1 The present invention relates to method and apparatus for golf practice and instruction. This method and apparatus may be used by a golf instructor as an aid in developing a golf student's swing technique, or may also 5 be used by the player himself to improve his own swing technique without the assistance of an instructor.

It- has been -found that most novice golf players have the physical ability to make long, accurate golf shots. In particular, most inexperienced golfers can be

10 taught to properly swing various types of golf clubs with relative ease provided that they are not attempting to actually hit a golf ball. Such "practice" swings can usually be executed with reasonably good form in a relaxed manner. However, when a novice golfer approaches and

15 focuses on a golf ball and concentrates on it in an attempt to actually make a shot, he often tends to swing in a manner entirely different from his practice swing. The difference in the "focused" and "practiced" swings may result from tension or excessive concentration by the

20 player on the ball. Golf instructors often attribute the difference between a player's "focused" and "practice" swings to his "hitting at the ball" rather than "swinging through the ball". In either case, the "focused" swing tends to be much poorer than the "practice" swing and,

-25 therefore, often results in a poor shot or often in missing the ball entirely. Furthermore, it is difficult for a

novice player to know the value of "swinging through the ball" because he often can only do so when he is not actually attempting to hit a ball. Despite conscious effort not to "hit at the ball" he, nevertheless, does so when a ball is in position to be hit.

The method and apparatus of the present invention permits a golf player to strike a golf ball using his more relaxed "practice" swing rather than a tense "focused" swing. Moreover, this method and apparatus permits a golf instructor to observe a student practicing his swing and choose a particular swing with which the student will strike a ball.

Golf has been traditionally taught by instructors who closely observe a student's swing and attempt to modify that swing until it conforms to accepted form. Concentra¬ tion is ^" devoted• to mechanical aspects of the swing which include keeping the leading arm firm, the head down, and leading the swing with the hips.. However, frequently the more intense the student's concentration, the more difficult it becomes for him to execute these mechanical aspects. Golf instructional aids have been devised which attempt to correct problems with a golfer's swing form. For example, U.S. Patent No. 3,918,721 discloses such a device which is intended to constrain certain of the golfer's swing movements to generally accepted form. Moreover, instructors have identified the problem, common among novice and more experienced golfer's alike, of "hitting at" rather than "swinging through" the ball. However, little has been done to actually demonstrate the different results to be achieved in play to the student.

Various devices for automatically teeing golf

2,-789,824 (Willcox) ; 2,838.,313 (Mozel) ; 2,259,916 (Wheeler et al.) and 2,335,280 (Hogeberg) . However, the primary purpose of these devices is to convey a golf ball to a tee location automatically. They permit a player to repeatedly make shots without manually teeing a new ball after each shot. They are not concerned with teaching a golf player to improve his swing nor are they designed to permit a novice golf player to use his practice swing to actually hit a shot. In a preferred embodiment to be described below in detail, the method and apparatus of the present invention for practicing and teaching golf permit a golf player to actually strike a golf ball with his "practice" swing. As noted above, the practice swing of many golfers tends to be far superior to their swing executed while concentrating on actually hitting a golf ball. Accordingly, the ball may be hit with a golfer's more relaxed swing to execute the best shots within his capability.

In its preferred embodiment, the method of the present invention for practicing golf comprises the step of projecting a golf ball into a ball hitting zone during the . course of the player's swing of his golf club while the club head approaches this hitting zone. The ball arrives in the hitting zone in the path of the club head immediately prior to the sweep of the head into the zone. The projecting step is performed.after the golfer has begun his swing motion and is completed in such a short time prior to arrival of the club head in the hitting zone that he cannot react by tensing and alter his swing. Thus, the golfer can strike the ball, with the smooth motion which he employs during practice and can readily appreciate the value of applying such a smooth swing to actual play.

In this preferred embodiment, he method further comprises the step of detecting the instant of movement of the golf club during the player's swing past a location in its path a predetermined distance backward of the hitting zone. The projecting step is then performed in response

to ^" the detecting step and includes projecting the ball into the zone within a predetermined time after the instant of detection.

I

The apparatus of the present invention, in its preferred embodiment, comprises a station which provides the golf ball hitting zone through which the head of a golf club is swept by a player performing- golf swings. projection apparatus, operable in the course of the player*s swing while the club head is approaching the hitting zone, is arranged to project a golf ball into the zone so that the ball will be in the path of the club head when it sweeps into the zone. A photodetector is provided to detect the instant of movement of the club past the predetermined location in its swing path backward of the hitting zone.

