Improvements in and relating to Vehicle Driving Mechanism.
Year: 1899

page_text: Date of Application, 16th Mar., 1809--Accepted, 29th Apr., 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Vehicle Driving Mechanism.
I, MOSES CARLYLE JOHNSON, of No. 43, Congress Street, in the City of Hartford,
County of Hartford and State of Connecticut, United States of America, Mechanical
Engineer, 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 invention relates to that class of structures in which a vehicle, as a
velocipede or bicycle, has as means for transmitting power intermeshing gears
and a connecting shaft extending from the driving to the driven member.
The object of my invention is to provide a geared driving mechanism with
gears and parts so connected and combined that they will accommodate
themselves to any change or deflection of the yielding frame of the vehicle, or
to any defect in adjustment of the bearings or any imperfect action of the shaft,
and one in which the gears will always keep in perfect mesh without binding
or cramping in use.
My invention is preferably shown and will be described in connection with a
bicycle as a light vehicle to which it is particularly adapted. In embodying my
invention in a working structure I employ gears having teeth which intermesh
at all times with a rolling action, said teeth being so disposed that each one
resembles to a degree a short section of a spiral of proper pitch, which section
will engage without undue friction a corresponding tooth or section of the
intermeshing gear and will operate thereon with a rolling action. The teeth
of the gears are of the same pitch and of the same inclination, and as moshed
will move upon cach other in proper engagement and rolling contact although
the frame of the vehicle may become bent or distorted and thrown out of its
normal correct position.
"
"
or
For convenience of description I have termed my new gear a "spiral”
screw gear, as the teeth most nearly constitute sections of spirals of somewhat
quick pitch. It is to be distinctly understood that my invention is not limited
thereto, as I consider to be within the scope of my invention any and all gears
(whether of screw or spiral form, so-called) which, while intermeshing to produce
a vehicle driving gear, will yet accommodate themselves to strains or deflections
of the vehicle frame or parts thereof without binding or friction, and will
consequently run as easily and as well in one position as in another. Therefore
while the form illustrated is preferable and works in practice without apparent
friction, yet other forms of gearing of the same or analogous types could be
employed and would work fairly well under similar conditions.
In the accompanying drawings:
Figure 1 is a side elevation of a bicycle embodying the invention.
Figure 2 is an enlarged plan of a portion of the frame, and the driving

page_text: Figure 3 is a side view of these parts with portions cut in section to show the
construction.
Figure 4 is a detail side view of a forging used at the driving wheel corner of
the frame.
I al
Figure 5 is a detail side view of the forging used at the crank corner of the 5
frame, and
Figure 6 is a sectional view of the spiral gear that is connected with the crank
shaft.
Like numerals refer to like parts throughout the several views.
Except as to the driving mechanism the bicycle is of ordinary construction, 1
having wheels 1, frame 2, saddle 3 and handle bar 4 with handles 5.
The crank shaft is supported in a socket in the crank hanger or bracket 8 and
has fast to it a crank 6 bearing pedals 7. The bracket 8 is part of the forging 9
which includes projections for attaching it to the frame parts. A spiral gear 11
is secured to a plate 10 fast to the crank shaft. On the periphery of the 1
cup-shaped part 12 of this gear the teeth are arranged to form small portions
of screw threads of quick pitch.
A spiral gear 14 is secured to the driving wheel, preferably to its hub 13,
the teeth of this gear being also of my improved form.
On the crank shaft bracket is a down-turned arm 15 and on the rear fork 2
bracket a like arm 17, and between these brackets ia a tie rod 18. Turning on
a thread cut on this tie rod inside of the arın 17 is a ball cone 19. and outside of
this arm the tie rod is provided with a holding nut 20. Turning on a thread
cut on the other end of this tie rod and fitting a threaded opening in the arm 15
is a ball cone 21, while outside of this latter cone a holding nut 22 is secured.
The arm 15 is split and provided with a binding bolt 23 for clamping the ball
come in position after it has been adjusted.
Balls are placed between the ball cones 19 and 21 and the ball caps 24 and 25
in the spiral pinions 26 and 27, and these spiral pinions are connected by a shaft 28.
Screws are passed through the flanges of this shaft and the spiral pinions
and ball caps for securing these parts together, and the shaft which connects
the spiral pinions so extends in the form illustrated that the upper teeth of the
spiral pinions mesh with the lower teeth of the spiral gears.
The teeth of the spiral pinion 26 are arranged as small portions of spirals
or short sections of screw threads on the same angle as the teeth of the spiral
gear 11, with which they mesh, and the teeth of the spiral pinion 27 are arranged
as small portions of spirals or short sections of screw threads on the same angle
as the teeth of the spiral gear 14, with which they nesh. All of the teeth of the
spiral gears and spiral pinions are pitched to the same angle and in the same
direction. These spiral gears and spiral pinions are not worms and worm wheels,
nor are they spur gears with angularly arranged teeth. The teeth of the spiral
gears and spiral pinions are all formed the same and are small portions of spiruls
or short sections of screw threads of quick pitch, and all portions of each pitch
line of all of the teeth of each of these spiral gears and spiral pinions are
equally distant from their axes of rotation. The teeth of the spiral gears are not
concaved, as are the teeth of worm wheels.
An important feature of my invention resides in forming the teeth of the
spiral gears and of the pinions on an angle of pitch across the axis of the gear
or pinica substantially equal to one half of the angle included between the
axis of the gear and the axis of the pinion meshing with it. This is a broadly
new feature in spiral gears, as is also the making of these screw or spiral gears
which intermesh with their teeth of the same angle of pitch with reference to
the axis of the respective intermeshing gears.
The spiral pinions 26 and 27, which are permanently connected with the shaft 28,
turn freely upon the balls that are supported by the ball cones on the tie
rod 18. The tie rod is permanently connected with the arm 17 of the forging 16

