Abstract:
A fully automatic jar opener for loosening a threaded cap includes a bottom jar retainer including substantially horizontal clamps automatically movable along a horizontal plane between an open position and a jar clamping position. The clamps, while in the jar clamping position, hold a jar substantially without slippage and a top jar retainer holds the cap substantially without slippage when the cap is subjected to a twisting force. A vertical drive automatically adjusts the relative vertical positions between the bottom and top retainers to apply a holding force on the cap. The automatic jar opener includes at least one electrically-controllable pneumatic actuator for moving for moving the clamps along the horizontal plane, and at least one motor for applying the twisting force to the top retainer and for adjusting the relative vertical position between the retainers. A controller automatically controls the pneumatic actuator and the motor and enables loosening of the cap with one single, discrete user command.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to jar openers and more particularly to automatic jar openers. 
     SUMMARY OF THE INVENTION 
     The invention relates to a fully automatic jar opener for loosening a threaded jar cap on a jar. The jar opener includes a bottom jar retainer including substantially horizontal clamps that are automatically movable along a horizontal plane between an open position and a jar clamping position. The clamps, while in the jar clamping position, hold the jar substantially without slippage when the jar cap is subjected to a twisting force. A top jar retainer holds the jar cap substantially without slippage when the twisting force is applied to the jar cap. The twisting force is applied to the jar cap by the top jar retainer. A vertical drive automatically adjusts a relative vertical position between the bottom jar retainer and the top jar retainer, the relative vertical position determines a holding force of the top jar retainer on the jar cap for a given jar size. The automatic jar opener includes one or more drivers for moving the clamps along the horizontal plane, for adjusting the relative vertical position between the bottom jar retainer and the top jar retainer, and for applying the twisting force to the top jar retainer. A controller automatically controls the action of the drivers and the movements of the clamps and enables loosening of the jar cap on a jar that has been placed in the opener with a single, discrete user command that is input on a user input device. 
     In particular embodiments of the invention, one of the drivers is a pneumatic actuator for moving the clamps along the horizontal plane, and one or more electric motors adjust the relative vertical position between the bottom jar retainer and the top jar retainer, and apply the twisting force to the top jar retainer. The controller sends a first control signal to a valve that controls the flow of pressurized fluid into the pneumatic actuator. Pressure changes within the pneumatic actuator activates a piston rod whose movement causes the clamps to move along the horizontal plane. 
     In particular embodiments of the invention, upon the discrete user command, the controller sends a first command signal to a driver resulting in movement of the clamps to the jar clamping position to hold the jar, whereupon the controller sends a second command signal to a driver resulting in movement of the vertical drive to move together the bottom jar retainer and the top jar retainer to apply the holding force to the jar cap, whereupon the controller sends a third command signal to a driver resulting in the twisting force being applied to the jar cap via the top jar retainer to loosen the jar cap. 
     The controller further sends a fourth signal to the driver resulting in movement of the vertical drive to separate the bottom jar retainer and the top jar retainer to release the holding force on the jar cap and a fifth signal to a driver resulting in movement of the clamps to the open position to release the jar. 
     In other embodiments of the invention, the fully automatic jar opener includes at least two motors, a first motor for applying the twisting force to the cap and a second motor for adjusting the relative vertical positions of the bottom and top jar retainers. 
     In one illustrated embodiment, the fully automatic jar opener includes three motors, a first motor for applying the twisting force to the cap, a second motor for adjusting the bottom jar retainer, and a third motor for adjusting the top jar retainer. Upon the discrete user command, the controller sends a first command signal to the second motor to move the clamps to the jar clamping position to hold the jar and a second command signal to the third motor to move the vertical drive to move together the bottom jar retainer and the top jar retainer to apply the holding force to the jar cap. After the clamps have been moved to the jar clamping position and the holding force has been applied to the jar cap, the controller sends a third command signal to the first motor resulting in the twisting force being applied to the jar cap by the top jar retainer to loosen the jar cap. 
     In particular embodiments of the invention, the jar includes side walls and a base and the clamps contact the jar on opposite side walls of the jar near the base of the jar. The clamps include gripping pads for contacting the jar and holding the jar substantially without slippage when the jar cap is subjected to the twisting force. The clamps define arcuate shaped jar contacting portions permitting clamping of different radii jars within a given range. 
