US3031635A - Socket for radio tubes or the like - Google Patents

Description

w. GLUCK 3,031,635

SOCKET FOR RADIO TUBES OR THE LIKE 2 Sheets-Sheet 1 April 24, 1962 Filed June 20, 1957 //VI/f'/V70/,

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April 24, 1962 w. GLUCK SOCKET FOR RADIO TUBES OR THE LIKE 2 Sheets-Sheet 2 Filed June 20, 1957 lfy/ Fla. /3

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United States Patent Office 3,031,635 Patented Apr. 24, 1952 3,031,635 SOCKET FOR RADIG TUBES OR. THE LIKE William Gluck, Yonkers, N.Y., assignor to Industrial Electronic Hardware Corp., a corporation of New York Filed June20, 1957, Ser. No. 666,916 2 Claims. (Cl. 339-14) cillary objects, relative to a laminated socket, are to greatly improve the high voltage breakdown characteristic; to avoid the need for assembly of wafers; and to make it possible to supply the purchaser with bases made of difierent desired plastics materials to suit his requirements.

Additional objects are to provide such a molded socket which may be readily pushed into mating holes in a printed circuit board, and which is preferably received with a firm snap engagement for dependable retention of the 7 socket pending a soldering operation, typically a pot soldering operation. Other objects areto' provide such a socket which may be made with or'w-ithout a center post, and with or without a ground strap, and to provide an improved groundstrap for improved electrical and mechanical connection between the ground strap and the center post.

Another object is to provide such asocket, the base of which may be automatically loaded with metal contacts in an assembly machine substantially the same as that disclosed in my copending application Serial No. 595,008 filed June 29, 1956, and entitled Manufacture of Vacuum Tube Sockets, since issued on'October 11, 1960, as Patent FIG. 12 is a section taken in the plane of the line 12--12of FIG. 10;

FIG. 13 is a fragmentary section taken approximately in the plane of the line 1313 of FIG. 10;

FIG. 14 is a fragmentary section taken approximately in the plane of theline 14-14 of FIG. 10;

FIG. 15 is a plan view similar to FIG. 10, but showing the base for a socket having nine pins instead of seven; 1 FIG. 16 is a section generally similar to FIG. 9, but showing" a socket having a center ground post and a ground strap;

FIG. 17 is a bottom plan view showing the ground strap drawn to enlarged scale;

FIG. 18 is a sectional view showing the interengaged relation of stacked sockets; and I FIGS. 19 and 20 are fragmentary sections at 20-20 of FIG. 16, with the contact omitted in FIG. 19.

Referring to the drawing, and more particularly to FIG. 1, the socket comprises a one-piece molded insulation base B, and a plurality of metal contacts C. Each contact comprises a single piece of sheet metal, and is formed out of a blank having the configuration shown in FIG. 8, which is appropriately pressed in a progressive die to take the form of the finished contact shown in FIGS. 3, 4 and 5. Each contact comprises a pin grip 12 which is preferably of the split sleeve type. It further comprises a generally cylindrical post 14. The grip and post are connected at their upper ends by a bridge 16. The postis longitudinally split at its lower end,'as shown at 18 in FIG. 5, in order to be resiliently compressible.

Referring now to FIGS. 10, 11 and 12, the insulation base B is generally circular, and is provided with a ring of holes 20 dimensioned to receive the pin grips 12 in FIG. 4). The base is also provided with a larger diameter ring of holes 22=dimensioned to receive the posts (14 in FIG. 4). As shown in FIG. 10, the top of the base has a plurality of radial slots 24 connecting the grip holes 20 and the post holes 22, for receiving the bridges-of the Still another object of the invention is to provide such a'socket which may be stacked or formed into sticks of superposed sockets, and which may be automatically insertedin a printed circuit board as described in my copending application Serial No. 579,664 filed April 20, 1956, and entitled Radio Tube Sockets,.since issued on November 29, 1960 as Patent, No. 2,962,690.