In. the preferred embodiment the apparatus is selectively operable to project a golf ball into the hitting zone only during a selected swing of a golf club by the player. This swing during which the ball is pro- jected, may be selected by the player himself or by an instructor. For example, an instructor may observe a player and choose a swing which he considers to be closest to.ideal. During this chosen, approximately ideal swing he may actuate the apparatus for projecting a ball into the hitting zone in the path of the club head and, thus, demonstrate the value of a smooth swing to the golf player.

Accordingly, it is an object of the invention to provide a method and apparatus for golf practice and instruction that permits a golfer to actually strike a ball using his practice swing rather than using a swing dis¬ torted by excessive concentration on properly striking a ball.

Other objects, features and advantages of the present invention will be pointed out in or will be under¬ stood from the following detailed description provided below, in conjunction with the accompanying drawings.

1 FIGURE 1 is a perspective view of the apparatus of the present invention illustrating a station which provides a golf ball hitting zone and a player poised to execute swings of his golf club. 5 FIGURE 2 is a front elevational view of the apparatus of the invention illustrating the photodetector for detecting movement of a golf club past a predetermined location during the golfer's swing and a system for delivering golf balls to a projection device. 0 FIGURE 3 is an enlarged front elevational view of the device for projecting golf balls into a hitting zone. FIGURE 4 is a partial cross-sectional view of a - device which may be incorporated into the apparatus of the invention for controlling delivery of golf balls to the 5 projection device.

FIGURE 5 ^" is a- schematic block diagram of the apparatus of the invention.

FIGURE 6 is a more detailed schematic circuit diagram of the apparatus of the invention. 0 FIGURE 1 illustrates a golf player P using the apparatus of the -present invention to practice golf. The . apparatus may be operated by the player himself or by an instructor to teach the player how to properly coordinate movement of a golf club C to execute a correct swing and 25 properly hit a ball for distance and accuracy.

In particular, the apparatus permits the player to hit a ball using his "practice" swing rather than his "focused" swing in a manner to be described in greater detail below. 3.0 As shown in FIGURE 1, the apparatus comprises a platform 10 which is mounted approximately one foot above ground level. The platform.has sufficient area to provide adequate support for the player P and to give him enough room to execute golf swings. A golf ball propulsion unit 35 12, which will be described in greater detail below, is mounted below the platform to selectively project a golf ball into a hitting zone immediately above the unit, E3R ^E AtT OMPI

through which the head of a golf club sweeps during club swings by ^" the player. (It will be noted that the platform 10 may be mounted at ground level and the ball propulsion• u it 12 may be recessed below ground level if desired.) The apparatus further comprises a photoelectric detector 14 that is aligned and focused to receive light which intersects the swing path defined by the shaft of a club swung by the player. A power unit 16 is connected to both the photoelectric detector 14. and ball propulsion unit 12, to power and coordinate operation of the apparatus in accordance with various events. A control unit 18 is provided through which the apparatus may be selectively actuated by the golf player himself or by an instructor.

The apparatus, which may assist in teaching golf swings of woods, irons, or wedges in accordance with that portion of the game the golf player wishes to improve, is used for golf practice and instruction as follows. A golf player first mounts the platform 10 and positions himself so that when practicing golf swings, the head of his club sweeps through the hitting zone Z immediately above the ball propulsion unit 12. Firther, as can be seen in FIGURES 1 and 2, the club shaft passes in its swing path in front of the aligned and focused photodetector so that light incident on it is interrupted during the club swings by the golfer. The photoelectric detector generates a signal, "in response to interruption of incident light by a ^~ swung golf club, that actuates the ball propulsion unit to project a golf ball into the hitting zone Z where it may be impacted by the head of the moving club. The control unit 18 is used to selectively enable the apparatus to project a ball into the hitting zone in response to a signal by the photodetector only during a selected practice swing by the player. Specifically, the player may execute several practice swings. However, only after the player achieves a. desired degree of comfort in his swings or after he has executed a given number of swings, the form and smoothness of which are acceptable to

1 an instructor or to himself, is the control unit actuated to enable the apparatus to project a ball into the hitting zone. In this manner, swings that are close to ideal for a golfer may be used to actually strike a golf ball. Since 5 the practice swing is usually better than one in which the player actually tries to strike a ball, his best form is used to execute the shot. This procedure thus demonstrates to the golf player the value of relaxation and smoothness when swinging a club. Further, as will be described in

10 greater detail below, the velocity with which most golf players swing a club and the proximity of the photoelectric detector to the ball projection unit are such that the ball is projected into the hitting zone much too late for the player to alter his swing in response to its arrival in

15 the hitting zone. This feature is of great value in teaching the player in accordance with the principles outlined above.

