US2736226A

US2736226A - mcbride

Info

Publication number: US2736226A
Authority: US
Publication date: 1956-02-28
Anticipated expiration: 1973-02-28

Description

Feb. 28, 1956 .1. w. MCBR D 2,736,226

KEY OPERATED MUSICAL INSTRUMENT Filed May 17, 1951 10 Sheets-Sheet 1 inn- Q v 1 1? b a, n

H R Q1 m V I W 11 $1 (4J1 a w v \Q INVENTOR. (Toy/v WMCBQ/DE,

KEY OPERATED MUSICAL INSTRUMENT Filed May 17 1951 10 Sheets-Sheet 3 Feb. 28, 1956 J. w. M BRIDE KEY OPERATED MUSICAL INSTRUMENT l0 Sheets-Sheet 4 Filed May 17 1951 Feb. 28, 1956 J. w. M BRIDE 2,736,226

KEY OPERATED MUSICAL INSTRUMENT Filed May 17, 1951 10 Sheets-Sheet 5 INVENTOR. p 16, zromv W MCBE/DE,

Feb. 28, 1956 J. w. M BRIDE KEY OPERATED MUSICAL INSTRUMENT l0 Sheets-Sheet 6 Filed May 17, 1951 INVENTOR.

'JO-HN WMCZBQ/DE,

BY flflr, 7

ATTORNEY.

w m3 mm R? w wn WNJN N E R L Feb. 28, 1956 J, w. MCBRIDE 2,736,226

KEY OPERATED MUSICAL INSTRUMENT Filed May 17, 1951 10 Sheets-Sheet 7 0 J66 J67 J66 J65 .164 16:; J52 J61 F7; .22.1/. z//// 2 i? 25 J60 129 g INVENTOR.

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Feb. 28, 1956 .1. w. M BRIDE 2,736,226

KEY OPERATED MUSICAL INSTRUMENT Filed May 17, 1951 10 Sheets-Sheet 8 L I 19.9 b

IN V EN TOR.

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W ArraeA/EK Feb. 28, 1956 J. w. M BRIDE KEY OPERATED MUSICAL INSTRUMENT l0 Sheets-Sheet 9 Filed May 17, 1951 Arr-maven Feb. 28, 1956 J. W. M

KEY OPERATED MUSICAL INSTRUMENT l0 Sheets-Sheet 10 Filed May 17 1951 M 2 M m W N United States Patent KEY OPERATED MUSICAL INSTRUMENT John W. McBride, Burbank, Calif., assignor to Bantar,

Incorporated, Burbank, Calif., a corporation of California Application May 17, 1951, Serial No. 226,853

30 Claims. (Cl. 84-315) This invention relates to musical instruments either of the wind or string type. In the string type, it has been proposed to use keys in adjusting the free vibrating length of any of the strings for determining the pitch, as shown, for example, in application Serial Number 110,262, filed on August 15, 1929, Patent No. 2,574,880, granted November 13, 1951, in the name of John W. McBride, and entitled Musical Instruments. In the wind type, keys may be used for determining the effective length of the pipe and, thereby, the pitch tone of the pipe.

It is one of the objects of this invention to make it possible to use power to operate the pitch varying mechanism, thereby relieving the performer of the task and permitting him more completely to center his attention upon his performance. Furthermore, the control effected in this manner may be made much more sensitive to the touch of the performer.

It is another object of this invention to provide a compact and simple drive for such pitch adjusting mechanisms.

It is still another object of this invention to provide a controlled power drive for this purpose, in which the extent of the movement of the key determines the movement of the power-operated pitch adjusting mechanism.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several embodiments of the invention. For this purpose there are shown a few forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a plan view of a musical instrument incorporatin g the invention;

Fig. 2 is a side elevation thereof;

Fig. 3 is an enlarged fragmentary sectional view, taken along a plane corresponding to line 3-3 of Fig. 1;

Fig. 4 is a sectional view, taken along a plane corresponding to line 44 of Fig. 3;

Fig. 5 is an enlarged fragmentary plan view, partly broken away, of the left-hand portion of the instrument shown in Figs. 1 to 4;

Figs. 6, 7, 9, and are sectional views, taken along planes corresponding to lines 6--6, 77, 9-9, and 101l) of Fig. 5;

Fig. 6a is a fragmentary sectional view, similar to Fig. 6, illustrating the rise of a slide in place of a roller for stopping the strings;

Fig. 8 is a view similar to Fig. 7, but illustrating another position of the control mechanism;

Fig. 11 is a sectional view, taken along a plane corresponding to line 11-11 of Fig. 10;

Fig. 12 is a plan view of an instrument incorporating a modified form of the invention;

2,736,226 Patented Feb. 28, 1956 Figs. 13, 14, and 15 are sectional views, taken along planes corresponding to lines 13-13, 14-14, and 15-15 of Fig. 12, the scale of Figs. 14 and 15 being enlarged;

Fig. 16 is a sectional view, taken along a plane corresponding to line 1616 of Fig. 14;

Fig. 17 is a sectional view, taken along a plane corresponding to line 1717 of Fig. 15;

Fig. 18 is a sectional view, taken along a plane corresponding to line 18-48 of Fig. 14;

Fig. 19 is a fragmentary view, on an enlarged scale, of a portion of the apparatus illustrated in Fig. 13;

Fig. 20 is a plan view of a further modified form of the invention;

Figs. 21, 22, and 23 are sectional views, taken along planes corresponding to lines 21-21, 2222, and 23-,-23 of Fig. 20, the scale of Figs. 22 and 23 being enlarged;

Fig. 24 is a sectional view, taken along a plane corresponding to line 24-24 of Fig. 22;

Fig. 25 is a sectional view, taken along a plane corresponding to line 25-25 of Fig. 23;

Fig. 26 is a sectional view, taken along a plane corresponding to line 2626 of Fig. 22;

Fig. 27 is a fragmentary View of one of the friction drive devices used in the instrument shown in Fig. 20;

