Improvements in and relating to Bicycles.
Year: 1897

page_text: Date of Application, 22nd Nov., 1897--Accepted, 15th Jan., 1898
COMPLETE SPECIFICATION.
Improvements in and relating to Bicycles.
I, JAMES EDWARD WILSON, a citizen of the United States of America, residing
at 122, William Street, in the City of Bridgeport, County of Fairfield and State
Connecticut, United States of America, Manufacturer, 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:-
My invention relates to an improvement in bicycles and kindred vehicles,
whereby the weight of the rider is sustained and carried free from the shock or
vibration incidental to the roadway, the object of my invention being to provide
the modern men's "diamond" and ladies' "drop frame" bicycles, whether of the
chain or chainless species, with a device which can be quickly applied or removed
by unskilled hands, without any mutilation, alterations or modifications of the
frame whatever.
I have conducted most careful experiments and have built and equipped bicycles
with my present improvement and I have ascertained that the conditions
absolutely necessary to success are as follows:
First, the resiliency of the auxiliary frame or lever must be capable of ready
adjustment to suit the weights of various riders on the same machine or to suit
the caprice of an individual rider who at times may wish a spring element more
or less stiff.
Second, the auxiliary lever must be light but must be of such form and strength
as to resist severe strain without deflection or injury.
Third, this auxiliary frame must not materially enlarge the dimensions of the
assembled machine or in any way interfere with the rider or his clothing or detract
from the appearance of the machine itself.
Fourth, the parts added to the machine to accomplish the results aimed at must
be so simple in construction and application, that any person who is competent to
care for a bicycle at all can put the improvement in place or remove it in a few
minutes.
Fifth, the improvement must be economical in cost as compared with the expense
of the bicycle itself.
I therefore submit that the hereinafter described construction fully meets the
conditions above stated, and will be readily understood by reference to the accom-
panying drawings, which form a part of this application and in which-
Figure 1 is a side elevation showing a bicycle having a chain and sprocket wheel
propulsion equipped with my improvement;
Figure 2 a section at the line a-a of Figure 1;
Figure 3 a section at the line b-b of Figure 1;
Figures 4 and 6 broken elevations showing my improvement applied in two
different ways to a chainless bicycle, and
Figures 5 and 7 are sections respectively at the lines ec, of Figure 4 and d-d,
of Figure 6.
1

page_text: Similar numbers of reference denote like parts in the several figures of the
drawings.
1 is the usual diamond frame of a bicycle, and 2 is the rear fork within which
the rear wheel is usually journaled. 3 is what I term a yoke lever provided with
hubs 4 near its rear end, which hubs are pivoted within the rear fork 2 at the
point where the rear wheel is usually supported. 5 is the rear wheel which is
supported and journaled within the rear extremity of the lever 3, while the for-
ward extremity of this lever extends around the wheel and is capable of swinging
in an arc of a circle in close proximity to the circumference of such wheel, as will
be more clearly set forth hereinafter.
At the extreme forward end of the lever 3 is an extension 7 which is perforated
at various points, as shown at 8, and secured to any convenient part of the frame
above is a clip 9.
10 is a coil spring whose extremities are secured to said clip and to said ex-
tension at any one of the perforated points 8, so that it will be clear that any
downward movement of the forward end of the lever 3 will be effected against the
resiliency of this spring.
When my improvement is used on a bicycle that employs a chain and sprocket
wheels, I form one of the hubs 4 which is nearest the chain with a pair of depend-
ing ears 11 between which is journaled an anti-friction roll 12 over which the
lower portion of the chain 13 is passed, so that it will be clear that said chain is
guided laterally between these ears so that there can be no shifting of the chain
which might cause it to ride improperly on the sprockets.
When pressure is applied to the cranks the rider has the benefit of a loose chain,
since the lever 3 will be lowered and will thereby draw the roll 12 away from the
chain, but when these conditions are reversed the spring will return the lever to
normal elevated position and said roll will thereby be carried up against the chain
to take up the slack.
