Induced air device for discharging spherical members
United States Patent 3905349
A device for discharging spherical members such as tennis balls, baseballs, etc., comprises a discharge tube through which the spherical members are adapted to be fed, which includes a discharge end and an opposite receiving end having a receiving tube therein for the passage of the spherical members through the receiving tube and into the discharge tube. A fan is arranged to discharge air into a chamber for flow in the annular space around the receiving tube into the discharge tube, and it produces a reduced pressure at the inner end of the receiving tube so that spherical members such as tennis balls, baseballs, etc., which are delivered to the receiving tube are induced to flow into the discharge tube. The apparatus also includes a detent in the form of an elastic rubber sleeve member which arrests a ball after it is first induced to flow through the receiving tube and into the discharge tube toward the discharge end thereof. After the ball is arrested, the pressure within the tube builds up until the arresting force of the detent is overcome and the ball is hurled outwardly from the discharge end of the discharge tube.
US Patent References:
/1082113.html
Diden - December 1913 - 1082113
Machine-gun toy
Stough - October 1920 - 1356664
Pneumatic gun
Boynton - January 1943 - 2307015
Pneumatic conveying apparatus
Sweeny - February 1943 - 2310265
Pneumatic gun
Hale - September 1944 - 2357951
/1082113.html
Diden - December 1913 - 1082113
Machine-gun toy
Stough - October 1920 - 1356664
Pneumatic gun
Boynton - January 1943 - 2307015
Pneumatic conveying apparatus
Sweeny - February 1943 - 2310265
Pneumatic gun
Hale - September 1944 - 2357951
Inventors:
Nielsen, John (Freeport, NY)
Church, Joseph H. (North Situate, RI)
Church, Joseph H. (North Situate, RI)
Application Number:
05/312874
Publication Date:
09/16/1975
Filing Date:
12/07/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
124/44.700, 124/50, 406/153, 124/56
International Classes:
A63B69/40; B65G51/28; B65G53/14; F41F1/04
Field of Search:
124/11R,29,3R,41,50,51R,51A,52,53 243/25 302/2R,21,24,25
US Patent References:
Primary Examiner:
Apley, Richard J.
Assistant Examiner:
Stouffer R. T.
Attorney, Agent or Firm:
Mcglew, And Tuttle
Claims:
What is claimed is
1. A ball throwing device comprising a cylindrical drum, support means for supporting each end of said drum on a base, said drum having its axis substantially horizontal and including a front end face with a ball throwing tube support bracket mounted thereon, a ball throwing tube pivotally supported on said bracket, said ball throwing tube having an intermediate flexible portion and an inner portion extending into said drum, a ball receiving tube in said drum extending into the inner end of said interior portion of said ball throwing tube, a fan in said drum providing an inducing air flow in the space between said receiving tube and the interior end of said ball throwing tube, a ball feed conduit extending into said drum from the top thereof, a trap door pivotally mounted adjacent the inner end of said ball feeding tube and being biased to a closed position, means for permitting one ball at a time to feed downwardly through said tube and against said trap door, said trap door being oriented to permit rolling of the ball from the delivery tube into said ball receiving tube whereby the inducing air flow causes the movement of the ball through said ball throwing tube, and detent means in said ball throwing tube for temporarily arresting said ball until the pressure therebehind builds up and for then hurling the ball outwardly from the discharge end of the throwing tube.
2. A device according to claim 1 including walls defining a back pressure chamber surrounding the inner end of said receiving tube at the interior of said drum around said ball feeding conduit, said drum having a remaining large area defining a back pressure supplementary area having a communication with said back pressure chamber and a valve means for regulating the communication between said back pressure area and said enlarged supplementary back pressure area.
