US2295034A

US2295034A - Tipping-off apparatus

Info

Publication number: US2295034A
Application number: US353524A
Authority: US
Inventors: Walter J Geiger; Reginald J Ayres
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1940-08-21
Filing date: 1940-08-21
Publication date: 1942-09-08
Anticipated expiration: 1959-09-08
Also published as: GB551283A; FR878771A; DE733916C

Description

Sept. 8, 1942. w. J. GEIGER ETAL T I PP ING OFF APPARATUS Filed Aug. 21, 1940 5 Sheets-Sheet l lnvewtors WalL'ter J. Geiger, R inald J. Agres, 10%

Their" A'ttovneg.

Sept. 8, 1942. w. J. GEIGER EIAL TIPPING OFF APPARATUS Filed Aug. 21, 1940 3 Sheets-Sheet 3 as F UJ 15 m m .mlwp F n T d A vwm a .W h xi m and similar devices.

Patented Sept. 8, 1942 TIPPING-OFF APPARATUS Walter J. Geiger, Cleveland Heights, and Reginald J. Ayres, University Heights, Ohio, assignors to General Electric Company, a corporation of New York Application August 21, 1940, Serial No. 353,524

9 Claims.

Our invention relates to a method and apparatus for sealing the openings or conduits in the enclosing envelopes of electric lamps and similar devices through which openings or conduits the said devices are exhausted and gas filled. More particularly, our invention relates to a so-called tipping-off method and apparatus for closing and sealing the vitreous exhaust or pump tube which is in communication with the interior of the envelope of a lamp or similar device.

It is the usual practice to provide the enclosing vitreous envelopes of electric lamps, radio,

tubesand other similar devices with a vitreous exhaust tube or other vitreous tubulation extending from said envelope through which the envelope is exhausted and filled with gas, the said tube or other tubulation being subsequently sealed, usually by fusing it. Some difiiculty is experienced in performing the sealing or tipping-off operations at the high speed of operation of the automatic exhaust apparatus with which they must be associated. Such difiiculties are due largely to variations in thickness and composition of the vitreous walls of the exhaust passage which affect the rate of heating thereof and the time required to render them plastic, and to variations in the heat supplied by the sealing apparatus. However, most difiiculty is experienced when the lamp or similar device contains gas at greater than atmospheric pressure as the vitreous walls cannot then be heated to the temperature ordinarily permitted since they could not withstand the gas pressure without blowing out.

One object of our invention is to provide a method and apparatus for determining the heated condition of the vitreous walls of the exhaust passage in order to permit said passage to be closed and sealed more readily than heretofore. Such method and apparatus permits more rapid heating of the vitreous walls of the passage andv mechanical working of said walls, since accurate control of the heating operation is afforded and the proper operation of the mechanical means is assured.

Another object of our invention is to provide a method and apparatus for closing and sealing the exhaust passage in a vitreous portion of a device having a gas filling greater than the subatmospheric pressures normally used for lamps The difilcultywith which the exhaust passa e is closed increases greatly when the gas pressure approaches and exceeds atmospheric pressure as some mechanical means must be provided to bring the walls of said passage together. The mechanical means must be timed to operate after the vitreous walls of the passage are heated to a degree which renders them plastic and workable but before said walls are heated to a degree where they no longer have suflicient strength to withstand the gas pressure within the envelope. The period of time during which the vitreous walls are between these diiierent degrees of heat is extremely short in high speed apparatus and the dimculty of determining the condition thereof is greatly increased. When the gas pressure in the device approaches atmospheric pressure said device must ordinarily be cooled before the tipping-off operation is brought about in order to reduce the pressure as much as possible. To operate in this manner ordinarily takes up two of the sixteen stations of the exhaust apparatus and limits the production of said apparatus. Our invention provides a method and apparatus for ascertaining the individual heat conditions and proper mechanical pinching apparatus under these particular conditions of operation.

Another object of our invention is to provide a method and apparatus for closing and sealing a portion of the exhaust passage without actual contact with the heated vitreous walls thereof.

A still further object of our invention is to provide apparatus for closing, sealing and tipping-off the vitreous exhaust tubes extending from the envelopes of such devices at a high rate of speed, in combination with the high speed rotating type of exhaust apparatus.

Other objects and advantages of our invention will appear from the following detailed description of species thereof and from the drawmgs.

