IMPROVEMENTS IN LAMPS
Year: 1881

page_text: LETTERS PATENT to Francis Robert Baker, of Birmingham, in the County of
Warwick, Mechanical Engineer, for an Invention of "IMPROVEMENTS IN
LAMPS."
PROVISIONAL SPECIFICATION left by the said Francis Robert Baker at
the Office of the Commissioners of Patents on the 18th June 1881.
FRANCIS ROBERT BAKER, of Birmingham, in the County of Warwick, Mechanical
Engineer. "IMPROVEMENTS IN LAMPS."
My Invention relates principally to lamps for burning volatile oils, which lamps
are provided with a storage reservoir from which oil is raised into a small receptacle
or wick cup, into which wick cup the wicks of the lamp dip oil, rising in the wicks
by capillary attraction. The wick cup requires replenishing from the reservoir
from time to time as the oil in the said wick cup is consumed.
My Invention is howover applicable wholly or in part to lamps for buring
fixed oil.
In such lamps as ordinarily constructed the piston or its packing is made of
leather or vulcanised india rubber. The oil acts injuriously on the leather or india
rubber, and soon renders them more or less inoperative, and the lifting or raising
mechanism ceases to act or acts imperfectly.
My Invention consists, first, of the improvements hereinafter, described in
constructing the pistons of the said lamps, whereby the inconveniences heroinbefore
referred to are obviated.
I make the pistons of the said lamps of the material known in commerce as
vulcanite. I take a circular disc of thin sheet vulcanite, and by means of dies and
a gentle heat I curve or turn inwards the marginal portions of the said disc. This
cupped vulcanite disc I support by means of a disc of metal underneath it, the
cupped vulcauite edge constituting the packing of the piston. A piston of the kind
described is unaffected by the oil, and as the cupped vulcanite disc is constantly
tending to return to the flat disc from which it is made any wear is compensated
for, and the tight working of the piston maintained.
Instead of making the cupped piston of vulcanite it may be made of celluloid.

page_text: My Invention consists, secondly, in constructing the mechanism for raising the
oil from the storage reservoir to the wick dipping cup in the following manner :-
The cylinder in which the piston described works is open at bottom, and is fixed
to the upper part of the storage reservoir.
Underneath the piston is a strong coiled spring, which forces it upwards. The
piston rod passes through a tubular nozzle at the closed top of the cylinder, which
nozzle opens into the bottom of the wick dipping cup. The piston rod is made in
two parts, the lower one fixed to the piston, and the upper part sliding on the lower
part, a weak coiled spring tending to separate them. The lower end of the upper
part of the piston rod has a series of planes made on it for the purpose hereinafter
explained, and the upper end of the said part of the piston rod is made slightly
conical, tapering downwards.
In order to charge the lamp with oil a long quick threaded screw key with n
handle for turning it, is engaged in a screw box in a collar at the head of the lamp.
By driving home the said screw key its end bearing on the top of the piston rod
forces the said piston rod and piston down until the piston, passing out of the
bottom of the cylinder, which is slightly trumped mouthed, permits the oil from
the reservoir to enter and fill, or nearly fill the cylinder. On withdrawing the
screw key the spring under the piston raises the piston into the cylinder, and forces
the oil to the wick cup, any overflow returning to the storage reservoir. As the
piston rod ascends its taper part emerging from the nozzle in which it works leaves
a. gradually increasing space between itself and the nozzle, thus making a passage
for the oil, increasing in size as the strength of the spring diminishes. The planes
formed on the lower end of the upper part of the piston rod permit of the ready
entrance and escape of air in the charging of the lamp, the depression of the upper
part of the piston rod bringing the part having the planes on it into a position
which permits of the ready escapo of the air between the said planes and the
nozzle.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Francis Robert Baker in the Great Seal Patent Office on the
14th December 1881.
FRANCIS ROBERT BAKER, of Birmingham, in the County of Warwick, Mechanical
Engineor. "IMPROVEMENTS IN LAMPS."
My Invention relates principally to lamps for burning volatile oils, which lamps
are provided with a storage reservoir from which oil is raised into a small receptacle
or wick cup, into which wick cup the wicks of the lamp dip, oil rising in the wicks -
by capillary attraction.
The wick cup requires replenishing from the reservoir from time to time as the
oil in the said wick cup is consumed.
My Invention is however applicable wholly or in part to lamps for burning
fixed oil.
In such lamps as ordinarily constructed the piston or its packing is made of
leather or vulcanized india rubber. The oil acts injuriously on the leather or
india rubber, and soon renders them more or less inoperative, and the lifting or
raising mechanism ceases to act or acts imperfectly.
My Invention consists, first, of the improvements herein after described in
constructing the pistons of the said lamps, whereby the inconveniences herein before
referred to are obviated.
I make the pistons of the said lamps of the material known in commerce as
vulcanite. I take a circular disc of thin sheet vulcanite, and by means of dies and
a gentle heat I curvo or turn inwards the marginal portions of the said disc. This
cupped vulcanite disc I support by means of a disc of metal underneath it, the
cupped vulcanite edge constituting the packing of the piston. A piston of the kind
described is unaffected by the oil, and as the cupped vulcanite disc is constantly
tending to return to the flat disc from which it is made, any wear is compensated
for, and the tight working of the piston maintained.
Instead of making the cupped piston of vulcanite it may be made of celluloid.
My Invention consists, secondly, in constructing the mechanism for raising the
oil from the storage reservoir to the wick dipping cup in the following manner :-
The cylinder in which the piston described works is open at bottom, and is fixed
to the upper part of the storage reservoir.
Underneath the piston is a strong coiled spring which forces it upwards. The
piston rod passes through a tubular nozzlo at the closed top of the cylinder, which
nozzle opens into the bottom of the wick dipping cup. The piston rod is made in
two parts, the lower one fixed to the piston and the upper part sliding on the
lower part, a weak coiled spring tending to separate them.
The lower end of the upper part of the piston rod has a series of planes mado on
it for the purpose herein after explained, and the upper end of the said part of the
piston rod is made slightly conical, tapering downwards.
In order to charge the lamp with oil, a long quick threaded screw key with a
handle for turning it is engaged in a screw box in a collar at the head of the lamp.
By driving home the said screw key, its end bearing on the top of the piston rod
forces the said piston rod and piston down until the piston, passing out of the
bottom of the cylinder, which is slightly trumpet mouthed, permits the oil from
the reservoir to enter and fill or nearly fill the cylinder. On withdrawing the
screw key, the spring under the piston raises the piston into the cylinder and forces
the oil to the wick cup, any overflow returning to the storage reservoir. As the
piston rod ascends, its taper part emerging from the nozzlo in which its works leaves
a gradually increasing space between itself and the nozzle, thus making a passage

