IMPRESSIONS OF THE PARIS SHOW.
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Further Notes on, and Criticisms of, Interesting Exhibits and Points in Design.
T AST WEEK, owing to the special
arrangements made by this journal, we were able to place before our readers the best illustrated and most complete report of the commercial vehicle exhibits at the Paris Show; at the same time we promised that we should deal in this issue with certain aspects to which considerations of the space then at our disposal forbade more than brief reference. • We will deal first with vehicles designed for specific and unusual purposes, and of these perhaps the most interesting were those built for the transport of petrol and petrol-electric railcars, which, incidentally, are becoming increasingly popular for use on the narrow-gauge lines which are laid in many parts of the country.
The largest railcar carrier was a Renault tractor-trailer with the wellknown epicyclic gear reduction in the tractor driving wheels and an exceptionally long lattice girder built trailer,' with its frame dropped behind the turntable—or, rather, its Renault equivalent, which we illustrated last week.
The railcar itself. was . of considerable interest. The 'drive was to the rear wheels only through a three-piece propeller shaft, with the last portion enclosed in a tubular 'torque member,
additional torque members being provided outside the wheels. A separate driver's compartment and duplicate controls were provided at each end. The seats were arranged in facing pairs at each side of a central gangway. A smaller type of Be Dion railcar was shown on a 6-ton, four-wheeled, platform lorry of the same make; in this case a powerful winch gear was provided at the forward end for drawing
the car, into position on the platform.
The third railcar carrier was a 12-ton trailer with a Crochet petrol-electric car to hold 45 passengers and to travel at 25 m.p.h.
What, in our opinion, constituted a. very important feature was the development of the fire-engine equipped for sup
plying " mousse,' or chemical fireextinguishing liquid, one of the attributes of which is that it can deal with a burning fluid such as petrol. A small machine of this type was shown by Citron and a larger one by S.O.M.U.A. These engines carry tanks containing chemicals which, when mixed with -water in the correct proportions, produce many times their volume of mousse, and the pumps utilized are so arranged that they can supply this mixture or water.
Here we have the light van, but in France there is the vogue for the " camionette," or light lorry. Most of the true vans are very large, but the small vehicle with a detachable tilt cover appears to meet all requirements in the direction of loads of from 10 cwt. to 25 cwt.
We noted in particular a Mile van specially built for the needs of the French butcher. This vehicle hada high back portion divided into three horizontal compartments and provided with a permanent cover and sides, whilst between this portion and the driver's cab was a roofed section with roll-up side curtains.
Battery electric vehicles have hitherto received but little encouragement in France, and in previous shows almost the sole representative of this style of vehicle has been exhibited by H. Crochet. This year there were some half a dozen models, including two by Berliet, the Laporte, the Crochet and the A.E.M. The last-named was staged by Societe d'Applications Electro Mecaniquee, who also had some electric industrial trucks, ono with an electrically operated lifting platform at the front resembling that used in the tier lift truck, which was described some time ago.
French designers appear to believe • that'an electric vehicle of the light type should be made closely to follow the lines of the petrol vehicle, and, at the first glance, it is difficult to Bee that the light Berliet and A.E.M. machines are other than petrol vans. The Berliet 15-cwt. electric van has two mechanical changes of speed and four controller speeds, giving eight in all, and the final drive is by cardan shaft to bevel gears
in a vertical banjo axle, the motor being series wound.
The Laporte 5-tan electric has two motors pivoted to the rear axle, and each has a change-speed gear between A and the final drive internal gear, thus giving 10 gear changes in all when the five controller positions are considered.
In this country the tendency' of designers is more and more to the simpliAcation of the drive, and mechanical hear changes are not looked upon at all favourably, as tending to absorb an undue proportion of the battery charge. We believe that this ideal of simplicity will soon become apparent in France if the electric receives encouragement.
The A.E.M. 10-cwt. electric van has certain unique features, including overhead worm drive to the front axle, a foot brake acting on all four wheels and a hand brake on those at the rear, eleetrictz. z'raking and recuperation, and totally enclosed motor.
Suction gas producers for use m motor vehicles have made a fair amount of headway, chiefly because they epee. ate very satisfactorily on charcoal, a fuel which can he obtained with ease throughout France. In this connection, A will be remembered that the Thornycroft type gave great satisfaction in the recent Government tests.4., We have already referred to the producer on the Panhard. In this the producer proper, with its hopper, is carried CM cross-bearers at the near side of the
B38 vehicle, whilst the purifier, almost. as big as the producer, balances the lastnamed at the off side, a dozen or so cooling pipes passing between the two.
The only other producer exhibited was the E.T.I.A., made by Delhaye et Mahieu. This closely resembled one of our English models, and had a neat scrubber, water tank, geared-up blower, and an air control on a vertical pipe which was carried immediately behind the dash. The fuel bunker was situated between the cab and body.
Perhaps the most interesting of the smaller exhibits was the rear axle of a Voisin chassis fitted with the Lavaud automatic gear, which embodied ' a awash plate and six connecting rods, each rod being fastened to the outer ring of a free-wheel device. This axle had already run 20,000 kiloms. A very unusual design—at least so far as commercial-vehicle chassis are concerned—was to be seen in the 3i-ton Renault. In this the front of the gearbox was carried in a spherical housing, whilst at the back was an extension ending in a fork, the arms of which were secured to a cross-member. The third shaft of the gearbox ran through this extension, and the transmission brake drum was carried between the arms of the fork. The propeller shaft was enclosed in a torque tube.
There appears to be quite a fight between the dual axle consisting of a separate load-carrying member and final drive through internal gears, and the double-reductien type and at the Show the latter seemed to be gaining the advantage. It is somewhat startling to find a double-redaction axle in the new 30-cwt. E.B. chassis.
Many chassis had unit engine and gearbox construction, but here, again, a change was observable, for, in certain instances, only the bottom half of the gearbox was embodied in the main cast,jog, thus leaving the clutch and its operating gear more accessible.
A great many of the exhibits had underslung springs, but in certain types the benefits thus obtained appeared to have been reduced by the fact that the frames had to be arched to clear the rear axle. A useful type was the Latil, with its cranked rear axle and final drive via short cardan shafts to internal gear rings in the rear wheels.
The number of tipping and loading gears was very considerably less than that shown last year, and it is worthy of note that hydraulic gears were fitted almost exclusively.
An unusual type was that employed by Fernand. In this, a virtually horizontal ram caused the body both to lift and tilt, the action resembling that employed in the Autocar tipper.
La Tribenne three-way tipper made use of two rants so pivoted that they could swing towards the front or rear of the vehicle to permit tipping to the back, whilst for side tipping the arched
• member joining the rams slid in a curved steel channel.
A feature of the ball-and-socket joints at each corner of the body was that the ball pin was not permitted other than a very slight movement until it actually entered the socket.