Spherical Shell And Spin Detector

Abstract

An indoor golf game including a spherical target which is arranged so that all points thereon are equidistant from the tee point. Golf balls rebound from the target at a low velocity, and are returned to the tee area by an inclined runway and a ball elevator system including a motor driven wheel which engages the ball at the tee area. Electrical switches arranged in an arcuate row relative the tee point are actuated by balls rolling down the runway and cooperate with sensors in the target and at the tee point to provide information relating to the theoretical free flight trajectory of the ball, which is projected on a scene of a golf course by a computer controlled golf ball spot projector. The target is formed of interchangeable components to enhance the overall life thereof and the sensors therein are in the form of spaced conductive rubber strips extending horizontally and vertically.

Description

BACKGROUND OF THE INVENTION

The ever increasing popularity of the game of golf has resulted, as of late, in a number of commercial establishments wherein the game of golf played on an outdoor course may be simulated indoors. Depending upon the manufacturer of the equipment used in such an indoor golf game, the same will provide a simulation of the outdoor game of a greater or lesser degree of realism and this difference is due to the degree of sophistication used in such games.

The more sophisticated games currently in commercial operation, in addition to the use of a plurality of scenes displayed on a screen to give the golfer a view as it would be seen from a particular location on a golf hole as is well known in the art, utilize ball spot projectors which project, on the projected scene, a spot of light and move the same both vertically and horizontally to depict the flight of the ball relative to the terrain depicted by the scene. Additionally, the size of the spot projected on the screen is regulated to give the illusion of distance.

Commercialized golf games utilizing such a ball spot projector have been extremely successful, principally due to the ball spot projection system which provides a visual display along the lines of that seen by the golfer on an outdoor course. However, in order to provide such a display, much more sophisticated equipment is required.

Quite surprisingly, one of the most expensive elements used in a system having a ball spot projector of the type mentioned previously is the data acquisition system which determines certain parameters of the initial trajectory of the ball hit from a tee point used in the indoor game and feeds appropriate parameter information to a computer which then utilizes the information to operate the ball spot projector.

Previously, photocell arrays have been utilized for detecting certain information and while successful, such photocell detecting matrices require a great deal of effort to install inasmuch as a plurality of the photocells must be used and a corresponding number of light sources are required. Each light source must be focused very precisely on its associated photocell and, of course, the photocells must be precisely located with respect to both the tee point and a target, which, in turn, must be precisely located with respect to a spin detector. Thus, such a system may be economically disadvantageous.

Other proposed data acquisition systems have a number of disadvantages in terms of their durability, nonlinearity of output due to geometry, inability to detect without error due to geometry, small size or other special requirements, and are either impractical, uneconomical, or both.

SUMMARY OF THE INVENTION

The invention relates to an improved data acquisition system for use in indoor golf games wherein a spherical target is arranged to have its center at the tee point of an indoor golf game so that all points on the target are equidistant from the tee point. As a result, the distance from the tee point and the target at any point therein is constant. Means are also provided to measure the time required for a ball to pass from the tee point to the target and since the distance is constant, the measurement of time will always provide an accurate indication of the initial velocity of a ball.

Furthermore, by means of conductive rubber matrices built within the target itself, information relative to the initial elevation angle of a shot hit from the tee point 22 may be provided in terms of an electrical signal and initial azimuth angle information may be provided in terms of an electrical signal.

The target is also formed of a material that will absorb a great deal of energy of a ball impacting thereagainst so that there is no danger of the ball rebounding from the target back to the tee to strike a golfer. Spin detecting means located just below the plane of the tee are arranged to receive the slowly rebounding ball and provide information as to side spin on the ball. For ease of construction, the spin detecting means merely comprise an arcuate array of switches interposed between the tee and the target with the center of the arc at the tee point.

The target is formed of a plurality of identical and/or symmetrical segments which may be readily interchanged to equalize wear and/or facilitate changing of a defective portion of the target thereby minimizing maintenance costs.

