Year: 1886

page_text: Date of Application, 1st Oct., 1886
Complete Left, 1st July, 1887.
Complete Accepted, 2nd Aug., 1887
I, CARL GUSTAV HOFFMANN of Leipzig in the Kingdom of Saxony, Germany,
Manufacturer, do hereby declare the nature of this invention to be as follows:-
This invention consists in an apparatus which allows the rise and fall of the
temperature of any place to be observed in some distant locality.
For this purpose an electric indicating apparatus is constructed, the hand of which
automatically indicates on a scale or dial the degree of temperature prevailing at the
respective place, for which purpose it points, as the temperature rises or falls, to the
respective number indicating the degrees.
The invention further consists in an arrangement, by means of which the surpassing
of the lowest or highest admissible temperature (which can be varied at pleasure) is
indicated by a bell. The apparatus is constructed as follows:
In a suitable case is lodged an axle a carrying the hand b. The latter passes over
a graduated are; the case is divided by a wooden wall into two partitions. In one of
these partitions is contained a ratchet wheel arranged loosely on the axle, the pawl
of which is pivoted to the armature of the electromagnet.
Through the coil of the electromagnet passes a permanent electric current, whereby
the armature is attracted. To the nave of the ratchet wheel is fixed a spring which
presses on a milled edge fixed to the axle, so that the ratchet wheel is geared
to the axle.
When the circuit is broken, the armature is released, and the ratchet lever turns
the ratchet wheel for one tooth to the right, which movement is followed by the axle a
with the hand b.
In the second partition is arranged analogous to the first a further ratchet con-
trivance with electromagnet and ratchet lever, with the only difference, that the
current passing through the coils of the electromagnet is a working current of a short
duration. Therefore the armature is released when at rest and is attracted, when the
current is connected, whereby the correspondingly arranged ratchet lever turns the
second ratchet wheel for one tooth to the left. This ratchet wheel is likewise situated
D

page_text: loosely on the axle a and is coupled rigidly with the axle a only at the instant the
circuit is closed by a special automatic coupling consisting of a rod enclosing the
axle and governed by the armature so that on descent of the latter the coupling
is engaged.
1
On the axle is situated a stationary contact disc of ebonite, wood or the like and
provided with as many metal contact plates as degrees are to be indicated, that is to
say as platinum wires are melted into the thermometer. From each of these plates
well insulated wire leads to clips arranged on the partition and from there to the
thermometer, through the platinum wires. The wires are of such a length between
the contact wheel and the partition that this wheel can turn as much as is required in
either direction. Over this contact wheel slide the two contact springs, one being in
constant contact with two contact plates, the other with one of these two, as mentioned
above, from each platinum wire of the thermometer a wire leads to the corresponding
plate of the contact wheel.
When the temperature, for instance, is 50° a galvanic current passes from the
positive pole of the battery through the first magnet coils, from there through the first
contact spring, the metal plate 50, on which the contact spring presses through the
corresponding wire to the platinum wire of the thermometer, which wire is melted in
at 50°, through the quicksilver of the thermometer and back to the negative pole of
the battery. The second contact spring presses for instance on the plate 53.
When the temperature rises to 53°, a current passes from the positive pole of the
battery through the coils of the second magnet, from there to the second contact
spring, through the plate 53, the corresponding wire, to the platinum wire, melted in
at 53° and from there through the quicksilver column back to the negative pole of the
battery. The electromagnet attracts its armature, couples the ratchet wheel with the
axle a and turns both for one tooth to the left. The hand now points to the cipher 53.
At the same time with the axle however the contact wheel, situated stationary on the
axle turns the distance of one plate to the left. Now the contact spring slides on
the plate 55, the second spring on plates 53 and 55. By the spring sliding on two
plates, the circuit of the electromagnet is not disengaged, when the contact wheel
turns to the left; therefore the first ratchet wheel does not turn. The hand carries a
small weak spring, which, when the hand turns, makes contact with metal plates fixed
radially in the dial; these plates are adapted to be connected through a metal plug r
at each degree with a metal arc. When the hand points to the respective plugged degree,
a current passes from the battery through the metal arc, the respective metal plate,
through the hand and the metal parts of the casing, therefrom to a bell action and
back to the battery. When therefore the two admissible highest and lowest degrees
are plugged in, the bell sounds, when these temperatures are attained. To ascertain
the lowest or highest temperature, that has prevailed in the course of the day, two
sinall hands are arranged so as to be taken along by the large hand in different
directions, but do not recede with the same, so that they have to be shifted together
again by hand in the evening and morning.
Dated this 1ot day of Antah 100

