US2678988A - Heat-treating mechanism for coil springs - Google Patents

Description

May 18, 1954 M. J. NELSON ET AL HEAT-TREATING MECHANISM FOR COIL SPRINGS Filed July 5, 1951 J33 INVENTORS May 18, 1954 v M. J. NELSON ET AL HEAT-TREATING MECHANISM FOR con. SPRINGS Filed July 5, 1951 4 Sheets-Sheet 2 INVENTORS flea 7 22M J/l/e sora May 18, 1954 M. JVNELSQN ET AL HEAT-TREATING uscuguxsm FOR 0011. SPRINGS Filed July 5, 1951 4 Sheets-Sheet 3 May 18, 1954 M. J. NEL$ON El AL 2,678,988

HEAT-TREATING MECHANISM FOR con. SPRINGS 4 Sheets-Sheet 4 Filed July 5, 1951 Patented May 18, 1954 UNITED STATES TENT OFFICE HEAT-TREATING MECHANISM FOR COIL SPRINGS Application July 5,1951, Serial No. 235,154

17. Claims. 1

The invention relates to a heater mechanism for heat treating coil springs. The heater mechanism of this invention is particularly adaptable for use with a coil. spring producing machine, suchas disclosed-in application Serial No. 700,197, filed by William E. Wunderlich on September 30, 1946, now Patent No. 2,664,202 or" Ju1y'22, 1952, for individually heat treating the coil springs as they are formed by the machine.

'lheprincipal object of this invention is to provide an improved heater mechanism for heat treating coil springs wherein the end turns of the coil spring are securely clamped and electrically contacted for passing electrical current therethrough. thereby eliminating arcing and-providing uniform heat treating throughout the length or" the coil spring, wherein electrical current is applied to the coil spring only when the end turns thereof are securely clamped and electrically contacted wherein the interval of time dur ing which electrical current is applied maybe readily adjusted for obtaining the desired heat treatment of the-coil springs, wherein the application of electrical current to and the clamping and electrically contacting of thecoil springs are positively and mechanically synchronized forfoolproof operation, wherein the heater mechanism may be readily adjusted for accommodating coil springs having different lengths, diameters, wire gauge and the like, wherein the heater mechanisin may be readily applied to coil spring producing machines for synchronous operation therewith, and wherein the heater mechanism is simple in construction, foolproof in operation and inexpensive to manufacture.

Briefly, the heater mechanism of this invention includes two pairs of clamping members, one pair clamping and electrically contacting one end turn.- of a coil spring and the other pair clamping electrically contacting the other end of the coil spring; Each pair of clamping members-includes a normally stationary clamping member and a clamping member movable toward and'away from the normally stationary clamping member. A pair of cams, operated by a rotatable shaft, move the movable clamping members toward and away from the normally stationary clamping members for securely clamping and electrically contacting each coil spring applied thereto. Means are provided for applying electrical energy to the clamping members electrically-to heat treat the springs clamped thereby. Control meansincluding switch means and cam means operated'by the rotatable shaft applies electrical energy to the clamping members and hence to the coil spring only when the coil spring is securely clamped and electrically contacted by the clamping members. The control means is adjustable to regulate the time interval during which electrical energy is applied to the clamped coil springs. The rotatable cam shaft may be driven in synchronisin with a coil spring producing ma chine for heat treating the coil springs as they are fabricated. The positions of the rotatable cam shaft and the various clamping members and cams operated thereby may be adjusted to accommodate coil springs of different lengths, diameters, wire gauges and the like.

llurther objects of this invention reside in the details of construction of the heater mechanism and in. the cooperative relationships between component parts thereof.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings, in which:

1 is a diagrammatic illustration of a coil spring producing machine of the type disclosed in the aforementioned William E. Wunderlich application with the heat treating mechanism of this invention applied thereto;

Figs. 2 and 3 are perspective views of a coil spring which may be heat treated by the heat treating mechanism of this invention, Fig. 2 illustrating the spring before heat treating and Fig. 3 illustrating the spring after heat treating;

Fig. 4 is a schematic wiring diagram of the means for applying electrical energy to the coil springs being heat treated and the control means therefor;

Fig, 5 is a front elevational view partly in section of the'heat treating mechanism of this invention illustrating the clamping members separated for receiving a coil spring;

Fig. 6 is a front elevational view of the heat treating mechanism showing a coil spring clamped by the clamping members for heat treating the coil spring;

Fig. '2 is a top plan view of the heat treating mechanism;

Fig. 8 is an end. elevational view of the heat treating mechanism-looking from the left of Figs. 5 and '7;

