Abstract:
The automatic ball collection system contains a blower sub-system and a collection device. The blower sub-system drives the balls on the ground towards the collection device, and the balls are then automatically collected by the collection device. The blower sub-system contains a number of blowing devices configured at the corners capable of producing air flow substantially along ground surface so as to push the balls to roll towards the collection device. As such, the players&#39; time and effort in constant bending and picking up balls, and the possible injury resulted as such are avoided.

Description:
(A) TECHNICAL FIELD OF THE INVENTION 
     The present invention is generally related to the sport of table tennis, and more particularly to a system for automatically collecting the halls on the ground of a table tennis court. 
     (B) DESCRIPTION OF THE PRIOR ART 
     Table tennis, also known as ping-pong, is a popular sport for all ages in which players hit a hollow ball back and forth across a net over a hard table. 
     During a game, if the ball drops on the ground, the players must bend or squat down to pick up the ball. The constant activity of picking up the dropped ball put significant burden on, and sometimes even injury to, the backs and knees of the players, especially for elder players. It is also quite often that the dropped ball rolls under the table, making the picking up even more difficult. It is not uncommon that more than one third of the time is spent on picking up balls during a game or practice. 
     Specifically during practice, a large number of balls are used and the dropped balls are spread around the court. Collecting the balls would consume a lot of time and effort. If the balls are left un-collected, the players may step on the balls, thereby damaging or tripping over the balls. 
     Currently, there is a ball collection system commercially available similar to a vacuum cleaner, which involves a base, an air guiding device, a flexible pipe, and a pressure adjusting device. Firstly, the flexible pipe is connected to a blowing end of the air guiding device and the balls on the ground are blown to a spot. Then, the flexible pipe is connected to a sucking end of the air guiding device and the balls gathered at the spot are sucked into a collection box of the base. The ball collection system still requires manual operation and the operator still has to bend or squat down. 
     SUMMARY OF THE INVENTION 
     As such, an automatic ball collection system for automatically collecting the balls spreading on the ground of a table tennis court so as to avoid the time and effort of the players in constant bending and picking up balls, and the possible injury resulted as such. 
     The ball collection system contains a blower sub-system and a collection device. The blower sub-system dives the balls on the ground towards the collection device, and the balls are then automatically collected by the collection device. The blower sub-system contains a first blowing device, a second blowing device, a third blowing device, and a fourth blowing device, each configured at a corner capable of producing air flow substantially along ground surface so as to push the balls to roll. 
     The collection device is configured inside an area surrounded by the first, second, third, and fourth blowing devices. The collection device contains a pipe, a fifth blowing device, and a basket. The pipe has a diameter larger than that of the balls P and has an air inlet positioned adjacent to the ground. The fifth blowing device has a fifth air outlet connected to an end of the pipe so that air is driven in the pipe. The basket is connected to the other end of the pipe for receiving the balls collected through the pipe. 
     The balls on the ground are first forced to roll towards the air inlet by the first, second, third, and fourth blowing devices. As the balls are in close proximity of the air inlet, they are then further drawn into the air inlet through the negative pressure created by the fifth blowing device. The balls are subsequently pushed along the pipe and finally received by the basket. As such, the players are free from the constant bending and picking up balls, and the possible injury resulted. 
     An optional control device could be configured to control the on/off and magnitude of air flow of the blowing devices at the corners and the fifth blowing device. The control device could be further electrically connected to a sensor to detect the location of the balls so as to achieve higher efficiency. 
     Each of the blowing devices at the corners could be installed on a ramp so that the balls would not roll into some dead space where the air flow from the corner blowing devices cannot reach. 
     The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which, a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic top-view diagram showing an automatic ball collection system according to an embodiment of the present invention. 
         FIG. 2  is a top-view diagram showing a blower sub-system of the automatic ball collection system of  FIG. 1 . 
         FIG. 3  is a perspective diagram showing a first blowing device of the automatic ball collection system of  FIG. 1 . 
         FIG. 4  is a perspective diagram showing a collection device of the automatic ball collection system of  FIG. 1 . 
         FIG. 5  is a perspective diagram showing an air inlet of the collection device of  FIG. 4 . 
         FIG. 6  is a perspective diagram showing an optional control device for the automatic ball collection system of  FIG. 1 . 
         FIG. 7  is a top-view diagram showing an optional net is configured with the automatic ball collection system of  FIG. 1 . 
         FIG. 8  is a perspective diagram showing the net of  FIG. 7 . 
         FIG. 9  is a perspective diagram showing an embodiment of the blowing devices as a cross-flow fan. 
         FIG. 10  is a perspective diagram showing a cross-flow fan of  FIG. 9  integrated with a top slant plate and two blocking plates. 
         FIG. 11  is a top-view diagram showing a blower sub-system of the automatic ball collection system of  FIG. 1  using the cross-flow fan of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
     As shown in  FIGS. 1 to 5 , an automatic ball collection system according to an embodiment of the present invention contains a blower sub-system  10  and a collection device  20 . The blower sub-system  10  drives the balls P on the ground towards the collection device  20 , and the balls are then automatically collected by the collection device  20 . 
     The blower sub-system  10  contains a first blowing device  11 , a second blowing device  12 , a third blowing device  13 , and a fourth blowing device  14 . The four blowing devices are for the generation and delivery of air flow. In the present embodiment, the four blowing devices are of the same device but this is not a requirement. As shown in  FIG. 3 , the first blowing device  11  has a first air outlet  111  and, similarly, the second, third, and fourth blowing devices  12 ,  13 , and  14  have an air outlet, respectively (as the blowing devices are identical, the other air outlets are not numbered). The air flow produced by the first, second, third, and fourth blowing devices  11 ,  12 ,  13 , and  14  are directed towards the ground through their respective air outlets. 
