US2247513A - Exhausting machine - Google Patents

Description

July 1, 1941. us 2,247,513

'-EXHAUSTING MACH INB Filed Nov. 9, 1939 3 Sheets-Sheet 1 Anthony J. Marshaus. b J's M W His A torne g.

J y 1941- A. J. MA'RSHAUS axnwsuue MACHINE Filed Nov. 9. 939

3 Sheets-Sheet 2 1 Aw m I Inventcr: Antho J. Marshaus.

July 1, l941.- MARSHAUS} 2,247,513

-.EXHAUSTING- MACHINE Filed Nov. 9, 1939 s Sheets-Sheet a Fig.7

Fig. 8

Inventor: Anthony .J. Marshaus,

His Attorngy.

atente July 1, wt

EXHAUSTDIG MACHILNE Anthony J. lvlarshaus, Cleveland, @hio, assignor to General Electric Company, a corporation of New York 8 Claims.

My invention relates to the manufacture of scaled electric lamps, discharge devices and the like, and more particularly to apparatus for exhausting, gas filling and then sealing such devices.

Electric discharge devices are exceedingly difflcult to exhaust completely of the many forms of contaminating substances that are held by the various parts thereof and which otherwise would pass into the interior atmosphere of the devices sometime during the life thereof. The contaminating substances are held very tenaciously but can be dislodged and drawn ofi during exhaust if the.device is heated to a high temperature and a discharge is supported during this operation. One object of my invention is to provide apparatus for automatically bringing about these and other exhaust operations in the form of a high production machine to allow the economical manufacture of devices of this type. Another object of my invention is to provide exhaust apparatus of suitable size and construction to handle elongated tubular light producing discharge devices, as Well as similar forms of incandescent lamps. Long tubular devices are too cumbersome to be handled in the usual manher and are so heavy as to require more support than is provided by the mere engagement of the exhaust tube with the exhaust port, as is common in the manufacture of ordinary incandescent lamps.

The introduction of a vaporizable metal, such as mercury, required in many discharge devices presents other dimculties, and another object of my invention is to provide apparatus in combination with the above type exhausting apparatus for introducing the vaporizable material into said devices. Since it is not possible to introduce the vaporizable material into such devices 1 the open air and then cause them to be ex- .iausted, the exhaust port is preferably arranged in an inverted position with the exhaust tube of the discharge device inserted from below, and a suitable dispenser, preferably of the type disclosed in my application Serial No. 223,519, filed August 16, 1938, is mounted thereon in such a manner that the vaporizable material falls by gravity through the exhaust port and into the discharge device.

Another object of my invention is to provide suitable apparatus for sealing or tipping off the exhaust tube after the exhausting and gas filling operations while the device is still held by the apparatus comprising my'invention. Other objects and advantages of my invention will apiii) till

pear from the following detailed description oi. a species thereof and from the accompanying drawings. I

In the drawings, Fig. 1 is a plan view of exhaust apparatus comprising my invention with various portions broken away to show the underlying portions; Fig. 2 is a vertical section through the apparatus along line 2-2 of Fig. 1 with an intermediate portion of uniform construction removed therefrom; Fig. 3 is a front elevation of one of the heads of said apparatus; Fig. 4 is an end elevation of an oven for overall heating of a discharge device; Fig. 5 is a diagrammatic perspective view of certain actuating mechanisms; Fig. 6 is an end view of mechanism for making electrical connections to a discharge device; Fig. 7 is a side elevation of actuating means for a mercury dispenser; Figs. 8 and 9 are plan and side views of exhaust tube tipping-oil means, the latter figure also showing the end of a discharge device in operative relation therewith and an end View of an oven for heating the exhaust tube and adjacent end of said discharge device; and Fig. 10 is an end elevation of the tipping-01d means on a larger scale and in operative relation to the discharge device shown in section.

