Abstract:
A spring mechanism comprising a spring element having a pair of arms separated by a gap, a tapered flexible tongue with an enlarged tip, and a tapered slot extending longitudinally through the tongue, wherein the tapered flexible tongue is operatively arranged to bend such that the tip enters the gap and engages the pair of arms. A case for a canister capable of dispelling material is also disclosed using the spring mechanism to bias a lid in a closed position.

Description:
FIELD OF THE INVENTION 
     The invention relates generally to a case for an aerosol canister, and, more specifically, to a flip top case for an aerosol canister and, even more specifically, to a spring mechanism for a flip top case for an aerosol canister. 
     BACKGROUND 
     Cases for aerosol or spray canisters typically include an actuator to engage the stem of the canister in order to dispel the canister&#39;s contents. There are a variety of aerosol dispensers that are used in many applications which include dispensing perfume, air fresheners, personal hygiene products, covering an article with a coat of paint, and dispensing cleaning products, amongst others. One specific application for an aerosol dispenser is as a personal defense device that, for example, directs a chemical repellant spray towards a potential human or animal threat. 
     Typical lids for dispensing actuators or cases for aerosol and spray canisters are intended to either prevent accidental discharge or provide easy dispensing. With respect to personal defense devices, easy dispensing is crucial to ensure the safety of the user when a threat presents itself. However, the reason personal defense devices are effective is because their chemical contents are indiscriminately extremely painful to anyone who comes into contact with it. 
     U.S. Patent Application Publication No. 2011/0006083 discloses a dispensing actuator for use on a container having pressurized contents configured for convenient one-handed manipulation and use. The dispensing actuator includes a hingedly moveable flip-open lid, and a laterally moveable button, which can be manipulated so that the button cooperates with the lid to move the lid from a closed position to an opened position. The dispensing actuator in this application further includes an inner, downwardly deflectable actuating element, operatively connected with a dispensing valve of the associated container. Resilient, downward deflection of the actuating element, after opening of the dispensing actuator lid, permits the contents of the container to be conveniently dispensed. Unfortunately, this dispensing actuator requires various movements by the user to spray the contents of the container and return the dispensing actuator to its original position. Pressing the button to open the lid, accurately positioning the user&#39;s finger over the actuator, depressing the actuator and then manually closing the lid is cumbersome, time consuming, and possibly dangerous in that the potential victim might not activate the device in time to thwart the threat. 
     U.S. Pat. No. 5,348,193 describes a case suitable for an aerosol dispenser being used as a personal defense device. The case is described as having a body with a moveable top protective flap to prevent accidental discharge of an aerosol can. The flap uses a spring disposed about a hinge for holding the flap in the closed position. The flap is described as being installed on the case by spreading (i.e., flexing) the material used to make the body of the case in the region of the hinge with a spread tool sufficiently so that the flap may be inserted into the hinge and then allowing the material to substantially return to its original shape. However, this process requires that the installation of the flap be performed soon after molding the case so that the body is sufficiently pliable. Unfortunately, if the flap dislodges from the hinge, the case is then useless to prevent accidental discharge of the chemical because the flap cannot be reassembled after the manufacturing process of the case. 
     Therefore, there is a long-felt need for an improved case for an aerosol or spray canister that minimizes the number of movements to dispel the canister&#39;s contents under pressure. There is also a long-felt need for a case that is simple to reassemble if it breaks. Further, there is also a long-felt need for a spring mechanism used in a flip top case that can be made of plastic in order to minimize manufacturing costs. 
     SUMMARY 
     The present invention comprises a spring mechanism comprising a spring element having a pair of arms separated by a gap, a tapered flexible tongue with an enlarged tip, and a tapered slot extending longitudinally through the tongue, wherein the tapered flexible tongue is operatively arranged to bend such that the tip enters the gap and engages the pair of arms. 
     The present invention also comprises a case for a canister capable of dispelling material comprising a main body to house the canister, the main body having a front aperture, a top lid to cover the main body, a spring non-rotatably secured to the main body and rotatably secured to the top lid, the spring comprising a tapered flexible tongue with an enlarged tip, and a tapered slot extending longitudinally through the tongue, and an actuator to direct dispelled material from the canister out of the main body through the front aperture. 
     A general object of the present invention is to provide a case with a flip top that minimizes the number of movements required to dispel the contents of the canister. 
