Patent Publication Number: US-11660520-B2

Title: Pneumatic ball launcher

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional application of co-pending U.S. application Ser. No. 17/178,284, filed on Feb. 18, 2021, which claims the benefits of Taiwan application Serial No. 109215973, filed Dec. 3, 2020, the disclosures of which are incorporated by references herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates in general to a ball-ejecting device, and more particularly to a pneumatic ball launcher that has a ball-positioning structure. 
     BACKGROUND 
     Currently, various types of ball-launching apparatuses are already available in the marketplace. These ball-launching apparatuses are to eject balls (such as tennis, baseball, golf, table tennis, etc.) for providing people with the convenience of ball sports (especially when individuals practice alone). 
     In the art, a conventional ball-launching apparatus mainly includes an ejecting tube, a ball-feeding tube connecting to a lateral side of the ejecting tube and a compressed-air ejecting device connected to one axial end of the ejecting tube, in which the compressed-air ejecting device is further connected with a gas tank. The compressed air in the gas tank is suddenly discharged to generate an impulsive push for the compressed-air ejecting device to strongly drive the ball to move along the ejecting tube. In this apparatus, the ball-driving force is parallel to an axial direction of the ejecting tube. Thereupon, the ball can be ejected out of the ejecting tube from a free end thereof at a high speed. 
     In the aforesaid conventional ball-launching apparatus, the user can adjust the air pressure inside the gas tank so as to vary the ejection speed of the ball. Ideally, as long as setting of the apparatus is complete, balls would be continuously ejected by the same angle, direction and range. However, due to some structural factors, the balls inside the ejecting tube are unable to be ejected at the same launch position. In particular, the balls may stray inside the ejecting tube, and extremely continuity and the ejection speed of the ball may be unstable. In addition, if the ball has an uneven surface such as the baseball or softball with stitches, then the balls inside the ejecting tube may move unevenly, and thus the aforesaid shortcoming in the ejecting continuity and stability of the apparatus would be raised. 
     In addition, when the conventional ball-launching apparatus meets a structural problem, and disassembling of the ball-feeding tube or other parts might be necessary, the related maintenance and service work upon the aforesaid mechanisms is usually complicated and time-consuming. 
     Thus, the issue how to provide an improved pneumatic ball launcher that can overcome the aforesaid shortcomings is definitely urgent and important to the skill in the art. 
     SUMMARY 
     Accordingly, in view of the aforesaid shortcomings in the art, it is an object of the present disclosure is to provide a pneumatic ball launcher for resolving these shortcomings. 
     In one aspect of this disclosure, a pneumatic ball launcher includes a tube, a ball pathway unit, a push unit, a holding unit, an airway unit and a pneumatic unit. The tube has a first axial end, a second axial end opposite to the first axial end, and a ball channel thereinside to connect spatially the first axial end and the second axial end. The ball pathway unit is used for connecting one end of the tube and wrapping part of the ball channel. The push unit, having oppositely a third axial end and a fourth axial end, includes a push bar, a slide base, a first driver and a second driver. The push bar, perpendicular to the tube, is used for protruding into the ball channel. The slide base is disposed slidably between the third axial end and the fourth axial end. The first driver, mounted at the slide base, is connected with the push bar for controlling the push bar to longitudinally displace in the ball channel to a fixed position. The second driver, connected with the slide base for controlling the slide base to displace, is used for moving the push bar along the tube to further push a ball to approach the first axial end. The holding unit, detachably connected with the first axial end, is used for holding the ball pushed by the push bar. The airway unit is connected with one end of the holding unit. The pneumatic unit includes a valve mechanism, a pneumatic cylinder and a gas tank. The valve mechanism has an exhalation end connected with the airway unit. The pneumatic cylinder, connected with the valve mechanism at one end thereof connecting the airway unit, is used for controlling the valve mechanism to close or open the exhalation end. The gas tank, connected with the valve mechanism, is used for storing a compressed air. When the valve mechanism opens the exhalation end, the compressed air in the gas tank is discharged into the holding unit via the airway unit to eject the ball out of the tube via the second axial end. An inner diameter of the tube is greater than an outer diameter of the ball, such that the flight pathway and the velocity of the ejected ball won&#39;t be affected. 
