US2625636A - Apparatus for crimping helical springs in innerspring construction - Google Patents

Description

Jan. 13, 1953' J. GAUCI ET-AL 2,625,636

APPARATUS FOR CRIMPING HELICAL SPRINGS IN INNERSPRING CONSTRUCTION Filed Dec. 28, 1949 4 Sheets-Sheet 1 1N VENTOR5 Jo'uwv 6'40 ATTORNEY Jan. 13, 1953 J. GAUCI ET AL 2,625,636

APPARATUS FOR CRIMPING HELICAL SPRINGS IN INNERSPRING CONSTRUCTION Filed Dec. 28, 1949 4 Sheets-Sheet 2 IN VENT 0R5 Joan 6540c! Aura/0: I 00100 ATTORNEYS Jan. 13, 1953 J. GAUCI ET AL 2,625,636

APPARATUS FOR CRIMPING HELICAL SPRINGS IN INNERSPRING CONSTRUCTION Filed Dec. 28, 1949 4 Sheets-Sheet 3 2 p 7 INVENTORS 14 Jsn-w 8006/ 3 191078106 0. 00mm! ATTORNEYS J 1953 J GAUCl ETAL 2,625,636

APPARATUS FR CRIMPING HELICAL SPRINGS IN INNERSPRING CONSTRUCTION Filed Dec. 28, 1949 4 Sheets-Sheet 4 ATTORNEYE Patented Jan. 13, 1953 APPARATUS. FOR- CBIMPING HELIGAL SPRINGS IN INNERSPRING} CON- STRUCTIGN Joseph Gauci, Jersey City, and AloysiusJ. Quinn, North Bergen, N. J assignors. to Comfort Spring Corporation, Baltimore, Md acorpora tion of Maryland Application December 28, 1949, Serial No. 135,-342

1 aims- The present invention relates to: the assembly and tying of the coil springs of innerspring units such as used in mattresses, cushions and the like. More particularly, the invention relates to apparatus for deforming or crimping the free ends of helical tie wires, called helicals employed for tying a group of coil springs into the innerspring assembly. The method of crimping helicals in innerspring constructions, which may be performed by the apparatus of the present application is described and claimed in} our copending application, Serial No. 135,343, filed December 28, 1949.

Machines have been devised for assembling lines of coil springs in adjacent rows with the end coils of the springs of one row overlapping corresponding end coils of those of an adjacent row, and then forming the helical and feeding it while rotating about its axis across the adjacent rows so that the. helical winds or screws itself about the overlapped portions of the end coils. Such a machine is disclosed in Patent No. 2,470,812 granted May 24, 1949, to Joseph Gauci and Daniel Krakauer. This machine is operated cyclically in intermittent motion whereby two adjacent rows of assembled springs are advanced to a tying position in the machine where the helical is formed and screwed across, the overlapped end coils, and then cut off beyond the end springs of the connected rows. While this is being done, a third row of springs is assembled adjacent the second row and 'advanced therewith to the tying position at the start of the next cycle. This isrep eated until the assembly is of required size. When it is removed from the machine and the ends of the helicals extending from the end coils of the assembly are crimped to prevent accidental displacement from the springs by unscrewing therefrom.

Various attempts have been made to perform this crimping operation automatically during the assembling operations, but so far as we are aware, no satisfactory means has heretofore been devised and the crimpingis performed by hand after the spring unit has been completely assembled. The usual manner ofcrimping is by cutting off the overhanging ends of the helicals close to the end coils of the springs at opposite ends of the rows and then bending the ends of the wire over the end coils of the helical.

The helical is formed of wire wound into a relatively high pitch helix, and we have found that by axially collapsing or decreasing the pitch of a few end coils of the helical to bring a few adjacent coils close together, the helical is etiii fectively prevented from unscrewing from the springs with which it is engaged. For the purpose of this application theterm crimping shall be. employed to. refer to such axialclos ing uplor collapsing the end turns or coils of thehelical.

It is an object ofv this invention, thereiore to provide apparatus for crimping the free ends of helicals in an innerspring assembly by axially compressing the end coils of such, helicals to decrease the pitch of the helix to. an extent to prevent accidental removal or unscrewing of the helical from the spring unit duefto. rotation. of the helical.

Anotherobject of the imientionv is to provide apparatus of the above character in which heat and axial pressure are applied to theend coils of the helical to crimp such helical ends.

