Improvements in Electrical Alarm Devices for Steam and other Pressure Gauges.
Year: 1895

page_text: Date of Application, 28th June, 1895-Accepted, 17th Aug., 1895
[Communicated from abroad by WILLIAM HENRY BRADT, of No. 415 Tenth
Street, and MELVILLE MARBLE, of No. 1513 Fifth Avenue, both in Troy.
New York, United States of America, Engineers.]
Improvements in Electrical Alarm Devices for Steam and other
Pressure Gauges.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 :-
This invention relates to electrical alarm devices for use in steam and other
pressure gauges and is illustrated in the accompanying drawing in which
Fig. 1 of the drawing is a plan view of the face of a gauge provided with the
improved circuit-closing mechanism.
Fig. 2 is a cross-section of same taken on the broken line 2-2, in Fig. 1.
The object of the invention is to provide a circuit-closing mechanism for
electrical alarm gauges which can be easily applied to known forms of pressure
and like gauges, and which can he easily adjusted to automatically close the
alarm-circuit when the gauge-pressure reaches any predetermined degree, high
or low.
A is the case-wall of the gauge which supports the operating mechanism, not
shown. A is the dial supported by the case. and A2 the index fixed upon the
shaft A. The mechanism for operating the index may be of any known form.
B is the cap or cover for the gange, comprising a metal rim B₁ and a glass B
together inclosing the dial and index. The cap is mounted upon the case-wall and
is free to rotate thereon.
C is a contact forming one of the circuit-closing electrodes of the device, fixed
upon and movable with the rim B' of the cap.
The contact projects through an aperture in the rim interiorly of the gauge
between the dial and the glass of the cap, and is insulated from the rim by the
washer B3 of rubber or other insulating material interposed between the offset
attaching end C' of the contact and the rim of the cap.
A binding-post D secured by its attaching-shank D' to the rim in connection
with the contact C affords a means for connecting the contact with one of the
battery-wires F. The binding-post is insulated from the rim by the insulating
washers B, B, the attaching-screw B passing through both washers and an
enlarged opening in the attaching-shank of the binding-post, the head of the screw
bearing upon the washer B'.
The inner end of the contact C is offset at C² into the path of the index A².
A narrow strip C³ of insulating material is secured to the under side of the
contact to insulate the same from the case-wall.
The index forms the other contact or electrode of the circuit-closing mechanism,
and may be connected with the other battery-wire F1 by means of the binding-
post D fixed upon the case-wall at any convenient point, the gauge-case and
intervening gauge-mechanism forming au electrical connection between the index
and such binding-post.

page_text: The wires F and F' form part of an alarm-circuit comprising a battery and an
electro-magnetic alarm-bell, not shown, which may be of any known form.
When the gauge-mechanism has imparted sufficient movement to the index, the
latter engages the contact C thereby closing the battery-circuit and operating the
alarm device in such circuit.
The cap being rotary upon the gauge-case, and the contact C being secured to
the cap, the contact can be adjustably located at any point in the path of the index
by rotating the cap.
The contact may be insulated from the index in any known manner.
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 correspondents, I declare that what I claim is:
In an electrical alarm-gauge, the combination with the index, of a cap having a
rotary perforated rim, a contact insulated from such rim and fixed thereon to
project through the rim-aperture into the path of the index, and means for
connecting the index and contact with the battery-wires, substantially as described.
Dated this 28th day of June 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.