Referring to Fig. 1, the apparatus shown comprises a plurality (thirty-two) of heads it which are mounted at regular spaced intervals about the periphery of a turret iii and are advarrced in turn through a similar number of stations by counter-clockwise indexing movements of the turret. Each head it is adapted to accommodate a single discharge device it as shown in. Figs. 2 and 3 and, during the movement through said stations, carries said device through the various steps of the cycle of operation. In this particularinstance, the discharge device it to be treated is a hot cathode discharge lamp having a relatively long tubular vitreous envelope ld with a fluorescent coating on the inside and the hot cathode assemblies or mounts iii sealed in each end. The discharge device ill is completely sealed except for the vitreous exhaust tube it extending from one end and is intro duced into the head it at one of the stations A, B or 0.

Introducing a discharge device it into a head l5 consists in first separating the pairs of jaws Til-22 and 2l,22 and, after the envelope itl has been gripped therebetween, in moving said discharge device upward through said jaws until the exhaust tube W is carried into the exhaust port 23. The jaws function as holding mes for the discharge device ii, the jaws 26- 2! of each pair being fastened directly to the hollow post or sleeve 2d mounted on the arm 25 extending from the turret it. Jaw 2i merely pivots on closing iorce of the helical torsion spring 2t extending between said arm 2d and the nut 39 on the upper end of the hollow pmt 2d. The spring is alsoiorces the rod 2i upward so that it is held in position.

The exhaust port 23 into which the exhaust tube 2d is pushed comprises a rubber washer 36, a head 32 in which said washer at is located, and a bracket 33 which is attached to the turret it and the head 82. In inserting the exhaust tube 283 in the port 23, it is pushed upward through the openings in the guide washer 3d and the rubber washer at until its end butts against the head 32, at which time the opening in said exhaust tube 2a is aligned with the axial passage 35 in said head 32. The function of the rubber washer 3|! is to seal the exhaust tube Ed in the head 32. Before the exhaust port is indexed from the loading stations, the operator turns the cap at by means of the arm at extending therefrom, so that it is screwed farther onto the head 32 and the rubber washer at is compressed to seal off the opening. The only other duty of the operator is to pull the leading-in wires 38-33 extending from the cathode assemblies it at both ends of the envelope it so that they extend outward from the device it toward the front and back of the head 15 respectively.

The succeeding indexing movement of the turret it which carries the head it into station D brings about the first operation in the exhaust cycle as said motion adjusts the rotary valve 39 under the center of the turret it so that'the proper exhaust connections are made to the port 23. The rotary valve is (Fig. 2) consists of upper and lower sections it and M respectively, and the rotation of the turret iii, which is connected to the upper section 363 through the pin 5321, causes said upper section to turn on the stationary lower section ll which rests on a raised center portion 53 of the frame and is kept in position thereon by the stud ll. The connection to the exhausting means (not shown) is made to the lower section at of the rotary valve 39 at $5, and a connecting passage 56 therein is now aligned with the passage iii in the upper section at of said valve 3Q which is connected through the pipe alt, the transparent (glass) trap to, the pipe to, the connection block it and the rubber tube 52 to the head 32 of the exhaust port 23. A spring 53 surrounding the pin it presses the upper and lower sections to and iii of the rotary valve together so that there is no leakage. file exhaust connection from the upper valve section iii to the exhaust port 23 is complete at all times, and

spondingly positioned connection as at 57 is provided for the exhaust connection.

The exhausting operation started at station D is continued at station E due to an exhaust connection made through the rotary valve 39, and isnow assisted by the heating action of the arcuate oven 58 which surrounds the device ii at this station. The oven ht is mounted on the frame in. the path of movement of the device ii which is carried through an opening in the end of the oven til normally closed, as shown, by the door 63. The door ti as shown in Fig. 4. is provided with grooved rollers 62 which ride on the track to and is slid bacl: away from the oven opening during indexing periods by movement oi the arms at on rod at which are connected to said door ti through the links 6% and brackets 5?. The rod 65 is held by the brackets to extending from the oven supwrting structure and is turned by means engaging the cam 69 on the main drive shaft id shown in Fig. 5. The cam 5% is engaged by the roller it on one end of the lever '52 which is pivoted on the pin it extending from the frame and which shifts the bar it (Figs. 1 and 5) longitudinally. The end of the bar it away from the lever E2 is held slidably by the bracket l5 on the frame and engages the arm it on the lower end of the rod through the pin it. A slot in the am it accommodates the pin ill and allows for the difference in the directions of movement thereof. An overhanging lip '38 on the top edge of the oven 6d keeps the upper portion of the door at thereagainst and forms a channel in which said door 5! is moved. The only other opening in the oven to is a slot in the top through which the exhaust tube 2% and the hollow post id extend. The side walls of the oven 66 are insulated by the mineral wool packing it and support the insulation buttons at on which the resistance wire at of the heater is wound in zigzag fashion.

