US3444620A - Shearing device - Google Patents

Description

United States Patent O U.S. Cl. 30-231 6 Claims ABSTRACT OF THE DISCLOSURE A stationary shear element and a movable shear element pivotally mounted on the former for relative angular displacement away from and back to a rest position. A bore in each element which, in the rest position of the movable shear, longitudinally communicate at a shearing plane dened by interacting shearing surfaces formed on the elements within the bores. A hypodermic syringe is received within the longitudinal bore in a manner such that the hub portion is disposed above the shearing plane in the movable element and a substantial portion of the cannula projects below the shearing plane in the stationary element whereby relative angular displacement of the elements from the rest position causes the cannula to be sheared from the hub.

Background of the invention Many types of hypodermic syringes and needle cornbinations that are being presently marketed or which have been marketed in the past may be sterilized after use, such as by exposing the unit to sterilizing temperatures of the range present in an autoclave or the equivalent. In this instance the unit is suitably sterilized for reuse at a later time. Therefore, the profession has developed sterilizers and containers for storing, under sterilized conditions, large quantities o-f syringes and/ or needles for indeterminate periods of time thereby to have available sterile parts when required.

It may be apparent that if these parts are to be later reused extreme caution must be exercised to segregate the sterile components from the unsterile components. Under situations where mass injections are performed this necessary control may break down and a contaminated needle may be inadvertently employed causing possible infection in a second or subsequent patient. Even if controls do not break down there is always the possibility that the needle being reused has not been properly sterilized and therefore, remains contaminated.

In order to obviate the necessity of controllably segregating once used needles during periods of great activity and thereafter subjecting these needles to sterilization the industry has developed needles and hypodermic syringes that are designed rfor a single usage. Thus, the cost factors involved in the requirement to maintain rather expensive sterilizing equipment and containers for maintaining the needles sterile once sterilized is obviated. Further, the time consuming process of sterilization is eliminated as is the chance that an unsterile needle will be reused, whether this needle is inadvertently reused prior to sterilization or whether the needle is not properly sterilized. Additionally, there is no chance of the needles becoming dull thereby causing undue trauma for the patient on repeated usage. These factors, among others, dictate that the better procedure costwise, timewise and patientwise is to destroy or render the hypodermic syringe and/or needle inoperative after an initial use rather than subject the components to sterilization procedures prior to any reuse.

At this time'no suitable destruction apparatus has been developed that has met with widespread acceptance. A proposal, to name one of many, has been advanced along the lines of a unit capable of crushing the hypodermic syringe and needle component, thereby rendering it unusable after an initial use. This proposal is not particularly suitable since a c r/ushing apparatus is envisioned by a relatively large, heavy and stationary structure that does not lend itself to portability thereby necessitating many units throughout a hospital or clinic. In View of these considerations the widely practiced method is merely that of breaking the cannula from its supporting hub, once the unit has been used, by hand. Obviously, there is always the chance that this procedure might precipitate injury or cause infection, as discussed. Injury may be incurred since the cannula tends to ily in random directions upon breaking and its sharply pointed tip may lodge itself Within sensitive parts of the body. Further, chance injury to janitors and similar personnel should be avoided by indiscriminate discard of needles.

In addition to possible infection or injury caused by reuse of contaminated needles or hand breaking of needles it should be pointed out that precautions should be taken to prevent salvage and reuse of discarded needles by addicts or other unauthorized persons.

SUMMARY OF THE INVENTION In view of the foregoing and in a broad sense the present invention is directed to a manual shearing device of the type adapted to shear a metal cannula portion from a supporting hub of a hypodermic syringe unit. The device includes a bracket having a top planar supporting surface and a generally vtransverse surface, a pivoting shear element having an axial bore of a configuration substantially complementary to the configuration of the syringe unit, an elongated stationary shear element 4with a transverse bore for receipt of the metal cannula portion mounted on the transverse surface of the bracket thereby to project in a generally normal direction, means mounting the pivoting shear element on the stationary shear element so that the bores are in alignment, and spring means for biasing the pivoting shear element to a stable position for receipt of the syringe unit and for returning the pivoting shear element to the stable position after relative movement of elements and consequent cannula shearing.

In view of the `foregoing the invention uniquely overcomes the problems and disadvantages brought out above and has for a principal object, the provision of a device which is of relatively uncomplex construction, one that may be mounted upon the carton in which the syringes are distributed whereby the carton collects the sheared components, one that may be conveniently and easily moved from one location to another and a device in which the operation is uncomplicated and effective whereby the cannula or needle portion of a syringe may be sheared from its supporting hub structure to render the syringe non-reusable.

