Near zero inertia pendulum golf swing trainer Swinky™

Description

BACKGROUND OF THE INVENTION

Prior art disclosed in the inventor's U.S. Pat. No. 5,474,299 golf swing trainer was incorporated into a machine that the inventor field-tested through several top-100 PGA golf instructors. It had a hefty twenty-pound pedestal with four hollow, 1-inch square steel leg, articulated by clamp knobs. It carried a ½-inch square hollow steel mast, and ½-inch diameter hollow fiberglass single-arm rotor eighteen inches long. Its initial rotor to club tether was ⅛-inch nylon twine looped about the bottom of the club grip. Rotor inertia was so great that its tip whipped around chaotically in six-inch orbits of its own when the rotor tip was whirled by hand at the speed of a typical golf swing. On one occasion, the rotor was attached to a club swung by an unskilled golfer and the whipping force that ensued was large enough to bend the rotor's ⅜-inch diameter steel axle and mast. Even by restricting its use to slow-motion swing training, rotor inertia was such that at the top of the backswing in full swings the golf club would be jerked sharply and the mast and pedestal would rock chaotically. Clearly a golfer using the trainer on his own could not rely on the machine's reactions to see or feel where his swing was defective.

The machine was redesigned and restricted for putting speed use with a ¼-inch diameter fiberglass rod connecting the rotor tip to a fixture that held the club grip. It proved to be excellent for demonstrating pendulum putting strokes, etc., to onlookers but was too invasive for anyone hoping to develop superior putting skill by holding the club in common with the machine.

A second machine followed with an 18-inch-long rotor of ½-inch diameter thin wall aluminum tubing atop the mast of a vertical tripod with spiked feet designed to be planted into turf. It was test-marketed as the Swing Boom™ by the inventor. A ¼-inch diameter solid glass fiber rod cantilever that had a swiveling club holding fixture connected the rotor tip to just below the club grip. In normal-speed swings, excessive inertia, torque, and bending moment arising from its rotor/club grip connection masked serious golfer error. After a few swings, the machine's spiked feet worked their way out of the ground and had to be replanted. When a nylon line replaced the fiberglass rod connection to the club shaft, the inertia problem was alleviated, but to no avail. It became obvious that the connection between rotor and club shaft was so unspecific that it could not help average golfers get the knack of keeping full control of the club throughout a swing. Lengthening of the rotor so the tether could squarely link the rotor tip to the neck of the club shaft failed to alleviate that problem because rotor inertia problems worsened. Addition of a second arm to balance the rotor also failed to make a useful stand-alone swing trainer.

The Swing Boom device, its predecessor cited above, and their rotor-based cousins of prior art all fail to fulfill their promises because of similar flaws. Either their swing guidance is too vague or the excessive inertia of their rotor/club linkage creates large false swing error signals that mask the struggling golfer's own errors. In heavy robotic machines that provide a club grip for the golfer to hang on to throughout the swing, or where the swinging club rests on a surrounding surface, the golfer typically fails to learn enough to reproduce the swing away from the machine.

The trainer of this invention evolved from years of personal trial and error experiences cited above. In a flash, Swinky™ conveys the essence of the advice, “Turn and wind up your torso in the backswing so the center of mass of the club automatically gets flung back close to its starting position through impact, at a tangent to the target.”

It imparts that skill effectively. Its pendulum swing logic conveys the very essence of the golf swing to its user. It does so by deftly skirting the flaws, limitations, and insurmountable communication problems of prior art devices and of many teaching pros whose students avoid them like the plague after a few lessons. Its 3D guidance is continuous as though the golfer and club were framed within a dynamic hologram.

The invention offers the golfer a nearly weightless, visually graphic string bridge, one end of which is anchored to the center of mass of the club and the other to the tip of a rigid, long, very light pendulum arm. The bridge and pendulum arm thereby react instantly to the swing. That direct visual and audio feedback is complemented by the swing-dependent reactions of the device's mast and tripod. Swinky™ lets the golfer really see, feel, and hear how to swing his club properly.

Swinky™'s novel features are:

