US 3917265 A
A pneumatic ball ejecting machine is provided which collects tennis balls which are returned to a common area. The tennis balls are returned to a pneumatic lifting means which lifts the balls one at a time. The balls are loaded one at a time into a chamber at a loading station. The chamber is rotated to an ejection position where the ball is ejected by a blast of air through a barrel which imparts a spin to the ball.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 Schrier et a1.
[ Nov. 4, 1975 PNEUMATIC BALL EJECTING MACHINE  Inventors: Michael Robert Schrier, Silver Spring; Jack Michael Eichner,
Greenbelt, both of Md.
 Assignees: Michael Robert Schrier; Jack Michael Eichner; Martin S. Sachs; Marvin Reich, all of Washington,
 Filed: Mar. 12, 1973  Appl. No.: 340,508
 US. Cl....; 273/30; 124/51 A; 124/11 R; 124/48; 124/30 R  Int. Cl.:; F4lf 1/04 Field of Search 273/29 A, 26 R, 26 D, 129, 273/30, 35 R, 201; 124/11 R, 45, 51 R, 51 A, 41, 48; 302/2 R  References Cited UNITED STATES PATENTS Von Kozurik 124/11 R 2,357,951 9/1944 Hale 124/11 R 3,009,703 11/1961 Jentsch et a1. 124/11 R 3,089,476 5/1963 Wolverton 124/51 A 3,306,613 2/1967 Mainers 273/26 D Primary ExaminerRichard C. Pinkham Assistant ExaminerT. Brown ABSTRACT A pneumatic ball ejecting machine is provided which collects tennis balls which are returned to a common area. The tennis balls are returned to a pneumatic lifting means which lifts the balls one at a time. The balls are loaded one at a time into a chamber at a loading station. The chamber is rotated to an ejection position where the ball is ejected by a blast of air through a barrel which imparts a spin to the ball.
18 Claims, 20 Drawing Figures US. Patent Nov. 4, 1975 Sheet 1 of8 3,917,265
n mN U.S. Patent 'Nov.4, 1975 Sheet2-of8 3,917,265
US. Patent Nov. 4, 1975 Sheet 3 of8 3,917,265
U.S. Patent Nov. 4, 1975 Sheet4 0f8 3,917,265
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U.S. Patent Nov. 4, 1975 Sheet 5 of8 3,917,265
U.S. Patent Nov. 4, 1975 Sheet 6 of s FIG. 14
Um? DE mfmvl Q m? n m? OE I 0 Tm 0 V Shest 7 of 8 US. Patent Nov. 4, 1975 US. Patent Nov. 4, 1975 Sheet80f8 -3,917,265
IITLI +l;| II II v w mmm FL EN k N N PNEUMATIC BALL EJECTING MACHINE The invention relates to a ball ejection machine and, more particularly, to a ball ejection machine which pneumatically loads balls by suction and ejects the loaded ball by a blast of air.
In summary, the prior art contains many ball ejecting machines which generally operate satisfactorily. However, these machines contain one or more limitations such as they are expensive to manufacture and are consequently costly to the consumer. The machines jam up in use, wear out the tennis balls, have a limited number of delivery trajectories, velocities and spins, and are generally unsuitable for the average homes.
The invention provides a unique ball delivery and return system for table tennis and similar ball games enabling a single player to play the game. An attachment is provided at the far end of a table, which comprises a net and associated collecting means, ball storage and delivery means, and power actuated ball delivery means, comprising means to impelling a ball sharply in an horizontal manner through various cylindrical barrels. The speed, direction and trajectory of the ball may be altered by making various adjustments to the delivery mechanism to satisfy the personal needs of each individual player.
