TRICYCLES AND BICYCLES "
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Thurstan Forshaw at the Office of the
Commissioners of Patents on the 6th April 1882.
THURSTAN FORSHAW of Smalley in the County of Derby
TRICYCLES AND BICYCLES
"
"IMPROVEMENTS IN
Heretofore bicycles have been constructed with a back bone either solid or
hollow, but my improved machine consists of a combination of a variety of parts,
namely a large wheel, having its axle revolving in either plain bearings or
frictionless ball bearings, carried by or forming part of the lower ends of a forked
arın terminating at its upper end in a swivelled bearing double handled, and
provided with the usual fittings in addition to which the swivelled bearing has a
bracket which projects to the rear, the lower end of the bracket is T shaped, and
has two axle pins, secured in it, upon each axle, a swivel boss turns, the top of each
boss has an arm which projects towards the front, each being hinged to a link, the
front ends of both links are connected to a double swivel piece, the front end of
which rocks on a stud in the lower end of an arm, having a square hole at its
upper end, which receives the square end of an axle pin, which rocks in the
bracket before named, the arm is secured on the axle pin, by a lock nut or nuts, on
the opposite side of the bracket to the arm, the axle pin projects, and carries a
toothed boss or spur wheel, the teeth of which take into the teeth of a short rack
sliding in bearings secured to or forming part of the underside of the bracket, the
outer end of the axle pin terminates in a square boss which forms a bearing for a
short vertical spindle, provided with a handle at the top, and a spring and sliding
catch bit above a slotted bracket, through which the spindle is passed, the slotted
bracket is secured to, and projects from one side of the bracket first named, the
'lower end of the vertical spindle has a toothed boss or spur wheel, secured on it,
which gears into the toothed boss before named, by such means the rider can move
the sliding rack either to the front or rear, each swivel boss is secured on the upper end.
of a steel tube, through each of which, a steel rod is passed, each rod being secured
to or capable of being adjusted upon the rear end of the sliding rack the lower end
of each rod, is hinged to an arm, projecting from the side of a vertical rod carrying
or forming a bearing at its lower end for the axle of a trailing wheel, the upper

page_text: end of each rod is swivelled in a bearing boss, secured on the lower end of each of
the steel tubes before named, one boss carries a spring catch, which holds the wheels
more firmly together, the two trailing wheels are alike, except that the stud at the
centre of one wheel takes into the centre of the other wheel.
Above the swivel bearing of each trailing wheel is a ball and socket joint, or a
double sliding joint, attached to the outer end of one of two levers, which are
crossed and rock on an axle pin which connects them, above the bracket first
named is a spring plate, to which the saddle is secured, the rear end of the plate is
hinged to two other spring plates, the lower end of each slides in a slotted bearing
boss, secured to the steel tubes. A bicycle constructed as above described enables
the rider to place both trailing wheels together, or to set them apart, and thus
convert the machine into a tricycle at will, while propelling it.