GB2089550A - Chord selector for guitar - Google Patents

Abstract

The device is arranged to be mounted above the finger board of a guitar and to select chord positions. It includes fingers 26 projecting downwardly, electromagnetic abutment means 40-46 for each finger, chord selecting keys 58 for activating certain of the electromagnetic abutment means according to the particular chord desired, and a depression plate 20 manually movable towards the finger board of the guitar and arranged to move towards the finger board only those fingers whose associated electromagnetic abutment means have been activated, these fingers then blocking certain strings at certain positions to give the desired chord. <IMAGE>

Description

SPECIFICATION Playing of stringed instruments This invention relates to the playing of stringed instruments such as a guitar. In particular, the invention relates to a device to enable a user to select particular chords for a guitar.

A great deal of skill and practice is required before anyone can become at all competent at playing stringed instruments. In the case of a guitar, the finger board is provided with a number of upstanding ridges known as frets to enable the player to define precise notes. Despite this, however, skilfull fingering is still required to select particular chords. Therefore, although the guitar is in many ways designed as an instrument for amateur use, a beginner cannot immediately use a guitar to accompany singing and the like.

It is therefore an object of this invention to provide a device which can select chord positions on stringed instruments such as guitars in a simple fashion.

According to the invention, there is provided a device for selecting chord positions for a stringed instrument such as a guitar, the device being arranged to be mounted above the finger board of the guitar, and including fingers projecting downwardly towards strings to be blocked during the playing of a chord, electromagnetic abutment means for each finger, chord selecting means for activating certain of the electromagnetic abutment means according to the particular chord desired, and a depression plate manually movable towards the finger board of the guitar and arranged to move towards the finger board only those fingers whose associated electromagnetic abutment means have been activated, these fingers then blocking certain strings at certain positions to give the desired chord.

With such a device, therefore, it is possible even for a beginner to select accurate chords without great difficulty. Thus the chords selecting means could be a simple keyboard or row of switches and so when one of these is ectuated and the depression plate moved towards the finger board, the selected fingers will engage the strings at the appropriate positions, press them down so that the strings engage the appropriate frets and thereby select the required chord. Then the user merely has to strum the strings to play the desired chord.

The fingers are arranged so that there is one for each string in each position along the string where the string may be required to be blocked for playing the selected chords. In a preferred embodiment of the invention, there are sufficient fingers to enable all normal major or minor chords to be selected but this is not essential. Instead it may be sufficient to provide the eight most commonly used major chords, namely Bb, E, A, D and F. In a yet simpler embodiment, it would be sufficient not to provide C minor and G minor chord positions since then it is only necessary to provide fingers for blocking the six strings at three frets along the length of certain of those strings.

The device of the invention can, of course, be arranged by appropriate selection of the operation of the electromagnetic abutment means to play any major or minor ninth, seventh or sixth chords, seventh augmented fifth chords, seventh diminished fifth chords, arid so on. Equally, the device can be designed to select full chords, i.e.

chords where all six strings are used, and half chords, i.e. where four strings are used.

Preferably, the fingers are resiliently urged away from the finger board but when an electromagnetic abutment means associated with a particular finger is operated that finger becomes blocked relative the depression plate and so movable against the finger board when the depression plate is manually moved. Any remaining fingers not blocked by their associated electromagnetic abutment means are not therefore urged against the appropriate strings. By arranging the device in this fashion, it is possible to use a relatively low power consumption such as can be obtained from, for example, a small storage battery since it is the manual movement of the depression plate which forces the fingers firmly against the appropriate strings to block those strings and only low power is necessary to cause the operation of the electrnmagnetic abutment means.By contrast, if the chosen fingers were to be forced against a string to block it by electromagnetic means, a relatively powerful electromagnet would be required and then a substantial power source would be necessary.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of the device shown mounted on the finger board of a guitar; Figure 2 is a side view of the device: Figure 3 is an underneath view of the device as shown in Figure 1; Figure 4 is a section of the device shown mounted on the finger board of a guitar; Figure 5 is a section taken at right angies to Figure 4; Figures 6 and 7 are sections similar to Figures 4 and 5 but showing the device after selection of a chord; Figure 8 is an end view of the device; Figures 9 and 10 are circuit diagrams showing the wiring used to operate the device shown in previous figures; and Figure 11 is a diagram showing a modified device according to the invention.

The chord selecting device 10 shovvn in the drawings comprises a base 1 2 having downwardly directed edges 14 and 1 16 which are designed to fit over and be attached to the neck of the guitar by means not shown. Upstanding from near the corners of the base 12 are four pins 18. These pins extend through holes 1 9 in a plate 20. Therefore that plate is capable of moving up and down the pins and is urged by means of springs 22 around the pins 1 8 towards its outer or upward position away from the finger board 24 of the guitar. It can, however, as will be described below, be pressed down against the action of the springs 22.

A number of fingers 26 are mounted on the base 12 and are connected to the base by means of small leaf springs 28. These springs normally hold the fingers in a direction towards the plate 20 and away from the strings 30 of the guitar. The lower ends 32 of these fingers extend through openings 34 in the base 12 and in addition slots 36 are provided to enable the associated leaf spring 28 to pass through the base when a finger is depressed relative the base.

Mounted on the underside of the plate 20 are a number of small solenoid-operated plungers 40, one associated with each of the fingers 26. Each solenoid-operated plunger contains a central movable core 42 which in the normal position is urged downwardly in the sense viewed in Figure 4 by means of a spring 44 which, when the solenoid .

coil 46 is activated, will be drawn inwardly into the coil against the spring so that the core extends out from the coil as shown in Figure 6.

