Improvements in Cycle Driving Mechanism.
Year: 1899

page_text: Date of Application, 28th Mar., 1899-Accepted, 13th May, 1899
Improvements in Cycle Driving Mechanism.
I, ELBRIDGE COLBURN DOOLITTLE, of Number 4223, Mantua Avenue, in the City
and County of Philadelphia, State of Pennsylvania, United States of America,
Silver Burnisher, 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 :-
-
The object of this invention is to provide a bicycle driving mechanism that shall
be efficient, readily constructed, capable of being made practically dirt proof, smooth
and noiseless in operation, not liable to get out of order, and which may be applied
to bicycles of the type most generally in use, with comparatively little change in
the frame of the machine.
The exact nature of the invention will appear from the following description,
reference being had to the accompanying drawings, in which;-Figure 1 is a side
elevation of part of a bicycle, having my invention applied thereto; Figure 2, a
plan view of Figure 1; Figure 3, a section on line, Figure 2; Figure 4, a
section, enlarged, on line 2-z, l'igure 1; and Figure 5, a section on line y―y,
Figure 2, looking toward the front.
In the said drawings, 1 is the rear bar of the frame of a safety bicycle; 2, the
forward bar; 3, the middle; and 4, the rear fork or back stay.
In adapting my driving mechanism to the machine, I make the hub of the usual
pedal crank shaft, 5, in two parts or barrel sections, 6, as seen in Figures 2 and 5,
and I provide the lower ends of the frame pieces, 2 and 3, with bifurcations,
marked 7 and 8 respectively, which are firmly united to the hub; the ends of the
bifurcations on one side being secured to the hub-section on that side, and the
bifurcations on the other side to the corresponding hub-section. Between these
bifurcations, and in a vertical plane bisecting the axis of the hub-sections and the
middle of the hub of the rear wheel of the bicycle, I place a ring, 9, which is
firmly attached, by rivets, screws, brazing, or other suitable means, to frame
pieces, 2 and 3, as also to the cross-bar, 4", Figures 2 and 3, of the rear fork.
Within this ring is fitted a rotatable annulus or wheel, 10, having internal teeth, 11.
The ring is so placed that the pedal crank shaft is below the center and near the
bottom thereof, and at the center or bottom angle of the frame, whereby the entire
strain comes upon the frame, and not upon the annulus.
In order to reduce friction to a minimum, I make opposite grooves, 9", 10",
Figure 4, in the inner face of the ring and the outer face of the annulus, respec-
tively, whereby when the two parts are put together, these grooves form a race-
way, r, which is filled with balls, b, such as are generally used in ball-bearings.
The annulus is maintained in place laterally by means, in the present instance, of
off-sets, 10b, adapted to receive lateral flanges, 9b, of the fixed ring. The balls
may be inserted into the race-way through an aperture in the face of the ring-
afterwards plugged up or the ring may be made in two parts, which are screwed
or riveted together after the balls have been inserted (as seen in Figure 4).
Upon the pedal crank shaft, 5, and between the hub-sections is mounted

page_text: gear, 12, whose teeth engage those of the annulus, 10; and upon a shaft, 13, that
is journalled in bearings, mounted in barrel casings, 14, of the bifurcations, 8, of
the frame-bar, 3, is a pinion, 15, whose teeth also engage those of the annulus.
Upon each of the projecting ends of the pinion-shaft, is a ball-bearing strap
eccentric, 16, which is connected by a rod, 17, with a similar eccentric, 18, mounted
on the ends of the hub, 19, of the rear wheel of the bicycle.
Having thus described the construction of my invention, the operation is as
follows:-
Upon rotating forward the pedal crank shaft, 5, in the usual way, the gear, 12,
thereon turns the annulus, 10-as indicated by the arrows in Figure 1-thus rotating
the pinion and eccentric shaft, 13, and so driving the bicycle forward by the eccen-
trics and their connecting rods. The sides of the annulus and the gears are
enclosed by suitable plates (not shown) secured to the sides of the ring, 9, whereby
the parts are encased and so protected from dust and dirt. This casing would also
be made sufficiently tight to hold a quantity of oil on the bottom, whereby the
surfaces in frictional contact would be constantly lubricated.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
1. In a cycle driving mechanism, the combination with the frame having the
hanger or hub in two separated barrel sections, the bifurcated frame pieces con-
nected to said sections, and the ring secured to the frame with its center above
the center of the said hub or hanger, of the crank shaft having the gear wheel, the
shaft journalled in the frame above the crank-shaft, the pinion thereon, the rotat-
able internally toothed annulus mounted in said ring and engaged by the Faid
pinion, the eccentrics on the end of the pinion carrying shaft, the similar eccen-
trics on the rear wheel hub, and the connecting straps and rods, substantially as
specified.
2. In a cycle driving mechanism, the combination with the frame having its
hub formed in two separated barrel sections, the bifurcated seat post whose furca-
tions are connected to the respective sections, and having barrel casings formed
thereon above the barrel sections of the hub, and the ring secured to said frame
between said sections and casings, with its center above the center of said hub
or casing, of the rotatable internally toothed annulus mounted in the said ring, the
shaft journalled in said casings, the pinion on said shaft engaging the teeth of
said annulus, which is geared to the crank-shaft, and the connected eccentrics on
the pinion shaft and rear wheel hub, respectively, substantially as specified.
Dated this Twenty-second day of February 1899.
ELBRIDGE COLBURN DOOLITTLE.