US3402584A - Spring coiling machine - Google Patents

Description

Sept- 24, 1968 E. v. CAVAGNERO 3,402,584

SPRING COILING MACHINE Filed July 29, 1965 7 Sheets-Sheet 1 [rman l d'auynero p 24, 1963 E. v. CAVAGNERO 3,402,584

SPRING oo ILINc; MACHINE 7 Sheets-Sheet 2 Filed July 29, 1965 p 1968 E. v. CAVAGNERO 3,402,584

SPRING COILING MACHINE Filed July 29, 1965 7 Sheets-Sheet 5 Sept. 24, 1968 Filed July 29, 1965 E. V. CAVAGNERO SPRING COILING MACHINE '7 Sheets-Sheet 4 p 24, 1963 a. v. CAVAGNERO 3,402,584

SPRING COILING MACHINE Filed July 29, 1965 7 Sheets-Sheet 5 p 4, 1968 E. v. CAVAGNERO SPRING COILING MACHINE '7 Sheets-Sheet 6 Filed July 29, 1965 Sept. 1968 E. v. CAVAGNERO 3,402,584

SPRING COILING MACHINE Filed July 29, 1965 7 Sheets-Sheet '7 United States Patent 3,402,584 SPRING CQILING MACHENE Erman V. (lavagnero, Torrington, Conm, assignor to The Torrington Manufacturing Company, Torrington, (Torin, a corporation of Connecticut Filed July 29, 1965, Ser. No. 475,721 24 Qlairns. (Cl. 72137) ABSTRACT OF THE DECLOSURE Spring coiling machines with separate and independent coiling and pitching tools for non-twist spring coiling, the coiling tool having a relatively flat wire engaging surface which does not influence pitch and first and second pitch tools provided respectively on opposite sides of the coiling tool; or, a pitch tool on one side of the coiling tool and a recoil tool on an opposite side.

The invention relates to an improved spring coiling machine of the type adapted for intermittently feeding predetermined lengths of wire, the said lengths of wire being coiled during feeding to form springs and the wire being cut off on the completion of feeding and coiling. While not necessarily so limited, the invention is particularly applicable to spring coiling machines of the type shown in Patent No. 2,119,002 issued May 31, 1938, to Bergevin and Nigro, Patent No. 2,455,863 issued Dec. 7, 1948, to E. W. Halvorsen and Patent No. 2,820,505 issued Jan. 21, 1958, to E. E. Franks et al.

More particularly, the invention relates to improved tooling in spring coiling machines of the type mentioned wherein the wire is fed against a coiling abutment or coiling tool which cooperates with an arbor for coiling of a spring about the arbor. At least one pitch tool is also provided in conventionally tooled coiling machines of the type mentioned and such tool engages the wire to pitch or separate the individual coils or convolutions of the spring during formation of the spring.

Conventional tooling of the type mentioned has been generally satisfactory over many years of use, but certain disadvantages have been encountered. A detrimental intermixture of coiling and pitching functions occurs in that a grooved coiling tool is conventionally employed and the wire is urged against one side or the other of the groove by a pitch reaction force during coiling. As the coiling tool and/or the pitch tool may be moved gradually and progressively during formation of a spring, there may be a further intermixture of control functions and accuracy in control is adversely affected. Still further, and particularly with regard to open springs, there is a significant problem of twisting of the wire during formation of a spring. This is particularly true when a substantial space exists between the coiling tool and the pitch tool and twisting of the wire may occur all the way back to the feed rolls.

Diificulties in controlling pitch and diameter accurately of course result in springs which depart from the rather severe tolerance requirements often encountered in present day practice. Twisting of the wire also has an adverse effect in maintaining close control over tolerances in the formation of springs and a further detrimental result arises in relatively low fatigue strength of springs having substantial twist. That is, springs formed with very low twist characteristics, or substantially without twist, have been found to exhibit substantially higher fatigue strength than springs formed with conventional tooling.

It is the general object of the present invention to provide improved coiling and pitching tooling so as to provide for the formation of springs with a higher degree of accuracy in both diameter and pitch control than has heretofore been obtainable and with a substantial reduction and even complete elimination of twisting of the wire during spring formation.

A further object of the invention resides in the provision of coiling and pitch tools wherein the coiling and pitching functions are kept wholly separate and independent of each other with a resulting substantial improvement in the ability to control precisely both spring diameter and pitch.

A still further object of the invention resides in the provision of coiling and pitch tools wherein a recoil feature is provided such that the wire is subjected to a slight reverse bend after initial bending by a coiling tool, still further improvement in accuracy being thus achieved.

A still further object of the invention resides in the provision of a combination recoil tool and shearing edge, the latter being usable with a conventional cut-off tool.

A still further object resides in the provision of a recoil tool in combination with a cooling tool and an arbor which engages a spring during formation thereof, the coiling tool having an associated means which operates the same to effect a slight modification in coil diameter at an end portion of a taper spring.

A still further object of the invention resides in the provision of pre-cast units which can be employed for trimming with a particular tool setup, the pre-cast units serving to straighten wire which may have a very slight bend or cast or, alternatively, to effect a very slight bend or cast as required in a trimming function.

The drawings show preferred embodiments of the invention and such embodiments will be described, but it will be understood that various changes may be made from the construction disclosed, and that the drawings and description are not to be construed as defining or limiting the scope of the invention, the claims forming a part of this specification being relied upon for that purpose.

Of the drawings:

FIG. 1 is an enlarged view of an improved spring coiling machine constructed in accordance with the present invention.

FIG. 2 is an enlarged fragmentary elevational view showing the various tools operable on wire for coiling the same into a spring.

