US2298937A - Method and machine for securely clamping filaments to leads - Google Patents

Description

J. H. GREEN METHOD AND MACHINE FOR SECURELY CLAMPING FILAMENTS TO LEADS Filed April 30, 1941 2 Sheets-Sheet l IN JTH 6?? CV WYQ Mm ATTORNEY mam-at: mm.

Oct. 13, 1942. J GREEN 2,298,937

METHOD AND MACHINE FOR SECURELY CLAMPING FILAMENTS TO LEADS Filed April 30, 1941 2 Sheets-Sheet 2 Z 1 .53 i I 1 0 I 3 i5 -57 E 5e; 55 7 I J3 47 LJLU J9 1 45 '6 45 621 I Z? W I 2 5 Z5 3 1 2744 9 2 T 0 O F 50 INVENTOR ff $255M.

ATTORNEY Patented Oct. 13, 1942 METHOD AND MACHINE FOR SECURELY CLAMPING FILAMENTS T LEADS James H. Green,

Westinghouse West Orange, N. J., assignor to Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation 01' Pennsylvania Application April 30, 1941, Serial No. 391,152 16 Claims. (01. 219-3) This invention relates to methods and machines for connecting filaments to leads in incandescent electric lamps, and more particularly to such for the sealed beam automotive type of lamps.

The principal object of my invention, generally considered, is to clamp filaments securely to their leads, by using heat to anneal the metal of the leads, so that poor contact therebetween is avoided.

Another object of my invention is the connection of filaments to associated leads in an incandescent electric lamp by slitting or notching the ends of the leads, positioning the filament with its end portions disposed in the lead notches so formed, closing said notches to clamp the end portions of the filament in place, and heating the split portions of said leads, simultaneously with the application of more closing pressure, to a temperature sufficient to anneal or eliminate some of the resiliency oi the metal and permanently set, without welding or melting, said split portions in position about the filament ends and avoid any possibility of loose connections.

A further object of my invention is the provision of apparatus for use in practicing the above-described method.

Other objects and advantages of the invention, relating to the particular arrangement and construction of the various parts, will become apparent as the description proceeds.

Referring to the drawings illustrating my invention:

Fig. 1 is a fragmentary elevational view of apparatus for practicing my invention, showing the clamping device in uppermost normally open position.

Fig. 2 is a view corresponding generally to Fig. 1, but showing the clamping device in lowered open position. I

Fig. 3 is'a view corresponding generally to Fig. 2, but showing the subsequent position of the device in which the clamping jaws have been closed or moved together to compress the split leads about the filament to be connected thereto.

Fig. 4 is a fragmentary elevational View, of the apparatus as it appears in Fig. 3, in the direction of the arrows IV-IV in said figure.

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

Fig. 6 is an enlarged bottom plan view of the lead gripping jaws shown in the preceding figures.

Fig. 7 is a fragmentary vertical sectional view on the line VIIVII in Fig. 6 in the direction of the arrows.

Fig. 8 is a fragmentary plan of one of the leads after splitting an end portion, a filament being shown in position prior to being gripped by said lead.

Fig. 9 is a view corresponding to Fig. 8, but showing the next position where the end portion of the filament has actually been clamped between the slit portions of said lead.

Fig. 10 is a detailed horizontal sectional view on the line X-X of Fig. 4, in the direction of the arrows.

The machine which is at present used for mounting filaments on the leads of lamps of the well-known sealed beam type, used mainly for automobile headlights, includes positions where the ends of the leads, to which the filaments are to be connected, are slit, and it first clamps the major filament and then the minor filament, in the previously slit portions of said leads. In some instances, due to the resiliency of the metal such as copper which forms the leads, the

clamping is not always as tight as might be desired, whereby a poor contact may occur between the filament end and the connected lead.

To improve this clamping operation and avoid the possibility of any looseness between a lead and a filament I have modified one of the jaws of the clamping device by insulating end portions thereof from the cooperating jaw to provide for the application of heating current through the split portion of the lead during the clamping operation. As the jaws close by hydraulic action to clamp the filament under a desired predetermined pressure, a sufiicient amount of current is passed through the compressed portion of the lead which grips the filament end portion to anneal and give a permanent set to the metal, whereby a tight and perfect electrical connection is produced without actually effecting a weld therebetween.

