US3472051A - Spring coiling machine - Google Patents

Description

14, 1969 c. R. BERGEVIN SPRING COILING MACHINE 8 Sheets-Sheet 3.

Filed March 17, 1967 INVENTOR.

CHARLES R. BERGEVIN A4 ATTORNEYS Oct. 14, 1969 c. R. BERGEVIN 3,472,051

SPRING COILING MACHINE Filed March 17, 1967 8 Sheets-Sheet 2 INVENTOR CHARLES R. BERGEVIN BY: 74 I M ATTORNEYS.

1969 c. R. BERGEVIN SPRING comma MACHINE Filed March 17, 1967 8 Sheets-Sheet S N I. UV E Cu QR YE m R S E R A H C FIG. 3

A; ATTORNEYS Oct. 14, 1969 c. R. BERGEVIN SPRING COILING MACHINE 8 Sheets-Sheet Filed March 17, 1967 I). \'ENT(')R.

CHARLES R. BERGEVIN wmzw wai I I I I l M ATTORNEYS.

Oct. 14, 1969 c. R. BERGEVIN 3,472,051

SPRING COILING MACHINE Filed March 17, 1967 8 SheetsSheet r. 'EN'TUR CHARLES RGEVIN .m ATTORNEYS.

Oct. 14, 1969 c. R. BERGEVIN 3,472,051

SPRING COILING MACHINE March 17, I 8 Sheet5-$heet 6 FICB? INYENTOR.

CHARLES R. BERGEVIN A ATTORNEY5.

1969 c. R. BERGEVIN SPRING 001mm MACHINE 8 Shee ts-Shee t Filed March 17, 1967 CHARLES R BERGEVIN 4 ATTORNEYS.

FIG. IO

4, 1969 c. R. BERGEVIN 3,472,051

SPRING COILING MACHINE Filed March 17, 1967 8 Sheets-Sheet 8 IF. VENTOR. CHARLES R. BERGEVIN ilzzzwq zzznmq A414. ATTORNEYS.

FIG. l2

United States Patent "ice 3,472,051 SPRING COILING MACHINE Charles R. Bergevin, 28 West View Terrace, Torrington, Conn. 06790 Filed Mar. 17, 1967, Ser. No. 623,954 Int. Cl. B21f 11/00, 3/10 U.S. Cl. 72-132 8 Claims ABSTRACT OF THE DISCLOSURE A machine for coiling helical springs from wire, in which the wire is fed longitudinally into engagement with a coiling abutment which deflects the Wire from its line of feed and bends it into a coil. A cutting anvil, which is completely independent of the arbor portion of the Wire guide, is mounted for movement into contact with the inside surface of the coil after it has been formed so that the spring can be cut from the wire against the anvil. Adjustment of the anvil into contact with the coil does not have any effect on the coil, thereby simplifying the setting up of the machine.

The present invention relates to wire-spring coiling machines and it relates more particularly to the type of machine which in rapid succession coils springs of the desired size, length and configuration according to individual customer specifications.

In the manufacture of wire springs, the number of identical springs to be made at any particular time is usually relatively small. This condition of necessity makes the machine set-up time a major part of the cost of the product. In most spring-manufacturing plants about 80% of the orders for springs are in quantities of 5,000 or less. Furthermore, almost every order at any particular time is for springs of different specifications. Spring coiling machines commonly in use today require an average set-up time of about two hours. Since these machines are capable of producing approximately 6,000 springs per hour, it takes the machine only one minute to turn out an order for 100 springsbut two hours time may have been required to set-up the machine. Set-up time is therefore the major factor in the cost of production.

The primary object of the present invention is the reduction of set-up time in wire-spring coiling machines, while at least maintaining or improving the production rate of the machine and quality of the springs that are coiled.

A spring coiling machine, which has been and still is widely used in the industry, is known as the segment type, the basic design for which is shown in the patent to Bergevin et al. 2,119,002. This type of machine gets its name from the fact that the mechanism for feeding the wire to the coiling tools includes a gear segment which is rocked back and forth, intermittently feeding the wire lengthwise with each stroke in one direction. The present invention is disclosed as being employed to advantage in this type of machine, but it will be understood that it can be used in any type of wire coiling machine wherein a predetermined amount of wire is fed from a continuous length of wire into engagement with coiling tools which bend it into the desired shape and then sever the spring thus formed from the supply of wire being fed.

