Abstract:
An improved hanger assembly is provided for use with bottles containing liquids, particularly glass vessels for holding liquids to be administered parenterally. The hanger includes a frangibly-activated hinge that biases the rotation of a hook or loop into a position to enable safe and expeditious hanging of the bottle. The assembly is a substantially rigid unitary construction made of material having a substantially uniform thickness, i.e., not having any elements protruding outside of the general profile of the bottle to be hung. The assembly maintains this profile until the frangibly-activated hinge is broken to allow rotation of the hook or loop into a position to permit hanging. Further, use of a frangibly-activated hinge permits the use of design and materials for the hanger assembly which reduce the risks of tearing the hanger and improve the bottle orientation when it is hung.

Description:
DESCRIPTION 
     This invention relates to hangers for containers, especially those liquid containers which require hanging by their bases. In particular, the field of this invention consists of hanging assemblies which attach to glass bottles of parenteral solutions for suspending the bottles during administration of the solutions. 
     Parenteral solution containers are generally glass or plastic bottles having a hanger molded into or attached to the base. The contents of a parenteral solution bottle are conventionally administered to a patient by resting the bottle on its base while puncturing or otherwise accessing the contents with a liquid flow conduit called an administration set, suspending the bottle by its base hanger at a point above the patient, accessing the patient&#39;s veins with the administration set and then allowing the contents to flow into the patient&#39;s vein. 
     Such bottles have been suspended by a wide variety of hangers, most of which involve a band which envelopes the bottle to a greater or lesser degree and a bail or handle that is connected to the band in various ways. For example, see U.S. Pat. Nos. 3,807,679; 3,635,367; and 2,652,054. Since thermoplastic bottles have become widely accepted many hanging systems are molded integrally with the bottle. Examples of such integral structures are illustrated in U.S. Pat. Nos. 3,384,258; 4,010,862; 3,387,732; and 3,901,339. 
     The known hanging structures are deficient from the point of view of ease and cost of manufacturing, safety and reliability, and user convenience. These deficiencies are particularly important in the medical industry where many of the products contained within the bottles are biologically active substances such as drugs to which attending staff or other patients should not be exposed by way of breakage due to accidental failure of a hanger assembly. Further, the hangers must be convenient to use, otherwise medical therapy will be proportionately delayed. Finally, the hangers should be constructed so that the containers are suspended entirely vertically, whatever the weight of fluid remaining in the bottle. This will ensure that the bottle graduation markings remain horizontal and parallel with the fluid meniscus throughout fluid administration. This eliminates guess-work in reading the level of fluid as it is administered and guarantees fluid drains from the bottle completely. 
     Accordingly, it is an object of this invention to provide a hanging assembly which is less costly to manufacture than heretofore existing systems. 
     It is another object of this invention to hang containers with less risk of rupture in the hanging systems than is attendant present systems. 
     A further object of this invention is to hang liquid containers vertically whatever the fluid level within the containers. 
     Another object is to eliminate protrusions from the general profile or outline of the containers so as to prevent inadvertent hooking or catching of the protrusions on obstacles and the resulting breakage or rupture of the container or its hanging assembly. 
     These and other objects of the invention will be apparent from consideration of this specification as a whole. 
     SUMMARY OF THE INVENTION 
     This invention provides an improved hanger assembly in which a tab containing a frangibly-activated hinge and a suspension means is molded or bonded to a skirt. The skirt is connected to a container or molded integrally with a container. The improved hanger assembly is compact and of substantially uniform thickness except where it is compact and pierced by passages or openings, i.e., no protrusions exist beyond the profile of the container to which the system is adapted. Thus the container may be rested on the hanger assembly without tipping over. It also needs no fasteners to hold elements of the hanger in place. The hinge has been found to be extremely reliable through multiple flexings and is effective in biasing the suspension means of the hanger into a vertical position convenient for rapid hanging and set up. An additional advantage is that the container can be rested on the hanger even after the hinge has been frangibly activated and the suspension means extended. 
    
    
     THE DRAWINGS 
     FIG. 1 is a top elevational view of the hanger assembly; 
     FIG. 2 is an enlarged sectional view taken along line 2--2 of FIG. 1; 
     FIG. 3 is an enlarged side elevational view of the hanger assembly in the process of being frangibly activated into operation; and 
     FIG. 4 is an enlarged sectional view of the frangibly-activated hinge after it has been opened. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows the hanger assembly as viewed from the bottom of a bottle or container (not shown) onto which it is engaged or into which it is integrally molded. A cylindrical skirt 10 depends from a flange 11 which projects inwardly of the upper skirt rim 12. 
     The flange 11 is enlarged over about 40% of its circumference to accommodate a tab 13 at a connecting region 14. The tab 13 includes a suspension means generally shown at 17, in this figure including a thickened loop 16 and a generally triangular hole 15 embraced by the loop which has dimensions that conform with conventional parenteral solution bottle hanging bars, rods or hooks. 
