US 2057599 A
Description (OCR text may contain errors)
TENNIS PRACTICE MACHINE Filed Oct. 26, 1934 2 Sheets-Sheet 1 5 0 20 ea u .Fdzzzanaoff. Jermq Oct. 13, 1936. E. H. SERRANO TENNIS PRACTICE MACHINE Filed Oct. 26, 1954 2 Sheets-Sheet 2 Patented Get. 13, 1933 PATENT OFFICE TENNIS PRACTICE MACHINE Edmundo H. Serrano, St. Louis, Mo., assignor to Luella J. Serrano, St. Louis, Mo.
Application October 26, 1934, Serial No. 750,219
This invention relates to tennis practice machines adapted to project a series of tennis balls at a player in varied trajectories and angles.
1 The primary object of this invention is to provide a device of the above mentioned character which is entirely automatic and which requires no attention whatsoever once the machine has been placed in operation.
A further object of this invention is to pro vide a machine of the above mentioned character having a wheeled frame to which is pivotally secured a ball carrying frame having a striker adapted to project balls in different heights.
'A' still further object of this invention is to provide a device of the above mentioned character having a ball striking member provided with two or more striking faces which will project a tennis ball in different horizontal angles.
A still further object of this invention is to provide means for feeding tennis balls at spaced intervals to a support directly in the path of the striking device and said means includes a novel arrangement comprising a receptacle having a series of chutes for receiving balls and novel means for allowing the dispensing of one ball at a time from said chutes.
A further object of this invention is to provide a support upon which the tennis balls are fed so as to be positioned in the path of the striking device and said support is provided with a plurality of surfaces adapted to cause irregularities in the travel of the ball after being struck by the striking member.
A further object of this invention is to provide a striking member for a machine of the above mentioned character, the movements of which will simulate the action of a human player.
A still further object of this invention is to provide a device of the above mentioned character controlled by an automatic switch whereby a predetermined number of balls may be projected after which the machine will be completely turned off and will become inoperative.
A still further object of this invention is to provide a rotary brush in a tennis ball receptacle adapted to re-knap and clean the balls prior to their release upon the ball support in the path of the striking member.
A still further object of this invention is to provide means for regulating the force of the blow struck by the striking element whereby tennis balls may be projected varied distances.
7 Other objects and advantages of the'invention will become apparent during the coarse of the following description forming a part of the specification and in which,
Figure 1 is a top plan view of the device embodying this invention illustrating the tennis ball receptacle and its circularly arranged chutes with respect to the striking element;
Figure 2 is a vertical front plan view partly in section illustrating the tennis ball receptacle in detail and further showing its relation with respect to the striking element and the other cooperative parts;
Figure 3 it a side plan view of the device embodying this invention illustrating the striker arm and the details of the operating construction along with other associated elements;
' Figure 4 is a transverse cross sectional view illustrating the drive arrangement and gearing for operating the several parts of the machine;
Figure 5 is a top plan view of the striking device showing the same greatly enlarged for the purpose of illustrating the details of construction;
Figure 6 is a side plan view of the striking member further illustrating the gut strings with respect to the playing surface;
Figure 7 is an end plan view showing the manner in which the gut strings are spaced and held in position;
Figure 8 is a fragmentary side view of a portion of the supporting frame and the adjustable connection between the tilting mechanism and the same carried by the frame plates.
In the drawings, wherein for the purpose of illustrating the invention and wherein like rei erence characters will be employed to designate like parts throughout the same, the reference character ID will generally be employed to designate a wheeled frame formed of angle bars spaced and braced by cross bars H. Through the wheeled frame 10 extends an axle l2 on the ends of which are casters or rollers I3. The opposite end of the wheeled frame In is provided with a foot 14 whereby said frame may be levelled with respect to the ground.
A pair of handle bars i5 is pivoted to the wheeled frame as at l6 and the upper ends of the handle bars l5 are connected by a horizontal bar ll so that the handle bars I5 may be moved outwardly so that the stops l8'will engage the wheel frame Ill and form a means of moving the machine from different positions to desired locations.
Extending upwardly from the wheeled frame ID are opposite supports l9 riveted to the wheeled frame as at 20 and having the upper ends thereof converging inwardly and connected as at 2|. Pivotally mounted between the vertical frame members l9 as at 22 is a frame structure comprising angle bars 23 joined at their intermediate portions by plates 24 and the lower end of the frame is provided with a floor 25 to which is bolted an electric motor 26 having an armature shaft 2! upon which are mounted pulleys 28 and 29.
