GB2263759A - Refrigerated vehicles - Google Patents

Abstract

In order to avoid the high cost of conventional conversion of a vehicle a goods vehicle has in its load space a removable refrigerator in the form of an insulated box 2. An electrically powered condensing unit 12 mounted on the exterior of the box is connected to a fan assisted forced air evaporator unit inside the box. The refrigerator is powered by an alternator drawn by the engine which provides the vehicle with motive power. <IMAGE>

Description

REFRIGERATED VEHICLES This invention relates to refrigerated motor vehicles.

Refrigerated vehicles are used to carry perishable foodstuffs. Conventional manufacture of a refrigerated motor vehicle of whatever size, involves the use of a vehicle having an existing van body, which is converted by insulating and fitting out with a condensing unit and an evaporating unit. The condensing unit has a compressor which is driven mechanically from an engine on the vehicle, usually the engine which provides the vehicle with motive power, but sometimes, e.g. on a refrigerated trailer by a separate small dedicated engine.

Many deliveries of perishable foods are currently carried out by un-refrigerated vehicles. However, European Economic Community, rules shortly to be implemented, require many more such deliveries to be undertaken in refrigerated vehicles. Conventional conversion of a vehicle is expensive. That poses a problem for the operators, who may feel that the high cost of conversion is unwarranted on a vehicle which is already several years old, and yet the cost of a new vehicle, on which the cost of conversion could, perhaps, be justified involves even more expense.

Further, a vehicle which previously may have had several uses will, after conversion, be largely only suitable for delivering perishable goods.

Against this background, a first aspect of the invention provides a goods vehicle having in its load space a removable refrigerator comprising an insulated box, a an electrically powered condensing unit mounted on the exterior of the box connected to a fan assisted forced air evaporator unit inside the box, the refrigerator being connected to receive electrical power from an alternator driven, in use, by an engine which provides the vehicle with motive power.

The cost of providing the vehicle with the removable refrigerator, in accordance with the invention, is estimated to be considerably less than the cost of traditional conversion, in one example about half. That makes the conversion of vehicles which are already in use much more justifiable.

Further, when the vehicle is replaced, the refrigerator may be removed and fitted to its successor, so that the cost of replacement is also lower. In most cases the refrigerator will be powered from the vehicle's existing alternator. In some cases, the vehicle's alternator will not have sufficient capacity and a second alternator or a replacement will be required, but fitting is considerably simpler than fitting a compressor to be driven directly by the engine. In li . 7;-1 addition provided the refrigerator may bedis6onnected, e.g. by means of a plug and socket, it may be removed when desired to use the vehicle for other purposes.

Once removed the refrigerator can be maintained cold by powering it from a supply off the vehicle, e.g. a mains convertor. Thus, one or more refrigerators may be filled in a dispatch centre and loaded after filling into a vehicle for delivery. Indeed, the refrigerator could be maintained cold from an external supply, even when remaining in the vehicle, a facility which is not available with a direct engine driven compressor with the result that conventional refrigerated vehicles require emptying, say, overnight when the engine is not running for extended periods.

The invention may be applied to vehicles of any size, however, it is most preferred in the form of a motor van, the insulated box being removable separately from the vehicle's body.

In that form the box is preferably so shaped and dimensioned as to slide through a rear door or doors in the vehicle's body, and between any wheel arches projecting above the general level of the floor of the load space.

Preferably so dimensioned and shaped as to substantially fill the vehicle's load space, the refrigerator may require no fixing, so being easily removable and replaceable. The refrigerator is preferably provided with a door or doors for access to the interior, the refrigerator door(s) being located behind a door or doors in the vehicle's body giving access to the load space.

Although it there may be sufficient ventilation provided without special provision, the vehicle is preferably provided with means for ventilating the load space in the vicinity of the condensing unit.

Direct engine driven compressors are found to be satisfactory even though they only run when the engine is running. In order to avoid a refrigerator in accordance with the invention from discharging the vehicle's battery, the refrigerator is preferably connected to the vehicle's alternator via a voltage sensitive switch which is arranged to complete the circuit only when the voltage produced by the alternator is above a predetermined threshold level.

The refrigerator preferably has a capacity of at least approximately 16 cubic feet.

In accordance with a second aspect of the invention, a refrigerator for a vehicle in accordance with the first aspect of the invention, is in the form of a removable unit comprising an insulated box, an electrically powered condensing unit mounted on the exterior of the box connected to a fan assisted forced air evaporator unit inside the box which so shaped and dimensioned as to slide through a rear door or doors in the vehicle's body between any wheel arches projecting above the general level of the floor of the load space so that the refrigerator substantially fills the vehicle's load space, the refrigerator being provided with a door or doors for access to the interior, the refrigerator door(s) being located, in use, behind a door or doors in the vehicle's body giving access to the load space.

The refrigerator is preferably provided in combination with a voltage sensitive switch for connection to the vehicle's alternator and arranged to complete the circuit, in use, only when the voltage produced by the alternator is above a predetermined threshold level.

One embod-iment of the invention will now be described, by way of example, with reference to the accompanying drawing, which is a schematic view, partly in section, of a refrigerator embodying the invention.

The refrigerator shown in the drawing is in the form of a box 2 having a hinged door 4. The box is shaped and dimensioned, on the one hand, to substantially fill the load space of a standard production motor van and, on the other hand, to slide through the van s rear loading doors and between the wheel arches if these extend above the floor of the load space.

