Dual Stringing Tennis Racket Machine and Method

Abstract

The invention is directed toward a machine and method for stringing two strings on a tennis racket substantially simultaneously. The machine is a racket stringing machine comprised of a mounting plate, a first string gripper and a second string gripper, a first string clamp and a second string clamp. The machine may be further comprised of an electromotor and means for control, a first string gripper arm and a second string gripper arm, a string clamp base, a machine base, and a pedestal. The method comprises the steps of threading a length of string with a first end and a second end through the grommets on a racket, threading the first end of the string through a first string gripper and the second end through a second string gripper, securing the ends of the length of string, and applying a desired tension on the length of string.

Description

FIELD OF THE INVENTION

The invention relates generally to a racket stringing machine and more specifically to an apparatus and method for stringing multiple strings onto a tennis racket simultaneously.

BACKGROUND OF THE INVENTION

Tennis racket stringing machines are known in the art. Historically, these machines comprise a racket mounting plate, string clamps, a string gripper, and a means for moving the string gripper distal from the mounting plate. The means for moving the string gripper could be by means of a manual crank or an electric motor. The racket stringing machine has only one string gripper.

When stringing a racket on a standard racket stringing machine, a user mounts the racket on the racket mounting plate and secures the racket to the mounting plate. The user starts by threading a string through opposing grommets on the racket. The user places one end of the string in the string gripper. The user then moves the string gripper distal from the mounting plate to place the appropriate level of tension in the string. When the tension in the string is at the appropriate level, the user clamps the string in place with string clamps. These clamps maintain the tension in the string throughout the stringing process.

The user continues stringing by threading one end of the string through an opposing grommet. The user threads the string parallel to the first length of string. To do this the user will rotate the racket mounting plate so that the string gripper is now on the opposite side of the racket as it was for the first length of string. The user will thread the string through the opposing grommet and secure the string in the string gripper. The user moves the string gripper distal from the mounting plate to achieve the desired tension in the string. When the tension in the string is set as desired, the user then moves the further string clamp from the first length of string and moves it to the second length of string. The user secures the string with the string clamp on the side of the racket on which the string gripper is situated so that the string tension is maintained. The user then turns the racket in the mounting plate so that the string gripper is now opposite of the clamp. The user threads the end of the string through the neighboring grommet and repeats the process of the tensioning and securing the string.

This standard method of stringing a racket is inadequate. The process is timely and overly repetitive. During the standard stringing process, a user can only tension and secure one length of string at a time. Also, the user must spin the racket mounting plate continuously. Thirdly, the clamps used on standard machines must be made thin. This is because in the stringing process a user is placing two clamps adjacent to each other on adjacent strings. The clamps must be made thin so that they can fit next to each other within the racket. The thin clamps are inadequate because they tend to break easily through the repetitive stringing process.

Standard racket stringing machines have a mounting frame to hold the racket. Standard racket mounting frames have a “V” shape, with an upper arm and a lower arm extending inward from the mounting rack a plethora of points. The upper arms extend from the mounting rack directly above the lower arms. The upper arms and the lower arms exist respectively in a plane which is perpendicular to the mounting rack. This structure is limited in that the grommets on the racket which are located within the “V” of the upper arms and lower arms are difficult to reach and slow the stringing process.

What is needed to overcome these problems is an apparatus and a method for stringing two strings on a racket simultaneously. Furthermore, what is needed is a mounting rack structure which dispenses with the planar structure of the upper arms and lower arms which extend from the mounting rack.

SUMMARY OF THE INVENTION

The invention is a racket stringing machine comprised of a mounting plate, a first string gripper and a second string gripper, a first string clamp and a second string clamp. The device is designed such that a user may thread a string through a racket and through said first string gripper and said second string gripper substantially simultaneously. The user may utilize said first string gripper and said second string gripper to apply tension to the ends of said string substantially simultaneously. The racket stringing machine may be further comprised of an electromotor, a means for controlling said electromotor, a first string gripper arm and a second string gripper arm wherein said first string gripper arm is connected to said first string gripper and said second string gripper arm is connected to said second string gripper, wherein said electromotor is utilized to move said first string gripper arm and said second string gripper arm. The racket stringing machine may further comprise a string clamp base, a machine base, and a pedestal. The string clamp base may be comprised of two separate string clamp base sections.

