Patent Publication Number: US-9884228-B2

Title: Racket-stringing machine

Description:
BACKGROUND 
     As a racket is used in play, the strings lose their tension over time and eventually require restringing. String tension is an important aspect of achieving reliable power from a racket. This is true for any racket that utilizes strings, such as for tennis, badminton, racquetball, squash, and so on. 
     Stringing a racket is a time- and labor-intensive endeavor. Even top-of-the-line professional machines still require substantial user input at each step of the process. A professional using a professional machine may still require over 30 minutes to string a single racket, with constant manual inputs required along the way. Several factors complicate the process of stringing a racket. One factor is tension. Each string must be tensioned at a precise level, and that tension needs to be consistent across all of the strings. Uneven tension in some strings will cause errant shots during play. As a result, while stringing a racket the user is constantly clamping and unclamping strings to maintain tension while feeding the string through the various holes in the racket&#39;s frame. Another factor is the process of weaving. While the “main” strings (typically aligned parallel to the longitudinal axis of the racket handle) are strung first, the “cross” strings (typically perpendicular to the main strings) must be weaved through the already-tensioned main strings. The tension in the main strings makes the weaving process more difficult and time consuming. 
     As a result, a need exists for a machine that can substitute some or all of the manual-labor aspects of racket stringing. The present disclosure provides a machine for automated racket stringing that is capable of identifying a type of racket, determining a type of string along with a desired string tension, and automatically string the racket at the desired tension. 
     Other systems, methods, features and/or advantages will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description and be protected by the accompanying claims. 
     SUMMARY 
     The following summary of the invention provides a basic understanding of some aspects of various embodiments of the present disclosure through the use of example embodiments. This summary is intended to supplement, and be read in conjunction with, at least the detailed description, claims, and drawings. 
     In one example embodiment, a device is provided for stringing a racket having a racket frame with holes in the racket frame. The device includes a frame and a cradle rotationally coupled to the frame. The cradle is configured to mechanically secure the racket via the racket frame. The device also includes a grasping element coupled to at least one of the frame and cradle and configured to engage a string and modify the position and/or tension of the string. The device further includes a clamp coupled to at least one of the frame and cradle and configured to engage the string and maintain the position and tension of the string. The device also includes an imagining device and a processor, the processor capable of receiving information from the imaging device indicative of a racket position, hole position, and/or string position, and providing instructions for operating the grasping element, clamp, and/or cradle. 
     The device can also include an actuator coupled to at least one of the frame and cradle and configured to modify the position of a tensioned main string. Further, the processor may be configured to provide instructions for operating the actuator. The device may also include a routing element couple at least one of the frame and cradle and configured to route a cross string perpendicular to the tensioned main string. Again, the processor may be configured to provide instructions for operating that actuator. The processor can also provide instructions at least partially based on the information received from the imaging device. The processor can also automatically obtain, via the Internet, information regarding the racket. Such information may include at least one of racket size, racket shape, racket model, hole layout, string size, and/or string tension. The device can further include a plurality of actuators coupled to at least one of the frame and cradle and configured to modify the position of a plurality of tensioned main strings in an alternating pattern. Continuing, the device can include a routing element coupled to at least one of the frame and cradle and configured to route a cross string perpendicular to the tensioned main strings in an over-under pattern. The device can also include a securing device coupled to at least one of the frame and cradle and configured to secure the tensioned string to the racket. The securing device can secure the tensioned string via at least one of mechanically tying, heating, melting, ultrasonic welding, gluing, and/or epoxying. Additionally or alternatively, the securing device can secure the tensioned string by mechanically coupling an anchor to the string. 
     In another embodiment, a method for stringing a racket is provided. The method includes securing the racket; gathering, via an imaging device, information regarding the racket; processing said information via a processor; providing, from the processor, instructions for causing the following steps to be carried out: feeding a string through a hole in the racket; tensioning the string; and clamping the tensioned string. The step of providing instructions can be based on at least some of the information processed via the processor. The instructions can further include biasing the tensioned string, and feeding an un-tensioned string perpendicular to the biased, tensioned string. The instructions may also include tensioning a plurality of main strings. Further, the instructions can include biasing fewer than all of the plurality of tensioned main strings, in an alternating order; and feeding a cross string through the plurality of tensioned main strings in an over-under manner. The instructions can also include securing the tensioned string to the racket. Securing may include at least one of mechanically tying, heating, melting, ultrasonic welding, gluing, epoxying, and/or mechanically coupling an anchor. 
     In another example embodiment, a method of identifying and stringing a racket is provided. The method includes, for example, gathering, via a camera, visual information regarding the racket; accessing, via a processor operatively connected to the camera, a database comprising information associated with a plurality of rackets; comparing the gathered visual information with the database information; and determining, based on the comparison, a stringing parameter of the racket, wherein said stringing parameter comprises at least one of a racket size, racket type, string layout, hole layout, recommended string size, and/or recommended string tension. 
