Balance Friction Clutch Driving Gear for Power Driven Vehicles.
Year: 1899

page_text: Date of Application, 5th July, 1899
Complete Specification Left, 2nd Apr., 1900-Accepted, 19th May, 1900
PROVISIONAL SPECIFICATION.
Balance Friction Clutch Driving Gear for Power Driven Vehicles.
We, ELIE EDOUARD MOLAS, EUGENE JULES LAMIELLE, and ALPHONSE HENRI
FRANÇOIS TESSIER, all of 45, Rue du Chemin Vert, Paris, France, Engineers,
do hereby declare the nature of this invention to be as follows:-
This invention relates to balance friction gear for actuating the driving
wheels of power driven vehicles the action of said gear being exclusively depen-
dent on the steering of the vehicle so that so long as the vehicle is travelling
in a straight line motion will under all circumstances be trans-
mitted equally to the two driving wheels whilst when the vehicle is travelling.
in a curve, motion will be transmitted to the two wheels proportionately to
the radii of the curves in which they travel, so that a constant balance of the
power transmitted to and utilized by each wheel will be maintained.
Reference is to be had to the accompanying drawings wherein Figure 1 repre-
sents a plan and Figure 2 a side elevation of the general arrangement of the
apparatus mounted on the swivelling fore carriage of an auto-motor vehicle.
Figure 3 shows separately upon a larger scale an internal face view of one of
the friction couplings. Figure 4 is a transverse section of the same on line A B
(Fig. 3). The same letters of reference denote like parts in the several figures.
The balance friction gear of this invention is intended to replace the ordinary
balance gear consisting generally of toothed gearing, which although it auto-
matically distributes the driving motion to the two wheels proportionately to
the radii of the curves in which they happen to be running can only do so,
provided the frictional resistances of the wheels upon the ground be equal.
Therefore when running in a straight line an inequality in the distribution of
the force will take place, should the resistances be unequal, the effect being
that should one wheel encounter an obstacle, a stone for instance the power
transmitted to that wheel will be decreased (just when it needs to be increased
since an obstacle has to be overcome), whilst that transmitted to the
other wheel will be correspondingly increased and thereby tend to-
cause the vehicle to describe a circle about the point of contact of
the blocked wheel as a centre, this tendency being only resisted by
the steering gear, which is liable to become strained by its frequent recurrence,
or again mounting the slope of a carriage entrance across the footpath or
other upward slope at an oblique angle is rendered the more difficult as the
wheel which first encounters the obstacle at once receives less power and the
balance gear thus tends to cause both wheels to surmount the obstacle at once.
It will thus be seen that the numerous accidents to mechanically operated
vehicles provided with ordinary balance gear are mainly due to the alternations
of the driving power transmitted to the two wheels according to the different
resistances presented by the ground over which they travel, such alternations
being always inverse to the needs of the case when travelling in a straight line.
In order to remedy these and other objections such as the breaking of teeth,
the seizing of parts etc., we have devised a gear having no toothed wheels and
whereof the action is solely dependent on the steering gear, so that the wheels
will be equally driven so long as the vehicle is running in a straight line.