Figs. 27a, 27b, and 270 are diagrammatic views illustrating the different positions of the drive shown in Fig. 27;

Fig. 27d is a fragmentary view similar to Fig. 21, of a modified form of drive mechanism;

Fig. 28 is a perspective view of one of the driven members shown in Figs. 22, 27, 27a, 27b and 27c;

Fig. 29 is a plan view of a further modified form of the invention;

Fig. 30 is a side elevation thereof;

Fig. 31 is a sectional view, taken along a plane corresponding to line 3131 of Fig. 29;

Fig. 32 is a sectional view, taken along a plane corresponding to line 3232 of Fig. 30;

Figs. 33, 34, and 35 are diagrammatic pictorial views of modified forms of the invention;

Fig. 36 is a side elevation, partially in section, of a further modified form of the invention;

Fig. 37 is a fragmentary side elevation of a further modification; and

Fig. 38 is a sectional view, taken along a plane corresponding to line 38-438 of Fig. 37.

Referring first to the form illustrated in Figs. 1 to 11, inclusive: the invention is shown as incorporated in a stringed musical instrument. The body 1 of the musical instrument may be made of wood, or other appropriate material. Since electromagnetic pickup means are utilized for amplification of sound produced by the sound generators in the instrument, the body 1 is not necessarily resonant.

At the right-hand end of the instrument, as shown most clearly in Figs. 1 and 3, there is shown an anchor 2 for the plurality of

tensioned springs

3, 4, 5, and 6 .that extend in parallel relation above the top of the body 1. The right-hand ends of these strings 4 are bridged across the arcuate portion 70f the anchor 2. The right-hand ends of these strings are anchored, as by the aid of knots 8 formed at'the ends of these strings, and which pass through appropriate apertures in the anchor member'Z.

At the left-hand end, the strings are supported by the slotted heads of the screws 9 that are arranged in a trans verse row across the left-hand portion of the instrument. These screws 9 are threaded into a metal plate 11, and nuts 10 are used to maintain these screws in position (Figs. 7 and 8). This metal plate 11 extends longitudinally of the instrument and overlies a cavity or recess 12. This cavity or recess 12 serves to enclose some of the operating portions of the device. The plate 11, as shown most clearly in Fig. 1, may be held in place over the cavity 12, as by the aid of the screws 13 at the right-hand end, and by the aid of similar screws 14 (Fig. at the left-hand end. The plate 11 has an upper surface which is flush with the upper surface of the body 1, as by appropriate rabbeting around the top edge of recess, 12. The tensioning of the strings is performed in a well known manner, as by the aid of the pegs 15 that serve to rotate the anchor pins 16 upon which the ends of the

strings

3, 4, 5, and 6 are wound.

Sound waves generated by the strings, due to the vibration of the strings, are picked up by an appropriate pick-up device 17 extending across the strings, as illustrated in Figs. 1 and 3. This pick-up device may be of any appropriate character, and may be connected electrically to appropriate sound impulse amplifying devices and loud speakers, as by the aid of a cable 19 (Fig. 1).

As shown most clearly in'Figs. 2 and 6, a supplemental resilient bridge device 18 is provided. This may be in the form of a rubber tube member flattened to an oval shape, or any similar resilient material, and filled with a liquid that produces a relatively soft finger-like touch on the strings.

Disposed beneath the strings 3 and 4 are a pair of rollers 20 and 21 having axes transverse to the strings (Figs. 5 and 6). These rollers, as hereinafter explained, are independently movable in a direction longitudinally of the strings 3 and 4. The rollers 20 and 21 can assume any position within limits along the length of the strings 3 and 4. Since they are independently movable longitudinally of the strings 3 and 4, the active lengths of the strings between these rollers, and between any of the rollers and the corresponding bridge, are adjustable by movement of these rollers.

Similarly,

rollers

22 and 23 cooperate with

strings

5 and 6.

In order to transmit movement to these rollers, four

flexible elements

24, 25, 26, and 27 are provided (see, particularly, Figs. 4, 5, 9, l0, and ll). Attached to element 24, as by the aid of a weld 28 (Fig. 11) is the bearing standard 29. This bearing standard extends across the adjacent flexible element 25, but is not fastened thereto. -It has the upright portions 30 and Wheels 31 (Fig. 10) for accommodating the spindle of the roller 21. Accordingly, longitudinal movement of the flexible element 24 causes a corresponding longitudinal movement of the roller 21.

In order to maintain the roller 21 in stable position, the roller 21 is provided at the ends of its spindle with tracking Wheels 31 frictionally engaging the top of plate 11. 7

Roller 2th is similarly connected to the flexible element 25, as by the weld 32 and the bearing standard 33.

Rollers

23 and 24 are also similarly supported by the standards 34 and 35 (Figs. 10 and 11) respectively attached to the

flexible elements

26 and 27.

Accordingly, longitudinal movement of any of these flexible elements causes a corresponding longitudinal movement of the roller attached to the elements.

Sprocket wheels are provided for moving the

elements

24, 25, 26, and 27. Thus, element 24, at its right-hand end, passes over an idler sprocket wheel 36 and, at its left-hand end, over a driving sprocket wheel 37 (Figs. 1, 4, 5, and 6). These sprocket wheels are supported on axes 1n the recess 12, as by the aid of standards 38 attached to the lower side of the plate 11. The teeth of the

sprocket wheels

36 and 37 pass through appropriate apertures 39 (Fig. 11) in the flexible element 24.

Similar idler sprocket wheel structures 4d, 41, and 42 are arranged at the right-hand portion of the instrument for the

flexible elements

24, 25, 26, and 27, respectively; and, at the left-hand end, driving

sprocket wheels

43, 44, and 45 are provided. As shown most clearly in Figs. 1, 3, 4, and 9, the plate 11 is provided with appropriate slots 46 to permit the

flexible elements

24, 25, 2 6, and 27 to pass over the plate 11 from the reQeSS 2.

Instead of

rollers

20, 21, 22, and 23, slides or skids may be used. Thus, as shown in Fig. 6a, the skid or slide 2% is shown as stopping the string 3. This slide may be attached to the flexible member 2 3-.

