Improvements in Motor Road Vehicles.
Year: 1896

page_text: Complete Con
Date of Application, 10th Nov., 1896
1007
1000
Improvements in Motor Road Vehicles.
I, VICTOR ETIENNE PRETOT, of 21 Boulevard Poissonnière, Paris, in the Republic of
France, Mechanician, do hereby declare the nature of this invention to be as
follows:-
The system of motor fore-carriage, which forms the subject of this invention,
enables me to apply instantly mechanical traction to any carriage or vehicle usually
drawn by horses; by being substituted simply for the ordinary fore-carriage it can
therefore also, and with more reason, be applied to the propulsion of any vehicle which
is exclusively a motor carriage.
In the following description I will set forth the arrangements which I have devised
for obtaining this important result without making so to speak any change in the
carriage proper, while rendering the steering of the same very easy and realizing the
various conditions of driving usually demanded in respect of motor carriages.
The frame, suspended by springs upon the axle, receives the entire mechanism and
in the first place the motor which may be of any suitable kind, such as a petroleum,
electric or other motor. Both to the frame and to this motor itself if necessary is
attached a cross provided with a toothed sliding crown for the steering of the fore-
carriage with another crown which is rigidly attached by means of flanges and screws
to the fore-carriage rim of the carriage, after the ordinary axle and its equipage have
been removed, in the case of a vehicle which is also adapted to be drawn by horses.
The main or perch bolt of the carriage is located and centred in the axis of the cross,
the solidarity of the whole being thus perfectly ensured.
For transmitting the movement of the motor to the wheel, the shaft of the latter
carries two drums, one receiving a simple belt and a crossed belt, and the other a
single belt, and in connection respectively with three pullies of a large diameter, and
two other smaller pulleys, one of each of the large and small pulleys being fixed upon
their common shaft and the other three pulleys being loose.
The shaft of these pulleys carries a chain pinion operating the crown or chain wheel
connected with the box or case of the differential gear transmitting an independent
movement to two pinions which are at the end of the intermediate shaft and which
actuate by chains the toothed crowns or wheels attached to the wheels of the fore-
carriage.
It will be understood that, according as one or the other of the three belts is caused
to actuate the shaft of the pinion, the latter will receive either a rapid or a slow
novement in the direction corresponding to the forward motion or a movement in
the opposite direction and at a small speed for moving the vehicle back if necessary.
For effecting the displacement of the belts, each of them is in engagement with
the fork of a lever presenting each a curvilineal slot with which engages a pin or stud
appertaining to another transverse lever. The curve of the slot is such as to cause
the belt guides to make all the required movements. As for example, the belt for
the backward movement is upon the fixed pulley, while the other two are upon the
loose pulleys. If the lever is moved back, the belt in action is brought back on to
the loose pulley whilst the other two do not move from their place, the studs or pins

page_text: on the lever moving in the concentric parts of slots in the levers. But if, after
having thus thrown out of action the rear movement, the motion is continued I
bring in its turn the second belt upon the fixed pulley, the other two forks remaining
immovable, the vehicle then moves forward at a small speed; lastly if the lever is
altogether brought to the rear, the before-mentioned belt in action will in the first.
place pass on to the loose pulley, after which the third belt is brought into engage-
ment with the small fixed pulley; this is the forward movement at a great speed.
The engagement of one or the other of the three belts is thus preceded and followed
by a time of return, during which all three are upon the loose pulleys: this is the
uncoupling of the mechanism and the stoppage of the vehicle.
The operation of the belt guide by the action of these slotted links in the form of
cams has the great advantage of rendering the displacement of the belts independent
and successive, and thus obviating the enormous widths which several of the pulleys
would require if the belts were displaced simultaneously. But another result of the
greatest importance will be achieved; this being the possibility of varying the speed
given to the vehicle in a proportion otherwise greater than that' resulting from the
difference of relation of the two couples of pulleys.
In fact nothing is easier than to give to the part of these cams, corresponding
respectively to the setting in action of one or the other of the belts, a certain
concentric extent, in the passage of which the lever will leave the said belt in its
place, but can act on the other hand upon the regulation of the speed which the
motor receives, thereby enabling ine to obtain for that of the vehicle corresponding
differences. Lastly such position, wherein the lever can make a certain movement
without bringing into engagement any of the belts with one or the other of the fixed
palleys, may be utilized for the application of the brake.
In order to bring the operation of this movement within reach of the driver despite
the relative angular displacements which the steering demands between the fore-
carriage and the vehicle properly so called, the short arm of the lever is connected by
a rod to a short lever whose shaft carries a forked lever in engagement with a sleeve
adapted to be displaced vertically upon the axis of the movement for the steering.
This sleeve is actuated in its turn by another forked lever, the axis of which, apper-
taining in that case to the principal part of the carriage, carries the lever under the
hand of the driver. Quite close to this lever is the hand wheel, the shaft of which
carries at its lower part the pinion acting through the intermediate pinion upon
the crown for the steering.
Accordingly the driving of the carriage consists in the operation of the hand lever
for the starting, the stoppage, the changing of the speed and the reversal of the
motion, and in that of the hand wheel for the steering."
This simplification, already considerable as compared with the systems which have
been in use up to the present time, may be further increased by making use of a
modified arrangement.
In this arrangement the shaft of the hand wheel performs the duty of the hand
lever. For this purpose the said shaft is connected with the pinion by a swivel joint
which leaves it free to oscillate without its discontinning to operate this pinion as
regards the rotary movement. A rod attached to a sleeve in which the shaft can turn,
then unites the latter to a short lever, which effects the movement for changing the
speed as previously.
Thus with the hand wheel alone the driver steers the carriage by causing the shaft
to turn upon itself, and resets it in motion, stops it and regulates the speed of the
same, by causing this same shaft to oscillate according to the swivel which serves as a
centre in the pinion.
As the mechanism is combined in such a manner that the great speed corresponds
to the position of the hand wheel moved forwards, and on the contrary the slow speed
and the counter movement to this same hand wheel brought back towards the driver,
the latter acts upon the hand wheel exactly in the same manner as when leading a
horse, which facilitates and renders surer the steering or driving of the vehicle.
It will be seen that the application of this fore-carriage to an ordinary carriage does