IMPROVEMENTS IN PACKING THE PISTONS AND OTHER PARTS OF STEAM AND OTHER ENGINES
Year: 1868

page_text: LETTERS PATENT to George Edinund Donisthorpe, of Loeds, in the
County of York, for the Invention of "IMPROVEMENTS IN PACKING THE
PISTONS AND OTHER PARTS OF STEAM AND OTHER ENGINES."
Sealed the 20th April 1869, and dated the 28th October 1868.
PROVISIONAL SPECIFICATION left by the said George Edmund
Donisthorpe at the Office of the Commissioners of Patents, with
his Petition, on the 28th October 1868.
I, GEORGE EDMUND DONISTHORPE, of Leeds, in the County of York,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
PACKING THE PISTONS AND OTHER PARTS OF STEAM AND OTHER ENGINES," to be as
follows:-
This Invention has for its object improvements in packing the pistons
and other parts of steam and other engines.
In order to form a steam or fluid-tight packing to a piston I place
around it a flexible bag of a ring form. I. fill this bag with oil or other
fluid, and by means of a passage through the piston and rod or in other
convenient way I put the bag in connection with a small reservoir in
[Price 8d.]

page_text: which the oil or fluid is contained at a pressure exceeding that of the
steam or other fluid with which the engine is worked. I also provide in
connection with the small oil or fluid reservoir the means for regulating
the pressure; this is conveniently done by providing it with a piston or
plunger forced inwards by an adjustable weight or spring. The portion
of the ring formed bag which comes in contact with the cylinder I in
some cases cover with thin and flexible sheet steel or with other metal.
In a similar way I render the glands of piston rods or other rods steam
or fluid tight; the annular bag is fitted into the cavity of the gland, aud
the rod passes through the centre of it. As before the interior of the
bag is put into communication with a small reservoir containing oil or
other fluid under pressure. The bag I prefer to make of leather, and it
may, as already mentioned, be protected on the wearing surface by means
of a flexible covering of metal. In place of using the bag in packing
glands I in some cases simply place a stout washer of leather or of felt
around the piston rod, and I force into the cavity of the gland between
the two washers oil or other liquid at a pressure exceeding that of the
steam or fluid in the cylinder. In some cases the washers even may be
omitted, and the gland then becomes simply a metal cylinder or guide
nearly fitting the rod, but allowing it to move freely, and midway of the
length of this gland is an annular groove into which the oil or liquid is
forced under pressure and it escapes by the minute space between the
piston rod and the cylindrical gland in quantity sufficient to lubricate
the parts. In a similar manner pistons may be packed with a liquid
packing, the piston being turned so as very nearly to fit the cylinder and
having a groove midway of its length into which the oil or liquid is
forced, and washers or leathers may be employed to prevent too free
escape of the lubricating liquid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Edmund Donisthorpe in the Great Seal
Patent Office on the 26th April 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
EDMUND DONISTHORPE, of Leeds, in the County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of October, in the

page_text: year of our Lord. One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Hor heirs and suc-
cessors, give and grant unto me, the said George Edmund Donisthorpe,
Her special licence that 1, the said George Edmund Donisthorpe, my
executors, administrators, and assigns, or such others as I, the said
George Edmund Donisthorpe, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle
of Man, an Invention for "IMPROVEMENTS IN PACKING THE PISTONS AND OTHER
PARTS OF STEAM AND OTHER ENGINES," upon the condition (amongst others)
that 1, the said George Edmund Donisthorpe, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date of
the said Letters Patent.
NOW KNOW YE, that I, the said George Edmund Donisthorpe, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
This Invention has for its object improvements in packings for the
pistons and other parts of steam and other engines.
In order to form a steam or fluid-tight packing to a piston or gland I
place around the piston or inside the gland a flexible bag of a ring form,
and this bag I distend by putting it in connection with a small reservoir
containing a fluid which is maintained at a pressure exceeding the
working differential pressure of the steam or other fluid with which the
engine is worked by means of a piston or plunger forced inwards into it
by a weighted lever or by a spring or otherwise. The action of the lever
should be so regulated as at all times to be a little above the working
pressure in the cylinder at all parts of the stroke, especially when great
expansion is adopted. In place of employing a bag as above described
a groove might be formed around the piston or the gland, and this groove
might be kept filled with fluid under a pressure greater than the working
pressure in the cylinder of the engine; the parts may either be made to

