Patent Application
20160104465
This application relates to some of the subject matter concerning methods and apparatus for holding wires or strings as disclosed in Applicant's U.S. Pat. No. 7,855,440, which issued Dec. 21, 2010, and Applicant's copending U.S. application Ser. No. 14/476,619, which was filed Sep. 3, 2014, the entirety of both of which are hereby incorporated by reference.
The present disclosure relates to the field of stringed musical instruments, and more particularly to bridges for stringed musical instruments.
It is common for a stringed musical instrument such as a guitar to have a bridge separating a playing zone of the musical strings from a connection zone of the strings. The ends of the strings are held securely in the connection zone, while the playing zone is the portion of the instrument in which vibration of the strings makes music. In conventional guitars, a base or ball of a musical string is immovably secured at a flange or other connector, and the string is pulled over a bridge member, which separates the string into the playing zone and a connection zone. Over time, the musical string will stretch or contract, leading to the string possibly sliding over the bridge member. Friction forces may resist such sliding, resulting in string wear and/or inconsistent tuning.
Some guitars may secure the ball of the musical string to a string holder employing a constant tension device. Such constant tension devices may act to maintain a constant or near-constant tension in a musical string as it stretches or contracts. In such cases, the string moves as it stretches or contracts, and friction forces of the string sliding over the bridge can lessen the effectiveness of such constant tension devices, as well as causing excessive wear to the string.
Various approaches have been attempted to reduce friction in bridges. For example, some bridges may include low-friction coatings such as graphite. Another bridge design uses a rolling member as a string saddle, which rolling member rotates about an axle. Such designs can still suffer from excessive friction, and rolling saddles tend to suffer from decreased resonance and/or buzzing due to lateral movement of the rolling saddle when the string is plucked.
Additionally, in state-of-the-art electric guitars, bridge members are adjustable in a longitudinal direction in order to adjust the length of the string (known as intonation) and up and down to accommodate a user's preferred string height. Such adjustments are usually accomplished by screw-based systems. However, such systems also tend to decrease resonance.
There is a need in the art for low-friction bridge having improved resonance and reduced, minimal or nonexistent buzzing. There is a further need for such a bridge that enables intonation adjustment, and which can be configured to hold the strings at various heights above the associated instrument body.
In accordance with one embodiment, the present specification provides a low-friction musical string support, comprising a roller, a first contact member and a biasing member. The roller is configured to roll within a race defined by opposing first and second race side walls, and has opposing first and second side faces that face the opposing first and second race side walls, respectively. The roller further has a circumferential groove configured to accommodate a musical string seated therein. The first contact member is interposed between the first race side wall and the first side face of the roller. The biasing member is configured to urge the first contact member into contact with the first side face of the roller. When the string moves longitudinally, the roller rolls within the race.
In one such embodiment, the roller is formed of a resonant metal, and the contact member is formed of a polymer. Another embodiment additionally comprises a second contact member interposed between the second race side wall and the second side face of the roller.
Yet another embodiment additionally comprises a second biasing member configured to urge the second contact member into contact with the second side face of the roller. In some such embodiments, the biasing member also urges the second contact member into contact with the second side face of the roller.
In a still further embodiment, the biasing member spans across both the first and second contact member. In yet another embodiment, the biasing member comprises an elastomeric band.
In another embodiment, the first contact member is positioned to engage the first side face of the roller at a point above a center of the roller.
In accordance with another embodiment, the present specification provides a kit for a bridge of a stringed musical instrument. The kit includes first, second and third sets of roller saddles, each roller saddle comprising a cylindrical body having a circumferential saddle formed therein. The saddle is adapted to accommodate a musical string seated therein. Each of the first, second and third sets of roller saddles have a plurality of identical roller saddles. The cylindrical body of the roller saddles in the first set has a first radius, the cylindrical body of the roller saddles in the second set has a second radius greater than the first radius, and the cylindrical body of the roller saddles in the third set has a third radius greater than the second radius. A race defines a rolling path of each of the roller saddles.
Another embodiment additionally comprises first and second base plates, the second base plate having a greater thickness than the first base plate, the first and second base plates configured to be selectively secured to a body of a musical instrument. In a further embodiment, the first and second base plate each define the race thereon.
