CN100347740C

CN100347740C - Capotasto

Info

Publication number: CN100347740C
Application number: CNB011416300A
Authority: CN
Inventors: 尼古拉斯·约翰·坎普林
Original assignee: G7th Ltd
Current assignee: C7th Ltd
Priority date: 2001-09-29
Filing date: 2001-09-29
Publication date: 2007-11-07
Anticipated expiration: 2021-09-29
Also published as: CN1409294A

Abstract

The present invention relates to a chord pillow (10) on a chord musical instrument. The chord musical instrument has a plurality of chords (4) and a neck (2), and the neck (2) comprise a fingerboard (6) and a back surface (8); the chord pillow (10) comprises a chord joint arm (12) and a gripping arm (14), and is set into a form that the chords (4) are pinned down and gripped. The arms (12 and 14) are mutually connected by surrounding a pivotal connection piece (16) and a shaft (1) in a form of pivotal rotation in such a position of the arms (12 and 14), and the position is adjacent to one side of the neck (2). The pivotal connection piece comprises a locking device (18) capable of being released, the locking device can selectively lock and unlock the corresponding pivot movement of the pivotal connection piece (16), the gripping arm (14) and the chord joint arm (12) at least in one direction in the process of operation; especially, the locking device (18) can selectively lock and unlock corresponding pivot movement removed in a gripping direction between the pivotal connection piece (16), the gripping arm (14) and the chord joint arm (12) and the musical instrument neck.

Description

Capotasto

Technical field

The present invention relates to the particularly capotasto used of guitar, Banjo or similar musical instrument of stringed musical instrument.

Background technology

Capotasto (being also referred to as capodastro, capodaster, capo tasto or cejilla sometimes) is a kind of known and by the stringed musical instrument player device that uses of guitar and Banjo player particularly.Capotasto can be used for for example guitar or the such stringed musical instrument of Banjo, one group of string that this stringed musical instrument has neck and extends along neck length.Neck comprises fingerboard part and the back near string.Have on the fingerboard that a plurality of projection and lateral extensometer are crossed the timbre of neck slightly from fingerboard/neck surface.During use, capotasto is with respect to the fingerboard that is provided with along neck, particularly with respect to the effect of the timbre constant chord of stretching out along the setting of fingerboard length and from fingerboard, so that reduce the effective length of string, and regulates the pitch that is produced by string thus.

When the neck of musical instrument uses capotasto, the arm of the bonding part of string or capotasto is arranged to vis-a-vis the surface of fingerboard pushes down string, to clamp string with respect to timbre and/or fingerboard.Come on the fingerboard for the bonding part with string and need capotasto, described capotasto comprises the appropriate device that can clip on the neck.In the design of multiple previous capotasto, the clamping of capotasto and neck is by using cumbersome clamping device to realize, what this clamping device adopted is thread mechanism, angle lever and other device, and these devices are handled difficult and/or installed very time-consuming.Particularly, the capotasto structure in past generally is such,, has to use two hands when a capotasto being installed to the musical instrument neck, it is taken off or moving its position that is.

Just comprise bar or thread mechanism with regard to the existing capotasto design that clamping load is provided, it has utilized the advantage of physical construction to a certain extent, clamping load is provided and is pressed onto capotasto on the string and makes it towards fingerboard to capotasto.Although use this physical construction to have the easier advantage that applies enough holding forces, it also can cause some problems.Particularly when using this layout, because the advantage on its physical construction makes applying excessive holding force unintentionally or unexpectedly than being easier to.This will cause string to produce overstress, particularly when used capotasto during near the timbre on the musical instrument, damages string easily, changes tone and/or the neck of damage musical instrument under extreme case.The player can't directly perceive or experience holding force and the pressure that applies with this capotasto.Therefore the player will lose " sensation " to a certain extent, and as is generally known, this is not wish the phenomenon that occurs.Another problem in these designs is need roughly adjust special adjustment or requirement that clamping device carries out in a way for the profile and the size of specific musical instrument and musical instrument neck.Therefore, using these capotastos on the single musical instrument that varies along its length on the neck of different musical instruments, different size and/or in the neck cross section is very difficult, time-consuming and inconvenient things.

