Filtered Connector Pin Contact

Abstract

Pin contact for filtered connector, having central metal element surrounded by a ferrite ferrule and an outer ceramic sleeve, and including flexible conductive washers end-loading the ferrule and sleeve, to provide flexibility, and prevent breaking.

Description

CROSS REFERENCES

Tuchto & Joseph Ser. No. 584,745 filed Oct. 6, 1966, now abandoned for continuation of Ser. No. 860,175 pending in Group 255, assigned to the assignee of the present invention.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a filtered connector used for example with an instrument enclosed in a case or cabinet. The conductor is utilized for making connection between an external conductor or cable, and internal conductors within the case. The filtered connector includes a main structural component mounted in the case, and pin contacts removably mounted in the structural component. The pin contacts include relatively fragile elements such as a ceramic sleeve which is subject to relatively easy breaking. In inserting the pin contacts into, and removing them from the structural component, they are often misaligned, heretofore causing serious breakage.

2. Description of the Prior Art

There is no known prior art relating to this invention.

SUMMARY OF THE INVENTION

The present invention relates to means for preventing breakage of the fragile elements of pin contacts of the character referred to above.

The pin contact of the present invention includes a central metal member and fragile ferrules or sleeves mounted thereon, and flexible and resilient washers on the central member and end-loading ferrules or sleeves, whereby to provide flexibility to the assembly and preventing breakage of the fragile components.

Other objects of the invention are to eliminate air voids with consequent constant inductance and uniform electrical properties; to enable a greater variety of metals to be used in the body portion of the pin contact; to increase the strength of the pin contact; and to provide a structure having a tendency to center itself while being inserted into the socket.

Other objects and advantages of the invention will appear from the following detail description taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

The single FIGURE of the drawing is an axial sectional view of the pin contact, shown in relation to the structural component of the filtered connector in which it is mounted, the latter being shown in dot-dash lines.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring in detail to the accompanying drawing, the pin contact of the invention is indicated in its entirety at 10 and shown mounted in a main structural component or member 12 of a filtered connector. The relationship of the pin contact to the main structural component is described in detail in the copending application referred to above, the present inventor being one of the coinventors of that application.

Referring first to the detail structure of the pin contact 10, this pin contact includes a metal body member, preferably of copper which for manufacturing purposes may be made of a plurality of separate elements connected together. The body member includes a central portion 16 in the form of a rod of reduced diameter, an enlargement or collar 18 adjacent the front forming a rearwardly facing shoulder 20, and another enlargement 22 at the rear forming a forwardly facing shoulder 24. The pin contact also includes a reduced diameter front element 23 which directly contacts with the contacts of an external connector. An internal conductor 26 is connected to the real element of the pin contact by suitable means such as by crimping as indicated at 28, this conductor 26 being connected with an instrumentality within the case in which the filtered connector is mounted, this case being indicated diagrammatically and fragmentarily at 30 (center bottom), both the aforesaid front and rear elements of the contact may be generally considered as electrical connection elements of the contact pin.

The pin contact includes a ferrule 32 of ferrite, preferably in the form of a plurality of sections butted end-to-end and mounted directly on the central reduced portion 16 of the body. Surrounding the ferrule 32 is an outer cylinder or sleeve 34 of ceramic material and preferably a single integral element, this cylinder preferably being longer than the ferrule 32, the ferrule and cylinder together being also indentified as ferrule means. The ceramic sleeve is brittle and easily breakable, while the ferrite ferrule is relatively disintegratable as from vibration. The cylinder or sleeve 34 forms a dielectric element of a capacitor indicated in its entirety at 36 and including, in addition to the ceramic sleeve, a pair of inner plates 38 and a single outer plate 40, both of which are generally cylindrical. The plates 38, 40 are preferably in the form of adherent coatings on the ceramic sleeve, applied in a known manner. The two inner plates 38 are spaced apart axially forming a gap as indicated at 42 and have radial flanges 44 at their ends turned over on the ends of the ceramic sleeve. The outer plate 40 is a single cylindrical sleeve formed on the outer surface of the ceramic sleeve and of shorter axial length than that ceramic sleeve.

Interposed between the ends of the assembly which include the inner ferrite ferrule 32 and the outer ceramic sleeve 34 on the one hand, and the shoulders 20, 24 on the other hand, are a pair of washers 46 of T-shape cross section, each having a reduced portion 48 fitted within the outer ceramic sleeve and engaging the end of the inner ferrite ferrule, and an outer large diameter portion 50 directly engaging the shoulders 20, 24 and also engaging the ends of the outer ceramic sleeve 34. The dimensions and proportions of the various elements are such that the washers 46 are at least partially compressed so as to provide a constant biasing effect on both the inner ferrite ferrule 32 and the outer ceramic sleeve 34 to provide axial centering effect and to fill all of the radial space between the ends of the outer ceramic sleeve and the central reduced portion 16 of the body. The washers 46 are of flexible and resilient nature, being of rubber, or rubberlike material, of known kind, containing conductive material therein to provide conduction between the inner plates 38 and the enlargements of the body through the shoulders 20, 24.

In the use of the pin contact, it is inserted into a pin cavity or aperture 52 in the structural component or member 12. This pin cavity 52 includes the large main portion 54 receiving the major portion of the pin contact and a reduced outer end portion 56 receiving the front pin element 23. A shoulder 58 is formed between the portions 54 and 56 of the pin cavity. Incorporated in the member 12 is a central plate 60 having prongs 61 extending into the pin cavity and engaging the outer plate 40 on the pin contact. The plate 60 has electrical contact engagement with elements 62 of the member 12 and through them with the element 30 of the case in which the device is mounted, all as fully described in the copending application referred to above.

