US3013326A

US3013326A - Tube assembly mechanism

Info

Publication number: US3013326A
Application number: US708586A
Authority: US
Inventors: Gerhard A Flodberg
Original assignee: Raytheon Co
Current assignee: Raytheon Co
Priority date: 1958-01-13
Filing date: 1958-01-13
Publication date: 1961-12-19
Anticipated expiration: 1978-12-19

Description

Dec. 19, 1961 G. A. FLODBERG 3,013,326

TUBE ASSEMBLY MECHANISM Filed Jan. 13, 1958 2 Sheets-Sheet l fv ver/v70@ Gsm/Ana ,4. 42006596 Trae/vs Y Dec. 19, 1961 G. A. FLODBERG 3,013,326

TUBE ASSEMBLY MEcHANIsM Filed Jan' 13' 1958 2 sheets-sheet 2 :Z7 /6\; H /6 2 29 32 J Y 46 v A i /29 45 I 7276/'34 44 /N VEA/Tof? GERHARD A. FLaDE/Q@ A Trae/wey United States Patent 3,013,326 TUBE ASSEMBLY MECHANISM Gerhard A. Flodberg, Concord, Mass., assigner to Raytheon Company, a corporation of Delaware Filed dan. 13, 1958, Ser. No. 708,586 11 Claims. (Cl. 29-25.19)

This invention relates in general to mechanisms for tube assembly and more particularly to mechanisms for assembling the multielectrode portions of vacuum tubes.

The present day methods of assembling multielectrode vacuum tubes make use of manual assembly of individual parts wherein an operator or line of operators assembles each electrode by hand on a vertical electrode-holding device with the help of tweezers and gravity-feed principles. As each electrode must be handled almost continuously in the operation by the hand itself or by tweezers held in the hand, the possibilities of damaging the electrodes are very great and subsequent losses in materials, time and money result. in addition, in order to perform the delicate assembly of electrodes an operator is required to have steady hands and must be trained carefully. Usually a relatively lengthy period of time is required before sutiicient dexterity is achieved. Damage to electrodes is particularly noticeable in assembling grid electrodes wherein a misalignment of a grid occurs because of a loose tit in the mica spacers and undesirable gaps between grid wires arise as the grid is manually dropped over and is brushed against the cathode. Normally, when an operator trained in assembling a particular tube is switched to the assembly of a different tube type, additional training is necessary before adequate results are achieved. The quality of work varies greatly when a large number of operators is used and nonuniformity in tube characteristics results.

Although automatic or semi-automatic devices are presently used in tube assembly, these devices are conventionally relatively complicated and may require large amounts of space, The invention herein described provides a relatively simple assembly device that can be adapted to automatic or semi-automatic operation. An operator using this invention can learn to make acceptable tube assemblies in a very short time, within the first hour of operation. No additional training is necessary in changing from one tube type to another as the invention can be adapted to assemble a large variety of tube types. The automatic or semi-automatic feature of the device assures uniform quality and, hence, more nearly equivalent tube characteristics. Reduction in the number of operators needed to assemble a predetermined quantity of tubes and ultimate savings in tube production costs result. Other desirable features of the invention can be seen as the operation of the invention is further described herein.

The invention utilizes a series of separate sliding channels which hold the particular electrodes needed for assembly. An indexing bar is accurately aligned with each channel in turn. The indexing bar has means for receiving and holding a mica spacer that is used rat one end of the electrode assembly. As the bar is aligned in turn with each channel the electrode associated with that channel slides forward either manually or automatically and one end of the electrode is inserted into the spacer in its correct position with relation to the other` electrodes on the indexing bar. The last channel contains means for gathering the loose ends of the electrodes so that they can be inserted into and fastened to a second mica spacer that is located in the last channel. Means are provided to bring the indexing bar back to its original position after the electrodes and spacers have been fastened together and means are further provided to eject the electrode assembly from the indexing bar so that the assembly can be used in another step in the assembly line process. The entire operation takes place in less than a minute and the steps FIG. 4 shows a sectional View of the plate channel slide l that is part of the invention:

FIG. 5 shows a sectional view of the mica spacer slide and the gathering means that are a part of the invention:

FlG. 6 shows a mechanical stop used in the invention:

FIG. 7 shows a portion of the device used to operate said mechanical stop:

FIG. 8 shows the ejector and air-cleaning device used in the invention: and p FIG. 9 shows a partially exploded view of an electrode assembly that has been assembled by using particular embodiment of the invention.