Other objects and advantages of the present invention Iwill readily come to mind during the course of the following discussion taken in conjunction with the drawings which illustrate the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a top plan view of the shearing device positoned within and supported by a collector container;

FIGURE 2 is a side elevational view of the shearing device as seen along the line 2-2 in FIGURE l;

FIGURE 3 is a view in side elevation, partly in section, showing the stationary shear member and the rotary shear member mounted thereon;

FIGURE 4 is a front elevation in section of the components of FIGURE 3, showing the rotary member in a rest position and having a hypodermic syringe disposed therein; and

3 FIGURE 5 is a view similar to FIGURE 4 but showing the rotary member having undergone a rotational movement about the stationary shear member.

DESCRIPTION OF THE PREFERRED EMBODIMENT The shearing apparatus, represented by the numeral 10, is of the mechanical hand operated type and generally includes a supporting bracket 12, a rotary shear element or member 14 and a stationary shear element or member 16.

Bracket 12 is preferably formed ofy a sturdy structural material, such as steel which may be stamped from a section of thin gauge stock and thereafter provided with a nickel plate coating for purposes as are well-known. The bracket is defined by a generally `U-shaped top planar portion 13 and a portion 11 struck from the top so as to project in a substantially normal direction. While not specifically shown in the iigures the top planar surface may be provided with suitable printed indicia.

As shown most clearly in FIGS. 1 and 2 the bracket is conveniently seated, for stability during usage of the apparatus, on a container, only the top surface 18 of which is shown. The container may be either the case in which the hypodermic syringes are shipped or another suitable supporting means as choice dictates. In the former case, the upper surface 18 is provided with a diecut hole 15 which is pushed out to receive the projecting portion 11 of bracket 12. The side walls of the portion 11 are generally tapered outwardly toward the surface 13 thereby to bind within the hole. Additional holding action, particularly against any twisting or unseating forces transmitted to the bracket during a shearing operation, is provided by a plurality of prongs 22 carried at the corners of bracket surface 13. The prongs are downwardly directed and configured so that they readily pierce the container 18 upon the application of necessary downward force. 'I'his force is applied after the tabs 20 have been engaged with the underside of container portion 1S.

FIG. 2 shows the bracket 12 in position on the container 18 which conveniently acts as a collector for the Sheared cannulas and other syringe parts. Since the bracket top surface is flat and the shearing components are either within or below the plane of surface 13 the collecting containers may be stacked for later distribution usage.

The shearing elements 14 and 16, best seen in FIG. 3, -are similarly formed of a sturdy material, such as tool or stainless steel, having a Rockwell C Scale hardness of from about 50 to 60. Additionally, the elements may be provided with a nickel plate iinish. Since the elements, together with the bracket and spring, to be discussed, are formed from metal the apparatus may be `autoclaved or otherwise subjected to similar sterilization procedures. Removal of the apparatus from its seated orientation is a relatively easy operation.

The rotary shear element 14 is of an elongated generally cylindrical construction. The element is provided with an axial opening or Well 24 which runs the length thereof. The element carries a second opening 26 which is transverse to and in communication with the opening 24. Opening 26 is cylindrical in shape, located in the rotary shear element in a position removed from the top and, as will be discussed, receives the stationary shear element 16 for mounting one element on the other.

As shown in the figures the portion of the well, above the opening 26, is of a configuration soas to be substantially complementary to the configuration of a conventional hypodermic syringe. The internal well surface is provided with a shoulder 25 that establishes the extent to which the syringe may be received. With conventional units the shoulder will thereby position the tip of the syringe hub immediately above the opening 26 so that substantially the entire cannula length projects through the opening 26 and into the lower rotary shear opening 28. The lower opening is of increased diameter and provides a path to the interior of the collector box for Sheared cannulas.

As most apparent in FIG. l, the communication between the openings 24 and 26 is provided by a passage 27 of relatively small dimension. The dimension is such that only the cannula portion, guided to the passage by the internal taper 29, may pass therethrough and thereby the apparatus uniquely and properly positions the cannula, irrespective of syringe type, for shearing.

Turning now to the stationary shearing element 16, it is seen that it is generally tubular in configuration and solid throughout except that it is provided with a transverse bore 38. Bore 38, when shearing element 14 is mounted, communicates with the upper and lower openings within the rotary element. The bore 38 is generally of an inverted conical shape at the point of communication with the upper opening and generally cylindrical thereafter. Thus, the passage 27 is formed by the abutting at apexes of inverted cones to dene a pair of interacting shearing surfaces.

As seen most clearly in FIG. 3 the stationary shear element includes a hub 30 that terminates in a unitary anged portion 34. The hub of stationary shear 16, on mounting, is supported in an opening 32 in the bracket portion 11. The extent of receival of the shear 16 through opening 32 is determined by the flange 34 which yabuts against and is connected to the back wall of projection 11 by spot welds 36 or the equivalent.

