Improvements in Electric Maximum Demand Indicators.
Year: 1899

page_text: Date of Application, 4th Dec., 1899
Complete Specification Left, 4th Sept., 1900-Accepted, 27th Oct.. 1900.
PROVISIONAL SPECIFICATION.
Improvements in Electric Maximum Demand Indicators.
We, ARTHUR WRIGHT, Electrical Engineer, of 26, Park Crescent, and THE
MUTUAL ELECTRIC TRUST LIMITED, of 111, Gloucester Road, both of Brighton,
in the County of Sussex, do hereby declare the nature of this invention to be
as follows:-
Our invention relates to electric maximum demand indicators by means of
which certain advantages are obtained.
Our invention consists essentially of two integers which for the purposes of
this specification we shall term respectively the liquid container and the tilter.
The liquid container consists of a vessel of such form that liquid may be trans-
ferred from one part (hereinafter termed the reservoir) to another part (herein-
after termed the receiver) in proportion to the angular movement or tilting
of the said vessel.
The said tilting or angular movement is produced by the integer herein before
termed the tilter and which consists of an electro-magnetic device capable of
tilting the liquid container through an angle which will vary with the current
passing through its coil or coils.
In a contemplated form of our invention the tilter consists of a coil having two
armature cores one of which is fixed and the other movable.
cores lie side by side within the coil and being similarly magnetized by the
These armature
current in the coil they tend to repel one another but as one is fixed the other
alone will move and the amount of its movement will vary with the current
traversing the coil.
To the said movable core is affixed a board or frame carrying the liquid
container. This liquid container, in the said contemplated form of our invention
consists of a short tube or other conveniently shaped vessel serving as a reservoir
for the liquid. From the lower part of the said reservoir a tube or passage
(hereinafter termed the feed pipe) passes to the upper part of a downwardly
projecting tube (hereinafter termed the receiver). At the point where the feed
pipe joins the receiver is a lip and the liquid container contains a liquid which
fills the reservoir and feed pipe up to the level of the said lip.
The liquid container, when the instrument is first put in position, has no liquid in
the receiver but only in the reservoir and in the feed pipe, such liquid extending
up to the level of the lip as aforesaid. When now a current is passed through
he coil angular movement of the free armature core takes place and the container
s tilted to such an angle that some of the liquid flows over the lip and into the
eceiver and the amount of liquid so transferred to the receiver is a measure of
he current passed through the coil. If the current is cut off the parts will
eturn to their normal position but the liquid in the receiver will remain there.
f now the current be switched on again and be a smaller current than that
reviously passed tilting will again take place but no more liquid will pass
rom the reservoir as the angular movement will not be so great as on the
revious passage of the current If however a current be passed through
Prime 77
11

page_text: coil greater than that previously passed a greater amount of tilting or of angular
movement will take place than was formerly the case and more liquid will be
tiansferred to the receiver. Hence the amount of liquid found in the receiver
after a definite period of time will give an indication of the maximum current
which has passed through the coil during that period.
To prevent spill from a sudden "kick" produced by a momentary current
a constriction is made in the feed tube so that a lag in the flow of the liquid
(which liquid is by choice one of inferior mobility) is produced.
To enable the liquid to be returned to the reservoir and feed pipe after the
maximum current (say at the quarterly reading of the meter) has been taken,
the upper part of the receiver may be connected to the upper part of the reservoir
by a tube (hereinafter termed the replacing tube) so that on turning the container
upside down the liquid will flow from the receiver into the reservoir.
It is obvious that the strength of the field and the repulsion between the
armature cores will vary with the ampere turns so that the field may have two
windings and be adapted for a three or more wire circuit.
It is also obvious that such a form of electro-magnetic tilter as the one
herein before described as a contemplated form would be likely to have a good
deal of residual magnetism but in an instrument of this kind such residual
magnetism is no drawback as it is obvious that no indication is recorded unless
it is greater than that of a previous one.
The amount of liquid in the receiver may be read off by an adjacent scale or
the receiver itself may be marked in degrees. Or, the reservoir may be so
marked or fitted with a scale, in which latter case the loss of liquid in the
reservoir indicates the maximum current passed.
Dated this 4th day of Theamben 1000
J. G. LORRAIN, M.I.E.E.,
Norfolk House, Norfolk Street, London, W.C.,
Chartered Patent Agent.
Improvements in Electric Maximum Demand Indicators.
We, ARTHUR WRIGHT, Electrical Engineer, of 26, Park Crescent, and THE
MUTUAL ELECTRIC TRUST LIMITED, of 111, Gloucester Road, both of Brighton,
in the County of Sussex, 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:-
-
Our invention relates to maximum demand indicators by means of which
certain advantages are obtained.
In order that our invention may be readily understood we shall proceed to
describe it with reference to the accompanying sheet of drawings, in which
Figure I is a front elevation of one form of instrument giving good results
in practice.
Figure II is a side view of the same.
Figure III shows a simple modified form.
By referring to Figures I and II it will be seen that the instrument consists
of two parts which for convenience of description we shall hereinafter term
the " tilting device" and the "tilted device." The tilting device may consist
of any convenient form of motor, the amount of whose deflection or movement
will vary with the current passing through it.

