AN IMPROVED THERMOSTATIC HEAT RECORDER AND ELECTRIC SIGNAL
Year: 1885

page_text: We, JOHN GILMORE, of the Vicarage, Lower Norwood, in the County of Surrey,
Clerk in Holy Orders, and WILLIAM RICHARD CLARK, of 3 Danby Road, in the
County of Surrey, Mechanician do hereby declare the nature of our invention
for "AN IMPROVED THERMOSTATIC HEAT RECORDER AND ELECTRIC SIGNAL" to be
as follows:-
Our invention relates to a device designed to automatically record the raising or
lowering of temperature to any given degree, and to automatically announce when
such degree is reached.
In order to carry out our invention, we utilise the differential expansion under
varying temperatures of two plates of metal joined in what we term a thermostatic
band, which is fixed at one end, the remainder of the band being free to move.
This thermostatic band is conveniently fixed behind the recording dial which is
to be employed in our device, and from its upper and free end projects a pin
through a suitable hole in the dial. Above the hole aforesaid, and upon a pivot,
are two long moveable arms, and the pin projects between these two, slightly below
the pivot.
As alteration in temperature inclines the pin attached to the thermostatic band
in either direction, so it will touch one or other of the indicating arms, and the
distance of travel before which contact takes place may be easily regulated by
moving the arms on the pivot.
The great length of the arms permits of increased relative travel at their free
ends, and these are made to move over a dial calibrated in any convenient manner
relatively to the range of temperature within which the device will be required to
operate. This dial plate is conveniently in the form of a segment of a circle.
The automatic recording of the fact of the given degree of temperature being
reached and the audible warning of same is effected electrically.
This we carry out by making the contact of the pin against either of the
indicating arms complete an electrical circuit operating a bell.
or gong in any
known manner.

page_text: It is obvious that the relative disposition of the various parts may be varied
without departing from our invention, as for instance, the whole of the parts might
be arranged upon the face of the dial, and the thermostatic band itself make the
electrical contacts.
In order that the observer may at any time verify the actual temperature, the
travel of the thermostatic band or projecting pin attached thereto is made to
operate a finger travelling over a clalibrated face on the dial, and indicating the
temperature.
An Improved Thermostatio Heat Recorder and Electric Signal.
We, JOHN GILMORE, of the Vicarage, West (formerly Lower) Norwood, in the
County of Surrey, Clerk in Holy Orders, and WILLIAM RICHARD CLARK, of
3 Danby Road, in the County of Surrey, Mechanician, 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 a device designed to automatically record the raising or
lowering of temperature to any given degree, and to automatically announce when
such degree is reached.
In order that our invention may be the better understood, we now proceed to
describe the same in relation to the drawings hereunto annexed, reference being
had to the letters and figures marked thereon. Like letters refer to like parts
throughout the drawings.
Figure 1 is a front elevation of our device.
Figure 2 is a back elevation of the same.
Figure 3 is a transverse section through the same.
In order to carry out our invention, we utilise the differential expansion under
varying temperatures of two plates of metal joined in what we term a thermostatic
band A, which is fixed at one end A¹ to the casing B, the remainder of the band
being free to move. The thermostatic band A is conveniently fixed behind the
face of the case B carrying the recording dial C, and at its upper and free end
projects a pin D through a suitable hole in the front of the casing. Upon the

page_text: pivot E, which is electrically insulated from the casing, and which is also conveniently
provided with a binding screw F, are fitted two long movable arms G G, the pin D
of the thermostatic band A projecting between these two arms, slightly below the
pivot. The said arms are further insulated from the casing at their extremities
by bands H of india-rubber or other insulating material, so that the said arms G G
are nowhere in metallic contact with the casing. Another binding screw K is
fitted to any convenient point. on the outer casing. The casing is conveniently
provided with a metal eye L, by which it may be nailed up against a wall or
suspended in any convenient situation.
As the alteration in temperature causes the thermostatic band and the pin at its
extremity to incline in one direction or the other, the pin will eventually touch one
or other of the indicating arms G G, and the distance of travel before such contact
takes place is easily regulated by moving the arms on the pivot.
Thus we
regulate the record of the rise or fall of temperature to the required degree.
M is the insulated arm freely swinging on the pivot E, with a counter balance
weight N, serving to keep this arm always resting on the point D of the
thermostatic band A, by which the actual temperature at any time may be
ascertained.
The great length of the arms G G, permits of great relative travel at their free
ends, where they are finished as pointers, and these are made to move over a dial
calibrated in any convenient manner, so as to indicate the range of temperature
within which the device will be required to operate. The dial plate is conveniently
in the form of a segment of a circle. To calibrate the said scale, the extreme
positions of the arms are ascertained by direct test, so that the point D on the end
of the thermostatic band A just comes into metallic contact with the two arms at
certain convenient extreme ranges of temperature, such as 10° and 130° fahrenheit;
the scale can then be uniformly divided between these extremes, as the angular
travel of a thermostatic band is found to be equal for equal increments of
temperature.
The automatic recording of the fact of the given minimum or maximum of
temperature being reached, audible warning of the same is effected electrically.
This we carry out by making the contact of the pin D on the extremity of the
thermostatic band A against either of the indicating arms complete the electrical
circuit between the binding screw E on the said arms and the binding screw K on
the casing. This electrical circuit may then be utilised. to operate a bell or gong
in any known manner, or to visibly record when such a maximum or minimum of
temperature has been reached by known electrical appliances.
In order that the observer may at any time verify the actual temperature, the
travel of the thermostatic band or projecting pin attached thereto operates the
finger M, indicating the actual temperature at any moment.
It is obvious that the relative disposition of the various parts may be varied
without departing from our invention, as for instance the whole of the parts might
be arranged on the face of the dial, and the thermostatic band utilised to make the
electrical contact itself without the use of the projecting pin.
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:-
1st The construction of a thermostatic heat recorder and electrical signal device,
in which a thermostatic band of diverse metals closes an electrical circuit at either
of two adjustable extremes of temperatures through adjustable fingers indicating
the same, and which may or may not have combined with it a finger constantly
recording the actual temperature at any time, substantially as and for the purposes
specified.
2nd In such a thermostatic heat recorder, the employment of two adjustable
arms which remain where fixed, electrical contact being made at a point near to

page_text: their pivot, and an indicating scale being used at their extreme points to record
the alarm temperature, substantially as and for the purposes specified.
3rd In a thermostatic heat recorder, the combination with a thermostatic band
of a freely moving light finger, counter balanced so that it always rests on one side
of the point of the thermostatic band, by which the movement of the thermostatic
band may be multiplied and indicated by the point of the said finger on a suitable
scale, substantially as and for the purposes specified.
..Lני
1712
L 1000
FELL & WILDING,
Agents for the Applicants.