Improvements in Friction Gearing, also applicable to Belt Gearing.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Friction Gearing, also applicable to Belt Gearing.
I, BRUNO JANSEN, of B 17/2 Maximilianstrasse, Augsburg, in the Empire of
Germany, Student of Technology, do hereby declare the nature of this invention
to be as follows:-
Where it is unnecessary in the transmission of power that the proportions of
transfer should be maintained always equal and the other local or the like circum-
stances allow, an arrangement is employed in which the transmission of the power
takes place by friction. Friction wheels are employed for the direct transmission
of power and may be formed either as peripherally engaging wheels, or one
of them as a disc or face wheel and the other as a peripheral wheel,
whilst for indirect transmission a belt or rope driving gear is employed. In the
latter the belt which serves as the intermediate part is carried round by friction
with the driving belt pulley and then, also by means of friction, carries with it
or rotates the belt pulley which is to be driven. In each case the parts which are
to be operated by friction must be pressed one against the other with a considerable
pressure and this pressure must be determined by consideration of the maximum
power to be transmitted and in the case of belts they must be stretched to corre-
spond to this power. In spite of this however when sudden alterations of power
arise, a slipping between the parts operating the transmission frequently takes
place. If this slipping is to be avoided, any jerks which may arise must be taken
into consideration in calculating the pressure at which the one part is pressed
on the other. In order to do this a pressure is necessary which frequently exceeds
Such
the maximum theoretically necessary for the transmission of the power.
needlessly high pressure requires however a stronger construction of the whole
apparatus and causes a more rapid wearing away of the same, and in ordinary
working where it is not at all necessary, it enhances the cost and causes among
other inconveniences greater wear and tear of the bearings.
This invention has for its object a device by means of which the pressure at
which the parts transmitting the power by friction are pressed one on the other
may be altered to an equal extent in the case of variations in the driving power,
sudden shocks or the like, in such a way that this pressure is also increased with
the increase of the power and vice versa. By this means the result is attained
that the pressure with which the friction parts are pressed together always corre-
sponds to the extent of power to be transmitted and therefore in normal working
too great a pressure does not exist, whilst in the case of alterations of the power
to be transmitted, and of sudden shocks, no slipping takes place.
In order to attain this object the friction wheel mounted on the driving shaft,
or in the case of belt gear, the driving belt pulley, is not firmly connected with
the driving shaft but the connection is produced by means of a spring which
maintains the connection intact in a certain position by means of a screw with a
very steep pitch, whilst in the case of alterations (for instance increases) in the
power to be transmitted, the spring is stretched by the displacement of a suitable

page_text: part, which is effected by means of the screw, so that the friction wheel connected
with the source of power is pressed more strongly against the other wheel, or in
the case of belts the belt is strained more tightly and thereby a greater pressing-on
pressure is obtained corresponding to the increased power.
In one form of construction a friction disc is mounted on the shaft which is to
be driven. A second shaft at right angles to the first named one and which
carries a friction roller is adjustable longitudinally in a sleeve operated by the
driving power, and said shaft is rotated by means of a pin travelling in a groove
of the said sleeve. The second shaft is mounted in suitable bearings and the
pressure with which the roller is pressed against the friction disc is determined by
the position of the said bearings. A third shaft for transmitting the driving power
is connected in any suitable manner with the sleeve hereinbefore mentioned, and
both this driving shaft and also the said sleeve are secured against displacement so
that these two parts can only describe a rotary movement. The connecting piece
effecting this consists of a flat pitched screw with a steep thread and also a second
sleeve. The last named screw engages in a part of the first sleeve which is provided
with a matrix screw, whilst the second sleeve has a slot in which a pin on
the driving shaft engages SO that the said screw and sleeve are
rotated together with the driving shaft, and may be adjusted along
An outer sleeve is placed over the said second sleeve
but does not share in the rotation of the latter, whilst it is carried with it
in its longitudinal displacement. This outer sleeve is connected with a strong
spring by means of a connecting rod, said spring having an elastic pressure pin
on its end which is opposite to the end on which the rod engages. The said
connecting rod is connected with the outer sleeve by means of a clamp piece.
mounted on the latter. The said spring is so fixed and of such a shape that on
the part on which the connecting rod engages being displaced the pressure pin
on the end of the spring bears against another pin which is connected with the
bearing of the second named shaft and thereby presses the friction roller mounted
on the said shaft against the friction disc and increases the extent of such pressure.
