Improvements in Magnesium Flash Light Apparatus.
Year: 1892

page_text: Date of Application, 28th Mar., 1892-Accepted, 30th Apr., 1892
COMPLETE SPECIFICATION.
Improvements in Magnesium Flash Light Apparatus.
1, HERBERT JOHN HADDAN of the firm of Herbert & Co. 18 Buckingham Street
Strand London W.C., Patent Agents do hereby declare the nature of this inven-
tion a communication to me from abroad by Eliza Beste of Weimar, in the Empire
of Germany 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 a lamp or device for producing a magnesium flash light
for use in photography, in which the magnesium powder is fed to the charge
chamber from a reservoir, by means of a spirally fluted shaft resembling a spiral
drill, and is blown from the charge chamber through the flame by means of a
compressed charge of air-gas.
In the annexed drawing
Fig. 1 shows the improved flash lamp in section, Fig. 2 is a front elevation
thereof partly in section and Fig. 3 is a sectional plan view.
a is the charge chamber or space into which the magnesium powder is fed through
a slits in the tube and from which it is blown through the passage b to the
orifice to pass through the flame. The tube contains a spirally fluted shaft w
which resembles a drill, its forward end projects into the base of the powder
reservoirt and near its rear end it is provided with a collar w' to prevent endwise
movement in the tube r.
For small apparatus the shaft w may be revolved by hand, but for automatically
working lamps of a larger sort, it may be revolved by a suitable motor through
bevelled gear i from the shaft y.
The revolution of the shaft we causes the powder to be forwarded along the spiral
groove and to fall out at the slit which is the only outlet and is of narrow width.
The grooves in the shaft become quickly filled with the powder since but little
falls from the slits, afterwards the charge falling from the slit is proportional to
the number of turns given to the shaft w. Since a certain amount of the powder
is carried along in the grooves beyond the slits and it is of importance that the
powder shall not become so choked as to prevent the shaft w from being turned,
the length of shaft w beyond the slit s is made with also a counter spiral or reversed
spiral groove n to carry back the powder as far as the slit s.
The necessary blast of gas for propelling the powder through the flame and
igniting the former, is obtained by drawing in the gas from the pipe m through the
valve by means of the piston k in the cylinder, which piston is drawn down by
a piston rod either by the operator at the time the photograph is about to be taken
or by the aforesaid motor if the lamp is to act automatically. When the piston
reaches the bottom of its stroke the piston is released and the spring forces the
piston upward compressing the charge of gas in the cylinder until the pressure is
sufficient to overcome the pressure of the spring a on the valve u, whereupon the
latter valve opens and the charge of gas passes at a into the powder charge
chamber a and carries the powder therein with it through the passage b to the
orifice where the mixture is ignited in the form of a substantially instantaneous
flash by passing through the flame f.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is ;-
1) In a magnesium flash light lamp or apparatus, the combination of the
chamber a through which a blast of 100-
1

page_text: containing a spirally fluted shaft w substantially as described, communicating with
said chamber by a slit s.
2) In a magnesium flash light lamp or apparatus, the combination of the
chamber a with lateral slit s for filling, the piston & in the cylinder, the spring,
gas feed pipe with valve r, and outlet passages with valve u, passage b and orifice b¹
whereby the compressed charge of gas may be obtained and utilized for the purpose
specified.
Dated this 28th day of March 1892.
HERBERT & Co.,
Agents to Applicant.