To accomplish the foregoing general objects, and other more specific objectswhich will hereinafter appear, my invention resides in the socket elements and their relation one to another as arehereinafter more particularly described in the following specification. I The specification.

is accompanied by drawings in which:

FIG. 1 is a side elevation of a socket embodying features of the present invention, and showing its relation to a printed circuit board and a vacuum tube;

FIG. 2 is a bottom plan view of a fragmentary portion of a printed circuit board;

FIG. 3 is a plan view of one of the metal contacts-forming a part of the socket;-

FIG. 4 is a side elevation of the same;-

FIG. 5 is an end View of the same;

FIG. 6 is a view showing an intermediate stage in the assembly of the contacts in the base;

FIG. 7 is a similar view but showing a later stage in the assembly operation;

FIG. 8 is a development of the sheet metal blank used to form the contact; I

FIG. 9 is a section taken approximately inthe plane of the line 99 of FIG. 1; 7

FIG. 10 is a plan view of the insulation base;

FIG. 11 is a bottom view of the insulation base;

contacts (16 in FIGS. 3 and 4). The slots 24 are rather deep, as is best shown in FIG. 12, and thus the contacts are received in and are recessed well below the top surface of the base, as is clearly shown in FIGS. 9' and. 16.

The socket is further provided with means to anchor the contacts in the base. For this purpose, the contact is provided with tangs on the post, and a lug on the pin grip. Thelatter is clearly shown at 26 in FIGS. 4 and 8 of the drawing. After thecontact has been inserted in. the base,

i this lug may be bent radially outward beneath the base,

as is shown at 26' in FIGS. 9 and 16. The change in position of the lug is also shown by comparison of FIGS; 6 .and 7, the latter figure showing how the lug may be bent .outward toward the post 14 by a suitable punch'28. The lug 26' prevents upward movement ofthe pin grip 12.

The post 14 is provided with tangs 30 (FIGS. 7, 9 and 16). To form these, the metal of the blank is preferably preliminarily slit as is indicated at 30 in'FIG. 8. During the formation of the contact, the excised metal is indented, as is best shown at 30 in FIG. 4. Thus, the post 14 is readily passed through its mating hole'22when loading the base with contacts. By thereafter .forcing a punch 32 downward into the hollow post, the indented metal is forced outward, as shown by the change from FIG. 6 to FIG. 7 of the drawing. 'In this way the two 'tangs' 30 are displaced outward beneath thebottom surface of the base B, and thereafter serve to hold the post against upward -movement relative to the base."

punch to transfer a contact downward into the base, and referring to FIGS. 6 and 7, the punch 32 serves to first insert the contact in the base, and continued movement of the punch after the contact has been seated in the base automatically projects the tangs 30 into locking position, as shown in FIG. 7.

The cooperation of the bridge 16 on one side of the base, and the lug 26' or/and tangs 30 on the other sidg, could suflice to anchor the contact in the base. How ever, I prefer to additionally employ ledges to positively support the pin grip against the force of insertion of a tube. These ledges are best shown at 34 in FIG. 19, and they positively support the lower end of the pin grip 12, as shown in FIG. 20. The ledges 34 are visible when the base (without the contacts) is viewed from above, as will be-seen in FIGS. 10 and 15.

The upper end of post 14 is provided with tabs 36 (FIGS. 3, 4 and to help support it at points remote from the bridge 16. Referring to FIG. 8, the parts 36 act later as the said tabs for the post. It will be understood that the base as molded is provided with recesses to receive the tabs 36. Referring to FIGS. and 12., the tabs are received in spaced recesses 40 (FIG. 10), which in the present case are triangular in outline.

The lug 26 is not bent directly against the insulation base, and the spacing between the bridge 16 and the lug 26 is slightly greater than the thickness of the insulation therebetween. Similarly, the spacing between the tabs 36 and the tangs 30 is slightly greater than the thickness of the insulation therebetween. Also, the width of the slots 24- (FIG. 10) is somewhat greater than the width of the metal bridge 16 of the contact. The holes 20 (FIG. 10)

which receive the pin grips are larger in cross section than the pin grips. The net eifect of all this is that the contacts are individually slightly movable or self-adjustable Within the base, so as better to adapt themselves to the pins of the vacuum tube, and to the holes in the printed circuit board. Moreover, the bridge 16 is not subjected to a direct stress each time a tube is inserted in the socket, for the bridge is elevated slightly from the base, when the lower end of the pin grip rests on the ledges 34. This prevents possible fatigue of the metal of the bridge.

Referring to FIGS. 4 and 5, the post 14- is substantially longer than the pin grip 1 2. It is hollow for stifiness. The lower end is pointed somewhat in the shape of a bullet nose, as shown at 42. The term pointed is intended to include rounded, for either will facilitate insertion of the socket in the holes of a printed circuit board.

