US2118668A - Radio tube mount - Google Patents

Description

May 24, 1938., H, M A N 2,11%,68

RADIO TUBE MOUNT Filed Oct. 23, 1957 INVENTOR ATTORNEY Patented May 24, 1938 UNITED STATES PATENT OFFICE RADIO TUBE MOUNT Application October 23, 1937, Serial No. 170,546

7 Claims.

This invention relates to radio tubes and more especially to the electrode assemblies or mounts of such tubes. A principal object of the invention is to provide an improved manner of aligning, and retaining in alignment, the various parts of a tube mount.

Another object is to provide an electrode mount for a radio tube or the like having at one end a metal collar of novel formation whereby the finished tube is singularly free from microphonic noises and liability of short circuits between the collar and remaining parts.

A feature relates to a radio tube mount having a metal collar and an associated mica spacer member having cooperating embossings and perforations to facilitate proper assembly and to prevent relative shifting of the mica with respect to the collar.

Another feature relates to the novel organization, arrangement and relative location of parts which go to make up an efficient and expeditiously assembled radio tube mount.

Other features and advantages not specifically enumerated will be apparent after a consideration of the following detailed descriptions and the appended claims.

While the invention will be described herein as embodied in one particular type of radio tube, it will be understood that this is done merely for explanatory piuposes and not by way of limitation to the specific embodiment shown. Accordingly in the drawing,

Fig. 1 is a vertical sectional View of a radio tube embodying the invention.

Fig. 2 is a cross-sectional View of the tube of Fig; 1 taken along the line 2-2 thereof and viewed in the direction of the arrows.

Fig. 3 is a cross-sectional view of the tube of Fig. 1 taken along the line 3-3 thereof and viewed in the direction of the arrows.

Fig. l is a partial side elevational view of the upper part of the tube of Fig. 1 with certain of the parts omitted for the sake of clarity.

Fig. 5 is an enlarged View of part of the metal collar and mica disc assembly of Figs. 1 to 1.

Referring more particularly to Fig. 1 the tube therein shown is of the type designated Sylvania Type 6K a triple grid super-control amplifier tube. The tube mount to be described, is enclosed within a metal enclosing envelope l which is hermetically sealed at its lower end to the metal cup 2 within which is seated the circular insulator disc 3 carrying the usual metal contact prongs 4 which, in the particular tube illustrated,

are eight in number. The metal cup or header 2 is provided with a series of metal eyelets 5 through which pass the various lead-in wires and into which are sealed the necessary mount support wires. In the well-known manner glass beads 6 are sealed into the top ends of the eyelets to insulate the wires from the header and to provide a vacuum tight seal between said wires and the header. A suitable exhaust tubulation (not shown) is connected to the header so that the envelope can be exhausted in the conventional manner, Preferably the eyelets 5 are disposed on the header on a circle concentric with the center of the header.

The tube mount is preferably of the unitary construction type comprising a cylindrical indirectly heated cathode I with any well known form of insulated heater filament on the interior thereof; a wire-wound control grid 8, having the turns thereof fastened to the side-rods 9, ill; a wire-wound shield-grid ll, having the turns thereof fastened to the side-rods l2, I3; a wire-wound suppressor grid l4 having the turns thereof fastened to the side-rods l5, l6; and a tubular metal plate or anode ll having oppositely disposed reentrant channels l8, 19 within which are received the plate side- rods 28, 2| and to which the plate is welded or otherwise fastened.

A pair of main vertical metal uprights or supports 22, 23 have their lower ends bent at right angles and welded to the header 2. Carried by the supports 22, 23 in spaced relation to the upper and lower edges of the plate I! are two cup- shaped metal collars 24, 25 each of which has in the bottom thereof an elongated slot 26 to allow the various side rods and the cathode sleeve to protrude therethrough without being short-circuited. While the collars may be fastened to the uprights 22, 23 in any suitable manner, it is preferred to strike out from the ends of the slots 26 integral tabs 21 which may be welded to the said uprights.

In order to space the various electrodes permanently and accurately from each other there are provided upper and lower insulator discs 28, 29 of mica or other suitable insulation, which are provided with suitable perforations to receive the ends of the cathode sleeve, and the various siderods illustrated. Preferably, although not necessarily, the discs 28, 29 are circular and of the same diameter as the associated collars 2t, 25. In order to center the discs with respect to the collar and to prevent relative movement therebetween should the disc diameter be less than the collar diameter, the latter is provided with a series of embossings 30 which cooperate with a similarly positioned series of perforations 3| in the mica discs. Preferably, and as shown in enlarged detail in Fig. 5, the perforations in the mica are slightly smaller than the maximum diameter of the embossings 30 so as to space the mica discs a predetermined distance from the bottom of the collar.

