GB2356577A

GB2356577A - Cue with aiming device

Info

Publication number: GB2356577A
Application number: GB0026149A
Authority: GB
Inventors: Andre Monteiro
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-11-05
Filing date: 2000-10-26
Publication date: 2001-05-30
Also published as: GB0026149D0

Description

2356577 n"PROVEMENTS IN BALL GANES The invention relates to improvements

in cues for ball games such as pool and 0 snooker and the like, and in enabling more accurate aiming and cueing action in such games. In particular, the invention relates to an aiming device for such cues.

It is known from GB 227685 to provide an aiming device comprising a laser which emits a beam parallel to the longitudinal axis of the cue and which beam can be displaced --transversely with respect to the cue axis a predetermined amount in order to assist a player in judging in which direction to strike the cue ball in order to cause an object ball to be directed in a predetermined direction following impact with a cue ball.

However, it has been found that the mathematical relationship between the direction of travel of the cue ball and object ball does not always follow the simple and well known geometrical relationship relied on in the technique of GB 227685. It has until now been thought that the distance of separation L between the centres of the cue ball and object ball at impact is determined by the equatdon L = (RC+RO) sin K -Equation One where RC is the radius of the cue ball, RO is the radius of the object ball and K is the desired direction of travel of the object ball with respect to the direction of travel of the cue ball just prior to impact with the object ball.

Accordingly, it is an object of the 'invention to provide a mechanism for compensating for this variation in the geometrical relationship of Equation 1 due to non-elastic and/or surface and/or material effects at impact. Moreover, it is an object of the invention to provide an aiming device comprising such a compensation mechanism.

It is another object of the invention to provide an improved aiming device.

2 According to one aspect of the invention there is provided a cue for a ball game such as snooker or pool having a cue ball and object ball, comprising an aiming device to enable a player more accurately to aim the cue ball at the object ball so as to cause the object ball to travel in a desired direction after impact by the cue ball, wherein the aiming device comprises a mechanism to compensate for the nature of the impact between the cue ball and object ball. It has been found that the nature of the impact is not entirely governed by a simple elastic impact. Accordingly, the compensation mechanism beneficially enables the aiming device more accurately to be used by compensating for any such non-elastic or other effects. Preferably the compensation mechanism enables aiming on the basis of L = X+(RC+RO) sin K - Equation Two where X is a compensation factor.

Preferably the au'nm'g device comprises a signal displaceable to one side of the cue for aiming at the object ball. Preferably the signal is generated by a laser. The laser signal can be in the form of a line. Preferably the line is substantially vertical in use and/or preferably the line has a fan of between 10 and 50' and more preferably 30.

Preferably the aiming device comprises an alignment mechanism enabling a user to determine the angle K of Equation 1, or the direction in which the cue ball should be hit in order to send the object ball along a desired direction, in accordance with Equation 1. The alignment mechanism preferably comprises a signal for aiming at the object ball for example the signal can be in the form of a circular beam such as a laser beam which is positioned at the top and centre of the object ball during alignment. Preferably the alignment mechanism comprises a device for aiming at the cue ball. The device can be the back section of the cue or can indeed be a signal such as a laser light for example set back parallel with the cue axis. Preferably the alig:nment mechanism comprises a device for alignment with the desired direction of travel of the object ball after impact with the cue ball. For example, the device can comprise a signal such as a laser beam which can be aimed at a pocket for example. Preferably the laser beam is a vertical line having a fan angle of between 10 and 50' and preferably about 30'. Preferably the centre of the beam is % 3 directed downwardly with respect to the longitudinal axis of the cue at an angle of between 51 and 25' and more preferably in the order of 10'.

Another aspect of the invention provides an alignment mechanism which is independent of a cue. Preferably such an alignment mechanism also features a compensation mechanism to account for the surface effects, and/or to follow Equation 2.

Preferably the compensation mechanism comprises a cam mechanism for displacing, an aiming laser to an appropriate position. Another aspect of -the invention --provides a compensation mechanism for use with an aiming, device for snooker or like ball games having a cue ball and object ball which mechanism enables determination of substantially the correct direction of travel of the cue to cause movement of the object ball along a desired path. Preferably the compensation mechanism facilitates incorporation of an offset factor to account at least in part for the experimentally observed behaviour of the cue ball and object ball.

