GB2136750A

GB2136750A - Conveyor car and other vehicles having power operated auxiliary equipment

Info

Publication number: GB2136750A
Application number: GB08407436A
Authority: GB
Inventors: Ronald William Hyde
Original assignee: POWER LIFTS Ltd
Current assignee: POWER LIFTS Ltd
Priority date: 1983-03-25
Filing date: 1984-03-22
Publication date: 1984-09-26
Also published as: GB8407436D0

Abstract

A conveyor car has a diesel traction engine 2, a hydraulic pump 12 in its hydraulic circuit for driving the conveyor, a battery operated electric motor 22, and an auxiliary pump 24, such that the drive for the conveyor can be derived from the diesel engine or from the electric motor selectively. Thus with the car stationary, the conveyor is driven from the battery 21, but if this fails the conveyor can be driven from the engine. A single pump can be driven selectively by the engine or the motor. In place of a conveyor the vehicle can have other auxiliary equipment and the drive can be other than hydraulic. <IMAGE>

Description

SPECIFICATION Conveyor car and other vehicles having power operated auxiliary equipment The invention relates to vehicles having power operated auxiliary equipment, more particularly but not exclusively a mobile conveyor known as a conveyor car, comprising a vehicle which supports an adjustable conveyor belt or the like.

Conveyor cars are used principaily at airports to move baggage and light cargo from, say, a baggage truck up to the cargo hold of a parked aircraft, or vice versa. They usually comprise a conveyor frame pivotably mounted on the vehicle chassis and a hydraulic circuit comprising a motor for moving the conveyor belt supported by the frame and also for operating two rams for changing the elevation and inclination of the conveyor frame. In use, the vehicle is driven to the aircraft, the conveyor frame is raised and angled to suit the loading or unloading conditions and thereafter the conveyor belt can be set into motion.

Most conveyor cars have a diesel engine which is used for traction and, when the vehicle is stationary, is left running to drive a hydraulic pump which powers a hydraulic motor for operating the rams and for moving the belt. The cost of keeping the engine running at idling speed all the time is considerable, the engine emits fumes into the aircraft and atmosphere and the engine life is comparatively short. It has therefore been proposed to provide battery driven conveyor cars but these also have disadvantages, mainly a high battery (accumulator) acquisition and replacement cost since the traction batteries must be large to propel the vehicle from the terminal building to the aircraft and back, quite apart from the long battery charging times.It is considered to be more efficient to use a diesel engine than traction batteries and, of course, if the batteries are exhausted during operation at the aircraft, the vehicle has to be towed away.

The conveyor car of the invention has been developed with these considerations in mind but it is thought that the invention is of wider applicability.

According to one aspect of the invention, a conveyor car vehicle has an internal combustion traction engine, a battery operated electric motor, and hydraulic pumping means in a hydraulic circuit for the conveyor belt, the arrangement being such that the drive for the pumping means may be selectively derived from the traction engine or from the electric motor. In one form the pumping means comprises a single hydraulic pump selectively driven by the traction engine or the electric motor. In another form the pumping means comprises a hydraulic pump driven by the traction engine and another pump driven by the electric motor, each able to supply the hydraulic circuit according to which pump is selected to be driven.

According to another aspect the invention provides a vehicle having an internal combustion traction engine, power operated auxiliary equipment intended to be driven whilst the vehicle is required to remain stationary, and a battery operated electric motor for operating the auxiliary equipment, the arrangement being such that the drive for the auxiliary equipment may be selectively derived from the traction engine or from the electric motor.

According to yet another aspect, the invention provides a vehicle having an internal combustion traction engine, power operated auxiliary equipment, a battery operated electric motor, and hydraulic pumping means in a hydraulic circuit for the auxiliary equipment, the arrangement being such that the drive for the auxiliary equipment may be selectively derived from the traction engine or from the electric motor.

And, finally, the invention also provides an adaptor kit for converting into a conveyor car or other vehicle as described above, a pre-existing l.C. engine driven vehicle having a hydraulic circuit that contains an engine driven pump, the kit comprising a battery operated electric motor for driving an additional separate hydraulic pump having pressure and suction conduits which can be connected to the respective pressure and suction lines of the engine driven pump.

An example of the invention is shown in the accompanying drawings, wherein Figure 1 is a perspective view of a conveyor car drawn up at the door to an aircraft cargo hold, and Figure 2 is a fragmentary diagram of a hydraulic circuit of the car modified by the incorporation of a battery conversion kit.

The illustrated conveyor car comprises a wheeled vehicle chassis 1 (Figure 1) propelled by a diesel engine 2 (Figure 2). Two pivot arms 3,4 hinged to chassis 1 support a frame or boom 6 for a conveyor belt 7 and can be swung by respective hydraulic rams 8,9 to elevate and incline frame 6 suitable for registering with the cargo door of an aircraft 11 adjacent to which the car is drawn up. Rams 8,9 and at least one driven roller over which conveyor belt 7 passes are operated hydraulically by a respective motor powered by a hydraulic pump 12 (Figure 2).

