IMPROVEMENTS IN TRICYCLES
Year: 1883

page_text: LETTERS PATENT to John George Parker, of Gracechurch Street, in the city
of London, and county of. Middlesex, Engineer for an Invention of
IMPROVEMENTS IN TRICYCLES
PROVISIONAL SPECIFICATION left by the said John George Parker at the
Office of the Commissioners of Patents on the 22nd November 1883.
JOHN GEORGE PARKER, of Gracechurch Street, in the city of London, and
county of Middlesex, Engineer, "IMPROVEMENTS IN TRICYCLES,"
My invention has for its object to produce a vehicle capable of being propelled
with great speed by a minimum of muscular effort, and which is of a substantial
character adapted for hard work upon rough roads.
For this purpose I construct the tricycle so that the person using it adopts a
standing position, instead of sitting, as with ordinary tricycles, and that the vehicle
is propelled by bringing the weight of the body to bear alternately upon one or the
other of two treadles, which are connected by two rods with a pair of cranks,
placed on an axle at an angle to each other, so that one crank goes up while the
other goes down. Two of the wheels are preferably made about six feet high and
mounted parallel on the same axle, (right and left of the driver) which may either
be the crank axle or connected with the same by suitable gearing, while the third
wheel is made much smaller. The two treadles turn on the same fulcrum which is
secured to the frame of the vehicle, and the effective length of the treadle is made
variable, which may be accomplished by shifting the treadles lengthways, or by
shifting the fulcrum. In the former case each treadle is provided with a slot for
adjusting and securing the lower end of the connecting rod, while another slot
serves for adjusting and fixing the pivotal bearings of the treadle.
In order to increase the strength of the wheels without increasing their weight,
I make the spokes of metallic tubes, instead of solid rods.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John George Parker in the Patent Office on the 22nd May 1884.
JOHN GEORGE PARKER, of Gracechurch Street, in the city of London, and
county of Middlesex, Engineer, "IMPROVEMENTS IN TRICYCLES."
My invention has for its object to produce a vehicle capable of being propelled
with great speed by a minimum of muscular effort, and which is of a substantial
character adapted for hard work upon rough roads.
For this purpose I construct the tricycle so that the person using it adopts a
standing position, instead of sitting, as with ordinary tricycles, and that the vehicle
is propelled by bringing the weight of the body to bear alternately upon one or the
other of two spring treadles, which are connected by two rods with a pair of
cranks, placed on an axle at an angle to each other, so that one crank goes up
while the other goes down. Two of the wheels are preferably made about six
feet high and mounted parallel on the same axle, (right and left of the driver)
which may either be the crank axle or connected with the same by suitable
gearing, while the third wheel is made much smaller. The two treadles turn on
the same fulcrum which is secured to the frame of the vehicle, and the effective
length of the treadle is made variable, which may be accomplished by shifting the
treadles lengthways, or by shifting the fulcrum. In the former case each treadle
is provided with a slot for adjusting and securing the lower end of the connecting
rod, while another slot serves for adjusting and fixing the pivotal bearings of the
treadle.
Instead of making each treadle like a one armed lever, to which the connecting
rods are attached and which, in its middle position, is approximately horizontal,
I prefer to provide each treadle with a second arm extending from the fulcrum
upward so as to form with the horizontal arm or treadle proper an angle and so
that the whole treadle forms a bell crank lever, the upright arm of which is slotted
for the reception of the pin of the rod which connects the treadle with the crank.
In order to render the effort of the driver and the transmission of power more
uniform, I attach to each treadle the lower end of a spring, (preferably a helical
spring) the upper end of which is attached to the frame of the tricycle, so that by
every down motion of the treadle the spring is set in tension, and thereby energy
stored up, which is subsequently expanded during the up motion, so as to assist the
motion of the treadles.
In order to increase the strength of the wheels without increasing their weight,
I make the spokes of metallic tubes, instead of solid rods.