Patent Publication Number: US-6905417-B1

Title: Automatic pool cue tip tapper

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of Provisional Application Ser. No. 60/406,198, filed Aug. 27, 2002. 

   FIELD OF THE INVENTION 
   This invention relates to devices for conditioning pool cue tips and more particularly to devices for treating pool cue tips to penetrate and remove a layer of glazed chalk and/or to create a pattern of minute depressions into which additional chalk may be received and retained. 
   BACKGROUND OF THE INVENTION 
   Various approaches to conditioning of pool cue tips have been taken, most of which involve some form of cutting, scuffing or piercing the tip leather and thus shortening its useful lifetime. In addition to this disadvantage, considerable skill is required to apply a tool with an exact and consistent amount of force so as to obtain a playable surface without damaging the leather. It would be preferable to provide a device that creates impressions capable of receiving chalk in the tip surface without inflicting damage. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a pool cue tip conditioning device comprising a series of components aligned in a generally tubular housing adapted for use in a vertical configuration, with the lower end of the device being pulled downward over a pool cue tip. A striker plate is slidably mounted adjacent the lower end of the housing, the plate on its lower side supporting an array of tip-indenting members and on its upper side having a contact knob for receiving blows from a plunger. The plunger, slidably mounted above the plate, has a flat bottom surface engaging the knob and an upper surface upon which a vertically extending post is mounted. The post is configured to engage a return spring which has a characteristic of causing the tip end of the post to be centered when pressure is applied by forcing the housing downward over a pool cue tip. A plug is provided between a work spring secured by an upper end of the housing and the upper end of the return spring, the plug at its bottom surface having an axially extending central aperture into which the upper end of the post is directed by action of the return spring upon application of pressure, which action results from structural features of the return spring. In particular, the return spring may comprise a generally triangular shaped compression spring having an off-axis bend at its smaller end and upper and lower turns of the spring substantially out of parallel with each other. When pressure is not being applied to the return spring, the plunger tip rests against a lower surface of the plug away from the central aperture, restraining the striker plate from movement. 
   Once pressure is applied, the plunger tip is centered by internal features of the main body, causing the tip to be released for movement into the plug aperture upward to the upper end thereof. At this point a work spring, substantially stronger than the return spring, forces the plug downward, slamming it back into the plunger, which in turn drives the striker plate into the cue tip over which the lower end of the device is placed. The force delivered in carrying out this action depends on the strength of the work spring in comparison with the return spring, and does not vary with the force exerted by a specific user. Less skill in application of force is therefore required. For best results a relative spring strength sufficient to create indentations capable of holding chalk without inflicting damage to the tip is preferred. 
   It is accordingly an object of this invention to provide a pool cue tip tapper device that delivers tip-striking blows of consistent strength, independent of skill on the part of the user. 
   Another object is to provide such a device that forms chalk-retaining indentations in a cue tip without inflicting damage to the tip. 
   Another object is to provide a pool cue tapper in which the force of application of striking blows is determined by relative strength of springs, rather than by mechanical skill of the user. 
   Other objects and advantages of the invention will be apparent from the following description and the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a tip-tapper device embodying the invention. 
       FIG. 2  is an exploded view thereof. 
       FIG. 3  is an end view showing an array of tapping fingers. 
       FIG. 4  is a view of the device, partly in section, showing a striker-driving plunger in a restrained position prior to being activated. 
       FIG. 5  is a view, partly in section, showing an array of tapping fingers being driven into a cue tip. 
       FIG. 6  is a sectional view of a main body housing of the device. 
       FIG. 7  is a side view of a return spring used in the device. 
       FIG. 8  is a sectional view of a bottom housing portion thereof. 
       FIG. 9  is a sectional view of a plug with an aperture into which the plunger tip is driven. 
       FIG. 10  is a sectional view of the plunger. 
       FIG. 11  is a sectional view of a cap for the tapper housing. 
       FIG. 12  is an enlarged sectional view of a striker plate and an array of fingers. 
