Improved Driving Gear for Safety Bicycles.
Year: 1891

page_text: Date of Application, 13th Mar., 1891
Complete Specification Left, 2nd Dec., 1891—Accepted, 2nd Jan., 1892-
PROVISIONAL SPECIFICATION.
Improved Driving Gear for Safety Bicycles.
I, NEWMAN TIBBITS, of Stoke Gifford Vicarage, in the County of Gloucester,
Clerk in Holy Orders, do hereby declare the nature of this invention to be as
follows:-
This invention which relates to safety bicycles consists in an arrangement of
driving mechanisin by the use of which chains and chain pulleys are discarded. The
frame is lightened, simplified and made more compact. Better control over the
steering is afforded.
Upon the shaft to which the driving cranks are secured, and concentric with the
said shaft, is a double spur wheel the axis of which is concentric with that of
the crank shaft but eccentric to that of the road wheel. This spur wheel gears
with two pinions the axis of each of which is eccentric to that of the spur
wheel.
The pinions are cast with the hub which is divided, the two parts being bolted
or otherwise secured together. The pinions rotate on ball bearings which intervene
between the pinions and the inner faces of collars carried by arms springing from
the fork. Motion is imparted from the crank shaft to the spur wheel which drives
the pinions and lub in a course eccentric to that of the crank shaft. Accordingly, the
rate of rotation of the crank shaft is transmitted in an accelerated degree to the
road wheel.
Dated this 12th day of March 1901
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.
COMPLETE SPECIFICATION.
Improved Driving Gear for Safety Bicycles.
I, NEWMAN TIBBITS, of Stoke Gifford Vicarage, in the County of Gloucester,
Clerk in Holy Orders, 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, which relates to safety bicycles, consists in an arrangement of
driving mechanism by the use of which chains and chain pulleys are discarded.
The frame is lightened, simplified and made more compact. Better control over
the steering is afforded.
Upon the shaft to which the driving cranks are secured, and concentric with
the said shaft, is a double spur-wheel the axis of which is concentric with that
of the crank shaft but eccentric to that of the road wheel. This spur-wheel
gears with two pinions the axis of each of which is eccentric to that of the spur-
wheel. The pinions are cast with the hub which is divided, the two parts being
bolted or otherwise secured together. The pinions rotate on ball bearings which
intervene between the pinions and the inner faces of collars carried by arms
springing from the fork. Motion is imparted from the crank shaft to the spur-
wheel which drives the pinions and hub in a course eccentric to that of the crank
shaft. Accordingly, the rate of rotation of the crauk shaft is transmitted in an
accelerated degree to the road wheel.

page_text: Referring to the accompanying sheet of drawings,
Fig. 1 thereon illustrates, in end view, and Fig. 2, in transverse section, my
improved mechanism for driving safety. bicycles.
Upon the shaft a to which the pedal cranks are secured is keyed a double
internally-toothed spur-wheel c-concentric with the shaft a. The spur-wheel c
gears with a pair of pinions d the axis of each of which is eccentric to that of the
spur-wheel c. The pinions d are cast with the hub e which is divided, the two
parts being bolted or otherwise secured together. The pinions rotate on ball
bearings, the balls being kept in place by the collars carried by the fork h
which for this purpose is divided at foot, as shown. The collar is in two parts
bolted together after adjustment. Motion is imparted through the crank shaft a
to the spur-wheel c which accordingly drives the pinions d in a course eccentric to
that in which the crank shaft a travels. The pinions being incorporated
with the hub e the latter and the road wheel with which it is concentric
rotate with the said pinions moving in their course eccentric to that of the
shaft a.
'
g
Accordingly, the rate of rotation of the shaft a is transmitted in an accelerated
degree to the road wheel.
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 :-
Mechanism for driving that class of velocipedes known as safety-bicycles, the
said mechanism consisting of a double internally-toothed spur-wheel such as c
secured on and concentric with the pedal crank shaft and gearing with a pair of
pinions d arranged eccentrically to the crank shaft and incorporated with a hollow
hub such as e concentric with the rim of the road wheel, the said pinions bearing on
balls intervening between them and collars or straps such as g carried by.limbs
extending from the fork of the frame, substantially as hereinbefore described and
shown in the accompanying drawing.
Dated this 13th day of November 1891.
NICHOLAS WATTS,
Bristol Bank Buildings, Bristol, Agent.