CA1079764A - Propulsion device for tennis balls and like spherical objects - Google Patents
Propulsion device for tennis balls and like spherical objectsInfo
- Publication number
- CA1079764A CA1079764A CA279,186A CA279186A CA1079764A CA 1079764 A CA1079764 A CA 1079764A CA 279186 A CA279186 A CA 279186A CA 1079764 A CA1079764 A CA 1079764A
- Authority
- CA
- Canada
- Prior art keywords
- drum
- trap door
- objects
- distributor
- spherical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B69/00—Training appliances or apparatus for special sports
- A63B69/40—Stationarily-arranged devices for projecting balls or other bodies
- A63B69/409—Stationarily-arranged devices for projecting balls or other bodies with pneumatic ball- or body-propelling means
-
- A—HUMAN NECESSITIES
- A63—SPORTS; GAMES; AMUSEMENTS
- A63B—APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT
- A63B69/00—Training appliances or apparatus for special sports
- A63B69/40—Stationarily-arranged devices for projecting balls or other bodies
- A63B2069/401—Stationarily-arranged devices for projecting balls or other bodies substantially vertically, e.g. for baseball
Abstract
A B S T R A C T
A population device is provided, designed especially for discharging tennis balls for practice purposes, at selected angles of inclination, and at a predetermined, selected velocity. Employed in the device is a distributor, which is disposed between a hopper and an air pressurizing drum, the distributor being designed to feed balls, one at a time, to the drum, at predetermined intervals.
Within the drum, the ball is directed into a receiving tube, being impelled forwardly therein responsive to the build-up of air pres-sure within the drum. Each ball is temporarily arrested by a radially expandable detent, until the pressure in back of the builds up to a predetermined value. The ball is thus caused to be freed from the detent, and propelled forcibly out of a barrel dis-posed at an adjusted angle of inclination.
The distributor is disposed between the hopper and drum in such fashion as to cause the spherical objects to be efficiently agitated within the hopper, by passage over the exteriorly cylin-drical surface of the drum while moving to the point at which the objects feed into the drum. Efficient agitation of the spherical objects within the hopper thus assures to the maximum extent that the distributor will be full charged with said objects.
A trap door, normally closed by air pressure within the drum, is moved with maximum speed to an open position responsive to the free fall of the a spherical object from the distributor into the drum, and moves with equal speed back to a closed position.
By holding the open time of the trap door to a minimum, it becomes possible for the device to be interiorly constructed with a simple receiving pipe characterized by an absence of annular induced air flow assemblies and other arrangements which have heretofore been employed.
A population device is provided, designed especially for discharging tennis balls for practice purposes, at selected angles of inclination, and at a predetermined, selected velocity. Employed in the device is a distributor, which is disposed between a hopper and an air pressurizing drum, the distributor being designed to feed balls, one at a time, to the drum, at predetermined intervals.
Within the drum, the ball is directed into a receiving tube, being impelled forwardly therein responsive to the build-up of air pres-sure within the drum. Each ball is temporarily arrested by a radially expandable detent, until the pressure in back of the builds up to a predetermined value. The ball is thus caused to be freed from the detent, and propelled forcibly out of a barrel dis-posed at an adjusted angle of inclination.
The distributor is disposed between the hopper and drum in such fashion as to cause the spherical objects to be efficiently agitated within the hopper, by passage over the exteriorly cylin-drical surface of the drum while moving to the point at which the objects feed into the drum. Efficient agitation of the spherical objects within the hopper thus assures to the maximum extent that the distributor will be full charged with said objects.
A trap door, normally closed by air pressure within the drum, is moved with maximum speed to an open position responsive to the free fall of the a spherical object from the distributor into the drum, and moves with equal speed back to a closed position.
By holding the open time of the trap door to a minimum, it becomes possible for the device to be interiorly constructed with a simple receiving pipe characterized by an absence of annular induced air flow assemblies and other arrangements which have heretofore been employed.
Description
~0~9~71~4 BACKGROUND OF THE INVENTION
1. Field of the Invention ;~
The invention relates generally to devices that propel forcibly, into the air, spherical objects such as tennis balls or the like, in selected, adjusted trajectoriesr for practice or training purposes.
1. Field of the Invention ;~
The invention relates generally to devices that propel forcibly, into the air, spherical objects such as tennis balls or the like, in selected, adjusted trajectoriesr for practice or training purposes.
2. Description of the Prior ~rt It is well known to provide propulsion devices for tennis balls and like spherical objects. It is also known to employ a ~ ;
pressure build-up, within a chamber to which the tennis balls are fed, in such fashion as to cause the tennis balls to be forcibly propelled from a barrel located at a selected angle of inclination, after being temporarily arrested by a detent within the barrel. In the prior art, ~hus, it h~s been well known to cause automatic feeding o the tennis balls to the drum or pressurizing chamber, with the intention of causing the balls to be propelled at pre-scribed, uniform intervals. Such devices as have heretofore been conceived for this purpose, however, have in general been compara-tively expensive, and despite the relative complexity and expen-2a siveness of construction thereof, have been unfortunately charac-; terized, in many instances, by a lack of full efficiency. Thus, in some instances the feeding of the tennis balls has been irregular, in that the time feeding devices, employed for the purpose of feeding the tennis balls into the pressurizing drum, have not operated in such fashion as to be completely charged or loaded with tennis balls as they approach the ball feeding position.
It has further been a characteristic of the prior artthat complex mechanisms have been needed within the drum, as for example, it has been characteristic of tennis ball propulsion
pressure build-up, within a chamber to which the tennis balls are fed, in such fashion as to cause the tennis balls to be forcibly propelled from a barrel located at a selected angle of inclination, after being temporarily arrested by a detent within the barrel. In the prior art, ~hus, it h~s been well known to cause automatic feeding o the tennis balls to the drum or pressurizing chamber, with the intention of causing the balls to be propelled at pre-scribed, uniform intervals. Such devices as have heretofore been conceived for this purpose, however, have in general been compara-tively expensive, and despite the relative complexity and expen-2a siveness of construction thereof, have been unfortunately charac-; terized, in many instances, by a lack of full efficiency. Thus, in some instances the feeding of the tennis balls has been irregular, in that the time feeding devices, employed for the purpose of feeding the tennis balls into the pressurizing drum, have not operated in such fashion as to be completely charged or loaded with tennis balls as they approach the ball feeding position.