Existing at present a lot of this example that comprises the capotasto design of clamping device.Propose and described some particular instances in these designs in following patent, described patent is: US4324165; US5492045; US4149443; And US5792969.

In other existing capotasto design, utilize spring device (being generally volute spring) that holding force is provided.At US600844; The example of this capotasto has been described among US4143576 and the US4583440.By means of these designs, the string engaging arms is connected with clamping limb with one end pivoting form.In use capotasto is cooperated with the musical instrument neck string engaging arms to be leaned against on the string and with string press to fingerboard, clamping limb leans against on the back side opposite with neck and supports this back side simultaneously.Volute spring is arranged in the pivot mounting so that promote two arms simultaneously, the neck of string and musical instrument is clipped between two arms, and holding force is provided.

As described in existing patent, the design of this capotasto be in use easily and easily and also the player can install with a hand.Yet because volute spring can apply strong power for the ad-hoc location on some musical instrument or the musical instrument neck, so may make capotasto that string and/or musical instrument are produced overstress.The holding force that is provided by spring will change with the width that arm is opened so that adapt to neck, and therefore, when using capotasto on the musical instrument neck at different size, holding force can change.In addition, when using this capotasto, the player can't control the holding force that applies, and its holding force is to determine by the hardness of spring.This obviously is that the musician is undesirable to the holding force that applied and the defective of pressure control aspect.In addition, for particular instrument, will produce overstress if spring is really up to the mark.The position of capotasto arm does not lock or is fixing, and capotasto fully relies on the elasticity of spring to remain on its due position.

Therefore, be desirable to provide a kind of improved capotasto, and wish that by providing capotasto to solve the problems referred to above, described capotasto is simple and be easy to use, and can not make the neck overstress of string or musical instrument and/or integral status is taken on a new look.

Summary of the invention

In one embodiment of the invention, provide a kind of capotasto that is used for stringed musical instrument, have many strings and a neck on the described stringed musical instrument.Neck comprises fingerboard and back.Capotasto comprises the string engaging arms, clamping limb and the pivot connector that two arms are connected mutually with pivotable form.The string engaging arms is suitable for crossing over the fingerboard extension above the string and being pressed on the string in use.Clamping limb is fit to cross over the back and and the backside bonded of neck in use.Pivot connector with pivotable form along on a certain position of described arm clamping limb being linked to each other with the string engaging arms, in use, described position is provided with near described neck, rotate thereby make described arm can carry out relative pivot each other, thereby can and be clamped between the described arm string and neck installation in use.In use, preferably pivot connector is set to a side of neck usually.Pivot connector (16) comprises releasable locking mechanism (18), be used for the unidirectional relative pivot motion of clamping limb (14) chord engaging arms (12) optionally to lock pivot connector (16), promptly prevent in the relative pivot motion of opening on the direction, and allow the relative pivot on closing direction to move.

This capotasto of this embodiment is devoted to utilize locking mechanism to address the above problem among the present invention, and described locking mechanism provides a device, and this device can be with the locking position of arm and capotasto on the position that is provided with by the player.Therefore can set the holding force that applies by capotasto so that the place near capotasto applies required power on the musical instrument neck, then by preventing that the locking device that arm and capotasto are opened from keeping this holding force by the player.

To locking device control in case optionally lock with untie pivot connector, clamping limb and string engaging arms away from each other and they leave the relative pivot motion of musical instrument neck, thereby when locking, prevent that capotasto from opening.In addition, preferably applying bias voltage to releasable locking mechanism makes the normal locking of pivot connector open to prevent capotasto.

Can make capotasto apply required holding force in this way near neck and by the locking device that has engaged.Therefore when applying required clamping force, needn't start locking device respectively and just capotasto can be installed easily.

