US2421780A - Socket structure - Google Patents

Description

June 10, 1947. w. #REAR 2,421,780

SOCKET S TRUCTURE I Filed March so, 1944 '2 Sheets-Sheet 2 Patented June 10, 1947 SOCKET STRUCTURE William Frear, Fox Chase, Pa., assignor, by mesne assignments, to Philco Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application March 30, 1944, Serial No. 528,726

Claims.

This invention relates to socket structures for electron tubes, and more particularly to a novel socket structure for use in a high frequency circuit.

In high frequency circuits employing electron tubes, it is usually desirable to connect at least some of the tube elements or electrodes to ground through a path having low impedance at the operating frequency. Thus it is common practice to connect-a condenser of appropriate capacitance between a tube electrode and ground so as to by-pass the high frequency currents to ground. For example, in the case of a screen grid tube, it is customary to connect a condenser between the screen grid and ground for the stated purpose.

At very high frequencies, the lead inductance introduced by the necessary connections employed in such instances presents substantial impedance to the high frequency currents and tends to defeat the purpose of the by-pass condenser. It is, therefore, desirable to reduce the length of the connecting leads as much as possible, but even very short leads are objectionable in this respect at extremely high frequencies. Although the lead inductance may be small where very short leads are employed, the inductive reactance due to such leads at extremely high frequencies may be of substantial value.

The principal object of the present invention is to provide an arrangement which eliminates such connecting leads entirely by embodying the aforementioned low impedance capacitance paths within the tube socket.

Another object of the invention is to provide a novel socket structure embodying built-in condenser elements which provide the desired low impedance paths between certain of the tube electrodes and ground.

A further object of the invention is to provide in such a structure novel condenser elements in the form of inserts which can be readily associated with the various contact elements of the socket.

A still further object of the invention is to provide a novel socket structure of this character employing interchangeable condenser and insulating inserts which are interchangeable to adapt the socket for Various types of tubes.

Other objects and features of the invention will be apparent as the description proceeds.

In the accompanying drawings:

Fig. 1 is an elevational view of a socket struc ture according to the present invention, showing the lower portion of a tube in operative association with the socket.

Fig. 2 is a plan view of the socket with the tube removed;

Fig. 3 is a sectional View of the socket structure, taken along line 3-3 of Fig. 2, also showing the tube in operative association therewith;

Fig. 4 is an exploded perspective view of certain elements of the socket;

Fig. 5 is a detail view, partly in section, of one of the condenser elements employed in the socket structure; and

Fig. 6 is a similar view of one of the insulating sleeves which are employed.

Referring particularly to Figs. 1 to 3, the socket structure may comprise a supporting base I which is adapted to support the component parts of the structure and which may be provided with apertured ears 2 for attachment to the usual chassis which is commonly employed in radio apparatus and the like. The supporting base l is preferably formed of suitable insulating material, although it may be formed, at least in part, of metallic material by reason of the socket construction, as hereinafter described.

The supporting base is provided with a plurality of recesses la (see Fig. 4) which are adapted to accommodate contact elements 3 for receiving the tube prongs. In the specific illustration, the base portion of a tube is shown at 4 and the usual contact prongs extending therefrom are shown at 5. The contact elements 3 may be of any suitable conventional or known form and may be held within the supporting base in any suitable manner. In the specific illustration, each contact element comprises resilient fingers 6, which receive the associated tube prong, and a terminal lug 1 extending through a slot in the bottom of the supporting base. As an example of one way of holding the contact elements in place, a detent or lug 8 may be struck out from the terminal portion 1 so as to engage the lower surface of the base and prevent upward movement of the contact element.

