US3348588A

US3348588A - Mercury dispenser

Info

Publication number: US3348588A
Application number: US362351A
Authority: US
Inventors: Ronald D Ayotte
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1964-04-24
Filing date: 1964-04-24
Publication date: 1967-10-24
Anticipated expiration: 1984-10-24
Also published as: GB1094531A; DE1230907B

Description

1967 i R. D. AYOTTE 3,348,588

MERCURY DISPENSER Filed April 24;, 1964 5 Sheets-She et 2 RONALD D. AYOTTE 4 INVENTOR.

Oct. 24,1967 R. D. AYOTTE 3,348,588

MERCURY DISPENSER Filed April 24. 1964 5 Sheets-Sheet. 5

' RONALD" D..AYOTT'E- TOR United States Patent 3,348,588 MERCURY DISPENSER Ronald D. Ayotte, Salem Depot, N.H., assignor to Sy vania Electric Products Inc., a corporation of Delaware Filed Apr. 24, 1964, Ser. N0. 362,351

8 Claims. (Cl. 141-61) 7 This invention relates to equipment for introducing .predetermined quantities of mercury into high pressure electric discharge lamps, commonly called mercury lamps. Such equipment has usually included, in the past, a large number of identical heads mounted upon a rotary exhaust machine. The introduction of mercury according to my invention, is done with a single head thereby eliminating the elaborate multi-head dispensing.

The use of multiple heads on rotary exhaust equipment has been quite common in the art. Such multiple heads, however, have been troublesome and rather diflicult to maintain. For example, the quantities of mercury dispensed into the arc tubes tended to vary slightly from one head to another. Moreover since the usual rotary exhaust machine had about thirtyheads, it was a time consuming operation to run different types of lamps on the same equipment. Each head had to be removed and new ones dispensing different quantities of mercury in their place.

The primary object of my invention is the elimination Y of multiple dispensing heads upon rotary exhaust machines and the substitution of a single head of novel construction.

Another object of my invention is to reduce the maintenance of dispensing heads for rotary exhaust machines and save time in changing heads .when different lamps are run on the same equipment. 7

The many other objects, features and advantages of my invention will become apparent to those skilled in 3,348,588 Patented Oct. 24, 1967 11 which terminates in a flange 13 and is mounted upon a support 12. A compressible gasket 31 is seated on the top of the flange 13 to retain it within the support and provide a leak free, tight connection between the dispensing head 1 and machine head 2.

The dispensing head 2 includes a receptacle 14 enclosing a mercury reservoir 15 containing a quantity of m'ercury 16. A threaded cap 17 is screwed on the top of the receptacle 14 and bears upon a vacuum tight sealing cap 18. An O-ring gasket is seated between the sealing cap 18 and the receptacle 14 to insure a vacuum tight seal.

The lower portion of the reservoir 15 terminates in a transfer column 19 through which mercury can flow. Disposed in communication with the transfer column 19, is an H-shaped slide 20. In the center of the slide 20 are a pair of spaced apart

orifices

21 and 22. The smaller of the orifices 22 is disposed so that it can be slipped directly beneath the transfer column 19 and then slid over a hollow needle 23. When orifice 22 is slipped beneath transfer column 19, the mercury flows in and fills it up. Because of a close fit between the bottom of reservoir 15 and base 24 upon which slide 20 rests, the mercury cannot leak out of the orifice 22 but can only be transferred. When the slide 20 is moved to a position above needle 23, the mercury drops when impelled with a gas jet, or can drop by gravity as desired, down into the exhaust tube 5 into the arc tube 6.

I prefer to extend the needle 23 downwardly through the hose 10 and into tube 9 and sometimes further, if desired. By using the long needle, the mercury can be dispensed into the arc tube 6 without splashing on the walls of the machine head and losing some. 1

A vacuum line 50 extends from an outside line 25, through the sealing cap 18 and axially within reservoir 15 to a position over slide 20 so that fluid-flow communication may be established within the arc tube 6.

The line 50 can be used to form a vacuum in the arc tube 6 and pump and fill as required by the manufacturing process.

the art upon reading the following specification when taken in conjunction with the accompanying drawings.

Of these drawings: FIGURE 1 is an elevational view, partiallyin cross section, showing the mercury dispenser and a plurality of machine headsmounted upon a rotary exhaust machine.

FIGURE 2 is a side-elevational view of the mercury dispensing station shown inFIGURE 1.

FIGURES 3 and 4 are cross-sectional views of the mercury reservoir and dispensing slide from my invention. FIGURES 5 and 6 are top plan views, partially in cross section, showing the means forclosing and covering the dispensing head when it is not beneath the mercury dispensing station.