     Another object of the present invention is to provide a spring mechanism to be used in a case with a flip top that can be manufactured out of plastic. 
     These and other objects, advantages and features of the present invention will be better appreciated by those having ordinary skill in the art in view of the following detailed description of the invention in view of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying figures, in which: 
         FIG. 1A  is a perspective view of a cylindrical coordinate system demonstrating spatial terminology used to describe the invention; 
         FIG. 1B  is a perspective view of an object in the cylindrical coordinate system of  FIG. 1A  demonstrating spatial terminology used to describe the invention; 
         FIG. 2  is a front perspective view of a preferred embodiment of the present invention; 
         FIG. 3  is a rear perspective view of a preferred embodiment of the present invention; 
         FIG. 4  is a bottom perspective view of the lid of the case of the present invention; 
         FIG. 5A  illustrates an embodiment of the present invention being used with a thumb partially inserted into the rear opening; 
         FIG. 5B  illustrates an embodiment of the present invention being used with a thumb fully inserted into the rear opening; 
         FIG. 5C  illustrates an embodiment of the present invention being used with a thumb fully inserted into the rear opening and depressing the actuator; 
         FIG. 6  is an exploded view of the embodiment shown in  FIG. 2 ; 
         FIG. 7A  is a front perspective view of the uncocked spring element; 
         FIG. 7B  is a front perspective view of the cocked spring element; 
         FIG. 7C  is a rear perspective view of the uncocked spring element; 
         FIG. 7D  is a rear perspective view of the cocked spring element; 
         FIG. 7E  is a rear view of the cocked spring element shown in  FIG. 6 ; 
         FIG. 7F  is a rear view of the uncocked spring element shown in  FIG. 6 ; 
         FIG. 7G  is a cross-sectional view of the cocked spring element taken generally along line  7 G- 7 G in  FIG. 7E ; 
         FIG. 7H  is a cross-sectional view of the cocked spring element taken generally along line  7 H- 7 H in  FIG. 7F ; 
         FIG. 8  is a rear view of the body illustrating the engagement mechanism; 
         FIG. 9A  is a top view of the main body; 
         FIG. 9B  is a top view of the main body with the actuator in place; 
         FIG. 10  is a perspective view of the actuator; 
         FIG. 11  is a perspective bottom view of the actuator; 
         FIG. 12A  is a front view of the main body with the lid and bottom cap removed; 
         FIG. 12B  is a cross-sectional view of the main body taken generally along line  12 B- 12 B in  FIG. 12A ; 
         FIG. 13A  is an enlarged fragmentary lateral view of the lid, spring and body engagement mechanisms in a resting position; 
         FIG. 13B  is an enlarged fragmentary lateral view of the lid, spring and body engagement mechanisms in a loaded position; and, 
         FIG. 14  is a perspective view of the bottom cap. 
     
    
    
     DETAILED DESCRIPTION 
     At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspect. The present invention is intended to include various modifications and equivalent arrangements within the spirit and scope of the appended claims. 
     Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. 
       FIG. 1A  is a perspective view of cylindrical coordinate system  80  demonstrating spatial terminology used in the present application. The present invention is at least partially described within the context of a cylindrical coordinate system. System  80  has a longitudinal axis  81 , used as the reference for the directional and spatial terms that follow. The adjectives “axial,” “radial,” and “circumferential” refer to an orientation parallel to axis  81 , radius  82  (which is orthogonal to axis  81 ), and circumference  83 , respectively. The adjectives “axial,” “radial” and “circumferential” also refer to an orientation parallel to respective planes. To clarify the disposition of the various planes, objects  84 ,  85 , and  86  are used. Surface  87  of object  84  forms an axial plane. That is, axis  81  forms a line along the surface. Surface  88  of object  85  forms a radial plane. That is, radius  82  forms a line along the surface. Surface  89  of object  86  forms a circumferential plane. That is, circumference  83  forms a line along the surface. As a further example, axial movement or disposition is parallel to axis  81 , radial movement or disposition is parallel to radius  82 , and circumferential movement or disposition is parallel to circumference  83 . Rotation is with respect to axis  81 . 
