GB2599502A

GB2599502A - A suspension system

Info

Publication number: GB2599502A
Application number: GB2114013.2A
Authority: GB
Inventors: Hawkins Jamie
Original assignee: Jamie Hawkins Ltd
Current assignee: Jamie Hawkins Ltd
Priority date: 2020-09-30
Filing date: 2021-09-30
Publication date: 2022-04-06
Anticipated expiration: 2041-09-30
Also published as: GB202015431D0; GB202114013D0; GB2599502B

Abstract

A retrofit vehicle cab suspension system is provided. The suspension system comprises at least one air damper 2 for mounting between a cab and an axle or chassis of a vehicle, a pressure protection valve 15, and a levelling valve 6. The pressure protection valve 15 comprises an inlet for connection to a compressed air supply of the vehicle, an outlet for supplying compressed air to the suspension system and a valve which closes the supply in response to a loss of pressure in the suspension system. The levelling valve 6 comprises an inlet for receiving compressed air from the outlet of the pressure protection valve 15, an outlet for supplying pressure to the at least one air damper 2, a mount 7 for supporting the levelling valve 6 on one of the cab and the axle or chassis, and an actuator 6b for controlling the flow through the valve 6. In use the suspension system further comprises: a control linkage 3 for connecting between the actuator 6b of the levelling valve 6 and the portion of the at least one air damper 2 connected to the other of the cab and the axle or chassis to which the levelling valve 6 is mounted. A kit of parts for the retrofit vehicle cab suspension is also disclosed.

Description

A Suspension System

Field

The invention relates to suspension systems and more particularly, but not exclusively to a suspension system for a cab in a vehicle, such as for example a tractor or an articulated vehicle or a bus, all of which vehicles have a cab in which a driver, pilot or operator sits, and all of the aforementioned vehicles being fitted with air brakes.

The term vehicle is intended also to include a digger, a combine harvester, a tractor, a crane and a grabber.

It is appreciated that the invention is not limited to the aforementioned provided such machine is equipped with a compressed air supply, for example an air braking system.

Background

Air suspension seats or cabs provide comfort to operators and drivers who may routinely have to spend many hours sat in vehicles in order to operate the or perform tasks with them. Such operators include stevedores, farmers and skilled drivers of heavy goods vehicles (HGVs) public service vehicles (PSVs), such as busses and coaches, and equipment that is liable to impart shocks and impacts to a driver or operator whilst seated in the vehicle or equipment.

Depending upon the vehicle configuration the suspension may act between the cab/seat and the chassis or axle of the vehicle (it may be appreciated that on a tractor and such heavy vehicles, in contrast to cars, there is often no suspension between the axle and chassis and as such components can be connected to the axle or chassis).

Prior Art

European patent application EP 2 813 416 (Haldex Brake Products GmbH) discloses an air suspension valve unit with electrically controlled solenoid valves (are controlled by a control unit and ventilate air suspension bellows on which a driver's cab is supported.

Japanese patent application JP2003026051 (Hino Motors limited) discloses a device for economizing air pressure consumed by adjusting the height of a car air spring which supports a cab on a chassis frame. A solenoid valve and its control unit controls air pressure to the air spring when the cab tilts thereby avoiding p[pressure loss.

United States patent application US 2010/0237656 (Grammar AG) discloses a devices for use with a suspension of a vehicle cab which includes at least one air spring for suspension of the cab. The air spring is arranged between the cab and a base frame, and a control device controls the supply and discharge of at least one additional volume to/from the air spring.

International patent application WO-A-2009/039351 (Bendix Commercial Vehicle Systems LLC) discloses a system for controlling vehicle loading on a multi-axle vehicle for improving manoeuvrability. The system includes a reservoir of pressurised air and a levelling valve that uses a relay valve to improve refill times when the vehicle returns from a dump mode operation to normal operation.

Although successful many of the aforementioned systems were expensive to install and complex to maintain. As a result many tractors and similar heavy vehicles may be supplied with less expensive shock and coil based cab/seat suspension. Such systems are significantly less comfortable for the driver than air suspension systems particularly over extended periods of operation.

There is, therefore, also a need in many applications for a retro-fit system which may be used to modify existing agricultural equipment, such as tractors.