A further aspect of the invention provides an aiming device for a cue for a ball game such as pool or snooker, which aiming device operably generates a signal comprising a beam which is alignable with the axis of a cue and which beam comprises a visible line when reflected back to the player for example by an object ball. Preferably the length of the line at the tip of a cue is greater than 10 nun. Preferably the length of the line is in the order of 10 to 1000 mm and more preferably in the order of 300 to 500 nun, and more preferably about 400 mm at the end of the cue. The end of the cue might be 700 mm. away from the aiming device.

Preferably the visible line is substantially vertical in use. In a particular form, the line is aenerated from a spot source such as a laser diode and an optical arrangement, such as a transparent rod-shaped lens, is used to generate the line. Preferably the line has a fan spread from the. source which spread is in the order of 10 to 500. More preferably the spread is in the orderof 30'.

4 Preferably the aiming device is displaceable to one side of the cue to aim. at the centre of the object ball.

In another preferred embodiment the compensation mechanism comprises means for moving the lens. Most preferably the lens is pivotable about a point at which it crosses the longitudinal axis of the laser beam in the plane of the longitudinal axis of said lens. In that way, the beam is displaceable to an appropriate position.

Beneficially, the length of the line has been found to provide a substantial benefit --when a player makes a cueing action since the player- is able to try to retain the line in a single direction along the direction of the cueing action for example, whereby the line does not wobble or move which would indicate a non-linear cueing action. The aiming device may be displaceable to the side of the cue to enable aiming making use of Equation I or 2.

The aiming device preferably comprises yaw adjustment which compensate for the yaw of the beam. The yaw adjustment preferably comprises a part relatively fixed on the outer surface of the cue and a part relatively movable about the outer surface of the cue.

Embodiments of the 'invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

FIGURE I is a side elevation view of a first embodiment of a cue according to the invention; FIGURE 2 is a schematic side elevation view of the cue shown in Figure 1 in use; FIGURE 2a is a schematic block drawing of the laser arrangement in the cue shown in Figure I and 2; FIGURE 3 is a schematic plan view of the direction of travel of a cue ball and object ball in use; FIGURE 4 is a schematic side elevation view of an aiming device according to the invention; FIGURES 5 and 6 are a schematic perspective and schematic plan view respectively of part of an alignment mechanism for the aiming device shown in Figure 4; FIGURES 7 and 8 are side elevation and plan views of a cam forming part of a compensation mechanism within the aiming device shown in Figure 4; FIGURES 9 and 10 are schematic plan and end elevation views of part of an aiming mechanism forming part of the aiming device shown in Figure 4; FIGURES I I and 12 are schematic plan and end elevation views of further parts of the aiming mechanism forming part of the aiming device 22 shown in Figure 4; FIGURE 13 is a schematic plan view of a dial for use for in the alignment part of the device shown in Figure 4; FIGURE 14 is a graph showing the observed additional offset or compensation factor required versus angle; FIGURES 15 and 16 are schematic plan and side elevation drawings respectively of an alignment and compensation device according to the invention; FIGURES 17 and 18 are schematic perspective and end elevation views of part of another embodiment of a cue according to the invention; and FIGURE 19 is a plan view of the rear section of the cue shovrn in Figure 4.

FIGURE 20 is a schematic cross section of another alminc, device in accordance ZD with the invention mounted on a cue.

6 FIGURE 20a shows how a lens of the aiming device is oriented.

FIGURE 21 is a view taken along the =-XXI in Figure 20.

FIGURE 22 is a view taken along like XXII-XXII in Figure 23.

FIGURE 23 is a cross section of part of the aiming device of Figure 20.

FIGURE 24 is an enlarge C7 d view of the part of Figure 22, and FIGURE 25 is a view taken along the =-X,'<IV in Figure 24.

FIGURE 26 is a schematic cross section of still another airing device in accordance with the invention mounted on a cue.

Referrin- to Flaures I and 2 there is shown a cue 10 accordinc, to the invention C comprising a front section 12 having a tip at one end for striking a cue ball. Front section 12 is attachable to a back section 14. Cue 10 comprises an aiming device 16 comprising a laser powered by a power source 18. The alming device 16 and laser are displaceable laterally with respect to the Iongitudinal axis A of cue 10. The method of the displacement can comprise a known displacement mechanism such as a four bar linkage in the form of a parallelogram as disclosed in GB 227685. However, the extent of lateral displacement of the aiming device can be deten-nined to comprise an additional offset as described later in relation to Figures 15 and 16. Moreover, aiming device 16 preferably generates a signal S in a direction substantially parallel with the longitudinal axis A of cue 10. Signal S is preferably in the form of a substantially vertical line from a substantial point source such as a laser diode housed within the aiming device 16. Preferably the spread of the laser beam in a fan F is substantially 300. Beneficially therefore a line is projected in front of the cue 10 which line has a significant length and which line can be aligned with object ball 0 by 7 lateral displacement of aiming device 16 away from the cue 10, or simply used to generate a line in front of the cue baH directly in line with axis A. Beneficially this line which has signif[cant length when projected on to the cue ball or playing surface assists a player in producing a smooth cueing action.