     The tab 13 also includes a frangibly-activated hinge 18. The hinge 18 comprises a generally V-shaped score 19 located across the center axis of the skirt 10 and penetrating at maximum depth about one-half of the way through the tab from the side of the tap opposite the upper skirt rim 12. The hinge 18 includes a bridge 20 or thickened region of the tab at the score line, one bridge being located at each end of the score 19 to aid in ensuring that the hinge will remain rigid until frangibly activated. A resilient lip 21 is interposed between the hinge 18 and the connecting region 14 to relieve stress on the hinge during activation and hanging. The arcuate opening defined by the arcuate flange 11 is only as wide as is necessary to allow rotation of the suspension means, about the hinge, although it may have an expanded area 22 where part of the flange 11 has been removed so as to allow entry of a prying means such as a finger (not shown) to frangibly activate the hinge. 
     FIG. 2 illustrates an embodiment of the hanger assembly which may be used with discrete rather than integrally molded containers. Such discrete or separate containers (not shown) are glass or plastic and are snapped into the cup-shaped hanger system substantially as shown in FIG. 3 and as will be further discussed below. This embodiment of the hanger system is the preferred embodiment of this invention. It includes the skirt 10, a first flange 11 projecting inward of the upper skirt rim 12, a ridge or second flange 23 for connecting communication with a bottle, a score hinge 18, a resilient lip 21 and a suspending means 17 including a loop 16 and a passage 15. The tab 13 is formed so that it substantially rigidly projects into the opening defined by the flange 11 or the skirt 10 at a downward angle of about 5° to 30°, generally about 20° from the plane of the flange. This ensures that the tab will not inadvertently protrude slightly above the rim 12 due to stresses in the hanger assembly when it is forced onto the base of a bottle if the tab projects outside of the bottom plane of the flange. The bottle will not sit flat on its base. The resilient displacement lip 21 permits the tab to be pressed into the plane of the flange by a bottle base (24 in FIG. 3) without breaking the tab. 
     FIG. 3 demonstrates a representative technique for frangibly activating the hinge. Bottle 25 is grasped in one hand (not shown) and a finger as shown is worked under the tab through the suspension means passage 15. The finger is contracted or pulled back in the direction indicated by arrow A so as to lift the tab in a direction up and away from the plane defined by the skirt rim 12. Lifting the tab through an arc of about 20° will rupture the restraining elements of the hinge, i.e., the bridges 20 and the hinge 18. 
     As shown in FIG. 4, the bridge 20 will be entirely fractured, while the hinge element is stretched and crevassed as generally shown at 26. The resulting frangibly-activated hinge is a fraction of its thickness prior to breakage, generally 50-75% of the unscored thickness. However, the principle contributor to flexibility of the hinge is the multiple fracturing of the hinge material along the length of the hinge; the material contains a great plurality of cracks, none of which is sufficient to separate the hinged components but which create a multiplicity of thin membranes. This thin thermoplastic laminae forms a flexible hinge. In addition, scoring the tab half way through results in a hinge that returns the suspension means to a vertical position if it is forced back more than 90° from its position before hinge activation. This is to be distinguished from scored metal hinges, in which nothing is broken until the metal fatigues and fails. 
     Suitable materials for making the frangibly-activated hinges used in the hanger assembly of this invention are generically termed hingeable organic polymers. Specific examples include polypropylene or mixtures of polypropylene and polyethylene. Other such polymers will be readily known to the ordinary artisan. A general test is that a 0.05 inch thick layer of polymer which is hinge-scored to a depth of 0.025 inch must be able to survive at least 100 flexings through 100° without separating. The hingeable organic polymer will generally combine to make up the resilient lip and the hinge together. However, that combination can be connected by conventional techniques to the flange and skirt which can be fabricated from any suitable material such as metal or plastics. The hanger assembly may be molded integral with a container. For example, the skirt may be extended or molded with other bottle elements to form the sides and top of a container or bottle. In this case the bottom of the bottle will be in the same position as the bottle bottom 24, but the flange 11 will be integrally molded into the bottle. Other equivalent embodiments will be readily apparent to the artisan. 
     Other suspension means than the loop of the preferred embodiment will also be apparent. For example, clips or snaps can be provided for connecting the suspension tab to complementary racks or stands. 
     The containers which are preferred to be used with the hanger assembly herein are parenteral solution administration bottles. Such bottles are especially characterized by the presence of fluid level indicia on the sides of the bottles and sterile closures at the fluid outlet. Such bottles are well known to the ordinary artisan, as are the sterile aqueous solutions of nutrients, drugs and electrolytes contained therein for parenteral administration.