Improvements in Cycle Propelling Mechanism.
Year: 1896

page_text: Date of Application, 1st Dec., 1896-Accepted, 23rd Jan., 1897
COMPLETE SPECIFICATION.
Improvements in Cycle Propelling Mechanism.
I, REGINALD HADDAN, of the Firm of Herbert Haddan and Co., of
18 Buckingham Street, Strand, London, W.C., Patent Agent, do hereby declare
the nature of this invention, a communication to me from abroad by Thomas
J. Armstrong, of Troy in the County of Miami, State of Ohio, in the United
States of America, Mechanical Engineer, and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :-
The invention relates to improvements in cycle propelling mechanism, the object
being to avoid dead centres in the actuation of the driving-crank-shaft; to propel
the machine by up and down movement of the pedals without revolving the latter
around the crauk-shaft; to reduce the sweep of the pedals to a minimum; to
attain great leverage upon the pedal-actuated cranks, and to accommodate the
employment of a large driving-sprocket or chain-wheel.
Another object of the invention is to attain the results indicated in the preceding
paragraph without materially increasing the weight of the machine.
With these objects in view, the invention consists in certain features of con-
struction, and combinations of parts hereinafter described and pointed out in the
claims.
In the accompanying drawings,
Figure 1 is a side elevation of a bicycle provided with the improved propelling
mechanism, and portions are broken away to more clearly show the construction
and to reduce the size of the figure.
Fig. 2 is an elevation, partly in section on line 2-2, Fig. 1.
Referring to the drawings, A designates the forward main wheel of the machine;
B, the rear main wheel; C the stationary seat-bearing-frame, and D, the steering
fork. E represents the crank-shaft that is horizontally arranged and suitably.
supported from frame C between wheels A and B. Shaft E is preferably located
as close to the rear wheel B as practicable. Shaft E is provided with two
cranks e, e, located at opposite ends respectively, of the shaft, and at opposite
sides, respectively, of the machine. Cranks e, e, are preferably arranged exactly
diametrically opposite each other. To the outer end of each crank e is horizontally
pivoted, at g, a lever G. The two levers G extend forwardly from their connection.
to the crank-shaft, and each of said levers, at its forward or free end, bears a
pedal G. A sprocket-wheel H is operatively mounted upon shaft E at the inner
side of one of the cranks, and said sprocket-wheel is operatively connected, by.
means of a chain h, with a sprocket-wheel b operatively connected with the rear
main wheel B of the machine. The crank-shaft supporting barrel or member C',
that is rigid with frame C, is provided with two depending arms or brackets C³, C,
rigid with opposite ends, respectively, of said member C'. Two vertically-
swinging sway-bars I, extending forwardly and rearwardly and arranged a suitable
distance below the rear or crank-engaging portions of the pedal-bearing-levers,
have their forward ends horizontally pivoted at I' to the different members C
respectively, of the machine's frame. Said sway-bars preferably extend rearward:
of the crank-shaft, and each of said bars, at its rear end, is horizontally pivoted
at I, to the rear and lower end of a forwardly and upwardly inclined link K whose