     As shown in  FIGS. 1 to 3 , the first, second, third, and fourth blowing devices  11 ,  12 ,  13 , and  14  are positioned at an area Z&#39;s four corners, all having their outlets facing the area Z. The tennis table and other related apparatus are placed in the area Z. Again, using the first blowing device  11  as example, each of the blowing devices has a turning member  112 , adjusting the air outlet  111 &#39;s direction. As such, the air flow produced and delivered by the blowing devices  11 ,  12 ,  13 , and  14  cover the entire area Z. A blowing device involving a turning member and an air outlet could be implemented in various ways such as an electric fan, and its details are omitted here. 
     As shown in  FIGS. 4 and 5 , the collecting device  20  is placed inside the area Z and contains a pipe  21 , a fifth blowing device  22 , and a basket  23 . The pipe  21  has a diameter larger than that of the balls P and has an air inlet  211  positioned adjacent to the ground. The air inlet  211  has an aperture larger than the balls P&#39;s diameter. The fifth blowing device  22  has a fifth air outlet  221  connected to an end of the pipe  21  so that air is driven in the pipe  21 . The basket  23  is connected to the other end of the pipe  21  for receiving the balls P collected through the pipe  21 . 
     As shown in  FIG. 1 , the way the present system collecting balls P on the ground is first to force the balls P to roll towards the air inlet  211  by the blowing devices  11 ,  12 ,  13 , and  14 . As the balls P are in close proximity of the air inlet  211 , they are then further drawn into the pipe  21  through the suction created by the fifth blowing device  22 . The balls P are subsequently pushed along the pipe  21  and finally received by the basket  23 . More specifically, the high-pressure air stream created by the fifth blowing device  22  not only creates the negative pressure to suck the neighboring balls P into the air inlet  211 , but also provides the force to roll the balls P in the pipe  21  into the basket  23 . 
     The basket  23  could be positioned an appropriate place depending on the actual environment and user requirement. In the present embodiment, it is positioned beneath and adjacent to an end of the table so that a player could easily pick up a ball collected in the basket  23 . 
     Each of the blowing devices  11 ,  12 ,  13 , and  14  could be any device capable of producing air flow such as a blower, a cross-flow fan, or an electrical fan. 
     As shown in  FIG. 6 , an optional control device  30  could be electrically connected to the blowing devices  11 ,  12 ,  13 ,  14 , and  15 , and related control software is installed and executed by the control device  30 . The control device  30  therefore could, for example, decide a sequence of turning on the blowing devices  11 ,  12 ,  13 ,  14 , and  15 , or provide a timing function. The control device  30  could be further electrically connected to a sensor at an appropriate place. The sensor could detect the location of the balls P and transmit the relevant information to the control device  30  which in turn could decide whether to turn on the fifth blowing device  22 , or simply to turn on one or more near-by blowing devices, so as to achieve higher efficiency. The sensor should be well understood for people in the related art and therefore it is not shown in the accompanied drawings. There is also no special requirement to the sensor and any sensor capable of detecting object location could be used. 
     As shown in  FIG. 3 , each of the blowing devices  11 ,  12 ,  13 , and  14  could be installed on a ramp  40  so that the balls P would not roll into some dead space where the air flow from the blowing devices  11 ,  12 ,  13 , and  14  cannot reach. 
     As further shown in  FIGS. 7 and 8 , a net  50  could be optionally raised by a number of moveable poles  51  surrounding the blowing devices  11 ,  12 ,  13 , and  14  so as to avoid the balls P from flying out of the area Z. Each pole  51  could have a water-filled base. When put to use, the bases are filled with water so as to provide solid foundations for the poles  51 . After use, the bases could be emptied to facilitate transportation. Furthermore, a band  52  could be configured along the bottom rim of the net  50 . With the band  52 , the stability of the net  50  is enhanced and the balls P will only roll smoothly along the band  52 , instead of sticking in the meshes of the net  50 . 
     Additionally, two slant guiding plates  212  could be configured at each of the two sides of the air inlet  211  facing two opposing sides of the area Z so as to facilitate the collection the balls P into the air inlet  211 . 
       FIGS. 9 to 11  illustrate an embodiment of the blowing devices where each of the blowing devices  11 ,  12 ,  13 , and  14  is implemented as a cross-flow fan A. Each cross-flow fan A contains an air outlet A 1  and a guiding member A 2  is configured in front of the air outlet A 1  so as to direct the air flow towards a specific direction. The guiding member A 2  contains a number of fans A 21 , a connecting rod A 22 , a linking rod A 23 , a disc A 24 , and a driving element A 25 . Each of the fans A 12  is pin-joined to the air outlet A 1  and is threaded through by the connecting rod A 22 . An end of the connecting rod A 22  is pin-joined to the linking rod A 23  which in turn is pin-joined to the disc A 24 . The disc A 24  is driven by the driving element A 25 . When the disc A 24  spins for an angle, the linking rod A 23  is engaged and therefore the connecting rod A 22  is put into a lateral back-and-forth movement. The fans A 21  are as such swung laterally relative to the air outlet A 1 . 
     As shown in  FIG. 10 , a plate A 3  is configured slantwise above the cross-flow fan A so that no balls P would accumulate on the cross-flow fan A. A number of vent holes A 31  could be configured on the plate A 3  to facilitate air circulation. Furthermore, two blocking plates A 4  are configured at the two lateral sides of the cross-flow fan A so as to prevent the balls P from entering some dead space between the cross-flow fan A and the walls. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.