US2788028A

US2788028A - Tubulation and glass ejection system

Info

Publication number: US2788028A
Application number: US421406A
Authority: US
Inventors: Lloyd S Hartley; Leonard A Malewicz
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1954-04-06
Filing date: 1954-04-06
Publication date: 1957-04-09
Anticipated expiration: 1974-04-09
Also published as: FR1121837A; GB768495A

Description

L. s. HARTLEY ET AL 2,788,028 TUBULATION AND GLASS EJECTION SYSTEM April 9, 1957 Filed April 6, 1954 INVENTORS: LEONARD A. MALEWICZ,

LLOYD s. HARTLEY,

THE! ATTO EY.

United States Patent 6 F TUBULATION AND GLASS EJECTION SYSTEM Lloyd 5. Hartley and Leonard A. Malewicz, Schenectady,

N. Y., assignors to General Electric Company, a corporation of New York Application April 6, 1954, Serial No. 421,406

Claims. (Cl. 141--65) Our invention relates to the manufacture of electronic tubes and pertains more particularly to equipment for evacuating the glass envelopes of electronic tubes.

In some equipment provided for the manufacture of electronic tubes, evacuation of the glass envelopes is one of the final operations. To assist in accomplishing this operation the tubes are each provided with a glass exhaust tube or tubulation adapted for extending into a compression head. The compression head is adapted for being operated to grip the tubulation in such a manner as to hold it in sealed communication with an exhaust chamber provided in an exhaust head. The exhaust head is adapted for being indexed to an exhaust position at which a vacuum is drawn on the chamber therein thereby to effect evacuation of the envelope through the tubulation. Thereafter, the tube is tipped-off. That is, a seal is effected between the tube proper and the tubulation very close to the former, and the tube and tubulation are separated, the tubulation having fulfilled its usefulness. Following tip-off the tubulation remains lodged in the compression head and must be removed. Additionally, on occasions broken off fragments of tubulation drop into the exhaust chamber and tend to affect adversely the operation of a vacuum control valve provided. therein. Heretofore, tubulation-pulling devices have been employed which, following tip-01f, operate to grip the externally extending portion of the tubulation and pull it out of the compression head. Such devices, however, add to the cost of the machine and were ineffective for removing broken glass from the exhaust chamber. Accordingly, a primary object of our invention is to provide, in tube manufacturing equipment, a new and improved arrangement for effecting tubulation and broken glass ejection from the tube exhaust means thereof.

Another object of our invention is to provide a single means effective for both ejecting tipped-off tubulations and in cleaning out the exhaust means of broken glass.

Still another object of our invention is to provide tubulation and broken glass ejecting means which reduces substantially the cost of constructing tube manufacturing equipment.

Further objects and advantages of our invention will become apparent as the following description proceeds and the features of novelty which characterize our invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In carrying out the objects of our invention, we provide an exhaust head including an exhaust chamber and a compression head for holding a tubulation in sealed communication with the chamber. Vacuum means is provided for evacuating the chamber .to exhaust a tube through the tubulation. The chamber is. adaptedfor being indexed, following tip-oif of thev tubulation, to a position at which means are eiffective for releasing the tubulation from the compression head, closing the chamber to the vacuum means and admitting a blast of compressed air into the chamber whereby the tubulation, and" glass frag: ments in the chamber are ejected. a

Patented Apr. 9, 1957 For a better understanding of our invention, reference may be had to the accompanying drawing in which:

Fig. 1 is a perspective and somewhat schematic illustration of our invention; and

Fig. 2 is an enlarged perspective view of an exhaust head partially sectionalized to illustrate constructional details of our invention.

Referring to Fig. l, we have shown an exhaust head generally designated 1 suitably mounted on one end of an arm 2. The other end of the arm 2 is pivotally mounted at 3 on a suitable machine turret 2a. By other means not shown, the turret 2a is adapted for being actuated to index the head 1 at a plurality of operating stations and which the illustrated station is the tubulationejection station.

As better seen in Fig. 2, the head 1 includes an exhaust chamber 4. The bottom side of the chamber 4 is adapted for being closed by a valve 5. For this purpose we prefer employing a pinch-off valve formed of rubber or any similar resilient material. The valve 5 is connected to a tube 6 and is provided for controlling communication between the chamber and vacuum pumping means not shown. The valve 5 is adapted for being operated by a clamp 7 pivotally mounted in the head at 8. Provided for cooperating with the clamp is a lever 9 pivotally mounted in the head at 10. The lever 9 carries at one end thereof a roller 11 which engages the outer surface of the clamp 7. This surface is so formed that in one rotative position of the lever 9 the roller 11 actuates the clamp 7 inwardly against the rubber valve for pinching. off the valve and thereby closing the chamber 4 against the vacuum being drawn thereon through the line 6. In another rotative position of the lever 9 the natural resilience of the valve 5 prevents the clamp 7 from closing the valve and, thus, the vacuum is permitted to be drawn on the chamber 4 through the line 6.

