GB2228239A - Vehicle silencer mounting system - Google Patents

Abstract

A vertical silencer box (30) is mounted on a chassis member (1) by a mounting system comprising a bracket (3) carrying an adjustable spigot or socket (5) which receives the foot of an upwardly extending support arm (10). The support arm (10) carries two clampable blocks (20) which, when slack, can be moved along and around the arm (10) for adjustment. Each block (20) carries a flexible steel strap (40) which can be tensioned around the silencer box (30). The arm (10) may be supported additionally by a stay (50). The mounting system can be assembled from standard components in many different configurations and is robust without reducing the payload or manoevrability of the vehicle. <IMAGE>

Description

TITLE: MOUNTING SYSTEM The present invention relates to a mounting system, notably to a bracket and clamp assembly for mounting a vehicle silencer upon the chassis of the vehicle.

BACKGROUND TO THE INVENTION: Most vehicles are equipped with one or more silencer systems for reducing the noise of the exhaust from the internal combustion engine powering the vehicle. In the majority of cases, the exhaust system is fitted horizontally within or under the chassis framework and is supported at a number of points along its length. However, in some cases a horizontally mounted exhaust system is not feasible; for example, where the vehicle is to be used on dusty ground, for the tractor units of articulated vehicles and where the chassis of the vehicle carries hydraulic equipment and the exhaust fumes could pose a safety problem for an operator of that equipment.

It has therefore been proposed that the body or box of the silencer system be mounted upright and immediately behind the body or cab of the vehicle. However, the exhaust system requires to be firmly supported to withstand the stresses encountered during use. On the other hand, massive support systems not only reduce the useful payload of the vehicle, but may also interfere with the manoeuvreability of an articulated vehicle. Furthermore, there is usually a wide range of designs of cab which can be fitted to any one chassis and there are variations in the dimensions of each design of cab or body. This can impose problems in the siting and securing of the means for mounting the silencer body or box in the desired position. We have now devised an improved form of mounting system for systems in which the silencer body or box is located substantially upright.The system of the invention can be assembled from standard components in a multiplicity of configurations so as to suit the vehicle chassis and cab design of the vehicle to which the silencer is fitted and yet provides a robust support for the exhaust system which does not significantly reduce the payload or maneouvreability of the vehicle.

SUMMARY OF THE INVENTION: Accordingly, the present invention provides a mounting system for a substantially vertically orientated silencer box for a vehicle, which system comprises: a. a bracket member adapted to be secured to the chassis of the vehicle and having a means, for example a socket therein, for receiving and securing in a desired orientation with respect to the chassis a support arm to which the box of the silencer is to be secured; b. a support arm adapted to be secured by the said means to the bracket so that the said arm extends upwardly from the chassis of the vehicle; and c. clamp means adapted to be secured to the support arm by securing means, the position of which clamp means can be adjusted both axially and angularly with respect to the axis of the supporting arm, the clamp means carrying one or more adjustable strap means adapted to encircle the box of a silencer to be mounted by the system and to be tensioned to grip the box of the silencer.

The invention also provides a vehicle having the box of its silencer system secured in an upright position by a system of the invention.

A silencer system for a vehicle typically comprises pipework leading from the engine to one or more metal boxes containing baffles or the like for reducing the noise emmission from the engine. Such systems can take a wide range of forms and constructions and the invention can be applied to all types of silencer system incorporating a silencer box or body, which is usually of a generally cylindrical form.

For convenience, the term silencer box is used herein to denote any container through which exhaust gasses are to pass and which acts to reduce the noise or other emmission from the engine. Thus, the term will denote conventional elongated metal circular, oval or other cross-section containers having transverse baffles or other means secured therein for reducing the noise emission of the exhaust; as well as containers containing catalysts for the treatement of the exhaust gasses to reduce the noxious material content thereof. However, the invention is of especial use in the mounting of substantially cylindrical steel bodied silencers and will for convenience be described in terms of such silencers.

The system of the invention comprises a bracket by which the support arm is mounted on the chassis of the vehicle.

This bracket can be welded, bolted or otherwise secured directly to a chassis member, usually one of the longitudinal girders or rails of the chassis. However, it is preferred that the bracket comprise a member which is bolted or otherwise secured to a vertical face of the chassis member to provide a horizontal surface upon which an adustable socket member is secured to receive the foot of the support arm. The socket member is preferably angularly adjustable about a vertical axis. Whilst the axis of the bore of the socket can be vertically aligned, it is preferred that it be at an angle of from 20 to 450 to the vertical. Typically, the socket is formed with a split in one wall thereof and is provided with a clamping mechanism whereby the foot of the support arm can be secured within the socket.