As described so far, the diesel conveyor car is conventional and most of the engine driven hydraulic circuit has been omitted from Figure 2 for clarity, except the aforementioned pump 12, a pressure conduit 13 leading from the pump via a check valve 31 to a hydraulic motor (not shown) for the conveyor drive, a suction conduit 14 between the pump and an oil tank or reservoir 16, a return line 17 between the said hydraulic motor and tank containing a filter 18, and two of the conduits 20 leading to a hydraulic motorforthe ram drive.

An adaptor or conversion kit to enable the pump 12 to be by-passed, i.e. to enable the rams and conveyor belt to be operated hydraulically as before but powered by a battery instead of the engine 2, comprises a battery pack 21 of one or more batteries electrically connected to a D.C. motor 22 via an isolating switch 23.The motor is connected to an auxiliary hydraulic pump 24 which, in turn, is connected in shunt across the engine driven pump 12 by a pressure conduit 26 containing a further non-return valve 29 and a suction conduit 27 and also connected to the return line 17 by way of a pressure relief valve 28. Ali the existing hydraulic valve gear and controls remain unchanged and no other components are essential for the purpose of the invention but it is desirable a sensing and timing switch 32 which interrupts the electric circuit from the battery pack if no articles are detected by a sensor on the conveyor for, say, 60 seconds, thereby conserving battery power until the conveyor is restarted manually.

The advantages of the invention include a much reduced operating cost, less polution and longer diesel engine life. Also, with the engine available as a back-up for the electric motor, it is possible to complete the conveying operation by switching over to engine power if the battery pack becomes exhausted and to use the engine to drive the car away.

This is a particularly valuable advantage for airport use where electric conveyor cars tend to be neglected as far as regular recharging is concerned but a broken down vehicle can play havoc with aircraft schedules.

An incidental but important advantage of the adaptor kit (albeit resulting in the presence of two hydraulic pumps where otherwise one would suffice) is that it enables the advantages of the invention to be obtained without the need for replacement of existing diesel engined conveyor cars.

Although the invention is described in relation to a conveyor car it is also applicable to other vehicles having an internal combustion traction engine and auxiliary equipment (whether hydraulic or not), hitherto conventionally driven by that engine while the vehicle is stationary (e.g. an airport van having a hoist raised and lowered to load meals and other cabin suppiies onto aircraft); in such cases the invention provides for the drive for the auxiliary equipment to be selectively derived from the traction engine or the electric motor as circumstances may require.

Claims

1. A conveyor car vehicle having an internal combustion traction engine, a battery operated electric motor, and hydraulic pumping means in a hydraulic circuit for the conveyor belt, the arrangement being such that the drive for the pumping means may be selectively derived from the traction engine or from the electric motor.

2. A vehicle having an internal combustion traction engine, power operated auxiliary equipment intended to be driven whilst the vehicle is required to remain stationary, and a battery operated electric motor for operating the auxiliary equipment, the arrangement being such that the drive for the auxiliary equipment may be selectively derived from the traction engine or from the electric motor.

3. Avehicle having an internal combustiontrac- tion engine, power operated auxiliary equipment, a battery operated electric motor, and hydraulic pumping means in a hydraulic circuit for the auxiliary equipment, the arrangement being such that the drive for the auxiliary equipment may be selectively derived from the traction engine or from the electric motor.

4. Avehicle according to claim 1 orclaim3 wherein the pumping means comprises a single hydraulic pump selectively driven by the traction engine or the electric motor.

5. A vehicle according to claim 1 or claim 3 wherein the pumping means comprises a hydraulic pump driven by the traction engine and another pump driven by the electric motor, each able to supply the hydraulic circuit according to which pump is selected to be driven.

6. A vehicle according to any preceding claim including a sensing and timing switch adapted to sense presence and absence of load to be moved by the conveyor or presence and absence of conditions requiring operation of such other auxiliary equipment (as the case may be), and to disconnect the supply of electricity from the battery in the absence for a predetermined period of time of sensed load or of the said required condition.

7. An adaptor kit for converting into a conveyor car or other vehicle as claimed in any preceding claim, a pre-existing l.C. engine driven vehicle having a hydraulic circuit that contains an engine driven pump, the kit comprising a battery operated electric motor for driving an additional separate hydraulic pump having pressure and suction conduits which can be connected to the respective pressure and suction lines of the engine driven pump.

8. A conveyor car substantially as shown in and hereinbefore described with reference to the accompanying drawings.

9. An adaptor kit according to claim 7 substantially as described with reference to Figure 2 of the accompanying drawings.