In one particular form, the signal S in the line is generated by a laser diode 19 powered for example by a series of batteries 18. The output from the laser diode is passed in to an optical component 17 such as a transparent rod, made for example of quartz, having a cylindrical axis in to the page as shown in Figure 2A. By selectirig the desired diam'eter'of rod 17, it is found that a signal S in a forniof a narrow line having a fan spread F in the desired range such as 30'.

In the event that the aiming device 16 is used other than to obtain a smooth cueing action or as a line for direction of travel of the cue ball (enabling better estimation by a player of the position to strike the cue ball), it is necessary for the aiming device 16 to be spaced laterally away from the longitudinal axis A of cue 10 as shown in Figure 3. The signal S is generated by aiming device 16. In order to determine the extent of displacement L for the aiming device, it was principally understood that the trigonometrical relationship shown in Figure 3 applied whereby L = (RC + RO) sin K (Equation 1) wherein as seen in Figure 3, RC is the radius of the cue ball, RO is the radius of the object ball and K is the angle between the direction of travel of the cue ball C and the desired direction of travel DO of the object ball 0. It is known to determine the angle K by aligning a central pivot of the aiming device 16 above the object ball 0 and directing the rear section 14 of the cue back towards the cue ball C. A further device such as an arrow as described in GB 227685 is used to pivot about the axis above the object ball 0 and point in the direction of DO in order to determine the angle x. Since RC and RO are known for any given game (though they are different for example in snooker, British pool and US pool) the separation L shown in Figure 3 can be determined. However, it is found that the actual value of L needed for such a system is L = X + (RC + RO) sin K (Equation 2) where X is an additional offset required to be added to. the theoretical value L in order to achieve the desired effect of sending the object ball 0 along path DO. For the simple mechanism shown in Figures I and 2, a separate device, as described later, can be used in order to determine.the actual value of L to which the aiming device 16 needs to be displaced away from axis A of cue 10. However, both the alignment aiming mechanism and a compensation mechanism can be configured within a single aiming device as now described in relation to the embodiment of the invention shown in Figures 4 to 13.

Referring to Figure 4 there is shown a cue 20 according to the invention comprising an aiming device 22 located near one end of the back section 24 of a cue which end is attachable to the front section in use. The aiming device 22 comprises an alignment mechanism 26, an aiming mechanism 28 and a compensation mechanism'30 which are ---intercormected as described below. The alignment mechanism 26 is used to determine the angle K as shown in Figure 3, and the compensation mechanism 3)0 is used to effect lateral displacement of the aiming mechanism 28 away from the longitudinal axis A of cue 20, in accordance with equation 2 given above. In other words, the compensation mechanism has a built in additional factor to allow for the experimentally observed surface effects or deviation from Equation 1.

Alignment mechanism 26 is shown in some detail in Figures 5 and 6 and comprises a manual alignment arm 32 pivotally attached to the cue at pivot 34. There is also provided a dial _3)6 (see Figure 13), and a counter-weight 3)8 for balancing the weight of the displaced elements of the aiming device 22 along ail axis transverse to the Ion itudinal axis A in use.

C7 C 91 A.rm 32 comprises an aperture 40 for pivot 34 and an alignment aperture 42 for reading dial 36. There is also provided a pointer 44 enabling a user to read dial 36 in use. Further pointers are described later with reference to Figure 13. An alignment laser 46 is provided at one end of arm 32. The output of laser 46 comprises a cylindrical lens 48 which generates a laser beam in the form of a line having a central axis B and a fan spread or angle F as shown in Figure 5. Preferably axis B is displaced below the horizontal axis H (parallel with axis A) thereby to project the laser beam on to the playing surface in use. Preferably the angle of tilt of B is in the order of 5' to-25' and more preferably in the order of 10'. Laser 46 is powered by a power source (not shown) and connected thereto by an electrical lead 50. The cylindrical body of laser 46 is mounted in a V-shaped goove 52 at one end of arm 32 enabling adjustment of laser 46 along the length of the groove thereby varying the displacement of axis CA with respect to axis AA which passes through the 9 pivot 34. This variation enables adjustment to suit different types of ball garnes whereby the separation of AA and CA is the sum of the radius of the cue ball (RC) and the radius of the object ball (RO). Once located in the. desired position, laser 46 is clamped using a nut 54 as shown in Figure 4. Laser 46 preferably comprises an outlet (not shown) which enables direction of light such as a laser beam along axis CA, and down past slot 42. In anotlier form a separate laser is provided on axis CA such as in cam 56.