Journalled in bearings 38 carried by a pair of opposite frame plates 24 as shown in Figure 4 is a shaft 3| on one end of which is fixed a collar 32 having a grooved pulley 33 so that a belt 34 may be trained thereover and around one of the armature shaft pulleys 28. The intermediate portion of the shaft 3| is provided with a worm 35 adapted to drive a shaft 36 at right angles to the shaft 3|. One end of the shaft 36 is journalled in an anti-friction bearing 31 secured in one of the frame plates 24 while the opposite end as at 38 is received in a bore 39 formed in a stub shaft 48 which is rotatably mounted in anti-friction bearings 4| mounted in the opposite frame plate 24. Rigidly secured to one end of the stub shaft 48 is a striker arm 42 having a striking member on the outer end which will be hereinafter more fully described.
Power is imparted to the rotary shaft 36 by means of a worm wheel 43 rigidly secured thereon and meshing with the worm 35 on the shaft 3|. Carried by the worm wheel 43 is a collar 44 having a set screw 45 for rigidly securing the worm wheel 43 and collar 44 to the shaft 36 and secured to the collar 44 as at 46 is a disk 41 to which is pivotally secured a dog 48 held in place by a threaded stub shaft 49 locked by a nut 56.
Rigidly secured to the stub shaft is a drum 5| to which is attached a notched wheel 52 adapted to be engaged by the pawl 48 thereby establishing a rigid connection between the shaft 36 with the stub shaft 48 at intervals. Anti-friction bearings 53 may be mounted between the drum 5| and the pawl carrying disk 41 and said anti-friction bearings are similar to the anti-friction bearings 4! whereby free and easy rotation may be provided.
The construction above described will effect the drive of the shaft 36 through the medium of the worm 35 and worm wheel 43 to cause the rotation of the pawl carrying disk 41 which pawl 48 will normally be urged toward the notched wheel 52 by means of a retention device 54 which will cause the clutching of the disk 41 with the toothed wheel 52 and will result in the drive of the stub shaft 40 through the drum 5|. Attached to the drum 5| are straps 55 and 56 and interposed in the straps 55 and 56 are rubber straps 51 and 58. The rubber strap 58 has connected thereto a strap 59 which passes over a pulley 60 secured in a sheave 6| passing through the floor 25 of the frame and the opposite end of the strap 59 extends through an opening 62 in a pivoted lever 53 having one of its ends connected as at 64 to one of the frame members 23 While the opposite end is provided with a detent 65 adapted to engage a notched segment piece 66 secured also to one of the vertical frame pieces 23. By connecting the opposite end of the rubber strap 51 with the strap-59 it will be obvious that the tension of both straps 51 and 58 may be regulated. to place the drum 5| under different, degrees of tension.
When the pawl 48 is received within the notch in the notched wheel 52, the drum 5| will be rotated against the tension of the rubber straps 51 and 58 as the straps 55 and 55 will wind upon the drum 5| and elongate the rubber straps 51 and 58. After the drum 5| has been rotated a predetermined portion of a revolution, the pawl 48 may be released from the notched wheel 52 by engaging a roller 6'! rotatably mounted between the arms 68, which arms are secured to one of the frame plates 24. The striking arm 42 is operated upon reverse rotation of the drum 5| after said drum has been rotated against the tension of the straps 55 and 56 and elastic elements 51 and 58 and-after the pawl 48 has been released by the trip member secured to the frame in the path of the pawl 48.
Secured to the stub shaft 40 is a pulley 69 having a V-shaped groove 19 in which is positioned a friction member having one of its ends as at 12 anchored to a bracket 73, suitably fastened to one of the side frame plate members 24 by means of a nut and bolt 15. The bracket 13 may be spaced from the frame plates 24 by means of a washer l6 and the opposite end of the friction clamp may be secured to a similar bracket 71 also secured to the frame member 24 by means of a nut and bolt 18 and as shown in Figure 3, a coil spring 19 is adapted to surround a bolt 89 to which the opposite end of the friction element H is connected so that one end of the coil springs will engage the bracket Ti and the opposite end will engage a disk 8| on said bolt 88 whereby the friction band H may be placed under tension in order to brake the rotation of the stub shaft 46 without shock and place the same under friction. I
Carried by the upper end of the vertical frame member 23 is a receptacle 83 having a sloping bottom 84 around which is positioned a shell 85 for the purpose of strengthening the construction. Arranged around the inner circumference of the receptacle 83 are chutes or guides 86 adapted to contain tennis balls in stacked relation and said balls are adapted to rest upon an annular shelf 81 to limit the downward travel of the tennis balls within the chutes 86. The chutes 86 are carried by a disk 88 secured to the upper end of a hollow shaft 89, the lower end of which is journalledin a frame piece 90' and is provided with a worm wheel 9| adapted to mesh with a worm 92 rigidly secured to the drive shaft 36. The annular shelf 8'! is provided with openings of sufficient diameter as at 94 and 94a for the passage of tennis balls whereby one ball at a time may be passed beneath the annular shelf 87 and into a chamber 95 as shown by dotted lines in Figure 2, where they are dispensed through an opening 960. onto the support 91. Slidably secured to the shelf 8'! is an adjustable plate 941) adapted to alternately cover the openings 94 and 94a and said plate may be adjusted by means of a thumb screw 940. If the plate 941) is positioned over the opening 94, the tennis balls will travel a complete revolution in the chamber 95 whereby the ball may be reknapped by the rotary brush. Otherwise the ball dropping through the opening 94 will be immediately dispensed. The disks 88 are provided with ten vertical chutes 86 each of which is adapted to'contain'six tennis balls in such a manner that the ballsmay be dispensed one at a time through the opening formed in the sloping floor 84 of the receptacle so that they may pass upon theirotary support 91 and be-guided thereon by the guideway 99. The. tennis balls are held in position upon the support 91 by means of an arm I secured to the receptacle 83 by means of the bracket IOI held in place by rivets or other fastening elements I02.