Another object of theinvention is to provide apparatus of the above character which ma form a part of or an attachment to an innerspring assembly machine of the type iorming and applying helicals to an innerspring unit and which is operated automaticallyv in synchronism with. the. assembly machine.

A still further-- object of the invention is topro vide apparatus of the above character which'inp rat s a t an po tin and positionin mechanism for forwarding the spring unit instep by step motion and accurately positioning the helical ends in place for the crimping operation.

With theabove objects and advantages in view, which w ll be ome more appa ent, durin 1111 course of the following description, the inven n consists in thepartsand combinations he after set forth th the understan ing t t 1 'Qhan s' a be m de therein, sha as th Size! 51: 39 nd. rran mentq arts Y W sub ti i n o equ valents without. e a, s from thespirit of the invention In d r m make th 1 3?- lea ersto p e edem q thereoi ha en a e, t e. u ll l n 1 the a pa yinedrai ine n whi h:

Fi ure 1 i front 1 rat o al. i w partly br ke away Qiiil qr mn a to t s WW i I an fo m n a art-.9? e a embl machin signage at vertical ss-sectional view taken along the line 2%2pf1i1giire l andshgwingthe immediate adjacent parts of the assembly niachine;

Figure 3 is a detailed sectional view taken along the line 33 of Figure 1 showing a part of the spring forwarding and helical positioning mechamsm;

Figure 4 is a plan view of one of the crimping units;

Figure is a vertical sectional view taken along the line 55 of Figure 4;

Figure 6 is a fragmental sectional view, similar to Figure 5, showing the parts in position occupied when the electrodes initially contact the helicals and before the helical is crimped;

Figure '7 is a horizontal sectional view taken along the line 1-1 of Figure 6, but showing the helical after it has been crimped; and

Figure 8 is a wiring diagram showing the electrical control circuit for the crimping unit.

The crimping apparatus embraced in this invention may be operated as a separate unit to crimp the helical ends of an innerspring unit after compete assembly of the unit. Preferably, however, and in line with rapid production methods. the crimping apparatus and its associated spring transport mechanism may form a part of or be an attachment to an innerspring assembly machine of the type disclosed in Patent No. 2,4 0, 12, referred to above, and operated in synchron sm with the assembly machine to crimp the opposite ends of the helicals successively as .the spring unit is being assembled by the machine. For the sake of brevity in the following descri tion only the discharge end of the spring assembly machine, immediately adiacent the crim ing mechanism, is shown in the accompanying drawings.

R f rring first to Figures 1 and 2 of the drawin s. there is shown the up er portion of the disch r e end of an innerspring assembly machine desi nated g n ally as I and ha in a frame designated enera ly as 2. J ournalled in the frame 2 is an nt rm ttent mot on convevor mechanism indicated generally as 3 which holds juxtaposed coil s rin s in adj ent rows extendin transversely across the machine in position with the to and bottom coils 4 of the sprin s 5 of one row o erlap ing the corresponding end coils 6 of the s' riTFs of the adiacent row (see Fi ures 4 and 5). With the adiacent rows of s rin s thus he d dur ng a dwell period of the conveyor 3, a helical 8 is fed respectively across the line of overlap of the to and bottom coils of the ad acent rows of sprin s. The le d ng end of the helical is fed a redeterm ned distance be ond the ast coils of the rows to leave a free end extens on 9. The fo lowing end of the he i al is out o an eoual distance from the o pos te end coi s of the connected rows to rovi e a similar free end extension. Afte each succeeding pair of he i als are applied. the spring unit is advanc d the distance between spring rows of the unit. the spring being d s harged from the conveyor 3 and the unit discharging from the dischar en of the machine.

At the discharge end of the machine there is provided a series of vert cally aligned. horizontal trac s In and H constituting a guide way I2 through wh ch the spring unit moves as it is discharged from the machine. The tra ks l0 and l are respectively secured at their op osite ends to cross rails I3 joined to the opposite sides of the frame 2 and extending transversely across the discharge end of the machine. Preferably I0 and I I respectively engage the top and bottcm coils of each spring to hold them under slight compression with the top and bottom helical extens ons 9 parallel and spaced a fixed distance apart.

Mounted to reciprocate between the rails of the guide way I2 is a spring transporting mechanism indicated generally as M for forwarding the spring unit step by step and positioning the helical extensions in position for crimping.

