IES81059B2 - Ambulance electrical control system - Google Patents

Abstract

An electrical control system for an ambulance having a driver's compartment (10) and a rear compartment (14) containing electrically-operated medical equipment (16L, 16R,18L,18R,20,22), comprising an electrical distribution panel mounted within the rear compartment. The panel has a plurality of over-current protection devices connecting an electrical power supply to the medical equipment, and at least one switching device in the rear compartment which, when closed, connects an electrical power supply to a further item of electrically-operated equipment, such as a siren (24) or light bar (26). Control means (42) are provided in the driver's compartment for closure of the switching device by the driver. The control system according to the invention avoids necessity of wiring the electrical harness carrying the current for the various electrical devices through the pillar cavitation of the ambulance frame.

Description

AMBULANCE ELECTRICAL CONTROL SYSTEM This invention relates to an electrical control system for an ambulance.

In the conventional electrical systems of present day ambulances it is normal procedure to route a large number of circuits from the driver's dash area to various items of switched and continuous current medical equipment throughout the vehicle. Most of this onboard auxiliary equipment is situated in rear of the vehicle to comply with the patient’s requirements and demands. Also, safety aspects of the ambulance, e.g. siren units, light bars (flashing lights), are mounted in both the front grill section and also on the roof area.

As a result, in the present day vehicle a large number of cables are routed through very small cavitations, typically the front pillar of the vehicle. During the routing of these circuits there is no way of knowing if sharp edges or reinforcing strips are present in the pillar; thus when the wiring harness is fitted there is no way of knowing whether or not damage is done or indeed potential damage exists.

Also, some of these cables could carry up to 25 amps and therefore a large current is present at the dash area. This is a potential safety hazard as it can result in fire or, at minimum, a blown fuse or tripped breaker. However, even this can be hazardous if a very seriously ill person is on board.

Because of such a large volume of circuits are routed through such a small cavitation the risks of such electrical failure is high. However, due to the cumbersome position of present fuseboards it is hard for ambulance staff to identify or replace a breaker or fuse.

It is an object of the present invention to provide an electrical control system for an ambulance in which these problems are avoided or mitigated.

Accordingly, the invention provides an electrical control system for an ambulance, the ambulance having a driver's compartment and a rear compartment containing electrically-operated medical equipment, the electrical control system comprising a plurality of over-current protection devices in the rear compartment connecting an electrical power supply to a plurality of items of said medical equipment, at least one switching device in the rear compartment which, when closed, connects an electrical power supply to a further item of electrically-operated equipment, and control means in the driver's compartment for closure of the switching device by the driver.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic side view of an ambulance showing the location of the main components of the electrical control system, and Fig. 2 is a block diagram of the electrical control 10 system.

Referring first to Fig. 1, an ambulance has a front compartment 10 constituting the driver's cabin separated by a bulkhead 12 from a rear compartment 14 constituted by the main body of the vehicle. The rear compartment 14 is fitted out with various items of electrically operated medical equipment, such as left and right incubators 16L, 16R and left and right suction devices 18L, 18R, which are desired to be under the control of medical personnel in the rear compartment of the ambulance. The rear compartment 14 also has a doctor's lamp 20 and a 12-volt auxiliary power socket 22. The ambulance also has various safety features such as a siren 24 at the front grill and a light bar (flashing lights) 26 on the roof, both of which are desired to be under the control of the ambulance driver in the front compartment 10.

Referring now additionally -to Fig. 2, an electrical distribution panel 28 is mounted on the rear of the bulkhead 12 or at any other reasonably accessible location in the rear compartment 14. The panel 28 contains a fuseboard 30 having a plurality of overcurrent protection devices 32, in this embodiment eight such devices 32. In their simplest form the devices 32 may be, and are shown in Fig. 2 as, simple fuses, but more preferably one would use resettable circuit breakers. As seen in Fig. 2, each of the top four fuses 32 of the fuseboard 30 connects a 12-volt battery 34 directly to a respective one of the items of medical equipment 16L, 16R, 18L and 18R. Likewise, the fifth and sixth fuses from the top of the fuseboard 30 connect the battery 34 directly to the doctor's lamp 2 0 and 12-volt socket 22 respectively. The battery 34 is preferably an auxiliary battery, separate from the main vehicle battery (not shown), although it is charged by the same charging system which charges the main vehicle battery.

The electrical distribution panel 28 also contains a bank of electro-mechanical relays 35, in this embodiment two relays. Each relay has a contact 38 movable between an upper (open) position shown in solid lines and a lower (closed) position shown in dashed lines. The left-hand relay 36 shown in Fig. 2, when its movable contact 38 is in the closed position, connects the auxiliary battery 34, via a respective fuse 32, to the siren 24. Likewise, the right-hand relay 36 shown i'n Fig. 2, when its movable contact 3 8 is in the closed position, connects the auxiliary battery 34, via a respective fuse 32, to the light bar 26.

