MENT IN VELOCIPEDES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I ARTHUR WILLIAM HIRST-of Poplar Walk, West Croydon-Surrey Bicycle
and Tricycle Maker-do hereby declare the nature of my invention for IMPROVE-
MENT IN VELOCIPEDES to be as follows:-
This invention consists of an improved arrangement of driving gear for
velocipedes whereby speed or power may be obtained at the will of the rider.
In applying my invention I fix on the crank shaft a toothed pinion enclosed by
an internal toothed wheel of a larger diameter which is fixed inside a box or casing
(skeleton or otherwise and carrying on its periphery a chain or toothed wheel used
for driving the velocipede. The smaller wheel or pinion being fixed on the crank
axle revolves always on the same centre but the casing carrying the internal toothed
wheel and the chain wheel runs on large hollow bearings and the hole in the
bearings is of such a diameter that the said casing may be brought away from the
centre on which the crank shaft and toothed pinion revolve so far as to admit of
the toothed pinion being brought into gear with the internal toothed wheel. When
this is effected the said internal toothed wheel is revolving on a different centre to
the crank shaft but one portion of the internal toothed wheel may be kept in gear
with the toothed pinion by means of a fork of a suitablo shape spanning the chain
wheel and holding the hollow bearings of the box or casing before mentioned in
the position described This fork is allowed to swivel on a pivot the required
distance to throw the internal toothed wheel in or out of gear with the toothed
pinion fixed on the crank shaft It will be understood that when these are in gear
the internal toothed wheel is revolving on a different centre to the pinion & when
out of gear they are revolving on the same centre. At the same time as the wheels
are thrown out of gear a suitable clutch (or one on each side may be used) is caused
to move endwise on a feather or key on the crank axle and is thrown into suitable
holes or projections on the side of the box or casing carrying the chain wheel before
mentioned and so locking it to the crank axle & causing it to rotate with the crank
axle as a solid chain wheel this effecting the driving required for speed. When the
clutch or cluches before mentioned are withdrawn & the box or casing carrying the
chain wheel is allowed to run loose in its bearings & moved into gear with the
pinion fixed on the crank axle the pinion communicates power at the point where
it gears with the internal toothed wheel and so effects the driving required for
power. At the point where the clutch or clutches are withdrawn and before the
box or casing is moved from the same centre as the crank shaft the crank shaft is
allowed to run free on its own bearings so that the rider may keep the crank shaft
from rotating when the velocipede is in motion as in descending hills.
Dated this 24th day of March 1884.

page_text: I ARTHUR WILLIAM HIRST of Poplar Walk Croydon, in the the county of
Surrey, Bicycle and Tricycle maker do hereby declare the nature of my said
invention for "IMPROVEMENT IN VELOCIPEDES," and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :—
My invention relates to an improved arrangement of driving gear for Velocipedes
whereby speed or power may by obtained at the will of the rider; and consists in
mounting the chain wheel on the crank shaft in such a manner that it may either
revolve on the same centre as the crank shaft, when an internal ring of teeth on it
will be clear of a spur pinion keyed on the crank axle; or it may revolve on a
different centre, so that the internal ring of teeth may engage and gear with the
pinion as aforesaid. In the former position i.e., when the centres coincide, a clutch
locks the two together and they revolve as one piece, but in the latter position
i.e., when the centres do not coincide the chain wheel revolves on a different centre
to the crank shaft, and the pinion on the crank shaft gears with the internal ring
of teeth on the chain wheel, and drives it at a speed inferior to itself, which causes
the driving wheels to revolve at a slower speed than the crank axle whereby greater
power is obtained.
In order that my invention may be fully understood I will moro particularly
describe it as applied to a side-geared tricycle making reference to the accompaning
drawing on which similar parts are marked with corresponding letters of reference.
Fig 1 is a cross section of the gear. Fig 2 is a side elevation showing the gear
quiescent, and Fig 3 is a side elevation (with the cover of the chain wheel removed)
showing it in gear for speeding down the machine to obtain power.
On the end of the pedal crank shaft A of the machine is keyed a pinion B. The
chain wheel C is mounted on a short hollow axlo D running in suitable ball
bearings at the end of the arm e of a light frame E pivotted at the centre x to the
frame of the machine. The internal ring of teeth on the chain wheel C are formed
of studs c. c. etc. passing through the cover F of the wheel and screwing into the
side of it; some of the studs c c etc. have heads and also serve to fix the cover F
to the wheel. On the centre of the cover F is formed a boss which is coned to
receive an adjustable cone pin G carried by the other arm e¹ of the frame E and
forming a bearing for the other side of the chain wheel. On the boss of the cover F
is mounted a sliding clutch H with three or more pins h. h. etc. which slide through
holes in the cover and engage with similar holes in the pinion B, when the centre
of the chain wheel coincides with the centre of the crank shaft and so locks them
together as shown by Fig 2. When the clutch is withdrawn so as to unlock the
chain wheel from the crank shaft, they are free to revolve independently and the
pedals may be used as foot rests but if the chain wheel is moved out of centre with
the crank shaft so as to bring the internal ring of teeth into gear with the pinion
on the crunk shaft as shown by Fig 3, the pinion will impart motion to the chain
wheel and drive it at a speed inferior to itself and the machine will be speeded
down for power.
The sliding clutch H is controlled by a forked arm, of the usual kind, mounted
on a rod carried in a bearing on the boss of the frame E. so that it may move
axially. The rod is continued upwards and terminates with a handle in a con-
venient position for manipulation by the rider. The sliding clutch is manipulated
by a radial movement of the rod and the chain wheel is put into gear with the
pinion by pushing the rod forward after the clutch is withdrawn.

page_text: It will be seen that when the machine is running at speed the centre of the
chain wheel and crank shaft coincide and the gear is quiescent, but when it is
running at power the gear is in motion and the chain wheel is running on a
different centre to the crank shaft.
In fitting this gear to central geared or other machines where the pedal axle
must run through the chain wheel I mount the chain wheel on two hollow axles
one on each side of it and fit the sliding clutch outside the boss of the wheel.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is -
First. The construction of a two speed gear for velocipedes substantially as
hercinbefore described and shown.
Secondly. A two-speed gear in which the chain wheel runs on the same centro
as the crank shaft at oue speed and on a different centre at the other speed
as and for the purpose herein before described and shown.
Thirdly-Mounting the chain wheel so that it may revolve at different centre
with respect to the crank shaft as and for the purposo described.
Fourthly. The chain wheel with an internal ring of teeth and mounted as
herein before described and shown, in combination with a pinion keyed on
the crank shaft.
r 1884.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer & Patent Agent,
Royal Courts Chambers,
70, 71 & 72, Chancery Lane, London, W.C.,
Agent for the Applicant.
is 20th day of December 1884.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer & Patent Agent,
Royal Courts Chambers,
70, 71 & 72, Chancery Lane, London, W.C.,
Agent for the Applicant.