As shown in FIGURES 2 and 3, the ball propulsion unit 12 comprises a solenoid 22 that includes an armature

20 24 having a hard head 26 mounted on its upper projecting end to strike a golf ball. The ball B is cradled in a ball support ring 21 at a location spaced slightly above the head 26. The ring 21 and head 26 register with a hole 20, somewhat larger than the golf ball, formed in platform

25 io. Upon energization of the solenoid the armature is thrust quickly from a rest position shown in solid lines in FIGURE 3 to an extended position shown in phantom ^■ lines. When the solenoid is deenergized, ^" the armature remains or returns to the rest position. Energization .of

30 the solenoid, as described in greater detail below, causes its armature to be thrust abruptly and rapidly upward so that the head 26 strikes a ball B resting on the support ring 21 and thus propels the ball quickly into the hitting zone Z above the platform 10. If not hit by a club head

35 being swung into zone Z, the ball would fly up through the hitting zone to a height well above it.

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1 ^" .The apparatus may also include a system for automatically feeding balls to the support 26 for pro¬ jection into the ball hitting zone. A suitable ball feeding system, as shown in FIGURES 1, 2 and 3, includes a 5 ball hopper generally indicated at 28, that is mounted above the platform 10. The hopper is formed with a funnel-like insert 30 which channels golf -balls to a curved feed tube 32. The tube is pitched slightly to a position under the platform where it leads onto the ball

10 support ring 21 over the head 26 of the armature of the solenoid. As can be seen in FIGURE 3, the lower inner surface of the tube 34, which defines a portion of a tube - outlet aperture 38, is substantially coextensive with the upper surface of the ball support ring. Accordingly,

15 balls may be channeled by gravity from the hopper 28 through the feed- tube 32 directly to the support ring 21 when the armature of the solenoid 22 is in its rest

: ^" position. Further, a ball-limiting vertical stop 36 is mounted opposite the outlet aperture 38 to prevent movement

20 of a golf ball beyond the support ring.

Control of the feeding of balls through the feed tube 32 may be accomplished by apparatus illustrated in FIGURE 4. There the pitch of the tube is exaggerated in the interest of clarity. The feed control apparatus

25 comprises, two solenoids, the first, 40, of which has an elongated armature 44 which is normally urged to.an up¬ wardly projecting position that extends into the interior of the tube 32. Conversely, the second solenoid 42 has an elongated armature 46 which is normally urged to a

30 retracted position withdrawn from the tube interior. Thus, in their deenergized condition, a leading ball B, is pre¬ vented from rolling down feed tube 32 on to the pedestal by

. .. projecting armature 44 ^" . However, after the ^* device of the present invention has been actuated in a manner to be

35 described in greater detail hereinafter, to project a ball into the hitting zone, the solenoids are energized to retract armature 44 of the first solenoid 40, permitting

ball B, to roll on to the support ring. Simultaneously, the armature 46 of solenoid ^' 42 projects into the interior of the tube 32 to restrain the adjacent ball B ₂ from move¬ ment. However, once ball B. has reached the support ring 5 or after another predetermined time, the solenoids are deenergized and are returned to their rest positions with armature 46 retracted from the tube and armature 44 pro¬ jecting into it.. Accordingly, a ball B ₂ rolls to the position occupied by ball B, in FIGURE 4, poised for 0 eventual delivery to the support ring over the main, ball projection solenoid 22.

