Improvements in Bicycles and Tricycles.
Year: 1890

page_text: Date of Application, 5th Apr., 1890
Complete Specification Left, 2nd May, 1890-Accepted, 12th July, 1890
PROVISIONAL SPECIFICATION.
Improvements in Bicycles and Tricycles.
I, THOMAS JEFFERSON THOMPSON of Greystones, County Wicklow, Ireland Member
of the Institution of Civil Engineers do hereby declare the nature of this invention to
be as follows :—
In the specification of a patent previously granted to me namely No. 17789 of 1889
I have described an improved system of suspending the frame and saddle of a bicycle
or tricycle so that the distance between the saddle and the treadle axle remains
constant or nearly so and yet the wheels are free to move spring connections and yield
to obstacles without communicating shock or jar to the frame or rider.
My present invention relates to improvements upon the modes of applying that
system to the wheels of bicycles and tricycles. As applied to the leading wheels of
bicycles it consists of the following mode of arranging the spring connections.
I so construct the steering fork that a flat spring projects at its upper part and
communicates by a second fork or rods with radius links hinged at the lower ends of
the steering fork. These radius links together with the first and second forks form
with the flat spring a species of parallel motion arrangement carrying the wheel axle
at one corner. This permits free movement of the wheel with its axle resisted by the
spring and from the main or steering fork, are projections clip the ends of the radius
links in order to damp or absorb the energy of motion of the wheel. Instead of
forming a parallel motion I may arrange the flat spring so that it projects from the
main fork and its end returns within it again so that the second fork or rods are in
line with the main fork but stand within it.
In this case the main fork projects below so as to allow for the length of the radius
links with clips. Instead of flat springs spiral springs may be used with the same
effect and my invention may be applied either to bicycles or tricycles with inclined
steering axes or vertical steering axes.
In applying my invention to the driving or hind wheels of tricycles I so construct
the frame of the machine that a projection from it carries the treadle axle between
the wheels. The seat and treadle axle bearing being firmly fixed to the frame no
change can occur in their relationship. The driving axle of the hind wheels is actuated
by pitch chain and a suitably shaped arm or link hingeing on the treadle axle itself or
in close proximity to it connects between it and the driving axle so that a constant
distance is maintained. The frame is mounted upon the driving axle by means of a
suitably guided flat spring extending across the machine between the wheels, and
resting upon a cross bar linked to the axle. In this way the wheels are free to rise
and fall compressing the spring and swinging the arm or link without interfering
with the distance between the saddle and the treadle axis.
Spiral springs may be used instead of the broad flat spring hereinbefore described
but I prefer the flat spring as simple in detail and more easily constructed.
Dated this 2nd day of Al 1800
CLERK & MARKS,
13, Temple Street, Birmingham, Agents for Applicant.
COMPLETE SPECIFICATION.
Improvements in Bicycles and Tricycles.
J, THOMAS JEFFERSON THOMPSON of Greystones, County Wicklow, Ireland Member
of the Institution of Civil Engineers do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
In the specification of a patent previously granted to me namely No. 17789 of 1889,
I have described an improved system of suspending the frame and saddle of a bicycle

page_text: or tricycle so that the distance between the saddle and the treadle axle remains constant
or nearly so and yet the wheels are free to move spring connections and yield to
obstacles without commucating shock or jar to the frame or rider. My present
invention relates to improvements upon the modes of applying that system to the
wheels of bicycles and tricycles. As applied to the leading wheels of bicycles it consists
of the following mode of arranging the spring connections.
I so construct the steering fork that a flat spring projects at its upper part and
communicates by a second fork or rods with radius links hinged at the lower ends of
the steering fork. These radius links together with the first and second forks, form
with the flat spring, a species of parallel motion arrangement carrying the wheel
axle at one corner. This arrangement permits free vertical movement of the wheel
with its axle; but resisted by the spring, so that the wheel easily mounts obstacles on
the road without communicating vibrations to the steering handles.
From the main or steering fork arc shaped projections clip the ends of the radius
links in order to damp or absorb the energy of vertical or vibratory motion of the
wheel.
Instead of forming a parallel motion, I may arrange the flat spring so that it
projects from the main fork, and its end returns within it again, so that the second
fork or rods are in line with the main fork; but stand within it. In this case the
main fork projects below, so as to allow for the length of the radius links with
clips.
Instead of flat springs spiral springs may be used with the same, effect and my
invention may be applied either to bicycles or tricycles with inclined steering axes or
vertical steering axes.
In applying my invention to the driving or hind wheels of tricycles I so construct
the frame of the machine that a projection from it carries the treadle axle between the
wheels. The seat and treadle axle bearing being firmly fixed to the frame no change can
occur in their relationship. The driving axle of the hind wheels is actuated by pitch
chain and a suitably shaped arm or link hingeing on the treadle axle itself or in close
proximity to it connects between it and the driving axle so that a constant distance
is maintained. The frame is mounted upon the driving axle by means of a suitably
guided flat spring extending across the machine between the wheels and resting upon
a cross bar linked to the axle. In this way the wheels are free to rise and fall com-
pressing the spring and swinging the arm or link without interfering with the distance
between the saddle and the treadle axle.
Spiral springs may be used instead of the broad flat spring hereinbefore described;
but 1 prefer the flat spring as simple in detail and more easily constructed.
In order that my invention may be properly understood and readily carried into
effect hereunto append two sheets of explantory drawings to be hereinafter
referred to.
Figure 1 shows in elevation one method of applying my invention to the steering
wheel of a bicycle or tricycle in which the steering fork axis is inclined.
Figure 2 shows a modification of this method with the spring returned upon itself.
It is shown as vertical at Figure 2 but the same modification may be applied to an
inclined fork.
Figure 3 is a view from the front of the forks in Figure 1, and
Figure 4 is explanatory of Figure 2.
Figures 5 and 6 show spiral springs utilized in place of a flat spring.
Figure 7 is a side elevation of my invention as applied to tricycles.
Figure 8 is an elevation of the driving wheels and spring support and
Figure 9 a plan showing driving connections.
Referring to Figure 1, the steering fork A, has attached to its upper portion the
flat spring B, and two radius rods or links CC pivot at its lower ends and connect
by rods D, D or a fork D with the spring B. The wheel axle E is carried by the
ends of the radius rods or links CC. In Figure 1 only one radius link C and one
rod D on one side of the fork D can be seen. In Figure 3 the fork D is seen in end
view and behind it the fork A and the spring B while at the lower end is shown the