-Referring to Figures 7 and 8, there is shown part of the compensation mechanism 30 which comprises a cam 56 havig a somewhat heart shaped cam surface 58. The shape 19. in fact preferably accurately determined for given- types of balls in accordance with experimentally observed behaviour at impact. Therefore the cam shape incorporates the additional offset required for accurate aiming as discussed in relation to Figure 14. The upper surface of cam 56 comprises a boss 60 which is at least in part threaded for co-operation with nut 54. The upper end of-boss 60 is preferably locatable within the casing of laser 46 in order to be fast therewith (for example by gluing or set by a grub rD screw). The underside of cam 56 carries a lower boss 62 for co-operating with a transfer plate 64 as described later. Preferably cam 56 comprises a central aperture 61 passing there through enabling light from laser 46 to pass along axis CA.

Referring to Figures 9 and 10, there is shown a transfer plate 64 which is carried by the lower boss 62 of cam 56. Lower boss 62 is received within aperture 66 in plate 64. Plate 64 comprises a first cam follower in the form of pin 68 and a second cam follower in the form of pin 70. Preferably both pins 68 and 70 are mounted in a bearing to enable rotation of the pins about their longitudinal axis thereby to reduce any ffictional effects when following cam surface 58.

Pin 68 is mounted in a pivot plate 74 which is pivotally attached to plate 64 by a pivot 76. A restoring mechanism such as a helical spring 78 attached to pivot plate 74 0 remote from pivot 76 is used to maintain pin 68 in contact with cam surface 58. One end of spring 78 is attached at pin 80 to a lower surface of transfer plate 64. Transfer plate 64 further comprises a pair of rods 82 and 84 which are received and located fast in apertures 86 and 88 (see Figure 10).

1 10 It should be noted that aperture 66 passes through plate 64. Indeed cue 20 comprises a slot 90 enabling projection of a laser beam from laser 46 along axis CA and onto an object ball when performing the alignment operation.

Rods 82 and 84 are journalled in an aiming plate 92 comprising a pair of bearings 94 and 96 as shown in Figures 11 and 12. Aiming plate 92 carries an upwardly projecting lug 98-which in turn supports an aiming laser 100. Aiming laser 100 can comprise a laser =1 C.1 diode powered by a battery source located within back section 24 of th:e cue 20 and __donnected thereto by a cable (not shown). Aiming laser 100 can comprise a laser diode and cylindrical lens similar to laser 46 shown in Figure 5 and device 16 as shown in Figure 2A.

Laser 100 generates a beam which is preferably in the form of a substantially vertical line having a central axis B displaced away from axis H which is parallel with the longitudinal axis A of the cue. Preferably central axis of beam B is displaced upwardly between 5 and 251 and more preferablymi the order of 10'. Preferably the fan angle F of the beam is in the order of 10 to 50' and more preferably in the order of 3)0'. See Figure 4.

Aiming plate 92 comprises a forward projecting arm 102 to which there is attached a linear bearing 104 using bolts 106. Preferably four bolts 106 are provided and preferably the orientation of bearing 104 with respect to axis A can be accurately determined by adjustment of the bolts. Bearing 104 is preferably a high precision linear bearing (or bearing stack) compnising pre-loaded ball bearings for example. Bearing 104 carries a I a) t= Z7 slider 108 which is rigidly attached to a second slider 110. Slider 110 is carried in a second high precision linear bearing 112 mounted to rear section 24 of cue 20 using bolts 114 located in recesses 116 within the cue.