In the drawings, Fig. 1 is a plan view of one species of tipping-off apparatus comprising our invention in combination with the adjacent portions of an exhausting and gas filling apparatus; Fig. 2 is a side elevation of the essential parts of the tipping-off apparatus on a larger scale; Fig. 3 is a perspective view of lamp positioning mechanism associated therewith; Fig. 4

is an end elevation of pinching and operating portions of our apparatus; Fig. 5 is a side elevation of the pinching portion of the apparatus from which portions have been broken away; Fig. 6 is a perspective view of a clutch forming part of the operating portion of the apparatus; Fig. 7 is a. perspective view oflamp supporting and lifting portions of a modification of our invention; Fig. 8 is a side elevation of a second modification thereof; and Fig. 9 is a perspective view of an exhaust tube sealed by said second modification.

In Fig. 1, four adjacent heads III of the exhausting and gas filling apparatus appear, although it will be understood that duplicate heads are mounted at regular intervals in a circular path adjacent the periphery of the turret II. Each of the heads I accommodates asingle incandescent lamp I2, in this instance, and provides an exhaust port for receiving the vitreous exhaust tube I3 of said lamp I2 as shown in Fig. 2. The turret II is indexed in a counter-clockwise direction and advances the heads I0 from station A, the loading station, through station B and others (not shown) at which the exhausting and gas filling operations are-automatically brought about, and finally carries said head I0 to stations C and D- Such apparatus is preferably that disclosed in the Patterson Patent 1,662,045 and provides a driven shaft (not shown) below the turret I I for operating the parts thereof in proper time relation to the indexing movements of said turret II.

A lamp I2 is placed in the head In at station A by a movement wh ch inserts the end of the exhaust tube I3 (F 2) into the central openings in the guide I4 and the compression rubber I5. the movement be ng completed when said end rests on the shoulder I6 of the body I I of said head If). The compress on rubber I engages the exhaust tube I3 only with sufficient pressure to keep the lamp I2 in an upright position and is not caused to seal sa d tube I3 in the body I1 unt l stat on B is rem-had.

In the indexing movement which follows, said lamp I2 is carried into station B and into the space between the opposite legs of the yoke I8 as indicated in Fig. 3. The yoke I8 is a portion of a positioning means at this station which lifts and thereby re-positions said lamp I2 so that the lower end of the seal I9, the point of reference, is at a definite level. Such apparatus is not always required as the length of the exhaust tube I3 can often be controlled with sufficient accuracy to establish the position of said lamp I2 as desired. The said positioning means essentially comprises plates 2lI-2I on the opposite legs of the yoke I8 which are raised to a fixed level during every cycle of operation of said means. The plates 202I are located at opposite sides of the path of movement of the exhaust tube I3 and are actuated through a corresponding movement of the slide 22 which is connected to said yoke I8 through the rod 23. The slide 22 is located in the ways of the bracket 2i extending from a portion of the frame of the exhaust machine below the turret II and takes a position determined by the particular portion of the wedge shaped cam 25 located below the roller 26 on the lower end of said slide. The cam 25 is mounted on the arm 21 attached to the vertical shaft 28 in the bracket 24 and is actuated by the usual form of cam-operated means (not shown) on a driven shaft of the exhaust machine connected to said arm 21 through rod 29.

The plates III-2| engage the lower surface of the seal. I 9 of the lamp I 2 and hold said lamp I2 in this newly established position until the compression rubber I5 is squeezed to grip the exhaust tube l3. This latter operation is performed by turning -the cap 30 so that it is screwed down on the body I! of the head I0 and causes the guide I4 to squeeze the compression rubber I 5 and is brought about eithenby manual adjustment of the cam 3| on said cap 30 or by mechanical adjustment of said cam 3 I by a portion (not shown) of said exhaust machine. The compression rubber I5 expands laterally so that it seals the exhaust tube I3 in the body I! and grips said tube I3 with sufficient force to resist its withdrawal. Both the plates 20 and 2i are returned to their former position before the head I0 and lamp I2 are indexed from this station. In instances where the exhaust machine provides a head having rubber connection means of different construction into which the exhaust tube I3 must be forced, the upward motion of the positioning means may be sufficient to move the lamp I2.