     In other embodiments of the invention, the fully automatic jar opener includes a housing defining clamp pivots. The clamps are constructed and arranged to move along a horizontal plane between the open position and the jar clamping position by pivoting about the clamp pivots. The clamps are slidably received on the clamp pivots allowing removal and replacement of the clamps. The clamps include arm portions pivotably connected to the clamp pivots and jar contacting portions slidably received on the arm portions. Each jar contacting portion defines an arcuate shaped inner profile permitting clamping of different radii jars within a given range. 
     In one illustrated embodiment, the top jar retainer includes a cone for gripping a variety of sizes of jar caps. The cone includes a gripping pad for contacting the jar cap and holding the jar cap substantially without slippage when the twisting force is applied to the jar cap. 
     In other embodiments of the invention, a switch is activated when a predetermined load is applied to the jar by the clamps and another switch is activated when a predetermined load is applied to the jar cap by the top jar retainer. The jar opener includes a housing defining a chamber for placement of the jar and a door with a third switch activated when the door is closed. 
     The automatic jar opener of the invention can be used to easily loosen a jar cap with one, single discrete user command. The opener can be used with jars having a variety of heights, owing to the adjustment of the position between the clamps and top jar retainer, and with jars having a variety of diameters owing to the cone shape. 
     Other advantages and features of the invention will be apparent from the following description of the preferred embodiment and from the claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagrammatic representation of an automatic jar opener according to the invention; 
     FIG. 2 shows a front view of the automatic jar opener of FIG. 1; 
     FIG. 3 shows a top view of the automatic jar opener as seen taken along lines  3 — 3  in FIG. 2; 
     FIG. 3 a  shows a side view of a gear train of the automatic jar opener as seen taken along lines  3   a - 3   a  in FIG. 3; 
     FIG. 4 shows a top view of the automatic jar opener as seen taken along lines  4 — 4  in FIG. 2; 
     FIG. 5 shows a partially cut away top view of the automatic jar opener as seen taken along lines  5 — 5  in FIG. 2; 
     FIG. 6 is a diagrammatic representation of some components of the automatic jar opener shown in a jar receiving position; and 
     FIG. 7 shows an alternative embodiment of the jar clamps of the invention. 
     FIG. 8 a  is a diagrammatic representation of an alternative embodiment of the jar clamps of the invention. 
     FIG. 8 b  is a diagrammatic representation of another alternative embodiment of the jar clamps of the invention. 
     FIG. 8 c  is a diagrammatic representation of still another alternative embodiment of the jar clamps of the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, an automatic jar opener  10  is shown for automatically loosening a threaded jar cap  20  of a jar  16 . A bottom jar retainer  12  for holding jar  16  includes clamps  14 ,  14   a  mounted for movement (indicated by arrows  13 ) in a horizontal plane between an open position, FIG. 6, and a jar clamping position, FIG.  1 . In the jar clamping position of FIG. 1, clamps  14 ,  14   a  apply a holding force, for example, 50 to 60 pounds, to side walls  25  of jar  16  near the base  27  of the jar. A top jar retainer  18  is mounted to move vertically (indicated by arrow  21 ) between an unloaded position, FIG. 6, and a cap loosening position, FIG.  1 . In the cap loosening position of FIG. 1, top jar retainer  18  applies a downward holding force, for example, 50 to 60 pounds, to jar cap  20 . Top jar retainer  18  also includes a cone  19  mounted to rotate about vertical axis  17  (arrow  22 ) to apply a twisting force, for example, 10 foot- pound, to jar cap  20  to loosen the cap. 
     Jar opener housing  23  includes a door  24  allowing access to a jar chamber  29  and platform  33  on which jar  16  is placed by the user. Door  24  includes a safety latch  26  which, upon closing door  24 , contacts a switch  28 . With door  24  closed, a single user command, for example, activating an input device such as switch  30 , instructs automatic jar opener  10  to loosen jar cap  20 . 
     Referring to FIGS. 2-4, clamps  14 ,  14   a  are mounted for movement along a rod  35  between the open position of FIG.  6  and the jar clamping position of FIG.  1 . Referring particularly to FIG. 3, clamps  14 ,  14   a  include slots  37 ,  37   a  containing threaded elements  34 ,  34   a  which are mounted on threaded rod ends  36 ,  36   a  of rod  35 . Rod ends  36 ,  36   a  are oppositely threaded such that rotation of rod  35  causes threaded elements  34 ,  34   a  to move toward or away from each other along guiding slots  31 ,  31   a  in a platform  33 . 
