The present invention relates generally to a racket stringer, and more particularly to a down-pressed clamp base, which is easily operable and has stable fastening force.
Badminton and tennis games have become more and more prosperous. Also, the requirements for the rackets used in these games have become higher and higher. Therefore, it is critical how to string the racket face.
Accordingly, in the stringing process, it is necessary to repeatedly fix the clamp base 90 on the rail 91 and release the clamp base 90. The conventional clamp base 90 has a rotary lever 93. By means of clockwise or counterclockwise rotating the rotary lever 93 to fix or release the clamp base 90, the bottom section of the clamp base 90 can fasten the rail 91 so as to fix the clamp base 90 on the rail 91. Reversely, when the bottom section of the clamp base 90 is released, the clamp base 90 can be moved along the rail 91.
However, in operation, the string is generally held by the clamp member 92 and then the clamp member 92 is released to rotate the rotary lever 93 for fixing the clamp base 90. At this time, the clamp base 90 is not yet fixed on the rail 91 so that when releasing the clamp member 92, an operator is easily to mis-operate the clamp base 90 and change the position thereof. As a result, it will be necessary to readjust the position of the clamp base 90. Moreover, in the conventional structure, in order to fasten the clamp base 90 on the rail 91, a user generally forcedly rotates the rotary lever 93 with the index finger and thumb. In the stringing process, it is necessary to fix and release the clamp base 90 many times so that after a long period of operation, the hand of the user is heavily burdened and the muscle of the user's hand is easy to get hurt. Furthermore, in case an excessive force is applied to the rotary lever 93, the bottom section of the clamp base 90 will be over-tightened on the rail 91. Under such circumstance, the user will have to exert greater force and cost more time to untighten the rotary lever 93. This leads to low stringing efficiency. In addition, the rotational operation of the rotary lever 93 fails to meet ergonomics and is not labor-saving or convenient. Therefore, those who are skilled in this field and on the market have long since tried to solve the problem how to more easily fix and release the clamp base 90 on the rail with effortless and keep a good fixing effect.
It is therefore a primary object of the present invention to provide a down-pressed clamp base, which can be fastened in a manner meeting ergonomics.
It is a further object of the present invention to provide the above down-pressed clamp base, which is easily operable with labor-saving.
It is still a further object of the present invention to provide the above down-pressed clamp base, which can be conveniently fixed on the rail of the racket stringer to hold the racket string without moving.
It is still a further object of the present invention to provide the above down-pressed clamp base, which can be locked on the rail of the racket stringer be a fixed fastening force without under-tightening or over-tightening so that the down-pressed clamp base will not fail to release due to over-tightening.
To achieve the above and other objects, the down-pressed clamp base of the present invention includes:
a main body having a space and a passage communicating with the space via a connection perforation;
a transmission member slidable disposed in the connection perforation, two ends of the transmission member being respectively directed to the passage and the space;
a leverage mechanism including a lever and a link, one end of the lever being a pivoted end pivotally connected with the main body, the other end of the lever being a levering section, the pivoted end of the lever having a pivot point, the lever being rotatable around the pivot point, one end of the link being a pivoted part pivotally connected with the lever, the other end of the link being a free end positioned in the passage and directed to the transmission member, when the levering section of the lever is rotated downward, the link being driven, whereby the free end of the link drives the transmission member to displace toward the space;
a fastening mechanism disposed in the space and drivable by the transmission member; and
a string holding mechanism disposed on the main body.
Preferably, the down-pressed clamp base further includes a subsidiary leverage assembly having a subsidiary lever pivotally disposed on the main body. One end of the subsidiary lever is a force application section, while the other end of the subsidiary lever is a pushing section corresponding to the levering section of the lever. When operating the force application section of the subsidiary lever, the pushing section pushes the levering section of the lever to move upward.
Preferably, in the above down-pressed clamp base, a receiving cavity is disposed at the other end of the main body opposite to the space. The receiving cavity communicates with the passage. A pressing section protrudes from a rear end of the pivoted end of the lever. The pressing section is positioned in the receiving cavity. The string holding mechanism has a hollow tube disposed on the receiving cavity. A stem body is disposed under the bottom section of the clamp member. The stem body is slidably fitted in the tube, whereby when the clamp member drops down, a bottom end of the stem body presses the pressing section.
