Patent Document

FIELD OF THE INVENTION 
     The present invention relates generally to articles for containing, storing, and transporting musical instruments which are capable of providing a humidity-controlled atmosphere, and specifically, to a humidity control system included as a component of a musical instrument carrying case. 
     BACKGROUND OF THE INVENTION 
     The environment in which a musical instrument is stored affects the reliability, sound, condition, and lifespan of that instrument. Musical instruments are typically stored in containers that are designed to be both easily portable and protective against environmental hazards such as wind, rain, dust, sand, and sun. However, conventional instrument cases are not built with the capability to protect instruments from the ongoing hazards of temperature and humidity, either high or low. 
     The presence or absence of atmospheric humidity, in particular, can affect the is lifespan and sound of many musical instruments, among them stringed, woodwind, brass, and percussion instruments. According to  Making Musical Instruments  by Irving Sloane, all instruments, stringed instruments in particular, are best built in a dry atmosphere. For example, a fiddle constructed in an atmosphere of about 65% relative humidity is likely to crack if moved to an area of 20% or less relative humidity. Since the converse does not hold true, instrument makers generally build instruments in a relatively dry environment, typically about 40%-45% relative humidity. In this way, they enable the instruments they construct to survive the normal extremes of humidity that a given instrument might encounter over time. 
     Though this type of precaution is taken in construction, the presence or absence of humidity, whether in the form of excessive moisture or of extreme dryness, can cause swelling, splits, cracks, checking, movement in glue joints, and distortion of woods or other materials in a given instrument. Any of these problems can damage or destroy an instrument. Potentially the most damaging situation in which an instrument, susceptible to changes in humidity, can be put is in an excessively humid atmosphere, coupled with rapid changes in temperature. This situation can easily cause permanent damage to an instrument, and often occurs when an instrument is transported from one location to another. 
     Though the prior art has in some ways recognized these problems, the solutions provided, as seen below, do not go far enough in an effort to protect valuable musical instrument from the depredations of temperature and humidity. 
     U.S. Pat. No. 4,674,630 (to Kirck) discloses a portable, self-enclosed reed case that maintains an environment most conducive to the reeds used in woodwind instruments. Kirck is silent regarding protecting the instruments themselves. 
     U.S. Pat. No. 5,219,075 (to White) discloses a musical instrument case cover that includes foam and plastic materials that retard the effects of the environment encountered outside the case itself The case provides protection for about five hours in extreme conditions and for about twenty-four hours in less extreme conditions. An important drawback to the White invention is that it seeks to maintain the ambient conditions prevailing at the time the case is closed. Thus, if the ambient conditions, at the time of closure, consist of extreme moisture and heat, these conditions are preserved within the case. 
     From the above, it appears that a long-felt need in the field has been for a device capable of allowing a musical instrument owners to consistently control and monitor the ambient temperature and humidity of the atmosphere in which the store, transport, or carry their instruments. Such a device would preferably allow the owner to control the atmospheric challenges of humidity and temperature generally encountered, thereby protecting the instrument for an extended period. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, an improved storage case for musical instruments is disclosed, which provides a humidity control system for a musical instrument carrying case. The invention includes at least two compartments venting into an inside portion of the case where a stored instrument is placed. Of these compartments, at least one is fitted for a desiccant pouch, likewise at least one of the other compartments is fitted for a humidifier. The number of compartments can vary by the size of the instrument or the needs an owner may have for protecting their instrument in a given local environment, typically two compartments are used, with one for the desiccant and one for the humidifier. Once the owner or caretaker determines the atmospheric conditions inside the case, a desiccant pouch can be added, or the humidifier engaged, in the appropriate compartment(s), as necessary. 
     The storage case of the present invention is typically used to maintain a constant relative humidity range between 45% and 55% but can be altered according to the needs of the instrument owner. These storage conditions work to maintain and protect the physical integrity of the instrument when stored, transported, or moved in the disclosed carrying case, thereby extending the lifespan and performance quality of the instruments so protected. 
     In one embodiment of the invention, a hygrometer is provided within the case in order to measure relative humidity. 
     In another embodiment a thermometer may be supplied to measure temperature within the carrying case. 
