US2848844A - Apparatus for tipping-off incandescent lamps and similar devices - Google Patents

Description

Aug. 26, 1958 A. w. SEITZ 2,848,844

APPARATUS FOR TIPPING-OFF INCANDESCENT LAMPS AND SIMILAR DEVICES Flled April 50, 1956 United States Patent Q APPARATUS FOR TlPIPING-OFF INCANDESCENT LAMPS AND SIMILAR DEVICES August W. Seitz, Euclid, Ghio, assignor to General Electric Company, a corporation of New York Application April 30, 1956, Serial No. 581,422

7 Claims. (Cl. 49-2) This invention relates in general to apparatus for exhausting and tipping ofi incandescent electric lamps and similar devices, and more particularly to apparatus for sealing or tipping off the exhaust tube of the device after the evacuation and, if desired, gas filling of the device.

The exhausting machines commonly in use at present for exhausting incandescent lamps and similar devices comprise, in general, an intermittently indexed carrier or turrent having, at spaced points around the periphery thereof, a plurality of exhaust heads for holding the incandescent lamp or other device to be exhausted. Each lamp is successively indexed from one position or work station to another and the exhausting and, if desired, gas filling of the lamp is gradually completed as the lamp completes the cycle of movement around the carrier. The last operation is the sealing off of the glass exhaust tube and the melting off thereof beyond the sealing point to separate the tipped oif lamp from the remainder of the exhaust tube. During the sealing and melting off of the exhaust tube, the softened portion thereof is stretched or drawn out, by bodily displacement of the lamp bulb away from the exhaust head of the machine, to attenuate and contract the said softened portion of the exhaust tube so as to assist in the sealing or closing of the same. During this exhaust tube stretching and severing operation, the gas fire which is directed against the exhaust tube to effect the necessary heating thereof, is moved along with the lamp so as to continue to heat the tipped off residue of the exhaust tube (i. e. the exhaust tip) so as to positively insure the complete hermetic sealing or closure thereof.

In the case of exhaust machines conventionally em ployed for the exhausting of miniature type incandescent lamps, the lamps are customarily held in the exhaust heads of the machine in a bulb-down position with their exhaust tubes extending upward into and being held in the exhaust heads to thereby support the lamps in place therein. To effect the stretching or elongation of the exhaust tube during the tipping-oh operation, the lamp bulb is displaced or carried downward into a lamp-receiving holder positioned directly underneath the exhaust head at the tipping-off station of the machine. Heretofore, this downward movement of the lamp bulb to effect the stretching of the exhaust tube has been produced by a pusher or pull-down member which simply pulls the lamp bulb downwardly into the lampeceiving holder. During this downward movement of the lamp bulb, however, to stretch and attenuate the glass exhaust tube, the lamp bulb becomes separated from the remaining portion of the exhaust tube held in the exhaust head of the machine so that the lamp bulb is no longer supported by the said remaining portion of the exhaust tube. Because of this termination of the support for the lamp during the downward displacement thereof, little if any control over the ultimate positioning of the lamp in the lamp-receiving holder has been afforded by the prior tipping-off mechanisms heretofore in use. As a ice result, the tipped-off lamp frequently becomes tilted during its downward movement into the lamp-receiving holder. Such tilting of the lamp during its downward movement shifts the glass bulb thereof out of alignment with the lamp-receiving pocket of the lamp holder, which then results in the glass lamp bulb either being crushed against the lamp-receiving holder, or the exhaust tip of the lamp being displaced to one side or the other of, and out of heating relation to the gas tipping-off fire. In the latter case, not only does the exhaust tip fail to receive the full amount of heating from the tipping-off fire to properly fire-polish and thus form and complete the exhaust tip, but the tipping-off fire is also apt to be directed against other parts of the lamp with resulting possibility of damage thereto. For instance, in the case of the miniature bi-pin incandescent lamp recently introduced on the market and having an external stem press provded with an exhaust tip located between a pair of pin-type lead-in conductors sealed through and projecting endwise from the stem press, the tilting of the lamp during its downward movement into the lamp-receiving holder often results in the gas tipping-ofi. fire being directed against one or the other of the projecting pin ends of the lead-in conductors, the resultant heating of which then causes the glass stem press to crack or the pin to be burned Off.

A further undesirable condition which is occasionally encountered with prior tipping-off mechanisms, because of the absence of control over the position of the lamp bulb during its downward movement to stretch and attenuate the exhaust tube, is that condition which occurs in those cases where, because of the normal variations in the wall thickness of the exhaust tubes on difierent lamps, a thin-walled exhaust tube is heated to its softened condition and is ready for stretching before the normal start of operation of the lamp pull-down mechanism. In such instances, the lamp bulb moves down of its own weight to stretch the exhaust tube and becomes separated therefrom before the operation of the pull-down member to effect such downward movement of the lamp bulb. When this occurs, the freely falling lamp bulb, being separated from and no longer supported by the exhaust tube, is then apt to either fall entirely outside the lamp-receiving holder instead of into the lamp-receiving pocket thereof, or else is apt to fall into the lamp holder in a tilted position. In either case, however, the desired continued heating and fire-finishing of the exhaust tip on the lamp by the tipping-off fire is prevented, with the result that the exhaust tip is not properly formed and completed in the desired manner.