It will be noted that the rotary support 91' is mounted on a shaft I03 suitably secured to the crosspiece I having the ends thereof secured to the vertical framem'ember 23. Said rotary support 91 is provided with three faces I06, one of which has one depression where the ball comes to rest and the striking arm projects it in one and the same direction, the second face has two depressions I20 and I2I so positioned that the ball will come to rest in either one of the depressions by chance and the striking arm' will project the ball in two directions to either corner of the tennis court. The third face I06 is smooth and level the ball coming to rest anywhere by chance and when struck by angled face of gut II1 willproject the ball at different directions.
The reversible striking element mounted on the end of the arm 42 comprises as shown in Figtires 5, 6 and '1, a shaft I01 securedto the free end of the striking element 42 by means of a nut I08 and provided on one end of the shaft I01 is a block I09 having a hub IIO for attachment to the end of the shaft I01 as by means of a screw III passing through the block I09 and having its threaded end screwed in the end of shaft I01, block I09 is moved away from block H2 thereby increasing tension of tennis strings II1. At the opposite end of the shaft I01 there is also provided a similar block having a hub II3 loosely mounted upon shaft I01 so that a coil spring H4 may normally urge the hub II3 away from the opposite block I09 this to take up the stretch in the strings and the give in a tennis racket frame at the time of impact with the ball. Rigidly secured upon the shaft I01 at the intermediate portion thereof is a guide block II5 drilled as at IIB for receiving a series of gut strings 1 which are trained around the guide blocks I09 and H2. The gut strings II1 extend through slots H8 formed in blocks I09 and H2 in the end walls as clearly shown in Figures 5, 6 and 7.
It will be noted that the striking element is adapted to pass directly above the tennis ball support 91 and Top Spin can be imparted to the tennis ball when striking face is tilted to strike the tennis ball above center and Undercut Spin can be imparted to the tennis ball when striking face is tilted to strike the tennis ball below center.
Extending through the hollow shaft 89 is a driven shaft I25 on the upper end of which is rigidly secured a disk I20 provided with a circular brush I21. The periphery of the brush is adapted to contact the tennis ball falling within the chamber 95 for the purpose of cleaning and re-knapping the balls after they have been used and worn smooth in regular play.
The lower end of shaft I25 is provided with a pulley I250. around which is trained as shown in Figure 4 a belt I29 extending over sheaves I30 mounted on axle I3I carried by a bracket I32 rigidly secured to one of frame plates 24 by a nut and bolt I33. The endless belt I29 passes downwardly and is trained over the armature pulley 29 mounted on the armature of the motor 25. Disk I28 attached to shaft 89 is provided with five slots I34 carrying rollers I35 which are adapted to engage a cam portion I30 formed intermediate the ends of a pivoted lever I31, one end of which is pivoted to a bracket I38 secured to one side frame plate member 24 by screws I39 and a pivot' pin I40 extending through the bracket I38 and through one end of the lever I31 and is'held in place by a cotter pin MI. The free end of the pivoted lever I31 extends through a slot in the opposite frame plate member 24 and is provided with a link I42 having one of its ends received in an opening I43 and its opposite end pivotally secured in the upper portion of the frame member 2I as at I44, and capable of being adjusted by means of the thumb screw connection I44a. as shown in Figures 2, 3 and 8.