If some form of leak detecting means is to be used with this apparatus, it is preferred that it be coupled to the exhaust connection on the, lower section ll ofthe rotary valve 89 leading to the exhaust. port 23 at this station E. The leak detecting means can be used either to close off the pinch clamp automatically or to give an alarm so that it can be closed ofi manually. If the exhaust ports 23 at stations D and E. or other stations, are connected. to the same exhaust means, the leak detecting means can also be ar-- ranged to close on the exhaust connection to the exhaust port it at station E as soon as it is discovered So that there is little leakage which can interfere with the exhausting operations at the other stations. in each of the succeeding stations up to station F, the exhaust operation is continued in the same manner as at the preceding stations. In each of these stations, the exhaust source is under the control of the rotary valve 39 and exhausting is carried on while the device ii remains in the oven to and is heated, preierabiy to a tempera ture near the softening point of the envelope it. The even so does not extend to station I? and, during the indexing movement to said station, the device it passes through an opening therein which is normally covered by a door (not shown). Said door corresponds to that provided at the opposite end of the oven Eli and is actuated in the same manner by a rod E32 connecting lever 52 (Fig. 5) and the arm it of the actuating means thereior.

The exhausting operation is continued at eta-=- tron F and the succeeding series of stations and it is not until station G is reached that any other additional operation is performed. In moving to station G, the leads tmd connected to the ends of the coiled filamentary cathodes dd oi the assemblies it at both ends of the discharge device ll wipe against the metal contact plates M 10- cated in their paths of movement, as shown in Fig. 6. The plates ht serve to make electrical connections to the cathodes 83 which permit them to be heated and the materials, such as barium carbonate, carried by the cathode assemblies to be changed to oxides having the desired electron emissive properties. The contact plates at at station G correspond to other contact plates M at the seven following stations all of which are fastened at one end to one of the four bands d of insulation extending around the path of movement. The insulating bands at are attached to metal bands at which are located-behind said insulating bands and are held in place by the rods ti extending upward from the frame and engaging said metal bands th through the brackets dd. At station G- and the three following stations, the electrical connections to the cathodes ti! are only those required to heat them and there is no difference in potential between the cathodes lit at opposite ends of the device ll. At station H, the next in order, it is preferred that no connections be made to the plates lit at all.

Before the discharge device ll. leaves station H, however, the dispenser so mounted on top oi the exhaust port it is caused to discharge a drop of mercury which falls down through the exhaust passage of said port 23 and into the discharge device ill. The purpose of the mercury drop is to create a vapor within the device ll which will support a local electrical discharge across portions of each of the electrodes or between their leads 38-48 and a main discharge from one cathode to the other to dislodge any other conterminating materials which may still remain in the other parts of the cathode assemblies it d cause activation of the remaining electron cryssive material on said parts.

The dispenser dd is preferably constructed as disclosed in my pending application referred to above. The said dispenser at this time is actuated by means of the solenoid di (Figs. 1 and 7) which is first moved down over the bell housing or thereof and is then energized. The solenoid M is mounted on the extending end oi the arm ill of insulating material attached to the upper end of the rod M which in turn is located in the hollow standard at (only partially shown) extending upward from the frame, and is moved vertically by the motion imparted to said rod 9d through motion of earn til (Fig. 5). The rod all is connected by the links hi to the lever lid which is pivoted on a pin extending from the frame and engages the cam db through the roller 99. During the downward movement of the rod 9d, metal pins itii mounted on the insulated block till carried by' said rod M and connected tothe leads of the solenoid at are carried into engagement with the connection means idt mounted on the hollow standard till which in turn are connected through the switch iilll (Fig. l) and switch Hi l (Fig. 5) to a source of electric current.