Referring to FIG. 2, an insulation panel or board 44, only a fragment of which is shown, has conductors 46, 48, etc. printed thereon, these leading to holes 50, 52 etc. In the present case, the socket is designed to receive a so called miniature tube having seven pins. There are seven holes at the spacing of eight, and these receive the lower ends of seven posts of seven contacts for the seven pins of the tube. However, dilferent numbers and spacings may be provided. The assembly is shown in FIG. 1, in which the socket is mounted on an insulation printed circuit board 44, and a miniature tube 54 having seven pins at its lower end is inserted in the socket.

Reverting to FIG. 5, the post 14 is bifurcated at its lower end, that is, there are legs 56 and 58 separated by diametrically opposed slots 18. The post is therefore resiliently compressible at its lower end, thereby facilitating insertion of the socket in the mating ring of holes in the board. The annular rib 60 acts as a stop means to limit insertion of the post in the panel. The lower end of the post is preferably provided with another annular bead 62, in consequence of which the post is received in the hole with a snap fit,and the socket is held securely in the board even before the soldering operation.

4 taper off at the slots 18 so that the diameter of the post as viewed in FIG. 4 is substantially uniform. The reason for this is that the legs 56 and 58 of thepost are compressible toward one another as viewed in FIG. 5, but the individual legs are not compressible from left to right as viewed in FIG. 4.

It will be understood that the bead 60 functions as a stop, and need not necessarily be a bead. For example, the upper portion of the post might be continued upward at the same elliptical diameter or cross-sectional shape as at the head 60, in which case the post would still function as here described. In other words, instead of thinking of the post as having two spaced beads 60 and 62, one might think of its as being a larger post having a constricted or necked portion where it is to receive the printed circuit board, the said constricted or necked portion having an axial length corresponding to the thickness of the printed circuit board with which the socket is to be used.

Referring now to FIG. 8 of the drawing, the blank comprises a body portion 64 with two depending leg portions 66 and 68, and a head portion 70*. The body and leg portions 64, 66, 68 are shaped to form the post 14. The head 70 is shaped to form the pin grip 12. The post and pin grip are located at opposite ends of a neck 16, and in the finished contact are bent substantially at right angles to the neck, which then acts as a bridge.

In FIG. 4, it will be noted that a disc of metal 15 has been struck inward and downward. This is formed from a generally circular cut 17 in the face of the post opposite the slit, as is best shown at 15, 17 in FIG. 8. The disc 15 forms a barrier or dam to prevent upward rise of either flux or solder. Either of these may tend to rise by capillary action, because of the comparatively small diameter of the post. Moreover, flux previously applied may tend to rise during the soldering operation because of the heat of the solder applied to the lower end of the post. Flux or/ and solder have been found objectionable if carried up high, and the'barrier :15 solves the problem. It will be understood that the barrier 15 is circular in the present case because the post is circular in section, and that if the hollow post had some other sectional shape, the barrier could be similarly modified in shape.

The socket shown in FIGS. 1 and 9 does not have a center ground post nor a ground strap. However, the base B is molded to accommodate either a ground post, or a combination ground post and strap. For this purpose, the

base is provided with a center hole 72 (FIGS. 10 and 11) I and with a side hole 74. Referring to FIG. 16 of the drawing, the center ground post 76 is inserted in the center hole, and is suitably secured therein. As shown in FIG. 18, the shank of post 76 preferably has a head 78 which acts as the lower part of an eyelet. The cylindrical upper end of the post is flanged outward, as shown at 80, thereby anchoring the post on the base.

Such a post may be used with or without aground strap. In FIG. 16, a ground strap 82 has been added. This exw tends radially out-ward from post 76, and is turned up Ward at 84 to engage a metal tube shield. To insure good electrical contact between the post and strap, and to anchor the strap on the post, the material at the center hole 86 (FIG. 17) of strap 82 is formed into a ring of serrations 88 which slope downward and inward to a dia-meter substantially smaller than the diameter of the center post. When the strap is forced over the free end of the post all the way up to the base, the serrations bite into the center post and insiu'e good electrical contact. They also hold the strap securely on the post. They fit around bead 78.

The strap may be provided with additional holding means, and in the present case, this consists of a small eyelet 9!) (FIG. 16) which passes through the previously mentioned side hole 74 of the base, and through a registering hole 92 (FIG. 17) in the strap 82.