As noted above, the filtered connector is specially adapted for removal of the pin contacts 10. These pin contacts may be inserted manually or by means of a tool and in so inserting them they are inserted fully until the enlargement 18 engages the shoulder 58. The main portion 54 of the pin cavity is only slightly larger than the pin contact in order to provide optimum positioning of the pin contact and consequent electrical contact engagement; the space between these two elements is here shown exaggerated. The pin contact is long relative to its diameter and if it is not aligned with the pin cavity in the inserting or removal steps, the pin contact may be cocked or bent, and the brittle ceramic sleeve 34 broken.

The flexible and resilient washers 46 provide flexibility to the structure, eliminating or greatly minimizing the damage noted. The washers allow pin deflection for angular misalignment between the pin contact and the pin cavity. The device is self-damping, that is, the rubber or material of the washers does not transmit shock and vibration. The compression provided in the washers increases the strength of the pin because of the axial or end-loading, both in position in the pin cavity and out of it. In the insertion or removal of the pin, any misalignment or bending is counteracted by a tendency of the elements of the pin contact to return to their original position. Another advantage is that the washers hold the sections of the ferrule in abutted relation to eliminate air voids between sections of the ferrule and to thereby avoid electrical discontinuities, constant inductance and consequent uniform electrical properties. The washer prevent disintegration of the ferrite ferrule heretofore caused by vibration imposed on the device. The structure enables insertion and removal of the pin a great number of times with standard tools without breaking or other damage to the pin.

While I have herein disclosed a preferred form of the invention it will be understood that changes may be made therein within the spirit and scope of the appended claims.

Claims

I claim:

1. In a filter contact unit for an electrical connector, an elongated conductive body having first and second end portions and an elongated central portion of reduced diameter with shoulders separating said end portions from said central portion, impedance means around said elongated central portion comprising a plurality of separate sections that are axially movable along said central portion, capacitance sleeve means of dielectric material surrounding said central portion, inner conductive sleeve means, outer conductive sleeve means on the outer surface of said capacitance sleeve means, and support and electrical connection means for resiliently supporting said capacitance sleeve means from said conductive body and for providing electrical connection between said inner conductive sleeve means and said conductive body, said support and electrical connection means including washers of a resilient conductive material interposed between said conductive body and said inner conductive sleeve means at each end of said capacitance sleeve means being in pressure engagement with said shoulders and compressed to hold said impedance sections butted in end-to-end relation.

2. In a filter contact unit as defined in claim 1, said inner conductive sleeve means including a first sleeve engaged by said washer and a second sleeve disposed in end-to-end spaced relation to said first sleeve, and said support and electrical connection means comprising a second washer interposed between said conductive body and said second sleeve, said second washer being engaged between said ferrule means and the other of said shoulders, the axial length of said capacitance sleeve means being less than the distance between said shoulders and greater than the length of said ferrule means, each of said washers being generally T-shaped and including the portion compressed axially between the ends of said capacitance sleeve means and said shoulders and a portion compressed radially between said capacitance sleeve means and said central portion with each washer being additionally compressed axially between said ferrule means and said shoulders.

3. An elongated filter pin contact having specified electrical signal transmission characteristics when positioned within an electrical connector of the type wherein a plurality of contact pins are both releasably retained and held in electrical contact with a conductive member within the connector and in specified respective operating positions so as to permit the selective insertion and withdrawal of said contacts from the connector on an individual basis through the use of manually manipulatable tools conditionally subjecting the contact to bending moments during the insertion and withdrawal of the contact in and from the connector said filter pin comprising: an axially substantially straight-line flexible elongated body of electrically conductive material having a central portion extending along a substantial part of the length of said body with electrically conductive shoulder means positioned at each extremity of said central portion, said body extending a substantial distance axially away from each of said shoulder means and said central portion to form first and second electrical connection elements at least one of which may be mechanically engaged by a manually manipulated tool for inserting and withdrawing the contact in and from a connector; ferrule means having inner and outer surfaces surrounding said central portion and extending along substantially the entire length of said central portion and interposed between but spaced apart from each of said shoulder means, said ferrule means comprising a body of brittle material having physical properties which cooperate with other elements of the ferrule means to establish said specified signal transmission characteristic, said body of brittle material extending along substantially the entire length of said ferrule means, said ferrule means further comprising at least one conductive contact means operatively coupled to elements of said ferrule to further at least in part define said transmission characteristics, said contact means being disposed on the inner surface of said ferrule means and extending substantially to the axial extent of one end thereof; at least one resilient electrically conductive body positioned at said one end of said ferrule and interposed in compression between said elongated body and said contact means and in compression between the outer end surfaces of said ferrule means and one of said shoulder means; and at least one resilient body positioned at the other end of said ferrule and interposed in compression between said elongated body and the inner surface of said ferrule and in compression between the outer end surface of said ferrule and the other of said shoulder means, the resiliency and mass of and the compression applied to said resilient bodies being selected so as to protect said body of brittle material from breakage upon the application of substantial bending moments between said first and second electrical connection elements.

4. A filter pin contact as defined in claim 3 wherein said elongated body is at substantially all points throughout its length circularly cylindrical with said central portion having a diameter substantially less than at least one of said electrical connection elements and both of said shoulder means having a diameter greater than said at least one electrical connection element and wherein the outer diameter of said ferrule means is substantially the same as said shoulder means and the inner diameter of said ferrule means is such as to slip fit over said reduced diameter central portion.