Referring to the drawings in detail, like parts being designated by like reference characters, there is shown in Fig. 1 a fragmentary view of one of the heads ID on a rotary machine which clamps the filaments II to the leads l2 and I3 and the duplex or third lead It extending from the corresponding seals in the reflector portion l5 of a sealed beam automotive type lamp.

The machine, generally designated by the reference character I6, is provided with a number of lamp-holding devices or pockets ll, arranged (on a rotary conveyor) in a circle about the periphery thereof, and adapted to respectively index with the heads l0, which perform the successive operations thereon; After a number of preliminary operations have been performed, the reflector portion l of a lamp carrying the single leads |2, l3 and double lead I4 bifurcated or split, as indicated at IS in Fig. 8, for the reception of an end portion 2| of an associated filament l I,

- is placed in registry with or indexed" under of a plate 29, likewise held by nuts 3| and 32 applied to reduced end portions of the standards 24 which pass through said plate. 4

Disposed between the standards 24 is a cylinder 33, carrying end plates 34 and 35, secured thereto, as by means of screws 30, which are notched to receive and slide on the standards 24.

Operating in the cylinder 33 is a piston 36, the rod 31 of which is provided with ports 38 and 39 to respectively allow for the admission of fiuid under pressure to one side or the other of the piston, for effecting lowering thereof from the position shown in Fig. 1 to that shown in Figs. 2, 3 and 4, or raising thereof from said lowered position. The fluid is applied to the port, 38 or 39, as the case may be, from supply pipe 4| or 42, controlled by valves operated automatically by electricity at the proper time, in accordance with the manufacturing sequence.

The cylinder 33 is secured to a central connecting member 43, as by means of pin 40, which member carries a block 44, slotted or grooved, as indicated at 45 and 46, and reciprocates in guides 50 carried by a cross head 41. The cross head 41 also carries the clamping jaws 46 and 49 pivoted thereto as indicated at 5|, and reciprocates in guides 60 on the bracket 23.

The cross head 41 is normally held in downward position, as compared with the block 44, by coil compression springs 52 mounted on carrying rods 53, extending between outstanding ears 54 on the upper portion of the cylinder 33 and a plate 55 secured to the cross head 41, as by means of screws 56 and 51.

The central frame 22 carries a stop member 58 which is engaged by the pivot pin 5|, when the cross head. 41 is moved downward by the cylinder 33, stopping further movement thereof and allowing follow-up movement of the block 44 against thepressure of the springs 52. A stopscrew 59 is threadably mounted in a lug 6| projecting from the rear of the cross-head 41, so that it is adjustable to engage the bracket 23 at the same time the pin 5| engages the stop member 58, and avoid eccentricity in the stopping force. A nut 62 serves to lock the screw in adjusted position. i This follow-up movement of the block 44 forces the wedge-shaped projection 63, which serves to define the adjacent boundaries of the slots. 45 and 46, between the rollers 64 and 65 carried by the upward extensions 66 and 61 of the clamping members 48 and 49, thereby causing said members to swing about the pivot 5| to grip the slit portions of the leads and clamp the filament ends in place with respect thereto.

In order to effect a guiding action on the leads,

as well as a gripping action on the split portions thereof, for clamping the filaments in place, the clamping jaws 48 and 49 not only have clamping projections extending toward one another, but are provided with relatively movable, resiliently actuated, lead guides arranged in a manner which will now be described.

The lower portion of the jaw 48 carries a plate 13 with a projection 68 which cooperates with a corresponding projection 69 on a plate 14 carried by the jaw 49 for closing the slit or grooved portion l9 of a lead, such as |2 or I3, and clamping the end portion 2| of a filament therein. Likewise the plate 13 has a projection 1| adapted to engage the corresponding projection 12 on the plate 14 for closing the slit portion of another lead for said filament, such as one of the branches of the double lead l4, and clamping thecorresponding filament end in tight relation with respect thereto. The plate 13 from which the projections 68 and 1| extend is fixed, with regard to the arm 48, but not integral therewith, and the plate 14 from which the projections 69 and 12 extend is fixed to the arm but not necessarily integral therewith.

The jaw 48 also carries a plate 15 slid-able beneath the plate 13 and the jaw 49 carries a plate 16, likewise slidable beneath the plate 14.

The plates 15 and 16 are provided with opposed and notched lead-gripping extensions 11 and 18 on the one, and 19 and 8| on the other, as shown most clearly in Figs. 6 and '1, which serve to resiliently grip the leads below the slit portions thereof, under the action of the yokes 82 and 83, pivoted about the same axis as the jaws 48 and 49, and urged together by a coil spring 84, the ends of which are connected to outstanding lugs 85 and 86, extending from yokes 82 and 83, respectively.