Fig. 9 is a Vertical sectional View taken substantially along the line 9 9 of Fig. 7

Fig. 10 is a sectional view taken substantially along the line ll-l t of Fig. '7

Fig; 11 is a view illustrating the position of the left endof the coil spring, as illustrated in Figs.

defense 3 5 and 6, and it is clamped by the left-hand clamping members;

Fig. 12 is a view similar to Fig. 11 but i1lustrating the position of, and the manner in which, the right end of the coil spring, as illustrated in Figs. 5 and 6, is clamped;

Fig. 13 is an enlarged sectional view through a pair of clamping members taken substantially along the line i3-l 3 of Fig. 14

Fig. i l is an elevational view of the right-hand clamping member of Fig. 13 loolring from the left; and

Fig. 15 is an exploded perspective view illus trating the manner in which the portion of the clamping member utilized for clamping the coil spring is constructed.

Referring first to Figs. 2 and 3, a coil spring to be heat treated is generally designated at it. It includes a plurality of inner convolutions or turns it and a pair of end turns H2. The end turns i2 terminate in knots 13. The coil springmay be plain as illustrated or the end turns thereof may be crimped or offset if so desired. When the coil spring is originally fabricated the knots it are located out of line, as illustrated in I Fig. 2, so that when the coil spring is heat treated the knots line up, as illustrated in Fig. 3, the heat treating of the coil spring causing a twisting within the coil spring.

Any suitable machine may be utilized for the purpose of fabricating the coil spring in and for purposes of illustration in this application Fig. l discloses a coil sprin producing machine generally designated at 55 which may be of the type disclosed in the aforementioned William E. Wunderlich application. The machine it includes a base or standard is and a coilin mechanism ii for coiling wire into the double ended coil spring Hi. When the coil spring ii] is thus formed it is grasped by fingers carried by radial arms iii of a transfer mechanism which is intermittently rotated in a counterclockwise direction, as illustrated in Fig. 1. The coil springs id thus formed and grasped by the fingers i d are advanced to a knotting mechanism wherein one end of the coil spring I5 is knotted as at I 3 and, if desired, crimped into an offset. The coil springs it are then advanced to a second knottin mechanism 22 wherein the other end of the coil spring is knotted and may also be crimped into an offset if so desired. The knotted coil springs iii are then advanced by the transfer mechanism to the heat treating mechanism of this invention, generally designated at 23. After the coil springs iii are heat treated they are advanced by the transfer mechanism to a stacked mechanism 23 wherein the heat treated coil springs are stacked in nested form. Since the coil spring producing machine, diagrammatically illustrated in Fig. 1, is fully disclosed in the afore mentioned William E. Wunderlich application, a further description thereof is not considered necessary. The heat treating mechanism 23 of this invention includes a supporting base 26 in the form of an angle member which is secured to the standard or support it of the coil spring producing machine by means of bolts 21. The upwardly extending leg of the supporting base 28 is provided with a plurality of holes 28 and is provided adjacent each end with vertically ar-- ranged slots 29. A pair of bearing blocks 30 are secured to the supporting base by screws 31 extending through the slots 29 and nuts 32. A rotatable cam shaft 33 is rotatably journalled by bearings 34 in the bearin blocks 30. By reason 4 of the vertical slots 29 the bearing blocks 39 and, hence, the cam shaft 33 may be vertically adjustably positioned as desired.

The right-hand end of the rotatable cam shaft 33, as viewed in Figs. 5 and '7, has a hub 35 keyed thereto by a key 353 along with a set screw 3! for holding the hub in proper position on the cam shaft. A gear at is secured to the hub 55 by means of bolts 39 so that as the gear 38 is driven, the cam shaft 32 is correspondingly rotated. As shown in Fig. l, the gear 38 meshes with a driving gear 43 carried by a shaft 4! which drives the lrnotting mechanism 22. The shaft ll makes one complete revolution in its operation of the lmotting mechanism 22 and'this is done during each cycle of operation of the coil spring producing machine. The gear 33 is preferably twice the size of the driving gear as so that during each cycle of operation of the coil spring producing machine the rotatable cam shaft 33 is driven through one-half a revolution.

The rotatable cam shaft slidably carries a pair of sleeves of identical construction, the sleeves d5 being k yed to the shaft 33 for rotation therewith by lreys ii. Each sleeve 35 rotatably and slidably carries a pair of clamping members, a normally stationary clamping member 47 and a movable clamping member t3 which is movable toward and away from the normally stationary clamping member 4?. Since the sleeves and the clamping members and elements associated with each sleeve are identical in construction, like reference characters have been utilized for like parts.

