WO2011109194A1

WO2011109194A1 - Tremolo stabilization system for stringed instruments

Info

Publication number: WO2011109194A1
Application number: PCT/US2011/025811
Authority: WO
Inventors: David A. Montoya
Original assignee: Montoya David A
Priority date: 2010-03-03
Filing date: 2011-02-23
Publication date: 2011-09-09

Abstract

A tremolo stabilization system for a stringed instrument, the stringed instrument having a sustain block mounted for pivotal movement with respect to the instrument. The system includes a force redirection body rotatably attached to the instrument and a connector for linking the sustain block to the force redirection body. Pivoting of the sustain block causes a torque to be applied to the force redirection body via the connector. A biasing member is included, which is connected at one end to the instrument and at the other end to the force redirection body. Application of the torque to the force redirection body causes the force redirection body to rotate, the force redirection body thereby applying a force to the biasing member. The force applied to the biasing member is not directly proportional to the pivotal displacement of the sustain block.

Description

TREMOLO STABILIZATION SYSTEM FOR STRINGED INSTRUMENTS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States Provisional Application No. 61/309,985, filed March 3, 2010, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

[0002] The present invention relates to tremolo systems for stringed instruments and, more particularly, to a system and method that utilizes a force redirection body for stabilizing and improving the function of the tremolo system.

Description of Related Art

[0003] For centuries, stringed instruments have been equipped with devices capable of altering the length of the strings, thereby causing the effective pitch of the strings to vary fluidly.

[0004] Particularly for guitar, but also with other stringed instruments, reducing the pitch during performance, or "diving," is more common than increasing the pitch. This is because increasing the pitch increases the likelihood of string breakage due to excessive string tension. Accordingly, many current tremolo devices share a bias toward reducing pitch instead of increasing it.

[0005] Tremolo device design began to mature during the middle of the 20th century, with several designs popularized, such as the FENDER® synchronized tremolo, the BIGSBY® vibrato tailpiece, or the FLOYD ROSE® tremolo system. These designs all incorporate basically the same concept of using springs to directly counterbalance the tension of the strings so that the bridge or tailpiece assembly may be moved manually from its neutral equilibrium position to vary the pitch of the strings. Variations upon this concept have included novel ways of fine tuning, friction reduction, modifications to fit various sizes and shape of instrument, and methods of tremolo activation.

[0006] However, tremolo devices, wherein the strings are directly counterbalanced with spring resistance, are prone to undesired or unpredictable effects due to the spring-string equilibrium being unintentionally altered, e.g., as a result of string breakage, non-tremolo- device bending of individual strings, pressure applied directly to the bridge or tailpiece assembly, or string tension variation during tuning. [0007] These types of devices also have another drawback wherein extreme changes in pitch require extreme manual effort to obtain, as the spring-string system is moved far from its neutral equilibrium.

[0008] Many devices and methods have been put forward to address the stability issues of said tremolo systems, such as U.S. Patent No. 4,903,568 to Itoh, or U.S. Patent No. 6,919,501 to Burton. However, locking the tremolo in position or using additional springs inserted linearly into the system adversely affects the function of the tremolo because the tremolo is either unable to be used at all, or requires excessive force from the user to be operated.

[0009] A device which allows for reliable and adjustable nonlinear counterbalancing of the strings would solve the above-described issues.

SUMMARY OF THE INVENTION

[0010] The present invention includes a tremolo stabilization system including a force redirection body to which springs are attached via a pivot, and to which the bridge assembly is attached via a pivot. This force redirection body acts as an intermediary so that the tremolo system is not a direct or linear spring-to-string relationship.

[0011] The force redirection body is attached to a pivot (or a composite pivot) which is attached to a base plate, and a spring system is attached to another pivot which is also attached to the base plate. The force redirection body is also connected to the spring system via a freely moving pivot, and connected to the bridge assembly via a connecting member and pivot. The base plate may be attached to the body of a guitar in the space where, in a traditional tremolo system, a simple spring or set of springs would reside.

[0012] Activation of the tremolo arm causes rotation of the force redirection body about its stationary pivot on the base plate. As the redirection body rotates, it causes tensioning or relaxing of the spring system. During rotation of the redirection body, a varying portion of the force of the spring system is redirected back into the base plate, such that the portion of the force of the spring system which effectively counterbalances the string forces through the bridge varies nonlinearly. Having the force directed into the base plate avoids placing unnecessary excessive stress on the instrument body.

