IMPROVE- MENTS IN BICYCLES AND TRICYCLES AND OTHER VELOCIPEDES."
Year: 1881

page_text: LETTERS PATENT to George Gilbert Marshall Vernum, of Birmingham, in the
County of Warwick, Mechanical Engineer, for an Invention of "IMPROVE-
MENTS IN BICYCLES AND TRICYCLES AND OTHER VELOCIPEDES."
PROVISIONAL SPECIFICATION left by the said George Gilbert Marshall
Vernum at the Office of the Commissioners of Patents on the 19th February
1881.
GEORGE GILBERT MARSHALL VERNUM, of Birmingham, in the County of
Warwick, Mechanical Engineer.
"IMPROVEMENTS IN BICYCLES AND TRICYCLES
AND OTHER VELOCIPEDES,
My improvements consist, first, in the following method of adjusting the bearings
of such bicycles, tricycles, and other velocipedes as have spherical antifriction
rollers-The adjustment of the said bearings is effected by means of a screw cap
ordinarily turned by hand. In order to be able to effect a more accurate adjust-
ment I employ a tangent screw taking into teeth on the edge of the screw cap, the
turning of the tangent screw being effected by a milled head on its end. A
By this means the adjustment of the bearing can be effected with the greatest
nicety.
My improvements consist, secondly, of the following arrangement of parts for
transmitting the rotary motion of the crank shaft of tricycles and other velocipedes
to the driving wheels:-
The driving wheels turn freely on their axes, the hub of the wheel having on its
periphery a ring like flange. Parallel to the hub is a toothed wheel, also working
freely on the axis. This toothed wheel has a nearly elliptical central cam, and on
the cylindrical base of the said cam a nearly rectangular frame turns freely, the
said frame extending nearly all across the inner face of the toothed wheel.
In this frame two sliding bolts work, the said bolts being pressed inwards by
springs. The elliptical cam is situated between the inner ends of the said sliding
bolts. When the elliptical cam is in such a position that its shortest diameter is in
a line with the axis of the bolts the said bolts are in their withdrawn position, but

page_text: when the said cam is turned it forces the said bolts outwards. As the said bolts
are situated within the ring like flange on the hub of the wheel, when they are
forced outwards they bear against the inner side of the said flange, and the hub of
the wheel is thereby locked to the toothed wheel, and is carried round with it.
The crank shaft transmits its motion to the toothed wheel carrying the elliptical
cam by toothed wheels or other gearing.
The action of the parts is as follows:-So long as the crank shaft is not pressed
upon by the foot of the rider the springs of the bolts withdraw the bolts, and the
driving wheels are ungeared from the toothed wheel carrying the central cam.
When however the cranks are pressed upon by the feet of the rider the elliptical
cam is turned through a small angle; the bolts are thereby forced outwards, and
the crank shaft is geared to the driving wheels. Hence, whenever the rider acts
upon the cranks the motion of the crank shaft is communicated to the driving
wheels, but as soon as he lifts his feet from the cranks the crank shaft is ungeared
from the driving wheels, and the tricycle or other velocipede travels on the driving
wheels which remain unconnected with the crank shaft until the rider again places
his feet upon the cranks.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Gilbert Marshall Vernum in the Great Seal Patent Office
on the 15th August 1881.
GEORGE GILBERT MARSHALL VERNUM, of Birmingham, in the County of
Warwick, Mechanical Engineer. "IMPROVEMENTS IN BICYCLES AND TRICYCLES
AND OTHER VELOCIPEDES.
"
My improvements consist, first, in the following method of adjusting the bearings
of such bicycles, tricycles, and other velocipedes as have spherical antifriction
rollers-The adjustment of the said bearings is effected by means of a screw cap
ordinarily turned by hand. In order to be able to effect a more accurate adjust-
ment I employ a tangent screw taking into teeth on the edge of the screw cap, the
turning of the tangent screw being effected by a milled head on its end.
By this means the adjustment of the bearing can be effected with the greatest
nicety.