The mode of working of this arrangement is as follows:
the same.
As long as the driving power remains constant the driving shaft carries the
internal sleeve with it, whilst the connection between the screw and the first
mentioned sleeve is maintained by means of the steep pitched thread and the
tension of the spring connected with the outer sleeve as this spring holds the
inner sleeve and the screw in position by means of the connecting rod and the
outer sleeve, the spring being so stretched that the pin mounted thereon presses
by means of the other pin on the bearing of the second named shaft and thereby
presses the friction roller against the friction disc to an extent corresponding to
the power to be transmitted. If however a greater power is to be transmitted, or
suddenly stronger impulses and shocks arise in the driving shaft, this shaft will
rotate more rapidly than the first named sleeve so that the screw is screwed further
into the said sleeve carrying along with it the inner and outer sleeves on the
driving shaft. This adjustment of the outer sleeve however by the intermediary
of the connecting rod stretches more strongly the spring connected with said
outer sleeve which in turn presses more strongly on the second pin by means of
the pressure pin connected with said spring so that the bearing of the second
shaft is pressed against the friction disc and the pressure with which the friction
roller presses on the friction disc is increased and any slipping between said
friction roller and the friction disc is prevented. When the power diminishes or
the shock ceases the screw unscrews itself from the first sleeve and the pressure
with which the friction parts are pressed together is again diminished by the
moving back of the parts so that in the case of normal working only the necessary
pressure exists.
Another form of construction allows of this invention being applied to the
driving gear of a bicycle having a variable proportion of transmission, the present,
improvement being located in the wheel hub and the device for altering the

page_text: transmission on the pedal crank, the cycle being a chainless one. A friction disc
is mounted on the driving axle (pedal axle) whilst a friction roller receives the
power and transmits it to the rear wheel by means of bevel gearing. In order to
allow of various degrees of transmission it is preferable to allow the
friction roller to engage on the same place of the friction disc so that in
order to obtain an alteration in the transmission the roller is formed as a cone the
largest and smallest diameter of which corresponds to the desired largest and
smallest transmission. This cone is adjustably mounted in the frame and by
means of suitable connections may be adjusted and fixed. In order to prevent,
in the case of pointed cones, the gearing from being too distant from the axle
and also to allow of the cone during the adjustment resting against the friction
disc, an elastic piece is inserted in the transmission shaft.
As the friction cone is fixed the friction disc must be made movable and capable
of being pressed against the cone with variable force in order to obtain an alteration
in the pressure at which it is pressed on. This friction disc is therefore provided
with a sleeve which is adjustably mounted in ball bearings and may be connected
with the casing of the ball bearings by means of a tongue and groove or may
carry the said casing round with it by friction. In order to allow of the pressure
at which the parts are pressed together being varied whilst travelling forward or
backward (forward or backward pedalling), the device hereinbefore described is
duplicated, one set acting in one direction of rotation and the other in the other.
Each of these arrangements consists of a steep pitched screw fixed on the pedal
axle which engages in a nut arranged in the sleeve on the friction disc. Each
of these nuts has a projection which engages in a suitable groove of the said sleeve.
A spring is provided between each of the nuts and a suitable bearing surface of
.
the sleeve.