It has further been a characteristic of the prior artthat complex mechanisms have been needed within the drum, as for example, it has been characteristic of tennis ball propulsion
3~ devices that air flow is induced into the discharge tube or barrel, through an annular chamber surrounding the barrel, a construction which has been made necessary due to excessive open time for the trap door or similar closure located at the entrance to the presY
surizing drum. ~
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Typical of ~he prior art devices is th~ proRulsion device shown in Nielsen Patent 3,905,349 issued Septen~er 16, 1975.
SU~IMAR~ OF THE INVENTI~
The invention in one aspect provides in a pxopulsion device for spherical objects, of the type including a discharge barrel, a communicating drum in which air pressure i9 built up behind each of said objects for propelling the same orcibly from the barrel, and a trap door normally closing and opening into said drum by air pressure within the drum, the improvement comprising:
means mounting the trap door and defining said opening in-to said drum so that a spherical object fed into the drum through said opening will build up kinetic energy while in free fall vertically ~downwardly through said mounting means into the drum to a:n extent e~Eecti~te to momentarily bias the door to a substantially vertical op~nposition while said object is still in free~ fall; said trap door, in so opening momen-tarily inhibiting free fall of the spheri-cal object, and means within thè drum to which said object, while .
regaining substantially free fall, will gravitate clear of the trap door, so as to permit an immediate return of the trap door to a closed position free of any restraint imposed thereon by thespherical object.
In ~ preferred form the apparatus includes an elongated drum disposed when in use at a position slightly inclined from the : horizontal, and formed to a circular cross-section in a preferred embodiment. Above and in closely spaced relation to the drum is a hopper designed to receive a large supply of tennis balls or like spherical objects intended to be propelled from the device. A dis-tributor is mounted for rotation in the bottom of the hopper, and includes an annular series of ball feed sleeves, extending about the axis of rotation of the distributor in such fashion as to cause , each ball feed sleeve to move into position over a ball feed open-ing formed in the top of the drum. The distributor is rotated at a selected, relatively slow rate of speed, and in accordance with the invention anti-bridging and agitating means is incorporated in ~0'~6~
the distributor within the hoppe~, to aid in preventing the b~lls from lodging in a static position in which they will not feed, one after the other, into successively following openings provided in the ball feed sleeves of the distributor.
Further summarized, the apparatus has a gravitational ;
feed pipe closed at its lower end by a trap door that is normally retained in closed position by a built-up air pressure within the drum or pressurizing chamber. The kinetic energy of a ball having free fall through -the feed pipe or tube in effect snaps the door -to open position, but only for an instant, because the ball falls freely past the trap door to an inclined ramp, in such a way as to almost instantaneously clear the door so that the door can be re-turned with equal speed to its closed position by the air pressure within the chamber.
The ball rolls clown the ramp to a receiver t~be, beinc~
moved therealong by air pressure building up in back o~ the ball, until the ball is temporarily arrested by a rubber detent which per se is known in the art. When the pressure within the chamber in back of the ball builds up to a predetermined value, the ball is forcibly discharged through the barrel, which is adjusted to a selected angle of inclination before the propulsion device is placed in operation.
BRIEF' DESCRIPTION OF THE DRAWI~GS
Figure 1 is a view o~ a propulsion device according to the present invention~ partly in side elevation and party in lon-gitudinal section, the barrel being shown in full and dotted lines in typical positions to which it can be adjusted;
Figure 2 is an enlarged, transverse sectional view, sub-stantially on line 2-2 of Figure l;
Figure 3 is a fragmentary, horizontal sectional view, substantially on line 3-3 of Figure 2;
Figure 4 is a front end view of the device, as seen ~rom 7976~
the line 4-4 of Figure li Figure 5 is an enlarged, fragmentary longitudinal sec-tional view substantially on line 5-5 of Figure 4, showing the detent as it appears prior to engagement of the same by a ball that is to be propelled from the barrel;
Figure 6 is a view similar to Figure 5, in which the detent is shown in position arresting a bal]., the ball being shown in dotted lines;
Figure 7 is a perspective view of the distributor per se;
Figure 8 is a sectional view taken diametrically through the distributor, substantially on line 8-8 of Figure 7; ~and Figure 9 is an exploded perspective view of the barrel support plates, DESCRIPTION OF TEI~ PREFERRED EMBODIMENT
My ball propulsion dev.ice 10 includes a cylindrical large diameter housing or pressurizing chamber 12 of circular cross-section, supported above the ground or other supporting surface S in a position inclined a few degrees from the horizontal through the provision of front and rear, U-shaped support legs 14, ; 20 16 respectively disposed in embracing relation to the chamber 12 and riveted, bolted, or otherwise secured to said chamber as at 18. The side portions of -the U-shaped support legs 14, 16 project upwardly above housing or chamber 12, in embracing relation to an elongated, generally rectangular hopper 20, to which the supports are riveted or otherwise fixedly secured at 22. Hopper 20 is formed wholly open at its top, to receive a large supply of tennis balls B. The front end of the hopper is provided with a screen 23, mounted in position to retain a sound-deadening ma-terial in an air intake chamber to be described hereinafter.
3a Mounted within housing 12, intermediate the opposite ends thereof, is a gear motor 24, secured fixedly to the top portion of housing 12, and having a stub shaft 26 projecting ' ', . . . ..
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upwardly to engage, far rotatiQn with the stub shaft, a depending ~;
hub 27 of a distributor 28 preferably formed as an integral, molded plastic member to include a centrally disposed, upstanding, hollow, large diameter boss or projection 30 extending upwardly ~-within the hopper to prevent "bridging" of balls within the hopper and formed with uniformly, angularly spaced~ longitudinally ex-tending, radially projecting agitator ribs 32. Projection 30 is, made hollow to promote economy in molding, and to increase light~
ness of the distributor, but in use the hollow center is closed by a cap 34. The distributor projection 30 extends upwardly into the hopper in concentric relation to an opening 35 formed in the bottom of the hopper for receiving the distributor, and when rotated during operation of the gear motor will agitate the balls contin-uously and will prevent bridging thereof, to assure that they will fall into the several, uniformly angularly spaced distributor ; sleeves 36 disposed about the projection 30 at the base thereo in a circular pattern, and located (Figure 1) in an open space 37 defined between the hopper 20 and the pressurizing chamber 12.
