Abstract:
A hand-held jar opener first stores rotational user energy in a clock spring while progressively closing a grip means to engage lids of different sizes. Next it grips the lid and provides mechanical advantage to the user to initially loosen it. Lastly it releases said stored rotational user energy to further unscrew the lid without additional user effort.

Description:
[0001]     This application claims priority on Provisional Patent Application No. 60/563,691 filed Apr. 20, 2004 
     
    
     FIELD OF INVENTION  
       [0002]     This invention relates to hand held tools which provide mechanical advantage to a user in loosening twist type jar lids.  
       BACKGROUND OF THE INVENTION  
       [0003]     In the prior art, Battles in U.S. Pat No. 6,679,138 B2 describes a bottle opener containing one or more fixed cams, or alternately a rolling cylinder, which can engage a narrow range of bottle top diameters. Rhodes in U.S. Pat No. 4,643,053 describes a device for loosening oil filters containing spring loaded eccentric cams which similarly can only engages a narrow range of filter diameters.  
         [0004]     In U.S. Pat. No. 1,593,947 Miller and Dirschauer describe a device for tightening a standard size fruit jar lid which contains rockable jaws and means to employ friction with the lid top to close said jaws. The rockable jaws are claimed with and without associated fulcrums at a fixed diameter from the device&#39;s center, but no alternative feature is described upon which said jaws may rock. This device can similarly only engages a narrow range of lid diameters  
       OBJECTS AND ADVANTAGES  
       [0005]     The principle object and advantage of the present invention is to provide a means to comfortably and intuitively loosen jar lids with a wide range of diameters. Presently available jar openers of the serrated V notch type are awkward to use because they require simultaneous application of radial and rotational force. Operation of the present invention is more like opening a jar unassisted, and is therefore more intuitive.  
         [0006]     A second advantage of the present invention is that rotational energy stored in a clock spring is reused to further loosen the lid. 
     