     The adverbs “axially,” “radially,” and “circumferentially” refer to an orientation parallel to axis  81 , radius  82 , or circumference  83 , respectively. The adverbs “axially,” “radially,” and “circumferentially” refer to an orientation parallel to respective planes. 
       FIG. 1B  is a perspective view of object  90  in cylindrical coordinate system  80  of  FIG. 1A  demonstrating spatial terminology used in the present application. Cylindrical object  90  is representative of a cylindrical object in a cylindrical coordinate system and is not intended to limit the present invention in any manner. Object  90  includes axial surface  91 , radial surface  92 , and circumferential surface  93 . Surface  91  is part of an axial plane, surface  92  is part of a radial plane, and surface  93  is a circumferential surface. 
       FIG. 2  is a front perspective view of case  100  of the present invention. Case  100  generally comprises main body  10 , actuator  70 , top lid  30 , bottom cap  95 , and spring element  50  (shown in  FIG. 6 ) connecting lid  30  with main body  10 . Case  100  and its constituents are preferably made out of molded plastic, however any material such as metal, rubber, elastomeric material, or a combination of any materials among its constituent parts may be used as appreciated by a person having ordinary skill in the art. 
     Main body  10  is cylindrical in nature and is adapted to enclose a canister containing a substance under pressure. In a preferred embodiment, case  100  is dimensioned with an axial length and a radius to engage a canister of pepper spray. However, it should be understood that case  100  may be manufactured with any combination of axial lengths and radii dictated by the type of canister that case  100  is to encompass. 
     Still referring to  FIG. 2 , main body  10  has circumferential aperture  12  to enable nozzle  72  (labeled in  FIG. 10 ) of actuator  70  to direct any dispelled material outward through case  100 . Aperture  12  is slightly elongated in the axial direction to accommodate the upward and downward movement of nozzle  72  when a user depresses actuator  70  to actuate the expulsion of the material within the canister and then releases actuator  70  to cease the expulsion of material. Further, finger ridges  14  and  15  are molded into main body  10  in order to create a better grip for the user and to increase the user&#39;s comfort while gripping case  100 . 
       FIG. 3  is a rear perspective view of case  100 . Protruding axial grips  16  are molded onto the rear of main body  10  in order to engage the user&#39;s palm and to further increase the user&#39;s grip while holding case  100 . Rear opening  20  is generally ellipsoidal in shape with its top arcuate curve defined by the rear of lid  30  and its bottom arcuate curve defined by the rear of main body  10 . Lateral lid wings  32   a  and  32   b  of lid  30  are shaped to extend axially downward to engage main body  10  and create interface  24  such that lid  30  disengages main body  10  at the vertices of the transverse diameter of rear opening  20 . 
       FIG. 4  shows the bottom of lid  30 . Lateral wings  32   a  and  32   b  rest on top of the rear of main body  10  (shown in  FIG. 2 ), and curved receptacles  38   a  and  38   b  rotatingly engage spring  50  (shown in  FIG. 6 ) near the front of main body  10 . Lid tabs  36   a  and  36   b  create a mechanical stop with their respective apices  166   a  and  166   b  (best illustrated in  FIGS. 14A and 14B ) of main body  10 . The bottom of lid  30  also has rear sloped guides  34   a  and  34   b  contiguous with their respective horizontal guides  35   a  and  35   b . The guides facilitate the insertion of the user&#39;s finger or thumb into rear opening  20  (shown in  FIG. 3 ), as will be described further with respect to  FIGS. 5A-5C . 
       FIGS. 5A-5C  illustrate a canister housed within case  100  and in the process of being used by a user. The left lateral lid wing has been removed from lid  30  in  FIGS. 5A-5C  in order to better illustrate the user&#39;s thumb position. The user is shown holding case  100  with his or her index finger above finger ridge  14 , his or her middle finger below finger ridge  14  and his or her palm proximate to axial grips  16 . To dispel the contents of the canister, the user inserts his or her thumb into the rear opening and depresses actuator  70 . 