[0013] The effective counterbalancing force can be at a maximum when the spring system and force redirection body are nearly perpendicular, and at a minimum or even null when they are coUinear. Rotation of the force redirection body past the null point can result in a reverse in direction of the force of the spring system on the force redirection body. [0014] To avoid undesirable or unexpected functioning, stoppers which limit the range of rotation of the force redirection body may be used.

[0015] Also, should it be desired that the bridge assembly be free to rotate through a certain range of motion without activation of the spring system, the stoppers used in conjunction with a bridge assembly connecting member may be used. Such use of stoppers can permit the use of stiffer counterbalancing spring tensions and promote more precise stabilization.

[0016] The present system may be adjustable via the use of an initial spring length adjustment screw, minimum and maximum degree rotation stoppers, an adjustable length bridge assembly connecting member, and via movable or selectable pivots for the force redirection body.

[0017] The present system may be sized and configured to be retrofitted into the same space occupied by a set of simple springs in a traditional tremolo system.

[0018] The present invention includes a tremolo stabilization system for a stringed instrument, the stringed instrument having a sustain block mounted for pivotal movement with respect to the instrument. The system includes a force redirection body rotatably attached to the instrument and a connector for linking the sustain block to the force redirection body. Pivoting of the sustain block causes a torque to be applied to the force redirection body via the connector. A biasing member is included, which is connected at one end to the instrument and at the other end to the force redirection body. Application of the torque to the force redirection body causes the force redirection body to rotate, the force redirection body thereby applying a force to the biasing member. The force applied to the biasing member is not directly proportional to the pivotal displacement of the sustain block.

[0019] The present invention also includes a method for using a tremolo stabilization system for a stringed instrument, the stringed instrument having a sustain block mounted for pivotal movement with respect to the instrument. The system includes a force redirection body rotatably attached to the instrument and a connector for linking the sustain block to the force redirection body, whereby pivoting of the sustain block causes a torque to be applied to the force redirection body via the connector. The system also includes a biasing member connected at one end to the instrument and at the other end to the force redirection body. The method for using this system includes the step of pivoting the sustain block to apply the torque to the force redirection body and cause the force redirection body to rotate, the force redirection body thereby applying a force to the biasing member. The force applied to the biasing member is not directly proportional to the pivotal displacement of the sustain block. [0020] Still other features of and modifications to the invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description, taken with the accompanying drawings, wherein like reference numerals represent like elements throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a perspective view of an embodiment of a tremolo stabilization system in accordance with the present invention;

[0022] FIG. 2 is an exploded view of the tremolo stabilization system shown in FIG. 1 ;

[0023] FIG. 3A is a front view of a prior art electric guitar equipped with a traditional tremolo bridge assembly;

[0024] FIG. 3B is a rear view of the prior art electric guitar shown in FIG. 3 A;

[0025] FIG. 3C is a rear view of an electric guitar having the tremolo stabilization system shown in FIG. 1 installed therein;

[0026] FIG. 4A is a front view of a traditional prior art tremolo bridge assembly;

[0027] FIG. 4B is a partial sectional side view of the traditional prior art tremolo bridge assembly shown in FIG. 4A;

[0028] FIG. 4C is an enlarged rear view of the traditional prior art tremolo bridge assembly shown in FIG. 4A;

[0029] FIG. 5V is a simplified illustration of the function of a typical tremolo system, wherein the system is in equilibrium;

[0030] FIG. 5W is a simplified illustration of the function of a typical tremolo system, wherein the tremolo system is being used to decrease the pitch of the strings;

[0031] FIG. 5X is a simplified illustration of the function of a typical tremolo system, wherein the tremolo system is being used to increase the pitch of the strings;

[0032] FIG. 5Y is a simplified illustration of the function of a typical tremolo system, wherein the pitch of a single string is being increased without the use of the tremolo system;

[0033] FIG. 5Z is a simplified illustration of the function of a typical tremolo system, wherein a single string is broken;

[0034] FIG. 6A is a simplified illustration of the concept of force redirection and internalization utilized by the present invention;

[0035] FIGS. 6B-6F show the simplified illustration of Fig. 6 A in various alternative positions; [0036] FIG. 7 A is a simplified illustration of the varying effective torques achieved by using the simplified system shown in FIG. 6A;