page_text: fit together with sufficient truth to prevent too free an escape of the
packing or lubricating fluid, or washers or leathers may be placed on
either side of the groove to limit the escape of the packing and
lubricating fluid. At the front of the groove around the piston or gland
split rings of metal may be placed if desired, so that the rings shall be
pressed outwards from the groove by the fluid; these rings will also
prevent too free an escape of the fluid from the groove around the piston
or gland; the outer diameter of the gland would have to expand, and at
the same time the internal portion would have to contract, to offect a
steam-tight packing on the piston rod. When I employ a bag packing
I prefer to form the bag from two strips of leather, the two ends of
each of which are first sewn together to form the strips of leather into
rings one larger than the other, and the two rings so fornied are then
sewn together edge to edge to form an annular bag. Each of the
strips of leather from which the bag is made has projecting from one
of its sides a short uarrow strip, and these short strips are sewn together
to form a tube leading into the annular bag. If the bag packing is
for a piston the bag is placed in a groove which is formed around the
piston, and in the short tube projecting from the bag is inserted a small
brass or copper tube which is passed through or connected with a
passage formed through the piston and through the piston rod, and to
the end of this pipe or passage I connect a small flexible pipe through
which the fluid from a small reservoir under pressure is led into the
bag packing; or the bag packing might otherwise be put in connection
with a reservoir of fluid under pressure. By this means not only will a
sound packing be obtained, but a small quantity of the fluid going
through the pores of the leather bag will affor. the required amount of
lubrication, or the end of the passage through the piston rod may be
otherwise put in connection with the snall reservoir in which the fluid
for expanding the packing and for lubricating is kept under pressure.
The fluid in the reservoir 1 keep under pressure by a weight or by a
spring; I prefer to employ for this purpose a piston which enters the
reservoir and is forced downwards into it by a weighted lever or by a
spring. If the lubricating fluid under pressure be alone employed for
effecting the packing, I (for packing a piston) form the piston to fit very
accurately to the cylinder as is now commonly done in what is known as
the Allen engine, and around the piston 1 form grooves of about t of an
inch broad, and from the groove a passage is led through the piston and
through the piston rod, and through this passage the packing fluid under

page_text: a pressure greater than the working. pressure in the cylinder of the
engine is led into the grooves around the piston, and by reason of the
piston fitting very accurately to the cylinder the too free escape of the
fluid from the grooves will be prevented. This arrangement is very
applicable in cases where water is employed as the lubricating fluid. As
before stated washers of leather or other packing may be employed on
either side of the groove to prevent too free an escape of the lubricating
and packing fluid, and also that split rings of metal may be placed into
the groove around the piston, or it might be a gland; such an arrange-
ment is shewn in the Drawing hereunto annexed. The piston is formed
in a very similar manner to what has heretofore commonly been the case,
except that the groove a in which the split rings b, b, are contained
is by a small passage c through the piston rod put in connection as
above explained with a small reservoir in which a lubricating liquid is
kept under a pressure greater than the working pressure in the cylinder
of the engine.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that what I claim
i8,-
First. Supplying hollow bag packings of the pistons and other parts of
steam and other engines with fluid from a reservoir in which the fluid is
maintained at a pressure greater than the pressure of the steam or other
fluid with which the engine is worked by means of a piston or plunger,
as herein described.
Second. Packing the pistons and glands of steam and other engines
by forming a groove around the piston or gland and keeping such
groove filled with a lubricating fluid under a pressure greater than the
pressure of the steam or other fluid with which the engine is worked.
In witness whereof, I, the said George Edmund Donisthorpe, have
hereunto set my hand and seal, this Twentieth day of April,
in the year of our Lord One thousand eight hundred and sixty-
nine
G. E. DONISTHORPE. (L.s.)