Said first string gripper and said second string gripper may each be comprised of a first string gripper plate, a second string gripper plate, an axel, a string support rod, and a means for moving said first string gripper plate and said second gripper plate along the length of said axel. Said first string gripper and said second string gripper may be further comprised of a first collar connected to said first string gripper plate, wherein said first collar includes a central void containing one or more ball bearings, a second collar connected to said second string gripper plate, wherein said second collar includes a central void containing one or more ball bearings, wherein said axel has grooves designed to receive said ball bearings, wherein said axel is positioned within the central void of said first collar and the central void of said second collar, wherein as said axel rotates, said ball bearings move through said grooves in said axel, and wherein as said axel rotates, said first string gripper plate and said second string gripper plate move independently along the length of said axel.

In another embodiment of the invention is a racket stringing machine comprised of a mounting plate, a first string gripper and a second string gripper, a first string clamp and a second string clamp wherein said first string clamp and said second string clamp disengage from the respective lengths of string automatically when said first string gripper and said second string gripper apply a desired tension to the subsequent lengths of string. Furthermore, said first string clamp and said second string clamp automatically reposition under said subsequent lengths of string after disengaging from prior secured lengths of string. In this embodiment the device is designed such that a user may thread a string through a racket and through said first string gripper and said second string gripper substantially simultaneously. The user may utilize said first string gripper and said second string gripper to apply tension to the ends of said string substantially simultaneously. This embodiment of the racket stringing machine may be further comprised of an electromotor, a means for controlling said electromotor, a first string gripper arm and a second string gripper arm wherein said first string gripper arm is connected to said first string gripper and said second string gripper arm is connected to said second string gripper, wherein said electromotor is utilized to move said first string gripper arm and said second string gripper arm. This embodiment of the racket stringing machine may further comprise a string clamp base, a machine base, and a pedestal. The string clamp base may be comprised of two separate string clamp base sections.

The invention utilizes a self-closing string gripper for use in a racket stringing machine comprising a first string gripper plate, a second string gripper plate, an axel, a string support rod, and a means for moving said first string gripper plate and said second gripper plate along the length of said axel. The self-closing string gripper may be further comprised of a first collar connected to said first string gripper plate, wherein said first collar includes a central void containing one or more ball bearings, a second collar connected to said second string gripper plate, wherein said second collar includes a central void containing one or more ball bearings, wherein said axel has grooves designed to receive said ball bearings, wherein said axel is positioned within the central void of said first collar and the central void of said second collar, wherein as said axel rotates, said ball bearings move through said grooves in said axel, and wherein as said axel rotates, said first string gripper plate and said second string gripper plate move independently along the length of said axel. The self-closing string gripper may be designed such that said grooves in said axel have a variable slope such that as said axel rotates said first string gripper plate and said second string gripper plate move along the length of said axel at variable speeds.

In another embodiment of the invention the racket stringing machine is comprised of a mounting plate, a first string gripper and a second string gripper, a first string clamp and a second string clamp, wherein said first string gripper and said second string gripper are in the form of spools, and wherein said spools implant tension on a racket string by turning and winding said racket string around said spools.

In another embodiment of the invention the racket stringing machine is comprised of a mounting plate, a first string gripper and a second string gripper, a first string clamp and a second string clamp, wherein said mounting plate is comprised of a mounting plate frame with a plethora of upper arms and lower arms, a first L-shaped lower arm, and a second L-shaped lower arm, wherein said upper arms extend inward and upward from said mounting plate frame, wherein said lower arms extend inward and downward from said mounting plate frame, wherein said lower arms and said upper arms are offset from each other on the mounting plate frame such that no lower arm is directly beneath any upper arm and no upper arm is directly over any lower arm, wherein said first L-shaped lower arm is located on the mounting rack in a position to receive the top of a racket, and wherein said second L-shaped lower arm is located on the mounting rack in a position to receive the handle section of a racket.

