GB2193290A - Tubular spacer - Google Patents

Abstract

A tubular spacer 24 which also functions as a spring has a single tubular body with portions of the tubular wall between the ends of the body removed to allow a limited degree of axial compressibility to the spacer. For example slots 34 can be cut part way through the wall. The degree of axial compressibility is limited by the position where the opposite faces of the slots come into contact with one another. <IMAGE>

Description

SPECIFICATION Tubular spacer This invention relates to a tubular spacer for spacing apart articles mounted on a common shaft. An example of such articles are clutch and brake pedals in a motor vehicle which have to be maintained at fixed, spaced relative positions.

According to the invention, there is provided a tubular spacer comprising a single tubular body having portions of the tubular wall between the ends of the body removed to allow a limited degree of axial compressibility to the spacer.

In a preferred embodiment, the removed portions are parallel-sided slots cut part-way through the body. The slots can be arranged in offset pairs so that the body can remain centered on a linear, central axis as it is compressed.

The amount of axial compressibility is determined by the opposite sides of the slots coming into contact with one another.

The external surface of the body can be non-round, e.g. by having a flat formed on it, in order to prevent the spacer from rotating about the shaft in use.

The spacer is preferably made from a plastics material such as an acetal copolymer which may be 10-15% glass filled.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a view of two motor vehicle pedals on a shaft where they are spaced apart by a spacer in accordance wtih the invention; Figure 2 is a plan view of the spacer alone; and Figure 3 is an end view of the spacer of Fig. 2.

Fig. 1 shows a pedal box where a brake pedal 10 and a clutch pedal 12 are fitted on a common shaft 14. The shaft is supported in metal brackets 16 and 18 which are welded to the vehicle bodywork.

Each pedal is of hollow section and has a transverse hole through which the shaft passes. Separate bushes 20 and 22 are provided to form a bearing surface for each pedal on the shaft. To space the pedals apart on the shaft, a spacer 24 is provided.

To assemble the pedals, the right-hand end of the shaft 14 is passed through the hole in the bracket 16, from the left-hand side. The brake pedal 10 with its bushes 20 and 22 is placed on the shaft, and then a washer 26 and a retainer clip 28 are put in place. The right-hand end of the shaft (which has a flat on it) is then located in a correspondingly shaped hole in the bracket 18. Next the spacer 24 is slid onto the shaft, noting that this is a clearance fit in the aperture through the bracket 16. Then the clutch pedal 12 with its bushes 20 and 22 is placed on the shaft followed by a washer 30 and a retaining clip 32.

This assembly operation is very much quicker and simpler than was the case when rigid spacers and separate spring washers were used.

The spacer itself is tubular and of plastics.

It has slots 34 cut through its walls, at right angles to the tube axis. Because a substantial amount of the tube wall is cut away in the region of these slots, the tube can be compressed by an axially applied force. The amount of possible axial compression is limited by the sum of the widths of the slots 34, as compression ceases once the opposing slot walls come into contact.

In one embodiment, the tube had an external diameter of 22mm, an internal diameter of 16mm and three pairs of two slots, each slot having a width of 2mm and a depth of 15mm. This gives a total possible compression of 6mm.

As can be seen in Fig. 3, a flat 36 is formed on the outside of the spacer, and this can locate in a suitably shaped aperture in the bracket 16 to prevent the spacer from rotating.

It is an important feature of the invention that the spacer as described provides both the spacing and the urging functions necessary to keep the pedals in their correct positions on the shaft and to take up any tolerances while allowing the pedals freedom to rotate on the shaft. Since the spacer itself will not rotate around the shaft axis, it experiences no wear and, where it passes through the bracket 16, it is only subjected to compression loads, and not abrasion.

The spacer of the invention can be used in applications other than the one described.

Such applications are those where components have to be held in fixed positions on a shaft and yet to have enough freedom of movement to rotate about the shaft.

The spacer can be constructed in ways other than as shown here. For example, a spiral slot or slots could be cut through the tube wall.

Another important feature is ease of assembly. The assembly sequence has been set out above, and is superior to that which had to be used when the springs and the spacer(s) were seperate components.

1. A tubular spacer comprising a single tubular body having portions of the tubular wall between the ends of the body removed to allow a limited degree of axial compressibility to the spacer.