Refern g to Figure 13 there is shown a plan view of dial 36 forming part of aiming device 22. Dial 36 comprises a series of graduations 120 around its outside curved edge. A zero or neutral position is indicated when pointer 44 is directed at the central graduation labelled zero, which is visible through aperture 42 in arm 32. A series of indications 122 of the direction of the cue ball after impact are provided. Further, a, series of indications 124 of the speed of the cue ball after impact with the object ball are provided. The appropriate indication 122 and 124 is indicated by one of pointers 126 and 128 carried by arm 32 adjacent to the axis AA. The approximate speed VF of the cue ball after impact is given by the equation VF = VI sin K, where VI is the initial speed of a cue ball. The direction of the cue ball after impact (see line DA in Figure 3) can be determined theoretically but it is found the direction depends on whether top or bottom spin is applied to the cue ball which can arise as a consequence of the length of travel of the cue ball before impact with an object ball. The triangular indications 122 represent the range of angles.for direction DA between the extremes of top and bottom spin applied to a cue ball for a given angle of impact K. The circle indicates the direction of travel of the cue ball for a:'long shot before impact with an object ball whereb]( effectively the cue b all has acquired a certain amount of top spin because of its roll along the playing surface.

The graduations 120 shown on dial 36 are preferably in the form of the actual angular displacement of the aiming laser 28 away from the longitudinal axis A of the cue 20. Accordingly, the value can be in degrees and -.0 from 0' to approximately 90' say.

There is shown in Figure 14 an experimentally observed curve 130 showing the additional offset value x in equation 2 (for an average billiard ball) above for a given angle >< between the approximate directions of travel DC and DO of the cue ball and object ball respectively (see Figure 3). Accordingly, it can be seen that the value of the offset increases towards the 40' or 45" and of course is zero at the extremes of K = 0 and 90'.

In use, the aiming device 22 is preferably used as follows. Axis CA is located directly vertically above the object ball 0 with the Iongitudinal axis A of cue 20 directed back towards the centre of cue ball C (a laser could be provided to assist in this by being directed back along axis A). Accordingly, manual alig;nment aim 32 is displaced about pivot 34 in the appropriate direction. Preferably laser 46 is turned on so as to generate a line along axis CA through all of the various component s shown in Figure 4.

Arm 32 is rotated so as to direct beam B from laser 46 along the desired direction of travel DO of the object ball after impact by the cue ball. For example by directing the laser beam from laser 46 at a pocket.

12 Rotation of the alignment mechanism 26 effects rotation of cam 56 about pivot axis AA. In turn, this rotation effects lateral displacement of transfer plate 64 to the appropriate side of the axis A of the cue. This is due to the following of cam 56 by pin 68 and 70 in co-operation with cam surface 58.

In turn, the lateral displacement of transfer plate 64 effects lateral movement of the aiming device 28 since aiming plate 92 is carried on rods 82 and 84 attached to transfer plate 64. Accordingly, aiming plate 92 is caused to move sideways and is carried in a --Iiiiea'r direction at 900 to axis A due to the alignmentof the high precision linear bearings and sliders 104, 108, 110 and 112 respectively.

Accordingly, since the separation of parallel axes AA and CA is set to the sum of the radius of the cue ball and object ball, rotation of the alignment laser 46 about pivot 34 (and hence axis AA) effects displacement of the aiming mechanism 28. If cam 56 had a circular profile or circular cam surface 58 then the extent of displacement of the aiming mechanism 28 would be in accordance with Equation 1. However, cam 56 is profiled so that rotation of the cam surface additionally incorporates the offset value x required to compensate for the experimentally observed behaviour of cue ball and object ball.

The profile of cam 56 as shown in Figure 8 is in this embodiment substantially sufficient to cover the entire range of rotation of the alignment mechanism 26 between 0' and 90'. However, different types of cam 56 could be used for example providing compensation for angles x between 0' and 60' (or any other value) as the upper limit. Also, the profile of cam 56 could be other than a monotonic shaped as observed in Figure 14 and could for example represent an initial region whereby curve 130 is followed and thereafter a substantially uniform offset is used for say angles K > 30' or 40'.

It is noted that the additional offset. x shown in. Figure 14 is for a specific radius of cue ball and object ball which balls are made of a specific type of material. Accordingly, appropriate graphs 130 are preferably determined for different radius of balls and different 13 types of material used for such balls, but an approximate graph can be used to cover most types of billiard balls.