My improvements consist, secondly, of the following arrangement of parts
for transmitting the rotary motion of the crank shaft of tricycles and other
velocipedes to the driving wheels :-
The driving wheels turn freely on their axes, the hub of the wheel having on its
periphery a ring like flange. Parallel to the hub is a toothed wheel, also working
freely on the axis. This toothed wheel has a nearly elliptical central cam, and on
the cylindrical base of the said cam a nearly rectangular frame turns freely, the
said frame extending nearly all across the inner face of the toothed wheel. In
this frame two sliding bolts work, the said bolts being pressed inwards by springs.
The elliptical cam is situated between the inner ends of the said sliding bolts. When
the elliptical cam is in such a position that its shortest diameter is in a line with the
axis of the bolts the said bolts are in their withdrawn position, but when the said
cam is turned it forces the said bolts outwards. As the said bolts are situated
within the ring like flange on the hub of the wheel, when they are forced outwards
they bear against the innerside of the said flange, and the hub of the wheel is
thereby locked to the toothed wheel, and is carried round with it. The crank shaft
transmits its motion to the toothed wheel carrying the elliptical cam by toothed
wheels or other gearing.
The action of the parts is as follows:-So long as the crank shaft is not pressed
upon by the foot of the rider the springs of the bolts withdraw the bolts, and the
driving wheels are ungeared from the toothed wheel carrying the central cam.
When however the cranks are pressed upon by the feet of the rider the elliptical
cam is turned through a small angle; the bolts are thereby forced outwards, and
the crank shaft is geared to the driving wheels. Hence, whenever the rider acts
upon the cranks the motion of the crank shaft is communicated to the driving
wheels, but as soon as he removes the pressure from the cranks the crank shaft is
ungeared from the driving wheels, and the tricycle or other velocipede travels on
the driving wheels, which remain unconnected with the crank shaft until the rider
again presses his feet upon the cranks.
I will now proceed to describe, with reference to the accompanying Drawings,
the manner in which my Invention is to be performed.
Figure 1 represents in front elevation, and Figure 2 in side elevation, a bearing
for a bicycle, tricycle, or other velocipede, the adjustment of the screw cap of the said
bearing being effected according to my Invention. a is the case containing the
anti-friction rollers or spheres and conical bearing surfaces, and b the screw cap
screwing in the case a for adjusting the moveable conical bearing surface. On
the edge of the screw cap 6 teeth c are made, and carried by the case a is a

page_text: tangent screw & taking into the said teeth c. The said screw d is turned by the
milled head d².
By turning the milled head d³ the screw cap b can be driven more or less into the
case a, and the moveable conical bearing surface adjusted very accurately and with
great facility.
Figure 3 represents in side elevation a portion of a tricycle containing mechanism
constructed according to my Invention for transmitting the rotary motion of the
crank shaft to the driving wheels; Figures 4 and 5 represent longitudinal vertical
sections of the hub of the driving wheel and the clutch of transmitting mechanism
of the same; Figure 6 represents a vertical section of Figure 4; and Figure 7
represents a vertical section of Figure 5, the said sections, Figures 6 and 7, being
taken on the lines e, e, Figures 4 and 5; Figure 8 represents in front elevation and
end elevation the rectangular frame in which the sliding bolts work; and Figure 9
represents a side elevation and section of the same; Figure 10 represents one of
the sliding bolts; and Figure 11 represents the toothed wheel and its cam, which
work upon the axle of the driving wheel.
As the driving wheel and crank shaft at opposite sides of the tricycle are provided
with the same kind of mechanism, I have only thought it necessary to represent
the mechanism at one side of the tricycle.
