While this construction renders the carriage as easy to steer as those in which the motors are connected with the rear axle, it sacrifices the advantage derived from applying the power to the front wheels, namely, the ability to turn round in a small space.
Another design for driving the front wheels which allows them to swing round independent pivots, is shown in [Fig. 14], which is a coupé made by Krieger in France. The power is supplied by two motors, one being mounted on each swivel point. The construction can be understood by considering that in the lower part of [Fig. 13] the motor would be secured to a suitable support at the end of the frame L, being held in such a position that the shaft would replace pivot D and a pinion mounted thereon would gear into wheel E. What the advantage of this construction may be, the writer is not able to point out; it certainly shows, however, that there are many ways in which the object sought may be accomplished.
Fig. 15. Jenatzy Dog-Phaeton.
American manufacturers of electric vehicles, at least the great majority of them, resort to spur-gearing to transmit the motion of the motor to the driving wheels, but with the French designers the chain and sprocket appears to be in great favor. [Fig. 15] shows a Jenatzy vehicle (French), in which the chain is used. This construction would not be received with favor by Americans, who as a rule desire to have the mechanical part of the apparatus hidden from view as much as possible. In the Jenatzy vehicle two chain gears are used, one on each side of the body, and from the engineering point of view this is the most desirable arrangement, as with it the driving wheels are independently operated and a compensating gear need not be placed upon the axle. The American designer, however, would in most cases be controlled more by the artistic appearance and would use a single chain which would be placed under the body of the carriage, and thus as much out of sight as possible.
[Fig. 16] shows an English design of electric dog cart. The mechanism consists of a single motor which is connected with the axle by means of spur gearing, this being so arranged that several different speeds can be obtained for the vehicle with the same velocity for the motor. To obtain variable speeds by means of gearing it is necessary to introduce a considerable amount of complication, and in this country the opinion of most designers appears to be that the gain effected thereby is not sufficient to compensate for the increased complication, and differential speed gearing is not often used.
Fig. 16. The Electric Motive Power Company’s Dog Cart.
A comparison of [Figs. 14] and [16] with [6] and [9] will clearly show that in so far as artistic effect is concerned, our manufacturers of electric vehicles have little to learn from Europeans, although the industry here is much younger than abroad. As to the operative merits, all that can be said is that the American carriages run so well and possess such endurance that it is probable that they are not second to any in these respects.