Capo capable of precise and convenient clamping force adjustment

Abstract

A capo capable of precise and convenient clamping force adjustment, comprising a front clamping arm (1), a rear clamping arm (2), a pressing arm (3), a pull rod, and a spring (4). The top of the front clamping arm (1) is provided with an adjustment inner sleeve (5); the top of the rear clamping arm (2) is provided with an adjustment limiting sleeve (6) mated with the adjustment inner sleeve (5); the pull rod is a threaded adjustment pull rod (7); one end of the threaded adjustment pull rod (7) is connected to the pressing arm (3); the spring (4) is sleeved on the threaded adjustment pull rod (7); a spring retaining ring (28) mated with the spring (4) is arranged in the adjustment inner sleeve (5); the other end of the threaded adjustment pull rod (7) passes through the adjustment inner sleeve (5) and the top of the front clamping arm (1) to be connected to an adjusting knob (8); an adjustment scale (29) is arranged on the adjustment inner sleeve (5); a plurality of balls (9) are arranged between the adjustment inner sleeve (5) and the adjustment limiting sleeve (6); and a plane bearing (10) is arranged between the adjusting knob (8) and the front clamping arm (1). The upper and lower clamping forces of the front clamping arm (1) and the rear clamping arm (2) are kept consistent as much as possible, so as to ensure precise pitch adjustment. In addition, the optimal pitch position on the scale can be found simply in a single tuning attempt, and thus it is convenient to adjust; and high precision and a small size are realized.

Description

Adjustable and convenient clamping force of the variable clamp Technical Field

[0001] This invention relates to a guitar auxiliary tool, and more particularly to a capo with precise and convenient clamping force adjustment. Background Technology

[0002] The capo's original purpose was to adjust the guitar's pitch. It's a common auxiliary tool in folk guitar singing, used to raise the key by a specific fret during key changes, harmonizing the melody with the singer's voice while maintaining the original fingering, greatly reducing the difficulty of key changes. It's widely used in flamenco, classical, and folk guitar playing. When used for solo pieces, the capo is usually placed between the first and fourth frets, with the second fret being the most frequent placement. Its use above the fourth fret is primarily seen in accompaniment.

[0003] Existing pitch clips are broadly divided into two categories: fixed clamping and sliding clamping. The existing fixed clamping type has the following drawbacks: 1. The tops of the front and rear clamping arms are hinged together using a single pivot point. This structure causes the upper clamping force to be greater than the lower clamping force during clamping, affecting its adjustment accuracy; 2. The tops of the front and rear clamping arms are hinged together using a single pivot point. This structure causes the upper clamping force to be greater than the lower clamping force during clamping, affecting its adjustment accuracy; 3. They are generally larger in size, affecting aesthetics and user comfort. Summary of the Invention

[0004] To address the shortcomings and deficiencies of the prior art, this invention provides a capo with a front and rear clamping arm connected by a linear bearing consisting of an adjusting inner sleeve, an adjusting limit sleeve, and ball bearings. The adjusting inner sleeve is moved by the tension of a threaded adjusting rod and the return of a spring, ensuring that the clamping forces of the front and rear clamping arms remain as consistent as possible, thus guaranteeing accurate pitch adjustment. The capo features an adjustment scale and corresponding indicator markings. Only one test is needed to find the optimal pitch position. Each use simply requires adjusting to the designated scale (the position of the indicator markings can be observed and recorded) and then clamping. This makes adjustment very convenient, highly accurate, compact, comfortable to use, aesthetically pleasing, and widely applicable.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a variable clamp with precise and convenient clamping force adjustment, comprising a front clamping arm and a rear clamping arm that cooperate with each other, a clamping arm for pressing the two together, a pull rod and a spring that cooperate with the clamping arm, wherein the top of the front clamping arm is provided with an adjusting inner sleeve, the top of the rear clamping arm is provided with an adjusting limiting sleeve that cooperates with the adjusting inner sleeve, the pull rod is a threaded adjusting pull rod, one end of the threaded adjusting pull rod is connected to the clamping arm, the spring is sleeved on the threaded adjusting pull rod, the inner sleeve is provided with a spring retaining ring that cooperates with the spring, the other end of the threaded adjusting pull rod passes through the inner sleeve and the top of the front clamping arm and is connected to an adjusting knob, the inner sleeve is provided with an adjusting scale, and the outer side of the adjusting knob is provided with an adjusting indicator mark that cooperates with the adjusting scale; a plurality of balls are provided between the inner sleeve and the adjusting limiting sleeve, the balls, the inner sleeve and the adjusting limiting sleeve constitute a linear bearing, and a planar bearing is provided between the adjusting knob and the front clamping arm.

