WO2006045124A1

WO2006045124A1 - A towed vehicle

Info

Publication number: WO2006045124A1
Application number: PCT/ZA2005/000159
Authority: WO
Inventors: Morne Inus Van Rooyen
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-10-21
Filing date: 2005-10-20
Publication date: 2006-04-27
Anticipated expiration: 2007-04-21

Abstract

A towed vehicle (10) which is wheeled and which includes a body (14) which has a drawbar member (24), a housing (16) attached to the body, at least one wheel (18) which is rotatably engaged with the body, and a cooling arrangement (20) on the body which has a mechanical drive means (40) engaged with the wheel, a compression refrigeration device (48) which is in communication with the housing and which is drivable by the mechanical drive means and a first engagement means (42) which enables the mechanical drive means and the refrigeration device to be connectable to one another.

Description

A TOWED VEHICLE

BACKGROUND OF THE INVENTION

[0001] This invention relates to a towed vehicle such as a trailer with a cold storage container used for the transport of cold or frozen goods as well as a cooling arrangement for use on a trailer of this kind.

[0002] It is known to fit a cold storage container on a trailer with a cooling unit which is electrically driven by electricity generated by a generator connected to the motor of a towing vehicle. The refrigeration capabilities of such a unit are limited as a result of the 12 volt or 24 volt power supply generated by the towing vehicle.

[0003] In order to improve the refrigeration capabilities of the cooling unit it is also known to fit the trailer with an independent fuel driven motor to drive the cooling unit. This is costly and often impractical especially where goods are transported in a relatively small container.

SUMMARY OF THE INVENTION

[0004] This invention aims to provide an alternative cooling arrangement for use on towed vehicles which have cold storage containers for the road transport of goods.

[0005] The invention provides a towed vehicle which is wheeled and which includes a body which has a drawbar member, a housing attached to the body, at least one wheel which is rotatably engaged with the body, and a cooling arrangement on the body which has a mechanical drive means engaged with the wheel, a compression refrigeration device which is in communication with the housing and which is drivable by the mechanical drive means and a first engagement means which enables the mechanical drive means and the refrigeration device to be connectabie to one another.

[0006] The first engagement means may include a first clutch member and a first control switch which is connected to the first clutch member. The first clutch member is preferably in the form of an electric clutch and the first control switch may be connected to a speedometer.

[0007] The towed vehicle may include a temperature switch which is connected to the first control switch.

[0008] The body may include a frame and a suspension which supports an axle to which the wheel is attached.

[0009] The housing is preferably enclosed and insulated and may be in the form of a cold storage container.

[0010] The mechanical drive means may include a first transmission transfer device which is connected between the wheel and the first engagement means. The first transfer device may include a primary pulley attached to the wheel, a drive shaft connected to the first engagement means, a first secondary pulley on the drive shaft, a first belt member which extends between the first primary pulley and the first secondary pulley and a first tensioning member which acts between the body and the first belt member.

[0011] The mechanical drive may include a second transmission transfer device between the drive shaft and the refrigeration device. The second transfer device may include a second secondary pulley which is engageable with the drive shaft, a third secondary pulley which is engageable with the refrigeration device, a second belt member which extends between the second and third secondary pulleys and a second tensioning member which acts between the body and the second belt member.

[0012] Preferably the wheel includes a hub from which the first primary pulley extends.

[0013] The first tensioning member may include a tension bar which is fixed to the body, a lever arm which extends from the tension bar and a roller which is rotatably attached to the lever arm and which abuts against the first belt member.

[0014] The refrigeration device may include a compressor with which the mechanical drive means is connectable, refrigerant circuitry connected to the compressor, a condenser which is connected to the circuitry and which is located outside the housing and an evaporator which is connected to the circuitry and which is located inside the housing.

[0015] The cooling arrangement may include an electric drive means which is connectable to the refrigeration device. The electric drive means may include an electric motor which is connectable to a power supply. The power supply is preferably external from the towed vehicle.

[0016] The cooling arrangement may include a second engagement means which is connected to the first engagement means and which enables the electric drive means and the refrigeration device to be connectable to one another. The second engagement means preferably includes a second clutch member which may be in the form of an electric clutch. The second engagement means may include a second control switch. [0017] The temperature switch may be connectable to the power supply.