FIG. 3 is an enlarged horizontal section taken generally as indicated at 3-3 in FIG. 2.

FIG. 4 is a somewhat schematic vertical sectional view showing operating means for a coiling tool.

FIG. 5 is a somewhat schematic vertical sectional view showing operating means for a pitch tool.

FIG. 6 is a fragmentary vertical section taken generally as indicated at 66 in FIG. 5.

FIG. 7 is a schematic illustration showing a spring coiling machine forming a second embodiment of the present invention.

FIG. 8 is a vertical section taken generally as indicated at 8-3 in FIG. 7.

FIG. 9 is a vertical section taken along a central plane in FIG. 7.

FIG. 10 is a horizontal section taken generally as indicated at Iii-10 in FTG. 7.

FIG. 11 is a schematic illustration showing a spring coiling machine forming a third embodiment of the present invention.

FIG. 12 is a schematic illustration showing a spring coiling machine forming a fourth embodiment of the present invention.

General organization Referring particularly to FIG. 1, it will be observed that an improved spring coiling machine illustrated generally at 10 comprises a frame means 12 supporting tooling and general operating and drive elements in the machine. Power may be supplied for operating the machine as by means of an electric motor 14 connected by means of a pulley 16 and a belt 18 with power transmitting means within the frame means 12. Such power transmitting means may be similar to or identical with those set forth in the above patents and need not be described in detail herein. Supply wire 29 moves from right to left through straighteners 22, 22 which may be of conventional design and enters a suitable passageway between a first pair of upper and lower feed rolls 24, 26. The feed rolls 2- 26 are driven in the directions indicated intermittently so as to advance the wire 24) leftwardly to a second pair of upper and lower feed rolls 28, 3a which in turn advance the wire to a quill 32. Handwheel adjustin means are provided at 34, 34 for the two pairs of feed rolls 24, 26 and 28, 30.

As best illustrated in FIGS. 2 and 3, the quill 32 is located immediately adjacent an arbor indicated generally at 36. A coiling tool is indicated generally at 38 and cooperates with the arbor 36 to coil wire about the arbor as it is advanced by the feed means comprising the aforementioned feed rolls. At least one pitch tool is also provided and a first pitch tool is indicated generally at 40 at a lower position beneath the arbor 36 for cooperation with a second pitch tool indicated generally at 42. The pitch tool 42 is located above the arbor 36. As mentioned, and as will be described more fully hereinbelow, the pitch tools 46 and 42 serve to separate the spring coils or convolutions or to pitch the same while the coiling tool 38 serves to control the diameter of the coils or convolutions.

The machine of the present invention also includes a recoil tool 44 which cooperates with the arbor 36 and with the coiling tool 33 and which also includes a shearing edge 46 for cooperation with a cut-off tool indicated generally at 48. As will be apparent, the cut-off tool 48 can be operated in timed relation with the feed rolls 24, 26 and 28, 30 so as to swing arcuately downwardly and sever the wire 20 at the completion of forming of each spring.

Mechanism for arcuately swinging the cut-off tool 48 will be described hereinbelow together with mechanism for moving the coiling tool 38 toward and away from the wire 20 and mechanism for moving at least one of the pitch tools forwardly and rearwardly during the formation of a spring. Still further, a means is preferably provided for rotating the quill 32 about its axis as a spring is formed. Such means will be described hereinafter.

For convenience in description hereinbelow in the specification and in the claims, terms such as forwardly, horizontal, vertical, longitudinal and lateral are employed but it is to be understood that such terms in no way limit the scope of the present invention. Thus the wire 28 may be described as being advanced horizontally and longitudinally, the arbor 36 can be said to extend laterally and generally horizontally, and it will be observed that the wire 20 is bent laterally and generally vertically upwardly in FIG. 2 in forming a coil spring. Still further, the wire 20 is bent generally laterally by the pitch tool 42 as best shown in FIG. 3. All of the said directions may be readily altered or changed within the sco e of the invention.

Quill and operating means therefor The quill 32 comprises an anti-twist means which restrains the wire 20 against twisting or rotation about its longitudinal axis. The wire 20 shown has a substantially square cross section and the quill 32 is provided with a longitudinally extending passage 50 of similar cross section. The passageway 50 has a discharge end 52 which is disposed immediately adjacent the arbor 36 in as closely spaced relationship as reasonably possible. The closely spaced relationship of the discharge end 52 of the quill 32 and the arbor 36 has an important bearing in the substantial reduction and elimination of twist. Whereas the wire 20 might otherwise tend to twist about its longitudinal axis back toward the feed rolls 24, 26 and 28, 30, the

d quill 32 restrains the wire against such twisting action as desired.

As best shown in FIG. 3, the quill 32 has a laterally extending rear portion or arm 54- disposed adjacent a bracket 56 provided with a suitable opening 60 for receiving a forward portion of the quill. The quill is rotatably received within the opening 69 and the arm 54 carries a pivot pin 62 which is received by a bifurcated member 64. The bifurcated member 64 connects with a rod 66 which extends downwardly to a pivot link 68, best shown in FIG. 1. The link 68 is pivotally connected at 7!) with a lower connecting element 72 mounted on the rod 66 so as to move the rod 66 upwardly and downwardly whereby to rotate the quill 32 about its longitudinal axis and to slightly twist a wire such as 20.

