US3183473A - Coupling devices - Google Patents

Description

May 11, 1965 E. cRosBY, JR

COUPLING DEVICES Filed Aug. 28, 1962 P19/0R A197' FERR/TE INVENTOR 3,183,473 CUPLING DEVICES Edward L. Crosby, Jr., Sarasota, Fla., assigner to Electro- Mechanical Research, Inc., Sarasota, Fla., a corporation of Connecticut Filed Aug. 28, 1952, Ser, No. 219,@8 3 Claims. (Cl. 339-143) This invention relates to coupling devices and more particularly to devices adapted to carry one or more detachable contacts for making the junctions between current-carrying conductors, the devices accomplishing at least a double function: that of establishing detachable connections and that of blocking the passage of noise and transient signals.

The problem of transient interference in audio and video circuits is familiar to most radio and television users. Thus when an electric razor, a food mixer, a motor, etc., are operated in close proximity to communication apparatus, the quality of reception is deleteriously affected. This problem becomes acute in modern aircraft and missiles where hundreds of sensitive navigation instruments are housed in too close proximity to large and noisy powerconsuming devices such as servos, ignition systems, electrohydraulic actuators, gas discharge devices, etc.

Generally, this problem was solved in one of two ways: either a radio-frequency choke was connected in series, or a filter capacitor was connected in parallel, with each current-carrying conductor. However, the required number of chokes or filters greatly increases the cost, volume, and weight of the communication apparatus.

Accordingly, inasmuch as most communication apparatus are connected to power supplies or other equipments and networks through connectors, it is a broad object of the present invention to provide new and improved coupling devices or connectors adapted to act both as coupling devices and as noise-and-transient-signal Suppressors.

This and other apparent objects of the invention are accomplished by making the coupling devices insulating members `(such as matrices, sockets, cores, etc.), which carry the contacts, of magnetic ferrite material.

The invention will be better understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIGURE 1 shows in cross-section a typical prior-art connector coupling an energizing source to a utilization device through a noise eliminating network;

FIGURE 2 shows a simple connector of the invention;

FIGURE 3 shows a socket of a transistor constructed in accordance with the teachings of the invention;

FIGURE 4 shows a circular type connector constructed in accordance with the invention; and

FIGURE 5 shows a printed circuit type connector constructed in accordance with the teachings of the invention.

Referring to FIGURE l there is shown a cross-section of a typical prior-art connector generally designated as lil, for detachably coupling wires 11 and 12. Connector may include a metallic shell 13, an insulating member or core 14 providing a rigid support for a female pin or contact 15 connected at 17 to wire 11, and an insulating core 18 providing a rigid support for a male pin or contact 16 connected at 19 to wire 12. The purpose of contacts 15 and 16 is to allow a negligible-resistance, detachable connection between wires 1.1 and 12. Cores 14, 18 merely act as insulating supports for pins 15, 16 respectively. If a metal shell 13 is employed as a return path for the current i flowing in wires 11 and 12, then cores 14, 1S also support the two half sections of the shell 13.

A typical function of connector 1i) is to detachably connect the input line of a utilization device 26 as a radio, to the output line 27 of a power supply .28. If no noise-and-transient-signal suppression is desired then line United States Patent O y 3,183,473 Patented May 11, 1,965

Fice

l12 may be directly connected to line 2.5. On the other hand, if such suppression is desired then either a radiofrequency choke Sil is connected in series with lines 12 and 25, or lines 12 and 25 are directly connected through a bus wire 32, and a large valued filter, as a capacitor 34, is connected between wire 32 and ground. The radio-frequency choke Sil acts as a high impedance and the filter capacitor 34 acts as a low impedance for the relatively high frequency noise-and-transient signals, as is well known.

It will be appreciated that often a prior-art connector such as shown in FIGURE 1 carries tens and even hundreds of contacts and, consequently, the required number of chokes or capacitors becomes prohibitively great for most compact communication installations.

IIn accordance with one characteristic of this invention the need for either radio-frequency chokes or filter capacitors is eliminated. This is accomplished by making at least one of the connectors insulating members of magnetic ferrite. As is well known, ferrites are produced by pressing and firing methods similar to those employed in the manufacturing of porcelain. Ferrites are relatively inexpensive and well suited for mass production. They are surprisingly suitable for making the connectors insulators because they have: (l) suflicient physical strength and hardness required for supporting the connectors contacts; (.2) high bulk resistivity required for proper intercircuit isolation; (3) high iinpermeability to humidity and sufricient chemical inertness both necessary for satisfactory operation under severe environmental conditions; and (4) a magnetic permeability required for making the connector function like a frequency selective resistor, i.e., act asa bus wire at relatively low frequencies, say below 1 to 10 megacycles, and exhibit the desired AC. resistance and impedance required for noise-and-transient-signal suppression, at higher frequencies from 10 to above 500 megacycles. In addition, unlike conventional chokes, the effective inductance of the contact carrying ferrite members is relatively low thereby avoiding undesirable interference with resonant circuits.