Other objects and advantages will become apparent from the following specification taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block view of a computing system for use in an indoor golf game which may use a data acquisition means made according to the invention;

FIG. 2 is a perspective view of an indoor golf game tee utilizing data acquisition means made according to the invention;

FIG. 3 is a fragmentary plan view of the tee area with parts broken away for clarity;

FIG. 4 is a fragmentary vertical section of the tee area with parts broken away for clarity;

FIG. 5 is an enlarged fragmentary vertical section illustrating a portion of the data acquisition means;

FIG. 6 is a vertical section illustrating switch means used for data acquisition purposes;

FIG. 7 is a graphlike schematic illustrating a portion of the construction of a target;

FIG. 8 is a fragmentary horizontal section illustrating the construction of the target;

FIG. 9 is an enlarged, fragmentary side elevation illustrating a portion of the target; and

FIG. 10 is a schematic illustration illustrating the relation of the target to spin detecting means.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the more sophisticated types of indoor golf games currently known, five signals determined by the initial trajectory of a shot are utilized in computation although the manner of utilization may vary. A typical indoor golf game computing and display system utilizing the five signals is illustrated in FIG. 1 in block form.

Typically, a signal is desired when the ball has been hit by a golfer and such a signal is provided by a tee trigger 12 which may be either photoelectric means or vibration sensitive transducer cooperating with a predetermined tee point to detect either the absence of a ball at the tee point or the impact between the club and the ball when the ball is being hit. Such means are well known in the art and need not be described further.

A second required signal is one which is generated when the ball, after being hit, has travelled a predetermined distance. This signal may be provided by collision impact sensing means in a target, and is utilized to permit a time measurement of the period required for the ball to pass from the tee point to the target.

A third signal indicating the initial signal of elevation of the shot is also utilized. Such a signal is obtained in the instant invention by means of an elevation matrix 13 in a target. Since the elevation means is included in the target, the generation of elevation information may also be used to provide the second signal mentioned in the preceding paragraph, namely, that which indicates when the ball has travelled a predetermined distance from the tee point.

A fourth signal indicating the initial azimuth angle is also required and the invention includes an azimuth matrix 14 also embedded in the target for generating such a signal. The azimuth matrix 14 may also serve alone or with the elevation matrix 13 to provide the second signal mentioned previously.

Finally, a fifth signal indicating side spin on the ball is required. Accordingly, a spin matrix 15 is provided.

The first and second signals which designate the time required for the ball to pass from the tee point to the target are used to control a timing means 16. Depending upon the nature of the system, the timing means may make use of such information to provide information relative to the initial velocity of the ball as it left the tee point or may be more directly converted into some sort of a distance measurement.

Inasmuch as the initial angle of elevation of a shot detected by the matrix 13 has an effect on the distance that a shot would travel, the information provided by the matrix is fed to a computer 17. Similarly, azimuth information from the azimuth matrix 14 is fed to the computer 17. Finally, spin information is ultimately fed to the computer 17.

However, inasmuch as spin is customarily measured in proportion to the degree of deviation of a ball from a rebound path which the ball would follow if it would not have spin placed thereon, before spin information becomes meaningful, it must be compared with azimuth information. Accordingly, information from both the azimuth matrix 14 and the spin matrix 15 is first provided to a spin displacement circuit 18 before being fed to the computer 17. Once the degree of displacement due to spin is determined by the circuit 18, and fed to the computer, the computer 17 is provided with all information required to vectorially resolve and project the theoretical free flight trajectory of the ball.

The computer 17 will typically determine the three vectorial components of the flight of the ball which are known in the art as the "X" component, the "Y" component and the "Z" component.

The "X" component represents the vector in a direction transverse to a line extending straightaway from the tee point and in a horizontal plane. The "Y" component represents the vector in the vertical direction and the "Z" component represents the vector along the aforementioned line extending straightaway from the tee point.

Signals representing the "X", "Y" and "Z" components are then fed typically to a ball spot projector 19 which customarily projects a spot of light on a scene depicting the view from a portion of a golf course and moves the spot in a manner to indicate the flight of the ball. The "X" signal causes movement of the projected spot in the right-left direction while the "Y" signal controls spot movement in the vertical direction. The "Z" component is typically used to control the size of the spot so that as the ball in its simulated flight flies further and further from the tee point, the size of the spot of light projected by the ball spot projector 19 is diminished.