The mechanism shown in the figures represents only one embodiment of the invention; in this case, a machine for assembling a double triode. However, as the description herein shows, similar mechanisms can be constructed and adapted'to assemble single triodes, tetrodes, pentrodes or other combinations of multielectrode tubes.

FIG. 1 shows an over-all pictorial sketch of the invention. The assembling mechanism is made up of four channel slides, 11, 12, 13, and 14, mounted in channels within the front portion of structure 15. Handles 16, 1'7, 18 and 19 are used to slide the bars forward in their respective channels. In the rear portion of structure 15 is mounted an indexing bar 10 that is capable of sliding in a channel within the rear portion of structure 15 in a horizontal direction perpendicular to the sliding motion of

channel slides

11, 12, 13 and 14. Indexing bar 10 is moved by means of handle 21. On the face of indexing bar 10 is an insert block 22 from which protrude two cathode locating pins 23 and two locking pins 24 which hold a mica spacer 32 such as is used in electron tubes and shown in FIG. 9. As handle 21 moves indexing teeth is caused to press against the end of restraining` lever 26 by the weight and pulley arrangement 27 which provides a force tending to move the bar 10 toward the left. The operator moves the bar to the right in opposition to this force and spring 54 causes lever 26 to engage one of the saw teeth and, thus allows the bar to be held in any of the four positions. When lever 26 is lifted by the operator by means of handle 2'8, the end of lever 26 is removed from the saw-tooth catch and, hencethe sawtooth arrangement is released and the bar 10, with its holding restraint removed, moves back to its first position whereby the insert 22 is again aligned with channel 11.

For this particular embodiment the channel slides 11, 12, and 13 each have a pair of grooved channels 29 that are shaped to hold the tube electrodes in the correct posi'- tion for essembly. Slide 11 holds a pair of cathodes, slide l2 holds a pair of grids, and slide 13 holds a pair of plates.

FIG. 2 shows a moredetailed sectional view of the cathode slide 11 assembly used to hold cathode electrodes 46 used in' the electrode assembly shown in FIG. 9. This` view shows one of the grooved channels 29 with cathode 46 resting in line with one of the cathode-locating pins 3 23 held in the insert block 22. The cathode slide 11 is moved forward until the cathode 46 is inserted over pin 23. Screw and nut arrangement 31 is set so that the slide is stopped when the screw hits plate 44 and there is no danger of damaging the cathodes or locating pins.

FIG. 3 shows a more detailed sectional view of a portion of the grid slide 12 assembly as the grid 45 is being inserted over the cathode 46. The grids 45 are held in grooves 29 that are shaped to prevent undesirable lateral or rockingV motion of the grids as the slide is moved forward. A screw and nut stop arrangement (not shown) is similarly provided at the handle end of the grid slide 12.

FIG. 4 shows a more detailed sectional view of a portion of the plate slide 13 assembly as the plate 44 is slid over the cathode and grid. Like the cathode and grid slides, the plate slide also has a stop arrangement at the handle end of the slide. lIn order to hold the plate 44 securely in the bottom mica spacer 32, the inserted ends of the plate are flanged open slightly. This is accomplished by providing projecting pins 55 in the insert block 22 (shown in FIG. l) so that, as the plate ends are inserted into the mica, the pins 55, having a slightly larger dimension than the plate ends, force the ends to open up.