     In one embodiment of this disclosure, the holding unit has a sealing ring for holding the ball pushed by the push bar. 
     In one embodiment of this disclosure, the holding unit has a taper opening for holding the ball pushed by the push bar. 
     In one embodiment of this disclosure, the ball pathway unit and the airway unit are detachably connected via a connecting pipe. 
     In one embodiment of this disclosure, the valve mechanism includes an outer casing and a valve. The outer casing, having one end formed as the exhalation end, the pneumatic cylinder being disposed at another end of the outer casing opposite to the exhalation end. The valve, disposed inside the outer casing, has one end thereof connected with the pneumatic cylinder and another end thereof facing the exhalation end. The pneumatic cylinder moves the valve with respect to the exhalation end to close or open the exhalation end. 
     In one embodiment of this disclosure, the valve mechanism has a compressed gas inlet for introducing a compressed air into the gas tank via the valve mechanism. 
     In one embodiment of this disclosure, the valve mechanism is connected with one end of the airway unit, another end of the airway unit is spatially connected with the ball channel, and the airway unit is perpendicular to the tube. In addition, the air out-going direction of the exhalation end is perpendicular to a longitudinal direction of the airway unit. 
     In one embodiment of this disclosure, the tube bifurcates a ball-feeding unit, and the ball-feeding unit includes a ball pathway and a stop block. The ball pathway, used for carrying a plurality of balls, is connected spatially with the ball channel. The stop block, disposed at a connection of the ball pathway and the ball channel, is displaced between a close position and an open position. When the stop block is at the close position, a spatial communication between the ball pathway and the tube is blocked. When the stop block is at the open position, the spatial communication between the ball pathway and the tube is made through so as to have the ball in the ball pathway to fall into the ball channel. 
     In one embodiment of this disclosure, an inner diameter of the tube is greater than an outer diameter of the ball. 
     In another aspect of this disclosure, a pneumatic ball launcher includes a first tube, a ball pathway unit, a push unit, a second tube, a holding unit, an airway unit, a third driver and a pneumatic unit. The first tube has a first axial end, a second axial end opposite to the first axial end, and a first ball channel thereinside to connect spatially the first axial end and the second axial end. The ball pathway unit is used for connecting one end of the first tube and wrapping part of the first ball channel. The push unit, having oppositely a third axial end and a fourth axial end, includes a first push bar, a slide base, a first driver and a second driver. The first push bar, perpendicular to the first tube, is used for protruding into the first ball channel. The slide base is disposed slidably between the third axial end and the fourth axial end. The first driver, mounted at the slide base, is connected with the first push bar for controlling the first push bar to longitudinally displace in the first ball channel to a fixed position. The second driver, connected with the slide base for displacing the slide base, is used for moving the first push bar along the first tube to further push a ball to approach the first axial end. The second tube has one end connected with the ball pathway unit and a second ball channel formed thereinside. The holding unit is disposed slidably in the second tube for holding the ball pushed by the first push bar. The airway unit is connected with another end of the second tube. The pneumatic unit includes a valve mechanism, a pneumatic cylinder and a gas tank. The valve mechanism has an exhalation end connected with the airway unit. The pneumatic cylinder, connected with the valve mechanism at another end thereof opposite to the end connecting the airway unit, is used for controlling the valve mechanism to close or open the exhalation end. The gas tank, connected with the valve mechanism, is used for storing a compressed air. When the valve mechanism opens the exhalation end, the compressed air in the gas tank is discharged into the second tube via the airway unit to eject the ball out of the first tube via the second axial end. 
     In one embodiment of this disclosure, the third driver utilizes a buckle unit to detachably connect a protrusive portion of the holding unit, and the buckle unit includes a buckling portion and a pin portion. The buckling portion is used for buckling the protrusive portion of the holding unit. The pin portion is used for pushing the holding unit to separate the buckling portion from the protrusive portion of the holding unit. 
     In one embodiment of this disclosure, the third driver utilizes a second push bar to control the buckle unit to displace in the second tube. 
     In one embodiment of this disclosure, the ball pathway unit and the airway unit are detachably connected via the second tube. 
     In one embodiment of this disclosure, an inner diameter of the first tube is greater than an outer diameter of the ball, and an inner side wall of the second tube can be mirror polished and treated with chemical nickel. 
     Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present disclosure and wherein: 
         FIG.  1    is a schematic exploded and cross-sectional view of a first embodiment of the pneumatic ball launcher in accordance with this disclosure; 
         FIG.  2    is a schematic cross-sectional view of  FIG.  1   ; 
         FIGS.  3 A- 3 E  show, in schematic cross-sectional views, different operation stages of the first embodiment of the pneumatic launcher in accordance with this disclosure; 
         FIG.  4    is a schematic exploded and cross-sectional view of a second embodiment of the pneumatic ball launcher in accordance with this disclosure; 
         FIGS.  5 A- 5 D  show, in schematic cross-sectional views, different operation stages of the second embodiment of the pneumatic launcher in accordance with this disclosure; 
         FIG.  6 A  is a schematic cross-sectional view of another embodiment of the holding unit in accordance with this disclosure; 
         FIG.  6 B  is a schematic cross-sectional view showing that the holding unit of  FIG.  6 A  holds a ball; 
         FIG.  7 A  is a schematic cross-sectional view of a further embodiment of the holding unit in accordance with this disclosure; and 
         FIG.  7 B  is a schematic cross-sectional view showing that the holding unit of  FIG.  7 A  holds a ball. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
     Referring to  FIG.  1   , a first embodiment 100 of the pneumatic ball launcher includes mainly a tube  10 , a ball pathway unit  46 , a connecting pipe  36 , a holding unit  20 , a push unit  60 , an airway unit  35  and a pneumatic unit  30 . 
     The ball pathway unit  46  and the airway unit  35  are detachable connected via the connecting pipe  36 . As shown, one end of the ball pathway unit  46  is shaped to have an inner step structure for receiving the connecting pipe  36  to further connect with the airway unit  35 . Practically, the connecting pipe  36  can be made of a metal or a non-metallic material. In the first embodiment of this disclosure, the tube  10 , the ball pathway unit  46 , the connecting pipe  36 , the holding unit  20 , the push unit  60 , the airway unit  35  and the pneumatic unit  30  are all modular designs, thus related maintenance and service can be much convenient, and the product reliability can be substantially enhanced. 
     The push unit  60 , disposed at a lateral side of the ball pathway unit  46 , includes a push bar  601   a , two drivers  601 ,  602  and a slide base  63 . An axial direction (Y-axis direction) of the push bar  601   a  is perpendicular to another axial direction (X-axis direction) of the tube  10 , and the push bar  601   a  can displace into the ball channel  13  in the Y-axis direction. 
     The push unit  60  has oppositely a third axial end  61  and a fourth axial end  62 . The driver  601  is connected with the slide base  63 . An axial line connecting the third axial end  61  and the fourth axial end  62  is parallel to a Z-axis direction. 
     The first driver  601  controls the push bar  601   a  to displace in the Y-axis direction between a standby position and a push position in the ball channel  13 . 
     The first driver  601  is perpendicular to the second driver  602 . According to this disclosure, the first driver  601  and the second driver  602  can be pneumatic cylinders, hydraulic tanks, mechanical devices, electric devices or the like devices. 
     The first driver  601 , mounted at the slide base  63 , and the slide base  63  is slidably disposed between the third axial end  61  and the fourth axial end  62 . 
     The second driver  602 , connected to one end of the slide base  63 , is to control the displacement of the slide base  63  so as to allow the push bar  601   a  to push a ball  50 A located close to a first axial end  11  to slide along the tube  10  in the axial direction. Practically, when the slide base  63  is pushed to the third axial end  61  by the second driver  602 , the push bar  601   a  would move with the slide base  63  to push the ball  50 A along the tube  10  to be held by the sealing ring  201  of the holding unit  20 , such that the ball  50 A can be well positioned. 
     Another end of the ball pathway unit  46  is to connect with one end of the tube  10 , while the other end of the ball pathway unit  46  is to sleeve part of the connecting pipe  36 . 