In accordance with still another embodiment, the present invention provides a low-friction musical string support. The support comprises a support bearing configured to roll over a race, and a roller saddle configured to roll upon the support bearing. The roller saddle comprises a string receiver configured to receive a musical string, which musical string is held at a tension. When the string elongates, the roller saddle rotates in a first rotational direction and the support bearing rotates in a second rotational direction.
In some such embodiments, the string receiver comprises a circumferential groove, and the support bearing comprises a circumferential ridge configured to fit complementarily within the circumferential groove of the roller saddle.
In accordance with still another embodiment, the present specification discloses a string system for a stringed musical instrument comprising a bridge module and a string holder module. The string holder module comprises a string tensioner configured to maintain tension in a corresponding string within a range about a perfect tune tension. The bridge module comprises a roller saddle having a circumferential groove and a string seated in the groove. The roller saddle can roll over a base plate.
In some such embodiments, when the string moves longitudinally the roller saddle rolls so that the string does not slide over the roller saddle surface.
The following description presents embodiments illustrating aspects of the present invention. It is to be understood that various types of musical instruments can be constructed and/or retrofitted using aspects and principles as described herein, and embodiments are not to be limited to the illustrated and/or specifically-discussed examples. Rather, additional embodiments may selectively employ various aspects and/or principles disclosed in the specification. Also, for ease of reference, embodiments are disclosed and depicted herein in the context of a four-string bass electric guitar. However, principles as discussed herein can be applied to other acoustic and electric instruments such as, for example, violins, harps, and pianos.
With initial reference to
A body string connection zone 44 is defined proximal of the bridge module 34 and a head string connection zone 46 is defined distal of the nut 38. A playing zone 48 is defined between the bridge module 34 and nut 38. String vibrations in the playing zone 48 are isolated from string vibrations in the body connection zone 44 and head connection zone 46 by the bridge module 34 and head nut 38, respectively.
With reference next to
In the illustrated embodiment, each string tensioner 50 comprises a connector 56 at its distal end to which a string ball 58 is attached. The string ball 58 is at the proximal end of each musical string 30, and functions to connect the string 30 to the tensioner 50. The string tensioner includes a primary spring 60 that is connected at its distal end to the connector 56 and at its proximal end to the frame 52. Preferably, the primary spring 60 is held in tension and longitudinally aligned with the string 30. As such, the primary spring 60 applies a longitudinal tension force to the attached musical string 30. In the illustrated embodiment, a plurality of secondary springs 62 which, in the illustrated embodiment, comprise thin metal sheets, are attached to the connector 56 and to a secondary frame 64. The secondary frame includes a plurality of stationary spring mounts 66 configured to hold the secondary springs 62.
As discussed above, the primary spring 60 is held in tension and correspondingly applies tension to the attached string 30. However, as the string 30 stretches and contracts over time, the primary spring 60 will correspondingly stretch or contract, thus changing the tension applied by the primary spring 60 to the string 30. The secondary springs 62 are configured to apply a force to the connector. However, only a portion of this force is directed as a force vector in a longitudinal direction. Preferably, the longitudinally-directed vector force changes as the primary spring 60 elongates and contracts. Also, the secondary springs 62 are chosen so that the variation in the longitudinal force vector generated by the secondary springs generally corresponds to the change in longitudinal force applied by the primary spring 60 so that the secondary and primary springs, taken together, apply a constant or near-constant longitudinally-directed tension force to the corresponding string 30 over a range of operation.
In such embodiments, as the string 30 stretches and contracts, the string tensioner 50 will maintain a constant or near-constant tension in the string, however, the string 30 will move. For example the position of the string ball 58 may move proximally or distally, and correspondingly the string 30 will move over the bridge 34. Excessive friction in the bridge could dilute the effectiveness of the string tensioner 50 in keeping tension in the string 30 at a constant or near-constant level.