The invention is a method of stringing two lengths of string on a racket simultaneously comprising the steps of threading a length of string with a first end and a second end through the grommets on a racket, threading said first end of the length of string through a first string gripper and said second end of the length of string through a second string gripper, securing said first end of the length of string with said first string gripper and securing said second end of the length of string with said second string gripper, and applying a desired tension on said length of string with said first string gripper and said second string gripper. The method may be further comprised of the steps of securing the length of string with a first string clamp and a second string clamp, removing said first end of the length of string from said first string gripper and removing said second end of the length of string from said second string gripper, threading said first end of the length of string through a grommet of said racket forming a first additional length of string, threading said second end of the length of string through a separate grommet of said racket forming a second additional length of string, threading said first end of the length of string through said second string gripper and said second end of the length of string through said first string gripper, securing said first end of the length of string with said second string gripper and securing said second end of the length of string with said first string gripper, applying a desired tension on said lengths of string with said first string gripper and said second string gripper, removing said first string clamp and said second string clamp from the length of string, repositioning said first string clamp and said second string clamp, and securing said first additional length of string with said first string clamp and securing said second additional length of string with said second string clamp.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a racket stringing machine allowing for stringing two strings simultaneously.

FIG. 2 is a view of the internal mechanics of the racket stringing machine.

FIG. 3 is perspective view of a self-locking string gripper utilized with the machine.

FIG. 4 is a side view of a self-locking string gripper utilized with the machine.

FIG. 5 is a perspective view of the mounting plate.

FIG. 6 is a side view of the mounting plate.

DETAILED DESCRIPTION OF THE DRAWINGS

Although the present invention will be described with reference to the exemplary embodiments shown in the drawings, it should be understood that the present invention can be embodied in many alternate forms or embodiments. In addition, any suitable size, shape or type of elements or materials could be used.

Referring to FIG. 1 and FIG. 2, the invention is a racket stringing machine allowing a user to string two strings on a racket 100 simultaneously. The machine is comprised of a mounting plate 140, a first string gripper 110, a second string gripper 112, a first string clamp 120, a second string clamp 122, a motor 160, a first string gripper arm 162, a second string gripper arm 164, and a means for controlling the motor 180. In this embodiment, the invention is further comprised of a base 150 and a pedestal 170.

To string a racket using the machine, a user places a racket 100 in the mounting plate 140. The user threads a string through opposing grommets in the racket 100. The user threads one end of said string through the first string gripper 110 and the other end of said string through the second string gripper 112. The user engages the means for controlling the motor 180 to actuate the motor 160. Herein after the means for controlling the motor shall be referred to as “control means”. The control means 180 can be any type of mechanical or electrical user interface for a user to control the motor 160. Such control means may take the form of a touch screen electrical display or simple mechanical buttons or switches. In other embodiments the control means may 180 be a button located on one or both of said string grippers 110, 112. As a user threads a string through said first string gripper 110, the user can engage the control means 180 by pressing a button on said first string gripper 110. When the user presses the button on said first string gripper 110, the motor 160 becomes engaged and moves said first string gripper 110 distal from the mounting plate 140. In another embodiment, the control means 180 is comprised of a second button on said second string gripper 112. In this embodiment, said second button is used to control the motion of said second string gripper 112. The control and movement of said first string gripper 110 is independent of the control and movement of said second string gripper.

