A New Electric Three-wheeler
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A. E. Morrison and Sons, Ltd., Introduces an 8-cwt. Three-wheeler and a Four-wheeled Tonner which are now in Production
FOR town delivery work, where calls are frequent and the overall daily mileage is relatively small, electric vehicles have many points in their favour. Usually, they are not so low in first cost as the equivalent petrol vehicles, but the operating costs are claimed to be exceedingly small, so that over a period of years the electric vehicle may show to advantage. New developments in this connection have been made by A. E. Morrison and Sons, Ltd., Gartree Street, Leicester.
Of the two new electric machines that we are able this week to announce, the three-wheeler is certainly the more interesting, as there are several departures from what might be termed standard practice, whilst the price of £130 for a complete van is distinctly low, and brings the machine within the purchasins' capacity of small tradesmen. The
li' cassis costs £120. The tonner, on the other hand, is really a development of the concern's existing 12-cwt. model, although its dimensions and electrical
equipment are larger. We will deal with the 8-cwt. model first.
The chassis is built up of channelsectioned side members adequately braced by cross-ties, which also form the means whereby the batteries are slung in position beside the rear axle. By utilizing this form of construction weight is , kept low, and no encroachment is made upon the freight space which, considering the moderate overall dimensious of the chassis, is considerable.
With a wheelbase of 6 ft. 4 ins, and a track (at the rear) of 4 ft., the body is 4 ft. 6 ins, long and wide, and 3 ft. 9 ins, high, giving a capacity of approximately 76 cubic ft., in addition to providing a seat for the driver and another for an assistant.
The frame channels run downwards froin the steering head and continue in 1338
a sweep right to the rear, adequate bracing being assured by a triangulated formation of channel-sectioned members, which are carried from the centrally disposed steering head to the side-members. A Brampton motorcycle-type spring fork is used and is coupled by a continuous roller chain to a short steering column, which carries an orthodox wheel, On the off side. Underslung semi-elliptic springs are fitted for the rear axle.
As we have already indicated, the batteries are slung in trays formed on each side of the rear axle. They are four in number, of 185 amp.-hour capacity and connected to give 48 volts. Current is supplied to a 10 h.p. motor by an interesting control gear operated from a controller box.
In the first position a special contactor arrangement puts all the batteries in parallel and the field coils into series ; the batteries would then be operating at 12 volts. In the second position the field coils are put into series-parallel and the batteries arranged to give 24 volts. Finally, the third position allows the full 48 volts to be used by the motor with the field coils in parallel.
T-hia arrangement,. of .course, gives a smooth get-away, and, when the controller is brought into the neutral position, the 'armature of the motor merely acts as a flywheel, no electrical energy being developed or dissipated.
Transmission is effected by a 3-to-i triple-roller-chain reduction drive from the rear of.the motor to a I:lardy-Spicer propeller shaft, thence by spiral-bevel axle to the wheels. A reverse gear is included in the design.
A simple but effective coupling has been devised for the brakes, a single cross-shaft being coupled to both the lever and the pedal, with an outrigged bracket installed near one of the controls, so that, in the event. of the shaft or a rod fracturing, one brake would be available for use.
The chassis of the tanner is produced in two forms, one being capable of dealing with ton loads and the other having a capacity for 25 cwt., the difference being largely bound up with the size and power of the batteries, which considerations, of course, have an effect upon the motor. The smaller type has compounded cells to give 72 volts, whilst the 25-cwt. model utilizes 88 volts, the capacity of the complete batteries being 185 amp.-hours at the 10-hour rate.
By reason of a compact arrangement of the controls and the driver's cab, the moderate wheelbase of 7 ft. 6 ins, and track of 4 ft. 8 ins, give a large freight space. In both the van and the lorry the length behind the driver's seat is 9 ft. 6 ins, and the inside body width 5 ft., whilst the height above the platform of the closed van is 4 ft. 6 ins.
A pair of swing doors at the rear of this vehicle ' gives uninterrupted ;access to the interior. The cab extends almost entirely in front of the axle, and entry and exit are easy.
Like the three-wheeled model the motor is controlled by a three-position switch, which, in the larger type, takes the form of a centrally disposed pedal.
It is, of course, well known that Morrison-Electric vehicles have a motor of special design, for which a higher efficiency than usual is claimed. The characteristics show that there is a rapid increase of torque as the rotation speed falls, so that, without using an auxiliary gearbox, efficiency on hills is assured. The motor, homed at the forward end of the chassis, drives through a chain reduction gear to a Hardy-Spicer propeller shaft, which is directly coupled to the spiral-bevel rear axle.
An interesting feature of the electrical equipment is the incorporation of a static rectifier type of charger in the vehicle, making it necessary merely to plug-iu when recharging is required. Two types of controlling meter are provided, one being slightly more expensive than the other. In the more costly type an indication of the amount of current left in the battery is recorded on a dial. As the vehicle is being used this meter runs down, so that the driver knows at a glance how much current is available for further running. During the process of charging the meter runs up again until it indicates a full battery, when the charger is automatically SWitched off. The less expensive model has an indicator, but the automatic switch for preventing over-charging is not provided.
The 1-ton vehicle costs £226 without the automatic switch-off and £234 with this equipment. The prices of the 25cwt. model are £246 and £254 respectively. The van prices are £4 higher than those of the lorry models already enumerated.