     As shown in  FIG.  2   , the pneumatic unit  30  includes a valve mechanism  31 , a pneumatic cylinder  32  and gas tank  33 . The valve mechanism  31  includes an outer casing  311  and a valve  312 . One end of the outer casing  311  is formed as an exhalation end  313  to connect the airway  34 , while another end thereof is connected with the pneumatic cylinder  32 . The valve  312 , disposed inside the outer casing  311 , has one end to connect the pneumatic cylinder  32 , while another end thereof is close to the exhalation end  313 . By having the pneumatic cylinder  32  to move the valve  312  of the valve mechanism  31  with respect to the exhalation end  313 , the exhalation end  313  can be either closed or opened. As shown in  FIG.  2   , the exhalation end  313  is in a close state. 
     The valve mechanism  31  is connected to one end of the airway unit  35 , and another end of the airway unit  35  is connected spatially with the airway  34 . A longitudinal direction (Y-axis direction) of the airway unit  35  is perpendicular to the axial direction (X-axis direction) of the ball channel  13 . A discharge direction (X-axis direction) of the exhalation end  313  is perpendicular to the longitudinal direction (Y-axis direction) of the airway unit  35 . The gas tank  33  is connected with the valve mechanism  31  via a connecting pipe  33   a . The valve mechanism  31  has a compressed gas inlet  314  for providing the compressed air to the valve mechanism  31 , and further to the gas tank  33 . The compressed air is stored inside the gas tank  33 . As shown in  FIG.  2   , the exhalation end  313  is in a close state. 
     Referring to  FIG.  2   , in order to clearly show the way of the holding unit  20  to hold the ball  50 A thereinside, the tube  10 , the ball pathway unit  46 , the connecting pipe  36 , the holding unit  20 , the airway unit  35  and the pneumatic unit  30  are all illustrated in a cross-sectional manner, but particularly the push unit  60  is omitted. 
     The tube  10  has a first axial end  11 , a second axial end  12  opposite to the first axial end  11 , and the ball channel  13  connecting the first axial end  11  and the second axial end  12  inside the tube  10 . 
     A ball-feeding unit  40 , bifurcation from the tube  10 , includes a ball pathway  41  and a stop block  42  connecting the pathway  41 . The ball pathway  41 , used for carrying a plurality of balls  50 B- 50 C, is connected spatially with the ball channel  13 . The stop block  42  is disposed at the connection of the ball pathway  41  and the ball channel  13 . The stop block  42 , connected with and also controlled by the driver  43 , is to displace in the Y-axis direction between a close position and an open position. In this disclosure, the driver  43  can be a pneumatic cylinder, a hydraulic tank, a mechanical device, an electric device or any the like. As shown in  FIG.  2   , the stop block  42  is at the close position to interrupt the spatial connection between the ball pathway  41  and the ball channel  13 . As the stop block  42  is elevated to reach the open position, the spatial connection between the ball pathway  41  and the ball channel  13  can be established, such that the balls  50 A- 50 C in the ball pathway  41  can be provided automatically into the ball channel  13  by gravity. 
     In order to ensure that only one ball can be supplied to the ball channel  13  in each open operation, thus a stop lever  44  can be introduced. An axial direction (Z-axis direction) of the stop lever  44  is perpendicular to the longitudinal direction (X-axis direction) of the ball channel  13 . The stop lever  44  is connected with the driver  45 , and so the driver  45  can control the stop lever  44  to displace in the axial direction (Z-axis direction) between a protrusive position and a retrieval position. In this disclosure, the driver  45  can be a pneumatic cylinder, a hydraulic tank, a mechanical device, an electric device or any the like. 
     As shown in  FIG.  2   , the stop lever  44  is at the retrieval position, and thus the balls  50 B- 50 C are stopped by the stop block  42  for not falling into the ball channel  13 . As the stop block  42  is elevated to reach the open position, the stop lever  44  also reaches the protrusive position to provide a free end thereof to contact one side of the ball  50 B in the ball pathway  41 , such that a plurality of balls  50 B- 50 C can be retained in the ball pathway  41 . Thereupon, it can be ensured that only the ball  50 A close to the stop block  42  in the ball pathway  41  is allowed to drop into the ball channel  13 . 
     The holding unit  20  has two through holes extended radially to align with the airway  34  of the airway unit  35 , and thus to connect spatially with the airway  34 . The holding unit  20  is connected with the first axial end  11  of the tube  10 . Practically, the holding unit  20  can be inserted into the airway unit  35 , the connecting pipe  36  and the ball pathway unit  46 , and can be fixed to one end of the airway unit  35  by specific fasteners such as screws. 