The normally stationary clamping member 4'! is journalled for rotation with respect to the sleeve 45 by a bearing 49 and, likewise, the movable clamping member as is journalled for rotation on the sleeve :5 by a bearing member 50. The normally stationary clamping member 41 abuts against a thrust bearing 5| which is positioned on the sleeve 55 by a screw-threaded collar 52, which in turn is locked in adjusted position by a locking collar 53. The collars 52 and 53 may be adjustably positioned on the screwthreaded portion of the sleeve 45 by means of a suitable tool extending into radial openings 54 in the collars 52 and 53. Thus the collar 52 determines the relative lengthwise positions of the normally stationary clamping member 41 and the sleeve 45. A spring 55 is interposed between the normally stationary clamping member ill and the movable clamping member 33 for normally separating these members.

A cam member 5% is secured to the movable clamping member 48 by means of screws 5'! and this cam member $56 is provided with a pair of diametrically opposed and longitudinally extending cam surfaces 58. A cam 58 is slidably carried by the sleeve "55 and abuts against a ring secured in an annular groove in the sleeve 45, the ring 69 limiting inward movement of the cam 59. The cam 59 is keyed to the sleeve 45 by a key 6! so that the cam 69 rotates with the sleeve 45 and, hence, with the shaft 33, although the cam 59 may move longitudinally on the sleeve 45. The cam 59 is also provided with a pair of diametrically opposed longitudinally extending cam surfaces 52 which cooperate with the cam surface 58 on the cam member 56. The cam 59 is normally maintained against the ring 68 by means of a spring 63, one end of which abuts the cam 59 and the other end of which abuts a collar 64 screw-threaded on the sleeve 45. The collar 64 is locked in adjusted position on the sleeve 45 by" means of a'screw-threaded lock collar 65, radial-'openingslifi in the collars 84 and 65 facilitating' their adjustment.

When the cam surfaces 58 and 62 are not in engagement, as illustrated in Fig. '7, the springs 59 separate the clamping members d? and 48, as illustrated in Figs. 5 and '7. However, when the cam shaft 33 and, hence,-the sleeve it rotate to a position wherein'the cam surfaces 58 and E52 engage each other, as illustrated in Fig. 6,the movable clamping members 48 are moved toward the normally stationary clamping members All for the purpose of clamping the end turns of a coil spring Ill therebetween. In the event that movement of the movable clamping member 48 toward the clamping member d? is impeded, as, for example, a knot l3 inadvertently being interposed therebetween, the cam 59 backs away from the ring 6% against the action of the spring t3. Accordingly, the spring acts as a strain release for the cam 59 to prevent breakage of the parts under these conditions.

As illustrated in more detail in Figs. 5 and 13 to 15, the upper ends of each clamping member 41 and A8 are provided with transverse recesses 68 and the extending portions of the clamping membersare provided with holes 69. The recesses 68 each receive an angular electrical insulating member 10 which is also provided with holes ii and a flared extension 12. In turn, each angular electrical insulating member it! carries an electrode 13 having tapped holes "M and a flared extension 15. Bolts 8G, electrically insulated by suitable electrical insulating sleeves 8i extend through the'holes 69 and H into the tapped holes 14 in the electrode F3 for securing the electrode 13 to, the clamping member 4'! and at the same time electrically insulating the same from the clamping member. One of the electrodes "it, as illustrated in Fig. 5, or more of the electrodes if so desired, may be recessed at it for receiving an angular insulating member 1 and an angular metallic wear plate '59, which in turn are provided with holes '53 for receiving the screws for holding the same in place. These angular electrically insulating members If and wear plates 19 overlie the electrodes '13 in order to prevent an inner convolution I of the coil spring it from contacting the electrodes, as illustrated in Figs.

5 and'll. This prevents any arcing at this point which would weaken the coil spring and which would also interfere with the proper heat treatment of the same. Since, in the operation of this particular form of the heat treating mechanism, the inner convolutions of the coil springs might engage the electrodes 13 at only one point, as illustrated in Figs. 5, 11 and 12, only one of the electrodes i3 is provided with the overlying electrical insulating member. Of course, if desired, the other electrode 13 may also be provided with this feature.

The flared ends '15 of the electrodes 73 are for the purpose of facilitating the insertion of the end turns of the coil springs between the two pairsof clamping members 4'? and 48. Electrical connection is made to the opposite extending ehds'of the electrodes l3. Here a flexible electrical conducting strip-83 is secured to the ends of the electrodes T3 of each pair of clamping members by means of screws 84 entering tapped holes 85- in the electrodes. Thus the electrodes of each pair of clamping members are electrically connected together and electrical energy may be suitably applied thereto by suitable connectors 86 held in place by the screws 84.

