Abstract:
The cartridge has two compartments normally for containing two substances of the mixture, which are separated by a preferential break member; one of the two compartments contains a liquid solvent, and is fitted with a bellows having an intake valve and for producing a pumping action by varying the volume of the bellows by exerting pressure on the bellows. The bellows first causes breakage of the member to mix the two substances, and then produces flow of the mixture to accelerate its reaction. The cartridge is insertable inside a cavity of a support for heating or cooling in predetermined conditions.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a disposable cartridge for mixing exothermic or endothermic reaction substances, and to an assembly of such a cartridge and a support for heating or cooling. 
     2. Description of the Related Art 
     Substances are known which, when mixed, produce an exothermic reaction generating heat, or an endothermic reaction absorbing heat from, i.e. cooling, the outside environment. Mixing normally consists of dissolving or solvation of a solute in a liquid solvent, and, since the solute is normally in the form of solid granules, must be assisted, e.g. by shaking the solvent-solute mixture, at the time of use, to speed up complete dissolution and reaction of the substances. 
     Various types of containers or cartridges are known which have two or more compartments containing different substances to be mixed at the time of use—typically for use as separate systems—and which are small enough to be shaken by hand. When the container is to be connected to a support for heating or cooling, however, very often the system as a whole cannot be shaken by hand when mixing the substances. In some known cases, the substances are placed inside a reusable container. In other known cases, involving disposable containers, the substances must still be mixed at the time of use inside the container detached from the support, by shaking the container, which must then be connected to the support while the exothermic or endothermic reaction is already taking place. 
     Known systems therefore have various drawbacks. In particular, connecting the container to the support while the reaction is in progress greatly impairs efficient use of the energy generated. Moreover, connecting and disconnecting the container to and from the support is a skilled, and therefore fairly high-cost, operation, in which the operator may come into contact with very hot surfaces. Finally, systems involving reusable containers call for washing and replacing the container, which is unfeasible for other than high-cost applications. 
     A disposable container, of the type used for medical infusions, is known comprising two compartments made of flexible plastic material and separated by a preferential break region, which is broken at the time of use by pressing on the wall of one of the compartments; and the container can then be shaken by hand to assist mixing of the two substances. This type of container, however, is unsuitable for heat exchange with a support. 
     In another known embodiment for food applications, the container for heating/cooling is incorporated in the heating/cooling system. The assembly as a whole, however, is of limited size and cannot be interfaced with external systems. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a disposable cartridge for mixing normally separate exothermic or endothermic reaction substances, and which is cheap and highly reliable. It is a further object of the invention to provide a cartridge for mixing substances with no need for manual shaking, and which can therefore also be used even when fitted to a substantially fixed system. 
     According to the present invention, there is provided a disposable cartridge for mixing exothermic or endothermic reaction substances, and which comprises two compartments having substantially rigid walls and normally containing two separate substances of the mixture; characterized in that said compartments are separated by a preferential break member; one of said compartments having means which can be operated to break said member and mix said substances; and said means also generating flow of the mixture to accelerate its reaction without shaking the cartridge. 
     According to the present invention, there is also provided an assembly of said cartridge and a support for heating or cooling, wherein the support is substantially fixed; said cartridge being connected to said support prior to operation of said means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred, non-limiting embodiment of the invention will be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  shows an axial section of a disposable cartridge for mixing substances in accordance with the invention; 
         FIG. 2  shows a partly sectioned view of a cartridge-support assembly. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 1 , number  5  indicates as a whole a disposable cartridge for mixing substances to produce an exothermic or endothermic reaction salvation. Cartridge  5  comprises a tapered body  6  having a given straight axis A; and body  6  comprises two compartments  7  and  8  having substantially rigid walls and containing two different, normally separate substances. 
     More specifically, the exothermic or endothermic reaction is produced by dissolving a normally granular solute  9 , normally contained in compartment  7 , with a liquid solvent  10  normally contained in compartment  8 . Solute  9  may be anhydrous calcium chloride (CaCl 2 ) for an exothermic reaction, and hydrous sodium thiosulphate (Na 2 S 2 O 3 ) for an endothermic reaction. Solvent  10  is normally water or, in the case of an exothermic reaction, an antifreeze mixture of water and ethylene glycol or ethyl alcohol. 
     More specifically, compartment  8  of solvent  10  comprises a substantially cylindrical first portion  11  having a lateral wall  12  coaxial with axis A. A second portion  13  of compartment  8  has a lateral wall  14  also coaxial with axis A, smaller in diameter than lateral wall  12 , and extending axially along almost the whole length of cartridge  5 . Portion  13  is housed inside compartment  7 , which has a lateral wall  15  also coaxial with axis A, so that compartment  7  has a substantially annular section, and walls  12  and  15  define the outer lateral walls of cartridge  5 . 
     More specifically, one end  16  of first portion  11  of compartment  8  communicates with a first end  17  of second portion  13 ; the relative lateral walls  12  and  14  are connected by a flat annular wall  18 ; and another end  19  of portion  13  is closed by a preferential break member defined by a very thin, breakable end wall  20 , preferably of a maximum thickness of 0.1 mm. 