• • 1. Its ultra-stiff carbon-fiber pendulum arm (10). It is virtually inertia-free, compared to a golf club that typically weighs ten ounces, by virtue of its slight 0.4-ounce weight and swing period close to two seconds, similar to that of a golfer's short irons.
  • 2. Its offset pendulum bob comprised mainly of the typical ten-ounce weight of the golfer's club, (concentrated at the club's center of mass, close to the neck of the club shaft) complemented by the negligible 0.1-ounce weight of the bob's visually graphic thirty-by-four-inch rectangular bridge made of taut strings.
  • 3. Loss of the bob bridge's rectangularity instantaneously signals swing flaw.
  • 4. If the carbon-fiber pendulum arm discovered by chance by the inventor and disclosed herein is replaced by a solid thirty-inch long and 3/16-inch or ¼-inch diameter glass fiber rod, the latter's inherent flexibility and high inertia during fairly good swings is excessive enough to mask swing errors that frustrate lower-handicap golfers.
  • 5. If only one line is used to link the pendulum and club shaft, swing guidance is ineffective.
  • 6. Use of light carbon-fiber for the pendulum arm is vital; light aluminum arrow shafts are unsafe because they are prone to fatigue and soon snap and fail disastrously.
  • 7. The swing period of Swinky's pendulum arm is akin to that of a golf club dangling by its handle in a golfer's hands. Consequently, all the golfer needs to do to swing with proper tempo is keep the rectangle intact. Proper swing tempo and stunning ball striking power and accuracy go hand in hand.
  • 8. Air speed whistling of the rectangle reflects club head speed.
  • 9. The tripod elements (1-9, 14, 15) hold the pendulum aloft on its mast right in front of the golfer with failsafe stability even on smooth concrete. The tripod has a built-in recoil-suspension system stemming from the firm hinge point and wide, adjustable horizontal span of its three legs (4-6) and vertical, rubber-tipped feet (1). These tripod features derive from overlapping the tripod's two hinged legs (5, 6) at their hinge point (15) under the neutral leg (4) without free play in the hinge (15). Essentially this feature allows the golfer to advance swing skill by presetting tripod stability without compromising safety.
  • 10. Steadiness of the tripod and mast confirms good swing technique. Rocking signals flawed swings.

SUMMARY OF THE INVENTION

The invention is a near zero inertia pendulum golf swing trainer that lets its user and onlookers see, feel, and hear how to swing a standard golf club properly.

It is made of a hinged assembly of hollow half-inch-square metal tubes. The trainer weighs about six pounds in the steel version, just two and a half pounds if of aluminum. Both versions erect without tools (FIG. 10) to form a three- to four-foot tall structure upon a tripod base.

Trainer logic is based on near zero inertia, pendulum swing guidance system that has three key elements:

• • 1. A highly flex-resistant, near zero inertia, thirty-inch long hollow carbon-fiber gravity pendulum arm (10), hung from a ¼-inch diameter metal axle atop a mast (8, 9) inclined at the lie angle of the golfer's chosen club (12). The mast support (7) is stepped upon the dual pivoting legs (3) and slider (2) of the neutral leg (4) of a tripod. Two legs (5, 6) of the tripod hinge open. They may be preset parallel to the ball-target line for better players or be angled out toward the golfer for beginners. Alternatively, the mast and pendulum can be inverted for greatest stability, with the pendulum overhanging neutral leg (3) of the tripod.
    • Mast height is set so the top of the pendulum will be chin-high in the golfer's address position (8). For pendulum putting, the mast can be set vertical. Pendulum motion then serves for gravitational swing tempo.
  • 2. The bridge (11) of the pendulum bob is made of a pair of light, thirty-inch-long strong strings. The strings at one end of the bridge are anchored to the tip of the pendulum arm (10). The pendulum is completed by anchoring the strings at the other end of the bridge to the neck of the club shaft (13) with the bridge lines just taut so the bridge rectangle spans the gap between club and pendulum arm in the golfer's address position. Thus completed, the bridge is an ideal swing guide consisting of a visually graphic, thirty-by-four inch airborne rectangle of negligible weight and inertia compared to the golf club. If the bridge lines become twisted together, they form only the short sides and diagonals of that rectangle. To acquire great ball-striking skill, the golfer adjusts his swing action to maintain that rectangle shape, preferably throughout the swing. If the golfer finds that for whatever reason he cannot maintain the rectangular shape during his swing, he can still find success by creating the rectangle at the bottom of his swing. Distortion of the rectangle is a strong signal that the golfer has lost circular motion control of the club head at that point. The pendulum arm should swing sweetly without tugs including at the transition from backswing to downswing. Air whistling over the lines reflects club head speed.
  • 3. The tripod's two hinged legs (5, 6) can be hinged toward the golfer if faulty swing habits make the mast and tripod rock. Bringing the hinged legs parallel to the ball target line decreases tripod stability, a safety feature that can be lessened experimentally, to test and advance swing skill. For greatest stability, the pendulum mast (9) can be removed, rotated 180 degrees, and replaced followed by inverting the mast support via its slider so the pendulum arm overhangs the foot (1) of the tripod's neutral leg (4).

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective depiction of the invention, Swinky™, the near zero inertia pendulum golf swing trainer set up and linked to a golf club for use by a nice golfer. Arrows indicate adjustability of its components.

(1) The 5/16-inch diameter 1.5-inch tall vertical rubber-capped foot of the free end of each of the tripod's three horizontal legs (4, 5, 6).

