An Improved Frame for Rear Driving Safety Bicycles and other Cycles.
Year: 1890

page_text: Date of Application, 4th July, 1890
Complete Specification Left, 6th Apr., 1891-Accepted, 13th June, 1891
PROVISIONAL SPECIFICATION.
An Improved Frame for Rear Driving Safety Bicycles and
other Cycles.
I, JOHN BOYD DUNLOP, of 50 Gloucester Street, Belfast, Veterinary Surgeon,
do hereby declare the nature of this invention to be as follows :-
This invention which is based upon that described in the Specification accom-
panying my application for Letters Patent No. 16119 dated 12th October 1889,
has for its object to produce a spring frame for safety bicycles and other cycles in
which flexible metallic bars or rods are employed to reduce vibration whilst
maintaining the position of the seat, relatively to the crank or driving axle, always
constant.
The improved frame according to my invention comprises two straight flat bars
of spring steel or similar material which are secured at their front ends to the
lower end of the steering post or socket, and at their rear ends to each end of the
axle of the rear or driving wheel. A vertical tube or seat pillar socket is supported
by means of lugs near the centre of the said bars of spring steel. Two bars of
spring steel are secured to the upper end of steering socket and the upper end of
seat pillar socket. One broad or two narrow bars of spring steel are secured to
the lower end of the seat pillar socket and suspend or support the anterior end
of the rear horizontal fork which is of the ordinary description. The front fork
may be also of the ordinary description excepting that its lower ends are bent
backwards and terminate in a position a few inches behind the axle of the front
wheel. The lower ends of said fork are connected to and supported on the ends of
the axle of the front wheel by means of two flat bars of spring steel (one on each
side of wheel), these bars being bent preferably in the form of a triangle. The
lower ends of said fork are each secured to one angle or side of the said triangle,
and each end of front axle to another angle or front side, of said triangular spring
steel bar.
י
P T 1
3000
JAMES STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C.,
Agent for Applicant.
COMPLETE SPECIFICATION.
An Improved Frame for Rear Driving Safety Bicycles and
other Cycles.
I, JOHN BOYD DUNLOP, of 50, Gloucester Street, Belfast Veterinary Surgeon
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 present invention consists essentially of improvements upon the device in
accordance with my Patent No. 16,119 of the year 1889 for "An improved frame
for rear driving safety bicycles and other cycles."
By the improvements under my present invention, I am enabled to accomplish
the same objects as those sought to be attained under my Patent of previous date
above identified but by means of a more simple and consequently less costly mode
of construction. Thus; (reference being had to the Specification of my Patent
No. 1611989 as also to the accompanying sheet of drawings illustrative of my
present invention) the front springs instead of being arranged parallelwise, are now
Dr

page_text: disposed so as to form two sides of a triangle, and, the lower horizontal spring S'
being straight, or nearly straight, is inclined, and passes direct from the steering
socket A to the axle of the rear wheel. The upper horizontal spring S stops
short at, and does not extend behind; the seat pillar socket; and, the rear
(perpendicular) fork is dispensed with.
The framing in accordance with my present improvements comprises a straight
flat bar of spring steel S₁ or similar material, secured at its front end to the lower
end of the steering post or socket A, and, at the rear end to the rear end of rear
horizontal fork B said spring is also secured by means of a lug and bolt or other
suitable means to the lower end of the seat pillar socket C. A similar straight
flat bar to that last described is secured to the top of the seat pillar socket C and
to that of the steering socket A.
A flat bar of spring steel S or of other suitable material is bolted or otherwise
properly attached to the lower end of seat pillar socket and lug formed on the
crank axle case.
The front spring arrangement hereinbefore referred to in accordance with my
present improvements consists of a flat bar of spring steel S or other suitable
material bent so as to assume a triangulated configuration or to form two sides of a
triangle and bolted or otherwise connected to a lug on the lower end of the fork
or extension F of the steering post or pillar D, as also to a supplementary fork E
in front, provided for the twofold purposes of maintaining the front wheel more
firmly in position and to serve as an attachment or support for mud guard.
Having now particularly described and ascertained the nature of of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
First In the manufacture of cycle frames the method of construction which
I adopt, whereby I am enabled to dispense with the rear perpendicular fork,
substantially as and for the purposes herein set forth.
Second-The triangulated arrangement of the front springs substantially as and
for the purposes herein set forth.
Third The improved frame for safety bicyles and other cycles substantially as
herein described and for the purposes specified.
Dated this 4th day of April 1891
JAMES
STEVENSON,
Gray's Inn Chambers, 20, High Holborn, London, W.C.,
Agent for Applicant.