Constituting the transport mechanism I4 is a slide block l5 which is mounted for longitudinal movement (fore and aft of the machine) between cne of the tracks H adjacent the lefthand side of the machine (as viewed in Figure l) and a parallel rail l6 which is secured between the lower cross rails l3 and below the said track A slide block II, similar to the slide block l5, is mounted for movement between one of the lower tracks Ila, adjacent the right-hand side of the machine, and a parallel rail IGa similar to the rail l6 and similarly secured to the cross rails l3. Extending between the slide blocks I5 and I is a cross rod 8 which extends beyond the slide blocks and is rigidly secured thereto.

Secured to the left-hand extension of the cross rod l8, beyond the slide block l5 (see Figure 1), is a spring forwarding member designated generally as l9, and secured to the right-hand extension of the cross rod I8, beyond the slide block I1, is a similar spring forwarding member designated generally as 20. The members l9 and 20 are essentially alike except that one is made right-hand and the other left-hand, and the same reference characters are applied to like parts on both members.

The spring forwarding members l9 and 20 each comprise a lower block 2| having a transverse hole therein which receives the cross rod I8 and in which this rod is secured. An upper block 22 is positioned vertically above the block 2| and is joined thereto by vertical plate 23. The upper block 22 of each of the members I9 and 20 is provided with a transverse hole, one axially aligned with the other, and an upper cross rod 24 extends between the members l9 and 20 and is secured in these holes in the blocks 22.

Secured to the inner end face of each of the lower blocks 2|, for fore and aft pivotal movement, is an upstanding hook member 25. (Forward as used herein isthe direction corresponding to the movement of the spring unit toward the discharge end of the machine, or to the left as viewed in Figure 2.) The forward face of each hook member 25 at the upper or free end thereof, is formed with a slight hook 26 while the upper rear face is formed with a downward and rearward bevel 21. Each hook member has a downwardly facing shoulder 28 on its forward edge and between this shoulder and a shelf 28a on the block 2| is positioned a compression spring 29 which urges the hook member in a rearward direction about its pivotal axis. This rearward pivotl movement s limited, however, to a substantially vertical position of the hook member by a pin 30 on the block 2| which engages the rear edge of the hook member. A similar but downwardly extending hook member 3| is similarly mounted on each of the upper blocks 22 in vertical alignment with the corresponding hook member 2 5.

The blocks 2| and 22 of the respective spring forwarding members l9 and 20 are vertically aligned and lie substantially in the paths of movement of the axes of the end springs of the spring unit. The hook ends 25 of hook members are horizontally aligned respectively with the top and bottom helicals of the spring unit moving between the tracks l0 and H. The connector plates 23 of the spring forwarding members are sufficiently offset from the hook members to clear the end springs of the unit.

A connecting rod 32 has a connection at one end thereof with the lower cross rod I8: adjacent the block while a second connecting rod 33 has a similar connection with the rod [8 adjacent the block IT. The opposite ends of the rods 32 and 33 are respectively connected to the freeends of a pair of crank arms 3d and 35. The cranks 3'4 and 35 are respectively secured to the inner ends of a pair of axially aligned rotary drive shafts 3E and 3'! which extend inwardly respectively from opposite sides of the machine and are journalled respectively in bearings 38 and 39 carried by the frame of the machine. The throw of the cranks 34 and 35 is such as to move the spring forwarding members 19 and it from a forward dwell position (shown in full lines in Figure 2) to a position rearwardly thereof a distance somewhat in excess of the horizontal spacing between adjacent helicals in the spring unit, and then back to the forward dwell position. The hook ends 23 of the hook members and BI are aligned vertically with the top and bottom helicals of the spring unit as stated above, and it will be seen that as the hook members are moved rearwardly they will, upon engagement with a pair of helicals, pivot forwardly to pass the helicals and then, upon forward movement, will engage the helicals and move the spring unit forwardly until the engaged heli-cals reach the forward dwell position.

Preferably the hook members engage the helical about the center of the end springs of the rows engaged thereby. Spring units are made, however, in various widths (6, 'l', 9 or 10 springs wide) counted from the right-hand side of the input end of the machine or left-hand side looking from the discharge end as in Figure l. The forwarding member it on the left-hand side of the machine, therefore, has a fixed transverse position aligned with the number one line of springs of the unit. The associated shaft 36.

bearings 38, crank S 5 and rod 32 also havefixed transverse positions on the machine. The righthand forwarding member 20, on the other hand, may be slid along the rods l8 and 24 so that the hook members will vertically align with the center of the opposite end springs of whatever width unit is being assembled.

