US3368559A - Hypodermic injector with safely held release means - Google Patents

Description

Feb. 13, 1968 SJ SARNOFF ET AL 3,368,559

HYPODERMIC INJECTOR WITH SAFELY HELD RELEASE MEANS Filed Sept. 17, 1965 QM N INVENTORJE Stanley J. Sarnoff 4 1 Geo/ye B. Gal/ ins BY WM M ATTORNEYS Patented Feb. 13, 1968 3,368,559 HYPODERMIC INJECTOR WITH SAFELY HELD RELEASE MEANS Stanley J. Sarnoff, 7507 Hampd'en Lane 20014, and

George B. Calkins, 6806 Selkirk Drive 20034, both of Bethesda, Md.

' Filed Sept. 17, 1965, Ser; No. 488,055

8 Claims. (Cl. 128218) This invention is directed to improvements over the hypodermic syringe disclosed in the patent to Stanley J. Sarnoff et al., 2,832,339, granted Apr. 29, 1958.

In particular, the invention relates to improvements in the release mechanism of the hypodermic syringe disclosed and claimed in that patent.

One type of hypodermic syringe comprises a hypodermic injector which can be carried on the person of the user with the needle thereof in a sheathed condition, the device being quickly and easily releasable by removing a safety pin and pressing a tube holding a medicament vial against the portion of the body which is to receive the medicament, while grasping an outer sleeve, the relative movement of sleeve and tube causing the needle to automatically move rapidly outwardly from the tube under the influence of a spring and the medicament in the vial to be ejected through the needle. This spring is normally retained under compression by a detent within the device.

It is possible, in the prior art devices including the device on which this is an improvement, to inadvertently cause ejection of the needle and ejection of medication after the safety pin has been removed, without relative sleeve and tube movement, this occurring, for example, by reason of rough handling or dropping of the syringe.

It is an object of this invention to provide improved detent means to minimize thechances of inadvertent release of the spring .with consequent inadvertent ejection of the needle and medicament.

Other objects will become apparent from a consideration of the following specification and claims when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of an improved hypodermic injector, the spring thereof being shown in released position and the injector incorporating the detent means of this invention;

FIG. 2 is a plan view of one form of detent forming part of the invention;

FIG. 3 is a plan view of a second form of detent forming part of the invention; and,

FIG. 4 is a diagrammatic view illustrating the position of parts with the detent, such as the flat detent of FIG. 2, partially operated for release of the spring.

Reference is made to the disclosure in the Sarnoff et a1. patent for such structure and mode of operation of the syringe as is not wholly disclosed herein.

Referring to the drawings herein and adverting particularly to FIG. 1, it will be noted that the vial holder structure herein may be made very similar to that shown in the Sarnoff et al. patent previously referred to, though the precise structure of vial holder therein is not the essence of the invention; any form of holder for vial and spring is suitable, so long as a shoulder is provided for detent engagement. The main difference, it will be noted, is in the configuration of a detent shaft and its action.

As a specific embodiment of the invention, FIG. 1 discloses in cross section and in released condition of the spring, an outer sleeve or sheath of plastic or metal open at the lefthand end and closed, except for a perforation 12, at the righthand end 14. Telescopingly mounted in the outer sleeve is a tube 16, also of plastic or metal, secured in any convenient manner to a metallic spring housing 18, open at the lefthand end 20 and closed by a collar 21 at the righthand end, except for a perforation 22, for the passage therethrough of a detent portion of the novel shaft to be described. The tube 16 is closed at the lefthand end, except for a perforation 24, to permit extrusion of the needle 26.

Within the lefthand end of the tube 16 is a vial 28, shown in FIG. 1 as emptied of its contents, the vial being provided with a rubber stopper 30, penetrated by the hollow needle, the needle having been driven through the rubber stopper and the contents of the vial having been ejected through a passageway in the needle by reason of a piston 32 within the vial having been driven to the left. The drive of piston 32 was effected by displacement of disc member 34, the disc being driven by the spring seat end 36 of a shaft 38, shaft 38 being driven in turn by reason of release of compression of a helical spring 40. The spring reacted between the spring seat on the shaft and the inside face of collar 21. The shaft, as shown. in FIG. 2, is provided near its end opposite the spring seat with a detent portion indicated generally as 42 in FIG. 2. The shaft 38 is cylindrical; the seat 36 is a circular flange and the detent end of the shaft is provided with a conical portion 44 and a slotted portion 46 extending completely through the shaft, the slot in the shaft extending but a short distance above the cone and a much longer distance below the cone. The cone has its conical portion 44 diverging away from the axis of the shaft in the direction of the seat and thereis a surface 50' extending outwardly from the shaft. This surface is normally parallel to and engages the upper surface of the collar 21 when the spring is under compression and the device cocked for operation. Also in cocked position and integral hollow bridging neck portion 52 of the shaft may extend thru aperture 12 in the outer sleeve to receive a locking pin (not shown) inserted into the device to prevent inadvertent unseating of the detent and release of the needle and medicament.

By reason of the slotted construction of the shaft and integral neck 52, however, undesired sliding of the detent surface 50 from oh? the collar 21 is made difficult as will become apparent. With the construction of the prior art, as in the Sarnoff et a1. patent previously referred to, pivoting of the arms supporting the detent portion occurs at the closed end of the slot. As a consequence any forces, as inertia forces, incurred when dropping the hypodermic device when the safety pin has been removed, which tends to slightly move the arms toward each other, angles the detent surface which engages the collar to present an acute angle between it and the collar surface, promoting sliding action of the detent surface in a direction to cause release of the shaft.