The two pairs of clamping members 41. and :48. extend downwardly below the rotatable cam shaft 33, the normally stationary clamping members 47 being wider than the movable clamping members Q8. The normally stationary clamping members 41' are normally clamped between the .upwardly extending leg of the supporting base 2-6 and a bar 88, this being accomplished by a bolt 89 extending through one of the holes 28 in the supporting base and a hole in the bar 88 along with a nut 99. Thus. the bar 88, in addition to clamping the normally stationary clamping members if in desired positions, also operates to prevent rotation of the clamping members 41 as the cam shaft 33 and, hence, the sleeye 45 are rotated. The movable clamping members 38 being narrower than the normally stationary clamping members 47 are not clamped torthe supporting base 26 so that these clamping :members 43 may be moved toward and away from the normally stationary clamping members 41. However, the bar 88, cooperating with the supporting base 26, does hold the movable clamping members 38 against rotation as the cam shaft 33 and, hence, the sleeve 45 are rotated. By loosening the bolt iia the stationary clamping members 4'! may be adjusted to desired positions along the cam shaft 33 for accommodating any desired length of coil spring H]. When the normally stationary clamping members 47 are thus moved to the desired positions, the. sleeves 45 and the other parts carried thereby are correspondingly moved. When the desired adjustment is obtained, then the bolt 89 is tightenedto maintain this desired relationship. The plurality of holes 23 in the supporting base-25 permit positioning of the clamping members substantially anywhere along the cam shaft 33. To accommodate coil springs of different diameters the cam shaft 33 and, hence, the clamping members carried thereby may be vertically raised or lowered by manipulation'of the bearing blocks 39. To adjust the pressure at which the clamping members ll and d3 clamp the end turns of the 5 coil springs, all that is necessary is to adjust the positions of the collars 52 and 53. The adjustment should be such that the electrodes 13 bite firmly the end turns 12 of the coil springs.

The cam shaft 33 adjustably carries for rotation therewith a cam having a pair of diametrically opposed cam surfaces 91, the cam 95 being secured to the cam shaft by a set screw 95. A conventional normally open electric switch 98 is secured underneath the cam 95 to the adjacent bearing block it by means of screws 9|. This normally open switch $8 is provided with a plunger act in turn carrying a cam follower illl which is operated by the cam surfacess'i on the cam 95. Thus, when the cam shaft 33 and, hence, the cam 95 are rotated, the cam surface 81 engages the cam follower ltd momentarily to close the switch 98. The cam 95 is so positioned on the cam shaft 33 that the switch 98 is momentarily closed only after the clamping members 6? and 43 have securely clamped the nd turns 12 of the coil spring to be heat treated. The switch 98 is provided with a suitable conduitconnector N12 for accommodating the lead wires thereof.

The end of the cam shaft 33 also carries another cam I05 having a pair of diametrically opposed cam surfaces Hit, the cam being .adjusta-bly secured to the cam shaft 33 by a set screw, not shown. Rotatably mounted on the cam shaft 33 between the cam Hi5 and the bearing block 30 is a switch supporting plate III'I having a lower outwardly extending portion I38 which carries a normally closed electric switch I09. The switch its is provided with a plunger III) which in turn carries a cam follower III to be engaged by the cam surfaces 33 as the cam shaft 33 is rotated. When a cam surface I33 engages the cam follower III the switch I39 is momentarily opened. The switch I09 is also provided with a suitable conduit connector II2 for accommodating the switch leads. The switch supporting plate It! is also provided with an upper outwardly extending portion its to which is secured a handle H3. By moving the handle H5 the plate iill and the switch I03 are correspondingly moved about the axis of the cam shaft 33 so that the switch I39 may be momentarily opened at various points in the rotation of the cam shaft 33, depending upon the adjustment of the switch carrying plate I37. Thus, the time at which the switch I33 is momentarily opened with respect to the time at which the switch 93 is momentarily closed may be adjusted at will by manipulation of the handle H5. The switch carrying plate it? is provided with an arcuate slot II6 which is concentric with the axis of rotation of the cam shaft 33.

overlying the switch carrying plate It! is a plate II8 having a lower inwardly extending portion I i 3 which is secured to the bearing block 33 by screws 23. The upper end of this plate H8 is provided with indicia Ifii cooperating with a suitable marker on the upwardly extending portion IIfil of the switch carrying plate iii! to indicate the interval of time between the closing of the normally opened switch 33 and the opening of the normally closed switch The top of the bearing block 30 has a bracket I22 secured thereto by screws I23 and a screw its is staked thereto. This screw 524 extends through the arcuate slot H3 and through a hole in the outer plate H3. A. wing nut E25 carried :by the screw I24 clamps the switch carrying plate Iil'I in adjusted position between the bracket I22 and the plate II8.

