Abstract:
A sight-through billiards aiming device for assisting players in executing bank and kick shots, including two handles rotatably connected to a base at a common rotational axis, the base having a reference element extending along a substantially straight line that intersects and is perpendicular to the rotational axis. The inside edge of each handle lies along a line that intersects and is perpendicular to the rotational axis. The handles move simultaneously and in opposite directions, so that the angle between the inside edge of the first handle and the reference element is always equal and opposite to the angle between the inside edge of the second handle and the reference element. In a preferred embodiment, each handle has a sighting element along its inner edge and terminating at the rotational axis.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates in general to the field of aiming devices used in billiards games. More particularly, the present invention relates to devices that assist players in aiming bank and kick shots. 
   2. Description of Related Art 
   Cue games, such as billiards, pool, and snooker, are played on a table bounded by elastic cushions. For convenience, such games are hereafter referred to collectively as “billiards”. During the course of billiards play, it is frequently necessary or desirable to direct the cue ball or an object ball into one or more cushions to redirect the ball toward its intended target. When the ball directed into the cushion is an object ball, the shot is known as a bank shot. When the ball directed into the cushion is the cue ball, the shot is known as a kick shot. 
   It is well known that a billiards ball will rebound from a cushion at or near the same angle that it approaches the cushion. However, the exact rebound angle is dependent upon the properties of the cushion, the velocity of the ball, and any spin possessed by the ball as it strikes the cushion. 
   Bank and kick shots, hereafter referred to collectively as “bank shots”, are among the most difficult billiards shots to master. Consequently, numerous techniques and devices have been devised to train or assist players in executing bank shots. One known method to determine the theoretical point along a cushion to aim a bank shot is to mentally calculate and visualize the aim point based on principles of geometry. The evenly spaced markings (for example, “diamond” markings) along the rails of most billiards tables are often used to assist in these mental exercises. However, such methods are complicated and readily subject to error. 
   U.S. Pat. No. 5,919,095 to Risner and U.S. Pat. No. 5,275,398 to Compton disclose the use of mirrors placed under or against the rail cushions. Such devices suffer the disadvantage that mirrors positioned on the playing surface can be distracting, especially when executing shots that do not require aiming assistance. Thus, the mirrors are not practical for use in routine play. Another disadvantage is that, to cover all sides of a billiards table, a plurality of mirrors is required. Therefore, the equipment is bulky and inconvenient to transport and set up. 
   U.S. Pat. No. 5,919,095 to Risner, U.S. Pat. No. 5,275,398 to Compton, and U.S. Pat. No. 5,520,581 to Mazzoli are typical of most of the known devices, in that they must be attached to or positioned on the playing equipment, such as the table, the balls, or the cue stick. The devices disclosed in U.S. Pat. No. 5,234,379 to Zotos, and U.S. Pat. No. 5,338,262 to Hayes attach to the billiards table and suffer the additional drawback that they leave a chalk mark on the table. The systems described in U.S. Pat. No. 4,882,676 to Van De Kop and German patent 4039315-A1 to Kunnecke do not attach to or contact the playing equipment, but both employ computer-controlled imaging systems and would be expensive to implement. 
   Many of the known devices, such as disclosed in U.S. Pat. No. 5,520,581 to Mazzoli and U.S. Pat. No. 4,082,270 to Josenhans, require the player to walk around the table, position the device, and then walk back to the shooting position. Such devices are time consuming and inconvenient to use. 
   The sight-through aiming device of the present invention averts the limitations of the known devices and represents a novel approach to the problem of identifying the theoretical aim point for billiards bank shots. 
   No devices are known for determining the theoretical aim point for a bank shot in billiards games played on a computer or video display screen. The present invention also fulfills this need. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is directed to an aiming device that assists the player in locating the theoretical point on the cushion of a billiards table to aim a bank shot. The device is comprised of a base, which includes a reference element disposed along a straight line. Two handles are rotatably mounted to the base at a common rotational axis that passes through and is perpendicular to the reference element. Each handle has a substantially straight inner edge that is disposed along a line that passes through and is perpendicular to the rotational axis of the handles. The device also includes a means for restricting the motion of the handles, so that when the player rotates the handles, they move simultaneously and in opposite directions, with the angle between the inner edge of the first handle and the reference element always substantially equal to the angle between the inner edge of the second handle and the reference element. 
   The billiards aiming device is operated in a hand-held fashion. The player locates the theoretical aim point by sighting through the device and aligning the reference element with the banking cushion, the inner edge of one handle with the ball to be banked, and the inner edge of the other handle with the target, which is typically another ball, another cushion, a pocket, or a predetermined location on the billiards table. The theoretical aim point is the point on the cushion that is seen by the player to be aligned with the point where the rotational axis of the handles intersects the reference element. 
   The aiming device of the present invention has the advantage that it is hand-held and does not attach to or in any way contact the playing equipment. This aspect may make the device more likely to be accepted for use in some levels of competitive play. This aspect also allows the theoretical aim point to be located quickly, with very little set-up time. The aiming device can also be conveniently carried and stored. 