page_text: The object of the tilting device is to move the tilted device in an angular
direction so that a record may be obtained as will be hereinafter described of
the maximum deflection during a given period, this maximum deflection corres-
ponding with the maximum current which has passed during that period. The
tilting device whilst acting as a motor may be any convenient form of electric
meter. In the form illustrated it consists of a solenoid 1 and a core 2, the said
core being sucked further inwards as the current passing through the solenoid
is greater. Said cord 2 is hung from cord 3 passing over pulley 4, the other
end of said cord being attached to one end of the spiral spring 5, whose other end
is attached to the fixed part 6. To pulley 4 is rigidly attached the board or
frame and to said board is bound the tilted device 8 by the straps 9, 9. 10 is
a stop designed to prevent frame 7 from being pulled by spring 5 beyond its
vertical position.
The tilted device, in the form of our invention illustrated in Figures I and II,
consists of a short tube 11 serving as a reservoir for a liquid contained in it.
From the lower part of said reservoir 11 a tube or passage 12 (hereinafter termed
the feed pipe) passes to the upper part of a downwardly projecting tube 13
(hereinafter termed the receiver). At the point where the feed pipe joins the
receiver is a lip 14 and the tilted device contains a liquid 15 which fills the
reservoir and feed pipe up to the level of the said lip. The tilted device, when
the instrument is first put in position (that is to say in the position shown in
Figure I and in which the receiver 13 is vertical), has no liquid in the said
receiver but only in the reservoir 11 and feed pipe 12, such liquid extending
as aforesaid up to the level of the lip 14.
When now a current is passed through the coil 1, core 2 is sucked downwards
and pulley 4 is pulled round against the action of spring 5 and the tilted device
is tilted in the direction shown by arrow a
a position (say that shown by dotted lines) that a certain amount of the liquid
through such an angle and to such
flows over the lip 14 and into the receiver 13. The amount of liquid so trans-
ferred to the receiver will vary as will be seen with the angular distance through
which tilting takes place, and is a measure of the current passed through the coil.
If the current is now cut off the parts will be returned to their normal position
by the pull of spring 5 but none of the liquid can come back from the receiver
to the reservoir as such portion as has flowed over lip 14 will now be retained at
the bottom of the receiver. If now the current be switched on again and be a
smaller current than that previously passed tilting will again take place but no
more liquid will pass from the reservoir 11 as the angular movement will not be so
great as on the previous passage of the current and consequently the level of
the liquid will not rise to the overflow lip. If however a current be passed
through the coil greater than that previously passed a greater amount of tilting
or of angular movement will take place than was formerly the case and more
liquid will be transferred to the receiver. Hence the amount of liquid found
in the receiver after a definite period of time will be an indication of the maximum
current which has passed through the coil during that period.
To prevent spill from a sudden "kick" produced by a momentary current
a constriction 16 is made in the feed pipe so that a lag in the flow of the liquid
(which liquid is by choice one of inferior mobility) is produced.
To enable the instrument to be reset, that is to say to enable the liquid to be
returned to the reservoir and feed pipe after the maximum current (say at the
quarterly reading of the meter) has been read off and noted, the upper part of
the receiver may be connected to the upper part of the reservoir by a tube 17
hereinafter termed the replacing tube) so that on removing stop-pin 10 and
turning the tilted device in the direction of arrow b until it is upside down the
liquid will flow from the receiver into the reservoir. The tilted device is then
moved back (so as to retrace its path in the opposite direction to arrow b), stop
pin 10 is re-inserted in its hole in the board and the parts again occupy the
position shown in full lines in Figure I.

page_text: The amount of liquid in the receiver may be read off by an adjacent scale or
the receiver itself may be marked in degrees. Or, the reservoir may be so
marked or fitted with a scale, in which latter case the loss of liquid in the
reservoir indicates the maximum current passed.
It is to be noted that a distinctive feature of the tilted device is that the portion
of liquid removed from the main body of said liquid does not rejoin the said main
body when the device returns to its normal position on the cessation of the current
or on any lessening of the current.
"
In our Provisional Specification we termed our tilted device the "liquid con-
tainer and our tilting device we termed the tilter." We prefer the designa-
tions employed in our present Complete Specification.
We desire it to be understood that we lay no claim to the tilting device.
In practice we arrange that the maximum deflection, that is to say the maxi-
mum angular distance through which the tilted device is moved by the action
of the current, is not so great as to allow of any back flow from the receiver
into the reservoir. Thus in an instrument of the form shown in the drawings
it would be dangerous to have a deflection of more than about ninety degrees
and we prefer to keep well within this limit. It will be obvious however that
the amount of deflection which may safely be permitted will vary with the
specific form of the tilted device.
Although in practice we prefer to make our tilted device with a feed pipe,
a constriction therein and a replacing tube, we can dispense with these parts
by simply leading the tube 13 into the side of the tube 11, as shown in Figure III.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:.
"
1. In an electric maximum demand indicator, a tilted device" consisting
of a vessel containing liquid and being of such form that liquid may be trans-
ferred from one part thereof to another part thereof in proportion to the angular
movement or tilting of the said vessel, but without allowing of the portion
transferred being returned to the main body of the liquid on the return of the
vessel to its normal position.
2. In a
"tilted device" as defined in Claim 1 the combination of a reservoir
a receiver and an overflow lip between the two.
3. In a "tilted device" as defined in Claim 1 the combination of a reservoir,
a receiver, a feed pipe with a constriction therein and an overflow lip.
4. In a
"
tilted device as defined in Claim 1 the combination of a reservoir,
a receiver, a feed pipe with a constriction therein, an overflow lip and a replacing
Tube.
Tube.
Dated this 4th day of September 1900.
For the Applicants,
J. G. LORRAIN, M.I.E.E.,
Norfolk House, Victoria Embankment, London, W.C.,
Chartered Patent Agent.