 5 and 6 the collar assembly 30 is fitted over the component 32 which is then placed into a receiving hole 34 in a structure or housing 36. A threaded nut 38 is fitted over the component (before insertion if necessary) and turned so that a flange 39 of the nut 38 abuts against the flange 20 of the collar assembly. Progressive turning of the nut causes the collar assembly 30 to move toward the structure 36 until the abutment surfaces 24, 26 engage corresponding abutment surfaces 40, 42 (not shown) formed on the structure.The movement of the collar assembly 30 may be due to either friction twisting as the nut 38 is turned or the inclined surfaces 25 slidably engaging corresponding inclined surfaces 44, 46 formed on the structure and guiding the collar assembly round until the abutment surfaces engage, or a combination of both friction twisting and sliding engagement of the inclined surfaces.

Once the abutment faces have engaged further tightening of the nut 38 will only serve to exert a longitudinal clamping load on the component 32 without imparting any torque thereon. The component thus becomes clamped between an inner flange 48 formed on the structure 36 and the abutment surface 22 on the collar assembly 30.

The relative dimensions of all the components are arranged so that after the nut is fully tightened a small axial clearance exists between each inclined surface 25 and those on the housing otherwise the component will not be forced against the inner flange 48 of the structure. If desired a washer can be employed between the nut and flange 20 of the collar assembly.

In the embodiment of figure 1 where there is one inclined surface and one straight surface between the abutment faces there is a danger of the inclined surface not properly engaging a corresponding surface on the structure. The advantage of having an inclined surface between each abutment surface on both sides is that it ensures that they engage corresponding inclined surfaces on the structure and that the collar assembly will not become jammed without the abutment faces engaging.

According to another aspect of the invention a second collar (figure 7) is utilised which in use is attached to the structure but may be manufactured separately. Corresponding abutment surfaces 40, 42 and inclined surfaces 44, 46 are formed on the collar prior to attachment to the structure.

The inclined surfaces 25 may be helical or straight scarfed cuts.

The collar assembly may be especially useful when a component is fastened to a structure where access is limited, for instance where a casing surrounds the structure.

A major advantage of the invention is that the component can be inserted at any orientation with respect to the structure and it will remain there during tightening of the nut. A key-way or equivalent would require the component to always be inserted at a fixed orientation which is not always convenient.

Claims (10)

1. A collar assembly for use in fastening a component to a structure, comprising a tubular collar having a longitudinal axis and provided with at least one generally longitudinal abutment surface which faces a generally lateral direction, for engagement with- a corresponding abutment surface which in use is fixed relative to the structure, said engagement thereby preventing relative rotation between the collar and the structure.

2. A collar assembly according to claim 1 further comprising a circumferentially extending abutment surface for clamping engagement with the component.

3. A collar assembly according to claim 1 or claim Z wherein the collar is further provided with at least one peripheral surface which is inclined with respect to the longitudinal axis and adapted for sliding engagement with a corresponding surface which in use is fixed relative to the structure.

4. A collar assembly according to claim 3 wherein the collar has two generally longitudinal abutment surfaces with two inclined peripheral surfaces each extending between the longitudinal abutment surfaces.

5. A collar assembly according to claim 4 wherein the two generally longitudinal abutment surfaces are of approximately equal length and disposed at substantially 1800 apart about the longitudinal axis.

6. A collar assembly according to any one of the preceding claims further comprising a second circumferentially extending abutment surface adapted to engage a nut or washer.

7. A collar assembly according to any one of the preceding claims wherein the collar has tubular inner and outer members.

8. A collar assembly for use in fastening a component to a structure comprising a tubular collar having a longitudinal axis the collar comprising: a flanged hollow inner member of generally circular section comprising at one end a first circumferentially extending abutment surface for clamping engagement with a nut and a second circumferentially extending abutment surface at an opposite end thereof for clamping engagement with the component; and a hollow outer member attached to or formed integrally with the Xnne, ."ember anlu provided with at least one generally longitudinal abutment surface which faces a generally lateral direction for engagement with a corresponding abutment surface which in use is fixed relative to the structure to prevent relative rotation between the collar and the structure and at least one peripheral surface with is inclined with respect to the longitudinal axis and adapted for sliding engagement with a corresponding surface which in use is fixed relative to the structure.

9. A collar assembly according to any one of claims 1 to 8 further comprising a second tubular collar on which the or each corresponding longitudinal abutment surface is formed and wherein the second collar is adapted to be attached to the structure.

10. A collar assembly substantially as described herein with reference to Figure 4 or Figure 4 and Figure 7.