Electrical energy is applied to the clamping members 31 and 43 and, hence, to the coil spring clamped thereby by means of a low voltage high current transformer which is designated generally at 533 in Fig. 4. This transformer is of conventional construction and has a primary I3I and a secondary i322, the secondary I32 being connected by suitable leads I33 to the connectors 33 carried by the electrodes 73. Electrical energy is supplied to the primary of the transformer means of conductors I33 and I35 leading from some source of power not shown. The application of electrical energy to the primary i3I of the transformer 533 is controlled by a relay having an operating coil 533 for operating switches I3'i, I33 and iii When the relay coil E33 is energized the switches I31, I33 and E33 are closed and when the relay coil I36 is deenergized these switches are opened. The switches I3! and A33 control the application of electrical energy to the transformer primary i3i so that when the relay is energized, electrical energy is applied to the transformer and when it is deenergized the application of electrical energy is interrupted. The switch I33 of the relay operates to complete a maintaining circuit for the relay.

The relay winding I 33 is controlled by the normally opened switch 93 and the normally closed switch Hi3 operated by the cam shaft 33.

Fill

It may also be controlled by a switch MI and a. start and stop switch I42. The switches I II, I42, 139 and 98 are connected in series with the relay coil 36 and the relay switch I39 is connected in shunt with the normally opened switch 93. In order to energize the relay coil I33 the switches MI, I42, I09 and 98 must be closed and the relay may be maintained energized through the switches I II, I42, I03 and I39 independently of the switch 98 until switch I09 or switches I4! and I42 are opened.

Assuming that the switches MI and I42 are closed and that the coil spring producing machine is in operation with a coil spring to be heat treated moved between the clamping members 47 and 48 and securely clamped therebetween, the normally opened switch 98 is thereafter closed to complete a circuit from the conductor I through switches I Il, I42, I39, 98 and relay coil I33 to the conductor I 34. This energizes the relay coil I33 for closing the switches I31, I38 and E39. Closure of the switches I31 and I38 applies electrical energy to the transformer I30 and, hence, causes electrical current to course the coil spring II) for heat treating the same. Closure of the switch i539 upon energization of the relay coil I36 completes a maintaining circuit for the relay coil I36 independent of the switch 33 so that when the switch 98 opens the relay coil remains energized. Upon further rotation of the ca .1 shaft 33 the normally closed switch its is opened at a point in the cycle depending upon the adjustment of that switch with respect to the cam shaft 33. Upon opening of this switch I09 the maintaining circuit to the relay coil I33 is broken and the relay becom tie-energized for opening the switches I31, and Opening the switches I31 and I38 interrupts the application of electrical energy to the coil spring i0 being heat treated. Opening of the switch I35 of the relay prevents the relay from again being energized until such time as the normally opened switch 93 is closed during the next cycle of operation. Thus electrical energy is applied to each coil spring clamped between the clamping members 4'! and S8 and the interval of time at which the electrical energy is so applied is dependent upon the adjustment of the normally closed switch I09. In all instances electrical energy is applied to the electrodes 13 only when the end turns of the coil spring I2 are securely clamped by the clamping members 4'! and 48. By adjusting the normally closed switch :139 the amount of heat treatment appliled to each coil spring may be regulated at w1 An indicating lamp I44 may be connected across the conductors I34 and I35 to indicate that the heat treating mechanism is in condition for operation and an indicating lamp I may be connected across the primary I3! of the transformer I33 for indicating the period of application of electrical energy to the coil spring being heat treated.

The switch ii in series with the relay coil I36 is operated by the clutch mechanism of the coil spring producing machine I5 so that the relay may be energized and electrical energy applied to the electrodes of the clamping members only when the coil spring producing machine is in operation. This effectively automatically prevents application of electrical energy to a coil spring when the coil spring producing machine is shut down. The start and stop switch I42 is conveniently located on the coil spring pro- 9. ducing machine l 5 so that the application of electrical energy through the electrodes of the heat treating mechanism may be interrupted at the will of the machine operator.

While for purposes of illustration one form of this invention been disclosed, other forms thereof may become apparent to those skilled in the art upon reference to this disclosure and, therefore, this invention is to be limited only by the scope or" the appended claims.