     In another embodiment of the invention, both the thermometer and the hygrometer are present as a part of the invention disclosed herein. These devices are preferably provided to enable the owner or caretaker of an instrument too easily to ascertain the environmental conditions in which the instrument in question has been placed. While both the thermometer and the hygrometer monitor the interior atmosphere of the instrument carrying case when it is sealed, the information provided by these devices may alternately be read only when the carrying case is open or the gauges may be constructed so that they can be read from the outside of the carrying case when it is closed. 
     In another embodiment of the invention disclosed herein at least one handle is securely attached to the exterior of said carrying case, to provide an ease in carrying said case. 
     In yet another embodiment of the invention the compartments adapted for the insertion of either the desiccant pouch or the humidifier are themselves releasably attached to the interior of the case by a fastening means. In this embodiment the compartments still vent into the interior of the carrying case, but said compartment(s) could be removed from the carrying case dependent upon the desires of the case owner. For this embodiment the fastening means could include Velcro, snaps, straps, adhesive, screws, bolts, &amp; pegs. 
     According to an embodiment of the invention, a storage apparatus for a musical instrument includes carrying means for carrying the musical instrument, and humidity control means attached on an inside of the carrying means for controlling humidity inside the carrying means. 
     According to an embodiment of the invention, a humidity control unit for a musical instrument carrying case includes control means attachable on an inside of the carrying case for controlling humidity inside the carrying case, and attachment means for attaching the control means to the carrying case. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a guitar case with an embodiment of the present invention installed therein. 
     FIG. 2 shows humidifier and desiccant compartments and their location within the instrument carrying case according to an embodiment of the present invention. 
     FIG. 3 shows a thermometer and hygrometer according to an alternate embodiment of the invention. 
     FIG. 4 shows a single compartment containing a solution of saturated salts according to an embodiment of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1-2, reference numeral  10  generally designates a instrument carrying case, having a handle  7 , variously designed to receive a plurality of musical instruments in an internal compartment  12  with an inside surface  14  adapted to receive a musical instrument (not shown). Case  14  is generally kept closed with a plurality of fasteners  8 . FIG. 1 depicts a guitar case, but a case designed for any instrument could also be adapted for the humidity control system of the present invention. 
     Reference numerals  16  and  18  generally designate two compartments adapted to receive a humidifier  20  and a desiccant filled pouch  22 . It should be noted that alternative embodiments of the invention envision the use of more than two compartments (e.g.  16  or  18 ), as needed by the instrument owner. In this description then, two compartments  16  and  18  are used for the sake of simplicity. The carrying case  10  has an inside surface  14 , which is smaller than an outer surface  24 , and forms a lip  26  therewith. The lip  26  preferably forms a humidity impermeable seal. The inside surface  14  tends to conform to the particular cut or curvature of the individual instrument for which the carrying case  10  is designed. 
     Compartment  16  is adapted to receive humidifier  20 , which operates to maintain the relative humidity of the inside surface  14  and the instrument placed therein when said instrument is stored, transported, or moved in the carrying case  10 . 
     The stability of the carrying case  10  environment is controlled by the owner or caretaker of the instrument carrying case as follows. When the case humidity is above 65% the owner inserts a desiccant pouch  22  into a designated compartment  18  within the case and removes the humidifier  20  from the other compartment  16 . Alternatively the humidifier  20  can be left in the carrying case  10  but not recharged with water. When the humidity within the case is below 35%, or the atmospheric conditions are dry, the desiccant pouch  22  is removed from its compartment  18 , and the humidifier  20  is returned to its designated compartment  16 . The most preferable humidity range to maintain within the interior of the carrying case  10  is 45% to 55% humidity. When these alternative strategies, used according to locale ambient humidity, are used, a stable environment is created and maintained for the musical instrument to be protected. In addition, the owner of the case retains the flexibility to select the exact desired humidity for their instrument by manipulating the amount of desiccant used, or controlling the recharging of the humidifier  20 . 
     The humidifier  20  consists of a container that preferably holds a clay  21  capable of absorbing moisture and thereafter slowly releasing it. “Clay” is used with its usual meaning as defined in  Compton&#39;s Interactive Encyclopedia  copyrighted by Compton&#39;s NewMedia, Inc. In the instant disclosure, a clay is the preferred compound to act as the humidifier. Clay is a generic term, which essentially refers to a number of species of fine-grained earths, plastic when wet, composed chiefly of hydrous aluminum silicate minerals. As is well known a variety of clays are used in the manufacture of brick, pottery and other ceramics. With respect to the use of clay as the chief component of the humidifier disclosed herein, the inventors rely upon the intrinsic nature of clay, when wetted, to retain moisture and give it up slowly. In this way a fully “charged” (e.g., charged by immersion in water) humidifier contains a significant amount of water which will be emitted slowly over time to inject moisture into an otherwise dry atmosphere, acting to maintain a relative humidity in the range most desired to preserve musical instruments. 