[0037] FIG. 7B is a graph of the effective torque vs. the angular position of the simplified system shown in FIG. 7A;

[0038] FIG. 8A is a graph plotting resistance force vs. bridge position, comparing the curve of a traditional tremolo system with a curve achievable with the present invention;

[0039] FIG. 8B is graph plotting resistance force vs. bridge position, comparing the curve of a traditional tremolo system with a curve achievable with the present invention including a range limiting stopper;

[0040] FIG. 9A is a top view of the tremolo stabilization system shown in FIG. 1, at maximum gross spring tension;

[0041] FIG. 9B is a top view of the tremolo stabilization system shown in FIG. 1, at neutral equilibrium;

[0042] FIG. 9C is a top view of the tremolo stabilization system shown in FIG. 1, at minimum gross spring tension; and

[0043] FIG. 9D is a top view of the tremolo stabilization system shown in FIG. 1, using a stopper to limit the range of motion of the force redirection body.

DETAILED DESCRIPTION OF THE INVENTION

[0044] The present invention will now be described with reference to the accompanying figures. For purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom" and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. It is to be understood that the specific system illustrated in the attached figures and described in the following specification is simply an exemplary embodiment of the present invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

[0045] FIG. 1 depicts an embodiment of the present tremolo stabilization system invention. The various components of the system shown in FIG. 1 are depicted in the exploded view of FIG. 2, which indicates how the various components may be assembled. The system shown in FIGS. 1 and 2 is discussed in detail below. [0046] The guitar represented in FIGS. 3 A, 3B, and 3C is of traditional construction consisting of a guitar body 92 on which a neck 93 is mounted, the neck 93 ending with a head and tuning machines 91. A recess is cut through the guitar body 92 at 90, in which a tremolo bridge assembly (further detailed in FIGS. 4A and 4B) is mounted. In the front view FIG. 3 A is a bridge assembly 90a to which one end of a plurality of strings is attached. The strings are stretched along the long axis of the guitar body 92 and neck 93 and securely fastened at the head and tuning machines 91. FIG. 3B is a rear view of the same assembly represented in FIG. 3 A, including a traditional prior art direct spring resistance system 90b. In FIG. 3C the previous spring system 90b in FIG. 3B has been replaced with an example of the present invention at 90c, which will be described in detail below.

[0047] FIG. 4A is a close-up view of the prior art tremolo bridge assembly 90a in FIGS. 3A and 3B. A bridge plate 100 is secured to the guitar body 92 via mounting screws 101 so that the bridge plate 100 has some freedom to rotate about the pivot axis made by the mounting screws 101. A plurality of saddles 103 are mounted to the bridge plate 100 via adjustable saddle mounting screws 104. Strings 102 are threaded through the saddles 103 and bridge plate 100. A tremolo arm 105 is mounted into the bridge plate 100 to facilitate manual rotating of the bridge plate 100 with respect to the mounting screws 101.

[0048] FIG. 4B shows a sustain block or lever 106 connected beneath the bridge plate 100. The sustain block 106 is the final mounting point for the strings 102. The sustain block 106 is connected to a spring system 107, 109, 110 via spring insert holes 108. The springs 107 are hooked onto a spring hanger 109 which is mounted directly into the guitar body 92 via spring hanger mounting screws 110.

[0049] FIG. 4C shows a plurality of springs 107 connected to sustain block 106. Adjustment of spring hanger mounting screws 110 will modify the length of the springs 107 by modifying the position of spring hanger 109. String insert holes 111 are the points where the string 102 ends are firmly connected to the sustain block 106, through which they are threaded.

[0050] As shown in FIG. 4B, activating the tremolo arm 105 manually in directions 105a and 105b will cause the bridge assembly 90a to pivot with respect to the bridge plate mounting screws 101. As shown in FIG. 4C, this pivoting will cause the lower face of the sustain block 106 to move in directions 106a and 106b with respect to the spring hanger 109. If the tremolo arm 105 is activated in the direction 105a in FIG. 4B it will cause the strings 102 to stretch, increasing the tension and so the effective pitch, and cause the lower face of block 106 in FIG. 4C to move towards the spring hanger 109 in direction 106a, decreasing the counterbalancing tension of the springs 107. If the tremolo arm 105 is instead activated in the direction 105b in FIG. 4B it will cause the strings 102 to relax, decreasing the tension and so the effective pitch, and cause the lower face of block 106 in FIG. 4C to move away from the spring hanger 109 in direction 106b, increasing the counterbalancing tension of the springs 107. For this traditional prior art tremolo system, the counterbalancing tension of springs 107 versus bridge position is represented in simplified graphs as line s in FIGS. 8 A and 8B.

