IMPROVEMENTS IN TRICYCLES AND LIKE VEHICLES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Samuel Chatwood at the Office of
the Commissioners of Patents on the 24th July 1880.
SAMUEL CHATWOOD, of 120, Cannon Street, in the City of London, Safe and Lock
Engineer. 'IMPROVEMENTS IN TRICYCLES AND LIKE VEHICLES."
This Invention has for its object improvements in tricyles and like vehicles.
I construct tricycles with two main or driving wheels and with a central
steering wheel behind. I form the treddle cranks upon the axle of the main
wheels, and I cause the rotary motion of the axle to be imparted to the wheels
through gearing, so that the main wheels may be rotated at a slower speed than
the axle.
The bosses of the main wheels have necks projecting inwards, and these are
received into bearings at the ends of an arched or bow frame, which frame is in
this way supported by the main wheels. From the centre of the arched or bow
frame an arm projects to the rear, and it has at its end a socket which receives the
stem of a fork in which the hinder or steering wheel is carried. The bow frame or
its arm also carries the driver's seat. Upon the main axle on either side, just
within the projecting necks of the main wheel bosses, a pair of pinions are arranged
to slide along a feather upon the axle. These pinions are under the control of the
rider, who can move them in or out along the axle.
For this purpose handles are provided in connection with forks entering circular
grooves between the pinions.
The projecting neck of each of the main wheel bosses also has a pinion upon it
of the same size as the larger of the sliding pinions on the same side of the machine.
In one position these two pinions of a size are close along side the one of the other,
and they then both gear with the same pinion on a stud axis projecting from the
side of the bow frame. Consequently, when the sliding pinions are in this position
the driving wheels rotate at the same speed as the cranked or treddle axis, the
pinion upon the stud axis serving to couple the two. The stud axis in each case
carries a second pinion of larger size formed of a piece with the first or mounted
with it upon same tube or hollow axis. The smaller sliding pinion of each pair can
be brought to gear with the larger pinion upon the stud axis, and the main wheel
is then driven at a slower speed than the main axle, upon which are the treddles.
D71

page_text: In an intermediate position.of the sliding pinions the main wheels are free and
can rotate independently of the axle. By a slight modification of the gearing the
wheels may be driven at a more rapid speed than the main axle, but this is seldom
needed.
I sometimes, in place of cranking the main or driving shaft, use a straight shaft,
and fix fast upon it two drums or pulleys; outside these and oscillating freely upon
the shaft, other drums or pulleys, each carrying one or more pawls, knuckles, or
silent feeds, which, on motion being given to the outer drums in one direction,
causes the pawls or knuckles to fasten upon the inner or fixed drums, thus giving
motion to the shaft; on giving motion to the outer drums in the opposite direction
the pawls or knuckles free themselves and allow the outer drums to oscillate back
to their original positions. The pawls are so arranged that when desirable the
motion of the shaft may be reversed.
On the peripheries of each outer drum is fastened a flexible connection, having
at the free end a stirrup or suitable attachment for the foot. The two outer drums
are so arranged that they oscillate in opposite directions at the same time, so that
the pawls or knuckles of one drum are giving rotation to the shaft while the other
is returning to its starting point.