1. A ball throwing device comprising a cylindrical drum, support means for supporting each end of said drum on a base, said drum having its axis substantially horizontal and including a front end face with a ball throwing tube support bracket mounted thereon, a ball throwing tube pivotally supported on said bracket, said ball throwing tube having an intermediate flexible portion and an inner portion extending into said drum, a ball receiving tube in said drum extending into the inner end of said interior portion of said ball throwing tube, a fan in said drum providing an inducing air flow in the space between said receiving tube and the interior end of said ball throwing tube, a ball feed conduit extending into said drum from the top thereof, a trap door pivotally mounted adjacent the inner end of said ball feeding tube and being biased to a closed position, means for permitting one ball at a time to feed downwardly through said tube and against said trap door, said trap door being oriented to permit rolling of the ball from the delivery tube into said ball receiving tube whereby the inducing air flow causes the movement of the ball through said ball throwing tube, and detent means in said ball throwing tube for temporarily arresting said ball until the pressure therebehind builds up and for then hurling the ball outwardly from the discharge end of the throwing tube.
2. A device according to claim 1 including walls defining a back pressure chamber surrounding the inner end of said receiving tube at the interior of said drum around said ball feeding conduit, said drum having a remaining large area defining a back pressure supplementary area having a communication with said back pressure chamber and a valve means for regulating the communication between said back pressure area and said enlarged supplementary back pressure area.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to devices for hurling or throwing articles and in particular to a new and useful device for discharging spherical members or balls such as tennis balls, baseballs and the like.
2. Description of the Prior Art
At the present time it is known to provide for pneumatically operable devices which are effective to hurl balls outwardly, for example, in a regular sequence. The known devices include means for feeding a series of balls one after the other into a tube which has an air flow therethrough in a manner such that the balls are positioned in the flowing airstream and then moved into association with a detent where they are held temporarily and then discharged into the atmosphere. In the known devices complicated mechanisms are provided for feeding the balls one after the other into the airstream in order that they may be ejected in a selected time sequence.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided an apparatus for inducing the inflow of balls into a discharge tube to cause the ball to flow against an elastic detent of improved construction which arrests the movement of the ball until the pressure behind the ball is built until the pressure has reached a propelling air flow force to hurl the ball outwardly from the discharge tube. Construction includes a receiving tube which is located at the receiving end of the dicharge tube and immediately adjacent a feeding pipe which feeds the spherical members or balls onto a trap door. The trap door is weighted to a closed position and the balls will only be delivered after the pressure in the discharge tube is reduced by the hurling of the previous ball outwardly and the inducing pressure immediately ahead of the receiving tube drops to a point at which the trap door lowers and a single ball is fed into the tube.
An important feature of the present invention is that the velocity of the balls may be adjusted simply and easily by regulating the rate at which the stored air in the air accumulation chamber can enter the discharge tube as the ball is being expelled.
A further important feature of the invention is the construction of the detent, which is in the form of an elastic sleeve having a widened diameter portion which is secured to the interior wall of the discharge tube and which includes a smaller diameter discharge end which forms a construction which permits the ball to pass therethrough only after the ball is acted thereupon by the pressure behind it to force it outwardly at a built up pressure force.
A still further feature of the invention is the construction of the device on an inexpensive container or drum which also includes a pivotal guide for a discharge end of the discharge tube. The discharge end of the discharge tube is advantageously pivotal and is connected to the receiving end of the discharge tube by a flexible connection or bellows-like member.
Accordingly, it is an object of the invention to provide an improved device for throwing balls and similar objects which includes a discharge tube and means for inducing a flow of a ball into the tube toward a detent therein and for building up the pressure behind the ball after it arrives at the detent to cause the pressure to be sufficient to overcome the holding force of the detent and to be hurled outwardly therefrom.
A further object of the invention is to provide a device for the automatic feeding of a series of balls to a receiving tube which is arranged at the receiving end of a discharge tube and which includes a fan for directing air in the annular space between the receiving tube and the discharge tube in order to produce a negative pressure at the inner end of the receiving tube and induce the inflow of a ball into the receiving tube for movement along the discharge tube toward the detent and to effect a gradual build up of pressure behind the ball after it arrives at the detent so that it overcomes the holding force of the detent and is hurled outwardly.
