Abstract:
Vessels formed to have a safety glass break-seal are described. The break-seal is formed as a hollow finger-like structure extending into the volume of the vessel which can be easily fractured by applying force to the inner surface of the structure. The break-seal design offers the advantage of being protected from external forces during shipment and handling of the vessel and the advantage of safety in that fracture of the break-seal structure does not leave sharp glass edges accessible to the hands of the user/operator. The safety glass break-seal vessel can be fitted with a secondary closure, such as an elastomeric septum, to provide protected access to the contained composition following fracture of the safety glass break-seal.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to glass containers. More particularly, this invention is directed to a vessel having a glass wall formed to allow the vessel to be opened by fracturing a portion of the vessel wall without producing exposed sharp edges. The vessel can be used for efficient transfer of fluid samples to a closed system.  
         BACKGROUND AND SUMMARY OF THE INVENTION  
         [0002]    Glass is proven material of choice for the packaging, storage and handling of chemicals, fluids, vapors, gases, solids or solutions, particularly where maintaining the stability and purity of the chemicals during shipping and storage is critical. The preference for use of glass for such applications derives principally from the fact that it is inert, and it exhibits low porosity making it impermeable to most compositions whether they be solids or fluids, including both gases and liquids. Hermetically sealed glass containers are often used for the packaging, handling and storage of small chemical compositions, most typically small samples of solid, liquid and gaseous chemical compositions destined for use in chemical research and development operations. Sealed glass vessels have also found use for the packaging and storage of pharmaceutical substances, typically in unit dosage form. The use of a sealed glass vessel for packaging and storage of most chemical substances prevents product loss and helps assure that the product is free from contaminants prior to the time it is removed from the container for use.  
           [0003]    One serious disadvantage of conventionally sealed glass ampules or tubes for the packaging, storage and delivery of chemical compositions is the hazard associated with the opening of the vessel by breaking a glass appendage, typically a protruding glass seal. Such has, from time to time, resulted in catastrophic glass vessel failure resulting in loss of the contained composition and injury to the user. Moreover, such glass vessels typically present exposed sharp glass edges (at the point of glass fracture) after opening which constitutes a safety hazard. The present safety glass break-seal containers are formed to provide a safe alternative for opening the sealed glass containers, optionally without scoring, and without generating sharp, exposed glass edges, thereby minimizing safety concerns for use and disposal of such containers.  
           [0004]    The safety glass break-seal vessels of the present invention are, in general, distinguished from other glass break-seal vessels in that the break-seal portion of the vessel designed to be broken off to open the vessel extends into the volume defined by the vessel walls as opposed to an externally extending glass appendix as is commonly found in traditional glass break-seal containers. Stated alternatively, perhaps in more common terms, the safety glass break-seal in the vessel of the present invention is internal in design as opposed to traditional glass break-seals that are external in design, which when broken off, invariably leaves behind an exposed sharp glass edge. The internal appendix design is such that the appendix, a hollow finger-like structure extending into the vessel, is protected from external forces during shipping and handling and when broken, for example, with a fracture element designed to engage the interior surface of the hollow finger-like structure and apply a glass fracturing force to the structure, will leave edges that are not accessible to the hands of the user/operator.  
           [0005]    The vessel can optionally include a secondary sealing system such as a flexible septum or a crimp top. A user manipulable fracture element for engaging the interior surface of the hollow inwardly projecting appendix can be captured between the portion of the vessel wall including the safety glass break-seal and, for example, a flexible septum designed to engage and form a seal against the vessel walls proximal to the glass break seal. In that embodiment of the invention the contained composition can be hermetically sealed in the glass vessel for storage and shipment, and the glass seal is broken by the user only when the first portions of the contained compositions are needed for use. Thereafter the contained chemical composition can be accessed through the septum, for example, with a hypodermic needle from time to time after the safety glass seal is broken.  
           [0006]    The present safety glass break-seal vessels are also designed to facilitate transfer of contained fluids to a closed system having a valved port. In one particular embodiment the vessels find use for delivering calibration samples to analytical instruments, for example, gas chromatographs or mass spectrometers.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]    [0007]FIGS. 1A and 1B are partial cross-sectional views of break-seal vessels of the present invention.  
         [0008]    [0008]FIGS. 2A-2D illustrate the steps for forming the break-seal structure on the vessels of the present invention using a heat source and a glass deformation element.  
