US3368558A - Two compartment cartridge - Google Patents

Description

Feb. 13, 1968 5. J. SARNOFF ET AL 3,368,558

TWO COMPARTMENT CARTRIDGE Filed Aug. 21, 1964 r INVENTORS Sfan/ew J. Sarnoff lll John W fialehger BY ATTORNEYS United States Patent ()fiice 3,368,558 TWO CUMPARTMENT CARTRIDGE Stanley J. Sarnofi, 7801 Woodmont Avc., Montgomery County, Md. 20014, and John W. Balenger, Montgomery County, Md.; said Balenger assignor to said Sarnoff Filed Aug. 21, 1964, Ser. No. 391,836 2 Claims. (Cl. 128218) ABSTRACT OF THE DISCLOSURE In a cartridge wherein medicament is stored in one compartment thereof and a double pointed needle in another compartment, means are provided to prevent the needle from piercing a wall separating the needle from the medicament compartment prior to full emergence of the opposite end of the needle through a wall separating the needle compartment with the ambient atmosphere.

This invention relates to a two compartment cartridge for use in a hypodermic syringe. More specifically, it relates to a two compartment cartridge wherein a hollow needle is stored in one of the compartments and a medication is stored in the other compartment.

It is an object of this invention to provide a positive means for ensuring that the needle be advanced from its storage position in the compartment to an operative position with the forward end of the needle exterior of the compartment before the rear end of the needle is brought into communication with the medicament in the rear compartment.

Other objects will become apparent after consideration of the following specification when taken in conjunction with the accompanying drawing in which:

FIG. 1 is a perspective view of the cartridge in unoperated condition, that is, with the needle in storage position.

FIG. 2 is an enlarged cross-sectional view of the cartridge, parts being broken away, in the storage position of the needle.

FIG. 3 is a similar view with the front end of the needle projected through the wall of the storage compartment and the needle about to penetrate into the medicament compartment.

FIG. 4 is a similar view with the rear end of the needle within the medicament compartment, and

FIG. 5 is an enlarged view of a portion of the advancing means.

Referring to the drawing in greater detail, at is indicated a cartridge casing in the form of a cylinder made of metal, plastic or glass, and here shown as of glass, within which is a rear medicament compartment 12 and a hollow needle front storage compartment 14. The two compartments are separated by a translatable wall 16, preferably of rubber, the medicament compartment being closed off by a piston 18, also preferably of rubber. A medicament 19, as a fluid medicament, is located in the compartment 12.

Within the front compartment is a hollow needle with a bevelled rear end 22 and a bevelled front end 24. The rear end of this needle normally rests in a recess 26 in wall 16 with its bevelled end close to a comparatively thin septum or membrane 28 between the recess 26 and a second registering recess 29. The forward end of the front compartment is closed off by a stopper 30, also preferably of rubber, the stopper being provided with a recess 32 accommodating the forward bevelled end of the needle. The closure 34 at the front end of the stopper is a comparatively thin membrane and it may project slightly be- 3,368,558 Patented Feb. 13, 1968 yond the outer surface of the stopper. The stopper is tightly frictionally held in the casing 10.

When pressure is applied to the piston 18, the wall 16 will be advanced due to the transmission of force through the liquid medicament 14. In the absence of control devices such as will be described, the bevelled ends of the needle would penetrate the membranes 28 and 34 in an order detremined by the sharpness of the bevelled ends of the needles, the thickness and density of the membranes, and the quality of the membranes. A further variable exists in that continued contact of the medicament with the rubber septum 28 may cause softening and deterioration of the rubber. Because of all of these variables, even though it may have been intended to have the membrane 34 pierced before the septum 28 was pierced, there was no certainty that this order of piercing would take place.

However, by interposing a releasable blocking device between the translatable wall 16 and needle it is possible to ensure the piercing of the membrane 34 and extrusion of the forward needle end beyond the stopper 30 prior to establishing communication between the medicament containing chamber and the lumen of the needle.

A description of the blocking device follows: Fixed to and surrounding the outer periphery of the needle, and at a slight distance from the diaphragm is an annular washer 36. Embedded in the face of the wall 16, as by being frictionally held in a recess in the wall, is a washer 38 freely surrounding the needle. This washer has one or more pliable fingers 40 extending toward and engaging the rear face of the washer 36. Any number of such fingers may be employed although three fingers equally spaced circumferen'tially of the washer 38 is preferred. Each finger has a toe portion 42 having a face parallel to the rear face of the washer bearing against the washer 36 and an inclined portion 44 forming a cam end of the finger. The toe portion has a bevelled edge 46 for a purpose which will be disclosed.

While not necessary, it is preferred to supply a metal washer 48 loosely surrounding the needle and serving to center the forward end of the needle to ensure penetration of the stopper 30 at the proper area. In a preferred form of the washer it is made with a rear conical surface rather than a plane surface to better act as a camming surface, as will be explained. In operation, when pressure is applied to the piston 18, as by thrust of a plunger rod of a syringe against the piston, the wall 16 is translated through the intermediary of the liquid link 19. Thereupon the toe 42 or the toes 42 thrust on the needle mounted washer 36 and drive the washer and afiixed needle through the membrane 34 of the stopper 30. The needle is thrust through the stopper by reason of the coupling action of the fingers until the cam portion 44 of pliable finger 40 engages the stopper 30 or the washer 48 where the latter is used. Since this end of the finger extends only slightly below the washer 36, washer 36 is now close to washer 48. The free end of each of the fingers, on further downward movement of the wall 16, slides along the rear surface of the washer 48 and radially away from the needle thereby freeing the toe from the washer 36 the cam portion 46 assisting such action. Now that the block between the needle and wall 16 is removed, the wall 16 slides along the length of the needle, causing the needle to pierce the septum 28. Continued movement of the piston, under the influence exerted by pressure on the piston 18 and liquid medicament 19 causes the forward face of the washer 38 to engage and drive the washer 36 into firm engagement with the washer 48, thereby preventing rearward movement of the needle 20. Also, medicament is now ejected from the needle.

Having thus described the invention, what is claimed is:

l. A cartridge comprising a casing, a piston adjacent one end of the casing, a translatable wall within the casing intermediate the ends of the casing, and a stopper at the other end of the casing, a medicament in a first compartment formed in the casing between the piston and translatable wall, a hollow needle in a second compartment formed in the casing between the intermediate wall and the stopper, and a mechanical drive connection between the needle and translatable wall having a part driven by the Wall and a part fixed to the needle to cause the needle to penetrate the stopper on displacement of the piston, and means engaged by a part of the mechanical connection in its displacement within the casing to uncouple the connection whereby the wall moves relative to the needle and the needle subsequently pierces the wall, the fiuid then being ejected through the needle, said drive connection comprising a washer afiixed to the needle and a pliable finger carried by the translatable Wall engaging the washer, the finger extending angularly in a direction toward the stopper and away from the needle, and the means for uncoupling the connection including a second Washer adjacent the stopper, the second washer being engaged by the end of the finger and effecting radial displacement of the end of the finger away from the needle.

2. The structure of claim 1 wherein the rear face of the "washer is conical with the conical apex of the Washer surrounding the needle.

References Cited UNITED STATES PATENTS 1,767,304 6/1930 Morton 128220 2,408,323 9/1946 Lockhart 128220 2,460,039 1/1949 Scherer 128218 RICHARD A. GAUDET, Primary Examiner.

D. L. BAKER, Assistant Examiner.

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