IMPROVEMENTS IN VELOCIPEDES
Year: 1869

page_text: PROVISIONAL SPECIFICATION left by William Bull at the Office of
the Commissioners of Patents, with his Petition, on the 22nd July
1869.
I, WILLIAM BULL, of Waltham Cross, in the County of Essex, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
VELOCIPEDES," to be as follows:-
This Invention relates to certain improvements in velocipedes, known
as bicycles and tricycles, and consists, firstly, in an improved crank
capable of increasing or decreasing the stroke. This has hitherto been
effected by setting the treddle on the crank by means of a screw nut
working in a slot in the crank bar, but I propose to form the crank bar
of a solid and square, angular, or polygonal section to receive a
corresponding hollow stem on which the treddle is jointed, by which
means the stem may be inserted in or withdrawn from the socket to any
extent required for the stroke, and may be fixed at such point by a
pivoted screw, pin, or other equivalent passing through the socket and
entering corresponding cavities in the stem. The shape of the stem and.
socket being square or of some angular section will prevent it from
turning, thereby maintaining the true position of the treddle. Another

page_text: method of effecting this object is to make a square socket in the crama
and to form the stem with a corresponding head to guide and steady
its motion within the socket, or vice versâ ; I then cut a screw thread
to receive a screw cap on which a collar and female screw are loosely
held, being free to turn in either direction but not to be removed, so
that by passing the screw stem through this screw and collar and then
affixing the square head the stem may be inserted in the socket, which
is then to be applied to the crank and secured in the well-known
manner; it will thus be clear that by turning the screw collar the
stem will be shortened or lengthened as required.
The next improvement consists in the application to the treddle of an
india-rubber bearing surface; this may be of vulcanized or other rubber
formed of a tubular section and stretched on the treddle so as to
surround the same, whether such treddle be of a cylindrical, square, or
triangular form, or made with a series of rods or bars between two discs
and enclosing the tubular metallic bearing on the crank shaft. By
this improvement the foot will always find a bearing whatever the
surface may be presented by the treddle, thus dispensing with the
balance weight now used to maintain the bearing surface in an uniform
position.
The third improvement consists in the application of a foot rest on
each side of the driving wheel, serving also as an assistance in mounting,
and avoiding the necessity of vaulting into the saddle. I propose to apply
a curvilinear bracket or arm to the two forks containing the leading wheel,
such brackets being capable of vertical adjustment on the fork by
means of set screws or clamps applied to their sliding bearings, which
may consist of cheeks bolted to the brackets and enclosing the forks.
The brackets are extended within the sphere or motion of the treddle
and driving wheel, and are supplied with toe pieces to receive the feet;
these receptacles may consist of sheet iron so bent or turned up as to
keep the feet free from the treddles and wheel, and an india-rubber or
leather pad may be attached within a ring or flange of metal to form an
elastic or yielding rest for the feet. By this improvement the acquisition
of the saddle seat is rendered easy and free from undue exertion, and in
descending a hill the feet may be removed from the treddles and
brought back to the rests, instead of being raised up to the level of the
saddle bar and supported above the leading wheel, thus affording a more
comfortable rest and avoiding the necessity of throwing back the body

page_text: as hitherto. A horizontal cam with a step or clutch motion is applied
to the guiding stem tube and connecting bar of the wheels to maintain
the leading and trailing wheels in one line when the handle is
released.