In another embodiment, displayed in FIG. 3, the control means 180 may be a pressure sensitive pad 117 located on one or both string grippers 110, 112. In this embodiment, the string is placed over the pressure sensitive pad 117. The user pulls the string over the pressure sensitive pad 117. When the string places pressure against the pressure sensitive pad 117, the pressure sensitive pad 117 sends a signal to the motor 160. The motor 160 activates and moves the respective string gripper 110, 112 distal from the mounting plate 140.

In the preferred embodiment, when the ends of the string are thread through the respective string grippers 110, 112, the user uses the control means 180 to activate the motor 160. The motor engages said first string gripper arm 162 and said second string gripper arm 164. Said first string gripper arm 162 is connected to and transfers motion to said first string gripper 110. Said second string gripper arm 164 is connected to and transfers motion to said second string gripper 112. When the motor 160 is activated, said first string gripper 110 and said second string gripper 162 move distal from the mounting plate 140. Said string grippers 110, 112 are designed so that as said string grippers 110, 112 move distal from the mounting plate 140, said string grippers 110, 112 automatically engage and secure the respective ends of the string.

The string grippers 110, 112 cause a desired tension to be placed in the string. When the desired tension is reached, the string grippers 110, 112 cease their distal movement. A user then raises said first string clamp 120 and said second string clamp 122 and secures the string with said first string clamp 120 and said second string clamp 122. The user may raise said string clamps 120, 122 and secure said string clamps 120, 122 to the string manually or via the control means 180. When said first string clamp 120 and said second string clamp 122 are secured to the string, the desired tension is maintained within the string.

Once secure, the user engages the control means 180 to reverse the motor 160. This reverse motion is transferred through the string gripper arms 162, 164, causing the string grippers 110, 112 to move proximate to the mounting plate 140. As the string grippers 110, 112 move proximate to the mounting plate 140, the string grippers 110, 112 automatically release the string.

The user then takes the respective ends of the string and threads each end through the next pair of grommets on the racket 100. The user threads one end of the string through the next pair of grommets closer to the user and threads the other end of the string through the next pair of grommets further away from the user. The user threads the ends of the string through the respective string grippers 110, 112. Preferably, the end of the string which had first been pulled by said first string gripper 110 is now threaded through said second string gripper 112 and the end of the string which had first been pulled by said second string gripper 112 is now threaded through said first string gripper 110. The user then engages the control means 180 to activate the motor 160. The motor engages both string gripper arms 162, 164.

Said string gripper arms 162, 164 transfer motion to the respective string grippers 110, 112, causing the string grippers 110, 112 to move distal from the mounting plate 140. Said string grippers 110, 112 automatically secure the ends of the string. Once the desired tension is placed in the strings, the user secures the lengths of string with the respective string clamps 120, 122. Said string clamps 120, 122 maintain the desired tension in the strings as the user disengages the string grippers 110, 112 from the ends of the strings.

In the preferred embodiment, said first string clamp 120 and said second string clamp 122 are raised manually and secured to the string manually by the user. When the user fully engages said first string gripper 110 and said second string gripper 112, and the desired tension is reached in the length of string, said first string clamp 120 and said second string clamp 122 automatically disengage from the string and the string clamp base 126 rotates to position said first string clamp 120 and said second string clamp 122 under the subsequent lengths of string.

In this embodiment, the string clamps 120, 122 sit on a string clamp base 126. The string clamp base 126 is designed to rotate about a central axis. The string clamp base 126 may rotate freely, or be moved by means of the motor 160. The string clamp base 126 may rotate 360 degrees. Optionally, the string clamp base 126 may rotate less than 360 degrees.

In one embodiment, the string clamp base 126 is split into two separate sections. Said first string clamp 120 is positioned on one section and said second string clamp 122 is positioned on the second section.