Succeeding indexing movements of the turret I I carry the lamp I2 to other stations for periods which permit it to be repeatedly exhausted and flushed, and finally exhausted and gas filled in the usual manner, and finally carries said head IIJ to station C. While at this station, C, that portion of the exhaust tube I3 which is to be closed and sealed is preheated by the flames from the burners 32 and 33 which normally lie out of the path of movement thereof but are carried into operative relation to the exhaust tube I3 between the indexing movements of the head I 0. The burners 32 and 33 are mounted on opposite ends of the U-shaped manifold 34 and are moved into position by the rocking motion of the shaft 35 to which said manifold 34 is connected by the clamp 36 and the vertically disposed rod 31. The shaft 35, in turn, is held by the sidewardly extending arm 38 of the bracket 39 and is operated through arm 40, rod 4| and lever 42 which are portions of means actuated by a cam (not shown) on a driven shaft of the exhaust apparatus. The bracket 39 is a stationary member, as it is mounted on a portion of the frame (not shown) of the exhaust apparatus below the turret II.

In the course of the movement of the burners 32 and 33 to the operative position, the metal shield 43, which is attached to the top surface thereof, is carried under the lamp I2 and into engagement with the lower extremities of the seal I9 thereof which prevent further motion and positions the burners 3233 longitudinally along the exhaust tube I3. positioning action, the shield 43 also serves to direct the splash and heat of the pre-heating flames away from the upper portion -of the exhaust tub I3 and the other parts of the lamp I2. The gas and air mixture used by the burners 32 and 33 in this instance is conducted to the manifold 34 through the flexible hose 44.

The period of operation of the burners 32 and 33 is relatively short and the exhaust tube I3 is heated to some point below that at which it becomes plastic and would change shape due to a difference between internal and atmospheric pressures. The lamp I2 shown contains gas at greater than atmospheric pressure and the heating of the exhaust tube I3 must not be such that said gas pressure can cause it to bulge. In every instance, the gas pressure within the lamp I2 is at a greater pressure than it will finally be because of the heat said lamp I2 contains at this time.

After a predetermined period at station C, the exhaust head I0 carries said lamp I2 to station D where the pre-heated portion of the exhaust tube I3 is again heated but this time only the exact amount required to bring said tube I3 to In addition to its a very definite degree of plasticity. The exhaust tube I3 must not soften to such apoint that the gas pressure within the lamp I2 can cause an opening to be blown therethrough or cause a substantial change in shape thereof but must be carried to such a point that it can be pinched shut by the jaws 45-46 (Figs. 1 and 2). To control the heating operation this closely is extremely difficult and necessitates separate control for each case due to variations in the amount of heat in the exhaust tube I3 at the start of the tipping operation and the heating effect of each of the different burners and differences in the size, distribution and composition of said exhaust tube l3. In many instances, the rate of indexing the exhaust heads I8 is so rapid that additional pre-heating burners must be placed at the station ahead of station C since the operating period of the apparatus at station D is shared by the burners 41-48 and the pinching jaws 45-46. The burners 41-48, as shown in Figs. 1 and 4, are each mounted on one end of rigid pipes .49 and 58, respectively, which pipes are held by a plurality of arms extending from the metal block 52 which in turn is.supported by the metal supports 53 on the extending portion 54 of the frame of the exhaust machine. The combustible gas mixture enters the opposite ends of the pipes 48-58 through the rubberhose 55, and preferably is made up of gases producing more heat than in prior instances. The burners 41-48 andpipes 49-58 are stationary members since they are located out of the path of movement of the head I8 and lamp I2 from station C to the unloading station D.

The heating period of the burners 41-48 is controlled by means engaging the lamp |2 during its movement to station D and comprises the pressure member or cup 56, which receives the upper portion of the exhaust tube I3 and the seal I9 of said lamp I2, and the resilient clip or holder 51 which receives the neck of the lamp bulb at the end of said movement. The cup 56 is mounted on the outer end of the arm 58 and is held at a position which permits the seal I8 to pass over the slotted bottom 59 thereof and is immediately moved up until said bottom 59 is against the lower extremity of said seal I9. The arm 58 is attached to the shaft 68 which is supported by the arms 6I-6I on opposite sides of the block 52 and is actuated by the arm 62 on the end of said shaft 68 which is connected to the rod 63 and the spring 64. The rod 63 is the only illustrated portion of the cam controlled operating means actuated by the main drive shaft of the exhaust apparatus and at this time adjusts said rod 63 so that the contracting force of the spring 64 is responsible for the movements of the cup 56. In this manner, a known amount of upward pressure is exerted against the cup 56 and the upper portion of the lamp I2, and a known tension is placed in the exhaust tube I3. Very soon thereafter, the exhaust tube I3 softens to a point where it is lengthened by the tension under which it is kept, and the resulting upward movement of said cup 56 carries the end of the screw 65 on the arm 62 (see Fig. 5) downward against the control pin 66 f the completely enclosed switch 61. The said switch 61 is a commercial type of single-pole single-throw switch made by The Micro Switch Corporation of Freeport, Illinois.