[0006] The present invention connects the front and rear clamping arms via a linear bearing consisting of an adjusting inner sleeve, an adjusting limit sleeve, and ball bearings. The adjusting inner sleeve is moved by the tension of a threaded adjusting rod and the return of a spring, ensuring that the clamping force of the front and rear clamping arms remains as consistent as possible, thereby ensuring the accuracy of pitch adjustment. The invention also features an adjustment scale and corresponding adjustment indicators. Only one test is needed to find the optimal pitch position. Each use simply requires adjusting to the specified scale (the position of the adjustment indicators can be observed and recorded) and then clamping. The adjustment is very convenient, highly accurate, compact, comfortable to use, aesthetically pleasing, and widely applicable.

[0007] Preferably, the adjustment knob includes an integrally formed knob body and an internal threaded connector, the internal threaded connector is connected to a threaded adjustment rod, the planar bearing is located between the knob body and the front clamping arm, and the adjustment indicator is located on the outside of the knob body.

[0008] This structure facilitates the assembly of the adjustment knob and the threaded adjustment rod, ensuring the stability and reliability of the adjustment.

[0009] Preferably, the threaded adjusting rod includes an integrally formed external thread section and a smooth rod section. The other end of the external thread section is connected to an internal threaded connector, and the other end of the smooth rod section is connected to a clamping arm. A connecting short rod that matches the clamping arm is provided at the end of the smooth rod section. The top of the clamping arm is provided with a rod groove that matches the smooth rod section and a cam head that matches the connecting short rod.

[0010] This structure ensures a secure assembly between the threaded adjusting rod and the clamping arm, thereby guaranteeing the stability and reliability of the clamping arm pulling the threaded adjusting rod.

[0011] Preferably, the top outer side of the front clamping arm is provided with a circular recess for mating with an internal threaded connector and an arc-shaped notch for mating with the knob body, and the outer side of the knob body is flush with the outer side of the arc-shaped notch of the front clamping arm.

[0012] This structure allows it to be made small in size and aesthetically pleasing in appearance.

[0013] Preferably, the cross-section of the adjusting inner sleeve is square, and the outer sides of the four corners are provided with ball grooves for mating balls. The cross-section of the adjusting limiting sleeve is also square, and the inner sides of the four corners are provided with ball grooves for mating balls. An arc-shaped chamfer is provided at the end of the adjusting inner sleeve.

[0014] This structure facilitates the assembly of the ball bearings and ensures smooth and reliable movement of the adjusting inner sleeve within the adjusting limit sleeve.

[0015] Preferably, there is a gap between the minimum scale position on the adjustment scale and the fixed end of the adjustment inner sleeve to allow the clamping arm to move. The maximum scale position on the adjustment scale is located in the middle of the adjustment inner sleeve. When the adjustment knob is rotated one full turn, the distance the adjustment inner sleeve moves is the distance between the maximum scale position and the minimum scale position.

[0016] This structure allows for a certain clamping distance on the clamping arm, ensuring reliable clamping.

[0017] Preferably, the top of the rear clamping arm is provided with a support block that cooperates with the clamping arm, and the support block is provided with a cam groove that cooperates with the clamping arm and a limiting groove that cooperates with the threaded adjusting rod.

[0018] This structure further ensures the stability and reliability of the clamping arm pulling the threaded adjusting rod.

[0019] Preferably, the end of the adjusting limit sleeve is provided with a limit end cap, and the rear part of the rear clamping arm is provided with a clamping arm groove that cooperates with the clamping arm. When the clamping arm is clamped, it is located in the clamping arm groove, and the outer side of the clamping arm is flush with the rear surface of the rear clamping arm.

[0020] This structure ensures good stability when the clamping arm is clamping, and also allows for minimizing the overall size of the product while maintaining its aesthetic appeal.

[0021] Preferably, the outer ring of the knob body is provided with anti-slip texture, and the outer side of the knob body is provided with a decorative panel.

[0022] This structure further improves its adjustment stability and aesthetic appearance.