As generally discussed above and as shown in the figures, the rotary shear member 14 is mounted on the stationary shear member 16 and secured for rotary movement by the retainer or clip 42. The retainer is received within an annular cut 40 on the stationary shear thereby, in a conventional manner, to secure the rotary shear. If the stationary shear element is properly oriented on the bracket 12 a longitudinal opening will be provided through the rotary shear element to permit a shearing operation.

In FIGS. 3 and 4 the rotary shearing element 14 is shown in the relaxed or inoperative position. This position is maintained by the relaxation tendency of a resilient means, such as torsion spring 44. As clearly shown in FIG. 3 the ends of spring 44 are restrained from rotation, respectively, by opposite sides of pin 46, carried by the rotary element 14.

When any torque is applied to move the rotary shear element from the relaxed position to the position of FIG. 5, or the reverse, one end or the other of spring 44 is carried with pin 46. The other end of spring 44 is restrained by the abutting surface 48 struck from bracket portion 11. Thus, rotation of the rotary shear element 14 in either the clockwise or counterclockwise directions (see arrows 50 in FIG. 2) places the spring in a load condition so that its bias returns the rotary shear to the position of FIG. 4.

While not shown in the figures suitable structure may be provided to limit the angle through which the rotary shear element may be rotated.

In operation, the shearing apparatus 10 is mounted upon a container case and xedly held in the mounted position by the retaining structure already discussed. With the rotary shear member in the relaxed position as shown in FIG. 4 a hypodermic syringe, indicated by the numeral 54, is introduced into the well 24 so that its projecting cannula 56 passes through the bore 38 in the stationary shear member 16 and the lower opening 28 in the well. Therefore, the substantial length of cannula passes through the shearing plane defined by the pairs of shearing edges 58 and 60. These edges are also of a high Rockwell hardness to retain their edge and not be marred through use. The interaction of the two shearing edges, when the well member is pivotally rotated (FIG. 5), causes the cannula portion 56 to be sheared from its supporting hub portion r62, adjacent the hub thereby rendering the hypodermic syringe unusable. Sheared cannulas and other syringe components are collected within container 18. The operator, to provide the necessary shearing torque for rotating the rotary shear member 14 from the position of FIG. 4 to FIG. 5, may conveniently grasp the projecting syringe barrel and use the barrel as a lever. Thus, rather easily the rotary shear is moved, as discussed, so that the shearing of the cannula is accomplished.

From the foregoing it is clearly seen that the objects and advantages as noted above are achieved and that other objects and advantages are carried out. While the foregoing description discloses a preferred embodiment of the present invention it is understood that this disclosure is by way of example only, not by Way of limitation, and that the invention is within the scope of the appended claims.

Having described the invention, I claim:

1. A shearingr apparatus `for shearing the needle cannula of a hypodermic syringe from its supporting hub comprising a bracket member adapted to be mounted on a container for collection of sheared parts, a rst elongated shearing element having a transverse bore whose outer limit defines a rst shearing edge mounted on said bracket member in a manner such that the first shearing ele-ment axis is substantially perpendicular to said bracket and the bore is spaced therefrom, a second shearing element removably received on the first element for relative angular movement with respect to the latter, said second element having a longitudinal central opening and a second shearing edge at the point of communication with said bore, and means for biasing the second element to a rest position with the opening and bore in alignment thereby to receive said hypodermic syringe so that substantially the entire cannula length is disposed below the shearing plane defined by the shearing edges whereby a relative angular displacement of said second shearing element causes said shearing edges to interact providing a shearing operation.

2. The shearing apparatus of claim 1 wherein said bracket member has a generally planar U-shaped top surface and downwardly projecting surface, said first element being stationarily mounted on said downwardly projecting surface.

3. The shearing apparatus of claim 1 further including means on said bracket member for removably securing the same to said container.

4. The shearing apparatus of claim 1 wherein said first shearing element includes a cylindrical collar and projecting neck portion, a flanged base on said collar mounting said element to said bracket, and an annular groove adjacent the neck end.

5. The shearing apparatus of claim 4 wherein said second shearing element is received on the first element between the collar and groove, and clip means received in said groove removably retaining said second shearing element.

6. The shearing apparatus of claim 2 wherein a tab projects from said downwardly directed bracket surface in the general direction of said second shearing element, a pin, said pin carried by said second shearing element and located in the plane of said tab, and said biasing means comprising a preloaded coil spring whose body is supported on said rst shearing element and whose ends are retained from rotation in said rest position by opposite sides of said pin and by said pin and tab when further loaded upon angular displacement of said second shearing element in either the clockwise or counterclockwise direction.

References Cited UNITED STATES PATENTS 964,561 7/1910 Salviolo 30-109 1,650,084 11/1927 Mason 30--131 X 1,849,261 3/1932 WintonV 30-231 X 3,370,353 2/1968 Weissman 30-233 MYRON C. KRUSE, Primary Examiner.

J. C. PETERS, Assistant Examiner.

U.S. Cl. X.R. 30-131, 240

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