     In yet another example embodiment, a method is provided for securing a string within a racket. The method can include providing a string having a mechanical stop on a first end; routing a second end of the string through a first hole; routing the second end of the string through a second hole; tensioning the string such that the mechanical stop abuts the first hole; and securing the second end of the string via at least one of mechanically tying, heating, melting, ultrasonic welding, gluing, epoxying, and/or mechanically coupling an anchor. 
     Additional features and advantages of the invention will be made apparent from the following detailed description of illustrative embodiments that proceeds with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following detailed description will be better understood when read in conjunction with the appended drawings, in which there is shown one or more of the multiple embodiments of the present invention. It should be understood, however, that the various embodiments of the present invention are not limited to the precise arrangements and instrumentalities shown in the drawings. 
         FIG. 1  is a side view of an example racket-stringing machine showing basic components. 
         FIG. 2  is a perspective view of an example racket-stringing machine. 
         FIG. 3  is a top view of an example racket-stringing machine and associated electronics. 
         FIG. 4  is a zoomed perspective view of an example actuator modifying the position of tensioned main strings while an example grasping element modifies the position of a cross string. 
         FIG. 5  is a perspective view of an example anchor affixed to a string to maintain tension and string position. 
         FIG. 6  is a block diagram illustrating a computer architecture a system through which the embodiments of the present disclosure may be implemented. 
     
    
    
     DETAILED DESCRIPTION 
     A device is provided for stringing a racket having a racket frame with holes in the racket frame. The device includes a frame and a cradle rotationally coupled to the frame and configured to mechanically secure the racket via the racket frame. The device also includes multiple elements coupled to at least one of the frame and cradle, including a grasping element configured to engage a string and modify the position and/or tension of the string, a clamp configured to engage the string and maintain the position and tension of the string, an imagining device, and a processor, the processor capable of receiving information from the imaging device indicative of a racket position, hole position, and/or string position, and providing instructions for operating the grasping element, clamp, and/or cradle. 
       FIG. 1  is a representative schematic depicting an example embodiment of a basic racket-stringing system.  FIG. 1  shows a racket-stringing device with a frame  110  for supporting the various components of the device. The frame  110  is made from a heavy duty material, such as steel or aluminum, and is shaped to provide stability to the device as it rotates and otherwise works on a racket. Coupled to the frame  110  is a cradle  115 . In some embodiments, the cradle  115  is rotationally coupled to the frame  110  such that it can rotate a full 360 degrees in both clockwise and counterclockwise directions. A small motor may be used within the cradle  115  to provide electric power for rotating the cradle  115 . The motor may be controlled by a computer  125  having a processor configured to process various types of information related to the racket, as described in more detail below. While the computer  125  is shown as being coupled to the frame  110 , it may be located in a remote location. If located remotely, the computer  125  is configured to receive information and communicate instructions wirelessly. 
     Also shown in  FIG. 1  is a camera  120 . The camera  120  can be used to gather visual information about the particular racket to be strung, such as the number of holes in the racket, the size of the racket, and the racket&#39;s orientation relative to the cradle  115  and/or frame  110 . The camera  120  provides information to the computer  125 , allowing the computer  125  to process information and make further determinations. For example, the camera  120  may provide a visual image to the computer  125 , and the computer  125  may access a database (either locally or via the Internet) to obtain further information about the racket such as the preferred string size, string tension, string layout, and so on. While the system is designed to operate with only one camera, any number of cameras may be utilized. Additional cameras can be used to increase the accuracy of the information provided to the computer  125 . 
     The racket is secured to the cradle  115  via securing elements  130 . At least two securing elements  130  are needed to secure the racket, but more may be used. Each securing element  130  includes at least one surface for contacting the frame of the racket and applying sufficient pressure to maintain the racket&#39;s position while the stringing process is ongoing. The securing elements  130  themselves are coupled to the cradle  115  such that they rotate with the cradle  115 . In this manner the racket can be rotated as desired, either by hand or via an electric motor operatively coupled to the cradle  115 . 
       FIG. 2  shows a perspective view of a more detailed embodiment of a racket-stringing device. Structural features similar to those identified in  FIG. 1  are labeled with matching element numbers. In the embodiment of  FIG. 2 , the computer  125  includes a display  225  for providing various types of information to a user. The face of the computer  125  may include buttons for operating the display  225 . Alternatively or in addition, the display  225  may be connected, via the computer  125 , to an external device such as a laptop or smartphone. 
