Improvements in or connected with Driving Mechanism for Velocipedes.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with Driving Mechanism for
Velocipedes.
I, ALFRED EBENEZER MAVOR, of The Northfleet Engineering Works, North-
fleet, in the County of Kent, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention generally refers to improvements in the driving mechanism of
velocipedes, wherein there is employed a pair of treadle-levers having a recipro-
cating action, and the said invention particularly refers, firstly, to the control
and operation of automatically acting devices for changing the point of applica-
tion of the load or power on the treadle-levers, and secondly, to means whereby
the treadle levers are retained in proper relative position to each other, at all
times of their motion, so that when one treadle lever is moved in either an upward
or a downward direction the other treadle-lever moves in proper rotation
thereto.
The first part of this invention has particular reference to the change of
climbing gear, such as is for example described in British Patent Specification
dated 2nd October 1895, No. 18426 by Fredrik Ljungstrom. In the machine
therein described, there are employed treadle-levers each having two arms, one
arm extending forwardly and carrying the pedal at its forward extremity, while
the second arm is upwardly directed, and from which the driving band or chain
extends. These compound treadle-levers are mounted and free to be rocked one
at each end of the axle carried by the bottom bracket.
Both treadle-levers being similarly fitted, one of same will now be described.
The upwardly directed arm which may conveniently be of rectangular section
and tubular formation, is formed with a series of indentations one above the
other at equal distances apart on its forward face, the rear face of the arm being
formed with a series of apertures extending one above another and at proper
distances apart. The loop of a yoke piece embraces the upwardly directed arm,
the forward end of the yoke having a roller adapted to engage in the indenta-
tions on the lever arm, while the rearward end of the yoke, which is a short
distance behind the rear face of the lever-arm is attached to a chain or cord
extending therefrom to clutch, or other driving, gear, on the rear driven
wheel.
Within and between the lateral members of the yoke, and on a pivot trans-
versely thereto, is pivotted a pair of engaging arms, one such extending upwardly
and one downwardly, the extending ends being provided with hooks, the barbs
of which face towards each other. These hook-ended arms are adapted to engage
when in action with the perforations of the front of the lever arm when the
engaging arms are adjusted at an angle with each other, the angular motion of

page_text: the lever arm relatively to the lesser angular motion of the yoke aiding in
bringing about such engagement, and substantially as described with reference
to such mechanism in Specification of Patent 18426/95 aforesaid.
Now according to the present invention improved means are provided for
placing the engaging arms in proper relative positions to each other, while the
treadle levers are in motion, and so that alteration of the position of the yoke upon
the treadle lever arm may be automatically effected.
Each engaging arm is extended beyond its pivot pin oppositely to its hooked
end, and such extensions have parts extending rearwardly, and so that when
these extensions are caused to approach each other the hooked ends are placed
in more forward positions and engage the apertures of the lever arm for adjust-
ment of the yoke, while when the rearward extensions of the hook arms are
distanced from each other the hooks are not in a position for action.
In order to effect this setting of the parts, a flexible connection such as a wire
or cord, is attached by its end to the topmost rearward extension of one of the
engaging arms, and passes freely through an aperture in the rearward extension
of the other engaging arm which latter extension is supported upon a suitable
abutment.
By this arrangement when the flexible connection is pulled downwardly the
hooked ends aforesaid are moved forwardly into their acting positions against
the action of a spring, which latter when the tension of the flexible connection
ceases, again returns the hooks to their in-active position.
The flexible connection extends along or in the frame of the machine to within
reach of the rider and is operated by a screw action, say for example by rotating
one of the handles on the handle bar; it will be understood that in its course
from say the handle bar, to the pedal lever, the flexible connection has to extend
through several angles, and in order to facilitate its working I cause the latter
to freely pass through the centre of a flexible sleeve composed of helically wound
wire, the convolutions of which are in contact with each other, and this sleeve
is fixed so that it does not share the lengthway motion of the flexible connection.
