A SIX-SPEED ELECTRICALLY OPERATED GEAR.
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A Resurn.6 of Recently Published Patent Specifications.
THE Societ6 d'Exploitation des Brevets Cotal, of Paris, in specific* tion ,No. 248,68, describe a six-speed gear in which all operations are governed electrically. The main principle of this gear resembles the Elma gear, on the experimental work in connection with which so much money and time were ,spent. As several similar gears have been patented recently, we will give a brief general explanation of the idea for the benefit of those who are not familiar with the workings of this promising type of change gear.
If a disc or ring of soft iron has a groove formed in its face, and a winding of wire be placed in this groove and an electric current, such as that from a battery, be passed through the wire, it transforms the disc into an annular magnet which will attract a plate to it with sufficient force to expel a film of oil and to set, up sufficient friction toform a two-part clutch and to 'transmit such power as is necessary to drive a motorcar. In the past, difficulties were encountered—not electric hut mechanical —as if the metal forming the magnet were of too soft a nature, it would score badly when in contact with the plate which formed the armature, whilst, if of a harder nature, residual magnetism would continue to hold the two parts together after the electric circuit was broken ; hi other words, the dutch formed would not let go. We understand, however, that these difficulties have now been overcome and that suitable steels have been found for the purpose.
The Elma gear was a most fascinating device, as one could put in the reverse while travelling at top speed forward. The result was that the car would slowly come to rest and equally gradually pick up on the reverse—all changes being made by the mere pressing of a button.
The present invention is an adaptation of the use of electro-magnetic couplings and unconplings of the various members forming the gear. Planetary and sun wheels are employed, and it is by the anchoring of the planet-carrying plates and the coupling of certain members by means of the electro-magnets that the six speeds and reverse are. obtained. We have not space here to describe all the combinations which produce the six 1146 speeds, but it is obvious that, once the electro-magnet form of coupling is made a practical device, the door is open to all sorts of combinations in which the principle can be employed.
A Means for Locking Nuts.
RENE DELIS, of Paris, in specifica
tion No. 249,852, shows a spring washer that will lock a nut to the part against which the nut bears. It much resembles the Grover washer in action, only that projecting serrations are formed on the underside of the washer, and a projecting spur on the spring tip of the washer engages in depressions made in the nut. It is curious that, in the face of numer ous patents that have been granted for locknuts, the castle nut and split-pin still hold their OW11. Many inventors seem to be ignorant of the fact that it is not merely necessary to lock a nut to the surface against which It bears, as it is quite possible for a bolt to work loose and even to fall out, leaiiing the nut behind it. What seems to be an essential fea-. tare of a lockout is that it should secure the nut to the bolt.
Shoes for Travelling Over Rough Ground.
CARLO PASSEGA, of Paris, in
specification No. 244,057, describes a set of shoes that can be fitted to an 'ordinary steel-tired wheel when the vehicle has to travel over rough ground. Holes are provided in the rim for the central bolt of the cross-bars, and for the steady-pins, which prevent the crossbars from assuming an angle with the axis of the wheel. The shoes are made so that each forms a channel for the wheel to roll along, the slots at the sides of the shoes being of such a shape that they will allow of rolling action of the wheel, and no slipping can take place as the sides of the slots in the cheeks of the shoes are the arcs of cycloids. Strakes are provided at the surface of the shoes that comes in contact with the ground to enable them to grip soft surfaces: A central arch is shown on the outer surface of each shoe, but no mention is made in the specification of what this arch may be or what function it performs.
A Hydraulic Clutch.
THE Maybach Motorenbau, Friedrichshafen, Germany, in specification No. 228,901, describe a dutch which is automatically operated by means of hydraulic pressure, The exact object of the invention is not made very clear in the specification, which appears to refer to the starting of engines while the gears are in mesh and not, as usual, when in neutral. It even refers to the starting of an engine while on a steep incline and with the gears engaged.
A cone clutch is provided in the flywheel, which has the usual: teeth for engagement by the pinion of the starting motor. A female cone slides an the engine shaft in the usual manner for engagement in the flywheel: A spring
is employed, not as usual to cause engagement, but to separate the two members of the clutch. A hydraulic cylinder surrounds the engine shaft and appears to be fitted with a packing ring which bears on the boss of the outer member, and another on the outside of the hydraulic cylinder, which bears inside an extension of the outer member. An .oil pump connected to the engine is always at work and supplies the pressure that keeps the two members of the clutch in engagement. A spring-actuated piston is mounted in a cylinder which relieves any sudden pressure of oil from the clutch, and so prevents a. too sudden engagement. No safety-valve arrangement is shown.
It would appear, as the hydraulic cylinder cannot revolve, that rotary movement must take place continuously between the hydraulic cylinder and the outer member of the clutch, which would necessitate the employment of some very efficient kind of packing ring to prevent leakage. It would almost seem that some special. object was in view that the specification has not made dear.