       FIG. 13  is a sectional view of an alternate plunger design. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1  of the drawings, there is shown an external view of a pool cue tip conditioning device  10 . The device has a bottom housing portion  12 , a main body housing portion  27  and a housing cap  66 . The main body portion includes a middle portion  26  and a lower sleeve portion  20 . Bottom housing portion  12  has an end flange  16  and a central opening  18  in which pool cue tips are received for treatment. An array of projecting fingers  32  are provided to come into contact with pool cue tips in a tapping treatment. 
     FIG. 2  shows housing parts  12 ,  27  and  66  positioned at bottom, middle and top positions and internal components in vertical alignment, including a striker plate  14  carried in housing portion  12 , a plunger  36  located in position to come into contact with striker plate  14 , a return spring  46  disposed over post  40  of the plunger, a plug  54  adapted to receive a tip  44  of the plunger in an aperture  62  at the bottom surface  60  of the the plug upon application of force to striker plate  14  and a work spring  58  urging the plug downward. 
     FIG. 3  provides an end view of the device, taken from below, showing a circular flange  16 , disposed around a central opening  18  configured to receive a pool cue tip and a concave array  30  of a multiplicity of fingers  32  positioned to produce indentations in inserted cue tips during a tapping procedure. 
     FIG. 4  shows the location and alignment of internal components of the device prior to activating the device by applying pressure to the striking plate  14  in a cue tapping procedure. In the configuration of this drawing, tip portion  44  of plunger  36  is restrained from entering aperture  62  of plug  54  by virtue of unique characteristics of return spring  46 . In particular, the return spring may comprise a generally triangular compression spring, bent off-axis at its smaller end so that the lower end is bent away from being parallel with the upper end. This causes the plunger tip to be held in contact with the bottom surface of the plug so that it will not become centered and thus will not be allowed to enter the aperture unless a pressure strong enough to overcome the work spring is applied. The work spring  58  has its upper end in contact with housing cap  66  and its lower end in contact with the top surface  56  of plug  54 , urging the plug downward. 
     FIG. 4  also shows connection of main body portion  27  of the housing with cap  66  at the top and with bottom housing portion  12 . At the top, external threads  68  of inner member  69  are engaged with internal threads  70  of cap  66 , while at the bottom external threads  24  of bottom housing  12  are engaged with internal threads  51  of middle housing portion  26 . 
   In the configuration of  FIG. 4  striker plate  14  remains in contact with flange  16  at the base of bottom housing portion  12 , inasmuch as the striker has not yet been driven upward by insertion of a cue tip into central opening  18  or by making contact with fingers  32 . Knob  34  of the striker allows plunger  36  to be tilted over, with flat disk  38  inclined away from parallel with the striker plate. Return spring  46 , in the absence of pressure from below, has its upper end  74  and its lower end  72  tilted away from perpendicular alignment with housing components of the device.  FIG. 4  also shows stop collars incorporated in the main housing body  27  to limit movement of operating components. Stop collar  52  limits downward movement of plug  54 , and stop collar  53  limits upward movement of plunger  36 . Lower surface  60  of plug  54  also restrains plunger tip  44  from upward movement until the plunger tip is centered and allowed to move into aperture  62  of the plug. 
     FIG. 5  shows the alignment of component parts of the device after a tip  78  of a pool cue  76  has been brought into contact with fingers  32  provided in the lower side of a striker plate  14 . Upward movement of cue stick  76  overcomes work spring  58 , causing tip  44  to become centered under aperture  62  of plug  54  by guiding action of return spring  46 . Upon being located in alignment with the aperture  62 , tip  44  is released for movement. The work spring  58 , being substantially stronger than the return spring, forces the plug downward over the tip until the tip comes into contact with the end of the aperture. As a result the plug is slammed downward against the plunger  36 , which in turn drives fingers  32  of the striker plate into cue tip  78 . Relative strengths of the return spring and the work spring may be chosen to obtain formation of indentations of the cue tip without penetrating the leather of the cue tip in a manner such as to inflict damage. 
