Improved Portable Incandescent Electric Safety Lamp.
Year: 1888

page_text: Date of Application, 25th May, 1888
Complete Specification Left; 1st Sept., 1888
Complete Specification Accepted, 29th Jan., 1889
Improved Portable Incandescent Electric Safety Lamp.
I THEOPHILUS COAD, of 10 Thorp Terrace, Forest Gate, Essex, Electrician do
hereby declare the nature of this invention to be as follows:-
The principal objects of this invention is to prevent ignition of gases by the
contact spark, and to protect the glass of the lamp from being broken.
In carrying out the above the lamp is hermetically sealed in a glass envelope, to
the latter is connected a flexible disc through which the wires from battery pass.
The contact is made by the points of the wires meeting other points and within a
small gas tight chamber. The flexible disc is operated either by atmospheric pressure
by exhausting the interior of envelope, which for this purpose is fitted with suitable
valve; or by a pressure of air within envelope, when the disc is extended by such
pressure the contact is made any cause which removes the pressure immediately
causes the circuit to be broken.
The lamp holder is insulated from the metallic portion of the case, springs are
attached to the loops of the lamp which pass through an opening in the holder, one.
being attached to the same the other to the flexible disc, by which means the lamp
is securely held and the springs form a path for the current. Two flexible springs
are attached to the battery case to which are connected the poles of the battery and
when the lamp is in position, the poles of the lamp are in contact with the aforesaid
springs thus completing the circuit. On front of the glass envelope an intensifying
lens may be used to concentrate and focus the light.
FREDERIC PRINCE,
Agent for Applicant.

page_text: performed to be particularly described and ascertained in and by the following
statement :-
In the safety lamp according to this invention the incandescent lamp is arranged
within a hermetically sealed glass envelope which if broken, without necessarily
breaking the lamp will immediately break the circnit of the current and so extinguish
the lamp; such a lamp holding arrangement being attached and electrically connected
to a suitable battery. To enable my invention to be properly understood I will, with
aid of the accompanying drawings proceed to fully describe it.
DESCRIPTION OF THE DRAWINGS.
Figure 1, front view of proposed form of battery without lamp holding
arrangement.
.
Figure 2, partial plan of same at line X Y figure 3.
Figure 3, sectional elevation of battery and lamp holding arrangement as attached.
Figure 4, front view of lamp holding arrangement.
Figure 5, underneath view of fig. 4.
Figure 6, sectional view at line X', Y' figure 5.
A, the battery case preferably made of vulcanite divided by partitions B into six
cells; C, the contact points connected to outside flat brass leads C' C³, terminating
with spring ends C³, C; D, projecting boss on front of battery for attachment by
screws of lamp holding arrangement. This consists of a metal base E, with flange E¹,
for securing to battery, and a flange E³, for holding the glass envelope F. In the
middle of the base E, is a flexible diaphragm G held hermetically tight: to this
diaphragm one of the spring connections for the lamp is attached or electrically
connected which makes contact with the head I, of stem I', when the diaphragm
is sufficiently depressed to complete the circuit. This depression is effected by a
pressure of air within the envelope F, introduced by an air pump through the
passage J, which is closed by a spring valve K, which admits the introduction of air
but prevents its exit. The projecting part of stem I, bears against the spring
contact C. To enable the circuit to be made and broken as desired the base EĘ is
fitted on the underside with a switch arrangement L, consisting of an eccentrically
held piece of vulcanite attached to a stem turned from the outside which depresses
the contact spring (*. The other spring connection for the lamp is attached to the
lamp support M, which is placed in contact with the spring part C³, of lead C", by
the peg N. The stem I and the peg N, are both insulated from the base E, by
vulcanite Q.

page_text: It will be readily understood that in place of the pressure of air within envelope F
the diaphragm could be moved to make and break circuit by creating a vacuum
within the envelope F but such is not so convenient as to operate the diaphragm by a
pressure within envelope as has been described.
The cover of the battery is secured by hinged bolts P, fitted with thumb nut Q;
R, band of leather to carry the lamp by.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what
I claim is.
A portable electric lamp for miners, consisting of the combination of a suitable
battery, and the base E provided with contact points and fitted with a hermetically
sealed glass envelope, within which is arranged a spring closing inlet air valve to
enable the envelope to be charged with compressed air and retain same, an incandescent
lamp holder electrically connected to one pole of the battery, and having one of the
connections for the lamp attached, and a diaphragm, having the other connection for
the lamp attached or electrically connected thereto, normally not in circuit, but so as
to complete the circuit on the depression of the diaphragm, all as described.
Dated this 1st day of September 1888.
FREDERIC PRINCE,
1, Quality Court, Chancery Lane, W.C.,
Agent for Applicant.
FREDERIC PRINCE,
1, Quality Court, Chancery Lane, W.C.,
Agent for Applicant.