The head 1 further includes a compression head 12 adapted for gripping and maintaining or holding the exhaust tube or tubulation 13 of an electronic tube to be evacuated in sealed communication with the exhaust chamber 4. The compression head 12 includes a resilient port member 14 formed of rubber or any similar resilient material. The port member 14 includes a vertical bore or passage 15 for receiving the tubulation 13 and is suitably seated on a shoulder 16 formed in a vertical boss 17 comprising part of the exhaust head 1. The boss 17 is externally threaded and receives thereover an internally threaded cap 18. The top portion of the cap 18 is centrally apertured, permitting extension therethrough of a substantially frusto-conical upper portion of the resilient port member 14. The just-described arrangement is such that when the cap is rotated in one direction, it screws down on the boss 17 and is elfective for compressing the resilient member 14 thereby to displace centripetally the wall of the bore 15 for sealing the tubulation 13 in the head. When rotated in the opposite direction the cap 18 tends to unscrew from the boss '57 and permits the member 14 to assume its unrestrained configuration whereby the tubulation 13 is released. As seen in Fig. 2, a limiting means in the form of a shoulder 19 is provide-cl in the head just beneath the member 14 for determining the extent of insertion of the tubulation 13 in the head. In the arrangement described to this point the evacuation of an electron tube envelope may be effected by inserting the tubulation 13 thereof in the compression head 12, rotating the cap lfithereby to compress the member 14 for sealing the tubulation in the head and opening the valve 5 by rotating the lever 9 to a position in which it is ineffective for actuating the clamp 7 to close the vacuum control valve 5. Thus, through the line 6 the vacuum pumping means (notshown)--willbe eifective for drawing a vacuum on the chamber 4 thereby to evacuate the tube through the tubulation 13.

Following evacuation of the electron tube envelope it is tipped-off. That is, a seal is elfected between the tube and tubulation thereby to seal the envelope, and the envelope and tubulation are separated. Thus, the tubulation 13 is left in the compression head 12 in the manner shown in the drawing. In order to eject the tubulation 13 from the compression head we have provided means for releasing the tubulation from the compression 'head and admitting a blast of compresed air into the exhaust chamber 4.

The releasing means, which also operates to accomplish gripping of the tubulation at other stations, comprises a cam shown in Fig. 1 and suitably secured to a collar 21 fastened securely to the cap 18. The cam. 20 is adapted for cooperating with stationary actuating means such as an air-operated piston 20a which is effective for actuating the cam when the head 1 is indexed into the tubulationejection position or station for rotating the collar 21 to unscrew the cap 18 whereby the resilient port member 14 is permitted to expand for releasing the tubulation 13. It will, of course, be understood that, if desired, actuation of the cam 29 can be accomplished manually by an operator or attendant.

Provided for admitting compressed air into the exhaust chamber 4 is a port 22 suitably formed in the head 1. Fitted to the port 22 is one end of an air line 23. The air line 23 is connected to a solenoid valve generally designated 24 mounted on the arm 2 and provided for controlling the flow of air through the port 22. On the side of the solenoid valve 24 opposite the air line 23 is provided a nipple 25 adapted for cooperating with a vertically moveable coupling member 26. The coupling member 26 is part of an arrangement stationarily mounted at the tubulation ejection position of the head, above referred to. This arrangement comprises a telescoping structure fitted to another air line 27 and including a coil spring 26a arranged to bias the coupling upward. By means of this structure the coupling member 26 is biased out of engagement with the nipple 25 and may be moved vertically into and out of coupling engagement with the nipple 25 when the head 1 is at the tubulation ejection position. Thus, connection is made between the line 27 and the valve 24 for supplying compresed air in a controlled manner to the exhaust chamber 4 through the passage 22. The valve 24 is adapted for normally preventing air passage therethrough. The valve 24 opens to permit the passage of compressed air therethrough when the exhaust head 1 is indexed to the tubulation ejection position by completing an electrical circuit therethrough when the head is in this position. This is accomplished by means of a pair of contacts 28 connected by