A bifurcated member 74 which carries upper and lower cam followers 76 and 73 respectively on upper and lower arms pivots about a pin 80 held by a bracket 82, whereby to pivot the aforementioned link 68. A cam 80 is mounted on and rotated by a suitable cam shaft 82 for operation of the quill 32 in timed relationship with the feed rolls 24, 26 and 28, 3%). As shown, the upper cam follower 76 is operative while the lower follower 78 is held in an inoperative position by means of a bias spring 84. Alternatively, the bias spring 84 may be connected by means of pins 86 and 90 to the upper arm of the bifurcated element 74 whereby to render the lower cam follower 78 operative and to render the upper follower 76 inoperative. Thus, convenient change-over is provided whereby the quill 32 can be rotated in one or an opposite direction in the formation of various types of springs.

As will be apparent, the quill 32 and the means for operating the same can be employed in order to substantially reduce and even completely to eliminate twist and the said elements can also serve to introduce and/or control twist in the wire of a coil spring.

Arbor The aforementioned arbor 36 has a cylindrical base portion 92 formed integrally with a rearwardly extending eccentric 94. The eccentric 94 is received in a suitable opening in a tool mounting element 96 and is secured in position by suitable binder screw 98. Thus, the eccentric 94 may be secured in a selected angular position within its opening in the element 36 whereby to adjust the position of the arbor 92. A forwardly projecting portion 100 on the arbor 92 carries a surface 192 which engages the wire 20 at its inner surface as it is formed into a coil about the arbor. Thus, the position of the surface 102 may be adjusted by rotating the eccentric 94 and securing the same at a selected angular position.

As mentioned, a recoil tool 44 is also provided and in the presently preferred form of the invention shown in FIGS. 1 to 6, the tool 44 is mounted upon the arbor 36. A transverse slot is provided in the arbor at 164 and the tool 44 is mounted therein for slidable movement beneath a hold-down bar 1%. Binder screws 1%, 108 pass through the hold-down bar and secure the recoil tool 44 in adjusted position. An adjusting screw 169 is preferably provided adjacent an end portion of the tool 44 whereby precisely to adjust the position thereof toward and away from the wire 20.

As shown, the recoil tool 4-4 has a wire engaging surface 110 which is curved gradually toward the aforesaid shearing edge 46. The shearing edge 46, formed at the outer terminus of the gradually curved surface 110, is adapted to cooperate with the cut-off tool 48 as previously mentioned.

Coiling tool and operating means therefor In accordance with the present invention, the coiling tool 38 is substantially linear or fiat in at least one direction so as to bend wire in a generally vertical and lateral direction for coiling about the arbor and yet permit free wire movement in other lateral directions. That is, in order that diameter and pitch control functions can be wholly separate and independent, it is important that the wire be free to move sideways or in said other lateral directions and that the coiling tool exert little or no influence upon the introduction of pitch to the wire. This latter function is provided wholly by the pitch tools in order to improve accuracy of control and avoid twist as mentioned above.

Preferably and as shown in FIGS. 1 to 6, the coiling tool 38 includes a coiling roller 112 which engages the wire 20 and cooperates in bending the same accurately upwardly and about the arbor 36 in engagement with the surfaces 192 and 110 whereby to coil a spring. The roller 112 is generally cylindrical and has a substantially flat peripheral surface as best illustrated in FIG. 3. Thus, the roller does not exert sideways forces, other than frictional forces, upon the wire 20 and there is little or no effect upon pitch control, the wire being free to move as necessary in the other lateral directions. A roller having a gradually curved peripheral surface is also contemplated for use within the scope of the invention, but such curvature will be so limited in degree as not to exert substantial forces on the wire restraining side-to-side or pitch introducing movements thereof.

A small shaft 114- supports the roller 112 for rotation about a horizontal axis and is mounted in turn in a rotatably adjustable holder 115 held in position by screws 117, 117 in an arm 116 which extends leftwardly therefrom and which is pivotally secured at a left-hand end portion to a pivot pin 118. The pivot pin 118 is secured at its ends in a yoke 120 and extends in a generally vertical direction so as to provide for pivotal or angular adjustments of the arm 116 in a generally horizontal plane. Horizontal adjusting screws 122 and 124 associated with the arm 116 and the yoke 120 respectively limit rearward and forward swinging movement of the arm.

The yoke 120 is in turn supported for pivotal movement at a left-hand end portion about a generally horizontal pivot pin 126. Adjustment of the yoke 120 and the arm 116 in the vertical plane may be accomplished by turning suitable upper and lower adjusting screws 128' and 130. Lock nuts 132 and 134 associated with the screws may of course be turned into engagement with adjacent stops 136 and 138 to secure the yoke 12!), the arm 116 and the coiling roller 112 in a selected vertical position.

As best illustrated in FIG. 3, the pivot pin 126 is formed integrally and projects forwardly from a slide 140 which is secured in a suitable horizontal guideway by upper and lower plates 142 and 144. Thus, the assembly comprising the slide 140, the yoke 120 and the arm 116 carrying the coiling roller 112, is slidable leftwardly and rightwardly as required for suitable adjustment of the coiling roller 112. A left-hand or away limit is established by a screw 146 engageable with a left-hand end portion of the slide 14%. Obviously, the slide 140 is urged leftwardly by engagement of a wire such as 20 with the coiling roller 112.

Left and right-hand movement of the slide 140 may also be efiected by an operating or control means in the course of formation of a spring whereby to form various types of springs having diameters which may vary from end to end. Various operating means may be used for moving the coiling roller in timed relation with the feed rollers 24, 26 and 215, 30 as a spring is formed, but a preferred means is shown in FIG. 4. Reference may be had to the aforementioned patents for more complete details in description and illustration.

