US1993714A - Method of making horn bells - Google Patents

Description

March 5, 1935.

1.. B. GREENLEAF METHOD OF MAKING HORN BELLS Filed July 30, 1952 2 Sheets-Sheet 1 drier n0 March 5, 1935. L. B. GREENLEAF Filed July 30, 1932 2 Sheets-Sheet 2 illlllnl IIIIII/l! Patented Mar. 5, 1935 PATENT OFFICE METHOD OF MAKING HORN BELLS Leland B. Greenleaf, Elkhart, Ind., assignor to C. G. Conn, Ltd., Elkhart, Indiana, a corporation of Indiana Application July 30, 1932, Serial No. 626,958

2 Claims.

This invention relates to horn bells and the method of manufacture thereof.

The type of horn bell now in common use on musical instruments, or any other instrument, is made of metal of uniform thickness, and the bell rim is rolled or provided with a reinforcing bead. This type of bell, when applied to a musical instrument such as a comet, bugle, or the like, is subject to material vibration and consequent impairment of the tone quality.

The principal object of my invention is to provide an improved horn bell which will not vibrate, and which results in an improved tone quality.

Another object of the invention is to provide an improved vibrationless horn bell and the method of manufacture thereof.

A third object of the invention is to provide a horn bell for a musical instrument the wall whereof is graduated in thickness to eliminate vibration therein.

Still another object of the invention is to provide a horn bell for a musical instrument the rim whereof is beadless, the wall thereof being graduated in thickness to eliminate vibration therein.

Yet another object is to provide a horn bell for a musical instrument the rim whereof is beadless, the bell wall being graduated in thickness from end to end thereof and thicker at the bell rim than elsewhere.

Other and more specific objects of the invention are mentioned and described herein.

The invention is illustrated in the accompanying drawings, wherein Figure 1 illustrates my improved horn bell applied to a bugle;

Figure 2 is an enlarged fragmentary view showing the finished bell, in section, applied to the main branch of a musical instrument;

Figure 3 illustrates a plan view of the circular rudimentary sheet metal blank from which my improved bell is made;

Figure 4 illustrates the condition of the rudimentary bell blank, in section, after the first operation thereon;

Figure 5 illustrates the condition of the bell, in section, after the second operation thereon;

Figure 6 illustrates the condition of the unfinished bell after the third operation thereon; same being in section;

Figure 7 illustrates the condition of the unfinished bell, in section, after the fourth operation thereon;

Figure 8 illustrates a view, partly in section. of the tools used in effecting the graduated thickness of the bell wall; and

Figure 9 illustrates a modified form of the tools used in the final operation on the bell wall in eifecting graduated thickness thereof.

Similar numerals of reference indicate like parts throughout the several views on the drawings.

Referring now to the details of the drawings the numeral 1 indicates a bugle provided with a main branch section 2, the latter having my improved bell section 3 connected therewith, The end of the main branch section 2 may be slightly flared where the base of the bell section 3 is soldered thereto, at which point the curves of the two elements merge harmoniously.

The bell section 3 may comprise the unrolled or beadless rim 4, the base portion 5, and the intermediate wall portion 6 which may be graduated in thickness from the base 5, where it is the thinnest, to the rim 4 where it may be the thickest. As illustrated, this graduation in the thickness of the bell wall is uniform, or substantially so. That is to say, the graduation in the bell wall thickness is continuous from the base thereof to the rim thereof. But this continuity of graduation in the bell Wall thickness is not necessarily essential to the production of the best results from this improved horn bell. The important feature ofthe invention requires that the wall of the bell adjacent the rim 4, and for a substantial-distance toward the base 5, shall be made relatively heavier and graduated in thickness to overcome the tendency to vibration in the bell when the bell rim is unrolled or beadless. As heretofore stated the base 5 of the finished bell 3 may be soldered to the branch 2 at 8.