The switch ltd limits the operation of the dispenser lit to times when the exhaust port 235 is functioning properly indicated by the position of the 'pinclnclamp closing cam dd. When the pinch clamp is open, the cam ti l engages the arm I06 causing it to bend and engage the contact arm Idl. Both contact arms ltd and till are mounted on a block of insulating material onthe arm ltd extending from the standard as. When the solenoid at is to be energized and the dispenser operated, the cam its actuates the switch mt which completes the connections from the solenoid hi to the source of electrical energy.

The magnetic field generated by the solenoid ti penetrates the aluminum bell housing ti and raises the magnetic armature lid (Fig. 2) and the tubular plunger lit attached thereto so that the opening ill in said plunger ii i containing the measured amount of mercury from the pool lit in the cup lid is carried above the end of tube t2, the head ill and the exhaust tube til insulating body ltd on. the end of the contact which deposits it in the interior of the device ll.

After the dispenser 9t has been operated, the rod as and solenoid at are moved upward away from operating relation therewith and the electrical circuit to said solenoid 9! is broken by movement of the pins lint from contact with the connection means HM. The switch it breaks the circuit at some later time, depending on the cam N19, and only controls the discharge time of the dispenser so. When the circuit to the solenoid M is broken flrstlthe weight of the armature i it moves the tubular plunger. I ll down into the mercury pool H3 so that another charge thereof flows into the opening M2 therein. The nut lit screws onto the upper end of the cup lid and presses the flange of the bell housing 92 thereagainst so that the interior of both said cup and housing is sealed on", from the atmosphere.

At the station following station H. the cathodes dd are heated to full operating temperature and, at the next two stations, said cathodes dd are again heated while full operating potential is applied thereto. The electrical connections for these conditions are applied through the plates M which engage the leads tttld' oi the device ill and result in a local discharge between portions of the leads td-tt' within the envelope and other portions of the cathodes 8d at all three stations, and a steady discharge through the device at the two latter stations even though the device is being exhausted as before. The local discharge serves to activate the electron emissive material on the inner portion of the leads 38-33 and the other portions of the cathodes $3 and, together with the major-discharge from end to end of the device, rids said device of any remaining contaminating materials. In some instances, the current applied to the cathodes d3 can be greater than is used during normal operation of the discharge device ill, in order to condition them completely.

At station .l, the next in order taken by the exhaust head it, the upper end of the device it which includes the cathode assembly it and the adjacent portion of the exhaust tube 26 are carried into the oven 5 it shown in connection with Fig. 9, which anneals and preheats these parts. No electrical connections are made to the discharge device i l at this station. The oven till consists essentially of outside and inside walls following the curvature of the path of travel of the device I1, and a split top which permits the exhaust tube 20 and hollow post 25 of the exhaust head I to move therethrough. Heat is furnished by a commercial type strip heater I attached to the inside and outside walls. The exhausting operation is also continued at this station J. The sheet I2I of heat insulating material mounted below each head I5 on the arm I22 extending from the turret I6 protects the exhaust port 23 from the heat of the ovens I50 and. I I9.

The heating and exhausting operations are continued at the next three stations and the heating alone is continued through station K. The heat is furnished by portions of the oven I I3 located at these stations whereas the exhaustin operation differs somewhat from that performed at earlier stations, the result of different connections made through the rotary valve 39. At these three stations, the mercury pumps I23 which are mounted as a single unit I2 3 below the turret I6 on the frame as indicated are caused to assist the exhausting operation.