The shafts 3t and 3'! have operative connections through suitable power transmission mech anism (not shown) to rotate them in unison through one complete revolution for each step of movement of the conveyor 3 and in syn-chronism with the conveyor movement.

Secured to a cross angle rail 48, forming a part of the rear framework of the assembly machine is an upstanding bracket ll having a fixed position at the left-hand side of the machine. Also secured to the rail M] is a similar upstanding bracket 42. Each of these brackets carries a helical crimping uni-t designated respectively and generally as 43 and M. The bracket 42 is adjustable along the rail toward and away from the bracket 4| to position the crimping unit carried thereby according to the width of the unit being assembled, as will be more clearly understood hereinafter. The crimping units 43 and 44 are essentially alike except that they are oppositely operated, and only the right-hand unit will be described in detail, the same reference characters designating like parts in both units.

.As best seen in Figures 4 and 5, the crimping unit comprises a rectangular plate. 4.5 which is secured to the upper end of bracket 42. Secured to the face of the plate 45, awayfrom the center of the machine, is the winding 45 of a solenoid 41 which is provided with an axially movable arma ture or plunger 48. The solenoid plunger 48 extends from the winding through an opening 45 in the. plate 45 toward thev center of the. machine and has secured thereto a vertically elongated head 50. Thehe-ad 50 carries a pair of sleeves 5| and 52 which project toward the center of the machine and are alignedaxially respectively with the top and bottom helical extensions 9 when, the helicals are positioned in the forward or dwell position of the spring forwarding members I!) and 20. The head 50 is guided for horizontal movement by a pair of pins 53 which are secured to the plate 45 and pass through apertures 54 in the head 50. Pins 53 have enlargements at their free ends to limit the inward or extended movement of the head.

Urgingthe plunger 48, and its head 58 to a retracted position, where the sleeves 5! and 52 will clear the path of movement of the helical extensions, are compression springs 55 which are positioned between a bar 56 secured to the outer end of the plunger 48 and brackets 5! secured to the solenoid.

Secured in the head 53 are a pair of pins 58, perpendicularly to the head and extending oppositely from the sleeves 50 and 51 and each having a head on its free end. Mounted for sliding movement on the pins 58 is a bar 59 which is yieldingly urged toward the head so by a pair of relatively light compression springs 63 which are positioned respectively around the pins 58 between the bar 59 and the heads of the pins. It is to be noted that the springs iii) are lighter, or exert less force than retracting springs 55, and it might also be noted here that the force exerted by the springs 59 is not sufiioient to overcome the stresses in the helical in its normal cold state.

Rigidly secured to the bar 59 and insulated therefrom are a pair of electrodes 5! and 62 which extend respectively with a sliding fit in insulating bushings 53 and 64 respectively fitting concentrically within and forming parts of the sleeves 5i and 52. It will be noted that the lengths of the electrodes are such that in normal expanded condition of the spring so, where the bar 59 engages the head 59, the tips of the electrodes lie closely adjacent the outer ends of the bushings 63 and 64 which, it will be seen, are outwardly bevelled-the front faces of the electrodes lying approximately at the rear end of the bevels. The electrodes ti and 62 are fitted respectively with connector strips 65 and 65 for connecting the electrodes in a circuit (to be described) with a source of current.

Describing now the control circuit for the solenoids and electrodes, reference is made to Figure 8 where it will be seen that one side 61 of an electric power line has a connection through a. lead 68, and the contacts of a normally open switch 69 (to be further described) with the winding 72 of a two-contact, normally open relay II. From the winding it a return is made through a lead 72 to the return line '13 of the power supply. A connection is made from the power line 6? through a lead '54 and one set of the normally open contacts l5 of the relay l! with one end of the winding #6 of both solenoids M, the opposite ends of which are connected through a lead 16 to the return power line 13. The power line 6,! has a connection througha lead 1.1., the other normally open contacts 18 of the relay II. and a time interval relay 19 with the winding 80 of a single contact, normally open relay 8|. The winding 88 has a return lead to the power line 13 through a lead 82. A lead 83 connects the power line 61 through the normally open contacts 84 of the relay 8! with the primary 85 of a pair of transformers 85, the return leads from which are made to the power line 73 through a lead 81. The opposite ends of the secondary windings 88 of the transformers 85 are connected through leads 89 and 90 respectively with the electrodes 6! and 52, the electrodes of one crimping unit being connected to one of the transformers 85 and the electrodes of the other unit being connected to the secondary of the other transformer.