The yokes are limited in their movement toward one another by set screws 81 and 88, respectively threaded to lugs 89 and 9! extending rearwardly from said yokes 82 and 83, respectively. Said screws may be locked in adjusted position, by nuts 92 and 93, with their adjacent ends adapted to engage opposite sides of a lug 94 depending from the lower end of the cross head 41, so that while the notched projections 11 and 18 move close enough to the notched projections 19 and 8| to lightly guide the leads, yet they are not pushed tightly into contact therewith, like the projections 68 and 69, 1| and 12, and, therefore, do not take an undesirable proportion of the heating current.

In order to make it possible to pass current between the projections 68 and 1| on the one side, and 69 and 12 on the other, for mere hot clamping, as distinguished from a welding operation involving melting of metal, the filament ends in the corresponding split portions of the leads, the plates 13 and 15 are insulated from their carrying jaw 46 and the yoke 02 by strips of mica or other suitable insulating material 95, 96, 91, 98 and 99, as well as insulation |0| for the screws I02, which secure a cross plate I03 beneath the sliding plate 15 for holding it assembled. No insulation, of course, need be provided on the jaw 49, yoke 83, or for the holding screws I04 for the cross plate I05, which underlies the slidable plate 16. Heavy insulated lead I06 serves for bringing current to the insulated plates 13 and 15, whereby it is adapted to travel therefrom through the slit portions of the leads mainly between the projections 68 and 1| on the one hand, and the registering projections 59 and I2 on the other to the grounded jaw 49.

In Fig. 2 are shown fragmentary portions of the arms 101 and I00, carrying fingers which grip, transfer, place, and hold the filament in position, while the ends thereof are clamped between the split portions of the leads. These fingers are not illustrated in detail as they are in commercial use for such a purpose.

In order to apply a desired amount of electrical energy to the split portions of the leads at the proper time, the insulated conductor I06 is con- .nected to one side of the low voltage secondary winding I09 of transformer H2, and the jaw 49 is connected to the other side by a conductor II I. The primary winding H3 of transformer H2 is connected through inertia timer II4, pressure controlled contacts II5-I I6, and rheostat III to power lines H8 and H9. The contacts H5 and H6 are automatically closed causing energization of the circuit through lines I06 and III, when the pressure in the gauge I2I rises to such an extent that the contact strip H6 is pushed into engagement with strip H5 by pressure-actuated arm I22 in said gauge. This action occurs when the desired pressure has been applied to the split leads to hot clamp the associated ends of the filament in place.

The apparatus described may be operated as follows:

The conveyor for the lamp-holding devices I'I, moves until the reflector portion I5 of a lamp, after the leads are split or notched as shown in Fig. 8, is indexed under the head EU, as shown in Fig. l. Fluid under pressure is then admitted automatically, by mechanism (not shown) on the machine, to the pipe 4! causing descent of the cylinder 33 until the cross head 41 moves down to the position shown in Fig. 2 where it is.

stopped by engagement of the pivot member 5| and set screw 59 with the stop member 58 and bracket 23, respectively Fig. 4 illustrates the engagement between the set screw 59 and bracket 23. The arms I01 and I08 then pick up a filament, in a well-known manner, transport and deliver it to the position, represented in Fig. 8, in which its ends are disposed between the open portions I9 where the leads, I2 and one branch of I4, for example, for said filament are split. While so held, the block 44 moves down, upon further increase in pressure in the cylinder 33, to cause the wedge-shaped portion 63 to move between the rollers 64 and 65, against the pressure of the springs 52, to cause the jaws 48 and 49 to close about the leads to the position represented in Figs. 3, 4, 5, 6 and 7, except that the wedge has only moved to the position where the parallel sides 10 and 80 engage the rollers 64 and 65, respectively. The notched portions 11, I8, I9 and BI, first embrace the leads below the split portions thereof, to insure that they are properly centered, and then further closing movement thereof is stopped by engagement between the set screws 81 and 88 and the lug 94 therebetween.

As the pressure in the cylinder 33 builds up further, the upper diverging sides 90 and I of the wedge-shaped portion 63 move down between the rollers 64 and 65, causing the projections 68 and II on the one hand, and B9 and I2 on the other, to squeeze the slit portions of the leads about the ends of the filament, until the pressure is such that the contacts I I and H6 are caused to engage, energizing the primary II3 of transformer H2 and applying a high current at low voltage through the slit portions of said leads to hot clamp them about the end portions of the filament until the current is shut off by the solenoid I23 of the inertia timer, pulling the contacts I24 and I25 to open position against the action of the weight I26.