Referring now to FIGURE 1, a plurality of

machine heads

1, 52 and 53 can be indexed beneath a single dispensing head 2..The

machine heads

1, 51 and 53 are 'mountedupon the rotary exhaust machine 3 and arc tube holders 4 protrude therefrom to.re tain exhaust tube 5 of arc tube 6. The holders 4 include'a casing 7 with an axial bore and a rubber retainer 8. Disposed within" the bore of the holders 4 is a tube 9 having one end of The other end of the hose 10 is seated upon'a nipple I tions for various operations in the cycle. When it is moved so that aperture 22 is disposed beneath transfer column 19, aperture 21 will be aligned beneath vacuum line 50. When aperture 22 is disposedover needle 23, it is aligned with vacuum line 50sothat the mercury will fall, when struck by a burst of gas, into the arc tube 6. Large aperture 21, at that time, is shunted to the side. Every time aperture 22 is aligned with transfer column 19, it will pick up a dosage of mercury which will be later dispensed when it is disposed over the needle 23. Y

Preferably slide 20 is moved from side to side by a pair of magnets. 27 and 28 disposed on opposite sides of the receptacle 14. When one of the magnets is energized, the broad leg of the H-shaped slide 20 will be drawn towards it. When the other magnet is energized, the slide 20 will again be moved. T o prevent interference with the operation of the magnet-s, receptacle 14, reservoir 15 and bars 24 are made from non-magnetic steel while slide 20 is made from ordinary steel which can be magnetized and hence freely moved from one side of the receptacle i to the other.

the gasket 31, moving with it the entire dispensing head and the needle 23. The cylinder is retracted sufiiciently high so that the distal end of needle 23 clears the top of the rubber gasket 31. In this way, the machine head which is disposed upon the rotary exhaust machine 3 can be indexed away and another machine head (not shown) with a new are tube indexed into its place.

When the new machine head is indexed beneath the dispensing head, the cylinder 29 forces the seat 30 upon the rubber gasket 31 and establishes a new vacuum seal. Afterwards, the various operations required to fill the arc tube are performed and a new are tube indexed into position as described previously.

Referring now to FIGURE 2, the dispenser head 2 is mounted upon a stand 33 which can be disposed upon the floor. Attached to the upper end of the stand 33 is the air or hydraulic cylinder 29 from which extends a piston arm 51. Suspended beneath the piston arm 51 is a yoke 35 which rigidly holds the receptacle 14 within a housing 36. The receptacle 14 is carried between the pair of carrier arms 34 which form the yoke. Extending outwardly from top of the screw cap 17 of the receptacle 14 is the vacuum line 25 formed of metal and connected to a flexible length of thick rubber tubing. When the piston 29 raises the yoke 35 and the dispensing equipment upwardly, the flexible portion of the line 25 will bend.

The magnets 27 and 28 (of which one is shown) are supported at the bottom of the receptacle 14 by a magnet holder 37. By removing the upper carrier arm 34, the receptacle 14 can be removed from the housing 15 easily when it is desired to change the quantity of mercury dosage.

One of the heads of the rotary exhaust number 3 is indexed beneath the dispenser head 2. Extending downwardly from the head is the compressible hose 10 which connects the arc tube and the dispenser 2. When the machine head 1 is indexed beneath the dispenser, pinch bar assembly 37 snaps open and hose 10 is free. At the same time, cover plate 39 is laterally moved away from covering the open end of hose 10. Covering the open end prevents the entrance of foreign particles into the head during the lamp fabrication steps.

FIGURES 3 and 4 show the dispensing slide 20 disposed in two positions. In FIGURE 3, the mercury-containing aperture 22 in slide 20 is disposed beneath the vacuum line 50. The mercury drop contained therein will either fall by gravity into needle 23 or be impelled by a blast of gas. When the drop falls it will pass through the entire needle into an arc tube (not shown). At the same time, larger aperture 21 is shunted to the side between the bottom of reservoir 15 and base 24.

Movement of slide 20 from the position shown in FIG- URE 3 to the new position of FIGURE 4 is accomplished by energizing magnet 28 which draws the slide towards it.

When in the new position, mercury will flow down transfer column 19 and fill up aperture 22. At the same time, aperture 21 is disposed beneath vacuum line 50 so that communication is established between needle 23 and hence the arc tube.

A seal is established between machine head 1 and dispensing head 2 by pressing seat 30 firmly against rubber gasket 31. On the other head, the seal is easily broken by merely retracting the dispensing head 2 upwardly. The head 2 is moved sufficiently high so that the end of dispensing needle 23 will clear the top of machine head 1 when it is indexed away from the dispensing head 2.

As shown in FIGURES and 6, while the machine head is disposed beneath the dispensing head, the hose is open and cover plate 39 is swung away.

As soon as the machine head is indexed away from the dispensing head, pinch bar 42 pivoted upon a fulcrum 43, is squeezed against hose 10 thereby shutting it 011. Roller 44 performs the squeezing. Simultaneous with the motion of roller 44, cover plate 39 is swung over the open end of the hose 10 to p event t re g p rticles from falling in. All of these motions are produced by the camming operation effected by a roller 45 attached to arm 46 rolling over camming surface 47.

The operation of the equipment is as follows: An arc tube 6 is maintained at or above atmospheric pressure with argon from line 38; the amount of positive pressure being immaterial. When the machine head 1 is indexed beneath the dispensing head 2, the argon flow from line 38 is continued until dispensing head 2 is lowered to set on gasket 31. A vacuum in the system, including the dispensing head 2, machine head 1 and arc tube 6, is then drawn through line 25 and large aperture 21. The ultimate vacuum is not important; generally 1 to 2 mm. of mercury is suflicient.

When the vacuum is formed, slide 20 is drawn by the energization of magnet 27 to a point where small aperture 22 carrying a fill of mercury lines up beneath vacuum line 50 and above needle 23. The vacuum is shut off While the slide is moving to the dispensing position and argon is blown down through the line 25. The blast, generally at a pressure of about mm. of mercury, discharges the mercury from the aperture 22 and drives it down the needle 23. Low pressure is preferably used so that the mercury does not splatter but rather drops as a ball. Following the initial low pressure blast, the argon pressure is increased to greater than 760 mm. of mercury to remove any traces of mercury which might cling to the dispenser. Also, the gas pressure in the arc tube is increased by this high pressure blast so that a positive pressure occurs and backflow of air into the arc tube 6 is prevented when the dispensing head 2 is moved.

When a positive pressure is created in the arc tube 6, the head 2 is moved upwardly and the hose 10 is clamped closed. The slide 20 is moved by magnet 28 so that small aperture 22 is beneath transfer column 19 and mercury will flow in. Machine head 1 is indexed away and new head I entered into place. A positive argon pressure is then created in head 2. Generally the quantities of mercury which can be dispensed with my device are less than about 2 to 5 mg. to as high as 250 to 300 mg. and greater.

It is apparent that modifications and changes can be made within the spirit and scope of the instant invention. It is my intention, however, only to be limited by the scope of the appended claims.

As my invention I claim:

1. A mercury dispenser for filling electric discharge devices comprising: a single dispensing head containing a mercury reservoir demountably disposed over a plurality of machine heads disposed upon radial arms of a rotary exhaust machine, each of said machine heads being adapted to be indexed beneath said dispenser head, said machine head including gasket means disposed therein; means for forming a temporary seal between said dispensing head and one of said gasket means; means for holding an arc tube within each of said machine heads; means for transferring a predetermined quantity of mercury from said reservoir to said arc tube held by the machine head which is temporarily sealed to said dispensing head; means for moving said dispenser head vertically with respect to said one machine head; whereby said temporary seal is formed by forcing said dispenser head upon said gasket means.

2. A mercury dispenser for filling electric discharge devices comprising: a single dispenser head and a plurality of machine heads each of which is demountably disposed therebeneat-h upon radial arms of. a rotary exhaust machine, each of said machine heads being adapted to be indexed beneath said dispenser head; a mercury reservoir disposed within said dispenser head; means for removing a predetermined quantity of mercury from said reservoir; hollow needle means extending downwardly from said mercury reservoir for transferring said mercury to an arc tube held by each of said machine heads; means for moving said dispenser head vertically with respect to said machine heads and means for temporarily sealing said dispenser head to one of said machine heads.

3. The dispenser according to claim 2 wherein said mercury removing means is an H-shaped slide having an aperture which can be filled with mercury from said reservoir and then moved to a position over the ingress of said needle.

4. The dispenser according to claim 3 wherein a pair of magnets are disposed on said dispensing head and adapted to move said slide from side to side.

5. A mercury dispenser comprising: a single dispensing head demountably disposed and vertically movable over a plurality of machine heads disposed upon radial arms of a rotary exhaust machine, each of said arms being adapted to be indexed beneath said dispenser head; said dispensing head including a receptacle enclosing a mercury reservoir; a transfer column extending downwardly from said reservoir; an H-shaped slide containing at least one aperture disposed beneath the base of said reservoir; a hollow needle offset from the egress of said transfer column and extending downwardly from said dispensing head; said aperture being disposed on said slide so as to be in communication with the egress of said transfer column when in a first position and the ingress of said needle when in a second position; each of said machine heads having an aperture into which said needle fits; a compressible gasket ring disposed about said aperture in each of said machine heads and adapted to fit against the bottom of said receptacle to form a seal when said dispenser head is moved downwardly thereon; means disposed in said machine heads for holding an exhaust tube in communication with the interior of an arc tube; said hollow needle being said hollow needle, said second aperture being disposed on said slide so as to enable the movement of gases therethrough when said first aperture is disposed beneath said transfer column.

8. The dispenser according to claim 7 including means for moving the machine head vertically with respect to the dispensing head.

References Cited UNITED STATES PATENTS 1,475,129 5/1923 Mayer 251137 2,336,998 12/1943 Mocs et al. 25 1-1-29 X 2,808,856 10/ 1957 Tiano et :al. 141-48 X 3,036,604 5/ 1962 Donofrio 141284 X 3,140,734 7/ 1964 Chauvin 14166 3,201,001 8/ 1966 Roberts et a1. 222|194 LAVERNE D. GEIGER, Primary Examiner.

E. I. EARLS, Assistant Examiner.