It is one object of my invention, therefore, to provide an improved tipping-off mechanism of the type referred to for tipping-off incandescent lamps and similar devices and which is free of the above-mentioned disadvantages.

Another object of my invention is to provide lamp tipping-oft apparatus of the type referred to which will positively support the lamp in place at all times during the course of the tipping-ofi operation.

A further object of my invention is to provide lamp tipping-off apparatus of the type referred to which will positively support and hold the lamp bulb in axial alignment with the exhaust tube of the lamp at all times during the displacement of the lamp bulb to effect the customary elongation of the softened glass exhaust tube during the tipping-off thereof.

A further object of my invention is to provide lamp tipping-off apparatus of the type referred to which will positively support and hold the lamp bulb in place at all times during the course of the tipping-off operation and which will operate to deliver the tipped-01f lamps in a predetermined inverted position into a lamp-receiving means or conveyor.

Briefly stated, in accordance with one aspect of the invention, a lamp tipping-E apparatus of the type referred to is provided with a vertically movable lamp-receiving holder at thetipping-off station of the exhaust machine, said holder being movable upwardly to engage and positively support the lamp as soon as the lamp is indexed to the tipping-off station of the machine and being movable downwardly in unison with the lamp pull-down means of the tipping-off apparatus,-during the customary pull-down of the lamp by the said means to elongate and sever the softened exhaust tube of the lamp, to thereby maintain the support of the lamp by the said holder following the severance of the exhaust tube;

In, accordance with a further aspect of the invention, a plurality of such lamp-receiving holders are mounted around the periphery of a tipping-elf turret which is mounted for vertical reciprocation at the tipping-oh station of. the exhaust machine and is intermittently indexed in timed relation to the operation of the main turret of the exhaust machine,;to carry the tipped-off lamps from the position in which they are received by the respective holder to an inverted position for delivery into a lamp conveyor or other receiving means.

.Further objects and advantages of my invention will appear from the following detailed description of a species thereof and from the accompanying drawing;

In the drawing, Fig. 1 is a front elevation of a lamp tipping-ofi apparatus comprising my invention and show ing a portion of an associated transfer conveyor, the parts being shown in their position immediately following the index of a lamp to the tipping-off station of a lamp exhaust machine, in position for tipping-off by the said apparatus...

Fig. 2 is a side elevation of the lamp tipping-off apparatus showing the parts thereof in position at the end of the tipping-off operation.

Fig. 3 is a fragmentary perspective view on an enlarged scale of the tipping-01f apparatus showing the parts in position at the start of the tipping-off operation.

Fig. 4 is a fragmentary vertical section on the line 4 4 of Fig. 1 showing the parts of the tipping-oh apparatus in position at an intermediate stage in the tippingerr operation in which the lamp bulb is positively supported and held in place in the lamp-receiving holder of" r the tipping-off apparatus, and

Fig. 5 is a diagrammatic perspective view of the operating cams and associated operating levers of the tipping.

off apparatus.

-Referrii1g to the drawings, the tipping-0E apparatus comprising my invention is therein illustrated as incorporated in a conventional type lamp exhausting machine such as employed to exhaust miniature type incandescent lamps, such exhaust machines generally comprising a plurality of lamp-receiving exhaust heads 1 located about the periphery of a turret (not shown) which is intermittently indexed to carry the lamps through a series of work stations where the exhausting and, if desired, gas filling operations of the lamp are performed. The exhaust heads 1, which are of the general type such as are cu stomarily used on miniature. lamp exhaust machines and shown, for example, 'in U. S. Patent 2,025,579, Donovan et al., dated December 24, 1935, are adapted to support the incandesecent lamps 2 to be exhausted by the exhaust tube 3 thereof in a bulb-down position, as shown. For such purpose, each exhaust head 1 is provided with an exhaust port in its underside which the-free end of the exhaust tube 3 on the lamp 2 is inserted and gripped to thereby support the lamp in place in the exhaust head with the exhaust tube extending vertically downward therefrom. At the time of their insertion in the exhaust heads 1, the lamps 2 are so oriented therein as to locate the plane of their terminal pins 6 tangentially to the path oftravel of the lamps 2 as they are advanced around the exhaust machine by the turret thereof. In the particular case illustrated, the incandescent lamp 2 is of the miniature bi-pin type such as disclosed in co-pending U. S. application Serial No. 549,424, Malm et al., filed November 28, 1955, and assigned to the assignee of the present invention. Such miniature bi-pin incandescent lamps comprise in general a small glass bulb 4 provided with an external stem press 5 having a pairof rigid terminal pin contacts 6 projecting endwise therefrom in spaced parallel relation, an exhaust tube 3 also projecting 'endwise from the stem press 5 at a location between the terminal pins 6. The exhaust tube, after evacuation of the lamp,

is tipped-off as indicated at 7 to thereby hermetically seal the lamp bulb. In the operation of the exhaust machine, the lamp 2, after evacuation and, if desired, gas filling thereof, is indexed through a series (preferably six in the present case) of work stations where the projecting exhaust tube 3 is preheated at a region immediately outward of the stem press 5 by gas fires (not shown) directed thereagainst at such station or stations, after which the lamp is then indexed to the next or exhaust tube tipping oft station where the exhaust tube is then severed and tipped-0E by the tipping-0E apparatus 8 comprising my invention.