page_text: Improvements in Apparatus for Ascertaining the Temperature
in a Distant Locality.
I, CARL GUSTAV HOFFMANN, of Leipzig in the Kingdom of Saxony, Germany,
Manufacturer, do hereby declare the nature of my 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 consists in an apparatus which allows the rise and fall of the
temperature of any place to be observed in some distant locality. For this purpose
an electric indicating apparatus is constructed, the hand of which automatically
indicates on a scale or dial the degree of temperature prevailing at the respective place
for which purpose it is caused to point as the temperature rises or falls, to the
respective number indicating the degrees.
This invention further consists in an arrangement by means of which the passing
of the lowest or highest admissible temperature (which can be varied at pleasure) is
indicated by a bell or audible signal. The apparatus is constructed as follows:
In a suitable case is journalled an axle a, carrying the hand indicator b. The latter
passes over a graduated arc, situated upon (but insulated from) the front wall (Fig. 1)
which may be of wood. The axle à carries a differential gear consisting of the
bevel wheel c and d situated loosely on a and the bevel wheel e adapted to loosely
revolve on its axle e' perpendicular to the axle a. The axle e is rigidly connected
with the axle a and revolves with the same. The toothed wheels k and fare rigidly
connected with the bevel wheel c and the tooth wheels and g with the wheel d. Below
the axle a is journalled a second axle m which carries the spring barrel i¹ with the
spring and the tooth wheel secured to the spring barrel and gearing into the
wheel g
On the axle m is also situated the ratchet wheel h', into which gears a
pawl fixed to the wheel h and carries along the latter in one direction; (Fig. 5)
tooth wheel h gears into the pinion f. The axle m carries a square head or equi-
valent for winding the spring, which is fastened at one end to the axle m and at the
cther to the barrel.
at
The tooth wheel gears into a pinion n' on whose axle n is situated the arresting
lever o (Fig. 6) which is held in its resting position by the stop hook pl revolvable
9. To the hook p¹ is connected the arm provided with a slot in which lies a pin
attached to the arm . The latter is situated on the armature of the electro
magnets. Through the coils of the electro-magnet circulates a constant current,
whereby the armatures' is attracted and secures the parts p₁ and p³ in its resting
position. The stop lever o may have two wings and be provided with two pins of
which catch at each balf revolution of o under the nose of the hook p² and slightly
raise the same.
The tooth wheel k gears into the pinion t, on the axle t' of which is
situated the stop-lever u (Fig. 5). The latter is held fast by the abutment pivoted
at w and connected to the arm v¹ embracing by means of a slit the pin of the armature

page_text: lever. This lever is secured to the armature x¹ of the electro magnet x.
The stop
lever u has two wings and carries two pins u¹ which on each half revolution (like the
pins o¹¹ but independently of these) slightly press down the lever ³ revolvable
about w.
.
Each of the shafts t¹ and n carries larger tooth-wheels t' which gear into pinions
whose axles are provided with wings or other means t³ (Fig. 2) for regulating the
velocities.
When for instance the circuit passing through the coils of the electro-magnets, is
interrupted (Fig. 6) the armatures is raised by spring s³. The armature lever³
raises likewise the arm r, which withdraws the hook p¹ connected with r.
The stop-
lever o is thereby freed and driven by the spring by means of the wheels i gl and n¹
completes a half revolution. Thereby one of the pins o¹ raises the part p³, which
carries back the parts pr² and the armature s' and the latter is held fast by the-
current which has meanwhile been again closed. Thereby however also the bevel
wheeld has been revolved and as the wheel k was arrested, the wheel e will have
rolled upon the same and turned the axle a in the direction indicated by an arrow (in
full lines).
When however the circuit is completed for a moment, in which are contained the
coils of the electro magnet, the latter attracts its armature x¹ (Fig. 5) whereby the
armature-lever a lowers the arm v¹ but raises the part v.
The stop lever u is released and makes a half revolution by means of the wheels hfk
and t and driven by the spring. During this movement one of the pins u¹ of the
lever u lifts the lever v2 and the pin of the latter presses the part v down again for
arresting u, raising at the same the parts and armature x by means of the
withdrawing spring ³.
The bevel wheel c has now been moved, while the wheel d stands still. Wheel e
therefore rolls upon the wheel d and revolves the axle a in the direction indicated
by dotted arrows.
These two circuits are completed and broken automatically by a contact cylinder A
(Figs. 2-4). This contact cylinder is rigidly coupled with the axle a and revolves
with the same. It is provided with as many metal rings z, insulated from one
another, as degrees of temperature are to be indicated, that is to say, as there are
platinum wires melted into the thermometer. Each metal ring z carries at one point
of its circumference a metal tooth. These rings z are so fastened on the shaft, that
their teeth stand placed in a half spiral round the whole cylinder (Figs. 2 and 3) so
that the sliding plates y y¹ situated thereover, come in contact successively with each
tooth on the revolution of the contact cylinder, and make contact with the same.
Upon each metal ring slides from below a contact spring z¹ which is connected with
the corresponding platinum wire of the thermometer. The slide plates y y! are
lightly pressed onto the nozzles of the rings by springs 2. These springs z² are
provided with wires which conduct the current away.
The mode of working of the whole apparatus may be seen from the diagram
Fig. 7.
As mentioned above a wire leads from each platinum wire of the thermometer to a
spring Zand the corresponding metal ring Z of the contact cylinder A from
degree 48 to the metal ring 48 from degree 50 to metal ring 50 and so on. If the
temperature is for instance 58° (Fig. 7) a galvanic current passes from the positive
pole of the battery B to the slide plate y, through the tooth of the respective metal
ring Z (58) through the slide spring Z' appertaining thereto, the respective lead to the
platinum-wire melted in at 58° through the mercury-column of the thermometer from
there through one of the return leads to the coils of the electro-magnet s and back to
the negative pole of the battery B.
The armature S of the electro-magnet is therefore attracted. The slide plate y¹
slides on the tooth of the metal ring z (60). When the temperature rises to degree 60,
a galvanic current passes from the positive pole of the battery B₁ through slide
sheet y¹ the tooth of the metal ring (60) the respective spring 21 and the conducting
wire to the degree 60 of the thermometer; hence through the said return lead to the

