US 3668321 A
An easily attachable and detachable coupling for electrical systems, such as earphones to audio amplifiers, comprising a coil on a magnetically soft ferromagnetic body and a second coil mounted on a permanent magnet. The first coil can be connected to an audio signal and the second coil connected to a pair of earphones.
Description (OCR text may contain errors)
United States Patent UNITED STATES PATENTS 2,379,664 7/1945 Stanko l79/l PC 12/1968 Holmes ..336/DlG. 2
Lang 1 June 6, 1972  MAGNETIC COUPLER FOREIGN PATENTS OR APPLICATIONS Inventor: Henry g, 73 Winter Street. 420,266 4 1947 Italy ..339 12 Waltham, Mass. 02154  Filed: Aug. 11, 1970 Primary Examiner-Kathleen H. Claffy Assistant E.raminer Horst F. Brauner N [211 App] 0 62,858 Attorney.loseph Zallen  US. Cl ..179/l PC, 336/DlG. 2  ABSTRACT  Int. Cl. ..H01f 27/26 v  Field of Search ..l79/l PC, 1 C, 82; 200/5109; An easily attachable and detachable coupling for electrical 339/12; 336/1 10, DIG. 2 systems, such as earphones to audio amplifiers. comprising a coil on a magnetically soft ferromagnetic body and a second  References Cited coil mounted on a permanent magnet. The first coil can be connected to an audio signal and the second coil connected to a pair of earphones.
6 Claims, 4 Drawing figures PATENTEDJUH 6 I972 SHEET 10F 2 AMP.
BACKGROUND OF INVENTION This invention relates to a coupling of electrical systems. In
particular it relates to an easily attachable and detachable coupling.
The common method of coupling electrical systems so that they may be easily attachable and detachable is by the use of plugs and jacks. However, plugs and jacks wear or distort from constant use and further require correct orientation for connection.
One object of this invention is to avoid the necessity of plugs and jacks which connect two pieces of electrical apparatus.
A further object of this invention is to provide easily attachable and detachable coupling means which do not require the fixed orientation of plugs and jacks.
Another object of this invention is to provide sucha coupling means which can be used to convert earphones to the output of an audio amplifier such as is used in radios, phonographs, and common receivers.
Other objects and advantages of this invention will be apparent from the description and claims which follow taken together with the appended drawings.
SUMMARY OF INVENTION The invention comprises broadly an easily attachable and detachable coupling for electrical systems in the form of two coils. The first coil is mounted adjacent a magnetically soft ferromagnetic body and is adapted to be connected across the output of an alternating current source. The second coil is mounted adjacent a permanently magnetized body and adapted to be connected across the input of a transducer. When the second coil is positioned adjacent to the first coil there is magnetic attachment and also inductive electrical coupling.
The alternating current source can be a power source or a source of signal of audio frequency. In the former case, the transducer, as for example an electric razor, receives its power from the first coil inductively and is very easily attached and detached.
Where the transducer is a loud speaker or a pair of earphones, the audio output which is inductively transmitted from the first to the second coil, is transformed into sound.
The first coil is preferably wound around the metal core which can be solid or laminated magnetically soft ferromagnetic material. The second coil is preferably around a permanently magnetized body made for example from permanently magnetized alloys such as aluminum, nickel,colbalt (Alnico or magnetic ceramic material.
The degree of efficiency of energy transferred is dependent on the number of turns of wire in the coils. Where the first coil is relatively elongated, a plurality of second coils may be attached to the same first coil. In this case a multiple number of transducers can be separately coupled to the same source of alternating current in a very rapid manner.
The second coil can be made of a small permanent magnet surrounded by the coil, both being molded in plastic or similar insulating material with a plastic cover wire leading to the transducer, as for example, a pair of earphones. This takes the place of the conventional earphone wire and plug combination.
One of the advantages of this invention is that a great number of transducers, as for example, sets of earphones, may be connected to a single metal strip. The metal strip can be part of the design of the source of alternating current, e.g., the amplifier, thus, increasing both its strength and appearance.
In addition, contrary to plugs and jacks, an inadvertent movement of the second coil would not cause any damage but merely pull it off the metal strip.
In addition, I have found it is feasible to have separate metal strips each connected to a different alternating current source mounted in close proximity. With such an arrangement, a plurality of second coils could be used to select difierent altemating current sources without interference. Where these sources BRIEF DESCRIPTION OF DRAWINGS earphones coupled to the amplifier.
SPECIFIC EXAMPLES OF INVENTION Referring now to the drawings, audio amplifier, which acts as an alternating current source, 1 1 has a wire 14-15-16 connected to its output terminals 12 and 13. Wire portion 15 is in a form of a coil wound on an elongated magnetically soft, ferromagnetic core 17. A pair of earphones 18 has its terminals connected to wire 19-20-190. Portion 20 of said wire is wound in the form of a coil on a permanently magnetized core 21. When the permanently magnetized core 21 with its coil 20 is brought adjacent to elongated core 17, core 21 is held in position on core 17 by magnetic attraction. At the same time, coil 20 is inductively coupled with'coil 15. In this manner the earphones 18 are coupled to the amplifier 11 by simply placing the core 21 with its coil 20 in a selected position on core 17.
The embodiment'illustrated'in FIGS. 2 and 3 differs slightly in that the corresponding coils have their axes parallel rather than perpendicular as in FIG. 1. Connected to the terminals 212 and 213 of amplifier 21 is a wire 214-216. Portion 215 is in a form of a coil whose ends are covered by magnetically soft ferromagnetic plates 222-223. The terminals of the pair of earphones 218 are connected to wire 219-220-290. Portion 220 of the wire is'in the form of a coil wound on a permanently magnetized core 221 covered by insulation so that the combination of coil 220 and core 221 provides a cylindrical disc 206 having a flat bottom face. Disc 206 can be positioned where desired on plate 222. When so positioned, it will be held in place by magnetic forces and will also have its coil portion 220 inductively coupled to coil 215.
The embodiment illustrated in FIG. 4 is essentially a multiple of that illustrated in FIG. 2. Thus, the exterior plate 222 of the coil plate assembly 215-222-223 is mounted flush in the wall of the housing for amplifier 224. Earphones 218-318-4 18 are shown magnetically and inductively coupled to the amplifier 224 by the simple placing of their corresponding coilcores 206-306406 on the plate 222. The earphone assembly 318 and 418 are of similar construction to earphone assembly 218. Thus, comprising respectfully a wire 319-390 connected to the earphone terminals and including a coil wound on the permanent magnetic core of 306 and a wire 419-490 connected to the earphones and including a coil portion wound on the permanently magnetized core of 406.
1. An easily attachable and detachable coupling for electrical systems comprising:
a. a coil (15) mounted adjacent a magnetically soft ferromagnetic body (17) and adapted to be connected across the output of an alternating current source l1); and
b. a second coil (20) mounted adjacent a permanently magnetized body (21) and adapted to be connected across the input ofa transducer (18);
positioning of the second coil (20) adjacent the first coil (15) providing inductive electrical coupling as well as magnetic attachment.
2. The coupling of claim 1 wherein the alternating current source is a source of signal of audio frequency and the transducer transforms the audio signal into sound.
3. The coupling of claim 1 wherein the magnetically soft ferromagnetic body is a core on which the first coil is wound.
4. The coupling of claim 1 wherein the magnetically soft ferromagnetic body comprises a plate covering the end of the