    
     BRIEF DESCRIPTION OF FIGURES  
       [0007]      FIG. 1 : Bottom perspective view while gripping lid of a jar;  
         [0008]      FIG. 2 : Bottom perspective view in open position;  
         [0009]      FIG. 3 : Top perspective view in open position;  
         [0010]      FIG. 4 : Exploded perspective view in open position;  
         [0011]      FIG. 5 : Bottom plan view in open position with dashed hidden lines and section line B-B;  
         [0012]      FIG. 6 : Section B-B view in open position;  
         [0013]      FIG. 7 : Bottom plan view while gripping lid of a jar with dashed hidden lines. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]      FIG. 1  is a perspective view showing the invention, as it may be held in a user&#39;s hand not shown, positioned to remove a conventional substantially round threaded lid  10  from a conventional jar  12 . A group of grip posts  14 A,  14 B, and  14 C bear against the circumferential surface of lid  10 . The bottom surface of a friction pad  20  bears against the top surface of lid  10  due to a user supplied holding force. In the preferred embodiment friction pad  20  is made of a high friction elastomer such as Santoprene®. The upper surface of friction pad  20  is adhered to the bottom surface of a radial guide plate  30 . Integral to radial guide plate  30  are a group of substantially radial slots  32 A,  32 B, and  32 C around which friction pad  20  is trimmed. Grip posts  14 A,  14 B, and  14 C extend respectively through radial slots  32 A,  32 B, and  32 C. Said slots are sized so that said posts can slide along them with minimal clearance. Radial guide plate  30  rotatably connects to a spiral housing  50  as detailed below. Spiral housing  50  is non-round so that the user may efficiently apply torque thereto.  
         [0015]     In the preferred embodiment the portion of the circumferential surfaces of grip posts  14 A,  14 B, and  14 C which extend through radial plate slots  32 A,  32 B, and  32 C are knurled to increase friction when bearing against lid  10 . Alternative surface treatments may use an adhesive bonded abrasive material or a high friction elastomer.  
         [0016]      FIG. 2  and  FIG. 3  are bottom and top perspective views showing the above components without jar  12  and lid  10 .  
         [0017]      FIG. 4  is an exploded view further showing a hub  36  integral to and projecting from the top of radial guide plate  30 . Hub  36  has a radial notch  38  in its circumferential surface. When unexploded a conventional clock spring  40  rests upon the top surface of radial guide plate  30 . Spring  40  is wound in the direction indicated by an arrow A. An inner spring end  42  of spring  40  engages radial notch  38 . Spring  40  is sized so that the rotational force required to wind it as installed is less than the rotational friction force between friction pad  20  and lid  10  resulting from typical user pressure against lid  10 .  
         [0018]     Further referring to  FIG. 4 , integral respectively to the top ends of grip posts  14 A,  14 B, and  14 C are disc portions  16 A,  16 B, and  16 C.  
         [0019]     Further referring to  FIG. 4 , spiral housing  50  is comprised of a spiral guide plate  52 , a top plate  54 , an edge guard  58 , and an end cap  70 . An interior hole  56  in top plate  54  is slightly larger in diameter than hub  36 . Spiral guide plate  52  has a group of spiral slots  60 A,  60 B, and  60 C which are sized so that grip posts  14 A,  14 B, and  14 C can slide along them with minimal clearance. Spiral guide plate  52  further incorporates a group of raised portions  62 A,  62 B, and  62 C which project slightly higher than the thickness of disc portions  16 A,  16 B, and  16 C. Spiral guide plate  52  lastly incorporates a center hole  64  sized to contain the outer diameter of spring  40 . Hole  64  has a radial notch  66  in its circumferential surface.  
         [0020]     When spiral housing  50  is unexploded grip posts  14 A,  14 B, and  14 C extend respectively through spiral slots  60 A,  60 B, and  60 C and disc portions  16 A,  16 B, and  16 C rest between top plate  54  and spiral guide plate  52 . Raised portions  62 A,  62 B, and  62 C attach to top plate  54  with conventional fasteners not shown. The orientation of spiral slots  60 A,  60 B, and  60 C is such that radial distances from the center of hole  56  to successive points on the outer surfaces of spiral slots  60 A,  60 B, and  60 C increase in direction A.  
         [0021]     When unexploded the bottom surface of spiral guide plate  52  of spiral housing  50  rests upon the top surface of radial guide plate  30 , and hub  36  projects into and freely rotates within hole  56 . As noted above, grip posts  14 A,  14 B, and  14 C project further respectively through radial slots  32 A,  32 B, and  32 C. An outer spring end  44  of spring  40  engages radial notch  66 .  
         [0022]     Edge guard  58  is a flexible ring fitted to the outer edges of spiral guide plate  52  and top plate  54 . In the preferred embodiment edge guard  58  is an efficiently gripped high friction compound such as Santoprene®.  
         [0023]     Lastly, end cap  70  connects to hub  36  and vertically restrains top plate  54  of spiral housing  50 .  
         [0024]      FIG. 5  shows a bottom plan view with dashed hidden lines. The orientation of spiral slots  60 A,  60 B, and  60 C described above is such that when a user rotates spiral housing  50  with respect to radial guide plate  30  in the direction indicated by arrow A, the outer surfaces of said spiral slots push grip posts  14 A,  14 B, and  14 C along radial slots  32 A,  32 B, and  32 C towards hub  36 . Turning spiral housing  50  in direction A also rotates outer spring end  44  in direction A thereby adding rotational energy to spring  40 .  
         [0025]      FIG. 6  is a section view corresponding to section line B-B of  FIG. 5 .  
         [0026]      FIG. 7  is another bottom plan view which shows the invention gripping lid  10 . Grip posts  14 A,  14 B, and  14 C are at intermediate positions within radial slots  32 A,  32 B, and  32 C. A ramp angle C is drawn between a line D tangent to the circumference of lid  10  at its point of contact with grip post  14 C and a line E tangent to the outer surface of spiral slot  60 C at its point of contact with grip post  14 C. In the preferred embodiment angle C is approximately 14 degrees. The particular paths of spiral slots  60 A,  60 B, and  60 C are loci of points at which analogous ramp angles are approximately constant for all allowed positions of spiral housing  50  with respect to radial guide plate  30 .  
         [0000]     Operation  
         [0027]     Operation of the present invention entails three stages. A first pre-engagement stage entails turning spiral housing  50  in direction A with respect to jar  12  while friction pad  20  bears against the top of lid  10 . As noted above, the rotational friction force resulting between friction pad  20  and lid  10  exceeds the force required to wind spring  40  as installed, so friction pad  20  and radial guide plate  30  do not rotate with respect to lid  10 . As the user turns spiral housing  50 , rotational energy is added to spring  40  and grip posts  14 A,  14 B, and  14 C simultaneously converge until they contact the circumferential surface of lid  10 . In thus converging said grip posts act to center lid  10  with respect to hub  36 . In practice the user may simultaneously rotate jar  12  in the opposite direction if held in his or her another hand to sooner engage lid  10 .  
         [0028]     In a second loosening stage grip posts  14 A,  14 B, and  14 C grip lid  10  by a means functionally analogous to that of a conventional roller clutch. A conventional roller clutch contains an inner race in contact with a group of rollers each pressed against a ramp by a spring. The inner race, rollers, and ramps are here analogous to lid  10 , grip posts  14 A,  14 B, and  14 C, and the outer surfaces of spiral slots  60 A,  60 B, and  60 C respectively. The force on said grip posts which is analogous that of said spring, however, is here applied by the user by turning spiral housing  50  with respect to jar  12 . This user supplied rotational force is translated from jar  12  through lid  19  and friction pad  20  to radial guide plate  30 , and acts on said grip posts through the surfaces of radial slots  32 A,  32 B, and  32 C. The interaction of said grip posts and said spiral slots then converts and magnifies the user applied rotational force into a radial griping force on lid  10 . When lid  10  is efficiently gripped in this way the user then loosens its bond to jar  12  by continuing to turn spiral housing  50 .  
         [0029]     In the task of opening ajar by hand the maximum torque applied to the lid is typically limited by the radial force applied by one&#39;s fingers in grasping it. The wrist can do the turning but it is the fingers that slip. The translation described above of a user supplied rotational force into a radial gripping force is therefore a principal advantage of the invention. No finger strength is required to grasp the lid. The overall size and shape of spiral housing  50  combine with the high friction properties of edge guard  58  to provide mechanical advantage to the user in applying the above rotational force.  
         [0030]     In a final unscrewing stage lid  10  is loose and the torque required to turn lid  10  diminishes. The user supplied rotational energy stored in spring  40  during said first pre-engagement stage now results in a torque on radial guide plate  30  in direction A with respect to spiral housing  50 . As the user continues to turn spiral housing  50  in direction A spring  40  spontaneously unwinds when said torque required to turn lid  10  diminishes to less than said spring supplied torque on radial guide plate  30 , less the torque required to overcome inertia and friction of said radial guide plate and said grip posts. With no additional user effort said unwinding of spring  40  then acts through friction pad  20  to further unscrew lid  10 . As spring  40  unwinds it also acts to return grip posts  14 A,  14 B, and  14 C to their original open positions, thus releasing lid  10  from said grip posts.