US2027181A - Sealing-in machine - Google Patents

Description

Jan. 7, 1936, J. R Alco 2,027,18

SEALING-IN MACHINE Filed Dec. l, 1934 A TTOR/VEY Patented Jan. 7, 1936 UNITED STATES PATENT OFFICEi 2,027,181 SEALING-IN MACHINE Joseph P.

Telephone York, N. Y.,

Laico, Brooklyn, N. Y.. assignor to Bell Laboratories, a corporation of New York Incorporated, New

Application December 1, 1934, Serial No. 755,555

15 Claims.

This invention relates to glass sealing-in machines and more particularly to `sealing-in heads for electric dischargeI devices.

An object of the invention is to hermetically In accordance with this invention the sealing i head comprises a rotatable frame having a portion for supporting the bulb and a base including a standard which is interconnected with a jig for mounting an electrode or aplurality of electrodes with respect to the bulb, the electrode or electrodes having' individual conductors which extend through the top of the bulb eccentric with respect to the axis of the bulb. The frame is mounted in a slidable condition with respect to the base portion which has a stable axis so that the axis of the frame may be changed at intervals to conform to the arrangement of conductors which are to be sealed in the bulb.

In one form ofthe invention the frame is connected to arotatable base to support a bulb in relation to an air supply connection projecting through the base which within the b ulb supports an electrode lor a plurality of electrodes in accurate position with their leading-in conductors projectingthrough apertures in the top of the bulb. This arrangement permits the sealing of the conductors of the electrodes in the bulb simply by aligning the conductors with the stable axis of theA head by a slidable adjustment of the frame supporting the bulb, While rotating the frame and bulb in a burner flame to seal the'conductors'to the bulb.

In accordance with another embodiment of the invention, the rotatable frame is mounted on a detail in the following description which applies to the accompanying drawing:

Fig. 1 is a view in elevation of a sealing-in head embodying the features of this invention and showing the manner in which the sealing opera` 5 tion is performed, portions of the head and the associated parts being shown in cross-section; Fig. 2 is a plan view ofthe structure of the head as shown in Fig. 1 and taken on the line 2 2;

Fig. 3'is apartial view in elevation head as shown in Fig. 1, but illustrating the assembly for sealing the ared stem into the bulb;

Fig. 4 is a partial view in elevation of a modified sealing-in head according to this invention with portions shown in cross-section to illustrate 15 the detail assembly;

Fig. 5 is another View in elevation of the head shown in Fig. 4, but rotated 90 degrees; and

Fig. 6 is an enlarged fragmentary view in crosssection showing the relation of the detail compo- 20 nents prior to forming the seal at the top of the bulb As shown in Fig. l of the drawing, a sealing-in head, of this invention, maybe provided with a rotatable base dle II adapted for application to a sealing-in machine, wherein it may be rotated by any suitable mechanism (not shown). Machines emplOying heads of similar character usually include a rotary conveyor uponwhich the heads are 30A disposed in spaced relation and the conveyor is operated intermittently by suitable indexing mechanism. Thus, the heads are carried around from one station to another and while at certain stations, such, for example, as the position for applying heat to the bulb for the sealing-in operation, mechanism operates to..rotate the head. The conveyor mechanism and the various parts thereof are not shown in the drawing inasmuch as machines of this type are well-known in the glass Working art. y

A central tubular standard I2 is rigidly attached to the base I 0 by screws I3 passing through a circular iange I4 of the standard and the base I 0. threaded portion I5 and a nipple termination I6. The standard therefore forms a continuing passageway of the tubular spindle II and both the standard and base rotate about a stable axis passing through the rectangular plate I1 having an elongated central slot I8 fits over the standard I2 and is seated in a horizontal position on ythe circular ange I4. The plate I] carries a pair of parallel bars or rods I9 and 20 which are secured at opposite ends 55T of the same 10 I0 having a central tubular spin- 25 'I'he standard I2 is provided with a 45 center of the passageway. A

of the plate by pins 2 l An adjustable bulb holder 22 extends between the rods ,19 and 2liand is secured to the rods by set screws 23, the plate, bars and bulb holder forming a frame structure of the sealing-in head. The frame is secured to the standard by a lock nut 24 which engages the threaded portion l5 of the standard and which may be manipulated by a handle 25, a washerv 26 being interposedbetween the lock nut and the plate l1. The assembly of the frame facilitates rapid and accurate adjustment for periodically changing the lateral relationship of the frame with respect to the base to offset the normal axis of the frame and cause the frame to rotate about an eccentric axis which is ln alignment with the stable axis of the rotatable base. 1