The same letters of reference indicate the same parts in Figures 1 to 11.
fis one of the driving wheels of the tricycle, and g is a portion of the fixed
frame; h is the hub of the driving wheel f, turning freely on its axle i, the said hub
being provided with a ring like flange h2; k is a toothed wheel also working freely
on the axle i. At the boss or central part of the said loose toothed wheel k is a
nearly elliptical cam 7, on the cylindrical base m of which a rectangular frame n
(shown separately in Figures 8 and 9) turns freely the said frame, extending nearly
all across the inner face of the said toothed wheel k (see Figures 6 and 7). In the
said frame n two sliding bolts p, p, (one of which is shown separately in Figure 10)
work, the said bolts being pressed inwards by the coiled springs q, q, (see Figures 4
and 5), and guided in the frame n by the pins r, r, taking into slots in the edges of
the bolts.
These springs q, q, lie in slots in the frame and bolts, one half of each slot being
made in the frame and the other half in the bolt. By an examination of Figures 4
and 5 it will be seen that one end of each spring takes an abutment against the
bolt p, and the other end against the frame n, so that the said bolts when at liberty
to move are forced inwards into the position represented in Figures 4 and 6. The
nearly elliptical cam / is situated between the inner ends of the sliding bolts p, p.
When the cam 7 is in the position represented in Figures 4 and 6, that is when its
shorter diameter is in a line with the axis of the bolts p, p, the said bolts are
pressed into their withdrawn or non-acting position. When however the cam l'is
turned through a small angle into the position represented in Figures 5 and 7 by
the pressure of the feet of the rider upon the pedals, it forces the bolts p, P
outwards and causes their outer ends to bear against the inner side of the flange h²
on the hub h. The toothed wheel k is thus locked through the bolts p, p, with the
hub h of the driving wheel f, and the said driving wheel is carried round with the
said toothed wheel. When the pressure of the feet of the rider is removed from the
pedals, the pressure of the bolts p, p, upon the cam 7 causes it to take the position
represented in Figures 4 and 6, and the toothed wheel k is no longer locked with
the hub h of the driving wheel.
The motion of the crank shaft s on which the pedals t are carried, is transmitted
through the toothed wheels u and v (see Figure 3) to the toothed wheel k on which
the elliptical cam 7 is fixed.
The action of the gearing or clutch mechanism is as follows:-
So long as the crank shaft s is not pressed upon by the feet of the rider, the bolts p, p,
take the withdrawn position, Figures 4 and 6, by the action of the springs 9, 9,
and the driving wheel fis ungeared from the toothed wheel k. When however the
pedals t of the crank shaft s are pressed upon the feet of the rider so as to give a

page_text: sudden motion to the said shaft s, the cam 7 is turned through a small angle into
the position represented in Figure 7. The bolts p, p, are thereby forced outwards
and the crank shaft s is geared with the driving wheel fin the manner before
described. Thus it will be understood that on the rider pressing upon the pedals t
and giving a sudden motion to the crank shaft 8, the motion of the crank shaft is
transmitted to the driving wheels, but as soon as the rider removes the pressure
from the pedals, the crank shaft is ungeared from the driving wheels.
Figures 12, 13, 14 and 15 represent a modification of the clutch or gearing
mechanism described, and Figure 16 represents in side elevation, and Figure 16 in
plan, the said mechanism applied to the crank shaft of a tricycle. In Figures 12
and 13 the clutch mechanism is represented out of action, and in Figures 14 and 15
in action. The same letters of reference indicate the same parts in Figures 12, 13,
14, 15, 16, and 16ª.
.
a is the crank shaft on which the toothed wheel b works freely, the said crank
shaft being supported by the fixed framing c in the manner represented. The
said loose toothed wheel b is hollow and is provided with an inner flange 6² similar
to that on the hub in the first described arrangement. In the hollow of the loose
wheel b are two nearly semi-circular bolts c, c, pressed together or inwards by the
coiled springs d, d. These bolts are carried by the covering plate e which is
connected to the boss f of the cam g fixed on the crank shaft a. The cam g has
four rises upon it as represented, and is situated between concavities in the opposed
faces of the two bolts c, c. When the pedals of the crank shaft a are not pressed
upon by the rider, the parts of the clutch or gearing mechanism occupy the
respective positions represented in Figures 12 and 13, that is, the bolts c, c, are
pressed inwards by the springs d, d, and the loose wheel b is ungeared from the
bolts c, c, which are connected to and turn with the crank shaft a.
however as the rider presses his feet upon the pedals and gives a sudden motion to
the crank shaft a, the cam g takes the position represented in Figures 14 and 15.