Each of the driving

sprocket wheels

37, 43, 44, and 45 is independently actuated by gearing operated by slidable

key structures

47, 48, 42, and 59. Since the key structures are similar, the key structure 49, shown most clearly in Figs. 7 and 8, may be described as representative of all of them.

The key 49 has an upper overlying portion 51 which passes through an appropriate guiding slot in the skirt 52 of plate 11. Key 49 also has a lower slide portion 53. The skirts 52 and 55' of the plate 11 are provided at their lower edges with slots serving to guide the slide 52. Thus, slot 54, provided in the lower edge of skirt 52, has shallow slots in its opposite sides to accommodate the edges of the slide 53 (Fig. 6). A similar slot guiding arrangement is provided at the lower edge of skirt 55.

Slide 53 carries a rack 56 which engages a pinion 57 mounted on a shaft 58. This shaft 523 extends longitudinally of the body 1, (Figs. 5 and 6). its right-hand portion is rotatably supported in a standard 59 (see, also, Fig. 9) that is supported on the plate 11. The left-hand end of the shaft 58 extends through the plate or. supported at its top edge on the plate 13..

The right-hand end of the shaft 58 carries a bevel pinion 61 which meshes with the corresponding bevel direction. The sprocket wheel 4 is correspondingly rotated by the aid of the bevel gears -51 and 62, and the flexible element 26 moves toward the right, as viewed in Fig. 1. The extent of the inward movement of the key 49 determines the extent of movement of the roller 23, which is longitudinally moved by the flexible element 25.

In order to return the roller 23 to the starting position when the key 49 is released, use is made of a torsion spring 63. One end of this torsion spring is anchored to the boss 64 mounted on the plate 66. The other end of the spring is anchored to a collar 65 that is attached to the end of the shaft 58. When the key 49 is urged inwardly, the spring 63 is wound up. When the key 49 is released, this spring moves the key to the starting position. A limit is placed upon the outward movement of the key 49 by the aid of the stop pin 66 carried by the slide 53. This stop pin abuts the skirt 55 in the released position of Fig. 7.

The key mechanism for moving the sprocket wheel 44 is substantially the same as the mechanism utilized for operating the

sprocket wheels

37, 43, and 45. As heretofore explained, these sprocket wheels operate the

flexible elements

24, 25, 26, and 27 for moving the four rollers toward the right, as viewed in Fig. 1.

Thus, the sprocket wheel 37 is operated by aid of the key 47 and the shaft 67 supported and operated in a manner already described in connection with shaft 58. The lower slide portion 63 of key 47 is provided with the operating rack 69, corresponding to operating rack 56 of key 49.

Similar rack, pinion, and shaft combinations are included for the operation of the other two

sprocket wheels

43 and 45.

In the form just described, manual operation of the keys serves to transmit power exerted by the fingers to operate the sprocket wheels.

In the form shown in Figs. 12 to 19 inclusive, the operation of any one of the four

keys

70, 71, 72, and 73 (Figs. 12 and 13) causes movement of the corresponding

rollers

74, 75, 76, and '77. As shown most clearly in Fig. 14, these rollers are constructed in substantially the same manner as

rollers

20, 21, 22, and 23 of the first form described, except that they have a greater axial length. The rollers are supported in such manner that the wheels 78 (Fig. 15) roll upon the plate 79 that forms the top of the instrument body 80.

In this instance, the

rollers

74 and 75 are elongated so as to cooperate with four

strings

81, 82, 83, and 84. Similarly,

rollers

76 and 77 are disposed beneath the four

strings

85, 86, 87, and 88, inclusive. The strings are all anchored at their right-hand ends in the anchor member 89 in a manner hereinbefore described in connection with Figs. 1 to 11 inclusive. Similarly, each of these strings is supported in the cross slot of a corresponding screw 90 mounted on the plate 79. The strings are furthermore anchored to the pins in turn rotatable by the aid of the pegs 92 in a well understood manner. These pegs 92 are appropriately supported by the sheet metal extension 93 of the body 80.

Each of the roller standards is provided with means for moving it longitudinally along the instrument, so that the friction wheels 78 contact and roll along the upper surface of plate 79. For example, the standard 95' (Fig. 15) is provided with a downwardly extending arm 96 which projects through the slot 97 of plate 79, said arm 96 for supporting a power-driven member 98. This power-driven member 98 is shown in dotted lines in Fig. 12. A corresponding power-driven member 99 is similarly connected to the standard of roller 77 (see Figs. 12 and 13).

There are two other power-driven

members

100 and 101 respectively for

rollers

75 and 76. These power-driven members are shown to best advantage in Figs. 13, 14, 15, and 17. Through

slots

97, 102, 103, and 104 in plate 79, extend their

corresponding support members

105, 106, and 107.

The driven

members

98, 100, 101, and 99 are guided for longitudinal movement by their

respective supports

96, 105, 106, and 107.

Movement of these driven

members

98, 100, 101, and 99 is effected by the aid of a friction drive roller 108 (Figs. 13 and 14). This driving roller engages the top edges of each of these

members

98, 100, 101, and 99. The lower edges of these driven members are accommodated in

idler rollers

109, 110, 111, and 112 (see also Fig. 18). Tilting of these driven members about the axes of these idler rollers is effectively prevented by the engagement of the wheels 78 with the plate 79. The idler rollers are each accommodated in

clevices

113, 114, 115, and 116.

Each of the driven members is urged toward the left by a tension spring 117 (Figs. 12 and 13). The righthand ends of these tension springs are anchored to the bent ends 118 of the driven members (see particularly Figs. 15 and 17). The left-hand ends of the springs 117 are anchored in the end wall 119 of the body extension 93.

Each of the driven

members

98, 100, 101, and 99 is wedge-shaped, having an upper edge 120 and a lower edge 121 that converge toward the left (Figs. 13).