The slide 140, shown in reduced scale in FIG. 4, has a rearward extension 143 of the pivot pin 126 for pivotally mounting a small link 150. The link 150 carries a pivot pin 152 at an opposite end portion which in turn extends through one end portion of a bellcrank 15 i pivotal about a pin 156. An opposite or lower arm of the bellcrank 154 is connected with a rod 158 and with a biasing spring 160. An adjusting mechanism 162 establishes the point of connection of the arm of the bellcrank 154 with the rod 158.

From the bellcrank 154 the rod 15"8 extends downwardly to one element 164 of a compound lever 166. A second element 168 of the lever 166 bears upon a longitudinally adjustable connector element 170. A mechanism 180 including a screw connected with the element 170 adjusts the position of the element along the element 164 whereby to adjust the position of the connection point bet-ween the two elements 164, 168 and thereby to adjust the mechanical advantage thereof. The element 164 is pivotally supported by an appropriate pin 174- which may be secured in the frame means 12 and the element 168 is pivotally supported at 176 and carries a cam follower at 178.

A cam 180 mounted upon and rotated by the aforementioned cam shaft 82 drives the mechanism comprising the follower 178, the elements 168, 164, the rod 158, etc. As will be apparent, downward or clockwise movement of the follower 178 will result in counterclockwise or downward movement of the rod 153, clockwise pivotal movement of the bellcrank 154 about the pin 156, and movement of the slide carrying the coiling roller 112 toward the wire 20. The biasing spring urges the slide 140, the other elements carried thereby, and the coiling roller 112 leftwardly or it can be said that the coiling roller is urged away from the wire 20 by the spring 160.

The adjusting mechanism 162 can be utilized to render the cam 180, the compound lever 166, the rod 158, etc. inoperative to move the slide 140 and the coiling roller 112. Thus, if it is desired to maintain the coiling roller in a fixed position, adjustment of the slide 141 may be effected by the aforementioned screw 146 and the mechanism 162 may be operated to render the aforementioned elements inoperative.

Adjustment of the longitudinal position of the connector element along the element 164 as effected by the adjusting means 172 can be accomplished to vary the magnitude and speed of movement of the coiling roller 112 relative to the wire 20. Obviously, provision can readily be made for the substitution of other cams for the cam 180 in order to provide the required varying diameter configurations of different types of springs.

The cam 180 shown is employed in coiling a taper or cone-shaped spring wherein the large end of the spring is coiled first and the diameter of the spring is gradually decreased as the spring is coiled. Thus, the coiling tool 112 must be moved gradually and progressively away from the wire 29 whereby to decrease the diameter of the spring. The portion of the cam 182 provides for the gradual movement of the coiling roller away from the wire for a gradually decreasing diameter of a spring as it is coiled about the arbor 36. As will be apparent, a portion of a next succeeding spring is coiled to a relatively small diameter between the surfaces 102 and 110 at the end portion of a cycle of coiling of a spring. That is, the cut-off tool 48 operates at the shearing edge 46 and leaves a portion of the wire 20 extending arcuately from the shearing edge 46 past the surface 110, the coiling roller 112 and the surface 162 back to the quill 32 as an initial portion of the first convolution of the next succeeding spring. The said portion has, however, been coiled to a smaller diameter than is required for the relatively large first convolution of the said next succeeding spring. In order to avoid inaccurate formation of the first convolution, the coiling roller 112 is urged abruptly toward and away from the spring wire 20. This serves to bend the wire toward the center of the arbor with the spaced portions of the wire in engagement with the surfaces 110 and 102 and to increase the diameter of the said portion of the wire. Thus, the said first portion of the first convolution of the next succeeding spring is provided at substantially the desired diameter and an undesirably small diameter first portion is avoided.

In providing the abrupt movement or bump of the coiling roller 112 toward and away from the spring, means comprising a sharp rise is provided on the cam 189 at 184. As will be seen, the rise 184 is arranged on the cam so as to occur after feeding and coiling and after cut-off,

the latter operation occurring approximately through the range 186 on the cam. Further, in order to provide the desired result of increasing the diameter of the said first portion of the wire, it is desirable to arrange the surfaces 110 and 102 in relation to the coiling roller 112 so that the said coiling roller is spaced approximately equidistantly from the said two surfaces.

Pitch tools and operating means therefor As mentioned, the pitch tools 4 9 and 42 are arranged on opposite sides of the coiling roller 112. Said tools have wire engaging surfaces 18-6 and 188 which are disposed on laterally opposite sides of the wire 29 as it is advanced by the feed rolls 24, 26 and 23, 30. The said surfaces 186 and 18S engage the wire and, in cooperation with each other and with the quill 32, bend the wire laterally and generally sideways whereby to introduce pitch with twisting of the wire held to a minimum. Substantially no effect on diameter control is encountered with the pitch .tools arranged as shown. It is important to note that the said pitch tools are arranged in close proximity to the coiling roller 112 and that excessive torsional moments on the wire are thus avoided. Further, the ciose proximity of the discharge end 52 of the quill 32 contributes to the introduction of pitch without twist. In accordance with the invention, the pitch tools 4t) and 42 and the coiling tool 38 are arranged in such closely spaced relationship as to engage the wire within one-half of one convolution thereof. As shown, there is approximately one-fourth of one convolution in an are extending between the wire engaging surface 186 and the wire engaging surface 188.

The pitch tool it) includes a tool element 196 which is adjustable generally toward and away from wire 20 and which has a binder screw 192 for securing the same in position. Further, the tool element 190 is adjustable generally toward and away from the coiling tool or roller 112 and a binder screw 194 is provided for securing the element in adjusted position in such direction.

