The present invention relates to the field of sports equipment and more particularly to a sports ball launcher for use in practice of games that utilize an inflated ball, including basketball, volleyball and soccer.
Many basketball players devote substantial time to practice activities, sometimes in groups or pairs, but often alone so that practice is normally limited to aspects of the game that do not require the presence of another person, e.g. dribbling and making hoop shots. Activities such as catching high passes and rebounds and face-off jumping normally require the presence and participation of at least one other person besides the player(s), e.g. a player or coach to throw the ball. Two players practicing face-off jumping require a third person to make a fair toss.
U.S. Pat. No. 5,575,482 discloses a SPORTS BALL LAUNCHER for basketballs, powered by elastic propulsion bands and features a two-wheeled cart and a ball-loading trough from which sequential launching can be automatic or manually controlled.
U.S. Pat. No. 4,164,928 discloses a BASKETBALL TOSSING DEVICE that is hand-held and thus is not practical for solitary practice U.S. Pat. No. 221,694 discloses a Spring-Trap for Throwing Target-Balls (volleyballs) vertically, that can be triggered remotely by a trip line.
These and other ball launchers of known art are less than satisfactory for solitary practice: upon initiating the launch manually (including the first launch in an automatic series) the player would not have sufficient time to move into place and get properly set for a jump, therefore satisfactory practice with such launchers would require the presence of another player or assistant to initiate the launching.
It is an object of the invention to provide a launcher for practicing basketball, or other inflated ball game such as volleyball, that can be controlled by a player in a manner to launch a ball conveniently and consistently without impacting the quality of the practice or the fairness between two players and without requiring the services of an additional person besides the player(s).
It is a further object to arrange for the player(s) to be allowed adequate time to get set in place for a launch.
It is a further object to enable the player to make pre-launch adjustments affecting the trajectory of the ball with regard to maximum height and landing distance offset from the ball launcher.
The objects of the present invention have been met in a ground-based inflated ball launcher, intended for solitary or one-on-one player sports practice, that provides an impulse of force that launches the ball upwardly in a trajectory of pre-adjustable velocity and angle of vertical inclination so as to obtain a desired maximum height and landing distance offset from the launcher. An adjustable timer allows a player to initiate a launch with enough time delay to then move into place and get set before the actual launch of the ball. In a preferred embodiment, the launch is powered by decompression of a coil spring that becomes compressed for loading by the user foot-pumping a treadle pad.
A timer module 18, attached to tubular member 16 near its upper end, is equipped with a knob 18A for setting a delay time for delayed launch and a pushbutton 18B for triggering an immediate launch.
A hinge joint assembly 20 includes two mating portions: upper portion 20A extending up into the lower end of upper tubular member 16 and lower portion 20B extending down into the upper end of lower tubular member 22. Portions 20A and 20B are seized together firmly by tightening clamp knob 20C, which can be released and re-tightened to reset the inclination of upper tubular member 16 relative to the vertical orientation of lower tubular member 22.
Hinge joint 20 is designed to limit the maximum angle of inclination available so that there is no risk of upsetting the launcher 10 off its base 24.
The lower end of lower tubular member 22 engages hub 24A of a reinforced circular base 24 which is made sufficiently large in diameter, e.g. 14 inches, to provide overall stability of launcher 10.
A treadle pad 26, mounted on an arm that extends through a vertical slot 24B in hub 24A of base 24, enables a user to load the launcher 10 by reciprocating foot-pump action on treadle pad 26. The extending arm is configured with a hinge 26A, located near hub 24A, by which the treadle pad 26 can be folded upwardly when not in use, for purposes of personnel safety.
Also, for purposes of safety, in addition to making ball-holder 14 and base 24 from resilient material, harder surfaces such as tubular members 16 and 22, and the underside of treadle pad 26 are preferably covered with soft foam material.
Ball holder 14 is attached to the upper end of tubular member 16, preferably in a threaded manner as shown, and is configured with a resilient circular membrane 14A in the region immediately beneath ball 12, through which the ball 12 is impacted for launching. Membrane 14A serves to keep dirt and debris out of the interior of launcher 10 and to avoid any damage to ball 12 when launched, thus membrane 14A must be made sufficiently durable to withstand repeated launchings yet resilient enough to provide sufficient transfer of energy to the ball 12.