Referring to Figures 15 and 16, there is shown an alignment and compensation device 140 according to the invention. Device 140 comprises a rear section 142 and front section 144 pivotally connected at pivot 158 having a pivot axis AA. Sections 142 and 144 comprise legs 146 which extend away from the main bodies and which legs carry pins 148 the furthermost end of which engages the playing surface such as a pool table in use. Front section 144 comprises a viewing aperture 150 which can comprise a 'lens or light zdtanganent. In a particular embodiment, viewing element 150 is an aperture having a diameter equal to the diameter of an object ball. Front section 144 far-ther carries an arrow 154 for alignment with the desired direction of travel DO of the object ball. Rear section 142 comprises an arrow 152 which in use is aligned with the direction of travel DC of the cue ball in use. Rear section 142 further carries a compensation indication scale 156. Preferably, front section 144 comprises a slot for engaging pivot 158 thereby enabling adjustment of the separation between axes AA and CA so that the separation is equal to the radius of the cue RC ball plus the radius of the object ball RO.

Legs 146 are preferably pivotally connected to front section 144 by pivots 160 1 thereby enabling adjustment in the location of the legs and hence pins 148 so as to. avoid balls located on the surface of the playing table in use.

In order to operate device 140, viewing aperture 150 is located directly above an object ball 0 with arrow 154 pointed along the desired direction of travel of the object ball. Indeed, a laser such as laser 146 can be provided for device 140 and thereby providing a light which is projected down a long axis CA and/or also along the direction of arrow 154.

Having located front section 144, the rear section 142 is oriented so that arrow 152 points back towards the centre of the cue ball. Again, a laser light can be provided preferably having a line shaped signal for accurate alignment with the centre of a cue ball.

14 Accordingly, the relative angular positions of sections 142 and 144 is determined during the alignment exercise and displacement of the sections about pivot 158. An arrow 162 is aligned along a specific part of the indicator 156 which is designed to incorporate.the additional offset shown in Figure 14 and a slot 164 in section 142 enables reading of a suitable alignment and compensation vaiue which is preferably transferred to an aiming device on a cue. The reading can be in terms of the distance representative of the extent of offset of device 16 or aiming device 28 tothe side of a cue or an analogue thereof.

In another form of simple cue comprising an aiming device, an aimifig device 170 a- shown in Figures 17 and 18 is provided. Here the-extent of offset L or rotation # of a beam B (is the form of a line preferably) to one or other sides of the cue is determined by rotating a dial 172 which sets the orientation of a laser 174 to a predetermined position. The separation of the laser beam B from the central axis of the cue is predetermined to the sum of the radius of the cue ball and radius of the object ball such that by rotating the cue until the image of the laser line B on the centre of the object ball is in a vertical orientation, the required amount of offset for the aiming device 170 is determined. Again, the value of the angle to be dialled in to dial 172 can be read off from an alignment and compensation device 140 wherein the indicator 156 is calibrated accordingly.

There is shown in Figure 19 a plan view of the back section 24 of cue 20 according to the invention. The plan view is given to show a preferred form of electrical storage for powering the aiming device 22. Accordingly, Figure 19 shows a switch 180 for interconnecting the various lasers and/or lighting elements within the aiming device 22 and a removable battery pack 182 substantially in the form of a cylindrical tube having a rear end adapted to engage a chamber 184 within back section 24 and also adapted to provide a suitable butt end to the cue such as a hemispherical rubber end. Chamber 184 has at its interior end a plug 186 for engaging a socket 188 in battery pack 182. The plug and socket 1.) C7 0 arranaement enable interconnection of suitable circuitry with the battery pack and therefore with the individual storage cells 190 such as rechargeable battenes. Beneficially, a cue O can be provided with a recharge G unit and two of the removable battery packs 182 such that a user is always able to have a fully charged battery pack 182 for use with a cue. The nature of the replaceable and or rechargeable device 182 forms an independent aspect of the invention.

Another embodiment of an aiming device in accordance with the invention is shown in figures 20-25.

The aiming device 200 comprises a support assembly 202 and a laser assembly 204, which-Pan have a torch-like configuration.

The laser assembly 204 comprises a tubular housing 206. The housing 206 houses rM a laser unit 208 and a cylindrical lens 210.

The lens 210 is designed to expand the laser beam in one direction only so as to give a line at a distance of up to, say, 200cm from the lens 210. The fan angle of the lens 2 10 is 3 0 degrees.

The lens 210 comprises adjustment means (not shown). The adjustment means allows the said lens 210 to be pivoted so that the longitudinal axis b (which goes into the page in figure 20) of the lens is movable to a position orthogonal with axes A and C as shown in Figure 20A. The lens 2 10 can be clamped in position using a grub screw 262.

