A Platform Tractor.
Page 9
Page 10
If you've noticed an error in this article please click here to report it so we can fix it.
Description of a Neat Electric Tractor, for Hauling Loads of Six Tons, for Use in Railway Stations, Goods Yards, and Warehouses.
Shortage of labour seems destined to serve in lieu of years of progress. It is having the effect in all branches of industry of demonstrating the advantages derived from the fuller and freer use of mechanical devices. A case in point is that of transference of baggage, or of goods capable of being made up into packages. This kind of work is of great importance on the platforms of stations and in goods yards, in quarries, in warehouses, and in factories. Hitherto hand-propelled trucks have been to all intents and purposes universal, at least in thiS country ; mechanically-propelled ones have been, it is true, used here and there for some years ; their number, however, is infinitesimal.
Mechanical Porters.
A familiar sight of late at Ae great London railway termin'als has been that of the small electric tractor pulling its load of 2, 3, 4 or more, small trucks, the latter loaded with a miscellaneous assortment of goods which ordinarily would have been pushed from
place to place On the same trucks by porters. It is this type of machine which seems likely to prove the most popular for the serviee we have in mind. In America it is widely used, and over there it is usually called a mechanical stevedore.
An American Machine.
We have from time to time published descriptions of suitable machines for this work. Our present article concerns a recent importation, an electric industrial tractor made by the Lansing Co., of Michigan, U.S.A., the sole agents for this country being Baxter and Caunter, Ltd., of 219, Tottenham Court Road. These handy machines are made in two sizes, for hauling loads of 2 and 6 tons respectively.
Two Models.
We recently inspected an example of the heavier model, and were favourably impressed by it. As there is very little difference in design between the two models, the following description of the one we saw will apply equally to the smaller machine. It will, of course, be understood that some small variations in weights and powers exist. We give a brief specification of each at the conclusion.
The Frame.
A small rectangular frame, strongly made of rolled steel joists, and well gusseted so as to withstand without deformation the bumps and bangs which it is likely to receive in the course of its daily service, is carried as to its front end on a pair of elliptical springs, themselves supported by a substantial, forged axle ; and at its rear end, through the medium of a pair of strong cast brackets, on the rear axle case.
Axles: Motor-vehicle Design Followed.
The front axle follows closely ordinary roadvehicle design with Ackermann steering. Timken roller bearings are used for the solid-rubber-tired wheels. The rear axle resembles very closely a
commercial-motor worm-drive axle ininiature. A machine-cut worm and wheel carried on New Departure ball bearings is contained within the cast steel axle case. It drives the rear wheels through the medium of floating axle shafts. The wheels themselves are carried, like those at the front, on Timken bearings, and the axle forms generally what is known as a full floating rear axle.
Motor Carried by Axle Case.
A bracket formed integral with the rear axle case extends forward and serves as a support for the Westinghouse motor. This motor is directly coupled to the worm. A feature of the, machine throughout is its accessibility, the whole of the worm gear and bevel differential gear being removable en bloc from underneath. The motor also, although totally enclosed and protected from the ingress of dust or other foreign matter, is nevertheless accessible in regard to its important points, such as the brushes and commutator. Ironclad Exide Batteries.
On the top of the framework, at the front end, is the metal casing within which is contained the control box switch, ampere-hour meter, steering gear, and brake-.gear. The rest of the space is taken up by the batteries. Ironclad Exide cells are used. . These are contained in a box and can readily be removed and replaced, the box itself running on rollers. They are totally enclosed, the top of the casing.being railed round and serving as accommodation for light parcels. A large door in the top allows ready access to the batteries for inspection: It is not necessary to remove them for this purpose.
The Control.
As to control, the -driver sits on the front end of the machine, his feet resting on a specially prepared platform which projects' forwardand below the frame (see our illustration 'of the frame). The steering wheel is at his right hand,and close by is the control lever, Which has three positions for motion in each directivn, forward and reverse, :besides the neutral notch. At his., left ,foot is the brake pedal. This operates on drums bolted to the rear wheels, and is interconnected with the control switch to the motor, so that putting-on the brake releases the control lever, whichiinimadiately flies back:to the neutral position. This arrangement has several advantages. In the first place, it is not Possible for the driver to throw a sudden overload on the batteries and motor, merely by putting cn his brake. Secondly, after the machine has been 'brought to rest by means of the brake, the • current is automatically Out off ; any accidental release would not cause the machine to be set. in motion. It also allows quick Control of. the: vehicle in ease of emergency and the necessity for sudden stoppage, pressure upon the pedal applying the brake and
cutting off the current... . . • '
. Accessories._ The battery, as stated, is the Ironclad • Exide. Accessories include, a Sangaino a,mpere-hOur meter, which shows at any time during the charge or discharge the amount of energy availa,ble in the battery ; a charging switch with charging running positions distinctly marked ; and a, standard charging plug, conveniently located.
Specifications; the 2-tonner.
The weight. of the smaller machine complete with batteries is 2600 lb., the overall dimensions being: length 6 ft. 8 ins, ; width 3ft. height 4 IL ; wheelbase 3 ft. ; wheel track 27 ins. ' • turning radius 5 ft. 6 ins. The wheels are 18 ins, diameter, and are normally supplied with Goodrich tires, 3 ins, wide on the front, and 4 ins, wide on the rear.
The Six-tonner.
The corresponding dimensions of the six-tonner are : weight 3000 lb:; length 7 ft. 8 ins. ; width 3 ft, 3 ins. ; height 4 ft. ; wheelbase 3 ft. 6 Ms. • wheel track 30 ins. ; turning radius 6 ft. 6 ins. The same diameter wheels are fitted as on the smaller machine, the tires being, however' 5 ths. wide on the rear wheels, and 3 ins, wide on the front.