While various forms of timing means 16, computer 17, spin displacement circuit 18 and ball spot projector 19 are known, one form of these elements ideally suited for use with the data acquisition means of the instant invention is disclosed in the copending application (Ser. No. 588,922,) of Russell et al., filed Oct. 24, 1966, entitled "Golf Game Computing System," now U.S. Pat. No. 3,513,707, and assigned to the instant application, the details of which are herein incorporated by reference.

The exemplary embodiment of a tee embodying a data acquisition system made according to the invention is illustrated in FIG. 2 and includes a tee area defined by a horizontal surface, generally designated 20, having a predetermined tee point 22 at which a golf ball is adapted to be disposed to be hit therefrom by a golfer when the game is being played. The horizontal surface 20 also includes an opening 24 which may provide the golfer with access to a ball return system.

Above the surface 20 there is mounted a scene projector 26 which is adapted to project scenes representing the view from various portions of one or more holes on a golf course on a generally vertically disposed screen, generally designated 28, located forwardly of the tee point 22. Adjacent the scene projector 26 there may be located a ball spot projector 19 which is operated by the computer 17 responsive to the data acquisition system of the instant invention to project a spot of light 32 on the screen 28. As is known in the art, the ball spot projector 19 is adapted to change the size of the spot of light 32 as well as to move the same up and down and to the left and right to indicate to the golfer the nature of the trajectory of a ball hit from the tee point 22.

Behind the screen 28 there is located a spherical target, generally designated 34, which forms part of the data acquisition system. The spherical target 34 has its center at the tee point 22 for purposes as will be seen hereinafter. At the lower edge of the target 34 and forwardly thereof interposed between the tee point 22 and the target 34 is located a ball rebound surface, generally designated 36, which generally slopes downwardly toward the tee point 22 so that balls rebounding from the target 34 roll along the ball rebound surface 36 to be received by a spin detector, generally designated 38, located forwardly of the tee point 22. The spin detector 38 is arranged in the form of a circular arc having its center at the tee point 22.

Before turning to a more detailed description of the just described components, certain general principles of operation of the invention will be briefly described to aid in the understanding thereof. Because the target 34 is spherical and has its center at the tee point 22, it will be appreciated that any ball hit from the tee point 22 without spin will tend to rebound back toward the tee point 22. However, if a ball hit from the tee point 22 has side-spin placed thereon by a golfer, even though it will hit the target 34 in a direction normal to the surface of the latter, it will not rebound directly toward the tee point 22 because of the effect of side-spin during the collision. Specifically, if it be considered that a right-handed golfer strikes a ball from the tee point 22 in such a way as to place so-called "hook" spin (commonly that type of spin on a ball which causes the same to curve to the left of a right-handed golfer in flight) on the ball, the ball will, upon encountering the target 34, tend to rebound to the right of the tee point 22. Similarly, for a ball hit with so-called "slice" spin (commonly that type of spin which will cause a ball in flight to curve to the right of a right-handed golfer), the ball will rebound from the target 34 in a direction to the left of the tee point 22. The purpose of the spin detector 38 is to measure the amount of such deviation from a line drawn between the point of collision and the tee point with the amount of such deviation being a measure of the degree of hook or slice spin imparted to the ball when it was hit.

Referring now to FIGS. 3 and 4, the specifics of the construction of the tee area 20 and the ball return surface 36 will now be described.

The tee area 20 is defined by three panels 40, 42 and 44 supported by a channel or I-beam framework, generally designated 46 which is secured by any suitable means to the floor 48 of the building in which the indoor golf game is to be installed. The nature of the arrangement is generally such that the upper surface of the panels 40, 42 and 44 is only about 15 inches above the floor 48 to avoid any necessity of a multilevel floor in the building.

The panel 44 is secured by means of a hinge 50 to the panel 42 which is fixed and panel 40 is secured by means of a hinge 52 to the fixed panel 42. As will be seen, the use of the hinges 50 and 52 permit ready swiveling of the panels 40 and 44 to expose spin detecting means 38 and a portion of a ball return associated with the ball return opening 24 in the tee area 20.

If desired, the upper surface of the panels 40, 42 and 44 may be covered with any suitable carpeting or artificial grass material to improve the aesthetic nature of the installation.