Each relay 36 is normally open (i.e. its contact 38 is in the upper position) , but may be closed by providing an energising current to flow through a respective relay solenoid 40. This is effected from the driver's compartment 10 as follows.

In the driver's compartment there is a control panel 42 containing a plurality of on-off switches 44, any of which may be individually actuated by the driver. In the present case only two such switches are shown, corresponding respectively to the two relays 36. The control panel 42 is preferably designed as an aeronautical-style switching console which is mounted between the driver's seat and that of his assistant or (as shown) over the driver's head.

The auxiliary battery 34 is connected in common to one side of the switches 44 via a conductor 46, while the other side of each switch 44 is individually connected to a respective one of the relay solenoids 40 via respective conductors 48, 50. Thus the ambulance driver is able to close a selected relay 36, and thus turn on the siren 24 or the light bar 26 as desired, by closing the corresponding switch 44 which causes an energising current to flow from the battery 34 to ground through the solenoid 40 in the selected relay.

It will be understood that although the foregoing has described a system with four items of medical equipment 16L, 16R, 18L and 18R, together with a lamp 20 and socket 22, more or less items of medical equipment could be provided, in which case each would connected to the battery 34 through a corresponding fuse 32 on the fuseboard 30. Also, there could be more devices than just the siren 24 and light bar 26 under driver control, in which case a like number of relays 36 would be provided on the distribution panel 28 each under the control of the driver from a respective switch 44 on the console 42.

The advantage of the above electrical control system is that the length of wiring harness to the items of medical and other equipment 16L, 16R, 18L, 18R, 20 and 22 in the rear compartment of the ambulance is greatly reduced, and also that the harness is no longer routed through the hazardous pillar cavitation.

As an alternative, it may be possible to mount the panel on the opposite side of the bulkhead whereby it is in the driver's compartment immediately adjacent the rear compartment, which would similarly avoid the necessity of wiring the harness through the pillar cavitation.

For those devices such as the siren 24 and light bar 26 5 which the driver has to have control over, the conductors 48, 50 running between the control panel 42 in the driver's cabin and the distribution panel 28 in the rear compartment need only be of very thin wire, since the relay solenoids 4 0 draw a very small current compared to the devices 24, 26 themselves. Thus these conductors 48, 50 may be individual strands of a multicore microwire 52 similar to telecom communication cable. Such cable, depending on the number of switching applications, is available with varying numbers of conductors (strands). The current flowing in any of the conductors to the relay solenoids 40 is typically never more than 200 mA, so that the overall diameter of the cable 52 would in most practical situations never need to be more than 1.00mm.

The cable 52 is preferably routed along the inside of roof from the switching console 42 to the distribution panel 28, as shown in Fig. 1, and does not need to pass through blind cavitation.

It will be understood that instead of relays 36, other power switching devices, such as electronic switching devices, may be used which are capable of switching a relatively large current irr 'response to a relatively small current drawn at a control input of the device.

To summarise the advantages of the above system: (1) There is no hazardous routing of main conductors. (2) Only a small current, e.g. 200mA, comes from the front switching console 42 due to the use of relays . (3) The distribution panel 28 is directly access to attendants in the rear compartment should any malfunction occur, e.g. should a circuit breaker trip the attendant can easily reset it or visualise the faulty circuit. (4) Ambulance staff have no longer need to look under the dash to find the fuse box.

Claims (5)

Claims:

1. An electrical control system for an ambulance, 5 the ambulance having a driver's compartment and a rear compartment containing electrically-operated medical equipment, the electrical control system comprising a plurality of over-current protection devices in the rear compartment connecting an electrical power supply 10 to a plurality of items of said medical equipment, at least one switching device in the rear compartment which, when closed, connects an electrical power supply to a further item of electrically-operated equipment, and control means in the driver's compartment for 15 closure of the switching device by the driver.

2. . An electrical control system according to Claim 1, wherein the control means comprises an electrical control circuit which when energised carries a current 20 of no more than 1 A.

3. . An electrical control system according to Claim 2, wherein the control means comprises an electrical control circuit which when energised carries a current 25 of no more than 500 mA.

4. . An electrical control system according to Claim 2 or 3, wherein the electrical control circuit is routed from the driver's compartment to the rear compartment other than through a from pillar of the vehicle.

5. . An electrical control system according to any 5 preceding claim, wherein the switching means comprises a switch actuable by a solenoid, the operation of the solenoid being controlled by the control means.