US1907533A

US1907533A - Method of and apparatus for mounting filamenis

Info

Publication number: US1907533A
Application number: US527871A
Authority: US
Inventors: Jr John Flaws
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1930-10-01
Filing date: 1931-04-06
Publication date: 1933-05-09
Anticipated expiration: 1950-05-09
Also published as: GB390807A; FR726725A

Description

J. FLAWS, JR

May 9, 1933.

METHOD OF AND APPARATUS FOR MOUNTING FILAMENTS Original Filed Oct. 1, 1950. 4 Sheets-Sheet 1 9: v mm fN'X/EN TUB. JUHZY FL A W5, JR.,

.Zii's A Trazazz-E Y.

May 9, 1933. J. FLAWS, JR

METHOD OF AND APPARATUS FOR MOUNTING FILAMENTS Original Filed Oct. 1, 1930 4 Sheets-Sheet 2 5:73, MM 4935 Arrows YT.

INK/EN? DR. JUHN FL All 1'! y 9. 1933- J. FLAWS, JR 1,907,533

METHOD OF AND APPARATUS FOR MOUNTING FILAMENTS I Original Filed Oct. 1, 1930 4 Sheets-Sheet 3 Hrs ATTQRNEYI May 9, 1933- J. FLAWS JR METHOD OF AND APPARATUS FOR MOUNTING FILAMENTS Original Filed Oct. 1, 1930 4 Sheets-Sheet 4 4 2 mm H m U, :2

7 T w L 5 VP w N g MW Y Patented May 9, 1933 UNITED STATES PATENT OFFICE JOHN FLAWS, JR., OF OLEVELAND HEIGHTS, OHIO, ASSIGNOR TO GENERAL ELECTRIC COMPANY; A CORPORATION OF NEW YORK METHOD OF AND APPARATUS FOR MOUNTING FILAMENI'S Original application filed October 1, 1930, Serial No. 485,686. Divided and Serial No. 527,871.

My invention relates to method and machines for mounting filaments on stems of electric incandescent lamps and similar articles. This application is a division of my application Serial No. 485,686, filed October 1. 1930. which is a continuation in part of w my application Serial No. 288,009, filed June view thereof; Fig.

1928. The object of my invention is to provide a method and combinations of mechanisms whereby a filament may be automatically mounted on a stem so that it is securely held by the anchors and so that its end are securely clamped to those of the leads carried by said stem. It is necessary in this art that there be close uniformity in the product as the electrical resistance depends upon the length of the filament between the leads. Moreover, the efficiency of the device depends upon the maintenance of the position of the filament.

The various features and advantages of my invention will appear from the following description of a species thereof, from the claims appended hereto and .from the accompanying drawings.

In the drawings, Fig. 1 is a side elevation of the filament mounting machine of my invention; Fig. 2 is a perspective View of a mount to which the filament has been attached by my machine; Fig. 3 is a perspective view of the filament shaping and positioning mechanism; Fig. 4 is a vertical section through the forming portion of this mechanism; Fig. 5 is a side elevation of the filament transferring mechanism; F ig. 6 is a plan view thereof partially in section; Fig. 7 is a front elevation of the leading-in wire hook-clamping mechanism; Fig. 8 is a perspective View of the mounting mechanism; Fig. 9 is a plan is a fragmentary plan view of the anchor wire bending and clamping dies in their open position; Fig. 11 is a fragmentary elevation showing the operation of one of the dies: Fig. 12 is a fragmentary plan view of the anchor clamping dies in their closed position; Fig. 13 is a fragmentary sectional elevation showing the operation of one of the anchor wire curling dies; and Fig. 14 is a vertical section through the mounting device.

this application filed April 6,

Referring now to the drawings, and more particularly to Fig. 1, my machine is made up of several units or mechanisms which operate in conjunction wit-l1 each other to mount a filament upon the stem 10 which occupies the position shown during the complete mounting operation. The means for supporting this stem may be such that each succeeding stem is placed manually in a single stationary holder, or said stems may be supported in a carrier comprising stem holders as shown in my application Serial No. 485,686 filed October 1, 1980. The stems are preferably of the usual tiplcss construction disclosed in Mitchell and lVhite Patent 1,423,956, and comprise a flare tube 10, an exhaust tube 11. an arbor 12, anchor or support wires 13, and leading-in wires 14. The stems are prepared for use in my mounting machine, as by the mechanisms disclosed in my aforesaid application, so that the ends of the leading-in wires are flattened, formed into open books and positioned.