     It is noted that the holding unit  20  of the first embodiment is connected with the first axial end  11  of the tube  10  in a detachable manner, such that maintenance of the sealing ring  201  can be much easier. In this disclosure, the sealing ring  201  can be made of SILICONE/VMQ, FPM/FKM/VITON, CR/NEOPRENE, NBR/NITRILE/BUNA-N, HNBR or any elastic material the like. 
     It shall be explained that the drivers  43 ,  45 ,  601  and  602 , the pneumatic cylinder  32  and the valve  312  can be controlled by a computer or adequate programs. In addition, the magnitude of the forcing for ejecting the ball is related to the capacity of the gas tank  33  and the air pressure entering the gas tank  33 . 
     Referring now to  FIG.  2   , and  FIG.  3 A  to  FIG.  3 E , operation of the pneumatic ball launcher of this disclosure includes the following steps. 
     Step  1 : As shown in  FIG.  2    and  FIG.  3 A , the stop block  42  is at the close position to retain the balls  50 A- 50 C in the ball pathway  41 , the push bar  601   a  is at the standby position, the compressed air is remained inside the gas tank  33 , and the exhalation end  34  is closed. 
     Step  2 : As shown in  FIG.  2    and  FIG.  3 B , the driver  601  of the push unit  60  protrudes the push bar  601   a  into the ball channel  13 , the stop block  42  is elevated to the open position so as to have the stop lever  44  to reach the protrusive position to retain the balls  50 B- 50 C in the ball pathway, and the ball  50 A drops into the ball channel  13  to form contact with the push bar  601   a.    
     Step  3 : As shown in  FIG.  2    and  FIG.  3 C , after the ball  50 A falls into the ball channel  13 , the stop block  42  is lowered back to the close position so as to retrieve the stop lever  44  back to the retrieval position, the driver  602  pushes the slide base  63  to move toward the third axial end  61 , and then the push bar  601   a  drives the ball  50 A to approach the holding unit  2  till a portion of the ball  50 A is held by the sealing ring  201  in the holding unit  20 . 
     Step  4 : As shown in  FIG.  2    and  FIG.  3 D , both the first driver  601  and the second driver  602  resume their own initial states and initial positions, and the slide base  63  contacts the fourth axial end  62 . 
     Step  5 : As shown in  FIG.  2    and  FIG.  3 E , the pneumatic cylinder  32  pulls the valve  312  to open the exhalation end  313  so as to suddenly discharge the compressed air inside the gas tank  33  into the airway unit  35 , the holding unit  20  and the ball channel  13 , and thus the ball  50 A is ejected out of the tube  10  via the second axial end  12 . In this embodiment, with the holding unit  20 , the ball  50 A can be located to an ejection position in the ball channel  13 . In accordance with the first embodiment of this disclosure, the ball can be a tennis, a baseball, a golf, a table tennis or any non-metallic ball. In addition, with the inner diameter of the tube  10  to be greater than the outer diameter of the ball  50 A, such that the flight path and velocity of the ball  50 A won&#39;t be affected. 
     After the ball  50 A is ejected, then go back to Step  1  to have the push bar  601   a  stopped at the standby position, the valve  312  is closed, and then Steps  2 - 5  can be orderly performed to eject another ball. By repeating Steps  1 - 5 , the balls can be ejected continuously. 
     Referring to  FIG.  4   , an exploded view of a second embodiment of the pneumatic ball launcher in accordance with this disclosure is schematically shown. A difference between this second embodiment and the aforesaid first embodiment is that, in this second embodiment, the holding unit  20  is further furnished with a protrusive portion  20   a . Thereupon, the driver  80  can be buckled to the holding unit  20  so as to control the movement of the holding unit  20  in the second ball channel  71  of the second tube  70 . Practically, the driver  80  can be buckled with the protrusive portion  20   a  of the holding unit  20  via a buckle unit  800 . 
     As shown in  FIG.  5 A , the buckle unit  800  includes a buckling portion  801  and a pin portion  802 . The buckling portion  801  is used for buckling the protrusive portion  20   a  of the holding unit  20 , and the pin portion  802  is used for pushing the holding unit  20  so as to separate the buckling portion  801  from the protrusive portion  20   a  of the holding unit  20 . As shown in  FIG.  4   , the driver  80  is connected to one end of the airway unit  35 , while another end of the airway unit  35  is detachably connected to the ball pathway unit  46  via the second tube  70 . 