We claim as our invention:

1. A lieate' mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member and a clamping member movable toward and away from -,;1e normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contasting the other end turn of the coil spring and including a normally stationary clamping member and a clamping member movable toward and away from the normally stationary clamping member, and a pair of cam means carried and rotated by the shaft for engaging and. moving the movable clamping members of the two pairs of clamping members.

2. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the base, a pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including normally stationary clamping mem ber and a clamping member movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member and a member movable toward and away from the normally stationary clamping member, a pair of cam means carried and rotated by the shaft engaging and moving the movable clamping members of the two pairs of clamping for applying electrical energy to two pairs of clamping members electrical-- ly to heat the coil spring clamped thereby, control means for controlling said last men tioned 5 including switch and cam means ca: led rotated by the shaft for oper ating the itch means to apply electrical energy to the two pairs or" clamping members only when the coil spring is clamped thereby.

3. A heater mechanism for heat treating coil springs comprising, a supporting base, a rotatably mounted on the base, a first pair or clamping members fixedly mounted at one position along the ior clamping and electrically contacting one end turn of a coil spring including a normally stationary clamping mema clamping member movable toward and the normally stationary clamping a second pair of clamping members :lly in. nnted at another position along the "t for clamping and electrically contacting the other end turn of the coil spring and inclutb normally stationary clamping member a clamping member movable toward and away from the normally-stationary clam-ping member,

10 a pair of cam means carried andoperated by the shaft for engaging and. moving the movable clamping members of the two pairs of clamping members, means for applying electrical energy to the two pairs of clamping members electrically to heat treat the coil spring clamped thereby, and control means for controlling said last mentioned means including switch means and means carried and rotated by the shaft for operating the switch means to apply electrical energy to the two pairs of clamping members only when the coil spring is clamped thereby, said control means being adjustable to regulate the time in- "erval during which electrical energy is applied to the two pairs of clamping members.

A heater mechanism for heat treating coil s1. .ings comprising, a supporting base, a shaft rotatably mounted on the base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member and a clamping member movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted-at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member and a clamping member movabletoward and away from the normally stationary clamping member, a pair of cam means carried and operated by the shaft for engaging and moving the movable clamping members of the two pairs of clamping members, means for applying electrical energy to the two pairs of clamping members electrical ly to heat treat the coil spring clamped thereby, and control means for controlling said last mentioned means including a relay, a first cam operated switch operated-bythe shaft for energizing the relay and a second cam operated switch operated by the shaft for deenergizing the relay to apply electrical energy to the two pairs of clamping members only when the coil spring is clamped thereby, one of said cam operated switches being adjustable to regulate the time interval during which the relay is energized and electrical energy is applied to the two pairs of clamping members.

5. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the base, a first pair of clamping members fixedly mounted at one position along the shaft having facing insulated electrodes for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member and a clamping member movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft having facing insulated electrodes for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member and a clamping member movable toward and away from the normally stationary clamping member, and a pair of cam means carried and rotated by the shaft for en" gaging and moving the movable clamping members of the two pairs of clamping members.

6. A heater mechanism for heat treating coil comprising, a supporting base, a shaft rotatably mounted on the base, a first pair of clamping members fixedly mounted at one position along t e shaft having facing insulated elecll trodes for clamping and electrically contacting one end turn of a coil spring and including a normally-stationary clamping member and a clamping member movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft having facing insulated electrodes for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member and a clamping member movable toward and away from the normally stationary clamping member, a pair of cam means carried and operated by the shaft for engaging and moving the movable clamping members of the two pairs of clamping members, and insulating means overlying the edges of at least one of the electrodes of the clamping members to prevent intermediate turns of the coil. spring from electrically contacting the electrodes.

7. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on. the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and e1ectrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried by the shaft and. a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, means for holding all of the clamping members against rotation with the shaft, and a pair of cams carried by the shaft and rotatable therewith and engaging the movable clamping members of the two pairs of clamping members for moving the same with respect to the normally stationary clamping members.

8. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a first pair of clamping members at one position along the shaft for clar ing and electrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and. movable toward and away from the normally stationary clamping member, a second pair of clamping members at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried by the shaft and a clamping member oarri :l by the shaft and movable toward and away from the normally stationary clamping member, means for bold" ing all of the clamping members against rotation with the shaft, springs interposed between the normally stationary and movable clamping members of each pair of clamping members for normally separating the pair of cams carried by the shaft rotatable therewith and engaging the movable clamping members of the two pairs of clamping members for moving the same toward the normally stationary clamp ing members against the action of the springs.

9. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and mov able toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, means for adjustably positioning the normally stationary clamping members of the two pairs of clamping members along the shaft and holding the same against rotation. with the shaft, means for holding the movable clamping members of the two pairs of clamping members against rotation with the shaft, and a pair of cams carried by the shaft and rotatable therewith and engaging the movable clamping members of the two pairs of clamping members for moving the same with respect to the normally stationary clamping members.

10. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, means for adjustably positioning the normally stationary clamping members of the two pairs of clamping members along the shaft and holding the same against rotation with the shaft, means for holding the movable clamping members of the two pairs of clampin members against rotation with the shaft, springs interposed between the normally stationary and movable clamping members of each pair of clamping members for normally separating the same, and a pair of cams carried by the shaft and rotatable therewith and engaging the movable clamping members of the two pairs of clamping members for moving the same toward the normally stationary clamping members against the action of the springs.

11. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft ro tatably mounted on the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and morable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically con- 13 tactin'g ithe other 'end' turn of the coil spring and including a normally stationary clamping member carried bythe shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, means for adjustably positioning the shaft with respect to the supporting base, 'means for adjustably' positioning the clamping members of the two pairs of clamping memhere along the shaft and for holding the same against rotation with'the shaft, and a :pair of cams carried by the shaft and rotatable therewith and adjustable therealong and engaging the movable clamping members of the two pairs of clamping members for moving the same'with respect to the normally stationary clamping members.

12. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and includinga normally stationary clamping member carried by the shaft and a clamping member carr'ied'by the shaft and movable toward and awayfrom the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried, by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, means for holding all of the clamping members against rotation with the shaft, springs interposed between the normally stationary and movable clamping members of each pair of clamping members for normally separating the same, a pair of cams carried by the shaft and rotatable therewith. and engaging the movable clamping members of the two pairs of clamping members for moving the same toward the normally stationary clamping members against the action of the springs, and means including spring means for permitting movement of cams away from their respective normally stationary clamping members in the event that movement of the movable clamping members toward their respective normally stationary clamping members is impeded.

13. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a pair of sleeves slidable on the shaft and keyed to the shaft for rotation therewith, a first pair of clamping members for clamping and electrically contacting one end. turn of a coil spring i cluding a normally stationary clamping member rotatably and slidably carried by one of the sleeves and a clamping member rotatably and slidably carried by said sleeve and movable toward and away from the normally stationary clamping member, a second pair of clamping members for clamping and electrically contacting the other end turn of the coil spring and ineluding a normally stationary clamping member rotatably and slidably carried by the other sleeve and a clamping member rotatably andslidably carried. by said last mentioned sleeve movable toward and away from the normally stationa-ry clamping member, a-collar adj secured to each sleeve for limiting lengtwie movement of the normally stationary clamping members carried thereby, springs located between the normally stationary and the movable clamping members of the two pairs of clamping members for normally separating the same, a cam slidably carried by each sleeve keyed thereto for rotation therewith for engaging the movable clamping members to move the same toward the normally stationary clamping members against the action of the springs, a second collar adjustably secured to each sleeve, a spring located between each said second collar and its associatedcam for permitting movement of the cams away from their respective normally stationary clamping lembers on the event that movement of the movable clamping members toward their respective normally stationary clamping members is impeded, means for adjustably positioning the sleeves and the elements carried thereby along the shaft and for securing the normally stationary clamping members in adjusted position to the supporting base and for holding the normally stationary clamping members against rotation with the shaft and sleeves, and means for holding the movable clamping members against rotation with the shaft and sleeves.

14. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, a second pair of clamping members fixedly mounted at another position along the shaft for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally stationary clamping member, means for holding all of the clamping members against rotation with the shaft, a pair of cams carried by the shaft and rotatable therewith and engaging the movable clamping members of the two pairs of clamping members for moving the same with respect to the normally stationary clamping members, means for applying electrical energy to the two pa'rs of clamping members electrically to heat treat the coil spring clamped thereby, and control means for controlling said last mentioned means including switch means and cam means carried and ro tated by the shaft for operating the switch to apply electrical energy to the two pairs of clamping members only when the coil spring is clamped thereby.