One of the reasons that it takes so long to set-up a machine such as that shown in the above-mentioned patent is that some of the adjustments that must be made in order to produce the desired spring, are intimately dependent on each other. Sometimes an adjustment that must be made early in the setting-up procedure is affected by another adjustment that cannot be made until much later in the procedure. Thus, an adjustment in one part 3,472,051 Patented Oct. 14, 1969 of the machine, which cannot be made until other settings have been made, frequently requires not only readjustment of an early setting, but also readjustment of all the intervening settings.

It is therefore an important object of the present invention to divorce the various parts of the coiling machine in such a manner that an adjustment in one does not create the need to readjust a previous setting. This is accomplished by arranging the parts of the machine so that they can be adjusted in sequence, with each portion of the spring to be produced remaining stable after each step in the set-up procedure.

A further object of the invention is to reduce the number of different adjustments which are required. An important object of the invention is to reduce the stock of too-ls needed in order to make springs of standard sizes.

It will be noted in the above-mentioned Bergevin et al. patent, as well as in the patents to Bergevin et al. 2,170,- 984, Halvorsen et al. 2,276,579, Franks et al. 2,820,505, Franks 3,009,505 and Bergevin 3,068,927, that all of the machines of this type employ a coiling arbor, against which the wire is bent as it is coiled and on which the coil is supported when it is cut. Although this method of coiling has certain desirable advantages over other systems of coiling that have been employed, it has serious disadvantages which the present invention does away with, while retaining the advantages of the original system. For example, in the existing machines that are exemplified by the patents mentioned hereinbefore, the Wire guide must be carefully adjusted with respect to the arbor for good control of the wire as it is forced into contact with the coiling surface of the arbor. The cutting blades must also be adjusted to mesh properly with the cutting surface of the arbor. Furthermore, because the inside diameter of the spring coil cannot greatly exceed the diameter of the arbor around which it is coiled, the arbor inherently limits the diameter range of diiferent springs that can be coiled on any particular machine to the largest arbor that will fit the machine. This is a definite and serious limitation of such machines. A large number of different sizes and shapes of arbors are also required in order to produce springs of the desired diameters. Because these coiling arbors must be of the highest quality, considerable expense is involved in maintaining a suitable stock. Frequently, it is necessary to grind them to exact size by a cut-and-try method, necessitating time-consuming removal and replacement of the arbor many times during set-up for a production run.

In accordance with the present invention, the coiling arbor is eliminated entirely, the wire being bent on an arbor portion of the wire guide through which it is fed. When a coil of the desired diameter is formed by properly adjusting the coiling point with respect to the wire guide, a tool holder located axially of the coil, and on which is mounted a cutting anvil that projects into the center of the coil, is adjusted so that the cutting anvil engages the inner surface of the coil and supports it when the spring is cut from the wire. Thus, an important advantage of my invention resides in rendering unnecessary the costly and time-consuming coiling arbors employed heretofore. On the other hand, prior coiling machines which have not employed coiling arbors have not been capable of making springs as precisely as present day requirements demand. For example, in the wire forming machines disclosed in the patents to Clay 3,025,889, 3,025,890, 3,025,891 and 3,026,012, it is impossible to coil a spring without a portion of the end extending laterally of the coil. While lateral ends are necessary in certain types of springs, they are completely unacceptable in most.

In other aspects of the present invention, the pitch tool for spacing the coils of the spring, as well as the cutters, are likewise mounted on the tool holder, so that they will be automatically and simultaneously brought into correct relation to the coil as the tool holder is adjusted to bring the cutting anvil into supporting engagement with the coil. At least two additional adjustments required in prior machines are thereby eliminated.