The housing 206 also contains elongate batteries 212 arranged along a longitudinal axis A-A of the housing thus streamlining the housing 206. A cap 214 locates on a first end 216 of the housing 206 to close said first end.

The cap 214 is- movable between two closed positions. The cap is moved inwards to push the batteries to the night as shown in Figure 20.

Contact means 218 are arranged adjacent the remote end of the battery 212 remote from the cap 214. The contact means 218 comprises a first contact in the form of a deformable piece of material 220 and a second contact in the form of a pin 222 in electrical communication with the laser unit 208.

16 The support assembly 202 comprises a support 223 in the form of a tubular body 224. Towards a first end 226 there is a first flange 227 and forwards a second end 228 there is a second flange 229. First flange 227 has a first surface notch 230 and the second flange 229 has a second surface notch 231. The notches 230, 231 are V-shaped in the embodiment shown and support the housing in use. The first flange 227 has a pair of bores 232, which are preferably threaded.

A ring shaped piece 234 has a tab 236. The tab 236 has two slots 238. The slots -238 coincide with the cavities 232. The slots 238 are -elongate and have longitudinal axes which follow a circle concentric to the cue.

Screws 240 locate through the slots 238 in the cavities 232. The ring shaped piece 234 is able to move rotationally to an extent limited by the slots 23 8.

The tubular body 224 has annular recesses 241, 242 towards each end of its inner surface 244.

First and second o-nings 248, 250 or shaft seals (which may comprise an inner rubber section and a spring bias which acts on said inner rubber section) sit in their respective recesses 241, 242.

A countersink 246, counterbore, or recess is provided in the tubular body 224. To facilitate that, an aperture 247 is drilled on an opposite side of the body 224.

During assembly a screw 250 is screwed through the tubular body 224 and into the housing 206 until the head of the second screw 250 sits in the recess 246. The screw is fastened in such a way that it is able to move.

It will be noticed that the axis of the housing 206 is substantially parallel to the.axis of the cue. In that way, the laser bearn from the laser unit 208 is projected along a line parallel to the cue.

17 In use rotation of the ring-shaped piece 234 tends to adjust the yaw of the beam. Preferably the screws 240 have a range of movement of 5' -10 with respect to the cue axis, most preferably 0 1 is 34.62', 02 is 41.29, giving a range of movement of 6.67".

Figure 26 shows a different support assembly 202. The support assembly 202 comprises arch-shaped supports 252, 254. An inner surface 256 of the supports 252, 254 matches the outer surface of the cue. One end 257 of a strap 258 is attached to the supp orts 252, 254. The strap 258 extends part of the way around the cue. An end 259 of the cue remote from the one end 257 is connected to the one end 257 by means of an adjustable tightener 260. Although the strap 258 may be made of textile such as nylon, it is preferable that the strap is metal. It will be appreciated that the metal strap will not wear out as quickly or easily as one made of, say, nylon. Conveniently, the strap 258 may be in two sections, said sections being fastenable together to form a tube-like piece which extends fully around the cue.

Claims

18 Claims

1. A cue for a ball game such as snooker or pool which employs a cue ball and an object ball, the cue comprising an aiming device to enable a player more accurately to aim the cue ball at the object ball so as to cause the object ball to travel in a desired direction after impact by the cue ball, wherein the aiming device comprises a compensation mechanism to compensate for the nature of the impact between the cue ball and object ball.

2. A cue according to claim 1, wherein the compensation mechanism is arranged to enable aiming substantially on the basis of; L = X+(RC+RO) sin K where, L is the distance of separation between the centres of the cue ball and the object ball at impact, RC is the radius of the cue ball, RO is the radius of the object ball, K is the desired direction of travel of the object ball with respect to the direction of travel of the cue ball, just prior to impact with the object ball, and X is a compensation factor.

3. A cue according to any preceding claim, wherein the aiming device comprises a signal displaceable to one side of the cue for aiming at the object ball.

4. A cue according to claim 3, wherein the signal is generated by a laser.

5. A cue according to claim 4, wherein the laser signal is in the form of a line.

6. A cue according to claim 5, wherein the line is substantially arranged to lie vertical in use.

7. A cue according to claim 5 or 6, wherein the line has a fan of between 10 and 500.

19

8. A cue according to any preceding claim, wherein the aiming device comprises an alignment mechanism enabling a user to determine the angle K or the direction in which the cue ball should be bit in order to send the object ball along a desired direction.