The tipping-off apparatus 8 according to the invention comprises lamp pull-down means preferably in the form of a flat horizontally disposed plate or arm member 9 beneath which the tubulated lamp 2 is carried and positioned during the course of its index movement to the lamp tipping-off station. To permit such movement of the lamp bulb 4 beneath the pull-down arm 9, the latter is' formed with an open ended slot 10 which extends in the path of movement of the tubulated lamp 2 to the tippingoif station with its open end facing toward the tubulated lamp during its index movement to the tipping-oft station, the exhaust tube 3 of the lamp 2 passing into and being accommodated within the slot 10 during the index movement of the lamp to the-said station. As shown in Fig. .3, the side walls of the slot 10 in the pull-down arm 9 are provided with opposed arcuately-recessed portions 11 defining, in effect, a circular opening or pocket in the arm member for the accommodation of the stem press 5 of the lamp during the subsequent lowering movement of the arm member 9 into engagement with the lamp bulb 4. The push down arm 9 is fixedly mounted on a vertically movable carriage 12 which is fastened on the upper end of a vertically extending actuating rod 13 vertically reciprocable in a guide block 14 fastened to a support bracket or standard 15 upstanding from a stationary part or table'portion 16 of the exhaust machine. The vertical reciprocating movement of the actuating rod 13 and its associated carriage 12 and pull-down arm 9 is controlled by a plate cam 17 mounted on the main cam shaft 18 of the exhaust machine and a cooperating horizontally-extending operating arm 19 pivoted atone end on a shaft 20 and connected at its other end to the lower end ofthe actuating rod 13. The operating arm 19 is provided with a cam follower roller 21 which rides on the edge or cam surface 22 of the plate cam 17, and a tension coil spring 23 is connected to the operating arm'19 to exerta constant downward force on the operating arm and the actuating rod 13 tending to hold the cam follower roller 21in continuous engagement with the edge 22 of the plate cam 17. To lock the actuating rod 13 against rotation in the guide block 14 and maintain the pull-down arm 9 in proper oriented position at the lamp tipping-off station with its slot 10 aligned with the path of travel of the exhaust tube 3 to the tipping-off station and withits lampaccommodating aperture 11' vertically aligned with the tubulated lamp 2 at the tipping-off station, the carriage 12 is provided with a depending vertical guide rod 24 which extends into and isvertically slidable within a corresponding guide opening (not shown) in the guide block 14 on the bracket 15.

As soon as the tubulated lamp 2 is indexed to and arrives at the tipping-off station, the carriage 12 is lowered through the operation of the cam 17, operating lever 19 and actuating rod 13, to lower the pull-down arm 9 into resting engagement with the bulb 4 of the lamp, as shown in Fig. 4. In such bulb-engaging position the pull-down arm 9 rests, around the lower rim of its bulb-receiving aperture 11, on the bulb 4 of the lamp, the lower rim of the aperture 11 preferably being beveled for such purpose, as indicated at 11', to conform more or less to the curvature of the bulb at the region of engagement therewith. The lowering movement of the carriage 12 is produced by the movement of a drop portion of the operating cam 17 opposite the cam follower roller 21 of the operating arm 19. The operating arm 19 is thereby permitted to swing downwardly under the influence of the tension coil spring 23 and the weight of the carriage 12. Because of the downward spring loading of the carriage 12, the lamp pull-down arm 9 is therefore yieldingly held down against the lamp bulb 4, in the manner shown in Fig. 4.

Fixedly mounted on the carriage 12, at a position slightly above the pull-down arm 9 thereon, is a gas burner or tipping torch 25 which is adapted to direct a high intensity sharp-pointed gas fire 26 against the exhaust tube 3 of the lamp 2 as soon as the latter is indexed to the tipping-off station of the exhaust machine. The gas burner 25 is connected by a flexible conduit 27 to a suitable source of a combustible gaseous mixture such as oxygen and a combustible burner gas, and it is so positioned on the carriage 12 as to direct the gas tipping-01f fire 26 diametrically across and above the circular lampreceiving aperture 11 in the pull-down arm 9, and approximately radially outward of the exhaust machine turret and centrally between the terminal pins 6 of the lamp 2 positioned at the tipping-off station, so as to impinge against the exhaust tube 3 only of the tubulated lamp 2 at a predetermined point immediately above the stem press 5 of the lamp when the pull down arm 9 is seated down against the lamp bulb 4 in the manner shown in Fig. 4. The heat of the gas tipping-off fire 26 then softens and melts the exhaust tube 3 of the lamp at the said point so as to then be in condition for tipping-01f.