       FIG. 5A  illustrates the user initially inserting his or her thumb into the rear opening. While the user&#39;s thumb is partially inserted into the rear opening, the tip of the user&#39;s thumb slides along the rear sloped guides  34   a  (shown in  FIGS. 4) and 34   b . Lid  30  is biased toward its closed position (shown in  FIGS. 2 and 3 ) by spring  50  ( FIG. 6 ) so the user is opposing this force initially in order to open the lid. Sloped guides  34   a  and  34   b  are configured to facilitate the rotation of lid  30  as well as to guide the user&#39;s thumb into a central position over actuator  70 . With the sloped guides  34   a  and  34   b  aiding in the rotation of lid  30 , the user can use a single substantially linear radial motion to insert his or her thumb. A single substantially radial motion, as opposed to requiring a prior and separate axial motion to lift the lid, decreases the possibility for the user to fumble while trying to depress actuator  70 . This may become especially important when the canister housed in case  100  contains pepper spray and the user is presented with a threat. 
       FIG. 5B  illustrates the user with his or her thumb in a central position over actuator  70 . In this position, the tip of the user&#39;s thumb engages horizontal guides  35   a  (shown in  FIGS. 4) and 35   b . The user is now in a position to depress actuator  70 . 
       FIG. 5C  illustrates the user depressing actuator  70  (visible in  FIGS. 5A and 5B ). In this position, horizontal guides  35   a  (shown in  FIGS. 4) and 35   b  generally rest on top of the user&#39;s thumb nail and may provide some downward force because lid  30  is biased in the closed position. While the user is depressing the actuator in the axial direction, finger ridges  14  and  15  (shown in  FIG. 2 ) help prevent main body  10  from slipping in the axial direction in the user&#39;s hand.  FIG. 5C  shows material being dispelled from the canister represented by dotted lines. 
       FIG. 6  is an exploded view of case  100 . A canister (not shown) is inserted axially upwards through the bottom of main body  10 . Bottom cap  95  is then attached to main body  10  in order to prevent the canister from falling out. Bottom cap  95  is secured to main body  10  by circumferential lip  96  engaging circumferential rim  41  of main body  10 . Actuator  10  is inserted axially downwards through the top of main body  10  and engages the stem of the canister via receiving port  74 . Nozzle  72  directs the discharged contents of the canister through circumferential aperture  12  of main body  10 . 
     Still referring to  FIG. 6 , spring  50  is attached to lid  30  by inserting spring arms  52   a  and  52   b  into curved receptacles  38   a  and  38   b , respectively. Lid  30  is rotatable because curved receptacle  38   a  is rotatable around arm  52   a  and curved receptacle  38   b  is rotatable around arm  52   b . When lid  30  is rotated to a certain extent, tabs  58   a  and  58   b  abut front edge  174  of lid  30 , thereby limiting rotation between spring  50  and lid  30 . Spring  50  is attached to main body  10  by inserting legs  54   a  and  54   b  into engagement mechanisms located inside main body  10  proximate to indents  13   a  and  13   b . Spring  50  is inserted into the main body engagement mechanisms with nozzle  72  of actuator  70  between spring legs  54   a  and  54   b . Spring  50  has curved surfaces  64   a  and  64   b  to accommodate nozzle  72 . Finally, lateral wings  32   a  (shown in  FIGS. 3) and 32   b  rest atop the rear portion of main body  10 . 
     Generally, with reference to  FIGS. 7A-7H , spring element  50  comprises arms  52   a  and  52   b , legs  54   a  and  54   b , and tongue  56 . Preferably, arms  52   a  and  52   b  are horizontal and colinear with each other while legs  54   a  and  54   b  are parallel to each other and run vertically in the axial direction when inserted into main body  10  (shown in  FIG. 6 ). Arm  52   b  has vertical slot  57   b , and arm  52   a  has an analogous vertical slot (not shown). Slot  57   b  and its analogous vertical slot on arm  52   a  engages rail  157   b  and  157   a  (shown in  FIG. 9A ), respectively, on the inside of main body  10 . Slot  57   b  and its analogous slot on arm  52   a  ensure that spring  50  is properly inserted into main body  10  as well as provide stability to arms  52   a  and  52   b  while lid  30  (shown in  FIG. 2 ) is rotating. Arms  52   a  and  52   b  are separated by gap  52   c.    
     Tongue  56  is flexible and provides a biasing torque against lid  30  (shown in  FIG. 6 ) into a closed position while arms  52   a  and  52   b  are rigid and provide stability within main body  10  (also shown in  FIG. 6 ). The geometry of tongue  56  enables spring element  50  to be manufactured out of plastic instead of metal requiring an appropriate yield strength that is typically used in spring mechanisms. Tongue  56  has a tapered shaft with an enlarged tip so that tongue  56  yields, or bends, more easily at its shaft. Further, a slot runs longitudinally through tongue  56  and is also tapered to reflect the shape of tongue  56 . The slot enables tongue  56  to bend with the appropriate spring constant for the desired required force. 
