GB2087321A - Vehicle suspensions for tandem axles - Google Patents

Abstract

Tandem axles 1 and 2 in a vehicle suspension carry downwardly projecting brackets 5 and 6 pivotally connected to opposite ends of longitudinal beams 3 formed with seatings for pairs of inclined spring bolster elements 13 of rubber and steel plate sandwich construction permitting pivotal movement of the beams 3 about a transverse axis. Triangular torque-arms 9 have their bases pivotally connected at 11 to the chassis structure 12 and their apices 8 pivotally connected to upstanding pillars 7 on the axles. Longitudinal location of the axes, especially under braking (and driving, in the case of live axles) is assisted by torque rods 15 pivotally connected atone end 16 to the chassis frame and extending under the axle 1 to pivots 17 on the brackets 5, the pivots being on the opposite side of the axle to the pivots 16, thereby reducing the angular pivotal movement of the pivots 16 and 17 of the rubber bush type. <IMAGE>

Description

SPECIFICATION Vehicle suspensions The present invention relates to a tandem suspension unit for a vehicle of the kind in which the vehicle load is sprung onto a beam structure having an axle attached to each end, the spring system permitting the beam structure to privot relatively freely about a horizontal transverse axis. The spring structure is preferably of the solid rubber type forming the subject of patent No. 1,408,403.

According to the invention there is provided a tandem-axle vehicle suspension comprising longitudinally extending beams each having an axle attached to each end and a spring system acting on each beam at a location between its ends and permitting pivotal movement about a transverse axis, and an arm pivotally connected at one end to a downward extension secured to the vehicle structure, the arm extending longitudinally beyond one of the axles to be pivotally connected at its other end to a bracket on the said one axle on the opposite side thereof to the downward extension.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of a suspension in accordance with the invention seen from the nearside; Figure 2 is a plan view of part of the suspension; and Figure 3 is an end view as seen from the right in Figure 3.

The suspension shown in the drawings is supported on a pair of exles 1 and 2 which may be driving or passive axles. It comprises two beams 3, one on each side of the vehicle, the ends of the beams 3 being pivotally connected by rubber bush joints at 4 to brackets 5 and 6 secured to the axles 1 and 2.

At its centre point, each axle 1,2 has an upstanding pillar 7 which is connected by a spherical rubber bush 8 to the apex of an A frame 9, the base of which is articulated by two similar connections 11 to a frame 12 secured to the vehicle chassis. The frame 12 is supported on the beams 3 by upwardly inclined and offset rubber and steel "sandwich" spring bolster elements 13 arranged in pairs. These permit the beams to pivot relatively freely relative to the frame 12.

Torque rods 15 are articulated at one end 16 to the frame 11 and at their other end they are articulated at 17 to the brackets 5. In order to ensure sufficient length for the torque rods 15 and thereby to avoid excessive angular movement of their articulations, the articulations 17 are beyond the articulations 14, the brackets 5 being extended for this purpose.

Inclinded hydraulic shock dampers 18 act between the chassis and the beams 3 to damp pivotal movement of the beams.

Each axle 1,2 carries mountings 19forthe road wheel brake actuators (not shown). Both these, and the brake adjusters indicated at 21, are clear of the suspension parts. Bump stops 20 for example of conventional rubber and steel plate sandwich type can be mounted on the beams 3 between each pair of bolster elements 13.

1. A tandem-axle vehicle suspension comprising longitudinally extending beams each having an axle attached to each end and a spring system acting on each beam at a location between its ends and permitting independent pivotal movement about a transverse axis, and an arm pivotally connected at one end to a downward extension secured to the vehicle structure, the arm extending longitudinally beyond one of the axles to be pivotally connected at its other end to a bracket on the said one axle on the opposite side thereof to the downward extension.

2. A suspension according to claim 1, wherein the arm passes beneath said axle and the axle carries an upwardly extending pillar pivotally connected to a further arm pivotally connected to the vehicle structure.

3. A suspension according to claim 2, wherein one of the arms is formed by at least one rod while the other is formed by a triangular member pivotally connected at one apex to the pillar and at its other two apices to the vehicle structure.

4. A tandem-axle vehicle suspension, substantially as hereinbefore described with reference to the drawings.

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

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Vehicle suspensions The present invention relates to a tandem suspension unit for a vehicle of the kind in which the vehicle load is sprung onto a beam structure having an axle attached to each end, the spring system permitting the beam structure to privot relatively freely about a horizontal transverse axis. The spring structure is preferably of the solid rubber type forming the subject of patent No. 1,408,403. According to the invention there is provided a tandem-axle vehicle suspension comprising longitudinally extending beams each having an axle attached to each end and a spring system acting on each beam at a location between its ends and permitting pivotal movement about a transverse axis, and an arm pivotally connected at one end to a downward extension secured to the vehicle structure, the arm extending longitudinally beyond one of the axles to be pivotally connected at its other end to a bracket on the said one axle on the opposite side thereof to the downward extension. An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of a suspension in accordance with the invention seen from the nearside; Figure 2 is a plan view of part of the suspension; and Figure 3 is an end view as seen from the right in Figure 3. The suspension shown in the drawings is supported on a pair of exles 1 and 2 which may be driving or passive axles. It comprises two beams 3, one on each side of the vehicle, the ends of the beams 3 being pivotally connected by rubber bush joints at 4 to brackets 5 and 6 secured to the axles 1 and 2. At its centre point, each axle 1,2 has an upstanding pillar 7 which is connected by a spherical rubber bush 8 to the apex of an A frame 9, the base of which is articulated by two similar connections 11 to a frame 12 secured to the vehicle chassis. The frame 12 is supported on the beams 3 by upwardly inclined and offset rubber and steel "sandwich" spring bolster elements 13 arranged in pairs. These permit the beams to pivot relatively freely relative to the frame 12. Torque rods 15 are articulated at one end 16 to the frame 11 and at their other end they are articulated at 17 to the brackets 5. In order to ensure sufficient length for the torque rods 15 and thereby to avoid excessive angular movement of their articulations, the articulations 17 are beyond the articulations 14, the brackets 5 being extended for this purpose. Inclinded hydraulic shock dampers 18 act between the chassis and the beams 3 to damp pivotal movement of the beams. Each axle 1,2 carries mountings 19forthe road wheel brake actuators (not shown). Both these, and the brake adjusters indicated at 21, are clear of the suspension parts. Bump stops 20 for example of conventional rubber and steel plate sandwich type can be mounted on the beams 3 between each pair of bolster elements 13. CLAIMS

1. A tandem-axle vehicle suspension comprising longitudinally extending beams each having an axle attached to each end and a spring system acting on each beam at a location between its ends and permitting independent pivotal movement about a transverse axis, and an arm pivotally connected at one end to a downward extension secured to the vehicle structure, the arm extending longitudinally beyond one of the axles to be pivotally connected at its other end to a bracket on the said one axle on the opposite side thereof to the downward extension.

2. A suspension according to claim 1, wherein the arm passes beneath said axle and the axle carries an upwardly extending pillar pivotally connected to a further arm pivotally connected to the vehicle structure.

3. A suspension according to claim 2, wherein one of the arms is formed by at least one rod while the other is formed by a triangular member pivotally connected at one apex to the pillar and at its other two apices to the vehicle structure.

4. A tandem-axle vehicle suspension, substantially as hereinbefore described with reference to the drawings.