   The aiming device of the present invention also has the advantage that the player can easily locate the theoretical aim point from either the same side or the opposite side of the table with respect to the banking cushion. Because the player can aim the shot from the opposite side of the table from the banking cushion, the player does not have to walk around the billiards table between aiming and executing the shot. 
   A further advantage of the aiming device of the present invention is that it is also particularly useful for aiming bank shots in billiards games that are played on a computer or video display screen. 
   Accordingly several objects and advantages of the invention are as follows: 
   (1) To provide a means of simply, quickly, and accurately locating the theoretical point on the cushion of a billiards table to aim a bank shot. 
   (2) To provide a sight-through billiards aiming device. 
   (3) To provide a billiards aiming device that is operable in a hand-held fashion and does not attach to or in any way contact the playing equipment. 
   Other objects and advantages are: 
   (4) To provide a billiards aiming device that can be used from either the same side or the opposite side of the billiards table with respect to the banking cushion. 
   (5) To provide a billiards aiming device that is easily transported and requires very little set-up time. 
   (6) To provide a billiards aiming device that is inexpensive and can be conveniently carried and stored. 
   (7) To provide a billiards aiming device that is useful for determining the theoretical aim point in billiard games played on a billiards table or played on a computer or video display screen. 
   Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of the preferred embodiments of the invention when taken in conjunction with the drawings and the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an environmental view of a billiards table and a player utilizing the present invention to aim a bank shot. 
       FIG. 2  is an environmental view of the billiards table and the present invention, showing the alignment of the invention with the cue ball, the cushion, and the object ball. 
       FIG. 3  is a top view depicting the alignment, from the player&#39;s perspective, of the first embodiment of the invention with the cue ball, the cushion, and the object ball. 
       FIG. 4  is a perspective view of the first embodiment of the invention in an open position and showing the rotational axis of the handles. 
       FIG. 5  is a top view of the first embodiment of the invention in the closed position. 
       FIG. 6  is a top view of the first embodiment of the invention in an open position. 
       FIG. 7  is a side view of the top end of the first embodiment of the invention showing the configuration of the handles as they meet the pivot pin. 
       FIG. 8  is a partial perspective view of a second preferred embodiment of the invention. 
       FIG. 9  is a partial perspective view of a third preferred embodiment of the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings in general, the illustrations are for the purpose of describing the preferred embodiments of the invention and are not intended to limit the invention thereto. 
   As shown in  FIGS. 4 through 7 , a first preferred embodiment of the billiards aiming device, generally referenced as  10 , includes a substantially rigid base  24  having a pivot pin  28  near the top edge  24   a  of the base  24  and a reference element  23 , which lies along a line that passes through the longitudinal axis of pivot pin  28 . The billiards aiming device  10  also includes handles  19  and  20 , which are rotatably connected to base  24  via pivot pin  28 . The rotational axis  40  of the handles  19  and  20  coincides with the longitudinal axis of pivot pin  28  and is perpendicular to the top surface of base  24 . The inner edges  19   a  and  20   a  of the, handles lie along lines that intersect and are perpendicular to the rotational axis  40  of the handles  19  and  20 . The widths of the handles  19  and  20  are preferably narrow enough near pivot pin  28 , so that the player&#39;s view of the reference element  23  is unobstructed as the player rotates the handles. Reference element  23  can be any of a variety of indicia, including those contained within, inscribed on, or mounted upon the base  24 . Alternatively, base  24  could terminate at rotational axis  40  so that reference element  23  is comprised of the top edge  24   a  of base  24 . 
   The first preferred embodiment also includes sighting elements  21  and  22 , which extend along the top, inner edges  19   a  and  20   a  of the handles  19  and  20 . It is advantageous for the top ends of sighting elements  21  and  22  to meet at rotational axis  40 , as depicted in FIG.  7 . Where the handles  19  and  20  overlap near pivot pin  28 , sighting elements  21  and  22  are not fixed upon the handles, to allow free movement of the handles with sighting elements about the pivot pin. The meeting point of the sighting elements  21  and  22  serves as a visual marker in aiming the bank shot, as described in detail below. 
   The billiards aiming device  10  further includes a means for imposing symmetrical motion of handles  19  and  20 , so that when the player rotates the handles, the handles rotate simultaneously and in opposite directions about pivot pin  28 . Accordingly, the angle  34  between the inner edge  19   a  and the reference element  23  is always equal and opposite to the angle  35  between the inner edge  20   a  and the reference element  23 . The range of motion of the handles is such that the absolute values of angles  34  and  35  can each vary from 0 to 90 degrees. 