The switch 81 indirectly controls the operation of the squeezing or pinching jaws 45-46 and,

when closed in this manner, causes the solenoid 68 (Fig. 4) to bring about the engagement of the clutch 69 of the operating apparatus for said jaws. At this time, the exhaust tube I3 has not softened sufliciently to permit any gas pressure in the lamp I2 to materially expand said exhaust tube I3 but said tube I3 has softened to a point where it can be worked satisfactorily by the jaws 45-46. In instances where the gas pressure in the lamp I2 is so low as to be below atmospheric pressure, this apparatus is adjusted so that the pinching or squeezing occurs when the exhaust tub I3 is softened the desired degree.

The movable armature 18 actuated by the solenoid 68 is connected to the arm 1| of the clutch 68 by the bar 12 and is raised by said solenoid 68 until the arm 1| takes the position shown in Fig. 6 and the movable dog 13 is permitted to shift and engage the teeth 14 on the driven clutch disk 15. The arm 1| is pivoted on the pin 16 extending from the bracket 11 on one portion of the frame and is lifted from the transverse slot 18 in the dog 13 so that the xpansion of the spring 19 contained within a well therein can move said dog 13 longitudinally in ways in the idling disc 88 of the clutch 69. The spring 19 also bears against a pin 8| extending outward into said ways in the idling disc 88 and quickly advances said dog 13 beyond the face of said disc 68 and into the path of one of the teeth 14 on the adjacent face of the driven disc 15. The idling disc 88 is fastened to a shaft 82 supported by the bracket 83 attached to a portion of the frame while the corresponding driven disc 15 is fastened to the shaft 84 supported by the bracket 65. The driven disc 15 receives its rotative force from an electric motor and speed reducer (not shown) which are connected thereto through the chain 86 and sprocket 61 and provides a source of power rotating faster than the drive shaft of the exhaust apparatus.

The first result of the engagement of the clutch 69 is to move the jaws 45-46 radially inward of the turret into operative relation to the exhaust tube I3 since both jaws are pivotally mounted on the pins 88-88 (Fig. 1) extending from the slide 89 (Fig. 4) and said slide 89 and the secondary slide 98 (Figs. 1 and 4) are moved forward as a unit by the lever 8| which is pivotallyconnected to the secondary slide 98 by pin 8|. The lever 9| is pivoted on the pin 92 extending from the metal suports 53 and is actuated by the crank motion of the pin 93 in the disc 84 on shaft 82 which motion is transferred to the lever 9| through the rod 85. The slide 89 moves forward until the nuts 96 on the stud 91 extending from the end thereof engage the yoke 98 on the end of .the block 52 whereupon the continued pressure of the lever 9| moves the sub-slide 88 in the ways in slide 89 causing the jaws 45-46 to pivot and close. The sub-slide 88 is held in these ways by the cover plate 99 and. when moved separately from slide 98. respositions the post I88,

which extends upward through a slot in the cover plate 99, with respect to the slide 89 and operates the toggle joint formed by the links |'|I to therebvpivot and close the jaws 45-45. The r dially inward movement of post I88 stretches the spring I82 extending between post I88 and the post I83 extending from the cover plate 98, and causes the jaws 45 and 46 to bring the dies |84 |84' into engagement with the heated and now plastic portion of the exhaust tube I3. The dies I84-I84 squeeze and pinch the walls of the exhaust tube I3 together until the exhaust passage therethrough is completely blocked off the said dies pressing a comparatively large portion of the opposite walls of said tube I3 together so that a verystrong and reliable seal is formed. The walls of the exhaust tube I3 are sufllciently plastic to seal together and are very quickly v cross bar I09 which causes them to operate as a single unit. Operation of the arms II--I08 is brought about by the separate motion of the subslide 00 in that it carries the cam I I0 against the end III of arm I08 and forces it upward, thus lowering the shields II06.