The mounting, are as follows: first, the filament is formed into a definite shape; second, both ends of the operations of my machine filament are fixed against movement in any direction; third, the filament is transferred to its final position with relation to the stem; fourth, the open hooks in the leading-in wires are closed about the filament; fifth, the support wires are positioned and gripped; and sixth, the ends of the support wires are curled about the filament, completing the mounting operation. All moving parts of my machine are operated in proper time relation with each other by cams (not shown) located below the machine which act through the operating rods shown.

The filament 15 first enters the forming mechanism shown in Figs. 3 and 4:, either by manual feeding or by an automatic feeding device such as shown in connection with this mechanism in Fig. 1. The filament is placed across the slide 18, as shown in Fig. 4. 4 The block 19 then moves forward clamping the filament against the semi-circular die 20. This motion is caused by lever 21 (Fig. 1) which operates against roller 22 on pin 23 of the bracket 24 and moves forward the subslide 25 to which bracket 24 is attached. The lever 21 is turned about pin 26 in the standard 27 by the link 28 which in turn is operated vertically by the drive rod 29. The motion roduced in the link 28 is transmittedto the ever 21 by the pin 30 which operates in a slot in the said link and which engages blocks 31 backed by'springs 32. The motion of the sub-slide 25 is transmitted to the block 19 b one of the brackets 33 which connects to t e rod- 34 to which the bracket is attached by means of the springs 35 and the collar 36. As the sub-slide 25 is moved forward until it is against the die 20, the filament will be formed to the shape of the said die. In this position the filament will be confined, except for its ends, in a recess in the sub-slide 25 as shown in Fig. 3. .The continued movement of the operating lever will cause the slide 18 in which the subslide 25- is held by the

plates

37 and 38 to beslid a short distance forward as'the sub-slide abuts against the die 20 carried by lever 39 which is pivoted on pin 40 carried by slide 18. The two pins 41 (only one being shown) hold the slide 18 in the standard 27 through springs 42 and slots in the standard allow their passage during the motion of the slide.

The ends of the filament protruding from sub-slide 25 are now positioned by another portion of my machine. As each end of the filament is acted upon by duplicate parts, that portion only of my machine which acts on one end of the filament will be described. The complete device is supported bybracket 43 and is operated by vertical motion of slide cam 44 shown in Fig. 3. At this point in the operation of the mechanism, the cam 44 is lowered by operating rod 45. The lowering of the cam 44 causes the filament to be positioned in the vertical plane by guide block 46 and the finger 47 which are brought together by the turning of

levers

48 and 49 respectively on a pin corresponding to pin 50. This action results from the movement of the wider portion of a leg corresponding to 51 of the slide cam 44 into position between the lower portions of

lovers

48 and 49 against the action of spring 52. The cam 44 in its movement also causes the flared-out portion of screw 53 to engage the end of the filament and thus positions the filament in the horizontal plane. This screw 53 is located in the end of arm 54 of lever 55 which is turned on pin 56 in the cover plate 57 against the action of spring 58 by the thicker portion 59 of the cam which is now located below roller 60 in the end of said lever. The transfer jaws, described hereinafter, grip the filament on the loop side just inside the positioning fingers and this insures that a definite length of filament will be presented to the leadingin wire hooks.

After the transfer jaws have gripped the filament, the positioning and the forming devices return to their rest or open position.- The return motion of the forming mechanism is not the reverse of the forming motion as sub-slide 25 travels to the left until cam 61 strikes slide 18, whereupon both the slide and the sub-slide are returned to the rest position. During the separate motion of the subslide 25, the forming die 20 is lowered by the lever 39 as the roller 62 engages the raised portion of the slot 63 in the cam.' The filament will thereby be allowed an unobstructed passage over guide 64 of the forming die 20.

. The transferrin mechanism of this machine carries the ament from the feeding mechanism just described to the mounting.

position where'the transferring mechanism also supports the filament during the mounting 0 eration. In Figs.- 5 and 6 where the trans erring mechanism is shown, the mechanism is shown in its position half through the cycle of operation rather than in the starting position as indicated in Fig. 1. One end of the filament is gripped by jaws 65 and 65' and the other by jaws 66 and 66' after the pairs of jaws have spread, as shown in full lines in Fig. 6. The jaws-are spread by the

cams

67 and 68 which turn them about pins 69 against the action of springs 70 and which are operated together by a pair of pins 71 in one and another pair 72 in the other which are engaged by the plate 73. The flat portion of cam 67 enters into a slot in the end of pin 74 which is turned by lever 75 which in turn is operated like another similar mechanism at the other position of the jaws by the rod 76. This rod is operated from the drive mechanism (not shown) by a pin which operates in slot 77.