page_text: coils of the electro-magnet and to the negative pole of the battery B¹. The electro-
magnet attracts its armature the stop lever u (Fig. 5) is disengaged and the
axle a revolves with hand b and contact cylinder A in the above described manner for
one division the direction of the dotted arrow (in Fig. 7 feathered arrow). The hand
points therefore to the number 60°. As also the contact cylinder A revolves for one
division, the slide plate y now slides onto the nozzles of the metal ring z (60),
y however onto (62). Thereby the circuit of the electro-magnet x is broken and
the armature x is retracted by spring.
When now the temperature falls below 60° the circuit of the electro magnets is
interrupted (since the tooth of the metal ring 60 has no longer any current) and the
armature s¹ is withdrawn by spring s³.
The stop lever o is released thereby (Fig. 6) as above described, and the axle a is
revolved for one division in the direction of the fully drawn or of the unfeathered
arrow (Fig. 7). The hand bis thereby returned to the number 58, the contact cylinder A
revolves likewise and now the slide plate y slides onto the tooth of the metal
ring Z (58) y on Z (60). The current passes through degree 58 and through the
tooth of the metal ring Z (58) and consequently the electro-magnets again attracts
its armature s¹ until the temperature next falls. It is obvious that this change is
effected at each degree, at which a platinum wire melted into the thermometer. The
hand b carries a small weak spring which when the hand turns makes contact with
metal plates fixed radially on the dial, these plates are adapted to be connected
through a metal plug 63 at each degree with an insulated metal are 6. When the
hand points to the respective plugged degree, a current passes from the battery B¹
through the metal parts of the work to the hand 6 through spring b², the respective
metal plate 6, plug 63, ring 64, to a bell action G and back to the battery B. The
bell G therefore sounds, when these temperatures are attained. To ascertain the
lowest or highest temperature, that has prevailed in the course of the day, two small
hands a and B are arranged so as to be taken along by the large hand b in different
directions, but not recede with the same, so that they have to be shifted together again
by hand in the evening or morning.
By means of this apparatus it is also rendered possible to make a record of tem-
perature from a distant place. For this purpose a toothed or friction wheel is to be
arranged on the axle a, which wheel moves at each rotation horizontally, a toothed
or friction rod, which is furnished with a writing pencil. This pencil writes on a paper
advanced by a clockwork in a given time for a certain distance and provided with
divisions in the known manner.
On this paper, a broken line is marked, which indicates the variations of
temperature.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is :-
To allow the temperature in a distant place to be ascertained, an electro-magnetic
hand or dial-work consisting in the combination of the axle a having hand b and
operated by differential gear c, e, d; electro-magnets and adapted to hold and to
release the said gears c or d; and a contact cylinder A constituted substantially as
described, the whole operating together as and for the purpose set forth.