'The sealing-in head of this invention accommodates a bulb or enclosing vessel 21 of a discharge device, such as a vthermionic amplifier tube, in which a plurality of electrodes are suitably spaced and the electrodes are provided with leading-in conductors which are sealed to the wall of the bulb for connectingthe electrodes to an external circuit. Generally, the leading-in wires for the electrodes are combined in a single press' which forms part of the stem of the device and are connected to terminal prongs on a base attached to one end-0f the device. j Various operating conditions may require avyariation of the location of the leading-in wires of the electrodes,

for instance, to increase the insulating paths 'between the various electrode leading-in wires or to decrease the length of the leading-in wires and realize negligible inductance inthe conductors lparticularly for ultra-high frequency operation of the device.

In distributing the various leading-inwires of the electrodes,*it has been found preferable to project the leading-in wire for the anode or grid or both through the top of the vessel 21. When a single leading-in wire is brought out through the top of the vessel or bulb along the axis of the bulb, the ordinary sealing head is adequate for lators and materially decreases production due to the time and care required to produce the seals.

The sealing head` f this invention overcomes these diiculties and in order to realize the facility of making these seals in accordance with this invention the various operations of sealingin the conductors will be described.

For purposes of illustration, the drawing shows a device in which the leading-in conductors for a grid or control electrode and an vanode project 65 through the top -of the bulb while an electron emitter or cathode has its leading-in wires sealed through the stem, the grid and anode leading-in wires being the sole supports of these electrodes. Such a device is disclosed and claimed in my 'copendingapplication, Serial No. 753,447, filed November 11, 1934. The bulb 21 is'of the usual pearshaped form and is seated in the bulb holder-'22 in the frame. The bulb is originally formedwith a 'tubular sleeve 28, as shown in Fig. 6, at the point through which the seal is to be made. Since the electrodes in the device shown are independently supported by their leading-in wires it is necessary to ,mount the electrodes in a suitable gauge or jig to insure accurate alignment and spacial relation between the electrodes in the' 5 final assembly. f In accordance with this invention the electrode jig comprises an elongated tubular metallic member 29 which is held in the bulb by a closure me'mber 30, such as a tapered stopper or plug. A 10 cylindrical metallic gauge or insert 3l is posltioned within the tubular member 29 and has a diameter slightly less than the internal diameter of a, helical grid which is mounted on two parallel support wires 32 and located within the cylindri- 15 cal orifice between the insert 3l and the tubular member 29. A metallic block 33 is positioned on the external surface of the tubular member 29 and is machined to receive an anode 34, the block and insert being pinned to the tubular member 29 20 l to prevent movement'. Each of these electrodes is provided with a leading-in conductor or wire 35 which carries a glass bead 36 having a depending skirt portion.31, the bead and skirt portion being preformed on the wire preliminary to inserting 25 the electrode inthe jig. It will be noted from Fig.

6 that the bead 36 is situated in the tubular sleeve 23.0fk the bulb so that the top thereof is slightly below the edge of the sleeve 28. A flexible hose 38 is connected to the tubular member 29 and the 30 nipple I6 of the standard, to facilitate the passage of a non-oxidizing gas, such as nitrogen, or

air, into the bulb 21 through the holes 39 in the tubular member 29 directly below the block 33.