Any one or more of sleeves 36 may be closed by removable caps 38.
~ 2Q Referring to Figure 2, disposition of the distributor :! base 39, comprised of the several integrally connected sleeves 36, the full height of the space between the top wall of the drum or chamber 12, locates the base substantially tangentially to the curvature of said top wall. As a result, balls loading into the sleeves contact the curved top surface of the wall of the drum.
As the distributor turns, the balls so loaded are cammed or biased upwardly and downwardly along paths parallel to the distributor axis between high points Bl- and low points B2- respectively, by the curved wall surface of the drum. They may at the same time be 3Q rotated, but primarily, their up-and-down motion in the sleeves causes them to agitate the tennis balls that are above but have not yet reached the distributor. This aids markedly in assuring :
: ., .
. . .
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ayainst "skipping" of distributor sleeves, that is~ increased assurance is provided for the feeding of balls into the drum at the regular intervals for which the machine is pre-set.
Formed in the top portion of chamber 12, between gear motor 24 and the closed rear end of chamber 12, is a feed opening 40, in registration with a depending, open ended, ball feed sleeve 42 fixedly secured to the wall of chamber 12 in position extending substantially vertically downwardly therein in close proximity to the gear motor and the rear end wall of the chamber. Balls B
feeding gravitationally through sleeve 42 drop onto a ramp or feed channel 44 of U-shaped cross-section, declining forwardly toward and fixedly mounted upon the rear end of an elongated receiver tube 46 extending parallel to the longitudinal center line of chamber 12 to the front end thereof, in close proximity to the bot-tom o~ the chamber. A~so aiding in positionin~ the balls B
over the distributor i9 ~ semi-circular back plate 47 Eixedly secured to the back end of the hopper in concentric relation and close proximity to~the distributor.
Hingedly mounted upon the lower end of ball feed sleeve 2Q 42 is a closure 48 free to gravitate to an open position thereof, but moving to a closed position when the chamber is pressurized.
Receiver tube 46, at its front end, is fixedly mounted upon a head end cover 50, formecl to include a flat, circular plate member 52, the inner surface o which is covered by a gasket 54 o~ foam rubber or the like, the periphery of which is compressed between plate 52 and an outwardly directed, peripheral flange 56 formed upon the open, front end of the body of the housing or pressurizing chamber 12. Securing cover 50 to the body of the chamber in sealing relation thereto is an expandable clamping ring 58 which is per se conventional, being of the type comprising a split ring element capable of being contracted radially to its clamping position through the provision of a hinged toggle lever ;
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and link assembly 60 connected between the ends of the split ring of the clamp. `
Close to the fron-t thereof~ receiver tube 46 is provided : -with a peripheral, radially outwardly directed mounting and sealing flange 62, adapted to bear against gasket 54 about a receiver tube mounting opening 64 formed in the gasket and plate constituting cover 50. Sheet metal screws 63 or the like extend through flange 62 and plate 52, compressing gasket 54 between the flange and plate about the mounting opening 64, to sealably secure the tube to the cover 50.
Above tube 46, the cover 50 is formed with an air inlet opening 66/ through which air is drawn into chamber 12 by a blower 68 mounted against the inner surface of the cover 50. An air intake space is def.ined at 70 forwardly oE the air inlet opening 66, between a pair of forwarclly project.ing, approximately trian-gular, transversely spaced, Elat discharge tube mounting p:Lates 72 fixedly attached to cover plate 52. The air intake space 70 is deined through the provision of the plates 72 and a cross plate 73 aEfixed to and extending be-tween said plates 72, the p~ate 73 2a having an air inlet port 74. The enclosed space 70 has a sound deadening effect, and in a commercial embodiment would preferably be lined with a material designed to absorb the sound of the blower motor to the maximum exten-t to promote quietness oE operation of the air propulsion device.
As seen from Figures 5 and 6, a flexible discharge tube 76, which can convenlently comprise a length of corrugated hose or the like, is clamped at 78, at its rear end, to the forwardly projecting end of receiver tube 46 in full communication with the receiver tube. Discharge tube 76, at its front end, projects for-wardly beyond the mounting plates 72/ and at its front end receivesthe inlet end of an elongated~ rigidly constituted barrel 80 opened into communication with discharge tube 76. A pair of identical kut 976~
opposite barrel support plates is provided, each of which includes an elongated part-cylindrical clamping sleeve elemen-t 84 integral at one end with an ear 86 apertured to receive a hinge pin 88 extending between the front ends of mounting plates 72. At 90, I
have illustrated a ring clamp, conventional per se, extending about the barrel support plates to clamp the same about the discharge tube 76 and barrel 80 in the overlapped areas thereof.
To further, sealably secure the discharge tube to the barrel received therein, there is provided a second ring clamp 92 disposed forwardly of the clamping sleeve elements 8~ in direct contact with the discharge tube, assuring positively against leakage of air through the joint between the flexible discharge tube 76 and barrel 80.
Removably press fitted at 9~ within the rear end 96 of barrel 80 is a detent assembly 98 constituted by a metal detent sleeve 100 adhesively or otherwise permanently bonded to the :inner surface of the rear end of a soft rubber, cylindrical, ball retainer member 104, the front end 106 of which projects beyond sleeve 100, and is normally radially contracted (see Figure 5) by reason of its inherent resiliency, to a diameter substantially less than that of the ball B to be propelled through the device. An oscillator such as shown in my co-pending application Serial No. 637,618, filed December ~, 1975, has been designated O and while not constituting a part of the present invention, is illustrated as being attachable to the discharge end of the barrel to indicate the adaptability of the present invention for use with said oscillator or equivalent device for varying the direction of travel of balls discharged in successively following order from the machine constituting the ~-~
present invention.