At station K, the lamp device I1 is provided with a second quantity of mercury, the first having been drawn out by the exhaust operations, and a specific amount of gas filling to give the lamp the proper characteristics. The mercury is introduced first by again operating the dispenser I 90 attached to the exhaust port 23, this time by brought about through the cam I33 on the shaft I29 and the lever I35 which engages said 'c'am I33 through the roller I35 and the supporting rod" I36 for said solenoid I through the links I31. As shown, the lower end of rod I35, the links I31 and the adjacent end of the lever I move in the hollow interior of the standard I33. A second switch I39 actuated by the cam I 40 on shaft I29 controls the period the electric valve II is open and therefore the amount of gas admitted into the passage in the lower section ZI of the rotary valve 39 from the source M2. The source M2 is kept at constant pressure to assure uniform amounts of gas being admitted at all times. By admitting the gas after the mercury, any stray beads of mercury which have become lodged in the exhaust port 23 or the exhaust tube 20 are carried into said device I1 with the gas.

The movement of the exhaust port 23 to the next station, L, causes the exhaust passage thereto to be sealed off in the rotary valve 39 and carries the device I1 clear of the oven M9 and into operating range of the tipping means I 43. The passage in the upper section of the rotary valve 39 which is part of the exhaust passage to this exhaust port 23 is at this time carried over a solid portion of the lower section 3B thereof.

The tipping means I53 is shown in Figs. 1, 8, 9 and 10, and during the indexing movement is located outward from the path of movement of the device I1. Immediately after the device I1 comes to rest, the guide M6, the burners I-I55 and the guard I35 which make up the essential (Fig. 5).

parts thereof, and which are located adjacent an intermediate portion of the exhaust tube 20, are moved in. about said exhaust tube 20 and then are lowered to the operating position shown. The guide M5, the burners M5-Ifi5 and the guard I46 are all mounted on the block I 11 on the inner end of the pipe I 48 which is mounted on the slide I49 through means permitting a limited amount of sideward as well as vertical readjustment of said parts to properly align and position them with respect to each exhaust tube 20 and dis charge device I1 taking this station. The vertical adjustment is allowed by the pins on the opposite sides of the block I50 on the pipe I43 which rest in upstanding bearings on corresponding sides of the yokeI5I. The sideward adjustment is allowed by the pivot (not shown) extending into the yoke I5I from the block I52 mounted on the top of the slide I49 and is limited by the turning moment of said yoke I5I before it strikes the upstanding flange I53 (Fig. 9) on the block I52.

The forward motion of the tipping means I33, the first to occur, results from an upward movement of the rod I54 which shifts the slide I69 to which it is.connected by the link I55 in the bracket I55 and which is produced by lever I51 The lever I 51, as shown, engages the lower end of the rod I55 which emerges from the support tube I58 for the bracket I56 and engages the cam I59 on theshaft I29 through the roller I60. The connection between rod I55 and the lever I51 is made by the links IBI which engage the loose collar I62 between the fixed collars I63 on said rod I54. In the forward movement, the exhaust tube 20 either passes directly into the slot I65 in the guide I45 or engages the flared open end thereof which causes the tipping means to shift position until'the exhaust tube 20 falls therein. Said exhaust tube 20 also enters the V-notch formed by the two portions of the guard I36 which are pivoted on the screw I65 and which separateuntil the said exhaust tube 20 enters the opening I66 therein. Normally both portions of the guard I36 are kept together by the spring I61 connecting their outermost ends.

The downward movement of the tipping means I33 results from a corresponding movement of the bracket I56 and the support tube I58 and carries the guard I56 against the seal I68 of the device I1 at which time the burners I45I 55 are at the proper operation relation therewith. The support tube I 58 extends downward through an arm (not shown) and the plate I69 extending from standard I38 which position it laterally and is constantly under the influence of the upward expanding force of the spring I10 which is located between plate I69 and the fixed collar IN on the support tube I58. Anychange in position of the tube I58 results from a change in the cam I12 which change is transferred thereto through the roller I13, the lever I16, the links I15, the loose collar I16 and the fixed collars I11. Both levers I51 and 115 are pivoted on studs extending from the arm I18 on the frame (not shown).