     It is noted that, in this second embodiment, the tube  10 , the ball pathway unit  46 , the second tube  70 , the holding unit  20 , the push unit  60 , the airway unit  35  and the pneumatic unit  30  are all modular designs, such that related maintenance and service can be much convenient, and the product reliability can be substantially enhanced as well. 
     Referring to  FIG.  4   , and  FIG.  5 A  through  FIG.  5 D , operation of the second embodiment of the pneumatic ball launcher of this disclosure includes the following steps. 
     Step  10 : As shown in  FIG.  4    and  FIG.  5 A , after the ball  50 A is pushed to enter the sealing ring  201  of the holding unit  20  via the push bar  601   a , the compressed air is stayed in the gas tank  33 , and the exhalation end  313  is in a close state. Then, the buckle unit  800  is buckled with the protrusive portion  20   a  of the holding unit  20 . 
     Step  20 : As shown in  FIG.  4    and  FIG.  5 B , when the push bar  80   a  is retrieved back into the driver  80 , the pin portion  802  is pushed out in the axial direction of the second tube  70  to contact at a bottom portion of the holding unit  20  so as to leave the clip portion  801  from the protrusive portion  20   a.    
     Step  30 : As shown in  FIG.  4    and  FIG.  5 C , the pneumatic cylinder  32  pulls the valve  312  to open the exhalation end  313  so as to suddenly discharge the compressed air inside the gas tank  33  into the airway unit  35 , the holding unit  20  and the second ball channel  71 . Thereupon, the holding unit  20  can be pushed to the first axial end  11 . With the holding unit  20 , the ball  50 A can be fixed at the standby position inside the ball channel  13 . In this second embodiment, the ball can be a tennis, a soft ball or any ball with a slight irregular surface. In addition, the inner side wall of the tube  70  can be mirror polished and treated with chemical nickel, so that the smoothness can be substantially enhanced. Thus, friction can be reduced while the holding unit  20  is sliding along the tube  70 . Also, by having the inner diameter of the tube  10  to be greater than the outer diameter of the ball  50 A, the flight path and velocity of the ball  50 A won&#39;t be affected. 
     Step  40 : As shown in  FIG.  4    and  FIG.  5 D , the holding unit  20  would be stopped by the internal step structure of the ball pathway unit  46 , but the ball  50 A would leave the sealing ring  201  due to inertial motion. Then, the ball  50 A would be ejected out of the tube  10  via the second axial end  12 . After the ball  50 A is ejected, then go back to Step  10 , where the push bar  601   a  is at the standby position, the valve  312  is closed, and the Steps  2040  can be orderly performed to eject another ball. By repeating Steps  1050 , the balls can be continuously launched. 
     Referring to  FIG.  6 A , another embodiment of the holding unit is schematically shown in a cross-sectional view. In this embodiment, one end of the holding unit  20  is furnished with a taper opening for holding the ball  50 A (see  FIG.  6 B ), and the aforesaid sealing ring  201  is waived. An angle θ of the taper opening can be determined by the size of the ball  50 A, preferably ranging from 5 to 10 degrees. 
     Referring to  FIG.  7 A , a further embodiment of the holding unit is schematically shown in a cross-sectional view. In this embodiment, one end of the holding unit  20  is furnished with a taper opening for holding the ball  50 A (see  FIG.  7 B ), and the aforesaid sealing ring  201  is waived. An angle θ of the taper opening can be determined by the size of the ball  50 A, preferably ranging from 5 to 10 degrees. 
     In summary, the pneumatic ball launcher provided by this disclosure introduces the holding unit to position the ball, so that the ball would be fixed inside the tube without unexpected moment. Thereupon, the aforesaid shortcomings of continuity in launching balls and stability in ejection velocity can be resolved. In addition, by introducing modular designs, the pneumatic ball launcher can be easily adjusted to meet different balls, thus related maintenance and service can be much convenient, and the product reliability can be substantially enhanced. 
     With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the disclosure, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present disclosure.