GB2288771A - Trailer with air suspension and a lift-axle - Google Patents

Trailer with air suspension and a lift-axle Download PDF

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Publication number
GB2288771A
GB2288771A GB9508290A GB9508290A GB2288771A GB 2288771 A GB2288771 A GB 2288771A GB 9508290 A GB9508290 A GB 9508290A GB 9508290 A GB9508290 A GB 9508290A GB 2288771 A GB2288771 A GB 2288771A
Authority
GB
United Kingdom
Prior art keywords
valve
air
control
load
platform
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9508290A
Other versions
GB2288771B (en
GB9508290D0 (en
Inventor
Anthony Arthur Varndell
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
M & G Tankers & Trailers Ltd
Original Assignee
M & G Tankers & Trailers Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by M & G Tankers & Trailers Ltd filed Critical M & G Tankers & Trailers Ltd
Publication of GB9508290D0 publication Critical patent/GB9508290D0/en
Publication of GB2288771A publication Critical patent/GB2288771A/en
Application granted granted Critical
Publication of GB2288771B publication Critical patent/GB2288771B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/0152—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the action on a particular type of suspension unit
    • B60G17/0155—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by the action on a particular type of suspension unit pneumatic unit
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
    • B60G17/04—Spring characteristics, e.g. mechanical springs and mechanical adjusting means fluid spring characteristics
    • B60G17/052—Pneumatic spring characteristics
    • B60G17/0523—Regulating distributors or valves for pneumatic springs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D61/00—Motor vehicles or trailers, characterised by the arrangement or number of wheels, not otherwise provided for, e.g. four wheels in diamond pattern
    • B62D61/12—Motor vehicles or trailers, characterised by the arrangement or number of wheels, not otherwise provided for, e.g. four wheels in diamond pattern with variable number of ground engaging wheels, e.g. with some wheels arranged higher than others, or with retractable wheels
    • B62D61/125—Motor vehicles or trailers, characterised by the arrangement or number of wheels, not otherwise provided for, e.g. four wheels in diamond pattern with variable number of ground engaging wheels, e.g. with some wheels arranged higher than others, or with retractable wheels the retractable wheel being a part of a set of tandem wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
    • B60G2800/20—Stationary vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
    • B60G2800/22—Braking, stopping

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Vehicle Body Suspensions (AREA)

Abstract

The trailer may have three air-sprung axles (2A, 2B, 2C, Fig. 1), the leading one (2A) of which can be raised or lowered by an air-bag (10) which is connected by line 21 to a manually operable actuation circuit AA controlled by a pneumatic control circuit BB. The control circuit BB includes a valve, eg a differential pilot valve 30, which is urged by a load-dependent input in line 34 against predetermined pressure in line 28. If the pressure in line 34 is greater, valve 30 exhausts the air-bag line 21 via line 32 so that the manual command from actuation circuit AA is overridden and the axle (2A) is lowered. Valve 30 is connected to a timing circuit CC via line 37 when the platform is loaded and the axle is lowered. A manoeuvre button 38 can be actuated manually to supply a pulse of air from line 44 via line 39 to pilot valve 40 which supplies pressurised air to a timing device 42 which supplies air to the actuator circuit AA so raising the axle 2A for a timed period eg to avoid excessive tyre wear when manoeuvring tightly with a laden trailer in a loading bay or marshalling yard. <IMAGE>

