Patent Abstract:
A mute mechanism for an electric string bass or other stringed musical instrument is permanently mounted on the body of the instrument and includes a rubber faced mute movable into and out of engagement with the instrument&#39;s strings by a manually shiftable slide readily accessible by a performer playing the instrument.

Full Description:
BACKGROUND OF THE INVENTION 
     This invention relates to stringed musical instruments, and deals more particularly with a mute mechanism intended to be permanently attached to such an instrument and readily manually shiftable between active and inactive conditions. 
     The mechanism of this invention includes a mute having a face, preferably provided by a pad or body of resilient material, pressed against the strings of the instrument when the mute is in its active condition. Such a mute is particularly well adapted for use with electric string basses and it is therefore herein shown and described in such environment. There is, however, no intention to limit the mechanism of this invention to such use, and instead it may be applied to a wide variety of other types of stringed instruments if desired. 
     SUMMARY OF THE INVENTION 
     The invention resides in a mute mechanism having a mute with a face adapted to engage the strings of the instrument when in an active position. The mute is supported for rectilinear movement along an axis perpendicular to its string engagement face to move it into and out of contact with the strings. A manually operable actuating member, shiftable between two positions, and a mechanical linkage or other motion transmitting means between the actuating member and the mute move the mute between its string contacting active position and its string non-contacting inactive position in response to movement of said actuating member between its two positions. 
     The invention further resides in the mute being carried by a base attached, or adapted for attachment to, an instrument body, in the actuating member being a slide slidably carried by the base, in a pair of links each pivotally connected at one end to the slide and pivotally connected at its other end to the mute for moving the mute relative to the base in response to movement of the slide relative to the base, and in the base having a recess for receiving the mute which recess has a cross-sectional shape complementary to that of the mute so that the walls of the recess restrain the mute to rectilinear sliding movement relative to the base. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a fragmentary plan view of an electric string bass equipped with a mute mechanism embodying this invention. 
     FIG. 2 is an end elevational view of the mute mechanism of FIG. 1 and taken on the line 2--2 of that figure, this figure showing the mute in its lowered or inactive position at which it is free of the strings. 
     FIG. 3 is a view similar to FIG. 2 but shows the mute in its raised or active position at which it contacts the strings. 
     FIG. 4 is a fragmentary sectional view taken on the line 4--4 of FIG. 3. 
     FIG. 5 is a sectional view taken on the line 5--5 of FIG. 4. 
     FIG. 6 is a view similar to FIG. 5 but shows the mute in its lowered or inactive position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawing, a mute mechanism 10 embodying the present invention is shown in FIG. 1 in combination with an electric string bass 12. This instrument has a solid wooden body 14 and a neck 16, with attached fret board 18, extending from one end thereof and terminating in a peg head 20. Each of four strings 24, 24 is anchored at one end to a tailpiece means indicated generally at 26 and at its other end to an associated one of four machine heads 28, 28 carried by the peg head 20. In passing from the tailpiece to the machine heads, the strings pass over and are stretched between a bridge near the tailpiece and a nut 30 adjacent the peg head 20. The bridge consists of four separate saddle members 32, 32 adjustably fixed to a base 34, preferably of die cast metal, in turn fixed to the instrument body 14. Each saddle member 32 supports an individual string 24. 
     In the illustrated case, the three components consisting of the tailpiece 26, the bridge and the mute mechanism 10 are combined with one another to form a single unit, and the base 34 is a part common to all three of these components. This, however, is not necessary to the invention and, if desired, the mute mechanism may be made separate from either or both of the tailpiece and bridge. In particular, in the description which follows, the base 34 provides the base of the mute mechanism but the mute mechanism may alternatively have a base separate from that of the bridge and tailpiece in other situations. 
     Turning now to FIGS. 2 to 6, the mute mechanism 10 includes a mute 36 comprised of a carrier 38 carrying a pad 40 of resilient material such as sponge rubber. A string engagement face 42 of the pad 40 faces and extends transversely across the four strings 24, 24. The mute 36 is received in a recess 44 of the base 34. This recess has a mouth facing the strings 24, 24 and the cross-sectional shapes of the recess and of the mute, in a plane generally parallel to the common surface defined by the strings, are complementary so that the mute is restrained by the walls of the recess to rectilinear movement toward and away from the strings, that is, to movement along an axis perpendicular to the string engagement face 42. 
     The mute 36 is movable relative to the base 34 between an inactive position, such as shown in FIG. 2, at which it is out of contact with the strings and an active position, such as shown in FIG. 3, at which it is held in engagement with the strings with the pad 40 being compressed between the strings and the carrier 38. 
     An actuating means for manually moving the mute between its active and inactive positions includes a manually shiftable actuating member in the form of a slide 46 having a handle portion 47 located on one side of the set of strings 24,24. A slide cavity 48 formed in the base 34, and communicating with the mute receiving recess 44, slidably receives the slide. The walls of the slide cavity 48 confine the slide 46 to rectilinear sliding movement relative to the base along the axis 50 shown in FIG. 6 between the two positions shown in FIGS. 5 and 6. Part of the slide cavity 48 is defined by a removable plate 52 held to the base 34, as by screws, as shown in FIG. 4. The base 34 and slide 46 have coengageable stop surfaces 54 and 56, FIG. 6, which are engageable as shown in FIG. 5 to limit leftward (as seen in the drawing) movement of the slide relative to the base. 
     The mute 36 is moved between its active and inactive positions in response to movement of the slide 46 between its two end positions by two links 58, 58 each pivotally connected to the slide 46 at one of its ends by a pivot pin 60 and pivotally connected at the other of its ends to the carrier part of the mute by a pivot pin 62. 
     It should further be noted from FIGS. 5 and 6 that the relative arrangement of the slide 46, mute 36, and links 58, 58 is such that as the slide is moved to the left to move the mute from its inactive (FIG. 6) position to its active (FIG. 5) position, the pivot pins 62, 62 move over center relative to the pivot pins 60, 60 just shortly prior to the FIG. 5 position being reached. Therefore, the pressure of the strings bearing down on the mute pad 40 will tend to hold the mute and slide in their FIG. 5 positions, that is with the stop surfaces 54 and 56 in engagement with one another, until the slide is manually shifted to the right to lower the mute.

Technology Classification (CPC): 6