As will be more apparent from the specific description hereinafter of one embodiment of the invention, an important advantage of the invention resides in the fact that, whereas coiling machines of this type have required at least fifty different coiling arbors and an equal number of pitch tools for coiling springs of standard sizes, machines designed in accordance with the present invention can coil springs with a considerably wider range of coil diameters, using only three different cutting anvils and pitch tools. The savings in the inventory of coiling tools alone is accordingly rather substantial. Furthermore, since the same cutting anvil is used for a wide range of spring diameters, the correct anvil for any particular spring is readily determinable in advance, whereas heretofore the proper coiling arbor to be used for any particular job could only be determined by trial and error. This alone greatly reduces the time required to set-up the machine.

These and other advantages and objetcs of the invention will be more apparent from the specific description hereinafter of one embodiment of the invention as shown somewhat diagrammatically in the accompanying drawings wherein,

FIG. 1 is a front view of a portion of a spring-coiling machine embodying the invention;

FIG. 2 is a fragmentary front view on a larger scale of the coiling area and tool-holder slide in the machine shown in FIG. 1, parts thereof being broken away and in section;

FIG. 3 is a vertical section through the front portion of the machine as viewed along the line 3-3 of FIG. 2;

FIG. 4 is a horizontal section taken on the line 4-4 of FIG. 3;

FIG. 5 is another horizontal section taken on the line 55 of FIG. 3;

FIG. 6 is a detail view of the upper cutter assembly shown in vertical section along the line 6-6 of FIG. 4;

FIG. 7 is a fragmentary view taken in vertical section on the line 77 of FIG. 1, certain portions of the machine being shown diagrammatically, the central section of the machine being broken away with some parts removed for convenience of illustration;

FIG. 8 is a fragmentary sectional view of a lower portion of the machine as seen along the line 8-8 in FIG. 7;

FIG. 9 is a fragmentary front view of only the coiling area of the machine, showing a spring being coiled;

FIG. 10 is a view taken in horizontal section on the line 10-10 of FIG. 9;

FIG. 11 is a view similar to FIG. 9, but showing the coiling tools set up for coiling a right-hand spring of smaller diameter; and I FIG. 12 is a detail view taken in vertical section on the line 12-12 of FIG. 3.

The coiling machine of the present invention is constructed and operates in a manner generally similar to that shown in the patent to Franks 3,009,505. Reference is therefore made to the Franks patent for the basic construction, wire feed mechanism and general operation of a machine of the type to which the present invention is primarily directed, only those parts of the machine which are necessary to an understanding of the invention being herein shown and described in detail. A frame and supporting structure for the machine, generally indicated by the reference numeral 10, carries the wire feeding and coiling devices, including substantially tangent upper and lower feed rolls 11, 11, which are intermittently rotated on drive shafts 12, 12 in the directions shown in FIG. 2, in order to feed the spring wire W through a passage 13 in a wire guide 14 consisting of a pair of upper and lower guide- plates 15 and 16, between which the passage 13 is formed. Guide- plates 15 and 16 are removably mounted on the frame of the machine by means of suitable clamping members 18, 18, so that they can be replaced with guide-plates of the desired size and length for the particular spring to be formed.

The wire W is projected by the feed rolls through the open end or tip 19 of the passage 13 into the coiling area of the machine indicated generally by the reference numeral 20, where it is bent by spring-forming tools to be described hereinafter into helical coils in order to form a spring S (FIGS. 9-11). During a complete cycle of operations of the machine, each spring is individually coiled and then cut by either one of a pair of cutters 22, 23 from the continuous length of wire W being fed through the wire guide 14 from a supply (not shown). Each cycle of the machine is completed with the cutting of each individual spring, and the cycle repeated successively until the desired number of springs has been coiled.

Referring now in greater detail to the coiling tools and to the means by which these tools are arranged and operate to coil springs of different diameter and pitch, it will be noted that in addition to the wire guide 14, the springforming tools consist basically of: a single coiling abutment or point 24 against which the wire is projected directly from the guide 14, a cutting anvil 26 which is mounted for vertical adjustment into supporting engagement with the inner surface of the coil and a pitch tool 28 disposed for engagement with the wire as it travels from the coiling point 24 to the anvil 26. As illustrated in FIGS. 1 and 2, a cutting blade 30 is rigidly mounted on the arm of the upper cutter 22 for precise meshing engagement with a cutting face 32 on anvil 26 for severing the wire after each spring is formed. A similar blade 31 is used in the lower cutter 23 when the spring is coiled downward as shown in FIG. 11. The cutters 22 and 23 move in a vertical plane indicated in FIG. 9 by the line X-X which passes through and includes the coiling axis.