       FIG. 7A  is a front perspective view of spring  50  in an uncocked, or “rest”, position meaning that no mechanical energy is stored. Leg grooves  66   a  and  66   b  are near the top of legs  54   a  and  54   b , respectively, proximate to arms  52   a  and  52   b , respectively. Leg grooves  66   a  and  66   b  provide another mechanical stop for when lid  30  (shown in  FIG. 6 ) rotates by engaging nibs  37   a  and  37   b  (shown in  FIG. 4 ), respectively. The first mechanical stop described above is tabs  58   a  and  58   b  engaging front edge  174  of lid  30 , thereby limiting rotation between spring  50  and lid  30 . Further, arms  52   a  and  52   b  have overhangs  59   a  and  59   b , respectively. Overhangs  59   a  and  59   b  are simply the result of substantially rectangular grooves on the interior lateral portions of arms  52   a  and  52   b , and will be explained in further detail with respect to  FIG. 7C . As described above with respect to  FIG. 6 , spring  50  has curved surfaces  64   a  and  64   b  to accommodate nozzle  72 . 
       FIG. 7B  is a front perspective view of spring  50  in a cocked position. In this position, the shaft of tongue  56  is bent and the tip of tongue  56  is configured between colinear arms  52   a  and  52   b . The tapered shaft and tapered slot  55  of tongue  56  enable tongue  56  to be fitted between arms  52   a  and  52   b  by being narrower than the gap between arms  52   a  and  52   b . Further, the shaft of tongue  56  may be forcibly squeezed narrower if needed to fit between arms  52   a  and  52   b . In a preferred embodiment, tongue  56  is held in the cocked position, which will be described in more detail with respect to  FIG. 7C . 
       FIG. 7C  is a rear perspective view of spring  50  in the uncocked position. In a preferred embodiment, tongue  56  has shoulders  61   a  and  61   b . Shoulders  61   a  and  61   b  act with overhangs  59   a  and  59   b  in order to hold tongue  56  in the proper cocked position. Overhangs  59   a  and  59   b  are simply the result of substantially rectangular grooves on the interior lateral portions of arms  52   a  and  52   b . The tops of the rectangular grooves are preferably angled upwards away from tongue  56  (best shown in  FIGS. 7G and 7H ) to fine tune the angle of the bend in tongue  56  when in the cocked position. However, tongue  56  may be held into the cocked position by the underside of lid  30  when attached to lid  30  without the presence of shoulders  61   a  and  61   b  and with overhangs  59   a  and  59   b.    
       FIG. 7D  is a rear perspective view of spring  50  in the cocked position. Curved surfaces  62   a  and  62   b  at the base of tongue  56  are to accommodate nozzle  72  (shown in  FIG. 6 ) on actuator  70  (also shown in  FIG. 6 ). 
       FIG. 7E  is a rear view of the cocked spring element shown in  FIG. 6 , and  FIG. 7F  is a rear view of the uncocked spring element shown in  FIG. 6   
       FIG. 7G  is a cross-sectional view of the cocked spring element taken generally along line  7 G- 7 G in  FIG. 7E . Angle α′ is the cocked angle between the base of spring  50  and leg  54   a , and angle θ′ is the cocked bend angle of bend  51  in the shaft of tongue  56 . Both cocked angles α′ and θ′ are smaller than the uncocked angles α and θ (shown in  FIG. 7H ), which generates tension in the material making up tongue  56  and thereby priming tongue  56  to provide a biasing torque. The tension in bend  51  provides most of the biasing torque for the spring action. 
       FIG. 7H  is a cross-sectional view of the cocked spring element taken generally along line  7 H- 7 H in  FIG. 7F . In  FIG. 7H , angle α is the uncocked angle between the base of spring  50  having curved surface  62   a  and leg  54   a . Angle θ is the uncocked bend angle of bend  51  in the shaft of tongue  56 . The top of the substantially rectangular groove of overhang  59   a  is shown angled upwards away from tongue  56  to fine tune the angle of the bend in tongue  56  when in the cocked position. 