Operation In use, the device is particularly adapted as propulsion equipment for tennis balls B. It may thus be positioned at or ~07~76~ ;
adjacent an end of a tennis court, with barrel 80 adjusted upwardly or downwardly (in Figure 1 the barrel is shown in full and in dot- :
ted lines in two of many positions to which it could be adjusted)l until it is at a selected angle of inclination desired by the user.
Hinge pin 88 is then tightened, as for example through the provision of wing nut 108, to retain the barrel in the selected position of adjustment. When adjusted to a steep angle as shown in full lines in Figure 1, -the barrel will discharge balls upwardly at a corres-ponding angle, to give a player located at the opposite end of the tennis court practice in returning lobs. Or, when lowered as for example to the dotted line position of Figure 1, the barrel will be located to discharge the tennis balls at a much lower trajectory, simulating hard forehand or backhand shots. If oscillator O is used, successively following balls wil:L be discharged to opposite corners of the court, thus to cAuse the player to be re~u.ired to traverse the width of the court, hitting, in succession, practice forehand and backhand shots.
With the device properly located and the barrel at the selected angle of inclination, a power cord 110 is plugged into a suitable outlet, not shown, to provide power for both the gear motor and the blower. An on-off switch 112 is moved to "on"
position to supply power to the motors.
Gear motor 2~ operates to rotate distributor 28 at rela-tively low speed. Typically, the distributor may be caused to rotate through a single 360 cycle each 12 seconds. In a distri-butor having six holes, as shown by way of example in the illus-trated embodiment, a ball will be caused to drop through feed opening 40 and ball feed sleeve 42 once every two seconds, assuming that all holes of the distributor are left open. Capping every 3Q other distributor sleeve 36 would thus produce discharge of a ball at four second intervals. Other intervals can be selected by other capping patterns.
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As the distributor ~otates, the several openings thereof will be charged with tennis balls, as they move toward registration with feed opening 40, with increased assura:nce of full charging of the distributor being given through the anti-bridging and agitating means 30, 32, and even more importantly by the up-and-down motion . of the balls within the distribu-tor sleeves.
When the blower (which could be a typical motor and blower such as used in ordinary domestic vacuum sweepers) is in operation, air will be drawn into the pressurizing chamber 12. The air, as it pressurizes the chamber, normally tends to bias closure 48 to the closed, dotted line position shown in Figure 1.
A ball gravitating through the sleeve 42 has a gravita-tional force overcoming the tendency of the closure to remain in its closed position, so tha-t the door swings to the ~ull line posit:Lon of Fi~ure 1 and thus allows the ball to clrop to channel
surizing drum. ~
~7g76~
Typical of ~he prior art devices is th~ proRulsion device shown in Nielsen Patent 3,905,349 issued Septen~er 16, 1975.
SU~IMAR~ OF THE INVENTI~
The invention in one aspect provides in a pxopulsion device for spherical objects, of the type including a discharge barrel, a communicating drum in which air pressure i9 built up behind each of said objects for propelling the same orcibly from the barrel, and a trap door normally closing and opening into said drum by air pressure within the drum, the improvement comprising:
means mounting the trap door and defining said opening in-to said drum so that a spherical object fed into the drum through said opening will build up kinetic energy while in free fall vertically ~downwardly through said mounting means into the drum to a:n extent e~Eecti~te to momentarily bias the door to a substantially vertical op~nposition while said object is still in free~ fall; said trap door, in so opening momen-tarily inhibiting free fall of the spheri-cal object, and means within thè drum to which said object, while .
regaining substantially free fall, will gravitate clear of the trap door, so as to permit an immediate return of the trap door to a closed position free of any restraint imposed thereon by thespherical object.
In ~ preferred form the apparatus includes an elongated drum disposed when in use at a position slightly inclined from the : horizontal, and formed to a circular cross-section in a preferred embodiment. Above and in closely spaced relation to the drum is a hopper designed to receive a large supply of tennis balls or like spherical objects intended to be propelled from the device. A dis-tributor is mounted for rotation in the bottom of the hopper, and includes an annular series of ball feed sleeves, extending about the axis of rotation of the distributor in such fashion as to cause , each ball feed sleeve to move into position over a ball feed open-ing formed in the top of the drum. The distributor is rotated at a selected, relatively slow rate of speed, and in accordance with the invention anti-bridging and agitating means is incorporated in ~0'~6~
the distributor within the hoppe~, to aid in preventing the b~lls from lodging in a static position in which they will not feed, one after the other, into successively following openings provided in the ball feed sleeves of the distributor.
Further summarized, the apparatus has a gravitational ;
feed pipe closed at its lower end by a trap door that is normally retained in closed position by a built-up air pressure within the drum or pressurizing chamber. The kinetic energy of a ball having free fall through -the feed pipe or tube in effect snaps the door -to open position, but only for an instant, because the ball falls freely past the trap door to an inclined ramp, in such a way as to almost instantaneously clear the door so that the door can be re-turned with equal speed to its closed position by the air pressure within the chamber.
The ball rolls clown the ramp to a receiver t~be, beinc~
moved therealong by air pressure building up in back o~ the ball, until the ball is temporarily arrested by a rubber detent which per se is known in the art. When the pressure within the chamber in back of the ball builds up to a predetermined value, the ball is forcibly discharged through the barrel, which is adjusted to a selected angle of inclination before the propulsion device is placed in operation.