Description of drawings

Below will only present invention is described with reference to example shown in the accompanying drawing, wherein:

Fig. 1 is the side view in partial cross-section according to capotasto of the present invention, and described capotasto is installed on the neck of stringed musical instrument;

Fig. 2 is the sectional view along capotasto midplane I shown in Figure 1;

Fig. 3 is the decomposition diagram of capotasto shown in Fig. 1 and 2;

Fig. 4-6 expression is according to the described capotasto of second embodiment of the invention, and wherein Fig. 4 is the side view in partial cross-section of capotasto, and Fig. 5 is the end-view that the direction of arrow II in Fig. 4 obtains when observing capotasto, and Fig. 6 is the exploded view of capotasto shown in the Figure 4 and 5;

Fig. 7-9 expression is according to the described capotasto of another embodiment of the present invention, and wherein Fig. 7 is the side view in partial cross-section of capotasto, and Fig. 8 is the cut-open view that the planar I II along capotasto shown in Figure 7 obtains, and Fig. 9 is the exploded view of Fig. 7 and capotasto shown in Figure 8.

Embodiment

Illustrated among Fig. 1-3 according to the described capotasto of first embodiment of the invention.With reference to Fig. 1, capotasto 10 to be arranged to be applied on the stringed musical instrument, described stringed musical instrument has the many strings 4 that extend along the length of musical instrument neck 2, and the position of string 4 is near the fingerboard surface 6 of neck 2.Fingerboard comprises a plurality of timbres, and these timbres are along the neck setting and laterally cross over neck, and from the surface of fingerboard 6 projection slightly.Capotasto 10 is arranged to can clamp string 4 when mounted, and string 4 is pressed to the fingerboard 6 of neck 2.Particularly, can string 4 be clipped on the timbre of fingerboard 6 by capotasto 10.

Capotasto 10 comprises the string engaging arms 12 that roughly becomes L shaped.Arm 12 comprises main string bonding part 7, thus this part crosses over that the width of neck 2 extends and also when being installed to capotasto 10 on the neck 2 this part engage with string 4 and string 4 is pressed to the fingerboard 6 of neck 2 and lean against on the fingerboard, particularly lean against on the timbre of fingerboard 6.On the major part 7 of string engaging arms 12 lower surfaces, be provided with elastic layer 11, its be approximately perpendicular to that fingerboard surface 6 is extended and also along and the side of pressing close to neck 2 extend.

Clamping limb 14 is installed on the string engaging arms 12 with pivotable form by pivot 16.Clamping limb 14 is roughly L shaped, and a side of arm 14 is an arc so that match with the general conventional shape of the musical instrument neck 2 that will apply capotasto 10.Clamping limb 14 has major part 15, and when installing to capotasto 10 on the neck 2, the back that described major part is crossed over neck 2 is stretched and leaned against and be bearing in usually on the back side 8 of the neck 2 relative with fingerboard surperficial 6.As shown in FIG., for preventing that neck 2 is produced infringement, and be provided with elastomeric layer 13 on the part of clamping limb 14, this material layer is arranged to against the form of musical instrument neck 2.Part 17 less on the clamping limb 14 is approximately perpendicular to major part 15, and is arranged to along the form of extending with a side of pressing close to neck 2.The pivot 16 that string engaging arms 12 and clamping limb 14 are rotationally connected mutually is positioned on the position of

arm

12,14 1 sides and is in the

shorter part

9,17 of

arm

12,14, and when installing to capotasto 10 on the musical instrument, the residing position of described pivot usually contiguous and/towards a side of neck 2.During use, thereby

arm

12,14 can be clipped between the

arm

12,14 around the neck 2 that axle 16 pivots rotate musical instrument, make string engaging arms 12 that string 4 is pressed to fingerboard 6, and be the timbre that props up fingerboard 6 specifically, simultaneously clamping limb 14 from go up in the other direction against and push down the back side 8 of neck 2.