The crimping unit is operated when the helicals comiecting a pair of adjacent rows of springs are positioned in crimping position between electrodes 6i and 82, i. e., in the forward dwell position of the spring transport mechanism. To this end the switch 58 may be placed in a position on the machine to operate, or be closed at the start of a dwell period of the machine. A convenient location for the switch is at the forward location of one of the slide blocks of the transport mechanism as seen in Figure 2. This switch may be of conventional quick acting design such as a normally open micro switch and may be mounted on one of the lower rails l carrying the bottom slide block i5 and be closed thereby as the block reaches its forward position by means of a rocker arm 9|, one end or" which is contacted by the block 15 and the opposite end of which depresses the plunger of the switch to close the switch contact.

In operation a spring unit is assembled in the machine as briefly described above and as more fully described in Patent No, 2,470,812. It will be recalled that the helical is applied in the machine during a dwell period of the holding conveyor 3, which is also the dwell period of the transporting mechanism. As the successive rows of springs are connected by the helicals, they are advanced through the discharge end of the machine and into the guide way l2 between the track It and H which horizontally align the end coils of the springs and the top and bottom helicals engaged thereby.

When the first connected rows of the spring unit has reached the rear location of the transport mechanism stroke and as the conveyor 3 is operating to move the next rows of springs to be connected into helical applying position in the machine, the spring forwarding hook members move rearwardly, fall behind the helicals of the first connected rows and then move forwardly to advance these rows through the guide way [2 and position the helical ends 9 in axial alignment with the electrodes 8i and 62. While the next helical is being formed and applied to the spring rows in applying position in the machine, the conveyor 3 and the spring transport mechanism [4 remain stationary in their respective dwell position for a time sufficient to form and apply the helicals.

When the slide blocks l5 and H move up to their forward position, the block l5 engages the rocker arm 81 and closes the switch 59 which completes the circuit from the power line 61-13 to the winding 70 of the relay Tl, energizing this relay and causing to drop in and close its normally open contacts. When the relay H drops in, circuit is completed to the windings 46 of the solenoids 47 and also to the winding 80 of the relay 8| through the normally closed time interval relay l9, energizing both solenoids 4! and causing the relay 8| to drop in and close its normally open contacts 84. Closing of the relay contacts completes the circuit from the power supply to the primaries of both of the transformers 85.

As the solenoids 4'! become energized, their plungers will be advanced, advancing the heads 50 and the sleeves 5i and 52 toward the ends of the helical extensions 9. Due to the resilient connection of the springs 60 between the head 50 and the electrode supporting bar 59, the clec trodes are also advanced until their tips contact the extremities of the helical extensions. Here the blocking resistance offered by the relatively stiff helicals overcomes this force of the springs 60 and electrode movement stops. The head 50 continues to advance, however, to the full extent of solenoid plunger movement and the sleeves 5i and 52 advance, relatively to the electrodes and telescope over the ends of the helical extensions as shown in Figure 6.

When the electrodes SI and 52 respectively contact the ends of the top and bottom helical extensions, a circuit is completed through the secondary of the transformer 88 and current flows from one electrode, through one helical extension, thence through the springs engaged by the helicals and through the other helical extension to the other electrode. Due to the fact that the wire composing the helical is of relatively small diameter, compared to the mass of the springs, the current takes the above path and because the small diameter wire of the helicals has relatively high electrical resistance, the extensions become rapidly heated, and relatively soft by removal of internal stresses. When sufficiently annealed or softened whereby the helical extensions offer less force than the springs 60, the force of these springs advance the electrodes toward the helicals and axially compress or collapse the heated convolutions of the helical extensions compressing them into close juxtaposition as shown in Figure 7. In order to prevent over-heating and burning the wire of the helical extensions, the time interval relay 19 is designed or adjusted to open after the helical coils have been softened just sufficiently to be compressed by the springs 60. Opening of the relay l9 breaks the circuit to the relay 8|, causing this relay to drop out and open the power circuit to the transformer 86.

