IMPROVEMENTS IN THE CONSTRUCTION OF VELOCIPEDES
Year: 1880

page_text: LETTERS PATENT to Thomas Mangnall Gribbin and John Mangnall, both of
20, Smedley Road, Manchester, in tho County of Lancaster, for an Invention
of "IMPROVEMENTS IN THE CONSTRUCTION OF VELOCIPEDES."
PROVISIONAL SPECIFICATION left by the said Thomas Mangnall Gribbin
and John Mangnall at the Office of the Commissioners of Patents on the 20th
March 1880.
THOMAS MANGNALL GRIBBIN and JOHN MANGNALL, both of 20, Smedley Road,
Manchester, in the County of Lancaster. "IMPROVEMENTS IN THE CONSTRUCTION
OF VELOCIPEDES."
That portion of the frame which is known as the fork, and to which is attached
the axle bearings, is constructed of a metal tube of an elliptical or oval section;
down the centre of the interior of this tube is fitted a second tube (preferentially
of a round section) to impart strength to the minor axis of the ellipse or oval
shape.
The spokes of the wheels are made of steel wire of U section, the convexity of
the wire being placed outwards.
The axle bearings of the wheels are constructed by placing around the axles and
inside a metal box a number of metallic rollers with their ends made of a conical
shape; each end of the bearing box is fitted internally with a metallic ring, which
is both sectionally & circumferentially round, and which bears upon the conical
ends of the rollers, binding them upon the axle of the wheel. One end of the
bearing box is fitted with a screw cap, which presses upon the bearing rings, and
determines the adjustment of the rollers round the axles.
Upon the axle of the driving wheels is placed a pulley, and by the side of the
pulley a lever acting from the axle as a fulcrum, at the other end of this lever is
hinged a second lever, upon which the foot of the rider acts; to this second lever
is attatched a block, saddle, or pin, which, when the lever is pressed down, acts upon
the periphery of the pulley, causing it to rovolve. When the levers are released
from pressure & spring, weight, or foot of the operator lift them to their original
position to be acted upon as before; by this means the length of the strokes of the
feet of the rider may be varied at will, & are quite independant of the rotation of
the wheel, as in the ordinary crank; two or more of this combination may be used
upon the same machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Mangnall Gribbin and John Mangnall in the Great Seal
Patent Office on the 18th September 1880.
THOMAS MANGNALL GRIBBIN, of Manchester, and JOHN MANGNALL, of Manchester,
both in the County of Lancaster. " IMPROVEMENTS IN THE CONSTRUCTION OF
VELOCIPEDES."
That portion of the frame which is known as the fork or forks, and to which is
attached the axlo bearings, is constructed of a metal tube of an elliptical or oval
section. Down the centre of the interior of this tube is fitted a second tube,
preferentially of a round section, which supports the flattest curves or sides of the
oval or elliptical shape, and prevents their collapse or indention. Fig. 1 in the
accompanying Drawings is a full sized cross section of a fork at its broad end.
The spokes of the wheels, which are of the usual "spider" construction, are made
of steel or other suitable metal of or approaching a U section, but are made solid at
each end about an inch in length. Upon one end is formed a head, and on the
other is formed a screw. This wire is identical with that used in umbrellas, and
known as " paragon frames."
The axle bearings of the wheels are constructed by placing around the axles and
inside a metal box a number of metallic rollers, which are preferentially made of
hardened steel. Each end of these rollers is made conical in shape. The bearing
box is fitted internally at each end with a hardened steel ring, which is sectionally
(or that portion which bears upon the rollers) and circumferentially round, and
they bear upon the opposite cones of the roller ends, pressing them upon the axle
of the wheel. As the rings bear upon the coned ends of the rollers it will be seen
that they are worked upon by the rollers by a different and smaller circumference
of the roller than that which bears upon the axle, and will consequently have a
slower motion along the ring than if the circumferences of the rollers bearing the
axle and rings were alike. Another modification of these rollers is to make them
much larger in the body than their coned axles in order to increase the difference
between the circumferences of the rollers bearing upon the axle and rings. One
end of the bearing box is fitted with a screw cap, which forces the bearing rings up
the coned ends of the rollers, thus determining their adjustment around the
axle.
To further illustrate this portion of our Invention Fig. in the accompanying
Drawings represents a front view of a fork with bearing box attatched, and Fig. 3
a section through A to B, Fig. 2. Both are full sized Drawings, and the letters in
cach correspond to the separate parts. X is the axle of the wheel, around which the
rollers C, C, are placed; B represents the bearing rings, and A is the bearing box
or case. Fig. 4 is a full sized Drawing of the rollers with the body made larger
than the coned ends, and which is recommended to be of a diameter equal in size
as the axle it is intended to work upon, the coned ends being at their broadest
part about one third the diameter of the body of the roller.
Upon the axle of the driving wheel is fixed a pulley (or pulleys), and by the side
of the pulley a lever acting from the axle as a fulcrum. At the opposite end of
this lover to the fulcrum is hinged a second lever, upon which the foot of the rider
acts by pressing it upon the periphery of the pulley, causing it to revolve. When
the levers are released from pressure a spring or weight brings them to their
original position to be acted upon again. Fig. 5 in the accompanying Drawings
shows a full sized olevation of this arrangement. P is the pulley; L, the first
mentioned lever; L, C, the lever upon which the foot acts; and H a hook to
which the spring or weight is attached to bring the levers to their original
position.

page_text: "
Having thus stated the nature of our Invention and described the manner of
performing the same, we declare that we claim, first, the insertion of a tube in the
interior of the ordinary hollow oval sectioned fork as herein described; secondly,
the employment of wire, substantially as herein described for spokes of "spider
wheels; thirdly, the construction of roller bearings, having the rollers with coned
cuds working between the axle and metallic bearing rings and upon differential
circumferences of the rollers; fourthly, we do not confine ourselves to the employ-
ment of these improvements always in combination, as by the adaptation of any of
them a corresponding benefit will be derived.
In witness whereof, we, the said Thomas Mangnall Gribbin and John Mangnall,
have hereunto set our hands and seals, this Fifteenth day of September,
One thousand eight hundred and eighty.
THOMAS MANGNALL GRIBBIN. (L.S.)
JOHN MANGNALL.
(L.S.)