Improvements in Means for Regulating the Speed of Steam Engines.
Year: 1891

page_text: Date of Application, 4th July, 1891
Complete Specification Left, 1st Apr., 1892-Accepted, 7th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Means for Regulating the Speed of Steam Engines.
I, ALEXANDER RODGER of 14, Hall Place Galashiels, in the County of Selkirk,
North Britain, Engineman, do hereby declare the nature of this invention to be as
follows:-
The purpose of my invention is to check and supply the admission of steam for
keeping the engine running at its proper speed under varying loads, and to prevent
racing or dragging. To do this, I employ two levers which cross each other
diagonally, and are connected together at, or near the centre, both working on a
common stud or pivot, this stud is fitted into a straight slot cut in a plate, free to
travel in both directions. Into one end of each lever a stud is put, having a small
roller fitted on it, and these work in two other slots in the same plate, one on each
side of the straight slot. The opposite ends of the levers are joined together by
two connecting links of the same length as the distance from the end of levers to
the central stud of pivot. To the central stud or pivot the rod from the governor
is attached, and from the joint of the two connecting links, the rod is continued to
the cut-off motion, throttle, or other check valve, as the case may require. Owing
to the side slots for the open end of the levers working in, being partly straight,
and partly curved, the motion of the joint of connecting links, and also the rod
attached thereto, is accelerated, when, by the action of the governor, the open ends
of the levers are brought to the curved parts of the side slots. By this quickening
of motion, the check and supply of steam to the cylinder is regulated in less time,
and keeps the engine running at a more uniform speed, under varying loads, than
can be obtained by the ordinary plain rod.
Dated th: Thin d... of I.1 1901
ALEXANDER RODGER.
COMPLETE SPECIFICATION.
Improvements in Means for Regulating the Speed of Steam Engines.
I, ALEXANDER RODGER, of 14, Hall Place, Galashiels, in the County of
Selkirk, North Britain, Engineman, 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, that is to say:-
"
The purpose of my invention is to check or diminish and to increase the admis-
sion of steam to an engine in order to keep it running at its proper speed under
varying loads and to prevent racing and dragging. To do this I employ any suit-
able known rotating governor, and I make the rod by which the action of the
governor is transmitted to the valve gear in two parts connected by a "lazy-tongs
linkage allowing the effective length of the rod to be increased or diminish, the
action of the linkage being controlled by cam grooves or slots in a fixed plate.
The cam grooves or slots are specially shaped in a manner to quicken the action of
the governor on the speed of the engine varying or tending to vary to an appre-
ciable extent from the proper or mean position.
And in order that my said invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings to
be hereinafter referred to and representing an example of my improved speed-
regulating mechanism.
In the drawing the mechanism is shown in elevation. The rod by which the
action of the governor is transmitted consists of two parts, A and B, in the same

page_text: vertical line, the upper part, A, (connected to the governor in any ordinary way)
being connected to the lower, part, B, by four linkage bars, C, D, E, F. The
lower linkage bars, E, F, are pin-jointed to the top of the lower rod, B, and have
their outer ends pin-jointed to the upper linkage bars, C, D, which are pin-jointed
to the bottom of the upper rod, A. The upper linkage bars, C, D, extend beyond
their joint with the rod, A, and have their outer ends fitted with antifriction
rollers which work in cam slots, G, H, formed in a bracket plate, J, which is to be
bolted to the engine framing or other suitable fixed part. The cam slots, G, H,
are of the curved form shown (which form may be varied in different cases) so
that if the rod, A, which is shown as in its 'normal position corresponding to the
proper speed of the engine, is raised in consequence of increase of speed, the ends
of the upper linkage bars, C, D, will be moved outwards. The effect of this will
be to make all the linkage bars move nearly horizontal and to diminish the
distance between the rods, A, and B, and consequently to make the lower rod, B,
rise to a greater extent than the upper rod, A, and act on the valve gear of the
engine correspondingly. If through decrease of speed the upper rod, A, descends
below the normal position, the reverse action will take place and the lower rod, B,
will descend to a greater extent than the upper rod, A.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
As means for regulating the speed of a steam engine, the combination with an
ordinary governor of a linkage connecting two parts of the rod transmitting
the governing action and controlled by cam slots or grooves in a fixed plate
substantially as hereinbefore described and as shown in the accompanying
drawings.
Dated this Thirty-first day of March 1892.
EDMUND HUNT,
Applicant's Agent.