A further object of the invention is to provide a ball throwing device which comprises a drum which is supported in a horizontal position by a U-shaped support at its front end and by a base bracket at its rear end and which includes an infeed conduit for balls on its top side and a throwing tube discharge at its one end and which carries an electric motor driven fan at its interior for inducing the infeed of balls and their throwing out through the outer discharge end of the throwing tube.
A further object of the invention is to provide a ball throwing device which is simple in design, rugged in construction and economical to manufacture.
For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a top perspective view of the ball throwing device constructed in accordance with the invention;
FIG. 2 is a partial transverse sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is a section taken along the line 3--3 of FIG. 2;
FIG. 4 is a section taken along the line 4--4 of FIG. 2;
FIG. 5 is a section taken along the line 5--5 of FIG. 2;
FIG. 6 is a perspective view of another embodiment of the ball throwing device;
FIG. 7 is a section taken along the line 7--7 of FIG. 6;
FIG. 8 is a section taken along the line 8--8 of FIG. 7; and
FIG. 9 is a section taken along the line 9--9 of FIG. 7.
GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, the invention embodied therein comprises a ball throwing device which includes a housing 10 which in the embodiment illustrated, comprises a cylindrical container of a size of a large paint can, for example, having a top cover 12 providing a mounting for a top housing portion 14. The container 10 advantageously rests on a supporting stand 16 which, for example, may have through openings 18 for the flow of air through an inlet 20 upon actuation of a fan 22. The fan 22 is provided with a discharge 24 which connects through a flexible hose 26 to a connection 28 into the top housing part 14. The top housing part 14 communicates with the container interior chamber 30 by a through passage 31.
In accordance with the invention the upper housing carries a discharge tube 32 having a discharge end at one end for the discharge of balls and a ball receiving end 32a at the opposite end located within the upper housing 14. A portion 32b of the discharge tube 32 is pivoted on upstanding brackets 36 for pivotal movement about a horizontal pivot member 38 in order to orient the discharge end (not shown) at a desired angle for the discharge of the balls 40. In order to permit the pivotal movement of the outer end portion 32b, the discharge tube 32 includes an intermediate portion 32c made of a flexible material or formed with a bellows-like wall to permit the pivotal movement.
In accordance with an important feature of the invention the outer discharge end of the tube 32 is provided with a detent means in the form of a sleeve 42 made of an elastic material such as rubber and which includes a wider diameter end portion 42a which is secured against the interior wall of the discharge tube 32 and a smaller diameter end 42b which is oriented toward the discharge end of the discharge tube 32. Balls 40 which are delivered to the detent sleeve 42 are held in the narrow diameter portion 42b until sufficient pressure behind the ball causes the narrow diameter portion 42b to expand and to release the ball for rapid flight out through the discharge end.
In accordance with a further feature of the invention, a ball receiving tube 44 is located at the receiving end 32a of the discharge tube 32 and includes a portion which extends into the tube 32 and defines an annular flow passage 46 between the receiving tube and the discharge tube. The receiving tube 44 supported on a partition 48 which divides the top housing portion 14 into a high pressure flow chamber 50 and a back pressure chamber 52. Air which is discharged through the discharge 28 from the fan 22 moves in the direction of the arrows 54 through the annular passage 46 and, when there is no ball in the detent 42, produces a reduced pressure immediately ahead of the inner end of the receiving tube 44. This also effects a reduction of pressure in the back pressure chamber 52 which, in accordance with a further feature of the invention, is located immediately below a ball feeding tube 54. Balls which are delivered into the tube 54 rest against a pivotal door 56 which is pivoted on a horizontal pivot 58 and which is closed by means of a weight 60 of a size capable of supporting a predetermined number of balls in the tube 54. When the pressure in the chamber 52 is reduced, the door 56 moves downwardly, as indicated by the arrow 62, to permit a ball to move along the door and into the receiving tube 44. The ball 40 is urged through the tube 44 by the reduced pressure immediately ahead of the inner end of the tube and is forced by the flow of the air from the fan through the discharge tube 32 into engagement with the detent 42.
