Electric Circuit Closing Devices.
Year: 1899

page_text: Date of Application, 8th June, 1899-Accepted, 22nd July, 1899
COMPLETE SPECIFICATION.
Electric Circuit Closing Devices.
I, FERDINAND WILKE, a Citizen of the United States, residing at No. 210, West
Exchange Street, in the City of Akron, County of Summit, and State of Ohio,
United States of America, Manufacturer, 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:―
My invention relates to means for automatically closing a normally open
electric circuit, and the object of the invention is to provide a circuit closing
device in which there is a separate element which is sensitive to heat and will
yield or surrender when a predetermined degree of temperature has been reached
in the room or place where such device is located, and by yielding to enable or
allow the electrical circuit to be thereupon closed, all substantially as described
and shown and particularly pointed out in the claims.
In the accompanying drawings, Fig. 1 is a central sectional elevation of the
device with the parts in open circuit relation, as occurs normally, and Fig. 2 is
a like elevation with the parts in closed relation as occurs abnormally, all as
hereinafter fully described.
A represents the base of the device which is designed to be attached to the
ceiling or wall of a room or to some other exposed part or place where the
temperature tests are to be taken. The said part A may itself be of insulating
or non-conducting material or a suitable insulation may, be employed between
it and the two contact members 2 and 3 fixed thereto.
The contact member or point 2 may he simply a strip of sheet or plate metal
or the like, such as copper, and in this instance is shown as bent twice at right
angles to bring the upper free terminal portion or end into relation for making
contact by the member 3, in a direction away from or opposite to the base A,
while the member 3 is made of a strip of suitable spring metal, and is so bent
and fashioned that it will exert and maintain as much spring tension or
resistance as the further construction of the device demands, and when
released will at once throw itself into touch with the contact point 2. The
normal and necessary relation of these two parts, therefore, is one of separation,
leaving an open and inoperative circuit.
Over these contact members or points is the cap or housing, C, within which
said points or elements are enclosed and sealed from the outside atmosphere,
and the cap is fastened to the base A through its flange 4 by screws or their
equivalent.
Projecting centrally from said cap, and in this instance integral therewith is
a neck portion 5 having a central axial bore in line with the spring contact
strip 3, and the plunger D extends through this bore, and has its ends pro-.
jecting beyond the bore at both ends to make operative connections at said ends.
This brings the inner end of the plunger to bear directly upon or against the
spring 3, about midway its length, but the bearing is a free one and the two
parts are not fastened together. This also leaves the plunger free to be removed
when occasion requires,

page_text: On the outer extremity of the neck 5 I employ what is shown here as a
three sided bracket E, fastened by nails or screws or otherwise on the end of
said neck, and the outer right angled portion d of the said bracket is preferably
found with a boss or seat opposite the outer end of plunger D, while the said
end of the plunger is formed with a cavity d².
Between the said parts D and E and engaged in said boss and cavity, respec-
tively, is a separate and independent fusible stick or piece, F, of such length
and strength as to raise the bolt D and the spring contact part 3 out of contact, as
in Fig. 1, and to hold said parts in that relation indefinitely and until a
sufficient degree of heat be developed to soften the said stick and cause it to
yield and bend as seen in Fig. 2.
The degree of heat or temperature at which such surrender shall occur depends
entirely on the character of the stick and the needs of the place. In any event this
will be determined by what may be regarded as reasonable precaution or the
danger point of temperature, and in some cases may be as low as say, 75° Fahren-
heit, while in others it may be 200° or upwards. The stick F, therefore, is made
of different degrees of quality in so far as its power of resistance is concerned,
and these are numbered or marked in such way as to denote the kind or quality
they are of. If the device were placed in a private residence as a precaution
against fire the stick might be made to yield, say, at one hundred degrees, or
thereabout, and so on according to circumstances.
It will be noticed that the stick F is wholly exposed outside the device, and that
though it yields or surrenders as seen in Fig. 2, when it is unduly exposed, it
yet holds its place, and if not melted away by a fire it remains there to be
taken out and straightened and used over again the same as before. Or if it should
be destroyed it can readily be replaced by any unskilled person about the house,
even by a child, and without the use of any tool or other means whatsoever.
I have mentioned private residence as a popular place of use for this
device, but it is no less useful in all other places where danger from over-
heating or of fire may occur, and among these places are green-houses, drying
rooms, or dryers of many different kinds for fruit and other purposes, kilns for
burning various articles and where excessive firing cannot be allowed, incubators,
and almost numberless places and uses in which a device of this kind can be
profitably employed.
The wires 6 and 7 run from the battery G, to the contact points 2 and 3, one
of said wires passing through an alarm bell or buzzer, H.
The stick F might in some cases be made of non-fusible material but in that
case mechanical connections or means of some kind would be required to
dislodge it in order to make contact. Such connection might be made with a
closed door or window, so that the alarm would be caused to ring if the door or
window were opened; or the same device with a fusible stick can be connected up
for both automatic and mechanical operation, making it to serve for danger from
heat or fire and also from attempts to steal through a door or the like.
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
1. In a device substantially as described, a suitable base and the contact
members thereon, a cap fixed to said base and having a neck provided with a
central bore from end to end and a bracket fixed to said cap, in combination
with a plunger projecting through said neck at both ends, and a fusible stick
engaged between the outer end of the plunger and the outer portion of said
bracket, substantially as described.
2. The combination of the base and the cap thereon having an outwardly
projecting neck with a bore through its center, a bracket extending beyond the
end of said neck and across the line of said bore, contact points within the cap on
said base, one of which is of spring metal, a plunger through said neck and

page_text: bearing on said spring contact point, and a separate stick engaged at one end by
said plunger and at the other end by said bracket, substantially as described.
3. In an automatic circuit closing device, the parts thereof comprising the
casing, the contact members located in an electric circuit, and means to hold
said members normally apart to keep the circuit open, consisting of a plunger
engaging one of said contact members and a fusible stick bearing against the
outer end of the plunger and exposed outside said casing, substantially as
described.
4. The combination of the casing, the contact members arranged in an electric
circuit, a slidable plunger in the said casing bearing against one of said contact
members and extending out through the casing, a bracket arm across the line of
said plunger and an exposed fusible stick interposed between the plunger and said
arm, substantially as described.
5. The casing and the contact members therein in a normally open circuit,
a plunger supported in said casing with one end arranged to press one of said
contact members out of contact, a fusible member engaging the opposite end
of said plunger and exposed to the outer air and means to hold said fusible
member in operative position against the end of said plunger to keep it depressed,
substantially as described.
Dated at Akron, Ohio this 25th day of May 1899