   In the preferred embodiments, the means for imposing symmetrical motion of handles  19  and  20  with respect to reference element  23  is a slide mechanism comprised of a pair of link arms  25  and  26 , which are pivotally connected to handles  19  and  20  by pivot pins  29  and  30  and pivotally connected to slide  27  via pivot pins  31  and  32 . Slide  27  moves along base  24  in slot  33 . Handles  19  and  20  include recesses  36  and  37  to accept link arms  25  and  26  and facilitate the smooth movement of the link arms between the base and the handles. Any number of other means known to those skilled in the art may be employed to impose symmetrical motion of handles  19  and  20 . For example, the threaded spindle and knurled disk system described in U.S. Pat. No. 3,280,466, which is hereby incorporated by reference, could be adapted to embodiments of the present invention. Accordingly, in lieu of the slide  27  and link arms  25  and  26 , a threaded spindle could be adapted to the handles  19  and  20 , with a knurled disk disposed in slot  33  to assure symmetrical motion of the handles. Also by way of example, the handles could be rotatably attached to the base  24  via a hinge instead of a pivot pin. 
   Preferably, the components of aiming device  10  are formed of substantially transparent materials, for example clear plastic, so that the billiards table and balls are visible through the device. Reference element  23  and sighting elements  21  and  22  may be colored or darkened to provide a visual contrast to the billiards table and balls. 
   Referring now to  FIG. 1 , there is shown a player utilizing a preferred embodiment of the billiards aiming device  10  to line up a bank shot. In this example, the player intends to hit the cue ball  13  into the cushion  12  of billiard table  11 , to bank the cue ball into object ball  14 . The expected path of the cue ball  13  is designated by dashed line  15 , and the theoretical aim point on the cushion  12  is designated by reference number  38 . It is preferred that the player stand next to the table approximately half-way between the ball that is being banked, in this case the cue ball  13 , and the target, in this case the object ball  14 . It is also advantageous for the player to close one eye when sighting through the aiming device  10 , to facilitate seeing a single image of the device. 
   It is an advantage of the present invention that the player may stand on the opposite side of the table  11  from the banking cushion  12 , as shown in  FIG. 1 , or the player may stand on the same side of the table  11  as the banking cushion  12 . In  FIG. 1 , the aiming device is held so that the top edge  24   a  of the device is positioned away from the player. If the player were to stand on the same side of the table as the banking cushion, the player would hold the device so that the top edge  24   a  is positioned toward the player. 
     FIGS. 2 and 3  illustrate the alignment of the aiming device  10  according to the present invention to determine the theoretical aim point for a bank shot. The player holds the aiming device  10  so that the reference element  23  is approximately parallel to the edge of the banking cushion  12 . The angle between the base  24  and the playing surface of billiards table  11  is otherwise inconsequential. The player then moves the device  10  along the banking cushion  12  and rotates the handles  19  and  20  so that reference element  23  appears to coincide with the edge of banking cushion  12 , and sighting elements  21  and  22  appear to bisect, respectively, the ball  13  that is being banked and the target  14 . Dashed lines  16 ,  17 , and  18  in  FIG. 2  depict the alignment of the aiming device  10  with the cushion and balls. In this example, the target  14  is a ball, but depending on the playing situation, target  14  could alternatively be another cushion, a pocket, or a predetermined location on the billiards table. 
   Turning now to  FIG. 3 , the theoretical aim point  38  is the point on cushion  12  that appears to the player to be aligned with the point where the rotational axis  40  of the handles intersects reference element  23 . In the preferred embodiments, this point can be visualized as the center of the top face of pivot pin  28 . In the first preferred embodiment, the meeting point of sighting elements  21  and  22  serves as a visual marker for this point of reference. The player then memorizes the location of the theoretical aim point  38 , sets aside the aiming device  10 , and hits the ball  13  into the cushion  12  at the aim point  38 . The “diamond” markings present on the rails of most billiards tables can be of assistance to the player in memorizing the theoretical aim point before the aiming device is set aside. 
   The present invention is also particularly useful for determining the theoretical aim point for bank shots in billiards games that are played on a computer or video display screen. Accordingly, the player holds the aiming device  10  in front of the display screen with the base  24  substantially parallel to the screen. Alignment of the aiming device  10  with the playing equipment as displayed on the screen and determination of the theoretical aim point are then as depicted in FIG.  3 . 
     FIG. 8  depicts a second preferred embodiment of the invention that omits sighting elements  21  and  22 . In this embodiment, the player aligns the ball  13  and its target  14  with the inner edges  19   a  and  20   a  of handles  19  and  20 . 
     FIG. 9  depicts a third preferred embodiment of the invention that includes reference element  39  located on base  24 , perpendicular to reference element  23 , and extending from pivot pin  28  toward the top edge  24   a  of base  24 . This additional reference element helps the player memorize the theoretical aim point  38  by visually projecting the theoretical aim point along reference element  39  and onto the rail of the billiards table. The player can then better visualize the location of the theoretical aim point with respect to the “diamond” markings on the rail of the billiards table. 
   Although the presently preferred embodiments of the invention are described and shown herein, it will be apparent to those skilled in the art to which this invention pertains that variations and improvements of the described invention may be made without departing from the spirit and scope of the invention as claimed herein. By way of example, additional elements or markings may be added to aiming device  10  to assist the player in aligning the device. 
   All modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the appended claims and their legal equivalents.