Obviously the teachings of this invention are not limited to any particular type connector or to connectors per se. The insulating support member carrying the contacts or pins of any electrical component or device can be made of ferrite to achieve the said double function.

In the following figures the same numerals refer to similar parts. Thus in FIGURE 2 is shown in accordance with the invention a simple connector for detachably coupling wires 111 and 1=2 with the aid of contacts or pins 15 and 16, respectively mounted or embedded in matrices 4t), il made of magnetic ferrite. Each matrix, obviously, can carry a plurality of pins suitably spaced apart. FIGURE 3 shows a typical base or socket 45 of a transistor. Base d5 can be conveniently made of ferrite to accomplish the above mentioned dou-ble function: that of connecting its female pins 45 to the male pins of a suitable transistor (not shown) and that of preventing noise, transient signals, and spurious oscillations from reaching the transistors electrodes. lt will be apparent that a vacuum tube socket can equally be made of ferrite. `FGURE 4 shows a conventional circular type connector, generally designated as 50, including a metallic shell 51, a core 52 for supporting the male pins 53, and another core 54 for supporting the female pins 5S. ln accordance with the invention, in the circular connector 'Sib at least one of the cores 513, 54 is made of magnetic ferrite.

ln FIGURE 5 is shown a printed circuit type connector, generally designated as 60, including a matrix 61 rigidly supporting iiexible contacts 62 for detachably coupling the printed circuit conductors 63 of the printed circuit board 64 to another printed circuit board or to an inter-connecting cable. The matrix 61 of the printed circuit connector ansa/irs 3. 60 is also made of magnetic ferrite to accomplish the above mentioned double function.

In operation, the invention makes use of a known phenomenon: when a bus wire is surrounded by or embedded in ferrite, its A.C. resistance and impedance are negligible only to the passage of relatively low frequency signals, but they can be selectively made to' become appreciabie to relatively high frequency signals. By choosing different types of ferrites the A.C. resistance and impedance can be selectively made to respectively assume various functions of frequency: in some applications it may be desired that the A1C. resistance and impedance remain substantially constant with frequency; in other applications, however, it may be desired that the AC. resistance or impedance either increase or decrease with frequency. in surn, at relatively low frequencies, say below 1 to 1() megacycles, the coupling devices of the present invention act in the circuits employing them as conventional coupling devices but atrelatively high frequencies, say from 10 to above 500 megacycles, the coupling devices function essentially as frequency selective resistors exhibiting a surprisingly low inductance thereby minimizing the undesirable interference with tuned circuits or the introduction of phase shifts and delays. Moreover it was rst experimentally established and then theoretically conrrned that when the coupling devices carry multiple contacts, an unexpected result is obtained in that there is no appreciable magnetic coupling between the contacts thereby avoiding any crosstalk between the current carrying conductors connected to the contacts.

It will be understood that the specific embodiments described above and illustrated in the drawings are susceptible of numerous modifications in form and detail within the scope of the invention. Gther modifications will be readily apparent to persons skilled in the art. The particular embodiments disclosed herein, therefore, are not to be regarded as imposing any limitations whatsoever upon the scope of the following claims.

What is claimed is:

1 A coupling device for detachably connecting at least one end of a first conductor to at least another end of a second conductor, said device comprising:

a coupling member, said member being made at least in part of ferrite for suppressing noise signals transmitted through said conductors,

a coupling terminal mounted in said member for receiving said one end of said first conductor, and

said coupling terminal being adapted for connection to said other end of said second conductor, thereby detachably establishing electrical contact between said first and second conductors.

2. The coupling device of claim l and further including another coupling member, said other coupling member being made at least in part of ferrite,

another coupling terminal mounted in said other coupling member for receiving said other end of said second conductor, and

said coupling terminal being adapted for connection to said other coupling terminal.

3. The coupling device of claim 2 and further including a metallic circular shell for supporting at least one of said coupling members.

References Cited hy the Examiner UNITED STATES PATENTS 2,038,353 4/36 Gardner et al 339-149 X 2,469,380 5/49 Frese 339-143 X 3,072,869 yl/63 Seidel M 333--24.2

r IGSEPH D. SEERS, Primary Examiner. o runnen-r H. KAMPE, Examiner.

Claims (1)

1. A COUPLING DEVICE FOR DETACHABLY CONNECTING AT LEAST ONE END OF A FIRST CONDUCTOR TO AT LEAST ANOTHER END OF A SECOND CONDUCTOR, SAID DEVICE COMPRISING: A COUPLING MEMBER, SAID MEMBER BEING MADE AT LEAST IN PART OF FERRITE FOR SUPPRESSING NOISE SIGNALS TRANSMITTED THROUGH SAID CONDUCTORS, A COUPLING TERMINAL MOUNTED IN SAID MEMBER FOR RECEIVING SAID ONE END OF SID FIRST CONDUCTOR, AND SAID COUPLING TERMINAL BEING ADAPTED FRO CONNECTION TO SAID OTHER END OF SAID SECOND CONDUCTOR, THEREBY DETACHABLY ESTABLISHING ELECTRICAL CONTACT BETWEEN SAID FIRST AND SECOND CONDUCTORS.

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