US 2241283 A
Description (OCR text may contain errors)
1941- l. E. WACKERLE 2,241,283
METHOD FOR FORMING MUSICAL STRINGS Filed April 20, 1940 INVEN TOR.
j I @1016 Edward Wacky-Z6,
Aiioruey mama M aim UNITED STATES PATENT OFFICE rm'rnon roa roaumo uusrcsr. srnmos hewisldward Wackerle, (sumo, m. Application sis-I1 :0. 1040, Serial No. 330,804
a Claims. (01. 57-160) forthe creation of a musical string having a heat setting or hardening material forming a coating for one or more metallic elements thereof,
A further object of the present invention is to provide a method for preparing musical strings wherein the heat setting material forming a part thereof can be hardened and aged during the formation of the complete string and thereby connecting the various elements of which the string consists in a permanent, aged and interlocked state.
Another and equally important object of the present invention is to provide an apparatus for forming or repairing musical strings wherein the thermo-setting or theme-softening materials used in the construction of the string may be heat treated during the formation or repairing of the string.
Other important objects of the present inventionwillbeinpartpointedout andinpartobvious from the following detailed description of the accompanying drawing.
In the drawing:
Fig. l is a side plan view of one form of apparatus for carrying out the present invention.
Fig. 2 Is a side plan view of a modified form of apparatus for forming musical strings.
Fig. 3 is a plan view of a third modification of apparatus for forming musical strings.
1'18. 4 is an enlarged vertical cross sectional detail view of a portion of the apparatus shown in Figs. 2 and 3, and
Fig. I is an enlarged side detail view of a musical string in the process of being formed.
Referring now more particularly to the accompanying drawing wherein like and corresponding parts throughout the several views are designatedby similar reference characters, numeral I indicates a string formed from electric resistance metallic material which is used as the base core for the forming of musical strings, as more fully set out in the aforementioned copending application, and upon which is applied a coating 2 which may consist of any thermoplastic or thermo-setting plastic, for instance, synthetic resins or other materials which can be cured, aged or hardened by applying heat thereto and which are preferably, although not necessarily, electrical insulators. Numeral I refers to a metallicband which iswounduponthe insulating ccatlnglandconnected thereto by cement or by contact with the coating. This particular string construction is. however, for example only.
A pair of hooks I, each formed upon the end of a shaft I which is rotatably mounted through and supported by a bearing I, has looped portions of wire I connected thereto. The outer end of either or both of the shafts I have a member for rotating the shaft connected thereto, such as, for example, a pulley I connected to a motor or other means by an endless belt.
Eachof the bearingsI arepodtioneduponan electrical insulating plate I and connected by meansofwiresland Iltoanelectri'caltransformer II,whichin turnisconnectedtoageneral electrical circuit.
In the formation of musical strings, the wire I is rotated by its connection to hooks I, whichare in turneach rotated by their shafts I due to the movement of pulleys I, or in the apparatus, such as shown in Fig. 1, by means of a pulley I operating upon one-shaft I and the rotation of the wire I and its connection to the other shaft I by the hook 4 thereof. A plastic, plastic ilbered by the addition of silk or cotton or both thereto, or other material can at that time be applied to the rotating wire I, whereupon, a smooth and rounded coating therefor can be formed. While the coating is being applied, current is supplied to the bearings I by their wires I and II from the adjustable transformer II in the amount found to be most desirable for the particular materials used. The current from one hearing I through the shaft I supported thereby to the wire I and from there to the other shaft I to the bearing in contact therewith, thus completing the circuit, but wire I, due to its low resistance to the passage ofcurrent,willbeheatedand,inthecaseofa thermo-setting material, will harden the coating 2 by driving the volatile materials in the coating 2 outwardly from the periphery thereof. During the thermo-setting of the coating 2, the band I can be readily applied to the rotating coating 2 and will adhere thereto before the coating 2 is fully hardened, In this manner, coating 2 will be firmly connected to both wire I and band 2 and, at the same time, will be completely aged for preventing the formation of cracks therein as well as permitting the elements I, 2 and I from becoming disassociated later on due to the agin that is, further setting and hardening of the coating 2. Additional coatings can be applied to the metallic elements of the musical string and several layers of metallic elements can be applied, one upon the other, before the coating with the insulating material or between successive coatings, but it is to be noted that an essential and indivisible part of the musical string is used for the heating of the insulating coating.
