AN IMPROVEMENT OR IMPROVEMENTS IN CYLINDER PISTONS OR PLUNGERS
Year: 1856

page_text: LETTERS PATENT to David Blair White, of Newcastle-upon-Tyne, in the
County of the Town of Newcastle-upon-Tyne, Doctor of Medicine, for
the Invention of "AN IMPROVEMENT OR IMPROVEMENTS IN CYLINDER PISTONS
OR PLUNGERS."
Sealed the 7th October 1856, and dated the 16th April 1856.
PROVISIONAL SPECIFICATION left by the said David Blair White at
the Office of the Commissioners of Patents, with his Petition, on the
16th April 1856.
I, DAVID BLAIR WHITE, of Newcastle-upon-Tyne, in the County of the
Town of Newcastle-upon-Tyne, Doctor of Medicine, do hereby declare the
nature of the said Invention for "AN IMPROVEMENT OR IMPROVEMENTS IN CYLINDER
PISTONS OR PLUNGERS," to be as follows:-
My Invention consists in constructing pistons or plungers which are com-
posed of framing and elastic packing, with the framing adjustable, in such
manner as to cause a lateral or outward extension or expansion of the elastic
packing, either by compression between plates or frames, or by a direct
extension or expansion of the packing produced without compression.
The following description illustrates the manner in which I believe my
Invention may be best performed, that is to say:-I construct the framing of
my improved pistons or plungers with plates, between which I place one or
more rings of indian-rubber packing, and by adjusting screws, I produce any

page_text: desired amount of compression, and thereby expand the packing outwardly,
any expansion inwardly being prevented by a collar or ring on one of the
plates. Or, instead of by compression, I directly extend or expand the indian-
rubber ring or rings, by means of a conical band or ring of metal which I move
and regulate by adjusting screws, so as to stretch the said ring or rings bodily
and force them outwards to the desired extent.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Blair White in the Great Seal Patent Office on the
15th October 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
BLAIR WHITE, of Newcastle-upon-Tync, in the County of the Town of
Newcastle-upon-Tyne, Doctor of Medicine, sent greeting.
:
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of April, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said David Blair White, Her special licence that I, the said David Blair
White, my executors, administrators, and assigns, or such others as I, the
said David Blair White, 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 "AN IM-
PROVEMENT OR IMPROVEMENTS IN CYLINDER PISTONS OR PLUNGERS," upon the
condition (amongst others) that I, the said David Blair White, my executors
or administrators, by an instrument in writing under my, or their, or one of
their hands and seals, should particularly describo 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 David Blair White, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, (that is to say):-
.
My Invention consists in constructing pistons or plungers which are com-
posed of framing and elastic packing, with the framing adjustable, in such

page_text: manner as to cause a lateral or outward extension or expansion of the elastic
packing, either by compression between plates or frames, or by a direct
extension or expansion of the packing produced without compression.
And having thus set forth the nature of my said Invention, I will now
proceed to describe the manner in which the same is to be and may be per-
formed, reference being had to the accompanying illustrative Drawing, and to
the figures and letters marked thereon.
The Figure 1 represents partly an elevation and partly a section of a
cylinder piston, pump box, or plunger for pumping, which is the particular use
to which my said Invention is more particularly applicable. The framing of
this box or plunger is constructed mainly of two principal plates or framės,
namely, an upper plate and a lower plate, marked a and b respectively; which
are adjustable, as regards their distance from each other, in the manner herein;
after described; and between these plates an elastic packing c, c, is placed;
which, by compression between these plates, becomes extended laterally or
outwards from the centre of the pump box, any expansion inwardly or towards
the centre being prevented by a collar or ring on one of the plates;
d is an
ordinary pump rod, jointed at e in the ordinary manner to the bow f, so as to
allow of a slight motion for action in the chamber. The ends of the bow
terminate in bolts g, g, which pass through both the plates; and the ends of
these bolts are forined with right and left threads or screws, and a pair of
corresponding nuts are furnished to each, which by this arrangement are not
so likely to work off or become loose. These bolts, together with two additional
ones which are also similarly made and furnished with corresponding nuts,
serve to hold the two plates or frames a and b together, and to give the adjust-
ment desired, whereby the same plunger or pump box may be modified in size,
so as to suit or be adapted to chambers of different diameters. Moreover,
the clasticity of the packing, for which I prefer to use two rings of vulcanized
indian-rubber, as shewn, will permit it to work into and fill up any uneven or
worn portions of the chamber, whereby a more perfect exhaust than heretofore
will be obtained under such circumstances.
The Figure 2, which is a bottom plan view of the lower plate b, explains
the disposition of the four bolts, the holes for receiving them being likewise
marked g, g. For the better security of the packing, I make the surfaces of
the plates a and b, between which the rings are gripped, with serrations or teeth
as represented.
The Figure 3 is a transverse section of a modification of the foregoing
cylinder piston, pump box, or plunger, in which the outward lateral extension
of the elastic packing which is produced is a direct extension or expansion

page_text: without compression, between the upper and lower plates or frames. This
section is taken in the direction denoted by the dotted line A, B, in Figure 4,
which is a top plan view of the upper plate; and Figure 5 is another trans-
verse section taken in the direction denoted by the dotted line C, D, also in the
said Figure 4. In these three Figures the same letters are employed as
in the Figures 1 and 2, to denote the corresponding parts. The principal
difference in construction is as follows:-m is a conical ring inserted between
the upper and lower plates; the two bolts g, g, and the two other bolts which
hold the plates together, passing loosely through it. Four smaller bolts (two
of which and also a portion of a third) are represented at n, n, n, in the
Figure 5, serve to draw up this ring m away from the lower plate and towards
the upper plate (double nuts being provided to each bolt), the effect of which
is to give the intended direct extension or expansion to the packing. It is to
be noted that the plates a and b do not approach each other; the bolts g, g,
which terminate the bow, and the two other holding bolts 9, 9, being formed
with shoulders bearing against the lower plate to prevent it; also that the
right and left threaded screws and double nuts to these four bolts are dis-
pensed with, split keys being substituted. And, lastly, I prefer to employ a
single ring of rubber in this case, as shewn, and to dispense with the serrations
on the plates. And I would observe that the action of the ring m may be
produced by forcing upwards from underneath, instead of by drawing upwards
from above, and that the ring itself may be inverted and may be drawn or
forced downwards as may be preferred.
In witness whereof, I, the said David Blair White, have hereunto set my
hand and seal, this Ninth day of October, One thousand eight hundred
and fifty-six.
DAVID BLAIR WHITE. (L.S.)