15. A heater mechanism for heat treating coil springs comprising, a supporting a ro'tata'bly mounted on the supporting base, a first pair of clamping members fixedly mounted at one position along the shaft for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and mow able toward and away from the normally tionary clamping member, a cond p of clamping members fixedly mounted at another position along the shaft for clamping electrically contacting the other end turn of the coil spring and including a normally stationary clamping member carried by the shaft and a clamping member carried by the shaft and movable toward and away from the normally tionary clamping member, means for ho ol g all of the clamping members against rotation with the shaft, a pair of cams carried by the t and rotatable therewith and engaging the movable clamping members of the two pairs of clamping members for moving the same with respect to the normally stationary clamping members, means including a relay, a first cam operated switch operated by the shaft for energizing the r and a second cam operated switch. operated by the shaft for deenergizing the relay to apply electrical energy to the two pairs of clamping members only when the coil spring is clamped thereby, one of said cam operated switches being adjustable to regulate the time interval c which the relay is energized and electrical ergy is applied to the two pairs of clan 1pm: members.

16. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a pair of sleeves slidable on the shaft and keyed to the shaft for rotation therewith, a first pair of clamping members for clamping and electrically contacting one end turn of a coil spring and includ ing a normally stationary clamping member rotatably and slidably carried by one of the sleeves and a clamping member rotatably and slidably carried by said sleeve and movable toward and away from the normally stationary clamping member, a second pair of clamping members for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member rotatably and slidably carried by the other sleeve and a clamping member rotatably and slidably carried by said last mentioned sleeve and movable toward and away from the normally stationary clamping member, a collar adjustably secured to each sleeve for limiting lengthwise movement or" the normally stationary clamping members carried thereby, springs located between the normally stationary and the movable clamping members of the two pairs of clamping members for normally separating the same, a cam slidably carried by each sleeve and keyed thereto for rotation therewith for engaging the movable clamping members to move the same toward the normally stationary clamping members against the action of the springs, a second collar adjustably secured to each sleeve, a spring located between each said second collar and its associated cam for permitting movement of the cams away from their respective normally stationary clamping members I in the event that movement of the movable clamping members toward their respective normally stationary clamping members is impeded, means for adjustably positioning the sleeves and the elements carried thereby along the shaft and for securing the normally stationary clamping members in adjusted position to the supporting base and for holding the normally stationary clamping members against rotation with the shaft and sleeves, means for holding the movable clamping members against rotation with the shaft and sleeves, means for applying electrical energy to the two pairs of clamping members electrically to heat treat the coil spring clamped thereby, and control means for controlling said last mentioned means including switch means and cam means carried and operated by the shaft for operating the switch means to apply electrical energy to the two pairs of clamping members only when the coil spring is clamped thereby.

1'3. A heater mechanism for heat treating coil springs comprising, a supporting base, a shaft rotatably mounted on the supporting base, a pair of sleeves slidable on the shaft and keyed to the shaft for rotation therewith, a first pair of clamping members for clamping and electrically contacting one end turn of a coil spring and including a normally stationary clamping member rotatably and slidably carried by one of the sleeves and a clamping member rotatably and siiclably carried by said sleeve and movable toward and away from the normally stationary clamping member, a second pair of clamping members for clamping and electrically contacting the other end turn of the coil spring and including a normally stationary clamping member rotatably and slidably carried by the other sleeve and a clamping member rotatably and slidably carried by said last mentioned sleeve and movable toward and away from the normally stationary clamping member, a collar adjustably secured to each sleeve for limiting lengthwise movement of the normally stationary clamping members carried thereby, springs located between the normally stationary and the movable clamping members of the two pairs of clamping members for normally separating the same, a cam slidably carried by each sleeve and keyed thereto for rotation therewith for engagthe movable clamping members to move the same toward the normally stationary clamping members against the action of the springs, a second collar adjustably secured to each sleeve, a spring located between each said second collar and its associated cam for permitting movement of the cams away from their respective normally stationary clamping members in the event that movement of the movable clamping members toward their respective normally stationary clamping members is impeded, means for adjustably positioning the sleeves and the elements carried thereby along the shaft and for securing the normally stationary clamping members in adjusted position to the supporting base and for holding the normally stationary clamping members against rotation with the shaft and sleeves, means for holding the movable clamping mem bers against rotation with the shaft and sleeves, means including a relay, a first cam operated switch operated by the shaft for energizing the relay and a, second cam operated switch operated by the shaft for deenergizing the relay to apply electrical energy to the two pairs of clamping members only when the coil spring is clamped thereby, one of said cam operated switches being adjustable to regulate the time interval during which the relay is energized and electrical energy is applied to the two pairs of clamping members.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,105,105 Zimmerman Jan. 11, 1938 2,116,327 Simmons May 3, 1938 2,124,329 Zimmerman l July 19, 1938 2,254,525 Hathaway et a1 Sept. 2, 1941 2,261,878 Hathaway Nov. 4, 1941 2,443,386 Waldie June 15, 1948 2,574,606 Willenborg Nov. 13, 1951

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