[0051] FIGS. 5V, 5W, 5X, 5Y & 5Z provide a simplified illustration of the mechanism described in the previous paragraph. The system is reduced to the head and tuning machines 91, strings 102, bridge assembly (represented by sustain block 106), springs 107, and guitar body 92.

[0052] In FIG. 5V the system is at neutral equilibrium. No external forces are applied.

[0053] In FIG. 5W, a force is being applied to the tremolo arm in direction 5Wb (this is representative of activation of the tremolo arm 105 in direction 105b in FIG. 4B). The tension is relaxed in the strings 102 and increased in the springs 107.

[0054] In FIG. 5X, a force is being applied to the tremolo arm in direction 5Xa (this is representative of activation of the tremolo arm 105 in direction 105a in FIG. 4B). The tension is increased in the strings 102 and relaxed in the springs 107.

[0055] In FIG. 5Y, an individual string 102 is being stretched. This is often done during performance to increase the pitch of individual string(s). However, the effect on the rest of the system is much the same as in FIG. 5W. The tension is relaxed in the remaining strings 102 and increased in the springs 107, causing the effective pitch of the remaining strings 102 to decline. This is usually an undesired effect. One solution to this problem is to simply increase the tension in the springs, but such increased tension makes it more difficult to utilize the tremolo system to intentionally decrease the pitch of the strings (as in FIG. 5W), particularly when decreasing the pitch far below the equilibrium pitch. As is explained below, the present invention may be used to increase the resistance near the equilibrium position, without increasing the resistance as one continues to further decrease the pitch.

[0056] In FIG. 5Z, an individual string 102 has broken. This often happens during performance or tuning. However, the effect on the rest of the system is much the same as in FIG. 5X. The tension is increased in the remaining strings 102 and relaxed in the springs 107, causing the effective pitch of the remaining strings 102 to increase. This is usually an undesired effect. One solution to this problem is to decrease the tension in the springs 107, which can make it more difficult to increase the pitch of the strings 102 as in FIG. 5X.. [0057] FIG. 6A is a simple illustration of the force redirection concept employed by the present invention. FIG. 6A shows a fixed pivot B, onto which one end of a freely pivoting body A of length F is connected. Body A is connected at the other end to the end of an extension spring C of length H at pivot D. The other end of spring C is connected to pivot E which is fixed a distance G from pivot B. Spring C pulls with force I against body A at pivot D. To maintain equilibrium, body A must react with force J, one component of which is Jp, collinear with axis BD, and the other of which is Jt, which is perpendicular to axis BD. Resistance force Jp is provided by the fixed pivot B, so the only effective external force necessary to maintain equilibrium is Jt.

[0058] FIGS. 6B-6F illustrate the effective torque k on the body A caused by spring C when the body A is rotated to various positions with respect to the fixed pivot B. In FIG. 6B, 6C & 6D, torque k is positive and in a clockwise direction. In FIG. 6E, torque k is 0 (zero). In FIG. 6F, torque k has reversed directions, and is now in a counterclockwise direction.

[0059] FIG. 7A illustrates visually the relationship between the value and direction of the effective torque k and the rotation of body A (as shown in FIG. 6A) over angle i. Maximum values (Ma & Mb) of k are reached when angle i is near 90 or 270 degrees, and values of torque k hit absolute zero (Na & Nb) when all pivots are collinear. This relationship is also represented in FIG. 7B which is the graph of the effective torque k versus rotation of angle i during the course of a complete revolution. The counterclockwise and clockwise torque zones make mirror images of each other.