The driving roller 108 is continuously rotated in a counterclockwise direction, tending to move the driven members toward the right as viewed in Fig. 13. This drive is effective only so long as the driving roller'108 and the corresponding

idler rollers

109, 110, 111, or 112 are in frictional contact with the upper and

lower edges

120 and 121. The direction of drive of the driving roller 108 is such as to move the driven members toward a position out of frictional contact, due to the slope between the upper edge 120 and the lower edge 121. Just as soon as the friction is reduced sufficiently, the drive is no longer effective, and the position of the driven member is stabilized when the force tending to move the driven member toward the right is equalized by the force of spring 117 tending to move the member to the left.

In order to predetermine to what extent any one of the driven members may be moved toward the right, the axial spacing between the driving roller .108 and the selected

idler roller

109, 110, 111, or 112 is adjusted. In the inactive position of Figs. 12 and 13, the roller 108,

although continuously rotating, has no driving effect since the wedge-shaped driven members 99 to 101 are in a position just sutficient to reduce the frictional force to an ineffective value.

Let it be assumed, for example, that roller 109 is adjusted upwardly. The friction is thereby increased on the opposite edges and 121. The roller 108 is now effective to move the driven member 98 toward the right, and this movement continues until the frictional force is reduced to a point where it is equalized by the force of spring 117. Accordingly, for every adjusted position of the roller 109, there is a corresponding adjusted position of the driven member 98.

Similarly, the adjusted positions of any of the

other rollers

110, 111, and 112 produce a corresponding adjusted position of the corresponding driven

members

100, 101, and 99. Since the positions of these driven members determine the positions of

rollers

74, 75, 76, and 77, the instrument may be played by providing keys that adjust the heights of these

idler rollers

109, 110, 111, and 112.

The mechanism for effecting the elevation of the idler rollers will be explained in connection with the roller 112. Similar mechanisms are provided for each of the

other rollers

104, 110, and 111.

The clevis 116 that supports the roller 112 is provided with a threaded shank 122 (Fig. 18). This shank is threaded into a nut member 123 that is rotatably mounted in a plate 124. This plate 124, in turn, is supported on a shelf 125 mounted on the body 80 (see particularly Fig. 14). The nut 123 has a hollow downward extension terminating in a collar 126. A torsion spring 127 is disposed around this extension. One end is anchored in the 'collar 126 and the other end is anchored in the shelf 125. A constant turning force is exerted upon the nut 123 by the spring 127 to move the threaded shank 122 downwardly to the inactive position of Figs. 13 and 14.

The nut 123 is provided at its upper end with a gear 128 (see, also, Figs. 14 and 16). This gear 128 is engaged by a rack 129. This rack 129 is mounted on the bottom of a slide 130 that is guided in appropriate guides in the

flanges

131 and 132 of plate 124. A stop pin 133 limits the movement of the slide 130 toward the right, due to the force of the torsion spring 127.

The slide 130 is adapted to be operated by the manually operable key 73, whch is integrally formed with the slide 130. Fig. 14 illustrates key 71 for operating the threaded shank 134 that carries the clevis 114 and roller 110. The structure, however, is identical with the structure of the key 73 except that the rack 135 (Fig. 16) operating this mechanism is appropriately spaced on the slide 136 of key 71 to engage the pinion 137.

The

keys

70 and 72 are similarly arranged, as shown most clearly in Figs. 12 and 16. These keys carry the

slides

138 and 139, respectively.

When any one of the

keys

70, 71, 72, and 73 is urged inwardly to any desired extent, the corresponding

idler roller

109, 110, 111, and 112 is urged into strong frictional contact with the corresponding driven

member

98, 100, 101, and 99. This, in turn, causes the driven member to be moved by the driving roller 108 toward the right to move the corresponding

roller

74, 75, 76, or 77 to a position that is determined by the position of the key.

The roller 108 is shown as covered by a semicylindrical member 140 (Fig. 14). This member may be formed integrally with plate 79. The roller 108 is connected by the aid of a shaft 141 with a driving pulley 142. The shaft 141 is supported on either side of the roller 108 by the arms 143. These arms, in turn, arepivotally supported on standards 144, and are connected by a transverse shaft 145 (see Fig. :12). Pulley 142 is operated by the belt 146 driven by a pulley 147 connected to an 7 electric motor 148, shown as mounted on the top of a loudspeaker cabinet 310. I

In order to obtain a tremolo or vibrato effect, the arms 143 are arranged to be oscillated so as to move the roller 108 alternately toward and from the driven members. For this purpose, one of the arms 143 is provided with a lever arm 149 that is oscillated by a link. 159 (see also Fig. 19). This link 150 has its lower end eccentrically mounted with respect to a shaft 151 operated at a desired speed by the motor 147 and

pulleys

152, 153

and belt 154. As the roller.188 is thus brought cyciically toward and away from the upper edge 128 of each of the driven members 99 to 1101, inclusive, a corresponding slight backward and upward movement of the driven members is effected.

In the form just described, the positioning of any one of the rollers that determine the free vibrating lengths of the strings is effected by urging any one of the

keys

70, 71, 72, and 73 inwardly to the required extent. The same general effect is produced in the form of the instrument illustrated in Figs. to 28.

The body 155 of the instrument is appropriately provided with a string anchor 156 and string tensioning means 157 arranged substantially as before. The body 155 is provided with a cover having depending sides attached to the top edge of the body 155. A plate 158 is disposed over a cavity or recess 159 in the cover 155. There are eight

strings

161, 162, 163, 164, 165, 166, 167, and 168 arranged generally in parallel relationship. Four

rollers

169, 170, 171, and 172 are supported and arranged substantially identically with the rollers described hereinbefore. They each include traction wheels 1'73 mounted to roll on top of the plate 158. Each of the bearing standards 174 for these rollers (see, also, Fig. 25) is provided with a downwardly extending bracket or ear 175. These ears extend through the

apertures

176 and 177 formed in the top plate 158.

In order to insure that the rollers 173 be properly guided, side guiding rails 173a and intermediate rail 1731b (Figs. '20 and 23) are attached to the plate 158.

