An Improvement in Spring Forks for Bicycles and other Velocipedes.
Year: 1889

page_text: Da.. of Application, 20.h Seut., 1889
Complete Specification Left, 20th June, 1890-Accepted, 9th Aug., 1890
PROVISIONAL SPECIFICATION,
An Improvement in Spring Forks for Bicycles and other
Velocipedes.
JOHN POLLITT 43 Lower Mosley Street Manchester in the County of Lancaster do
hereby declare the nature of this invention to be as follows:-
Instead of the ordinary fork bridged over the top of the wheel, I carry the sides of
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the fork upwards several inches, then join them by a cross piece through which is
bored a hole of sufficient sizo to allow the steering tube to pass through. On the
bottom end of steering tube is fixed another similar cross piece, but with a hole
through the end of each arm through which the fork sides pass, and are free to slide
up and down. The fork sides are held securely together by the top cross piece and
by the spindle of the wheel at the bottom. The bottom cross piece on steering tube
turning the fork in steering, by both sides, and at the same time allowing it free play
up and down.
A spiral spring is placed on the steering tube above the cross piece,
and held at the top by a lug. When the wheel strikes any obstacle the fork sides
slide up, and compress the spring, which absorbs vibration.
Dated this 19th day of Sentember 1889
COMPLETE SPECIFICATION.
An Improvement in Spring Forks for Bicycles and other
Velocipedes.
JOHN POLLITT of 43 Lower Mosley Street Manchester in the County of Lancaster,
Electrician and Engineer do 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 :-
Instead of the ordinary fork bridged close over the top of the wheel.I carry the
sides of the fork upwards and parallel to each other for several inches and then join
them by a cross head through the middle of which the steering bar or tube passes and
slides this cross head is fastened to the top of the fork sides by means of screws so as
to give a ready means of interchanging the parts when desired. The bottom of the
steering tube has fixed upon it another cross head the ends of which is fitted to engage
with and slide along the two parallel extensions of the fork above alluded to.
Above the cross piece joining the fork extensions and upon the steering tube is
fixed a collar or lug and between this and the cross head of the fork is placed a spring
of suitable strength and length to resist the vibrations which the wheel inay encounter
through any unevenness of the road it traverses.
Another method of constructing the above is to retain the ordinary bridge piece
joining the sides of the fork close to and over the wheel and for the aforementioned
parallel extension to pierce the same at each side and in the middle of this bridge
piece is fixed a pillar projecting upwards in this case the concussion spring is placed
over or encircling this pillar and between the fixed cross head of the steering tube and
the above mentioned bridge. A further modification places the spring upon the top
of this pillar and inside the steering tube which has a collar or other abutment fixed
within it between which and the top of the pillar is placed the spring.
In all cases the parallel extensions of the fork sides are retained and used in the
double capacity of spring slide and steering guides.
In order to further explain my Invention I make reference to the accompanying
drawings riz.
Fig. 1 A. A are the fork extensions connected and fastened together on their top

page_text: portions by means of the cross piece and screws. The steering har or tube B passing
through the midille of the cross piece as a slide, C. C. is the cross head to the steering
tube B sliding along the parallel bars A. A. through openings at the ends of C. C.
D is the abutment collar on steering tube and S is the spring.
Fig. 2 shows the modification having the bridge piece over the top of wheel with
central pillar and spring encircling it, and placed between crosshead of steering tube
and bridge piece of fork.
Fig. 3 shews further modification with spring inside steering tube as at Y and with
internal abutment at 0.
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 1
claim is:
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1. The extension of the fork sides in a parallel and upward direction above the top
of the wheel and their use as slide bars or guides to the steering bar or tube.
2. The particular method herein described vs. by crossheads fixed to the steering
tube and fork sides respectively and capable of a sliding motion along each other.
3. The modified arrangements of the spring as described and drawn.
4. The fixing together of the top of the fork sides by means of a cross piece in
connection with screws giving a ready interchangibility of parts.
Dated this 19th day of June 1890.
JOHN POLLITT.