[0060] FIG. 8A is a graph representing the resistance force r of two tremolo counterbalancing systems versus the position q of the bridge. Essentially, the resistance force r is the force applied to and resisted by the springs, and the position q represents the pivotal displacement of the sustain block. The equilibrium position is at e. The a zone represents movement wherein the tremolo system is used to increase the pitch and tension in the strings 102 (i.e., movements in the direction 105a in FIG. 4B and 106a in FIG. 4C, resulting in the configuration of FIG. 5X). The b zone represents movements wherein the tremolo system is used to decrease the pitch and tension in the strings 102 (i.e., movements in the direction 105b in FIG. 4B and 106b in FIG. 4C, resulting in the configuration of FIG. 5W). The dotted line s in FIG. 8A represents the linear resistance force curve of a prior art simple, direct spring system, as is shown in FIGS. 4A, 4B, and 4C. The slope of line s is shallow at e, which leads to the tuning problems shown in FIG. 5Y & 5Z. In particular, when the slope of the resistance force curve is shallow, there is only small variation in the resistance force at bridge positions near the equilibrium, so it only takes small external forces to move the bridge away from neutral equilibrium and cause tuning problems. Events such as string breakage (FIG 5Y) or individual string bending (FIG 5Z) can have a strong effect on the neutral equilibrium bridge position for a system having force curve s. As the bridge position moves farther into the b zone along line s, the resistance force grows stronger and stronger, requiring more external manual force applied via the tremolo arm for activation.

[0061] Referring again to FIGS. 1 and 2, the tremolo stabilization system of the present invention includes a base plate 20 having a plurality of mounting holes 20c through which a plurality of mounting screws 25 may be inserted into the guitar body (FIG. 3C Ref. No. 92) thereby securing the base plate 20 to the guitar body. A pivot 20a protrudes perpendicularly from base plate 20.

[0062] A force redirection body 26 having a pivot end 26a and a free end 26b is mounted onto the pivot 20a through a hole 26d at the pivot end 26a of the force redirection body 26, and is secured onto the pivot 20a via a retaining ring 27 which is affixed to the pivot 20a. The pivot end 26a of the force redirection body 26 is thus rotatably attached to the instrument. A generally hook-shaped spring linkage 29 is mated into the force redirection body 26 by aligning and mating a hole in the spring linkage 29 with a hole 26e at the free end 26b of the force redirection body 26. A free pivot hinge 28 is mounted through hole 26e and spring linkage 29, and is secured with retaining ring 30 to attach the force redirection body 26 and spring linkage 29 securely while still allowing each to rotate freely along a plane substantially perpendicular to the pivot 20a. The spring linkage 29 is thus pivotably attached to the force redirection body 26. The pivot 20a and free pivot hinge 28 may be made of a low friction material, may be lubricated or coated with a friction reducing material such as oil, grease, or teflon, or may use other suitable means of providing low friction such as ball bearings.

[0063] A bridge-assembly-connecting member 31 is passed through a bridge assembly connector 33 and mated with a connecting adjuster nut 34 via internal threads. The bridge- assembly-connector 33 is mounted onto the sustain block 36 of a typical bridge assembly (note the sustain block 36 is the counterpart of FIG. 4B & 4C Ref. No. 106) via connector bolts 35. As is apparent from Figs. 1-2 and 4B, the sustain block 36 has a pivot end 36a and a free end 36b, the sustain block 36 being mounted for pivotal movement with respect to the instrument about the pivot end 36a, upon application of a force to a tremolo arm. The bridge- assembly-connecting member 31 may be connected or linked to the sustain block 36 in a manner which is known in the art other than with the bridge- assembly-connector 33 and nut 34, provided that the connecting member 31 has sufficient freedom to move transverse to the direction of the hole in the bridge-assembly-connector 33, permitting the connecting member 31 to remain attached to the pivot 26f without inhibiting rotation of the force redirection body 26. The bridge-assembly-connecting member 31 is mounted onto the force redirection body 26 via connecting pivot 26f and secured via retaining ring 32, such that the bridge-assembly- connecting member 31 is able to rotate freely about the connecting pivot 26f. Because the force redirection body 26 is configured to rotate about the pivot end 26a thereof, and the connecting pivot 26f is proximate to the pivot end, the connecting pivot 26f defines a pivot lever to which the connecting member 31 is attached, to enable the connecting member 31 to apply a torque to the force redirection body 26, as discussed below.

[0064] A spring base pivot or pivot member 38 slides into base plate slot 20d, while a spring tension adjustment thumbscrew 37 passes through pivot 38 and threads onto a spring hook nut 39 which is internally threaded. The spring base pivot 38 includes a protruding portion with a flange that extends below the base plate slot 20d so that the spring base pivot 38 is securely held connected to the base plate 20, but can rotate freely along a plane substantially perpendicular to the pivot 20a. Although the spring base pivot 38 shown in FIGS. 1 and 2 is configured to rotate or pivot with respect to the instrument, the spring base may also be attached to the base plate in a stationary manner. Springs 41 may be hooked onto the spring hook nut 39 at one end, and at the other hooked onto spring linkage 29. Thus, the springs 41 are attached at one end to the instrument, via spring pivot 38, and at the other end to the free end 26b of the force redirection body 26, via the spring linkage 29, such that the springs 41 may pivot with respect to the instrument when force redirection body 26 rotates, as discussed below.

