IMPROVEMENTS IN SCREWED BUSHES FOR THE BUNG HOLES OF CASES, AND IN APPARATUS EMPLOYED POR FIXING OR WITHDRAWING THE SAME
Year: 1871

page_text: LETTERS PATENT to John Dunbar, of Glasgow, in the County of
Lanark, North Britain, for the Invention of "IMPROVEMENTS IN
SCREWED BUSHES FOR THE BUNG HOLES OF CASES, AND IN APPARATUS EMPLOYED
POR FIXING OR WITHDRAWING THE SAME."
Sealed the 24th May 1872, and dated the 29th November 1871.
PROVISIONAL SPECIFICATION left by the said John Dunbar at the
Office of the Commissioners of Patents, with his Petition, on the
29th November 1871.
I, JOHN DUNBAR, of Glasgow, in the County of Lanark, North Britain,
5 do hereby declare the nature of the said Invention of "IMPROVEMENTS
IN SCREWED BUSHES FOR THE BUNG HOLES OF CASKS, AND IN APPARATUS EMPLOYED
FOR FIXING OR WITHDRAWING THE SAME," to be as follows, that is to say :-
This Invention relates to certain improvements in that class of bushes
which are held in the bung holes of casks by means of a screwed thread
on the exterior of the bush entering into the wood around the bung hole,
and to apparatus to be employed for fixing or withdrawing the said

page_text: bushes. Various forms of such screwed threads have hitherto been used,
such for example as those set forth in the Specification of Letters Patent
granted to William Hurrell, No. 648, A.D. 1867, and to James Gillies,
No. 2653, A.D. 1869.
According to this Invention the upper part of the screw thread is
made flat or nearly so, whilst the under part of the thread is curved, or
in place of using a curved form for the under side it may also be made
flat. By means of either of these forms of screw thread a much more
secure hold of the bush in the bung hole is obtained.
.
The apparatus for fixing or withdrawing the bushes consists of two
eccentric discs, one of which is fixed to or forms part of a shaft, the
other is loose thereon, that is to say, it is capable of revolving on the
shaft, so that when placed inside the bush and turned round either to
screw the bush inwards or withdraw it the edges of the two discs seize
against the interior of the bush and hold it tightly, the grip or hold :
increasing with the degree of force applied to the lever by which it
is actuated by reason of the tendency of the two eccentrics to form
a figure of enlarging diameter in proportion as their major radii recede
from each other.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Dunbar in the Great Scal Patent Office on
the 29th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DUNBAR, of Glasgow, in the County of Lanark, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in the
33rd year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Dunbar, Her special license that I,
the said John Dunbar, my executors, administrators, and assigns, or
such others as I, the said John Dunbar, my executors, administrators,
or assigns, should at any time agree with, and no others, from time

page_text: 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 SCREWED BUSHES FOR THE
BUNG HOLES OF CASKS, AND IN APPARATUS EMPLOYED FOR FIXING OR WITHDRAWING
THE SAME," upon the condition (amongst others) that I, the said John
Dunbar, by an instrument in writing under my hand and seal,
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
calender months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said John Dunbar, do hereby declare the
nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings,
and to the letters and figures marked thereon, that is to say :-
My said Invention relates to certain improvements in that class of
bushes which are held in the bung holes of casks by means of a screwed
thread on the exterior of the bush entering into the wood around the
bung hole, and to apparatus to be employed for fixing or withdrawing
the said bushes. Various forms of such screwed threads have hitherto
been used, such for example as those set forth in the Specification of
Letters Patent granted to William Hurrell, No. 648, A.D. 1867, and
to James Gillies, No. 2653, A.D. 1869.
According to this Invention the upper part of the screw thread is
made flat or nearly so, whilst the under part of the thread is curved, or
in place of using a curved form for the under side it may also be made
flat. By means of either of these forms of screw thread a much more
secure hold of the bush in the bung hole is obtained.
The apparatus for fixing or withdrawing the bushes consists of two
eccentric discs, one of which is fixed to or forms part of a shaft, the other
is loose thereon, that is to say, it is capable of revolving on the shaft,
so that when placed inside the bush and turned round either to screw
the bush inwards or withdraw it, the edges of the two discs seize against
the interior of the bush and hold it tightly, the grip or hold increasing
with the degree of force applied to the lever by which it is actuated by

page_text: reason of the tendency of the two eccentrics to form a figure or enlarging
diameter in proportion as their major radii recede from each other.
It is obvious that this mode of enlarging the diameter of the apparatus
may be considerably modified.
And in order that my said Invention may be properly understood, I
now proceed more particularly to set forth the system, mode, or manner
in or under which the same is or may be used or practically carried into
effect, that is to say :-
On the Sheet of Drawings hereunto appended, Figure 1 is a side
elevation of my improved bush for the bung holes of casks; Figure 2
is a plan thereof, whilst Figure 3 is a vertical section of the same. As
shewn by Figures 1, 2, and 3, the bush A is constructed with a slight
taper, and is furnished with a flanch a at its upper edge. The outside
of the said bush A. is formed with a screw or spiral thread B, as shewn
at Figures 1 and 3 of the Drawings, by which it is fixed into the bung
hole of the cask; the screw or spiral thread B differs in construction
to those herein-before referred to as hitherto in use. As shewn more
particularly by the vertical section, Figure 3, the screw or spiral thread B
is formed flat or nearly so at its upper part, whilst the under part is
curved. At Figures 4, 5, and 6 are shewn respectively a side elevation,
a plan, and vertical section of my improved bush A, the screw or spiral
thread C of which is formed rectangular in transverse section, that is to
say, with its upper and under faces flat, as shewn more particularly at
the vertical section Figure 6. By means of either of these forms of
screw threads a much more secure hold of the bush in the bung hole is
obtained.
The bushes shewn on the appended Sheet of Drawings may be con-
structed of cast iron, malleable cast iron, brass, or other metal, and they
are fixed and tightened in the bung holes of the casks to which they
are applied, or withdrawn therefrom by means of the apparatus or
instrument, one form of which is shewn in side elevation at Figure 7;
Figure 8 being a plan, Figure 9 an end elevation, and Figure 10 a
vertical section of the said apparatus or tool, whilst Figures 11 and 12
are detailed views of the same. This form of the apparatus or tool
consists of two eccentric discs A and B, respectively constructed with
a slight taper in order to correspond with the form of the interior of the
bushes. The eccentric disc A is fixed to or forms part of a short shaft C,

