US2845521A - Method and means for soldering conductors - Google Patents

Description

July 29, 1958 R. w. TRICKLE, JR 2,845,521

METHOD AND MEANS FOR SOLDERING CONDUCTORS Filed April 22, 1955 INVENTOR RUSSELL W. TRICKLE, Jr.

ATTORNEYS United States Patent METHOD AND MEANS FOR SOLDERING CONDUCTORS Russell W. Trickle, Jr., Janesville, Wis., assignor to Dittmore-Freimuth Corp., Milwaukee, Wis., a corporation of Wisconsin This invention relates to the joining of electrical and electronic conductors.

The invention relates particularly to the soldering of conductor ends to obtain a butt type joint in which the wires do not overlap. This type of butt joint is desirable in various kinds of electronic work, such for example, as the joining of the center conductor in a coaxial cable splice since the center conductor must be joined with little or no change in electrical characteristics and mechanical strength.

When joining such conductors, particularly of the smaller diameters, difiiculty has been encountered in aligning the ends. for a butt type joint, since the conductors are usually composed of strands or solid or tubular conducting material or of copper covered steel wires commonly called copper-weld. It has been difficult not only to hold these small and highly flexible conductor ends in abutted relation but also to apply the solder in a manner to avoid the formation ofan enlarged solder joint or splice that has to be dressed down to the diameter of the conductor ends.

The principal object of the invention is to provide a new method and means by which either a straight splice or a T-splice may be quickly, easily and inexpensively made without. the necessity of special skill on. the part of the operator.

Another object of the invention is to provide a simple and inexpensive tubular connector of breakable material which will aid in aligning the conductors, prevent small flexible conductors from being bent out of alignment, prevent the intermingling of the strands of stranded conductors and thereby increasing the size of the joint, and prevent the solder from building up to a larger diameter than the rest of the conductor and hence eliminate the need for dressing the soldered joint or splice.

Another object is to provide a conductor holder or connector of the above indicated character made of a ceramic or equivalent brittle and frangible material so that after it has served' its purpose, it may be readily crushed and removed from the soldered joint.

Another object is to provide such a tubular or beadlike connector which will enable a third conductor to be united with the aligned conductor ends to provide a T- splice or joint such as quite commonly used in the community T. V. systems.

With the above and other objects and advantages in view, the invention resides in the novel combinations and arrangements of parts and the novel features of construction hereinafter described and claimed, and illustrated in the accompanying drawings which show the present preferred embodiment of the invention.

In the drawings:

Fig. l is a view of two opposed conductor ends with portions of their insulating covering being stripped back, the one at the left being inside elevation and the one at the right in longitudinal section;

Fig. 2 is an enlarged top view of a breakable bead or connector;

Patented July 29, 1958 Fig. 3 is a transverse section taken on line 3-3 in Fig. 2;

Fig. 4 is a longitudinal section through the connector tube or bead showing it applied to the ends of two conductors tobe joined and ready for the heating and soldering operations;

Fig. 5 is a view similar to Fig. 4 but showing the jaws of an electric soldering transformer applied to the two conductor ends, the connector tube being in elevation;

Fig. 6 is an elevation of the solderedcon'ductor as it appears when the connector tube has been broken off of the splice; and

Fig. 7 is a view similar to Fig. 4 but showing a third conductor arranged to form a T-splice or joint.

Referring more in detail to the drawings the numerals 10 and 11 denote two similar electrical conductor wires the ends of which are to be soldered in a butt type joint. The wires may be covered by any suitable insulation 12; and if so, the insulation is stripped back from the end portions of the conductors, as seen in Figs. 1, 4 and 5, to enable the method to be carried out. The conductor wires are usually of copper and may be solid or tubular or copper covered steel, and they may be composed of fine strands twisted or braided together. The invention is particularly useful in butt soldering conductors of smaller sizes such as /e" diameter or less since their bared ends are quite flexible and hence difficult to hold in. abutted relation.

In thepractice of the invention the baredends of the conductors are inserted in the opposite ends of a holding element 13 which is preferably of tubular shape and made of a readily breakable material so that it may be easily crushed and removed after it has served itspurpose; This disposable molding device or connector element. may be of elongated cylindrical shape and has a straight continuous bore 14 of a diameter corresponding to that of the conductors so that they will have an easy fit therein and may be pushed into the ends. Formed in the tubular connector, preferably midway of its ends, is a circular radially extending opening or hole 15 which preferably has the same diameter as the bore, as seen in Fig. 3. The conductor ends are pushed into the connector 13 so that their extremities will abut or substantially abut at a point opposite the hole 15 as shown in Fig. 4. The primary purpose of the hole opening 15 is to permit solder to be applied to the abutted conductor ends, and that is preferably done after the ends of the wires have been heated, as later described. The tubular connector is preferably made of ceramic material but it may be made of any moldable plastic such as glass or other refractory material which is brittle or frangible so that the device may be easily cracked off of the soldered joint with a pair of pliers or other tool by crushing it. The bead or connector 13 will be made in dififerent sizes according to the sizes of the conductors to be joined. If the device is to connect conductor Wires of small diameter such as A3" or less, it need not be longer than and the thickness of its wall may be about .062".