page_text: for the oil, increasing in size as the strength of the spring diminishes. The planes
formed on the lower end of the upper part of the piston rod permit of the ready
entrance and escape of air in the charging of the lamp, the depression of the upper
part of the piston rod bringing the part having the planes on it into a position which
permits of the ready escape of the air between the said planes and the nozzle.
I will now proceed to describe, with reference to the accompanying Drawing,
the manner in which my Invention is to be performed.
Figures 1 and 2 represent in vertical section a lamp containing my improvements.
In Figure 1, the lamp is represented in tho act of charging the cylinder with oil
from the storage reservoir, the piston and piston rod being held down in their
depressed position; and in Figure 2 the lamp is represented in use, the piston
forcing a continuous supply of oil from the cylinder into the dipping cup, tho
overflow returning to the storage reservoir.
The same letters of reference indicate the same parts in both Figures; a is the
storage reservoir constituting the body of the lamp, and b is the cylinder fixed
concentrically in the upper part of the said reservoir a. The bottom of the
cylinder is open and is slightly conical or trumpet mouthed as represented; c, c², is
the tubular nozzle surmounting the cylinder b and projecting into the hollow
pillar d of the lamp and tubular dipping cup e, in which cup e the wicks of the
lamp dip, the oil rising in the wicks by capillary attraction.
In the said dipping cup e is a lever catch f turning on the centre f", and worked
by the thumb scrow f³ external to the lamp for holding the piston and piston rod
in their depressed position; g, g², is the piston working in the cylinder b and
pressed upwards by the strong coiled spring h. The piston is made of a circular
disc g of thin sheet vulcanite having its marginal portion cupped inwards, the
cupped edges constituting the packing of tho piston, as represented in Figure 2.
The capped vulcanite piston or disc g is supported on the metal base or disc g³, the
cupped vulcanite disc being secured to the middle of tho metal base by means of a
shoulder at the lower part of the piston rod, and an external screw nut taking
upon the projecting end of the piston rod, as seen in Figure 2.
Instead of making the cupped piston g from a flat disc of vulcanite, it may be
made by moulding india rubber in a soft or uncured state, the moulded cupped
disc being afterwards vulcanized or cured in the ordinary way. Or the cupped
piston may be made of celluloid.
The piston rod of the piston / is made in two parts, marked respectively i and k,
the lower part i being fixed to the piston g, g², and the upper part being capable of
sliding in the lower part i, a weak coiled spring tending to separate them (seo
Figure 1). The lower part i of the piston rod does not completely fill the nozzle c,
but an annular space or a series of passages is left between the said parts and also
between the head e' of the nozzle and the upper part k of the piston rod for the
passage of the oil from the cylinder b to the dipping cup c. The lower part i of
the piston rod has a central passage in it (seo Figure 1) which opens at top by
holes m, m, into the dipping cup e, and at bottom (when the two parts of the piston
rod are in their compressed state) by the holes at n (see Figure 1) into the annular
space between the lower part i of the piston rod and the nozzle c. Near the lower
end of the upper part k of the cylindrical piston rod, a series of planes or flats p, p,
is made. These planes or flats, when the compound piston rod i, l, is in its
compressed state, form with the top of the part of the piston rod a series of air
passages, which permit of the air to pass from the nozzle c into the central passage
of the piston rod and to escape at the holes m at top, or to enter the said passages.
By this means air is allowed freely to pass in on depressing the piston, and air to
escape when the cylinder b is being filled. When the two parts of the piston rod are
in their expanded or normal state, as in Figure 2, the planes p, p, on the upper part
of the piston rod are raised above the top of the lower part i of the piston rod, and
the air passages described between the two parts are closed by the cylindrical part
of the rod. The portion at 2 of the upper part of the piston rod is made slightly
conical, tapering downwards as represented. This is for the purpose of increasing