     Clamps  14 ,  14   a  are mounted to rotate about pivots  32 ,  32   a . Pivots  32 ,  32   a  are defined by clamps through bores  132 ,  132   a  received on extension rods  134 ,  134   a  of blocks  136 ,  136   a  (FIG.  2 ). During movement of clamps  14 ,  14   a  along rod  35  and about pivots  32 ,  32   a , threaded elements  34 ,  34   a  slide within clamp slots  37 ,  37   a . The arcuate shape of jar contacting portions  47 ,  47   a  of clamps  14 ,  14   a  permit clamping of different radii jars within a range. Additionally, clamps  14 ,  14   a  may be slidably received on threaded elements  34 ,  34   a  and extension rods  134 ,  134   a  to permit easy replacement of the clamps to accommodate different ranges of sizes for jars  16 . 
     Referring particularly to FIGS. 3 a  and  4 , to rotate rod  35 , a motor  40  with worm gear  42  drives a gear  44 . Axle  46  of gear  44  drives a helical gear  48  (supported by bearing  49 ) which in turn drives a helical gear  50  attached to rod  35 . 
     Referring to FIGS. 2 and 4, top jar retainer  18  includes a mount  60  with threaded holes  62 ,  62   a  received on lead screws  64 ,  64   a  of a vertical drive  63 . Lead screws  64 ,  64   a  are mounted for rotation within bearings  65  to move top jar retainer  18  vertically (indicated by arrow  66 ) between the unloaded position of FIG.  6  and the cap loosening position of FIG.  1 . To rotate lead screws  64 ,  64   a , a motor  70  with worm gear  72  drives a gear  74  attached to lead screw  64   a . A belt  75  mounted on pulleys  77 ,  77   a  couples motion of lead screw  64   a  to lead screw  64 . Idler  79  keeps belt  75  under tension. 
     Referring to FIGS. 2,  4  and  5 , mount  60  of top jar retainer  18  is received on a square rod  78  for rotation therewith. To rotate cone  19 , a motor  80  with worm gear  82  drives a gear  84  attached at one end  78   a  of square rod  78 . At the opposite end  78   b  of square rod  78  is a gear drive including gears  86 ,  88  and  90 . Gear  90  is mounted to cone  19  for rotation therewith. 
     Referring to FIG. 3, clamps  14 ,  14   a  include non-slip surfaces  110 , for example, a rubberized foam such as that found on the backing of place mats or scatter rugs, to hold the jar substantially without slippage when the jar cap is subjected to the twisting force. As shown in FIG. 2, cone  19  also includes a non-slip surface  110 , which, when combined with the holding force applied by top jar retainer  18  on jar cap  20 , holds jar cap  20  substantially without slippage when the twisting force is applied to the jar cap. The inclined shape of cone  19  permits engagement between surface  110  and a variety of different sized caps. 
     Referring to FIGS. 3 and 4, in the illustrated embodiment, when clamps  14 ,  14   a  contact jar  16  and apply the holding force to the jar, an opposite force directed along arrows  140  is applied to the clamps and a related force directed along arrows  142  is applied by the clamps to rods  134 ,  134   a . A slot  138  in platform  33  and slots  140 ,  142  in block  136   a  allow clamp  14   a  and block  136   a  to move in the direction of arrow  142  in response to this force. Block  136   a  abuts a first end  148  of a lever  150 . Movement of block  136   a  causes rotation of lever  150  about a pivot  152 . A second end  154  of lever  150  is attached to an extension spring  156 . Rotation of lever  150  acts against extension spring  156 . Extension spring  156  is set, for example, by turning an adjustment screw  158 , such that rotation of lever  150  about pivot  152  an amount necessary to activate a limit switch  160  corresponds to the desired clamp load on jar  16 . A compression spring  162  acts on block  136   a  against extension spring  156  such that block  136   a  is not free- floating within slots  138 ,  140  and  142  when clamps  14 ,  14   a  are in their open position. 