(2) The mast angle support slider, integral to tripod neutral leg 4, preset parallel to the lie angle of the club.

(3) The 15-inch-long dual leg pivot assembly. It buttresses the tripod mast support (7) from opposite sides of the nose (15) of leg 4.

(4) The 27-inch-long, 0.5-inch square hollow neutral leg of the tripod.

(5) The 24-inch-long, 0.5-inch square hollow left leg of the tripod.

(6) The 23-inch-long, 0.5-inch square hollow right leg of the tripod.

(7) The tripod hollow mast support (27 inches long by 0.5 inches square) preset parallel to the club shaft. The hinge point of the mast support is ten inches from mast slider (2).

(8) The pendulum mast height-adjustment device.

(9) The 34-inch-long, 0.5-inch square hollow pendulum mast, set to match the height of the golfer's chin at address.

(10) The 0.4 ounce, 3/16-inch outside diameter, ⅛-inch interior diameter hollow thirty-inch-long carbon-fiber pendulum arm hung by its hub/mast axle (14) atop the tripod mast (9, 8, 7).

(11) The heart of the pendulum bob. Its near-weightless visually graphic bridge, a thirty-by-four inch rectangle formed of taut, stretch-resistant thread of 1/16 inch gauge mason's twine at swing address position. One narrow end of the bridge is anchored on the neck of the club shaft (12), the other on the tip of the pendulum arm (10), thus completing the trainer pendulum.

(12) The golf club in its address position. Its lie angle determines mast angle.

(13) The end of the pendulum bob bridge anchored to the neck of the club shaft (12), for example by a noose at the end of each of its two lines separated by a spacer.

(14) The pendulum axle atop the mast (7-9).

(15) The overlap of tripod legs (4, 5, 6) at their hinge point.

DETAILED DESCRIPTION OF THE INVENTION

The invention is a near zero inertial pendulum-based golf swing trainer. Folded up it is about the size of a golf umbrella. It can be unfolded and set up without tools in seconds. Its swing guidance logic is designed to let a user clearly see, feel, and hear how to swing his golf clubs expertly.

See FIG. 1. The top of a mast (14) is preset to be chin-high in front of a golfer. The mast is held aloft by a tripod so the mast is parallel to the shaft of the club the golfer will swing. Atop the mast is the pendulum axle (14) from which swings a pendulum arm (10). It is an extremely rigid 3/16-inch-outside diameter-⅛ inch inside diameter and thirty-inch-long carbon-fiber arrow shaft weighing 0.4 ounces. Consequently the pendulum arm has negligible swing inertia compared to the golf club. The swing period of both the pendulum arm and club is about two seconds.

The pendulum bob bridge rectangle (11) is a pair of thirty-inch long lines of mason's twine that provide graphic visual feedback. Their respective ends are anchored four inches apart, one end anchored on the tip of the pendulum arm, the other on the neck of the club shaft. The golfer completes the pendulum bob by adjusting his swing address position so that the bridge becomes a rectangle with its lines barely taut and free of twist. The bridge rectangle remains unaltered as long the golfer's swing is ideal, namely a circular motion congruent with the longitudinal axis of the mast axle.

Distortion of the rectangle and lurching of the trainer's tripod base signal the onset of a faulty swing move, so all the golfer has to do to swing properly is keep the rectangle whole, whereby the tripod and mast remain steady.

Five thirty-inch-long, ½-inch-square sections of hollow tubing of 0.065-inch wall thickness of either steel or aluminum are preassembled so that each hinge point of the trainer will remain snug for the trainer's useful life. The trainer has a total weight of about six pounds if made of steel or two and a half pounds if made of aluminum. Each section is drilled, bolted to its mate, and the bolts welded, thus forming the snug hinges (2, 3, 7, 15) behind the mast support (7) and tripod's built-in spring suspension system (1, 2, 5, 6, 15).

A key feature of that suspension system is the overlap of the tripod legs (5, 6) at their hinge point (15) under the nose of the third leg (4). Mast slider (2) is machined or injection-molded of acetal resin or equivalent, which can also serve to make the pendulum hub.

A 0.4-ounce carbon-fiber, Kevlar™-fiber, or boron-fiber arrow shaft ( 3/16-inch outside diameter, ⅛-inch inside diameter) thirty inches long (9, 10) with one end anchored through its hub made of ½-inch diameter aluminum tubing of 0.065-inch wall thickness, mounted to mast axle (14) at the top of mast (7, 8, 9) makes the preferred pendulum. The pendulum hangs by its hub on a 0.25-inch diameter brass axle that pivots through the top of the thirty-inch-high mast.

Nylon mason's string makes the pendulum bob bridge with noosed ends for anchorage to club and pendulum arm, four inches apart.