[0065] A base plate safety stop block or stopper 20b extends upward perpendicular to the base plate 20, and has an internally threaded opening. A stopper screw 40 is threaded through the threaded opening in the base plate safety stop block 20b. The stopper screw 40 may be sturdily padded or be overlaid with a very stiff spring where it abuts the force redirection body 26 when activated.

[0066] FIG. 9 A shows the embodiment of the present invention depicted in FIGS. 1 and 2, when the tremolo is used to decrease the tension and pitch of the strings, such that the bridge position is at the extreme end of zone b in FIG. 8A. FIG. 9B shows the embodiment of the present invention depicted in FIGS. 1 and 2, in a neutral equilibrium bridge position, represented by point e in FIG. 8 A.

[0067] When the system is in the equilibrium position shown in FIG. 9B, and the sustain block 36 is then moved in direction b shown in FIG. 9A (via a user pressing down on the tremolo bar), the following movements of the components occur, general, as the sustain block 36 pivots away from the pivot end 26a of the force redirection body 26, thereby applying a force to the pivot lever 26f via the connector 31 and causing the force redirection body 26 to rotate about the pivot end 26a, the corresponding movement of the free end 26b applies a force to the springs 41 that changes the length of the springs 41 and pivots the springs 41 with respect to the instrument. During these movements, the force applied to the springs 41 is not directly proportional to the pivoting displacement of the sustain block 36.

[0068] In particular, the bridge assembly connector 33 and bridge-assembly-connecting member 31 pull on the connecting pivot 26f, which in turn causes the force redirection body 26 to rotate counter-clockwise (as viewed in FIG. 9A) about the pivot 20a at the pivot end 26a. As the force redirection body 26 rotates in this manner, the free end 26b rotates in the counter-clockwise direction (with respect to pivot 20a) and moves toward the sustain block 36. Because the spring linkage 29 is connected to the force redirection body 26 via free pivot hinge 28 at the hole 26e, the spring linkage 29 is pulled toward the sustain block 36. Due to the simultaneous rotations of the force redirection body 26 about the pivot 20a, and the spring linkage 29 about the pivot hinge 28, the spring linkage 29 moves in a curved path both toward the sustain block 36 and also transverse to the sustain block 36 in a direction generally toward the base plate safety stop block 20b. As the spring linkage 29 moves in this manner, the spring base pivot 38 may also rotate. The relative movements of these components may be further appreciated by comparing FIG. 9A and 9B,

[0069] When the system is in the position shown in FIG. 9A, the springs 41 are at maximum tension. However, the above-described force redirection causes most of the force from the springs 41 to be acting upon the base plate 20 via pivot 20a, as opposed to on the sustain block 36, as occurs in the prior art tremolo systems shown in FIGS. 4A-C described above. The springs 41 pull on the spring linkage 29, which in turn applies most of that force to the pivot 20a and free pivot hinge 28. Since these forces are all applied to substantially collinear pivot points, the torque on the force redirection body 26 is substantially diminished. The configuration shown in FIG. 9A is similar to the simplified illustration shown FIG. 6e. Because the torque reduces as the springs reach their maximum tension (when the system moves from the configuration in FIG. 9B to that of FIG. 9A, see FIG. 7B), the incremental force required to increase the tension in the springs as the springs approach their maximum tension is substantially less than in prior art systems.