9. A cue according to claim 8, wherein the alignment mechanism comprises a signal for aiming at the object ball.

10. A cue according to claim 9, wherein the signal comprises a circular beam such as a laser beam which is positioned at the top and centre of the object ball during alignment.

11. A cue according to claim 8, 9 or 10, wherein the alignment mechanism comprises a device for aiming at the cue ball.

12. A cue according to claim 10 or 11, wherein the device comprises a back section of the cue.

13. A cue according to claim 10 or 11, wherein the device comprises a signal such as a laser light for example set back parallel with the cue axis.

14. A cue according to any of claims 8 to 13, wherein the alignment mechanism comprises a device for alignment with the desired direction of travel of the object ball after impact with the cue ball.

15. A cue according to claim 14, wherein the device comprises a signal such as a laser beam which can be aimed at a pocket for example.

16. A cue according to claim 15, wherein the laser beam comprises a vertical line having a fan angle of between 10 and 50'.

17. A cue according to claim 16, wherein the fan angle is about 300.

18. A cue according to any of claims 12 to 17, wherein the centre of the beam is directed downwardly with respect to the longitudinal axis of the cue.at an angle of between 50 and 250.

19. A cue according to claim 18, wherein the centre of the beam is directed downwardly with respect to the longitudinal axis of the cue at an angle in the order of 10'.

20. An alignment mechanism for use with a cue for a ball game such as snooker or pool which employs a cue ball and an object ball, wherein the aligmnent mechanism enables a user to determine an angle K, or the direction in which the cue ball should be hit in order to send the object ball along a desired direction.

21. An alignment mechanism according to claim 20, wherein the alignment mechanism also features a compensation mechanism to account for the surface effects, and/or to follow Equation 2.

22. An alignment mechanism according to claim 2 1, wherein the compensation mechanism comprises a carn mechanism for displacing an aiming laser to an appropriate position.

23. A compensation mechanism for use with an aiming device in accordance with any of claims 1 to 19, for snooker or like ball games having a cue ball and object ball, wherein the mechanism enables determination of substantially the correct direction of travel of the cue to cause movement of the object ball along a desired path.

24. A compensation mechanism according to claim 23, wherein the compensation mechanism facilitates incorporation of an offset factor to account at least in part for the experimentally observed behaviour of the cue ball and object ball.

25. A compensation mechanism according to claim 21 or 22, wherein the compensation mechanism comprises means for moving the lens.

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26. A compensation mechanism according to claim 21 or 22 or 34, wherein the lens is pivotable about a point at which it crosses the longitudinal axis of the laser beam in the plane of the longitudinal axis of said lens

27. An aiming device for a cue for a ball game such as pool or snooker, which aiming device operably generates a signal comprising a beam which is alignable with the'axis of a cue and which beam comprises d visible line when reflected back to the player for example by an object ball.

Aii - aiming device according to claim 27, wherein the length of the line at the tip of a cue is greater than 10 mm.

29. An aiming device according to claim 28, wherein the length of the line is in the order of 10 to 1000 mm.

30. An au'= g device according to claim 29, wherein the length of the line is in the order of 300 to 500 mm.

31. An aiming device according to claim 30, wherein the length of the line is about 400 mm at the end of the cue.

32. An aiming device according to claim 31, wherein the end of the cue might be 700 mm away from the aiming device.

33. An aiming device according to any of claims 27 to 32, wherein the visible line is substantially vertical in use.

34. An aiming device according to any of claims 27 to 33, wherein the line is generated from a spot source such as a laser diode and an optical arrangement, such as a transparent rod-shaped lens, is used to generate the line.

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35. An aiming device according to any of claims 27 to 33, wherein the line has a fan spread from the source which spread is in the order of 10 to 50'.

36. Am aiming device according to claim 35, wherein the spread is in the order of 300.

37. Am aiming device according to any of claims 27 to 36, wherein the aiming device is displaceable to one side of the cue to aim at the centre of the object ball.

38. An aiming device according to claim 39, wherein the yaw adjustment mechanism comprises a part relatively fixed on the outer surface of the cue and a part relatively movable about the outer surface of the cue.

38. Am aiming device according to any of claims 27 to 36, wherein the aiming device is displaceable to the side of the cue to enable aiming ffiaking use of Equation 1 or 2.

39. An aiming device according to any of claims 27 to 38, wherein the aiming device comprises a yaw adjustment which compensate for the yaw of the beam.