One end of the sleeve aforesaid is located immediately under the lower exten-
sion of the hooked engaging arm and serves as the abutment against which
the pull of the connection acts.
The second part of this invention refers to the means employed to control the
relative motions of the levers in order to prevent an angular upward movement
of one lever relatively to the other and thereby dis-arranging the driving gear,
such means being composed as follows:-I provide a lug on the circular boss
of each lever arm. A metallic or other cord or chain is fixed by one end to
one such lug, passes partly around and under the boss towards the rear of machine,
extends upwardly, passes over an adjustable tension pulley, then downwardly to
the rear part of the boss of the opposite treadle lever, and under same, the
end of the cord being fixed to the lug on the said treadle lever. The means by
which the tension pulley may be adjusted and maintained in position may con-
sist of a serrated guide bar by which the bearing pin of the pulley is carried,
the same being locked in position by means of a washer having a serrated face,
held by a nut to the face of the serrated guide bar. By this means when one
treadle lever is litted the opposite treadle lever is depressed. Increased pro-
pelling power is thus obtained, particularly if the foot of the rider is rigidly
connected to the pedal, and the upward stroke is therefore operative.
In some cases I adopt a spiral spring to keep the tension pulley in tension.
Dated this 13th day of October 1898

page_text: Improvements in or connected with Driving Mechanism for
Velocipedes.
I, ALFRED EBENEZER MAVOR, of The Northfleet Engineering Works, North-
fleet, in the County of Kent, Engineer, 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:-
This invention generally refers to improvements in the driving mechanism of
velocipedes, wherein there is employed a pair of pedal-levers having a recipro-
cating action, and the said invention particularly refers, firstly, to the control
and operation of automatically acting devices for changing the point of applica-
tion of the load or power on the pedal-levers, and secondly, to means whereby
the pedal-levers are retained in proper relative position to each other, at all
times of their mouon, so that when one pedal-lever is moved in either an upward
or a downward direction the other pedal lever moves in a proper relation
thereto.
In order that my invention may be readily understood I will describe same with
reference to the accompanying drawings, whereon Fig. 1 shews in side elevation
the bicycle, or velocipede driving gear with my improvements applied thereto.
Fig. 2 being a sectional rear end elevation, taken about the line X Y of Fig. 1,
the yokes and driving cords hereafter described having been removed.
Fig. 3 is a side elevation drawn to a larger scale than the previous figures,
and shewing the change gear hereafter described. Fig. 4 is a rear sectional
end elevation taken on the line X Y of Fig. 3, Fig. 5 is a perspective view
of climbing hooks forming a portion of the change gear, and Fig. 6 shews the
gear in action.
Similar letters of reference refer to like parts in the several figures of the
drawings.
The first part of this invention refers to improvements in the change or
climbing gear of velocipedes of the type such as is for example described in
British Patent Specification dated 2nd October 1895, No. 18426, by Fredrik
Ljungstrom.
In such a type of machine, and as partly illustrated in the accompanying
drawings, there are employed pedal levers each having two arms A A¹, one
arm A extending forwardly and carrying the pedal at its forward extremity A³,
(although the pedals are not shewn in the drawing), while the other arm Ais
upwardly directed and carries one end of a driving band or chain which extends
rearwards to the driving drum upon the road wheel axle. These compound pedal
levers are mounted and free to be rocked one at each end of the axle carried by
the bottom bracket B, Fig. 2, of the machine frame B¹.
Both pedal-levers being similarly fitted, one of same will now be described,
with reference to the accompanying drawings.
The upwardly directed arm A which may conveniently be of rectangular
section and tubular formation, is formed with a series of indentations Cone above
the other at equal distances apart on its forward face, the rear face of the arm
being formed with a series of apertures D, extending one above another and at
proper distances apart. The upwardly directed arm A¹ passes through the loop
of a yoke E, the forward end of the yoke E having a roller E adapted to engage
in the indentations C on the lever arm A¹, while the rearward end of the yoke E,
which is a short distance behind the rear face of the lever arm A, is attached to

page_text: the cable chain or cord F, extending therefrom to clutch, or other driving gear,
on the rear driven wheel.