BRIEF' DESCRIPTION OF THE DRAWI~GS
Figure 1 is a view o~ a propulsion device according to the present invention~ partly in side elevation and party in lon-gitudinal section, the barrel being shown in full and dotted lines in typical positions to which it can be adjusted;
Figure 2 is an enlarged, transverse sectional view, sub-stantially on line 2-2 of Figure l;
Figure 3 is a fragmentary, horizontal sectional view, substantially on line 3-3 of Figure 2;
Figure 4 is a front end view of the device, as seen ~rom 7976~
the line 4-4 of Figure li Figure 5 is an enlarged, fragmentary longitudinal sec-tional view substantially on line 5-5 of Figure 4, showing the detent as it appears prior to engagement of the same by a ball that is to be propelled from the barrel;
Figure 6 is a view similar to Figure 5, in which the detent is shown in position arresting a bal]., the ball being shown in dotted lines;
Figure 7 is a perspective view of the distributor per se;
Figure 8 is a sectional view taken diametrically through the distributor, substantially on line 8-8 of Figure 7; ~and Figure 9 is an exploded perspective view of the barrel support plates, DESCRIPTION OF TEI~ PREFERRED EMBODIMENT
My ball propulsion dev.ice 10 includes a cylindrical large diameter housing or pressurizing chamber 12 of circular cross-section, supported above the ground or other supporting surface S in a position inclined a few degrees from the horizontal through the provision of front and rear, U-shaped support legs 14, ; 20 16 respectively disposed in embracing relation to the chamber 12 and riveted, bolted, or otherwise secured to said chamber as at 18. The side portions of -the U-shaped support legs 14, 16 project upwardly above housing or chamber 12, in embracing relation to an elongated, generally rectangular hopper 20, to which the supports are riveted or otherwise fixedly secured at 22. Hopper 20 is formed wholly open at its top, to receive a large supply of tennis balls B. The front end of the hopper is provided with a screen 23, mounted in position to retain a sound-deadening ma-terial in an air intake chamber to be described hereinafter.
3a Mounted within housing 12, intermediate the opposite ends thereof, is a gear motor 24, secured fixedly to the top portion of housing 12, and having a stub shaft 26 projecting ' ', . . . ..
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upwardly to engage, far rotatiQn with the stub shaft, a depending ~;
hub 27 of a distributor 28 preferably formed as an integral, molded plastic member to include a centrally disposed, upstanding, hollow, large diameter boss or projection 30 extending upwardly ~-within the hopper to prevent "bridging" of balls within the hopper and formed with uniformly, angularly spaced~ longitudinally ex-tending, radially projecting agitator ribs 32. Projection 30 is, made hollow to promote economy in molding, and to increase light~
ness of the distributor, but in use the hollow center is closed by a cap 34. The distributor projection 30 extends upwardly into the hopper in concentric relation to an opening 35 formed in the bottom of the hopper for receiving the distributor, and when rotated during operation of the gear motor will agitate the balls contin-uously and will prevent bridging thereof, to assure that they will fall into the several, uniformly angularly spaced distributor ; sleeves 36 disposed about the projection 30 at the base thereo in a circular pattern, and located (Figure 1) in an open space 37 defined between the hopper 20 and the pressurizing chamber 12.
Any one or more of sleeves 36 may be closed by removable caps 38.
~ 2Q Referring to Figure 2, disposition of the distributor :! base 39, comprised of the several integrally connected sleeves 36, the full height of the space between the top wall of the drum or chamber 12, locates the base substantially tangentially to the curvature of said top wall. As a result, balls loading into the sleeves contact the curved top surface of the wall of the drum.
As the distributor turns, the balls so loaded are cammed or biased upwardly and downwardly along paths parallel to the distributor axis between high points Bl- and low points B2- respectively, by the curved wall surface of the drum. They may at the same time be 3Q rotated, but primarily, their up-and-down motion in the sleeves causes them to agitate the tennis balls that are above but have not yet reached the distributor. This aids markedly in assuring :
: ., .
. . .
1C~7~76~
ayainst "skipping" of distributor sleeves, that is~ increased assurance is provided for the feeding of balls into the drum at the regular intervals for which the machine is pre-set.
Formed in the top portion of chamber 12, between gear motor 24 and the closed rear end of chamber 12, is a feed opening 40, in registration with a depending, open ended, ball feed sleeve 42 fixedly secured to the wall of chamber 12 in position extending substantially vertically downwardly therein in close proximity to the gear motor and the rear end wall of the chamber. Balls B
feeding gravitationally through sleeve 42 drop onto a ramp or feed channel 44 of U-shaped cross-section, declining forwardly toward and fixedly mounted upon the rear end of an elongated receiver tube 46 extending parallel to the longitudinal center line of chamber 12 to the front end thereof, in close proximity to the bot-tom o~ the chamber. A~so aiding in positionin~ the balls B
over the distributor i9 ~ semi-circular back plate 47 Eixedly secured to the back end of the hopper in concentric relation and close proximity to~the distributor.
Hingedly mounted upon the lower end of ball feed sleeve 2Q 42 is a closure 48 free to gravitate to an open position thereof, but moving to a closed position when the chamber is pressurized.
Receiver tube 46, at its front end, is fixedly mounted upon a head end cover 50, formecl to include a flat, circular plate member 52, the inner surface o which is covered by a gasket 54 o~ foam rubber or the like, the periphery of which is compressed between plate 52 and an outwardly directed, peripheral flange 56 formed upon the open, front end of the body of the housing or pressurizing chamber 12. Securing cover 50 to the body of the chamber in sealing relation thereto is an expandable clamping ring 58 which is per se conventional, being of the type comprising a split ring element capable of being contracted radially to its clamping position through the provision of a hinged toggle lever ;
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and link assembly 60 connected between the ends of the split ring of the clamp. `
Close to the fron-t thereof~ receiver tube 46 is provided : -with a peripheral, radially outwardly directed mounting and sealing flange 62, adapted to bear against gasket 54 about a receiver tube mounting opening 64 formed in the gasket and plate constituting cover 50. Sheet metal screws 63 or the like extend through flange 62 and plate 52, compressing gasket 54 between the flange and plate about the mounting opening 64, to sealably secure the tube to the cover 50.
Above tube 46, the cover 50 is formed with an air inlet opening 66/ through which air is drawn into chamber 12 by a blower 68 mounted against the inner surface of the cover 50. An air intake space is def.ined at 70 forwardly oE the air inlet opening 66, between a pair of forwarclly project.ing, approximately trian-gular, transversely spaced, Elat discharge tube mounting p:Lates 72 fixedly attached to cover plate 52. The air intake space 70 is deined through the provision of the plates 72 and a cross plate 73 aEfixed to and extending be-tween said plates 72, the p~ate 73 2a having an air inlet port 74. The enclosed space 70 has a sound deadening effect, and in a commercial embodiment would preferably be lined with a material designed to absorb the sound of the blower motor to the maximum exten-t to promote quietness oE operation of the air propulsion device.