         [0009]    [0009]FIG. 3A illustrates a “C”-shaped deformation element, and FIG. 3B depicts a vessel with a curved safety break-seal formed using said element.  
         [0010]    [0010]FIG. 4 is a cross-sectional view of a break-seal on a vessel of the present invention wherein the finger-like structure extending into the volume of the vessel is scored proximal to its base.  
         [0011]    [0011]FIGS. 5A and 5B depict the positioning and use of a fracture element to open the safety break-seal vessels of the present invention.  
         [0012]    [0012]FIG. 6 illustrates use of a blade-shaped fracture element to open a break-seal of this invention by axially applied force to the inner surface of the break-seal.  
         [0013]    [0013]FIG. 7A is a cross-sectional view of a safety break-seal vessel of this invention wherein the finger-like structure was formed with a blade-shaped deformation element. FIG. 7B is another cross-sectional view of the vessel of FIG. 7A rotated 90° and illustrates the use of a blade-shaped fracture element to open a blade-shaped safety break-seal of the present invention with force applied by rotation of the fracture element.  
         [0014]    FIGS.  8 A-C are cross-sectional views of alternate embodiments of the safety break-seal vessel including a flexible septum for engaging the break-seal end of a vessel of the present invention and including a fracture element that can be manipulated by applying pressure to the flexible septum to fracture the break-seal to open the sealed vessel.  
         [0015]    [0015]FIG. 9 is a perspective view of the vessel of FIG. 8C.  
         [0016]    [0016]FIG. 10 illustrates use of a safety break-seal vessel of the present invention to transfer a fluid sample to a closed system.  
         [0017]    [0017]FIGS. 11A and 11B illustrate alternate embodiments of the safety break-seal vessel.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0018]    A vessel  10  having safety break-seal  12  is provided for containing a composition  14  under hermetically sealed conditions. In one embodiment vessel  10  is of cylindrical cross-section and comprises a glass wall  16  which can be clear or tinted (for example, to provide protection of vessel contents from light) having an interior surface  20  defining a volume  22  for containment of the chemical  14  and an external surface  24 . At least a portion of the glass wall  16 , most typically an end wall  18  of vessel  10 , is formed as a hollow finger-like structure  26  having a base  28  and a base-distal portion  30  extending into the volume  22  which structure forms safety break-seal  12 . The hollow finger-like structure  26  has an exterior surface  32  which forms a portion of the interior surface  20  of the glass wall  16  and an interior surface  34  which forms a portion of the exterior surface  32  of the glass wall  16  of vessel  10 . While the break-seal vessel can be of any cross-sectional shape, in one embodiment vessel  10  is of generally cylindrical cross-section and has a major axial dimension  36  and a minor lateral dimension  38  and end wall  18 . In one embodiment end wall  18  includes the portion of the glass wall formed as a hollow finger-like structure  26  which can extend into volume  22  along an axis substantially parallel to the major axis of vessel  10  (FIG. 1A) or along an axis generally oblique to the major axis of vessel  10  (FIG. 1B). The hollow finger-like structure  26  can itself have a substantially linear axis (as illustrated in FIGS. 1A and 1B) or it can be formed to have curved or arcuate axis (FIG. 3B). In one embodiment vessel  10  is hermetically sealed and contains a gas at subambient to moderate pressure. Alternatively, the vessel can be use for packaging, shipment and storage of liquid or solid compositions such as chemical reagents or pharmaceutical compositions. Optionally the finger-like projection  26  extending into the volume  22  of the vessel  10  is scored, preferably proximal to the base  28 .  
         [0019]    [0019]FIG. 4 illustrates a break-seal on vessel  10  wherein the hollow finger-like structure  26  has a score line  40  near its base  28 . Score line  40  can be formed, for example, with a small abrasive wheel having a diameter approximating the diameter of base  28  at score line  40  or by using a carbide steel, a diamond, or other hard material, sharp tipped scoring tool. Score line  40  facilitates opening of the vessel and minimizes the production of glass shards during opening of the vessel by fracture of the safety glass break-seal  12 .  