The additional metallic coatings can be connected to the electric current by contact with wire I at two points thereof and, in this manner, heat can be applied to successive coatings or to both sides of a coating, such as by connecting the ends of band 3 to the loops of 'wire I, thus heating coating 3 from both sides thereof.
Musical strings having a thermoplastic coating can be repaired with the present apparatus by applying heat to said plastic by the metallic element and thereby permitting the tightening or correction of the position of the several elements relative one .to the other.
In Fig. 2 of the drawing is shown a modified form of apparatus which has the current passing from the transformer II by wire 9 to a bearing 6 in a similar manner to that shown and described for Fig. 1, but the opposite end of the wire I is connected to wire Ill by means of a brush l supported from bearing 6 by an arm it, which brush l5 contacts a cylinder l3 which has the hook I! connected thereto. As best shown in Fig. 4 of the drawing, an insulating sleeve l8 encases shaft H which is, in turn, rotatably supported through bearings 6, and sleeve l8 has the bore of cylinder l3 encasing the same. Cylinder l3, which is formed from an electrical conducting material, is thereby insulated from shaft ll by sleeve l8 and receives current from bush l5, which it passes to hook i2 and from there to wire I for completing the circuit when current is passed by the transformer II in amounts as desired. An electrical insulating sheet l1 supports both of bearings 6 for insulating the same against possible contact with a ground.
In Fig. 3 of the drawing, the wire i receives its current from hooks l2 which are connected to cylinders l3. Cylinders I 3 receive their current by brushes l5, which brushes are each connected by one of the wires 9 and HI to the transformer II. and the cylinders l3 are rotatably carried with shafts l4 and sleeves l8, as shown in Fig. 4. In both of the modifications of Figs. 2 and 3, the shafts ll can be rotated by means of a pulley or other rotating instrumentalities and the brushes l5 are maintained in a fixed position by arms l6 but contact the rotating cylinder l3. However, the arrangement of Fig. 3 can be mounted upon a metal support or the like, without the bearings 6 being grounded and this particular modification has that advantage over the other devices disclosed herein.
Musical strings of varying constructions can be rapidly and completely formed by the present apparatus, which strings will maintain their delicate balance, weight, flexibility and correct size throughout their life, thereby assuring that the string will at all times be in the best playing condition possible. Further, the string can be 7 that disclosed in Fig. 5 can be readily formed upon the present apparatus and by following the general idea as set forth herein.
The apparatus can be readily modified but such modifications thereof as come within the scope of the appended claims are deemed to be a part of the present invention.
1. A method of producing a musical string consisting of heating a metallic wire by passing electrical current therethrough and applying a coating of a thermo-setting material to said heated wire.
2. A method of producing a musical string consisting of heating a metallic wire, covering said heated wire with a thermo-setting material and applying a. metallic skin to said coating before the same is completely hardened.
3. A method of producing a musical string having metallic and thermo-setting elements consisting of passing an electric current through said metallic elements for heating the same and conducting the heat from said metallic elements to said thermo-setting elements.
4. A method of producing a musical string consisting of rotating an extended metallic wire, passing an electric current through said string for heating the same and encasing said heated string with a heat-setting material while said string is rotating.
5. A method of producing a musical string consisting of rotating a metallic wire, heating said rotating wire and encasing said heated rotating wire in a series of coatings of .thermo-setting material and metallic material.
6. A method of repairing a musical string having a metallic elementand a thermoplastic coating therefor consisting in maintaining said string in an extended position, passing an electrical current through said metallic element for heating said element and said coating, and adjusting the metallic element relative to said coating while heated.
7. A method of producing a composite musical string which consists in retaining a metallic core in an extended position, jointly heating and rotating said core while in its extended position, winding a metallic wrapping upon said core, applying a heat-curing phenolic plastic to said core and between the rovings of said metallic wrapping and winding a second metallic wrapping upon said first mentioned metallic wrapping and said phenolic plastic.
8. A method of producing a composite musical string which consists in retaining a metallic core in an extended position, rotating said core while in its extended position, electrically heating said core while rotating the same, applying a heatcuring phenolic plastic to said core, winding a metallic wrapping upon said phenolic plastic for electrically insulating said metallic wrapping from said metallic core and causing the phenolic plastic to exude through the rovings of said metallic wrapping.
LEWIS EDWARD WACKERLE.