In the illustrated embodiment, the string tensioner 50 has structure as illustrated. However, it is to be understood that other string tensioner configurations can be employed, including other embodiments of tensioners that apply a constant or near-constant force over an operational range. For example, Applicant's issued U.S. Pat. No. 7,855,330 discloses embodiments of constant tension devices that can maintain musical strings at a constant or near-constant tension in order to maintain string tune. Embodiments as disclosed in the '330 patent, closure of which is incorporated by reference in its entirety, can also be employed as a string tensioners. Still further, some string holder module embodiments may not adjust with the strings, but may more traditionally hold the string balls at a constant, fixed position. Such traditional embodiments may still benefit from the principles and aspects discussed herein.
With continued reference to
With reference next to
With additional reference to
With particular reference again to
Preferably, a width of the elongated channel 80 between the first and second channel side walls 86, 88 approximates a width of the roller saddle 90, but enables the roller saddle 92 role within the channel 80 unobstructed by the channel side walls 86, 88. Preferably, the roller saddle 90 rolls on the base plate 100. However, in other embodiments, the roller saddle may ride over and be supported upon the surface of the guitar body 22.
As discussed above, the string 30 is seated in the groove/saddle 98. Since the roller saddle 90 readily rolls on the base plate 100, when the string 30 expands and contracts, the roller saddle 90 will roll to accommodate such movement and the string 30 will not slide relative to the surface of the saddle 98. As such sliding friction of the string 30 over the saddle 98 is minimized or totally avoided in favor of rolling friction of the roller saddle 90 over the base plate 100, which is much less than sliding friction.
Most preferably, the roller saddle 90 is formed of a solid block of a choice vibrational material such as bronze, brass or titanium. Preferably, the base plate 100 is also formed of a choice vibrational material. As such, resonance from the vibrating string 30 is easily transferred through the roller saddle 90 and base plate 100 to the guitar body 22, and back to the string 30.
As discussed above, accomplished guitarists wish to adjust the length of each guitar string 30 in order to attain proper tuning. Such length adjustment, known as intonation, typically involves independent positioning of each bridge member to set the desired length for the corresponding guitar string. In operation, a user may first select the desired intonation location of the roller saddle 90 by placing the roller saddle within the elongated channel 80 and rolling and/or pushing it to a desired position for intonation. Once intonation is completed, and the string has been put in place and is under tension, the roller saddle can operate normally, rolling with very low friction as the string stretches or contracts. Indeed, preferably, the roller saddle experiences no sliding-based friction, and only experiences the relatively-low rolling friction.
As discussed above, in the illustrated configuration, as the string 30 stretches or contracts a given length, the roller saddle will rotate. In fact, the rotating roller saddle will translate longitudinally to a lesser extent that the string translates longitudinally. As such, the roller saddle configuration dampens the effect string translation may have on intonation positions, and the saddle 98 translates less than does the string.
A user may also wish to adjust the height of the strings 30 relative to the guitar body 22. To this end, preferably a base plate 100 is selected having a thickness that will place the strings 30 at or near a desired height above the guitar body 22. With additional reference to FIG. 5, a user can then select a desired roller saddle size. More specifically, a kit may be provided, which kit may include the bridge module 34 and multiple sets of roller saddles, each set of roller saddles having a different radius. For example, with particular reference to
It is to be understood that, in other embodiments, height adjustment can be accomplished by other structures. For example, the bridge module may include screws that adjust the height of the entire module relative to the guitar body.
With particular reference again to
As shown, each race 70 additionally includes a pair of support surfaces 110 atop each channel side wall 86, 88. Spaced apart adjustment holes 112 preferably are formed through each support surface 110.
With additional reference to
With continued reference again to
In the illustrated embodiment, a biasing member 140, such as a small coil spring, extends into each receiver 130 and engages a race side wall 142 so as to urge the elongated bar 122 to rotate about a pivot point 144, and thus bias a contact surface 146 of the contact member 120 against the corresponding side face of the roller saddle 90.
In the embodiment illustrated in
With additional reference to
The user can change the position of the contact members 120 by pulling upward on the elongated bar 122 so that the pin 124 is removed from its associated hole 112. The user can then insert the pin 124 into another one of the holes 112 as desired. Preferably, the contact members 120 on opposite sides of the channel 80 are inserted into symmetrically aligned holes 112 so as to exert a symmetrical biasing force on the associated roller saddle 90. In additional embodiments, a detent structure can be provided on the pin 124 or holes 112 so that the pins 124 do not slide out of holes 112 unintentionally.