[0018] The invention also provides a towed vehicle which is wheeled and which includes a body which has a drawbar member, a housing attached to the body, at least one wheel which is rotatably engaged with the body and a cooling arrangement on the body which has a mechanical drive means which is engaged with the wheel, an electrical drive means fixed to the body and a compression refrigeration device which is in communication with the housing and which is selectively connectable to the mechanical drive means and the electrical drive means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is further described by way of examples with reference to the accompanying drawings in which:

Figure 1 is a perspective view of a trailer according to the invention;

Figure 2 is a schematic representation of a cooling unit used in the trailer of Figure 1 ;

Figure 3 is a partial side view of the trailer of Figure 1 ; and

Figure 4 is a sectioned and partial plan view of the trailer of Figure 1.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0020] Figure 1 shows a towed vehicle or trailer 10 which is coupled to a towing vehicle 12. The trailer 10 has a body 14, a housing or container 16 attached to the body 14, two spaced apart wheels 18, each of which is rotatably engaged with the body 14, and a cooling arrangement or unit 20 on the body 14.

[0021] The body 14 is manufactured from appropriate metal components and has a frame 22 connected to a drawbar 24 which is coupled to the towing vehicle 12. [0022] The container 16 is enclosed and insulated and in the form of a cold storage container used for the cold storage and transport of cold or frozen goods. The container 16 has a door 26 through which access to an interior 28 of the container 16 is gained.

[0023] The wheels 18 are interconnected by an axle 30 which is attached to the frame 22 by a torque suspension 32.

[0024] Each of the wheels 18 has a tyre 34 fixed to a hub 36. Each hub 36 is bolted to a drum 38 which is attached to the axle 30.

[0025] As is shown in Figure 2 the cooling unit 20 has a mechanical drive 40 which is connected to a first electric clutch 42, an electric drive 44 which is connected to a second electric clutch 46 and a compression refrigerator system 48 connected to the first and second clutches 42, 46.

[0026] The mechanical drive 40 is shown in detail in Figures 3 and 4 and has a first transmission transfer device 50 which acts between one of the wheels 18 and the first clutch 42. The first transfer device 50 has a primary pulley 52 which is fixed to the wheel 18A by way of the drum 38, a drive shaft 54 which is fixed to the frame 22 and connected to the first clutch 42, a first secondary pulley 56 which is attached to the shaft 54, a first belt 58 which extends between and runs over the primary pulley 52 and the first secondary pulley 56, and a first tensioner 60 which acts between the frame 22 and the first belt 58.

[0027] The shaft 54 is attached to the frame 22 by way of appropriate bearings 62. The belt 58 is looped, flexible to at least a limited extent and V-shaped in cross-section. The first tensioner 60 has a torsion bar 62 which is fixed to the frame 22, a lever arm 66 which extends from the torsion bar 64 and a roller or jockey wheel 68 which is rotatably attached to the lever arm 66 and which rotatably abuts against the first belt 58.

[0028] The first clutch 42 is in the form of a known electric clutch and a first control switch 70 is connected to the first clutch 42. The first switch 70 is connected to a speedometer 72 and a temperature switch 74. The speedometer 72 measures the speed of travel of the trailer 10 in a known manner and the temperature switch 74 is in communication with the container 10 and measures the temperature in the interior 28 of the container 16 in a known manner. In combination the first clutch 42 and first switch 70 act as a first engagement system to selectively connect the mechanical drive 40 to the refrigerator system 48.

[0029] A second transmission transfer device 5OB acts between the first clutch 42 and the refrigerator system 48. The second transfer device 5OB has a second secondary pulley 76 which is connected to and extends from the first clutch 42, a third secondary pulley 78 which is attached to the refrigerator system 48 and a second belt 82 which is similar to the first belt 58 and which extends between the second secondary pulley 76 and the third secondary pulley 78. A second tensioner 84 which is similar to the first tensioner 60 acts between the frame 22 and the second belt 82.

[0030] The electric drive 44 has an electric motor 86 which is in the form of a 2.2 kilowatt single phase motor. The motor 86 is connectable to a power supply 88 which is external from the trailer 10. The power supply 88 is in the form of a conventional 240 volt electrical mains connection and the temperature switch 74 is also connectable to the power supply 88. [0031] A second control switch 89 is connected to the second clutch 46 which is used to engage and disengage the second clutch 46. In combination the second clutch 46 and the second switch 89 act as a second engagement system to selectively connect the electric drive 44 to the refrigerator system 48.