page_text: When the vehicle is steered to right or left, the wheel which has to run in the
curve of smaller radius is uncoupled to the extent necessary to permit of its
slower motion, while the other wheel is coupled up more tightly so as to com-
pensate for the difference of power utilized, the uncoupling being effected gradu-
ally and proportionately to the difference of length of the ground travelled
over by the two wheels.
The friction gear consists essentially of a pair of friction couplings enabling
a progressive frictional engagement within wide limits. Each coupling com-
prises a drum (Figures 3 and 4) keyed on the driving shaft or upon an inter-
mediate shaft b by which power is transmitted either directly to the driving
wheels, or to the pinions actuating the same. The drum a contains the movable
parts by means of which the progressive frictional engagement is obtained and
comprise a boss c keyed on a shaft d one end of which turns in a liner e carried
by the drum a as a bearing. The other end of said shaft carries either the
driving wheel or the pinion for operating the same. Arms on the boss care
connected by bolts f, f working in radial slots to two semi-circular seginents
or shoes g, gi faced with leather h for making contact with the interior circum-
ference of the drum a, the two segments g, g being moved radially by means
of pairs of right and left, screws i, ¹ screwing into nuts pivoted by gudgeons j
in ears fixed to the segments g,g, the pivotal axes of the nuts being perpen-
dicular to their bores so that the nuts are enabled to adapt themselves to the
movement of the segments g. g. The screws i, i are turned by lever arms,
connected by toggle links m, m³ to a grooved collar a capable of sliding upon
shaft d, but keyed thereto by a groove and feather so as to rotate therewith."
By the sliding movement of sleeve a, the screws will be turned and force the
shoes g, g¹ more or less tightly against the rim of the drum a according to the
amplitude of the movement. The two collars are operated through lever
and links connections from the steering gears upon the movements of which
the friction gears thus depend.
9, 9'
In the example illustrated a crank pin o placed in rear of the king bolt P
coupled by rods q q¹ to bell crank levers r, coupled by pin and slot connec-
tions to rods s, coupled to the arms of forked levers t, t' which engage the
grooves of the collars. Springs a connected to the forks, tend to hold the
coupling in engagement under the tension, but are counter-acted by the rods
when in tension, but not when in compression. Thus the tension on the rod q
when the crank pin o is moved by the steering gear to the position shown in
dotted lines, overcomes spring u and causes the clutch to which rod is connected
to be slackened proportionately to the shorter travel of the wheel running in the
smaller curve, whilst the thrust on the rod g' merely causes the bell-crank lever l
to play in the slot of connecting rods, thus allowing the spring freedom to cause
the corresponding coupling. to be tightened to its utmost extent.
The lengths of the rods q, q' are so adjusted by screw couplings
normal running in a straight line the studs of the bell-crank levers r,
at the ends of the slots of the rods s, s¹.
Dated th: 5th 1T1 1000
that in
will be
Balance Friction Clutch Driving Gear for Power Driven Vehicles.
We, ELIE EDOUARD MOLAS, EUGENE JULES LAMIELLE, and ALPHONSE HENRI
FRANÇOIS TESSIER, all of 45, Rue du Chemin Vert, Paris, France, Engineers,

page_text: do hereby declare the nature of this invention and in what manner the same is
to be performed to be particularly described and ascertained in and by the follow-
ing statement:—
This invention relates to balance friction gear for actuating the driving
wheels of power driven vehicles, the action of said gear being exclusively depen-
dent on the steering of the vehicle so that so long as the vehicle is travelling
in a straight line motion will under all circumstances be trans-
mitted equally to the two driving wheels, whilst when the vehicle is travelling™
in a curve, motion will be transmitted to the two wheels proportionately to
the radii of the curves in which they travel, so that a constant balance of the
power transmitted to and utilized by each wheel will be maintained.
Reference is to be had to the drawings accompanying our Provisional Specifi-
cation wherein Figure 1 represents a plan and Figure 2 a side-clevation of the
general arrangement of the apparatus mounted on the swivelling fore-carriage
of an auto-motor vehicle. Figure 3 shows separately upon a larger scale an
internal face view of one of the friction couplings. Figure 4 is a transverse
section of 'the same on line A B (Figure 3). The same letters of reference denote
like parts in the several figures."
The balance friction gear of this invention is intended to replace the ordinary
balance gear consisting generally of toothed gearing, which although it auto-
matically distributes the driving motion to the two wheels proportionately to
the radii of the curves in which they happen to be running can only do so
provided the frictional resistances of the wheels upon the ground be equal.
Therefore when running in a straight line an inequality in the distribution of
the force will take place, should the resistances be unequal, the effect being
that should one wheel encounter an obstacle, a stone for instance, the power
transmitted to that wheel will be decreased (just when it needs to be increased
since an
obstacle has to be overcome), whilst that transmitted to the
other wheel will be correspondingly increased and thereby tend to
cause the vehicle to describe a circle about the point of contact of
the blocked wheel 08 a centre, this tendency being only resisted by
the steering gear, which is liable to become strained by its frequent recurrence,
or again mounting the slope of a carriage entrance across the footpath or
other upward slope at an oblique angle is rendered the more difficult as the
wheel which first encounters the obstacle at once receives less power and the
balance gear thus tends to cause both wheels to surmount the obstacle at once.
It will thus be seen that the frequent tendency to lateral deviation of
mechanically operated vehicles provided with ordinary balance gear are mainly
due to the alterations of the driving power transmitted to the two wheels owing
to the different resistances presented by the ground over which they travel such
alternations, being always inverse to the needs of the case, when travelling in a
straight line. In order to remedy these and other objections such as the breaking
of teeth, the seizing of parts etc., we have devised a balance friction gear having no
toothed wheels and whereof the action is solely dependent on the steering gear,
so that the wheels will be equally driven so long as the vehicle is running in a
straight line.
When the vehicle is steered to right or left, the wheel which has to run in the
curve of smaller radius is uncoupled to the extent necessary to permit of its
slower motion, while the other wheel is coupled up more tightly so as to com-
pensate for the difference of power utilized, the uncoupling being effected gradu-
ally and proportionately to the difference of length of the ground travelled
over by the two wheels.
The friction gear consists essentially of a pair of friction couplings enabling
a progressive frictional engagement within wide limits. Each coupling com-
prises a drum a (Figures 3 and 4) keyed on the driving shaft or upon an inter-
mediate shaft b by which power is transmitted either directly to the driving