The ball rebound surface 36 is formed of a canvas or other suitable material stretched taut about a pair of arcuate forms 60 and 62, both of which have their centers of curvature on a vertical line drawn through the tee point 20. The canvas defining the ball rebound surface 36 includes at opposite ends, loops 64 which receive rods 66. Portions of the loops 64 are cut out so that hook members 68 may be engaged with the rods 66 and secured to the form 62 or to a spring 70 secured to the form 60. The use of the springs 70 insures that the canvas forming the rebound surface 36 will be maintained taut at all times.

As best seen in FIG. 4, it will be noted that the upper end of the form 60 is somewhat lower than the form 62 so that the ball rebound surface 36 slopes rather gently from left to right. As mentioned, the purpose of this slope is to insure that balls rebounding from the target 34 will be returned to the spin detector 38.

The base of the target 34 is located adjacent the form 62 to complete the geometric interrelation between the rebound surface 36 and the target 34. Finally, side members 70 and 72 along with a center member 74 are interposed between the forms 60 and 62 to maintain the two in the proper relationship with respect to each other. Additionally, the upper edges of the side members 70 and 72 may be located a slight distance above the upper surface of the canvas forming the ball rebound surface 36 to aid in confining balls to the rebound surface 36.

Adjacent the forwardmost end of the tee area 20 and to the sides thereof, there may be provided cylindrical posts 80 interposed between the floor 48 and the ceiling (not shown) of the building for supporting strands comprising the penetrable screen 28.

As viewed in FIGS. 3 and 4, the form 60 is located just under and rearwardly of the forward edge of the tee area 20 as defined by the forward edge of the panel 44. Depending from the forward edge of the panel 44 and just above the end of the canvas defining the ball rebound surface 36 is the spin detector 38. The spin detector 38 is comprised of some 37 switches 82 mounted on brackets 84 (FIGS. 5 and 6). The brackets 84 are, in turn, secured to a form 86 which is arcuate in shape and has its center located at the tee point 22. As will be described in greater detail hereinafter, each one of the switches 82 is adapted to be actuated by a ball rolling on the rebound surface 36.

As mentioned in the preceding paragraph, 37 of the switches 82 are employed. In the exemplary embodiment, there is one central switch which is located on a line extending straight away from the tee point 22 toward the target 34. The next 10 switches on either side thereof are spaced from each other a distance of 1.degree. and the 11th switch on each side is spaced from the 10th switch by a distance of 11/2.degree.. Thereafter, the remaining switches are spaced from each other a distance of 2.degree.. In any event, some 37 spin detecting zones are defined by the switches 82. Of course, a greater or lesser number could be used depending upon the degree of accuracy required of the data acquisition system.

Extending from the rightmost end of the ball rebound surface 36 as seen in FIGS. 3 and 4, is a ball return surface 100 which is comprised of a solid panel covered with a canvas layer. The ball return surface 100 again slopes gently from left to right and its leftmost end is mounted in close proximity to the rightmost end of the ball rebound surface 36 by means of brackets 102 mounted on the form 60 and bearing adjustment bolts 104. The upper ends of the adjustment bolts 104 serve to support the return surface 100.

The rightmost end of the return surface 100 is supported by a hook member 106 which is secured to a member 108 of the supporting frame 46. The member 108 is located approximately at the forwardmost end of the platform member 40.

As best seen in FIG. 3, the sides of the ball return surface 100 include retaining elements 110 which are arranged to converge from left to right. The retaining members 110 have their upper surface at a level higher than the upper surface of the return surface 100 to provide a retaining function and as a result, when a ball has passed the spin detector 38 and is rolling on the return surface 100, it will tend to be directed to a point 112 adjacent the forward edge of the platform member 40. The point 112 is arranged to provide an opening for the returning ball to a three rail return system comprised of a center rail 114 and two side rails 116 which extend from the point 112 to a location behind the tee point 22. The two side rails 116 are somewhat higher than the center rail 114 so as to confine the golf ball and the overall arrangement is such that the track defined by the rails 114 and 116 slopes gently from left to right as viewed in FIGS. 3 and 4 until an elevating point 120 is reached. The point 120 is very low in close adjacency to the floor 48 and elevator means, generally designated 122, are arranged to elevate golf balls received at the point 120 to a collector 124 disposed just below the ball return opening 24. The elevator means includes an arcuate channel member 126 which is arranged to receive balls from the rails 114 and 116 at the point 120 and also empties into an opening 128 in the collector 124.