Description

TRAILER WITH AIR SUSPENSION SYSTEM The invention relates to trailers incorporating air suspension systems for the load platform. Such trailers comprise a main chassis having axles and road wheels upon which is mounted a load carrying platform. An air spring suspension unit is associated with each axle in the form of an air bag adjacent each wheel.
The trailer may have a number of axles, for example three, to allow it to carry up to the legally authorised maximum weight. However, there will not always be sufficient load on the platform to require the use of all three axles so one of the axles may be lifted to avoid excess wear on the tyres. In another instance, when the trailer is laden and the vehicle first moves off there is a tendency for the tyres of the wheels carrying the load to be eroded because of the high frictional contact between the wheels and the substrate. The wear can remove the tyre tread and the tyre side wall. This problem is particularly severe when the trailer is manoeuvred in a restricted area, for example a loading bay or marshalling yard of a freight depot. A large amount of material can be removed from the tyre resulting in an intolerable reduction in its useful life. In such a case it is useful to raise at least one axle.
It is known to remove the load on one axle by dumping the air from the air bags associated with that axle, allowing the axle to be raised for a predetermined time period until manoeuvring is complete.
It is known from EP-A-0284572 to provide a pneumatic circuit incorporating means to override a switch to exhaust an air bag and lower the axle when the load exceeds a predetermined value. the means is a pneumatic controller which is operated only after a delay set by a pneumatic delay unit, in order to avoid false triggering caused by the vehicle travelling over bumps in the road. The pneumatic controller is an integrated unit not accessible to the driver of the vehicle.
It is on object of the invention to provide a control arrangement for raising and lowering a load-carrying platform of a road vehicle which is manually actuable so as to move the platform when required.
According to this invention in one aspect there is provided control arrangement for raising and lowering a load-carrying platform of a road vehicle relative to a supporting axle of the platform, the load carrying platform being supported by an air bag, the arrangement comprising valve means for controlling the supply of pressurised air to the air bag, manually operable control means coupled to the valve means and arranged to raise the axle relative to the platform, and a pneumatic control circuit responsive to the load on the platform and coupled to the valve means, the pneumatic control circuit being arranged to override the manually operable means to prevent the axle from being raised when the load exceeds a predetermined threshold, characterised by further manually operable control means coupled to the valve means and including delay means, the further manually operable control means being arranged to raise the axle relative to the platform when the load on the platform exceeds the threshold and for a period set by the delay means.
Preferably the pneumatic control circuit is activated by pressurised air only, and preferably the further manually operable control means is also activated by pressurised air only.
In a preferred aspect the pneumatic control circuit comprises a pilot valve having a control port coupled to air pressurised by the load and having a first condition when the load is at or below the threshold in which a source of pressurised air is connected to a first output line and a second condition when the load is above the threshold value in which the source of pressurised air is connected to a second output line, the first output line being connected to an input port of the valve means and the second output line being connected to an input port of a further valve, the further valve forming part of the manually operable control means and having a first condition in which the second output line is blocked and a second condition in which the second output line is connected to the input port of the further valve.
In yet another preferred feature the further valve is a pilot valve having a control port connected to manually operated control means which, when actuated, applies pressurised air to the control port and sets the pilot valve to its second condition, the control means also being arranged to apply pressurised air to an input of pneumatic delay means whose output is connected to a further control port of the pilot valve, pressure at the further control port being arranged to set the pilot valve to its first condition whereby activation of the manually operable control means sets the pilot valve to its second condition for the time period.
Preferably the pneumatic control circuit comprises a differential pilot valve having a first control port connected to air pressurised by the load and a second control port connected to regulated air pressure, the pilot valve being controlled by the pressure difference at the control ports.