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883) as allowed by.
the decision of the Comptroller General of the 3rd day of February, 1899.
1, THEOPHILUS COAD, of 10, Thorp Terrace, Forest Gate, Essex, Electrician, do
hereby declare the nature of this invention to be as follows:-
The principal objects of this invention is to prevent ignition of gases by the contact
spark, and to protect the glass of the lamp from being broken.
The
In carrying out the above the lamp is hermetically sealed in a glass envelope, to
the latter is connected a flexible disc through which the wires from battery pass.
contact is made by the points of the wires meeting other points and within a small
gas tight chamber.
The flexible disc is operated either by atmospheric pressure by
exhausting the interior of envelope, which for this purpose is fitted with suitable
valve; or by a pressure of air within envelope. When the disc is extended by such:
pressure the contact is inade: any cause which removes the pressure immediately
causes the circuit to be broken.
The lamp holder is insulated from the metallic portion of the case, springs are
attached to the loops of the lamp which pass through an opening in the holder, one
being attached to the same the other to the flexible disc, by which means the lamp is:
securely held and the-springs form a path for the current,
Two flexible springs are attached to the battery case to which are connected the
poles of the battery and when the lanp is in position the poles of the lamp are in
contact with the aforesaid springs thus completing the circuit. On front of the glass
envelope an intensifying lens may be used to concentrate and focus the light.
Dated this 25th day of May 1888
FREDERIC PRINCE,
Agent for Applicant.

page_text: performed, to be particularly described and ascertained in and by the following
statement:-
In the safety lamp according to this invention the incandescent lamp is arranged
within a hermetically sealed glass envelope which if broken, without necessarily
breaking the lamp will immediately break the circuit of the current and so extin-
guish the lamp; such a lamp holding arrangement being attached and electrically
connected to a suitable battery.
To enable my invention to be properly understood I will, with aid of the accom-
panying drawings proceed to fully describe it.
шень.
Figure 2, partial plan of same at line X Y Figure 3.
Figure 3, sectional elevation of battery and lamp holding arrangement as
attached.
Figure 4, front view of lamp holding arrangement.
Figure 5, underneath view of Figure 4.
Figure 6, sectional view at line X, Y¹ Figure 5.
A, the battery case preferably made of vulcanite divided by partitions B into six
cells; C, the contact points connected to outside flat brass leads CC, terminating
with spring ends C³, C; D, projecting boss on front of battery for attachment by
screws of lamp holding arrangement. This consists of a metal base E, with flange E¹,
for securing to battery, and a flange E², for holding the glass envelope 1. In the
middle of the base E, is a flexible diaphragm Gheld hermetically tight to this
diaphragm one of the spring connections for the lamp is attached or electrically con-
nected which makes contact with the head I, of stein 11, when the diaphragm is
sufficiently depressed to complete the circuit. This depression is effected by a
pressure of air within the envelope F, introduced by an air pump through the
passage J, which is closed by a spring valve K, which adınits the introduction of
air but prevents its exit. The projecting part of stem 1', bears against the spring
contact C. To enable the circuit to be made and broken us desired the base E
is fitted on the underside with a switch arrangement I, consisting of an eccen-
trically held piece of vulcanite attached to a stem turned from the outside which
depresses the contact spring C. The other spring connection for the lamp is
attached to the lamp support M, which is placed in contact with the spring
part C3, of lead C, by the peg N. The stem I and the peg N, are both
insulated from the base E, by vulcanite O.
It will be readily understood that in place of the pressure of air within envelope F
the diaphragm could be moved to make and break circuit by creating a vacuum
within the envelope F but such is not so convenient as to operate the diaphragm by
a pressure within envelope as has been described.
The cover of the battery is secured by hinged bolts P, fitted with thumb nut Q;
R, band of leather to carry the lamp by.
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 :-
A portable electric lamp for miners, consisting of the combination of a suitable
battery, and the base E provided with contact points and fitted with a hermetically
sealed glass envelope, within which is arranged a spring closing inlet air valve to
enable the envelope to be charged with compressed air and retain same, an incandes-
cent lamp holder electrically connected to one pole of the battery, and having one
of the connections for the lamp attached, and a diaphragın, having the other con-

page_text: nection for the lamp attached or electrically connected thereto, not in circuit when
the diaphragm is in a raised position but so as to complete the circuit on the
depression of the diaphragm, all as described.
Dated this 1st day of September 1888.
FREDERIC PRINCE,
1, Quality Court, Chancery Lane, W.C., Agent for Applicant.