At the start of the next cycle of the machine, and as the forwarding mechanism starts its retracting movement, the block I5 releases from the rocker arm 9| allowing the switch 69 to open and break the energizing circuit to the relay H, allowing this relay to drop out and break the energizing circuit to the solenoids 41. As the solenoids become de-energized, the springs 55 retract the plungers and heads 50 with their sleeves 5| and 52 moving these out of the paths of the springs and permitting the spring unit to again be advanced to bring the next pair of helicals into crimping position.

From the foregoing it will be seen that the invention provides a relatively simple, rapid apparatus for crimping helical ends and moreover one which can be fully automatic in operation as a part of or attachment to an innerspring assembly machine and accurately timed for synchronous operation therewith.

We claim:

1. Apparatus for crimping a helical of an innerspring unit wherein the helical has a free end extension from the springs engaged thereby comprising means for exerting axial pressure on the aecaese 9. extremity of said free end of the helical extension, and means for passing an electric current through said pressure exerting means, said free end extension, and through the springs engaged thereby, to heat the free end extension to an annealing temperature whereby the axial pressure compresses the helical.

2. Apparatus for crimping a helical of an innerspring unit wherein the helical has a free end extension from the springs engaged thereby comprising means for passing an electric current through said free end extremity to heat the same to an annealing temperature, said current passing means including a movable electrode inaxial alignment with the extension and engaging the free extremity thereof, and resilient means exerting a yielding pressure on the electrode axially of the extension and toward the same to axially collapse the coils of the helical extension heated by said current.

3. Apparatus for crimping a helical of an innerspring unit wherein the helical has a free end extension from the springs engaged thereby comprising means for passing an electric current through said free end extremity to heat the same to an annealing temperature, a guide sleeve adapted to axially receive said extension, said current passing means including an electrode mounted for axial movement in said sleeve to engage the free extremity of said helical extension received in the sleeve, and resilient means exerting a'yielding pressure on the electrode and urging the same axially toward the helical extension to axiallycollapse the coils thereof heated by said current.

4. Apparatus for crimping helicals of an innerspring unit, wherein a helical engages top and bottom coils respectively of springs in adjacent rows thereof and the helicals have free end extensions from the end springs of said rows, comprising a pair of electrodes, support means mounting the electrodes respectively for axial movement along the axes of said helical extensions respectively at the top and bottom coils of said springs, resilient means for urging the electrodes axially into pressed engagement with the free extremities of the helical extensions, and means for passing an electric current from one to the other of said electrodes through said helical extensions and to heat the same to annealing temperature whereby said extensions become axially collapsed under the pressure of the electrodes.

5. Apparatus according to claim 4 including a pair of non-conductive sleeves carried by the support means and in which said electrodes respectively are mounted for axial movement, said sleeves serving respectively to receive the helical extensions and axially align the same with the electrodes.

6. Apparatus according to claim 5 including a support for the spring unit having spaced parallel rails engaging the end coils of said springs and holding the helical extension axes in planes which include respectively the axes of said sleeves, and means for moving the springs between said rails into axial alignment with said sleeves.

7. Apparatus for crimping helicals of an innerspring unit, wherein a helical engages top and bottom coils respectively of springs in adjacent rows thereof and the helicals have free end extensions from the end springs of said rows, means for supporting at least the end coils of a pair of adjacent spring rows with the spring extension in fixed parallel relationship and spaced a pre- 10 determined distance apart, a pair of non-conduc tive cylindrical sleeves having inside diameters to closely receive respectively said extensions, a movable support for the sleeves positioning the same in axial alignment with said extensions, said support having a normal retracted position holding the sleeves in spaced axial relation to the free extremities of the extensions, an electrode mounted for concentric axial movement within each sleeve, compression means urging the electrodes to forward positions adjacent the ends of the sleeves facing the extensions, means 'foradvancing the support to telescope said sleeves over the helical extensions retracting the electrodes into the sleeves against the force of said'compression means, and means for passing anelectric current from one to the other of said elece trodes through said helical-extensions to heat the same to annealing temperature whereby theforce of said compression means acting on the electrodes will axiallycollapse theannealedlcoilsof the helical extensions. I T

8. Apparatus according to claim 7 including spring means urging said support to the-retracted position thereof, solenoid means for advancing the support, circuit means for simultaneously connecting said solenoid and said electrodes with a source of current, and means for breaking said circuit.