Capotasto 10 also comprises releasable locking mechanism and the release handle 20 that general usefulness 18 is represented, an end of this release handle is installed around pivot 16 in the mode that can pivot equally.Relative pivot motion between locking mechanism 18 locking pivot connectors and clamping limb 14 and the string engaging arms 12, thereby when when locking, two

arms

12,14 relative motion on a direction (being at direction of operating under the current situation) are at least prevented or are limited.By operation release handle 20 thereby locking mechanism 18 is thrown off

permission arm

12,14 and carry out the pivot rotation around pivot 16, allow

arm

12,14 to produce pivot to each other with pivot connector and rotate and relative motion,

arm

12,14 in this case is moved away from each other and capotasto 10 is opened.

Locking mechanism 18 comprises the breechblock 24 of little roller shape, and it is positioned at and embeds cone tank or gap (generally representing with 22).Form between the arc faying face 26 on the other side in the mild angle end face 28 of described cone tank shorter part 9 on string engaging arms 12 and the clamping limb 14.The shape of the relative arch surface 26 in the clamping limb 14 is the center with the center of circle of pivot 16.The angle that the angle end face 28 of string engaging arms 12 is had forms cone tank or gap 22 between two

surfaces

26,28, as shown in Figure 1, this cone tank or gap 22 narrow down attenuating on the direction on the left side.Therefore, the size of groove 22 1 ends (right hand end shown in Figure 1) between two

surfaces

26,28 is a bit larger tham the diameter of roller 24 and is slightly smaller than the diameter of roller 24 at narrow end (the left hand end among Fig. 1).By means of the inclination of groove 22, can make

arm

12,14 produce pivots and rotate, two arms are moved away from each other and capotasto 10 is opened, the motion of two arms drives roller 24 and it is shifted to narrow end, and roller embeds on narrow end and is stuck in the groove 22.So just,

arm

12,14 being pinned the pivot that has

limited arm

12,14 simultaneously rotates.Yet,, will make roller 24 push the thicker end of groove 22 to if arm in another direction, that is, makes capotasto 10 closures and makes it mutually towards the motion of clamping direction.So just, roller 24 is discharged down from the lock-out state that engages with

rooved face

26,28, so

arm

12,14 can carry out on this direction, and pivot rotates and motion.

Release handle 20 comprises the slit 25 that 30,32, two projections formation of two projections can make the end of ball 24 freely keep.Be provided with little spring 34 between the shorter part 9 of release handle 20 chord engaging arms 12, little spring is subjected to bias effect rotates the end generation pivot of release handle 20, thereby push roller 24 to narrow end by projection 32 it is entered in the groove 22.This helps lock

arm

12,14 and can guarantee that locking mechanism 18 shifts to latched position automatically.

Make capotasto 10 open and

arm

12,14 is moved away from each other in order to

untie arm

12,14, need operation release handle 20 also to move it, thereby by the wide end of roller 24 being shifted to groove 22 towards the projection of groove 22 narrow ends.Subsequently, roller 24 will be thrown off from the

surface

26,28 of groove 22 and be made the chucking releases, and then make

arm

12,14 move apart and capotasto 10 is opened.

Hairspring 36 is arranged between string engaging arms 12 and the clamping limb 14.Thereby but spring 36 be arranged to pusher

arm

12,14 toward each other pivot rotate form with capotasto 10 closures and/or clamping musical instrument neck 2.Yet it should be noted that the spring that spring 36 is preferably very thin and its only apply acting force to

arm

12,14 as mild as a dove.In order to use capotasto 10 better, spring 36 does not provide enough holding forces usually.In other embodiments even can omit this biasing spring 36.In addition, hairspring 36 can be arranged to and carry out opposite pivot rotation each other and to open capotasto 10 thus by pusher arm 12,14.Can open capotasto 10 in this way at an easy rate and it is taken off from neck 2.Yet only when being in unlock state, capotasto 10 and locking mechanism 18 just can produce this motion.