The recesses in the supporting base which accommodate the contact elements are considerably larger than the contact elements in order to accommodate the members now to be described. In at least some of the recesses, there are disposed hollow cylindrical condensers 9, one of which is clearly shown in Fig. 5. Each condenser comprises a cylindrical dielectric sleeve I 0, an inner metallic portion II and an outer metallic portion l2. These condensers may be constructed in any suitable manner but they are preferably constructed by forming a conductive coating on the inner and outer surfaces of the dielectric sleeve. This may be done, according to modern methods, by a plating process which is made possible by improved technics, as well known to those skilled in the art. In such case, the dielectric sleeve may be formed of ceramic or plastic material which lends itself to such process. It will be obvious, however, that other constructions may be resorted to. For example, the conductive portions of the condenser may comprise metallic tubular members which may be placed within and over the dielectric sleeve.

When the condensers are inserted in the socket recesses, the inner conductive surface of each condenser is firmly engaged by the resilient fingers 6 of the associated contact element, as shown in Fig. 2. Thus the inner plate element of each condenser is electrically connected to the associated contact element by reason of the firm engagement therebetween.

In those of the socket recesses which are not occupied by condensers, there are provided insulating sleeves l3, one of which is clearly shown in Fig. 6. These insulating sleeves have the same dimensions as the condensers so that the two are interchangeable to adapt the socket structure for different types of tubes.

A metallic plate or disk 14 (Figs. 3 and 4) serves as a grounding member for the various condensers and this disk is provided with an apertured ear l5 aligned with one of the apertured ears of the socket base. Accordingly, the disk 14 may be electrically connected to the supporting chassis by means of a metallic fastening element, such as a screw, passing through the said apertured ears. The disk I4 is provided with suitable openings or apertures t accommodate the various condensers and insulating sleeves, as clearly shown in Fig. 4. Suitable provision is made for establishing a good electrical connection between the disk (4 and the outer metallic surface of each condenser. With this in view, small contact fingers I la may be turned out from the disk [4, as shown in Fig. 4, for engagement with the condensers. Of course, any other suitable provision may be made for this purpose. For example, the outer metallic surfaces of the condensers may be soldered to the grounding disk [4. The condensers and insulating sleeves may be held in place in any suitable manner. In the device illustrated, the frictional engagement of these elements by fingers G and [4a is sufficient for this purpose.

An apertured insulating disk l6 serves to hold the grounding plate M in place and also provides an insulating cover therefor. The socket parts may be held together by means of a central hollow rivet I! which may be configured, as shown in Fig. 2, to cooperate with a corresponding locating pin is on the tube base so as to properly locate the tube prongs, as will be well understood.

It will be seen from the foregoing description that the socket structure elminates the need for external by-pass condensers and associated connections, thereby obviating the undesirable effects of external connections, as previously mentioned. Furthermore, the socket structure conserves space which would otherwise be necessary for the external condensers. Moreover, since the condensers and insulating sleeves are interchangeable, it is possible to employ the same socket structure for various types of tubes, it being merely necessary to insert the condensers and insulating sleeves in the appropriate socket recesses for the particular tube to be employed in any instance.

It will be understood, of course, that the invention is not limited to the specific structure illustrated which is intended merely to represent one form thereof. Various other embodiments of the invention may be resorted to without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A socket structure for use with a device having contact prongs, said structure comprising a supporting base having recesses therein, a plurality of contact elements disposed in said recesses and adapted to engage the said prongs, a plurality of hollow cylindrical members each disposed in one of said recesses and surrounding the contact element therein, at least some of said members being condensers having coaxial conductive portions, the inner ones of which engage the associated contact elements, the others of said members being formed entirely of insulating material, said members being interchangeable so as to associate the condensers with desired elements of said device, and a grounding member engaging the outer conductive portions of the condensers.

2. A socket structure for use with a device having contact prongs, said structure comprising a supporting base having recesses therein, a plurality of contact elements disposed in said recesses and adapted to engage the said prongs, a plurality of hollow cylindrical members each disposed in one of said recesses and surrounding the contact element therein, at least some of said members being condensers each of which consists of a ceramic sleeve having inner and outer metallic coatings, the inner ones of which engage the associated contact elements, the others of said members being insulating sleeves, said members being interchangeable so as to associate the condensers with desired elements of said device, and a grounding member engaging the outer metallic coatings of the condensers.