The mode of action is as follows:-
The nut is acted on by the spring and the pitch of the screw on the pedal axle,
causing it to adjust itself to correspond with the power to be transmitted so
that the disc is pressed on the cone with the necessary force. The nut carries the
sleeve and the disc with it which transmit the power through the cone and bevel
gearing to the rear wheel. On an increase of the power taking place the nut is
displaced along the screw (as the axle is not adjustably mounted) so that the
spring is more stretched and thus increases the pressure with which the disc is
pressed on the cone. In this case the duplicate nut is inactive. In back pedalling
however the duplicate set comes in a similar manner into action, whilst the first
set remains out of action. This is attained by the threads of the two nuts being.
pitched in opposite directions.
In another form of construction a shaft carrying a driving belt or rope pulley
is connected with the driving shaft by means of a screw having a steep pitched
thread and the position of these parts to one another is determined by means
of a spring which is stretched in proportion to the power to be transmitted.
A sleeve having a pin is mounted on the driving shaft in such a way that the said
sleeve is carried along with the said shaft on the latter being adjusted but does
not share in the rotation of the same. The pin on the sleeve engages in a fork
shaped end of an elbow lever pivotted at a suitable point, a drawbar or the like
being attached to the other arm of the said lever. This drawbar connects the
elbow lever with another lever which latter carries at its end a pressure roller which
influences the tension of the belt by means of which the power is transmitted to
the driven belt pulley.
In order to maintain the tension of the belt at a constant level and to prevent the
device for altering it coming into play for instance when the roller passes over
the joint of the belt, a spring is preferably arranged in the draw bar before
mentioned.
The working of the apparatus is as follows:-
As soon as an alteration in the power to be transmitted takes place, that is
to say the steep pitched screw is screwed into its sleeve, the other sleeve on the

page_text: driving shaft is moved to the right, so that the elbow lever draws the drawbar
which in turn presses the roller on the belt by means of the lever connected with
said drawbar so that the pressure of the belt is increased. When the power to be
transmitted decreases, the roller is pressed less strongly on the belt and allows the
pressure of the latter to diminish and partially relieves the bearing from the
pressure arising from the tension of the belt.
Dated this 13th day of August 1898.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.
COAT LINIE DIMOITICATION.
Improvements in Friction Gearing, also applicable to Belt Gearing.
I, BRUNO JANSEN, of B 17/2 Maximilianstrasse, Augsburg, in the Empire of
Germany, Student of Technology, 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 following statement:-
Where it is unnecessary in the transmission of power that the proportions of
transfer should be maintained always equal and the other local or the like circum-
stances allow, an arrangement is employed in which the transmission of the power
takes place by friction. Friction wheels are employed for the direct transmission
of power and may be formed either as peripherally engaging wheels, or one
of them as a disc or face wheel and the other as a peripheral wheel (edge runner),
whilst for indirect transmission a belt or rope driving gear is employed. In the
latter the belt which serves as the intermediate part is carried round by friction
with the driving belt pulley and then, also by means of friction, carries with it,
or rotates the belt pulley which is to be driven. In each case the parts which are
to be operated by friction must be pressed one against the other with a considerable
pressure and this pressure must be determined by consideration of the maximum.
power to be transmitted and in the case of belts they must be stretched to corre-
spond to this power. In spite of this however when sudden alterations of power
arise, a slipping between the parts operating the transmission frequently takes
place. If this slipping is to be avoided, any jerks which may arise must be taken
into consideration in calculating the pressure at which the one part is pressed
on the other. In order to do this a pressure is necessary which frequently exceeds
the maximum theoretically necessary for the transmission of the power. Such
needlessly high pressure requires however a stronger construction of the whole
apparatus and causes a more rapid wearing away of the same, and in ordinary
working where it is not at all necessary, it enhances the cost and causes among
other inconveniences greater wear and tear of the bearings.
This invention has for its object a device by means of which the pressure at
which the parts transmitting the power by friction are pressed one on the other
may be altered to an equal extent in the case of variations in the driving power,
sudden shocks or the like, in such a way that this pressure is also increased with
the increase of the power and vice versa. By this means the result is attained
that the pressure with which the friction parts are pressed together always corre-
sponds to the extent of power to be transmitted and therefore in normal working
too great a pressure does not exist, whilst in the case of alterations of the power
to be transmitted, and of sudden shocks, no slipping takes place.