While for some purposes a soft solder may be used, it is preferable to use silver solder which has a melting point lower than that of the conductor wires and to heat the conductor ends before applying the solder. The heating is preferably done by passing an electric current through the conductors. That may be done by the use of an electric soldering transformer 16, a portion of which is shown in Fig. 5. Such a soldering transformer is disclosed in application Serial No. 485,404, filed February 1, 1955, in which I am one of the joint applicants, the application having matured in Patent No. 2,771,540 issued November 12, 1956. The transformer includes two pairs 17 and 18 of opposed terminal jaws adapted to be clamped on the conductor ends 10 and 11 at or 3. adjacent the ends of the connector. The jaws are tightened on the ends by screws 19, and when the current is applied to the transformer, heat developsinside the ceramic bead between the conductor ends. The silver solder is applied through the hole and allowed to flow for a'few seconds. The current is then turned off and the jaws 17 and 18 are disconnected from the wires. The ceramic bead or connector may then be cracked off with a pair of pliers by crushing it, leaving the completed joint with the solder 20 connecting the wires.

If it is desired to make a T-splice, the same procedure is carried out but while the solder is in a molten condition the bared end 21 of a third conductor is inserted in the hole 15, as seen in Fig. 7 so that the ends of the three conductors will be united by the solder. The current is then turned off and when the solder is hard the ceramic bead may be removed. A suitable soldering flux may, of course, be used in the soldering operation.

It will be seen that the use of the invention will enable an unskilled person to quickly and easily produce either a straight or a T-splice in which the soldered portion of the joint will have practically the same diameter as the conductor wires that are joined, and hence the joint will have substantially the same mechanical strength and electrical characteristics of the other portions of the conductors. The use of the bead aids in aligning the ends of the conductors, and with small flexible conductors supports them while they are hot so that they do not bend out of alignment. With stranded conductors it prevents the strands from intermingling and increasing the size of the joint. With larger relatively stiff conductors, the use of the device enables the joint to be formed so that it will have the same diameter as that of the rest of the conductor and hence no dressing of the joint will be necessary.

From the foregoing, taken in connection with the accompanying drawing, it will be seen that novel and advantageous provision has been made for carrying out the objects of the invention, and while preferences have been disclosed, attention is invited to the possibilty of making variations within the scope of the invention as claimed.

I claim:

'1. As an article of manufacture, a disposable molding device for use in makinga soldered joint between small size electric and electronic conductors which are highly .4 flexible and provide a molded splice having the same diameter as the joined conductors, said device comprising a one piece tubular element into the ends of which two bared conductors may be pushed, said element being made of brittle frangible material and having a continuous bore of a diameter corresponding to that of the conductors to hold the latter axially alined and against flexing, said bore being intersected by a radial opening in the element opposite which the conductor ends may be abutted, said opening being of sufficient size to permit solder to be introduced through it into said bore to unite the abutted conductor ends when they are electrically heated, the brittleness of said element permitting it to be readily crushed and broken away after the solder hardens to leave a splice having the same diameter as that of the joined conductors.

2. The hereindescribed disposable mold for use in making a soldered joint between highly flexible electronic conductors having a diameter of 3 8" or less and to provide a molded splice having the same diameter as the joined conductors, comprising a straight one-piece cylindrical body of tubular form with a continuous cylindrical bore and with a circular radially extending opening in communication with the bore adjacent the center of the body, said bore having the same diameter as the conductors, whereby when two conductors are pushed into the ends of the bore and their extremities abutted at said opening the conductors will be held in axial alinemerit and prevented from flexing, said radial opening also having the same diameter as the conductors to permit solder to be introduced into the opening at the abutted conductor ends to unite them when they are electrically heated, and to permit the bared end of a third conductor to be pushed into the molten solder in the opening to form a T-splice in which all solder parts have the same diameter as the three conductors.

References Cited in the file of this patent UNITED STATES PATENTS 355,611 Howson Jan. 4, 1887 653,033 McIntire July 3, 1900 2,618,234 Armacost Nov. 18, 1952 2,677,746 Duch et a1. May 4, 1954 FOREIGN PATENTS 151,921 Austria Dec. 10, 1937

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