Both lever 78 which holds the upper set of aws 6566 and lever 79 which holds the lower set of jaws 65' and 66 are operated about the

spindles

80 and 81 respectively bythe cam 82. This cam engages the

hardened inserts

83 and 84 in these levers and operates against springs 85 in the other ends thereof. Slide 86 (Fig. 6) is operated vertically on the pin 87 by a drive rod (not shown) thereby controlling the open and closing of the jaws. The flange 88 of this slide engages roller 89 on pin 90 in the lever 91 on the end of said cam 82. I

The jaws have, by the above mechanism, been opened, spread apart, closed upon the filament, moved together again, and now the complete jaw assembly is both turned and moved to the right, thereby transferring the filament. The mechanism is only turned through approximately 178 at this time but completes the full 180 of movement after the assembly has been moved to the right and the jaws spread, thus lowering the ends of the filament into the open hooks in the leading-in wires after the ends thereof have been positioned. The cam 82 and the spindles and 81 are supported by the cylinder 92 which rides in the ball bearings 93 and which is 0 erated by the gear 94. The spindles are helf in the cylinder by the collar 95 which rides in a slot cut around the end of each spindle and the gear 94 is attached to the cylinder by the pm 96 which engages a slot cut in said gear. The lock nut 97 and washer 98 hold the cylinder in place against the ball bearings 93 in the bracket 99 which carries stop 100 which in turn en ages said Washer in limiting the rotation of the cylinder to 180. To keep rack 101 engaged with gear 94 so that the vertical motion of the rack rotates the cylinder assembly, the yoke 102 which rides upon the

bushings

103 and 104 is employed. Means for moving said rack is provided by arm 105 (Fig. 1) which operates through blocks 106 and springs 107, and which is operated by drive rod 108.

Means formoving the aforesaid mechanism horizontally is provided by lever 109 which is operated from the drive mechanism by lever 110 which is also supported by spindle 111. Lever 109 engages roller 112 on pin 113 in the yoke 114 projectingfrom the'base of bracket 99 which is held in the standard115 by the

plates

116 and 117. The length of the movement is controlled by the

nuts

118 and 119 on the rod 120 in the bracket which engage arm 121 extending from the standard. The movement to the right of this mechanism locates the leading-in wires of the stem. The leading-in wires are engaged by the

pins

122 and 123 in the

arms

124 and 125 respectively which are supported from rod 126 in the bracket 99 by the clamping blocks 127.

After the leading-in wireshave been located, as just described, the jaws are spread, positioning the ends of the filament just above the open hooks in the ends of the leading-in wires. The spreading of the jaws occurs as cam 128 is turned by lever 129 which is engaged by rod 76 like the similar mechanism at the other position of the aws. The filament is then lowered into the hooks as the jaws complete the full 180 of move-.

ment.. All further operation of this mecha- 3 nism is completed after the filament has been mounted by that particular portion of my machine. These movements consist in the opening and moving together of the jaws and the return transferring motions.

That portion of the filament mounting apparatus for locating and bending the anchor support wires 13 and then curling their ends about a coiled filament placed adjacent thereto is carried in a bracket 130 located below the stem 10 and, as shown in Figs. 1 and 8, comprises a pair of upwardly extending

rods

131 and 132 having slidably mounted thereon upper and

lower platforms

133 and 134 respectively. The bracket 130 is mounted on a pivot 135 carried in a standard 136 extenddevices carried thereby into proper working alignment with the lower portion of the stem. The rotation of the bracket is accomplished by operating means (not sh wn) whose action is such as to swing the lowerend of rod 132 thereby causing the bracket 130 to rotate about pivot 135 placing the upper platform 133 in a position where it partially surrounds the lower portion of the lamp stem and the lower platform 134 directly below it.