     To initially charge humidifier  20 , humidifier  20  is immersed in water, a cap (not shown) is then closed, excess water is wiped off, and humidifier  20  is returned to the case  10 . 
     Desiccant pouch  22  preferably contains any one of a plurality of anhydrous compounds or compounds capable of absorbing moisture from the ambient air such as a buffered silica gel or a saturated salt solution. When exposed to an environment that contains significant moisture, the selected anhydrous substance absorbs moisture and in this way removes it from the local environment inside the instrument case  10  disclosed herein. 
     Compartments  16  and  18  can also be releasably attached to the interior surface  14  of the case  10 . Fastening means such as clips, snaps, Velcro, or bolts would be employed to secure compartments  16  and  18  into the interior surface  14  of case  10 . 
     Referring to FIG. 3, a plurality of air passages  28  in a partition  30  are small enough to retain the humidifier  20  in compartment  16  while allowing for free vapor exchange between the inside of case  10  and the humidifier  20 . Likewise, a plurality of air passages  32  in a partition  34  are small enough to retain the desiccant  22  in compartment  18 , while allowing for free vapor exchange between the inside of case  10  and the desiccant pouch  22 . Compartments  16  and  18  can include opening and closing means such as hinges  33  to enable access to the desiccant or humidifier. 
     FIG. 3 also shows an alternative embodiment of the present invention which permits the temperature of the interior of the carrying case  10  to be monitored through the presence of a thermometer  36 , whose gauge  37  is present in the inside surface  14  of the carrying case  10 . Alternately, the carrying case  14  is constructed so that the gauge  37  of the thermometer  36  is readable from the exterior of carrying case  10  when said case is closed. 
     In another embodiment, the humidity of the interior of the carrying case  10  is monitored through the presence of a hygrometer  38 , whose gauge  39  is present in the inside surface  14  of the carrying case  10 . Alternately, the carrying case  14  is constructed to that the gauge  39  of the hygrometer  38  is readable from the exterior of carrying case  10  when the case  10  is closed. 
     In embodiments of the invention containing the hygrometer  38 , the owner of the carrying case  10  (also an instrument storage apparatus) can use it to monitor the internal humidity of the case  10  and maintain the humidity for any geographic location in which the owner is located or through which the owner is travelling. 
     The preferred desiccant will be one in which the composition thereof will contain at least 40% silica gel with the balance being composed of activated charcoal. Silica gel is a colloidal suspension of silicic acid made by dialysis from action of hydrochloric acid on water glass; when dried to 5% water, it resembles coarse sand and absorbs gases, especially water vapor, readily. The activated charcoal also functions to reduce or remove odors occurring within the case. Preferably, the silica gel makes up 60% of the desiccant mixture with activated charcoal. In addition, it is also preferred that the activated charcoal is derived from processed coconut husks, since this source appears to have superior capabilities in the reduction of odors. 
     With regards to the silica gel used as a desiccant within this disclosure, it is known that buffered silica gels can be used to regulate relative humidity. Silica gel will absorb a known amount of water within a particular relative humidity range. Thus, when initially developed a given mixture of desiccant containing silica gel can be conditioned to maintain or retard movement away from a target relative humidity in a given local atmosphere, as within a closed instrument case. 
     Referring to FIG. 4, an alternative embodiment uses only one compartment  40  having a container  42  with a saturated salt solution therein, which can be used as both a desiccant and humidifier to control and maintain the relative humidity in an instrument carrying case. Saturated salt solutions will supply water vapor to a maintain a target relative humidity as long as any undissolved salt remains. Saturated salts can absorb close to 100% of their volume in water. Once absorbed this solution can then allow desorption of 100% of total water trapped by the salt solution. The result is that the salt crystals employed as a desiccant can in fact contribute to the maintenance of a given relative humidity, and require less relative maintenance than a silica gel desiccant. Species of salt formulations useful for this purpose are nitrate salts such as calcium, sodium, or magnesium nitrate. Alternative salts which are also useful at the relative humidity ranges that should be maintained for instrument storage are sodium dichromate, or potassium carbonate. 
     Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.

Technology Category: 3