The pitch tool 42 has a main body portion 1% and an angularly arranged portion 198 which projects forwardly as best illustrated in FIG. 3. The said portion 198 defines the aforesaid wire engaging surface 188 at a front end portion thereof.

Operating means for moving the pitch tool 42 during formation of a spring whereby to control or vary the pitch of a spring throughout its length may take several different forms within the scope of the invention. Pitch control and operating means of the type shown in the aforementioned patents are referred to here. In the embodiment of the invention shown, a slide 200 is provided for front to rear generally horizontal movement in a suitable guideway in the aforementioned tool holder or element 96. The pitch tool 42 is secured to a front end portion of the slide by suitable screws 262 and a drive mechanism for the slide is provided at a rear end portion in the form of a bracket 294 and a short link 2% extending to a bellcrank 268 best illustrated in FIG. 5.

The bellcrank 2&8 is pivotally connected to the link 296 and is supported for pivotal movement about a pin 210 by means of a suitable bracket 212. A pivot pin 214 connects the bellcrank 203 with a vertical rod 216 and an adjusting mechanism 218. The rod 216 extends downwardly to a compound lever 220 having elements 222 and 224. A slidable connector element 226 is mounted on the element 222 and an adjusting means 228 secures the element 226 in selected position along the length of the element 222. A pivot pin 230 connects the rod 216 with the element 222 and a pivot pin 232 provides for swinging movement of the element 222 about its right-hand end portion. A pivot pin 234 supports the element 224- which in turn carries a cam follower 236. A pitch control cam 238 is mounted upon and rotatably driven by the aforementioned cam shaft 82.

As will be apparent, rotation of the cam 238 in engagement with the follower 236 will result in pivotal move- The aforementioned cut-off tool 48 cooperates with the shearing edge 46 as mentioned and includes a tool element 242 adjustably secured in a holder 244 and provided with an adjusting screw 246. The holder 244 is mounted upon a swingable arm 248 biased upwardly or in a clockwise direction by a spring 250. The arm 248 is pivotally secured about a sleeve 252 mounted on an adjustable eccentric 2533.

A shaft 254 disposed within and supporting the eccentric 253 and the sleeve 252 is independently rotatable. The said shaft 254 carries an operating arm 256 which in turn supports an adjustable pusher element 258 and a cover plate 26%). The pusher element 258 has an arcuate end portion 262 which engages a complementary arcuate surface 264 on the aforesaid arm 24%. Thus, when the arm 256 is pivoted in a counterclockwise direction, the surfaces 262 and 264 are engaged whereby to pivot the arm 248 in a counterclockwise direction and to swing the tool holder 244 and the tool element 242 downwardly. Downward arcuate movement of the tool element 242 results in a cutting action in cooperation with the shearing edge 46 whereby the wire 20 is severed at the shearing edge and a spring is completed.

Operating means for the shaft 254 are not shown and may vary widely within the scope of the invention. Reference may be had to the aforementioned patents for full illustration and description of such operating means.

Adjustment of the eccentric 253 may be coordinated with adjustment of the arbor eccentric 94 whereby to vary the arc of movement of the tool element 242 with the position of the shearing edge 46.

Embodiment of FIGS. 7, 8, 9 and 10 In the schematic illustration of FIG. 7, there is shown a pair of feed rolls comprising an upper roll 26c and a lower roll 268. Wire 20a, of circular cross section, is advanced intermittently from right to left through a first pre-cast unit 270 and a second precast unit 272 to antitwist rolls 274. Three pairs of anti-twist rolls each comprising an upper roll 276 and a lower roll 278 are shown but the number of rolls may vary widely. Tl e rolls 276 are urged downwardly by biasing means such as springs or hydraulic cylinders or other means not shown, and the rolls 278 may be similarly urged upwardly. The peripheral surfaces of the rolls 276 and 273 are preferably grooved as shown at 28th in FIG. 8. That is, a generally V-shaped groove is provided in each of the said rolls and the wire 20a is received within the said grooves. Thus, the groove defining surfaces firmly engage the wire 20a under the urging of the aforesaid biasing means and secure the wire against rotation or twisting about the longitudinal axis of the wire.

Preferably and as shown, an arbor 282 is provided with a generally V-grooved portion at 284 on a side thereof spaced from a coiling tool 286 and arranged generally toward the feed rolls 266, 268. An additional grooved and upwardly biased anti-twist roll 288 cooperates with the grooved portion 284 of the arbor 282 and restrains the wire 29a against twisting or rotation about its longitudinal axis, immediately prior to engagement of the wire with a first pitch tool 29% Thus, the anti-twist means extends to a location in close proximity to the coiling and pitch tools. Such location of the anti-twist means contributes importantly to the reduction of twist and to the close control of diameter and pitch as mentioned previously.

The coiling tool 286 is shown schematically as comprising a roller mounted on a stub shaft 292 for rotation about a generally horizontal axis. The roller 286 preferably has a flat cylindrical surface similar to the roller 112 described above. Thus, the wire is not restrained from sideways or pitching movement by the roller 286 and the coiling and pitching functions are maintained wholly separate and independent from each other.

The first pitch tool 2% is arranged in close proximity to the coiling tool 286 and cooperates with a second pitch tool 294 and the anti-twist means comprising the grooved arbor portion 284- and the additional anti-twist roll 288 whereby to introduce pitch into a spring coiled from the wire a. As will be observed, the pitch tool 294 is also located in close proximity to the coiling tool 286 and the three tools comprising the said coiling tool and two pitch tools are arranged within the bounds of an arc which extends through one-half of one convolution of a spring coiled from the wire 20a.