All downward movement of the tipping means I53 after the guard I36 engages the device I1 is absorbed by rotation of said tipping meanson pins extending from the block I50 and is against the expanding force of the spring I19 which engages the arm I extending from the yoke I5I and the yoke IBI engaging the pipe connection I82. The connecting arm of the yoke, I8I passes through the spring I19 and slides in an opening in the arm 550;. In the downward movement,

the flared inner'portion N5 of the guard is carried into the hollow interior of the vitreous stem I83 so as to protect said stem I83 from the heat of the downwardly and inwardly directed fires from the burners which are now concentrated on a very limited area of the exhaust tube 20 therein.

The combustible gas mixture is conducted to the burners l45-l45 from the control valves H84 and M35 which are in turn connected to the sources of the gases through flexible rubber hoses and which discharge said gases into a common passage in the connection I82, the pipe M8 and branch passages leading to said burners I45-M5 in the block M1. The exhaust tube 20 is quickly softened by the fires, as it still retains most of the heat received in the oven H9, and it flows together to seal oil? the passage therein before the tipping means again moves down. In the downward movement, the tipping means is tilted until the block I50 rests on the yoke l5! whereupon it and the device I] are moved down. The device I?! slides in the jaws 2I--22 and 2l'--22' during this period. The purpose of this final movement of said tipping means is to stretch the fused portion of said exhaust tube so that the fires sever the said tube 20 and tip it off. The heated and semi-annealed condition of the stem I83 and seal I68 retards any cracking and breaking thereof due to the nearness of fires from burners 545-445. Following this operation, the tipping means is raised and moved outward to its rest position and the exhaust head [5 and the device ll! are carried to the next station.

The next station is M, and it and the following stations are provided to allow an operator to unload the finished device I! from the apparatus and remove the stub of the exhausttube 20 remaining in the exhaust port 23. When these operations have been performed, the exhaust head I5 is ready to be indexed into station A and start another cycle of operation.

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

1. Apparatus for exhausting and gas filling an electric discharge device comprising a plurality of heads each including an exhaust port for receiving and making ages-tight connection to an exhaust tube extending from the device, a dispenser mounted on said exhaust port of each of said heads and arranged to introduce a quantity of vaporizable material therein, a carrier for supporting said heads and advancing the devices through a plurality of stations in turn, valving means connected to said exhaust port and adjusted by movements of said carrier for making the exhausting and gas filling connections thereto while said device moves from station to station, and means at one of the stations for operating said dispenser to cause a quantity of the vaporizable material to be discharged into said port and pass into the device.

2. Apparatus for exhausting and gas filling an electric discharge device comprising a plurality of heads each including an exhaust port for receiving and making a gas-tight connection to an exhaust tube extending fromthe device, a dispenser mounted on said exhaust port of each of said heads and arranged to introduce a quantity of vaporizable material therein, a carrier for supporting said heads and advancing the devices through a plurality of stations injturn, valving means connectedto said exhaust port and adjusted by movements of said carrier for making the exhausting and gas filling connections there? to while said device moves from station to station,

an oven at one of said stations for heating the said discharge device all over, and means at another of said stations for operating said dispenser to cause a quantity of the vaporizable material to be discharged into said port and pass into the device.

3. Apparatus for exhausting and gas filling an electric discharge device comprising an exhaust port for receiving and making a gas-tight connection to an exhaust tube extending from the device, a carrier for supporting said exhaust port and advancing the device through a plurality of stations in turn, means arranged in position to be engaged by leadsextending from thedevice at one of the exhaust stations for making electrical connections thereto and causing operating conditions to be established therein during exhaust. means for introducing a quantity of vaporizable material into said device at said station to cause it to operate, means at a station following the exhaust stations for again causing the introduction of a quantity of vaporizable material into said 'device to replace that drawn out during exhaust, and means at a succeeding station for tipping ofi the exhaust tube to seal the device.

