A New or Improved Form of Apparatus suitable for Lighthouses and the like.
Year: 1898

page_text: Date of Application, 30th Dec., 1898-Accepted, 16th Dec., 1899
COMPLETE DIDUIFICATION.
A New or Improved Form of Apparatus suitable for Lighthouses
and the like.
I, JOHN ARCHIBALD PURVES, Bachelor of Science and Fellow of the Royal
Society of Edinburgh, of 53, York Place, Edinburgh, Scotland, Civil Engineer,
do hereby declare the nature of my invention and in what manner the same
18 to be performed to be particularly described and ascertained in and by the
following statement:—
My invention relates to a new or improved form of apparatus suitable for
lighthouses and the like whereby certain advantages are obtained
In order that my invention may be more clearly understood I have illustrated
one form of my invention in the accompanying diawings
Figure 1 is a sectional elevation
Figure 2 18 a plan
Figure 3 18 an elevation looking upon the face of the panel
Figures and 5 are sectional elevations of two other forms of my invention
Figure 5 represents a double apparatus of the same type as that shown in
Figure 1
In the drawings A is the dioptic apparatus.
B and C are spindles or bearings
D is the lamp, d the chimney, the outer chimney, D¹ the cowl or ventilator,
E the eclipse, F the pivot upon which the upper eclipse works, G the large
external toothed wheel, H the small toothed wheel which gears with G, I a
train of wheels communicating with the cam 1, K the reflector, L the pipe for
oil supply, L' the constant level oil cistein, M the wheel attached to the lower
part of the apparatus, N the wheel gearing with M, O the machine which which
actuates N In Figures 3, 4 and 5 1 represents the case containing the machine
for actuating the eclipse which in these figures is of the up-and-down type.
My invention 18 as follows
A dioptric or other light duecting apparatus is employed such as that repre-
sented by A in the accompanying drawings, and it is preferable to make this
dioptric or other light directing apparatus of maximum dimensions, that 18
to say in the case of the usual dioptric apparatus, a single panel subtending at
its focus 180 degrees in azimuth, and 180 degrees in altitude as nearly as possible.
In Figure 4 two panels of 180 degrees are employed and in this aangement
the luminary may be fixed relative to the apparatus The glass-work of the
panels is kept in place by the usual gun-metal or other settings Now instead
of placing such a panel or panels upon a revolving cainage, as has been done
in the past, we affix to the upper and lower points of this panel or panels as
in Figure 4 superior and inferior spindle anlangements, such as are represented
in the drawings at B and C The spindles may be used in conjunction with
ball, roller or other bearings We now cause in the case of the first illustrated
apparatus the panel A along with the lamp 1) and its accessories, eclipser E and
its accessories, reflector K and cistern L' with its accessories, to revolve around
the imaginary axial line B C In order to communicate this rotary motion.
we make use of a machine O driven by suitable power, such as a falling weight
or spring which drives the wheel N which gears with the wheel M affixed to
the lower part of the apparatus.

page_text: The mechanism of machine 0 18 not shown as it may be of any of the well
known types already used in lighthouse work
The lamp D is in the first form illustrated one of the usual type It differs
however in this respect from these that it is provided with an outer cylindrical
chimney in addition to the usual chimney d. d¹ being surmounted by the
ventilating cowl I) which is necessary on account of the rotation of the lamp
round the axis B C. The lamp D 18 supplied with oil in the first place from
the constant level cistein L', while this cistein in the second place is supplied
by a pipe which leads to the top spindle which is made hollow to admit of the
passage of oil
In conjunction with lamp and revolving dioptric apparatus we employ an eclip-
sei E. The form of eclipser in the diawings consists of a semi-cylinder of sheet
metal or other suitable material silvered so as to act as a reflector and pivoted
at F, and capable of evolving about F so as to block out all light from the lamp
in the direction of the dioptric apparatus It will be seen that both the reflector K
and eclipsei act as light strengthening agents. This eclipser 18 worked inter-
mittently by the cam , wheel tiain I, internal wheel H, and external wheel G.
The external wheel G is fixed with reference to the evolving apparatus so that
when the apparatus is revolved by the machine O and wheels M and N, the
wheel H 18 set in motion thereby actuating the cam > In the case illustrated
in Figure 4 the eclipser 18 of the vertical type. The method of actuating an
eclipse is well known and does not form a part of this invention
It will now be seen that by such an arrangement as that just described and
illustrated in Figures 1 to 3 of the diawings, we have a means whereby through
the use of a single dioptric panel supported by spindles at top and bottom along
with the eclipser device we can produce a species of group-flashing light more
powerful than has yet been possible, and with characteristics far more varied
should this be desired
At
Suppose for example that we desue a tuple flashing light. We start the
apparatus with the eclipser E behind the lamp, and the apparatus then revolves
through three complete tuins, thus producing a group of three flashes.
the end of this period the cam which has been slowly actuated through the
chain of wheels I, releases a catch fixed to the foot of the eclipser which then
flies 1ound and occupies the position E¹ (The eclipser E constantly tends to
1otate in the opposite direction from that of the apparatus under the influence
of a spring) The eclipser E then remains in the position E¹, in which position
all light is cut off from the dioptic apparatus for a certain period of time.
This period constitutes the dark interval between the groups of flashes, and
at the end of this period the eclipser is again released by the action of the cam
and again occupies the position E, and so on
It is clear that any form of dioptric catadioptric or other arrangement which
will serve to diect the beam emitted by the lamp into the desired direction
can be employed, and it is further clear that other forms of illuminant as well
as the ordinary oil-lamp are equally applicable The eclipsing device may also
be of any form which will put out or eclipse the light and instead of encircling
the lamp it may be made to encircle and to rotate outside of the apparatus itself.
It may moreover be actuated by a separate mechanism from that which causes
the revolution of the apparatus. The eclipsing device may also consist of a
means whereby the source of the luminary can be cut off, such for example as
the turning off of gas or electric current
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:
Firstly The employment of any eclipsing or shutting-off device in conjunction
with a revolving spindle apparatus substantially as set forth
Secondly The employment of a spindle, spindles or the like with or without

page_text: ball, roller or other bearings affixed to a dioptric panel, panels or other light-
duecting agents by means of which such light-directing agents may be made
to revolve about an axis passing vertically through the spindle, spindles on the
liko.
Thirdly. The employment of a spindle, spindles or the like with or without
ball, 1oller or other bearings affixed to a dioptric panel, panels or other light-
directing agents by means of which such light directing agents may be made
to revolve about an axis passing vertically through the spindle, spindles on the
like, in conjunction with a luminary which forms an integral part with the light
directing apparatus, and consequently revolves with it along with a reflecting
arrangement if necessary, or in conjunction with a luminary which is stationary
o1 revolves axially with the apparatus.
Fifthly The method of and apparatus for producing flashing or group-flashing
lights substantially as set forth.
Tlated than 20th
Janecombau 1000
JOHN A. PURVES,
53, York Place, Edinburgh.