[0023] Preferably, the inner side of the front clamping arm is provided with a front rubber pad, the inner side of the rear clamping arm is provided with a rear rubber pad, the length of the front clamping arm is greater than the length of the rear clamping arm, a portion of the front rubber pad is embedded in the front clamping arm, and a portion of the rear rubber pad is embedded in the rear clamping arm.

[0024] This structure allows it to effectively protect the guitar while ensuring clamping stability.

[0025] This invention connects the front and rear clamping arms via a linear bearing consisting of an adjusting inner sleeve, an adjusting limit sleeve, and ball bearings. The adjusting inner sleeve is moved by the tension of a threaded adjusting rod and the return of a spring, ensuring that the clamping force of the front and rear clamping arms remains as consistent as possible, thus guaranteeing accurate pitch adjustment. The invention also features an adjustment scale and corresponding indicator markings. A single test tuning is sufficient to find the optimal pitch position. Each use simply involves adjusting to the designated scale (the position of the indicator markings can be observed and recorded) and then clamping. Adjustment is very convenient, highly accurate, and compact. It essentially integrates with the guitar during use, offering comfortable operation, an attractive appearance, and wide applicability. Attached Figure Description

[0026] Figure 1 is an exploded view of the present invention;

[0027] Figure 2 is a schematic diagram of the structure of the present invention;

[0028] Figure 3 is a structural schematic diagram of one angle of the adjustment knob in this invention;

[0029] Figure 4 is a structural schematic diagram of another angle of the adjustment knob in this invention;

[0030] Figure 5 is a schematic diagram of the threaded adjusting rod in this invention;

[0031] Figure 6 is a schematic diagram of the support block in this invention;

[0032] Figure 7 is a structural schematic diagram of the rear clamping arm at one angle in this invention;

[0033] Figure 8 is a structural schematic diagram of the rear clamping arm from another angle in this invention;

[0034] Figure 9 is a structural schematic diagram of one angle of the front clamping arm in this invention;

[0035] Figure 10 is a structural schematic diagram of the front clamping arm from another angle in this invention;

