Year: 1888

page_text: Date of Application, 10th Apr., 1888
Specification Accepted, 22nd June, 1888
A communication from abroad by DANIEL DRAPER, of Hastings on Hudson, New
York, United States of America, Meteorologist.
I, WILLIAM PHILLIPS THOMPSON, F.C.S. M.I.M.E. of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6 Bank Street, Manchester, both in
the County of Lancaster, and 323 High Holborn, in the County of Middlesex, Civil
Engineer, 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 :-
The invention relates to the class of apparatus employed for giving a continuous
record of the variations in temperature occurring at any given point.
The object of the invention is to provide simple and convenient means for giving
a permanent record which will be exposed to view at all times during the period
covered by the record card, and to provide means for automatically giving an alarm
in case the temperature rises or falls beyond predetermined limits.
The apparatus is preferably constructed in substantially the following manner :-
Upon an arbor of a suitable clock-train there is placed a record chart properly divided
into sections corresponding to days and hours, and by concentric circles into degrees
for indicating temperature. A recording pen which is moved by thermostatic strips
rests upon the surface of this chart and inoves toward and from its center as the
temperature increases or decreases. The chart and recording arm are protected by a
glass case capable of being opened conveniently for the purpose of removing the chart
and replacing it; and upon this cover there is fastened a metallic arm which carries
These points are
two contact points extending into the path of the recording arm.
adjustable toward and from the center of the chart, and the plate carrying them is
preferably curved to correspond to the are described by the contact arm, so that the
contact points may easily be adjusted opposite any required degrees of temperature as
marked upon the chart. The recording arm is preferably connected through the frame

page_text: of the machine while the contact points carried upon the curved plate upon the glass
cover are also provided with a binding-post whereby it may be connected with an
electric conductor.
In the accompanying drawing, figure 1 is a front view of the apparatus, figure 2 is
a side view partly in section, figure 3 is a horizontal section, and figure 4 is a plan of
the support for the registering arm.
Referring to the figures, A represents a frame preferably of cast iron for supporting
the various parts. This frame is included in a box B. A suitable clock mechanism Bi
is also contained in the box B. This mechanism is of any convenient character,
preferably an eight-day movement. Upon the arbor of this clock-train which is
arranged to make one revolution in 7 days there is carried a plate C and at the center
of the plate there is a post c upon which there screws a nut 6. A flat pin c¹ projects
from the plate a short distance one side of the center. A chart slips over the
post c and the pine passes through the chart thus preventing it from turning.
Suitable clamps ², c³ and c, at the edges of the plate hold the chart in position.
Curved radial lines d, d, divide the chart into divisions representing the days of the
week, and intermediate lines d', d, divide it into hours. These radial lines are curved
to correspond to the are described by the recording point of carried upon the end of
the recording arm F. Concentric lines e, e, divide the chart into other divisions
serving to indicate different degrees of temperature.
The recording arm F is more or less resilient and presses the recording point lightly
against the surface of the chart. It is carried upon the arbor g supported in a
suitable frame or yoke G at the base of the instrument. This arbor is provided with
two levers Hand H having curved widened faces. These faces are grooved to
receive thin wires or cords and respectively. The wire ' is fastened at one end
to the end of the thermostatic strip K¹ and the end of the wire is fastened to the
end of a thermostatic strip K². The ends of the two strips are so located as to lie in
planes parallel with the points of attachment of the wires to the curved levers. The
other ends of the thermostatic strips are secured to the frame A. The strips are
reversed with reference to each other, so that any change of temperature will tend to
bend one strip toward the arbor and the other strip away from the arbor so that the
two strips combine to move the arbor and thus the recording arm. Any jar which is
given to the machine will be absorbed by the two arms so that no resultant effect will
be manifest upon the recording arm.
The arm Fis preferably loosely mounted upon the arbor 9: but it is provided with
an extension passing between two adjustable set screws f and turning through
lugs in a bracket f, which is rigidly attached to the arbor, and by means of these
screws the position of the recording point with reference to the chart and the
thermostatic strips may be very nicely adjusted.
The levers Hand H2 are preferably also adjustable upon the arbor g being held in
position by the set' screws h³ and h.
For the purpose of giving an alarm in case the temperature exceeds or falls below
any predetermined limits, there is attached to the glass front plate M with which the
case is closed, a curved plate n. This is fastened by studs passing through suitable
holes formed in the glass, and cushioned by washers n¹ and n. The plate n is curved
to correspond with the are described by the recording point and it is provided with a
longitudinal slot m through which there extend two limiting stops p and p². These
are bound in any required position by the nuts and they are respectively provided
with contact pins t¹ and 2, which are preferably of platinum. Platinum points may
also be formed upon the portion of the recording arm F which is opposite the pins, if
desired. By adjusting the pins above the points on the chart, which indicate any
desired limits of temperature, the alarm will be sounded when either of these limits is
reached.
The binding-post P¹ is fastened to one end of the curved plate n and the second
binding post P is fastened to some portion of the frame or case of the instrument, and
these two binding-posts constitute the terminals of any suitable alarm circuit. The
connection from the binding-post P2 to the arun F will be through the frame of the

page_text: machine, the arbor g, also the wires and h² (in case metallic wires are employed),
and thus with the recording arm F. It will be seen that as the alarm plate n is
fastened to the glass plate it will be swung out of the way of the recording arm when
the door is open to replace the chart. Moreover, when the door is closed the
points cannot be reached, so that unwarranted access to the contact points will be
prevented.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed as communicated to me
by my foreign correspondent, I declare that what I claim is :---
1. In a recording thermometer, the combination with a clock movement and a chart
carried thereby, of thermostatic strips, a recording lever actuated thereby, a plate
extending over the chart, and insulated contact-points carried upon said plate and
adjustable by reference to the chart to any desired points thereon, said points
constituting one terminal of an electric circuit, said recording arm constituting the
other terminal.
2. In a recording thermometer, the combination with the recording arm, the
revolving chart and the thermostatic strips for moving the arm with reference to the
chart, of the plate placed in front of said chart and carrying limiting contact stops
adjustable to any desired points in the divisions on the chart, said stops being
designed to constitute the terminals of an electric circuit, substantially as
described.
3. In a recording thermometer, the combination with the recording arm, of the
chart, the limiting stops adjustable with reference to the divisions upon said chart, a
support for said stops, the plate of insulating material carrying the support in front of
the chart, the binding post attached to said support and extending through said plate
whereby electrical connection may be made with the support outside of the plate,
substantially as described.
Dated this Ninth day of Anvil 1000
WM. P. THOMPSON & Co.,
Agents for the Applicant.