The length 01' time electrical energy is applied to the split portions of the leads forhot clamping the same, is controlled by the adjustment of the weight I20, while the strength of the current applied during this time is controlled by adjustment of the rheostat Ill, whereby the exact amount of heat desired for the purpose is applied. I have found that approximately four cycles of sixty-cycle current at amperes gives satisfactory results.

After the major" filament, has been clamped in position between slit portions of a lead I2 and one branch of the lead I4, pressure inthe pipe H is released and applied in the pipe 42 to cause the jaws to open. lT'he arms I01 and I08 then move away, the cross-head 41 rises, and the conveyor moves the reflector I5 to the next position, where another filament, the minor or passing beam filament, is clamped between the two remaining leads thereof, that is, I3 and I4.

From the foregoing it will be seen that I have devised a method and machine for overcoming loose clamping, that sometimes occurred using a filament-mounting machine without provision for heating the unions between the leads and filaments, to thereby overcome the normal resiliency of the metal and efiect a permanent set of the copper or other lead metal, with consequent perfect electrical contacts without melting or welding between it and the tungsten filament.

Although a preferred embodiment of my invention has been disclosed, it will be understood that modifications may be made within the spirit and scope of the appended claims.

I claim:

1. The method of uniting the end portions of a filament to leads of a lamp. comprising positioning said filament with said end portions longitudinally disposed in side notches in said leads, closing said notches and clamping the material defining them about the received end portions of said filament, and heating said closed notched portions, during the application of pressure, to a temperature merely sufilcient to anneal and set the lead metal about the filament end portions.

2. The method of uniting a filament to leads of a lamp stem, comprising positioning said filament with its end portions longitudinally disposed in side notches in said leads, closing said notches about the received ends portions of said filament to squeeze the notch-defining material thereabout and clamp them in place, and heating the notched portions simultaneously with the application of more closing pressure, to a temperature merely sufficient to anneal and permanently set them in position about said filament end portions and avoid loose connections.

3. The method of uniting a filament to leads of a lamp stem, comprising longitudinally slitting the sides of said leads adjacent the ends, positioning said filament with its end portions alined with said leads and disposed in the lead notches formed by such slitting, closing said notches to clamp the end portions of said filament in place, and heating the slit portions simultaneously with the application of more closing pressure, to a temperature merely sufiicient to permanently set them in position about said filament end portions and avoid loose connections.

4. The method of uniting the end portions of a filament to leads of a lamp, comprising positioning said filament with said end portions longitudinally disposed in side notches in said leads, closing said notches about the received end portions of said filament to squeeze the notch-defining material thereabout and clamp them in place, and passing an amount of electrical energy through said closed notched portions, during the applicationvof pressure, predetermined so that it heats said portions to a temperature merely sufficient to permanently set the lead metal about the filament end portions and thereby avoid loose connections. 7

5. The method of uniting a filament to leads of a lamp stern, comprising longitudinally slitting the sides of said leads adjacent the ends, positioning the end portions of said filament'alined with said leads in the notches so formed in said end portions, closing said notches to clamp the adjacent end portions of said filament in place, and simultaneously passing electric current through said notched portions to heat them to a temperature merely sufiicient to permanently set the unions and avoid loose connections.

6. The method of uniting a filament to leads of a lamp stem, comprising longitudinally slitting the sides of said leads adjacent the ends, posi tioning clamping jaws over said end portions, transporting a filament and holding it in position between said jaws, with its end alined with said leads and portions disposed in the lead notches formed by said slitting, moving said jaws together to clamp the end portions of said filament in place, and simultaneously passing electric current from one of said clamping jaws to the other through the clamped portions of said leads and the united filament therebetween, to heat said portions to a temperature merely sufficient to permanently set them in place about the filament end portions and avoid loose connections.

7. Apparatus for clamping filaments in place with respect to leads of incandescent electric lamps comprising means for holding such filaments with their end portions alined with said leads and lying in side notches adjacent the end portions of the latter, means for causing jaws to squeeze the notched portions of said leads about the filament end portions received therein, and means for heating said notched end por tions during said clamping operation to a temperature merely sufiicient to set the metal thereabout and avoid loose connections.