After the bracket 130 has been rotated to the working position, the first operation is to bend downwardly the anchor support wires so as to place them in a position where they may be conveniently engaged by dies which loop them around a coiled filament later placed adjacent to them. This bending operation is accomplished by a plurality of bending and clamping members comprising the

plates

138, 139, 140 and 141 slidably mounted in the upper platform 133 (Fig. 9). As shown in Figs. 10 and 12, the plate 141 carries a pin 142 which extends over and at right angles to one of the anchor support wires 13 and the plate 139 carries the oppositely disposedpins 143 and 144 which extend over and at right angles to the remaining anchor support wires 13. The plates are held away from each other by means of the cam rods 145 carried by the lower platform 134. These cam rods extend upwardly through openings 146 in the plates and hold the said plates back against the action of springs 147 (Fig. 9) as the thicker portion of said rod is now in place behind rollers 148 on pins 149. The springs are confined in wells in each of the plates and operate against tongues 150 protruding from the lower surface of

plates

151, 152, 153 and 154 which also confine the said plates in their ways in the upper platform 133. As the bracket comes into position the plates are in their open position and the

pins

142, 143 and 144 are located somewhat above the anchor support wires as shown in Figs. 10 and 11. In starting, the upper platform is moved downwardly at which time the bending pins contact with their respective anchor support wires carrying them downwardly and inwardly toward the center of the stem, their path of travel being shown in dotted lines in Fig. 11. During the downward travel of the upper platform 133, the plates are forced inwardly toward each other by the springs 147 as rollers 148 ride upon the inclined cam surfaces of the cam rods 145. WVhen the upper platform has reached the limit of its downward travel, the rollers 148 are on the low point of the cam rods and the

inner tions

157 and 158 of the

pin carrying plates

139 and 141 so as to allow the pins to ride over the shallow sections on their downward travel. This variation in thickness will be noticed by comparing Figs. 11 and 13. The lowering and raising of the upper platform is accomplished by operating rod 159 pivotally attached to the said platform by the joint 160.

The anchor support wires 13 being located and properly positioned as shown in Figs. 1.1, 12 and 13, the next step is to place the filament coil in the open hooks of the leads 14 and adjacent the lower portions of the said anchor supports. This is accomplished automatically by the filament coil transferring mechanism as previously described. When the filament has arrived at the mounting position, the next step is to curl the ends of the anchor support wires around the filament. This is accomplished by a series of dies 161 which are adapted to simultaneously engage the lower ends of the support wires and curl or wrap them about the filament coil. The dies 161 are carried on block 162 in the lower platform 134 and are mounted so as to be in accurate alignment with the lower ends of the anchor support wires which contact with the grooved portions 163 of the said dies during the upward movement of the lower platform. During the course of the upward movement of the platform the anchor support wires follow the grooves 163 causing said wires to be curled around the filament coil as the lower ends of said grooves are semi-circular as shown in Figs. 13 and 14. When the anchor wires have been but half curled, as shown in Fig. 14, the

weights

164, 165 and 166 (Fig. 9) drop upon the filament, pushing it into the half formed loop. These weights are held on the tapered points of blocks 167 and are normally held in their raised position by the weight of rods 168. In this position the key 169 of rod 168 is in engagement with the protruding end 170 of the weight. The weights drop as bolts 171 raise rods 168 but only to the extent allowed by the fingers 172 and the screw 173. The raising and lowering of the lower platform 134 is accomplished by operating rod 174 pivotally connected to the bottom of the platform.

The open hooks of the leads are closed about the ends of the filament coil by a clamp-.

ing device which is raised into position adjacent said hooks. As shown in Figs. 1, 5 and 7, the clamping device comprises the

jaws

175 and 17 6 pivotally mounted on slide 177 which in turn is slidably mounted in the standard 115. The clamping device is moved upwardly simultaneously with the lower platform 134 by operating rod 178. When the jaws 17 3 and 176 have reached their proper position ad'acent the open books of the leads, an adjusta 1e stop 179 (Fig. 1) carried by the slide 177 abuts against a stationary lug 180 thereby stopping the upward movement of the said slide. Operating rod 178 continues to move upwardly against the action of a spring 181 causing the jaws to be rotated about

studs

182 and 183 by

links

184 and 185 which are connected to block 186 carried on the end of said rod and to said jaws. The jaws then contact with the hooks and force their open ends against the

stationary jaws

187 and 188 thereby closing them about the filament coil. The

inserts

189 and 190 in the ends of the stationary jaws enable these surfaces to be replaced and the plates 191 (only one being shown) keep the

jaws

175, 176, and 187, 188 in place. The anchor wires are straightened by the fingers 192 and strike said wires as the slide 177 is raised. These fingers are located on the springs 193 in the wells of arm 194 in which they are held by the plate 195.