A motor driven wheel 130 is arranged to have its periphery disposed adjacent the open end of the arcuate channel 126 and as a result, when a golf ball is received at the point 120, it will be contacted by the wheel 130 and the direction of rotation of the latter is such that it will cause the ball to roll within the channel 126 upwardly until it is passed through the opening 128 in the collector 124 to be received and retained in the latter. Thereafter, a golfer may obtain a golf ball simply by reaching through the opening 24 and removing a ball from the container 124.

Turning now to FIGS. 5 and 6, the nature of the mounting of the switches 82 will be described in greater detail. The switches 82 are conventional microswitches having a rotary actuator 130 protruding from the side thereof. A pair of screws 132 are used to secure the microswitches 82 to the brackets 84. The brackets 84 are, in turn, secured by a screw 134 to the form 86 which, in turn, is secured to the underside of the panel 44.

If desired, for adjustment purposes, a pair of vertically elongated slots 136 may be provided to receive the screws 132 to provide for vertical adjustment of the microswitches 82. By the same token, a horizontally elongated slot 138 in the brackets 84 permits horizontal adjustment of the location of the microswitches.

Secured to the rotary actuator 130 of each microswitch 82 is a wirelike element having a vertically depending portion 139 which terminates in a horizontally elongated loop 140. The horizontal extent of the loops 140 is such that it is impossible for a ball to pass from the rebound surface 36 to the return surface 100 without contacting at least one of the loops 140 and thereby causing rotation of the corresponding microswitch actuator 130. Additionally, the microswitches 82 are mounted such that the loops 140 associated with the actuators 130 are located at approximately the rearmost edge of the form 60 and a level above the rebound surface 36 less than the diameter of a golf ball. As a result, when a ball rolls down the rebound surface 36, it will contact one of the loops 140 thereby causing counterclockwise rotation (as seen in FIG. 5) of the corresponding actuator 130 causing the microswitch 82 to generate an electrical signal indicating that the same had been actuated by a rebounding golf ball. After passing the microswitch actuator loop 140, the ball will then continue to roll onto the return surface 100 to ultimately be returned to the collector 124 described previously.

Referring now to FIG. 7, the general azimuth and elevation detection geometry will be described. The target 34 is comprised of four quadrants 150, 152, 154 and 156. The geometry of the quadrant 152 is identical to that of the quadrant 154 and similarly, the geometry of the quadrant 156 is identical to the geometry of the quadrant 150. Furthermore, the geometry of the quadrant 154 is the mirror image, i.e., symmetrical to, of the quadrant 150. Thus, it is only necessary to describe the geometry of the quadrant 150.

The quadrant 150 includes a plurality of vertically elongated azimuth angle detection zones and a plurality of horizontally elongated elevation angle detection zones. As will be seen hereinafter, the detection zones define both an azimuth angle detection matrix and an elevation angle detection matrix, the specific of which will be described in greater detail hereinafter.

As viewed in FIG. 7, the leftmost vertically elongated or azimuth angle detection zone, designated 158, has an arcuate extent of one-half of 1.degree. with respect to the tee point 22. Continuing from left to right, the zone 158 is followed by 10 zones 160 each having an arcuate extent of 1.degree.. Thereafter, there are provided five azimuth detection zones 162 each having an arcuate extent of 2.degree..

From top to bottom as viewed in FIG. 7, the quadrant 150 includes a first elevation angle detecting zone 164 which has an arcuate extent of 5.degree. with respect to the tee point 22. Thereafter, there are six elevation detection zones 166 each having an arcuate extent of 12/3.degree.. Finally, the lowermost elevation angle detection zone 168 has an arcuate extent of 5.degree..

Each azimuth angle detection zone whether it be the zone 158, the zones 160 or the zones 162 is separated from the adjacent zone a distance of three-sixteenth of an inch. Similarly, each of the elevation angle detection zones whether it be the zone 164, the zones 166 or the zone 168 is separated from the adjacent elevation angle detection zones by three-sixteenths of an inch.