Reverting to FIG. 2, the printed circuit there shown is intended for use with a center ground post, and a printed flat 98 (FIGS. and 11) at the omitted, contact. The

radially directed ground strap passes through flle gap provided by the omitted contact, and when bent upward, as

shown in FIG. 16, does so at the fiat 98. The side hole 74 for rivet 90 is located near the flat 98.

The molded base is preferably raised or thickened at the bottom to provide insulation barriers between adjacent pin grips, and between the pin grips and the center ground post and ground strap. Referring to FIGS. 11 and 12, the parts 100 between the pin grip holes 20 form insulation barriers. This barrier applies also to the outwardly turned lugs 26' (FIG. 16), which are received at the recessed surfaces marked 102 (FIG. 12). The extra thickness of insulation is maintained on the circular are 104 (FIG. 11), and is carried outward at 106 and 108. The generally circular wall 104 acts as an insulation barrier between the center ground post and the pin grips.

The walls 106 and 108 act as an insulation barrier between be used to fix the orientation of the base. The studs 112 shown at the top of the base are intended merely to limit the maximum insertion of tube prongs by physically bearing against the bottom end of the tube. The recess 114 (FIG. 11) on the bottom of the base may be used to receive the tongues of a tube shield which is not removable as in my copending application Serial No. 684,968, filed September 19, 1957, and now Patent No. 2,990,532, or the saddle for a tube shield which is removable.

As so far described, the socket has seven contacts, but it willbe understood that similar features of construction may be used for a socket receiving a different number of pins, and FIG. 15 is a plan view of an insulation base similar to FIG. 10, but showing the base of a socket having nine contacts at the spacing of ten. The holes 120 are for the pin grips. The holes 122 are for the posts. The radial slots 124 are for the bridges. The center hole 126 is for a center ground post. The side hole 128 is for the ground strap eyelet. The studs 130 correspond to the studs 112, and so on. The contacts used are the same as those previously described, and similar provision is made to receive the pin grips at ledges 34, and the top tabs, as well as the outwardly curled bottom lug 2-6 and the tangs 30. p

An important advantage of the present socket, when provided with center ground post in preferred form, is that the sockets may be stacked or formed into a stick of connected sockets. This is in accordance with the disclosure in my U.S. application Serial No. 579,664, now Patent 2,962,690 mentioned above, which describes a machine for automatically inserting sockets in printed circuit boards. For stacking, the lower end of the center post 76 (FIGS. 16 and 18) is so related dimensionally to the upper end of the center post, that the lower end of the post 76 of an upper socket 130 may be received in the upper end of the post 132 of a subjacent socket 134 with a resilient fit, and preferably with a snap engagement. In the specific form here illustrated, the lower end is undercut at 136 (FIG. 16), and is radially slit to be resiliently compressible. This mates with an annular space formed by the bead 138 (FIG. 18) of post 132 (corresponding to bead 78 of post 76) Thus, the sockets may be anchored together with a snap fit.

The relative length of the contact posts 14 is preferably such that the lower ends of posts 14 are reecived in the upper ends of the holes formed in socket 134 for its posts. In other words, the lower ends of posts 14 of the upper socket, are received in the large ring of holes in the base of the lower socket when the center posts are engaged with their snap engagement, and this additionally steadies the stack of sockets, and holds them against relative rotation so that they may be maintained in uniform orientation, that is, with the flats all on one side.

It will be understood that the snap engagement between superposed sockets may be obtained in different fashion. For example, the lower end of thecenter post may be rigid, and the upper end of the center post may be provided with yieldable mating means. Such an arrangement is disclosed in my copending application Serial No. 663,852 filed June 5, 1957, and entitled Stacking Radio Tube Socket, since issued June 21, 1960 as Patent 2,942,230, and the center post there disclosed may be used in the present socket in lieu of that here shown.

It is believed that the construction, the method of assembly, and the method of use of my improved molded socket for printed circuits, as well as the advantages thereof, will be apparent from the foregoing detailed description. Compared to a laminated socket, the present socket has a one-piece insulation body; requires no assembly of wafers; no eyelet or other means to assemble them; has a voltage breakdown about three times as high; and the plastics material may be varied to suit the needs of a 1 customer. Thus, the base may be molded out of a black general purpose phenolic plastics material, or it may be molded out of a yellow colored mica filled phenolic, and so on.