[0070] The prior art tremolo system of FIGS. 4A-C require more force to be applied to the tremolo bar 105 the more the player desires to reduce the pitch (i.e., by pressing the tremolo bar 105 in direction 105b in FIG. 4B). By contrast, the present invention can require less force as the minimum pitch is approached. This effect is illustrated by the comparison of curves s and t in FIG. 8A. The solid curve t in FIG. 8A represents one possible resistance force curve that can be achieved through use of the present invention. As the bridge position moves towards the extreme end of the b zone, manual activation of the tremolo bar 105 becomes easier due to the reduction in counterbalancing force from the springs. The curve t is also steeper at e than curve s, representing an improvement in stability and a lessening of the issues illustrated by FIG. 5Y & 5Z. In particular, when the curve is steeper it takes stronger forces to move the bridge away from the equilibrium position (in either direction). Events such as string breakage (FIG. 5Z) or individual string bending (FIG. 5Y) may still have an effect on the neutral equilibrium bridge position, but such effects may be less drastic or even imperceptible. In circumstances less sudden or severe than string bending and breakage, such as when tuning the instrument strings, the undesirable effects described above with respect to FIGS. 5Y and 5Z are likewise mitigated or eliminated.

[0071] As shown in FIG. 9A, the base plate safety stop block 20b may be configured to function as a stopper to prevent the force redirection body 26 from rotating past a predetermined point, by being shaped and positioned to abut against the force redirection body 26 when the force redirection body 26 has rotated up to the predetermined point. The predetermined point would effectively set a maximum amount of pitch decrease that may be obtained via use of the present tremolo stabilization system.

[0072] FIG. 9C shows the embodiment of the present invention depicted in FIGS. 1 and 2, when the bridge position at the extreme end of zone a in FIG. 8 A, and the springs 41 are at minimum tension. In this position the performance of the invention is similar to a standard spring system in that the relationship between the force and bridge position is more linear than when the bridge position is in the b range. As shown in FIG. 8A, both the present invention and prior art can have linear relationships in the a zone. When the tremolo stabilization system moves from the equilibrium position of FIG. 9B to the position of FIG. 9C (i.e., when the user pulls the tremolo bar 105 in direction 105a of FIG. 4B, causing the free end 36b of the sustain block 36 to correspondingly move in direction a shown in Fig. 9C), the relaxing tension in the springs 41 permits the springs 41 to pull the spring linkage 29 toward the spring base pivot 38, which in turn causes the force redirection body 26 to rotate in the clockwise direction. If the tremolo bar 105 is released, the tension in the strings of the instrument will pull the system back into equilibrium as shown in FIG. 9B. [0073] As shown in FIG 9D, the range of motion stopper screw 40 may be used to prevent the rotation of the force redirection body 26 beyond a predetermined point, by sizing and positioning the stopper screw 40 such that a stop portion 26g of the force redirection body 26 interferes with and cannot move past the stopper screw 40. As shown in Fig. 9D, the bridge assembly connector 33 and connecting member 31 are configured such that pivoting of the sustain block 36 past a predetermined point (e.g., as established by the positioning of the stopper screw 40 and stop portion 26g) disengages the connecting member 31 from the sustain block 36. hi this manner, the springs 41 may be set to remain at equilibrium or any other desirable tension. The connecting adjuster nut 34 and connecting member 31 may be permitted to slide freely through bridge assembly connector 33 until the bridge assembly and sustain block 36 return to a position that engages the connecting adjuster nut 34, at which position the system will again engage the other components thereof.

[0074] FIG. 8B is similar to FIG. 8A except in that curve t represents the invention wherein the range limiting stopper (FIG. 2, Ref. No. 40 and FIG. 9D, Ref. No. 40 & 26g) is used to create a discontinuous resistance force curve. At e, the curve t represents a very stable equilibrium, all but eliminating the issues illustrated by FIG. 5Y & 5Z. In particular, the resistance force on curve t is much stronger in zone b near the equilibrium than in curve s, so bending individual strings will have minimal effect on the springs and thus on the remaining unbent strings (solving the problems discussed above arising in the FIG. 5Y situation). The resistance force from the device is null in zone a on curve t. This means that even if a string breaks, the device is incapable of pulling the equilibrium past the range limiting stopper, and is thus unable to affect string tuning at all in zone a (solving the problems discussed above arising in the FIG. 5Z situation). Also, as in FIG. 8A, when the bridge position moves towards the extreme end of the b zone, manual activation of the tremolo bar 105 becomes easier due to the reduction in counterbalancing force.