[0036] In the diagram: 1. Front clamping arm, 2. Rear clamping arm, 3. Clamping arm, 4. Spring, 5. Adjusting inner sleeve, 6. Adjusting limit sleeve, 7. Threaded adjusting rod, 8. Adjusting knob, 9. Ball bearing, 10. Surface bearing, 11. Knob body, 12. Internal threaded connector, 13. External threaded section, 14. Smooth rod section, 15. Connecting short rod, 16. Circular concave shape, 17. Arc-shaped notch, 18. Ball groove, 19. 20. Chamfered corner, 21. Ball bearing groove, 22. Support block, 23. Limiting end cap, 24. Pull rod groove, 25. Cam head, 26. Cam groove, 27. Limiting groove, 28. Pressing arm groove, 29. Spring retaining ring, 30. Adjustment scale, 31. Adjustment indicator, 32. Minimum scale position, 33. Maximum scale position, 34. Decorative panel, 35. Anti-slip texture, 36. Front rubber pad, 37. Rear rubber pad. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0038] As shown in Figure 1-10, a variable clamp with precise and convenient clamping force adjustment includes a front clamping arm 1 and a rear clamping arm 2 that cooperate with each other, a clamping arm 3 for pressing the two together, a pull rod and a spring 4 that cooperate with the clamping arm 3, an adjusting inner sleeve 5 at the top of the front clamping arm 1, and an adjusting limiting sleeve 6 that cooperates with the adjusting inner sleeve 5 at the top of the rear clamping arm 2. The pull rod is a threaded adjusting pull rod 7, one end of which is connected to the clamping arm 3. The spring 4 is sleeved on the threaded adjusting pull rod 7, and the adjusting inner sleeve 5... The inner part of the knob is equipped with a spring retainer 28 that matches the spring 4. The other end of the threaded adjustment rod 7 passes through the top of the inner adjustment sleeve 5 and the front clamping arm 1 and is connected to an adjustment knob 8. The inner adjustment sleeve 5 is equipped with an adjustment scale 29, and the outer side of the adjustment knob 8 is equipped with an adjustment indicator 30 that matches the adjustment scale 29. Several balls 9 are provided between the inner adjustment sleeve 5 and the adjustment limit sleeve 6. The balls 9, the inner adjustment sleeve 5, and the adjustment limit sleeve 6 constitute a linear bearing. A plane bearing 10 is provided between the adjustment knob 8 and the front clamping arm 1. The adjustment knob 8 includes an integrally formed knob body 11 and an internal threaded connector 12. The internal threaded connector 12 is connected to the threaded adjustment rod 7. The plane bearing 10 is located between the knob body 11 and the front clamping arm 1. The adjustment indicator 30 is located on the outer side of the knob body 11. The threaded adjusting rod 7 includes an integrally formed external threaded section 13 and a smooth rod section 14. The other end of the external threaded section 13 is connected to an internal threaded connector 12, and the other end of the smooth rod section 14 is connected to a clamping arm 3. A connecting short rod 15 that mates with the clamping arm 3 is provided at the end of the smooth rod section 14. The top of the clamping arm 3 is provided with a rod groove 23 that mates with the smooth rod section 14 and a cam head 24 that mates with the connecting short rod 15. The outer side of the top of the front clamping arm 1 is provided with a circular recess 16 that mates with the internal threaded connector 12 and an arc-shaped notch 17 that mates with the knob body 11. The outer side of the knob body 11 is flush with the outer side of the arc-shaped notch 17 of the front clamping arm 1. The adjusting inner sleeve 5 has a square cross-section, and ball grooves 18 that mate with the balls 9 are provided on the outer sides of the four corners. The adjusting limiting sleeve 6 also has a square cross-section, and ball grooves 20 that mate with the balls 9 are provided on the inner sides of the four corners. An arc-shaped chamfer 19 is provided at the end of the adjusting inner sleeve 5. A clearance is left between the minimum scale position 31 on the adjustment scale 29 and the fixed end of the adjustment inner sleeve 5 to accommodate the movement of the clamping arm 3. The maximum scale position 32 on the adjustment scale 29 is located in the middle of the adjustment inner sleeve 5. When the adjustment knob 8 rotates one full turn, the adjustment inner sleeve 5 moves a distance between the maximum scale position 32 and the minimum scale position 31. The top of the rear clamping arm 2 is provided with a support block 21 that mates with the clamping arm 3. The support block 21 is provided with a cam groove 25 that mates with the clamping arm 3 and a limiting groove 26 that mates with the threaded adjustment rod 7. The end of the adjustment limiting sleeve 6 is provided with a limiting end cap 22. The rear part of the rear clamping arm 2 is provided with a clamping arm groove 27 that mates with the clamping arm 3. When the clamping arm 3 is clamped, it is located in the clamping arm groove 27, and the outer side of the clamping arm 3 is flush with the rear surface of the rear clamping arm 2. The outer ring of the knob body 11 is provided with anti-slip texture 33, and the outer side of the knob body 11 is provided with a decorative panel 34.The front clamping arm 1 has a front rubber pad 35 on its inner side and the rear clamping arm 2 has a rear rubber pad 36 on its inner side. The length of the front clamping arm 1 is greater than the length of the rear clamping arm 2. Part of the front rubber pad 35 is embedded in the front clamping arm 1 and part of the rear rubber pad 36 is embedded in the rear clamping arm 2.

[0039] When in use, open the clamping arm, clamp it onto the guitar at the desired tuning position, and tighten the clamping arm. The threaded adjustment lever moves the adjustment knob and the front clamping arm towards the rear clamping arm, clamping both arms onto the guitar. At this point, the spring is held in place by the spring retainer inside the adjustment sleeve. Because the front and rear clamping arms are clamped by translation rather than rotation, the clamping force is kept as consistent as possible, ensuring accurate tuning and wide applicability. To release, open the clamping arm and move the adjustment knob in the opposite direction of the rear clamping arm using the threaded adjustment lever. The spring returns to its original position, pushing the front clamping arm in the opposite direction of the rear clamping arm, releasing the guitar.

[0040] When tuning is needed, connect the testing instrument to the guitar. If the pitch is too high or too low, open the clamping arm. Use the threaded adjustment lever to move the adjustment knob in the opposite direction of the rear clamping arm. At this time, the spring returns to its original position, pushing the front clamping arm in the opposite direction of the rear clamping arm, exposing the adjustment scale on the inner adjustment sleeve. Manually rotate the adjustment knob to a certain angle and record the position of the adjustment scale. Then, tighten the clamping arm again and continue testing until the pitch is accurate. At this time, you can also observe the position of the adjustment indicator on the adjustment knob to determine the scale that needs to be adjusted at that position and record the position of the adjustment indicator. The next time you use it, you do not need to open the clamping arm to adjust it again. Just align the adjustment indicator directly with that position. It is very convenient to use.