The cam g is thereby made to press outwards the bolts c, c, and cause them to
bear against the inner flange 62 of the toothed wheel b and carry round the said
wheel, the motion of the toothed wheel b being transmitted to the driving wheel
by toothed or other gearing, as will be understood by an examination of Figure 16.
The action of the parts of this mechanism is essentially the same as that of
corresponding parts of the arrangement first described.
As soon
Or the parts may be modified in the manner illustrated in Figures 17, 18. 19,
and 20, Figures 17 and 18 representing the gearing out of action, and Figures 19
and 20 the same in action.
In this modification no springs are employed, and the bolts h, h, turn on the
centres i, i. The ends of the arms of the said bolts are serrated, and the inner
flange 6 of the loose toothed wheel b on the crank shaft a is also serrated. The
cam k fixed on the crank shaft a has the form represented, the arms of the said
cam engaging respectively with the two bolts h, h, in the manner represented.
When there is no pressure put upon the pedals the parts occupy the respective
positions shown in Figure 17, and the toothed wheel b is not geared to the crank
shaft a.
When however the pedals are pressed upon by the rider and a sudden motion
given to the crank shaft a, the cam on the said shaft takes the position
represented in Figure 19, so as to turn the bolts h, h, upon their centres i, and cause
the opposite serrated arms to engage with the serrated inner flange b² of the toothed
wheel b. The toothed wheel b is thereby geared with the crank shaft a, the motion
of which is transmitted to the driving wheels in the manner herein before
described.
When the crank shaft is moved in a direction contrary to that represented in
Figure 19, the other ends of the serrated arms of the bolts h, h, engage with the
flange 62 so that the wheel b is geared with the crank shaft by the turning of the
latter in either direction.
The arrangements represented in Figures 12 to 20 both inclusive may be applied

page_text: to the axles of the driving wheels instead of to the crank shaft, but I prefer to
apply them to the crank shaft as illustrated in the Drawing; and the arrangement
represented in Figures 3 to 11 both inclusive may be applied to the crank shaft
instead of to the driving wheels.
The clutch or gearing mechanism described and represented may be applied to
velocipedes having more than three wheels for transmitting the motion of the
crank shaft to the driving wheels.
Having now described the nature of my Invention and the manner in which
the same is to be performed I wish it to be understood that I claim as my
Invention,-
First. The improvement in such adjustable bearings for bicycles, tricycles, and
other velocipedes as have spherical antifriction rollers herein before described and
illustrated in Figures 1 and 2 of the accompanying Drawings, that is to say,
adjusting the said bearings by turning the screw cap of the bearing by means of
a tangent screw taking into teeth in the edge of the screw cap.
Secondly. The improvements in transmitting the rotary motion of the crank shaft
of tricycles and other velocipedes to the driving wheels herein before described
and illustrated in Figures 3 to 11, both inclusive of the accompanying Drawings,
that is to say, the combination of the flanged hub h, h2, turning loosely on the axle
or shaft, the frame n and sliding bolts p, p, with the wheel k and its cam / turning
loosely on the said axle or shaft, the said parts being constructed, arranged, and
operating, substantially as described and illustrated.
Thirdly. The modifications herein before described and illustrated in Figures 12
to 20, both inclusive of the accompanying Drawings for the same purpose.
In witness whereof, I, the said George Gilbert Marshall Vernum, have
hereunto set my my hand and seal, this Tenth day of August, in the year
of our Lord'One thousand eight hundred and eighty one.
Witness,
GEORGE GILBERT MARSHALL VERNUM. (L.S.)
RICHARD SKERRETT,
37, Temple Street,
Birmingham.