     Referring to FIG. 2, cone  19  includes a spring  114  located within a recess  116  in housing  60 . A switch  118  located within recess  116  is activated when the spring has been depressed a predetermined distance corresponding to the desired vertical load. Motor  80  includes a potentiometer  170  for measuring the rotation of cone  19 . The cone is generally rotated about one-half turn to loosen cap  20 . 
     Automatic jar opener  10  includes a controller  100  for automatically controlling motors  40 ,  70  and  80 . Triggering of switch  160  sends a signals to controller  100  indicating that the desired clamp force of clamps  14 ,  14   a  on jar  16  has been reached. Controller  100  then commands motor  40  to hold this position. Similarly, triggering of switch  118  sends a signal to controller  100  indicating that the desired vertical load of cone  19  on jar  16  has been reached. Controller  100  then commands motor  70  to hold this position. Controller  100  monitors potentiometer  170  during rotation of cone  19  and stops rotation of motor  80  when the cap has been turned about one-half turn. 
     Referring to FIG. 6, in use, jar  16  is placed between open clamps  14 ,  14   a . Door  24  is closed with safety latch  26  contacting switch  28 . The user then pushes switch  30  sending a signal to controller  100  to loosen jar cap  20 . From this point, jar opener  10  is under automatic control. Controller  100  sends signals to motors  40  and  70  resulting in the closing of clamps  14 ,  14   a  and the lowering of cone  19 . When the desired loads of clamps  14 ,  14   a  and cone  19  on jar  16  has been reached, as determined by monitoring switches  160  and  118 , respectively, controller  100  sends a signal to motor  80  to turn cone  19  one-half-turn. Controller  100  then directs motors  40  and  70  to open clamps  14 ,  14   a  and lift cone  19 . Door  24  can then be opened. If door  24  is opened before completion of the cap loosening cycle, as determined by monitoring door sensor  28 , controller  100  stops all movement. 
     Other embodiments of the invention are within the scope of the following claims. 
     For example, controller  100  can monitor the current draw of motors  40  and  70 , as is well known in the art, to determine and maintain the desired loads on jar  16 . Alternatively, motors  40  and  70  can include slip clutches designed to apply only the desired loads to jar  16 . The three motors  40 ,  70  and  80  can be replaced with one or two motors and appropriate drive linkages. 
     Cone  19  can include a serrated inner lining to aid in gripping jar cap  20 . 
     Referring to FIG. 7, clamps  214 ,  214   a  include arms  215 ,  215   a  and jar contacting portions  216 ,  216   a . The inner arcuate shaped profiles  218 ,  218   a  of jar contacting portions  216 ,  216   a  permit clamping of a variety of sized jars. Jar contacting portions  216 ,  216   a  may be slidably received on rods  220 ,  220   a  of clamps  214 ,  214   a  for ease of replacement. 
     Referring to FIGS. 8 a - 8   c , clamps  302  and  302   a ,  402  and  402   a , and  502  and  502   a  are mounted to rotate about pivots  304  and  304   a ,  404  and  404   a , and  504  and  504   a , respectively. Pneumatic actuators  306 ,  406 , and  506  and  506   a  are connected to respective fluid supply tubes  308 ,  408 , and  508  for the delivery of pressurized fluid. Solenoid valves  310 ,  410 , and  510  are joined to and interrupt tubes  308 ,  408 , and  508  and are controlled by electronic controller  100 . Piston rods  314 ,  414 , and  514  and  514   a  project slidably from pneumatic actuators  306 ,  406 , and  506  and  506   a , respectively. 
     In FIG. 8 a , clamps  302  and  302   a  contain sets of engaging teeth  316  and  316   a  that mesh with each other so that the movement of one of clamps  302  or  302   a  causes a reciprocal movement by the other one. Piston rod  314  is connected to clamp  302 . 
     In FIG. 8 b , piston rod  414  has teeth  418  that mesh with engaging teeth  416  and  416   a  on clamps  402  and  402   a , respectively. 
     In FIG. 8 c , fluid supply tube  508  is capable of delivering pressurized fluid to both pneumatic actuators  506  and  506   a . Piston rods  514  and  514   a  are connected to clamps  502  and  502   a , respectively. 
     Actuators  306 ,  406 ,  506 , and  506   a  have spring returns. Alternatively, the actuators could be driven in both directions by providing additional solenoid valves and providing two controlled pneumatic supplies to the actuators.