Improvements in Cycle Gearing.
Year: 1894

page_text: Date of Application, 8th June, 1894
Complete Specification Left, &th Mar., 1895-Accepted, 13th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in Cycle Gearing.
I, JAMES KERR, of Gallos Street, Dromore, County Down, do hereby declare
the nature of this invention to be as follows:-
This invention relates to the gearing for cycles and it has for its object to so
construct and arrange the same that a large increase of speed will be obtained at
the expense of a very little additional power over the present arrangements.
In carrying out my invention I fit on the pedal axle a preferably hollow or box
wheel having internal teeth which mesh with an internal pinion fitted on one end of
a short countershaft or axle which is carried in bearings on the frame. At the other
end of this counter-shaft is another pinion wheel which drives by means of a chain,
as usual, the chain wheel on the driving axle of the cycle.
The number of teeth in the different wheels may be varied so as to produce the
maximum of speed with the minimum of effort.
Dated this 7th day of June 1894
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.
COMPLETE SPECIFICATION.
Improvements in Cycle Gearing.
I, JAMES KERR, of Gallos Street, Dromore, County Down 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 :-
This invention relates to the gearing for cycles and it has for its object to so
construct and arrange the same that an increase of speed will be obtained at the
expense of a very little additional power over the present arrangements.
And in order that my said invention may be properly understood, I have
hereunto appended an explanatory sheet of drawings, whereon,
Fig. 1 is a side view of a bicycle with my gear applied thereto.
Fig. 2 is a plan of the gearing to an enlarged scale.
Fig. 3 is a part section of part of the gear, to an enlarged scale.
Fig. 4 is an end view of the gear Fig. 2.
Fig. 5 is a side view.
Fig. 6 is a detail view.
Referring to the drawings :-
The frame of the cycle has a double bottom bracket a, a made preferably in one
piece, with two axles or spindles therein, one of which is fixed whilst the other c
is revoluble. The part a of the bracket is of a D shape internally as shown at Fig. 6
whilst the spindle is round at each projecting end but D shaped at the part within
the bracket, consequently it is prevented from revolving within said bracket. The
spindle b is also prevented from moving laterally, within the bracket a, by means of
jam nuts d, d', one at each side of the bracket. Carried on the ends of the spindle b,
preferably in ball bearings as shown at Fig. 3, are box wheels el with internal
teeth ƒ on them which mesh with pinions g, g', one at each end of the countershaft
e,

page_text: or spindle c which latter runs in ball bearings in the bracket a¹. This spindle has
a sprocket pinion h on it which drives the chain j and driving wheel o as usual.
In Fig. 2 the pinions 9 are indicated by dotted lines..
The pedal cranks k, kare either cast on the box wheels e, e¹ or bolted to them.
m in Fig. 3 are the balls of the ball bearing.
The pinions g, g' are keyed to the spindle c.
With this construction the cyclist gets a direct drive on the pinions g, g¹ and
counter-spindle or shaft c and thereby obtains the best results.
The number of teeth on the different wheels may be varied so as to produce the
maximum of speed with the minimum of effort.
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
and desire to secure by Letters Patent is :-
:-
The improved cycle gear consisting of a bottom bracket carrying two spindles
one of which is fixed and the other revoluble the fixed spindle having two internally
toothed or box wheels running freely thereon and which are driven direct by pedal
cranks said box wheels driving pinions on the secondary spindle and so actuating
the chain gear, substantially as herein before described with reference to the
drawings annexed.
Dated this 7th day of March 1895.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.