Improvements in Regulating Apparatus for Air-compressing Machines.
Year: 1890

page_text: Date of Application, 17th Jan., 1890
Complete Specification Left, 17th Oct., 1890-Accepted, 22nd Nov., 1840
PROVISIONAL SPECIFICATION.
Improvements in Regulating Apparatus for Air-compressing
Machines.
A communication from abroad by Doctor RUDOLF PROELL, of Dresden, Saxony,
German Empire, Civil Engineer, and the firm of O. L. KUMMER & Co., of the
same place, Machine Makers.
1, JOHN CLAYTON MEWBURN of 55 and 56 Chancery Lane in the County of
Middlesex, Fellow of the Institute of Patent Agents, do hereby declare the nature of
this invention to be as follows:-
:-
This invention has reference to regulating apparatus for air compressing machines
and has for its object a pressure governor or regulator, and the peculiar combination
of the latter with the levers or mechanism of a speed governor or regulator, each of
the two governors acting in a distinct and special manner upon the speed of the steam
engine which works the air compressing machine.
By the combined action of the two governors, the steam engine is automatically
adjusted to work at greater or less speed according to the greater or less supply of com-
pressed air necessary for the air reservoirs or for the pipes, and is prevented exceeding
a certain number of revolutions.
I will proceed to describe the construction, arrangement and operation of the
combined device.
There is a piston within a cylinder which communicates with the space or pipes
containing the compressed air.
There is a coiled spring within an expansible casing. By means of a three arm or
ireble lever connection the pressure of this spring is put in equilibrium with the
pressure against the piston so that the latter is placed at a certain position within its
cylinder. A counter link guides a pir or bolt to which the movable case of the
spring is attached in a slot of one arm of the lever in such a manner that the product
of the spring pressure and of the lever another arm of which is connected with the
piston rod will only slightly vary with the piston stroke in regard to the pivot of the
lever, so that the variations of the pressure remain within certain limits dependent
upon the working of the steam engine.
one,
The third arin of the lever or any suitable point of the latter or any suitable point
of the counter link is connected with any device which regulates the pressure of the
steam admitted to the steam engine. This connection, however, is not a direct
but indirect by means of a lever the pivot of which is arranged on the mechanism
connected with a speed governor.
For instance suppose that the regulation of the steam engine is effected by valves
the earlier or later shutting of which valves is regulated by the position of a particular
lever or member of the regulating mechanism. This member or lever is suspended by
means of a rol from one end of a bell crank or angle lever the pivot of which is
attached to a rod of the speed governor.
The bell crank or angle lever is connected at its other end by a rod with the pressure
governor, while another rod connects the pivots of the three arm lever and the bell
crank lever, thereby guiding the latter pivot in a certain prescribed race or course.
The action of the mechanism and connections above described is as follows: If there
is a certain normal pressure of air in the pipes or passages of the system and this
pressure falls or rises in consequence of too great or too small a consumption of such
compressed air the pressure regulator or governor will, while the speed regulator or
governor remains at its lowest position, regulate the expansion or the pressure of the
admitted steam in such a manner that the steam engine will work slower or quicker

