Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS1520795 A
Publication typeGrant
Publication dateDec 30, 1924
Filing dateApr 26, 1921
Priority dateApr 26, 1921
Publication numberUS 1520795 A, US 1520795A, US-A-1520795, US1520795 A, US1520795A
InventorsStewart Barr Lester
Original AssigneeStewart Barr Lester
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
US 1520795 A
Previous page
Next page
Description  (OCR text may contain errors)

Dec. 30, 1924. 1,520,795


SYRINGE Filed April 26, 1921 g m Mm Kfm Patented Dec. 3Q, 1924..



Application filed April 26, 1921,

To a whom it may concern:

Be it known that l. Lns'rnn STEWART Earn, a citizen of the United States, and residing at lVashington, District of Columbia, have invented certain new and useful Improvements in Syringes, of which the following is a specification.

The present invention relates to hand pumps or syringes and particularly to articles of this class adapted to be used by physicians.

In treating certain diseases of the nasal cavities and sinus, for instance, it is frequently desired to introduce an antiseptic solution into the affected regions of the head and to later force this solution out by pumping into the cavities occupied by the solution, the air displacing the liquid. To carry out this method of treatment fluid syringes have been utilized, the general practice being to connect a syringe containing liquid to a pipe or conduit which extends into the head of the patient and to force the liquid therethrough, after which the syringe is disconnected from the pipe, charged with air instead of liquid, again connected to the pipe, and operated to force the air into the head cavities of the patient to displace the liquid. Usually this operation is repeated several times in order to be sure that all of the liquid is expelled from the cavities. These repeated disconnections and connections of the syringe and tube are very annoying to all and painful to the patient if the inserted end of the tube is pulled or moved.

The principal object of the present invention is to provide a syringe which is adapted to supply the displacing air referred to above, without disconnecting the syringe and pipe. Other objects and features of novelty will be apparent from the description taken in connection with the drawings in which:

Figure 1 is a longitudinal sectional view through a syringe embodying the invention; and

Figure 2 is a section on line 2-2 of Figure 1.

In the form of the invention illustrated the syringe comprises a cylinder 10 closed at one end by head 10' and at the other by the cap 11. the head 10' having an opening 12 to slidably receive a rod 13 rigidly connected to the piston 14 and the cap 11 having a threaded opening 1.5 to receive the short tube or nozzle 16, The cap has a rela.

Serial No. 464,563.

tively small aperture 17 in its side wall which is aligned with a lateral opening 18 in tube 16, this latter opening being provided to bring the bore 19 of the tube into com munication with the interior of the pump chamber.

A stop 20 on rod '13 limits the forward movement of piston 14 and a knob 21 is provided for convenience in moving the piston. Valves 22 and 23 control respectively openings 1? and 18, these valves being coneshaped and mounted rigidly upon a short transverse rod or stem 24, one end of which extends through opening 17 and through a slot 25 in a leaf spring 26 secured to the ex terior of cap 11. A bracket 27 slidably supports the stem 24 and constitutes a guide therefor. The spring 26 normally holds stem 24 in raised position with valve 22 in closed position as shown in Figure 1, but pressure of the thumb or finger is sufficient to flex the spring and to depress stem 24. unseating valve 22 and seating valve 23 thereby opening the passage 17 so that air may freely enter the pump chamber and closing passage 18 to prevent the flow of fluid theiethrough in either direction.

In operating the improved syringe the pump chamber may first be filled with liquid by inserting the outer end of tube 16 into a vessel containing liquid and moving the piston 14 to the right Figure 1), the liquid being drawn in by suction. Tube 16 may then be connected to a tube leading to a point to be treated and piston 14 moved to the left to force the fluid out of the pump chamber. During this operation valve 22 has remained seated and valve 23 open. Now to charge the syringe with air, rod 24 is moved inwardly by the pressure of the thumb or finger exerted on its outer end and overcoming the resistance of spring 26, to close port 18 and open poit 17. Piston 14 is then moved to the right and in this movement the pump chamber becomes filled with air and does not create a suction in the port 19 of tube 16 or in the tube connected thereto. When the pump chamber is filled with air, that is when piston 14 is at the right hand end of the cylinder (Figure 1) the pressure of the thumb or finger is removed from the end of rod 24 and spring 26 acts to seat valve 22 and unseat valve 23. Piston 14 may then be moved to the left discharging the air with which the p mp ber i new fi ed, which will be forced through the tube and to the same point as the liquid. By simply pressing with the thumb or finger on the end of valve stem 24: and moving piston .14 at the proper time the syringe may be utilized to pump air and at no time is a suction created tending to draw the liquid previously pumped back into the pump chamber. The convenience of the instrument will be realized by those skilled in the art in which it is an improvement. lt is obvious that changes in the design and arrangement of parts may be made Within the scope oi the invention, which is not limited to the exact form described and illustrated. For example, the form of valve means shown may be varied and also the means to hold the air valve in closed position.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In a syringe of the class described for successively pumping liquid and air. in combination, a pump chamber having a discharge nozzle and an opening in its Wall a djacent said nozzle, means Within said chamber to selectively control the flow of fluid through said opening and nozzle operable from the outside of the pump chamber and means normally holding said control means in position to prevent flow through said opening.

2. In a syringe of the class described for successively pumping liquid and air in combination, a pump chamber having two openings therein for the passage of fluid, a valve Within said chamber for each of said openings, control means operable from Without the chamber to move the valves, and means normally holding said control. means in such position that one of said openings is closed.

3. In a syringe of the class described. in combination, a cylinder having two open-- ings in one end thereof'tor the pasnage of fluid, a manually operable piston in said cylinder, a member having two valves into gral therewith and operable from without the cylinder to bring one of said valves into position to close one of said openings and to simultaneously move the'other valve to uncover the other opening, and means normally tending to hold one of said valves in closed position, for the purpose set forth.

In testimony whereof I hereunto aliixflmy signature.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3828781 *Dec 6, 1971Aug 13, 1974Rothman EMethod for withdrawing menstrual fluid
US5246011 *Jan 30, 1992Sep 21, 1993Caillouette James CFine needle aspiration syringe
US5651372 *Jun 28, 1995Jul 29, 1997Caillouette; James C.For retrieving body tissue samples
U.S. Classification604/26, 604/236
International ClassificationA61M3/00
Cooperative ClassificationA61M3/00
European ClassificationA61M3/00