The bell 3 is formed from a single circular sheet metal disk '7 of uniform thickness, said disk being substantially thicker than the finished bell base 5 and Which may be equal to the thickness of the finished rim 4, although, in the operation of the tools hereinafter mentioned, the bell rim 4 may be slightly thinner than the blank 7 when the bell is finished.

The disk 7 is first subjected to four diiferent operations to produce the different shapes illustrated in Figures 4 to 7, inclusive, which represent the several steps necessary to produce a bell member having a wall of uniform thickness preparotry to subjecting it to the method which produces the finished bell having a wall of graduated thickness, and these four preliminary steps may be effected by the well known spinning .method, which is well known in the metal working art.

In Fig. 4 the blank '7' has been spun into a cup-like formation; in Fig. 5 it has been spun bell-shape with an end wall 9 therein; in Fig. 6 the end wall 9 has been partially removed; and in Fig. 7 the end wall 9 has been fully removed and the final general shape of the bell established with a wall of substantially uniform thickness. The bell is now ready for the final step or operation of the method, viz: the operation to graduate the thickness of the wall thereof, to accomplish which a mandril 10 and a special tool carrying rollers 12 and 13 is utilized. The special tool comprises the two rollers 12 and 13 which may be mounted upon the shafts 14 and 15, respectively, said shafts being operatively mounted in a frame or cage element 16 in angular relation to each other, said cage being provided with a carrier shaft 17 adapted to be mounted in any suitable machine for feeding -or actuating said cage and its rollers toward the mandril 10. The mandril 10 is provided with a shaft 11 arranged substantially axially of the cage shaft 17 and may be so mounted that rotation may be effected in any desirable manner of the mandril 10. The mandril 10 is shaped to conform to the interior of the bell 3, the latter being mounted thereon for operation thereon by the rollers 12 and 13, as hereinafter described.

The rollers 12 and 13, which may be substantially truncated pear-shape in formation, are so arranged that the mandril 10 may be thrust between them as the cage 16 is urged toward said mandril, and said rollers are so arranged and formed that the initial contact with the hell 3 is effected by said rollers adjacent the bell base and with the point 18 of the rollers, or adjacent said point. Continued pressure on the cage 16 causes a greater area of contact of the rollers 12 and 13 with'the exterior surface of the bell, due to the thinning of the wall thereof, and ultimately said rollers have a full contact with the exterior surface of the bell, the last or final point on the bell to be contacted or engaged by said rollers being the rim thereof. And as soon as the rollers 12 and 13 are in engagement with the bell rim 4 the final step of the method is completed and the bell is substantially finished and may then be made ready for soldering it to the branch 2 of the instrument. From the foregoing it will be obvious that the engagement of the rollers 12 and 13 with the bell 3 is a progressive engagement, beginning at the base of the bell and finishing at the bell rim, with a full engagement of the bell surface by said rollers at the completion of the final operation of said bell.

In Fig. 9 a modified form of the rollers 12 and 13 is illustrated, and a different arrangement thereof is provided. Therein, the roller shafts 14 and are arranged in parallel relation and the rollers 12 and 13 are formed in a plurality of disks 19 of varying sizes. In this construction of the rollers 12 and 13 the largest of the disks 19 engages, the bell base initially, and the smallest of said disks effects engagement with the bell rim to complete the bell, the result being substantially the same as that produced by the tool illustrated in Fig. 8.

I claim:

1. The method of making a horn bell which comprises the formation of a rudimentary bell section from a single sheet metal blank, said bell section having an end wall, then removing said bell section end wall, then rolling the bell section thus formed until the bell wall varies in thickness from the bell base to the bell rim.

2. The method of making a sheet metal horn bell which comprises the spinning of the rudimentary bell body with an integral end wall at one end thereof, then removing said bell end wall, and then rolling the bell section thus formed progressively from the bell base to the bell rim until the bell wall varies in thickness from the bell base to the bell rim with the minimum thickness at the bell base.

LELAND B. GREENLEAF.

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