In some embodiments, a cover can be attached atop the support surface 110 to prevent the contact members 120 from falling out of the holes. With reference again to
In the illustrated embodiment, the elongated bars 122 rest upon support surface 110. In additional embodiments, one or more of the contact members can include a pin that is longer than the corresponding holes 112 so that when the pin is inserted into the hole the elongated bar 122 will be spaced from the support surface 110.
In the illustrated embodiment, the contact members 120 are positioned relative to the associated roller saddle 90 so that the pivot point 144 is near a center of the roller saddle and most preferably proximal of a center of the roller saddle 90, while the distal end 128 of the elongated bar 122 is positioned distal of the roller saddle 90. As such, the elongated bar 122 pivots inwardly a small amount to take up play that may exist between the side faces 94, 96 of the roller saddle 90 and the channel side walls 86, 88 in order to minimize or prevent buzzing.
In the illustrated embodiment, each of the elongated bar 122 on opposite sides of the channel pivot inwardly. In additional embodiments, the elongated bar 122 on only one of the sides may pivot, while the opposing elongated bar remains stationary. In still further embodiments, only a single contact member is employed, biasing the roller saddle from only one side of the channel. Preferably, the opposing channel wall can be lined with a low-friction material, such as Teflon-infused Delrin. The contact member thus biases the roller saddle into contact with the low-friction material lining the channel wall, thus minimizing or eliminating buzzing during operation.
With particular reference to
A break angle α is defined as the angle between the string 30 proximal of the saddle 98 and the string 30 distal of the saddle 98. Notwithstanding the benefits of the force exerted by the string 30 onto the roller saddle 90 by virtue of the break angle α, because of the break angle α, a longitudinally-directed vector force exerted by the string 30 tends to urge the roller saddle 90 longitudinally in a distal direction. Of course, a friction force between the roller saddle 90 and the base plate 100 provides some resistance against the longitudinally-directed break angle vector force. However, there is a risk that, when the string 30 and roller saddle 90 are vibrating, the longitudinally-directed break angle vector force may cause the roller saddle 90 to slide distally over the base plate 100, possibly moving the roller saddle 90 out of the selected intonation position. However, the biasing force exerted by the opposing contact members 120 also exerts a longitudinally-directed vector force component directed proximally in opposition to the break angle vector force, and thus resists the break angle vector force.
Additionally, if the string 30 is de-tensioned, such as by a string breaking, the biasing force exerted by the opposing contact members 120 will tend to hold the roller saddle 90 in its position. Thus, the user will not have to start from scratch in finding and setting the proper intonation upon restringing the guitar 20. Also, the roller saddle 90 will tend not to fall out of the channel 80 upon de-tensioning of the corresponding string 30 because it is held in place by the contact members 120.
With reference next to
With reference again to
In a preferred embodiment, the contact members 120 are constructed of a low friction material so that even though the contact members are exerting a biasing force on the side faces 94, 96 of the roller saddle 90, the roller saddle can still roll with minimal friction being exerted by the contact members 120. In one preferred embodiment, the elongated bars 122 are formed of a Teflon-infused Delrin material having a very low coefficient of friction, such as within a range of less than about 0.2, and more preferably between about 0.07-0.14 so that, when combined with the biasing force, there will be less than 10 cents of change in aural tone when the string is loaded at about 30 pounds of tension. In another embodiment, the elongated bars 122 are formed of a choice vibrational material such as is used for the roller saddle.
In the embodiments illustrated herein and discussed above, the contact members 120 are configured to pivot while exerting a biasing force on the side faces of the roller saddle. Additional embodiments may employ different structure to exert a biasing force on one or more side faces of the roller saddle. For example, in another embodiment the contact member can comprise an elongate bar that traverses all or much of the length of the channel, and is biased inwardly so as to be biased inwardly against a side face of the roller saddle in any position of the roller saddle along the length of the channel. Such biasing can be provided by springs such as coil springs, torsion springs, flat springs, leaf springs or the like, or by other materials such as elastomers in compression or tension.