       FIG. 2  shows a string tensioning device  220  attached to the computer  125 . The string tensioning device  220  may be provided as a stand-alone device, or may not be provided at all. In some embodiments the strings are tensioned by a grasping element  230 , as explained further below. In other embodiments the grasping element  230  positions a string within the tensioning device  220  to achieve the desired tension for the string. 
     The grasping element  230  may be attached to the frame  110  or the cradle  115 . In  FIG. 2  the grasping element  230  is attached to the cradle  115 , and more particularly to a side slot  245  running along the side of the cradle  115 . The racket stringing device may have one grasping element  230  or may have a plurality of grasping elements  230 . The grasping element  230  obtains instructions from a processor of the computer  125  and modifies the positions of strings during the racket-stringing process. For example, the grasping element  230  may pick up a piece of string from a dispensing area, feed the string through a hole in the racket, and then pull the string to a corresponding hole on the opposite side of the racket. Alternatively, the grasping element  230  may pass the string off to a different grasping element  230  located on an opposite side of the racket frame in order to maintain contact with the string at all times and increase accuracy. The grasping element  230  is configured to provide a calculated amount of tension to the string as it is strung through the racket. The string tension may be set at predetermined intervals, or may be maintained through the entire stringing process. 
     One or more clamps  210  may also be utilized to maintain string tension.  FIG. 2  shows two clamps  210 , each mounted along a slot  235  in the cradle  115 . The clamps  210  may be moved, either manually or automatically, along each corresponding slot  235 . In order to orient the clamps  210  to both main string and cross strings, the clamps  210  can be rotationally mounted within the slots  235  and can be manually or automatically rotated 360 degrees to match the orientation of the racket strings. The clamps  210  operate to hold a string in a particular position, thereby maintaining tension. The clamps  210  may be used in conjunction with the grasping element  230  to maintain tension as the grasping element  230  routes the un-tensioned portion of a string throughout the racket. 
       FIG. 2  also shows an actuator  215 . One purpose of the actuator  215  is to modify the position of tensioned main strings in order to allow for a cross string to be routed. This is described in more detail with respect to  FIG. 4 . The actuator  215  is located within a central slot  240  and may slide back and forth within that slot  240  as desired. The actuator  215  may also rotate in order to position the actuator  215  appropriate as well as move the actuator  215  out of the way when necessary. For example, in some embodiments the actuator  215  can be rotated such that the length of the actuator  215  corresponds with the center slot  240 , and the actuator  215  may be retracted to fit partially or even wholly within the slot  240 . In use, the actuator  215  is pushed upward to bias every other tensioned main string to facilitate weaving a cross string through. 
       FIG. 3  shows a top-down view of an example racket-stringing device with a racket  310  secured to the device via securing elements  130  of the cradle  115 . Camera  120  and computer  125  are also shown in communication with the rest of the racket-stringing device. In this embodiment the camera  120  and computer  125  are wirelessly connected to one another and to the rest of the device. Of course, hardwire connections may be used instead of, or in addition to, the wireless connections. 
       FIG. 3  also shows three grasping elements  230 . Although the grasping elements  230  are represented as blocks, they may take the form of the grasping element  230  shown in  FIG. 2 . These grasping elements  230  can be used to route both main strings and cross strings, set tension of the strings, and tie off or otherwise secure strings to the racket  310  after routing them. Clamps  210  are shown slidably mounted in slots  235 , while the actuator  215  is shown slidably mounted in center slot  240 . 
     The actuator  215  is configured to engage at least one of the main strings after the main strings have been tensioned and secured. As shown in  FIG. 4 , the actuator  215  can engage, for example, every other main string. In  FIG. 4  the actuator  215  is shown engaging main strings  435  while not engaging main strings  430 . The actuator  215  lifts every other main string  435  to allow for a routing element  410  to route a cross string  420  through the main strings  430 ,  435 . Because the actuator  215  has moved main strings  435  relative to main strings  430 , the routing element  410  is able to route cross string  420  in a weaved, over-under pattern through the main strings  430 ,  435 . 
     In the embodiment shown in  FIG. 4 , three cross strings  420  have already been routed by the routing element  410 , and a fourth cross string  420  is shown being routed. As each cross string  420  is routed, the actuator  215  moves in a direction parallel to the main strings, in an amount corresponding to the holes through which the next cross string will be routed. In this embodiment, each cross string  420  that has been routed has been secured to the frame of the racket  310  via anchors  440 . 
     The anchors  440  may be mechanical in nature, such as a clamp, crimp, or clip that attaches to the string and prevents the string from being pulled through the holes in the racket  310 . Alternatively, the anchors  440  may be a manipulation of the string itself, such as, for example, a knot tied in the string, a melted portion of string, an ultrasonically welded portion of string, and so on. The anchors  440  may also be glued or epoxied, or otherwise bonded to the racket  310  to prevent the string from pulling through. 