Hinged to the base 12 about a point 50 is an outer cover 52. This cover 52 engages the plate 20 around a pivot lug 54. Therefore, when the cover is hinged and pressed downwardly (see Figure 8), the engagement between the cover and the plate causes the latter to be pushed towards the base 12 from the position initially shown in Figures 4 and 5 to the position finally shown in Figures 6 and 7.

On the cover are mounted a number of keys 58 for selecting particular chords. These keys are arranged to activate selected coils of the soienoids to cause blocking of certain strings to give a desired chord.

Pressing a selected key activates certain of the coils and then as the user continues to press that key downwardly, the cover 52 is caused to hinged downwardly so depressing the plate 20 towards the base 12.

When the plate 20 is urged towards the base 12, a core 42 will not normally engage its associated finger 26 unless the associated coil 46 has been activated. If it has been activated, however, it will engage the top of its associated finger 26 and then pressing the cover 52 downwardly towards the finger board 60 (Figure 1) will cause that finger also to move downwardly and its lower end will then engage the appropriate string 62 and cause it to become blocked at the appropriate fret 64. Thus, for example, referring to Figure 7, the second and third strings 62 will in this example have become blocked at a particular fret whilst the remaining strings 63 will not have been blocked.

Referring next to Figure 3, a particular arrangement of the fingers 26 can be seen and it will be noted that they are arranged so that there are five rows of fingers spaced apart the width of the strings 62. The particular arrangement as will be seen below results in the possibility of selecting as half-chords all of the major and minor chords for the notes Bb, E, A, D, G, F and C.

Referring next to Figures 9 and 10, it can be seen that one key 58 is provided for each of the chords to be chosen. The keys are in the form of electrical switches and they are wired to particular solenoid coils 46. Thus each switch has three or four output contacts 58a joined to one end of an appropriate solenoid coil 46 and a common switch contact 58b leading to one pole of a battery 66, the other pole of the battery being linked in common to the other end of all of the solenoid coils 46.

Taking, for example, the depression of the key 58 to play the C minor chord, this will cause activation of the solenoid coils 46a, 46b, 46c and 46d. Therefore, when in turn the cover 52 is completely hinged downwardly, by continued pressure on the C minor key 58, the fingers 26a, 26b, 26c and 26d which are associated with those solenoid coils are pushed downwardly and cause blocking of the appropriate strings 62 at the correct frets for the C minor chord.

Naturally, any particular set of chords can be chosen by appropriate wiring and appropriate positioning of the fingers and the positioning shown in Figure 3 does, as noted above, enable one to produce as half chords the most commonly used major and minor chords.

Referring finally to Figure 11 , this shows a modified arrangement for operating the plate 20.

In this embodiment, the cover 52a is hinged about the point 50a. One end of a link 70 rests on the base 1 2a and at its other end it is hinged to another link 72 and to a small wheel 74 in contact with the underside of the cover 52a. In turn, the other end of the link 72 is pivoted to an additional link 76 and to one arm of a crank 78 about a pivot point 80. The other end of the additional link is pivoted to one arm of another crank 82. These cranks 78 and 82 are pivoted to the base 12 about points 84 and 86, respectively, and the outer ends of their other arms are pivoted in turn about points 88 and 90, respectively, to the plate 20.An arrangement of links such as these is provided at either end of the plate 20 so as to ensure that the plate is moved downwardly relative the base 12 whilst it is kept accurately parallel to the base 12a.

When the cover 52a is hinged downwardly about the point 50a, the underside of the cover bears against the wheel 74. This in turn causes the link 70 to pivot about its end resting on the base 12a, and so the link 72 is moved towards the right as viewed in Figure 11. As a result, the two cranks 78 and 82 pivot about their pivot points 82 and 86 in a clockwise sense as viewed in Figure 11 and the plate 20 is drawn downwardly towards the base 12a.

The arrangement for moving the plate 20 shown in Figure 11 has the advantage that it occupies only relatively small height and so the overall height of the device over the finger board or neck of the guitar can be relatively low.

Claims (6)

1. A device for selecting chord positions for a stringed instrument such as a guitar, the device being arranged to be mounted above the finger board of the guitar and including fingers projecting downwardly towards strings to be blocked during the playing of a chord, electromagnetic abutment means for each finger, chord selecting means for activating certain of the electromagnetic abutment means according to the particular chord desired and a depression plate manually movable towards the finger board of the guitar and arranged to move towards the finger board only those fingers whose associated electromagnetic abutment means have been activated, these fingers then blocking certain strings at certain positions to give the desired chord.

2. A device as claimed in Claim 1 in which the chord selecting means comprises a row of switches or a keyboard controlling switches which are operated by depressing them in a direction towards the strings of the guitar, continued depression moving the depression plate and activated fingers to block selected strings.

3. A device as claimed in Claim 1 or Claim 2 in which the electromagnetic abutment means comprise a plunger movably by an electromagnet associated with each finger into engagement with that finger when that finger is to block a string.

4. A device as claimed in Claim 3 in which the electromagnetic abutment means are mounted on the depression plate.

5. A device as claimed in Claim 3 or Claim 4 in which the fingers are resiliently urged away from the finger board of the guitar, that resiliency being overcome by the engagement of a plunger with a finger to be operated and movement of the depression plate towards the finger board.

6. A device for selecting chord positions for a stringed instrument such as a guitar, substantially as herein described with reference to Figures 1 to 10 or to Figure 11, of the accompanying drawings.