According to the above arrangement, when pressing down the lever, via the link, the lever pushes transmission member to drive the fastening mechanism so as to fix the clamp base on the rail of the racket stringer. The operation of the lever is convenient and labor-saving and meets ergonomics. When the lever is levered upward, the clamp base is released. Moreover, in the design of the present invention, when pressing down the levering section, the action forces of the lever, the link and the transmission member are collinear, whereby the clamp base is fixed on the racket stringer by a fixed fastening force without over-forcing or under-forcing.
In addition, when loosening the down-pressed clamp base, the lever can be alternatively operated by means of levering the subsidiary lever or making the string holding mechanism drop down.
The present invention can be best understood through the following description and accompanying drawings, wherein:
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A main body 20, the main body 20 is sequentially formed with a space, a passage 22 and a receiving cavity 23 from one end to the other end. In this embodiment, the space is a downward tapered conic hole 21 at least passing through a bottom face of the main body 20. The passage 22 communicates with the conic hole 21 via a connection perforation 24. One end of the passage 22 is formed with a pivot hole 25 proximal to the receiving cavity 23. The pivot hole 25 is substantially normal to an axis of the connection perforation 24. A pad body 221 and an elastic member 222 are disposed on a bottom section of the passage 22. The pad body 221 is made of a material with lower friction and has a plane top face. The elastic member 222 is a compression spring. The receiving cavity 23 communicates with the passage 22 via a groove 232. An adjustment member 231, which is an adjustment screw, is screwed in a bottom section of the receiving cavity 23. The height of the adjustment member 231 is adjustable. A cover board 26 is mated with the main body 20 to cover the main body 20 so as to conceal the conic hole 21 and the passage 22.
A transmission member 30 slidably fitted through the connection perforation 24. Two ends of the transmission member 30 can respectively protrude into the conic hole 21 and the passage 22. In this embodiment, the transmission member 30 includes a slope block 31 and an arched block 32. The slope block 31 is proximal to the conic hole 21. An end face of the slope block 31 directed to the conic hole 21 is a slope 311. The slope block 31 is formed with a central threaded hole 312. An adjustment member 33 is screwed in the threaded hole 312. The adjustment member 33 can be a screw, which can be rotated within the threaded hole 312 to adjust the length protruding from the other end face of the slope block 31. One end of the adjustment member 33 is in contact with the arched block 32. The arched block 32 is proximal to the passage 22. An end face of the arched block 32 directed to the passage 22 is an arched face 321. The slope block 31 contacts the arched block 22 via the adjustment member 33. The length of the transmission member 30 is adjustable.
A leverage mechanism 40, which includes a lever 41 and a link 42. One end of the lever 41 is a pivoted end 411, while the other end of the lever 41 is formed with a levering section 412. The cover board 26 is formed with a window 261 for the lever 41 to extend through, whereby the levering section 412 is positioned outside the cover board 26. One end of the link 42 is a pivoted part, which is pivotally connected with the body of the lever 41 via a shaft rod 421 as a rotational fulcrum. The position of the pivoted part of the link 42, (that is, the position of the shaft rod 421), is between the pivoted end 411 and the levering section 412 of the lever 41. The pivoted end 411 of the lever 41 is pivotally connected at the pivot hole 25 of the main body 20 via a pin member 414, whereby the lever 41 is rotatable within the main body 20 around the pin 414. A pressing section 415 protrudes from the rear end of the pivoted end 411. The pressing section 415 extends into the receiving cavity 23. One end of the elastic member 222 positioned in the passage 22 is fitted with a protrusion block 416 under the bottom of the lever 41. The elastic member 222 serves to provide an elastic energy to always push the lever 41 upward. A rolling member 43 is pivotally disposed at the free end of the link 42 via a pivot pin 431 and received in the passage 22. The rolling member 43 can roll on the pad body 221 and contact with the arched block 32 of the transmission member 30. In this embodiment, the link 42 is composed of two side-by-side arranged arm members 422. One end of the two arm members 422 are pivotally disposed on two sides of the shaft rod 421. The rolling member 43 is pivotally disposed at the free ends of the two arm members 422 via the pivot pin 431. In this embodiment, the rolling member 43 is a roller. The pad body 222 can reduce the frictional force against the roller. An outer circumference of the rolling member 43 abuts against the arched face 321 of the transmission member 30.
A fastening mechanism 50, which includes an operation block and a clamping block 52. In this embodiment, the operation block is a conic block 51 received in the conic hole 21. The transmission member 30 serves to push the conic block 51 to move up and down. A connection rod 511 extends from the bottom of the conic block 51, which is a threaded rod. The clamping block 52 is screwed on the connection rod 511.