The dies I04-I04 are preferably provided with matching ridges II2 which can be caused either to groove the exhaust tube I3 so that it can be broken off at a predetermined point or to shear off said exhaust tube I3 as shown. The latter arrangement is preferred in that the lamp I2 is released from the head I0 at this time and, while still held by the clip 51, is lifted by further movement of said clip 51 and cup 56 caused by the further contraction of the spring 64 until the lamp is placed in a discharge chute (not shown) located above this apparatus.

The apparatus is immediately returned to its original position by the clock-wise movement of the lever 9I on the downward stroke of the pin 93. A repeat operation would then occur except that the mechanism controlled by the armature I0 of solenoid 68 is disconnected from the clutch 69 which automatically disengages and stops said pin 93 at the bottom of its stroke. The disconnecting action is brought about by the engagement of the cam II3 (see Fig. 6) on the idling disc 80 of said clutch 69 with the roller II 4 on the end of the lever II5 which is connected to bar I2 (which is, in turn, connected to armature I0 of solenoid 68) through the link H6 and which shifts said bar I2 so that the vertically elongated portion of the inverted L-shaped slot I I1 is about the pin H8. The arm II is then forced down by the expansion of the spring II9 which is located between it and the immediate lower surface of the frame and further rotation of the idling disc 80 carries a relatively narrow exposed portion of the groove 18 in th dog I3 against the wedge shaped end of arm 1|. Still further movement of the idling disc 80 causes the end of the arm II to force the end of the dog I3 outward and the opposite end away from the teeth I4 of the driven disc 15. At the end of the movement, the dog I3 engages the shoulder I20 on the arm II and stops all movement and the switch 61 is again opened so that the solenoid 68 permits the rod I2 to fall to its former position. The cam H3 in this interval passes beyond the roller II 4 and the full pressure of the leaf spring I2I which extends down from the immediat frame portion is free to move the lever II 5 and rod I2 back to its earlier position as the pin H8 is again located in the wider or lateral portion of the slot III. In the return movement of the sub-slide 90, the cam III) is carried away from the end III of lever I08 and other means are provided for keeping the shields IDS-I06 in position before the burners 4I-48. Such means consists of the rod I22 (Fig. 4) which extends between lever I01 and the collar I23 on the vertically disposed push rod I24, and other means actuated by a cam (not shown) on a driven shaft of the exhaust machine which moves the push rod I24. After this particular head I0 is indexed out of station D and the succeeding head I0 is about to move into said station, the push rod I24 is re-adjusted so that'the shields IDS-I06 are moved upward and no longer cut off the flames from the bumers 4I-48. The exhaust head I0 is then indexed to the loading station where the cap 30 is turned so as to release the pressure on the compression rubber I5, and the stub of the exhaust tube I3 is taken therefrom.

In instances when it is not desired to remove the lamp I2 directly-after the pinching operation as when the exhaust tube I3 is not completely sheared off, it is preferred that the modification of the apparatus shown in Fig. 7 be used. The modification provides a movable plate I25 in combination with each of the exhaust ports I0 which limits the extent to which the exhaust tube I3 can be inserted therein and definitely establishes the position of the lamp l2. The lamp I2, in this instance, is pushed down, upon insertion, until the seal I9 rests on the asbestos pad I26 on the plate I25 at which-time it is also located between the three padded pins I2I of holding means also combined with the exhaust ports I0. The plate I25 is mounted on the arm I28 which is pivotally mounted on the pin I29 extending from the bracket I30 whereas the pins I21 are attached to the plate I3I which is attached to the upper part of the bracket I30. The bracket I30 in turn is mounted on th upper end of a post I32 held by an extending portion I33 of the turret II adjacent the exhaust port I0, The position of th plate I25 must be established so that it will be properly aligned with the other portions of my apparatus when indexed into the station occupied thereby and is under the control of the stop screw I34 carried by the extending portion I33 of the turret I I against which the bottom of the bracket I28 rests. A helical spring I35 is located between plate I25 and plate I3I in order to keep said plate I25 in the lower position.

