Improvements in Driving Gear for Bicycles and other Machines.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Improvements in Driving Gear for Bicycles and other Machines.
I, ARTHUR DOYLE, Architect, of Room 1, Coleman Building, Front Street, Seattle,
in the County of King and State of Washington, United States of America, do
hereby declare the nature of my invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:
The object of the invention is to provide a new and improved driving gear for
bicycles and other machines, which is simple and durable in construction, and
arranged to require but a short up and down movement on the part of the rider's
feet, to develop a large amount of power and to run the machine at a high rate
of speed, and at the same time enable the rider or operator to augment at will
the driving force by hand power.
The invention consists of novel features and parts and combinations of the
same, as will be fully described hereinafter and then pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar characters of reference indicate corresponding
parts in all the figures.
Figures 1 and 1" show a side elevation of the improvement as applied to a
bicycle for men;
Figure 2 is an enlarged side view of the foot gear with parts in a different
position;
Figure 3 is a plan view of the same;
Figure 4 is a transverse section of the same, on the line 4-4 in Figure 2;
Figure 5 is a similar view of the same, on the line 5-5 in Figure 2; and
Figure 6 is a side elevation of the improvement as applied to a bicycle for
women.
The bicycle shown in Figures 1 to 5 inclusive is provided with the usual front
wheel A, the rear or drive wheel B and the frame C, on each side of which is
fulcrumed at D¹ a toggle member D of a primary toggle, said member D being
pivotally connected with a member D². On the pivot between the two members
s arranged a pedal E, adapted to be engaged by the foot of the rider. The outer
end of the toggle member D2 is hung on a link F fulcrumed on the frame C, and.
on said end of the member D2 is formed an angular arm -D, pivotally connected
with a link G having a pivotal connection - with a link G¹, fulcrumed
n a link H hung on the member D of the primary toggle. The pivotal end of
he link G¹ is formed with an angular arm G2 connected with the member I of a
econdary toggle operating in conjunction with the primary toggle previously
mentioned, said member I having pivotal connection with the member I'; and
etween the pivotal connections of the members I, I, and the links G, G¹ is
rranged a link J, so that the secondary toggle opens and closes, as hereinafter
ore fully described.
The member I of the secondary toggle has its free end hung on a link K
ilcrumed on the frame C, and said free end of the member I is formed with an
agular arm I2, pivotally connected by a connecting rod L with a wrist nin V
24

page_text: a gear wheel N, secured on a shaft N2 journaled in suitable bearings in the
frame C. The gear wheel N is in mesh. with a pinion N secured to the hub of
the rear or drive wheel B, so that the rotary motion given to the gear wheel N is
transmitted by the pinion N³ to the rear or drive wheel B.
The wrist pins N of the two gear wheels N on the opposite sides of the frame
stand diametrically opposite each other so that the pedal E on one side of the
frame is in an uppermost position, while the pedal on the other side is in a
lowermost position, or vice versa; that is, when one pedal moves upward the other
moves downward.
When the several parts are in the position illustrated in Figure 1 and the
operator presses with his feet on the pedal E, then the primary toggle consisting
of the members D and D2 opens up and the members D and D2 move in align-
ment with each other at the time the pedal E is in its lowermost position, as
indicated in Figure 2. During this opening up of the toggle members D and D³,
the member D by swinging rearward on the link F and turning thereon, causes
the arm 13 to impart a closing movement to the links G, G', which had been
in alignment with each other, so that the said links now move into an angular
position relatively to each other, and in so doing so the link G¹ by its arm Ga
imparts a forward movement to the member I of the secondary toggle and a
similar movement to the member I', so that the latter swings forward on the
link K, and by the arm I³ causes the connecting rod L to impart a rotary motion
to the gear wheel N. The secondary toggle, consisting of the members I, I',
moves into an open position with the primary toggle, owing to the connection
of the links G, G¹ with the said members I, I by the link J, and consequently
the primary toggle by means of the said links not only transmits the motion
given to the pedal E, but increases the stroke of the secondary_toggle and con-
sequently that of the connecting rod L. By this arrangement I am enabled to
increase the length of the stroke and crank arm three or four fold, and at the
same time reduce the pitch or angle formed by the toggles in the same or in a
greater ratio, both of which give the maximum of power with a minimum of
pedal action or foot lift.