In accordance with the invention, a vertically movable bulb holder 28, located at the tipping-off station of the machine in a position below the exhaust head 1 located thereat, is elevated so as to be in bulb-supporting relation to the lamp 2 (Figs. 1 and 3) as soon as it arrives, i. e. approximately simultaneously with its arrival, at the tipping-off station. As a result of such support of the lamp bulb 4 by the holder 28, the lamp bulb, upon subsequent lowering of the pull-down arm 9 into resting engagement with the bulb 4, is in effect clamped and positively held in place between the pull-down arm 9 and the bulb holder 28 in the manner shown in Fig. 4, thereby maintaining the support of the bulb in a true vertical as well as oriented position following the softening of the exhaust tube 3 by the tipping-off fire 26.

As shown in Fig. 1, a plurality of such bulb holders 28 are provided around the periphery of a vertically disposed tipping turret 29 which is rotatably mounted on a horizontal shaft or pin 31), extending radially of the main turret of the exhaust machine, for intermittent rotation or index movement about the said pin. The shaft or pin 30 is fixedly mounted on a slide 33 and projects from the face of a stationary part 31 of a rotary valve 32 the other or rotary part of which is constituted by the turret 29 itself. The stationary part 31 of the rotary valve 32 is fixedly mounted on the slide 33 which is vertically reciprocable in a guideway 34 in the front face of the guide block 14. The slide 33 is retained within the guideway 34 by cover plates 35 fastened to the guide block 14.

The slide 33 is vertically reciprocated, to raise and lower the tipping turret 29, by a vertically extending actuating rod 36 connected at its upper end to the slide 33 and at its lower end to one end of a more or less horizontally extending operating arm 37 pivotally mounted at its other end on the pivot shaft 20. Pivotal movement of the operating arm 27, to effect the up and down movement of the slide 33 and associated tipping turret 29, is controlled by a plate cam 38 mounted on the cam shaft 18. For such purpose, the operating arm 37 is provided with a cam follower roller 39 which rides against the periphery or edge 40 of the cam 38. A tension coil spring 41 is connected at one end to the operating arm 37 to exert a constant downward force on the said arm 37 and associated actuating rod 36 tending to maintain the cam follower roller 39 in constant engagement with the periphery or cam surface 40 of the cam 38.

The bulb holders 28 on the tipping turret 29 extend radially outward from the periphery thereof and are provided at their outer ends with bulb-receiving pockets or recesses 42 (Fig. 4) of a shape (hemispherical in the particular case illustrated) conforming more or less to the shape of the lower portion of the tubulated lamp bulb 4 in the exhaust head 1. The bulb holders 28 are of the suction type adapted to hold the lamp bulbs 4 therein by the force of a vacuum created within the bulb-receiving pocket 42 of each holder. For such purpose, each bulb holder 28 is provided with a passageway 43 extending therethrough radially of the turret 29 from the bottom of the bulb pocket 42 into the turret 29 and terminating in a port 44 in the face of the turret abutting the face of the stationary part 31 of the rotary valve 32. Each bulb holder 28 is continuously connected to a source of vacuum through its respective port 44 from the time the holder 28 is located in its uppermost or lamp-receiving position until it is indexed to the station immediately preceding its lowermost or lamp-releasing station. For such purpose, the stationary part 31 of the rotary valve 32 is provided with an arcuate vacuum-supplying manifold or recess 45 in the face thereof engaged by the turret 29, which vacuum manifold 45 is co-extensive with the path of travel of the vacuum port 44 of each bulb holder 28 from the time the bulb holder is in its uppermost or lamp-receiving station until it is indexed away from the said station preceding the lamp-releasing station of the bulb holder. The arcuate vacuum manifold 45 in the stationary part 31 of the rotary valve 32 is connected by a conduit 46 to a suitable source of vacuum (not shown).

During the index of the bulb holder 28 to its lowermost or bulb-releasing station from the preceding station, the vacuum supply port 44 of the bulb holder passes beyond the end of the continuous vacuum supply manifold 45 so as to terminate the supply of vacuum to the lampreceiving pocket 42 of the bulb holder from the manifold 45. The supply of vacuum to each bulb holder 28 is continuously maintained, however, during the full period of its index to its lowermost or lamp-releasing station, from a second auxiliary arcuate manifold or recess 47 in the face of the stationary part 31 of the rotary valve 32, with which manifold 47 the vacuum port 44 of the bulb holder communicates during the course of index movement of the holder to its lowermost or lamp-releasing station. The manifold chamber 47 is connected by a flexible conduit 48 to a two-way acting control valve 49 (Fig. 5) which alternately connects the conduit 48 first to a source of vacuum, during the index movement of each bulb holder 28 to its lowermost or lamp-releasing station, and thence to a source of compressed air after the bulb holder 28 is positioned at its lowermost or lampreleasing station, the pulf of air thus produced in the bulb holder 28 serving to eject the lamp therefrom. The operation of the valve 49 is controlled in proper time relation to the index movement and dwell of the tipping Q a". 2, tmret ,9 byaca QmQunt d on t e m, Shaft 18 and a i henpe at ng plu eri o t e r r at e. operat n otthetiefns-fi pp fi prising my invention, the tipping turret 29 is moved upwardly from its lowermost position to its elevated position, by the, operation of the cam 38, operating arm 37 and actuating rod 36, to raise an empty bulb holder. 28 o the turret 29 into substantial bulb supporting engage ment with; the lamp bulb 4atthe tipping-ofi station of the exhaust rnachine,, as shown in Fig. 1. The timing of the up ward movement of thetipping turret 29 by the cam 38 is .such as to carry the bulb holder 28 to its uppermost position, and into substantial bulb-supporting engagement with the lamp bulb 4;,approximately simultaneously with the arr val of the tubulated lamp 2 at the tipping-oft station. The bulb holder 28 is thus located in bulb-supporting relation to the lamp bulb at the very start,of, and consequently throughout the full duration of, the ensuing lamp tipping-otf operation. above described elevation of the tipping turret 29 to its uppermost position it is indexed or rotated in a clockwise direction, as indicatedhy the arrow in Fig. l, to advancean empty holder 28 from the station preceding, and carry it to the lamp-receiving station (i. e., the upperinost station) of the tipping turret. This index movement of the tipping turret 2 9 is produced by the operation of a ratchet and pawl mechanism 52 which is actuated, on the upward movement of the tipping turret, by the engagement of a stationary upper stop arm memher with a roller 54 mounted on the free end of a swing arm 55 pivotally mounted at its other'end on the pivot pin 30 of the tipping turret. The said swing arm 55 carries a pawl 56 pivoted at one end on a pivot pin 57 extending from the swing arm and the other or free end of which is constantly held in engagement with the teeth 58 of a ratchet wheel 59, fixedly mounted on the tipping turret 29, by the force of a torsion coil spring 160 fitting over the pivot pin 57. The engagement of the roller 54 with the stop arm 53, during the upward movement of the tipping turret 29, causes the swing arm 55 topivotdownWardly (i. e. in a clockwise direction as viewed in Fig. 1) about the pivot pin 30, thereby causing the pawl 56 to rotate and index the ratchet wheel 59 and associated tipping turret 29 in a clockwise direction. The stop arm 53 is fastened on a stationary support column or bracket 61 upstanding from a stationary or table portion 16 of the machine, and it is adjusted to the proper elevational setting on the bracket 61 to pause; the exact amount of rotational index movement of the tipping turret 29, on the upward stroke ofthe turret-carrying slide 33, to properly position the empty bulb holder 28 of the tipping turret in its bulb-receiving position in vertical alignment with the lamp bulb 4 in the exhaust head 1 of the machine.

a To positively lock the tipping turret 29 in-place in its proper indexed position, against uncontrolled rotational movement therebeyond, a second or turrent-lockingfpawl 62 is provided for engagement with the ratchet wheel 59.. The said locking pawl 62 is pivoted at one end on a pin 63 extending from a support arm 64 fixedly mounted on the pivot pin 30 of the tipping turret 29. The other or free end of the locking pawl 62 is constantly held in engagement with the periphery of the ratchetwheel 59 by a. torsion coil spring 65 fitted over the pawl pivotpin 63, and it is provided with a yfl-shaped toothportion 66 which, at the completion of each index movement of the tipping turret 29, snaps into and meshes within a respective one of a series of corresponding V-shapednotches 67 inthe periphery of the ratchet wheel 59 to thereby lock the said wheel and the associated tipping turret 29against uncontrolled advance pivotal 'movement on-its pivot pin 30 beyond its proper indexed position. The upward stroke of the slide 33and associated-tipping turret- 29 is sotimed,-with respect to the index movement of the exhaust machine turret carrying During the arisen the exhaust head 1, as to cause the upwai'dly moving empty bulb hol der 28 of the tipping turret to index and move in unison with and u ing the course of such index movement, to move upwardly around and receive inits pocket the lamp bulb lhcated in the corresponding exhaust head 1 of the exhaust machine.

Immedi ofan exhaust head 1 to thetipping-off station of the machine and arrival of the tubulated lamp 2 at said station, the pulldown arm9 is lowered into resting engagement with the lamp bulb 4, as shown in Fig. 4, through the lowering of the carriage '12 by the operation of the cam 17, operating lever 19 and actuating rod 13. With thejpull-down arm'9 thus resting against the lamp bulb 4, the latter then is, in effect, clamped in place between the bulb holder 28 and the pull-down arin 9 and thereby kept from tilting upon subsequent pull down of the lamp bulb to stretch ands'ever the softened exhaust tube 3 thereof. V

After the lapse of a short interval of time (i. e. a few seconds) following the engagement of the pull-down arm 9 with the lamp bulb 4, of sufiicient duration to cause the exhaust tube 3 to be heated by the tipping-off fire 26 to the required softened condition for tipping off, the

pull-down arm 9 and tipping turret 29 are moved downwardly in unison through the operation of the cams 17 and 38 to thereby lower the lamp bulb so as to stretch and elongate the softened portion of the exhaust tube 3, causing it to attenuate and become severed at a point closely adjacent the stem press 5 of the lamp, as shown in Fig. 2. The downward movement in unison of the pull-down arm 9 and tipping turret 29 is assured by the engagement of an overhanging lip 68 on the pulldown arm carriage 12 with the upper end of the slide 33 which carries the tipping turret. By moving downwardly in unison, the pull-down arm 9 and bulb-holder 28 thus maintain the positive support of the lamp bulb 4 therebetween throughout the full period of the exhaust tube stretching and severing operation. As a result, the lamp bulb 4, after severance of the exhaust tube 3 at the softened region thereof, is prevented from tipping and I instead is kept in true vertical position throughout the full downward movement of the lamp bulb, thereby maintaining the residue of theexhaust tube on the lamp bulb (i. e. the exhaust tip 7 thereon) in proper vertical alignment with, and in heat-receiving relation to the tipping-cit fire 26 so as to become thoroughly fused and hermetically sealed and otherwise properly formed and completed. After the stretching and severance of the exhaust tube 3, the softened lower'end or stringer portion of the remnant of the exhaust tube remaining in the exhaust head 1 is blown to one side as indicated at 69 in Fig. 2, by

a timed air jet from a nozzle 70 mounted on the carriage 12 and connected to a source of compressed air, so as to be clear of the parts of the tipping-off apparatus 8 during the ensuing index movement of the exhaust machine turret. Preferably in addition, a soft gas fire from a gas burner 86 is directed against the remnant of the exhaust tube 3 remaining in the exhausthead 1, approximately at the uppermost region of stretching of the exhaust tube, so as to prevent the spring back or return of the deflected softened lower end portion 69 of the exhaust tube remnant to its initial position directly above the exhaust tip 7 of the tipped-01f lamp, thereby avoiding the dropping of molten glass from the softened lower end 69 ofrthe exhaust tube remnant down onto the exhaust tip 7 and resultant building up of a large mass or collection of glass thereon.

.During the unitary downward movement of the tipping turret 29 and pull-down arm 9 to sever the exhaust tube 3, theroller 54 on the turretindexing swing arm 55 engages a lower stationary stop arm member 71 fastened on. the support bracket 61 to thereby cause the swing arm: 55 to be pivoted counter clockwise, as viewed in Fig. 1, a suflicient amount to carry the free end of a'tely upon completion of the index movement the pawl 56 upwardly beyond the next tooth 58 on the ratchet wheel 59, thus placing the turret indexing mechanism 52 in readiness for the next index movement of the tipping turret 29. The lower stop arm 71 is preferably adjusted at such an elevational position on the support bracket 61 as to produce a slight amount of overtravel of the pawl 56 beyond the next tooth 58 of the ratchet wheel 59, thereby insuring the engagement of the pawl 56 with the next ratchet wheel tooth and the subsequent index of the tipping turret 29.

Following the arrival of the tipping turret 29 and pull-down arm 9 at their lowermost position (Fig. 2), the tipping-01f fire 26 then continues to heat and fire polish the exhaust tip 7 remaining on the lamp to transform it into the desired finished form. This heating of the exhaust tip 7 by the tipping-off fire 26 continues until just before the start of the next index of the main or exhaust head carrying turret of the exhaust machine, at which time the tipping-off operation is completed and the carriage 12 and the slide 33 are then elevated once again to start the next cycle of operation of the tipping- 01f apparatus 8. The start of this upward movement of the carriage 12, however, occurs slightly ahead of the start of upward movement of the slide 33 and associated tipping turret 29 so as to insure that the lamp pull-down arm 9 will be elevated a sufficient distance relative to the tipped off lamp 2 in the bulb holder 28 of the tipping turret, as to clear and not interfere with the lamp 2 on the subsequent rotative index of the tipping turret 29 during the elevation thereof to its upper or lamp-receiving position. To aid in preventing any such interference with the tipped-off lamp 2 during the rotative index of the tipping turret 29, the pull-down arm 9 may be provided with a slot 72 as shown in Fig. 3 for permitting the passage therethrough of the stem press 5 and terminal pins 6 of the lamp during the rotative index of the tipping turret.

During the period the tipping turret 29 is located in its lowered position, the lamp 2 in the lowermost bulb holder 28 is released or discharged therefrom by the interruption of the vacuum supply to the said bulb holder through the operation of the control valve 49. The discharge of the lamp 2 from the bulb holder 28 at such time preferably is positively assured by the connection of the bulb holder to a source of compressed air through the operation of the control valve 49, the resulting jet of air produced in the bulb holder serving to positively eject the lamp 2 therefrom.

As they are discharged from the bulb holder 28, the lamps 2 may be directed by a chute (not shown) into a suitable storage container or receptacle. If desired, however, they may be placed in turn on a suitable conveyor 73 for transport thereby to other apparatus for performing further operations on the tipped-oil lamp. As shown in Figs. 1 and 2, the conveyor 73 may be of the chain type comprising a pair of horizontally disposed endless chains 74- which run around sprockets 75 (only one of which is shown in Fig. 2) located at the opposite ends of the conveyor and mounted on vertical shafts 75'. Mounted on the conveyor chains 74, at spaced points therealong, are a plurality of lamp holders 76 each of which, in the particular case shown, comprises a pair of vertically extending spring finger ja-ws 77 which, in their normal spring-closed position, are adapted to grip and clamp the terminal pins 6 of the lamp therebetween to thereby support the lamp in place on the conveyor. The conveyor 73 is intermittently advanced, in timed relation to the vertical reciprocating movement of the tipping turret 29, to position successive empty lamp holders 76 directly underneath the lowermost bulb holder 28 of the tipping turret so as to be in position to receive the terminal pins 6 of the lamp 2 between the opened upper jaw ends 78 of the spring fingers 77 when the lamp in the lowermost bulb holder 28 of the tipping turret reaches its lowered position at the end of the downward stroke of the slide 33 and associated tipping turret 29. At such instant, the spring jaws 77 are in their opened position so as to freely receive the terminal pins 6 of the lamp 2 therebetween. The opening of the jaws 77 is effected, during the time the empty lamp holder 76 is in its said lamp-receiving position, by upward movement of a wedge cam 79 into engagement with cooperating inward V-shaped cam surfaces 80 on the spring fingers 77. Each lamp holder 76 is provided with such a wedge cam 79 which is vertically reciprocable in the lamp holder between the spring fingers thereof. The wedge earns 79 are spring loaded, as by compression coil springs 81, so as to be normally urged downwardly out of engagement with the cam surfaces 80 of the spring jaws 77, thereby allowing the spring jaws 77 to close by virtue of their own spring tension. The wedge cams 79 are moved upwardly, to open the spring jaws 77 during the dwell of each lamp holder 76 at its lamp-receiving station, by the pivotal movement of an operating lever 82 into engagement with the lower end of the wedge cam 79. The pivotal movement of the operating lever 82 is controlled by a face cam 83 mounted on the cam shaft 18, and by a cam follower or operating arm 84 cooperating with the face cam 83 and connected to the operating lever 82 by a vertical actuating rod 85. The vertical movement of the wedge cam 79 to open and close the spring jaws 77 is so controlled by the operation of the face cam 33 as to open the spring jaws 77 before the lamp 2 in the lowermost bulb holder 28 of the tipping turret 29 reaches its lowermost position on the downward stroke of the slide 33 and associated tipping turret, and to close the spring jaws 77 so as to grip and firmly hold the lamp 2 before the release and ejection thereof from the bulb holder 28 by the interruption of the vacuum supply thereto and the subsequent air jet produced therein. The intermittent advance or index movement of the chain conveyor 73, in proper time relation to the operation of the tipping turret 29, may be produced by any suitable means, such as by a ratchet and pawl mechanism similar to that shown for the tipping turret 29 and actuated from the main cam or drive shaft (not shown) of the exhaust machine.

It will be evident from the above description that by the provision of the vertically movable bulb holder 28, the lamp 2 is positively held in place against tilting to one side or the other during the tipping-off operation such as might otherwise result in the tipping-off fire 26 striking against one or the other of the lamp terminal pins 6 and either burning off the said pin or cracking the glass stem press 5 of the lamp. In addition, by positively supporting and holding the lamp 2 in place in the bulb holder 28, from the very outset of the lamp tipping-off operation until after the tipped-off lamp is inserted in the jaws 77 of the conveyor 73, the orientation of the lamp 2 and its terminal pins 6 is continu ously maintained. This may be of advantage in subsequent lamp processing operations, as where the tippedolf lamps 2 are to be transferred from the conveyor 73 into other lamp-processing apparatus, in predetermined oriented position therein.

Although a preferred embodiment of my invention has been disclosed, it will be understood that the invention is not to be limited to the specific construction and arrangement of parts shown but that they may be widely modified within the spirit and scope of my invention as defined by the appended claims.

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

1. Apparatus for tipping-off the exhaust tube of an electric lamp supported by its exhaust tube in bulb-down position in an exhaust head of a lamp exhaust machine, comprising a vertically movable bulb holder disposed beneath the exhaust head for supporting and holding the bulb of the said lamp, a vertically movable carriage provided with lamp pull-down means for engageirierit'with the upper side of the lamp bulli'bn downward movement of the carriage, a burneripo'sitioned on said carriage to direct a gas tipping-off fire against the exhaust tube'of said lamp, and actuating rneans for elevating said holder into bulb-holding position prior to the'softenin'g of' the exhaust tube by said tipping-off fire and thereafter lowering both said pull-down means and bulb holder in' unison, while'maintained in engagement with the lamp bulb, to move the lamp bulb downwardly and thereby stretch and sever the softened exhaust tube.

2. Apparatus for tipping-oif the exhaust tube of an electric lamp supported by its exhaust tube in bulb-down position in an exhaust head of a lamp exhaust machine, comprising, a vertically movable bulb holder'di's'po'sed beneath the exhaust head and having a socket for receiving and holding the bulb of said lamp, means connecting said socket to a source of vacuum to produce a suction in said socket for holding the bulb in place therein, a vertically movable carriage provided with lamp pull-down means for'engagem'ent with the upper side of the lamp bulb on downward movement of the carriage,

a burner positioned on saidcarriage to' direct a gas tippingoif fire against the exhaust tube'of said lamp, and actuating means for elevating said holder into bulb-holding position prior to the softening of the exhaust tube by said tipping-off fire and thereafter lowering both said pull down means and bulb holder in unison, While maintained in engagement with the lamp bulb, to move the lamp bulb downwardly and thereby stretch and sever the softened exhaust tube.

3. Apparatus for tipping-oft the exhaust tube of, an electric larnp supported by its exhaust tube in bulb-down position in an exhaust head of a lamp exhaust machine, comprising a vertically movable. carriage provided with lamp pull-down means engageable'with' the upper side' of the lamp bulb on downward movement of the carriage, a burner positioned on said carriage to direct a gas tipping off fire against the exhaust tube of said lamp, a vertically reciprocable bulb holderengageable with the bulb of said lamp to hold and support it in place, operating means for moving said carriage downwardly to lower said pull-down means into engagement with the lamp bulb and'direc'tthe said tippingofl? fire against the portion of the exhaust tube to be tipped-elf, actuating means for elevating said bulb-holder into bulb-holding engagement with the lamp bulb'prior to the softeningof theexhaust tube, by said tipping-01f fire, and means for operating said actuating means and operating means to thereafter lower said pull down means and bulb holder in unison to move the lamp bulb downwardly so as to stretch and sever the softened portion of the exhaust tube.

4. Apparatus of the character specified in' claim 1 and having an air nozzle positioned on said carriage above said burner to direct an air jetagainst the softened lower portion of the exhaust tube remnant remaining in the exhaust head to deflect the said exhaust tube portion to one side of the tipped-E lamp in said holder.

5. Apparatus for tipping-01f the exhaust tube of an electric lamp supported by its exhaust tube in bulb-down position in an exhaust head of a lamp exhaust machine, comprising a vertically movable carriage provided with lamp pull-down means engageable with the upper side of the lamp bulb on downward movement of the carriage,

a burner positioned on said carriage to direct a'gas: tipping-0E fire against the exhaust tube of said lamp, a

vertically arranged tipping turret located beneath the exhaust head and provided around its periphery, with a plurality of bulb holders for engaging and holding the lamp bulb, said turret being mounted for both rotational direct 'tlietsaid tipping-off fir 12 I and vertical reciprocating movement;op rating means-for matting said airiage dart/awards to inner said pan d'ojwn'fmeans into engagpjrrient with the lamp bulb and e ag ainst the por tion; of the exhaust tube to betipped bli, actuating means" for rot'a-i tivelyindexing'said' turret and elevating it to carry each bulbhold'e'r in succession .'to' the top of said turret 'and elevatedt intobiilb-holdingengagement with the lamp bulb 'priorto' the 'soft'ening'of the exhaust tube by said tipping-01f fire, and means for operating said actuating" means and operating mans to thereafter ldwef'said pulldown man s andiur ret"iri unis0n to move th e larrip biilb vertically downward so as tostretch andsever the 's'oftend portion of the exhaust ruse.

haust head to deflect the said exhaust tube portion to'on'e" side of the tipped-01f lamp in said holder."

7. Apparatus for tipping-oft the exhaust tubeof an electric: lanip supp ortd its exhaust tube inbulb-dovvn position in an exhaust head of alanip exhaust maehnie'; comprising 'aver'tically'movablecarriage at said station provided with lamp pull-down means engageable with the upper, side of the bulb' o'f the lamp in said exhaust head on' downward movement of the carriage, a burner positioned on saidcarriage to direct a gas tipping-off are againstthe'exhaust tube" of said lamp, a vertically ar ranged tipping'tur ret located beneath the exhausth eadi and provided a'round its' periphery with a plurality of' bulb holders for engaging and holding the lamp bulb, a

vertically reclpro'cab le slide 'on'whi'ch said turret 'isipivotally'rnounted for rotation about its axis, turret indexing means c ompris' 'g alratchet, wheel onsaid turret. and, a swing arm iverea'o'n said slideand carrying a pawl engaged with said ratchet wheel, an upper stop "member" engaged by 'said swing arm during'the upward stroke of said slide'to 'pivot the said arm'iand pawl so as to'rotativelydndxl the, turret, actuating means for vertically moving 'saidslide' to elevate" and index the said turret to its uppe'r' positionand locatea'n empty bulb-holder there of intbulb holdingpositionZin engagement with"the la'rnp1. bulb insaid exhaust head, operating meansfor vertically movingisaid carnageta lower'the pull-down means there; on'intorestingiengagernent with'the lamp bulb'in'said exhaust head, said actuating and 'operanng'mean's runner" acting to then lower the said slide and 'car'riag'ein unison;

after a time interval suflicient'to cause the exhaustptube to' become heated vand softened by said'tipping-ofi fire, to cause the said pull-down means and the said bulb holder on the turret'to move the lamp bulb downwardly, while maintained in supported position therebetween, to thereby stretch and sever the softened tube, a lower stop" member engaged by said swing arm during the downward strokeof said slide'to pivot'and return the said arm and pawl to their initial'position in readiness for their next' turret indexin'g' str'oke, and means for operating said actuating means and operating means in proper time relation.

References Cited in the'file of this patent UNITED STATES PATENTS 1,885,758 Parker Nov. 1, 1932' 2,006,568 Gustin et al July 2, 1935 2',02 5,'579* Donovanet a1. Dec. 24;,193'5- 2,153,370 Donovan et a1. Apr. 5, 1939 2,295,034 Geiger et a1. 'Sept. 8,, 1942"

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