The mounting operation now being completed, the transfer jaws release the filament and return to the forming mechanism for another filament, and platform 134 is lowered so as to withdraw the, dies 161. At the same time the clamping device is lowered away from the ends of the leads and the upper platform 133 is raised thereby withdrawing the bending and clamping

plates

138, 139, 140 and 141, and releasing the anchor support wires held between them. Finally the bracket 130 is rotated away from the stem which is removed and replaced by another.

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

1. The method of mounting a filament on a stem which comprises supporting said stem with lead wires and anchors extending therefrom, definitely fixing the position of said anchors, positioning a shaped filament adjacent to the ends of said anchors by temporary supporting means independent of said lead .wires or anchors and then curling the ends .of said anchors about said filament while clamping securely intermediate portions of said anchors.

2. The method of mounting a filament on a stem which comprises supporting said stem with lead wires and anchors extending therefrom, bending said anchors to a definite angle with said stem, gripping a filament and positioning it adjacent to the ends of said anchors by temporary supporting means independent of said lead wires or anchors and then curling the ends of said anchors about said filament while clamping intermediate portions of said anchors and maintaining a grip pairs of fingers for abuttingagainst the ends on said filament.

3. In an apparatus for mounting filaments, the combination of a stein holder, a plurality of members arranged to engage anchors extending from said stem to bend them to proper angles and to clamp intermediate portions thereof,curling dies, means independent of said anchors for temporarily positioning a filament adjacent to the ends of said anchors and means for operating said curling dies and for operating saidmembers to clamp said anchorsduring the curling operation.

4. In an apparatus of the class described, the combination with means for supporting a stem with an anchor extending therefrom of members adapted to clamp an intermediate portion of said anchor, a curling die'disposed adjacent to said members and means for causing said die to engage'the free end of said anchor and to curl it into a closed loop.

5. In an apparatus of the class described, the combination'with means for supporting a stem with anchors extending therefrom of a plurality of sets of members each set being adapted to clamp an intermediate portion of an anchor, curling dies disposed below said membersand means for causing said dies to engage the free ends of said anchors and to curl them into closed loops. I

G. In an apparatus of the class described, the combination of a die, a slide movable to 'form a filament around said die with ends projecting therebeyond, a filament transferrmg device comprising pairs of jaws for gripping said projecting filament ends, mechanism for moving said transferring device and for opening and closing said pairs of Jaws, mechanism for moving said slide and means whereby said mechanisms are caused to operate in proper time relation.

7. In an apparatus of the class described, the combination of a pair of cooperating members for holding a filament in a definite form with projecting ends and means for positioning said ends to be received by a. transferring device comprising a pair of fingers for each of said ends, one of said fingers having a groove therein and the fingers of each pair being movable relative to each other to position said ends in the same horizontal plane,

8. In an apparatus of the class described, the combination of a pair of cooperating members for holding a filament in a definite form with projecting ends and means for positioning said ends to be received by a transferring device comprising a pair of fingers for each of said ends, one of said fingers having a groove therein and the fingers of each pair being movable relative to each other to position said ends in the same horizontal plane, and a pair of fingers movable at substantially right angles to the direcof said filament and positioning them in the same vertical plane. Y

9. In anapparatus of the class described, the combination of means for presenting a filament formed into an arc shape'with its ends, aligned and a transferring mechanism comprising twopairs of jaws, one for each end ofthe said filament, rotatably mounted, means for rotating said pairs of jaws back and forth from the position of presentation .of said filament to that of a stem comprising leading-in conductors with hooked ends and means for opening and closing said jaws" in proper time relation with their rotation to grip said filament at the presentation position and to transfer it so that its ends are located in said leading-in wire hooks. v

10. In an. apparatus of the class described, the combination of means for presenting a filament formed into an arc shape with its ends aligned and a transferring mechanism comprising two pairs of jaws, one for each end of the said filament, rotatably mounted, means for rotating said pairs of jaws back and forth from the position of presentation time relation with their rotation to grip said filament at the presentation'position and to transfer it so that its ends are located in said leading-in wire hooks.