The function of the apparatus of the present invention, to project a ball into the hitting zone ' immediately-prior to arrival of the club head therein swung 5 by a golfer, may be explained with reference to- the schematic block diagram shown in FIGURE 5. As shown there, the apparatus includes -the photoelectric detector 14 which is connected between ground 46 and a source of voltage 48. The photodetector is normally heavily saturated and 0 heavily conducting because of its continuous illumination by ambient light. However, when a club shaft being swung bya player reduces the illumination to the photodetector . momentarily, current therefrom is reduced to produce a positive-going voltage transient across a photodetector 5 load resistor 50 connected between the photodetector 14 and voltage source 48. The positive-going voltage transient is coupled through a capacitor 52 to an amplifier 54, which may be a conventional multistage saturating amplifier, to be amplified to a standard level. The 0 amplified voltage transient, in turn, triggers a controll- .- able delay generator 56 which may be a onostable multivibrator of conventional design. The delay generator is arranged to introduce a delay of further transmission

^• of the positive-going voltage transient, which may be

35 controlled by either the instructor or by the player him¬ self over a range sufficient to accommodate different club swing speeds of different players. However, for any given

setting of the delay control, the monostable delay introduced by the generator is substantially constant. The amount of delay introduced-by the delay generator 56 is set by a potentiometer 58 mounted in the instructor's control unit 18. The delay should be adjustable over a range of about 1 to 30 milliseconds, a range which is sufficient to accommodate variation in club swing speed for_ most golfers. This provides, for instance, a period of from 20 to 50 milliseconds from the moment of downswing detection to the moment of hitting.

The delayed output voltage transient from the monostable delay generator is coupled through an AND gate 60 to the input of an output amplifier 62. However, transmission of the voltage transient to the amplifier 62 is dependent upon its concurrence at the AND gate with an enabling signal also ^* conducted from the instructor's control unit- 18. ^" In particular, an enabling switch 64 connected through ground 46 to an input to the AND gate 60 is operable by the instructor as noted above to selectively actuate the apparatus only during or for a particular swing by the player (of course, as noted, the control unit 18 may be arranged for operation by the player himself).

Assuming concurrence of the voltage transient and the enabling signal at the AND gate, the transient is conducted from the output amplifier 62 to the gate of a power amplified 66 in the form of a silicon controlled rectifier (SCR) . The power amplifier 66 is normally non¬ conducting. However, when it receives the positive-going transient from the remainder of the system, it is rendered conducting to actuate the ball propulsion solenoid 24 in a manner described above.

The electromotive power for actuation of the solenoid is derived from a-storage capacitor 68 which is connected to a power unit 70 through a load resistor 72. The power unit, which will be described below, maintains the storage capacitor in a fully charged state. However, when the power amplifier is rendered conducting by a signal

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from the output amplifier 62, the stored electromotive ^* power is instantly conducted therethrough to the ball propulsion solenoid 24 to cause the solenoid to impart a short, quick impulse to its armature and thus strike a golf ball to "pop" it into the hitting zone.

The control circuit may be equipped to discrimi¬ nate between slow interruptions of light to the photo¬ detector and a fast interruption of light thereto such as that caused by a swing o a golf club. This may be accomplished by choosing a capacitor 52 which passes only a positive-going voltage transient of a shorter than specific duration. In the embodiment illustrated, a single activation of the photodetector circuit can trigger the ball propulsion unit; so the enabling switch should be actuated after the backswing of the player's club. By the provision of a counter in the control circuit, however, the circuit can be modified to respond to more than one signal from the club swing detector. For instance, when two successive voltage transients from the swing detecting circuit are required for actuation of the ball propulsion unit the enabling switch can be operated by the instructor or the player before the player begins the backswing of a full swing selected for hitting the ball.

The components of the power unit 70 and their interconnection with certain other components of the apparatus of the present invention may be described with reference to FIGURE 6. The power unit 70 comprises a circuit breaker 74 that may be a master on/off switch from a source of voltage 75, preferably 115 volts A.C. at 60 cycles per second. Further, the circuit breaker provides protection for the circuitry in the event of malfunction. A lamp 76 is connected in series in the circuit breaker circuit with the primary winding 77 of a transformer 78. The lamp provides a resistance path to the primary winding and serves as an indication that the system is "on" condition. The circuit connecting the primary winding of transformer 78 to the voltage source 48 is completed by

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1 two normally closed contacts 80a_ and 80b_ of a doublethrow relay 82, the function of which will be described in greater detail below. When the circuit is completed to the primary winding 77, the secondary winding 79 of the 5 transformer 78 is connected to the input terminals of a bridge rectifier 88, which produces a D.C. voltage that charges the storage capacitor 68. Further, a voltmeter 90 provides a visual indication of when the storage capacitor is properly charged.