Vans of different types may require boxes of different shape and dimensions in order to fill the load space efficiently. A minimum preferred size is expected to provide about 16 cubic foot of space inside the box.

As may be seen from the sectional part of the drawing, the box has an outer skin 6 and an inner skin 8 separated by a layer of insulating material 10, e.g.

a 5 cm layer of styro foam which is equivalent to about 10cm of polystyrene foam. The skins may be any suitable material, e.g. aluminium sheet. The door is similarly constructed and insulated.

Such a construction may be used to produce a refrigerator which can be cooled by a condensing unit 12 having a compressor driven by as little as a 1/5 horse power electric motor. The condensing unit 12 illustrated contains a compressor, not separately identified, which is driven by a 12 volt or 24 volt electric motor 14 which also drives a fan schematically shown at 16, to draw air through a heat exchanger 18.

The condensing unit 12 is illustrated mounted in a recess in what, in the vehicle, is the front of the box, i.e. opposite the door, so as to allow maximum dimension for the box whilst remaining within the dimensions which can slide in and out of the loading doors of the motor van. In other arrangements the condensing unit 12 may be mounted in a recess on a side of the box.

Cooling inside the box is air by a fan assisted forced air evaporator in which the fan 22 is again shown schematically. In the arrangement illustrated the evaporator 20 is shown mounted inside the roof of the box. In other arrangements the evaporator may be mounted on a wall of the box or on the roof beneath the condensing unit 12.

Electrical power is supplied to the refrigerator to drive the motors of the condensing unit and the evaporating unit 20 via a power lead 24 which terminates in male connectors 26 e.g. a plug. The male connectors are received by female connectors 28 mounted in the vehicle and connected via a solenoid 30 to an alternator 32 driven by the engine, not shown, which provides the vehicle's motive power. In some cases a larger alternator may need to be fitted to the vehicle, but in most cases it is expected that the standard alternator will have sufficient capacity to power the refrigerator. The solenoid 30 disconnects the refrigerator form the alternator until its output voltage has reached its design output of 12 volts or 24 volts, dependent on type.The refrigerator will thus not run unless the vehicle's engine is running, so ensuring that it does not flatten the vehicle's starting battery.

Refrigerators embodying the invention may be made in sizes to suit any desired vehicle and offer the advantage that special conversion of the vehicle is avoided except for connections to the vehicle's electrical system. In most cases it will be preferred that the refrigerator will substantially fill the vehicle's load space. However, there will be some users, especially of heavy goods vehicles, where it is desired to refrigerate only part of the load space, leaving part of the van available for goods which do not require refrigeration. In such cases it may be found suitable to mount the box on wheels and it may be found necessary to secure the box during transit. An arrangement,similar to that illustrated, in which the condensing unit is mounted in a recess on the outside of the box may have benefits in protecting the condensing unit against damage when loading into or unloading form the vehicle, or if the refrigerator shifts during transit.

The vehicle's load space is preferably ventilated in order to ensure adequate cooling for the condensing unit. Ventilation may be forced by a rotary ventilator which may be electrically powered or wind powered. The ventilator is preferably fitted in the vicinity of the condensing unit.

Claims (10)

1. A goods vehicle having in its load space a removable refrigerator comprising an insulated box, a an electrically powered condensing unit mounted on the exterior of the box connected to a fan assisted forced air evaporator unit inside the box, the refrigerator being connected to receive electrical power from an alternator driven, in use, by an engine which provides the vehicle with motive power.

2. A goods vehicle as claimed in claim 1, in the form of a motor van, the insulated box being removable separately from the vehicle's body.

3. A goods vehicle as claimed in claim 2, wherein the box is so shaped and dimensioned as to slide through a rear door or doors in the vehicle's body between wheel arches projecting above the general level of the floor of the load space.

4. A goods vehicle as claimed in claim 2 or 3, wherein the refrigerator substantially fills the vehicle's load space and is provided with a door or doors for access to the interior, the refrigerator door(s) being located behind a door or doors in the vehicle's body giving access to the load space.

5. A goods vehicle as claimed in any of claims 2 to 4, wherein the vehicle is provided with means for ventilating the load space in the vicinity of the condensing unit.

6. A goods vehicle as claimed in any preceding claim, wherein the refrigerator is connected to the vehicle's alternator via a voltage sensitive switch which is arranged to complete the circuit only when the voltage produced by the alternator is above a predetermined threshold level.

7. A goods vehicle as claimed in any preceding claim, wherein the refrigerator has a capacity of at least approximately 16 cubic feet.

8. A refrigerator for a vehicle as claimed in any preceding claim, in the form of a removable unit comprising an insulated box, a an electrically powered condensing unit mounted on the exterior of the box connected to a fan assisted forced air evaporator unit inside the box which so shaped and dimensioned as to slide through a rear door or doors in the vehicle's body between wheel arches projecting above the general level of the floor of the load space so that the refrigerator substantially fills the vehicle's load space, the refrigerator being provided with a door or doors for access to the interior, the refrigerator door(s) being located behind a door or doors in the vehicle's body giving access to the load space.

9. A refrigerator as claimed in claim 8, in combination with a voltage sensitive switch for connection to the vehicle's alternator and arranged to complete the circuit, in use, only when the voltage produced by the alternator is above a predetermined threshold level.

10. A refrigerator as claimed in claim 8 or 9, wherein the refrigerator has a capacity of at least approximately 16 cubic feet.