From the foregoing description of the makeup of the elevation angle and azimuth angle detection zones and the quadrants 150, 152, 154 and 156, it will be appreciated that either the quadrant 150 or the quadrant 154 could be substituted for either the quadrant 156 or 152. For example, if quadrant 150 is rotated 180.degree. it can be installed in place of quadrant 156 and quadrant 156 when rotated 180.degree. can be installed in place of quadrant 150. As will be seen in greater detail hereinafter, the actual physical construction of the quadrants 150, 152, 154 and 156 and their manner of assemblage into the target 34 is such that such interchanging may take place.

This unique feature of the construction provides a significant advantage in terms of prolonging the life of the overall target 34. For example, the vast majority of shots hit in an indoor golf game will strike the target in the quadrants 152 and 156 near their point of adjacency as seen in FIG. 7. As a result, the greatest degree of wear on the target 34 will take place in this area with very little wear occurring in the quadrants 150 and 154. Thus, an owner or lessee of an indoor golf game in order to maximize total target life may at some point before total failure of the quadrants 152 and 156 disassemble the target 34 and substitute the quadrant 152 for the quadrant 154 and the quadrant 156 for the quadrant 150. Thereafter, the relatively unworn quadrants 150 and 154 will be subjected to the most wear and only after all four quadrants have been equally deteriorated will it be necessary to replace the target 34.

The physical construction of the quadrants forming the target 34 is best illustrated in FIG. 8. The target 34 includes a rigid metal backing 170 which is comprised of a spherically shaped support portion 172 and a rearwardly extending flange 174. The radius of curvature of the spherical portion 172 is such that the center of the spherical surface thereof would be located at the tee point 22 as mentioned previously.

Adhered to the spherical portion 172 by means of any suitable adhesive is an open celled foam pad 176. The foam pad 176 is, in turn, covered by a thin neoprene base sheet 178. Secured in turn to the sheet 178 is a butyl rubber pad 180.

The makeup of the structure as described thus far is such as to provide a ball impacting material having a high hysteresis loss so that the elasticity of the collision of a ball with the target 34 will be minimized so that the ball will rebound at a very low rate, essentially dropping from the collision to the ball rebounding surface 36 to roll therealong to the spin detector 38.

Secured in turn to the butyl rubber pad 180 is a plurality of first detecting strips 182 formed of conductive rubber. The strips 182 are spaced from each other and have a width corresponding to that required by the geometry of the elevation of azimuth angle detecting zones described previously in conjunction with FIG. 7.

Thereafter, a plurality of foam insulator discs 184 are adhesively secured to the strips 182. The foam insulator discs are relatively thin and circular in shape. In the exemplary embodiment, they have a diameter of about one-quarter inch and are located on seven-sixteenths of an inch, staggered centers.

Thereafter, additional conductive rubber detecting strips 186 (only one of which is shown) are secured to the discs 184 and located with respect to the conductive rubber strips 182 such that they extend transverse thereto from detecting zones. Again, the width of the strips 186 correspond to the required width of the azimuth angle or elevation angle detecting zone described previously in conjunction with FIG. 6 as required.

It should be noted that the conductive rubber strips 182 can form either the azimuth angle detection zones or the elevation angle detection zones with the conductive rubber strips 186 forming whichever angle detection zone is not assigned to the strips 182.

Finally, the entire assemblage is covered by a second neoprene cover 188 against which a golf ball will impact.

From the foregoing description of the composition of the target 8, it will be appreciated that when a ball impacts against the neoprene cover 188, the entire target will be compressed to absorb the kinetic energy of the golf ball. Such compression of the target will also result in one of the conductive rubber strips 186 being driven into electrically conductive contact with one of the conductive rubber strips 182. Typically, the establishment, even though temporary, of the electrical connection between a strip 186 and a strip 182 will cause any suitable circuit to firstly provide a signal indicating which of the strips 182 was contacted and a second signal to indicate which of the strips 186 was contacted thereby providing both elevation and azimuth angle information. Preferably, the establishment of the circuit will also indicate that a ball was collided with the target for purposes of establishing the second signal required in timing the period required for the ball to move from the tee point 22 to the target 34.

As mentioned previously, the compression of the target sandwich described previously will also absorb most of the kinetic energy of the ball causing the same to drop to the rebound surface 36 to roll through the spin detector 38 thereby providing spin detection information. Of course, after the ball rebounds from the target, the presence of the foam insulator discs 184 will, due to their inherent resiliency, separate the strips 182 and the strip 186 at the point of impact of the ball on the target and normally maintain the strips at such point in an electrically nonconducting relationship.