Once the ball is engaged with the detent 42 the pressure behind the ball begins to build up completely into the receiving end of the discharge tube and through the receiving tube 44 into the back pressure chamber 52. This causes the door 56 to shut and permits a further build up of the back pressure until the ball held by the detent 42 is hurled with great force outwardly through the discharge end of the discharge tube 32.
In accordance with a further feature of the invention, the hurling force or velocity of the ball may be varied by varying the build up of back pressure within the container which acts to eject the ball held by the detent 42. This is controlled by regulating the flow area from the chamber 30 of the container 10 through the passage 32 into the back pressure chamber 52. This is done by the provision of a valve member 64 which, as shown in FIG. 3, is pivoted on a vertical pivot 66 and which includes a widened end portion 64a which partly covers the opening to the passage 32. A spring 66 biases the valve member 64 so that the end 64b thereof engages against a cam 68. The cam 68 is carried on a rod 70 which extends upwardly through the cover 12 and the top housing portion 14 and terminates in a control knob 72 which may be actuated by varying the rate of discharge of the balls.
A very important feature of the invention is that it effects automatic control of the pressure at which a ball will be hurled outwardly by a simple valve control mechanism. The operating mechanism for feeding the balls is advantageously completely automatic and the velocity at which the balls will be thrown will depend upon the build up of the back pressure within the chamber and the resilient force which acts on the ball by the detent 42.
The detent 42 is an improvement over the known detents for devices of this nature inasmuch as it comprises a complete sleeve which engages around the whole periphery of the ball and provides a tight seal of the ball passage so that no air pressure escapes during the operation. The arrangement is such that when a ball is finally ejected from the mechanism the pressure in the container reduces so that the next ball is fed by the downward movement of the trap door. The feeding motion of the ball is enhanced by the reduced pressure which is created ahead of the receiving tube so that the ball quickly moves through the receiving tube and is thrown against the detent to cause the trap door to immediately close and stop the feeding of the balls. The weight on the trap door 60 and the sizing of the fan is such that the operation will be rapid and automatic and will require very little maintenance or change. Changes can be made by varying the diameter of the small diameter portion 42 of the detent 42 or by varying the material in which it is made so as to change its elasticity. In addition the size of the weight 60 may be changed as well as its fulcrum arm for regulating the operation of the door 56. Also the size of the container chamber 10 may be varied as desired to produce the preferred operating pressure conditions. In some instances it has been found desirable to form the top housing portion 14 as an integral part of the container 10 and to arrange the container so that it is disposed on its side and with the discharge tube being arranged substantially parallel to the axis of the container rather than normal to it as indicated in FIG. 2.
FIGS. 6-9 show another embodiment of a ball throwing device generally designated 100 which includes a cylindrical container 102 which is arranged with its longitudinal axis substantially horizontal and it is supported on a base plate 104 at its front end by a U-shaped upstanding frame 106. The frame is provided with supporting bolts 108 which extend into the cylindrical container 102 and support it at its front end. The rear end is supported on a small bracket 110 having a ground engaging portion 110a which may be oriented in accordance with the slope of the supporting base 104, for example, to support the container at an orientation in which its longitudinal axis is substantially horizontal.