   The main body portion  27  of the housing for the device is shown in  FIG. 6 . This component has an upper sleeve  50  provided with threads for engagement with a cap and a lower sleeve portion  26  also provided with threads for being connected to bottom housing portion  12 . Two stop collars are preferably incorporated in the main body portion to limit the extent of movement of operating components. Lower stop collar  53  limits upward movement of the plunger, and upper stop collar  52  limits downward movement of the work spring. 
     FIG. 7  shows details of a suitable return spring for use in the preferred embodiment. Although the invention is not limited to specific dimensions of components, the return spring  46 , which is a generally triangular compression spring with a bent-off axis at its smaller end, may have a diameter  75  at its upper end  74  of 0.625 inch and at its lower end  72  a diameter of 0.350 inch. Overall expanded length as shown is 1.10 inch. At its lower end the spring is bent away from being parallel with the upper end to the extent of 15 to 20 degrees. The return spring preferably is comprised of a 0.032 inch music wire and may have 7 to 9 turns in the coil. When pressure is not being applied to this spring at its lower end in which the plunger tip is inserted, the spring holds the plunger tip away from the aperture of the plug. Upon compression of the return spring by force applied to its lower and smaller end the spring and plunger become aligned symmetrically and are centered, allowing the plunger to move freely into the aperture of the plug. 
     FIG. 8  is directed to bottom housing portion  12 , which includes an end flange  16  and a central opening  18  for insertion of cue sticks to enable tapping of tips on the sticks. External threads are provided on this portion for making connection with mating internal threads on the main body portion of the housing. 
     FIG. 9  shows a plug  54  contacted from above by work spring  58  and from below by plunger tip  44 , which bears against lower surface  60  of the plug or against the upper end of aperture  62  upon being centered as described above. 
     FIG. 10  and  FIG. 13  show two versions of plungers which may be used. Each of these plungers (out of scale with other components) have a cylindrical upper tip portion  44  sized to fit into aperture  62  of the plug and a circular flat bottom disk  38 ,  82  sized to fit within lower housing portion  12 . Lower post portion  36 ,  80  receives the lower end portion of the return spring, the lower post portion  36 ,  80  being cylindrical as in the plunger of  FIG. 10  or frustro-conical as in  FIG. 13 . Each of the plungers have a transition zone  42  between upper and lower portions of the post. 
     FIG. 11  shows a cap  66  fror placement on the main body of the housing. Internal threads are provided for engagement with external threads at the upper end of the main body. 
   As shown in the enlarged view of  FIG. 12  the striker plate  14 , which fits across the interior of bottom housing portion  12 , has a metal disk  28  with a concave pocket at its lower side and an arcuate knob on its topside. An array  30  of fingers  32  are disposed within the pocket and are arranged to have their points form a concave pattern conforming to the rounded shape of a pool cue tip. The metal disk  28  may have a thickness of 0.200 inch, and the rounded knob  34  may have a thickness of 0.150 inch at its center and a diameter of 0.400 inch. Fingers  32  are preferably pyramidical in shape, having a height of 0.040 inch, and are located on 0.050 inch centers. Points of the fingers may have an angle of 40 degrees with relation to horizontal. Curvature at a radius of 0.390 inch provides a suitable rounded shape for the pocket. 
   Suitable dimensions for housing components may include the following: the cap—an overall length of 1 inch, an internal height of 0.700 and a diameter of 0.910 inch; the main body—an internal diameter of 0.600 inch, external diameter of 1.160 inch, threaded upper portion of main body, height 0.500 inch; height above upper stop collar, 2.00 inches; bottom, internally threaded portion of main body, height of 0.900 inch. Lower stop collar defines internal passage with diameter of 0.370 inch. Below this stop collar the main body housing has a diameter of 0.650 inch extending to threaded portion, where diameter is 0.675 inch. 
   For the embodiment described above the work spring may comprise a compression spring made of 0.050 inch music wire having an expanded length of 2¼ inches. The housing is preferably made of polycarbonate formed by injection molding. The striker plate may be made of an aluminum alloy such as 7075 or harder alloy fabricated by computer-aided machining. 
   While the preferred embodiment has been described above in specific terminology, this description is for illustrative use only, and it is to be understood that the invention is limited only as indicated by the appended claims.