In another aspect, the invention provides a method of manually raising or lowering a load-carrying platform of a road vehicle, the vehicle having a control arrangement comprising valve means for controlling the supply of pressurised air to the air bag which in use supports the platform, relative to an axle of the vehicle, manually operable control means coupled to the valve means and arranged to raise the axle relative to the platform, and a pneumatic control circuit responsive to the load on the platform and coupled to the valve means, the pneumatic control circuit being arranged to override the manually operable means to prevent the axle from being raised when the load exceeds a predetermined threshold, the method comprising actuating manually operable control means coupled to the valve means to raise the axle relative to the platform for a time period when the load exceeds the threshold value.
Preferably the time period is set by delay means associated with the control means.
Preferably the method includes activating the control means by pressurised air only.
In order that the invention may be well understood it will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a plan view of a subframe of the rear part of a trailer; and Figure 2 is a circuit diagram of the invention.
As shown in Figure 1, a trailer 1 includes three transverse axles 2A, 2B, and 2C, each having respective wheels 3A, 3B and 3C at each end. An air spring suspension unit 4A, 4B and 4C is associated with each respective wheel. Pipelines 5 are connected to each bag on each side of the trailer to draw pressurised air from a reservoir, not shown, and the pipelines are in communication with a height level valve 6 arranged to distribute pressurised air between the six bags according to the load on the platform.
As shown, a supplementary air suspension spring bag 10 is present in front of the leading axle 2A. Control valves 7 are present in the pipeline 5 to isolate the air bags 4A when required to raise the front axle.
The circuit shown in Figure 2 comprises three subcircuits, an actuator circuit AA for raising and lowering the front axle, a control circuit BB for the actuator circuit and a timing control circuit CC. The actuator circuit AA is arranged to actuate the air spring bag 10 to raise the front axle 2A, the control circuit BB energises the lifting means, not shown, such that the lifting will take place only when there is a predetermined load on the platform and the timing circuit CC provides a means for controlling the period for which the front axle is raised.
The actuator circuit AA comprises a three way two port pilot valve 20 which is connected by line 21 to provide an output to the bag 10 under conditions explained below. The line 21 includes a spring biased pressure regulator 22 with which is associated a gauge 23. One side of the valve 20 is connected to a manual switch 24 and the other side is connected to an exhaust line 25. The input line 26 to the valve 20 is connected via a shuttle valve 27 to one side of a 5 way 2 port differential pilot valve 30 which forms part of the control circuit BB.
The control circuit BB comprises an input line 28, which is connected to a pressure regulating valve 29 associated with a gauge 31, and supplies air to the 5 port 2 way differential valve 30 at a predetermined pressure. The pressurised air supply is connected to the actuator circuit AA via line 32 and maintains the front axle 2A in a raised condition.
A pressure relief valve 33 incorporating a non-return valve 35 and a reservoir 36 is connected to the opposite side of the 5 port 2 way differential pilot valve 30. Air is supplied to the pressure relief valve 33 by input line 34 and the pressure in the relief valve builds up according to a load on the platform (not shown). When the pressure in the pressure relief valve 33 reaches a threshold value it supplies the 5 port 2 way differential pilot valve 30 with air at a pressure greater than that from input line 28 thus triggering it. The air in the air bag 10 will be exhausted via the actuator circuit AA, lowering the axle to accommodate the load and overriding depression of the switch 24. The rate of exhaustion of the air will depend on the overload of the vehicle platform.
The 5 port 2 way differential pilot valve 30 is connected to a timing circuit CC via line 37 only when there is a load on the platform and the axle is lowered. A manoeuvre button 38 is manually activated to supply a pulse of air from input line 44 via a line 39 to a 3 way 2 port differential pilot valve 40. The pilot valve 40 is triggered to supply pressurised air via line 41 to a timing device 42.
The timing device 42 includes a number of chambers through which pressurised air must pass. The input and output lines of the timer 42 may be moved to alter the timing of the device.
The timer 42 will supply air from input line 45 via line 46 and the pilot valve 40 to the actuator circuit AA, and to the air bag 10 to raise the front axle 2A. When the timer 42 stops, the 3 port 2 way pilot valve 40 will be triggered by a pulse of air from the timer via line 43 to de-enable the actuator circuit AA and hence exhaust air from the lift bag 10 lowering the front axle 2A.
The pneumatic circuit of Figure 2 is not limited to the embodiment shown in the circuit diagram. For example, the pressure regulating valve 29 and its associated gauge 31 of the control circuit BB may be substituted by a 3 port 2 way variable sprung pilot valve supplied by input line 28 with its output connecting to the 5 port 2 way differential pilot valve 30.