As shown in Figure 8, the link I42 is detached from the connection I43 and from the upper end of the support 2I whereby the frame 24 may be held stationary by passing the thumb screw through the supporting frame a sufficient distance to engage the series of apertures I42a formed in a plate I421) secured to the frame plates 24. When the thumb screw is engaged with the plate M21) as above described, the link I42 will be in the position shown in Figure 8 and when it is desired to tilt the frame at every other shot the link I42 is connected to the end of the cam bar I31 as at I43 by means of the thumb screw I44a thereby making it necessary to withdraw the thumb screw as shown in Figure 8 and with the same connect lever I31 at I43 to link I42 which is attached to frame I9. Three different tilting angles are possible by connecting thumb screw in three separate holes in link I42.
As disk I28 rotates, the lever I31 is rocked on its pivot I40 which'causes the swinging frame 23 to be rocked on its pivot 22 with respect to the stationary frame I9 whereby tennis balls may be projected alternately in high or low trajectories.
Automatic means is provided for stopping the motor 26 after a predetermined number of balls have been projected and said means comprises a cam I50 mounted upon one end of the shaft 30 adapted to engage a pivoted dog I5I which may be secured to the frame piece 24 and may have its end held into engagement with a ratchet wheel I52 secured to a stub shaft I53 mounted on a suitable bracket I54. The opposite end of the stub shaft I53 is provided with a hand knob I55 having a pointer I56 adapted to register with the graduations on a dial attached to side frame piece 24. One end of a spring I51 is presented to the ratchet wheel I52 in a frictional manner to' hold the wheel in position after it has been stepped a single notch by the pivoted dog I5I. The spring I51 is connected to one of the frame plates 24 as at I59 and has its opposite end encircling the ratchet wheel I52 and is connected to the pivoted dog I5I for normally holding the pivoted dog into engagement with the teeth on the ratchet wheel I52. A stud is adapted to be secured to one of the radial faces of the ratchet wheel I52 and said stud may engage the arm of a snap switch which may be in a suitable circuit. The switch is not shown but any form of conventional snap switch may be provided having a pivoted lever sufficiently long enough to be engaged by the stud carried upon the ratchet wheel I52. By adjusting the pointer I56 to the graduations on the frame plate 24 (not shown) said graduations may be in the terms of a number of balls projected, which setting will bring the stud on the ratchet wheel I52 into position so that after a predetermined number of balls have been shot and the shaft 36 has been rotated a predetermined number of times to cause the cam I to step the ratchet up to the desired number of balls projected the stud provided on the ratchet wheel will engage theswitch arm and break the circuit through the power supply and motor 26. The motor 26 effects rotation of the shaft 3| by means of the belt and pulley connection between the pulley 28 of the motor and the pulley 33 on the shaft 3 I, rotation of the shaft 3| being transmitted by the worm and worm wheel devices to the disk 4'! that carries the dog 48 for rotation. of the drum 5| that effects rotation of the stub shaft 40 carrying the striker arm 42. The striker arm 42 is moved in a counter-clockwise direction from the position shown in'Figure'3 by action of the motor drive and during such movement, the tension devices 51 and 58 have the tension thereon increased by movement of the strap members 55 and 56 so that when the dog 48 is released from its engagement with the drum 5|, the spring devices 51 and 58 effect a sudden clockwise movement of the striker arm 52 for impinging the ball for the delivery thereof.
It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.
1. A ball projecting machine comprising a base member, a swinging frame carried by the base frame, a receptacle secured to the upper end of the swinging frame adapted to receive a plurality of balls in stacked relation, means for dispensing said balls singly, a support for receiving said balls having a plurality of curved surfaces and different depressions, and means for projecting said balls after they have been dispensed upon said support.
2. A ball projecting machine comprising a base frame, a swinging frame carried by the base frame, a receptacle secured tothe upper end of the swinging frame, means in said receptacle for supporting a plurality of balls in stacked relation, means for dispensing said balls singly, a support for receiving said balls having arcuately curved surfaces, a striking arm for engaging said balls for projecting the same in one or different directions, means for operating the strikirrg arm and means for swinging said frame with respect to the base frame. whereby different trajectories may be imparted to said balls.
3. Av ball projecting machine comprising a base frame, a swinging frame carried by the base frame, means for dispensing a plurality of balls carried by the upper end of the swinging frame, a support for receiving said balls, a striking arm for engaging the balls and projecting the same in one. orv different directions, means for operating the swinging arm comprising a driven shaft, a motor for driving said shaft, a clutch connecting said shaft to the swinging arm, and means for tripping said clutc 4. A ball striking machine having a striking arm, means for operating the striking arm comprising a motor driven shaft, a clutch for connecting the motor driven shaft to the striking arm, means for placing the striking arm under tension and means for tripping said clutch.
5. A ball striking machine having a striking arm having a ball engaging member on the free end thereof which is strung with regular gut strings one surface a flat plane for projecting the balls in one direction and the opposite surface with two planes at angles to each other for projecting the ball in different directions.
EDMUNDO H. SERRANO.