It will therefore be clear that sudden shocks on the frame can neither cause the
chain to become displaced or to ride improperly on the sprockets, nor effect any
rattling of such chain.
Referring to Figures 4, 5, 6, and 7, I will now describe the manner in which
my improvement is applied to what is now known as the "chainless wheel."
The yoke lever is provided with hubs which are pivoted at the end of the rear fork,
and within the rear extremity of this lever the rear wheel is journaled, all as herein-
before described with respect to the construction shown at Figure 1.
The main shaft case 14 is supported within a bridge 15 carried by the frame,
and within this case is the main shaft which carries at its front and rear ends
bevel gears which latter mesh respectively with the bevel gears on the crank shaft
and on the shaft of the rear wheel.
It will of course be apparent that the resilient dropping of the frame in the
manner hereinbefore set forth would effect the separation of the rear set of gears,
and I have therefore made provision whereby the movements of the frame will not
have the slightest effect on the contact between these gears.
16 is the bevel gear on the hub of the rear wheel, and 17 is the bevel
gear which
meshes with the gear 16 and which is carried by the rear end of the main shaft 18,
which end of the shaft is journaled within the yoke lever. I provide a universal
joint 19 in this shaft 18 at a point immediately opposite to the pivotal point of
the yoke lever, so that it will be clear that the swinging or tilting movements of
this lever will effect precisely the same swinging or tilting movements in the shaft
from the point 18 as a pivotal center, and therefore it will be evident that the
relative position between the gears will not be disturbed in the slightest degree.
Referring to Figures 6 and 7, the pivoting and other arrangements of the yoke
lever and the journaling of the rear wheel, are precisely the same as herein before
described, but in this instance I secure a bevel gear 20 to one of the pivot pins 21
of the yoke lever outside the frame, and I also mount a spur gear 22 rigid on this
pin on the inside of the yoke lever, which spur gear meshes with a spur gear 23

page_text: rigidly mounted on the hub of the rear wheel. The rear gear 24 of the main shaft
meshes with the gear 20 and thereby imparts motion to the rear wheel.
In this construction it will be noted that the swinging or tilting movements of
the yoke lever cannot effect the separation of the gears, because the pivot arcund
which such movements are effected is also the axis of the gear 20, while the pro-
vision of the spur gears on the hub of the rear wheel and on the inner end of this
pivot cause the proper rotary motion to be transmitted to the rear wheel.
I have not entered into any minute description of the parts of the chainless
wheel, or of the parts of the wheel which employs a chain and sprocket disks,
since
invention has nothing whatever
my
to do with these matters,
but relates solely to the provision of means for effecting the proper
resilient action to the frame of the machine when the latter is travel-
ling over obstructions or rough places, and therefore I do not wish to be
limited in the use of my improvement to any particular construction of machine.
Should a greater spring resistance be desired, the lower end of the spring is
simply attached to one of the perforations 8 further out toward the end of the
extension 7, since this will increase the effective length of the forward end of the
lever from the pivotal point of the latter.
It will thus be seen and readily understood, that when the rider mounts the
machine, the entire frame will automatically drop under his weight, and moreover
the latter can be readily calculated from the position of the forward end of the
lever 3 in its vertical displacement against the resiliency of the spring, it being of
course clear that a heavy man will cause this extremity to be thrown in a lower
plane while a light man will not cause it to be depressed so far.
It is absolutely necessary that this yoke lever should extend and be located
inside the bicycle frame, for were it located outside the frame it would be im-
practical and dangerous because it would interfere with the leg movements of the
rider and would continually catch in his clothing, and in all modern machines
that I know of, owing to the small clearance of the crank, such arrangement would
interfere with the running of the machine.
Also it is absolutely necessary that the distance between the pivotal point of
the yoke lever and the point where the rear wheel is supported should be as short
as possible, and that the forward extremity of the yoke lever should be distant
from the pivotal point of the latter as far as possible, in order that a light and
sensitive spring element may be employed and in order that the weight of the rider
may be thrown as much as possible on the axle of the rear wheel.