The invention provides a unique and improved ball delivery and returning device whereby a player can practice to gain expertise or play for amusement. Upon activating the ball delivery means, a ball or succession of balls are automatically propelled at different spins and directions toward the player at the opposite end of the table. The returned bouncing or rolling ball is restrained within the confines of the return sector of the table by a returning device comprising a net that is positioned directly opposite the player. Upon impact with the net, the ball rolls back to the collecting device under the table and is automatically stored for recycling.
An object of the invention is to provide a table tennis ball delivery machine that will not jam or clog.
Another object of the invention is to provide a table tennis ball ejecting machine which is reliable and inexpensive to manufacture.
A further object of the invention is to provide a delivery device that can be adjusted to alter the speed, direction and trajectory of the propelled ball.
Still another object of the invention is a simple method of automatically collecting a number of balls and storing the balls in a storage chute adjoining the ball ejection device.
Other objects and many of the intended advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 is a top view of a tennis table equipped with the inventive ball ejecting mechanism, a catching means and a ball return means;
FIG. 2 is a side view of FIG. 1;
FIG. 3 illustrates, in perspective, the details of the ball return means utilized in the present invention;
FIG. 4 is a side view of a mechanism for preventing the jamming of the ball return mechanism utilized in the present invention;
FIG. 5 is a top view of FIG. 4;
FIG. 6 illustrates the ball loading and ejecting mechanism of the present invention;
FIG. 7 illustrates a tennis ball being sucked into the magazine of the present invention;
FIG. 8 illustrates the magazine in the ejecting mode with a ball in position to be ejected;
FIG. 9 illustrates the air return and delivery system utilized in the present invention;
FIG. 10 illustrates the ball return mechanism utilized in the present invention;
FIG. 11 illustrates the means that assures that only one ball will be lifted at a time;
FIG. 12 illustrates the passage of a table tennis ball through the barrel of the present invention;
FIG. 13 illustrates a modified ball ejecting means that may be utilized in the present invention;
FIG. 14 illustrates a clutch mechanism for use in the present invention;
FIG. 15a illustrates a front view of the ball ejecting machine of the present invention;
FIG. 15b illustrates a first side view of the ball ejecting machine of the present invention;
FIG. 15c illustrates a back view of the ball ejecting machine of the present invention;
FIG. 15d illustrates a second side view of the ball ejecting machine of the present invention;
FIG. 152 illustrates a top view of the ball ejecting machine of the present invention; and
FIG. 16 illustrates a second variation of the modification of the ball ejecting machine of the present invention.
Referring to FIGS. 1, 2 and 3, wherein a table 21 is provided with a table tennis net 23. The table is provided with a ball catching net 25 which catches the returned table tennis ball. A ball return trough 27 surrounds the table 21. The net 25 is connected to the trough 27 to assure that the returned table tennis balls drop into the trough 27. The ball return trough 27 is positioned over the trough 29 which leads the table tennis balls to the ball lifting means 33 of the ball ejecting machine 31. The details of machine 31 and ball lifting means 33 will be hereinafter discussed in greater detail. The ball ejecting machine 31 is mounted on legs 35. Controls 41 for controlling the operation of the ball ejecting machine 31 are mounted on the edge of the table 21.
Referring to FIG. 3, wherein common elements illustrated in FIGS. 1 and 2 contain the same numerical indicia and perform the same functions as heretofore described.
The ball return trough 27 is sloped to cause the table tennis balls to return to the center point 41 where a jam preventing means is located.
FIGS. 4 and 5 illustrate the details of the jam preventing means located at point 41. A trap door 43 is provided which is designed to be in the closed position. To this end a non-illustrated spring assures that the trap door 43 remains closed. Alternately the trap door 43 may be weighted and balanced so that it returns to its original position due to the force of gravity. Trap door 43 is designed to give table tennis balls arriving from the left priority over table tennis balls arriving from the right which are automatically backed up behind the trap door 43. After the last left table tennis ball falls through the trap door 43, the trap door 43 returns to the horizontal position which is the closed position permitting a table tennis ball from the right to roll onto the trap door 43. The ball opens the trap door 43 permit- 3 ting the ball to fall to trough 30. The weight of the table tennis ball is sufficient to open trap door 43. Trough 30 is connected to trough 29. The remaining table tennis balls continuously operate the trap door 43 until the last table tennis ball enters return trough 29.