[0032] The motor 86 has a fourth secondary pulley 90 and a third belt 92 which is similar to the first belt 58 and which extends between the fourth secondary pulley 90 and a fifth secondary pulley 91 which is engaged with the second clutch 46. A third tensioner 94 which is similar to the first tensioner 60 acts between the frame 22 and the third belt 92.

[0033] The refrigerator system 48 is of known construction and has a compressor 96 which is selectively connectable to the mechanical and electrical drives 40, 44 by way of the respective first and second electric clutches 42, 46. The compressor 96 is in communication with and connected to refrigerant circuitry 98A, a condenser 98B and an evaporator 98B. The condenser 98B is located on the body 14 outside the container 16 and the evaporator 98C is located in the interior 28 of the container 16.

[0034] In use the first transfer device 50 is driven by the wheel 18A when the trailer 10 is towed by the towing vehicle 12. The speedometer 72 measures the speed at which the trailer 10 is travelling and when a selected speed is reached the first switch 70 engages the first clutch 42. The first clutch 42 connects the mechanical drive 40 with the compressor 98 and the compressor 98 is driven by the mechanical drive 40 which results in the cooling of the interior 28 of the container 16 in a known manner by way of the refrigerator system 48. [0035] When the travelling speed of the trailer 10 falls below the selected speed the first switch 70 disengages the first clutch 42 in order to disconnect the mechanical drive 40 and the compressor 98. This ensures that no additional strain is placed on the towing vehicle 12 at low speeds. Additionally the temperature switch 74 monitors the temperature of the interior 28 and when the temperature in the interior 28 falls below a selected temperature the temperature switch 74 initiates the first switch 70 to disengage the first clutch 42 in order to disconnect the mechanical drive 40 and the compressor 98. When the temperature in the interior 28 rises above the selected temperature then the temperature switch 74 initiates the first switch 70 to engage the first clutch 42 in order to connect the mechanical drive 40 and the compressor 96, provided that the trailer 10 is travelling above the selected speed.

[0036] The electric drive 44 is used to drive the compressor 96 when the trailer 10 is stationary. The motor 86 is then connected to the appropriate power supply 88 and the second clutch 46 is engaged by way of the second control switch 89. The second clutch 46 connects the electric drive 44 with the compressor 96 to allow the motor 86 to drive the compressor 96. Again the interior 28 is cooled in the manner described and when the temperature in the interior 28 falls below a selected temperature then the temperature switch 74 interrupts the power supply 88 to the motor 86 and the motor 86 stops in order to conserve energy. When the temperature in the interior 28 rises above the selected temperature then the temperature switch 74 re-instates power supply 88 to the motor 86 and the refrigerator system 48 is re-activated.

[0037] While the electric drive 44 drives the compressor 96 the second and third secondary pulleys 76, 78 and the second belt 82 are rotated in unison with the fifth secondary pulley 91. The first clutch 42 however remains disengaged and the mechanical drive 40 is not connected to the compressor 96.

[0038] When the trailer 10 is prepared for towing the power supply 88 is disconnected and the second control switch 89 is initiated to disengage the second clutch 46 in order to disconnect the electric drive 44 from the compressor 96. During travel the compressor 96 is driven by the mechanical drive 40 in the manner described.

[0039] Each of the first, second and third tensioners 60, 84, 94 ensures that each of the respective first, second and third belts 58, 82, 92 remains tensioned. This is of particular importance when the trailer 10 is in motion and there is relative movement between the frame 22 and the wheel 18A, as the wheel 18A rides on a road surface 100 and the suspension 32.

[0040] By varying the size of the primary and secondary pulleys 52, 56, 76, 78, 90 and 91, the relative operating speeds of the shaft 54, belts 82, 92 and compressor 96 can be adjusted and selected for optimum performance at various speeds of travel of the trailer 10 and operating speeds of the motor 86.

[0041] That the cooling unit 20 allows the selection of either the mechanical drive 40 or the electric drive 44 for the driving of the compressor 96. Strain on the towing vehicle 12 is reduced by the first clutch 42 and first control switch 70 which restricts connection of the mechanical drive 40 with the compressor 96 to situations when the trailer 10 travels above a selected speed and the temperature in the interior 28 rises above a selected temperature. The electric drive 44 adds flexibility to the cooling unit 20 as this allow for the continuous cooling of the interior 28 when the trailer 10 is stationary. [0042] Through experimentation the applicant has found that at atmospheric temperatures of between 17° Celsius and 30° Celsius and for a container 16 with a 4800 litre capacity, the interior 28 can be cooled to approximately -30° Celsius when the trailer 10 travels at a speed of above 60 kilometres per hour.