The string clamp base 126 sections may be moved independently of one another. Optionally, said first string clamp 120 and said second string clamp 122 may be freely moved and positioned on each respective string clamp base section. In the utilization of this embodiment, the string clamps may be positioned such that the angle of the string clamps 120, 122 is less than 180 degrees. In this embodiment, the sections of the string clamp base 126 are each connected to a central axel. The sections of the string base clamp 126 rotate independently about the central axel. Optionally, the sections of the string clamp base 126 may have springs positioned between the sections of the string clamp base 126. The springs are connected to the respective sections of the string clamp base 126. The springs allow the sections of the string clamp base 126 to default to a position where the first string clamp and the second string clamp are 180 degrees apart. The sections of the string clamp base 126 may be moved together, compressing the spring on one side of the string clamp base 126 and extending the spring on the opposite side of the string clamp base 126. The sections of string clamp base 126 may be moved together such that the first string clamp 110 and the second string clamp 112 are positioned at an angle less than 180 degrees. After the stringing process where the sections of the string clamp base 126 are positioned close together, the springs return to their original position, moving the sections of the string clamp base 126 to their respective original position where the first string clamp 110 and the second string clamp 112 are positioned 180 degrees apart. In one embodiment, the sections of the string clamp base 126 are moved manually. Optionally, the sections of the string clamp base 126 may be moved by an electromotor. The sections of the string clamp base 126 may rotate about the central axel up to 360 degrees of rotation. Preferably, the sections of the string clamp base 126 rotate +/−30 degrees.

Optionally, the first string clamp 120 may rotate on the string clamp base 126 while the second string clamp 122 remains fixed in its original position. Preferably the string clamp base 126 rotates the first string clamp 120 and the second string clamp 122 automatically when a user has engaged the tension of the string grippers 110, 112.

Optimally, the string clamps 120, 122 preserve the tension in the lengths of the string until the string grippers 110, 112 have applied the desired level of tension to the subsequent lengths of string. Once the desired level is reached, the string clamps 120, 122 release the prior lengths of string and the string clamp base 126 rotates the string clamps 120, 122 to the subsequent lengths of string. In this embodiment of the invention, the release of the strings by the string clamps 120, 122 and the rotation of the string clamp base 126 occur automatically when the user engages the string grippers 110, 112 to pull the ends of the string.

The invention further comprises a machine base 150. The machine base 150 provides structural support for the other components of the machine. The machine base 150 may be set on a table top or any other location desired by the user. In this embodiment, the machine base 150 is set on a pedestal 170. The pedestal 170 allows a user to stand while using the machine.

Other embodiments of the invention may further utilize special self-closing string grippers 110, 112. Referring to FIG. 3 and FIG. 4, the first said string gripper 110 is in the default position. While the following description is made in terms of the first said string gripper, the following is equally applicable to said second string gripper 112. In the default position the first said string gripper 110 is proximate to the mounting plate 140. In the default position, said first string gripper 110 is positioned beneath the plane of the mounting plate 140. Such position allows a user to rotate the mounting plate 140 as desired without the handle of the racket 100 contacting the first string gripper 110. When a user moves said first string gripper 110 distal from the mounting plate 140, said first string gripper 110 moves upward so that the string is being pulled level with the plane of the mounting plate 140. Optionally, the user may make the string gripper 110 remain below the plane of the mounting plate 140 in order to string the racket 100 while the racket handle is positioned over the string gripper 110.

The string gripper 110 is comprised of a first gripper plate 111 and a second gripper plate 113 said first gripper plate 111 and said second gripper plate 113 mounted on an axel 119 and a string support rod 115. Optionally, the string gripper may be further comprised of a pressure sensitive pad 117 which is used as part of the control means 180. Said first gripper plate 111 and said second gripper plate 113 are positioned substantially parallel in the default position. As the first string gripper 110 moves distal from the mounting plate said first gripper plate 111 and said second gripper plate 113 move inward toward each other until said first gripper plate 111 and said second gripper plate 113 compress the string threaded through the first string gripper 110. Said first gripper plate 111 and said second gripper plate 113 place sufficient pressure on the string threaded between said first gripper plate 111 and said second gripper plate 113, such that the string is immovable within the first string gripper 110.