4. ,Apparatus for exhausting and gas filling an electric discharge device comprising an exhaust port arranged to receive and make a gas-tight connectionfrom below to an exhaust tube extending upwardly from the device, a dispenser mounted onsaid exhaust port and arranged to introduce a quantity of a vaporizable substance therein, a carrier for supporting said exhaust port and advancing the device through a plurality of stations in turn, valving means connected to said exhaust port and adjusted by movements of said carrier for making the exhaust and gas filling connections thereto while said device moves from station to station and means at one of the stations for operating said dispenser to cause a quantity of the vaporizable material to be discharged into said port and thence fall by gravity through said exhaust tube into the device.

5. Apparatus for exhausting and gas filling an electric discharge device comprising a. movable carrier, a plurality of heads on said carrier each comprising an exhaust port for' receiving and making a gas-tight connection to an exhaust tube extending from the device, a mercury dispenser mounted on each of said heads and arranged to introduce a quantity of mercury through the associated exhaust port into the associated discharge device, cam means for closing ofl said exhaust port in case a leaky discharge device or no discharge device at all is carried thereby, means at one of the stations taken by said heads for operating said dispenser to discharge a quantity of mercury into the associated discharge device, and means controlled by said cammeans-for rendering the said dispenser inoperative when said cam means is in a position closing ofi said exhaust port,

6. Apparatus for exhausting and gas filling an electric discharge device comprising a movable carrier, a plurality of heads on said carrier each comprising an exhaust port for receiving and making a gas-tight connection from below to an exhausttube extending from the device, an enclosed mercury dispenser mounted on each of said heads above the exhaust port and arranged to introduce a quantity of mercury through the associated exhaust port into the associated discharge device, means connecting both said dispenser and said exhaust port to a source of vacuum, cam means for closing off said exhaust e I i i port in case a leaky discharge device or no discharge device at all is carried thereby, means at one of the stations taken by said heads for operatingsaid dispenser to discharge a quantity of mercury into the associated discharge device, and means controlled by said cam means for rendering the said dispenser inoperative when said cam means is in a position closing ofif said exhaust port.

7. Apparatus for exhausting and gas filling an electric discharge device comprising a movable carrier, a plurality of heads on said carrier each comprising an exhaust port for receiving and making a gas-tight connection from below to an exhaust tube extending upwardly from the discharge device, a mercury dispenser mounted on each of said heads above its exhaust port and arranged to introduced a quantity of mercury therein, valving means connected to the said exhaust ports and adjusted by movements of said carrier to make the exhaust and gas filling connections thereto while said heads are moved from station to station by said carrier, an oven surrounding the path of movement of the discharge devices and adapted to heat them all over while they are being exhausted, contact means arranged in position to be engaged by leads extend- .ng from each of said discharge devices; for making electrical connections thereto to heat the electrodes of said device and thereby activate them during exhaust, means for subsequently causing a quantity of mercury to be delivered from the dispenser into the associated discharge device, additional contact means arranged to be engaged by the leads extending from said discharge device to cause a discharge to be initiated between the electrodes thereof, means at a station following the exhausting stations for again causing the dispenser to deliver a quantity of mercury to the associated discharge device, and

each of said heads above its exhaust port and arranged to introduced a quantity of mercury therein, valving means connected to the said exhaust ports and adjusted by movements of said carrier to make the exhaust and gas filling connections thereto while said heads are moved from station to station by said carrier, an oven surrounding the path of movement of the discharge devices and adapted to heat them all over while they are 7 being exhausted, contact means arranged in position to be engaged by leads extending from each of said discharge devices for making electrical connections thereto to heat the electrodes of said device and thereby activate them during exhaust, means for subsequently causing a quantity of mercury to be delivered from the dispenser into the associated discharge device, additional contact means arranged to be engaged by the leads extending from said discharge device to cause a discharge to be initiated between the electrodes thereof, a second oven surrounding the path of movement of the upper portion of each of the discharge devices to anneal and preheat the adjacent parts thereof, means at a station following the exhausting stations for again causing the dispenser to deliver a quantity of mercury to the associated discharge device, and means at a subsequent station for tipping oif the exhaust tube to seal the discharge device.

ANTHONY J. MARSHAUS.

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