     Compartment  7  of solute  9  has an end wall  21  located a small distance from wall  20  and having a fitting  22  closed, for example, by a plug  23 . Alternatively, wall  21  may have no fitting  22 , and wall  15  may be fitted to the rest of the cartridge once filled with solute  9 . 
     Compartments  7  and  8  are preferably made of low-cost plastic material, e.g. low-density polyethylene (LDPE), which is fitted to end  19  in any manner. Thin wall  20  of compartment  8  may also be made of the same material and formed, for example, in one piece or integrally with compartment  8 . 
     Alternatively, thin wall  20  may be made separately of medium-density polyethylene (PE) or ethyl vinyl acetate (EVA), or may be made of a thin sheet of metal, e.g. aluminium. If cartridge  5  has a fitting  22 , thin wall  20  is inserted inside cartridge  5  through fitting  22  and soldered to end  19  of portion  13  in any known manner. In any case, thin wall  20  may have a groove (not shown) to assist breakage. 
     Cartridge  5  also comprises means that can be operated to break the preferential break member to mix the two substances, and to generate flow of the mixture to dissolve it faster and so accelerate its reaction without shaking cartridge  5 . Such means is to be understood broadly to include any pressurizing source that can be actuated to increase or decrease pressure within an interior. Said means can be, for example, a thumb actuated pump or a bellows, indicated as a whole by  24 , which increases pressure inside compartment  8 . More specifically, one example is a bellows  24  comprises an undulated lateral wall  26  made of elastic material of such a thickness as to enable it to be compressed and extended. Undulated wall  26  is fixed in any known manner to a flange  27  at the opposite end to end  16  of portion  11  of compartment  8 , so that bellows  24  is also coaxial with axis A. 
     Bellows  24  also comprises a substantially flat, top cover wall  28  preferably made of the same material as undulated wall  26 . Cover wall  28  is of such a thickness as to be substantially rigid, and has an opening in which is fixed in any known manner an intake valve  29  for filling bellows  24  with air, but preventing air from escaping. Finally, a conduit  31  is formed inside lateral wall  12  of portion  11  of compartment  8  to connect compartment  7  to the outside and release any surplus air pumped in by bellows  24 . 
     Cartridge  5  is inserted removably inside a seat defined by a cavity  32  ( FIG. 2 ) of a support  33  to be heated or cooled in given conditions. To ensure correct insertion of cartridge  5 , lateral wall  12  of portion  11  of compartment  8  has a shoulder  34  defining the axial position of cartridge  5  inside cavity  32 . Wall  15  of compartment  7  may also have a groove for exhausting any air from cavity  32  when mounting cartridge  5 . 
     Assuming support  33  cannot, or for any reason is not to, be shaken to produce the exothermic or endothermic reaction, e.g. assuming support  33  is defined by a fixed hydraulic circuit container forming part of a complex apparatus, cavity  32  in this case is defined by a wall  36  of support  33 . If the liquid in support  33  is subject to occasional changes in state in particular operating or stasis conditions, temporary heating or cooling may be required to restore operation. 
     Substances  9  and  10  are inserted into cartridge  5  as follows. First, the required amount of solute  9  is inserted inside compartment  7  through fitting  22 , which is then either closed using plug  23  or heat sealed. If compartment  7  has no fitting  22 , compartments  7  and  8  are prepared separately. Compartment  7  is first filled with solute  9 , and wall  15  is then fitted, e.g. hot fitted, to compartment  8 . 
     Finally, solvent  10  is inserted into compartment  8  in any known manner, e.g. via intake valve  29 . 
     To heat or cool support  33 , after inserting exothermic or endothermic cartridge  5  inside cavity  32 , wall  28  of bellows  24  is acted on repeatedly, e.g. pressed with a finger, so that, when a given air pressure is reached inside compartment  8 , thin wall  20  breaks, and solvent  10  flows partly into compartment  7  and into contact with the granules of solute  9 . 
     Continuing the action on wall  28  of bellows  24 , the air pumped by the bellows into compartment  8  produces flow in the solution and mixture, which is also transmitted to compartment  7 , thus assisting dissolution of solute  9  in solvent  10 , i.e. accelerating the solvation reaction. The generation or subtraction of heat produced by the reaction is thus accelerated with no need to shake cartridge  5 , which, after use, can be removed from cavity  32  and replaced with a new cartridge ready to restore operation of support  33  when necessary. 
     The advantages, as compared with known systems, of the cartridge according to the invention will be clear from the foregoing description. In particular, one or more substances in the mixture need no longer be poured each time into a mixer; the mixture need not be shaken manually, either before or after fitting cartridge  5  to support  33 ; and none of the heat produced or subtracted by cartridge  5  during the reaction is lost. 
     Clearly, changes may be made to the cartridge as described herein without, however, departing from the scope of the accompanying Claims. For example, intake valve  29  may be located in lateral wall  12  of portion  11 , and/or conduit  31  may be formed in lateral wall  15  of compartment  7 ; thin wall  20  may be designed to open peripherally or so that a limited portion of its area opens; and thin wall  20  may be defined by a limited portion of lateral wall  14  of portion  13  of compartment  8 . 
     All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety. 
     From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.