In order to attain this object the friction wheel mounted on the driving shaft,
or in the case of belt gear, the driving belt pulley, is not firmly connected with

page_text: the driving shaft but the connection is produced by means of a spring which
maintains the connection intact in a certain position by means of a screw with a
very steep pitch, whilst in the case of alterations (for instance increases) in the
power to be transmitted, the spring is stretched by the displacement of a suitable
part, which is effected by means of the screw, so that the friction wheel connected
with the source of power is pressed more strongly against the other wheel, or in
the case of belts the belt is strained more tightly and thereby a greater pressing-on
pressure is obtained corresponding to the increased power..
Some forms of construction of this arrangement for direct and indirect trans-
mission (friction wheels and belt gear) are shown in the accompanying drawings.
It must be remembered however that friction wheels are particularly suited for
those cases in which an alteration in the transmission is required. In the two
forms of construction of friction wheels shown therefore they are shown for
transferring variable transmission.
Figures 1 and 2 show a form of construction in elevation and sectional plan
respectively in which the friction wheel is connected with the power shaft and
the disc is mounted on the shaft to which the power is to be transmitted, whilst
Figures 3-7 are details. Figure 8 is another form of construction in which
the friction disc is connected with the power shaft and operates whether the shaft
is running forward or reversing (backwards), such as is suitable for cycle gear.
Figure 9 is an elevation of the friction wheel and Figure 10 a diagram of its
use for driving a cycle with variable gear.
Figures 11 and 12 are diagrams in side and front view respectively of the
application of this arrangement to belt gearing.
In the form of construction shown in Figures 1-7 a friction disc b is mounted
on the shaft which is to be driven. A second shaft at right angles to the first
named one and which carries a friction roller is adjustable longitudinally in a
sleeve e (the bearing of which in Figure 2 for the sake of clearness is shown
turned 90°) operated by the driving power, and said shaft is rotated by means of
The shaft d is mounted in
a pin travelling in a groove f of the said sleeve c.
suitable bearings h and the pressure with which the roller is pressed against the
friction disc is determined by the position of the said bearings. A third shaft i
for transmitting the driving power is connected in any suitable manner with the
sleeve e herein before mentioned, and both this driving shaft and also the said
sleeve e are secured against displacement so that these two parts can only describe
a rotary movement. The piece connecting the parts e and i consists of a coarse
or steep pitched screw with a square thread and also a second sleeve 7. The
screw engages in a part of the sleeve e which is provided with a matrix screw,
whilst the sleeve 7 has a slot m in which a pin on the driving shaft i engages,
so that the said screw and sleeve / are rotated together with the driving shaft i,
and may be adjusted along the same. An outer sleeve o is placed over the said
sleeve but does not share in the rotation of the latter, whilst it is carried with
it in its longitudinal displacement. This outer sleeve o is connected with a strong
spring by means of a connecting rod p, said spring having an elastic pressure
pin r on its end which is opposite to the end on which the rod engages.
The said connecting rod is connected with the outer sleeve o by means of a
clamp piece t mounted on the latter. The spring y is so fixed and of such a shape
that on the part on which the connecting rod p engages being displaced the
pressure pin ŕ on the end of the spring bears against another pins Figs. 4 and 5
which is connected with the bearing of the second named shaft. and thereby
presses the friction roller c mounted on the said shaft against the friction disc b and
increases the extent of such pressure.
The mode of working of this arrangement is as follows:-
As long as the driving power remains constant the driving shaft carries the
internal sleeve with it, whilst the connection between the screw and the
sleeve is maintained by means of the steep pitched thread and the tension of
the spring connected with the outer sleeve as this springs holds the inner sleeve

page_text: and screw k in position by means of the connecting rod p and the outer sleeve o,
the spring being so stretched that the pin mounted thereon presses by means
of the pins on the bearing of the shaft d and thereby presses the friction roller c
against the friction disc b to an extent corresponding to the power to be trans-
mitted. If however a greater power is to be transmitted, or suddenly stronger
impulses and shocks arise in the driving shaft, this shaft will rotate more rapidly
than the sleeve e so that the screw k is screwed further into the said sleeve
carrying along with it the inner and outer sleeves and o on the driving shaft.