During operation,

arm

12,14 pivots are rotated open capotasto 10 by depressing release handle 20, and because release handle 20 is arranged to supporting the form of a part of string engaging arms 12, so

arm

12,14 can be moved away from each other.Then capotasto 10 location is made

arm

12,14 surround the neck 2 of musical instrument and release handle 20 is discharged.Capotasto 10 on the neck 2 is with closure and make

arm

12,14 move toward one another thereupon, this motions that locking mechanism 18 allows on this direction.This process is facilitated by means of hairspring 36, if hairspring is installed, and the bias voltage that hairspring will apply towards make-position arm 12,14.By player's while

extrusion arm

12,14, clamp pressure is located capotasto 10 and string 4 is clipped in fingerboard surface 6 on neck 2.The size that the player can come to determine clamp pressure in this way and determine to exert pressure.After having applied power, the locking mechanism 18 that automatically engages stops capotastos to be opened, and with

arm

12,14 remain on keep add clamping, the make-position of holding force.In order to take off capotasto 10, can depress release handle 20, thus locking mechanism 18 is discharged, the pivot that

arm

12,14 is done remove mutually rotates, and capotasto 10 is opened and from neck 2 it is taken off.Can also be easily and discharge capotasto easily and it is partially opened, it is slided on the diverse location of neck 2 along neck 2.

From above description, can notice, can be very simply and easily place capotasto 10.Particularly, since locking mechanism 18 can automatically engage to guarantee that

arm

12,14 is locked on the correct placement location by required holding force, so if necessary, can place capotasto 10 with a hand.

Two other exemplary embodiment of the present invention has been shown among Fig. 4-9.These two embodiment are identical with above-mentioned first embodiment basically, and used identical reference marker for identical parts.Specifically, the string engaging arms 12 that these two embodiment comprise, it is connected in pivotable mode with clamping limb 14, and described pivot is arranged on an end of

arm

12,14 and the close in use position of musical instrument neck 2 one sides.This embodiment also comprises locking mechanism 18, and it is used to pin the pivot motion of

arm

12,14 and

release handle

50,62, can operate

release handle

50,62 unlocked mechanisms 18.Can be with using this two embodiment with the roughly the same mode of first embodiment.The details that main significant difference between these embodiment is locking mechanism 18 with for adapting to the pivot structure of the

arm

12,14 that these different locking mechanisms 18 are provided with.

In the embodiment shown in Fig. 4-6, capotasto 40 comprises can be around rotary locking mechanism 51 pivotally supported arms 12,14.Mechanism 18 comprises outer ring member 45, and this outer ring member is positioned at string engaging arms 12 and is fixed to the upper.Yet, also outer ring member 45 and string engaging arms 12 can be made of one on the other hand.In ring 45, be provided with socket 47 and two

arms

12,14 so and pivotally connected of stretching out from clamping limb 14.The excision of a part of socket is made it to form

cone tank

42a, 42b between excision face 47a, the 47b of surperficial 45a, the 45b of ring 45 and socket 47.Roller 44a, 44b are positioned at

cone tank

42a, 42b, and wherein the diameter of

roller

44a, 44b is a bit larger tham the narrow end of cone tank 42a, 42b.

Little spring

46a, 46b placed in groove 42a, the 42b and it is arranged to apply bias voltage and to push it against surperficial 45a, 47a and 45b, the 47b that the narrow end of

groove

42a, 42b determines itself and groove 42a, 42b to roller engage.Therefore, the effect of

roller

42a, 42b likes a breechblock and is stuck in groove 42a, the 42b.Thus, motion that can restricted

arm

12,14 also prevents that by feat of the

taper orientation arm

12,14 from opening and being locked.

