IMPROVEMENTS IN GOVERNORS FOR STEAM ENGINES AND OTHER MOTORS
Year: 1880

page_text: LETTERS PATENT to George Frank Pottle, of Boston, in the County of Suffolk,
in the State of Massachusetts, in the United States of America, for an
Invention of "IMPROVEMENTS IN GOVERNORS FOR STEAM ENGINES AND OTHER
MOTORS."
COMPLETE SPECIFICATION filed by the said George Frank Pottle at the
Office of the Commissioners of Patents on the 1st January 1880.
GEORGE FRANK POTTLE, of Boston, in the County of Suffolk, in the State of
Massachusetts, in the United States of America. "IMPROVEMENTS IN GOVERNORS
FOR STEAM ENGINES AND OTHER MOTORS."
The nature of my Invention consists in combining with a revolving shaft a spiral
thread and screw nut, the nut having resisting wings or fans, the whole being
immersed in some suitable fluid or its equivalent, so that upon the revolution of
the shaft the resistance to the wings or fans on the nut will prevent the same from
revolving as fast as the shaft, and thus give the nut a tendency to traverse the
shaft longitudinally. This tendency of the nut to move on the shaft is resisted to
a certain extent by a weighted lever, but the resistance thus offered is not sufficient -
to withstand a too rapid velocity of the shaft, in which case the lever operates on a
valve and through it the motive force, and thus regulates the velocity of the shaft
and motor. My Invention also consists in combining within a suitable chamber an
inlet pipe or orifice, also an outlet pipe, the inner end of which projects into the
chamber so far as to admit of an accurately fitting sleeve or hollow cylinder passing
over and onto it. I place within the said chamber a solid cylinder of even diameter
with the outside of the outlet pipe and of the inside diameter of the sleeve, the
axis of the solid cylinder being in line with the centre of the outlet pipe. The end
of the solid cylinder is fixed at a short distance from the end of the outlet pipe, so
that there may be a free passage from the chamber into the outlet pipe, unless the
space between the end of the solid cylinder and end of the outlet pipe is enclosed
by the above mentioned sleeve, which is made to slide on both the cylinder and outlet
pipe, and thus to enclose the ends of both, and thus cut off any passage of steam,
gas, or fluid.

page_text: The form of my device is entirely immaterial, but I have adopted the one shown
in the Drawings, and a convenient one. A represents a cylindrical chamber sup-
ported immediately above the valve chamber; within and extending from the
chamber A I place a shaft H, said shaft having a screw thread h, Figure 2, upon
it. This shaft H¹ is driven by a belt from the motor, which acts on the pulley E',
and through it and the shaft E upon the gear E", which in turn engages with the
gear H on the shaft H'. N is a screw nut having resisting wings or arms N¹, N¹,
(see Figures 2 and 3). H" is a tube fitting loosely upon the screw shaft H¹, its
lower end resting on the nut N, and its upper end terminating in a stem H¹¹,
which passes up through the cap A', Figures 1 and 2. The stem H is connected
to a weighted lever K by a link K', said lever K being pivoted to the standard K".
W is a weight attached to the lever K to regulate the amount of resistance to be
offered by the tube H to prevent the nut N from rising on the shaft H'. L is a
link to connect the lever K to the regulator valve. P, P, &c., are vertical projec-
tions made on the interior of the chamber A, and serve to resist the flow of the
fluid when the nut is caused to revolve. The action of my Invention is as
follows: The chamber A is filled with oil or pulverized plumbago, &c., &c., and
the device is connected with the motor; the link L is attached to the regulator
valve, and the whole adjusted so that the fan nut N, N¹, will remain at the bottom
of the chamber so long as the motor is doing its maximum work and running at
the normal speed. Now if the motor is free from some of its work, then the
velocity will increase and the fan nut N, N¹, will rise, and acting through the tube
Hand spindle H¹ lift the lever K and link L, and through it cause the regulator
valve to cut off the supply from the motor. The chamber C is formed by the
metallic shells G, G', which may be bolted or otherwise fastened together. J,
Figure 1, is an orifice, through which steam, gas, or other fluid is admitted; M is
an outlet pipe, the end M¹ of which projects inwardly, as shown in Figures 2 and 4;
O is a solid cylinder attached by the arm or bracket O', Figure 4, to the shell of
the chamber. This cylinder O is of the same diameter as the outside of the outlet
pipe M, and is accurately adjusted in line with it, so that the sleeve F may slide
and fit onto both the solid cylinder O and the pipe M. The end of the solid
cylinder O is placed at a short distance from the end of the pipe M, as shown, so
that when the sleeve F is in the position shown in Figure 2 there is a free passage
from the chamber C to the outlet pipe M. When the sleeve F is moved down-
wardly, as shown in Figure 4, it will embrace the end M¹ of the outlet pipe M, and
close the annular passage S, Figure 4, and thus cut off communication between the
chamber C and the outlet pipe M. The sleeve F is operated by a forked link R,
which is in turn pivoted to the arm T by a pin i, Figures 2 and 4, the arm being
made fast to a shaft U, which is operated by the link L. This form of a valve is
particularly adapted for use in connection with governors, as the pressure upon it
is so evenly balanced that it requires but the slightest force to operate it. With
this form of valve the amount of opening, that is, the area of passage may be regulated
with the greatest accuracy.

page_text: CLAIM.
I claim as my Invention, first, the combination of the revolving screw shaft
H', the fan nut N, fans N', N¹, and the fluid-inclosing-chamber A, with the lifter
tube H, stem H, and weighted lever K, substantially as described and for the
purpose set forth; second, in a valve chamber C the combination of the solid
cylinder H, the outlet pipe E, and the sliding sleeve F, all operating together sub-
stantially as described and for the purpose set forth.
In witness whereof, I, the said George Frank Pottle, have hereunto set my
hand and seal, this Tenth day of December, A.D. 1879.
GEORGE FRANK POTTLE. (L.S.)