By reason of the closed at both ends slotted construction disclosed herein, when an unintended force tends to move the detent surface, because of the two pivots provided by the ends of the slot in the shaft and the shortness of the portion of the slot above the surface 50 compared to the remaining ortion of the slot, the surface 50 angles in an opposite direction to that which occurs in the prior art. Therefore, as seen diagrammatically in FIG. 4, the springiness in the material of the shaft and the angularity of the surface is such as to tend to restore the detent to locked position.

Normal release of parts is effected by telescoping action of the outer sleeve with respect to the holder for the vial, whereupon the wall surrounding the perforation 12 engages the conical surface portions of the detent and forces them together sufliciently to allow the detent to pass through the opening 22, the slotted portion permitting suflicient flexing of the walls of the shaft to take place to permit this action.

In the modified form of invention shown in FIG. 3, instead of the shaft and seat being cylindrical, the same maye be made of a flat bar, as bar 54, rectangular in cross section, thereby saving material. The neck or bridge piece 56 is hollow and cylindrical to permit insertion of the locking pin referred to hereinabove. When no safety pin is employed, the entire shaft, including the bridge piece at the end of the slotted portion, may be fiat.

Having thus described the invention, what is claimed is:

1. A spring propelled control element for a hypodermic injector comprising a shaft of resilient material, a spring seat at one end of the shaft, a detent adjacent to but removed from the other end of the shaft, said detent having a sloping surface diverging in a direction toward the spring seat and a second surface intersecting the first surface and extending laterally from the shaft, said shaft being slotted longitudinally of the shaft from a point close to but not at said one end of the shaft and closer to said one end than the second surface, to a second point along the shaft beyond said second surface, said slotted portion of the shaft from the second intersecting surface level to the second point being longer than the remainder of the s'otted portion.

2. A spring propelled control element for a hypodermic injector comprising a shaft of resilient material, a spring seat at one end of the shaft, a slotted portion in the shaft extending from adjacent one end of the shaft but removed from the end thereof and extending toward the spring seat, a detent on the shaft adjacent to said one end of the shaft and positioned intermediate the length of the slotted portion, said detent comprising a surface sloping divergently in the direction of the spring seat end of the shaft and a second surface intersecting the first surface and extending laterally from the shaft, the slotted portion between the second surface and the seat end of the shaft being longer than the remaining portion.

3. The structure of claim 1 wherein the shaft is a fiat member and there is provided a second detent, the detents being at the same level along the length of the shaft and extending from the shaft on opposite side of the flat member.

4. The structure of claim 1 wherein the shaft is a cylindrical member, and the portion of the shaft on the one end thereof is constituted of a collar integral with the portions of the shaft on each side of the slotted portion thereof.

5. The structure of claim 4 wherein the detent is in the form of a frustum of a cone with the slotted portion passing through the frustum of the cone.

6. The structure of claim 1 wherein the material is a plastic.

7. The structure of claim 1 wherein the material is metallic.

8. In a hypodermic syringe device, a vial for fluidhaving a puncturable sealed opening, a hypodermic needle withdrawn therein in alignment with such sealed opening, a piston within said vial, said needle being drivably secured to said piston and drivable through such sealed opening in response to pressure acting upon said piston,

a holder for said vial, said holder mounting a driving spring positioned for urging said piston outwardly, and means for releasably holding said driving spring in a compressed condition, saidmeans comprising a shaft of resilient material, a seat seating said driving spring at one end of the shaft, a detent on said shaft close to the other end of the shaft and engageable with but releasable from a portion carried by the holder, said detent having a sloping surface diverging in a direction toward the spring seat and a second surface intersecting the first surface and extending laterally from the shaft, said shaft being slotted longitudinally of the shaft from a point close to but not at said one end of the shaft, and closer to said one end than the second surface, to a second point along the shaft beyond said second surface, said slotted portion of the shaft from the second intersecting surface level to the second point being longer than the remainder of the slotted portion, and means engaging the sloping surface to move it toward the axis of the shaft to unseat the detent and release the spring from compression.

References Cited UNITED STATES PATENTS 2,832,339 4/1958 Sarnoff et a1. 128-218 2,871,856 2/1959 Stiener 128216 3,320,955 5/1967 Sarnoff 128218 FOREIGN PATENTS 955,180 1/1950 France.

RICHARD A. GAUDET, Primary Examiner.

D. L. BAKER, Assistant Examiner.

Claims (1)

1. 2. A SPRING PROPELLED CONTROL ELEMENT FOR A HYPODERMIC INJECTOR COMPRISING A SHAFT OF RESILIENT MATERIAL, A SPRING SEAT AT ONE END OF THE SHAFT, A SLOTTED PORTION IN THE SHAFT EXTENDING FROM ADJACENT ONE END OF THE SHAFT BUT REMOVED FROM THE END THEREOF AND EXTENDING TOWARD THE SPRING SEAT, A DETENT ON THE SHAFT ADJACENT TO SAID ONE END OF THE SHAFT AND POSITIONED INTERMEDIATE THE LENGTH OF THE SLOTTED PORTION, SAID DETENT COMPRISING A SURFACE SLOPING DIVERGENTLY IN THE DIRECTION OF THE SPRING SEAT END OF THE SHAFT AND A SECOND SURFACE INTERSECTING THE FIRST SURFACE AND EXTENDING LATERALLY FROM THE SHAFT, THE SLOTTED PORTION BETWEEN THE SECOND SURFACE AND THE SEAT END OF THE SHAFT BEING LONGER THAN THE REMAINING PORTION.

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