As seen from Figures 5 and 6, a flexible discharge tube 76, which can convenlently comprise a length of corrugated hose or the like, is clamped at 78, at its rear end, to the forwardly projecting end of receiver tube 46 in full communication with the receiver tube. Discharge tube 76, at its front end, projects for-wardly beyond the mounting plates 72/ and at its front end receivesthe inlet end of an elongated~ rigidly constituted barrel 80 opened into communication with discharge tube 76. A pair of identical kut 976~
opposite barrel support plates is provided, each of which includes an elongated part-cylindrical clamping sleeve elemen-t 84 integral at one end with an ear 86 apertured to receive a hinge pin 88 extending between the front ends of mounting plates 72. At 90, I
have illustrated a ring clamp, conventional per se, extending about the barrel support plates to clamp the same about the discharge tube 76 and barrel 80 in the overlapped areas thereof.
To further, sealably secure the discharge tube to the barrel received therein, there is provided a second ring clamp 92 disposed forwardly of the clamping sleeve elements 8~ in direct contact with the discharge tube, assuring positively against leakage of air through the joint between the flexible discharge tube 76 and barrel 80.
Removably press fitted at 9~ within the rear end 96 of barrel 80 is a detent assembly 98 constituted by a metal detent sleeve 100 adhesively or otherwise permanently bonded to the :inner surface of the rear end of a soft rubber, cylindrical, ball retainer member 104, the front end 106 of which projects beyond sleeve 100, and is normally radially contracted (see Figure 5) by reason of its inherent resiliency, to a diameter substantially less than that of the ball B to be propelled through the device. An oscillator such as shown in my co-pending application Serial No. 637,618, filed December ~, 1975, has been designated O and while not constituting a part of the present invention, is illustrated as being attachable to the discharge end of the barrel to indicate the adaptability of the present invention for use with said oscillator or equivalent device for varying the direction of travel of balls discharged in successively following order from the machine constituting the ~-~
present invention.
Operation In use, the device is particularly adapted as propulsion equipment for tennis balls B. It may thus be positioned at or ~07~76~ ;
adjacent an end of a tennis court, with barrel 80 adjusted upwardly or downwardly (in Figure 1 the barrel is shown in full and in dot- :
ted lines in two of many positions to which it could be adjusted)l until it is at a selected angle of inclination desired by the user.
Hinge pin 88 is then tightened, as for example through the provision of wing nut 108, to retain the barrel in the selected position of adjustment. When adjusted to a steep angle as shown in full lines in Figure 1, -the barrel will discharge balls upwardly at a corres-ponding angle, to give a player located at the opposite end of the tennis court practice in returning lobs. Or, when lowered as for example to the dotted line position of Figure 1, the barrel will be located to discharge the tennis balls at a much lower trajectory, simulating hard forehand or backhand shots. If oscillator O is used, successively following balls wil:L be discharged to opposite corners of the court, thus to cAuse the player to be re~u.ired to traverse the width of the court, hitting, in succession, practice forehand and backhand shots.
With the device properly located and the barrel at the selected angle of inclination, a power cord 110 is plugged into a suitable outlet, not shown, to provide power for both the gear motor and the blower. An on-off switch 112 is moved to "on"
position to supply power to the motors.
Gear motor 2~ operates to rotate distributor 28 at rela-tively low speed. Typically, the distributor may be caused to rotate through a single 360 cycle each 12 seconds. In a distri-butor having six holes, as shown by way of example in the illus-trated embodiment, a ball will be caused to drop through feed opening 40 and ball feed sleeve 42 once every two seconds, assuming that all holes of the distributor are left open. Capping every 3Q other distributor sleeve 36 would thus produce discharge of a ball at four second intervals. Other intervals can be selected by other capping patterns.
g7~
As the distributor ~otates, the several openings thereof will be charged with tennis balls, as they move toward registration with feed opening 40, with increased assura:nce of full charging of the distributor being given through the anti-bridging and agitating means 30, 32, and even more importantly by the up-and-down motion . of the balls within the distribu-tor sleeves.
When the blower (which could be a typical motor and blower such as used in ordinary domestic vacuum sweepers) is in operation, air will be drawn into the pressurizing chamber 12. The air, as it pressurizes the chamber, normally tends to bias closure 48 to the closed, dotted line position shown in Figure 1.
A ball gravitating through the sleeve 42 has a gravita-tional force overcoming the tendency of the closure to remain in its closed position, so tha-t the door swings to the ~ull line posit:Lon of Fi~ure 1 and thus allows the ball to clrop to channel
4~. The ball enters the rear end of the receiver tube 46. As a result, air that would normally tend to flow out of the chamber 12 through receiver tube 46 has its passage blocked. This causes the air to be diverted toward the drop pipe or feed sleeve 42, as a 2Q result of which the diverted flow of air forces the closure 48 to its dotted line, closed position.
The movement o~ the closure to open position and back to ; its normal closed position is very rapid, indeed almost a snap action. The ball has free fa].l in a path directly normal to the :
plane of the closed trap door, so as to snap it to open position.
:-: The door does not impede the free fall of the ball, moving to an : open position completely to one side of said path. Further, the ball does not .impede the immediate return of the door to a closed position under pressure of the air induced into the drum, since the ball falls to a position on the ramp completely clear of the path of swinging movement of the trap door.
: Air pressure in back of the ball that has entered the 1C~797~4 , receiver tube is thus built up, so as to push the ball along the receiver tube until it reaches the radially contracted detent or retainer member 104. Member 104 restrains the ball until the air pressure in back of the ball builds up -to a predetermined value.
In a typical, commercial embodiment, three pounds of air pressure has been found wholly adequate for this purpose. When the air pressure builds up to this extent, -the ball is suddenly forced through the detent and propelled with great force out of the barrel 80.
