An Improved Safety Appliance for Centrifugal Governors.
Year: 1897

page_text: Date of Application, 13th July, 1897
Complete Specification Left, 21st Feb., 1898-Accepted, 26th Mar., 1898
PROVISIONAL SPECIFICATION.
An Improved Safety Appliance for Centrifugal Governors.
I, JAMES MILNER, of Kirk Smeaton, Pontefract, in the County of York, Engineer,
do hereby declare the nature of this invention to be as follows:-
In my Specification No. 12875 of 1896 I described a safety appliance for a
centrifugal governor so arranged that should accident happen to the strap or
driving gear of the governor so as to stop it, the balls in descending from their
outspread condition, would strike a handle projecting in their path and thus cause
a valve rod to be moved so as to reduce supply of working fluid to the engine. The
handle above referred to as described in my former specification, had to be put
in position by hand after the governor balls became outspread; my present
invention relates to means of effecting this automatically, and thereby providing
against the negligence of the attendant who might forget to put the handle in
proper position.
For this purpose, I fit the handle to move on one face of a disc on the other
face of which is the cam path by which the valve rod is held up except when it
is turned partly round by the movement of the handle so as to release the valve,
which is then depressed by a spring. The disc has also on its circumference a cam
which, as it revolves, depresses a trigger in opposition to a spring. The disc is
caused to revolve slowly by worm or other suitable gear connecting it to the shaft
which drives the governor. After the engine has worked for some time, so as to
attain its proper speed, the governor balls being then outspread, the disc in the
course of its slow rotation comes to such a position that the trigger is released,
and this urged by its spring moves the handle into the path which the governor
balls occupy when they drop, so as to be ready to be acted on by them should the
driving gear of the governor accidentally fail. When the handle is thus pro-
truded the disc which carries it is disengaged from the driving gear and remains
stationary.
Instead of employing a spring trigger to move the handle out, the handle itself
may be pivotted on the disc and urged outwards by a spring but kept in by a
stationary shell surrounding the disc except at part of the circumference at
which part the handle is protruded.
Dated this 13th day of July 1897
ABEL & IMRAY,
Agents for the Applicant.

page_text: An Improved Safety Appliance for Centrifugal Governors.
I, JAMES MILNER, of Kirk Smeaton, Pontefract, in the County of York, Engineer,
do hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement: —
In my Specification No. 12,875 of 1896 I described a safety appliance for a
centrifugal governor so arranged that should accident happen to the strap or
driving gear of the governor so as to stop it, the balls in descending from their
outspread condition, would strike a handle projecting in their path and thus cause
a valve rod to be moved so as to reduce supply of working fluid to the engine. The
handle above referred to as described in my former specification, had to be put
in position by hand after the governor balls become outspread; my present
invention relates to means of effecting this automatically and thereby providing
against the negligence of the attendant who might forget to put the handle in
proper position.
For this purpose I modify the safety appliance as I shall describe referring to
the accompanying drawings.
Fig. 1 is a front view, Fig. 2 is a side view, Fig. 3 is a part side view with
worm wheel removed, shewing the handle in its raised position.
In these figures, the parts corresponding to those shewn in the drawings annexed
to my previous specification are marked by like letters of reference and, for the
sake of clearness I now describe them as they were then described.
A is the rod, which as the governor balls expand, is moved downwards acting
either directly or through levers and rods on a valve, sluice or the like, so as to
close it when the governor attains excessive speed, and is moved upwards by a
counterweight or spring opening the valve as the speed of the governor becomes
less.
On this rod A. I fix adjustably a pair of collars B between which is free to play
to a certain extent a forked arm C projecting from a vertically sliding bar D
having a head E.
At the side of this bar is mounted a cam disc F having a flat
side G. This cam dise is at the back of and made in one piece with a larger
disc H which can revolve on a stud I and has in its front a groove forming a guide
for a slide K having a slot through which the stud I passes, and in which there is
a piece i pressed against the stud by a spring which urges the slide K into such
a position that a tooth L projecting from its front face may engage with ratchet
teeth m on the back of a worn wheel M. This wheel is driven by worm n from
another worm wheel N driven by a worm thread p on the circumference of one of
the bevil wheels P that drive the governor. Under the slide K is a slide Q urged
upwards by a spring 9 which is stronger than the spring under i.
The upper
ends of the slides K and Q are rounded, the end of Q being somewhat inclined.
The apparatus operates as follows:-
When the governor begins to revolve the slide K. not being over Q but urged
by the spring under occupies such a position that its outer end forms part of
the circumference of the disc H and its tooth L is engaged with the ratchet
teeth m.
These being on the slowly revolving worm wheel M cause the slide K
and disc H to revolve slowly until the slide coming into the position shewn in 4
Fig. 3 is forced upwards by the spring slide Q its tooth L being thus disengaged
from the ratchet teeth m. Owing to this disengagement, the slide K and disc H
remain at rest notwithstanding that the wheel M continues to revolve. The
upper part of the slide K has a rearward projection k which lies in the path of

page_text: the governor balls when they drop owing to accidental stoppage of the gear which
drives the governor. When this happens the ball, still revolving, though more
slowly, strikes the projection k, and thus causes the slide K and disc H to turn
round to the position shewn in Figs. 1 and 2, in which position the cam F on
the back of H presents its flattened side G under the head E allowing the rod D to
descend in obedience to the spring which urges it downwards. The fork C being
thus despressed acting on the lower collar B causes the rod A to descend closing the
valve or sluice to which it is connected and thus effecting stoppage of the engine
or machine, when the governor happens to cease control of the speed.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is:
⚫ -
A safety appliance for a centrifugal governor constructed and operating sub-
stantially as described with reference to the drawings.
Dated this 21st day of February 1898.
ABEL & IMRAY,
Agents for the Applicant.