It will be apparent from the general arrangement of the coiling tools, as shown for example in FIGS. 2 and 9, that the wire W is fed directly into engagement with the coiling point 24, instead of into contact with a coiling arbor before it engages the coiling point, as in the machines shown in the patents to Franks 3,009,505 and others. The bend in the wire W is therefore formed entirely between the coiling point 24 and the open end or tip 19 of wire guide 14. The diameter of the springs to be coiled is accordingly determined solely by the position of the coiling point 24 with respect to the tip 19 of the wire guide. On the other hand, in coiling machines which use a coiling arbor, the size of the arbor, over which the wire is bent, plays an important part in bending the wire to the desired coil diameter. Moreover, the particular arbor to be used can only be determined by trial and error, and each time the arbor ischanged, for example, in order to dispose its anvil face properly with respect to the cutter, the diameter of the spring is affected. Consequently the coiling point must be readjusted with each change in the arbor. Such readjustment usually occurs many times during each set-up of the machine and adds substantially to the time required to put it in. operation.

In the arrangement employed in accordance with the present invention, the diameter of the spring is obtained with just one adjustment of the coiling point, and no further adjustment for diameter is required. The trial-anderror system required heretofore in order to adjust for diameter is accordingly completely eliminated in the present machine.

Since in the present coiling arrangement the bend in the wire starts at the tip 19 of wire guide 14, guide'plates l5 and 16 confine the wire along both its upper and lower surfaces for the entire distance from the feed rolls 11, 11 to the tip 19, from which it is projected into engagement with the groove 24 in the end of the coiling point. Due to springback of the wire after it leaves the coiling point,

the central axis of the coil formed should lie in a vertical plane XX (FIG. 9) somewhat rearwardly, or to the right as viewed in FIGS. 2 and 9, of the tip 19 of the wire guide, so that the blade on the vertically moving cutter 22 cuts the wire straight across. Such precise cutting of the wire is highly desirable, and even essential in some cases. In order to locate the central axis of the spring in the plane XX, guide- plates 15 and 16 are furnished in different lengths, so that the tip 19- can be located the desired distance beyond the plane XX, depending on the diameter of the spring, the size of the wire being coiled, the material of which it is made and its degree of temper, all of which affect the amount of spring-back of the wire from the bend formed by the wire guide and coiling point. It is contemplated that about six sets of wire guides will be required in order to handle most situations.

COILING POINT ADJUSTMENT As will be seen in FIG. 1, coiling point 24 is removably mounted on a holder 34, which is suitably fixed to an elongated arm 36 that is pivoted at 37 to a slide 38 and extends from its pivot 37 toward the wire guid 14. Slide 38 may be shifted axially of the line of feed of the wire in a slide frame 39 so that the coiling point 24 can be moved toward and away from the tip 19 of wire guide 14. An adjusting screw 40 at the outer end of slide frame 39 may be used for moving slide 38 and the arm 36 mounted thereon, so that th coiling point 24 can be set at the desired position for coiling springs of uniform diameter. However, in order to coil a spring which varies in diameter, as for example one which is smaller at both ends than it is in the center, the slide 38 is released by the adjusting screw 40 and moved longitudinally of the line of wire feed during each springforming cycle by a cam-actuated mechanism (not shown). The control mechanism for shifting the coiling point toward and away from the wire-guide tip 19 is conventional in coiling machines of the type shown in the before-mentioned patent to Franks and therefore need not be described here.

In addition to being adjustable lengthwise, the coiling-point arm 36 may also be pivoted up or down about its pivot point 37, in order to set the coiling point 24 at the desired angle with respect to the coil so that the Wire does not accidentally jump out of the groove 24'. Furthermore, where it is desired to form torsion ends on the spring, the coiling point may be moved completely out of the way of the wire by swinging the holder 34 and arm 36 up or down on its pivot 37.