11. In an apparatus of the class described, the combination of means for presenting a filament formed into an arc shape with its ends aligned and a transferring mechanism comprising two pairs of jaws, one for each end of the said filament, rotatably mounted, means for rotating said pairs of jaws back and forth from the position of presentation of said filament to that of a stem comprising leading-in conductors with hooked ends and anchor wires, means for thereafter causing a. movement of said jaws substantially horizontally toward said leading-in wires and anchors, andmeans for opening and closing said jaws in proper time relation with their rotation to grip said filament at the presentation position and to transfer it so that its ends are located in said leading-in wirehooks.

12. In an apparatus of the class described.

the combination of means for presenting a comprising two pairs of jaws, one for each end of the said filament, rotatably mounted, means for rotating said pairs of jaws back and forth from the position of presentation of said filament to that of a stem comprising leading-in conductors with hooked ends and anchor wires, means for thereafter causing 511L3 movement of .said 'aws substantially hori-' zontally toward said leadingin wires and anchors, members comprising positioning pins for engaging said leading-in wires during said movement, and means for opening and closing said jaws in proper time relation with their rotation to gripsaid filament at the presentation position and to transfer it so that its ends are located in said leading-in wire hooks.

13. In an apparatus for mounting filaments, the combination of a stem holder, a plurality of members comprising a plurality of radially disposed slidable plates provided with means arranged to enga e anchors extending from said stem to bend them to proper angles and to clamp intermediate portions thereof, curling dies, means independent of said anchors for temporarily positioning a filament adjacent to the ends of said anchors and means for operating said curling dies and for operating said members to clamp said anchors during the curling operation.

14 In an apparatus for mounting filaments, the combination of a stem holder, a plurality of members comprising a plurality of radially disposed slidable plates having pins extending therefrom to engage and bend said anchors and the contiguous ends of said plates being shaped to clamp said anchors, curling dies, means independent of said anchors for temporarily positioning a filament adjacent to the ends of said anchors and' means for operating said curling dies and for operating said members to clamp said anchors during the curling operation.

15. In an apparatus for mounting filaments, the combination of a stem holder, a plurality of members comprising a plurality of radially disposed slidable plates provided with means arranged to engage anchors extending from said stem to bend them to proper angles and to clamp intermediate portions thereof, a plurality of movable straightening fingers disposed below said anchors so as to engage portions thereof between said clamped portions and said stem, curling dies, means independent of said anchors for temporarily positioning a filament adjacent to the ends of said anchors and means for oper ating said curling dies and for operating said members to clamp said anchors during the curling operation and said fingers for straightening said anchors.

16. In an apparatus for mounting filaments, the combination of a stem holder, a plurality of members arranged to engage anchors extending from said stem to bend them to proper angles and to clamp intermediate portions thereof, curling dies, means independent of said anchors for temporarily positioning a filament adjacent to the ends of said anchors, means for operating said curling dies andifor operating said members to clamp said anchors during the curling operation, movable weights positioned to drop upon said filament and means for causing said weights to drop during the curling operatlon to hold said filament against thepartially formed anchor loops.

17. In an apparatus for mounting filaments, the combination of a stem holder, a plurality of members arranged to engage anchors extending from said stem to bend them to proper angles and to'clamp intermediate portions thereof, curling dies, means independent of said anchors for temporarily positioning a filament adjacent tothe ends of said anchors, means for operating said curling dies and for operating said members to clamp said anchors during the curling operation, weights pivoted above so as to drop upon said filament and means for causing said weights to drop during the curling operation to hold said filament against the partially formed anchor loops.

18. The method of mounting a filament on a stem having straight anchors and lead wires with hooked ends extending therefrom which comprises supporting said stem, definitely fixing the positions of said anchors and lead wires, positioning a shaped filament adjacent to the ends of said anchors by temporary supporting means independent of said lead wires or anchors and then curling the ends of said anchors about said filament and also clamping. the hooked ends of said lead wires about said filament.

In witness whereof I have hereunto set my hand.

JOHN FLAWS, JR.

CERTIFICATE OF CORRECTION.

Patent No. 1,907,533. May 9, 1933.

JOHN FLAWS, JR.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 12, for

"end" read "ends"; and line 72, for "books" read '-'hooks"- page 2, line 48,

for "lower" read "power"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed-this 1st day of August, A. D. 1933.

I M. J. Moore.

(Seal) v Acting Commissioner of Patents.