US2696697A

US2696697A - Machine for bending envelopes for curved fluorescent lamps

Info

Publication number: US2696697A
Application number: US230826A
Authority: US
Inventors: Wiener Charles; Frank J Camarata; Greiner Arno
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1951-06-09
Filing date: 1951-06-09
Publication date: 1954-12-14
Anticipated expiration: 1971-12-14

Description

Dec. 14, 1954 c. WIENER ETAL 2,696,697

MACHINE FOR BENDING ENVELOPES FOR CURVED FLUORESCENT LAMPS Filed June 9, 1951 6 Sheets-Sheet 1 Dec. 14, 1954 C, WIENER Em 2,696,697'v MACHINE FOR BENDING ENVELOPES FOR CURVED FLUORESCENT LAMPS Filed June 9, 1951 6 vSheets-Sheet 2 ATTORN EY De@ 14, 1954 c. WIENER Erm.

MACHINE FOR BENDING ENVELOPES FOR CURVED FLUORESCENT LAMPS 6 Sheets-Sheet C5 Filed June 9, 1951 ffy.

lNvENToRs amm/Ez, Ff owne/2779 and lf//Ym BY* ATTORNEY Dec. 14, 1954 c. WIENER ETAL 2,696,697

MACHINE FOR BENDING ENVELOPES FOR 'CURVED FLUORESCENT LAMPS Filed June 9, 1951 6 Sheets-Sheet 4 Z 7 0 M 4M aww 0J 5mm $40 @iw Y 4. 4 N.h 4 4 Ww Wray V. www M Zi www J \Z f rv 54. 5 A 4l. un n/J aJ Zad Z vl .EMY N B y, o E M u- W n 5 C 3 5 WU M Z M m.\ d l WM 4 I M w Z 5% 64. M W1 M 9 wlw 1.l

j UJ/k Dec. 14, 1954 C. WIENER ET AL 6 Sheets-Sheet 5 Filed June 9, 1951 z MZ b 445% 4 .Ma W oo 0J M Zd WMMMV rw WW .7 Z M 4. M

QQYQUQ Dec. 14, 1954 c. wir-:NER ETAL 2,696,697

MACHINE FOR BENDING ENVELOPES FOR CURVED FLUORESCENT LAMPS Filed June 9, 1951 6 Sheets-Sheet 6 97 60N/Kassen v /WICSr/PPLY i' 3 mf v Y ATTORNEY United States Patent Office 2,696,697 Patented Dec. 14, 1954 MACHINE FR BENDING ENVELOPES FOR CURVED FLUORESCEN T LAMPS Charles Wiener and Frank E. Camarata, Bloomiield, and

Arno Greiner, Irvington, N. J., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application June 9, 1951, Serial No. 230,826

8 Claims. (Cl. 49-7) This invention relates to tube-bending machines and, more particularly, to a machine for lehring and bending the coated tubular envelopes of curved fluorescent lamps.

Fluorescent lamps having their tubular envelopes bent in the form of a half circle are sold by the assignee of the present application under the trade-mark Circlaro The short length of the Circlarc lamp permits its operation on a small choke as ballast with a manual or glow switch starter. The base pins are desirably located 1n a plane extending at an angle of 45 to the plane of the lamp, thus allowing the pins of two opposing lamp bases to overlap and reducing the thickness of a two lamp holder to a minimum.

The manufacture of this lamp generally comprises Washing and drying the bulb, coating the bulb with a fluorescent mixture or phosphor, drying the coated bulb to remove the volatile solvent or diluent in the coating mixture, baking or lehring the dry, coated bulk to burn out and entirely remove the carbonaceous binder and simultaneously straighten any crooked bulbs, bending the lehred bulb to the Circlarc configuration, sealing the mounts into each end of the bulb to form the lamp, eX- hausting, basing, and testing the lamp.

To reduce production costs, improve quality and increase production, it has been found advantageous, according to our invention, to provide an automatic machine for lehring the tubular coated bulbs and bending the lehred bulb into the Circlarc conguration. This machine consists of a lifter-feeder mechanism, a lehring oven, a rotatable slidable turret carrying the lower molding dies, an upper molding die mechanism and an automatic synchronizing mechanism. The lifter-feeder mechanism has two sets of rotating and reciprocating rollers for automatically advancing the bulbs through the lehring oven, which is maintained automatically at the desired lehring temperature.

When a bulb reaches the last roller of the lifter-feeder mechanism, it is automatically dropped into a lower molding die. An upper molding die follows immediately and forms the bulb to the desired shape. gas such as nitrogen is automatically blown into the bulb to shape the body of the bulb against the walls of the mold. The upper molding die is then retracted and the lehred formed bulb expelled from the lower molding die by the simultaneous rotation and lowering of the turret.

The principal object of our invention, generally considered, is to provide a machine which lehrs tubular phosphor-coated bulbs or envelopes for discharge lamps and automatically forms the lehred coated envelopes into the desired curved configuration.

An additional object is an automatic machine, comprising a lifter-feeder mechanism, a lehring oven, a rotatable. slidable turret having a plurality of lower molding dies, an upper molding die mechanism, and an automatie synchronizing control mechanism, for reducing the cost, increasing the production rate, and improving the g1' quality of the lehring and forming operations in the production of Circlarc fluorescent lamps.

Other objects and advantages of the invention relating to the particular arrangement and construction of the various parts will appear to those skilled in the art to r which it appertaius as the description thereof proceeds, both by direct recitation thereof and by implication from the context.

Referring to the drawings, in which like numerals of refe-rence indicate similar parts throughout the several views:

During forming a I Fig. 1 is a side elevational view of the lehring and bending machine of our invention in the normal starting position;

2 is a front elevational view of the machine of 1g.

Fig. 3 is an axial sectional View of the machine, on the line ill-Hl of Fig. 2 in the direction of the arrows;

Fig. 4 is a fragmentary sectional view of the upper and lower molding die, at the position of Fig. 3, and of the delivery end portions of the lifter-feeder mechanism, howing how lehred bulbs are fed into the lower molding ies;

Fig. 5 is a transverse sectional view of the machine on the line V-V of Fig. 3 in the direction of the arrows;

Fig. 6 is a sectional View of the one-way turret clutch on the line Vl-VI of Fig. 5 in the direction of the arrows;

Fig. 7 is a sectional View of the rotatable outer portion of the lower die heating system manifold valve on the line VII- VII of Fig. 5 in the direction of the arrows;

Fig. 8 is a sectional view of the stationary inner portion of the lower die heating system manifold valve on the line VH1-VIII of Fig. 5 in the direction of the arrows;

Fig. 9 is a sectional view on the line .IX-IX of Fig. 8 in the direction of the arrows;

Fig. 10 is a sectional view of the upper molding die mechanism and a lower molding die before plugs are dropped into the ends of the lamp envelope to be formed.

Fig. 1l is an elevational View of the plug tripping mechanism for the upper molding die mechanism, before said plugs drop into the ends of the lamp envelope to be formed;

Fig. 12 is a sectional View, similar to Fig. l0, with the plugs in the ends of the formed lamp envelope;

Fig. 13 is an elevational View, similar to Fig. l1, showing the mechanism when the plugs are in the ends of the formed lamp envelope;

Fig. 14 is an elevational view of the valve-tripping mechanism for directing nitrogen into the tube during forming;

Fig. 15 is a timing diagram illustrating the cooperative automatic operation of the component parts of the machine;

Fig. 16 is a schematic diagram showing the wiring and piping of the machine;

Fig. 17 is an elevational View of a lehred and formed Circlarc lamp envelope;

Fig. 18 is an elevational view of a completed Circlarc lamp;

Fig. 19 is a horizontal sectional view on the line XiX-XIX of Fig. 3, in the direction of the arrows;

Fig. 20 is a fragmentary sectional view corresponding with a portion of Fig. 4, but showing the lifter-feeder mechanism in another position;

Fig. 21 is a fragmentary plan of end portions of the lifter-feeder rollers, on the line XXI*XXI of Fig. 3, in the direction of the arrows.

Referring now to the drawing in detail, and particularly to Figs. l and 2, the reference numeral 24) designates the machine frame of one embodiment of our automatic lehring and bending machine 22. This machine frame comprises a bottom platform 24, two turret support pedestals 26, a lehring oven frame 28 (Fig. l) on said platform, and an upper molding die frame 30 on said pedestals.

Each of said pedestals 26 has essentially a vertical channel portion 31 (Fig. 1) having an axial turret mechanism slot 32 (Fig. 3) cut transversely therethrough substantially the length of pedestal 26, a top at ange portion 33 (Fig. 2), and at the bottom a anged foot portion 34 secured to the platform 24 by suitable nuts and bolts. The

3 tion 33 of each pedestal 26 is the bottom support plate 42 (Fig. 2) of upper molding die frame 30, projecting horizontally inwardly from said pedestal 26. This plate 42, a cast metal member, has two suitable hollow vertical sockets or hubs 44 on its inner end, connected by a Vertical end plate 46 and supported and reinforced by triangular shaped side members 48.

Threaded into and projecting from sockets 44 are the upper molding die vertical support rods 50 (Fig. 2) which support the upper molding die casting 51 and are inserted into downwardly projecting sockets or hubs 52 -on the casting 51. Depending axially from and below casting 51 is the upper molding die mechanism 53. Near the bottom the front rods 50 are reinforced by a horizontal member 49 shown in Fig. 2.

Turret or spider mechanism The turret mechanism 35 comprises a turret 54 (Figs.

flanged portions 64 of turret 54. T'he outer portion 72 of die 66 is recessed into the desired semi-toroidal configuration. The rear edge of each die 66 adjacent the jlehring oven 39 is cut off at the open ends as at 73 (Figs. 3 and 5) to facilitate delivery of the lehred bulb to the die 66. As shown particularly in Figs. 10 and 12, suitable symmetrical recesses 74 are cut into the die on both sides between the inner portions 70 and the outer portions 72 for mounting gas burners 76, twenty in the present embodiment, ten on each side, for optimum heatling eflciency. When the turret mechanism 35 is at the bottom of its Vertical travel, the lower extremities of the bottom die 66 rest on the supports 77 (Fig. 5), suitably bolted to platform 24.

The hollow turret shaft 56 is supported, as shown in 3Figs. 2 and 5, at each end outwardly from the center of machine 22 by the following adjacent assemblies; namely, an inner support assembly 78, a clutch housing and gear assembly 80, a turret mechanism slide block 81, and an outer valve assembly 82.

The inner support assembly 78 (Fig. 5) comprises bearing 84 and a lower flanged foot portion 86. The bearing 84 is lined with a bushing or sleeve 87 which fits shaft 56 and permits rotation of said shaft therein. The lower flanged portion 86 is bolted to a bracket 90 which is similarly affixed to the inner side of a turret `mechanism sliding block retaining plate 93, hereinafter described.

The clutch housing and gear assembly 80 (Figs. 2

`and comprise a large vertical drive gear 94 for rotating the turret mechanism 35 and a clutch 96.

The gear 94 has a bushing 97 therein similar to bushing 87. Gear 94 engages a rack 98 suitably mounted on the front iside of vertical channel portion 31 of pedestal 26.

The clutch 96, as shown in Fig. 6, consists of a housing 100 and a clutch braking plate 102, suitably pinned to shaft 56 at 101, but free to slide within housing 100 in counterclockwise direction. Three clutch recesses 104, shown arranged at approximately 120 intervals,

are cut triangular in cross section into the periphery of plate 102. In each recess 104, a clutch roller 106, con- 'nected by a spring 107 to the rear radial side wall of the recess, is contained between housing 100 and the bottom of recess 104.

Assuming housing 100 rotates in counterclockwise `direction with reference to Fig. 6, rollers 106 are wedged between housing 100 and recesses 104 in plate 102 by springs 107, thus permitting the clutch braking plate 102 and shaft 56 to rotate in a counterclockwise direction. Conversely, during clockwise movement of housing 100, rollers 106 are forced toward the springs 107, thus preventing the clutch braking plate 102 and shaft 56 from turning.

Where shaft 56 passes through a suitable cylindrical hole in the mechanism slide block 81, an appropriate bushing 108 (Fig. k5) similar to bushings 87 and 97 is provided. This block 81 slides in vertical slot 32, of

v2 and 3) mounted on a horizontal hollow turret shaft pedestal 26 and is secured therein in slidable engagement by an inner and an outer iiat retaining plate 93, one on each side of said block. The outer plates 93 (Figs. 1 and 3) are of inverted T-shaped configuration and bolted to the block 81 at its upper end. Each plate overlaps slot 32, thereby sliding on channel portion 31 of pedestal 26.

The outer valve assembly 82 (Fig. 5) comprises a rotatable outer valve head assembly 110 and a stationary inner valve seat assembly 112, which consists of an inner flanged member 114 pinned to a stationary valve seat 116. Member 114 is secured to the outer turret mechanism sliding block retaining plate 93 by means of threaded connections (not shown). Into complementary cylindrical holes cut into the abutting faces of member 114 and seat 116, is inserted a bushing 118 and a suitable compression spring 120 for maintaining the valve seal. As shown in Figs. 8 and 9, the outer face of seat 116 has an annular gas supply groove 122 cut therein. A portion 123 of this groove is of large rectangular cross section extending about 240 of the periphery (Fig. 8) to supply the required gas for the forming operation of the bulb, the remainder 124 being of reduced rectangular section, for reducing gas ow during the annealing operation hereinafter described.

Between shaft 56 of machine 22 and valve seat assembly 112 (Fig. 5), and extending to the rotatable outer valve head assembly 110 of the valve at the end of shaft 56, is a bushing 125 having a flanged end 126 overlying a valve plate 128, as hereinafter explained.

The rotatable outer valve head assembly 110 of valve assembly 82 has an outer member 127 and the cylindrical valve plate 128 separated by the iiange portion 126 of bushing 125. As shown in Fig. 5, plate 128 rotates on the shank of bushing 125, in engagement with its flange 126, and is thereby held in sealed contact with valve seat 116. Six cylindrical holes 131, arranged 60 apart are cut through plate 128, as shown in Fig. 7, so as to be in complementary engagement with the annular gas supply groove 122 in valve seat 116.

Gas heating system The gas heating system 58 of the turret or spider mechanism 35 is carried, as shown in Fig. l, from a gas mixer and compressor (not shown) by a suitable line 132 (Fig. l) having a iiexible portion 133 to an inlet connection 134, in the underside of stationary valve seat 116, as shown in Fig. 5. From connection 134, as shown in Fig. 8, the gas runs through a nipple 135 in and projecting from a cylindrical hole 136 in the wall of seat 116. Said hole bends through 90 into the annular gas supply groove 122 in stationary valve seat 116 as shown in Fig. 5. From the annular gas supply groove 122, gas is supplied to ten of the twenty burners 76, in each of the six lower molding dies 66, by one of six similar lines, each of which has the following construction:

The gas flows from groove 122 through a nipple 137 in and projecting from holes 131 (Fig. 2) in the outer valve plate 128, as shown in Fig. 5, through a flexible connection 138 and a nipple 139 connecting with a port 140 in outer member 127 of the rotatable outer valve head assembly 110. This port is connected to a horizontal pipe line 142 within shaft 56. This line which passes through the wall of shaft 56 and the wall of the outer projections 62, connects to a T 143 near its point of emergence. From one side of the T 143, a line 144 feeds into one end of a reservoir 145, within the body of a die 66 for supplying gas to the twelve burners 76, six on each side, in the central recesses 74 of die 66, as shown in Fig. 5. From the other side of T 143, a line 145er, runs into the die 66 and supplies with gas by suitable connections (not shown) the four burners 76, two on each side, in the adjacent end recesses 74 of die 66. As shown in Figure 5, the gas is supplied to the remaining ten gas burners 76 by a system, identical to the above described means, and on the other side of the bending machine 22.

The gas seal between the abutting surfaces of rotatable outer valve plate 128 and stationary valve seat 116 is maintained in the following manner. The outer member 127, the iianged end 126 of bushing 125 and outer valve plate 128 are put in compression and the valve surface of plate 128 is compressed against the valve surface of valve seat 116 by the above described members of the gas heating system. In turn, the six compression springs 120 inside the bushings 118 in the complementary holes in the abutting surfaces of the valve seat 116 and the inner flanged member 114 compress the valve surface of valve seat 116 against the valve surface of plate 128, thereby maintaining the gas seal in the outer valve assembly 82.

T Llrret drive mechanism The turret drive mechanism 60 is operated by cornpressed air and consists of two pistons 146 (Fig. 16) operating in cylinders 149, connected to a drive shaft 147 (Fig. 2) running transversely along the front of machine 22, and through suitable bearings 148 attached to pedestals 26.

The drive shaft 147 is further supported by two brackets 151 which are located between the pillars 26 and have their bases bolted to bottom platform 24. Each cylinder 149 is supplied from a compressed air line system 150 (Fig. 16). Each piston 146 is connected by a rod 153 to a cross head 154 (Fig. l) which drives a crank 158 on shaft 147 by means of a connecting rod 156, and with a gear train 159 forms a drive system 157 The compressed air line system 150 for the turret driving mechanism 35 introduces the compressed airthrough line 160 and a valve 161, as shown in Fig. 16, to a T connection 162. A line 163 carries the air on one side of the T 162 to the upper molding die mechanism, as hereinafter described. Another line 164 leads from the other side of T 162 through a regulating valve 165 to a two-way valve 166 operated by solenoids 167 and 167', the armature 168 of which is pinned to the operating handle of valve 166 at 169. On the outlet side of valve 166, a line 170 carries the air through a regulating valve 171 to the top of air cylinders 149 for m0- tivating the upward motion of the turret mechanism 35. Another line 172 on the other outlet side of said valve 166 leads through regulating valve 173 to the bottom of a cylinder 150 for effecting the downward motion of the turret mechanism 35.

Each main air cylinder 149 is mounted on a horizontal top ange 174, shown in Fig. 3, of a support bracket 176 of generally right triangular cross section, which in turn is bolted to the channel portion 31 of pedestal 26 near its top. This bracket 176 depends vertically be low cylinder 150 and has a slot 178, shownL in Fig. 2, cut into and running the length of its front face 180.

The cylinder 149 has a piston 146 with a rod 153 (Fig. 16) connected to a cross-head 154 (Fig. 2). This cross-head 154 rides in slot 178 and the connecting rod 156 is pivotally connected thereto at 188. The lower end of rod 156, in turn, is pivotally connected at 190 (Fig. 1) to crank 158 which is fixed to drive shaft 147.

On each end of drive shaft 147 is secured a gear 194, as shown in Figs. 2, 3 and 19. In turn, each gear 194 engages a driven gear 196 on a horizontal shaft 198 (Fig. 19) which runs in a bearing of an end bracket l 200 attached to the side wall of foot portion 34 of pedestal 26 (Fig. 2). A gear 294, preferably identical with gear 196, is fixed on shaft 198 between bracket 200 and the side wall of foot member 24.

A gear 206, similar to

gears

204 and 196, fastened on an idler shaft 208 meshes with gear 204. To complete the gear train 159 for raising and lowering turret mechanism 35, two vertical racks 218 (Fig. 3), one of which engages gear 204 and the other gear 206, are located within bracket 200 and bolted to the lower portion of the outer turret mechanism sliding block retaining plate 93.

Operation of turret or spider mechanism According to our invention, at the start of the bending cycle the turret mechanism 35 rests in its lowermost position on adjustable stops 89 and supports 77 (Fig. 2). When operation of the automatic synchronizing control mechanism 41 of the machine 22, as hereinafter described, eiects actuation of solenoid 167, the valve 166 (Fig. 16) admits compressed air to line 170 and opens line 172 to the atmosphere, thereby forcing each of the pistons 146 downward in their cylinders 149. As shown in Fig. 1, the downward motion of piston slide block 154, in the slot 178 of bracket 176, and the connecting rod 156, rotates counterclockwise the crank 158 and drive gear 194 on shaft 147. In turn, driven gear 196 and gear 2114 rotate clockwise. The clockwise rotation of gear 284 and the counterclockwise rotation of gear 206 on the racks 210, affixed to slidable retaining plates 93, raises the turret mechanism 35. During the upward motion of mechanism 35, the clutches 96 permit each gear 94 on shaft 56 to rotate on rack 98 clockwise with respect to Fig. 1, without turning shaft 56.

During the downward movement of the turret 54, the two way valve 166 operated by solenoid 167', opens line to the atmosphere and admits compressed air to line 172, as shown in Fig. 16. The upward motion of piston 146 moves the gear train 159 in the opposite direction, thereby causing the racks 210 to move downward on

gears

204 and 206, and the drive gears 94 to rotate counterclockwise, as shown in Fig. l on rack 98. Clutches 96 lock gears 94 to shaft 56. The shaft 56, turret 54, and of course the lower molding dies 66 rotate exactly 60 counterclockwise during the calculated downward travel of mechanism 35. During the rotation of mechanism 35, the gas supply to burners 76 of the uppermost die 66 is reduced by means of the rotation of the uppermost hole 131 in outer valve plate 128 from engagement with large cross-section 123 of gas supply groove 122 in stationary valve seat 116, to engagement with reduced cross-section 124 of said groove, thereby reducing the temperature of said uppermost die 66 and annealing the lehred formed envelope in said die before discharge at the end of the next rotation cycle.

Upper molding die mechanism The upper molding die mechanism 53, as shown in Figs. 2, 5, 10 and l2, comprises an upper molding die assembly 212, suspended from casting 51 on vertical rod 214 (Fig. 2), a nitrogen blowing system 216, a gas heating system 218, an upper molding die driving mechanism 221i and a water cooling system 221.

The upper molding die assembly 212 consists of a generally T shaped casting 222 (Fig. 5), desirably of the same thickness as lower dies 66 of the turret 54, having an upper horizontal portion 223 axially aligned with a vertical foot portion 224, to which is bolted an upper molding die 225.

As shown in Figs. 10 and 12, an axial clearance aperture 226 is cut for shaft 214 in the vertical foot portion 224. In the body of the horizontal portion 223 above aperture 226 and in the body of the foot portion 224 below slot 226, there are provided a series of mutually interconnected cooling chambers 227.

The bulb-receiving cavity of this molding die 225 is of semitoroidal shape and is dimensioned to engage complementarily any one of the six lower molding dies 66 with a formed and lehred bulb or envelope 374 of the desired circular cross-section therebetween, as shown in Fig. 17.

A guide plate 229 depends on each side of the lower end of die 225 to insure proper aligned engagement of the upper molding die 225 and any of the lower molding dies 66, as shown in Fig. 3.

Into each side of the body of molding die 225 are cut two symmetrical recesses 239 (Figs. l() and 12), similar to inner recesses 74 of lower die 66. In each of these recesses 23@ are provided, in this embodiment three burners 232 for heating the mold.

Pivoted at each corner of the upper surface of the horizontal portion 223 of casting 222 is a guide roller 234 (Fig. 5) which rolls up and down on the adjacent forward upper molding die support rod 59.

The vertical shaft 214 slides within an axial hole 236 (Figs. l0 and l2) extending through the horizontal portion 223 of casting 222, to the aperture 226 therein. The lower end of shaft 21.4 is threaded and secured within the aperture 226 by a washer 237 and nut 238, On shaft 214 and bolted to the upper surface of portion 223 is a compression spring guide 249 of diameter suitable to house the lower end of a compression spring 242. The upper end of spring 242 engages an adjustable stop or collar 244 which is fastened to shaft 214.

Above stop 244 and on shaft 214, as shown in Fig. 2, is a larger compression spring 246 which has its upper end in Contact with the lower surface of casting 51. Shaft 214 passes axially through casting 51, in slidable contact therein, and thence into an air cylinder 250 which is mounted on casting 51 in axial alignment with shaft 214. Nithin air cylinder 258 is provided a piston 252 (Fig. 16) which is aiiixed to the upper end of shaft 214.

Nitrogen blowing system The system 216 for blowing nitrogen into each end v of the bulb during the forming operation by the upper die 225 and a lower die 66 comprises mechanism for each end of said bulb. Each system comprises a plug mechanism 254, a plug tripping mechanism 256, and a nitrogen supply system 258.

Each plug mechanism 254, as shown in Figs. l and 12, comprises a plug 260 on the end of a vertical hollow shaft 262 which is slidable through an outer and upper lip 261 of upper molding die 225, a bushing 264 in upper horizontal portion 223 of casting 222. An adjustable stop 268 (Fig. 10) between portion 223 and casting 51, and an adjustable stop 270 (Fig. 2) above casting 51 are provided on said shaft. Plug 266, suitably of rubber-like material, has a tapered lower end to fit the circular ends of the envelopes being formed. Each bushing 264 is in a housing 265 which projects above and below the upper horizontal portion 223, and is secured at its lower end to the upper lip 261 of die 225, as by welding. Each adjustable stop 268, is secured to its shaft 262 a predetermined distance above housing 265 to limit the downward travel of plug mechanism 254. Each stop 270 is xed on its shaft 262 a distance above casting 51 predetermined by the positioning of the plugtripping mechanism 256 mounted on spider 51.

The plug tripping mechanism 256, as shown in Figs. l1 and 13, consists of a trip arm 272 pivoted on a vertical rod 274, a tension spring 276 for securing one end of arm 272 to the rod 274 and an adjustable trip arm positioning device 278. The length of arm 272 is designed so that its unsecured inner end is engaged by stop 270, but not by shaft 262, during its required movement. The trip arm positioning device 278 consists of a bolt 280 screwed through a threaded portion of a collar 282 on rod 274. The upper end of bolt 280 limits counterclockwise motion of the arm 272.

The nitrogen supply system 258, as shown in Fig. 2, consists of an inlet line 284 from a nitrogen supply, (not shown) a trip valve 286 mounted on the upper horizontal portion 223 of casting 222, adjacent the stop 244 on the lower end of shaft 214, as shown in Fig. 14; and a connecting

line

288 and 290 from valve 286 to each of the hollow shafts 262 of the plug mechanism 254. This valve 286 has a horizontal valve release arm 287 which is engaged by stop 244, thus admitting nitrogen as hereinafter explained.

Gas-heating system The gas-heating system 218 for upper molding die mechanism 53 is generally similar to the gas heating system 58 for the lower molding dies 66. It comprises an inlet gas line 292, as shown in Fig. 2, from a mixer and compressor (not shown), which runs into the body of upper molding die 225 and feeds, by connecting lines (rllot shown) therein, burners 232 located in recesses 230 t erein.

Upper molding die driving mechanism The upper molding die driving mechanism 220 is operated like turret drive mechanism 60 by compressed air and consists of the above-mentioned air cylinder 250 having its piston 252 affixed to shaft 214 and a com-- pressed air line system 294, as shown schematically in Fig. 16.

From T connection 162, `system 294 has a line 163 running through a regulating valve 297 to a two-way valve 298, similar to valve 166, of the turret mechanism compressed air line system. This valve 298 is operated by a

solenoid

299, and 299 having an armature 300 connected to the operating handle of said Valve. A line 301 connects one outlet side of the valve 298 through a regulating valve 302 to the bottom of air cylinder 250. The other outlet side of valve 298 is connected by a similar line 303 through a similar valve 304 to the top of air cylinder 250.

A water cooling system 221, as shown in Fig. 2, cools the upper molding die mechanism 53 and consists of an inlet line 304 entering the casting 222 and running through the wall thereat to the cooling chamber 227 below clearance aperture 226. Water outlet line 306 leaves the casting 222 and runs to the drain.

Operation of upper molding die mechanism When the operation of the automatic synchronizing admits compressed air into line 303 and opens line 301 to the atmosphere. Air then flows into the top of cylinder 250, thereby forcing the shaft 214 and upper die mechanism down into contact with the work and a lower molding die 66. During the downward travel, stop 270 (Fig. 2) on each hollow shaft 262 of plug mechanism 254 is arrested by trip arm 272 (Figs. 1l and 13) of plug tripping mechanism 256 until the upper molding die 225 forms the lehred envelope into the curved configuration, and particularly forms the open end portions of said envelope into upright position to receive the plugs 260, as shown in Fig. 10.

In this position, plugs 260 are resting against outer lips 261 of die 225. When die 225 travels the remaining short distance, as shown in Fig. 12, into lower die 66, stop 270 is pulled downwardly past and freed from trip arm 272, thus permitting plugs 260 to drop into the open ends of the envelope being formed therebetween. Simultaneously, collar 244 strikes the horizontal valve release arm 287 of valve 286 (Fig. 14), thus opening said valve and releasing nitrogen under pressure somewhat higher than atmosphere through hollow shaft 262, for the purpose of shaping the envelope to the exact coniiguration of the combined die.

When valve 298 of system 294 opens line 303 (Fig. 16) to the air and admits compressed air into line 301 and thence the bottom of cylinder 250, piston 252 and the upper molding die mechanism 53 is raised.

Lehring oven and associated mechanism The lehring oven 39 on upper platform 38 of frame 28, as shown in Fig. 3, consists of an oven body 308, insulating side members 310 and two cooperating lifterfeeder mechanisms 312 on opposite sides of the oven 39. t This oven body is of the usual box-like structure having insulated walls, and incoming gas fuel line connected to a series of radiant burners 439 in the underside of said oven. Thebody 308 is mounted a suitable distance above the platform 38 (Fig. l) and the lifterfeeder mechanism 312 on said platform to permit the operation of said mechanism 312, as hereinafter explained. Side members 310 are extensions of the sides of oven body 308 to retain uniform heating and minimize draft effects. A thermocouple depending below the bottom of oven body 308 and a coordinated automatic gas ow control system (not shown) maintain constant temperature in the lehring oven.

The lifter-feeder mechanism 312, as shown in Figs. 1, 3, 4, 20 and 21, comprises a rst set of rollers 314 and a second set of rollers 315 (Fig. 3), a roller-rotating mechanism 316 (Fig. 2l), and a roller lifting and lowering mechanism 318 (Fig. 3). The individual rollers, as shown in Figs. 4, 20 and 2l, are designated from left to right as shown in said first two figures by numerals 320 to 327, inclusive. The rst roller 320 is rotatable about a xed axis, counterclockwise as viewed in Figs. 4 and 20. The near ends of the

rollers

321, 323, 325, etc., as viewed in Fig. 4, are pivotally supported from above by overhanging operating arms, corresponding with those designated 420 in Fig. 21, while the opposite ends of said rollers are correspondingly supported by underhanging operating arms, corresponding with that designated 421 in Fig. 2l.

This means that, while both ends of the roller 320 are mounted about fixed pivots, all of the other rollers are mounted on shafts which are swingable to alternately raise the two sets of

rollers

314 and 315 from the normal position illustrated in Fig. 3. The operations are thus, irst to one position, such as illustrated in Fig. 4, and then to another position, such as illustrated in Fig. 20.

This alternate raising and lowering is effected by two drive bars, like those designated 425 and 426 (Fig. 21), at each end of the two sets of rollers. Only two of these bars are illustrated in Fig. 21, but the other two bars correspond, one of these others being shown in Fig. 1 and designated 332. In other words, the roller 321 is carried at its far end, as viewed in Figs. 4 and 20, by an underhanging operating arm 421 and at its near end by an overhanging operating arm, like that designated 420 in Fig. 21. The next roller 322 is carried by its far end by the overhanging operating arm 420, and at its near end by an underhanging operating arm, like that designated 421 in Fig. 21. The succeeding rollers are alternatively mounted; that is, the rollers 323, 325 etc. are

mounted like the roller 321, while the

rollers

324, 326, etc., are mounted like the roller 322.

The underhanging operating arms have depending cranks with their ends bifurcated, as indicated at 428 (Fig. 4), to receive studs or bolts 429 on the drive bar 426, while the overhanging operating arms 421B have cranks 430 (Fig. with their ends bifurcated, as indicated at 431, to receive corresponding studs or bolts 432 on the drive bar 425. This means that each of the rollers of the first set, that is, those comprising

numbers

321, 323, 325, etc., are operated by a pair of bars, one of which is designated 426 and acts on cranks 427 from underhanging operating arms, while the other 332 is similar thereto but engages cranks depending from overhanging operating arms, like those designated 420.

Both of the drive bars 32 and its companion 426 at the near ends of the rst set of rollers 314 and at their rearward extremities respectively, are pivotally connected, as shown in Fig. l, to levers 334 by means of intermediate links 330. Said levers are pivotally mounted, as indicated at 335, and their other or lower ends pivotally connected to adjustable connecting rods 336. The other extremities of the rods 336 are pivotally secured to cam drive levers 338, pivotally mounted at their opposite or lower ends on the platform 40. These levers 338 carry rollers 337 which are held in operative engagement with cams 340 by means of springs 341. These cams are mounted on a timing shaft 342 of the lifter-feeder driving and control mechanism 41. The shaft 342 is operated by a motor 344 as by means of a sprocket wheel, chain, and gear box system 346.

It will be understood that the drive bars 332 and 426, acting through one overhanging and one underhanging operating arm at opposite ends of each roller of one set 314 reciprocate in unison with one another, while those namely 425 and its companion not shown, acting through one underhanging and one overhanging operating arm at opposite ends of each roller of the other set 315 reciprocate in unison with one another, but at times intermediate the operation of the other drive bars.

This operation is illustrated, diagrammatically, in Fig. 15, where the peak 433 represents raising of the first set of rollers 314, while the peak 434 represents raising of the second set of rollers 315, by corresponding simultaneous reciprocation of the corresponding drive bars. This alternate operation of the sets of rollers is effected by the positioning of the cams on the shaft 342, the peak 435 on the cams operating one set of rollers being set 180 from the peak 436 on the cams for operating the other set of rollers, so that glass tubing 437 on the rollers, as shown in Figs. 1, 3, 4 and 20, after being received from a guide 438 leading from a supply hopper (not shown) are advanced step by step through the oven by the alternate raising and lowering of the sets of rollers where they are heated to the desired softening temperature, as by means of radiant heater units 439, until they pass over the final roller 320 and are guided into the uppermost die of the spider 54 over guard member 441.

During all this bulb transfer operation by the rollers through the oven, said rollers are turned by the shaft 422 (Figs. l and 2l), driven in any desired manner, and connecting with the respective rollers of the second set 315 by means of gears 442, 443, etc. (Fig. 2l), on said shaft 422, respectively meshing with gears 444 and 445, etc. mounted on shafts 446, 447, etc., carrying on their inner ends gears 448, 449, etc., driving gears 450, 451, etc., respectively mounted on the shafts of

rollers

322, 324, etc., through

idlers

452, 453, etc.

The rollers of the rst set 314 are rotated in a corresponding manner through a shaft (not shown) corresponding with that designated 422 and driven in a similar manner through gears and shafts corresponding with those designated 442 to 453, inclusive, at the near ends of the rollers, as viewed in Figs. 3, 4 and 20. The roller 320 is driven directly from a gear on the shaft corresponding with the shaft 422, but not shown, meshing with a gear on the other end of its shaft, but not shown.

It will, therefore, be seen that the rollers will not only alternately raise and lower to advance the tubing while being lehred in the oven, but they are simultaneously rotated so that the tubing is correspondingly rotated and uniformly heated around its periphery.

Automatic synchronized control system of machine The automatic synchronized operation of the lehring bending machine 22 is shown schematically in Fig. 16`

iand egiplained by reference to the timing diagram of Also on timing shaft 342 (Fig. 1) of lifter-feeder mechanism 312, and synchronized with lifter-feeder cams 340, are an upper molding die mechanism cam 350 in roller engagement with a normally closed microswitch 352, an up lower molding die cam 354, and a down lower molding die cam 356 (all shown in Fig. 16) in similar roller engagement, respectively, with normally

open microswitches

358 and 360.

Cam 354 is so secured to shaft 342 that at the start of the bending cycle its raised portion 355, extending about 60 of its circumference, for closing the switch 358 and the up circuit of turret mechanism 53, is ready to engage the roller of switch 358.

Cam 350 is secured to shaft 342 so that its raised portion 351 extending about 120 of its periphery for closing the down circuit of upper die mechanism 53 by means of switch 352, engages the roller of switch 352 immediately after switch 358 is again open. Switch 352 is normally closed in the up circuit of mechanism 53.

Cam 356, having a raised portion 357 extending about 60 in this showing, of its periphery for closing switch 360, is secured to shaft 342 so as to engage the roller of switch 360 about of 1A; of one revolution after switch 352 is again opened, in order to prevent rotation of turret mechanism 35 before the retraction of upper molding die mechanism 53.

To prevent self inflicted machine destruction, a normally open safety microswitch 362 (Fig. 2) is provided in series with microswitch 352 in the upper molding die mechanism down solenoid circuit. For a similar reason normally closed safety microswitch 363 (Fig. 2) is provided in series with the microswitch 360 in the down solenoid circuit of the turret mechanism.

Switch 363, as shown in Fig. 2, has a vertically depending arm 364 for opening said switch aixed to the outer edge of the horizontal portion 223 of casting 222 of the upper molding die mechanism just below one of the.

guide rollers 234. The lower portion of said arm 364 is suitably tapered inwardly to properly engage roller 366 en a spring-tensioned contact arm 368 of switch 363. This contact arm 368 is pivotally mounted on the lower extremity of guide rod 50, just above horizontal reinforcing member 49.

The switch 362 (Fig. 2) is secured to the underside of bottom support plate 42. The switch operating arm 372 is suitably mounted on the upper surface of the inner support assembly 78 of turret mechanism 35. A main switch 373 (Fig. 16) is provided for starting motor 344.

Synchronized automatic operation of machine As motor 344 starts to rotate shaft 342, cam 354 closes v switch 358 and actuates the up circuit of solenoid 167,

as shown in Fig. 16. Armature 168 of solenoid 167 operates valve 166, thus opening line 172 to the atmosphere and admitting compressed air into line 170, thereby movtug-)et mechanism 35 upward and closing switch 362 Simultaneously, as shown in Fig. l5, through the synchronized action of lifter-feeder mechanism cam 340 on shaft 342, said mechanism 312 delivers a lehred bulb 374 into the upright lower molding die 66 immediately below the xed roller 320.

As the roller of switch 358 completes its contact with raised portion 355 of cam 354, the roller of switch 352 engages the raised portion 351 of cam 350, thereby closing switch 352 to the down circuit of mechanism 53 and activating the down circuit of solenoid 299 of the upper molding die mechanism 53. This closes circuit to solenoid '299 to cause armature 300 to operate valve 298, thus opening line 301 to the atmosphere and admitting compressed air through line 303 to cylinder 250. Upper molding die mechanism 53 moves downward onto the bulb 374, now held in the upright one of the lower mold- .ing dies 66, opening the switch 363 and forming the bulb 374 into the desired curved configuration 376, as shown in Fig. 17.

When the roller of switch 352 Aleaves raised portion 351 of cam 350, switch 352 opens the down circuit of solenoid 299 and closes the up circuit of the solenoid 299. The upper molding die mechanism 53 slides upward, and about midway through the retraction cycle `of mechanism 53, as shown in Fig. l5, safety switch 363, in series with 1 1 switch 360, closes and the roller of switch 360 contacts the raised portion 357 of cam 356, thus closing the down circuit of solenoid 168 and causing the simultaneous 60 forward rotation and downward travel of turret mechanism 35.

Simultaneous with the rotation of turret mechanism 35, a bulb 376 formed on the preceding cycle is discharged automatically from its lower molding die 66.

After the discharge of the lehred formed bulb 376 from machine 22, a mount 378 is sealed in each end of the bulb 376 and the lamp 380 thus formed is exhausted, based with suitable bases 382, and tested to provide the finished product, shown in Fig. 18.

Although preferred embodiments of our invention have been disclosed, it will be understood that modifications mayl be made within the spirit and scope of the appended claims.

We claim:

1. An automatic synchronizing control mechanism for a machine for lehring and bending uorescent lamp envelopes, said automatic synchronizing control mechanism comprising a timing shaft rotatable by a motor and a sprocket chain system, an upper molding die mechanism cam on said shaft in contact with a roller of a normally closed microswitch in series with a normally open safety microswitch both in the down circuit of the upper molding die mechanism; an upper circuit lower molding die cam in contact with a normally open microswitch in the up circuit of the turret mechanism; and a down circuit lower molding die cam in contact with the roller of a normally open microswitch in electrical series with a normally closed safety microswitch in the down circuit of the turret mechanism.

2. An automatic synchronized machine for lehring and bending phosphor-coated envelopes comprising a machine frame, a lehring oven on said machine frame, a lifterfeeder mechanism on said machine frame in said oven for continuously rotating and advancing said envelopes through said oven, a rotatable and slidable turret mechanism on said machine frame adjacent the delivery end of said lifter-feeder mechanism and having a plurality of lower molding dies, a vertically reciprocable upper molding die mechanism on said machine frame above said turret mechanism for engagement with said dies and said envelopes therebetween, and an automatic synchronizing control mechanism for synchronizing the automatic operation of said lifter feeder mechanism, turret mechanism and upper molding die mechanism.

3. An automatic synchronized machine for lehring and bending phosphor-coated envelopes comprising a machine frame, a lehring oven on said machine frame, a lifterfeeder mechanism on said machine frame in said oven for continuously rotating and advancing said envelopes through said oven, a rotatable and slidable turret mechanism on said machine frame adjacent the delivery end of said lifter feeder mechanism and having a plurality of lower molding dies, a vertically reciprocable upper molding die mechanism on said machine frame above said turret mechanism for engagement with said dies and said envelopes therebetween, and an automatic synchronizing control mechanism on said machine frame for synchronizing the automatic operation of said lifter-feeder mechanism, turret mechanism and upper molding die mechanism, said machine frame comprising a bottom platform, turret support pedestals upstanding from said platform, a lehring oven frame on said platform, and an upper molding die frame on said pedestals.

4. An automatic synchronized machine for lehring and bending phosphor-coated envelopes comprising a machine frame, a lehring oven on said machine frame, a lifterfeeder mechanism on said machine frame in said oven for continuously rotating and advancing said envelopes through said oven, a rotatable and slidable turret mechanism on said machine frame adjacent the delivery end of said lifter-feeder mechanism and having a plurality of lower molding dies, a vertically reciprocable upper molding die mechanism on said machine frame above said turret mechanism for engagement with said dies and said envelopes therebetween, and an automatic synchronizing control mechanism for synchronizing the automatic operation of said lifter-feeder mechanism, turret mechanism and upper molding die mechanism, said lifter-feeder mechanism comprising a rst set of rotatable liftable rollers and a second set of rotatable liftable rollers connected to a roller rotating mechanism and a roller lifting mechanism.

5. An automatic synchronized machine for lehring and bending phosphor-coated envelopes comprising a machine frame, a lehring oven on said machine frame, a lifterfeeder mechanism on said machine frame in said oven for continuously rotating andV advancing said envelopes through said oven, a rotatable and slidable turret mechanism on said machine frame adjacent the delivery end of said lifter-feeder mechanism, a vertically reciprocable upper molding die mechanism on said machine frame above said turret mechanism for engagement with said dies and said envelopes therebetween, and an automatic synchronizing control mechanism for synchronizing the automatic operation of said lifter-feeder mechanism, turret mechanism and upper molding die mechanism, said turret mechanism comprising a turret having a plurality of lower molding dies projecting therefrom and mounted on a horizontal hollow turret shaft, a gas heating system within and on said turret and a turret driving mechanism.

6. An automatic synchronized machine for lehring and bending phosphor-coated envelopes comprising a machine frame, a lehring oven on said machine frame, a lifterfeeder mechanism on said machine frame in said oven for continuously rotating and advancing said envelopes through said oven, a rotatable and slidable turret mechanism on said machine frame adjacent the delivery end of said lifter-feeder mechanism, a vertically reciprocable upper molding die mechanism on said machine frame above said turret mechanism for engagement with said dies and said envelopes therebetween, and an automatic synchronizing control mechanism for synchronizing the automatic operation of said lifter-feeder mechanism, turret mechanism and upper molding die mechanism, said upper molding die mechanism comprising an upper molding die assembly mounted from said machine frame on a vertical rod, a nitrogen blowing system, a gas heating system and a water cooling system on said upper molding die assembly and an upper molding die driving mechanism.

7. An automatic synchronized machine for lehring and bending phosphor-coated envelopes comprising a machine frame, a lehring oven on said machine frame, a lifterfeeder mechanism on said machine frame in said oven for continuously rotating and advancing said envelopes through said oven, a rotatable and slidable turret mechanism on said machine frame adjacent the delivery end of said lifter-feeder mechanism, a vertically reciprocable upper molding die mechanism on said machine frame above said turret mechanism for engagement with said dies and said envelopes therebetween, and an automatic synchronizing control mechanism for synchronizing the automatic operation of said lifter-feeder mechanism, turret mechanism and upper molding die mechanism, said automatic synchronizing control mechanism comprising a timing shaft rotatable by a motor and a sprocket chain system, and on said shaft an upper molding die mechanism cam in contact with a roller of a normally closed microswitch in series with a normally open safety microswitch, both in the up circuit of the upper molding die mechanism; an up circuit lower molding die cam in contact with a normally open microswitch in the up circuit of the turret mechanism; and a down circuit lower molding die cam in contact with the roller of a normally open microswitch in electrical series with a normally closed safety microswitch in the down circuit of the turret mechanism.

8. In an automatic synchronized machine for bending uorescent lamp envelopes and having a machine frame, an upper molding die mechanism comprising an upper molding die assembly mounted from said machine frame on a vertical shaft, a gas blowing system, a heating system, and a water-cooling system on said upper molding die assembly, and an upper molding die driving mechanism.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,707,203 Thornley Mar. 26, 1929 2,260,517 Hamilton Oct. 28, 1941 2,314,173 Sperlich Mar. 16, 1943 2,494,871 Greiner Ian. 17, 1950 2,494,872 Greiner et al. Jan. 17, 1950 2,527,249 Gallagher Oct. 24, 1950 2,566,014 Archbold Aug. 28, 1951 2,575,746 Cartun Nov. 20, 1951