Referring to FIG. 6, which shows the details of the ball returnloading and ejecting means. A fan 51 which may be a turbine fan or any other high capacity fan, is connected to an exhaust or pressure line 53. The fan 51 is also connected to a suction line or vacuum line side 55. The free end of vacuum line 55 is connected to a boot 57. The air exhaust or pressure line 53 is provided with a valve 59 and a venturi 61 for creating a suction or vacuum in line 63.
Suction line 63 is connected to ball return line 65 for creating a lifting force in ball return line 65. A hole 67 is provided as a means to assure that only one ball will be liftedinto the vertical section of the ball return line 65. It is important to note that when a ball is above the hole 61 insufficient vacuum remains below the hole 67 to lift a second ball.
Referring to FIG. 7, which illustrates an exploded view of the magazine 71 as well as FIG. 6. The maga zine 71 is provided with a series of chambers 72, 73, 74, 75 etc. Each of the chambers 72 etc., in the magazine is provided with a hole 81 which aligns itself with a hole 91 in the boot 57. In operation the suction in vacuum line 55 provides a suction force on the table tennis ball in the return line 65 causing the ball to enter the chamber 72. The magazine 71 is provided with a back cover plate 85 and a front cover plate 87 which contains the loaded balls in their respective chambers. The hole 89 is provided in the back cover plate 85 to permit the balls to be sucked into the respective chambers of the magazines. The front cover plate 87 and the back cover plate 85 are mounted on the bottom plate 90.
Referring to the ball ejecting position of the machine illustrated in FIGS. 6 and 8, we have illustrated a ball in chamber 74 which is ready to be ejected. The hole 93 in front cover 87 is axially aligned with the hole 91 in back cover 85 to permit theball to pass through the front cover when an ejecting force enters by way of the hole in the back cover. A sealing member 95 is provided for covering the respective holes 81 thereby avoiding an air leak at this point. The velocity of the ejected table tennis ball may be varied by varying the air pressure in line 53. This may be done by opening the valve 59 or by any other suitable means.
The barrels 99 through 103 are mounted in a unit between barrel covers 105 and 107. Each of the barrels are mounted at a slightly different angle to provide different trajectory for the ejected balls. A front'cover plate 109 is also fixedly mounted to the base memberv 90. A motor 121 is provided with reduction gear box 123 which has an output that turns a friction drive wheel 125. The on-off switch 127 for motor 121 and fan 51 is mounted on control unit 41. The speed selection dial 129 controls the speed of rotation of motor 121.
Referring to the operation of FIG. 6 during which reference will be made to FIGS. 7 through 12. Turning on the machine supplies power to the machine causing the motor 121 to rotate the magazine 71, and to rotate the barrels 99 through 103 between cover plates 107 and 109. The fan 51 creates an exhaust pressure in line 53 and a suction or vacuum in line 55. Part of the exhaust air is ejected through the venturi 61 creating a suection or vacuum in line 63.
In the discussion of the ball return means, reference will be made to FIGS. 6, 10 and 11. As illustrated in FIG. 10, balls arriving at the bottomof ball return means 65 will remain on the bottom as long as a ball is in the lifting stage as illustrated. As soon as a ball reaches the top portion of the ball return 66 then another ball will be lifted. The hole 67 assuresthat insufficient air vacuum exists to lift a new ball as long as one is being lifted. In an actual working embodiment, the hole 68 was made three-eighths of an inch in diameter. It is to be noted that a ball being lifted above the hole 67 reduces the vacuum below it. The reduction in vacuum at the hole in combination with the permitted en-. trance of air at the hole prevents a secondball from being sucked up past the hole 67. As soonas=the ball being lifted passes bend 69 the suction increases to the point that a new ball is clrawn into the lifting cycle. This lifting means assures the absence of jamming which would occur when a plurality of balls arrive one after another and are suspended in the return means 65 without any of them ever reaching the top 66. j
A ball waiting at the top 66 will be sucked into an empty chamber in magazine 71 when it arrives in the loading position as follows. The ball is sucked into the chamber 76 by the vacuum in line 55 through boot 57 by way of holes 81 and 91. The ball is sucked in so rap.
idly that the magazine 71 keeps on rotating and does not need to be stopped.
When a loaded chamber, illustrated as chamber 74, reaches the top position as illustrated in FIGS. 6 and 9, the air pressure in line 53 causes the ball to be ejected. The diameter of the barrels is slightly larger than the diameter of the balls as illustrated in FIG. 12. The ejected ball is caused to ride on the bottom, top and sides of the barrel and is also caused to be bounced about in the barrel, thereby imparting a spin to the ball as ittraverses the barrel. Since the spin is imparted to the ball by riding on the sides of the barrel, the machine ejects the balls with an infinite variety of spin. It is emphasized that each barrel is pointed in a slightly differ ent direction thereby ejecting the balls at different.
spins and directions. The time interval that elapses between balls is controlled by varying the speed of the rotating motor 121.
Referring to the modified ball ejecting machine illustrated in FIGS. 13 and 14, there is provided a barrel 201 which is mounted at both its ends in .a fashion which permits the barrels to be rotated aboutits central axis by motor 207 which drives a friction driving gear The embodiment illustrated in FIG. 13 contains a clutch mechanism 221 which permits one to stop the rotation of the barrels so that only one barrel. will re-.
main in the firing position. The details of the clutch are illustrated in FIG. 14. The barrels are connected to the perimeter of the element 223. Theclutch contains a slidable hollow shaft225 which is keyed to shaft231 and rotates with shaft 231. The clutch is shown in its disengaged position where it is held by detent 241 and ball 245. When the keyed hollow shaft 225 is shifted to the left, a dry rubber element 227 is compressed against bearing surface 228, causing the unit 223 to rotate. When the shaft is shifted to the left the detent ball 245 will ride in the left detent 243. With the clutch in the left position, the barrels will be continuously I rel will be in the firing position. When a singlebarrel is held in the firing position, all the ejected balls will land in the same area on the table enabling the user to continuously practice a single shot. i
In FIG. 16 the motor 251 is shown in solid lines iii-the engaged position, wherein a friction gear 253 causes the barrel in the firing position to be rotated about the central axis of the barrel. The motor 25l maybe rotated to dashed line position wherein the barrels will not be rotated. 1
Having thus described the invention as exemplified by a preferred embodiment,'obvious changes and modifications by persons skilled in the art are deemed to fall within the spirit and scope of the disclosure and appended claims.
What is claimed is:
1. Apparatus for projecting a ball, comprising,
balls located at a first level,
a magazine located at a second level,
means for lifting balls one at a time from said first level to said second level,
means for loading said lifted ball from said second level into said magazine, means for ejecting said ball from said magazine, said means for lifting balls comprises a hollow vertical section of pipe extending from said first level to said second level, and having an internal diameter slightly greater than the ball to be lifted; and
means providing a vacuum at one end of said pipe and a vacuum reducing hole on the side of the opposite end of said pipe whereby when a first ball is lifted past said hole, a second ball will not be lifted into said pipe.
2. A ball ejecting apparatus as defined in claim 1, wherein said magazine is provided with a plurality of chambers each of said chambers being provided with a hole in their respective sides, a vacuum line being in operative relation with said hole in the side of said chamber, each of said chambers having a loading posi tion during its operating cycle, whereby the vacuum in said vacuum line draws said ball from the lifting means into said chamber when said chamber is in the loading position.
3. A ball ejecting apparatus as defined in claim 2,
which is provided with a plurality of barrels each of said barrels being aimed in a slightly different direction, each of said barrels being axially aligned with a respective chamber and means for rotating said barrels in unison with said chambers in said magazine, whereby said balls are ejected through said barrels in a slightly different direction.
4. A ball ejecting apparatus as defined in claim 2, which is provided with a barrel through which a ball is to be ejected, wherein said barrel is axially aligned with a chamber and said ejecting means.
5. A ball ejecting apparatus as defined in claim 4, wherein said barrel is free to rotate about its longitudinal axis, and means for rotating said barrel in operative relationship with said barrel.
6. Apparatus for ejecting tennis balls, comprising:
means for generating air pressure for ejecting tennis balls; 7 means for generating a vacuum;
a reservoir for holding a plurality of balls at a first level;
means for lifting tennis balls one at a time from said reservoir to a second level regardless of the number of balls present in said reservoir;
a magazine containing. a chamber having a loading position, said generated vacuum being operatively' -chambers, a plurality of barrels, each of said barrels being aligned with a respective chamber in said magazine.
8. A tennis ball ejecting apparatus as defined in claim 7, wherein said means for lifting tennis balls is provided with a source of vacuum to lift tennis balls, said ball lifting means comprising a vertical hollow pipe with the source of vacuum connected to one end of said hollow pipe, means for preventing more than one ball at a time from being lifted by said vacuum in said vertical hollow pipe, comprising a hole in the side of said hollow pipe, said hole being located at the other end of said hollow pipe.
9. A tennis ball ejecting apparatus as defined in claim 8, wherein said means for rotating said magazine comprises a motor driving a friction gear, said friction gear riding in frictional engagement to the periphery of said magazine, and means for electrically controlling the speed of said motor connected to said motor.
10. An apparatus for ejecting tennis balls as defined in claim 9, but further characterized by having a tennis table, said tennis table being provided with a trough for returning tennis balls to said ball lifting means.
11. An apparatus for ejecting tennis balls as defined in claim 10, but further characterized by said ball return means having a jam preventing means, said jam preventing means comprising a trap door which permits balls to enter from one side at a time.
12. A table tennis ball ejecting machine comprising:
a means for creating a source of air pressure;
means for generating a source of vacuum;
a magazine provided with a plurality of chambers, each of said chambers being provided with a hole in its side;
means for lifting one tennis ball at a time;
means for rotating said magazine;
a table tennis ball loading position for said chambers in said rotating magazine;
a vacuum boot having a hole therein through which a suction is supplied to said chamber in said loading position, whereby a tennis ball is sucked into said chamber from said tennis ball lifting means;
means for supplying said source of air pressure to said chamber in the ejecting position to eject said table tennis balls;
means to seal the holes in the side of said chambers when said chambers are in the ball ejection position; and
a plurality of barrels, each of said barrels being provided with a respective chamber, said barrels being rotated in unison with said chamber.
13. A tennis ball ejecting machine as defined in claim 12, but being further provided with a back cover for said magazine, said back cover having a hole for the loading position for said chamBErs, and a hole for the ejection position of said chanibfir.
14. A tennis ball ejecting machine as defined in claim 13, but being further provided with a front cover for said magazine, said front cover having a hole in the ball ejection position of said chamber.
15. A table tennis ball ejecting machine as defined in claim 14, but further characterized by having a clutch for disengaging the rotating barrels from the rotating magazine, whereby a single barrel is used for ejecting balls from each of said chambers.
16. A table tennis ball ejecting machine as defined in claim 15, but further characterized by having means for rotating said barrel about an axis running through the 18. A table tennis ball ejecting machine as defined in claim 17, but further characterized by having means for rotating said barrel about an axis running through the center of said barrel, whereby the rotating barrel adds a rotational component to the ejected table tennis ball.