United States Patent Office
2,720,880
DISPOSABLE CARTRIDGE SYRINGE
Seldon V. Wbitaker, Devon, and Philip A. Dei-ham, Port
Kennedy, Pa., assignors to J. Bishop & Co. Platinum
Works, Malverny Pa., a corporation of Pennsylvania
Application July 9,1954, Serial Pio; 442,295
7 Claims. (Cl. 128—218)
This invention relates to a disposable cartridge syringe for use with ampoules or cartridges of medicinal agents to be injected, said ampoules being of the type having a perforatable diaphragm sealing one end and a piston sealing the other end and slidable in the ampoule to discharge the liquid therefrom.
An object of our invention is to provide a disposable syringe of the type referred to which is inexpensive and easy to operate. More particularly an object of our invention is to facilitate the handling of the syringe after the insertion of the ampoule or cartridge.
The invention is illustrated in the accompanying drawings in which:
Fig. 1 is an exploded perspective view showing the needle, the syringe barrel, the ampoule and the piston rod,
Fig. 2 is a sectional view of the assembled parts of the syringe,
Fig. 3 is an enlarged section on the line 3—3 of Fig. 1 showing a continuous ridge on the inner wall of the syringe barrel adjacent the open end thereof,
Fig. 4 is a perspective view showing a single circular projection on the inner wall of the barrel adjacent the open end thereof,
Fig. 5 is a sectional view showing spaced apart ridge sections on the inner wall of the barrel adjacent the open end thereof, and
Fig. 6 is a top plan view showing the barrel slightly elliptical in cross section with ridge sections on the opposite less curved sides thereof.
It will be appreciated that for the purpose of illustration the size of the ridge and ridge sections and the circular projection are somewhat enlarged.
Referring to Figs. 1, 2 and 3 of the drawings 1 is a double pointed needle having the longer end 2 for injection, the shorter end 3 for puncturing the diaphragm of the ampoule and the externally knurled, internally screw threaded hub 4 which fits the screw threaded nose 5 of the syringe. The needle is of course made of metal such as stainless steel.
The syringe barrel 6 comprises the usual cylindrical portion 7, the nose 5 referred to above, the wings 8 to be engaged by the fingers of the operator, the window 9 and the internal ridge 10 (see Fig. 3). The barrel is made of synthetic resin or plastic material such as polyethylene which may be opaque or translucent and is slightly flexible, elastic and deformable. The window 9 may be an opening through the wall of the barrel or merely a relatively thin area through which the contents of the barrel may be seen.
The ridge 10 is formed to a size permitting the ampoule 11 to be inserted into the syringe barrel but preventing the ampoule from being removed from the barrel. The slight flexibility and elasticity of the material of which the barrel and the integral ridge 10 are made make it relatively easy to provide a syringe barrel and ridge into which the standard amopule readily may be inserted by the
pressure of the fingers and from which the ampoule rarely, if eyer, will fall put.
As illustrated in Figs. I, 2 and 3 the syringe barrel 6 is circular in cross section and the ridge 10 is continuous
5 but we have found it to be advantageous as illustrated in Fig. 6 to make the syringe barrel 6' slightly elliptical in cross section so that it may be deformed to circular cross section to permit the introduction of the cartridge after which the barrel will return to its elliptical cross
Iq sectional shape. We have further found that instead of a continuous ridge a single, or two or more spaced apart circular projections 22 (see Fig. 4) or a single or.two or more spaced apart short ridge sections 23 (see Fig. 5) rriay be used. A pair of pppositely disposed ridge sec
15 tions 23 each extending 30° more of less around the circumference of the barrel have been found to give excellent results, particularly when the barrel is slightly elliptical in cross section and when the ridge sections are located in the less sharply curved sides of the ellipse as
20 illusfratect in Fig. 6. It will be appreciated that either the circular or the elliptical cross sectional shape Of the' barrel may be used with either the continuous ridge, the single circular projection or spaced apart circular projection or the single ridge section or spaced apart ridge sections.
25 The ampoule illustrated in Figs. 1 and 2 is of conventional construction i. e. it is made of glass and has a cylindrical body portion 12, a neck portion 13, a flange 14, a metal cap 15 having a central opening 16, the perforatable e. g. rubber diaphragm 17, and a piston 18 pro
30 vided with the screw threaded projection 19. The piston rod 20 may be formed of metal or synthetic resin or plastic and is provided with the screw threaded socket 21 adapted to fit onto the projection 19. A simpler conventional form of ampoule is one in which the neck 13, flange
35 14, cap 15 and diaphragm 17 are replaced by a rubber plug fitted into the end of the cylindrical body of the ampoule and having a thin central area to facilitate penetration by the needle.
In use the ampoule is first inserted into the syringe bar
40 rel. This may be done either at a central supply point or at the place where the syringe is to be used. The short end 3 of the needle is inserted through the nose 5 and pushed by means of the hub 4 until it has perforated the diaphragm 17 and the hub 4 is then screwed onto the
45 nose 5. The rod 20 is then attached to the projection 19 and the syringe is ready for an injection.
The projection or projections 22 or the ridge or ridge sections 23, with or without the slightly non-circular shape of the syringe barrel, serve not only to position the car
50 tridge within the syringe barrel where it is protected against breakage and secured against accidental loss but also the very important function of retaining the cartridge in the barrel against pull applied by the operator when, in making an injection and after inserting the needle but before
55 advancing the piston to discharge the contents of the cartridge, he pulls backwards on the piston rod in order to determine whether the needle has penetrated a blood vessel.
It is within the scope of our invention to vary the
60 cross sectional shape of the ridge 10 or the projection or projections 22 or the ridge sections 23. That is, instead of making them semi-circular in cross section in a plane through the longitudinal axis of the syringe barrel, their surfaces may be tapered outwardly at a smaller angle to
65 facilitate easier insertion of the ampoule into the body and tapered inwardly at a greater angle to more positively resist outward movement of the ampoule. Or, since the ampoules designed for a given capacity of injectable may vary in size i. e. they may be shorter and of greater
70 diameter or longer and of less diameter, the projections or ridges may be tapered inwardly and made to extend ind