10 When the capacitor 68 is fully charged, an instructor may condition the apparatus for operation as described above. In particular, he depresses the enabling switch 64 before the downswing of a club swing which has been selected for actually hitting a ball, which usually

15 will be a swing made as a practice swing after earlier practice swings have approximated the player's ideal swing. Upon coincidence of the signal produced by ^"" closing the enabling switch 64 with reception of the signal from the photodetector, as indicated by the circle

20 92, the pulse is allowed to pass through resistor 94. The signal is then conducted to the gate 94 of the sili¬ con-controlled rectifier 66, permitting quick discharge of the storage capacitor 68 though the coil 98 of the solenoid 24. Accordingly, the solenoid becomes suddenly energized

25 and will "pop" a golf ball into the hitting zone in the manner described. The propulsion is effected, for instance within about 20 milliseconds from the moment of actuation of the rectifier ^~ 66. ^{~~ *} —

Rendering the silicon-controlled rectifier

30 conducting at coincidence of a second from the enabling switch with a voltage transient from the photodetector circuitry also energizes the relay 82 through a diode 100 to close the center contact 80b_ against the third of the relay contacts 80c_. This completed circuit energizes the

35 ball feed control solenoids 40 and 42 through voltage source 99 described with reference to FIGURE 4. Simultaneously, it prevents recharging of capacitor 68

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until the electromotive power stored therein has been dissipated through relay 82 and solenoid 24. When the charge has been completely dissipated, the contacts 80a_ and 80b of relay 82 are restored to their normally closed condition to reenergize storage capacitor 68 for the next cycle of the apparatus of the invention. Typical components suitable for use in the circuit, described with reference to FIGURE 6 are listed below in Table 1. ^*

TABLE 1 Component Manufacturer Part No. Rating

Circuit Breaker (74) Heineman Electric AM12 KH

- Appliance Lamp (76) General Electric 115v. 40 watt

Transformer (78) Radio Shack 115 v. Pri. 60 Hz

Silicon Bridge 5 Rectifier (88) Any 200 v. 6 amp.

Volt Meter (90) Any 100 Volts 1 ma. Full scale

Storage Capacitor General Electric A-9-51502, 14,000 (Computer Grade) MFD. 0 (68) 60 Volts D.C.

Relay (82) Guardian Electric A 410-365391-13, 24 Volts D.C. Single pole/ Doublethrow 5 Diode, Silicon (100) Any . 100 Volt, 1 amp.

Silicon Controlled Rectifier (66) Sylvania ECG5522

Resister (94) Any 240 ohms, 1 watt

Solenoid (24) Any Automotive Start 0 Solenoid. Modified

It will, of course, be appreciated that other components comparable to those listed may be used in the circuit to achieve satisfactory results. It is also to be understood that the photoelectric detecto -14 may be a 5 detector arranged opposite a lamp from which a beam of intense light is projected to a detector so that the light beam will be interrupted by the downswing of a club toward the hitting zone. BU E CT

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1. The apparatus of the present invention described in detail above may be used in accordance with an instructional method for teaching a player ^' to property ^■ execute a golf swing. The apparatus can be used to 5 practice this method which comprises the step of projectin a ball into the hitting zone of a club head in the course of a swing of a golf club while the head is approaching the hitting zone. -Further, as noted above, the projecting step is usually performed in the•course of a practice swin

10 by the golfer. A particular swing is selected by an instructor or by the player himself as being closest to ideal during a segment of the player's practice session. The instant of movement of the club past a given location in its swing path is detected at a predetermined distance

15 backward of the hitting zone. Moreover, the ^" time between detection of movement of the club past this predetermined location in actual projection of ball into the hitting - zone may be set in accordance with the club head speed and the characteristics of the swing executed by the golfer so

20 that a ball arrives in the zone immediately prior to the club head.

It has been found that use of both the method an apparatus of the present invention results in substantial improvement of play by .both experienced and inexperienced

25 golfers. Using these aids, the golfer learns the value of swinging his-club in a relaxed, smooth fashion. With enough practice, he can learn to use all advantages characteristic of his practice swing for actually playing the game.

30. Accordingly, although a specific embodiment of the method and apparatus of the present invention have been described above in detail, it is to be understood . that this is for purposes of illustration. Modifications may be made to the method and apparatus by those skilled

35 in the art in order to adapt it to particular applications for teaching golf.