IMPROVEMENTS IN AUTOMATIC LUBRICATORS
Year: 1879

page_text: LETTERS PATENT to Frank Wirth, of the Firm of Wirth and Company,
Patent Solicitors, at Frankfort on the Main, in the Empire of Germany, for
the Invention of "IMPROVEMENTS IN AUTOMATIC LUBRICATORS." A communi-
cation from Joseph Patrick, Engineer, of Frankfort on the Main, in the
Empire of Germany.
Sealed the 28th October 1879, and dated the 24th July 1879.
PROVISIONAL SPECIFICATION left by the said Frank Wirth at the Office
of the Commissioners of Patents on the 24th July 1879.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany. "IMPROVEMENTS IN AUTOMATIC
LUBRICATORS." A communication from Joseph Patrick, Engineer, of Frankfort on
the Main, in the Empire of Germany.
In this apparatus I make use of the differential expansion of two different kinds
of metal when exposed to one and the same temperature to effect a passage for the
oil or other lubricant or fluid.
In carrying the said Invention into practice I construct the apparatus as follows,
that is to say-I provide a small bar of steel furnished with a conical head and
with a screw thread at its lower end, by which it is screwed into an interior oil
cup, the said conical head plugging the hole in the bottom of the said cup. It will
thus be seen that as steel expands much less than gun metal, of which the apparatus
is chiefly made, the tube shaped end with which the cup is provided in expanding
and thus becoming longer will carry the said steel bar downwards with it, and
leave a very small opening between the conical head and its scat, through which
the oil passes. The apparatus being attached to a steam engine and the pressure of
steam being equal above and below the oil, except at the moment when the piston
momentarily closes the passage to the cylinder, when the steam in the upper part
of the apparatus has more time to expand than that in the lower, it forces a small
quantity of oil through. During all other times the oil will continuously but
slowly pass through partly by its own weight, partly by the affinity which grease
has for metals, and partly by capillary attraction.

page_text: It will be understood that the tighter the said steel bar is screwed in and locked
by the nut provided for the purpose at a normal temperature, the less oil will pass
out when the apparatus is heated and in use, and vice versa. When the machine
with which the said lubricator is connected stops working, the metals contract, and
the supply of oil is stopped. A sieve is provided and is secured by a nut. This
sieve prevents any grit or the like entering the seat of the conical head. Fine holes
are made to prevent any condensed steam getting into the oil. The inner cup hangs
within the outer one by a rim; the apparatus is filled at the top and attached to
the engine at the lower part of the apparatus.
The steel bar can be inserted from below or above.
I do not confine myself to the precise details of construction above described as it
will be obvious that an apparatus embodying the chief novel feature of my Inven-
tion may be constructed in various manners.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by.
the said Frank. Wirth in the Great Seal Patent Office on the 7th November
1879.
FRANK WIRTH, of the Firm of Wirth and Company, Patent Solicitors, at
Frankfort-on-the-Main, in the Empire of Germany. "IMPROVEMENTS IN AUTOMATIC
LUBRICATORS." A communication from Joseph Patrick, Engineer, of Frankfort-on-
the-Main, in the Empire of Germany.
My Invention relates to apparatus wherein the differential expansion of metals
when heated is utilized to effect a communication between the oil reservoir and the
chamber into which the oil is to be introduced. I thus produce an automatic
lubricator, which has no taps, valves, wick, springs, or similar movable parts, and
which will not be subject to wear out or fail to operate.
It will at once be obvious that different metals can be used for this purpose, and
that the said lubricators can be made of various sizes and shapes.
The metals I have found advantageous to use are gun metal and steel. The
shape and general arrangement of the apparatus which I have found to answer in
practice is represented in the accompanying Drawing, wherein two lubricators are
shewn partly in elevation and partly in section, like parts heing indicated by the
same letters in both Figures.
The lubricator represented in Figure 1 consists of an outer gun metal cup A, in
which a second gun metal cup B hangs by a conical rim K. The latter is drilled
through at b to connect the space between the cups A and B with the inside of the
cup B, and thus equalize the pressure or vacuum as the case may be. The two
cups are held tightly, the one within the other, and a steam tight joint is effected by
a lid F, which is provided with an air tight compartment J, serving to prevent con-
densation in lubricators which are much exposed as on locomotives and the like.
The lid F has a hole G in its centre, through which the apparatus is filled; a screw
cap H fits on the lid F, closing the hole G.
The bottom of the cup B has a hole bored through, into the upper conical end of
which the conical point of a steel plug C fits, the said plug being carried by a tube E
cast in one piece with the cup B. The plug C is screwed into the tube E, and can
be adjusted as required. A strainer L is provided to stop any impurities which
may have entered the apparatus.
It will thus be seen that as soon as the said apparatus becomes warm the steel
plug expanding less than the gun metal into which it is screwed is lifted some-
what out of its conical seat and a passage is thus opened, through which the oil
passes, partly by its own weight and partly by capillary attraction, the pressure or
vacuum, as the case may be, being equal above and below. When the engine or
machine stops and the apparatus cools, the metals contract and the plug again
tightly closes the said passage or hole, preventing all waste of oil when the engine
or machine is not working. The said hole cannot become stopped, as each time the
metals contract the steel plug forces out any substance which may form an
obstruction.
The consumption of oil can be regulated by tightening or unscrewing the plug C,
as the case may be; this operation can be effected with an ordinary screw driver
passed through the hole G.
Freezing of the said apparatus is prevented even in the coldest weather, the space
between the two cups being filled with steam, which, as soon as the machine starts,
melts the oil at once.
The apparatus represented in Figure 2 is constructed with the plug put in from
below. In other respects the parts are the same as in Figure 1, except that the
lid F is fitted with a shackle H, through which a screw passes, carrying a conical
head piece serving to close the opening G.

page_text: It will be understood that lubricators can be made with several plugs in place
of one; also that discs can be substituted for the said plungers if preferred.
Having thus fully described the said Invention and the manner of performing
the same, I wish it underseood that I claim,-
First. A lubricator constructed to operate by the differential expansion of metals
when heated, substantially as set forth.
Second. The cups A and B in combination with the lid F, substantially as set
forth.
Third. The manner of placing the regulating pin or plug in the lubricator shewn
in Figure 1, so that it can be regulated or adjusted through the opening G without
removing the lid, as above set forth.
In witness whereof, I, the said Frank Wirth, have hereunto set my hand and
seal, this Third day of November, in the year of our Lord One thousand
eight hundred and seventy nine.
TRATT
FRANK WIRTH. (L.S.)