The first string gripper 110 is designed such that there is a means for said first gripper plate 111 and said second gripper plate 113 to compress the string automatically as the first string gripper 110 moves distal from the mounting plate 140.

In the preferred embodiment, the axel 119 connects the first string gripper plate 111 and the second string gripper plate 113. The axel 119 contains grooves with a variable slope. Ball bearings fitting within a collar are attached to said first gripper plate 111 and said second gripper plate 113. The ball bearings fit within the grooves in the axel 119. As the axel turns the ball bearings glide through the groove, moving the collar attached to said first string gripper plate 111. As the collar moves along the groove, said first string gripper plate 111 moves inward toward said second gripper plate 113. The ball bearings in the collar attached to said second string gripper plate 113 move along a separate groove in the axel 119. As the axel 119 turns, the ball bearings move through the groove, moving the collar attached to said second string gripper plate 113. As the collar moves along the groove, said second string gripper plate 113 moves inward toward said first string gripper plate 111. Preferably the grooves in the axel 119 have a variable slope such that said first string gripper plate 111 and said second string gripper plate 113 move inward quickly at first, then, when said first string gripper plate 111 and said second string gripper plate 113 are within the space to engage the string, said first string gripper plate 111 and said second string gripper plate 113 move inward toward each other very slowly. Preferably, when said axel 119 first rotates, said first string gripper plate 111 and said second string gripper plate 113 move inward toward one another a large proportion of the distance between said first string gripper plate 111 and said second string gripper plate 113. Then, with further rotation of the axel 119, said first string gripper plate 111 and said second string gripper plate 113 move inward a small proportion of the distance between said first string gripper plate 111 and said second string gripper plate 113.

The means may include a pair of variably threaded screws on which the first gripper plate 111 and second gripper plate 113 are mounted. As said first gripper plate 111 rotates on the first said variably threaded screw, the rotation of the first gripper plate 111 along the thread causes the gripper plate to move inward toward said second gripper plate 113. Said second gripper plate 113 is mounted on a variably threaded screw with an opposite thread. As said second gripper plate 113 rotates on the opposite thread, the rotation causes said second gripper plate 113 to move inward toward said first gripper plate 111.

In another embodiment of the self-locking string gripper, the first string gripper is comprised of ball bearings under said first gripper plate 111 and said second gripper plate 113. Said ball bearings allow said first gripper plate 111 and said second gripper plate 113 to slide toward one another. Said first string gripper plate 111 and said second string gripper plate 113 are positioned in a “V” shape with the narrow end of the “V” closest to the mounting plate 140. As the first string gripper 140 moves distal from the mounting plate 140, the friction from the string slides the first gripper plate 111 and the second gripper plate 113 toward the narrow end of the “V”. As the first gripper plate 111 and the second gripper plate 113 slide toward the narrow end of the “V”, said first gripper plate 111 and said second gripper plate 113 further compress the string within the string gripper 110. Said compression generates sufficient tension on the string to prevent the string from moving within the string gripper 110.

In another embodiment of the invention said first string gripper 110 and said second string gripper 112 are in the form of spools. The user wraps the string around the spool. To tension the string, the user engages the motor 160 which causes the spool to turn. The turning of the spool wraps the string around the spool until the string is taught between the spool and the mounting plate 140. The spool continues to turn until the appropriate tension is placed on the string.