Movement of the

rollers

169, 170, 171, and 172 is effected by driven

members

178, 179, 188, and 181 arranged in general parallel relationship. These driven members are coupled respectively to the roller supports 174, as by the aid of the round bars 182, 183, 184, and 185 (Figs. 23 and 25). These round bars pass through the ears or projections and are provided with appropriate means preventing relative axial movement of these rods, but permitting angular movement about the longitudinal center line of the respective driven members.

The driving mechanism for each of the driven members 1'78, 179, 180, and 181 is identical and, accordingly, only one of them need be described in detail. a

The driven member 181 has a lower surface which corresponds to a Warped surface having a straight line generatrix moving in a direction normal to the center line of the driven member 181 but varying in angular position. The upper surfaces of these members are plane. Thus, for example, in the inactive position illustrated in Figs. 20, 21 and 22 the lower right-hand edge 186 (Fig. 25) of the driven member 181 is horizontal. However, the lower left-hand end 187 (Figs. 21 and 28) is at an angle to the horizontal, as indicated by the dotted line 188 of Figs. 22 and 28.

A friction drive member 189 (Figs. 21, 22, 23, 26, 27, 27a, 27b, 27c) is driven on a vertical axis 190 which is normal to the center line of the driven member 181. The convex upper surface 191 is in frictional contact with the lower surface of the driven member. When the driven member 181 is in contact with the convex surface 191 at the crest, the rotation of the driving member 189 has no effect upon the driven member 181. In this symmetrical position, as indicated in Figs. 22 and 27a, whatever frictional force may be exerted by rotation of memher 189 on one side of the axis 190 is exactly neutralized by the frictional force operating on the other side of the axis. This is true because the direction of linear movement is opposite on opposite sides of the axis.

If member 181 is tilted about the axis of rod 185, so to engage the convex surface 191 to the right of the axis 190 (Fig. 27b), then rotation of the member 189 in a clockwise direction, as viewed in plan (Fig. 20), will advance the member 181 to the right. This advancement to the right continues only until the point of contact between the surface 191 and the member 181 is at the crest of the surface 191 (Fig. 270). In other words, the lower surface of the member 181 being a warped surface,

' the forward movement of the driven member 181 continues only until this warped surface arrives at a position where symmetry is attained and the driven member 181 contacts the crest of the convex surface 191, as in Fig. 270.

The farther the tilt at the beginning of the motion, the farther the member 181 must be moved before this condition of equilibrium is reached. The movement continues until the line corresponding to the generatrix of the warped surface of member 181 assumes a position normal to the axis 198 (Fig. 270). In this tilting movement, the rod (Figs. 23 and 25) is angularly moved about the longitudinal axis of the member 181. Sufficient play is permitted so that any minor deviation of this longitudinal center line of the member 181 has little of feet upon the operation of the device.

The driven

members

188, 179, and 178 are similarly controlled and driven by the driving

members

192, 193, and 194. These driving members all rotate in the same direction about their

axes

195, 196, and 197 (Fig. 24).

The driving member 189 is directly coupled to a small electric motor 198 (Figs. 20 and 21) mounted upon a vertical wall 199 of the body 166. This motor 198 is directly coupled to a sleeve 21)!) (Figs. 22 and 26) appropriately journalled in a shelf 2121 supported within the body 155.

Sleeve 288 has a spur gear 282 mounted thereon which is in mesh with an idler 203 (Fig. 24). This idler 203, in turn, rotates the gear 284 coupled to the driving member 192. Another idler 285 transmits motion for gear 284 to another gear 2'85 coupled to the driving member 193. Lastl, an idler gear 207 couples the gear 206 to the gear 288 coupled to the driving member 194-. In this way, motor 198 imparts rotation in clockwise direction to all of the

gears

282, 284, 286, and 288.

The sleeve 2% is coupled by spline connection to a shaft 289. This shaft extends into the hollow extension 210 of the drive member 189. it is coupled to the drive member 189 by the aid of a cross pin 211. A compression spring 212, disposed in the hollow member 288, beneath the shaft 289, serves to urge the drive member 189 into frictional contact with the lower surface of the driven member 181.

Tilting of the driven

members

173, 7 18-8, and 181 is accomplished by the aid of the four

keys

213, 214, 215, and The key 213 is shown to best advantage in Fig. 22, and is similar to the other keys 21%, 215, and 216. This key is pivoted on common cross shaft 217 (see, also, Fig. 21) that is appropriately supported by the cover 166. A tension spring 218 is provided for each key to rge the key to the inactive position of Fig. 22. These keys operate in a wide slot 219 provided in the sheet metal cover member 168.

Key 213, when pushed inwardly and rotated in a counterclockwise direction, serves to urge a link 221 toward the left, as viewed in Fig. 22. This link 221) is pivoted, at its left-hand end, to actuator 221 having a right-angle bend 222, (see, also, Figs. 27a, 27b, 270). This bend 222 erminates in an extension 227 which projects through a pair of ears 225 extending from the cross strap 226 fastened to the upper edge of housing member 160. Joined to this projection 227 are the arms 228 and 229 (Figs. 27a, 27b, 27c) serving as mountings for the rollers 9 223 and 224. These rollers thus oscillate about the axis of the extension 227. They are provided with flanges "engaging, respectively, the opposite edges of'the driven member 178. In this way, this driven member is guided appropriately for longitudinal movement.

Similar linkages are provided for each of the driven

members

179, 180, and 181. The links are coupled to the members 221, progressively becoming larger and longer, as indicated most clearly in Fig. 22. The longest link 230 is connected to rollers that engage the upper surface of the driven member 181 by the aid of an actuator 221.

As hereinbefore stated, the extent of movement of any one of the

connections

213, 214, 215 and 216 determines the angular position of driven

members

178, 179, 180, and 181 about their respective longitudinal center lines. This, in turn, determines the extent of movement toward the right to attain a balanced position in which the surface of the driven member is in contact with the convex surface 191 at the very crest thereof. The greater the amount of movement of the key, the greater the movement must be of the driven member to attain this balanced or equilibrium position.