The mica discs may be held in place on the supports 22, 23 in any well-known manner, for example, by metal eyelets, or by swaging the supports above and below the discs. Preferably however, the said mica discs are held in place by engaging the end turns of the various grids. In other words the micas are prevented from moving vertically by engaging the end turns of the grids, and they are prevented from shifting horizontally by reason of the embossings 30 which partially project into the mica disc perforations 3|. It should be noted that the perforations in the collars through which the plate side- rods 20, 2| pass, are materially larger in diameter than the said side-rods so as to avoid short circuiting of the parts. With the construction as described, the plate is independently supported so far as vertical displacement is concerned and for this purpose the plate side-rod 20 may be welded at its lower end to a support wire (not shown) sealed into a glass-bead and eyelet (not shown in Fig. 1) similar to those shown. Likewise electrical connection to the ends 32, 33 of the cathode heater is made through the lead-in wires 34, 35 sealed into the associated glass beads and eyelets 36, 31. The cathode sleeve may be held in place against vertical displacement in any wellknown manner, for example, it may be flattened at its upper end to extend laterally beyond the edge of the associated perforation in the upper mica disc 28. The cathode sleeve may be supported at its lower end by a metal tab 38 welded to one of the lead-in wires (not shown). The upper ends of the control grid side-rods 9, H] are connected by a metal strap 39 which in turn is connected by a lead-in wire 40 insulatingly sealed through the upper end of the envelope l. A contact cap 4| is connected to the lead-in wire 39, said cap being insulatingly supported on the top of the metal envelope. The shield grid H is connected through side-rod l3 at its lower end, to a lead-in wire 42 sealed into the header 2 by an eyelet and glass bead seal. Likewise the suppressor grid M is connected through the lower end of side-rod l5 to the lead-in wire 43 insulatingly sealed into the header 2; and plate I1 is connected through the lower end of side rod 20 to a lead-in wire also insulatingly sealed into the header.

The method of assembly of the various parts is believed to be obvious from the foregoing description. Suflice it to say that the metal collar 24 is positioned on the uprights 22, 23 and welded thereto, whereupon the mica disc 29 is dropped into the collar so that the embossings 30 register with the perforations 3 l The cathode sleeve is then supported in place with its lower end passing through the mica. The grids are then assembled on the lower mica with their lower end turns engaging the mica. The plate electrode I! with its side- rods 20, 2| is then assembled on the lower mica. The upper mica 28 may then be assembled over the cathode and side-rods and all the electrodes properly centered by being held in a suitable jig. The collar 24 is then assembled over the upper ends of the cathode and side-rods with the embossings 30 registering with the perforations 3| in mica disc 28 and the tabs 21 are then welded in place. The strap 39 with its lead-in wire 40 is then welded to the grid siderods 9, Ill. The cathode, shield-grid and suppressor grid may then be connected to their respective lead-in wires in the header 2. The metal envelope I is then welded to the header 2 and then evacuated in accordance with any well-known exhaust schedule, it being understood that the lead-in wire 40 is first insulatingly sealed through the top of the envelope. It will also be understood that a suitable getter is mounted at a convenient place within the envelope and is flashed at the appropriate part of the exhaust schedule. After the tube has been evacuated and sealed off, the base 3 with its contact prongs is applied, and the various lead-in wires are connected to the corresponding prongs. If desired the base 3 may be provided with a suitable locking and guiding key (not shown) to facilitate insertion of the tube in a corresponding contact socket.

While one specific embodiment of the invention has been illustrated, it will be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention. For example, while the drawing shows the micas and collars aligned and spaced by a set of four embossings, a greater or less number may be employed. Preferably, the embossings 30 and the perforations 3| are located symmetrically with respect to the horizontal and vertical centers of the collars and micas so that the alignment of one embossing with its associated mica perforations automatically aligns the remaining embossings and mica perforations. While the invention has been illustrated in a radio tube of the metal envelope type, it can be equally well embodied in a radio tube of the glass bulb type.

What I claim is:

1. A radio tube mount including a plurality of electrodes, at least one insulator disc having perforations to receive projections from said electrodes to maintain them in axially spaced relation, a metal collar positioned adjacent one end of the mount, and cooperating embossings and perforations on the collar and disc to maintain the electrodes in fixed spaced relation to the collar.

2. A radio tube mount including a cathode and at least one electrode having side rods, an insulating spacer disc through which said side rods pass, a metal cup-shaped member within which said disc is seated, a plurality of struck up projections on the bottom of said cup-shaped member and a corresponding plurality of perforations in said disc, said perforations registering with said projections but being of smaller diameter whereby said disc and cup-shaped member are locked against relative axial movement while being maintained spaced from each other.

3. A radio tube mount including an electrode assembly and means to maintain the spacing of the electrodes, the last-mentioned means comprising a cup-shaped metal member carried by the mount, and a mica disc seated within said member, said member having a plurality of embossed projections registering with correspond-- ing perforations in said disc.

4. A tube mount according to claim 3 in which the embossings have inclined sides and partially project into said perforations to maintain the said member and said disc in predetermined spaced relation.

5. In combination a header, a pair of metal uprights fastened at their lower ends to said header, an electrode assembly including at least one wire wound grid with side-rods, a lower insulating spacer member through which said side rods project, an upper insulating spacer memher through which said side-rods pass, a metal cup-shaped member fastened adjacent the upper ends of said uprights, a plurality of embossed projections on said cup-shaped member registering with a corresponding plurality of perforations in said upper insulating member to maintain the horizontal and vertical spaced relations between said cup-shaped member and said grid.

6. In combination a header, a pair of metal uprights fastened at their lower ends to said header, an electrode assembly including a plurality of concentric electrodes, upper and lower micadiscs through which portions of said electrodes pass to maintain the axial alignment thereof, upper and lower metal collars within which said mica discs are seated, means to fasten said collars to said uprights, and means to prevent relative shifting between the mica discs and the collars, the last-mentioned means including a plurality of embossed projections on said collar entering a corresponding plurality of perforations in said discs.

7. The combination according to claim 6 in which certain of the electrodes are in the form of Wire-Wound grids and the mica discs contact with the end turns thereof.

HARRY M. GAUN.

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