US2775271A - Lamp exhaust head - Google Patents

Description

Dec. 25, 1956 E. E. YEO ETAL LAMP EXHAUST HEAD Filed June 16, i955 Fig. 2

Weird INVENTORS; DAVID P. DRaw/v BY ERNESTE- EO ATTORNEY.

LAMP EXHAUST HEAD Ernest E. Yeo, Wenham, and David P. Drown, Beverly, Mass, assignors to Sylvania Electric Products Inc., Salem, Mass., a corporation of Massachusetts Application June 16,1955, Serial No. 515,852

3 Claims. (Cl. 141-384) Ourinvention relates to machinery useful in making incandescent lamps and in particular to an improved exhaust head bymeans of which an individual lampmay be mounted for the automatic exhausting, flushing and filling operations performed on the rotating turret of a conventional exhaust machine. 6

In the normal process of lamp manufacture a mount comprising a stem, a filament and an exhaust tube is assembled into a bulb and the two are flame sealed. Then the lamp is transferred to an exhaust machine'where appropriate instrumentalities operate to exhaust the bulb, flush the bulb with nitrogen and then fill the bulb with an inert gas. Customarily the exhaust machine comprises a rotating turret with a number of heads into which the bulbs are clamped, the heads communicating with sweeps terminating in the interior of the machine in ports which are brought successively into communication with the several exhaust and gas manifolds. Inasmuch as there are occasional breakages of bulbs or mounts taking place in the machinery preceding the exhaust machine, it happens from time to time that an exhaust head will not receive a lamp; it is therefore necessary to have a valve in each head in order that the empty heads can be sealed ofi.

Inevitably dirt and dust are sucked into the exhaust heads from the lamps, and it is therefore frequently necessary to dismount the heads for cleaning. Moreover the low pressures involved lead inescapably to failures of even the best valves and seals. In the past it has been an expensive and time consuming operation to take apart the heads either to clean them or to renew valves or sealing elements, since the entire machine is necessarily shut down for a rather lengthy period.

The most important object of our invention is to improve the efficiency of lamp making machinery.

Another object of the invention is to facilitate the operations of cleaning or repairing exhaust valve heads.

An important feature of our invention resides in a selfcontained unitary head adapted to be mounted on an exhaust machine by a single bolt and including in addition to means for clamping and sealing the exhaust tube of a lamp, an easily accessible filter and a simple, easily removable valve.

We have found in practice that an exhaust machine equipped with the improved heads of our invention may be provided with a number of spare heads, and a head which becomes defective for any reason can be replaced in about thirty seconds, thus reducing to an absolute minimum the time during which the exhaust machine must be stopped in the event of any difficulty with any of the heads. Furthermore, in the event the valve of a head becomes defective, usually by the deterioration of a sealing ring, the valve may be removed and replaced in a matter of a few seconds. Consequently the efficiency of the machine'is greatly increased, as will be appreciated by those familiar with machinery operating at very high rates of production.

2,775,27l Patented Dec. 25, 1956 "ice head constructed in accordance with the invention, and

Fig. 2 is a bottom plan of the exhaust head shown in Fig. 1.

As will be apparent from an inspection of Fig. 1, the exhaust head of our invention is organized about a compact aluminum casing 16 which is mounted upon the external rim or turret 10 of an exhaust machine equipped with a plurality of radially extending sweeps 12 which project through the turret rim 10. The casing 16 is secured to the rim 10 by means of a single bolt 18 and a centering stud 20 set into the rim 10 and extending into an appropriate hole in the face of the exhaust head. Extending through the casing is a transverse bore 22 enlarged at the inner end of the casing 16 to receive a metal bushing 24 provided with an internal wall 26 having a relatively small central aperture 28. The bushing 24 is sealed in air-tight relation to the casing 16 by means of two spaced rubber sealing rings 30. The exhaust sweep 12 is received in the inner end of the bushing 24 and an air-tight seal is secured by means of a rubber sealing ring 14 contained in a groove cut adjacent the end of the exhaust tube 12.

Adjacent the wall 26 of the bushing 24 is a downwardly extending port 32 in alignment with a passage 34 cut into the interior of the casing 16 and leading to a relatively large internal chamber 36 which serves to accommodate a porous bronze filter member 38. The sealing rings 30 span the wall 26 and the port 32. The chamber 36 forms an opening at the bottom of the casing 16 which is normally closed by a bottom cover 40 having outwardly extending cars 39 through which bolts are passed into the casing 16 so that the cover may be drawn tightly against the bottom of the casing 16, a sealing ring 41 being interposed between the two members to provide an air-tight seal between the two. The bottom cover 40 also has an upwardly projecting flange which fits into the chamber 36 and bears against the filter 38 to hold it in position.

The bottom cover 40 has a central vertical passage 42 opening into the chamber 36 and embraced by a thick relatively soft rubber ring 44. The bottom cover 40 is externally threaded to receive a clamp 46 which includes a thrust block 51 bearing against the bottom of the rubber ring 44 and supported in bearings 50 mountediat the bottom of the clamp 46. For operating the clamp there is provided a lever 48 which is secured in fixed relation to the clamp and adapted to be operated by external means (not shown), a stop member 49 being provided on the bottom cover 40 to limit the opening movement of the lever 48.

In the normal operation of the machine, a lamp is presented upside down to the head and thrust upwardly so that its exhaust tube passes through the rubber ring 44. Then the lever 48 is operated to rotate the clamp memher and compress the rubber ring tightly around the exhaust tube so that the lamp is then held firmly in position and in air-tight sealing relation with the interior of the bottom cover 49 and the casing 16.

Mounted for reciprocation in the bore 22 of the casing 16 is a valve plunger 54 having an enlarged inner head on which is mounted a sealing ring 56 of slightly larger normal diameter than that of the interior of the bushing 24 into which the head of the plunger extends. Mounted on the extreme inner end of the plunger 54 is a rubber sealing ring 58 of suflicient diameter to embrace the aperture 28 formed in the wall 26 in the bushing, when ..the. valve plunger. is .at. its extreme inner position,.. thrust against the wall 26. Surrounding the intermediate portion of the valve plunger 54 is a spiral compression spring '60ivbearing. 1 at :itsxinnerzend againstv .the enlarged iheadsofwthe.plunger and at itsouterend upon the inner .surfaceof a collar62: slidably .mountediupon' the valve plunger 54 and. limited in its movement rthereon by means of-a pin 64 passing through the. collarand through :aneelongated: slot 66, cut'through thervalve.:plunger 54. :A pivot. pin' 68 passing ithrough the outerend of the valve1plunger'54 provides pivotal support for a earn lever 70 which embraces the end of the valve.plunger wand extends outwardly therefrom. The cam lever.70 is so.dimensionedthat'when it ismoved' to the position into contact with the surface of the wall 26, thus closing the. aperture 28.

.In order to holdv the valve in'proper operating position, there is provideda keeper 72 surrounding the .headof the bolt 18 andprojecting downwardly to engage a shoulder cut into the upper face of the collar 62. ,Inorder to remove the valve, it is only necessary to loosen ;;the nut 102 on the endof the bolt 18 and slide up the keeper 72. The valve plunger andits associated elements :can. then. be withdrawn entirely from. the head; or the ,head may be totally removed as a unit from the machine by removing the nut. The result is considerable flexivbility in operation, since inorder to install a spare head it is necessary only. to remove the nut 102, slide the casing 16 outwardly of the rim 10, slide a new head onto the bolt 18 (centering it by the pin 20) and then replacing the nut 102. As previously explained, the valve plunger canbe replaced even more simply by loosening the same nut 102.

,In normal operation the turret 10 is rotated into position to receive a lamp, at which time the valve is closed and .the clamp is opened. It a lamp is then inserted into the head with its exhaust tube 110 passing through the rubber ring 44, the next operation is to rotate the clamp .lever 48 in order to clamp and seal the lamp into the .head and thento operate the cam lever 70 to open the valve. -.lever 70 is not actuated so that the valve remains closed.

If no lamp is presented to the head, the cam Although the embodiment of our invention shown in .:the. drawings and described above represents the best 4 .mode..now...known. to us for practicing the invention, it will be obvious to those skilled in the art that the head may be modified in several respects without departing from the spirit of the invention as defined in the appended claims.

We claim:

1. An exhaust head for lamp-making machinery, comprising a casing having a through-and-through bore, the bore being enlarged adjacent one end to reoeivea bushing, a pair of spaced resilient sealing members 'interposedbetween said bore and the bushing, an apertured partition disposed internally in said bushing and disposed between said sealing members, an inlet passage formedin said casing and extending through said bushing adjacent said partition and between said sealing members, said bushing being adapted to receive at one end an exhaust pipe on the side of the partition opposite the inlet passage, a valve plunger received in the bore and bushing, sealing .means carried byysaid. plungerv effective to. touchsa'id .partition andclose said aperture, cam operatedmeans effective to retract the valve plunger to, open said aperture,.and spring means normally urging the plunger inwardly to closed position.

2. An exhaust. head for lamp-making machinery, comprising a casing having a bore, an apertured partition in said bore, a passage communicating with said bore adjacent said partition, a valve plunger received in said bore, a resilient sealing member carried at the inner end of said plunger to seal the aperture in said partition when the plungeris thrust inwardly, a resilient sealing ring mountedon said plunger, resilient means normally urging said valve plunger inwardly to closed position, cam operated. means. for retracting said plunger, and means for releasably. clamping the exhaust tube. of alampainto communication with said passage.

3. An'exhaust head for lamp-making machinery, comprising a casing having a first bore for receiving the end ofan exhaust line, and a second bore, an apertured .wall separating said .bores, an inlet passage communicating with said second bore, said casing also having a chamber communicating with said inlet passage, a filter mounted in-said chamber, a valve plunger received in the second bore, sealing means mounted on said plunger for closing the aperture in said wall when the plunger is thrust inwardly, cam operated means 'for reciprocating the plungenand means. for. clamping the exhaust tube of a lamp into communication with said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,522,969 Smith Sept. 19, 1950

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