3. In a socket structme for use with a device having contact prongs, a supporting base at least a portion of which is formed of insulating material and has recesses therein, a plurality of contact elements carried by said base within said recesses and adapted to engage the said prongs, at least one condenser member disposed in one of the said recesses and engaging the contact element therein, and at least one insulating member disposed in another of said recesses and being geometrically similar to said condenser member so as to be interchangeable therewith.

4. In a socket structure for use with a device having contact prongs, a supporting base at least a portion of which is formed of insulating material and has cup-shaped recesses, a plurality of contact elements carried by said base within said recesses and dapted to engage the said prongs, at least one condenser member of annular form seated in one of said recesses and surrounding the contact member therein, and at least one insulating member seated in another of said recesses and being geometrically similar to said condenser member so as to be interchangeable therewith.

5. A socket structure for use with a device having contact prongs, said structure comprising a supporting base having recesses therein, a plurality of contact elements disposed in said recesses and adapted to engage the said prongs, a. plurality of annular members each disposed in one of said recesses and surrounding the contact said member having recesses extending depthwise but terminating short of the full depth to provide cup-shaped receptacles in said member, contact elements seated in said receptacles and adapted to engage the said prongs when the latter are inserted in said receptacles, and at least one condenser of tubular form seated in one of said receptacles and surrounding the contact element therein, said condenser engaging the associated contact element and thus being electrically connected thereto.

7. A socket structure for use with a device having contact prongs, said structure comprising a supporting base member of substantial depth, said member having similar recesses extending depthwise but terminating short of the full depth to provide cup-shaped receptacles in said member, contact elements seated in said receptacles and adapted to engage the said prongs when the latter are inserted in said receptacles, at least one condenser of tubular form seated in one of said receptacles and surrounding the contact element therein, said condenser engaging the associated contact element and thus being electrically connected thereto, and at least one insulating member of tubular form seated in another of said receptacles and surrounding the contact element therein.

8. A socket structure for use with a device having contact prongs, said structure comprising a supporting base member of substantial depth, said member having recesses extending depthwise but terminating short of the full depth to provide cup-shaped receptacles in said member, contact elements seated in said receptacles and adapted to engage the said prongs when the latter are inserted in said receptacles, said contact elements having terminals extending from the bottoms of said receptacles, at least one condenser of tubular form seated in one of said receptacles and surrounding the contact element therein, said condenser engaging the: associated contact element and thus being electrically connected thereto, and a grounding member carried by said base member and engaging said condenser.

9. A socket structure for use with a device hav ing contact prongs, said structure comprising a supporting base member of substantial depth, said member having recesses extending depthwise but terminating short of the full depth to provide cup-shaped receptacles in said member, contact elements seated in said receptacles and adapted to engage the said prongs when the latter are inserted in said receptacles, at least one condenser of tubular form seated in one of said receptacles and extending therefrom, said condenser surrounding and engaging the contact element in said receptacle, an apertured grounding plate carried by said base member and engaging the extended portion of said condenser, and an-apertured cover member engaging said plate and secured to said base member.

10. A socket structure for use with a device having contact prongs, said structure comprising a supporting base member of substantial depth, said member having recesses extending depthwise but terminating short of the full depth to provide cup-shaped receptacles in said member, contact elements seated in said receptacles and adapted to engage the said prongs when the 1atter are inserted in said receptacles, at least one condenser of tubular form seated in one of said receptacles and extending therefrom, said condenser surrounding and engaging the contact element in said receptacle, at least one insulating member of tubular form seated in another of said receptacles and extending therefrom, an apertured grounding plate carried by said base member and engaging the extended portions of said condenser and said insulating member, and an apertured cover member engaging said plate and secured to said base member.

WILLIAM FREAK.

REFERENCES CITED The following references are of record in the file of this patent:

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