Improvements in Fountain Ink Wells.
Year: 1892

page_text: Date of Application, 23rd Sept., 1892-Accepted, 29th Oct., 1892
COMPLETE SPECIFICATION.
Improvements in Fountain Ink Wells.
I, JOHN W. MACDONALD, of the City of Pittsburgh, County of Allegheny,
State of Pennsylvania, Gentleman, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement and accompanying drawings:-
The purpose of this invention is the production of an ink well, that will practically
seal from the atmosphere the contents of the well and thus prevent the evaporation
thereof; overcome the annoying difficulty heretofore met with in ink wells of this
class of the ink rising in the supply tube as air within the well becomes expanded
by a rise in the temperature until it overflows the same; and by forming it of
fewer parts to simplify its construction and thereby cheapen its cost to the
public.
Referring to the accompanying drawings;
Fig. 1, is a central cross sectional elevation of a complete ink well showing
said improvement.
Figure 2, is a central cross sectional view in perspective of rubber diaphragm
used in said well but somewhat enlarged.
Fig. 3, is a central cross sectional view of supply tube.
Fig. 4, is a central cross sectional view somewhat enlarged showing shape assumed
by diaphragm after being expanded to position on neck of supply tube.
Fig. 5, is a central cross sectional view showing relative position of central
portion of diaphragm and supply when filling bottle.
In constructing said ink well a body 1 Figure 1 is formed of glass with a
central cylindrical reservoir and provided with a shoulder 2 around and near the
top thereof, and having a screw thread 3 in its peripheral face immediately below
said shoulder. From elastic rubber a circular diaphragm Figure 2 is formed
provided with a flange 4, the inner diameter of which Hange is such as to permit
of its fitting neatly over the neck of the body 1, Figure 1, and of such depth as
to leave a small space between its lower edge and the shoulder 2, for the purpose
hereinafter stated.
The central part of said diaphragm is thickened or re-enforced and through said
thickened part a central tapered aperture 5 is formed leaving upon the under side
of said diaphragm and around said opening the flange 6 the greatest diameter of
said aperture being slightly smaller than that of neck of a supply tube to be
fitted therein. Between said central aperture and the circumference of the diaphragm,
the diaphragm is shaped to form an annular chamber 7 preferably of the size and
shape shown in Figure 2. Between channel 7 and the central aperture one or more
perforations (8) or air passages are made in said diaphragm which latter it is to
be noted should be made thinner in that part forming the channel 7 and extending
inward to the edge of the central aperture 5 than is that part outside said channel
and next the circumference of the diaphragm for the purpose hereinafter stated.
From some suitable material a supply tube Figure 3 is formed having an enlarged
or funnel-shaped mouth 9 and externally shaped to form a neck 10 and an annular
projection 11.
A cap or cover 12 is formed of suitable material and centrally apertured to
permit of the free movement within it of the upper extremity of the supply tube
Figure 3.
A circular flange 13 extends downward from the outer edge of said cap piece and
is provided upon its inner face with a screw thread to fit the thread 3 upon the body 1

page_text: Figure 1. Upon the under side of cap 12, and next the inner face of the flange 13
an annular collar 14 is formed of such size as to fit loosely over the neck 10 of
body 1 Figure 1.
To put said improvement into operation the supply tube Figure 3, is forced
through the tapered aperture 5, in the diaphragm Figure 2, until it meets the
projection 11, Figure 3. The neck 10 of said tube being somewhat larger than
the greatest diameter of the aperture 5 and much larger than its smallest diameter
will cause the diaphragm to expand against its elasticity and this expansion being
greatest in the flange 6, tends to force the upper surface of said diaphragm between
the channel 7 and neck 10 up against the projection 11 of the tube Figure 3 as
shown somewhat enlarged in Figure 4 thereby closing the perforations or air
passages 8. The diaphragm with supply tube which is of a length to reach to
near the bottom of the reservoir being placed in position upon the neck 13 of the
body 1, the cap is screwed down until, the collar 14 comes against the top of the
diaphragm. The flange 4 of the diaphragm will not now touch the shoulder 2,
Figure 1 but if the cap be further screwed down it will cause all that part of
the diaphragm outside the channel 7 to be slightly expanded and at same time
seal the joint by the flange 4 pressing upon the shoulder 2, Figure 1.
To fill the reservoir the supply tube is grasped about its upper extremity and
slightly raised, Figure 5, which movement will uncover the air passages 8 when
the ink may be poured through the tube to the interior of the well, after which
upon being released the supply tube by the elastic action of the rubber of the
diaphragm will resume its former position and in so doing close the air passages 8,
and again seal the contents of the reservoir from the open atmosphere. If the
supply tube be now depressed by thrusting a pen into the funnel mouth thereof
the air opening 8, already closed will be made still tighter by the resistance offered
by the elastic diaphragm, which being also depressed causes the ink to rise
to the pen only to return to the reservoir when the pen is withdrawn from the
supply tube.
It has been common heretofore in this class of ink wells for the ink to rise in
the supply tube with an expansion of the air in the reservoir of the well until the
same overflowed. In the device here shown, while an expansion of the air in the
reservoir of the well will cause the ink to rise in the supply tube to a certain
height, it will not rise high enough to overflow the tube for the reason that as
the expansion pressure of the air comes against the inside of the diaphragm the
same together with the supply tube will be slightly raised, thereby uncovering the
air passages 8 and allowing of an equalization of the pressure within the well with
that of the open atmosphere, thus permitting the ink forced up into the tube
to drop back into the well. The supply tube will then resume its former
position closing the air passages 8 and again scaling the ink from the open
atmosphere.
By making the central part of the diaphragm much thinner than that part of
greater diameter and extending to the edge of the diaphragm, and forming between
said parts of different thickness the annular channel 1, Figure 2, the slight
depression of the tube caused by thrusting a pen into its funnel shaped mouth
will cause only that part of the diaphragm within the circle formed by the channel 7
to be depressed.
The area of piston surface will be thus greatly reduced.
A slight depression of this small piston surface will however cause the ink to
rise to the mouth of the supply tube; and while the diaphragm so constructed
will be sufficiently sensitive the depression of so small an area of the diaphragm
will prevent the ink being so rapidly forced through the supply tube as to cause it
to spout from the top thereof as has been the case heretofore in fountain ink wells
of this class where the whole surface of the diaphragm is depressed by slightly
depressing the supply tube.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
1st. The improved fountain inkstand as described and shown.
2nd. The improved elastic diaphragm as described and shown.
Dated this 7th day of September 1892.
JOHN W. MACDONALD.