lead lines

29 and 30 to the solenoid valve 24 and adapted for moving into engagement with a corresponding pair of brushes 31 when the head 1 is moved into the ejection position. One of the brushes 31 is connected by a line 32 to a power source generally designated 33. The other brush is connected by another line 34 to one side of a switch 35. The other side of the switch 35 is connected by a line 36 to one side of a solenoid valve 37 provided for controlling the flow of compressed air into the line 27 from a compressed air source (not shown) connected to the valve 37 by a tube 38. The other side of the solenoid valve 37 is connected by still another line 36 to the power source 33. The switch 35 is arranged to be controlled by a movable contact member 40 which is normally biased to a position in which the switch 35 is open. The contact member 40 is adapted for being actuated by a member generally designated 41 suitably connected by an arm 42 to the upwardly biased coupling arrangement referred to above and located at the tubulation ejection position. Actuation of the arm 42 can be accomplished by any suitable arrangement such as a cam 42a mounted on a relatively fixed frame of the machine for downwardly displacing the arm 42 and the attached coupling 26 and the contact-actuating member 41 when the head is in the tubulation ejection position. 01' course, if desired, the downward displacement can be effected manually by the operator. Thus, it will be seen that the contacts 28 and brushes 31 will be out of engagement and no circuit will be completed through the solenoid valve 24 whereby the line 23 will be maintained closed thereby to prevent admission of air into the exhaust chamber 4 through the passage 22 when the head 1 is out of the tubulation ejection position, as during evacuation of the chamber 4 by the vacuum means (not shown). Additionally, regardless of the position of the contact member 40, the power circuit to the air control solenoid 37 will be broken and no air will be supplied through the line 27 whenever the head is out of the tubulation ejection position. When, however, the head 1 is indexed to the above-referred-to tubulation ejection position, the cam 9 is actuated by means mounted on the machine frame, such as an air-operated piston 91: and is thereby rotated about its pivot 16 for actuating the vacuum valve clamp 7 thereby to close the valve 5 to prevent contamination of the vacuum system when the compressed air is admitted into the chamber 4 and the compression head passage 15 is opened by ejection of the tubulation. It will be understood that cam 9 can also be actuated manually, if desired.

Substantially concurrently with the actuation of cam 9 other stationary means such as the air piston 20 is effective for engaging the cam 20 thereby to rotate the cap 18 of the compression head for relieving the pressure on the resilient member 14 thereby to release the tubulation from the grip thereof. Following release of the tubulation 13 in the just-described manner the camming means 42 is effective for depressing the connecting member 42 thereby to actuate the coupling 26 downwardly against the bias of the spring 26 into coupling engagement with the nipple 25 for completing an air circuit therebetween. Additionally, downward actuation of the member 42 is effective for actuating the member 41 to close the switch 35. concomitantly the contact members 28 move into engagement with the brushes 31 whereby an electrical circuit is completed through the solenoid 24 for opening the line 23 to complete an air circuit between the lines 23 and 27 through the engaged coupling 26 and nipple 25. Additionally, the completed electrical circuit energizes the compressed air control solenoid valve 37 for admitting compressed air into the line 27. Thus, a blast of compressed air is admitted into the exhaust chamber 4 whereby the released tubulation 13 is ejected and any fragmentary glass in the chamber is blown out through the port 15. The air blast continues until the member 42 is permitted to rise under the influence of the cam 42 and the spring 26 whereby the coupling 26 is also moved out of engagement with the nipple 25. This action additionally elevates the member 41 for opening the switch 35 to break the control circuit whereby the solenoid 24 is deenergized for closing the line 23 to the atmosphere thereby to prevent contamination of the vacuum system during the exhaustion of a succeeding tube envelope.

Additionally, when the head 1 moves out of the tubulation ejection position, the circuit controlling the valve 24 is further broken by the contacts 28 moving out of engagement with the brushes 31. Thus, regardless of any intentional or accidental movement of the member 42 whereby the switch 35 might be closed the valve 24 will be elfective for maintaining the line 23 closed to the atmosphere thereby to prevent contamination of the vacuum means until the head is again moved into the tubulation ejection position.

Thus it will be seen that we have provided, for use with vacuumtube exhaust means, a new and improved single means effective for both ejecting tipped-off tubulations and in cleaning out the exhaust means .of broken glass following an exhaust operation. It will be seen further that not only does our structure provide a simply means for ejecting the tubulation and cleaning out the exhaust means but it is of such a nature that it will reduce substantially the cost of constructing tube manufacturing machinery of the type adapted for exhausting electronic tubes.