page_text: the size of the oil passage between the summit of the nozzle c and the rod k, as
the strength of the piston spring & diminishes.
9 is the long quick threaded screw key used for charging the cylinder 6 with oil
from the storage reservoir a. the said key has a handle o at top for turning it
(shown detached from Figure 1), and is recessed at bottom for taking upon
the pointed top of the upper part of the compound piston rod. The said screw
key is engaged when in use with a screw box r made in a bar crossing the top of
the dipping cup e. Oil to fill the storage reservoir a is poured into the mouth of
the hollow pillar d. The oil entering the said pillar passes to the bottom thereof
and escapes at the perforations 8, 8, at its base into the storage reservoir a.
The overflow from the dipping cup is returned in the same way to the storage.
reservoir.
In order to charge the cylinder b with oil from the storage reservoir a, the screw
key 7 is introduced into the screw box r and driven down until its end engages
with and depresses the upper part of the piston rod. This motion forces together
the two parts of the piston rod, and compresses the spring between them, as
represented in Figure 1, and thereby makes the side air holes at n in the two parts
coincide, and at the same time brings the planes or flats at p, p, into a position
which permits of the ready entrance and escape of air between the said planes
and the hollow piston rod. The continued descent of the screw key q forces
down the piston rod i, k, (the two parts now moving together) and the piston g, I³,
until the said piston passing out of the bottom of the cylinder b, permits the oil
from the reservoir a to fill or nearly fill the said cylinder, tho parts now occupying
the respective positions represented in Figure 1. In order to hold down the piston
until the lamp is required to be lighted, the lower end of the lever catch f is made
by means of the thumb screw f³ to engage with a shoulder t on the piston rod k,
as seen in Figure 1. A spring may be used to press the lower arm of the lever
catch into its acting position. Having filled the cylinder b and fixed down the
piston, the screw key q is withdrawn, and the burner may lie attached to the lamp.
When it is wished to light the lamp, the lever catch f is removed from the
shoulder t by pressing inwards the upper arm of the said lever catch by the thumb-
scrow into the position represented in Figure 2. The piston g, g², is thereby
released. The upper part of the piston rod now takes its expanded position by
the action of the spring 1, and the air passages are closed. The spring h raises the
piston in its cylinder and forces a continuous supply of oil from the said cylinder
into the dipping cup e through the space between the nozzle c, c², and piston rod i, h,
any overflow of oil from the dipping cup returning to the storago reservoir a in the
manner illustrated in Figure 2. As the piston rod ascends, its taper part
emerging from the summit or top e² of the nozzle e leaves a gradually increasing
space between itself and the said nozzlo, thus making a passage for the oil, increasing
in size as the strength of the piston spring / diminishes.
The piston described and represented may be used with lamps, generally provided
with pistons for forcing the oil into the wick dipping cup.
Having now described the nature of my Invention and the manner in which
the same is to be performed, I wish it to be understood that I claim as my
Invention of "Improvements in Lamps,"
First. The construction of the pistons of such lamps as are provided with storago
reservoirs, from which the oil is forced to a dipping cup by the action of a piston
herein before described and illustrated in the accompanying Drawing, that is to
say, making the piston of vulcanito or celluloid supported upon a metal base, the
vulcanite or celluloid portion of the piston being cupped at its edge, and con
stituting the packing of the piston for the purpose and substantially as described
and illustrated.
Secondly. Constructing the piston rods of the oil forcing pistons of lamps in two
parts, and the combination with the compound piston rod of the tubular nozzle
herein before described and represented in the accompanying Drawing.
Thirdly. The arrangement or combination of parts for permitting of the entrance

page_text: and ready escape of air during the filling of the reservoir and charging of the
cylinder with oil, substantially as herein before described and illustrated in the
accompanying Drawing.
Fourthly. The arrangement or combination of parts for increasing the sizo of
the passage for the oil from the nozzle to the dipping cup as the strength of the
piston spring diminishes herein before described and illustrated in the accompanying
Drawing.
Fifthly. The arrangements or combinations of parts for forcing down the piston
for replenishing the lamp cylinder with oil, and for holding the said piston in its
depressed position prior to use, herein before described and illustrated in the
accompanying Drawing.
Lastly. The general arrangement or combination of the parts of the lamp, herein
before described and illustrated in the accompanying Drawing.
In witness whereof, I, tho said Francis Robert Baker, have hereunto set my
hand and seal, this Twelfth day of December, in the year of our Lord One
thousand eight hundred and eighty one.
Witness,
RICHARD SKERRETT,
37, Temple Street,
Birmingham,
FRANCIS ROBERT BAKER, (L.S.)