page_text: forward and upper end is horizontally pivoted to the adjacent pedal-lever-bearing
crank of the crank-shaft, preferably by the same pivot g that secures said lever to
the crank-shaft. Each bar I, at any suitable point, between its fixed end and the
connected link K, preferably at a centrally located point, has horizontally pivoted
thereto one end of another link L arranged parallel with said link K, and having
its opposite end horizontally pivoted to the aforesaid adjacent pedal-bearing lever.
Each sway-bar I is preferably arranged parallel with the connected pedal-bearing
lever.
It will be observed that when, during the operation of the machine, one of the
pedals is at the starting extremity of its downward-stroke, the other pedal has not
yet completed its downward stroke, as shown in dotted lines in Fig. 1, and that
when the last-mentioned pedal has completed its downward stroke, the other pedal
is in its downward sweep or stroke, as shown in solid lines in said figure. Hence,
while power is being applied to the lower pedal in the last portion of the downward
stroke of said pedal, power is also applied to the upper and downwardly-moving
pedal, so that power, in the operation of the machine, is continuously applied, and
dead centres are avoided. The pedal-bearing-levers are preferably as long as the
proximity of the crank-shaft to the axis of the main rear wheel will accommodate.
The sweep or stroke of the pedal-bearing levers is comparatively short and
considerably less than the length of the levers. A short sweep or stroke of the
pedals, it is obvious, is desirable to enable the operator to keep his feet in contact
with the pedals during the operation of the machine.
The great leverage involved in, and the facility of operating the improved
propelling-mechanism, also accommodates the employment of a driving sprocket-
wheel much larger in diameter than the driving-sprocket-wheels heretofore
employed, and it follows that great speed can be obtained by this propelling
mechanism with remarkable facility.
It will be observed therefore, that the improved bicycle-propelling mechanism
possesses the following important advantages or meritorious features; namely,
avoiding dead centres in the operation of the cranks; great leverage; short pedal-
stroke or sweep; simplicity and durability in construction; accommodation of
diametrically large driving-sprocket-wheel, and the ability of the rider or operator
not only to propel the machine with great rapidity and facility, but to assume a
natural, erect and comfortable attitude during the operation of the machine.
As shown in Fig. 2, one of the depending-arms or brackets C2 is bent or extends
around and transversely of the periphery of the driving-sprocket-wheel to accom-
modate the location of said wheel.
Referring again to the advantages of this propelling-mechanism, it will be
observed that said mechanism's vertically-swinging sway-bars are pivoted to the
machine's frame at one end, and are shown extending rearward of the connected
pedal-bearing-lever, and thereby accommodate the movement of their free ends,
during the operation of the propelling-mechanism, into comparatively close
proximity to, and rearward of, the crank-shaft, and thereby overcome the dead
centre considerably. The operator's leg, being bent at the top of the downward
pedal-stroke, is, of course, incapable of exerting nearly as much power as it is
capable of exerting at the lower extremity of said stroke when it is approximately
straight.
By this improved construction, it is obvious that the greater leverage is had
during the commencement of the pedal's downward stroke, and hence, the leverage
is the greatest when the power of the operator's leg is the weakest. This advantage
is due to the location of the vertically-swinging sway-bars below the crank-shaft, and
facilitates riding up-hill. Also the operator is not dependent upon momentum to
carry the crank over the dead centre, but the lower pedal has enough power
applied to it to carry the upper pedal over said centre considerably, because, as
already indicated, the one pedal has commenced its downward stroke before the
other pedal has reached the lower extremity of its downward stroke, so that the
operator applies power with both feet for a short time.

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what I
claim is;-
1. In a machine of the character indicated, the combination of the relatively
stationary frame, and driving-crank-shaft provided with two cranks at opposite
sides, respectively, of the two operating levers operatively connected with the
different cranks, respectively; two vertically-swinging sway-bars pivoted at one
end to the aforesaid frame adjacent to the different operating levers, respectively;
a link connection between the other end of each sway-bar and the crank-engaging-
end of the adjacent operating lever, and another link connection between each
operating lever and connected sway-bar a suitable distance from the first-mentioned
connection between said bar and lever, substantially as and for the purpose set
forth.
2. In a machine of the character iudicated, the combination with the suitably
supported driving crank-shaft provided with two cranks located at opposite sides,
respectively, of the shaft, and the relatively stationary frame extending below said
shaft; of the two operating levers connected, substantially as indicated with the
different cranks, respectively, two vertically-swinging sway-bars pivoted to the
aforesaid frame adjacent to the different operating-levers, respectively, and
arranged below the crank-shaft; a link connection between each sway-bar and the
crank engaging end of the adjacent operating lever, and another link connection
between each lever and connected sway-bar a suitable distance from the first-
mentioned connection between said bar and lever, substantially as shown, for the
purpose specified.
3. In a machine of the character indicated, the combination with the suitably
supported driving crank-shaft provided with two cranks located at opposite sides,
respectively, of the shaft, and the relatively stationary frame extending below said
shaft; of the two forwardly-extending operating levers operatively connected
with the different cranks, respectively; the two vertically swinging sway-bars
pivoted, at their forward ends, to the aforesaid frame and arranged below the
different levers, respectively, and extending rearwardly of the shaft; links
operatively connecting the rear ends of the different sway-bars, respectively, with
the rear ends of the different operating levers, respectively, and another connecting
link between each operating lever and the connected sway-bar a suitable distance
forward of the first mentioned connection between said bar and lever, substantially
as shown, for the purpose specified.
Dated this 1st day of December 1906