page_text: by the end of the ball cone 19 and the nut 20 and is adjustably connected at
the other end with the arm 15 of the forging 9 by the ball me and nut 22.
When the binding bolt 23 is loosened the ball cone 21 can be turned to take
up all wear, and when the bolt is tightened and the nut is turned up the ball
cone and tie rod are secured in position, and this ties the arms of the forgings
together.
The rotation of the spiral gear 11 that is imparted by the rotation of the
cranks is transmitted to the connected spiral pinions 26 and 27 and from these
transmitted through the spiral gear 14 to the hub of the driving wheel.
In the light running machine embodying this invention the arrangement of
spiral gears and spiral pinions is such that the end thrust given by the spiral
gear 11 to the spiral pinion 26 is toward the spiral pinion 27, and the
resistance to end thrust of the spiral gear 14 against the spinal pinion 27 is toward
the spiral pinion 26. Thus the end thrusts of these parts are in directions
toward each other aud to a great extent counteract each other in such manner
as to practically eliminate all the effect of end thrust. The end thrust in one
direction is greater than in the other only as one spiral gear is larger than the
other, and this small difference is borne by the balls, which sustain the end
thrust as well as support the spiral pinions. This balancing of the end thrust
also permits the use of light supporting brackets and dispensing with the tie,
if desired, for there is no tendency to force the brackets apart.
With bevel gears and bevel pinions, also with worm-wheels and worms, it
the frame that supports them becomes bent, so that the axes of the pinions or
worms are out of line with the axes of the gears or worm wheels, or if the pinions
or worms are drawn away from the axes of the gears or worm wheels, or if the
pinions or worms become twisted out of the correct alinement, the teeth will
not properly mesh and will so bind as to cause much friction and jamming.
The pitch lines of the teeth of bevel gears and hevel pinions must all converge
to a common center, which is the intersection of their axes. If the supports of
the bevel gears or bevel pinions, or if the frame which bears the supports springs
and becomes out of line in the least, the pitch lines of the teeth of the bevel
gears and bevel pinions will not converge to the necessary point and there will
be friction and wear, if not jamming and collapse. If the axis of a worm ia
carried to one side of the plane of rotation of the mille of the teeth of the worm
wheel, there will be binding and wear, if not jamming and total stoppage.
With my improved spiral gears and spiral pinions illustrated herein all such
defects are eliminated: the teeth of the spiral pinions will mesh with the teeth
of the spiral gears and drive without slip that is. they can be made to engage
with an exceedingly small amount of friction and they will intermesh and run
just as freely if under any accidental stress the spiral pinions are drawn out of
their normal positions toward or from each other or if the spiral pinions are not
properly adjusted on the tie rod. The spiral pinions will mesh with the spiral
gears and run just as freely if the teeth of the spiral pinions are forel more or
less to either side of the plane of rotation of the center of the teeth of the spiral
gears or if forced from normal position nearer to or away from the axes of the
spiral gears, so that if the frame of the bicycle becomes slightly sprung or bent.
cr the pinion connecting shaft becomes twisted or damaged, or the crank shaft
or hub of the driving wheel becomes dislocated, or the bearings get out of
adjustment, or the teeth of the spiral pinions or spiral gears become worn this
driving mechanism will operate to transmit power from the pedals to the driving
wheel without necessitating an increase of effort above that required when the
parts are in their normal alinement and adjustment.
The spiral pinions may be located above, so as to mesh with the tops of the
spiral gears, instead of being below and meshing with the bottoms of the
spiral gears, and the tie rod may be placed outside instead of inside the shaft,
or even dispensed with, if desired, without departing from the invention.