The container 102 is inexpensively and simply converted to a ball throwing machine by securing a U-shaped mounting bracket 112 to the front face 102a by securing means such as securing bolts 114. The bracket 112 provides a support for a pivot 116 of a throwing tube support 118 which engages around a throwing tube 120. The throwing tube 120 includes an intermediate bellows portion 12a which flexibly connects it to an interior portion 120b. The interior portion 120b is flared at its inner end 120c, and an entrance tube 122 projects into this inner end and defines an annular inducing air flow passage 123 between it and the surrounding tubular portion 120b. A small strip 124 extends through the tubular portion 120b and the entrance tube 122 and provides a runway guide for balls 126 which are induced to flow into the entrance tube and through the throwing tube 120. The balls 126 are delivered through a delivery chute or feed conduit 128, which may, for example, be connected to a widened hopper (not shown). The balls 126 when they feed into the delivery conduit 128, will first engage against a feed regulating member generally designated 130 which has one arm portion 130a which extends through an opening 132 of the conduit and blocks the passage of the ball. The rate of feeding is controlled by a small electric motor 134 arranged in a housing portion 136 and and which drives through a crank arm 7 and a link 139 to the ball feed regulating member 130. The ball feed regulating member is biased by a spring 140 to a position at which it engages with the end 130a and also another end 130b into the receiving recesses 132 and 132' of the delivery conduit 128. Rotation of the crank arm 137 causes the end 130a to move out of the recess 132 to permit a ball 126 to feed downwardly and when this occurs the arm portion 130b moves into the recess 132' to block the further downfeed of another ball until the first ball has cleared the passage.
A ball 126 which does move downwardly in the delivery chute 128 past the feeding arm 130 will open a trap door 140 which is pivoted at 142 and which is weighted by a weight 144 so that it will be normally closed. The weight of the ball opens the trap door 140 and the ball is induced by air flow which is generated by a fan 146 which has a discharge 146a into a space surrounding the tubular portion 120b so that an inducing air flow will enter into the annular space 123 and flow through the flowing tube 120. As soon as a ball 126 is delivered to the entrance tube 122 it is urged by the inducing air flow to move through the inner tubular portion 120b and the bellows 120 a until it moves into a detent 148. The detent comprises a resilient sleeve having a small diameter portion 148a which is smaller than the size of the ball 126 which is being used, so that it arrests the forward movement of the ball at least temporarily. This causes the the pressure produced by the fan 146 to build up backwardly behind the ball and into a back chamber 150 and partially into an enlarged chamber 152 at the interior of the container 102. The amount of air which flows into the enlarged chamber 152 will depend on the position of a valve member 154 which is located to at least partially close a a communicating opening 156 between the back pressure chamber 150 and the enlarged chamber 152. The valve 154 is regulated by an adjusting knob 158 which may be rotated to rotate the valve member 154 in order to vary the size of the opening 156. By this simple means the total back pressure which is generated by the fan can be regulated to thereby produce a regulation upon the amount of force which is built up behind the ball 126 and thus the amount of force at which it would be hurled outwardly from the throwing tube 120, and hence the velocity of the ball. By this simple adjustment a wide variation on the distance at which the ball will travel and the speed of its travel may be obtained.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
1. Field of the Invention
This invention relates in general to devices for hurling or throwing articles and in particular to a new and useful device for discharging spherical members or balls such as tennis balls, baseballs and the like.
2. Description of the Prior Art
At the present time it is known to provide for pneumatically operable devices which are effective to hurl balls outwardly, for example, in a regular sequence. The known devices include means for feeding a series of balls one after the other into a tube which has an air flow therethrough in a manner such that the balls are positioned in the flowing airstream and then moved into association with a detent where they are held temporarily and then discharged into the atmosphere. In the known devices complicated mechanisms are provided for feeding the balls one after the other into the airstream in order that they may be ejected in a selected time sequence.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided an apparatus for inducing the inflow of balls into a discharge tube to cause the ball to flow against an elastic detent of improved construction which arrests the movement of the ball until the pressure behind the ball is built until the pressure has reached a propelling air flow force to hurl the ball outwardly from the discharge tube. Construction includes a receiving tube which is located at the receiving end of the dicharge tube and immediately adjacent a feeding pipe which feeds the spherical members or balls onto a trap door. The trap door is weighted to a closed position and the balls will only be delivered after the pressure in the discharge tube is reduced by the hurling of the previous ball outwardly and the inducing pressure immediately ahead of the receiving tube drops to a point at which the trap door lowers and a single ball is fed into the tube.
An important feature of the present invention is that the velocity of the balls may be adjusted simply and easily by regulating the rate at which the stored air in the air accumulation chamber can enter the discharge tube as the ball is being expelled.