Optionally, in another embodiment, the invention further comprises a mounting plate 140 containing multiple points of contact with the racket 100. Referring to FIG. 4 and FIG. 5, an embodiment of the mounting plate 140 is shown. The mounting plate 140 contains a plethora of upper arms 142 and a plethora of lower arms 144. In the prior art, the upper arms 142 and lower arms 144 are positioned within the same vertical plane and make a “V” shape. In the embodiment presented in the invention, the upper arms 142 and lower arms 144 are offset from one another such that no lower arm 144 is directly beneath any upper arm 142 and no upper arm 142 is directly above any lower arm 144. The upper arms 142 extend inward and upward from the mounting plate 140. The upper arms 142 extend at an angle upward from the mounting plate 140. The lower arms 144 extend inward and downward from the mounting plate 140. The lower arms 144 extend at an angle downward from the mounting plate 140. The vertical space between the lower arms 144 and the upper arms 142 is sufficient to permit a racket 100 to be inserted between the upper arms 142 and the lower arms 144. The angle of the lower arms 144 pushes the racket 100 upward toward the upper arms 142. The angle of the upper arms 142 pushes the racket 100 downward toward the lower arms 144. The pushing of the upper arms 142 and the lower arms 144 on the racket 100 ensures that the racket 100 and string bed are centered in the mounting rack 140 and always held at the same height.

The mounting plate 140 contains two L-shaped lower arms 141, 143. The first L-shaped lower arm 141 is located at 0 degrees and the second L-shaped lower arm 143 is located at 180 degrees. Said L-shaped lower arms 141, 143 extend under the racket 100 at the handle location and at the upper end opposite from the handle. Said L-shaped lower arms 141,143 extend under the racket 100 and then extend upward inside the racket 100. This prevents the racket 100 from compressing and deforming during the stringing process. The upper arms 142 and the lower arms 144 can be positioned at any location point on the sides of the racket 100. Preferably the upper arms 142 and lower arms 144 are positioned at approximately 80 degrees, 100 degrees, 260 degrees, and 280 degrees. With the space between the respective upper arms 142 and lower arms 144, the lower arms 144 are positioned at approximately 75 degrees, 105 degrees, 255 degrees, and 285 degrees. The upper arms 142 are positioned at approximately 85 degrees, 95 degrees, 265 degrees, and 275 degrees.

In other embodiments, there are any number of upper arms 142 and lowers arms 144 positioned around the mounting rack 140. In other embodiments, the upper arms 142 and lower arms 144 are placed at any position on the mounting rack 140. With the upper arms 142 and lower arms 144 positioned at different points from one another, a user has less issue with threading a string through a grommet that is located beneath an upper arm 142 or over a lower arm 144.

Claims

1. A racket stringing machine comprising

A mounting plate

A first string gripper and a second string gripper

A first string clamp and a second string clamp

2. The device as in claim 1

Wherein a user may thread a string through a racket and through said first string gripper and said second string gripper substantially simultaneously

Wherein said first string gripper and said second string gripper apply tension to the ends of said string substantially simultaneously

3. The device as in claim 2 further comprising

An electromotor

A means for controlling said electromotor

A first string gripper arm and a second string gripper arm wherein said first string gripper arm is connected to said first string gripper and said second string gripper arm is connected to said second string gripper

Wherein said electromotor is utilized to move said first string gripper arm and said second string gripper arm.

4. The device as in claim 3 further comprising

A string clamp base

A machine base

A pedestal

5. The device as in claim 4 wherein said string clamp base is comprised of two separate string clamp base sections

6. The device as in claim 5 wherein said first string gripper and said second string gripper are comprised of

A first string gripper plate

A second string gripper plate

An axel

A string support rod

A means for moving said first string gripper plate and said second gripper plate along the length of said axel

7. The device as in claim 6 wherein said first string gripper and said second string gripper are further comprised of

A first collar connected to said first string gripper plate Wherein said first collar includes a central void containing one or more ball bearings

A second collar connected to said second string gripper plate Wherein said second collar includes a central void containing one or more ball bearings

Wherein said axel has grooves designed to receive said ball bearings

Wherein said axel is positioned within the central void of said first collar and the central void of said second collar

Wherein as said axel rotates, said ball bearings move through said grooves in said axel

Wherein as said axel rotates, said first string gripper plate and said second string gripper plate move independently along the length of said axel.

8. The device as in claim 1 wherein said first string clamp and said second string clamp disengage from the respective lengths of string automatically when said first string gripper and said second string gripper apply a desired tension to the subsequent lengths of string.