The discharge of the ball from the barrel of course now opens the receiver tube to the free passage of air therethrough, for a moment. As a result, the closure gravitates to an open position, substantially simultaneously with or just .in advance of dropping o~ another ball into -the feecl channe:L, causing repetit.ion Oe the propulsion cycle previously described herein.
The abstract of this application is not intended to con-stitute a comprehensive discussion of all the principles, possible modes or applications of the invention disclosed in this document, and should not be used to interpret the scope of the claims which appear hereinafter.
The movement o~ the closure to open position and back to ; its normal closed position is very rapid, indeed almost a snap action. The ball has free fa].l in a path directly normal to the :
plane of the closed trap door, so as to snap it to open position.
:-: The door does not impede the free fall of the ball, moving to an : open position completely to one side of said path. Further, the ball does not .impede the immediate return of the door to a closed position under pressure of the air induced into the drum, since the ball falls to a position on the ramp completely clear of the path of swinging movement of the trap door.
: Air pressure in back of the ball that has entered the 1C~797~4 , receiver tube is thus built up, so as to push the ball along the receiver tube until it reaches the radially contracted detent or retainer member 104. Member 104 restrains the ball until the air pressure in back of the ball builds up -to a predetermined value.
In a typical, commercial embodiment, three pounds of air pressure has been found wholly adequate for this purpose. When the air pressure builds up to this extent, -the ball is suddenly forced through the detent and propelled with great force out of the barrel 80.
The discharge of the ball from the barrel of course now opens the receiver tube to the free passage of air therethrough, for a moment. As a result, the closure gravitates to an open position, substantially simultaneously with or just .in advance of dropping o~ another ball into -the feecl channe:L, causing repetit.ion Oe the propulsion cycle previously described herein.
The abstract of this application is not intended to con-stitute a comprehensive discussion of all the principles, possible modes or applications of the invention disclosed in this document, and should not be used to interpret the scope of the claims which appear hereinafter.
Claims (5)
1. In a propulsion device for spherical objects, of the type including a discharge barrel, a communicating drum in which air pressure is built up behind each of said objects for propell-ing the same forcibly from the barrel, and a trap door normally closing and opening into said drum by air pressure within the drum, the improvement comprising: means mounting the trap door and defining said opening into said drum so that a spherical object fed into the drum through said opening will build up kinetic energy while in free fall vertically downwardly through said mounting means into the drum to an extent effective to momentarily bias the door to a substantially vertical open position while said object is still in free fall; said trap door, in so opening momentarily inhibiting free fall of the spherical object, and means within the drum to which said object, while regaining substantially free fall, will gravitate clear of the trap door, so as to permit an immediate return of the trap door to a closed position free of any restraint imposed thereon by the spherical object.
2. In a propulsion device for spherical objects, the improved construction set forth in Claim 1, wherein said trap door mounting means comprises a substantially vertical feed tube within the drum, having a lower end on which the trap door is hingedly supported.
3. In a propulsion device for spherical objects, the improvement set forth in Claim 1 wherein the means for mounting the trap door comprises a substantially vertical feed tube having an upper end secured to the drum in registration with a feed opening formed in the drum, said feed tube being of a length such as to cause an object passing through the tube to build up said kinetic energy by free gravitational fall through the tubes, the tube having a lower end to which the trap door is hingedly connected.
4. In a propulsion device for spherical objects, the improved construction set forth in Claim 1 wherein the means for mounting the trap door comprises a feed tube disposed in a substantially vertical position within the drum, the feed tube having an upper end secured to the drum in registration with a feed opening formed in a wall of the drum, the feed tube having a lower end to which the trap door is hingedly connected, the upper and lower ends of the feed tube being spaced apart in a vertical direction a distance such as to cause objects passing through the feed opening to build up kinetic energy while in free fall through the tube, to an extent to cause the falling objects passing through the feed tube to forcibly bias the trap door to open position, said means to which said objects gravitate clear of the trap door within the drum comprising a ramp spaced vertically from and below the trap door a distance such that objects moving past the trap door will continue in free fall past said trap door onto the ramp without imposing any restraint upon the trap door tending to restrict the same in its movement to its normal, closed position.
5. In a propulsion device for spherical objects, the improvement of Claim 4 wherein the trap door, when in its open position, is supported substantially in a vertical plane at one side of the feed tube, wholly clear of the gravitational path through which said spherical objects fall through the tube past the trap door onto said ramp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA340,594A CA1088969A (en) | 1976-06-08 | 1979-11-26 | Propulsion device for tennis balls and like spherical objects |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/694,119 US4027646A (en) | 1976-06-08 | 1976-06-08 | Propulsion device for tennis balls and like spherical objects |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1079764A true CA1079764A (en) | 1980-06-17 |
Family
ID=24787471