A further important feature of the invention is the construction of the detent, which is in the form of an elastic sleeve having a widened diameter portion which is secured to the interior wall of the discharge tube and which includes a smaller diameter discharge end which forms a construction which permits the ball to pass therethrough only after the ball is acted thereupon by the pressure behind it to force it outwardly at a built up pressure force.
A still further feature of the invention is the construction of the device on an inexpensive container or drum which also includes a pivotal guide for a discharge end of the discharge tube. The discharge end of the discharge tube is advantageously pivotal and is connected to the receiving end of the discharge tube by a flexible connection or bellows-like member.
Accordingly, it is an object of the invention to provide an improved device for throwing balls and similar objects which includes a discharge tube and means for inducing a flow of a ball into the tube toward a detent therein and for building up the pressure behind the ball after it arrives at the detent to cause the pressure to be sufficient to overcome the holding force of the detent and to be hurled outwardly therefrom.
A further object of the invention is to provide a device for the automatic feeding of a series of balls to a receiving tube which is arranged at the receiving end of a discharge tube and which includes a fan for directing air in the annular space between the receiving tube and the discharge tube in order to produce a negative pressure at the inner end of the receiving tube and induce the inflow of a ball into the receiving tube for movement along the discharge tube toward the detent and to effect a gradual build up of pressure behind the ball after it arrives at the detent so that it overcomes the holding force of the detent and is hurled outwardly.
A further object of the invention is to provide a ball throwing device which comprises a drum which is supported in a horizontal position by a U-shaped support at its front end and by a base bracket at its rear end and which includes an infeed conduit for balls on its top side and a throwing tube discharge at its one end and which carries an electric motor driven fan at its interior for inducing the infeed of balls and their throwing out through the outer discharge end of the throwing tube.
A further object of the invention is to provide a ball throwing device which is simple in design, rugged in construction and economical to manufacture.
For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a top perspective view of the ball throwing device constructed in accordance with the invention;
FIG. 2 is a partial transverse sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is a section taken along the line 3--3 of FIG. 2;
FIG. 4 is a section taken along the line 4--4 of FIG. 2;
FIG. 5 is a section taken along the line 5--5 of FIG. 2;
FIG. 6 is a perspective view of another embodiment of the ball throwing device;
FIG. 7 is a section taken along the line 7--7 of FIG. 6;
FIG. 8 is a section taken along the line 8--8 of FIG. 7; and
FIG. 9 is a section taken along the line 9--9 of FIG. 7.
GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings in particular, the invention embodied therein comprises a ball throwing device which includes a housing 10 which in the embodiment illustrated, comprises a cylindrical container of a size of a large paint can, for example, having a top cover 12 providing a mounting for a top housing portion 14. The container 10 advantageously rests on a supporting stand 16 which, for example, may have through openings 18 for the flow of air through an inlet 20 upon actuation of a fan 22. The fan 22 is provided with a discharge 24 which connects through a flexible hose 26 to a connection 28 into the top housing part 14. The top housing part 14 communicates with the container interior chamber 30 by a through passage 31.
In accordance with the invention the upper housing carries a discharge tube 32 having a discharge end at one end for the discharge of balls and a ball receiving end 32a at the opposite end located within the upper housing 14. A portion 32b of the discharge tube 32 is pivoted on upstanding brackets 36 for pivotal movement about a horizontal pivot member 38 in order to orient the discharge end (not shown) at a desired angle for the discharge of the balls 40. In order to permit the pivotal movement of the outer end portion 32b, the discharge tube 32 includes an intermediate portion 32c made of a flexible material or formed with a bellows-like wall to permit the pivotal movement.
In accordance with an important feature of the invention the outer discharge end of the tube 32 is provided with a detent means in the form of a sleeve 42 made of an elastic material such as rubber and which includes a wider diameter end portion 42a which is secured against the interior wall of the discharge tube 32 and a smaller diameter end 42b which is oriented toward the discharge end of the discharge tube 32. Balls 40 which are delivered to the detent sleeve 42 are held in the narrow diameter portion 42b until sufficient pressure behind the ball causes the narrow diameter portion 42b to expand and to release the ball for rapid flight out through the discharge end.