Since the target 34 is comprised of four sectors, it is necessary that such sectors be secured together. As indicated in FIG. 8, a second sector also includes a rigid metal base having a spherical support portion 172 and a flange 174. By means of bolts 190 and nuts 192 together with such spacing washers 194 as may be desirable, adjacent sectors may be secured together. Of course, the second sector will have a sandwich composition secured to its spherical portion 172 in the same manner as described previously, although the geometry of the arrangement of the tapes 182 and 187 therein may differ according to the geometrical requirements of the specific sector.

In order to insure uniform rebound and detection characteristics at the junction between adjacent sandwich compositions, the foam pad 176 of both sandwiches adjacent the interface between the sectors includes a recess 196. When the sectors are secured together, a small butyl rubber insert 198 is located in the two recesses 196 of adjacent sectors so that a ball impacting on the interface thereon will not tend to push the foam pads 176 to the side which could result in a highly elastic collision and injury to a golfer. That is, because a ball impacting at the interface will cause movement of the butyl rubber inserts 198, the foam pads 176 will be fully compressed and not separated and a relatively inelastic collision will result.

FIG. 9 illustrates one method by which an electrical connection can be made with the tapes 182 and 186. Specifically, one of the conductive rubber strips 186 is shown emerging from a side of its corresponding sector and includes a narrowed, rearwardly turned tab 200 to which an electrical connector 202 is secured. An electrical wire 204 is, in turn, secured to the connector and is led to a second connector 206 which is secured by means of screws 208 to one of the flanges 174 at the side of the target (as opposed to that at an interface between two sectors forming the target). Any suitable means may be then used to connect the connector 206 to a computing circuit.

FIG. 10 illustrates the interrelationship between the vertically elongated detecting zones 158,160 and 162 and the various spin detecting switches 82. It will be recalled from the description of FIG. 6 that each half of the target 34 includes 16 azimuth angle detection zones. In practice, the narrowest of the zones 158 is connected with the zone 158 on the adjacent sector so that a total of 31 azimuth angle detection zones are present.

The central one of the spin detecting switches 82 is then arranged with respect to the tee point 22 so that it is directly in line with the single central azimuth angle detection zone defined by the detection zones 158. On either side of the central switch 82 are located 10 of the switches which switches are spaced at 1.degree. increments. Thereafter, there is a 11/2.degree. increment between the 10th and 11th switch on each side of the central switch 82 and thereafter the remaining switches are spaced at 2.degree. increments.

As a result of the foregoing, it will be recognized that while there are only 31 azimuth angle detection zones provided, there are some 37 spin detection zones provided. Such an excess of spin detection switches is necessary in order to insure that a shot directed to one of the endmost azimuth angle detection zones having spin thereon will have the spin detected. For example, if a right-handed golfer were to slice a shot hitting the leftmost azimuth angle detection zone illustrated in FIG. 9, it would be clear that the ball would rebound to the left of a line drawn between the tee point 22 and such azimuth angle detection zone. Were only an equal number of azimuth angle detection zones and spin detection zones provided, no spin detection zone would be capable of detecting the path of rebound and the side-spin on such a ball would go undetected. However, because of the provision of three extra spin detection zones on each side of a line drawn between the tee point 22 and the endmost azimuth angle detection zones, the spin on such shots can be detected.

From the foregoing, it will be appreciated that a data acquisition system made according to the instant invention provides significant advantages over those heretofore known. For example, it enables the detection of spin without requiring a multilevel floor in a building necessitated by the usual pit required for housing the spin detection equipment. Furthermore, the use of a data acquisition system wherein a low velocity rebounding ball provides spin information precludes the possibility of injury to a golfer and obviates any requirement for means to prevent such injury.