         [0020]    With reference to FIGS. 2A-2D, the safety glass break-seal  12  on vessel  10  is formed by heating a portion of the wall  16 , for example, an end wall  18 , of an empty glass vessel with a flame  27  (FIG. 2B) to a temperature at which it is sufficiently softened to allow it to be deformed with a deformation element  29 , for example a blunt graphite needle (for example, one having a slightly conical shaped tip), into the softened glass to form the inwardly extending hollow finger-like structure  26  from which it is immediately withdrawn leaving the finger-like structure  26  formed in end  18 . Optionally the portion of the vessel  10  proximal to-the safety glass break-seal  12  formed in the wall of vessel  10  can be annealed to release mechanical strain in the safety glass break-seal structure by reheating the glass to temperatures just below the softening point of the glass followed by slow cooling. The finger-like structure  26  can be formed to have a substantially linear axis itself substantially parallel to the major axis of the vessel, or the deformation element can be used to form the finger-like projection to have an axis oblique to the major axis of the vessel (FIG. 1B). With reference of FIGS. 2 and 3, the shape of the finger-like structure is determined generally by the shape of the deformation element. For example, by using a “C”-shaped deformation element (FIG. 3A), the finger-like structure  26  forming break seal  112  can be formed to have an arcuate axis. Similarly, the cross-sectional shape of the hollow portion of the finger-like structure will be generally defined by the cross-sectional shape of the deformation element. Thus, the cross-sectional shape of the hollow portion of the finger-like structure can be generally circular, ovoid, square, rectangular, triangular or trapezoidal. In other words, the fracture element has to grip the inner surface of the break-seal when torque is applied.  
         [0021]    The opening of vessel  10  incorporating the safety glass break-seal  12  of this invention is illustrated in FIGS. 5A and 5B. A fracture element  46 , for example, a metal pin or nail, is inserted into the hollow finger-like structure  26  to contact its inner surface  34 . Leveraged force is applied to inner surface  34  of hollow finger-like structure  26  by applying gradually increasing lateral force to fracture element  46  until the hollow finger-like structure  26  fractures to open vessel  10 .  
         [0022]    Fracture element  46  can also be used to apply an axial fracture force to the hollow finger-like structure  26 . The application of axially (substantially parallel to the major axis of the vessel) oriented forces to fracture the finger-like structure  26  can be particularly effective where the finger-like structure has been formed to have an arcuate axis (FIG. 3B) or a linear axis oblique to the major axis of the vessel (FIG. 1B). With reference to FIG. 6 axially applied forces can also be effective to open the break-seal when they are applied using a fracture element  146  having a lateral dimension smaller than the lateral dimension of the hollow portion of the finger-like structure  26  at its base  28 , but larger than the lateral dimension of the hollow portion of the finger-like structure  26  at its base distal end  30 . As the fracture element  146  is pushed into the hollow portion of the finger-like structure  26 , it contacts its inner surface  34  so that the axial force is translated into a break-seal fracturing force. In one preferred embodiment the fracture element used in this procedure is in cross-section a blade  31  or a star-shaped structure so that applied fracture forces are concentrated at two or more points on the inner surface  34  of the hollow finger-like structure  26 . Alternatively the cross-sectional shape of the fracture element  46 , 146  and the hollow portion of finger-like structure  26  defined by its inner surface  34  can be selected so that a fracture force can be applied to inner surface  34  by rotation of the fracture element  146  after it is inserted into the hollow finger-like structure  26 . Generally, the application of rotational force can be used to open the safety break-seal of this invention where the fracture element is sized to be inserted into the hollow portions of the finger-like structure and where at least one dimension of the cross-section of the break-seal contacting portion of the fracture element is greater than the minimum dimension of the cross-section of the hollow portion of the finger-like structure. Thus, if fracture element  46  and hollow finger-like structure  26  are, for example, each of rectangular cross-section (see FIGS.  7 A/ 7 B), rotation of fracture element  146  after it is inserted into the hollow finger-like structure  26  to contact its inner surface  34  works to fracture finger-like structure  26  and open break-seal  12 . The cross-sectional shape of fracture element  46  (FIG. 5);  146  (FIG. 7) can be the same or different than the cross-sectional shape of the hollow portion defined by the inner wall  34  of the finger-like structure  26 .  
         [0023]    With reference to FIGS. 8A-8C, vessel  10  can be fitted with a secondary closure  42 , for example, a flexible septum sized to frictionally engage end proximal wall portion  44  of vessel  10  to cap and define a supplemental volume  48  with the end wall  18  of vessel  10 , including the portion of the vessel wall  16 , 18  formed as the hollow finger-like structure  26 . In one embodiment fracture element  46  is positioned in contact with the inner surface  34  of the hollow finger-like structure  26  and extends into supplemental volume  48  defined by the secondary closure element  42  and the end wall  18  of vessel  10 . Secondary closure  42  is typically in the form of a flexible hood or septum that is frictionally engaged with the end wall proximal portion  44  of the vessel  10  and is transparent or translucent to facilitate user manipulation of the fracture element  46  to open the break-seal  12  with the secondary closure  42  in place on vessel  10 .  