Within and between the lateral members of the yoke E and on a pivot E
transversely thereto, is pivotted a pair of engaging arms G G₁, best seen at
Figs. 3, 4 and 5, one such engaging arm G extending upwardly and one G¹
downwardly, the extending ends being provided with hooks the barbs of which
face towards each other. These hook-ended arms G G¹ are adapted to engage
when in action with the perforations or apertures D on the front of the lever
arm A', when the engaging arms G G¹ are adjusted at an angle with each other,
the angular motion of the lever arm A¹ relatively to the lesser angular motion
of the yoke E aiding in bringing about such engagement, and substantially as
described with reference to such mechanism in Specification of Patent 18426/95
aforesaid.
Now according to the present invention improved means are provided for
placing the engaging arms G G¹ in proper relative positions to each other,
while the pedal levers A A' are in motion, and so that alteration of the position
of the yoke E upon the treadle lever arm A¹ may be automatically effected.
Each engaging arm G G¹ is extended beyond its pivot pin E2, and such
extensions H H form tails to the hooked arms G G¹; from near the end of each
extension H H¹, there is a lug H³ H³, extending rearwardly at about right
angles to the extensions H H₁ of the arms G G¹.
Between the ends of the lugs H3 H³ there is fitted a helical spring J in com-
pression, which tends to force the lugs apart, and thereby holds the extensions
or tails H H' in front of the hooked ends of the arms G G', the latter hooked ends
then coming against stop projections H H on the lugs H2 H³. When in this,
the normal position of the device, and as is shewn at Figs. 3, 4 and 5, the hooks,
blinded by the extensions H H are wholly inoperative, and cannot engage the
apertures D of the arms A¹ at any part of the stroke of the said arms.
Now in order to uncover the hooks and allow them to engage with the afore-
said apertures D it is necessary to bring the extensions or tails H H rearwards,
and thereby to cause the hooked ends G G₁ to advance forwards, and such
movement is effected by causing the lugs H2 H3 to approach each other.
In order to effect this setting of the parts, a flexible connection, such as a
wire or cord K, is attached by its end to the topmost rearward lug H2 of one of
the extensions H', and passes freely through an aperture in the rearward exten-
sion of the other lug H³, which latter lug H³ is supported upon a suitable
abutment.
The flexible connection K extends along, or in the frame of the machine,
to within reach of the rider and is operated by any suitable means such as by
a screw action, say for example by rotating one of the handles on the handle
bar, or by levers or the like, not shewn in the drawing; it will be understood
that in its course from say the handle bar, to the pedal lever the flexible con-
nection K has to extend through several angles and in order to facilitate its
working I cause the latter to freely pass through the centre of a flexible sleeve L
composed of helically wound wire, the convolutions of which are in contact with
each other, and this sleeve is fixed so that it does not share the lengthway
motion of the flexible connection.
The end of the sleeve aforesaid is located immediately under the lower lug H³
of the extension H and serves as the aforesaid abutment against which the pull
of the connection K acts.
By this arrangement when the flexible connection K is pulled downwardly
the hooked ends of the arms G G' aforesaid are moved forwardly into their acting
positions, as shewn at Fig. 6, against the action of the spring J, which latter,
when the tension of the flexible connection K ceases, again returns the hooks
to their inoperative position.