       FIG. 8  illustrates lid  30  attached to a cocked spring  50 , and engagement mechanism  150  of main body  10 . With respect to spring  50 , tongue  56  (shown in  FIGS. 7A-7H ) is angled toward the front of main body  10 , and legs  54   a  and  54   b  are inserted axially downwards proximal to the front of main body  10 . 
     Engagement mechanism  150  has a symmetrical set of elements starting with partial through bores (shown as bores  156   a  and  156   b  in  FIG. 9A ) in flat platforms  160   a  and  160   b  to snugly receive spring leg  54   a  and  54   b , respectively. Flat platforms  158   a  and  158   b  extend axially upwards from platforms  160   a  and  160   b  and contain semicircle partial through bores with the lateral interior semicircles unbound by platforms  160   a  and  160   b . The diameter of the partial through bores in platforms  160   a  and  160   b  are slightly larger than the diameters of the partial through bores in platforms  158   a  and  158   b . The slightly larger diameters facilitate the insertion of spring legs Ma and  54   b  into the partial through bores of platforms  160   a  and  160   b  by acting as guides and decreasing the precision required for assembly. Apices  166   a  and  166   b  extend radially inward and axially upwards from platforms  158   a  and  158   b , respectively, and act as mechanical stops to tabs  36   a  and  36   b , respectively, on lid  30 . Engagement mechanism  150  also has curved surface  164  extending radially inward and sloping axially downward from the front of main body  10 . Curved surface  164  is described in more detail with respect to  FIGS. 13A and 13B  below. 
       FIG. 9A  is a top view of main body  10 . Lateral rails  157   a  and  157   b  extend into the interior of main body  10  and extend axially downward to curved surface  164 . As was explained above, arm slot  57   b  (shown in  FIGS. 7A-7H ) and its analog on spring  50  engages rail  157   b  and  157   a , respectively, to ensure that spring  50  is properly inserted into main body  10  as well as provide stability to spring arms  52   a  and  52   b  while lid  30  (shown in  FIG. 2 ) is rotating. Partial through-bores  156   a  and  156   b  are shown with a slightly smaller diameter than the partial through bores of platforms  158   a  and  158   b , respectively. Apices  166   a  and  166   b  extend radially inward from platforms  158   a  and  158   b , respectively. Main body  10  also has shelf  172  extending radially inward, which will be explained in further detail with respect to  FIG. 12B . 
       FIG. 9B  is a top view of main body  10  housing actuator  70 . Nozzle  72  is shown to sit between platforms  160   a  and  160   b  and does not extend radially beyond main body  10 . Apices  166   a  and  166   b  extend radially inward to at least partially constrain any radial movement of actuator  70 . 
       FIG. 10  is a front perspective view of actuator  70  with its nozzle  72 . 
       FIG. 11  is a bottom rear perspective view of actuator  70  with its nozzle  72 . Actuator  70  engages the canister with receiving port  74  and the substance contained within canister is dispelled through bore  76  within receiving port  74  and redirected through nozzle  72 . 
       FIG. 12A  is a front view of the main body with the lid and bottom cap removed.  FIG. 12B  is a cross-sectional view of the main body taken generally along line  12 B- 12 B in  FIG. 12A . Shelf  172  extends radially inward from main body  10  and has an interior circumferential surface  175 . Circumferential surface  175  has a greater axial length than shelf  172  and extends from the top radial surface of shelf  172  axially downward. Bottom surface  176  rests on top of the canister (not shown). The stem of the canister extends axially upward through shelf  172  and engages receiving port  74  of nozzle  70 . When actuator  70  is depressed, the contents of the canister are dispelled through the canister stem and axially upward into duct  180 . The only outlet for the contents of the canister is into channel  182  of nozzle  72 , thereby directing the contents out of main body  10  through aperture  12 . 
     Main body  10  also has internal axial ridges (ridge  170  is shown) that extend radially inward to at least partially constrain any radial movement of the canister. The internal axial ridges, such as ridge  170 , accommodate any radial expansion or contraction of the canister throughout its use by allowing the canister to expand in the gaps between the ridge without puncturing the canister and without compromising stability between main body  10  and the canister. In a preferred embodiment, four internal axial ridges are used, but as few as zero may be used and as many may be used without compromising the pressure within the canister. 