         [0024]    In one example of the use of vessel  10  having secondary closure  42  as illustrated in FIGS. 8A-8C, the supplemental volume  48  defined by the secondary closure  42  and end wall  18  of vessel  10  is preflushed with an inert gas, for example, helium or argon, before opening the vessel  10  by fracturing the safety break-seal. Volume  48  can be preflushed with an inert gas, for example, by inserting a needle (not shown) that both injects the gas and provides for a venting port or alternatively, one needle can be used for flushing gas input and another needle for venting the volume. After opening the vessel  10  by breaking safety glass seal  12  with secondary closure  42  in place, the user can safely draw small aliquots of gas or liquid out of the open vessel without introducing atmospheric contamination. In this embodiment of the invention the glass break-seal  12  will allow secure long-term storage, whereas the secondary closure  42 , for example the flexible septum, will provide a secondary seal for providing at least short-term integrity of the sample after opening of the glass break-seal.  
         [0025]    With reference particularly to FIG. 8C, there is illustrated an embodiment of the break-seal vessel  10  of this invention where the secondary closure  42  is formed from a segment of elastomer tubing, for example Tygon® tubing, which is friction-fitted to the end proximal wall portion  44  of vessel  10  and thereafter (or before it is fitted on vessel  10 ) the elastomer tubing is heat-sealed to complete formation of the secondary closure  42 . Secondary closure  42  thus formed provides the function of a septum that can be pierced with a needle to access the contents of vessel  10  following fracture of safety glass break-seal  12 . It is contemplated that vessel  10  fitted with secondary closure  42  can be opened without use of a separate fracture element  46  by first using a needle/needles to flush supplemental volume  48  with an inert gas, and thereafter extending the needle to contact the inner surface  34  of the hollow finger-like structure  26  of safety glass break-seal  12  to apply force sufficient to fracture the finger-like structure  26  to open the vessel and allow access and sample removal through the same needle.  
         [0026]    The safety glass break-seal vessel  10  can be used to facilitate transfer of a fluid sample into a closed system. With reference to FIG. 1O there is illustrated use of a vessel  10  containing gas  15  for transfer of the gas to a closed system  50  having valved port  52 . A section of flexible tubing  56  having a first end  58  and a second end  60  and an internal diameter sized to receive the end wall  18  of vessel  10 , including safety glass break-seal  12 , and to sealingly engage the end proximal wall portion  44  of vessel  10 . First end  58  of the section of tubing is connected to valved port  52  of closed system  50 . Fracture element  46  is positioned to contact the inner surface  34  of finger-like structure  26  of safety glass break-seal  12 . The end wall  18  of vessel  10 , including the safety glass break-seal  12  is inserted into second end  60  of the section of the tubing to form a gas-sealed connection between the vessel  10  and the valved port  52 . Optionally valved port  52  is initially opened to evacuate the volume in the tubing between the end wall  18  of vessel  10  and valved port  52 . Preferably with valve  54  in the port closed position, fracture element  46  is manipulated to break the finger-like structure  26  to allow the contained gas into the tubing. Valve  54  is thereafter opened to allow transfer of the gas from the vessel  10  and tubing  56  through port  52  and into closed system  50 .  
         [0027]    Vessel  10  formed to include the safety glass break-seal  12  of the present invention can be formed in a wide variety of shapes and volumes unique to the intended application. Typically the safety glass break-seal structure  12  is formed on empty vessels which are designed to be filled through a separate open, but sealable filling port. Thus, with reference to FIG. 11A, the safety glass break-seal  12  is formed in a closed end of a glass vessel  210  having an opposite open end  19  which can thereafter be connected to a sample filling system and thereafter hermetically sealed. In one embodiment of the invention (see FIG. 11B) safety glass break-seal  12  is formed in the wall of a standard glass ampule having, as well, a traditional external break-seal structure. Such modified ampules can be opened either in the traditional way, i.e., by snapping off the top structure, or by triggering the safety glass break-seal  12  formed in the wall of the ampule.  
         [0028]    It will be appreciated by those skilled in the art that the above-illustrated embodiments are but examples of the invention and that other embodiments utilizing the safety glass break-seal structure detailed above are within the scope of the invention as claimed.