Thus, when the yoke E is in its lowest position upon the arm A¹ as shewn in
the drawings, and it is desired to raise same thereon while the pedal levers are

page_text: in motion, the flexible connection K is pulled, by say rotating the handles on
the handle bar, and the flexible abutment L acting against the lower lug H³
the hooks are brought into their operative positions. Upon the next upward
motion of the pedal, the arm A¹ is brought into a backward angular position,
such as shewn at Fig. 6, and the upper hook G engages in one of the apertures
of the arm A¹; upon the descent of the pedal and the upward and forward motion
of the arm A, the yoke E is brought into an angular position relatively to the
pull of the driving cord F, and consequently the yoke E is rocked about the
centre E², the roller E is brought into the next upper notch C, and the hook
becomes disengaged. If it is not desired to shift the yoke still further up the
arm, then the hooks are again rendered inoperative by releasing the pull on the
flexible cord K, and the devices assume the position shewn at Fig. 3.
The second part of this invention refers to the means employed to control the
relative motions of the pedal levers, in order to prevent an angular upward
movement of both levers at the same time, and thereby rendering the dis-arrange-
ment of the driving gear practically impossible. Such means are composed as
follows: I provide a lug M Fig. 1 on the circular boss A³ of each pedal lever.
A metallic or other cord or chain N is fixed by one end to one such lug M, passes
partly around and under the boss A³ towards the rear of machine, extends
upwardly, passes over an adjustable tension pulley P, then downwardly to the
rear parts of the boss A3 of the opposite pedal-lever, and under same, the end
of the cord being fixed to the lug M on the said treadle lever. The means by
which the tension pulley P may be adjusted and maintained in position, may
consist of a serrated guide bar R, fixed to the machine frame, and the bearing
pin P of the pulley P is carried by this guide bar R, the bearing pin P1 being
locked in position by means of a washer having a serrated face, held by a nut
to the face of the serrated guide bar R.
In some cases I may adopt a spiral spring to keep the tension pulley in
tension.
By this connection of one pedal-lever with the opposite, pedal-lever, when one
pedal-lever is lifted the opposite pedal is depressed.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. In driving mechanism for velocipedes of the type herein stated, the devices
for changing the point of application of the load or power on the pedal-lever
arms, while the latter are in motion, comprising upon each lever arm the com-
bination with a yoke embracing the said lever arm, a roller in front of the yoke
to engage in indentations in the forward face of the lever arm, and a connecting
flexible cord or the like from the rear of the yoke to actuate driving gear on
the road wheel; of a transverse pivot carried by the yoke rearward of the arm,
a pair of oppositely extending hooked arms fulcrummed on the pivot capable of
being caused to engage with perforations in the rear face of the lever arm, an
extension of each hooked arm beyond the pivot and forming tails to the hooked
arms, and a spring acting between lugs on the extensions to normally cause the
latter to cover the hooks and prevent engagement of same with the lever arm,
a flexible connection connected to one of the lugs, and a flexible abutment to
support the other lug, and means for operating the connection from the handle
bar of the machine in order to uncover the hooks, and cause them to engage
the lever arm to raise or lower the yoke on such lever arm, substantially as
described.
2. In driving mechanism for velocipedes of the type herein stated, the improved
means and devices for changing the point of application of the load or power on
the pedal lever arms, while the latter are in motion, arranged and acting sub-
stantially as described and shewn with reference to Figs. 1 to 6 of the accom-
panying drawings.

page_text: 3. In driving mechanism for velocipedes of the type herein stated, the means
for controlling the relative motions of the pedal levers composed of a metallic
or other cord or chain fixed at one end to the circular boss of one pedal lever,
passing rearwardly partly around and under the said boss, then extending up-
wardly over an adjustable pulley carried by the frame of the machine, and then
downwardly under and partly around the boss of the other pedal lever to which
the other end of the cord is fixed, substantially as described.
4. In driving mechanism for velocipedes of the type herein stated, the device
for controlling the relative motions of the pedal, levers, constructed, arranged,
and acting substantially as and for the purposes described with reference to
Figs. 1 and 2 of the accompanying drawings."
5. The driving mechanism for velocipedes all combined arranged and acting
substantially as and for the purposes described with reference to the accompanying
drawings.
BREWER & SON,
London & Leeds, Agents for the Applicant.