Summary of the invention

According to an aspect of the invention there is provided a cab suspension system comprising: at least one air damper for mounting between a cab and an axle or chassis of a vehicle; a levelling valve for receiving compressed air from a supply and proving a controlled supply of air to the at least one air damper; and a control linkage extending between the at least one air damper and the levelling valve.

In another aspect of the invention there is provided at least one air damper for mounting between a cab and an axle or chassis of a vehicle; a pressure protection valve comprising an inlet for connection to a compressed air supply of the vehicle, an outlet for supplying compressed air to the suspension system and a valve which closes the supply in response to a loss of pressure in the suspension system; a levelling valve comprising an inlet for receiving compressed air from the outlet of the pressure protection valve, an outlet for supplying pressure to the at least one air damper, a mount for supporting the levelling valve on one of the cab and the axle or chassis, and an actuator for controlling the flow through the valve; wherein the suspension system further comprises: a control linkage for connecting, in use, between the actuator of the levelling valve and the portion of the at least one air damper connected to the other of the cab and the axle or chassis to which the levelling valve is mounted.

Advantageously, by providing a control linkage between the air damper and levelling valve embodiments may provide a simple, robust, and reliable control arrangement particularly suitable for a retro-fit system. Further, it may be noted that the pressure protection valve in embodiments ensures that the suspension system can be safely installed as a retrofit system without compromising safety. In the unlikely event of a leak in the suspension system the pressure in the supply will be maintained (which may be necessary for essential systems such as air brakes).

Ideally the system comprises a pair of air dampers and wherein the linkage connects to one of the air dampers.

Preferably the control linkage is connected to at least one air damper and the levelling valve, via a flexible coupling, for example a ball joint, at each end of the control linkage. The control linkage is a direct mechanical control connection which provides a reliable, simple and robust arrangement.

In some embodiments the levelling valve is mounted to the cab and the linkage extends to the axle or a chassis side of the at least one air damper.

The levelling valve advantageously comprises an outlet(s) for supply of air to the at least one air damper and wherein the, or each, outlet comprises at least one swivel connector.

It is understood that the invention may be supplied as a kit of parts comprising a cab suspension system, according to any preceding claim for retro-fitting to a tractor.

Ideally the kit further comprises a mounting bracket for connecting the levelling valve to suit the particular size and type of cab.

Optionally the invention may be provided as a kit which includes a mounting bracket for connecting the, or each, air damper to the axle or chassis of a tractor. Ideally the air damper mounting bracket comprises a locating member for connecting an end of the control linkage to the air damper.

The kit may further comprise an air supply T-pipe having an inlet for connection to an output of the levelling valve and first and second outlets for connection to an inlet on each of a pair of air dampers.

Optionally the kit may include a pressure protection valve for providing a connection from a compressed air system, of the vehicle to which it is fitted, to the inlet of the levelling valve.

Ideally the pressure protection valve is configured to connect to an air brake system of the vehicle or system.

According to another aspect of the invention there is provided a method of retrofitting an air cab suspension system, the method comprising: providing at least one air dampers; providing a levelling valve; connecting the air damper(s) to a supply of compressed air on a vehicle via the levelling valve; connecting a linkage between the levelling valve and the air damper.

In another aspect, the invention comprises a method of retrofitting a vehicle air cab suspension system, the method comprising: providing at least one air damper; providing a pressure protection valve; providing a levelling valve; connecting the pressure protection valve as an interface between the air cab suspension system and a supply of compressed air on the tractor; connecting an outlet of the pressure protection valve as to the at least one damper via the levelling valve and; connecting a control linkage between the levelling valve and the air damper.

The vehicle may for example be a tractor.

Optionally the step of connecting the air dampers to a supply of compressed air comprises connecting the levelling valve to the air brake system.

The method further comprises providing a pressure protection valve in the air brake system.

Preferably providing an air damper comprises removing and replacing an existing spring shock assembly between the cab and axle or chassis of the vehicle.

Optionally removal of spring shock assemblies includes removal of the shock mounting bracket and installation of an air damper includes installation of a new mounting bracket.

A preferred embodiment of the invention will now be described, by way of example only, and with reference to the following drawings.