That portion of the modified apparatus mounted on the turret II is of no further use until all exhausting and gas filling operations have been completed and the exhaust port' I0 has been indexed into a station corresponding to station D. At this time, the exhaust tube I3 is heated by the flames from burners (not shown) corresponding to those used in the prior instance and is placed under tension by the upward movement of the plate I25 which is actuated by a corresponding motion of arm I36 carrying said arm I36 into engagement with the roller I3I on the pin I38 in outer portion of said plate I25. The arm I36 corresponds to the arm 58 of the prior apparatus in that it applies a definite force to the exhaust tube I3 which causes it to stretch when it is sufficiently plastic to be worked and in that it causes the pinching jaws (not shown) to close at the moment the stretch occurs. The bumers 4'I--48 and the operating means for arm 58 are preferably used in combination with this latter apparatus although said burners must be arranged in a different manner to be out of the path of movement of the apparatus 0n the turret II as it is moved to and from the modified apparatus. The extent to which the exhaust tube I3 is stretched is governed by the stop screw I39 in the bracket I30 which limits the upward movement of'the plat I25. The pinching laws are also preferably those of the prior apparatus but are only closed such an amount that the exhaust tube is flattened and grooved, and not until it is completely sheared off. The'posts I21 and the plate I25 must then hold and support the lamp I2 which is immediately indexed from this station. During the indexing movement, the roller I31 passes onto the track I40 which is arranged so that the plate I25 i kept up against the seal I9 of said lamp l2. The usual form of mechanisms for unloading the lamp I2 are sufficiently strong to automatically cause the exhaust tube I3 to be broken off at the weakened or grooved point.

The modification or our invention shown in Fig. 8 is located adjacent the tipping-off station of the exhaust and ga filling apparatus and is comprised of a plurality of burners I4I (only one of which appears in the drawings) which direct flames against the exhaust tube I3. The burners I4I heat a selected portion of said exhaust tube I3 adjacent the seal I9 of the lamp I2 and can, if desired, be movably mounted so as to be shifted to and from operative relation to said exhaust tube I3 very much as in our other apparatus (Fig. 1). In this instance the exhaust tube I3 is subjected to a definit tortional strain by the rotational efforts of the vacuum cup I42 which engages the top of the lamp I2 so that when the said tube finally reaches a temperature where it is no longer strong enough to resist the rotational force, it then starts to twist. The twisting movement indicates that the exhaust tub I3 is heated to a safe temperature to be tipped off and is continued until the lamp I2 i turned a number of complete revolutions and an appreciable length of said exhaust tube I3 is twisted. At the moment the lamp I2 and the vacuum cup I42 begin to rotate, it is preferred that the heating effect of the burners I4I be discontinued either by a reduction in the amount of the combustible gas mixture supplied thereto or by the insertion of shields between said burners MI and the exhaust tub I3. The walls of the exhaust tube I3 are, at such times, sufliciently heated to be drawn into contact with each other by the twisting motion and seal to each other before cooling takes place. The twisting force is very definitely established in that it results in the deformation of the exhaust tube I3 which is the controlling element in the method and is therefore directly responsible for the timing of the operations of the apparatus which close the passage in said exhaust tube I3.

The period of operation of the burners HI and the cup I42 starts when the turret II carries the exhaust port I holding the lamp I2 to the station shown as the exhaust tube I3 is then placed in operative relation to said burners HI, and the cup I42 is immediately lowered onto the lamp I2. The vertical movement of the cup I42 is, however, separately produced and is brought about through a corresponding movement of the spindle I43, the arm I44 and the vertical standard I45 all of which are fastened together so that they move as a unit. The standard I45 is located out beyond the edge of the turret II and it directly engages apparatus (not shown) actuated by the cam shaft (also not shown) of the exhausting and gas filling apparatus below the turret II which makes it possible to carry the cup 2 to and from engagement with the lamp I2 in proper time relation to the movements of the exhaust port I0. The cup I42 must grip the top of the lamp I2 with suflicient tenacity to cause it to turn therewith and is therefore constructed so as to seat firmly on the top of the lamp I2 and pull thereon with the suction force of vacuum. The universal joint formed by the head I46 of said cup I42 and the flared fitting I41 on the end of said spindle I43 permits said cup I42 to adjust itself to the top of the lamp I2 whereas the gasket I40 of asbestos or the like seals the juncture between said cup I42 and the lamp I2. A spring I49. located between a post in the spindle I43 and a second post I50 in the head I46 of the cup I42 holds said cup I42 in place during the intervals it is not in contact with the lamp I2. The spring I49 is located in the hollow center of the spindle I43 which provides for the vacuum connection to the cup I42 in that it is closed at the top by the plug I5I and is connected to the chamber I52 in the arm I44 by the openings I53 in the side walls of the spindle. Stufling boxes I54 at opposite ends of the opening in the arm I44 holding the spindle I43 prevent leakage thereabout whereas the pipe nipple I55 and the flexible hose I56 connect the vacuum source (not shown) to said chamber I62.

