Year: 1888

page_text: Date of Application, 28th June, 1888
Complete Specification Left, 17th Oct., 1888
Complete Specification Accepted, 23rd Nov., 1888
I, Dr. MARTIN OVERLACH, of Frankfort-on-the-Main, in the Empire of Germany,
Physician, do hereby declare the nature of this invention to be as follows:-
This invention relates to syringes designed for injection and other purposes and
comprises means for tightening the piston in the cylinder of the same, in order to
provide for a sure and easy operation.
For this purpose the piston rod is provided at its upper end with a disc and a
screw threaded part upon which is fitted a nut. A ring or piston which can consist
of cork, leather or other elastic material is placed upon the screw threaded part
between the aforesaid nut and disc. If the nut is turned so that it approaches the
disc, the ring between them is pressed outward by means of a taper part or projection
on the nut, in consequence of which the ring or piston will bear more firmly against
the wall of the cylinder. If however the said nut is screwed upward on the piston
rod, the taper projection will pass more or less from the central opening of the ring
or piston which is thus allowed to contract so that it is decreased in circumference
and bears less firmly against the wall of the cylinder. Therefore by causing the nut
to move up and down upon the piston rod the ring or piston can be pressed more or
less powerfully against the wall of the cylinder.
In order that it shall not be necessary to completely remove the ring or piston from
the cylinder each time an adjustment is to be effected, I have devised the arrangements
hereinafter described.
In one of these arrangements the nut placed upon the screw-threaded part of the
piston-rod is made with longitudinal ribs, and between its taper projection and the
said disc is arranged the said ring or piston.
In order to press this ring or piston more or less firmly against the wall of the
cylinder, it is slid into the cylinder far enough for the nut to enter a space in the
upper cap of the cylinder, which is provided with the longitudinal ribs. If the
piston-rod is now turned, the nut cannot take part in this motion, because its
longitudinal ribs bear against the ribs in the upper cap, so that according to the

page_text: turning movement of the piston rod the screw-threaded part of the latter will be
screwed further into or from the nut, thus causing this nut either to approach or
recede from the said dise. In the former case the ring or piston between the nut
and dise is pressed outward through the medium of the taper part or projection and
forced firmly against the wall of the cylinder; whereas in the second case the ring or
piston as soon as the taper projection leaves the central opening in the same will
contract by reason of its elasticity so that the contact between the ring or piston and
the wall of the cylinder becomes less firm.
In another arrangement the lower cap of the cylinder can be provided with longi-
tudinal ribs in lieu of the upper cap, in which case the nut upon the piston rod must
be placed on the lower side of the elastic ring or piston so that its ribs will pass
between the ribs in the lower cap when the piston rod is caused to pass to the lower
extremity of its movement.
In a third arrangement the taper part has a prolongation forming a thin serew which
can be screwed up and down in the piston rod, whereby the elastic ring or piston
placed between the said taper part and dise is pressed more or less outward. On the
taper part is formed a dise provided with a rib which, when the piston is moved to the
upper end of the cylinder, enters a groove or recess in the cap, so that, if the piston
rod is turned, the taper part cannot follow this movement, but is enused to move
inward or outward in the piston rod according as the piston rod turns from the right
to the left or vice versa.
Dated this 28th day of June 1888.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: 1, Dr. MARTIN OVERLACH of Frankfort-on-the Main in the Empire of Germany,
Physician 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:
My invention relates to syringes designed for injection and other purposes, and
comprises means for tightening the piston or plunger in the cylinder of the same, in
order to provide for a sure and easy operation.
My said invention is illustrated in the accompanying drawing the figures of which
are horeinafter referred to.
In carrying the said invention into practice the piston rod a is provided at its upper
end with a disc or collar n and a scrow threaded part upon which is fitted a nut b. A
ring or piston d which may consist of cork, leather or other suitable material i
placed upon the screw-threaded part between the aforesaid nut and disc n. If th
nut is turned so that it approaches the disc n the ring between them is presse
outward by means of a taper part or projection m on the nut, in consequence of
which the ring or piston will bear more firmly against the wall of the cylinder C.
If on the other hand, the said nut is screwed upward on the piston rod
the taper
projection m will pass more or less from the central opening of the ring or piston d
which is thus allowed to contract so that it is decreased in circumference, and bears
less firmly against the wall of the cylinder. Therefore by causing the nut ₺ to move
up and down upon the piston rod a the ring or piston can be pressed more or less
powerfully against the wall of the cylinder."
a,
In order that it shall not be necessary to completely remove the ring or piston from
the cylinder each time an adjustment is to be effected I have devised the arrangements
hereinafter described.
In one of these arrangements as shown in Figure 1 the nut placed upon the screw-
threaded part of the piston rod a is made with longitudinal ribs and between its
taper projection m and the said disc n is arranged the said ring or piston d.
In order to press this ring or piston more or less firmly against the wall of the
cylinder, it is slid into the cylinder C far enough for the nut 6 to enter a space in the
upper cap of the cylinder, which is provided with the longitudinal ribs.. If
the piston-rod a is now turned, the nut 6 cannot take part in this motion, because its
longitudinal ribs & bear against the ribs i in the upper cap k so that according to the
turning movement of the piston rod a the screw-threaded part of the latter will be
screwed further into or from the nut, thus causing this nut either to approach or
recede from the said disc. In the former case the ring d or piston between the nut
and disc is pressed outward through the medium of the taper part or projection m
and forced firmly against the wall of the cylinder, whereas in the second case as soon
as the taper projection m leaves the central opening in the same, the ring or piston will
contract by reason of its elasticity so that the contact between the ring or piston and
the wall of the cylinder becomes less firm.

page_text: In the arrangement shown in Figaro 2 the lower cap of the cylinder C can ho
provided with longitudinal ribs in lieu of the upper cap, in which case the nut 6 upon
the piston rod a must be placed on the lower side of the olastic ring or piston so that
its ribs will pass between the ribs in the lower cap when the piston rod is caused to
pass to the lower extremity of its movement.
In the arrangement shown in Figure 3 the taper part m luas a prolongation forming
a thin sorew which can be screwed up and down in the piston rod a whereby the
elastic ring or piston d placed betwoon the said taper part and dise n is pressed more
or less outward. On the taper part is formed a disc provided with a rib h which
when the piston is moved to the upper and of the cylinder Centers a groove or
recess in the cap & so that, if the piston rod a is turned, the taper part in cannot
follow this movemont, but is caused to move inward or outward in the piston rod a
according as the piston rod turns from the right to the left or vice versa.
Having now particularly described and ascertained the nature of my said invon-
tion and in what manner the same is to be performed, I declare that what I
claim is;
Lu injecting syringes and generally in syringes of similar construction the arrange
ment of a piston, in which a screw nut b is so arranged that, when the piston rod is
drawn out or pushed in, the said nut enters one of the caps or closing the cylinder
and is here fixed in such a manner that by rotating the piston rod the said nut will
be screwed up or down upon the screw threaded portion of the said rod, whereby the
circumference of the piston itself, by reason of the expansion of the ring d, can be
increased or diminished at will as required.