page_text: axle E. The steering rod F is incline in this case and the whole weight of the
frame G is carried by the spring B. Arc pieces H, H, project from attachments
rigidly fixed to the fork A and the radius links are clipped by those arc pieces practically
as described in the specification to which I have already referred. Figure 2 is a
modification of this arrangement in which my improvements are so adapted that the
axis of the steering rod F is in line or nearly so with the plane of the fork or rods D.
To accomplish this the spring B attached to the fork A is returned upon itself, so that
the end of the fork D or the ends of the rods D pass within the fork A and connect
the ends of the radius links C with the spring B. The lower end of A must be bent
as shown, in order to allow for a convenient length of radius link and to permit of the
action of the arc pieces H which is the same as I have herein before described. When
the steering rod is vertical the motion may be communicated from the steering handle
by the wheel and chain I.
The system shown in Figure 2 may be equally applied to an inclined axle and a
spiral spring may be caused to act at the upper end of D between it and the fork A
instead of the flat spring B. Figure 4 shows a plan of the lower part of the fork A and
connections as seen in Figure 2. Figure 5 shows a method of using spiral springs to
connect by rods or fork D to the radius links C which method has in every respect
the same effect in action as the flat spring. The spiral spring K takes the load and
the spring L steadies the radius links.
Another arrangement is shown in Figure 6 in which the radius links are extended
at or near right angles from their points of hingeing with the steering fork, and the
springs K, L are placed as shown below the junction of the fork.
Figures 7, 8, & 9 show a tricycle constructed according to my invention. The
frame diverges at M to form a fork N, N (Figures 7 and 8) the ends of which hinge
at 0, 0, to suitably formed projections on the spring P. This spring has a centre
guiding boss Q working on a turned projection from the bar S and a nut Tis intended
to adjust the tension of the spring. The saddle U is mounted on the frame in any
convenient manner and the weight comes upon the spring P which presses by its two
ends on the rod S. The rod S connects to the tricycle axle V by two or more
projecting pieces. An arm W projects from the frame M and carries the bearing
for the treadle axle X which is placed between the wheels as seen in Figures 8
and 9. The treadle axle and the saddle are thus kept at an invariable distance
and the axle V is connected to the treadle axle by the hingeing link A¹ which may
be of any convenient form as shown, and the connection allows vertical movement
of the wheel without communication of shock or jar to the saddle, or varying its
distance from the treadle axis. Figure 8 shows by end elevation the arrangement
of flat spring P and its connections clearly, so that from it together with the side
elevation Figure 7, a clear idea may be formed of the nature of my device as
applied to the rear wheels of tricycles. Figure 9 is a plan showing the connection
between the treadle axle and the rear axle in which is seen the connecting link A¹.
This link may connect by a single sleeve or bush as shown, or it may be of forked
shape and terminate in two bushes. The driving chain and wheels are duly
indicated.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
I. In bicycles or tricycles, the use of a combination for supporting the frame and
its load, of a fork such as A, with radius links as C, rods or fork as D, and spring as B
(Figure 1) substantially as and for the purposes hereinbefore described and illustrated
in the accompanying drawings.
II. In bicycles or tricycles the use of a combination for supporting the frame and
its load, of a fork such as A, with radius links such as C, rods or fork as D, and
spring as B (Figure 2) substantially as and for the purposes hereinbefore described
and illustrated in the accompanying drawings.
.
III. In bicycles or tricycles the arrangement of supporting device shown in

page_text: Figure 5 of the accompanying drawings in which spiral springs are used substantially
as and for the purposes herein before described and illustrated in the accompanying
drawings.
IV. In bicycles or tricycles the arrangement of supporting device shown in Figure 6
of the accompanying drawings, in which spiral springs are used substantially as and
for the purposes hereinbefore described.
V. The arrangement of spring P, rod S, axle V, and link A¹ for tricycles as shown
in Figures 7 and 8, substantially as and for the purposes hereinbefore described and
illustrated in the accompanying drawings.
1000
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for Applicant.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for Applicant.