To this end, a link 42 is pivotally connected to the underside of the coiling-point arm 36 at its end opposite pivot point 37 for moving the coiling point vertically out of engagement with the wire, in order to form a straight end in producing torsion springs, for example. Link 42 is actuated by a cam 44 on a cam shaft 46 which is driven in timed relation with the feed rolls 11 by drive means (not shown). Cam shaft 46, which is journaled in the frame of the machine, makes one revolution during each spring-forming cycle. The lower end of link 42 is pivoted to the outer end of an intermediate lever 48, which in turn is pivoted at St} on the frame of the machine. A push-pull rod 52, having a turn-buckle 54, is pivoted at 55 to lever 48 intermediate the link 42 and pivot block 50. The lower end of rod 52 is pivoted to a cam lever 56, which raises and lowers rod 52 and link 42 according to the movement and shape of cam 44. Lever 56 is pivoted at 58 on the frame of the machine for pivotal movement in a vertical plane and has a cam-following roller 60 at one end in position for engagement with cam 44. As shown in FIG. 1, push-pull rod 52 is pivoted to lever 56 at a point A intermediate. roller 60 and pivot pin 58. When coiling torsion springs, cam 44 draws the coiling point 24 downward and out of engagement with the wire W for forming a straight end on the spring.

It will be appreciated that in coiling torsion springs the coiling point must be moved in one direction for righthand springs and in the opposite direction for left-hand springs. In the machine here illustrated, left-hand springs are coiled when the coiling point bends the Wire upward as shown in FIG. 2, and right-hand springs are coiled when it is bent downward as shown in FIG. 11. Accordingly when left-hand torsion springs are coiled, the coiling point is moved downward as just described. However, where the springs are to be coiled with a right-hand helix, the wire is bent downward so that the coil is formed below the level of the wire feed, and consequently in order to form torsion ends, th coiling point 24 must be raised so that it can move out of engagement with the wire being fed through the quide 14. To this end, a second pivot point B is provided on the cam lever 56 on the opposite side of its pivot pin 58 from roller 60. The lower end of push-pull rod 52 may therefore be disconnected from lever 56 at point A, and reconnected at point B. Alternate point B is located the same distances from the pivot pins 55 and 58, respectively, as is the point A, so that the same amount of movement is imparted to the coiling point, but in the opposite direction, when the rod 52 is shifted from A to B. It will be apparent, therefore, that in coiling right-hand springs the rod 52 will be connected to lever 56 at B instead of at A as shown. A suitable tension or compression spring (not shown) is provided for holding the cam lever 56 in position for engagement with cam 44.

Where it is not desired to form torsion ends, the torsion control linkage just described is rendered inoperative by lengthening push-pull rod 52 by means of turnbuckle 54, so that the cam-following roller 60' moves out of engagement with cam 44. In addition, when it is necessary to fix the coiling point 24 rigidly in a vertical direction, a pair of oppositely disposed positioning screws 62, 64 on forwardly projecting portions of the slide block 38 are turned into engagement with the upper and lower sides of arm 36. When forming torsion ends on the spring, the positioning screws 62 and 64 are of course backed off far enough to permit arm 36 to swing up or down.

CUT-OFF MECHANISM After the coiling point has been adjusted for the particular diameter, or the desired variation in diameter, of the springs to be coiled, the next step in setting up the machine is to position the cutting anvil 26 against the inner surface of the coil thus formed, in order to support the wire when the cutter is actuated. To this end, the anvil 26 is mounted on a vertically movable tool holder 66, which is disposed in back of the tip 19 of the wire guide 14 such that the anvil 26 extends forward from holder 66 inside the coils of the spring S, as best shown in FIGS. 9 and 10. The tool holder 66 forms the integral mid-portion of a vertically elongated slide assembly 67, which is supported for vertical adjustment on an upright 68 that comprises a rigid part of the frame 10 of the machine. A dovetail groove 69 is provided in upright 68 for slidably receiving a mounting plate 70, to which slide assembly 67 is rigidly fastened by means of a pair of bolts 71, 71 at both its upper and lower ends and by another bolt 72 in the center.