Release handle 50 also is installed on the pivot 1 with pivotable form, and this release handle 50 comprises the socket 52 that constitutes capotasto 40 centrally-pivoted axles.Two projections that form release handle 50 reach near in the locational groove 42a of

roller

44a, 44b, the

42b.Projection

48a, 48b are arranged to when release handle 50 moves,

projection

48a, 48b promote

roller

44a, 44b and overcome the power of biasing

spring

46a, 46b and then be disengaged with

groove

42a, 42b, rooved

face

45a, 47a and 45b, 47b, thus release mechanism 18 and allow

arm

12,14 motions.

Although locking mechanism 18 shown in this embodiment comprises a pair of

groove

42a, 42b and

roller

44a, 44b, obviously, can use any amount in other embodiments.

Additional groove

42a, 42b and

roller

44a, 44b are set, have increased locking intensity simply, but this has also increased the complicacy of device by increasing surface area.

In the embodiment shown in Fig. 7-9, capotasto 60 comprises locking mechanism 18, and this locking mechanism is made of wound form spring clutch component, and described wound form spring clutch component is around the pivotally connected setting between the arm 12,14.The spring clutch component comprises the volute spring 66 of tight winding, and its end and cylindrical pivot boss 69 in string engaging arms 12 closely cooperates.Spring 66 and boss 69 coaxial being installed in the cylindrical sleeve 71 that forms on clamping limb 14 1 ends, thus two

arms

12,14 can be rotated around axle 1 pivot of boss 69 and sleeve 71.One end of release handle 62 boss 69 and spring 66 same and that pivot 1 centers in the sleeve 71 are coaxially pivotally installed.First end 67 of spring 66 is radially outward outstanding and embed in the locating slot 70 in the clamping limb 14.Second end 65 of spring 66 is equally radially outward outstanding and embed in the locating slot 68 in the release handle 62.The winding arrangement of spring 66 should be arranged to make string engaging arms 12 and clamping limb 14 move toward each other and be close to capotasto 60, for example capotasto 60 is close on the neck 2 of musical instrument, the coil of spring 66 is opened, make

arm

12,14 carry out pivot motion freely.By making spring coil more closed on boss 69, can stop

arm

12,14 motion in the opposite direction, in other words, but stop

arm

12,14 is moved away from each other and motion that capotasto 60 is opened.The further motion of

lock arm

12,14 on this direction thus, therefore, in case capotasto is close to and applies the pressure of setting, the motion that arm 12,14 just can not be moved away from each other and can not capotasto 60 being opened by locking mechanism 18.

In order to open capotasto 60 and

arm

12,14 to be removed, for example, for capotasto 60 is taken off from neck 2,, need mobile release handle 62 that the coil of spring 66 is opened, they no longer are locked on the boss 69.Thereby just can make

arm

12,14 motion subsequently and carry out pivot and rotate and open capotasto 60.

Though in each embodiment, described multiple preferred locking mechanism for the arm that locks capotasto, obviously, also can use other known locking mechanism 18 in other embodiments of the invention, particularly rotary locking mechanism.

In above-mentioned all embodiment, locking mechanism 18 generally all is provided with and prevents that

arm

12,14 from installing at discharge non-two-way (reversible) of the motion of a direction (that is,

arm

12,14 being moved away from each other to open capotasto) head lamp brush guard pivot.Yet locking mechanism 18 allows to move on another direction that more is close to.When capotasto is close to, capotasto is remained on the use location of setting by applying the holding force of setting by the player, just can easily capotasto be installed and is close on the neck 2 of musical instrument.In addition, because locking mechanism 18 allows to be close to motion, so needn't start one independently locking device capotasto is locked on the position, this is because as shown in FIG., and locking mechanism 18 can be arranged to it and be biased to latched position and in fact it can automatically be used for capotasto is remained on being close on the position of locking.In other words, with required pressure the capotasto extruding is in place, is held in place automatically by locking mechanism then, described locking mechanism can prevent that capotasto from getting loose, but allows it to be clamped on the neck.In order to take off capotasto, can unclamp locking mechanism simply, capotasto is opened.