With the arrangement shown in FIG. 7, the coiling and pitching functions are carried out separately and independently of each other and a high degree of accuracy can be achieved in both pitch and diameter control. Moreover, twist is reduced to a minimum and high quality springs are obtained. However, still further improvements in accuracy of control and in ease of adjustment are obtained with the pre-cast units 270 and 272. The said units serve to provide a very slight preliminary bend or cast, or to remove such slight bend or cast, and may be said to introduce a trimming function. Adjustments may be made at the coiling tool and the pitch tools, and a first supply coil of wire may be employed in producing a large number of springs. On exhaustion of the supply coil, a new supply coil may be introduced and the wire may have a slight cast in one direction or another. In such case, the pre-cast units 270 and 272 may be employed to eliminate cast. In other cases, it may be desirable in order to trim the machine to introduce cast or a slight bend. Pre-cast units 276) and 272 are equally well suited to such uses.

In FIG. 9 there is shown a vertical section of the precast unit 272 including first and second stationary elements 296 and 29S disposed on opposite sides of an adjustable element 300. Each of the elements 296, 298 and 300 is provided with a gradually curved wire engageable surface 392. The surfaces 302 are formed by walls of openings 304, 304 which may vary in cross section but which are shown as being circular for the left to right passage of the wire 20a. An adjusting means for the element 300 comprises an adjusting screw 306 entered in a suitable opening in a support member 308.

As Will be apparent, the element 360 can be adjusted vertically whereby to displace the opening 304 therein in the downward vertical direction with respect to the openings 304, 304 in the elements 296 and 298. With the element 300 so displaced, the upper surface 302 of the wall 304 in the said element engages the wire 20a and displaces the same laterally or vertically downwardly whereby to eliminate or introduce a cast or slight bend as required.

The pro-cast unit 271 best shown in FIG. 10, includes elements 306 and 368 which are fixed in position and a centrally located element 310. The element 310 is adjustable horizontally by means of a suitable adjusting screw 312 entered in a support 314. Openings 316, 316 in the elements 3%, 3G8 and 310 are preferably circular in cross section and have gradually curved surfaces 318, 318 adapted to engage the wire 20a.

As will be apparent, the pre-cast unit 270 serves to introduce or eliminate a slight bend or cast in the wire 20a in the horizontal plane. Thus, the pre-cast unit 272 may be employed as a trimming device for coiling or diameter control tools whereas the pre-cast unit 270 may be employed as a trimming device for the pitch tools and their control and adjusting means.

W Embodiment of FIG. 11

In FIG. 11 there is shown in schematic illustration a tool arrangement particularly well suited to the production of torsion springs as well as other types of springs. Wire 20b is advanced leftwardly by feed rolls 266a and 268a. Pre-cast units 270a and 272a may be identical with those described above in connection with FIG. 7. Similarly, anti-twist rolls 276a and 278a may be identical with the rolls 276 and 278 mentioned above. Still further, a grooved portion 284a of an arbor 232a cooperates with an anti-twist roll 288a in the manner of the arbor 282, the grooved arbor portion 284 and the anti-twist roll 28%. The roll 238a is, however, somewhat smaller in diameter than the aforementioned roll 288 in order to provide sufiicient space for the specific tool arrangement of FIG. 11.

In FIG. 11, a first pitch tool 290a may be substantially identical with the pitch tool 290 of FIG. 7, but it is to be observed that the pitch tool 290a is disposed substantially directly beneath the arbor 282a whereas the tool 290 is arranged angularly and leftwardly with respect to a vertical line through the center of the arbor 282. A second pitch tool 294a corresponds to the aforementioned tool 294 and is located opposite the tool 290a with respect to a coiling tool 286a.

The coiling tool 286a may vary from the aforementioned tool 286 in the provision of a fiat end surface on a rod-like tool in place of the roller of the tool 286. It is to be observed that the tool 286a has a fiat end portion so as not to restrain the wire 20a in sideways lateral movement, Thus, the coiling and pitch functions are maintained separate and independent from each other whereby to achieve the aforesaid high degree of accuracy in diameter and pitch control and to avoid twist of the wire.

A second and important distinction with regard to the coiling tool 286a resides in the location of the tool on a center line 320 which extends outwardly from the arbor 282a and which is angularly related to a center line 322 of wire feed movement in such manner that the coiling tool can be moved away from the wire and thereby clear the said center line of wire feed movement. The center line 322 in FIG. 11 will be seen to be horizontal so as to require removal of the tool 286a from a horizontal position. That is, if the tool 286a were located in a gen-: erally horizontal position as shown in FIG. 7, linear movement of the tool away from the wire would be incapable of effecting clearance of the center line of wire feed movement. Such movement is necessary in order to provide a straight end portion on a spring as is required in a torsion spring.

With the arrangement shown in FIG. 11, it is unnecessary to move the coiling tool 286a arcuately or in any complex motion and it is instead necessary merely to withdraw the tool linearly as indicated by the arrow 324. Withdrawal of the tool 286a from engagement with the wire 20b through a short distance allows a trailing edge portion of a spring to be formed linearly as required.

The specific angle at which the tool 286a is located between vertical and horizontal planes may vary substantially. As will be apparent, a compromise is reached between an optimum angle for coiling and an optimum angle for ready withdrawal of the tool from engagement with the wire. The angle of the center line 320 of the tool is spaced at least fifteen (15) degrees from both vertical and horizontal planes, or from the line of wire movement and a line perpendicular thereto, and is shown as being approximately thirty degrees (30) from the vertical.