[0041] In this invention, the front clamping arm clamps onto the strings on the front of the guitar. Since the strings have a certain tension, the spring can buffer the tension of the strings and prevent rigid compression of the strings.

[0042] The planar bearing in this invention is a small-sized planar bearing purchased from the market. Its main function is to ensure that the adjustment knob rotates smoothly, stably and reliably.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable clamp with precise and convenient clamping force adjustment, comprising a front clamping arm and a rear clamping arm that cooperate with each other, a clamping arm for pressing the two together, a pull rod and a spring that cooperate with the clamping arm, characterized in that: The top of the front clamping arm is provided with an adjusting inner sleeve, and the top of the rear clamping arm is provided with an adjusting limiting sleeve that cooperates with the adjusting inner sleeve. The pull rod is a threaded adjusting pull rod, one end of which is connected to the clamping arm. The spring is sleeved on the threaded adjusting pull rod. The inner sleeve is provided with a spring retainer ring that cooperates with the spring. The other end of the threaded adjusting pull rod passes through the adjusting inner sleeve and the top of the front clamping arm and is connected to an adjusting knob. The adjusting inner sleeve is provided with an adjusting scale, and the outer side of the adjusting knob is provided with an adjusting indicator mark that cooperates with the adjusting scale. Several balls are provided between the adjusting inner sleeve and the adjusting limiting sleeve. The balls, the adjusting inner sleeve, and the adjusting limiting sleeve constitute a linear bearing. A plane bearing is provided between the adjusting knob and the front clamping arm.

2. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 1, characterized in that: The adjustment knob includes an integrally formed knob body and an internal threaded connector. The internal threaded connector is connected to a threaded adjustment rod. The planar bearing is located between the knob body and the front clamping arm. The adjustment indicator is located on the outside of the knob body.

3. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 2, characterized in that: The threaded adjusting rod includes an integrally formed external thread section and a smooth rod section. The other end of the external thread section is connected to an internal threaded connector, and the other end of the smooth rod section is connected to a clamping arm. A connecting short rod that matches the clamping arm is provided at the end of the smooth rod section. The top of the clamping arm is provided with a rod groove that matches the smooth rod section and a cam head that matches the connecting short rod.

4. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 2, characterized in that: The top outer side of the front clamping arm is provided with a circular recess for mating with an internal threaded connector and an arc-shaped notch for mating with the knob body. The outer side of the knob body is flush with the outer side of the arc-shaped notch of the front clamping arm.

5. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 1, characterized in that: The adjusting inner sleeve has a square cross-section, and ball grooves for mating balls are provided on the outer sides of the four corners. The adjusting limiting sleeve also has a square cross-section, and ball grooves for mating balls are provided on the inner sides of the four corners. An arc-shaped chamfer is provided at the end of the adjusting inner sleeve.

6. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 1, characterized in that: There is a gap between the minimum scale position on the adjustment scale and the fixed end of the adjustment inner sleeve to allow the clamping arm to move. The maximum scale position on the adjustment scale is located in the middle of the adjustment inner sleeve. When the adjustment knob is rotated one full turn, the distance the adjustment inner sleeve moves is the distance between the maximum scale position and the minimum scale position.

7. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 3, characterized in that: The top of the rear clamping arm is provided with a support block that cooperates with the clamping arm. The support block is provided with a cam groove that cooperates with the clamping arm and a limiting groove that cooperates with the threaded adjusting rod.

8. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 2, characterized in that: The end of the adjusting limit sleeve is provided with a limit end cap, and the rear part of the rear clamping arm is provided with a clamping arm groove that cooperates with the clamping arm. When the clamping arm is clamped, it is located in the clamping arm groove, and the outer side of the clamping arm is flush with the rear surface of the rear clamping arm.

9. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 2, characterized in that: The outer ring of the knob body is provided with anti-slip texture, and the outer side of the knob body is provided with a decorative panel.

10. The adjustable clamp with precise and convenient clamping force adjustment as described in claim 2, characterized in that: The front clamping arm has a front rubber pad on its inner side, and the rear clamping arm has a rear rubber pad on its inner side. The length of the front clamping arm is greater than the length of the rear clamping arm. A portion of the front rubber pad is embedded in the front clamping arm, and a portion of the rear rubber pad is embedded in the rear clamping arm.

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