It is understood that the power and efficiency of a toggle depends entirely on
the pitch or angle which is formed to the horizontal-that is-the toggle is very
powerful when the angle is small, and increases as the toggle descends, and
becomes as it approaches the horizontal almost infinite. On the other hand the
power decreases rapidly as the angle is increased until an angle of about 45°
is reached, after which the power exerted downwardly or vertically is greater
than the longitudinal or horizontal power transmission.
By the construction shown the length of the stroke is relatively larger, while
the angle formed by the toggle is comparatively smaller, thus giving the maximum
of power by a minimum of foot lift.
The motion lost in the descending of the primary toggle 1) when approaching
the horizontal, is taken up and restored by the links G, G¹ acting on the secondary
toggle, consisting of the members I and II, it being understood that the links G, GI,
also descend on the downward movement of the pedal E and recede from the
horizontal, thus equalizing the motion of the connecting rod L throughout its
entire stroke. A similar adjustment takes place so far as the power transmission
is concerned, so that a uniform force is applied for driving the bicycle forward.
The necessary or supplementary toggles are for the special and specific purpose
of increasing the length of stroke and crank arm and for reducing the pitch or
angle formed by the toggles, both of which features are essential to the produc-
tion of the greatest amount of power and speed, and also for the additional
purpose of equalizing the motion of the connecting rod and for reducing the pedal
action or foot lift. Both the primary and secondary toggles and also the links
always flex in the same direction and at the same time, up or down as the case
may be.
The shaft N2 is preferably provided with a crank arm N, pivotally connected

page_text: by a link O with an arm P secured on a shaft PI journaled on the frame C. On
this shaft P¹ is fastened a tube Q, in which is adjustably held a hand lever Q
under the control of the operator, so that when the latter moves the hand lever
forward or backward, a rocking motion is given to the shaft P¹ so that the arm P,
the link O, and the crank arm N assist in imparting a rotary motion to the
shaft N2, to assist in driving the bicycle forward. The bicycle is also provided
with a steering device of the following description.
On the upper end C₁ of the steering post C is arranged a transverse pivot pin ca
engaged by one end of a horizontally extending link f, pivotally connected with
a slide g extending transversely, and mounted to slide in a bearing or guide h
secured at its under side to a segmental arm extending through a slot in the
upper brace C of the bicycle frame and secured to the brace by a transverse pin j
engaging one of a series of holes in said arm i.
The link is preferably made in two parts fl f telescoping one into the
other, so that upon shifting the slide transversely in its bearing, the steering
post C and the fork are turned in the steering head of the frame to turn the
wheel A to the right or left, according to the direction in which the slide 9 is
moved. By the rider taking hold of the slide g and its bearing the slide can be
readily clamped in position, so as to prevent the steering post C from turning and
hold the steering wheel A in the desired direction.
The woman's bicycle shown in Figure 6 is similar in construction to the one
above referred to with the exception that the frame C is changed in form, and the
member I¹ of the secondary toggle I is without the arm 12 and is directly con-
nected to the link K' having its free end connected with the connecting rod L'
for a crank wheel N6 in the form of a sprocket wheel, connected
by a sprocket chain N7 with a sprocket wheel N8 on the hub of the rear
or drive wheel B. The operation and action is precisely the same as the one
above described, it being understood that the slight change in the connection
between the member I¹ and the connecting rod L by way of the link K¹ does
not change the motion of the various parts. The hand power is omitted in the
figure referred to.
The link K may be attached at its upper end to the primary toggle, instead of
the secondary toggle as shown.
I do not limit myself to the constructions shown and described for transmitting
the power, and it is expressly understood that both the gear wheel and pinion or
the sprocket and chain appliances may be dispensed with, and the power applied
through the connecting rod to a crank on the axle of the driving wheel direct.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
The pedal-operated primary toggle when so arranged in connection with a
secondary toggle that the primary toggle swings at one end from a fixed fulcrum
and the secondary toggle connects at one end with the swinging support of the
primary toggle and at the other end with the driving mechanism.
Dated this 23rd day of May 1899
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.