This adjustment of the outer sleeve o to the left, Fig. 2 however by the intermediary
of the connecting rod stretches more strongly the spring y connected with said
outer sleeve which in turn presses more strongly on the pin s by means of the
pressure pin connected with said spring so that the bearing of the shaft dis
pressed against the friction disc band the pressure with which the friction roller c
presses on the friction disc is increased and any slipping between said friction
roller and the friction disc is prevented. When the power diminishes or the
shock ceases the screw unscrews itself from the sleeve e and the pressure with
which the friction parts are pressed together is again diminished by the moving
back of the parts so that in the case of normal working only the necessary pressure
exists.
A
The form of construction shown in Figs. 8--10 allows of this invention being
applied to the driving gear of a bicycle having a variable ratio of transmission,
the present improvement being located in the wheel hub and the device for
altering the transmission on the pedal crank, the cycle being a chainless one.
friction disc is mounted on the driving axle (pedal axle) whilst a friction
roller receives the power and transmits it to the rear wheel by means of bevel
gearing u In order to allow of various degrees of transmission it is preferable
to allow the friction roller to engage on the same place of the friction disc so that
in order to obtain an alteration in the transmission the roller c¹ is formed as a cone
the largest and smallest diameter of which corresponds to the desired largest and
smallest transmission. This cone is adjustably mounted in the frame and by means
of suitable connections may be adjusted and fixed. In order, in the case of pointed
cones, to prevent the gearing from being too distant from the axle and also to
allow of the cone c¹ during the adjustment resting against the friction dise 4, an
elastic piece is inserted in the transmission shaft.
As the friction cone c¹ is fixed, the friction disc must be made movable and
capable of being pressed against the cone with variable force in order to obtain an
alteration in the pressure at which it is pressed on. This friction disc is therefore
provided with a sleeve which is adjustably mounted in ball bearings and may
be connected with the casing of the ball bearings by means of a tongue and
groove or may carry the said casing round with it by friction. In order to allow
of the pressure at which the parts are pressed together being varied whilst travelling
forward or backward (forward or backward pedalling) the device hereinbefore
described is duplicated, one set acting in one direction of rotation and the other
in the other.
Each of these arrangements consists of a steep pitched screw fixed on
the pedal axle, which screw engages in a nut ele arranged in the sleeve on the
friction disc. Each of these nuts has a projection a¹² which engages in a suitable
groove m of the said sleeve. A spring q¹² is provided between each of the
nuts ee and a suitable bearing surface of the sleeve c².
The mode of action is as follows:
The nut e¹ is acted on by the spring q' and the pitch of the screw k¹ on the pedal
axle causes it to adjust itself to correspond with the power to be transmitted so
that the disc is pressed on the cone with the necessary force. The nut e¹
carries the sleeve and the disc with it which transmit the power through
the cone c¹ and bevel gearing u to the rear wheel. On an increase of the power
taking place the nut el is displaced along the screw (as the axle is not
adjustably mounted) so that the spring is more stretched and thus increases

page_text: the pressure with which the disc b₁ is pressed on the cone c¹. In this case the
duplicate nut is inactive. In back pedalling however the duplicate set e² q
comes in a similar manner into action, whilst the first set e¹ remains out of
action. This is attained by the threads of the two nuts being pitched in
opposite directions.
In the form of construction shown in Figs. 11 and 12 a shaft w carrying a
driving belt or rope pulley e² is connected with the driving shaft by means of a
screw having a steep pitched thread and the position of these parts to one
another is determined by means of a spring (not shown in the drawing) which is
stretched in proportion to the power to be transmitted. For this arrangement the
form of construction shown in Figs. 1 and 2 and also that in Fig. 8 may also
be employed and the respective details are only shown in Fig. 2.