The rotational force with which the lamp I2 is turned is transferred to the cup I42 from the spindle I43 by the pin I50 which is carried by the head I46 of the former and which is located in a slot in the fitting I41 of the latter. Said force originates in the shaft I51 which is coupled to said spindle I 43 through the bevel gears I68 and I59. The shaft I51 is held in bearings in the arm I44 and is turned by the gravitational pull of the weight I60 which hangs from the rope i6! wound about the drum I62 on the outer end of said shaft I51. The size of the weight Itiu, of course, can be varied so as to produce the definite rotational force desired and is selected after consideration of the gas pressure in the lamp, the size and strength of the exhaust tube and the 'rapidity with which said exhaust tube is heated.

As hereinbefore stated, the exhaust tube I3 must not be heated until it no longer has suflicient strength to remain intact but must be heated to some point where it can be worked. The manner in which the apparatus operates must also be taken into account and in some instances it may be desirable to use an exhaust tube of greater than normal wall thickness to properly meet all operating conditions.

Both the suction and the twisting operations are desirable only when the cup I42 is in engagement with the lamp I2 and means can be provided in combination with the cam shaft of the exhausting and gas filling apparatus for confining these operations to the proper periods. A vertical shaft I63 within the hollow standard I45 and the inter-meshing bevel gears I64 and I65 provide the means of connecting the cam shaft actuated means to the shaft I51 of the twist producing means. The shaft I63 and the gears I64 and I65 also provide means of turning the drum I62 and rewinding the rope I61 after each succeeding cycle of operation. The exhaust tube I3 is twisted a sumcient number of times to cause an appreciable portion of said exhaust tube I3 to be drawn together, as shown in Fig. 9, and

ordinarily must be twisted four to ten times to duce this operation. Such means can be operated' from a cam on the cam shaft-of the exhausting and gas filling apparatus and can actuate the hollow standard I45. The exhausttube I! now is drawn down to such a size that it may not have suillclent strength to support the lamp I2 and the plate I66 and posts I61 which extend therefrom are depended upon to support said lamp I2. The posts I61, of which there are three in number, are. located about the neck of the lamp I! as in the prior instance shown in Fig. 7 and are fastened to the plate I66 which. in turn, is attached to the arm I68. Said arm I68 is pivotally attached to the block I69 by the pin I10 in the manner of the arm I28 in Fig. 7 and is swung upward so that plate IE6 is kept against the seal I! of the lamp I2 by the expansion of the spring I. A well in the arm I68 is provided to hold the spring I'll which butts against the block I69. After the closure is made by twisting. the exhaust tube I! can be severed by cold cutting or by fires, depending on the shape of tip desired. Either of these operations can occur at a succeeding station taken by the head ll if desired.

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

1. The method of sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere which comprises heating a portion of the exhaust tube while the said tube portion is exposed to the said surrounding atmosphere, mechanically exerting on said tube, while it is being heated,'an external force to produce a strain in said tube of sufficient magnitude to rapidly deform the heated portion of the tube when it becomes sufliciently plastic to be thus deformed but before said tube portion becomes sufficiently plastic to be ruptured by the internal gas pressure, and thereafter preventing additional heating of said tube which would render it sufficiently plastic to be ruptured by said internal gas pressure.

2. The method of sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere which comprises heating a portion of the exhaust tube while the said tube portion is exposed to the said surrounding atmosphere. mechanically exerting on said tube, while it is being heated. an external force to produce a strain in said tube of sufficient magnitude to rapidly deform the heated portion of the tube when it becomes sufliciently plastic to be thus deformed .but before said tube portion becomes sufficiently plastic to be ruptured by the internal gas pressure, and squeezing the said heated and deformed tube portion immediately after the deformation has started so as to seal it and preventing additional heating of said tube which would render it sufficiently plastic to be ruptured by said internal gas pressure.

3. The method of sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere which comprises heating a portion of the exhaust tube while the said tube portion is exposed to the said surrounding atmosphere, mechanically exerting on said tube, while it is being heated, an external force to produce a twisting strain in said tube of sufficient magnitude to rapidly deform the heated portion of the tube when it becomes sumciently plastic to be thus deformed but before said tube portion becomes sufflciently plastic to be ruptured by the internal gas pressure, and thereafter preventing additional heating of said tube which would render it sumciently plastic to be ruptured by said internal gas pressure.