In order to seal the leading-in wire, for in- 35 stance; the anode leading-in wire, in the bulb 21, vthe lock nut 24 is turned in a counter-clockwise direction and the frame with the bulb held therein is shifted to one side until the conductor 35is in alignment with the normal axis of the 40 standard I2 -and base lll whereupon the nut 24 is tightened to prevent movement of the plate l1 from its altered position. When the head ls advanced to the sealing position on the conveyor, it will be rotated about an axis passing through 45 the standard, bulb sleeve 28 and conductor 35. Two opposed burner llames 40 are directed toward the sleeve 28 to render `the glass plastic until it collapses about the bead 35 and the conductor 35 to form a homogeneous union with the bead. 50 During the fusing operation, air or gas entering the bulb equalizes the internal pressure with respect to the external pressure to prevent puncturing of-the plastic glass in the vicinity of the seal yand to aid in the formation by avoiding undue 55 strains in theglass. vSince the hottest part of the flame is at the point where the sealing is performed no detrimental elects occur in the other seal which passes through the broad part of the flame during each revolution of the head. co After the completion of the seal as described above, the head is moved to an inactive position so that the operator may adjust the head for sealing the other conductor in the top of the bulb. To accomplish this, the operator loosens the nut 65 24 and shifts the frame to `a position wherein the conductor 35 of the grid is in alignment with the normal axis of .the standard and base and when this adjustment is made the operator tightens nut 24 to maintain the adjustment. The 70 head is advanced to a second sealing position and is rotated to seal the grid leading-in conductor 35 in the bulb in the same manner as described in connection with the anode leading-in conductor. I 75 After the seals are completed at the top of the Abulb the frame may bey shifted to a central position as shown in Fig. 3. In this position the electrode jig may be removed by releasing the hose coupling 38 from the nippleA I6 and withdrawing the plug 30 from the bottom of the bulb. In

removing theA jig care should be exercised, to

prevent (damage to the grid and alteration of the spacing between the grid and the anode which remain in position in the lbulb due to their attachment to the supporting leading-in conductors. 'I'he completion of the sealing-ln process consists in mounting a stem holder 4| on the nipple I6 of the standard l2. A glass stem 42 supporting a cathode or electron emitter-,(not shown) is mounted on the holder 4| with the exhaust tube 43 extending through the V.center of the holder. 'I'he head is then advanced to a third position on the conveyor and rotated in the flames of two opposed burners 44, to seal the neck of the bulb to the iiare of the stem 42.

In the form of the invention shown in Fig. 1 the standard is rigidly fastened to the rotatable `base and only the frame is moved so that it is necessary to provide a flexible coupling between the bulb and the standard. In a modification of the invention shown in Fig. 4 the tubular member 29 which forms part of the electrode jig may bedirectly mounted on the top of the standard. In this construction, a rotatable sub-base 45 is providedwith a diametrical groove or slot 46. The standard I2 is provided with a circular flange termination 41 which slides in the groove 48 while the stem of the standard extends through a central aperturev in a connecting block or base portion 48 which supports the upright posts I9 and 20. At the ends of the diametrical slot 46 are stopV pins 49 which extend through the bottom of the rotatable sub-base 45. In this construction the frame of the head which includes the upright posts, standard and block 48, may be reciprocally shifted in a horizontal direction and adjusted in position by `the nut 24, to align the conductor to be sealed in the top of the bulb along the axis of the sub-fbase 45, the axis of the conductor being normally eccentric with respect to the axis of the bulb. Since the 'standard is shifted with the frame it is necessary to by-pass the air passageway around the slot 46 and this is accomplished by forming parallel passageways 50 and 5| inthe sub-base 45 and base portion 48, respectively, to communicate with the orifices in the spindle and standard I2. The passageways 50 and 5| are provided withnipples 52, to receive the ends of a h ose connection 53 whereby air or gas projected Vthrough the spindle is conveyed to the interior of the bulb to perform the same function as described in connection with Fig. 1. 'I'his arrangement permits the location of a stem mount or a separate jig directly on the standard to align the electrodes with respect to the bulb prior to completing `the sealing operations of the leading-in wires in the top of the bulb and the stem to the lower end of the bulb.

While the invention has been disclosed as applied to a discharge device with two eccentric conductors, it should be understood that the heads of this invention are not limited to such a specific application since it is obvious that the invention may beapplied to other forms of bulbsin which one or more than two conductors are sealed in eccentric positions with respect to the axis of the bulb and therefore the invention is only to be I limited within the scope of the appended claims.

What is claimed is:

1. A head for a sealing-in machine comprising a bulb holder,a rotatable base supporting said bulb holder, and means for offsetting said bulb holder with respect to the axis of said base.

2. The combination in a sealing-in machine .3 comprising a holder adapted to support a bulb having'an aperture eccentric with respect to the axis of the bulb, an electrodesupporting member associated with said holder and adapted to be inserted into the bulb in said holder for aligning 10 a conductor on an electrode with respect to the eccentric aperture, a rotatable base, and a slidable coupling between said holder and base for locating the bulb aperture and electrode conductor in alignment with the axis of said base. l5

'3. The combination in a sealing-in machine comprising a head including a holder for supporting a bulb having an aperture eccentric with respect to the axis of the bulb, an electrode mount adapted to be inserted into the bulb for aligning 20 a conductor on an electrode with respect to the eccentric aperture, a rotatable base, a slidable coupling between said holder and base for locating the bulb aperture and electrode conductor in alignment with the axis of said base, and a 25 tubular standard associated with said base'and holder for injecting an air supply into said bulb.