Claims (9)

  1. A control arrangement for raising and lowering a load-carrying platform of a road vehicle (1) relative to a supporting axle (2A) of the platform, the load carrying platform being supported by an air bag (10), the arrangement comprising valve means (20) for controlling the supply of pressurised air to the air bag, manually operable control means (AA) coupled to the valve means (20) and arranged to raise the axle relative to the platform, and a pneumatic control circuit (BB) responsive to the load on the platform and coupled to the valve means, the pneumatic control circuit being arranged to override the manually operable means to prevent the axle from being raised when the load exceeds a predetermined threshold, characterised by further manually operable control means (CC) coupled to the valve means (20) and including delay means (42), the further manually operable control means being arranged to raise the axle (2A) relative to the platform when the load on the platform exceeds the threshold and for a period set by the delay means (42).
  2. 2 A control arrangement according to Claim 1, wherein the pneumatic control circuit (BB) is activated by pressurised air only.
  3. 3 A control arrangement according to Claim 1 or Claim 2, wherein the further manually operable control means (CC) is activated by pressurised air only.
  4. 4 A control arrangement according to any preceding Claim, wherein the pneumatic control circuit (BB) comprises a pilot valve (30) having a control port coupled to air pressurised by the load and having a first condition when the load is at or below the threshold in which a source (28) of pressurised air is connected to a first output line 02) and å ss6nd condition when the lôad is above the threshold value in which the source of pressurised air is connected to a second output line (37), the first output line being connected to an input port of the valve means (20) and the second output line being connected to an input port of a further valve (40), the further valve (40) forming part of the manually operable control means (AA) and having a first condition in which the second output line is blocked and a second condition in which the second output line is connected to the input port of the further valve (40).
  5. 5 A control arrangement according to Claim 4, wherein the further valve (40) is a pilot valve having a control port connected to manually operated control means (38) which, when actuated, applies pressurised air to the control port and sets the pilot valve (40) to its second condition, the control means also being arranged to apply pressurised air to an input of pneumatic delay means (42) whose output is connected to a further control port of the pilot valve, pressure at the further control port being arranged to set the pilot valve to its first condition whereby activation of the manually operable control means (38) sets the pilot valve (40) to its second condition for the time period.
  6. 6 A control arrangement according to any preceding Claim, wherein the pneumatic control circuit (BB) comprises a differential pilot valve (30) having a first control port connected to air pressurised by the load and a second control port connected to regulated air pressure, the pilot valve being controlled by the pressure difference at the control ports.
  7. 7. A method of manually raising or lowering a load-carrying platform of a road vehicle, the vehicle having a control arrangement comprising valve means for controlling the supply of pressurised air to the air bag which in use supports the platform, relative to an axle of the vehicle, manually operable control means coupled to the valve means and arranged to raise the axle relative to the platform, and a pneumatic control circuit responsive to the load on the platform and coupled to the valve means, the pneumatic control circuit being arranged to override the manually operable means to prevent the axle from being raised when the load exceeds a predetermined threshold, the method comprising actuating manually operable control means coupled to the valve means to raise the axle relative to the platform for a time period when the load exceeds the threshold value.
  8. 8. A method according to Claim 7, wherein the time period is set by delay means associated with the control means.
  9. 9. A method according to Claim 7 or 8, including activating the control means by pressurised air only.
GB9508290A 1994-04-29 1995-04-24 Control arrangement for supporting axle of vehicle Expired - Fee Related GB2288771B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9408525A GB9408525D0 (en) 1994-04-29 1994-04-29 Trailer with air suspension system

Publications (3)

Publication Number Publication Date
GB9508290D0 GB9508290D0 (en) 1995-06-14
GB2288771A true GB2288771A (en) 1995-11-01
GB2288771B GB2288771B (en) 1997-10-08