A sleeve of having a pin is mounted on the driving shaft i in such a way that
the said sleeve is carried along with the said shaft i on the latter being adjusted
but does not share in the rotation of the same. The pin o² on the sleeve engages in
a fork shaped end of an elbow lever pivotted at a suitable point a, a drawbar or
the like y being attached to the other arm of the said lever. This drawbar
connects the elbow lever at with another lever which latter carries at its end
a pressure roller z which influences the tension of the belt a by means of which
the power is transmitted to the driven belt pulley 2.
In order to maintain the tension of the belt at a constant level and to prevent
the device for altering it coming into play, for instance when the roller passes
over the joint of the belt, a spring y is preferably arranged in the draw bar y
before mentioned.
The working of the apparatus is as follows:-
As soon as an alteration in the power to be transmitted takes place, that is to say
the steep pitched screw is screwed into its sleeve, the sleeve o on the driving
shaft is moved to the right, Fig. 12, so that the elbow lever draws the draw-
bar y which in turn presses the roller z on the belt by means of the lever connected
with said drawbar so that the pressure of the belt is increased. When the power
to be transmitted decreases, the roller is pressed less strongly on the belt and
allows the pressure of the latter to diminish and partially relieves the bearing
from the pressure arising from the tension of the belt.
my said
Having now particularly described and ascertained the nature of
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1. A friction wheel gearing having an automatic adjustment of the frictional
pressure to correspond with the power to be transmitted characterized by the
driving shaft and a shaft carrying one friction wheel being connected by means
of a steep pitched screw standing under the pressure of a spring, the said spring
being stretched, after each adjustment of the screw connection, according to the
power to be transmitted whereby both friction wheels are pressed against one
another, substantially as herein before set forth.
2. A form of construction of friction gear such as described characterized by a
connecting piece, formed of a screw () and a sleeve (), which screw is screwed
into another sleeve (e) connected with the shaft (d) of the friction roller (c), being
connected with a spring (q) in such a way, as to alter by its displacement the ten-
sion or pressure of the spring (7) whereby the bearings (h) of the said shaft (/) are
altered in position in order to suit to the actual power to be transmitted the fric-
tional pressure of the friction roller (c) mounted on the said shaft (), against
the wheel (b) to be driven, substantially as described.
3. A form of construction of the friction wheel gearing hereinbefore described,
characterised by a screw (¹) being arranged on the driving shaft (i) with a
nut (e) connected by tongue and groove to a portion of the driving wheel (61)
formed as a sleeve ², said screw being adapted to adjust the nut which by means

page_text: of a spring located between it and the friction wheel (61) presses the wheel or
disc (6) against the cone (c) to be driven, substantially as described.
4. A form of construction of the friction gearing hereinbefore described,
characterised by the application of two similar arrangements e¹ q¹ and ²² q³,
the nuts (and) of which have threads pitched in opposite directions, whereby
the frictional pressure of the friction wheels is adjusted to the power to be con-
veyed, for either direction of rotation of the driving shaft (¹) substantially as
described.
5. The application of the hereinbefore described arrangement of friction gearing
to a chainless cycle with a variable speed gear characterised by the friction
wheel (c) which is not mounted on the pedal axle being adjustably arranged and
formed as a cone, the largest and smallest diameters of which correspond to the
largest and smallest transmission desired substantially as described.
6. A form of construction of the herein before described arrangement in friction
gearing to adapt it to be used for belt or cord gearing, characterised by the
arrangement of a pressure lever (r) having a roller (-) pressing against the
belt () which roller, upon a change in the power being transmitted and the
corresponding adjustment of the shaft (i), is pressed by means of suitable inter-
mediate mechanism more or less against the belt in order to suit the tension of
the same to the actual power transmitted substantially as described.
Dalad this 8th day of Mar 1899.
W. P. THOMPSON & Co.,
Of G, Lord Street, Liverpool, Agents for the Applicant.