An elevating screw 74, having a hand knob 76 at its upper end, for positioning the slide assembly 67 vertically, extends freely through a hole in an upper cross-member of the frame 10 into threaded engagement with the mounting plate 76. Thus, by rotating screw 74 the slide assembly and holder 66 are moved up or down so that the anvil 26 can be brought into contact with the inner surface of the coiled wire. As noted hereinbefore in connection with the control mechanism for forming torsion ends, provision is made for coiling either above the line of wire feed for a left-hand spring or below the line of feed for a right-hand spring. To this end, the front face of tool holder 66 is provided with a pair of sockets 77 and 78, one above and one below a horizontal center- 7 line through the holder, so that anvil 26 can be placed either above or below the wire guide 14, depending on which way the springs are to be coiled. The anvil is rigidly fixed in the tool holder by suitable means, such as set screws 79, 79 (FIGS. 2 and 3).

As shown in FIGS. 1-6 and 9, the machine is setup to coil left-hand springs, with the anvil 26 located in the upper socket 77 so that it can be moved from a position just above the tip 19 of wire guide 14 upward until it engages the inner side of the spring being coiled, in the manner best illustrated in FIG. 9. When a right-hand spring is coiled, the anvil 26 is removed from the upper socket 77, and the slide assembly 67 lowered until the lower socket 78 is positioned just below wire guide 14. Anvil 26 is then placed in socket 78, so that when the coil is formed below the line of feed as illustrated in FIG. 11, the anvil can be adjusted downward into contact with the coil by lowering the slide assembly 67. Suitable means are provided for locking the slide assembly in adjusted position, such as set screws 70, 70 (FIG. which are threaded through the outer edge of upright 68 into engagement with a groove 70 extending along the edge of mounting plate 70.

In accordance with a particularly advantageous aspect of the present invention, adjustment of anvil 26 into operative engagement with the coil automatically brings one of cutters 22, 23 into proper position for cutting each spring S from the wire W during the coiling operation. This is accomplished by mounting the cutters 22, 23 on the slide assembly 67 for movement therewith as the cutting anvil 26 is moved into engagement with the inner surface of the spring coil. As best shown in FIGS. 26, each of the cutters 22, 23 has an arm 80, 81 which is pivoted to the slide assembly on a horizontal pivot pin 82, 83, located respectively above and below the toolholder portion 66 of the slide assembly. Arms and 81 move in a vertical plane perpendicular to the line of feed of the wire W within a pair of openings 84, 85 formed between the mounting plate 70 and the main body of the slide assembly 67 directly above and below the sockets 77, 78 for the anvil 26. In the arrangement shown in FIGS. 2-6, blade 30 is clamped to the outer end of the arm 80, so that it meshes with the cutting face 32 on anvil 26 which is located in socket 77. A clamping plate 86 and bolts 87, 87 are provided at the outer end of each cutter arm for securing the blade 30 thereto.

When coiling springs of large diameter, it may be necessary to remove the blade 30 from the cutter not being used so that it does not engage the wire guide 14 as the slide assembly 67 is adjusted to one of its limits of movement in order to bring the anvil 26 into engagement with the coil. Thus as shown in FIGS. 2 and 9, the slide assembly 67 is located near its upper limit, bringing the lower cutter 23 close to the wire guide 14. The blade 30 is accordingly shown removed from the lower cutter.

The rear end of each cutter arm opposite its blade 30 is provided with a roller 88 which engages an annular cam surface 89 at each end of a cam cylinder 90, that is fixed on a vertical actuating shaft 91. Actuating shaft 91 is supported for rotary movement within a pair of bearing bosses 92 and 93 which are integral with, and extend rearwardly from, the upper and lower ends, respectively, of the slide assembly 67. Shaft 91 is prevented from moving axially with respect to the slide assembly by positioning collars 94, 94 fixed outwardly of thrust bearings 95, 95 on the outer sides of bearing bosses 92, 93. It is apparent therefore that the actuating shaft 91 is supported axially by slide assembly 67 and moves vertically therewith. Consequently, the tool holder 66, and complete cutter assembly, including both cutters 22 and 23 and the actuating shaft 91, all move vertically as a unit when the elevating screw 74 is rotated.