In the mechanism illustrated in Figs. 27, 27a, 27b, and 270, the driving element 189 has a convex top surface 191, and the driven member 181 has a warped surface cooperating with the surface 191. However, this arrangement may be reversed. As shown in Fig. 27d, the driving element 189a has a flat top surface. The driven member 181a has a lower convex surface 191a that-is generated by an are that is moved parallel to the longitudinal axis of the driven member, and angularly moved to produce a curved warped surface. The operation of this form is similar to that already described.

There is indicated in Fig. 21 a loudspeaker frame 231 which may be appropriately supported on the framework that forms the body 155.

Furthermore, a tremolo or vibrato eifect'may be attained in this form of the instrument by the aid of a crank 232 (Fig. 22) mounted on the end of a shaft 233 driven from the motor 198. This -crank-232 operates a link 234. The link inturn operates a slide 235 through which the hollow extensions 210 of the driving

members

189, 192, 193, and 194 extend, as shown most clearly in Fig. 26. The slide 235 is guided in the guides 236 supported above the shelf 201. Accordingly, as the crank 232 is operated, the driven members 189 cyclically incline through a definite angle about the axes of the pins 211 (Fig. 26). This, of course, servesto change cyclically the point of contact between the driven members of the respective driving members.

The mechanisms hereinbefore described are not necessarily limited to stringed musical instruments. For example, in the form shown in Figs. 29 to 33, inclusive, a wind musical instrument is illustrated having aplurality of

pipes

237, 238, 239, and 240. These pipes are arranged above the top surface of a body 241.

The right-hand ends of these pipes form the inlet ends. Each of these pipes is accordingly provided with a slot having a tapered edge 243. These ends of the pipe are supported by being telescoped within a body 244 that is provided with passages for distributing air to these pipes. The air inlet 245 may be connected to any appropriate source of compressed air. This inlet is provided with a branch passage 246 leading to a'vertical channel 247 (Fig. 31) which, in turn, communicates with the horizontal channel 248directly connected to the inlet of pipe 237.

Similar branches 249, 250, and 251 lead, respectively, to the vertical channels that are connected to the

horizontal channels

252, 253, and 25 leading, respectively, to the-inlet ends of the

pipes

238, 239, and 240.

Controlling the passage of air to -these channels are the

keys

255, 256, 257, and 258. These keys ar'eof-substantially identical structure, one of them being shown to best advantage in Fig. 31. Key 255 'is provided with aslide member 259 guided in'a slot in thebody 244. A

compression spring 260 operates to urge the key to the extreme righthand position corresponding to the inactive position of the key. The lzey is stopped from further movement by the aid of the inwardly turned flange 261 which engages the left-hand side of the body 244. The slide 259 is provided with a plurality of spaced apertures 262. These spaced apertures alternately connect the inlet 24 with the channel 248 as the key 255 is moved toward the left, as viewed in Fig. 31. Accordingly, a trill effect may be produced by the reciprocation of this key.

The other

key structures

256, 257, and 258 are substantially identical with the key 255, except that the apertures corresponding to apertures 262 are appropriately placed longitudinally of these keys to control

corresponding channels

252, 253, and 254.

Each of the

pipes

237, 238, and 239 is provided adjacent its lower portion with a slot (Fig. 32), as well as a guide 264 for the accommodation of a slide 265. The slide 265 has a depending flange 266. Obviously, the position of the slide 265 determines the effective length of the corresponding pipe. Thus, in the position shown, the pipes have a minimum effective length. Movement of any of the slides 265 toward the right causes an increase in the effective length of these pipes.

For effecting this movement, use is made of a mechanism such as that disclosed in Figs. 1 to 11, inclusive. Thus, there is a driving sprocket wheel 267 associated with each slide 265 for advancing a flexible element 268. The idler sprocket wheels 269 are provided adjacent the right-hand end of the instrument.

The

keys

270, 271, 272, and 273 are arranged, as described in connection with Fig. 5, for rotating any one of the sprocket wheels 267 to the desired extent against the torsion of the springs 274. A pictorial view of this structure is shown in Fig. 33. Sprocket wheel 267 is shown as driving the flexible element 268. This element 268 is coupled, as by the yoke 275, to the slide 265. Each of the

keys

270, 271, 272, and 273 carries a rack, such as 276, rotating a pinion 277 mounted on the shaft 278. This shaft, in turn, rotates the sprocket wheel 267 by the aid of the bevel gearing 279.

The slides determining the effective lengths of the pipe may be operated by a mechanism similar to that disclosed in Figs. 12 to 19, inclusive. Thus, as shown in Fig. 34, a driven member 230, similar to driven member 98 of Fig. 14, is caused to advance to move the slide 265 by the aid of the driving roller 281 operating on the top edge of the member 288. The lower edge of member 281) is guided in the grooved idler 282, the height of which is controllable, as before,'by movement of the key 283.

In the form shown in Fig. 35, the pipe 246 is provided with a slide 284 that is operated by a driven member 285. This driven member 285 is operated in the same manner as the driven

members

178, 179, 180, and 181 of the form shown in Figs. 20 to 28. This driven member, having a warped surface in contact with the driving member 286, may be angularly adjusted by'the aid of a key 287. This my 287, by the aid of the

linkage

288 and 289, tilts the rollers 290 that bear upon the upper plane surface of the driven member 285.

The effective lengths of the pipes may be varied by the aid of telescoping tubes in place of the sliding structure. Thus, in the form shown in Fig. 36, the pipe telescopes within an adjustable pipe section 292. This pipe section 292 is carried by a support 293 that may be moved toward the right by any of the types of mechanisms hereinbefore described.

