259,566. Aubry, E., and Boreau, G. Oct. 7, 1925, [Convention date]. Addition to 200,505. Stringed instruments.-The construction described in the parent Specification is modified in respect of (a) the bow mounting, and (b) the mounting of the instrument. (a) The pressure of the bow on the string is maintained constant during the stroke by increasing the pressure applied to the bow-holder during the passage of the bow from heel to point, thus counteracting the increased resiliency. The bow a is held between upper and lower rubber blocks b2, b3 in a holder b pivoted at b1 on a carriage c moved along rails e, e1 by wires c6, c7 as in the parent Specification. Hinged to the carriage c at f2 is a smaller carriage f, running on a rail d1 passing through it, and connected by links g, g5, g7 to the holder b at g8. The link g5 extends beyond the fulcrum g6 and carries rollers h2 running on a rail a pivoted at d2. Collapse of bellows d5 under the control of the perforated record-sheet raises the end d3 of the rail d, and as the carriage c moves to the left bringing the bow from heel to point over the string i, the rollers h2, fulcrum g6 and pivot g8 are raised, increasing the bow-pressure. Further control of the bow-pressure may be obtained by a similar collapse of bellows d6, tilting the rail d1 and lifting the link g. The bow a may be adjusted in the holder b about the stick as axis. (b) The instrument is rocked under the bow to bring the required string into playing position, with an added straight-line transverse movement, so that the arc in which the strings lie has a rolling motion under the bow. The cradle m is pivoted at m1 on the carriage k, and is connected by two pairs of links n1, n2 to pulleys n loosely mounted on the carriage and connected by links n4 to fixed points n5, so that on drawing the carriage transversely between guides as l2, by the operation of bell-cranks p1 by means as described in the parent Specification, the cradle is simultaneously tilted, producing a rolling motion under the bow.
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