Mechanism for withdrawing the tool 286a is not shown in FIG. 11 and may vary widely within the scope of the invention. The diameter control mechanism of the preferred embodiment of the invention shown in FIGS. 1 through 6, for example, is readily adaptable for use in withdrawing a coiling toolsuch as 286a as required in the formation of torsion springs.

Embodiment of FIG. 12

in FIG. 12 there is shown an embodiment of the invention wherein feed rolls 26612 and 26812 advance wire 26c intermittently toward the left through pre-cast units 2701) and 2725. Anti-twist rolls 27512 and 27812 restrain the wire against movement about its longitudinal axis and an arbor 28% engages the wire and cooperates with a coiling tool 236]; in coiling a wire. Pitch tools 29% and 2%!) cooperate with each other and with the antitwist rolls 2'76b and 27% to pitch the wire as it is coiled into a spring.

The feed rolls, the pre-cast unit, and the anti-twist rolls may be identical with those described above for FIG. 11. The arbor 28% is substantially the same as the arbor 232a except for the elimination of the aforesaid portion 2340. That is, the arbor 282 is circular and does not include a grooved portion for cooperation with an additional twist roll such as 288a. Accordingly, no such additional twist roll is provided.

The coiling tool 286!) is movable toward and away from the wire as indicated by an arrow 326 along a center line 3.28. The center line 328 is approximately at fortyfive degrees (45) between horizontal and vertical planes and the tool 286]) is readily adaptable to the formation of torsion springs in the manner described above.

In comparing FIGS. 11 and 12, it will be observed that the FIG. 11 embodiment of the invention has the advantage of an anti-twist means in very close proximity to the coiling and pitch tools. That is, the arbor portion 234a and the additional anti-twist roll 288a provide for restraint against twisting of the wire at a location substantially closer to the tools than in the FIG. 12 embodiment. In the FIG. 12 embodiment an advantage is found in the additional space provided for the provision of the coiling tool 2865 and the pitch tools with and 29411.

The invention claimed is:

1. In a spring coiling machine, the combination of feed means for intermittently advancing a wire in a horizontal longitudinal direction, an arbor which extends laterally and generally horizontally and which is adapted to engage wire advanced longitudinally by said feed means, a coiling tool arranged adjacent said arbor on a side thereof generally opposite said feed means to cooperate with the arbor and to coil wire thereabout, said coiling tool having a wire engaging surface which is substantially flat in at least one direction so as to bend wire in a generally vertical and lateral direction for coiling about said arbor and yet permit free wire movement in other lateral directions, and first and second pitch tools arranged on opposite sides of said coiling tool each with a wire engaging surface, said wire engaging surfaces being disposed on laterally opposite sides of wire advanced by the feed means and being arranged in close proximity to the coiling tool whereby cooperatively to bend the wire laterally and to introduce pitch with twisting of the wire held to a minimum.

2. The combination in a spring coiling machine as set forth in claim 1 wherein said coiling tool and said first and second pitch tools are so arranged in closely spaced relationship as to engage the wire within one-half /2) of one convolution thereof.

3. The combination in a spring coiling machine as set forth in claim 1 and including an anti-twist means arranged between said feed means and arbor and having a wire discharge end immediately adjacent said arbor, said anti-twist means having a longitudinal passageway for the advancement of wire therethrough, and the wire being engaged by the anti-twist means while in said passageway and being thereby restrained against rotary movement about its longitudinal axis.

4. The combination is a spring coiling machine as set forth in claim 3 wherein said anti-twist means comprises a quill having a passageway shaped to accommodate wire having a noncircular cross section.

5. The combination in a spring coiling machine as set forth in claim 4 and including a means connected with said quill and operable in timed relation with said feed means and as wire is advanced to move the quill and rotate wire passing therethrough about its longitudinal axis.

6. The combination in a spring coiling machine as set forth in claim 3 wherein said anti-twist means comprises a series of pairs of upper and lower rolls having grooved peripheral surfaces so as to form therebetween said longitudinal wire passageway, said rolls having associated biasing means urging the groove defining surfaces of the rolls of each pair into firm engagement with wire therebetween and thereby restraining the wire as aforesaid.

7. The combination in a spring coiling machine as set forth in claim 6 wherein an additional grooved roll is provided together with a grooved portion on said arbor, said grooved portion of the arbor being on a side of the arbor spaced from the coiling tool and arranged generally toward the feed means, and wherein a biasing means is provided to urge said additional roll toward the arbor and to urge the groove defining surfaces into firm engagement with the wire therebetween.

S. The combination in a spring coiling machine as set forth in claim 1 wherein said coiling tool comprises a' cylindrical roller rotatable about a generally horizontal axis and having a substantially fiat peripheral surface for engaging the wire.

9. The combination in a spring coiling machine as set forth in claim 8 and including a coil diameter control means connected with said coiling roller and operable in timed relation with said feed means as wire is advanced and coiled to move the roller generally toward and away from said arbor.

10. The combination in a spring coiling machine as set forth in claim 1 and including a pitch control means connected with at least one of said pitch tools and operable in timed relation with said feed means as wire is advanced and coiled to move the pitch tool generally laterally toward and away from the adjacent and engaged wire.

11. The combination in a spring coiling machine as set forth in claim 1 wherein said coiling tool is movable along and arranged to engage wire along a center line extending outwardly from the arbor, said line being angularly related to the line of wire feed movement such that coiling tool movement away from the wire can be effected to release the tool from engagement with the wire and clear the line of wire feed movement whereby to provide a spring with a straight end portion.

12. The combination in a spring coiling machine as set forth in claim 11 wherein said center line extends between the line of wire feed movement and a line perpendicular thereto and is spaced at least 15 in angular inclination from each of said lines.