page_text: It is unnecessary to employ a tie rod, as the bearings will support the shaft
and spiral gears sufficiently, owing to the lack of end thrust with this form of
spiral gears and pinions. These spiral gears and spiral pinions are simply as
to form, and they are readily applied without adding to the weight of the bicvele.
They can be applied in a neat and attractive manner without materially
increasing the ordinary spread of the frame or increasing the distance between
the cranks, and they can he enclosed in dust proof caps or oil cases if desired.
A bicyclo provided with this style of driving mechanism will be very durable
for the wearin of the gears and pinions and all small twists or bends or RHY
ordinary spreading or yielding of the frame will not affect the transmission of
power from the cranks to the driving wheel, which transmission of power by
this form of spiral gears and spiral pinions, arranged to eliminate 'end thrust,
is accomplished with practically no loss.
The machine embodying this invention and having the enumerated
characteristics and advantages can be manufactured for less comparative cost
than other form of machine now in use because of the elimination of the
requirements of accuracy of construction and adjustment of the driving
mechanism.
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:
1. In combination in a vehicle, a geared driving mechanism including a
driving member, a spiral gear fast to auch driving member, a driven member
with a spiral gear, a connecting shaft bearing spiral pinions in mesh with the gears
on the driving member and driven member respectively, and means for imparting
motion to the driving member.
2. In a geared driving mechanism for vehicles, in combination, a driving
member provided with the spiral gear, a driven member placed at an angle with
the driving member and having a spiral gear in mesh with the first named gear.
the teeth of the intermeshing gears consisting of short sections of screw threads
all pitched to the same angle and in the same direction.
3. In a geared driving mechanism for vehicles, in combination with the
frame and wheels, a crank shaft, a driving wheel shaft or hub, a connecting
shaft, gears on the crank shaft and driving wheel respectively, pinions on the
connecting shaft in mesh with the crank shaft gear and driving wheel gear
respectively, all of said gears and intermeshing pinions having teeth consisting
of short sections of screw threads or spirals pitched to the same angle and in
the same direction on the respective gear wheels and pinions, the said angle of
pitch of the teeth with reference to the axis of the gear being equal substantially
to one half the included angle formed by the axes of the intermeshed gears and
pinions.
4. In a bicycle, in combination, a pair of wheels, a frame supported by the
wheels, a crank shaft supported by the frame, a spiral gear connected with the
crank shaft, a spiral gear connected with the hub of the driving wheel, and a
pair of spiral pinions connected together by a hollow shaft and supported by
bearings on the frame in such manner that the teeth of the pinions mesh with
the teeth of the spiral gears, substantially as specified.
5. In a bicycle, in combination, the wheels, the frame supported by the
wheels, a crank shaft supported in the crank shaft bracket, a spiral gear
connected with the crank shaft, a spiral gear connected with the hub of the
driving wheel, a spiral pinion meshing with the spiral gear connected to the
crank shaft, a spiral pinion meshing with the spiral gear at the driving wheel
hub, a shaft connecting the spiral pinions, and means including ball bearing
devices for supporting and connecting the said shaft with arms projecting from
portions of the frame of the wheel, and the arms.

page_text: 6. In a bicycle, in combination, the wheels, the frame supported by the
wheels, the crank shaft supported by the frame, a spiral gear connected with
the crank shaft, a spiral gear connected with the hub of the driving wheel,
a spiral pinion meshing with the spiral gear at the crank shaft, a spiral
pinion meshing with the spiral gear at the driving wheel hub, a
hollow shaft connecting the spiral pinions, a rod extending through the hollow
shaft and through arms projecting from a portion of the frame, said rol bearing
near each end a ball cone, one of said ball cones being threaded and free to turn
in a threaded opening in the arm, a binding bolt for clamping the threaded
ball cone
in position, and balls between the ball cones and spiral pinions,
substantially as specified.
7. In a bicycle having a rear driving wheel, geared driving mechanism
extending between the crank shaft bracket and the driving wheel, a driving gear
including a pair of screw gear wheels at the pedal crank axle, a pair of similar
screw gear wheels at the driving wheel axle, and a shaft supported on the
bicycle frame at its side and carrying the driven wheel of the front pair of gears
and the driving wheel of the rear pair.
8. In a bicycle, in combination with the frame, wheels and craak shaft, the
crank shaft and the hub of the driving wheel having screw or spiral gears thereon,
of a shaft carried by the frame and having screw or spiral pinions thereon each
meshing with the gears on the crank shatt and driving wheel hub respectively,
the pitch of the teeth of said gears and pinions being in the same direction and
of the same angle, whereby motion is communicated from the crank shaft to the
driving wheel and the end thrusts of the intermediate connecting pinions and
shaft are eliminated, substantially as and for the purpose specified.
L
655
VAHO
IO.
MOSES CARLYLE JOHNSON.
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C.
Agents for the Applicant.