While we have shown and described a specific embodiment of our invention, We do not desire our invention to be limited to the particular form shown and described, and we intend by the appended claims to cover all modifications within the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. In envelope exhaust equipment, a chamber, holding means providing an opening into said chamber and eifective for sealably connecting an envelope tubulation in communication with said chamber, through said opening, said chamber being subject to accumulation of tubulation fragments, means for closing said chamber completely except for said opening provided by said holding means, and means for admitting compressed air into said chamber, thereby to eject said tubulation from said holding means and said fragments from said chamber.

2. In envelope exhaust equipment, a chamber, means for holding an envelope tubulation in communication with said chamber, said chamber being subject to accumulation of tubulation fragments, vacuum means for exhausting said chamber, means for admitting compressed air into said chamber, thereby to eject said tubulation from said holding means and said fragments from said chamber, and means for closing said chamber to said vacuum means during admission of said compressed air thercinto.

3. In envelope exhaust equipment, including a tubulation ejection position, a moveable head including a chamber and holding means, said holding means providing an opening into said chamber and being operable for sealably connecting an envelope tubulation in communication with said chamber through said opening, said chamber being subject to accumulation of tubulation fragments, said head being positionable at said tubulation ejection position, and means operable by movement of said head into said ejection position for releasing said holding means, for closing said chamber completely except for said opening provided by said holding means and for admitting compressed air into said chamber at said ejection position, thereby to eject said tubulation from said holding means and said fragments from said chamber.

4. In envelope exhaust equipment, a movable head including a chamber, means for holding an envelope tubulation in communication with said chamber, said chamber being subject to accumulation of tubulation fragments, vacuum means for exhausting said chamber, said head being positionable at a tubulation ejection position, means for closing said chamber to said vacuum means at said ejection positions and means for admitting compressed air into said chamber at said ejection position, thereby to eject said tubulation from said holding means and said fragments from said chamber.

5. In envelope exhaust equipment, a movable head including a chamber, means for holding an envelope tubulation in communication with said chamber, said chamber being subject to accumulation of tubulation fragments, vacuum means for exhausting said chamber, said head being positionable at a tubulation ejection position, means for closing said chamber to said vacuum means at said ejection positions, means for admitting compressed air into said chamber at said ejection position, thereby to eject said tubulation from said holding means and said fragments from said chamber, and means effective for permitting air passage through said last-mentioned means into said chamber only when said head is in said ejection position.

6. In envelope exhaust equipment including a tubulation ejection position, a movable head including a chamber and releasable holding means for holding an envelope tubulation in sealed communication with said chamber, said chamber being subject to accumulation of tubulation fragments, said head being positionable at said tubulation ejection position, means for releasing said tubulation from said holding means at said ejection position, and means at said ejection position for admitting compressed air into said chamber, thereby to eject said released tubulation and said fragments from said holding means and chamber.

7. In envelope exhaust equipment, a movable head including a chamber, releasable means for holding an envelope tubulation in communication with said chamber, said chamber being subject to accumulation of tubulation fragments, vacuum means for exhausting said chamber, said head being positionable at a tubulation ejection position, means at said ejection position for closing said chamber to said vacuum means, means at said ejection position for releasing said tubulation, and means at said ejection position for admitting compressed air into said chamber, thereby to eject said tubulation from said holding means and said fragments from said chamber.

8. In envelope exhaust equipment, a movable head including a chamber, releasable means for holding an envelope tubulation in communication with said chamber, said chamber being subject to accumulation of tubulation fragments, vacuum means for exhausting said chamber, said 'head being positionable at a tubulation ejection position, means at said ejection position for closing said chamber to said vacuum means, means at said ejection position for releasing said tubulation, means at said ejection position for admitting compressed air into said chamber, thereby to eject said tubulation from said holding means and said fragments from said chamber, and means operated by movement of said head out of said ejection position for preventing air passage through said lastmentioned means into said chamber.

9. In envelope exhaust equipment, an exhaust chamber, holding means disposed above said chamber and effective for holding the lower end of the tubulation of an envelope in communication with said chamber thereby to effect evacuation of said envelope through said tubulation, and means for admitting fluid under pressure into said chamber below said lower end of said tubulation, thereby to eject said tubulation from said holding means and to expel any loose matter from said chamber.

10. In envelope exhaust equipment, a chamber, holding means disposed above said chamber and effective for holding the lower end of the tubulation of an envelope in communication with said chamber, means for exhausting said chamber thereby to exhaust said envelope through said tubulation, and means for admitting fluid under pressure into said chamber below said lower end of said tubulation, thereby to eject said tubulation from said holding means and to expel any loose matter from said chamber.

References Cited in the file of this patent UNITED STATES PATENTS