A string holding mechanism 60 have a hollow tube 61 assembled in the receiving cavity 23. A clamp member 62 is mounted on the tube 61. A stem body 621 is fixedly disposed under the bottom end of the clamp member 62. The stem body 621 is up and down movably fitted in the tube 61. The length of the stem body 621 is longer than that of the tube 61, whereby the bottom of the stem body 621 of the clamp member 62 can touch the pressing section 415 of the lever 41. Two opposite holding jaws 622 and a rotary bar 623 are disposed on the clamp member 62. The rotary bar 623 can be rotated to adjust the gap between the holding jaws 622. When the gap between the holding jaws 622 is minified, the string is held. The clamp member 62 of the string holding mechanism 60 pertains to prior art and is not the subject of the present invention so that the clamp member 62 will not be further described hereinafter.
A subsidiary leverage assembly 70, which includes a shafted block 71, a subsidiary lever 72 and at least one elastic element 73. The shafted block 71 is fixed on the top face of the main body 20 or integrally formed on the main body 20. The subsidiary lever 72 is pivotally connected at the lugs 711 of the shafted block 71 and rotatable. One end of the subsidiary lever 72 is a force application section 721, while the other end is a pushing section 722. The pushing section 722 is positioned on the same side as the levering section 412 of the lever 41 and under the levering section 412. The force application section 721 of the subsidiary lever 72 and the levering section 412 of the lever 41 are positioned on different sides. The elastic element 73 is disposed between the subsidiary lever 72 and the main body 20. The elastic element 73 exerts elastic force onto the subsidiary lever 72 to keep the force application section 721 of the subsidiary lever 72 levered upward, while the pushing section 722 levered downward in normal state. In this embodiment, the subsidiary lever 72 has two side-by-side arranged plate bodies. Each plate body is pivotally disposed at the lug 711 of the shafted block 71 via a pivot member 723. In this embodiment, the pushing section 722 of the subsidiary lever 72 is formed as two legs positioned under the levering section 412. In this embodiment, there are two elastic elements 73, which are torque springs each having an annular body section and two leg sections. The annular body section is fitted on the pivot member 723, while the two leg sections respectively abut against the main body 20 and the subsidiary lever 72 as shown in
A first cap 46 and a second cap 76 are respectively capped on the levering section 412 of the lever 41 and the application section 721 of the subsidiary lever 72 so as to beautify the appearance and facilitate pressing of the lever 41 and the subsidiary lever 72. The two caps 46, 76 are only denoted in
The down-pressed clamp base 10 of the present invention is mounted on a rail 80 of a racket stringer (not shown). When stringing the racket, the clamp base 10 serves to hold the string of the racket. The rail 80 is formed with a slide slot 81. After the connection rod 511 of the fastening mechanism 50 is fitted through the slide slot 81, the clamping block 52 is screwed onto the connection rod 511. The string holding operation of the string holding mechanism 60 is not the subject of the present invention and thus will not be redundantly described hereinafter.
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When it is desired to release the down-pressed clamp base 10 from the fastening state, there are three ways to achieve this. First, as shown in
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In the down-pressed clamp base of the present invention, the leverage mechanism 40 is operated by means of pressing up and down the lever 41. An operator can apply a force to the lever 41 with his palm to press down the lever 41. Such force application manner meets ergonomics and the operation is labor-saving and convenient. Moreover, even after a long period of operation, the muscle of the operator will not be hurt. Also, each time the leverage mechanism 40 is forcedly pressed down, the force applied by the link 42 to the transmission member 30 for pushing the fastening mechanism 50 is fixed. Therefore, the fastening mechanism 50 will not stuck or fail to release due to over-forcing. Furthermore, when unlocking the clamp base, there are three ways to loosen the leverage mechanism 40, that is, levering the lever 41 upward, pressing down the subsidiary lever 72 or dropping down the clamp member 62. An operator can select any of the three ways to unlock the clamp base according to the current operation condition or personal use habit so that the operation is facilitated.
The structure of the down-pressed clamp base of the present invention is such designed that the down-pressed clamp base can be operated in a novel mode different from the rotation operation manner of the rotary bar of the conventional clamp base. Also, the down-pressed clamp base of the present invention can solve many shortcomings of the conventional clamp base.
The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.
Number | Date | Country | Kind |
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107118362 A | May 2018 | TW | national |
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Number | Date | Country | |
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20190366161 A1 | Dec 2019 | US |