Brief Description of the Drawings

Figure 1 shows the primary set of components provided in a kit in accordance with an embodiment; Figures 2 and 3 show initial steps of preparing a tractor to retrofit a suspension system in accordance with methods of embodiments; Figure 4 shows the step of installing a first air damper on a tractor in accordance with embodiments; Figure 5 shows an isolated view of an air supply T-pipe for use in embodiments; Figure 6 shows the step of preparing the opposite side of the tractor; Figure 7 shows an enlarged view of the second air damper in accordance with an embodiment; Figure 8 shows the connectors of the levelling valve in an embodiment; Figure 9 shows the swivel connectors of the levelling valve of figure 8; Figure 10 shows the levelling valve and control linkage in an assembled configuration; Figure 11 shows adjustable mounting arrangement for the levelling valve in embodiments; Figure 12 shows the mounting arrangement and levelling valve of figure 11; Figure 13 shows the control linkage in an assembled configuration; Figures 14a, 14b and 14c show some of the alternate configurations of the pressure protection valve in embodiments; Figure 15 shows a bulkhead adaptor for use in embodiments; Figure 16 shows the levelling valve in situ; Figure 17 shows an overall view of a 4 support plates, 2 bolts, nuts and washers; Figure 18 illustrates how the bolt securing top eye of the shock absorber is removed; Figure 19 shows two new support plates being fitted on top of an air bag facing inwards and being secured with an additional longer bolt; and Figure 20 shows how plates are aligned to be level with the top of the air bag and tighten the bolt.

Detailed Description of Preferred Embodiment of the Invention The components as would be provided in a typical kit in accordance with an embodiment are shown in Figure 1 in a pre-assembled condition. For clarity only a single one of each component is shown in Figure 1, but where multiple components are typically included it is noted below.

The kit as shown comprises: an air hose 1; two air dampers 2, which (as will be described below) are to be fitted in use between the cab and axle or chassis of a vehicle; a control linkage 3, which comprises a rod 3a with a connector (which may include a spherical bearing) 3b and 3c at each end; an air supply T-pipe 4, a first (right hand side) mounting bracket 5, a levelling valve 6, having a body 6a and an actuator 6b; an adjustable valve mounting plate 7; a second (left hand side) mounting bracket 8, including a locating pin 8a; a bulkhead adaptor 9; an T-pipe connector 10, an inlet elbow 11; a pipe connector 12; two swivel connectors 13; two swivel connector elbows 14; a pressure protection valve 15, a plurality of bolts 16, 17 and 18; at least one washer 19; and at least one locknut 20.

The kit in accordance with embodiments provides everything needed to convert a vehicle with a compressed air supply (e.g. a vehicle such as a tractor with air brakes) to having an air suspension cab mounting. The method of will now be described with now be described with reference to Figures 2 to 16. The description will also enable the skilled person to fully appreciate the operation of the resulting suspension system when installed In order to prepare a vehicle 100, in this case a tractor, for installation a jack 125 is used to raise the rear of the tractor and to enable axle stands 120 to be positioned to support the vehicle 100. One of the vehicle wheels 110a On this case the right-hand wheel) may then be removed as shown in Figure 2 to provide ease of access. As shown in Figure 3, a lifting frame 130 (or other suitable lifting method) may then be used to raise the cab and take the weight off the spring shock assembly of the tractor so that the shock 150 can be removed along with its associated mounting bracket 160.

With the original coil shock 150 removed the first air damper 2a can be installed between the cab and chassis/axle of the tractor (with the lifting frame 130 still holding the weight of the cab). In the illustrated embodiment this is carried out by installing a new right hand mounting bracket 5 (although in some embodiments the air damper 2 dimensions may be sufficiently matched to the original coil shock 150 for the original mounting bracket 160 to be used). It is not essential whether the mounting bracket is connected to the chassis/axle or the damper first and the order of connection may be selected based on ease of installation. The air inlet port of the air damper 2a is positioned to face towards the gearbox.

In the next step the air supply T-pipe 4 will be connected, and this is shown in isolation in Figure 5. It can be noted that the pipe has a short section 4a and two longer sections 4b and 4c extending from the T-shaped intersection. The T-pipe 4 is placed over the over the gearbox of the tractor and the fed around pipes and cables to find a suitable and tidy location. As will be explained further below the short end 4a will connect to the levelling valve 6 and the two longer ends 4b, 4c will connect to the air dampers 2. With the Y-pipe 4 in position the first end 4b can be connected to the first air damper 2a (for example via push fit coupling).

The cab of the tractor may now be lowered and the first wheel 110a refitted before removing the second (left-hand) wheel 110b. The step of removing the existing spring shock (and if necessary associated mounting bracket) is then repeated for the second side of the tractor as shown in Figure 6.

