IMPROVED APPARATUS FOR TRANSMITTING MOTIVE POWER
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Arthur Macdonald Blair and Charles
Fairbairn at the Office of the Commissioners of Patents on the 18th March
1880.
ARTHUR MACDONALD BLAIR and CHARLES FAIRBAIRN, both of Manchester, in
the County of Lancaster. "IMPROVED APPARATUS FOR TRANSMITTING MOTIVE
POWER."
The object of this Invention is to transmit stored up power from a pent up
spring or weight descending from a height through a peculiarly constructed escape-
ment wheel to a crank in order to produce continuous rotary or reciprocating
motion. A train of wheels, such as is used in a clock, is employed to transfer the
power onward to the escapement wheel. A pendulum hung in front of the
escapement regulates the speed and quantity of power transferred from the escape-
ment to the crank.
The escapement has two sets of pins or teeth, one set on the periphery, and
radiating from the centre, which serve to give the impulse to the crank through
the connecting rod. The second set of teeth is on the side of the wheel which
gives the impulse to the pendulum at the same instant and controls the machine.
The distance of the pins or teeth from one another is regulated by the size of the
escapement wheel and the throw of the crank.
The pendulum rod may be made flat or hollow with a slot up one side of it. At
the top of the rod, but on its support, is a small pulley as near the point of
suspension as possible, and in a line with the pendulum when it is at rest. A
string fastened to the weight or "bob" passes up the rod or tube over the pulley
and down to a small lever on the foundation, which is worked by the foot of the
operator. By this means the pendulum weight can be raised or lowered, and the
speed of the machine increased or diminished at pleasure.
At a proper distance from the top of the pendulum rod are two arms, one on
each side, with a pallet on each, which work into the side teeth of the escapement,
and these pallets are shaped in such a way as enables them to control the escape-
ment wheel as well as give the impulse to the pendulum.
The connecting rod is fastened to the crank at one end in the usual manner; the
other end has a semicircular fork a little larger than the escapement wheel, but
embracing one half of it. The two ends of the semicircle are made of a form
suitable for receiving the impulse from the radial teeth of the escapement wheel in
137

page_text: each direction, that is, the upper side of the semicircle receives its impulse from
the upper side of the escapement, while the under side of the semicircular end of
the connecting rod receives its impulse from the lower side or half of escapement
wheel in the opposite direction.
Accordingly the upper impulse of the escapement is a pull, and the lower is a
push, and the pallets or ends of semicircle are shaped to suit these conditions.
When in operation the end of the connecting rod (or upper end of the semicircle)
is caught by one of the radial teeth and carried forward to the end of the stroke,
but just immediately before the end of the stroke one pallet of the pendulum
reaches its point to control or hold the escapement, and the momentum communi-
cates to the fly wheel and crank, carrying the crank past its dead centre, and also
releasing the pallet of the connecting rod from contact with the escapement wheel;
but the onward motion of the connecting rod has lifted the semicircular end of the
connecting rod by sliding up an inclined plane, and thus brought the lower end of
the semicircle into contact with the under side of the escapement, which now
begins the return stroke, the pendulum at the same time returning to renew the
operation at the other end of the stroke.;
A tapered piece projects from the upper side of the semicircle at the end of the
connecting rod, and this coming in contact with a pulley of a suitable form fixed
to the framing serves to lift the connecting rod up as described to bring the
lower side of semicircle into contact with the under radial teeth of the escapement
wheel for the return stroke.
In order to stop the machine instantaneously or to control its action within
narrower limits than is possible through altering the length of the pendulum, a
small wheel is provided gearing into the escapement with its spindle prolonged to
reach the front of the machine. On the spindle is a handle, by which the speed is
controlled at pleasure or stopped altogether.
The handle and wheel being worked by the hand alone, and thus controlling the
impulse from the machine itself.
When this machine is used for driving a sewing machine the varying tension of
the thread will be used through the last described gearing to stop the machine.
Let the thread pass over a pulley at the end of a very small weighted lever, the
motion of the free end of the lever through a varying force communicating with
the machine by raising the small handle stops it instantaneously.
It will be evident from the foregoing description that any of the ordinary clock
trains of wheels with many of the numerous escapements, such as the dead beat
recoil or gravity escapements, might be used for transmitting power through the
pendulum for very small measures of power. A connecting rod fastened to a
point in the pendulum could transfer power through a crank.
Another combination might be used consisting of a sliding bar supported on
rollers or pulleys, this sliding bar having pallets, which work into the escapement,
giving the reciprocating motion. The pendulum is now fastened by a connecting
rod or pin in a slot to the sliding bar, the other end of which might take the end
of the connecting rod, or by means of a multiplying lever communicate motion to
the crank, having a larger throw than could be used with direct motion.
The machines could be constructed in such a manner that a number of springs
might be used one after another.
In some instances there may be occasions when a pendulum is inapplicable or
inconvenient. A cam or cams placed on the crank shaft lifting a rod or lever
might be used to control the machine, for in place of a pendulum allow a short rod
carrying the pallet arins to take the place of the pendulum. To this is connected
the lever worked up and down by the cams, and by altering, that is, adjusting the
length of the pallets or pallet arms, the pendulum might be dispensed with, and
the machine controlled as to speed and power given out.
The spindle, on which the escapement wheel is mounted, is made capable of
sliding on end in order to allow the wheel to be clear of the pallets, while still
retaining connection with the train of wheels or remaining in gear.

page_text: When light springs or weights are used as the first mover a handle is fitted
onto a square at the extreme end of the spindle, by turning which the spring is
again compressed or the weight lifted to renew the operation.
•
When a very strong spring or heavy weight is used a worm wheel may be
keyed on the spindle, and a worm or endless screw is used to wind up the motive
force.
'
Or a separate apparatus in the form of a screw press or long lever may be used
to compress the spring or a series of springs, which being placed in their place and
released are ready for work.
When the spring is compressed by the latter arrangement it may be held in
compression by a bolt ready to be released.