It would never do to locate the pivotal point of the yoke lever about midway of
its length, for in that event the extremity of the lever which supported the wheel
would have an excessive movement while the forward extremity of such lever
would not have sufficient play to take advantage of enough of the spring element
to counteract the shocks and vibrations while passing over obstructions and rough
roads.
Moreover, if the pivotal point of this lever were located midway of its length,
the frame of the machine would have to be cut off, that is to say, the rear fork
would have to be shortened, so that the rear wheel could be brought close enough
to the frame to permit the rider to mount. Unless the frame was cut off in this
manner, the whole machine would be so long and there would be such a distance
between the rear wheel and the saddle that it would be practically impossible for
the rider to mount.
I have ascertained by actual experiment that the pivotal point of this yoke
lever must be in close proximity to the journal of the rear wheel, and therefore it
will be seen that I am enabled to use an ordinary diamond frame of a bicycle with-
out materially altering its dimensions as to length.
A bicycle equipped with my improvement rides with surprising case and com-
fort to the rider and imparts the most intense exhilaration, and this is due solely
to the fact that I employ an extremely sensitive and responsive spring element,
and I am enabled to do this, as I said before, owing to the fact that the distance

page_text: between the forward end of the yoke lever and the pivotal point of the latter is
several times greater than the distance between such pivotal point and the journal
of the rear wheel.
In modern bicycles, both those which employ a chain and those known as the
chainless bicycles, a rigid frame with a proper degree of lightness is always sought
for, but the shock and incident strain to which such a frame is subjected frequently
causes the latter to become warped or sprung, and this gives rise to such inaccuracies
as will cause great wear both on the chain and sprocket wheels where the latter
are employed as a means of propulsion, and also in the chainless wheels this wear-
ing or straining of the frame is very apt to interfere with the proper alignment
and meshing of the gears to the extent that the latter will become worn.
It is therefore desirable that the rigid frame should yield to such shocks or jars
without detracting from the benefits which the rigidity of such a frame is intended
to confer and it will therefore be clear, that by reason of the fact that the applica-
tion of my invention enables the frame to yield without in the slightest degree
affecting the relations which exist between the mechanical devices used to propel
the bicycle, I have succeeded in really increasing the sustaining power of the
frame and greatly relieving the same without adding to the weight thereof, and in
increasing the life of the frame as well as the life of the propelling devices.
My invention is the result of most careful experiments and the construction
which I have shown herein has been practically demonstrated and found to possess
eminent advantages.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim, is:-
_
1. In a bicycle, the combination of the rear fork, with the yoke lever pivoted in
close proximity to its rear extremity to the end of said fork and inside the latter,
the rear wheel journaled in the rear end of said lever immediately beyond the
pivotal point thereof, the forward extremity of said lever extending within the
bicycle frame and around the forward portion of the rear wheel, and the spring
element connected to said frame and to the forward end of said lever whereby
the latter is rendered resilient, substantially as set forth.
2. In a bicycle, the rear fork of the frame supported on a swinging or tilting
yoke lever in close proximity to the rear end thereof, the rear or forked end of said
lever fulcrumed on the axle of the rear wheel, the forward or loop end of said lever
extending forward within the frame and surrounding the forward portion of the
wheel, and a spring or equivalent resilient element supporting said lever, sub-
stantially as set forth.
3. In a bicycle employing a chain and sprocked wheel construction and wherein
the rear wheel is supported and journaled within a lever pivoted to the rear fork
and having a resilient action, the combination with said chain of an anti-friction
support therefor carried by said lever and moving in harmony therewith, sub-
stantially as set forth.
4. In a bicycle of the chainless species and wherein the rear wheel is supported
and journaled within a lever pivoted to the rear fork and having a resilient action,
the main shaft which carries the propulsion gears provided with joints or flexible
portions which yield in harmony with the swinging or tilting movements of said
lever, substantially as set forth.
11- 00
1
1007
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.