US1354268A - Banjo - Google Patents

Description

Patented Sept. 28, 1920.

v1/mme M70/43% G. SANDSTROM.

BANJO.

APPLlcATIoN FILED Dsc. n.19

vGCEORGrE SANDSTROM, 0F OAKLAND, CALIFORNIA.

BANJO. Y

Specification of Letters Patent.

Patented Sept. 28, 1920.

Application led December 12, 1917. SeralNo. 206,746.

T0 all whom t may concern.'

Be it known that I, GEORGE SANDsrRoM, a citizen of the United States, residing at the city of Oakland, in the county of Alameda and State of California,'have invented a new and useful Banjo, of which the following is a specication.

My invention relates to improvements in tightening devices for banjo heads and other musical instrumentsl having peripheral resonating drums or rims tob'e used in connection with a iexible vibrating head, and has for its object to provide a simple and easy method of tightening or relaxing the flexible head.

Another object of my invention is the construction of a banjo head with a minimum amount of supporting material of a non* vibrating character, in contact with the resonating portions thereof.

A still further obj ect of my invention is to provide a tightening device for flexible heads in musical instruments which may be quickly and accurately adjusted to the desired tension by the operation of a small number of simple parts.

lVith the above and other objects in view, I have invented the device illustrated in the accompanying drawings, in which Figure 1 is a rear elevation, showing a ring 4 in position with rim 1.

Fig. 2 is a section on line 2 2.

Fig. 3 is a sectional view of a portion of a side elevation of my device, enlarged to show the method of attaching brackets 11 to rim 1 and the working combination of set` screw 6 and fiat rings 4 and 5.

Fig. 4 is a view partly in section, showing the wire fastener and the action of the screws which tighten the resonating head.

Similar numerals refer to similar parts throughout the several views in the drawings, in which 1 indicates my open resonating rim which has an annular shoulder 2 in its inside circumference designed to protect the edges of the flexible head 7; 8 is the neck and is shown only for the purpose of making clear the manner in which rim 1 is attached thereto; 4 is a flat ring made of any suitable material preferably of metal, having an annular groove 10 in its outside circumference to receivea cord 8, and having a multiplicity of holes interiorly threaded to engage with threaded set screws 6; 5 is a flat ring similar to 4, but having no holes or annular groove and when in position sets parallel to ring 4'; 6 are set screws threaded to engage with the threads in the holes of ring 4, with their points resting against the inside surface of ring 5 so that their rotation from leftto right will press the two rings apart; is a flexible head of suitable shape and material-which is litted over the outer circumference of ring' 5" and has its edges drawn down and fitted under cord 8 in groove 10; 9 are the two ends of cord bound together and holding flexible head 7 in place; l1 are brackets which are rigidly attached at their rear ends to the inside surface of ring 5 and have their front ends rigidly attached to the inside surface of rim 1 by screws 12; 13 is a rivet passing through the rear end of brackets 11 and ring 5 and lirmly attaching the two together.

To operate my device, a head of flexible material of a kind usually employed in the making of banjo heads, is fitted over the outside of ring 5 to which has been rigidly affixed the brackets 11, and its outer edges are drawn over and brought beneath cord S in groove 10 in the outer circumference of ring 4; rings 4 and 5 are thus brought into a parallel position with their flat surfaces facing each other. The set screws 6 are then screwed into the holes made to receive them in ring 4 until the points of the said set screws are brought into Contact with the inside surface of ring 5; the parts thus held together by the flexible head '7 are pressed into position in rim 1 and the brackets 11 are attached to the inside circumference of the said rim 1, by screws l2. To stretch the flexible head to the desired tension, set screws 6 are rotated to the right and the ring 4, having the outer edges of the said head firmly held to it by cord 8, is drawn away from the said ring 5 by the pressure of the points of the said set screws 6 against the inside surface of the said ring 5.

Having now described my invention, that which l claim to be new and desire to procure by Letters Patent is:

1. A tightening device for banjo heads and other musical instruments having an open rim, a flexible head interposed within the opening of the said rim, an annular lip integral with the said rim and projecting inwardly from the top thereof, a fiat top ring fixedly attached by screw 13 and by bracket 11, to the inside circumference of the said rim over which the said head is drawn, a bottom flat ring interposed parallel to the said top ring and having in its outside circumference an annular groove, a cord embedded therein, the outer edge of the said flexible head passing within the said groove and being firmly held by the said cord; a

ring provided with holes and interiorly threaded, a multiplicity of set screws in the rim, a flat top ring iixedly attached as shown, to the inside circumference of the said rim over which the said head is drawn; a bottom flat ring interposed parallel tothe said top ring, and having in its outer circumference an annular groove, Va cord or cable Vadapted to engage with the said groove, the outer edge of the said flexible p head being passed between the said groove and the said cable; aY ring provided with holes and interiorly threaded, a multiplicity of set screws in the said holes and engaging the threads thereof and the points of the said set screws resting on the lower surface of the said topl ring, by means of which the said flexible head is pressed firmly stbantially as described.

GEORGE 'SANDSTROML against the annular lip in thesaid rim, sub-

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