In accordance with a further feature of the invention, a ball receiving tube 44 is located at the receiving end 32a of the discharge tube 32 and includes a portion which extends into the tube 32 and defines an annular flow passage 46 between the receiving tube and the discharge tube. The receiving tube 44 supported on a partition 48 which divides the top housing portion 14 into a high pressure flow chamber 50 and a back pressure chamber 52. Air which is discharged through the discharge 28 from the fan 22 moves in the direction of the arrows 54 through the annular passage 46 and, when there is no ball in the detent 42, produces a reduced pressure immediately ahead of the inner end of the receiving tube 44. This also effects a reduction of pressure in the back pressure chamber 52 which, in accordance with a further feature of the invention, is located immediately below a ball feeding tube 54. Balls which are delivered into the tube 54 rest against a pivotal door 56 which is pivoted on a horizontal pivot 58 and which is closed by means of a weight 60 of a size capable of supporting a predetermined number of balls in the tube 54. When the pressure in the chamber 52 is reduced, the door 56 moves downwardly, as indicated by the arrow 62, to permit a ball to move along the door and into the receiving tube 44. The ball 40 is urged through the tube 44 by the reduced pressure immediately ahead of the inner end of the tube and is forced by the flow of the air from the fan through the discharge tube 32 into engagement with the detent 42.
Once the ball is engaged with the detent 42 the pressure behind the ball begins to build up completely into the receiving end of the discharge tube and through the receiving tube 44 into the back pressure chamber 52. This causes the door 56 to shut and permits a further build up of the back pressure until the ball held by the detent 42 is hurled with great force outwardly through the discharge end of the discharge tube 32.
In accordance with a further feature of the invention, the hurling force or velocity of the ball may be varied by varying the build up of back pressure within the container which acts to eject the ball held by the detent 42. This is controlled by regulating the flow area from the chamber 30 of the container 10 through the passage 32 into the back pressure chamber 52. This is done by the provision of a valve member 64 which, as shown in FIG. 3, is pivoted on a vertical pivot 66 and which includes a widened end portion 64a which partly covers the opening to the passage 32. A spring 66 biases the valve member 64 so that the end 64b thereof engages against a cam 68. The cam 68 is carried on a rod 70 which extends upwardly through the cover 12 and the top housing portion 14 and terminates in a control knob 72 which may be actuated by varying the rate of discharge of the balls.
A very important feature of the invention is that it effects automatic control of the pressure at which a ball will be hurled outwardly by a simple valve control mechanism. The operating mechanism for feeding the balls is advantageously completely automatic and the velocity at which the balls will be thrown will depend upon the build up of the back pressure within the chamber and the resilient force which acts on the ball by the detent 42.
The detent 42 is an improvement over the known detents for devices of this nature inasmuch as it comprises a complete sleeve which engages around the whole periphery of the ball and provides a tight seal of the ball passage so that no air pressure escapes during the operation. The arrangement is such that when a ball is finally ejected from the mechanism the pressure in the container reduces so that the next ball is fed by the downward movement of the trap door. The feeding motion of the ball is enhanced by the reduced pressure which is created ahead of the receiving tube so that the ball quickly moves through the receiving tube and is thrown against the detent to cause the trap door to immediately close and stop the feeding of the balls. The weight on the trap door 60 and the sizing of the fan is such that the operation will be rapid and automatic and will require very little maintenance or change. Changes can be made by varying the diameter of the small diameter portion 42 of the detent 42 or by varying the material in which it is made so as to change its elasticity. In addition the size of the weight 60 may be changed as well as its fulcrum arm for regulating the operation of the door 56. Also the size of the container chamber 10 may be varied as desired to produce the preferred operating pressure conditions. In some instances it has been found desirable to form the top housing portion 14 as an integral part of the container 10 and to arrange the container so that it is disposed on its side and with the discharge tube being arranged substantially parallel to the axis of the container rather than normal to it as indicated in FIG. 2.