Compared to molded sockets previously made, the present socket has the advantage of having a small compact insulation body, with minimum vertical dimension. It has the advantage that contacts may be automatically assembled with the base, and the finished sockets may be automatically inserted in printed circuit boards, by means of automatic machinery already developed for use with laminated sockets, because in the present molded socket, the base is relatively thin and wafer-like, and is dimensionally comparable to a laminated socket. The socket may be made with or Without a center ground post, and with or without a ground strap. The sockets may be stacked. A barrier against flux and solder is provided, as Well as an improved connection between the center ground post and the ground strap.

It will be apparent that while I have shown and described my improved socket in several preferred forms, changes Tnay be made in the structures shown without departing from the scope of the invention, as sought to be defined in the following claims.

I claim: v I

1. A socket for printed circuits, said socket comprising a one-piece molded insulation base, and a plurality of metal contacts, each contact comprising a single piece of sheet-metal formed into a pin grip and a post connected at the upper end of the post by a bridge, said insulation base being generally circular and provided with a ring of open ended holes to receive the pin grips, a larger ring of open ended holes to receive the posts, and a plurality of radial slots on the upper side of the base connecting the grip holes and post holes for receiving the bridges, said base having narrow support ledges beneath the pin grips at the bottom of the pin grip holes to positively support the pin grips against downward movement without obstructing the passage of tube pins through the pin grips, said posts being disposed transversely of the base and extending downward from the base, the inner portion of the base radially inward of the posts being thicker than the vertical height of the pin grips, the peripheral portion of said base receiving the posts having a thickness only about half that of the inner portion receiving the pin grips, said posts being hollow for stiffness and the peripheral portion of said base being sufficiently thick around the upper ends of the posts to hold the posts in desired upright position, the posts having outwardly excised tangs directly beneath the base to prevent upward movement of the posts, the lower ends of the pin grips having lugs bent radially outward toward the posts to prevent upward movement of the pin grip, the posts being substantially longer than the pin grips and each being longitudinally split at its lower end to be resiliently compressible, the lower tip of each post being shaped to facilitate insertion in a mating hole in a printed circuit panel having a ring of such holes, said posts having means to limit their insertion in said panel with the base and pin grips spaced above the panel and with the lower tips of the posts passing through and somewhat beyond the panel for soldering to printed circuitry.

2. A socket for printed circuits, said socket comprising a onepiece molded insulation base, and a plurality of metalcontacts, each contact comprising a single piece of sheet-metal formed into a pin grip and a post connected at the upper end of the post by a bridge, said insulation base being generally circular and provided with a ring of holes to receive the pin grips, a larger ring of holes to receive the posts, and a plurality of radial slots on the upper side of the base connecting the grip holes and post holes for receiving the bridges, said posts being disposed transversely of the base and extending downward from the base, the inner portion of the base radially inward of the posts being thicker than the vertical height of the pin grips, the peripheral portion of said base receiving the posts having a thickness only about half that of the inner portion receiving the pin grips, said posts being hollow for stiffness and the peripheral portion of said base being sufficiently thick around the upper ends of the posts to hold the posts in desired upright position, means to prevent upward movement of the contacts, a center ground post, a ground strap extending radially from the center ground post at the height of the bottom of the peripheral portion of the base, whereby the inner portion of the base provides an insulation barrier between the pin grips and the center ground post and strap, the postslb'eing substantially longer than the pin grips and each being longitudinally split at its lower end to be resiliently compress ible, the lower tip of each post being shaped to facilitate insertion in a mating hole in a printed circuit panel having a ring of such holes, said posts having means to limit their insertion in said panel with the base and pin grips spaced above the panel and with the lower tips of the posts passing through and somewhat beyond the panel for soldering to printed circuitry.

References Cited in the file of this patent UNITED STATES PATENTS 1,987,118 Lodge June 8, 1935 2,448,339 Williams Aug. 31, 1948 2,551,844 Kueck May 8, 1951 2,652,522 Vanderhoot Sept. 15, 1953 2,683,259 Lowther July 6, 1954 2,689,337 Burtt Sept. 14, 1954 2,745,080 Otferman May 8, 1956 2,796,593 Offerman June 18, 1957 2,797,397 MacFadden June 25, 1957 2,814,024 Narozn-y Nov. 19, 1957 2,857,582 Wintriss Oct. 21, 1958 2,863,131 Carlzen et a1 Dec. 2, 1958 2,962,690 Gluclt Nov. 29, 1960 FOREIGN PATENTS 576,589 Great Britain Apr. 11, 1946

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