page_text: :
.
wheels, or to the pinions actuating the same. The drum a contains the movable
parts by means of which the progressive frictional engagement is obtained.consist-
ing of a boss c keyed on the shaft done end of which turns in a liner e carried
by the drum a as a bearing. The other end of said shaft carries either the
driving wheel or the pinion for operating the same. Arms on the boss care
connected by bolte f, working in radial slots to two semi-circular segments
or shoes g, g' faced with leather for making contact with the interior circum-
ference of the drum a, the two segments g, g being movable radially by means
of pairs of right and left screws, screwing into nuts pivoted by gudgeons j
in ears fixed to the segments g, y' the pivotal axes of the nuts being perpen-
dicular to their bores so that the nuts are enabled to adapt themselves to the
movement of the segments g, gl. The screws i, are turned by lever arms,
connected by toggle links m m to a grooved collar capable of sliding upon
shaft d, but keyed thereto by a groove and feather so as to rotate therewith."
By the sliding movement of sleeve n, the screws will be turned and force the
shoes g. g more or less tightly against the rini of the drum a according to the
amplitude of the movement The two collars are operated through lever
and link connections from the steering gear upon the movements of which
the friction gears thus depend.
In the example illustrated in Figures 1 and 2 in which the apparatus is shown
as applied to the swivelling fore-carriage of an auto-motor vehicle a crank pin o
placed in rear of the king bolt p is coupled by rods q, q' to bell crank levers r, r
coupled by pin and slot connections to rods s, s¹ coupled to the arms of forked
levers t, which engage the grooves of the collars . Springs u connected to
the forks t, t' tend to hold the coupling in engagement under the tension, but
are counteracted by the rods q, q' when in tension, but not when in compression.
Thus the tension on the rod q when the crank pin o is moved by the steering
gear to the position shown in dotted lines in Figure 1, overcomes spring and
causes the clutch to which rod is connected to be slackened proportionately
to the shorter travel of the wheel running in the smaller curve, whilst the thrust
on the rod q merely causes the bell-crank lever to play in the slot of con-
necting rods, thus allowing the spring freedom to act on the forked lever and
cause the corresponding coupling to be lightened to its utmost extent.
The lengths of the rods q, q' are so adjusted by screw couplings y that in
normal running in a straight line the studs of the bell-crank levers r, will be
at the ends of the slots of the rods s, s¹.
It is to be understood that the forms, dimensions, details and materials employed
in the construction of our apparatus may be varied without in any way departing
from the principle of the invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. In a power driven vehicle the combination with the steering gear of balance
friction clutch couplings applied to transmit the driving power from a common
shaft to the two driving wheels respectively, the clutches being spring actuated
in the direction of engagement, and being connected with the swivelling fore
carriage so as to be actuated in the direction of disengagement by the swivelling
motion of the fore carriage in such manner that the tightness of coupling of the
clutches and the power transmitted to the respective driving wheels will be
equal when running in the straight, and will be proportional to the radii of the
ourves in which the wheels travel when running in a curve as specified.
2. In a power driven vehicle the combination with the steering gear, of balance
friction clutch couplings respectively corresponding to the two driving wheels
and consisting each of a drum on the common driving shaft, in combination
with friction segments revolving with the driving wheel. or intermediate shaft,
and adapted to be moved radially into or out of frictional contact with the drum

page_text: by means of screws operated by toggle mechanism actuated by a sliding collar
and of a spring tending to throw the clutch into gear, and link and lever mechan-
ism acting on the collar and spring and connected to a crank on the swivelling
fore carriage so as to overcome the spring and slacken the clutch, when the fore
carriage is swivelled in such direction as to guide the carriage towards the side at
which the said clutch and corresponding driving wheel are situated, substantially
as specified!
14 CHIS
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.