FIGS. 6-9 show another embodiment of a ball throwing device generally designated 100 which includes a cylindrical container 102 which is arranged with its longitudinal axis substantially horizontal and it is supported on a base plate 104 at its front end by a U-shaped upstanding frame 106. The frame is provided with supporting bolts 108 which extend into the cylindrical container 102 and support it at its front end. The rear end is supported on a small bracket 110 having a ground engaging portion 110a which may be oriented in accordance with the slope of the supporting base 104, for example, to support the container at an orientation in which its longitudinal axis is substantially horizontal.
The container 102 is inexpensively and simply converted to a ball throwing machine by securing a U-shaped mounting bracket 112 to the front face 102a by securing means such as securing bolts 114. The bracket 112 provides a support for a pivot 116 of a throwing tube support 118 which engages around a throwing tube 120. The throwing tube 120 includes an intermediate bellows portion 12a which flexibly connects it to an interior portion 120b. The interior portion 120b is flared at its inner end 120c, and an entrance tube 122 projects into this inner end and defines an annular inducing air flow passage 123 between it and the surrounding tubular portion 120b. A small strip 124 extends through the tubular portion 120b and the entrance tube 122 and provides a runway guide for balls 126 which are induced to flow into the entrance tube and through the throwing tube 120. The balls 126 are delivered through a delivery chute or feed conduit 128, which may, for example, be connected to a widened hopper (not shown). The balls 126 when they feed into the delivery conduit 128, will first engage against a feed regulating member generally designated 130 which has one arm portion 130a which extends through an opening 132 of the conduit and blocks the passage of the ball. The rate of feeding is controlled by a small electric motor 134 arranged in a housing portion 136 and and which drives through a crank arm 7 and a link 139 to the ball feed regulating member 130. The ball feed regulating member is biased by a spring 140 to a position at which it engages with the end 130a and also another end 130b into the receiving recesses 132 and 132' of the delivery conduit 128. Rotation of the crank arm 137 causes the end 130a to move out of the recess 132 to permit a ball 126 to feed downwardly and when this occurs the arm portion 130b moves into the recess 132' to block the further downfeed of another ball until the first ball has cleared the passage.
A ball 126 which does move downwardly in the delivery chute 128 past the feeding arm 130 will open a trap door 140 which is pivoted at 142 and which is weighted by a weight 144 so that it will be normally closed. The weight of the ball opens the trap door 140 and the ball is induced by air flow which is generated by a fan 146 which has a discharge 146a into a space surrounding the tubular portion 120b so that an inducing air flow will enter into the annular space 123 and flow through the flowing tube 120. As soon as a ball 126 is delivered to the entrance tube 122 it is urged by the inducing air flow to move through the inner tubular portion 120b and the bellows 120 a until it moves into a detent 148. The detent comprises a resilient sleeve having a small diameter portion 148a which is smaller than the size of the ball 126 which is being used, so that it arrests the forward movement of the ball at least temporarily. This causes the the pressure produced by the fan 146 to build up backwardly behind the ball and into a back chamber 150 and partially into an enlarged chamber 152 at the interior of the container 102. The amount of air which flows into the enlarged chamber 152 will depend on the position of a valve member 154 which is located to at least partially close a a communicating opening 156 between the back pressure chamber 150 and the enlarged chamber 152. The valve 154 is regulated by an adjusting knob 158 which may be rotated to rotate the valve member 154 in order to vary the size of the opening 156. By this simple means the total back pressure which is generated by the fan can be regulated to thereby produce a regulation upon the amount of force which is built up behind the ball 126 and thus the amount of force at which it would be hurled outwardly from the throwing tube 120, and hence the velocity of the ball. By this simple adjustment a wide variation on the distance at which the ball will travel and the speed of its travel may be obtained.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.