Improvements in Speed Indicators.
Year: 1899

page_text: Improvements in Speed Indicators.
I, THOMAS WILSON MCLEOD, of 117, Gloucester Road, Bootle, in the County
of Lancaster, Instrument Maker, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to apparatus for indicating the speed or rate
of revolutions of machinery, but more especially the rate of revolutions of
engines, by which the speed or rate at each and every instant, and the varia-
tions, can be ascertained and indicated. And it has reference to that type of
such indicators wherein a fluid, say water, is pumped to a gauge which is
adapted to shew by the pressure of fluid pumped, the number of revolutions
per unit of time; the pumps, of course, being driven suitably from the engines,
or the machine, the speed of which it is desired to indicate."
According to this invention, I employ three single acting pumps, the pump
cylinders being open at the top; and the plungers of which are worked from a
shaft, preferably by eccentries, arranged on the shaft at 120 degrees from one
another. This shaft will be suitably driven, say by bevel gearing and shafting,
or other gearing, from the engines, and preferably at a reduced speed, by means
of the said gearing; so that the velocity of movement of the pump pistons is
comparatively low.
These plungers or pistons are supplied with fluid, say water, from a tank,
and their discharge is forced into a chamber, which is connected by a pipe with
the indicating gauge, and also with the water cistern, this latter connection
being an aperture or conduit, the amount of opening or capacity of which is
capable of regulation by an adjusting plug or cock.
In action, the pumps draw water past an inlet valve from the water cistern,
and discharge it through a delivery valve into the water chamber, which will
be under a certain pressure; and as this pressure varies according to the speed
at which the pumps are driven, this variable pressure will be transmitted to
the indicating gauge, and will there show the rate of revolutions per unit of
time, say per minute; the gauge being so adapted, of course, that a certain
pressure corresponds or is equivalent to a certain rate of revolutions of the
engines, per minute. The control of this pressure is governed by the adjustable
outlet of the pressure water chamber, to the water return or circulating cistern
(which may be open to the atmosphere); and, in one case, may consist of a
coned screw plug, working in the outlet aperture, and adjusted by being screwed
in or out, more or less. When the required opening is obtained, the screwed
plug is locked by a lock nut or other suitable means: and the adjusting head
or part enclosed in a casing, fitted over the plug case.
In one special arrangement, the cylinders of the pump are fixed side by side
on the top of the pressure water chamber: and the shaft, from which the
plungers of this pump are driven, is mounted on bearings in brackets on the
water chamber. The cylinders are open on the top, and the plungers work
direct from the eccentric rods. The inlet and outlet valves may be of the lift

page_text: type, placed on either side of each cylinder, and connected respectively with
the water return cistern, and with the water pressure chamber.
Dated this 11th day of January 1899.
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.
I, THOMAS WILSON MCLEOD, of 117, Gloucester Road, Bootle, in the County
of Lancaster, Instrument Maker, 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:-
-
This invention has reference to apparatus for indicating the speed or rate
of revolutions of machinery, but more especially the rate of revolutions of
engines, by which the speed or rate at each and every instant, and the varia-
tions, can be ascertained and indicated. And it has reference to that type of
such indicators wherein a fluid, say water, is pumped to a gauge which is
adapted to shew by the pressure of fluid pumped, the number of revolutions
per unit of time; the pumps, of course, being driven suitably from the engines,
or the machine, the speed of which it is desired to indicate.
According to this invention, I employ three single acting pumps, the pump
cylinders being open at the top; and the plungers of which are worked from a
shaft, preferably by eccentrics, arranged on the shaft at 120 degrees from one
another. This shaft will be suitably driven, say by bevel gearing and shafting,
or other gearing, from the engines, and preferably at a reduced speed, by means
of the said gearing; so that the velocity of movement of the pump pistons is
comparatively low.
These plungers or pistons are supplied with fluid, say water, from a tank,
and their discharge is forced into a chamber, which is connected by a pipe with
the indicating gauge, and also with the water cistern, this latter connection
being an aperture or conduit, the amount of opening or capacity of which is
capable of regulation by an adjusting plug or cock.
In action, the pumps draw water past an inlet valve from the water cistern,
and discharge it through a delivery valve into the water chamber, which will
be under a certain pressure; and as this pressure varies according to the speed
at which the pumps are driven, this variable pressure will be transmitted to
the indicating gauge, and will there show the rate of revolutions per unit of
time, say per minute; the gauge being so adapted, of course, that a certain
pressure corresponds or is equivalent to a certain rate of revolutions of the
engines, per minute. The control of this pressure is governed by the adjustable
outlet of the pressure water chamber, to the water return or circulating cistern
(which may be open to the atmosphere); and, in one case, may consist of a
coned screw plug, working in the outlet aperture, and adjusted by being screwed
in or out, more or less. When the required opening is obtained, the screwed
plug is locked by a lock nut or other suitable means; and the adjusting head
or part enclosed in a casing, fitted over the plug case.
The invention is illustrated in the accompanying drawings, in which Figure 1
is a side elevation, and Figure 2 is an end elevation of the apparatus, while
Figure 3 shews in detail the section of the discharge regulating or adjusting
device.
Referring to the drawings, represents a tank or cistern containing water,
from and to which such water is drawn, and returned by the pumps. is a
chamber into which the water is first discharged from the pumps, and consti-

page_text: tutes the pressure chamber; and c designates generally the regulating or
governing device, between the chamber and the tank a, by way of which
the return from to a takes place.
d represents the three forcing pumps, which are fixed on the upper part
or cover of the tank u, they being single acting, and operated by the eccen-
tries e disposed at equal distances apart, on a horizontal driving shaft f; that
is, these pumps are arranged upon the three throw principle. However,
more pumps, if desired, may be used.
"
The pumps have each an inlet and discharge valve; and these are respec-
tively placed in the valve boxes d' and d², each lift valve box d being in
connection with the tank a by a pipe g, and the discharge box d² communi-
cating with the chamber through the pipes h.
The pipes on the pressure chamber b are those connected with the indicators,
and through which the hydraulic communication between the pressure chamber
and these instruments, is provided. The pressure regulating or governing
device c is fixed or mounted on the chamber b, and communication between b
and a exists by way of the passage in c, an interior chamber in c, and a
pipe k, connecting with the tank a. The aperture, that is to say, the amount
of opening between 6 and the chamber is regulated by the coned plug 1,
which is adapted as shewn, to screw up and down in the body of the device c.
The actuating part of this coned regulating plug is enclosed in the casing m,
which will be locked, say by an ordinary key lock, to the casing, through an
eye n.
In operation, the pumps d draw up water or liquid from the tank a, and
discharge it by the discharge pipes h into the discharge or pressure vessel ;
and the pressure created therein is transmitted hydraulically, by the water in
the pipes i, to the indicators. These indicators will be so arranged that a
certain pressure existing in them, will cause the pointer (or its equivalent) to
stand in a certain position, and the speed scales are so marked that this pointer
will correspond with a certain and corresponding rate of movement or revolu-
tions of the engine. Hence, as the hydraulic pressures of the apparatus serve
as the rate of movement of the engine, the movement of the indicator will
synchronise with it.
By the employment of the three throw pump arrangement (or more might
be used) the pressure in the chamber is made uniform; and, consequently,
there is no pulsating or want of steadiness in the indicator: and this is assisted
by the use of the air vessel on the upper part of chamber, and the regulated
outlet. To adjust the instrument, in order that the speed indicated by the
indicator, shall correspond with that of the engines to be indicated or in other
words, to make the indicator of the instrument true, the coned plug is screwed
up or down, restricting or making larger, more or less, the area of discharge
by way of the passage j.
It is not necessary that the speed of the shaft f on the pumps should be the
same as that of the engines or machine and by suitable gearing between it
and the shaft f, the speed of the pumps may be reduced to anything required
and suitable.
In the drawings shewn, a supplemental indicator is provided on the instru-
ment, marked with figures to represent the revolutions of the engine from
the shaft f. When the instrument is in operation, the point of this indicator
will revolve over the dial, and by timing its movements from one division to
another, the speed of the engines and the indicator or indicators proper will
be checked.
Having now particularly described and ascertained the nature of thi
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1 A hydraulic sneed indicating annarafus comprising
1311Bar
lianid

page_text: supply chamber, from which liquid is drawn by the said pump; a chamber
to which liquid is discharged from the pump; and a liquid escape regulating
device between the latter chamber and the former on the return liquid conduit,
by which the pressure in the discharge chamber is regulated; for the purposes
set forth.
2. In a hydraulic speed indicating apparatus, in which pressure of water
created by pumps is adapted to serve as a medium for indication, a regulating
device on the discharge from the pumps, by which the pressure is adjusted or
regulated, and correctness of the apparatus or device secured.
3. In a hydraulic speed indicating apparatus, the combination with a liquid
service vessel, and discharge vessel, of three throw pumps, adapted to deliver
into the pressure vessel, so as to obtain a uniform pressure in the indicating
instrument; substantially as set forth.
4. A hydraulic speed indicating apparatus, comprising a liquid supply vessel;
multiple pumps thereon; a discharge or pressure vessel; and a return or dis-
charge regulating device; arranged and adapted to operate as set forth and
as shewn in the drawings.
Dated this 11th day of Octob 1900
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.