Additionally, by utilizing the spherical ball impacting surface having its center located at the tee point, all errors in determining a time required for the ball to pass from the tee point to the detection matrix are eliminated thereby enabling a more accurate determination of the characteristics of the shot. Another advantage resides in the unique construction of the detecting surfaces in the target 34 with respect to prior art detection systems. For example, no time consuming and costly focusing of photocells and light sources is required. Furthermore, it is only necessary to accurately locate the target 34 and the spin detector 38 with respect to the tee point 22 in contrast to prior art systems where two sets of light sources in photocells as well as a shell and a spin detector had to be accurately located with respect to the tee point. Additionally, the movable and compressible portions of the target required for signalling are nonmetallic and nonbrittle so that they are capable of extended wear without failure.

Finally, the unique construction of the target 34 and four sectors permits the equalization of the wear on all sectors of the target so as to enhance the usefulness thereof.

Having described the specific embodiment of our invention as required by 35 U.S.C., we do not wish to be limited to the details set forth, but rather, to have our invention construed broadly according to its true spirit as set forth in the following claims.

Claims

We claim:

1. A data acquisition system for an indoor golf game comprising: means defining a tee area having a predetermined tee point therein; a target spaced from said tee point and formed of a material having a high hysteresis loss whereby the collision of a golf ball therewith will be highly inelastic, said target presenting a generally spherical surface to said tee point with the center of said spherical surface being located at said tee point; spin detecting means located between said tee point and said target and adapted to receive a low velocity ball rebounding from said target and for providing information relative to the location of the rebounding ball; horizontally arranged means within said target for, when hit by a golf ball, providing information relative to the initial angle of elevation of the ball hit from the tee point; generally vertically arranged means within said target for, when hit by a ball, generating information as to the initial angle of azimuth of a ball hit from the tee point; means associated with said tee point for providing information when a ball has been hit therefrom; and means on said target for providing information when a ball has collided therewith.

2. The data acquisition system of claim 1 wherein said spin detecting means comprises a plurality of switch means, each adapted to be actuated by a rebounding ball, located in an arc having its center at said tee point.

3. The data acquisition system of claim 2 wherein a ball rebounding surface is interposed between said target and said spin detecting means.

4. The data acquisition system of claim 3 wherein each said switch means comprises a switch having an actuator located above said rebounding surface a distance less than the diameter of a golf ball.

5. The data acquisition system of claim 1 wherein said target comprises a rigid backing having a layer of an opened celled foam on the tee side thereof and a layer of rubber on the tee side of the foam layer; said horizontally arranged means comprising a plurality of generally horizontal, spaced conductive rubber strips located on the tee side of said rubber layer; said vertically arranged means comprising a plurality of generally vertically arranged, spaced, conductive rubber strips located on the tee side of said rubber layer; nonconductive means interposed between said horizontal rubber strips and said vertical rubber strips normally maintaining said horizontal rubber strips and said vertical rubber strips in a spaced, nonconducting relation; and a protective covering located on the tee side of said rubber strips.

6. The data acquisition system of claim 5 wherein said rigid backing, said foam layer, said rubber layer and said protective covering are formed in at least two symmetrical portions with said rubber strips included therein, releasable means for securing said portions together to define a single target and means for releasably electrically interconnecting at least some of the rubber strips in each portion whereby the portions may have their locations interchanged to minimize localized wear and extend the life of the target.

7. A data acquisition system for an indoor golf game comprising: means defining a tee area having a predetermined tee point therein; a target spaced from said tee point and presenting a generally spherical surface to said tee point with the center of said spherical surface being located at said tee point; means associated with said tee point for providing a signal when a golf ball is hit therefrom; means associated with said target for providing a signal when a golf ball impacts against said target; and means for utilizing said two signals.

8. A data acquisition system according to claim 7 wherein said target includes a generally horizontally arranged electrical matrix for providing information relative to the initial angle of elevation of a ball hit from said tee point, and a generally vertically arranged electrical matrix for providing information relative to the initial azimuth angle of a ball hit from said tee point; said means for providing a signal when a golf ball impacts against said target being comprised of at least one of said matrices.

9. A data acquisition system according to claim 8 wherein said horizontally arranged matrix comprises a plurality of generally horizontal electrically separated conductive rubber strips; said generally vertically arranged matrix comprises a plurality of electrically spaced, vertical conductive rubber strips; and said target further includes inherently resilient means interposed between said horizontally arranged strips and said vertically arranged strips for normally electrically separating the same except when a golf ball impacts against said target to thereby drive one of said horizontal strips and one of said vertical strips together.