page_text: at a certain ratio, thereby equalizing again the production and the consumption of
compressed air.
If in so working the pressure regulator or governor arrives at either of its extreme
positions it will produce an electric contact by means of a lever or by other suitable
means, thereby either stopping the steam engine automatically (by means of a suitable
device) as will be well understood or giving an audible signal for indicating to the
engine driver that a second steam engine should be started for the increased supply
of compressed air. In the latter case that is to say if the signal sounds, there being
not enough air pumped into the pipes or passages, and there being danger that the
steam engine in spite of the reaction of the pressure governor or regulator may
obtain a higher speed than is admissible, the speed governor or regulator begins to
act raising the pivot of the bell crank or angle lever, thereby creating or causing an
additional shifting or movement of the expansion mechanism, so that the steam
engine will obtain a speed which at the bighest position of the speed governor does
not exceed a certain amount. Especially in starting the engine if there is no air
pressure whatever in the pipes or passages the action or regulation specified will
take place in which case the speed governor will in the first instance regulate the
speed of the engine alone until after a time air pressure is created within the pipes or
passages, and then the pressure governor or regulator will begin to act.
The invention is particularly adapted for use in connection with a system of com-
pressed air for working motors in towns or districts.
...
J. C. MEWBURN.
COMPLETE SPECIFICATION.
Improvements in Regulating Apparatus for Air-compressing
Machines.
A communication from abroad by Doctor RUDOLF PROELL, of Dresden, Saxony,
German Empire, Civil Engineer, and the Firm of O. L. KUMMER AND
COMPANY, of the same place, Machine Makers.
I, JOHN CLAYTON MEWBURN of 55 and 56 Chancery Lane in the County of
Middlesex, Fellow of the Institute of Patent Agents, 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 air compressing installations it is of importance to keep the air pressure as
nearly as possible the same, although the consumption of compressed air may differ
very widely at different periods. The steam or other motors which compress the
air cannot therefore be run at a constant speed, but their speed should be in inverse
ratio to the pressure of the air within the receivers or mains. On the other hand
the speed of the engines should not exceed the limit for which they and the air
compressors are intended. This invention consists in the combination of two
governors for the control of the speed of the engine, one of which governors is
dependent upon the air pressure in the main while the other is a centrifugal governor.
I will proceed to describe the invention with reference to the accompanying
drawings in which Figure 1 is a sectional elevation of the governor which is dependent
upon the air pressure in the main, and Figure 2 is a side elevation of the same
governor with a diagrammatic representation of the centrifugal governor and of
the levers and connections between the two governors and the valve of the engine.
C is a cylinder in which an air-tight piston K can move. The space underneath
the piston is connected with the compressed air space. A connecting rod connects the
piston K with a three armed lever a, b, c, the arm c of which presses upon a spring h
which spring is of a suitable power to balance the pressure of the compressed air on
the piston. If the air pressure is at its highest normal level it will compress the
spring so far that the two ends a and b of the three armed lever assume the positions a
and Figure 2. To the fixed point d a bridle rod is attached, the other end

page_text: of which rod is supported at the point e by a rod u of a suitable shape; this rod u is
at its point v connected with the centrifugal governor. Upon the point e is also
arranged a bell-crank f, e, g, the point of which is connected with the point b by a
rod s.
It will thus be seen that the connections d, b, fe form a movable parallelogram
or trapezium. Supposing that there was sufficient pressure in the mains and con-
sequently under the piston that the engines are required to run so slow that the
centrifugal governor would not come into operation, then the point e would be a fixed
point, and the setting of the expansion gear or throttle valve lever m, which is con-
nected to the point g by means of the rod o attached at 9, would solely depend upon
the pressure governor. The lower the pressure in the main, the lower the point g
will be held by the described levers and connections and the faster the engine will
The position of the point q under the action of the pressure governor will vary
the position of the bell crank correspondingly varying between feg
run.
from say q to wever, the pressure in the mains should fall so low that the air
and fe g.
pressure governor alone cannot prevent the engine from adopting a higher speed than
is intended, then the centrifugal governor comes into play and regulates the engine
to the predetermined speed even if there should be no pressure at all in the mains.
This it effects by lifting the upper end of the rod to the position v¹, the point e
would therefore be lifted to e¹ and the point 9 to g².
The invention above described may be further extended for giving signals or
stopping automatically one or more engines in case the engines at work exert too
little or too much power respectively. This can be done by one or more electrical
contacts which are closed by a switch or switches in connection with either governor.
One of the modes in which this can be put into practice is shown in Figure 1. The
one arm of a two armed lever which has its fulcrum at y is connected with the pin
at c while the other arm moves over a series of electric contacts. If the pressure in
the mains falls so low that the arm reaches its limit in the one direction, then an
electric contact is formed and a bell z or other signal is put into action showing that
more motive power must be added while if the pressure reaches its limit in the other
direction another contact is formed which may either give a similar signal or the
electric current may be utilized to stop one or more engines automatically by a suitable
arrangement.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me and in what manner the same is to be performed I
declare that what I claim is :-
1. For the purpose of regulating the supply of compressed air to a system of
receivers and mains, the combination of a pressure regulator or governor and a
centrifugal governor by means of suitable levers in such a manner that the highest
admissible pressure in the mains, as well as the highest admissible speed of the
engines, are both controlled substantially as hereinbefore described and represented
in the accompanying drawings.
2. The combination with the arrangement of a pressure governor and a centrifugal
governor referred to in Claim 1, of one or more electrical contacts whereby signals
are given when the highest admissible pressure of air in the mains or the highest
admissible speed of the engines is attained, or whereby the steam in the latter case is
automatically cut off from one or more engines, substantially as hereinbefore described
with reference to the accompanying drawings.