8. Apparatus for clamping filaments in place with respect to leads'of an incandescent electric lamp, comprising means for holding said filaments with their end portions in longitudinal notches in said leads, a head carrying jaws, means for causing said jaws to descend and come together to squeeze the notched portions of said leads about said filament end portions, and means forapplying merely enough heat to said notched portions while squeezed, to overcome the natural resiliency of the metal and permanently set said leads about the associated filament ends.

9. Apparatus for clamping filaments in place with respect to leads of an incandescent'electric lamp, comprising a conveyor for moving the lead portions of said lamps in a circular path, means for transporting filaments one by one to and holding them with their end portions in notches in said leads when indexed at a certain place along said path, a head carrying jaws, means for causing said jaws to descend and come together to squeeze the notched portions of said leads about said filament end portions while so held, and means for applying merely enough heat to said notched portions while squeezed, to overcome the natural resiliency of the metal and permanently set said leads about the associated filament ends, to thereby avoid loose connections.

10. Apparatus for clamping filaments in place with respect to leads.of incandescent electric lamps, comprising means for transporting filaments one by one to and holding them with their end portions in notches in said leads, jaws for clamping said filaments in place in said lead notches, means for causing said jaws to descend and come together to squeeze the notched portions-of said leads about said filament end portions, and means for applying merely enough heat to said notched portions while being squeezed to permanently set the notched portions of said leads about the filament end portions without welding them thereto.

11. Apparatus for clamping filaments in place with respect to leads of an incandescent electric lamp, comprising means for holding a filament with its ends portions in notches in said leads, a head carrying jaws, hydraulicly operated piston-cylinder means for causing them to reciprocate vertically, stop means for arresting downward movement of said jaws, whereby said hydraulicly operated means then causes said jaws to close about and squeeze the notched portions of said leads to clamp the filament end portions in place therein, means insulating one of the clamping portions of said jaws, electrical connections to said insulated portion and other jaw, and means controlled by the hydraulic pressure supplied to said cylinder to cause electrical current to pass between said jaws through the clamped portions of said leads, when the pressure therebetween reaches a predetermined amount, to heat the squeezed metal, overcome the natural resiliency thereof, and permanently set said leads about the associated filament end portions.

12. The method of clamping filaments in place with respect to leads of an incandescent electric lamp, comprising holding said filaments with their end portions lying in longitudinal notches in the sides of said leads, causing jaws to squeeze the notched portions of said leads about said filament end portions, and applying merely sufiicient heat to said notched portions while squeezed to overcome the natural resiliency of the metal and permanently set said leads about the associated filament ends.

13. The method of clamping filaments in place with respect to leads of incandescent electric lamps, comprising transporting filaments, one by one, to and holding them with their end portions lying in longitudinal notches in said leads, causing jaws for clamping such filaments in place in said lead notches to squeeze the notched portions of said leads about said filament end portions, and applying merely suflicient heat to said notched portions while being squeezed to anneal and set the lead metal about the associated filament end portions.

14. Apparatus for uniting the end portions of a filament to leads of a lamp, comprising means for positioning said filament with its end portions alined with, and disposed in longitudinal notches in said leads, means for closing said notches about the adjacent end portions of said filament, and means for heating said closed notched portions during the application of pressure, merely enough to anneal and set the lead metal about the filament end portions.

15. Apparatus for clamping filaments in place with respect to leads of an incandescent e ctric lamp, comprising means for holding a ament with its end portions in notches in said leads, a head carrying Jaws, means for causing said Jaws to close about and squeeze said notched portions of saidleads to clamp said filament end portions in place therein, means insulating one 0! the clamping portions or said Jaws, electrical connections to said insulated portion and other Jaw, and means to cause electrical current to pass between said Jaws through the clamped portions or said leads, when the pressure therebetween reaches a predetermined amount, to heat the squeezed metal and permanently set said notched portions about the associated filament end portions.

' 5 end portions of said leads, clamping jaws, means /for causing said jaws to close about and squeeze the notched portions of said leads to clamp said filament end portions in place therein, means insulating the clamping portion of one of said 10 jaws, electrical connections to said insulated portion and other jaw, and means acting in synchronism with the application of pressure by said jaws, to cause electrical current to pass between the latter through the clamped portions of the 15 leads, when the pressure therebetween reaches a predetermined amount, to heat the squeezed metal merely enough to permanently set it about the associated filament end portions.

JAMES H. GREEN.

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