Shown in place in
The plunger core assembly 28 moves as a whole in a longitudinal, i.e. substantially vertical, work stroke in which vertical movement of rods 28A and 28E (
Unidirectional hold/release module 32 is securely fastened inside tubular member 16 near its upper end. A steel hold/release grip plate 32A is constrained at its right hand end by an overhead fulcrum and is configured at its left hand end with a drive arm that extends into timer 18 through vertical slot 16A configured in the wall of member 16. Grip plate 32A is held in a “floating” manner along with an associated steel coil spring 32B beneath, in a metal shell 32C which is securely fastened to upper tubular member 16.
A main steel coil spring 30 is located within tubular member 16, bearing against coil drive collar 28C at the upper end and supported at the lower end on upper hinge portion 20A, which is configured with a central clearance bore which is dimensioned to guide the lower end of upper plunger rod 28A, and flared to a larger bottom opening to accommodate link 28D for different angles of inclination as set by hinge joint 20.
A central clearance hole in plate 32A is dimensioned for a close clearance fit rod 28A so that when plate 32A is inclined away from perpendicular to rod 28A as shown, urged clockwise by upward bias of spring 32B and fulcrum constraint at the right hand end, the edges of the central clearance hole of plate 32A exert a strong binding friction action on rod 28A that prevents any upward travel of rod 28A. This binding friction action is positively re-enforced: it actually intensifies as the spring 30 become further compressed and the required holding force increases. However, following launching, with the coil holding force removed, plate 32A repositions slightly counterclockwise so as to release the grip on rod 28A and allow the plunger assembly 28 to travel downwardly as required in the re-loading pump strokes.
Recoil spring 36, resting on the top side of coil support collar 28F of rod 28E, with its top end constrained against the bottom end of hinge portion 20B, is relatively weak, serving to stabilize lower plunger rod 28E against overshooting during the launch stroke and ensuring that, after launching, plunger assembly 28 returns to its proper location in the unloaded condition as shown in
A unidirectional loading grip module 34, located and securely fastened in the lower end portion of lower tubular member 22 within hub 24A includes a pump grip plate 34A held in the horizontal position shown against the lower side of a solid bulkhead collar 34B by a coil spring 34C which is supported on a portion of base 24. Bulkhead collar 34B is securely fastened to tubular member 22 and is configured with a central clearance hole that guides the upper end of lower rod 28E whose lower end is guided and constrained in a clearance hole configured in base 24 as shown. With pump grip plate 34A located horizontally as shown, its central clearance hole allows lower rod 28E to move freely up or down; however rod 28E is held in the upward location of the plunger core assembly as shown by link 28 due to light force from main coil spring 30 which is at or near in its full length in this unloaded condition, holding upper rod 28A in this upward location via coil drive collar 28C.
The pump drive grip plate 34A extends through a vertical slot 24B configured in hub 24A and in lower tubular portion 22, and is coupled by a hinge joint 26A to treadle pad 26, whose lower side is covered with a foam layer 26B.
As the plunger core assembly moves downwardly, in the hold/release grip module 32, hold/release grip plate 32A, rotating slightly counterclockwise as shown, indicated by the small separation from pushbutton 18B seen in timer 18, allows the upper rod 28A to move downwardly, pulled down by link 28D in response to downward movement of lower rod 28E as driven by grip plate 34A from foot pressure on treadle pad 26.
When the foot is lifted from treadle 26 for another pump stroke, the treadle 26 and pump grip plate 34A will be automatically returned to their uppermost position (as seen in
At this stage, a weak launch could be performed by actuating timer 18 or pushbutton 18A; however, more typically, further pumping will be performed via treadle 26, repeating the pump stroke cycle described above in connection with
After the launcher 10 has been loaded to the desired launch strength, launching is executed by actuating timer 18 or pushbutton 18A: depression of the extending arm of hold/release grip plate 32A releases upper rod 28A and thus releases the plunger core assembly to travel rapidly upward as driven by the force of spring against collar 28C so that drive head 28B launches the ball 12 upwardly by striking membrane 14A.
As shown separately in the side view of
Pump grip plate 40A is actuated by a connector link 44 which is driven by a lever system at the bottom including treadle 26 connected by hinge 26A to a pump lever arm 46 whose right hand end is pivoted to the right hand side of lower tubular portion 22 and base hub 24A by a hinge or fulcrum constraint. This arrangement provides leverage gain at the treadle 26, and thus can br designed to operate at reduced pumping force and increased length of vertical pump stroke compared to the direct pump drive in launcher 10.
Apart from the differences described above, the remaining structure of launcher 10A and the loading and launching procedure are essentially the same as described above in connection with the first implementation: launcher 10 (
Path 46 represents the parabolic trajectory of ball 12 when launched at an angle a of inclination from vertical, 5 degrees as shown, and Y represents the maximum height of path 46.
