A Platform-steered Industrial Truck
If you've noticed an error in this article please click here to report it so we can fix it.
Single-wheel Control of Starting, Stopping and Braking on New Machine for Internal Transport AN electrically propelled industrial truck, embodying a number of unusual features, has recently been introduced by Steels Engineering Products, Ltd., Crown Works, Sunderland,
Probably the most important feature in machines of this kind is the ease with which they can be started, stopped and steered, and considerable attention would seem to have been given in the present instance to these points.
In the Electric Eel truck, as it is called, the steering, for instance, is effected through the driver's platform, which is made to tilt laterally by moving the weight of the body from one side to the other. It is claimed that this system imposes less fatigue and strain on the driver than does the more usual tiller, b'ar or wheel systems.
Starting, stopping and brake control and speed changing are all operated through the medium of a single vertically disposed hand wheel, which always moves in the direction of travel. In the case of the truck having an elevating platform, the latter is .raised by means of two hydraulic jacks operated by an electric motor.
Three speeds in each direction, are provided, the movement of the control wheel being so regulated that the operative cannot go from " start" to top speed without passing through the various stages. The same wheel controls the electric brakes, which begin to function when the wheel has passed through the neutral position.
There are two systems of braking, one electrical under wheel control, and the other mechanical. The latter is operated by a lever on the " dead man's hand " principle, as when the hand-grip is released, either deliberately or accidentally, the current is automatically., interrupted and the brakes are applied.
An electrically welded frame is employed and half-elliptic leaf springs form the suspension. A high degree of efficiency is claimed for the transmission system, in which there is no intermediate reduction gear, chains or shafts. Two series-wound tractiontype motors are installed—one to each driving wheel—a system which removes the necessity of fitting a mechanical differential. Each driving wheel is
driven direct by a single pinion so that transmission losses are reduced to a minimum.
On the 30-cwt. trucks the motors operate on 40 volts, and on. the 50-cwt, machines the pressure is 80 volts. In the first instance, batteries up to 160 amp-hr. capacity can be installed, and on the 50-cwt. trucks the amp.-hr. capacity of the batteries that can be accommodated is 128.
It is understood that the production of Electric Eel trucks is to be on a large scale, which should have the effect of reducing the price to the purchaser,