Figs. 37 and 38 illustrate a form of adjusting mechanism described in detail in the prior application hereinabove identified. In this form, the

arcuate members

294 and 295 have

edges

296 and 297 which form helical tracks. These

members

294 and 295, as explained in said prior application, may be rotated in opposite directions. A roller-298 has bearing

flanges

299 and 300 cooperating 11 1 with these edges 2% and 297. As the members 2% and 295 are rotated in opposite directions, the roller 2% is moved in a direction parallel with the axis of rotation. This roller may be connected to a yoke Sill, as shown in Fig. 37. This yoke 301 may, in turn, be connected to a slide 302 for operating a telescoping pipe 393 to de ermine the efiective length of the pipe.

The inventor claims:

1. In a friction drive mechanism for a selectively positionable load: a linearly movable member for positioning the load and having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; one of said rollers operating as a driving roller; and means for adjusting the spacing between the axes of the rollers.

2. In a friction drive mechanism for a selectively positionable load: a linearly movable member for positioning the load and having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; one of said rollers operating as a driving roller; means for adjusting the spacing between the axes of the rollers; means for rotating the driving roller in a direction to move the member toward disengaging position with respect to the rollers; and means for resiliently urging said member to engaging position.

3. In a friction drive mechanism for a selectively positionable load: a linearly movable member for positioning the load and having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; a pair of threadedly engaged parts, one of said parts supporting one of the rollers, the thread axis being transverse to the axis of the said roller; gear means for rotating the other of said parts; and means for driving at least one of the rollers.

4. in a friction drive mechanism for a selectively positionable load: a linearly movable member for positioning the load and having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; a pair of threadedly engaged parts, one of said parts supporting one of the rollers, the thread axis being transverse to the axis of the said roller; gear means for rotating the other said parts; means for driving at least one of the rollers; the direction of the drive being toward disengaging position with respect to the rollers; and means for resiliently urging said member to engaging position.

5. In a friction drive mechanism for a selectively posi tionable load: a linearly movable member for positioning the load and having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; means resiliently urging the member to increase the friction with respect to the rollers; means for driving one of the rollers in a direction to reduce the friction; means for adjusting the spacing between the rollers for determining the extent of movement of said member required to reduce the friction to a value counterbalanced by said resilient urging means; and means operated by the driving means for cyclically moving the rollers apart and together.

6. In a musical instrument: a sound generator; means for adjusting the pitch of said generator; and means coupled to the pitch adjusting means for moving it, comprising a linearly movable driven member having converging surfaces on opposite faces; friction rollers respec-' tively engaging said surfaces; one of said rollersoperating as a driving roller; and means for adjusting the spacing between the axes of the rollers.

7. In a musical instrument: a sound generator; means for adjusting the pitch of said generator; and means coupled to the pitch adjusting means for moving it, comprising a linearly movable driven member having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; one of said rollers operating as a driving roller; means for adjusting the spacing between the axes of the rollers; means for rotating the driving roller in a direction to move the member toward disengaging position with respect to the rollers; and means for resiliently urging said member to engaging position.

8. In a musical instrument: a sound generator; means for adjusting the pitch of said generator; and means coupled to the pitch adjusting means for moving it, comprising a linearly movable driven member having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; a pair of threadedly engaged parts, one of said parts supporting one of the rollers, the thread axis being transverse to the axis of said roller; gear means for rotating the other of said parts; and means for driving at least one of the rollers.

9. in a musical instrument: a sound generator; means for adjusting the pitch of said generator; and means coupled to the pitch adjusting means for moving it, comprising a linearly movable driven member having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; a pair of threadedly engaged parts, one of said parts supporting one of the rollers, the thread axis being transverse to the axis of said roller; gear means for rotating the other of said parts; means for driving at least one of the rollers; the direction of the drive being toward disengaging position with respect to the rollers; and means for resiliently urging said member to engaging position.

107 In a musical instrument: a sound generator; means for adjusting the pitch of said generator; and means coupled to the pitch adjusting means for moving it, comprising a linearly movable driven member having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; means resiliently urging the member to increase the friction with respect to the rollers; means for driving one of the rollers in a direction to reduce the friction; means for adjusting the spacing between the rollers for determining the extent of movement of said member required to reduce the friction to a value counterbalanced by said resilient urging means; and means operated by the driving means for cyclically moving the rollers apart and together.

11. in a stringed musical instrument: a tensioned string; adjusting means movable longitudinally of the string for determining its free vibrating length; and means for moving said adjustable means, including a linearly movable driven member having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; one of said rollers operating as a driving roller; means for adjusting the spacing between the axes of the rollers; means for rotating the driving roller in a direction to move the member toward disengaging direction with re spect to the rollers; and means for resiliently urging the member to engaging position.

12. In a wind musical instrument: a pipe; means movable in a direction longitudinally of the pipe for adjustmg the effective length of the pipe; and means for moving said movable means including a linearly movable driven member having converging surfaces on opposite faces; friction rollers respectively engaging said surfaces; one of said rollers operating as a driving roller; means for adjusting the spacing between the axes of the rollers; means for rotating the driving roller in a direction to move the member toward disengaging direction with respect to the rollers; and means for resiliently urging the member to engaging position.

13. In a friction drive mechanism: a linearly movable driven member; a rotary driving member having a curved surface of revolution about its rotary axis; said driven member having a surface in contact with said surface of revolution; the movement of the driven member being transverse to said axis; the said surface of the driven member being generated by a line transverse to said axis and having a continuously variable angle with said axis; and means for tilting said driven member about the surface of revolution.

14. In a friction drive mechanism: a linearly movable driven member; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a surface in contact with said surface of revolution; the movement of the driven member being transverse to said axis; the said surface of the driven memher being generated by a line transverse to said axis and having a continuously variable angle With said axis; and means for tilting said driven member about the surface of revolution; said driven member thereby continuing the drive until the area of contact is symmetrical about the axis.

15. In a friction drive mechanism: a linearly movable driven member; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a surface in contact with said surface of revolution; the movement of the driven member being transverse to said axis; the said surface of the driven member being generated by a line transverse to said axis and having a continuously variable angle with said axis; and means for tilting said driven member about the surface of revolution, so that the area of contact may fall along the crest of the convex surface or at either side of the crest.