Obviously, if this locking mechanism can lock prevent

arm

12,14 on the direction of opening or even the pivot on both direction motion, still can use the locking mechanism 18 of other type.

Other example that may use as the locking mechanism of adequate types comprises brace type clutch coupling or ratchet-wheel gear.Obviously, however, but also there is the locking mechanism of other adequate types in a large number.

Yet, when locking, use any locking mechanism 18 all can appear at the possibility that has play in the mechanism 18.This play should be reduced to minimum so that with capotasto fix in position correctly, and apply the holding force of setting.In order to remove any little play,

elastic layer

11 and 13 and make it to have enough elasticity so that regulate the play of expection can be set on arm.

Claims

1. capotasto (10) that is used on the stringed musical instrument, described stringed musical instrument has many strings (4) and neck (2), and said neck (2) comprises fingerboard (6) and the back side (8), and described capotasto (10) comprising:

String engaging arms (12), its top that is arranged in string (4) is crossed over fingerboard (6) extension and is in use pushed down string (4);

Clamping limb (14), it is arranged to cross in use the back side (8) of neck (2) and engages;

Pivot connector (16), its in pivotable mode with clamping limb (14) and string engaging arms (12) along described arm (12,14) interconnect on a certain position, the set-up mode of described arm is, make the described neck of arm rest (2) in use, rotate thereby make arm (12,14) can carry out pivot relative to one another, so that string (4) and neck (2) be in and be clamped between the said arm (12,14);

It is characterized in that, pivot connector (16) comprises releasable locking mechanism (18), be used for the unidirectional relative pivot motion of clamping limb (14) chord engaging arms (12) optionally to lock pivot connector (16), promptly prevent in the relative pivot motion of opening on the direction, and allow the relative pivot on closing direction to move.

2. capotasto according to claim 1 wherein applies bias voltage so that open to prevent capotasto (10) with locking device (18) locking with the pivot normal locking of part (16) that is dynamically connected to releasable locking device (18).

3. capotasto according to claim 1, wherein pivot connector (16) comprises hairspring (36), this spring is arranged to promote string engaging arms (12) and clamping limb (14) and is rotated toward each other or be separated from each other.

4. capotasto according to claim 1, wherein locking device (18) comprises at least one breechblock (24), the cone tank (22) that cooperatively interacts with at least one and breechblock, described cone tank is on the first and second opposed facing surfaces (28,26) form between, centering on clamping limb chord engaging arms (12,14) pivot connector (16) pivot is between moving period, two surfaces move relative to each other, make in breechblock (24) embedded groove (22) and therefore limit the relative motion on first and second surfaces (28,26) and therefore pivot connector (16) is locked, thereby prevent the motion of arm (12,14) at least one direction.

5. capotasto according to claim 4, wherein breechblock comprises rolling member (24).

6. capotasto according to claim 5, wherein breechblock comprises spherical parts.

7. according to each described capotasto among the claim 4-6, wherein first surface (28) comprises the part of string engaging arms (12), and second surface (26) comprises the part of clamping limb (14).

8. according to each described capotasto among the claim 4-6, elastic device (34) wherein is set so that shift onto breechblock (24) in the cone tank (22) and make breechblock and first and second surfaces (28,26) engage.

9. according to each described capotasto among the claim 4-6, wherein have a release handle (20), this release handle is arranged to breechblock (24) to be released cone tank (22) and make it and first and second surfaces (28,26) disengaging.

10. according to each described capotasto among the claim 1-3, wherein locking device (18) comprises the wound form spring clutch, and this clutch coupling is provided with and is arranged in to open to limit around pivot connector (16) on the direction around pivot connector (16) and is pivotable.

11. capotasto according to claim 10, wherein pivot connector (16) comprises cylindrical end tangs (69), described wound form spring clutch comprises volute spring (66), this volute spring (66) matches and has a pivotally connected motion around cylindrical end tangs (69), and this spring (66) is wrapped on the cylindrical end tangs (69) more closely on the direction opening.