page_text: whilst the other eccentric disc B is loose or capable of revolving thereon,
and is prevented from sliding or being drawn off by means of the nut D,
which is secured on the lower end of the short shaft C. The upper end
of the short shaft C is formed with a square head I, by means of which
the lever for actuating the apparatus or tool is attached. Notches or
indentations a are cut on a portion of the periphery of the disc A, shewn
more particularly at the detailed view Figure 11, which is an end
elevation of the eccentric disc A and shaft C, with the lower eccentric
disc E and nut D removed. The eccentric disc B is also constructed
with a serrated or fluted periphery b, as shewn more particularly at the
detailed view Figure 12. When the eccentric discs A and B are placed
inside a bush, and the shaft O is turned round by means of the lever
fitted on the square head I, either to screw the bush inwards or with-
draw it, the edges of the eccentric discs A and B seize against the
interior of the bush and thereby hold it, the hold or grip increasing with
the degree of force applied to the lever by which the apparatus is
actuated by reason of the tendency of the two eccentrics to form a figure
of enlarging diameter in proportion as their major radii recede from each
other. The position of the eccentric discs A and B at the point of
maximum divergence of their major radii is shewn at the Diagram
Figure 13 of the Drawings.
Figure 14 is an elevation of another modification of my improved
apparatus or tool for fixing or withdrawing screwed bushes from the
bung holes of casks; Figure 15 is a plan, and Figure 16 an end
6 elevation thereof; whilst Figures 17, 18, and 19 are detailed views of
the same. Under this modification the apparatus or tool consists of
a short shaft F, part of which near its lower extremity is formed into
an eccentric d, shewn more particularly at the detailed views Figures 17
and 18. This part fits into an eccentric hole e, which is constructed at
O the lower end of a grooved collar G, more particularly shewn at the
detailed plan Figure 19. This collar is situated upon and surrounds
the lower extremity of the short shaft F, as shewn at Figures 14, 15,
and 16. The outside of the collar G is tapered, as more particularly
shewn at Figure 14, in order to correspond with the taper in the screwed
5 bush. A nut H is screwed to the lower end of the shaft E, which prevents
the collar G from sliding or being drawn off. When the collar G is
placed inside the bush and the apparatus or tool is actuated by means
of a lever applied to it, the eccentric d acting on the eccentric part of

page_text: the ring e expands the same; an opening x being cut through one side
of the ring G to leave it free to expand, thereby increasing the grip or
hold of the bush in proportion to the degree of force applied to the
lever. The ring G returns to its original diameter on the shaft F being
turned in an opposite direction.
E
At Figure 19 is shown in dotted lines a pin or stud m passing through
the collar G and projecting at the interior part thereof. The inner end of
the stud m fits into a groove n formed on the shaft F, as shewn in dotted
lines at Figure 17.. The object of so placing the stud m in the groove n
being that the shaft F cannot be turned beyond a certain point in either 1
direction without turning the spring collar G, so that limits are thereby
set to the expanding action of the eccentric d. The employment of the
stud m is not essential; it is however preferred to use it.
Figure 20 is an elevation of a third modification of my improved
apparatus for fixing or withdrawing screwed bushes from the bung holes 1
of casks; Figures 21 and 22 being plans of the ends thereof respectively,
whilst Figures 23, 24, and 25 are detailed views of the same. Under
this modification of the apparatus the expansion of the collar G is
effected by means of the mechanical equivalent of the eccentrics
employed in the two preceding modifications, namely, a square F 2
which enters a square hole or opening h formed therein, as shown at
the plan of the collar G, Figure 25. The spring G is cut through at 1,
as is the collar G at x in the preceding modification.
On referring to the detailed plan, Figure 25 of the Drawings, it will
be observed that the opening is situatedmid way in one side of the 2
square hole or opening h, but in lieu of so arranging the opening i it
may be situated between any of the angles formed by the square hole or
opening h, as shown in dotted lines at Figure 25.
It is obvious that when the collar G³ is placed within a bush and the
shaft Fis turned by a lever applied to it the spring collar G¹ is expanded 3
by the action of the square portion F upon the sides of the hole in the
ring G, and the collar G¹ returns by its elasticity or spring to the
original diameter, when the shaft F¹ is turned in the opposite direction.
Having now described the nature of my said Invention, and the
system, mode, or manner in or under which the same is or may be used 3
or practically carried into effect, I would observe in conclusion that

page_text: what I consider novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent, is,—
First. The construction of metallic bushes for the bung holes of casks
with screwed threads, which are shaped as herein-before described and
delineated at Figures 1, 3, 4, and 6 of the annexed Sheet of Drawings.
Second. The arrangement and construction of expanding apparatus
or tools herein-before described and shewn upon the annexed Sheet of
Drawings.
In witness whereof, I, the said John Dunbar, have hereunto set my
hand and seal, this Twenty-eighth day of May, One thousand
eight hundred and seventy-two.