16. In a friction drive mechanism: a linearly movable driven member; a rotary driving member having a curved surface of revolution about its rotary axis; said driven member having a surface in contact with said surface of revolution; the movement of the driven member being transverse to said axis; the said surface of the driven member being generated by a line transverse to said axis and having a continuously variable angle with said axis; means for tilting said driven member about the surface of revolution; and means operated cyclically for oscillating the axis of the rotary member.

17. In a friction drive mechanism: a linearly movable driven member; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a surface in contact with said surface of revolution; the movement of the driven member being transverse to said axis; the said surface of the driven member being generated by a line transverse to said axis and having a continuously variable angle with said axis; means for tilting said driven member about the surface of revolution; and means operated cyclically for oscillating the axis of the rotary member.

18. In a musical instrument: a sound generator; means movable in a rectilinear direction for adjusting the pitch of said generator; a linearly movable driven member connected to said means; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a Warped surface in contact with said surface of revolution; the elements of the surface being transverse to the axis; and means for tilting said driven member about the surface of revolution.

19. In a musical instrument: a sound generator; means movable in a rectilinear direction for adjusting the pitch of said generator; a linearly movable driven member connected to said means; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a warped surface in contact With said surface of revolution; the elements of the surface being transverse to the axis; means for tilting said driven member about the surface of revolution; and means operated cyclically for oscillating the axis of the rotary member.

20. In a stringed musical instrument: a tensioned string; means movable longitudinally of said string for adjusting the free length thereof; a linearly movable driven member connected to said means; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a warped surface in contact with said surface of revolution; the elements of said surface being transverse to said axis; and means for tilting said driven member about the surface of revolution.

21. In a stringed musical instrument: a tensioned string; means movable longitudinally of said string for adjusting the free length thereof; a linearly movable driven member connected to said means; a rotary driving memher having a convex surface of revolution about its rotary axis; said driven m'ember'h'avin'g a'warped surface in contact with said surface of revolution; the elements of said surface being transverse to said axis; means for tilting said driven member about the surface of revolution; and means operated cyclically for oscillating the axis of the rotary member.

22. In a wind musical instrument: a pipe; means movable in a direction longitudinally of the pipe for adjusting the effective length of the pipe; a linearly movable'driven member connected to said means; a rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a warped surface in contact with said surface of revolution; the elements of the surface being transverse to the axis; and means for tilting said driven 'me'rnber about the surface of revolution.

23. In a friction drive: a linearly movable driven member; a-rotary driving member having a convex surface of revolution about its rotary axis; said driven member having a warped surface in contact with said surface of revolution; the elements of the surface being transverse of the axis; and means for tilting said driven member in a plane transverse to the linear movement of the driven member.

24. In a friction drive mechanism: alinearly movable driven member; a rotary driving member having an axis of revolution transverse to the direction of movement of the driven member; said members having contacting surfaces, at least one of said surfaces being convex, the contacting surface of the driven member being generated by a line moving parallel to said linear direction and continuously angularly moving about an axis paralleling said linear direction; and means for adjusting the relative angular position of the axis of revolution about said linear direction.

25. In a musical instrument: a sound generator; means movable in a rectilinear direction for adjusting the pitch of said generator; a linearly movable driven member connected to said means; a rotary driving member having an axis of revolution transverse to the direction of movement of the driven member; said members having contacting surfaces, at least one of said surfaces being convex, the contacting surface of the driven member being generated by a line moving parallel to said linear direction and continuously angularly moving about an axis paralleling said linear direction; and means for adjusting the relative angular position of the axis of revolution about said linear direction.

26. In a musical instrument: a sound generator; a linearly movable member cooperable with the sound generator for adjusting the pitch of said generator; a rotary driving member; means for continuously rotating said driving member; means effecting a transmission between the members; and means responsive to the extent of movement of said linearly movable member for correspondingly adjusting the ratio of transmission.

27. In a musical instrument: a sound generator; a linearly movable member eooperable with the sound generator for adjusting the pitch of said generator; a rotary driving member; means for continuously rotating said driving member; means effecting a transmission between the members for linearly moving said linearly movable member; means for adjusting the initial ratio of transmission; and means responsive to the extent of movement of said linearly movable member for adjusting the ratio of transmission to zero.

28. In a musical instrument: a sound generator; a linearly movable member cooperable with the sound generator for adjusting the pitch of said generator; a rotary driving member; means for continuously rotating said driving member; means effecting a transmission between the members for linearly moving said linearly movable member; means responsive to the extent of movement of said linearly movable member for adjusting the ratio of transmission to zero; and means for adjusting the exr 15 tent of movement of said linearly movable member required for operation of said responsive means.

29. In a musical instrument: a sound generator; a linearly movable member cooperable With the sound generator for adjusting the pitch of said generator; a rotary driving member; means effecting a friction coupling between the members; means responsive to the extent of movement of said linearly movable member to render said friction coupling inefiective further to move said linearly movable member; and adjustable means for varying the extent of movement of said linearly movable member required to operate said responsive means.

30. In a musical instrument: a sound generator; a linearly movable member cooperable with the sound generator for adjusting the pitch of said generator; a rotary driving member; means for continuously rotating said driving member; means effecting a transmission between the members for linearly moving said linearly movable member; means defining an initial limited position of said linearly movable member; means adjusting the ratio of transmission at the said initial position; and means for reducing the ratio of transmission in accordance With the extent of movement of said linearly movable member from said initial limited position.

References Cited in the file of this patent UNITED STATES PATENTS 134,679 Knaifi Ian. 7, 1873 w 16 Chevers Feb. 3, Marsters Apr. 25, Smenner Aug. 4, Reifiel June 17, Mann et al. Oct. 13, Legler Jan. 5, Kingsley a Feb. 2, Lazare et al July 23, Guibeand June 28, Schulz May 12, Bringe June 20, Strane May 13, McBride Aug. 23, Bradley Oct. 4, McBride Feb. 28, Verderber Sept. 18, Billeci July 29,

FOREIGN PATENTS Germany Mar. 25, Germany Nov. 19, France Sept. 24, Italy Nov. 8,