       FIG. 13A  is a magnified view of spring  50  connecting lid  30  and main body  10  in a closed position. Front edge  174  and tongue  56  are shown to be substantially horizontal, which is an angular difference from the sloped top of the substantially rectangular grooves of overhang  59   a  shown in  FIGS. 7G and 7H . By situating tongue  56  horizontally, tongue  56  is now loaded against front edge  174  and provides a biasing torque to front edge  174  of lid  30  (forcing edge  174  in a generally upwards direction) causing lid  30  to be in the closed position. When in the closed position, interfaces  24   a  (shown in  FIG. 3  as between lid wing  32   a  and main body  10 ) and  24   b  (not shown) act as the mechanical stop to the rotation of lid  30 . So, like the cocked position of spring  50 , the closed position of lid  30  generates a loaded static state for spring  50 . 
       FIG. 13B  is a magnified view of spring  50  connecting lid  30  and main body  10  while in the maximum open position. To get to the maximum open position, the user inserts his or her thumb under lid  30  causing lid  30  to rotate around arm  52   b . Tongue  56  is pushed in a generally downwards direction causing spring  50  to become loaded against front edge  174 . Curved surface  164  enables front edge  174  to swing down into main body  10 . Bend angle θ′ of bend  51  (shown in  FIG. 7G ) decreases, which increases the tension in tongue  56 . Increasing or decreasing the bend angle of bend  51  is considered to be dynamic as opposed to static. The maximum open position is also considered dynamic because elements of case  100  (shown in  FIG. 2 ) do not self-sustain tongue  56  in a position without intervention of the user. 
     The counter-clockwise rotation of lid  30  in  FIG. 13B  is prohibited by various mechanical engagements. Lid  30  is prohibited from further rotation with respect to spring  50  by the abutment of front edge  174  on spring tab  58   b . Lid  30  is also prohibited from further rotation with respect to spring  50  by the engagement described above with reference to  FIGS. 7A-7H  where front edge  174  abuts front spring grooves  166   a  and  166   b . In  FIG. 13B , lid  30  is prohibited from further rotation with respect to main body  10  by the abutment of lid tab  36   b  with apex  166   b . Also, spring  50  is securely fixed to main body  10  through engagement mechanism  150  (shown in  FIG. 8 ) interacting with spring legs  54   a  and  54   b  (shown in  FIGS. 7A-7H ), and lateral rails  157   a  and  157   b  (shown in  FIG. 9B ) interacting with arm slots  57   a  and  57   b  (shown in  FIGS. 7A-7H ). 
       FIG. 14  is a bottom perspective view of bottom cap  95 . Bottom cap  95  has radial aperture  97  so that case  100  (shown in  FIG. 2 ) can be attached to a key ring or chain or a string. Groove  94  enables a multitude of attachment accessories such as the key ring, etc., to fit through aperture  97 . 
     Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention as claimed. 
     LIST OF REFERENCE NUMBERS 
     
         
           10  Body 
           12  Circumferential aperture 
           13  Indents 
           14  Finger ridge 
           15  Finger ridge 
           16  Grips 
           20  Rear opening 
           24  Lid-Body rear interface 
           30  Lid 
           32  Lateral lid wings 
           34  Sloped guides 
           35  Horizontal guides 
           36  Lid tabs 
           38  Lid curved receptacles 
           41  Circumferential lip 
           50  Spring 
           52  Arms 
           54  Legs 
           56  Tongue 
           57  Lateral slits 
           58  Arm tabs 
           59  Overhangs 
           61  Tongue tabs 
           62  Tongue curve 
           64  Tongue base curve 
           66  Leg groove 
           68  Leg larger diameter interface 
           70  Actuator 
           72  Nozzle 
           74  Receiving port 
           76  Bore 
           95  Bottom cap 
           96  Circumferential lip 
           100  Case 
           150  Body engagement mechanism 
           154   s  Support bases 
           156   s  Partial through-bores 
           157  Lateral guides 
           158  Level 1 of partial through bore 
           160  Level 2 of partial through bore 
           162  Semicircle partial through bore 
           164  Curved internal body surface 
           166  Apices 
           168  Lateral guides label 
           170  Body internal ridges 
           172  Body shelf 
           174  Front edge of lid