4. A head for a sealing-in machine, comprising a bulb frame including parallel upright members and a slotted connecting member, a rotatable 30 base, means coupling said connecting member to said base, a hollow standard extending through said slotted connecting member, an electrode jig adapted -to be enclosed in the bulb, and an air supply coupling member connecting said jig to 35 said standard.

5. A head for a sealing-in machine comprising a bulb frame including-parallel upright members and a connecting member, a rotatable base,

means coupling said connecting member to said 4d base, a hollow standard extending through said connecting member, a jig adapted to be enclosed 'n the bulb, an air supply coupling member connecting said jig to said standard, and means for adjusting said frame laterally with respect -to 45' said base.

6. A head for a sealing-in machine comprising -a bulb frame incllfding parallel upright members ,an offset position in a fragile bulb by means of a rotary head including a frame for the bulb and a base supporting the frame, which involves the method of mounting the bulb having an eccentric aperture in the top thereof in said frame, positioning a conductor having a preformed bead seal within said bulb with the bead seal positioned in saideccentric aperture, shifting said frame to locate said aperture and conductor in the same axis of said base, and fusing saidbead seal in said bulb "by the rotary action of said head in a burner flame adjacent the junction of said bead seal and apertured bulb. Y 70 8. The art of machine sealing a conductor in an offset position in a fragile bulb by means of a rotary head including a frame for the bulb and a base supporting the frame, which involves the aperture in the top thereof in said frame; posi, tioning a conductor having a preformed bead seal `within said bulb with the bead seal extending through said eccentric aperture, shifting said frame to locate said aperture and conductor in the same axis of said base, fusing said bead seal to said bulb by the rotaryaction of said-head in said electrodes having their conductors with preformed bead-seals thereon projecting upwardly in spaced relation, placing said jig on a central standardof a frame on a rotatable base, supporting a glass bulb on said frame to enclose said electrodes with the conductors extending through offset lapertures in the top thereof, shifting said frame to align one of said conductors with the axis of said base, rotating said frame, fusing the aligned apertured bulb and bead seal on one conductor, shifting said frame v to align the other conductor with the axis of said base, fusing said Vlast mentioned aligned apertured bulb and conductor, and removing said bulb and electrodes lfrom said frame and jig.

10. A head for a sealing-in machine comprising a bulb support, a mount support adapted to `posi tion an, electrode within the b ulb, a leading-in conductorextending from the electrode eccentric with respect to the axis of the bulb and projecting through ,said bulb, a rotatable base connected to said bulb support, and means for 'slidably shifting said bulb support with respect to said base to align the leading-in conductor extending tnrugn the bulb with the stable axis of said base. v

11. A rotatable head for a sealing-in machine comprising a frame having a slotted portion, a standard extending through said slotted portion and positioned within said frame, and means for f locking said standard in said frame eccentric `with respect to the normal axis thereof.

12. A rotatable head for a sealing-in machine comprising a frame having a base portion, a

standard projecting from said base portion, a

sub-base portion adjacent said base portion, and interconnecting means joining said base and subbase portions for slidably adjusting said base portion transversely with respect to Said subbase portion.

13. A rotatable head for a sealing-in machine vcomprising a frame having a slotted portion, a

rotatable base, a standard extendingfrom said y base through the slotted portion of said frame, 20.

and means for locking said frame in various ec- Acentric positions with respect to said standard.

14. A rotatable head fora sealing-in machine comprising a base having a diametrical channel, a frame superimposed on said base, a central standard attached to said frame and having an enlarged end portion slidable in said channel, means for adjusting the position o said frame with respect tosaid base, and a exibie tubular connection between said base and frame. f

15. A rotatable head for a sealing-in machine comprising a base having an elongated channel, a frame superimposed on said base, a central standard attached to said frame 'and having an enlarged end portion slidable in said channel, v

means for adjusting the position of said framewith respect t'o 'said base, and a locknuton said standard adjacent said frame for adjusting said frame eccentric with respect to said base. a

x JOSEPH P. LAICO. o

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