With reference next to
The illustrated roller saddle 160 also comprises side faces 172 and side ridges 174 adjacent the side faces 172. The illustrated side ridges 174 have a diameter greater than the adjacent cylindrical body 169 and preferably are placed so as to hang over the side edges 166 of the race 162, also to help align the roller saddle 160 as the cylindrical body 169 rolls over the race 162.
It is to be understood that, in additional embodiments, the roller saddle 160 may not include the side ridges 174, so that the cylindrical body 169 is guided only by the saddle 170 being engaged with the elongated ridge 168 or, alternatively, the race 162 may not include the ridge 168 so that the cylindrical body 169 is guided only by the side ridges 174 being aligned with the side edges 166 when rolling over the race 162.
With reference next to
A race 200 comprises an elongated base plate 202 having a proximal end 204 and a distal end 206. An elongated groove 210 is formed along the length of the elongated base plate 202. The groove 210 preferably is shaped generally the same as the groove/saddle 184 and complementary to the circumferential ridge 194 of the support bearing 190 so that the support bearing 190 rolls upon the base plate 202 with the ridge 194 received in the elongated groove 210, which guides the support bearing 190.
As shown in
As the string 30 stretches or contracts, portions of the string at the roller saddle 180 will translate distally or proximally. In the illustrated embodiment, the string 30 will not need to be slid over the saddle surface during such translation. Instead, the roller saddle will rotate to accommodate such translation.
As best shown in
A similar, but oppositely directed, effect will occur when the string 30 translates proximally, which is represented schematically as moving from the arrangement in
Notably, in guitars, the total range of translation of the musical string 30 during operation and even during stretching and contracting of the string 30 can be relatively low, such as less than about 0.12 inches, more preferably less than about 0.08 inches, and most preferably about 0.06 inches. Thus, it is anticipated that embodiments applied to guitars have operational lengths of longitudinal string translation within or approximating these ranges.
As depicted in
In additional embodiments, the roller saddle, the support bearing, and/or the race can be shaped to define one or more cams that can cancel out or reduce the change in height h1. For example, although in some embodiments the roller saddle and support bearing have been described as cylindrical, and the race as flat, in other embodiments one, the other, or both of the roller saddle and support bearing may not be cylindrical, and/or the race can be inclined or curved. As noted above, the range of translation of the string can be quite small, preferably spanning only a portion of the circumferential surface of either bearing.
In one embodiment, the groove/saddle of the roller saddle can be cammed so that a vertical distance h2 between the point at which the string contacts the saddle surface and the point at which the roller saddle contacts the support bearing is smallest at a central portion of the range of motion, and increases on both sides, thus maintaining the string height h1 at or near a constant value. Similarly, in other embodiments the upper and or lower surface of the support bearing can be configured so that the point at which the string contacts the saddle surface remains at a substantially constant height from one end of the operational range of rotation/translation to the other. The race can also be curved, for example having a concave curvature, to counteract height change during translation of the support bearing. In still other embodiments, combinations of such camming structures can be employed.
In still further embodiments, the race can be configured so that the position of the race can be manually translated proximally or distally by the user during tuning so that the string can be centered in the range of operation when at a desired perfect tune position or tension.
The embodiments discussed above have disclosed structures with substantial specificity. This has provided a good context for disclosing and discussing inventive subject matter. However, it is to be understood that other embodiments may employ different specific structural shapes and interactions.
Although inventive subject matter has been disclosed in the context of certain preferred or illustrated embodiments and examples, it will be understood by those skilled in the art that the inventive subject matter extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. In addition, while a number of variations of the disclosed embodiments have been shown and described in detail, other modifications, which are within the scope of the inventive subject matter, will be readily apparent to those of skill in the art based upon this disclosure. It is also contemplated that various combinations or subcombinations of the specific features and aspects of the disclosed embodiments may be made and still fall within the scope of the inventive subject matter. For example, the roller saddles and races described in connection with
This application claims priority to U.S. Provisional Application Ser. No. 62/063,329, which was filed Oct. 13, 2014, the entirety of which is hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62063329 | Oct 2014 | US |
