US1539815A - Banjo - Google Patents

Description

May 2s, 1 925. 1,539,815

W. F. LUDWIG BANJO Filed March. 27, 1924 Patented May 26, 1925.

UNITED STATES 1,539,815 PATENT OFFICE.

WILLIAM F. LUDWIG, OF CHICAGO, ILLINOIS, ASSIGNOR TO LUDWIG & LUDWIG, INC., OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS. i

BANJO.

Application filed March 127, 1924. Serial No. 702,287.

To aZZ whom it may concern:

Be it ,known that'I, WILLIAM F. LUDWIG, a citizen of the United States of America, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Banjos, of whichthe following is aspeciflcation.

This invention relates to that type of banjos in which the skin head is stretched over two concentric rings in order to provide primary and secondary resonating chambers in the body of the banjo, and the present improvement has for its object:

To provide a structural formation and combination of parts whereby a free and unimpeded outflow of sound through and from the annular chamber formed by the pair of concentric rings of the banjo body is attained in a simple and effective manner,

and by means of which the component parts of the banjo body are interconnected in a ready and substantial manner, and a substantial bearing or abutment is provided for the tensioning screw bolts .of the head or skin of the instrument, all as will hereinafter more fully appear.

In the accompanying drawing:

The drawing is a view, one-half in side elevation and one-half in axial section of a banjo body embodying the preferred form of the present invention.

In the present improvement the inner ring 1 constitutes the main member of the banjo body, and comprises a lower and approximately cylindrical ring portion 2, the upper part of which is formed with an annular outstanding flange 3, adapted for supporting attachment to the outer ring 5 of the banjo body, as hereinafter described, and in addition provide abutments for the adjusting nuts of the hereinafter described series of tensioning bolts 6 of the-skin head of the instrument. g

The upper portion 1 of the aforesaid inner ring 1 of the banjo body comprises a ring shape part 6, smaller in diameter at top than the lower ring portion 2 and flared outwardly and downwardly to melt and merge into the top of said lower portion2. The formation is adapted to impart an approxi mately bell shape to the inner and main cavity of the banjo body and provide a very effective outward transmission of the sound produced by the main and central portion of the skin head 7 of the banjo.

' The outer body ring 5 above referred to, comprises upper and lower ring portions 8 and 9 of different diameters integrally connected together by a reversely curved central ring portion 10, as shown.

The diameter of the ring 5 is sufliciently greater than the diameter than that of the upper portion 1 of the inner rmg member 1 in order to provide an annular sound passage 11 between the parts, with said passage having a gradually increasing downward and outward flare or area and ending in a series of exit orifices or passages 12 formed in the lower part of the ring 5. The orifices 12 are preferably formed by a series of semicircular or like notches in the lower edge of lower portion 9 of the ring 5, with the top surface of the outstanding flange 3 aforesaid forming the bottom wall of said orifices. With the described construction the flange 3 provides the sole support upon which the outer ring 5 rests and is supported, with the concentricity of the two rings 1 and 5 maintained by an abutment shoulder 13 at the meeting point of the flange 3 and the lower portion of the inner ring 1.

In the present construction the top edgeof the outer ring 5 extends a distance above the corresponding top edge of the inner ring 1, in order to provide a clear and unobstructed sound passage above the inner ring 1 and between said inner ring 1 and the skin head 7 of the instrument. The skin head 7 is stretched over the outer ring 5, by the usual skin hoop 1 1 and a series of tensioning screw bolts 6, having at their upper ends hook formations for engagement over skin hoop 14, and at their lower ends screw threaded formations for the reception of the adjusting nuts 16 of any usual form.

With the described arrangement of the inner and outer rings 1 and 5, the annular chamber or passage 11 between said rings has unimpeded communication with the main inner chamber of the instrument, and due to the described outward expanded form of said chamber 11, a very free passage of the sound through the exit passages 12 in the side of the instrument.

c Having thus fully described my invention, what I claim and desire to secure by Letters Patent, is

1. In a banjo or the like, in combination, a banjo body formed by a pair of concentrically arranged inner and outer rings, the

inner ring having an out turned flange at its mid-height forming a supportfor the outer ring, a skin head supported by the outer ring and provided with a skin hoop. and tensioning screw bolts engaging said skin hoop and having adjusting nuts adapted to bear against the underside of the aforesaid flange, the outer ring extending a distance above the inner ring and having a series of orifices in its lower edge.

2. In a banjo or the like, in combination, a banjo body formed by a pair of concentrically arranged inner and outer rings, the inner ring having an upper portion of a smaller diameter than its lower portion and flared to meet and merge into the same, said inner ring having an out turned marginal flange at its mid-height to form a support for the outer ring, said outer ring having an upper portion of a smaller diameter than its lower portion and integrally connected thereto by a reversely curved ring portion, a skin head supported by the outer ring and provided with a skin hoop, and tensioning screw bolts engaging said skin hoop and having adjusting nuts adapted to bear against the underside of the aforesaid flange, the outer ring extending a distance above the inner ring and having a series of orifioes in its lower edge.

Signed at Chicago, Illinois, this 26th day of March, 1924.

\VILLIAM F. LUDWIH.

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