13. In a spring coiling machine, the combination of feed means for intermittently advancing a wire in a horizontal longitudinal direction, an arbor which extends laterally and generally horizontally forwardly and which is adapted to engage wire advanced longitudinally by said feed means, a coiling tool arranged adjacent said arbor on a side thereof generally opposite said feed means to cooperate with the arbor and to coil wire thereabout, at least one pitch tool, and at least one pre-cast unit disposed between said feed means and arbor and comprising at least three wire engageable surfaces at least one of which is adjustable in a lateral direction corresponding at least generally with a direction of bending of the wire during coiling and pitching.

14. The combination in a spring coiling machine as set forth in claim 13 and including both a diameter and a pitch pre-cast unit disposed between said feed means and arbor and each comprising at least three wire engageable surfaces at least one of which is adjustable in a lateral direction, the said lateral directions of adjustment corresponding respectively at least generally with the direction of bending of the wire during coiling and pitching.

15. In a spring coiling machine, the combination of feed means for intermittently advancing a wire in a horizontal longitudinal direction, an arbor which extends generally laterally and horizontally forwardly and which is adapted to engage wire advanced longitudinally by said feed rolls, a coiling tool arranged adjacent said arbor on a side thereof generally opposite said feed means to cooperate with the arbor and to coil wire thereabont, at least one pitch tool engageable with the wire, and a recoil t-ool engageable with the wire after it has first engaged the arbor and the coiling tool, said recoil tool serving to effect a slight reverse bend in the wire.

16. The combination in a spring coiling machine as set forth in claim 15 and including a cut-off tool movable toward and away from the wire adjacent said recoil tool, said recoil tool including a shearing edge which cooperates with said cut-olf tool on movement of the latter toward said wire whereby to sever the wire.

17. The combination in a spring coiling machine as set forth in claim 15 wherein said coiling tool has a wire engaging surface which is substantially flat in at least one direction so as to bend wire in a generally vertical and lateral direction for coiling about said arbor while permitting free wire movement in other lateral directions, and wherein first and second pitch tools are provided and arranged on opposite sides of said coiling tool each with a wire engaging surface, said wire engaging surfaces being disposed on opposite sides of wire advanced by the feed means and being arranged in close proximity to the coiling tool whereby to bend the wire laterally and to introduce pitch with twisting of the wire held to a minimum.

18. The combination in a spring coiling machine as set forth in claim 15 and including a coil diameter control means adapted to provide a taper spring, said control means being connected with said coiling tool and being operable in timed relation with said feed means as wire is advanced to move the tool away from the wire whereby gradually and progressively to decrease the diameter of the convolutions of a spring coiled about the arbor, and said control means also including means for abruptly moving said coiling tool toward and away from the wire whereby to bend a portion of a convolution to a diameter slightly larger than its coiled diameter, said last mentioned means being operable in timed relation with said feed means so as to cause said bending to occur at an initial portion of the first convolution of each successively formed spring, said convolution being formed to a relatively small diameter at the end of a preceding spring. 19. The combination in a spring coiling machine as set forth in claim 18 wherein a cut-off tool is included in the machine and is operable on the wire at least approximately at said recoil tool and when said feed means is eter of a portion of a convolution when said feed means tioned means is operable as stated to increase the diameter of a portion of a convolution when said feed means is inoperable to advance wire.

20. The combination in a spring coiling machine as set forth in claim 19 wherein said coiling tool is spaced approximately equidistant from a first point at which the wire engages the arbor and said recoil tool.

21. The combination in a spring coiling machine as set forth in claim 1 wherein there is provided at least one pre-cast unit comprising at least three wire engageable surfaces at least one of which is adjustable in a lateral direction of bending of the wire during coiling and pitching.

22. The combination is a spring coiling machine as set forth in claim 1 and including both diameter and pitch pre-cast units disposed between said feed means and arbor and each comprising at least three wire engageable sur faces as least one of which is adjustable in a laterial direction, the said lateral directions of adjustment corresponding respectively at least generally with the direction of bending of the wire during coiling and pitching.

23. The combination in a spring coiling machine as set forth in claim 15 wherein there is provided at least one pre-cast unit disposed between said feed means and arbor, said pre-cast unit comprising at least three wire engageable surfaces at least one of which is adjustable in a lateral direction of bending of the wire during coiling and pitching.

24. The combination in a spring coiling machine as set forth in claim 23 and including both diameter and pitch pre-cast units disposed between said feed means and arbor and each comprising at least three wire engageable surfaces at least one of which is adjustable in a lateral direction, the said lateral directions of adjustment corresponding respectively at least generally with the direction of bending of the wire during coiling and pitching.

References Cited UNITED STATES PATENTS 357,380 2/1887 Goodard 72-145 408,006 7/ 1889 Fowler 72-145 642,339 1/ 1900 Krummel 72-145 972,928 10/1910 Schneider 72-145 1,762,556 6/1930 Marshall 72-132 2,614,606 10/1952 Kirchner 72-1 35 CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner.

U.S. DEPARTMENT OF COMMERCE PATENT OFFICE Washington, D.C. 20231 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,402,584 September 24, 1968 Erman V. Cavagnero It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 20, "The" should read This Column 2, line 18, "cooling" should read coiling Column 3, line 67, "passage" should read passageway Column 5, line 10, "accurately" should read arcuately Column 11, line 74, "is" should read in Column 14, lines44 and 5, "eter of a portion of a convolution when said feed means tioned means is operable as stated to increase the diam-" should read inoperable to advance wire, and wherein said last mentioned means is operable as stated to increase the diam- Signed and sealed this Srd'day of March 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents

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