FIG. shows a detailed view of top mica spacer slide 14 and the gathering means 47 used for holding the electrodes in position while the top mica spacer 43 is being assembled to the electrodes. The gathering means is shown also in FIG. 1 and consists of a pair of jaws 34 which can be opened and closed by the actuation of lever 35 to which the operator imparts a vertical motion. Lever 36 is used to raise the gathering jaws 34 to a position in which they loosely enclose the free ends of the electrodes. To prevent damage to the gathering jaws and to the assembled electrodes as the top mica spacer 43 is placed over the electrode ends, a mechanical stop 61 is moved into place as the jaws are brought upward. Theoperation of this mechanical stop is explained as follows with the help of FIGS. 6 and 7. As the gatherer is moved upward, pin 57 moves upward to4 strike leg mounted on a rotary plate 59 that is in turn mounted on a shaft 60, as shown in FIGS. 5 and 7. A plate 61 is mounted at the other end of shaft 60 as shown in FIGS. 5 and 6. When the gatherer is in its up position the rotary plate and, hence, the shaft is rotated against theforce of spring 62, thereby causing stop plate 61'to move to the position shown by the solid line in FIGS.4 5 and 6. In this position plate 61 acts as a stop to restrict the channel slide 14 from moving too far forward and, hence, prevent damage to the gatherer jaws. In this position the slide has moved forward enough so that the top mica spacer is in a position to allow the electrode ends to be inserted into the spacer. As the gatherer is moved downward, the pin 57 is removed from leg 58 and spring 62 causes the plate 59 and shaft 60 to rotate in theopposite direction. Thus, stop plate 61 is rotated to the position shown by the dotted line 63 and the' slide 14 is, therefore, allowed to slide forward a short distance further until screw 56 hits a second stop plate 64 that prevents damage to the electrode assembly. p Y

FIG.`8 shows a particular embodiment of the devices that are used to eject the completed electrode assembly and to clean outth'e insert block 22. The ejection of electrode assembly 65 is caused by moving a plunger 66 through thev hole 67 in the 'insert block 22 (shown also in FIG. 1). The plunger is moved when the solenoid 68is energized. The solenoid can be arranged to be energized by a microswitch (not shown) that is activated when the indexing bar returns to its initial position. As the plunger moves forward, it may, for example, be used Vto 'open a valve (not shown) which allows air to be injected through air hose 69 and out the holes in insert block 22. Thus, insert block is cleaned out and prepared for the next assembling operation. assembly 65 drops into tray 70.

FIG. 9 shows a partially exploded view of a completed electrode assembly that has been constructed by the assembling mechanism of the embodiment of the in vention that is shown in FIG. 1 to FIG. 4. The

mica spacers

32 and 43 at either end have openings 40, 41 and 42 into which the plates 44, grids 45 and cathodes 46, respectively, are inserted.

In order to assemble the double-triode tube of the embodiment described in the drawing the operator first places the bottom mica spacer 32 onto the block insert Z2 of the indexing bar 10 by sliding the spacer over the locating pins Z3. The spacer is held in the correct position in the insert 22 by means of locking pins 24. The indexing bar is positioned so that the insert is placed in a line with the cathode slide 11. The operator then slides the handle 16 of the cathode slide 11 forward and the two cathodes are pushed over the locating pins and inserted into the bottom mica spacer. The cathode channel slide is then withdrawn from the indexing bar and the indexing bar is moved to the right by means of handle 21 and is locked by means of the saw-teeth 25 in a position which lines up the cathodes in the block The ejected insert 22 with the grid slide 12. The operator then` slides the handle 17 of the grid slide 12 forward and the two grids are pushed over the cathodes and inserted into the bottom mica spacer. The grid slide and the indexing bar are very accurately aligned to prevent the grids from accidentally brushing the cathodes and separating the grid wires. The grid slide is Withdrawn and the indexing bar which now holds bottom mica spacer, cathodes and grids is moved to the right again and is locked into position in a very accurate alignment with the plate slide 13. The operator slides the handle 18 of the plate slide 13 forward and thereby pushes the plates over the cathodes and grids and inserts the plates into bottom mica spacer. As the plates slide forward, the ends of the plates that have been inserted into the spacer are flanged open' so as to rmly fasten the plates to the spacer. The plate slide is withdrawn and the indexing bar now holding the bottom spacer, cathodes, grids and plates is moved to the right again and is locked in position in very accurate alignment with the top mica spacer slide 14. Lever 36, which is attached to the gathering means 47, is moved upward until the gatherer jaws 34 loosely enclose the free ends of the electrodes. Lever 35`is then pushed to a locked position to close the gathering jaws, thereby causing the ends of the electrodes to be drawn together in Va correct alignment preparatory to placing the top mica spacer 43 in position.