Referring now more particularly to FIGS. 7 and 8, the cutter-actuating shaft 91 extends downward below the coiling area of the machine and is supported at its lower end by a bracket 97 rigidly mounted on the frame of the machine. Shaft 91 extends through a pair of vertically spaced guide blocks 98, 99 on bracket 97 for both axial and rotary movement therein. A crank arm 100 for rotating shaft 91 is positioned between guide blocks 98, 99, which prevent the crank arm from moving axially with shaft 91. The lower section of shaft 91 is formed on its periphery with longitudinally extending serrations 101, which mate with internal serrations in the boss of crank arm 100, so that rotary movement can be imparted to shaft 91 by the crank arm, while permitting shaft 91 to move longitudinally when the slide assembly 67 is adjusted up or down.

Power for turning the cutter-actuating shaft 91 is provided by a cam 102 on a cam shaft 103 through a cam lever 104 and pull-rod 105 (FIG. 8). Cam shaft 103, which is driven in timed relation with the wire-feed mechanism, is supported on the frame 10 of the machine for rotation about an axis parallel to the feed- roll shafts 12, 12 and may conveniently be the main drive shaft by which power is supplied for operating the various parts of the machine. Cam lever 104 is pivoted at one end on a pivot shaft 106 which is mounted on the frame of the machine parallel to cam shaft 103. Pull-rod 105 is pivoted to the other end of lever 104, which extends downward from shaft 106 on the opposite side of cam shaft 103 from crank arm 100. A cam roller 107 is journaled on lever 104 intermediate its ends for engagement with the cutter cam 102. Pull-rod 105 is adjustably connected to the outer end of crank arm 100, with an adjusting nut 108 provided thereon for adjusting the point at which cam roller 107 is engaged by cam 102. A tension spring 109, stretched between the lower end of cam lever 104 and a mounting tab 110 on the upper guide block 98 of bracket 97, continuously urges cam roller 107 toward cam 102, in order to return cutter-actuating shaft 91 to its normal position.

It will be seen from the foregoing that each time cutter cam 102 makes one revolution, shaft 91 is turned through a predetermined degree of arc in a clockwise direction, as viewed in FIGS. 4 and 5. The cam rollers 88, 88 on cutter arms 80 and 81 are thereby moved outwardly of each other by the cams 89, 89 on the ends of cam cylinder 90, thereby forcing the opposite ends of the cutter arms inwardly into their cutting positions. Upon rotation of the cutter-actuating shaft 91 in the opposite direction, the cutting ends of arms 80, 81 are swung outward to their normal positions under the urge of a pair of coil springs 112, 112, one of which is compressed between the rear end of each cutter arm 80, 81 and a lug 114 on each bearing boss 92, 93.

By mounting the cutters 22, 23 on the slide assembly 67 with the cutting anvil 26, the cutting blade 30 remains in proper relation with the anvil at all times, so that no adjustment of the cutter arm is required after the anvil has been moved into position against the inside of the coil as illustrated in FIG. 9. However, between cuts it is necessaly for the cutters to retract rearwardly from the vertical plane YY (FIG. 3) in which the wire W is bent as it is coiled, so that they do not interfere with the wire while the coil is being adjusted to the desired diameter. This is accomplished by mounting the cutter arms 80, 81 so that they can move perpendicular to the plane Y-Y, as well as pivot on their pivot pins 82, 83.

Since the cutters 22 and 23 are identical, but for the fact that they are inverted with respect to each other, only the upper cutter 22 will be referred to in describing the manner in which they retract rearwardly. Referring, therefore, more particulaly to FIGS. 5 and 6, the cutter arm 80 is provided with a horizontally elongated slot 116 within which is slidably received a pivot block 118. Block 118 is journaled on pivot pin 82 which, in turn, is sup ported at its opposite ends in the tool holder 66 and mounting plate 70.