[0075] The present tremolo stabilization system may be adjusted and fine tuned in various ways to achieve various customizable and non-linear resistance force curves, as in curves t of FIGS. 8 A and 8B. The spring tension may be customized by using fewer or more than two springs 41 (as shown in FIGS. 9A-D), or using larger or smaller sizes or gauges of springs. Various types of springs such as compression, extension, or even torsion springs may be used. Alternatively, elastic bands or other suitable elastic members aside from springs may be used. As will be appreciated by those skilled in the art, any biasing member (i.e., any component that is capable of applying a biasing force to the force redirection body 26) may be suitable for and within the scope of the present invention. In addition to springs or elastic bands and cords, other suitable biasing members may include but are not limited to flexible members biased to remain in a non-flexing position, and hydraulic or pneumatic cylinders biased to resist expanding or contracting the volumes of their respective fluids or gases.

[0076] The distance between the spring base pivot 38 and the pivot 20a may be increased or decreased, e.g., via using the spring tension adjustment thumbscrew 37 to move the position of the spring hook nut 39 closer to or further away from the spring base pivot 38. The distance between the pivot 20a and the free pivot hinge 28 may be increased or decreased by appropriately sizing the force redirection body 26. Likewise, the distance between pivot 20a and the connecting pivot 26f may be altered. The positioning and sizing of the stop portion 26g on the force redirection body 26, stopper screw 40, and base plate safety stop block 20b may be adjusted to provide any desirable limits on the range of rotation and motion of the force redirection body 26. The length of the connecting member 31 may be adjusted by screwing or unscrewing the threaded adjuster nut 34. These and other variations and modifications may be utilized to customize the force resistance curves of the tremolo stabilization system to a user's desire.

[0077] The invention has been described with reference to the embodiments disclosed herein. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Claims

THE INVENTION CLAIMED IS:

1. A tremolo stabilization system for a stringed instrument, the stringed instrument having a sustain block mounted for pivotal movement with respect to the instrument, the system comprising:

a force redirection body rotatably attached to the instrument;

a connector for linking the sustain block to the force redirection body, whereby pivoting of the sustain block causes a torque to be applied to the force redirection body via the connector; and

a biasing member connected at one end to the instrument and at the other end to the force redirection body,

wherein application of the torque to the force redirection body causes the force redirection body to rotate, the force redirection body thereby applying a force to the biasing member, the force applied to the biasing member not being directly proportional to the pivotal displacement of the sustain block.

2. The tremolo stabilization system of claim 1, wherein a stopper is configured to prevent rotation of the force redirection body past a predetermined point.

3. The tremolo stabilization system of claim 2, wherein the stopper is attached to the instrument and is configured to abut the force redirection body upon rotation of the force redirection body to the predetermined point.

4. The tremolo stabilization system of claim 2, the force redirection body further comprising a stop portion; wherein the stopper is attached to the instrument and is configured prevent rotation of the force redirection body past a predetermined point by abutting the stop portion of the force redirection body upon rotation of the force redirection body to the predetermined point.

5. The tremolo stabilization system of claim 4, wherein the position of the stopper is adjustable.

6. The tremolo stabilization system of claim 4, wherein pivoting of the sustain block toward the force redirection body past a predetermined position disengages the connector from the sustain block.

7. The tremolo system of claim 6, wherein the length of the connector is adjustable.

8. The tremolo system of claim 1, wherein the equilibrium length of the biasing member is adjustable.

9. The tremolo stabilization system of claim 1, wherein the biasing member is a tensioned spring.

10. The tremolo stabilization system of claim 1, wherein the biasing member is connected to the force redirection body via a linkage member, the linkage member being pivotably attached to the force redirection body.

11. The tremolo stabilization system of claim 10, wherein the linkage member is generally hook-shaped.

12. The tremolo stabilization system of claim 1, wherein the biasing member is configured to pivot with respect to the instrument upon rotation of the force redirection body.

13. The tremolo stabilization system of claim 1 , wherein the biasing member is connected to the instrument via a pivot member, the pivot member being configured to pivot with respect to the instrument.

14. The tremolo stabilization system of claim 1, wherein the system is sized and configured for retrofitted installation into a stringed instrument.

15. A method for using a tremolo stabilization system for a stringed instrument, the stringed instrument having a sustain block mounted for pivotal movement with respect to the instrument, the system comprising:

a force redirection body rotatably attached to the instrument; a connector for linking the sustain block to the force redirection body, whereby pivoting of the sustain block causes a torque to be applied to the force redirection body via the connector; and

the method comprising the step of:

pivoting the sustain block to apply the torque to the force redirection body and cause the force redirection body to rotate, the force redirection body thereby applying a force to the biasing member, the force applied to the biasing member not being directly proportional to the pivotal displacement of the sustain block.