The support arm comprises a suitable length of rod, tube or the like. The arm can be straight or, more preferably, can be bent to provide one or more substantially vertical sections when mounted in position on the bracket. Thus, a particularly preferred form of the support arm is a tubular member having a single bend in it adjacent its foot. The precise form, size and configuration of the support arm can be readily selected to suit the design of the combination of the vehicle chassis, body/cab and silencer box with which it is to be used. Furthermore, by rotating the foot of the arm in the socket by which it is secured to the chassis, the transverse and axial position of the upright portion of the arm with respect to the chassis can be adjusted to accommodate variations in the design and dimensions of the chassis/cab upon which it is to be used.

The support arm carries one or more clamp means by which the silencer box is to be secured to the support arm. The clamps means preferably comprises a block or the like which is slideably mounted on the support arm and which can be moved axially along the arm and which can be rotatated upon the arm so that the position and orientation of the block upon the arm can be selected as desired. The block can be secured in the desired position on the arm by a radial locking mechanism, for example a grub screw or the like, or by a tangentially acting clamp. Thus, the block can have a split wall and transverse tightening screws which act to close the split in the wall and secure the block upon the arm.

The clamp means carries one or more strap means which act as tension belts which are to pass around the box of the silencer and to be tensioned so as to grip the box. The strap means can be provided by a flexible fabric, metal or other continuous band or chain, which is anchored to the clamp block, passes around the silencer box and is then secured by buckles or the like to the clamp block by which the belt or chain can be tensioned to the desired extent to secure the silencer box in position. Alternatively, the strap can be of the Jubilee clip style. The strap is of sufficient size to encompass the circumference of the silencer box and may therefore be demountably attached to the clamp block so that a range of sizes of strap can be used with a single clamp block.As stated below, straps can also be used to secure the heat shield for the silencer box and these can be secured to a common clamp box with the silencer box securing straps.

The clamp block preferably presents a curved face to the silencer box so that the box seats firmly against the clamp block when in position. Alternatively, a demountable curved fitting can be provided between the block and the silencer box to provide such a seating. The clamp block can also carry a member which extends axially and can provide part or all of the curved fitting, which member carries a radially inwardly directed projection which locates upon the upper or lower rim of the silencer box to aid support of the box during tightening of the clapming straps.

It is preferred that the support arm carry at least two clamp blocks and associated strap means, so that the silencer box is supported at upper and lower points to impart stability to the silencer box. It is also preferred that one or more stays or secondary support arms be provided to support the support arm from another point on the chassis, which can be axially separated from the support arm locating support bracket, to provide lateral support from the other longitudinal member of the chassis.

Preferably, such secondary support takes the form of a stay attached by a clamp mechanism to the upper, free end of the support arm and connected to a mounting on a chassis member transversely removed from that carrying the support arm.

It is also preferred that the mountings for the secondary support incorporate compliant mountings so that the secondary support can accommodate variations in the exact location of the support arm for the silencer box.

Many silencer systems incorporate a heat shield which at least partially encompasses the silencer box with an air gap between the outer wall of the silencer and the inner face of the heat shield. The heat shield can be mounted directly upon the silencer box by suitable spacers.

However, it is within the scope of the present invention to secure the heat shield in place by one or more straps tensioned around the heat shield from the clamp blocks in a manner similar to that described above for mounting the silencer box itself on the support arm.

The mounting system of the invention can incorporate other features to aid or enhance its operation. Thus, the support arm and/or the stay of the secondary support can be made in two or more sections so that they are axially extensible or collapsible to suit different vehicles.

The mounting system of the invention provides a simple and effective means for mounting a wide range of sizes and shapes of silencer boxes upon a wide range of chassis with different cab designs using a series of standardised components. Futhermore, we have found that the system of the invention provides a remarkably secure mounting for the silencer box without the need for heavy-weight components.

DESCRIPTION OF THE DRAWINGS: The invention will be described by way of illustration only with respect to a preferred embodiment thereof shown in the accompanying drawings in which Figure 1 is a diagrammatic elevation from the rear of the chassis showing the system in position; and Figure 2 is a plan view from above of the system shown in Figure 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT: A vehicle chassis comprises two longitudinal frame members 1 and 2. To one member i is welded or bolted a bracket 3 which provides a substantially horizontal mounting plate 4.

To plate 4 is attached a socket 5 whose bore is angled at approximately 450 to the vertical. The base of socket 5 is secured to plate 4 by a number of bolts symmetrically located about the axis of the socket, preferably passing through arcuate slots in plate 4, so that the angular orientation of the socket with respect to the bracket 3 can be varied.

The socket 5 has an axial split in its wall, with two bolts 6 for closing the split to clamp the wall of the socket onto the foot of a support arm 10 located within the socket. This allows the position and orientation of the foot of the arm 10 within the socket 5 to be adjusted.