The installation of the second air damper 2b and associated mounting bracket 8 is then carried out in the same manner as the first damper 2a. As shown in Figure 7 the mounting of the second air damper 2b includes a bolt including a locating pin 8a with a ball joint at an outer end. This pin 8 is used to mounting one end the linkage rod 3 to the levelling valve 6 (see Figure 13 below). When correctly mounted the ball of the pin 8a will face the gearbox and the air connector will be on the opposite side to prevent it from touching the linkage rod 3. Once this assembly is mounted the air pipe 4c can be connected to the air damper 2b.

With both air dampers installed, the levelling valve 6 can be installed. The body 6a of the levelling valve includes an inlet port (numbered 1) and an outlet port (numbered 2). A swivel connector 13a and 13b is connected to each port of the valve (as shown in Figure 8). Swivel elbows 14a and 14b can then be connected (for example they may be push fit) into the swivel connectors 13a, 13b. As shown in Figure 10, a first end 3b of the linkage rod 3 is connected to the actuator potion 6b of the levelling valve 6.

Whilst levelling valve 6 could be provided with an integrated mounting arrangement (for example formed as part of its casing), in order to provide increased installation flexibility it is advantageous to have an adjustable mounting. As such, the mounting plate 7 may be first attached to the valve 6 using bolts 16 as shown in Figure 11. Subsequently the mounting plate 7 can be attached to a convenient mounting point on the cab of the vehicle as shown in Figure 12.

In most cases the cab will be pre-fitted with mounting holes (for example mount points for optional features such as a gearbox breather and an electric handbrake). The levelling valve 6 is positioned using the mount 7 to ensure that the end 3c of linkage rod 3 is able to attach to the lower ball joint 8c without obstructing other components, as shown in Figure 13. The ends 3b and 3c of the linkage rod 3 can be arranged to allow them to float freely on the rod once installed.

At this stage the short section 4a can be connected to the outlet port "2" of the levelling valve.

The final stage of installation requires the connection of the suspension system to the supply of compressed air of the vehicle. As shown in Figures 14a, 14b and 14c to accommodate attachment to a variety of vehicles, the pressure protection valve 15 can be assembled into a variety of configurations with the T-fitting 10 and the elbow connector 11. A user is, therefore, able to select an appropriate configuration for their vehicle and assemble a pressure protection valve assembly which best suits the needs. As shown in Figure 15, the bulkhead fitting 9 may be used to connect the valve assembly 15 and air supply through a bulkhead 105 of the vehicle. Once an appropriate configuration is assembled for the valve 15 it can be attached to the air supply of the vehicle. The air hose 1 can be connected from the pressure protection valve 15 to inlet port "1" on the levelling valve 6.

Thus, the suspension system can now be operational with compressed air being supplied through the pressure protection valve 15 to the levelling valve 6 via pipe 1. The levelling valve 6 can subsequently supply air through the T-pipe 4 to the air dampers 2. The levelling valve 6 is fixed relative to the cab of the vehicle and the lower portion of the air damper 2b having the location pin 8a is fixed relative to the chassis/axle of the vehicle. The control linkage 3 is, therefore, responsive to relative movement between the cab and chassis/axle and acts upon the actuator 6b of the levelling valve to control actuation thereof. Importantly, should any significant leak develop in the suspension system that causes a loss of pressure the pressure protection valve 15 will automatically close to maintain operational pressure in the supply of compressed air on the vehicle.

Referring now to Figures 17 to 20, there is shown in Figure 17 various support plates, bolts, nuts and washers. These are fitted as follows: Firstly an air tank is drained. Then the rear of the tractor is raised and supported for example on two axle stands below the final drive cases. Using suitable equipment the rear righthand wheel is safely removed. Using suitable lifting gear the cab is raised to remove the load off the spring shock assembly.

If necessary excess air can be drained from air bags by pushing a quick connector on a T-piece in an airline and releasing the air pipe. It is important that these are reconnected prior to use. It is also important to ensure the cab is safely supported whilst fitting the support plates as the cab may drop onto bump stops if not supported whilst air is being released from the air tank.