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Family Applications (2)

Application Number Title Priority Date Filing Date
GB9408525A Pending GB9408525D0 (en) 1994-04-29 1994-04-29 Trailer with air suspension system
GB9508290A Expired - Fee Related GB2288771B (en) 1994-04-29 1995-04-24 Control arrangement for supporting axle of vehicle

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB9408525A Pending GB9408525D0 (en) 1994-04-29 1994-04-29 Trailer with air suspension system

Country Status (3)

Country Link
AU (1) AU2312995A (en)
GB (2) GB9408525D0 (en)
WO (1) WO1995029837A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0714796A1 (en) * 1994-11-24 1996-06-05 Accesorios Y Elevadores Valencia, S.L. Vehicle wheel elevation valve with automatic lowering
GB2356608A (en) * 1999-11-29 2001-05-30 Sdc Trailers Ltd Semi-trailer assembly
US6572124B2 (en) * 2001-02-28 2003-06-03 Smc Corporation Of America Lift axle control system
US9533540B2 (en) 2014-03-04 2017-01-03 Hendrickson Usa, L.L.C. Parking brake interlock for automatic lift axle
US10611206B2 (en) 2013-03-13 2020-04-07 Hendrickson Usa, L.L.C. Air suspension control system
US11220151B1 (en) 2020-12-10 2022-01-11 Norgren Gt Development Llc System and valve assembly for controlling a retractable axle of a vehicle

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0284572A2 (en) * 1987-03-27 1988-09-28 VIBERTI VEICOLI INDUSTRIALI S.r.l. Device for raising one of the axles of a semi-trailer road vehicle and lifting assembly therefor

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3201141A (en) * 1962-06-26 1965-08-17 Fruehauf Corp Tandem axle wheel suspension including axle lift
SE338928B (en) * 1966-08-30 1971-09-20 Boliden Ab
DE2439588C3 (en) * 1974-08-17 1981-07-23 Robert Bosch Gmbh, 7000 Stuttgart Actuating device for the lifting device of a lifting axle
US4854409A (en) * 1987-11-19 1989-08-08 Lear Siegler, Inc. Lift axle control system
GB2282111A (en) * 1993-09-24 1995-03-29 M & G Tankers & Trailers Ltd Lift axles

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0284572A2 (en) * 1987-03-27 1988-09-28 VIBERTI VEICOLI INDUSTRIALI S.r.l. Device for raising one of the axles of a semi-trailer road vehicle and lifting assembly therefor

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0714796A1 (en) * 1994-11-24 1996-06-05 Accesorios Y Elevadores Valencia, S.L. Vehicle wheel elevation valve with automatic lowering
ES2113802A1 (en) * 1994-11-24 1998-05-01 Accesorios Y Elevadores Valenc Vehicle wheel elevation valve with automatic lowering
GB2356608A (en) * 1999-11-29 2001-05-30 Sdc Trailers Ltd Semi-trailer assembly
GB2356608B (en) * 1999-11-29 2002-08-14 Sdc Trailers Ltd Semi-trailer assembly
US6572124B2 (en) * 2001-02-28 2003-06-03 Smc Corporation Of America Lift axle control system
US10611206B2 (en) 2013-03-13 2020-04-07 Hendrickson Usa, L.L.C. Air suspension control system
US9533540B2 (en) 2014-03-04 2017-01-03 Hendrickson Usa, L.L.C. Parking brake interlock for automatic lift axle
US11220151B1 (en) 2020-12-10 2022-01-11 Norgren Gt Development Llc System and valve assembly for controlling a retractable axle of a vehicle

Also Published As

Publication number Publication date
WO1995029837A1 (en) 1995-11-09
GB9408525D0 (en) 1994-06-22
GB2288771B (en) 1997-10-08
AU2312995A (en) 1995-11-29
GB9508290D0 (en) 1995-06-14

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Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19990424