In another form of the invention a third wheel (not shown) which is rotatably engaged with the frame 22 can be used in a similar manner as described herein to provide the mechanical drive 40. The third wheel can for example be hydraulically lowered into contact with the road surface when mechanical drive of the compressor 96 is required. When the travelling speed of the trailer 10 falls below the selected speed or when the temperature in the interior 28 falls below a selected temperature the third wheel is hydraulically raised away from the road surface and mechanical drive of the compressor 96 is terminated. In this example the first clutch 42 is thus replaced by a hydraulic system which induces mechanical drive to the compressor 96.

Claims

1. A towed vehicle which is wheeled and which includes a body which has a drawbar member, a housing attached to the body, at least one wheel which is rotatably engaged with the body, and a cooling arrangement on the body which has a mechanical drive means engaged with the wheel, a compression refrigeration device which is in communication with the housing and which is drivable by the mechanical drive means and a first engagement means which enables the mechanical drive means and the refrigeration device to be connectable to one another.

2. A towed vehicle according to claim 1 wherein the first engagement means includes a first clutch member and a first control switch which is connected to the first clutch member.

3. A towed vehicle according to claim 2 wherein the first clutch member is in the form of an electric clutch.

4. A towed vehicle according to claims 2 and 3 wherein the first control switch is connected to a speedometer.

5. A towed vehicle according to claims 2, 3 and 4 which includes a temperature which is which is connected to the first control switch.

6. A towed vehicle according to any one of claims 1 to 5 wherein the body includes a frame and a suspension which supports an axle to which the wheel is attached.

7. A towing vehicle according to any one of claims 1 to 6 wherein the housing is preferably enclosed and insulated.

8. A towing vehicle according to any one of claims 1 to 7 wherein the housing is in the form of a cold storage container.

9. A towed vehicle according to any one of claims 1 to 8 wherein the mechanical drive means includes a first transmission transfer device which is connected between the wheel and the first engagement means.

10. A towed vehicle according to claim 9 wherein the first transfer device includes a primary pulley attached to the wheel, a drive shaft connected to the first engagement means, a first secondary pulley on the drive shaft, a first belt member which extends between the first primary pulley and the first secondary pulley and a first tensioning member which acts between the body and the first belt member.

11. A towed vehicle according to claim 10 wherein the mechanical drive includes a second transmission transfer device between the drive shaft and the refrigeration device.

12. A towed vehicle according to claim 11 wherein the second transfer device includes a second secondary pulley which is engageable with the drive shaft, a third secondary pulley which is engageable with the refrigeration device, a second belt member which extends between the second and third secondary pulleys and a second tensioning member which acts between the body and the second belt member.

13. A towed vehicle according to claim 10, 11 or 12 wherein the wheel includes a hub from which the first primary pulley extends.

14. A towed vehicle according to any one of claims 10 to 13 wherein the first tensioning member includes a tension bar which is fixed to the body, a lever arm which extends from the tension bar and a roller which is rotatably attached to the lever arm and which abuts against the first belt member.

15. A towed vehicle according to any one of claims 1 to 14 wherein the refrigeration device includes a compressor with which the mechanical drive means is connectable, refrigerant circuitry connected to the compressor, a condenser which is connected to the circuitry and which is located outside the housing and an evaporator which is connected to the circuitry and which is located inside the housing.

16. A towed vehicle according to any one of claims 1 to 15 wherein the cooling arrangement includes an electric drive means which is connectable to the refrigeration device.

17. A towed vehicle according to claim 16 wherein the electric drive means includes an electric motor which is connectable to a power supply.

18. A towed vehicle according to claim 17 wherein the power supply is external from the towed vehicle.

19. A towed vehicle which is wheeled and which includes a body which has a drawbar member, a housing attached to the body, at least one wheel which is rotatably engaged with the body and a cooling arrangement on the body which has a mechanical drive means which is engaged with the wheel, an electrical drive means fixed to the body and a compression refrigeration device which is in communication with the housing and which is selectively connectable to the mechanical drive means and the electrical drive means.