     An anchor  440  may also be used to secure the string on the opposite side of the racket. For example,  FIG. 5  shows a string  510  that has been pulled through a hole in the racket  310 . An anchor  440  is affixed to the string  510  in a manner such that the anchor  440  maintains its position on the string  510  and prevents the string  510  from being pulled back through the hole in the racket  310 . The anchor may be affixed by the grasping element  230 , the routing element  410 , or another device dedicated to securing anchors  440  to the string  510 . 
     All of the mechanical elements described herein may be controlled via a computer, and more precisely through a processor associated with a computer. Those skilled in the art will recognize that the program instructions for software applications implementing all or a portion of one or more embodiment(s) of the present disclosure may be written in a programming language such as Java or C++, and that the database may be implemented with a database package such as Microsoft Access™ or a database management system (DBMS) such as Microsoft SQL Server™, Microsoft SQL Server CE™, IBM DB2™, MySQL, or postgreSQL. 
       FIG. 6  is a block diagram illustrating a computer architecture of the system  1000  through which the embodiments of the present disclosure may be implemented. A system bus  1002  transports data amongst the Central Processing Unit (CPU)  1004 , RAM  1006 , the Basic Input Output System (BIOS)  1008  and other components. The CPU  1004  may include a cache memory component  1024 . The computer system  1000  may include one or more external storage ports  1017  for accessing a hard disk drive (HDD), optical storage drive (e.g., CD-ROM, DVD-ROM, DVD-RW), flash memory, tape device, or other storage device (not shown). The relevant storage device(s) are connected through the external storage port  1017  which is connected to the system bus  1002  via a disk controller  1022 . A keyboard and/or pointing device (e.g., mouse, touch pad) can be connected to the keyboard/mouse port(s)  1012 , and other I/O devices could be connected to additional I/O port(s)  1013 , which are connected to the system bus  1002  through the I/O controller  1005 . Additional ports or devices, such as serial ports, parallel ports, firewire adapters, or biometric devices (not shown), may be utilized through the I/O controller  1010 . A display device can be connected to a display device port  1014  which is connected to the system bus  1002  through the video controller  1015 . A network device (not shown), including but not limited to an Ethernet device or other device having networking capability, can be connected to a network port  1020  which is connected through the network controller  1016  to the system bus  1002 . 
     The computer system  1000  may be wirelessly connected to a network device that is configured for wireless operation (not shown), including but not limited to wireless routers, using an antenna  1028  connected to a wireless controller  1026  connected to the system bus  1002 , where the antenna transmits/receives signals to/from the network device. The computer system  1000  may include one or more USB ports  1023 . A USB device (not shown), including but not limited to a printer, scanner, keyboard, mouse, digital camera, storage device, PDA, cellular phone, biometric device, webcam, and I/O adapters can be connected to the USB port  1023  which is connected to the system bus  1002  through the USB controller  1011 . Other devices, such as cellular phones, PDAs, and other portable devices may also be connected wirelessly via a wireless I/O antenna  1032  that is connected to a wireless I/O controller  1030 . Examples of wireless I/O technologies include, but are not limited to, Bluetooth, Infrared (IR), and Radio-Frequency (RF). Audio devices, such as microphones, speakers, or headphones may be connected to a sound port  1038  that is connected to a sound controller  1034  that is connected to the system bus  1002 . Expansion slots  1018  can include Industry Standard Architecture (ISA) slots, Peripheral Component Interconnect (PCI) expansion slots, PCI Express expansion slots, Accelerated Graphics Port (AGP) slots or any other slot generally known in the art to allow additional cards to be placed into the computer system  1000 . These slots can be used to connect network cards, video cards, sound cards, modems and any other peripheral devices generally used with a computer. The computer system  1000  also includes a source of power (not shown), including but not limited to a power supply connected to an external source of power, and/or an internal or external battery. These devices are generally well-known to those skilled in the art, and a detailed discussion thereof is omitted here for convenience only and should not be considered limiting. 
     The embodiments of the present disclosure can be included in an article of manufacture (e.g., one or more computer program products) having, for instance, computer useable or computer readable media. The media has embodied therein, for instance, computer readable program code means, including computer-executable instructions, for providing and facilitating the mechanisms of the embodiments of the present disclosure. The article of manufacture can be included as part of a computer system or sold separately. 
     While specific embodiments have been described in detail in the foregoing detailed description and illustrated in the accompanying drawings, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure and the broad inventive concepts thereof. It is understood, therefore, that the scope of the present disclosure is not limited to the particular examples and implementations disclosed herein, but is intended to cover modifications within the spirit and scope thereof as defined by the appended claims and any and all equivalents thereof.