In the following calculations, the effect of air friction on the ball is neglected as negligible, apart from the potential influence of wind.
For simplification, instead of referencing to ground level, calculations are referred to the elevation at the top end of the launcher 10, typically 4 to 5 feet above ground which is about shoulder-level of player 48. Thus, for Y=30 feet, the actual height would be 34 to 35 feet above ground level.
The reduced height due to inclination Y/Yv can be calculated from Yv*cos(a), this relatively small: about 3.5% for a=15 degrees and proportionately less for smaller angles.
It is of particular interest to the user to be able to estimate the horizontal distance X of the ball landing point from the launcher 10 as a function of maximum height Yv. This can be estimated from X=4*Yv*sin(a): thus for Yv=30 feet and a=5 degrees, X=10.46 ft., a reasonable working distance.
The airborne time period can be found from the calculus-derived basic rule of gravity for a falling body, Y=−(g/2)*t^2 =−16*t^2, the one-way time, which is the same for the up path as for the down path, can be calculated as t=(Y/16)^−2: for this example t=1.37 seconds, thus the total airborne time is 2*t=2.74 seconds.
The horizontal velocity can be calculated by first calculating the “muzzle velocity” from Vm=g*t: for this example 32*1.37=43.84 ft/sec i.e. 29.88 mph, from which the horizontal velocity can be calculated: Vh=Vm*sin(a), i.e. Vh=3.82 ft/sec (2.6 mph) for this example.
This indicates that the influence of wind must be considered mind since a 3 mph wind is roughly equivalent to a 5 degree inclination, and could substantially double or nullify the effect of the 5 degree inclination, depending on the wind direction.
In the above described implementations, the friction gripping principle for driving a rod, including a pump module and a hold/release module, each utilizing a tilted grip plate with a central binding hole and typically spring-loaded, is known and used in common apparatus such as caulking guns for its ability to drive a rod longitudinally with a pumping action in a simple and economical manner. Also a similar form of hold/release module is utilized as an adjustable stop that fits onto a pipe member of a utility clamp system. It is well known that this principle of positively re-enforced frictional uni-directional binding action can be utilized with many different locations and arrangements of the two modules anywhere along a working region of the rod as alternatives to the particular locations and arrangements described above and shown in the drawings.
Unidirectional drive functions for pumping and hold/release can also be accomplished by application of principles other than frictional binding, through the use of standard mechanical apparatus such as ratchet gears with spring-loaded pawls, rack-and-pinion arrangements, and the like, however such implementation would tend to be substantially more costly.
As an option, the invention could be practiced in simplified manually-launched embodiment wherein timer 24 is omitted and launching is initiated by simply depressing an extending portion of the grip plate of the hold/release module as the manual launching control.
An electrical actuator coupled to the extending release arm of grip plate 34A would open the possibility of utilizing wired or wireless remote control, with or without the provision of a timer.
As an alternative to a mechanical timer, electrical implementation would work in conjunction with an electrical actuator and could indicate delay time on a numeric readout. Alternatively the time delay could provided by other methods such as hydraulic or pneumatic.
As an alternative or supplement to spring 32, motive force for launching could be provided pneumatically, hydraulically or electrically by adapting known technology. Thus the need for manual pumping could be eliminated or minimized, and other methods of adjusting the force and resulting ball height would be facilitated.
As an alternative to loading by foot-operated treadle as described above, a hand-operated pump could be provided to operate in a similar manner: a pump handle could be mounted at a convenient height at a chosen location on the tubular body of the launcher and coupled directly, or by internal or external linkage to the pump grip module.
As alternatives to hinge joints 20 or 42 as shown above, a locking or high friction ball joint could be employed, or a “gooseneck” arrangement with stiffly flexible corrugated tubular construction for at least some portion of the main tubular body.
There are additional variations utilizing hand, foot or powered loading with which the invention may be practiced.
Instead of utilizing the compressed condition of the coil spring to store energy for launching, the stretched condition could be utilized, either with a coil spring or other commercially available stretch cord.
The invention may be embodied and practiced in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description; and all variations, substitutions and changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
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4164928 | Meares | Aug 1979 | A |
5462285 | O'Patka et al. | Oct 1995 | A |
5597160 | Mims | Jan 1997 | A |
5800288 | Mims | Sep 1998 | A |
6019096 | Snyder et al. | Feb 2000 | A |
6843241 | Newcomer | Jan 2005 | B1 |