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA279,186A Expired CA1079764A (en) | 1976-06-08 | 1977-05-26 | Propulsion device for tennis balls and like spherical objects |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US4027646A (en) |
| CA (1) | CA1079764A (en) |
Families Citing this family (41)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52129752A (en) * | 1976-04-23 | 1977-10-31 | Nippon Oil Co Ltd | Novel composition |
| US4094294A (en) * | 1977-01-31 | 1978-06-13 | Richard Speer | Ball projecting device |
| AT361816B (en) * | 1977-11-17 | 1981-04-10 | Kainz Norbert Dipl Ing | PLANT FOR CONVEYING TENNIS BALLS TO A BALL THROWING MACHINE |
| US4273095A (en) * | 1978-04-06 | 1981-06-16 | Richard Speer | Pneumatically-operated ball projecting device |
| US4212284A (en) * | 1978-04-06 | 1980-07-15 | Richard Speer | Pneumatically-operated ball projecting device |
| US4207857A (en) * | 1978-05-18 | 1980-06-17 | Balka William J Jr | Automatic ball server |
| US4241717A (en) * | 1978-05-30 | 1980-12-30 | Maurice Mariani | Oscillating flight control device for a ball projecting machine |
| US4250862A (en) * | 1978-07-31 | 1981-02-17 | Richard Speer | Ball projecting device capable of providing spin |
| US4345578A (en) * | 1978-07-31 | 1982-08-24 | Apollo Systems, Inc. | Ball projecting device capable of providing spin |
| US4233953A (en) * | 1978-10-30 | 1980-11-18 | Prince Manufacturing Co., Inc. | Propulsion device for tennis balls and like spherical objects having an improved programmed discharge of the oscillatory type |
| US4291665A (en) * | 1979-10-26 | 1981-09-29 | Prince Manufacturing Co., Inc. | Propulsion device for spherical objects having an oscillating support frame providing a programmed discharge of said objects |
| US4372283A (en) * | 1981-05-14 | 1983-02-08 | Balka Jr William J | Ball serving apparatus having independently operating horizontal and vertical firing barrel oscillating means |
| US5225257A (en) * | 1992-06-04 | 1993-07-06 | Exxon Chemical Patents Inc | Fluorine treatment of stretch/cling films |
| US5816232A (en) * | 1997-05-15 | 1998-10-06 | Cm Support, Inc. | Paintball loader having active feed mechanism |
| USRE45986E1 (en) | 1999-12-16 | 2016-04-26 | Gi Sportz Direct Llc | Spring loaded feed mechanism for paintball loader |
| US6213110B1 (en) | 1999-12-16 | 2001-04-10 | Odyssey Paintball Products, Inc. | Rapid feed paintball loader |
| WO2003059467A1 (en) * | 2002-01-15 | 2003-07-24 | Hollrock Engineering, Inc. | Batting system |
| US6889680B2 (en) | 2002-04-12 | 2005-05-10 | National Paintball Supply, Inc. | Differential detection system for controlling feed of a paintball loader |
| US6830044B2 (en) * | 2003-01-21 | 2004-12-14 | Howard E. Hansen | Pneumatic ball projecting apparatus |
| US6915792B1 (en) * | 2004-04-06 | 2005-07-12 | Chih-Sheng Sheng | Paintgun with a revolving disc for feeding paintballs |
| US7343909B2 (en) | 2004-04-28 | 2008-03-18 | Kee Action Sports I Llc | Mechanical drive assist for active feed paintball loader |
| US20070017495A1 (en) | 2004-10-14 | 2007-01-25 | Heddies Andresen | Procedure and device for feeding balls into the projectile chamber of a handgun |
| US7234456B2 (en) * | 2004-10-14 | 2007-06-26 | Kee Action Sports | Device for feeding balls into the ball chamber of a handgun |
| US7445003B2 (en) * | 2004-12-03 | 2008-11-04 | Lob-Ster Inc. | Oscillating ball throwing machine |
| US7694669B2 (en) | 2004-12-08 | 2010-04-13 | Kee Action Sports I, Llc | Paintball loader feed mechanism |
| US8100119B2 (en) * | 2005-05-13 | 2012-01-24 | Hall David L | Paintball system |
| US7841950B2 (en) * | 2005-08-16 | 2010-11-30 | Thomas Davidson | Products and methods for ocular enhancement and methods for conducting business thereby |
| US7921835B2 (en) | 2005-09-15 | 2011-04-12 | Kee Action Sports I Llc | Wireless projectile loader system |
| WO2007044546A2 (en) * | 2005-10-06 | 2007-04-19 | Kee Action Sports I Llc | Self-regulation paintball agitator system |
| WO2007044822A2 (en) | 2005-10-11 | 2007-04-19 | Kee Action Sports I Llc | Magnetic drive bypass system for paintball loader |
| US8251050B2 (en) | 2005-10-11 | 2012-08-28 | Kee Action Sports I Llc | Magnetic drive bypass system for paintball loader |
| US7854220B1 (en) | 2006-05-11 | 2010-12-21 | Terry Neumaster | Stretchable tension paintball agitator with deflecting arms and displacement tips |
| WO2007139934A2 (en) | 2006-05-25 | 2007-12-06 | Kee Action Sports I Llc | Self-regulating valve assembly |
| US7694452B2 (en) * | 2007-08-27 | 2010-04-13 | Croisetiere Leo R | Bait launcher |
| CN105849500A (en) | 2013-06-21 | 2016-08-10 | Gi运动直接有限公司 | Compressed gas gun having internal feed mechanism |
| US20150328524A1 (en) * | 2014-04-17 | 2015-11-19 | Marc Backowski | Multi sport ball rolling, levitating, tosssing and throwing system |
| ES2770864T3 (en) * | 2015-01-15 | 2020-07-03 | Byoung Koo Cho | Ball game training apparatus |
| CN110478876A (en) * | 2019-09-09 | 2019-11-22 | 滨州学院 | A kind of sport fixed point shootaround teeing apparatus |
| US10914546B1 (en) * | 2019-11-15 | 2021-02-09 | Arlos Franklin Casto, Jr. | Pneumatic ball launcher for facilitating launching of a ball |
| USD961002S1 (en) | 2019-12-30 | 2022-08-16 | Kore Outdoor (Us), Inc. | Projectile loader |
| USD992671S1 (en) | 2020-10-08 | 2023-07-18 | Canadian Imperial Bank Of Commerce, As Agent | Projectile launcher and loader |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2646785A (en) * | 1950-11-21 | 1953-07-28 | Goldman Martin | Ball throwing device |
| US3277879A (en) * | 1964-04-30 | 1966-10-11 | Edward E Sayette | Ball-throwing machine |
| US3584614A (en) * | 1968-12-04 | 1971-06-15 | Tibor Horvath | Automatic ball thrower |
| US3905349A (en) * | 1972-12-07 | 1975-09-16 | John Nielsen | Induced air device for discharging spherical members |
| US3917265A (en) * | 1973-03-12 | 1975-11-04 | Michael Robert Schrier | Pneumatic ball ejecting machine |
| US3855988A (en) * | 1973-04-13 | 1974-12-24 | Prince Mfg Inc | Ball throwing machine |
| US3990426A (en) * | 1975-07-22 | 1976-11-09 | Gilbert Stokes | Tennis ball throwing machine |
-
1976
- 1976-06-08 US US05/694,119 patent/US4027646A/en not_active Expired - Lifetime
-
1977
- 1977-05-26 CA CA279,186A patent/CA1079764A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US4027646A (en) | 1977-06-07 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |