Automatic ball control apparatus

This invention relates to an automatic ball control apparatus readily connectable to a ball ejector barrel on a ball ejector machine to impart top spin to ejected tennis ball members. The automatic ball control apparatus includes a ball top spin actuator assembly in one embodiment which includes 1) a fixed extension sleeve assembly secured to an outer end of the ball ejector barrel; 2) a sliding actuator sleeve assembly mounted about the fixed extension sleeve assembly; and 3) a spin actuator paddle assembly pivotally connected to the sliding actuator sleeve assembly. The spin actuator paddle assembly includes a main support lever member which is periodically pivotable to contact and impart top spin motion to a contacting tennis ball member. A second embodiment includes a ball top spin actuator assembly including 1) a fixed extension sleeve assembly secured to an outer end of the ball ejector barrel; and 2) a spin actuator paddle assembly connected to the fixed extension sleeve assembly. The spin actuator paddle assembly includes a main support level member having an arcuate contact surface which is pivotal to contact a tennis ball member to impart top spin thereto. The automatic ball control apparatus is operable to impart a combination of lateral, oscillating, and top spin motion to a tennis ball in a random fashion.

This invention has been described in a Disclosure Document, Number 228754, 
entitled "Vertical Oscillator in Combination with Automatically Controlled 
Top Spin Apparatus for use with Pneumatic Tennis Ball Machines", filed on 
Jun. 6, 1989 in the United States Patent Office. 
PRIOR ART 
A patent search on this invention revealed the following United States 
Patents: 
______________________________________ 
U.S. Pat. No. 
Invention Inventor 
______________________________________ 
2,182,369 
BASEBALL PROJECTING 
Christopher T. 
APATUS Barron 
2,935,980 
TENNIS BALL SERVER John P. Garver 
3,640,263 
AUTOMATIC BALL- Barry V. Rhodes 
THROWING MACHINE 
4,270,511 
APATUS FOR SHOOT- 
Goro Ehama 
ING A CURVE BALL 
4,570,607 
TENNIS BALL THROWING 
Gilbert A. Stokes 
MACHINE WITH CONTIN- 
UOUS ROTATABLE BAR- 
REL HAVING FRICTION 
STRIP ON ONE SIDE 
ONLY OF INNER WALL 
______________________________________ 
The Barron patent discloses a baseball projecting apparatus having a device 
thereon to contact a baseball and impart a curve to the thrown baseball. 
The Garver patent discloses a tennis ball server operable to serve a tennis 
ball, impart a spin to the tennis ball, and teaches the known prior art 
structure of utilizing air pressure to eject subject tennis ball. 
The Rhodes patent discloses an automatic ball-throwing machine utilizing 
air pressure and having a means for directing tennis balls along different 
trajectories. 
The Ehama patent discloses an apparatus for shooting a ball along a curved 
path in the practice of baseball, tennis, or table tennis. 
The Stokes patent discloses a tennis ball throwing machine having a movable 
ejector barrel having means therein for spinning the subject tennis ball. 
BACKGROUND OF THE INVENTION 
Prior to this invention, automatically controlled top spin in combination 
with vertical oscillation by a tennis ball machine has not been effected. 
There has been need of economical means of providing vertical oscillation 
in combination with automatically controlled variable top spin to a tennis 
ball member propelled by a tennis ball ejector machine. The principal need 
for such a device is to provide tennis ball member trajectory to between 
the base line of a tennis court and near a tennis net on a receiver's side 
of the tennis court while automatically providing the required amount of 
top spin to prevent the tennis ball member trajectory going beyond a base 
line of the receiver's side of the tennis court before contact with the 
court's surface while simultaneously employing maximum ball velocity and 
lob height of the ball above the tennis net. The present invention is 
designed for attachment to existing or newly manufactured pneumatic type 
ball ejector machines employing a rigid barrel attached to a flexible 
air/ball conveyor hose with a collar attached to an adjustable bracket. 
This invention provides a greater variety of practice to all levels of 
tennis play for tennis players using above described tennis ball ejector 
machines prior to this invention. The present invention may be 
incorporated in the manufacture of new tennis ball ejector machines of the 
type described, whether or not having horizontal oscillating movement. 
PREFERRED EMBODIMENT OF THE INVENTION 
In one preferred embodiment of this invention, an automatic ball control 
apparatus is operable to be utilized in combination with a ball ejector 
machine including a main support housing mounted on a support wheel 
assembly having a ball receptacle housing which holds tennis ball members 
to be ejected therefrom. The ball ejector machine has a ball discharge 
assembly which is operable to utilize air pressure to pick up a tennis 
ball member and to discharge same outwardly through a ball ejector barrel. 
The ball ejector barrel is controlled through a barrel oscillator assembly 
which is operable to move the ball ejector barrel in an oscillating 
(up-and-down path) and including lateral movement of the ball ejector 
barrel in order to randomly eject tennis balls from one side of a tennis 
court across a tennis net into both tennis serve and back court areas in 
an randomly selected pattern. 
The automatic ball control apparatus can be utilized with the vertical and 
lateral oscillator assembly of the prior art and includes a ball top spin 
actuator assembly having 1) a fixed extension sleeve assembly connected to 
the ball ejector barrel; 2) a sliding actuator sleeve assembly mounted on 
the fixed extension sleeve assembly; and 3) a spin actuator paddle 
assembly connected to the sliding actuator sleeve assembly. 
The fixed extension sleeve assembly includes a fixed sleeve member 
connected by a sleeve anchor clamp to the ball ejector barrel. A sleeve 
stop clamp is connected to an outer end of the ball ejector barrel. The 
fixed sleeve member is provided with anchor slots and 3) cam connector 
slots. 
The sliding actuator sleeve assembly includes a movable sleeve member, a 
sleeve actuator member being a compression spring member mounted between 
one end of the movable sleeve member and the sleeve anchor clamp and 
positioned about the fixed sleeve member, and a paddle actuator cam member 
mounted in the cam connector slots. 
The movable sleeve member includes a cam receiver slot, a chain connector 
bracket secured to a top surface, and an adjustment opening having a set 
screw therein to adjust an amount of allowable axial movement of the 
movable sleeve member on the fixed sleeve member. 
The paddle actuator cam member has an inclined cam surface which contains a 
portion of the spin actuator paddle assembly on vertical movement of the 
ball ejector barrel. 
The spin actuator paddle assembly includes 1) a spin paddle assembly 
pivotally connected to the movable sleeve member; 2) a ball actuator lever 
member connected to the spin paddle assembly; and 3) a paddle bias member 
being an elastic band mounted about the ball actuator lever member and the 
movable sleeve member. 
The spin paddle assembly includes a main support lever member having a 
lever actuator assembly connected thereto. The main support lever member 
is of a U-shape in transverse cross section having a bottom wall with a 
hinge member for piovtal connection to a lower surface of the movable 
sleeve member. 
The lever actuator assembly consists of a roller member rotatably mounted 
on a support shaft which is connected to one end of the main support lever 
member. 
The ball actuator lever member includes an arcuate support body having an 
outer arcuate contact surface to receive a tennis ball member thereagainst 
to achieve a top spin thereto and anchor bolt members for securing the 
arcuate support body to an outer end of the main support lever member. 
A second embodiment of a ball top spin actuator assembly includes 1) a 
fixed extension sleeve assembly which is secured to an outer end of the 
ball ejector barrel; and 2) a spin actuator paddle assembly. The fixed 
extension sleeve assembly includes a fixed sleeve member connected by wing 
nut members contacting an outer surface of the ball ejector barrel. 
The spin actuator paddle assembly includes a spin paddle assembly pivotally 
connected to a movable cam actuator assembly which, in turn, is connected 
to the fixed sleeve member. 
The spin paddle assembly includes a main support lever member having an 
actuator cam member and a ball actuator lever member mounted thereon. The 
ball actuator lever member includes an arcuate contact surface to engage 
the tennis ball members thereagainst to impart top spin thereto. 
The actuator cam member is provided with a cam surface to be engaged by the 
movable cam actuator assembly to pivotally move the ball actuator lever 
member. 
The movable cam actuator assembly includes a cam support channel secured to 
an outer lower surface of the fixed sleeve member and a sliding cam 
assembly connected to the cam support channel. 
The cam support channel is of a generally U-shape in transverse cross 
section having a lever spring member therein connected at one end to the 
fixed sleeve member and engagable with the ball actuator lever member to 
bias in one direction of rotational movement. 
The sliding cam assembly includes a main cam body member having a chain 
connector section attached to one end of a cable or beaded chain member 
which, in turn, is connected to a portion of the ball ejector machine. 
On vertical movement of the ball ejector barrel, the sliding cam assembly 
is operable to engage an actuator a cam surface of the actuator cam member 
to pivot the ball actuator lever member to vary contact with an ejected 
tennis ball member to impart varying degrees of top spin thereto on 
vertical oscillation and lateral movement of the ball ejector barrel. 
OBJECTS OF THE INVENTION 
One object of this invention is to provide an automatic ball control 
apparatus for providing controlled and automatic variable top spin to a 
tennis ball member in combination with vertical oscillation when attached 
to, or made a part of, a ball ejector machine for providing greater 
versatility in tennis practice. 
Another object of this invention is to provide an automatic ball control 
apparatus which is easily and readily attached to existing ball ejector 
machines without alteration thereto and requiring a minimum amount of 
tools and skill for mounting thereon. 
One other object of this invention is to provide an automatic ball control 
apparatus having a ball top spin actuator assembly easily connected to 
existing or new tennis ball ejector machines to provide trajectory to 
ejected tennis ball members of varying heights while simultaneously 
providing automatically controlled variable top spin with subject top spin 
varying in ratio to height of a tennis ball member lob trajectory. 
One further object of this invention is to provide an automatic ball 
control apparatus which can be readily attached to new or existing tennis 
ball ejector machines and having a ball top spin actuator assembly 
operable to contact a tennis ball member in varying degrees on its final 
ejection to provide variable top speed to the tennis ball member in ratio 
to a tennis ball member lob trajectory therefrom. 
Still, one other object of this invention is to provide an automatic ball 
control apparatus which can be built into new or attached to existing 
tennis ball ejector machines which is economical to manufacture; simple to 
install; providing greater versatility in movement of a tennis ball member 
from the tennis ball ejector machine; providing a greater practice 
versatility to any tennis ball ejector machine in existence; and 
substantially maintenance free. 
Various other objects, advantages, and features of the invention will 
become apparent to those skilled in the art from the following discussion, 
taken in conjunction with the accompanying drawings, in which:

The following is a discussion and description of preferred specific 
embodiments of the automatic ball control apparatus of this invention, 
such being made with reference to the drawings, whereupon the same 
reference numerals are used to indicate the same or similar parts and/or 
structure. It is to be understood that such discussion and description is 
not to unduly limit the scope of the invention. 
DESCRIPTION OF THE INVENTION 
Referring to the drawings in detail and, in particular to FIGS. 1 and 4, an 
automatic ball control apparatus of this invention, indicated generally at 
12, is utilized in conjunction with a tennis ball ejector machine 14 which 
is placed behind a base line on a tennis court 16 of a conventional nature 
having a central tennis net member 18. 
The tennis ball ejector machine 14 is operable in order to propel tennis 
ball members 30 through a ball trajectory 20 as specifically noted in FIG. 
4. It is seen that the tennis ball members 30 ejected from the ball 
ejector machine 14 have various trajectories such as a low trajectory to 
land just across the tennis net member 18 and an elevated trajectory to 
land adjacent the base line in the receiver's court. 
Due to the nature of the automatic ball control apparatus 12 of this 
invention, the tennis ball members 30 are randomly ejected and cover 
important areas of the receiver's side of the tennis court 16 such as an 
area close to a back service line, laterally to the court's parallel side 
lines, and rearwardly to the base line. The ball ejector machine 14 is 
mounted on a support wheel assembly 24 so as to be easily movable to any 
desired location on the tennis court 16. 
As noted in FIG. 1, the ball ejector machine 14 includes a main support 
housing 22 having a ball receptacle housing 26 therein and a ball 
discharge assembly 28. The ball receptacle housing 26 is operable to 
receive and hold numerous tennis ball members 30 for automatically feeding 
same into the ball discharge assembly 28. 
The ball discharge assembly 28 can be of various types, normally of a 
pneumatic type, to propel the tennis ball members 30 outwardly therefrom 
as shown in FIG. 4. 
The ball discharge assembly 28 includes 1) a support post member 32; 2) a 
first conveyor tube bracket 34 secured to the support post member 32; 3) 
an adjustable conveyor tube bracket 36 pivotally connected to the first 
conveyor tube bracket 34; 4) a hose guide bracket 38 generally of square 
shape secured to an outer end of the adjustable conveyor tube bracket 36; 
5) a ball conveyor assembly 40 having one end connected to a pneumatic 
output from the ball ejector machine 14; 6) a barrel oscillator assembly 
42 connected to the adjustable conveyor tube bracket 36; and 7) a flexible 
connector assembly 44 connected at one end to the support post member 32 
and at an opposite end to a portion of the automatic ball control 
apparatus 12. 
The support post member 32 is capable of partial, reciprocal rotation 
through a mechanism in the ball ejector machine 14 to move the 
interconnected hose guide bracket 38 horizontally in a manner to be 
explained. 
The first conveyor tube bracket 34 is of a generally U-shape having a back 
wall 46 secured by a bracket member 35 to the support post member 32 and 
integral, parallel side walls 48. 
The adjustable conveyor tube bracket 36 is connected by connector members 
50 to the first conveyor tube bracket 34. The connector members 50 are 
operable to permit pivoted movement of the conveyor tube bracket 36 and 
being locked in a given selected elevational position to vary the 
trajectory of the tennis ball members 30 when ejected from the ball 
ejector machine 14. 
The ball conveyor assembly 40 includes 1) a flexible ball conveyor hose 52 
secured at one end to a pneumatic propulsion mechanism of the ball ejector 
machine 14; 2) a rigid connector sleeve 54 secured to an outer end of the 
flexible ball conveyor hose 52; and 3) a ball ejector barrel 56 normally 
constructed of a rigid cylindrical steel or plastic material having its 
inner end connected to the rigid connector sleeve 54. 
The barrel oscillator assembly 42 includes 1) an oscillator bracket 
assembly 60 mounted about the rigid connector sleeve 54; 2) an oscillator 
crank assembly 62 connected to the oscillator bracket assembly 60; and 3) 
a drive gear and motor assembly 64 interconnected to the oscillator crank 
assembly 62 and, additionally, secured through an angle iron member 65 to 
a lower outer surface of the adjustable conveyor tube bracket 36. 
The oscillator bracket assembly 60 includes a stepped bracket member 79 and 
a pair of sleeve connector clamp members 66, each having a central 
semi-circular opening 67 and secured to each other by anchor nut and bolt 
members 68. The sleeve connector clamp members 66 are securely clamped 
about the rigid connector sleeves 54. 
The oscillator crank assembly 62 includes a first crank member 70 having 
one end connected to the stepped bracket member 69 and, at an opposite 
end, connected to a second crank member 72 which, in turn, is connected to 
the drive gear and motor assembly 64. 
The first crank member 70 has a connector end 74 connected by a shaft 
portion 75 to the stepped bracket member 79 and having an opposite end 
connected to a connector bolt 76. 
The second crank member 72 has a connector end 78 connected to the 
connector bolt 76 and an opposite end has a drive shaft hole 80 to receive 
an output shaft 69 from the drive gear and motor assembly 64. 
The connector bolt 76 allows relative rotational movement at the connected 
ends of the first crank member 70 and the second crank member 72. 
The drive gear and motor assembly 64 is of a conventional nature powered 
through a power cord and control means 81 having a gear reduction drive 
motor in order to rotate the output shaft 69 which is secured to the 
second crank member 72. 
Therefore, on comparison of FIGS. 2 and 3, vertical oscillating movement is 
achieved through the oscillating crank assembly 62 to move the ball 
ejector barrel 56 in an oscillatory path. The ball ejector machine 14, 
through the controlled partial rotational movement of the support post 
member 32 and the oscillating movement of the barrel oscillating assembly 
42, operates to achieve lateral plus vertical oscillating movement of the 
ball ejector barrel 56. 
The automatic ball control apparatus 12 includes a ball top spin actuator 
assembly 86 which is connected to the ball ejector barrel 56. More 
specifically, the ball top spin actuator assembly 86 includes 1) a fixed 
extension sleeve assembly 88 connected to the outer end of the ball 
ejector barrel 56; 2) a sliding actuator sleeve assembly 90 which is 
mounted about the fixed extension sleeve assembly 86; and 3) a spin 
actuator paddle assembly 92 which is pivotally connected to the sliding 
actuator sleeve assembly 90. 
As best shown in FIG. 8, the fixed extension sleeve assembly 88 includes a 
cylindrical fixed sleeve member 94 connected at one end by a sleeve anchor 
clamp 96 to the outer end of the ball ejector barrel 56 and having a 
sleeve stop clamp 98 secured to an outer end of the ball ejector barrel 
56. 
The fixed sleeve member 94 has a connector end 102 provided with a pluralty 
of spaced anchor slots 104 and cam connector slots 106 to receive a cam 
member therein as will be explained. The anchor slots 104 are provided in 
order to obtain a firm clamping action about the outer end of the ball 
ejector barrel 56 when serving the sleeve anchor clamp 96 thereon. 
The sliding actuator sleeve assembly 90 includes 1) a movable sleeve member 
108; 2) a sleeve actuator member 110 mounted between the sleeve anchor 
clamp 96 and an outer end of the movable sleeve member 108; and 3) a 
paddle actuator cam member 112 to be mounted within the cam connector 
slots 106 on the fixed sleeve member 94. 
The movable sleeve member 108 includes 1) a flat connector surface 114; 2) 
a cam receiver slot 116 to permit the paddle actuator cam member 112 to 
extend therethrough; and 3) a chain connector bracket 118 to be connected 
to an outer end of the beaded chain member 84. The flat connector surface 
114 is operable to secure a hinge member 122 thereto for pivot connection 
to the spin actuator paddle assembly 92. 
The threaded adjustment opening 120 is operable to receive a set screw 124 
therein for top spin adjustment purposes as will be explained. 
The sleeve actuator member 110 comprises a compression spring member 126. 
The paddle actuator cam member 112 is provided with connector legs 128 
mounted through the cam connector slots 106 in the fixed sleeve member 94 
and having an inclined cam surface 132. 
As best shown in FIG. 8, the spin actuator paddle assembly 92 includes 1) a 
spin paddle assembly 134 pivotally connected to the hinge member 122; 2) a 
ball actuator lever member 136 connected to one end of the spin paddle 
assembly 134; and 3) a paddle bias member 138 operably connected to the 
ball actuator lever member 136 and mounted about the movable sleeve member 
108. 
The spin paddle assembly 134 includes a main support lever member 140 of 
generally U-shape in transverse cross section and having a lever actuator 
assembly 142 connected at an opposite end thereof. The main support lever 
member 140 includes a bottom wall 144 having integral parallel side walls 
146 and spaced connector holes 148 in the bottom wall 144. 
The lever actuator assembly 142 includes a support shaft 150 having a 
roller member 151 mounted thereon and connected to one end of the main 
support lever member 140 opposite from attachment of the ball actuator 
lever member 136. 
The ball actuator lever member 136 includes an arcuate support body 154 
having an outer arcuate ball contact surface 156 and is secured by anchor 
bolt members 158 connected to the arcuate support body 154. The use of the 
anchor bolt members 158 allow the arcuate support body 154 to be removed 
and replaced on wear of the arcuate contact surface 156 during a 
maintenance operation. 
The spaced connector openings 148 may be aligned slots permitting axial 
adjustment of the arcuate support body 154 for top spin adjustment as will 
be noted. 
The paddle bias member 138 is a flexible elastic band 160 which may be 
constructed of a rubber material. 
As noted in FIGS. 11-13, inclusive, a second embodiment of the invention is 
a ball top spin actuator assembly 162 which achieves a similar operation, 
purpose, and function of the first embodiment being the ball top spin 
actuator assembly 86. 
The ball top spin actuator assembly 162 includes 1) a fixed extension 
sleeve assembly 164 which is releasably connectable to an outer end of the 
ball ejector barrel 56; and 2) a spin actuator paddle assembly 166 which 
is connected to the fixed extension sleeve assembly 164. The fixed sleeve 
member 168 has an inner central ridge 169, threaded anchor holes 170, 
paddle connector holes 172, and a forward spring connector hole 173. 
The anchor holes 170 are operable to threadably receive respective wing nut 
member 174 therein for releasably anchoring to the ball ejector barrel 56. 
As noted in FIG. 11, the spin actuator paddle assembly 166 includes a spin 
paddle assembly 176 pivotally connected to and cooperating with a movable 
cam actuator assembly 178. 
The spin paddle assembly 176 includes 1) a main support lever member 180; 
2) an actuator cam member 182 secured to one end of the main support lever 
member 180; and 3) a ball actuator lever member 184 secured to an opposite 
end of the main support lever member 180. 
The main support lever member 180 is of U-shape in transverse cross section 
having a bottom wall 186 with integral parallel side walls 188. The bottom 
wall 186 is provided with elongated spaced aligned connector slots 190 and 
a cam connector hole 192. The side walls 188 are provided with aligned 
pivot connector holes 194 for connection to the movable cam actuator 
assembly 178 as will be explained. 
The actuator cam member 182 is of a wedge shape connected to one end of the 
main support lever member 180 by a bolt member 195 extended through the 
cam connector hole 192 into a threaded opening 197 in the actuator cam 
member 182. 
The actuator cam member 182 is provided with an outwardly, upwardly 
inclined cam surface 196 engagable with the movable cam actuator assembly 
178. 
The ball actuator lever member 184 is similar to the previously described 
ball actuator lever member 136 having an arcuate support body 198 with an 
upper arcuate contact surface 201. The arcuate support body 198 includes 
anchor bolts 203 extended therefrom and mountable within respecive ones of 
the connector slots 190 and secured in an adjusted position by wing nuts 
205. 
The arcuate contact surface 201 is constructed of an abrasive type material 
so as to impart top spin to a tennis ball member 30 contacting same as 
will be explained. 
The movable cam actuator assembly 178 includes a cam support channel 208 
which is connected to an outer lower surface of the fixed sleeve member 
168 and a sliding cam assembly 210 mounted within the cam support channel 
208. The cam support channel 208 is of generally U-shape in transverse 
cross section including a bottom wall section 212 with integral parallel 
side wall sections 214. 
The bottom wall section 212 has 1) a spring slot 216 therein operable to 
receive a portion of a lever spring member 221 therethrough; and 2) anchor 
holes 218 for securing to a lower surface of the fixed sleeve member 168 
by anchor bolt members 223 mounted in the paddle connector holes 172. 
The side wall sections 214 each have an aligned pivot connector hole 220 to 
receive a support member therethrough. 
The sliding cam assembly 210 includes a main cam body member 222 and a 
support lever connector assembly 224. The main cam body member 222 is of 
generally L-shape having a chain connector section 226 at one end and a 
bias connector section 228 at an opposite end. 
The chain connector section 226 includes 1) a ring receiving slot 230 to 
receive a ring member 231 connected to an outer end of the beaded chain 
member 84; and 2) a threaded anchor hole 232 to receive a lock bolt member 
234 therein and trained through the ring member 231 in the assembled 
condition. 
The bias connector end 228 has a support shaft 238 to receive one end of a 
tension spring 236 thereabout. The tension spring 236 is of a conventional 
type having hook portions 237 on opposite ends thereof. 
The support lever connector assembly 224 includes a pivot support pin 240 
having holes at opposite ends thereof to receive anchor clip members 242 
therethrough to hold the pivot support pin 240 in the assembled condition 
when it is mounted through the aligned pivot connector holes 194 and the 
pivot connector holes 220. 
USE AND OPERATION OF THE INVENTION 
In the use and operation of the automatic ball control apparatus 12 of this 
invention, it can be used in the manufacture of a new ball ejector machine 
14 but is constructed so as to be readily attached to existing ball 
ejector means such as a tennis ball ejector machine in a retrofit 
installation procedure. 
In the assembled condition of the automatic ball control apparatus 12 with 
the ball top spin actuator assembly 86 as noted in FIGS. 9 and 10, the 
fixed sleeve member 94 is telescopingly mounted about an outer end of the 
ball ejector barrel 56 and the sleeve anchor clamp 96 is mounted about the 
anchor slots 104 and clamped thereon. 
The compression spring member 126 is telescopingly mounted about the fixed 
sleeve member 94 abutting the sleeve anchor clamp 96. 
The movable sleeve member 108 is telescopingly mounted about the fixed 
sleeve member 94 having an inner end in abutting engagement with the 
compression spring member 126. 
The stop sleeve clamp 98 is secured to an outer end of the ball ejector 
barrel 56 and serves as a limit to forward movement of the movable sleeve 
member 108 being urged in this direction by the compression spring member 
126. 
In this condition, it is noted that the movable sleeve member 108 has the 
spin actuator paddle assembly 92 pivotally connected thereto by the hinge 
member 122. 
The paddle bias member 138 is telescoped about the movable sleeve member 
108 and holds the main support lever member 140 in a position as noted in 
FIG. 9 which imparts the least top spin to a tennis ball member 30 being 
projected by the ball ejector machine 14. 
The set screw 124 is movable axially so as to contact the sleeve stop clamp 
98 providing an adjustment feature to control pivotal movement of the main 
support lever member 140 and, thus, amount of variable top spin to be 
imparted to the tennis ball member 30. 
Next, the beaded chain member 84 is connected to the chain anchor bracket 
118 secured to a top surface of the movable sleeve member 108. This beaded 
chain member 84 is adjustably connected between the support post member 32 
and the chain connector bracket 118 to a desired tension which affects 
operation of the spin actuator paddle assembly 92. 
In the operation of the ball top spin actuator assembly 86 in the assembled 
condition, it is obvious that the ball ejector machine 14 is placed on the 
tennis court 16 preferably behind the server's base line as noted in FIG. 
4. 
An electrical power cord is connected to the ball ejector machine 14 in 
order to power its operating mechanism. The ball ejector machine 14 may 
utilize a pneumatic type pressure ball ejecting means for propelling the 
tennis ball members 30 along the ball trajectories 20 as noted in FIG. 4. 
At this time, the ball discharge assembly 28 would be energized and the 
barrel oscillating assembly 42 operates through the drive gear and motor 
assembly 64 with its rotating drive shaft 69 to move the second crank 
member 72 and the first crank member 70 in an oscillating motion to 
provide vertical movement to the ball ejector barrel 56. 
Concurrently, the support post member 32 would be rotated in a back and 
forth motion in order to move the ball ejector barrel 56 in a lateral 
path. 
On energization of the ball ejector machine 14, it is noted that the tennis 
ball members 30 are periodically projected outwardly through the ball 
ejector barrel 56 as noted by an arrow 246. As noted in FIG. 9, there is a 
minimum contact of the tennis ball members 30 with the arcuate contact 
surface 156 which imparts a rotational motion to the tennis ball members 
30 as noted by an arrow 248. 
In the condition of FIG. 9, it is noted that the movable sleeve member 108 
is held against and compresses the compression spring member 126 due to 
pull excerted by the beaded chain member 84. This condition is caused when 
the barrel oscillator assembly 42 is in its lowermost position having a 
maximum pull by the beaded chain member 84. 
The maximum condition of obtaining top spin on the tennis ball members 30 
is noted in FIG. 10 which is at the uppermost vertical position of the 
ball ejector barrel 56 and there is a slack condition of the beaded chain 
member 84. The compression spring member 126 contacts a rear surface of 
the movable sleeve member 108 to move it to a forwardmost position. 
In this maximum top spin condition, the roller member 152 contacts the 
inclined cam surface 132 of the paddle actuator cam member 112. This 
operates to pivot the main support lever member 140 about the hinge member 
122 in a clockwise direction as noted in FIG. 10. This movement is against 
the force of the paddle bias member 138 which operates to move the main 
support lever member 140 in a counterclockwise direction when in the 
position as noted in FIG. 9. 
The ball top spin actuator assembly 86 can be adjusted to provide varying 
top spin effects on the tennis ball members 30 through 1) adjustment of 
the beaded chain member 84 in its adjustable connection and amount of 
slack between the chain connector bracket 118 and the support post member 
32; 2) adjustment of the set screw 124 in the adjustment opening 120 with 
its contact with the sleeve stop clamp 98; 3) adjustable axial movement of 
the arcuate support body 152 in the connector openings 148; and 4) using a 
paddle actuator cam member 112 having a different inclination from the 
inclined cam surface 132. 
In the operation of the second embodiment of the ball top spin actuator 
assembly 162, basically the identical results are achieved on the tennis 
ball members 30 as shown in FIGS. 12 and 13. 
In the assembly of the ball top spin actuator assembly 162, the fixed 
sleeve member 168 is telescoped over an outer end of the ball ejector 
barrel 56 into abutting engagement with the inner central ridge 169. The 
fixed sleeve member 168 is secured in position by the wing nut members 174 
extended through the threaded anchor holes 170 into locking engagement 
with an outer surface of the ball ejector barrel 56. 
The spin actuator paddle assembly 166 is pivotally connected by the support 
lever connector assembly 224 to the cam support channel 208 secured to an 
undersurface of the fixed sleeve member 168 by the anchor bolts 223. 
Next, the beaded chain member 84 has its connector ring 231 mounted within 
and connected to the chain connector section 226 as noted in FIG. 12. The 
slack in the beaded chain member 84 can be adjusted with the opposite end 
fixed to a portion of the ball ejector machine 14 to affect the axial 
movement of the sliding cam assembly 210. 
The lock bolt member 234 is preferrably constructed of a nylon material and 
a head portion 235 contacts the cam surface 196 of the actuator cam member 
182 during operation. The lock bolt member 234 isd adjustable axially in 
the threaded anchor hole 232 to regulate pivotal movement of the main 
support lever 180 between minimum and maximum limits and resultant 
variable top spin imparted to the tennis ball members 30. 
On operation of the second embodiment with the ball top spin actuator 
assembly 162, it is noted that tennis ball members 30 are projected by the 
ball ejector machine 14 outwardly through the ball ejector barrel 56 as 
noted by an arrow 250. 
The condition in FIG. 12 applies a minimum amount of top spin to the tennis 
ball members 30 as noted by an arrow 252 in FIG. 12. The tennis ball 
members 30 contact the arcuate contact surface 201 to impart top spin to 
the propelled tennis ball members 30. 
As noted in FIG. 12, there is a slack condition of the beaded chain member 
84 whereupon the tension spring 236 holds the main cam body member 222 in 
a forward position. This slack condition would occur when the ball ejector 
barrel 56 is at its lowest point of trajectory caused by the barrel 
oscillating assembly 42 of the ball ejector machine 14. 
In a maximum top spin condition as shown in FIG. 13, the tennis ball 
members 30 contact the arcuate contact surface 201 on the main support 
lever member 180 in its fully tilted position in a clockwise rotational 
movement. 
In this maximum top spin condition, the actuator cam member 182 contacts 
the main cam body member 222 to cause the subject pivotal movement of the 
main support lever member 180. The main cam body member 222 is moved to a 
rearward position due to pull by the beaded chain member 84. This 
condition arises on the maximum vertical position of the ball ejector 
barrel 56 due to the oscillating movement through the barrel oscillator 
assembly 42. 
The ball top spin actuator assembly 162 is adjustable between the minimum 
top spin condition of FIG. 12 and the maximum top spin condition of FIG. 
13 through adjustment features being 1) adjustable movement of the ball 
actuator lever member 184 due to its bolt and slot interconnection to the 
main support lever member 180; 2) slack in the beaded chain member 84; 3) 
axial movement of the lock bolt member 234; and 4) replacement of the 
actuator cam member 182 having different inclinations of the cam surface 
196. 
In the ball top spin actuator assembly 162, the tension spring member 237 
and the lower spring member 221 operate to move the main cam body member 
222 to the minimum top spin condition. 
It is noted in the automatic ball control apparatus 12 that both 
embodiments of the ball top spin actuator assemblies 86 and 162 operate 
similarly in achieving movement of the spin paddle assemblies 134 and 176 
into different pivotal positions relative to the ball ejector barrel 56. 
The main difference being that, on various embodiments of ball ejector 
machines 14, the beaded chain member 84 may be attached to a respective 
ball ejector machine 14 either above or below the ball ejector barrel 56. 
The automatic ball control apparatus is easily attachable to existing ball 
ejecting machines requiring a minimum amount of tools and skill plus 
utilizes existing holes and parts of the prior art tennis ball ejecting 
machines. The ball top spin actuator assemblies are economical to 
manufacture; easy to install on new or existing ball ejecting machines; 
readily adjustable to vary the top spin imparted to tennis ball members; 
compatible with the combination of oscillating and lateral movement of the 
ball ejector barrel; and substantially maintenance free. 
It is obvious that the automatic ball control apparatus can be used to 
impart top spin to baseballs, ping pong balls, and the like. 
While the invention has been described in conjunction with preferred 
specific embodiments thereof, it will be understood this description is 
intended to illustrate and not to limit the scope of the invention, which 
is defined by the following claims: