US3000272A

US3000272A - Lamp base solder trimming apparatus

Info

Publication number: US3000272A
Application number: US766778A
Authority: US
Inventors: Kvet Otto
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1958-10-13
Filing date: 1958-10-13
Publication date: 1961-09-19
Anticipated expiration: 1978-09-19

Description

Sept- 19, 19 1 o. KVET 3,000,272

LAMP BASE SOLDER TRIMMING APPARATUS Filed on. 1a, 1958 2 Sheets-Sheet 1 lnven toT-i O b ko Kve L', by 0M ,4

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Sept. 19, 1961 O. KVET LAMP BASE SOLDER TRIMMING APPARATUS 2 Sheets-Sheet 2 lnvefi tor: O t tc Kve t; awf

Filed Oct. 13, 1958 9 His A t l," w-ne e United States Patent 3 000,272 LAMP BASE SOLDEIE TRIMMING APPARATUS Otto Kvet, South Euclid, Ohio, assignor to General Electric Company, a corporation of New York Filed Oct. 13, 1958, Ser. No. 766,778 2 Claims. (Cl. 90-14) My invention relates generally to apparatus for the manufacture of electric lamps and more particularly to the basing or finishing operation wherein the base of the lamp is assembled with the bulb or envelope and the leadin wires extending from the bulb are united by globules of solder with contact members on the base. Still more particularly, my invention relates to novel apparatus for trimming the solder globules.

Certain multiple filament incandescent lamps of the so-called three-way or three-lite type having a pair of filaments of different wattages in the envelope, are provided with a base comprising a metal screw shell carrying at its end a center contact and a concentric intermediate ring contact with the end contact at a higher elevation than the ring contact. A common lead-in wire from one end of each of the filaments is connected to the base shell, and 'a lead-in wire from the other end of each filament is connected and attached to the respective end and ring contacts by a globule of solder on the upper surface of the contact. There has been some difficulty with such lamps when installed in the users socket in that sometimes one filament would light and the other would not. It has been found that this is often caused by irregular heights of the solder globules. If one or the other of the globules of solder is too high, the lamp will not be screwed into the socket quite far enough and there may be no contact at the other terminal, especially if the globule of solder there happens to be low.

It is an object of my invention to provide apparatus which will overcome this difiiculty by cutting both globules of solder down to a proper height. Further objects and advantages of my invention will appear from the following detailed description of a species thereof and from the drawings wherein:

FIG. 1 is a perspective View of trimming apparatus comprising my invention;

FIG. 2 is an elevation, in section, showing the cutter member in operative relation to a lamp base; and

FIG. 3 is a perspective view of the cutter member.

Referring to FIG. 1 of the drawing, the trimming mechanism is shown at one station of a so-called finishing machine which may be generally of the type shown in Patent 1,708,756, Fagan et al., and which comprises a turret, -a fragment of which is shown at 1, and which has mounted at its periphery a plurality of heads or lamp holder means 2 which are periodically indexed from station to statiton by suitable indexing means. The head 2 comprises a bracket 3 in which is supported a vertical spindle 4 which is spring-loaded to be normally urged upward and which is lowered for loading and unloading purposes by engagement of a roller 5 on the lower end thereof with a suitable cam arranged along the path of travel of the roller. At its upper end, the spindle 4 carries three fingers 6 forming a cradle for the lower bulbous end portion of the glass bulb 7 of a lamp 8.

The lamp 8 has attached to the upper end of its bulb 7 a base comprising a screw-threaded metal shell 9 having attached to its upper end an insulating web 10 (FIG. 2), of glass or organic plastic for example, having frustoconical portions in which are secured an intermediate ring-shaped metal contact 11 and an end contact eyelet 12, the end contact 12 being at 'a higher level than the ring contact 11. The bulb 7 contains a pair of filaments and a plurality of lead-in wires (not shown). One of the lead-in wires is connected to an end of both filaments and Patented Sept. 19, 1961 extends outwardly from the bulb and is connected to the base shell 9 in any desired manner, as by a drop of solder 13 or by welding; two other lead-in wires are connected to the ends of respective filaments and extend from the 'bulb 7, one lead-in wire extending through the eyelet end contact 11 and being attached thereto by a globule of solder 14, and the other lead-in wire extending through an aperture in the ring contact 11 and being attached thereto by a globule of solder 15.

The lamp 8 is firmly held in the head 2 by upward pressure of the spindle 4 which presses the upper periphery of the base shell 9 against a stationary apertured base plate or holder 16 which is fixedly attached to the upper end of the bracket 3, the end and ring contacts 11 and 12 being exposed above said plate 16.

In accordance with my invention, the

solder globules

14 and 15 are trimmed to a predetermined lever by a cutter member 17 having a central or inner end face 18 with cutting teeth in its surface, and an outer concentric end face 19 also provided with cutting teeth. The surface of face 18 is recessed within and spaced vertically above the surface of face 19 a distance substantially equal to the vertical spacing between the upper surfaces of end contact 12 and ring contact 11. The face 18 is part of a circular head portion 20 having an axially extending stem or shank 21, and the face 19 is part of a ring-shaped portion 20 surrounding the head portion 20 and secured thereto by a 'set screw 22. A stop pin 23 projects axially downward from the head portion 20 and beyond the surface of face 19 a short distance equal to the desired finished height of the

solder globules

14 and 15; the pin is secured in an axial bore in head portion 20 by a set screw 24.

As best seen in FIG. 2, the cutter 17 is mounted with its vertical axis 25 offset from the vertical axis 26 of the

holder members

4, 6 and 16 and the lamp 8 therein, preferably a distance approximately equal to the medial radius of the ring contact 11, and is arranged so that the pin 23 engages the ring contact 11 at a point diametrically opposite the solder globule 15.

Suitable mechanism is provided for rotating the cutter 17 about its axis and for reciprocating it vertically toward and away from the head 2 and the lamp 8 therein. As herein illustrated, the cutter is rotated by an electric motor 27 (FIG. 1) which is lowered and raised by a cam 28 in proper timed relationship with the dwell period of the indexing cycle of turret 1. The cutter 17 is supported by engagement of its shank 21 with the interior of the hollowed shaft 29 of motor 27, and is resiliently coupled thereto by a helical spring 30 surrounding the shaft 29 and compressed between the upper surface of the head portion 20 and a shoulder 31 on said shaft. The cutter '17 is free to move longitudinally relative to the shaft 29 a distance determined by the engagement of a pin 32 on shank 21 with the walls of apertures 33 in said shaft.

The motor 27 mounted on a plate 34 which is guided for vertical movement along

posts

35 and 36 upstanding from a stationary table 37. The plate 34 is actuated through a link 38, arm 39, shaft 40, arm 41, push rod 42, and arm 43 which carries a roller 44 engaging the surface of the edge cam 28. During indexing of the turret 1, the motor 27 and cutter 17 are held in their uppermost positions by engagement of the roller 44 with a high uniform portion 45 of the cam 28, and when the head 2 comes to rest during the dwell period of the turret, the roller '44 moves down to and along the low portion 46 of the cam 28 to lower the motor 27 and cutter 17, the motor 27 preferably being connected to rotate the cutter 17 continuously and directly at a speed of 1725 r.p.m., for instance. Due to the weight of the motor 27, the actuating linkage is preferably partially counterbalanced by a spring-loaded arm 47 which is fixed to shaft 40 and 3 is connected at its free end to a spring 48 anchored to table 37. It will be understood that the shaft 49 for cam 28 is connected with the shaft of the indexing cam (not shovm) for turret 1 so as to make one revolution for each indexing cycle of the turret.

In the operation of the device, when the head 2 comes to rest at the station occupied by the trimming mechanism, the revolving cutter 17 is lowered by the cam 28 to bring the

cutting surfaces

18 and 19 into engagement with the

solder globules

14 and 15, respectively, and trim them to a desired height determined by the engagement of the stop pin 23 with the ring contact 11 of the lamp base. As shown in FIG. 3, the teeth in the cutting faces '18 and 19 are preferably of spiral shape to throw the solder cuttings outwardly away from the lamp base. However, in order to definitely assure the absence of cuttings on the top of the base, a rotary brush may be arranged to sweep them oil? at the next station taken by the head 2 when it is indexed away from the solder trimming station. 7

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

1. In an electric lamp making apparatus, the combination of lamp holder means having a vertical axis for supporting a lamp comprising a bulb having a base at the upper end thereof with a center contact and a concentric ring contact at the upper end of the base and with the center contact spaced vertically from and at a level above the ring contact, and a globule of solder on the upper surface of each said center and ringcontact connecting thereto respective lead-in wires extending from the said bulb, said holder means holding said lamp with its center contact in the said axis of the holder, and solder trimming mechanism comprising a cutter arranged to be above said holder means and having inner and outer concentric lower end faces with cutting teeth therein, the said inner face being recessed within the said outer face so that the said faces are spaced apart vertically a predetermined distance corresponding to the vertical spacing of said center and ring contacts of said lamp base, a stop pin projecting axially downward from the inner face of said cutter a predetermined small distance beyond the outer face thereof, means mounting said cutter with its vertical axis offset from the vertical axis of the lamp holder means a distance approximately equal to the medial radius of the ring contact on the lamp base, means for rotating said cutter about its axis and urging it resiliently downward to bring the stop pin thereon into engagement with a portion of the ring contact of the lamp base approximately diametrically opposite the solder globule thereon whereby to trim down to predetermined heights the respective solder globules on said center and ring contacts.

2. Apparatus as set forth in claim 1, wherein the teeth on the faces of said cutter are of spiral shape.

References Cited in the file of this patent UNITED STATES PATENTS 1,785,978 Quinn Dec. 23, 1930 1,997,694 Mon'ck et a1 Apr. 16, 1935 2,069,386 Paluclm' Feb. 2, 1937 2,454,269 Braucher Nov. 23, 1948 FOREIGN, PATENTS 154,912 Great Britain 1920