The support arm 10 is an aluminium, steel or other tube having a 450 bend therein, so that its upper portion is aligned substantially vertical. The position of the longitudial axis of the vertical portion of the arm 10 relative to the chassis member 1 and the wall of a cab mounted on the chassis can be adjusted by rotation of the socket 5 upon plate 4 and/or by rotation of the foot of arm 10 within the socket 5 and/or by varying the depth of insertion of the foot of the arm into the socket.

The arm 10 carries two clampable blocks 20 journalled thereon, whose position on the vertical portion of the arm can be varied by slackening off tightening bolts 21 which secure the blocks 20 on the arm 10 to permit the blocks 20 to move axially upon the arm 10 and to rotate about the axis of the arm 10. The blocks 20 each present a concaved seat 22 to the silencer box 30 when this is in position.

The blocks 20 also carry transverse lugs 23 to one of which is anchored one end of a flexible steel strap 40. The other end of the strap 40 is attached to a vertical pin passing through the opposed lug 23 which can be rotated to tension the strap 40 around the silencer box 30. As shown dotted in Figure 2, the strap 40 can be of various lengths to encompass different diameter silencer boxes, and/or each block 20 can carry two straps of different lengths, one to secure the silencer box, the other, larger one to secure a heat shield as described below. The blocks 20 can be rotated upon arm 10 so that they can be positioned to accept silencer boxes which are off-set from the plane of arm 10 if required.

The upper end of arm 10 is supported by a stay 50 attached by compliant mountings to the upper end of arm 10 and to the other (2) of the longitudinal members of the chassis via bracket 51. The stay 50 can be formed from two telescopic sections so that it can accommodate different positions of the arm 10.

A silencer box 30 is attached to support arm 10 by passing the straps 40 around the box and drawing them tight to seat the box against the concave seats 22 on the blocks 20.

This provides a secure mounting for the box and can readily accommodate variations in the location of the silencer box with respect to the chassis or the cab without the need to provide different components as has hitherto be necessary with conventional mounting systems for silencer boxes.

As indicated above, the silencer box will usually carry a heat shield 60. This can be secured thereto, eg. by welding or the like, so that there will be a gap between the heat shield and the wall of the silencer box through which the strap 40 can be passed, as shown in Figure 2.

Where the heat shield is separate from the silencer box, it may be secured in position by passing secondary straps 40 around the heat shield and securing them to the same or different clamp blocks 20 supporting the silencer box.

Alternatively, the heat shield can carry lugs or the like through which the straps 40 securing the silencer box pass so that the straps secure both the silencer box and the heat shield in place. The position of the heat shield can thus be adjusted independently of the silencer box if desired to optimise its position.

The invention has been described above in terms of the bracket 3 carrying a socket into which the foot of arm 10 fits. However, it will be appreciated that other forms of mounting which permit rotation and axial adjustment of the position of the arm relative to the bracket can be used.

Thus, the bracket can carry a spigot in place of the socket and the tubular foot of the support arm 10 can be fitted onto the spigot and clamped in place. Furthermore, the arm 10 can have a squared, triangular or other polygonal crosssection and the spigot or socket on bracket 3 can have a corresponding configuration so that the relative angular orientation of the arm and socket/spigot can be secured in stepwise increments.

Claims (7)

WHAT WE CLAIM IS:

1. A mounting system for a substantially vertically orientated silencer box as hereinbefore defined for a vehicle, which system comprises: a. a bracket member adapted to be secured to the chassis of the vehicle and having a means for receiving and securing in a desired orientation with respect to the chassis a support arm to which the box of the silencer is to be secured; b. a support arm adapted to be secured by the said means to the bracket so that the said arm extends upwardly from the chassis of the vehicle; and c. clamp means adapted to be secured to the support arm by securing means, the position of which clamp means can be adjusted both axially and angularly with respect to the axis of the supporting arm, the clamp means carrying one or more adjustable strap means adapted to encircle the box of a silencer to be mounted by the system and to be tensioned to grip the box of the silencer.

2. A mounting system as claimed in claim 1 wherein the means for receiving and securing the support arm comprises a member having a socket therein adapted to receive the foot of the support arm.

3. A mounting system as claimed in either of claims 1 or 2 wherein the support arm comprises an elongated tubular member whose longitudinal axis has at least one bend in it whereby the transverse and longitudinal position of the axis of a silencer carried upon the support arm can be varied with respect to the chassis of the vehicle.

4. A mounting as claimed in any one of the preceding claims, wherein a secondary support arm is provided to support the upper end of the support arm.

5. A mounting system as claimed in any one of the preceding claims, wherein the silencer box carries a heat shield and this is adapted to be secured in position by a strap member carried by the clamp means.

6. A mounting system for a silencer box for a vehicle substantially as hereinbefore described with respect to and as shown in the accompanying drawings.

7. A vehicle having an internal combustion engine whose emissions are passed through a silencer box, characterised in that the box of its silencer is secured in an upright position with respect to the chassis of the vehicle by a mounting system as claimed in any one of the preceding claims.