9. Apparatus according to claim 8 in which said circuit breaking means includes a time interval relay in series with said electrodes .to break the circuit to the electrodes after a time interval calculated to heat the extensions .suflicient to permit axial collapse thereof under the force of said compression means.

10. In a machine for assembling innerspring units of the type in which adjacent rowsof .coil springs are connected by helicals encircling ad,- jacent portions of corresponding to and bottom coils respectively of the springs of said adjacent rows, the said helicals having free end extensions from opposite ends of saidrows, the machineiineluding intermittently operated conveyor .means for successively positioning adjacent rows of springs at a station in the machine to receive said helicals during dwell periods of the conveyor means and subsequently advancing said adjacent rows beyond a discharge end of the machine, the improvement comprising a pair of electrodes positioned adjacent the discharge end of the machine, respectively and in normally spaced axial relation to the opposite extremities of said extensions, one electrode of each pair being axially aligned respectively with the top and bottom extensions in a dwell position of the conveyor, support means for each pair of electrodes including resilient compression means backing up the electrodes, power means synchronized with said conveyor means to move the support means toward the spring unit and move the electrodes axially into yielding engagement with the extremities of the extensions adjacent thereto during said dwell periods, and means for passing an electric current from one to the other electrode of each pair through the helical extensions while engaged thereby to heat said extension to annealing temperature whereby said compression means acting on the electrodes will axially collapse the coils of the extensions heated by said current.

11. Apparatus according to claim 10 including guiding support means for the spring unit receiving the same at the discharge end of the machine and guiding the helical extensions in planes respectively including the electrodes, and

transporting mechanism operating in synchronism with said conveying means engagin the helicals and positioning the extensions thereof in axial alignment respectively with the electrodes during said dwell period.

12. Apparatus according to claim 11 in which the power means for moving the electrodes comprises solenoid means, circuit means for connecting this solenoid means with a source of energizing current and switch means in the circuit means operative by movement of the transport means into helical aligning position to close the circuit means.

13. Apparatus according to claim 12 including a circuit also closed by said switch means for connecting the electrodes to the source of current, said electrode circuit including a time interval relay in series with the electrodes to break the circuit thereto after a predetermined heating interval of time.

14. In a machine for assembling innerspring units of the type in which adjacent rows of coil springs are connected by helicals encircling adjacent portions of corresponding top and bottom coils respectively of the springs of said adjacent rows, the said helicals having free end extensions from opposite ends of said rows, the machine including intermittently operated conveyor means for successively positioning adjacent rows of springs at a station in the machine to receive said helicals during dwell periods of the conveyor means and subsequently advancing said adjacent rows beyond a discharge end of the machine, the improvement comprising a pair of electrodes positioned adjacent each side of the discharge end of the machine, movable supports for said electrodes for positioning them in normally spaced axial relation to the opposite extremities of said extensions, a nonconductive sleeve surrounding each electrode and in which the electrodes are axially movable, said sleeves being carried by the electrode support and respectively receiving the helical extensions upon movement of the support toward the spring unit,

one electrode of each pair being axially aligned respectively with the top and bottom extensions in a dwell position of the conveyor, said electrode supports including resilient compression means backing up the electrodes, power means synchronized with said conveyor means to move the support means toward the spring unit and move the electrodes axially into yielding engagement with the extremities of the extensions adjacent thereto during said dwell periods, guiding support means for the spring unit receiving the same at the discharge end of the machine and guiding the helical extensions in planes respectively including the electrodes, transporting mechanism operating in synchronism with said conveying means engaging the helicals and positioning the extensions thereof in axial alignment respectively with the electrodes during said dwell period, and means for passing an electric current from one to the other electrode of each pair through the helical extensions while engaged thereby to heat said extension to annealing temperature whereby said compression means acting on the electrodes will axially collapse the coils of the extensions heated by said current.

JOSEPH GAUCI. ALOYSIUS J. QUINN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,262,814 Lewis Apr. 16, 1913 2,159,860 Platz May 23, 1939 2,254,525 Hathaway et al. Sept. 2, 1941 2,394,822 Teplitz Feb. 12, 1946 FOREIGN PATENTS Number Country Date 458,197 Great Britain Dec. 15, 1936 499,254 France Feb. 6, 1920

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