2. A spacer as claimed in Claim 1, wherein the removed portions are parallel-sided slots cut part-way through the body.

3. A spacer as claimed in Claim 2, wherein the slots are arranged in offset pairs so that

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Tubular spacer This invention relates to a tubular spacer for spacing apart articles mounted on a common shaft. An example of such articles are clutch and brake pedals in a motor vehicle which have to be maintained at fixed, spaced relative positions. According to the invention, there is provided a tubular spacer comprising a single tubular body having portions of the tubular wall between the ends of the body removed to allow a limited degree of axial compressibility to the spacer. In a preferred embodiment, the removed portions are parallel-sided slots cut part-way through the body. The slots can be arranged in offset pairs so that the body can remain centered on a linear, central axis as it is compressed. The amount of axial compressibility is determined by the opposite sides of the slots coming into contact with one another. The external surface of the body can be non-round, e.g. by having a flat formed on it, in order to prevent the spacer from rotating about the shaft in use. The spacer is preferably made from a plastics material such as an acetal copolymer which may be 10-15% glass filled. The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a view of two motor vehicle pedals on a shaft where they are spaced apart by a spacer in accordance wtih the invention; Figure 2 is a plan view of the spacer alone; and Figure 3 is an end view of the spacer of Fig. 2. Fig. 1 shows a pedal box where a brake pedal 10 and a clutch pedal 12 are fitted on a common shaft 14. The shaft is supported in metal brackets 16 and 18 which are welded to the vehicle bodywork. Each pedal is of hollow section and has a transverse hole through which the shaft passes. Separate bushes 20 and 22 are provided to form a bearing surface for each pedal on the shaft. To space the pedals apart on the shaft, a spacer 24 is provided. To assemble the pedals, the right-hand end of the shaft 14 is passed through the hole in the bracket 16, from the left-hand side. The brake pedal 10 with its bushes 20 and 22 is placed on the shaft, and then a washer 26 and a retainer clip 28 are put in place. The right-hand end of the shaft (which has a flat on it) is then located in a correspondingly shaped hole in the bracket 18. Next the spacer 24 is slid onto the shaft, noting that this is a clearance fit in the aperture through the bracket 16. Then the clutch pedal 12 with its bushes 20 and 22 is placed on the shaft followed by a washer 30 and a retaining clip 32. This assembly operation is very much quicker and simpler than was the case when rigid spacers and separate spring washers were used. The spacer itself is tubular and of plastics. It has slots 34 cut through its walls, at right angles to the tube axis. Because a substantial amount of the tube wall is cut away in the region of these slots, the tube can be compressed by an axially applied force. The amount of possible axial compression is limited by the sum of the widths of the slots 34, as compression ceases once the opposing slot walls come into contact. In one embodiment, the tube had an external diameter of 22mm, an internal diameter of 16mm and three pairs of two slots, each slot having a width of 2mm and a depth of 15mm. This gives a total possible compression of 6mm. As can be seen in Fig. 3, a flat 36 is formed on the outside of the spacer, and this can locate in a suitably shaped aperture in the bracket 16 to prevent the spacer from rotating. It is an important feature of the invention that the spacer as described provides both the spacing and the urging functions necessary to keep the pedals in their correct positions on the shaft and to take up any tolerances while allowing the pedals freedom to rotate on the shaft. Since the spacer itself will not rotate around the shaft axis, it experiences no wear and, where it passes through the bracket 16, it is only subjected to compression loads, and not abrasion. The spacer of the invention can be used in applications other than the one described. Such applications are those where components have to be held in fixed positions on a shaft and yet to have enough freedom of movement to rotate about the shaft. The spacer can be constructed in ways other than as shown here. For example, a spiral slot or slots could be cut through the tube wall. Another important feature is ease of assembly. The assembly sequence has been set out above, and is superior to that which had to be used when the springs and the spacer(s) were seperate components. CLAIMS

1. A tubular spacer comprising a single tubular body having portions of the tubular wall between the ends of the body removed to allow a limited degree of axial compressibility to the spacer.

2. A spacer as claimed in Claim 1, wherein the removed portions are parallel-sided slots cut part-way through the body.

3. A spacer as claimed in Claim 2, wherein the slots are arranged in offset pairs so that the body can remain centered on a linear, central axis as it is compressed.

4. A spacer as claimed in Claim 2 or Claim 3, wherein the amount of axial compressibility is determined by the opposite sides of the slots coming into contact with one another.

5. A spacer as claimed in any preceding claim, wherein the external surface of the body is non-round.

6. A spacer as claimed in Claim 5, wherein the body has a flat formed on it, in order to prevent the spacer from rotating about the shaft in use.

7. A spacer as claimed in any preceding claim and made from a plastics material.

8. A spacer as claimed in Claim 7, wherein the plastics material is fibre-reinforced.

9. A spacer substantially as herein described with reference to the accompanying drawings.