When the gathering jaws are locked, the operator slides the handle 19 of the top mica spacer slide 14 forward and thereby pushes the micar spacer onto the ends of the electrodes. Mechanical stop 61 prevents the slide fr'ornrnoving too far forward and damaging the gathering jaws. When the topmica spacer is in position the operator pushes lever 35 downward to open the gathering jaws and then pushes lever 36 downward to lower the gathering mechanism to its original position. When the gatherer moves downward, mechanical stop 61 is rotated to its inoperative position. The slide 14 is then moved a slight distance forward to position the top mica'relatively firmly over the electrodes. The slide is then withdrawn slightly and slid forward again with a relatively large force in order to flange open the ends of the plate electrode and thereby to tirmly lock the top spacer in place over the electrode structures. ing the plates onto the top and'bottom spacers it is assured that the plates, grids and cathodes are all thus firmly held in place between the top and bottom mica spacers. The slide 14 is then withdrawn to its original position.

Now that the electrodes are assembled, the operator By lock-` lifts handle 28 which removes the lever 26 from the sawteeth 25 at the bottom of the indexing bar, and the indexing bar carrying the assembled electrodes is returned to its initial position opposite the cathode slide 11 by means of weight and pulley device 27. When the bar has moved to its initial position at the left, a microswitch is activated and solenoid 68 is energized. The energization of solenoid 68 causes the plunger 66 to move forward rapidly and strike the bottom mica spacer, thereby causing the assembled electrode structure to slide off the locating pins. Thus the electrode assembly is ejected from the indexing bar and is caused to fall into a tray 70 underneath the assembly mechanism. As the plunger moves forward, a valve is actuated and air is caused to be injected into the system through the air hose 69 and out the holes in the insert 22. Hence, any residue left in the insert is cleaned out and the system is left ready for use in assembling another electrode structure.

The embodiment shown in the drawing and described herein is not to be construed as representing the only embodiment of the invention. For instance, many of the manual features, such as the handles used to operate the indexing bar, the electrode-holding and spacer-holding slides, the gathering means and the indexing bar release may be replaced with some sort of automatic device which may use spring, hydraulic and/or electronic `means associated with it to bring about the correct sequence of operation. The invention can be adapted to assemble the electrodes for a large variety of tubes including single triodes, double triodes, tetrodes, pentodes or other combinations of multielectrode tubes. A large number of microswitches and solenoids may be used in the automatic sequencing of many of the operations. The entire structure may be mounted horizontally or ot the horizontal in order to give the operator the most convenient visual operation. Hence, the invention is not to be limited to the embodiment described herein except as defined by the appended claims.

What is claimed is:

'1. An electrode assembling mechanism comprising a structure provided with a plurality of channels, movable indexing means including means for holding a first spacer for successively aligning said first spacer with each of said channels, holding means slidably supported in said channels, all but one of said holding means being adapted to receive a variety of electron tube electrodes and said one of said holding means being adapted to receive a second spacer, said holding means being slidable in said channels toward and away from said first spacer as said irst spacer is laligned with each of said channels whereby the outer ends of said electrodes are successively inserted into said rst spacer and said second spacer is mounted on the inner ends of said electrodes, and means for fastening said irst and second spacers to said ends of said electrodes.

2. An electrode assembling mechanism as described in claim 1, wherein there is provided a means adapted to be interposed between said spacer-holding means and said indexing means for gathering and holding said inner ends of said electrodes in a fixed relationship as said second spacer is mounted on the inner ends of said electrodes.

3. An electrode assembling mechanism as described in claim l, wherein there is provided a means for ejecting said assembled electrodes from said electrode assembling mechanism.

4. An electrode assembling mechanism as described in claim 3, wherein said ejecting means comprises a plunger means for striking said assembled electrodes, and solenoid means for moving s-aid plunger.

5. An electrode assembling mechanism as described in claim l, wherein there is provided a means for restricting the length of travel of each of said electrode-holding means and said spacer-holding means.