Figure 18 shows how the bolt securing top eye of the shock absorber is removed and Figure 19 shows two new support plates being fitted on top of air bag facing inwards and secure with the additional longer bolt supplied. Figure 20 shows how plates are aligned level with the top of the air bag and tighten the bolt. Once fitted the cab is lowered onto the bump stop. The cab supports are then removed, and the wheel is replaced. The process is then repeated with the other wheel.

It will be appreciated that variation may be made to the aforementioned embodiment without departing from the scope of protection as defined by the claims. For example, the embodiment described above uses a standard air damper 2 and is able to ensure that the system can be fitted to a variety of vehicles by providing mounting brackets 5 and 8 which are tailored to the required vehicle.

In other embodiments the need for such custom mounting brackets may be removed though an appropriate selection of the dimensions of the dampers, for example by using a custom-made damper. In such arrangements the kit of parts may no longer require mounting brackets since the existing brackets/mounting points of the vehicle may be utilised and as such it is appreciated that a universal kit could therefore be provided.

Claims

Claims 1. A retrofit vehicle cab suspension system comprising: at least one air damper for mounting between a cab and an axle or chassis of a vehicle; a pressure protection valve comprising an inlet for connection to a compressed air supply of the vehicle, an outlet for supplying compressed air to the suspension system and a valve which closes the supply in response to a loss of pressure in the suspension system; a levelling valve comprising an inlet for receiving compressed air from the outlet of the pressure protection valve, an outlet for supplying pressure to the at least one air damper, a mount for supporting the levelling valve on one of the cab and the axle or chassis, and an actuator for controlling the flow through the valve; wherein the suspension system further comprises: a control linkage for connecting, in use, between the actuator of the levelling valve and the portion of the at least one air damper connected to the other of the cab and the axle or chassis to which the levelling valve is mounted.
2. The system according to claim 1, comprising a pair of air dampers and wherein the linkage connects to one of the air dampers.
3. The system according to claim 1 or 2, wherein the control linkage is connected to at least one air damper and the levelling valve, via a flexible coupling, for example a ball joint, at each end of the control linkage.
4. The system according to claim 1, 2 or 3, wherein the levelling valve is mounted to the cab and the linkage extends to the axle or a chassis side of the at least one air damper.
5. The system according to any of claims 1 to 4, wherein the outlet and/or the inlet of the levelling valve comprises a swivel connector.
6. A kit of parts comprising a retrofit cab suspension system, according to any preceding claim for fitting to a vehicle.
7. The kit according to claim 6, further comprising a mounting bracket for connecting the levelling valve to a vehicle cab.
8. The kit according to claim 6 or 7, comprising a mounting bracket for connecting the, or each, air damper to the axle or chassis of a vehicle.
9. The kit according to claim 8, wherein air damper mounting bracket comprises a locating member for connecting an end of the control linkage to the air damper.
10. The kit according to any of claims 6 to 9, further comprising an air supply T-pipe having an inlet for connection to an output of the levelling valve and first and second outlets for connection to an inlet on each of a pair of air dampers.
11. The kit according to any of claims 6 to 10, further comprising a pressure protection valve for providing a connection from a compressed air system of the tractor to the inlet of the levelling valve.
12. The kit according to claim 11, wherein the pressure protection valve is configured to connect to the air brake system of the tractor.
13. The kit according to any of claims 6 to 12, wherein the pressure protection valve comprises a plurality of inter-connectable members.
14. A method of retrofitting a vehicle air cab suspension system, the method comprising: providing at least one air damper; providing a pressure protection valve providing a levelling valve; connecting the pressure protection valve as an interface between the air cab suspension system and a supply of compressed air on the tractor; connecting an outlet of the pressure protection valve as to the at least one damper via the levelling valve and; connecting a control linkage between the levelling valve and the air damper.
15. The method according to claim 14, wherein the step of connecting the pressure protection valve as an interface comprises connecting the pressure protection valve to the air brake system.
16. The method according to any of claims 14 or 15, wherein providing an air damper comprises removing and replacing an existing spring shock assemblies between the cab and axle or chassis of the tractor.
17. The method according to claim 16, wherein removal of the spring shock assemblies includes removal of the shock mounting bracket and installation of an air damper includes installation of a new mounting bracket.
18. The method according to any of claims 14 to 17, wherein the step of connecting an outlet of the pressure protection valve to the at least one damper via the levelling valve comprises connecting an inlet of an air supply T-pipe to an output of the levelling valve and connecting the first and second outlets of the T-pipe to inlets on each of a pair of air dampers.