9. The device as in claim 8 wherein said first string clamp and said second string clamp automatically reposition under said subsequent lengths of string after disengaging from prior secured lengths of string

10. The device as in claim 9

Wherein a user may thread a string through a racket and through said first string gripper and said second string gripper substantially simultaneously

Wherein said first string gripper and said second string gripper apply tension to the ends of said string substantially simultaneously

11. The device as in claim 10 further comprising

An electromotor

A means for controlling said electromotor

A first string gripper arm and a second string gripper arm wherein said first string gripper arm is connected to said first string gripper and said second string gripper arm is connected to said second string gripper

Wherein said electromotor is utilized to move said first string gripper arm and said second string gripper arm

12. The device as in claim 11 further comprising

A string clamp base

A machine base

A pedestal

13. The device as in claim 12 wherein said string clamp base is comprised of two separate string clamp base sections

14. A self-closing string gripper for use in a racket stringing machine comprising

A first string gripper plate

Second string gripper plate

An axel

A string support rod

A means for moving said first string gripper plate and said second gripper plate along the length of said axel

15. The device as in claim 14 further comprising

A first collar connected to said first string gripper plate Wherein said first collar includes a central void containing one or more ball bearings

A second collar connected to said second string gripper plate Wherein said second collar includes a central void containing one or more ball bearings

Wherein said axel has grooves designed to receive said ball bearings

Wherein said axel is positioned within the central void of said first collar and the central void of said second collar

Wherein as said axel rotates, said ball bearings move through said grooves in said axel

Wherein as said axel rotates, said first string gripper plate and said second string gripper plate move independently along the length of said axel.

16. The device as in claim 15 wherein said grooves in said axel have a variable slope such that as said axel rotates said first string gripper plate and said second string gripper plate move along the length of said axel at variable speeds.

17. The device as in claim 1 wherein said first string gripper and said second string gripper are in the form of spools

Wherein said spools implant tension on a racket string by turning and winding said racket string around said spools

18. The device as in claim 1 wherein said mounting plate is comprised of a mounting plate frame with a plethora of upper arms and lower arms, a first L-shaped lower arm, and a second L-shaped lower arm

Wherein said upper arms extend inward and upward from said mounting plate frame

Wherein said lower arms extend inward and downward from said mounting plate frame

Wherein said lower arms and said upper arms are offset from each other on the mounting plate frame such that no lower arm is directly beneath any upper arm and no upper arm is directly over any lower arm.

Wherein said first L-shaped lower arm is located on the mounting rack in a position to receive the top of a racket

Wherein said second L-shaped lower arm is located on the mounting rack in a position to receive the handle section of a racket

19. The method of stringing two lengths of string on a racket simultaneously comprising

Threading a length of string with a first end and a second end through the grommets on a racket

Threading said first end of the length of string through a first string gripper and said second end of the length of string through a second string gripper

Securing said first end of the length of string with said first string gripper and securing said second end of the length of string with said second string gripper

Applying a desired tension on said length of string with said first string gripper and said second string gripper

20. The method as in claim 19 further comprising the steps of

Securing the length of string with a first string clamp and a second string clamp

Removing said first end of the length of string from said first string gripper and removing said second end of the length of string from said second string gripper

Threading said first end of the length of string through a grommet of said racket forming a first additional length of string

Threading said second end of the length of string through a separate grommet of said racket forming a second additional length of string

Threading said first end of the length of string through said second string gripper and said second end of the length of string through said first string gripper

Securing said first end of the length of string with said second string gripper and securing said second end of the length of string with said first string gripper

Applying a desired tension on said lengths of string with said first string gripper and said second string gripper

Removing said first string clamp and said second string clamp from the length of string

Repositioning said first string clamp and said second string clamp

Securing said first additional length of string with said first string clamp and securing said second additional length of string with said second string clamp