6. An electrode assembling mechanism comprising a stmcture provided with four channels, movable indexing means including means -for holding a iirst spacer for successively aligning said iirst spacer with each of said channels means for holding cathodes, means for holding grids, means for holding plates and means for holding second spacers, each of said holding means being supported in one of said four channels and being slidable toward and away from said irst spacer as said first spacer is aligned with each of said channels whereby one of the ends of each of said cathodes, grids, and plates is successively inserted into said iirst spacer and said second spacer is mounted on the other ends of said cathodes, grids, and plates, and means for fastening said iirst and second spacers to said cathodes, grids, and plates.

'7. An electrode assembling mechanism comprising a structure provided with four channels, movable indexing means including means for holding a -irst spacer for successively aligning said first spacer With each of said channels, means for holding a cathode in a rst of said channels, means for holding a grid in a second of said channels, means for holding a plate in a third of said channels, means for holding a second spacer in `a fourth of said channels, each of said holding means being supported in one of said four channels and being slidable, toward and away from said first spacer as said first spacer is aligned with each of said channels whereby one of the ends of said cathode, grid, and plate is successively inserted into said lirst spacer and said second spacer is mounted on the other ends of said cathode, grid, and plate, and means for fastening said iirst and second spacers to said cathode, grid, and plate.

8. An electrode `assembly mechanism comprising a structure provided with a plurality of channels, a plurality of holding means supported in said channels, a first quantity of said holding means adapted 'oo receive a variety of electrodes and the remaining qu-antity o'f said holding means adapted to receive spacers, mounting means supported by said structure in the vicinity of said channels, movable indexing means supported by said structure for successively aligning said mounting means and each of said channels, said holding means and said mounting means being relatively movable toward and away from each other at each successive alignment of said channels with said mounting means, said spacers and said electrodes thereby being mounted on and supported by said mounting means to provide an electrode assembly, and means for fastening said electrodes to said spacers.

9. An electrode assembling mechanism comprising a structure provided with a plurality of channels, -a plurality of holding means supported in said channels, all but one of said holding means adapted to receive a variety of electron tube electrodes having outer and inner ends and said one of said holding means adapted to receive a Ilirst spacer, a second spacer-holding means, movable indexing means for successively aligning said second spacerholding means and each of said channels, said plurality of holding means and said second spacer holding means being relatively movable toward and away from each other as said second spacer-holding means is successively aligned with each of said channels, the outer ends of said electrodes Ibeing thereby successively inserted into said second spacer and said first spacer being thereby mounted on said inner ends of said electrodes, Iand means yfor fastening said spacers to said ends of said electrodes.

10. An electrode assembly mechanism comprising a structure provided with a plurality of channels, a plurality of holding means supported in said channels, `a first quantity of said holding means adapted to receive a variety of electrodes and the remaining quantity of said holding means adapted to receive spacers, mounting means supported by said structure in the vicinity of said channels, moveable indexing means supported by said structure for successively aligning said mounting means and each of said channels, said holding means and said mounting means being relatively movable toward and away from 7 each other at each successive alignment of said channels with said mounting means, said spacers and said elec trodes thereby being mounted on and supported by said mounting means to provide an electrode assembly.

1l. An electrode assembling mechanism comprising a structure provided with a plurality of channels, a plurality of holding means supported in said channels, all but one of said holding means adapted to receive a variety of electron tube electrodes having outer and inner ends and said'one of saidV holding means adapted to receive a first spacer, a secondspacer holding means, moveab1e indexingmeans for successively -aligning said second spacer holding means and each of said channels, said plurality of holding means and said second spacer hold- 8 ing means being relatively moveable toward and away from each other as said second spacer holding means is successively aligned with each of said channels, the outer ends of said electrodes being thereby successively inserted into said second spacer and said first spacer being thereby mounted on said inner ends of said electrodes.

References C ited in the le of this patent UNITED STATES PATENTS 1,930,630 Conn Aug. l, 1933 2,721,374 Pilas Oct.- 25, 1955 2,807,866 Gartner Oct. l, 1957 2,842,832 Chase et al July 15, 1958 2,884,684 Wollte et al. May 5, 1959