4. Apparatus for sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere comprising means for heating a portion of said exhaust tube while the said tube portion is exposed to the said surrounding atmosphere, mechanical means exterior of said envelope exerting a continuous strain on said tube while it is being heated tending to deform it, the said strain being of sufficient magnitude to rapidly deform the heated portion of the tube when it becomes sufllciently plastic to be thus defor'med but before said tube portion becomes sufficiently plastic to be ruptured by the internal gas pressure, and means for preventing additional heating of said tube which would render it sumciently plastic to be ruptured by said internal gas pressure.

5. Apparatus for sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere comprising means for heating a portion of said exhaust tube, while the said tube portion is exposed to the said surrounding atmosphere, and mechanical means exterior of said envelope exerting a continuous strain on said tube while it is being heated tending to deform it, the said strain being of suflicient magnitude to rapidly deform the heated portion of the tube when it becomes sufficiently plastic to be thus deformed but before said tube portion becomes sufficiently plastic to be ruptured by the internal gas pressure, clamping jaws arranged to pinch the heated and deformed tube portion immediately upon deformation thereof, means operative upon deformation of said tube portion for causing said clamping jaws to close upon said tube portion, and means for preventing additional heating of said tube which would render it sufliciently plastic to be ruptured by said internal gas pressure.

6. Apparatus for sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere comprising means for heating a portion of said exhaust tube, mechanical means exterior of said envelope exerting a continuous strain on said tube while it is being heated tending to deform it, the said strain being of sufficient magnitude to rapidly deform the heated portion of the tube before said tube portion becomes sufliciently plastic to be ruptured by the internal gas pressure, clamping jaws arranged to pinch the heated and deformed tube portion immediately upon deformation thereof, and means actuated by movement of the said mechanical strain-exerting means for causing said clamping jaws to close upon said tube portion.

7. Apparatus for sealing an exhaust tube extending from a sealed envelope containing gas at a pressure above that of the surrounding atmosphere comprising means for. heating a portion of said exhaust tube, mechanical means exterior of said envelope exerting a continuous strain on said tube while it is being heated tending to stretch it, the said strain being of sufficient magnitude to rapidly stretch the heated portion of the tube before said tube portion becomes sufficiently plastic to be ruptured by the internal gaspressure, clamping jaws arranged to pinch the heated and stretched tube portion immediately upon stretching thereof, and means actuated by movement of the said mechanical strainexerting means for causing said clamping jaws to close upon said tube portion.

8. Apparatus for sealing an exhaust tube extending from a sealed envelope comprising means for, supporting and rigidly gripping the end of said exhaust tube, means for heating a portion of said exhaust tube, a pressure member engaging said envelope, a lever carrying said pressure member at one end, spring means engaging the opposite end of said lever and resiliently urging the pressure member in a direction tending to stretch the exhaust tube while it is being heated. clamping jaws arranged to pinch the heated and stretched tube portion immediately upon stretch- 9. Apparatus for sealing an exhaust tube extending from a sealed envelope containing gas ing thereof, and means for causing said clampat a pressure above that of the surrounding atmosphere comprising. means for supporting and rigidly gripping the end of said exhaust tube, means for heating a portion of said exhaust tube while the said tube portion is exposed to the said surrounding atmosphere, means engaging said bulb and tending to twist the exhaust tube while it is being heated. the twisting force of said last-named means being of sufficient magnitude to rapidly twist and seal ofi the heated portion of the tube when it becomes sufiiciently plastic to be thus deformed but before said tube portion becomes sufiiciently plastic to be ruptured by the internal gas pressure, and means for preventing additional heating of said tube which would render it sumciently plastic to be ruptured by said internal gas pressure.

WALTER. J. GEIGER. REGINALD J. AYRES.

calm-numor cdmcndn. I Patent Io. =2,295,o5h; 7 September 3,19 2.

WALTER "J. enema, 31' AL.

It is hereby certified 'thit error appears .in the pr 1 nted apecliticetion of the 'above numbered patent requirfrng correction fellows :1 Page L-eec- 0nd column; line 65, for-slide 90" reed el1de 89-; line 61;, utter upward mart "from slide 90 and that the audmettera' Patent should be read with this correction therein that the seine may conform to the record of the case, in the Petent Office.

Signed m1 sealed this in; day, or December, A. n.-19LL2'.

I I Henry-Van'Airedale", v (Seal) Acting Commissioner of Patents.