Cutter arm 80 is moved outward, or forward, to its operative position as shown in FIGS. 3 and 6, by a rocker arm 120 pivotally mounted on the underside of a support 122 that is bolted to the back of the bearing boss 92 for the actuating shaft 91. Support 122 extends downward from boss 92 so that rocker arm 120, which pivots in a horizontal plane on a vertical pin 123, is positioned for engagement of a roller 124 at its one end with the flat rear end surface of cutter arm 80, while a cam roller 126 at its opposite end engages the periphery of cam cylinder 90. A cam groove 128 (FIG. 5) is formed in the periphery of cylinder 90, so that a shaft 91 is turned in a counterclockwise direction from the position shown in FIG. 5, roller 126 drops into groove 128, permitting the opposite end of rocker arm 120 to swing back. A return spring 130 (FIG. 6), located in a recess 132 in the upper edge of cutter arm 80, is compressed between the back end of recess 132 and a stud 134 fixed in the slide assembly 67 and extending downward into the opening 84, in which cutter arm 80 is free to swing, and into recess 132 of arm 80. Return spring 130 continuously urges cutter arm 80 rearward against the roller 124 on rocker arm 120, and therefore moves cutter arm 80 back when cam roller 126 drops into cam groove 128.

It will be noted from FIG. 5 that in this particular case the cam groove 128 and annular cam surface 89 on cam cylinder 90 are disposed with respect to each other so that just before the outer end of cutter arm 80 reaches its outermost limit of pivotal movement following each cut, the arm 80 is retracted rearwardly. Conversely, when cutter-actuating shaft 91 is rotated in the opposite direction, cutter arm 80 immediately moves forward and is then swtmg inward into cutting relation with anvil 26. The lower cutter 23 is constructed in the same way as the upper cutter 22, operating in the same way and simultaneously with the operation of the upper cutter. However, only one of the cutters is actually in use at a time, depending on the direction in which the springs are to be coiled.

PITCH CONTROL MECHANISM The pitch tool 28 is mounted on the tool holder 66 in one of two holes 136, 138 provided therefor above and below the horizontal centerline of the holder and adjacent the mounting sockets 77, 78 for the anvil 26. The head 139 of pitch tool 28 may be of any desired shape in order to best engage the Wire W ahead of the cutting anvil 26 and to bend it axially of the spring S being coiled. It is desirable, however, to have a portion of the head 139 of the pitch tool almost touching or actually in engagement with the side of the anvil opposite its cutting face 32. Due to the fact that the pitch tool 28 is mounted on and moves with the tool holder 66 and, consequently, with cutting anvil 26, adjustment of the tool holder in positioning the anvil against the inner surface of the spring coil will at the same time move the pitch tool so that in most cases it is automatically in position for proper engagement with the coil. Accordingly, except where it is necessary to change the size of the anvil 26 for cutting extra heavy wire or for coiling springs of diameters smaller than the diameter of the anvil normally used, the same pitch tool will be used.

Furthermore, due to the fact that the pitch tool is located on the upstream side of the cutting anvil 26, the portion of the coil left on the machine between the coiling point 24 and the anvil 26 after each cut, as shown in FIG. 2, remains in contact with the pitch tool. This provides better control of the wire, and makes it possible to coil more accurate springs than prior machines have been capable of where the pitch tool is on the downstream side of the cutter. In conventional machines, moreover, after each cut the wire end must find its way over, and contact the pitch tool, thus creating an unstable condition and cansing greater wear of the pitch tool as a result of the sharp end on the wire. Moreover, the shape of the pitch tool must be quite exact in such prior arrangements in order to provide clearance for the cutter, while ensuring that the end of the wire is picked up and led over the wire guide. On the other hand, in the present arrangement, the shape of the pitch tool is not critical. As long as the head 139 can be brought into contact with the anvil 26 by rotating the pitch tool in its socket 136, 138, there is no need to change or reshape it. It is contemplated that only three different cutting anvils will be required to coil the range of springs which conventional machines are designed to handle. Similarly, no more than three pitch tools will be needed.

The pitch tool 28 has a cylindrical shank 140 which fits closely within the proper hole 136 or 138 and extends rearwardly completely through the holder 66 for longitudinal movement therein. Rearward of tool holder.

66 is provided a push block 142, which is supported by a pair of vertically spaced guide rods 144, 144 projecting forwardly into guide holes 146, 146 in the rear of the tool holder parallel to the shank 140. Guide rods 144, 144 are threaded into suitable sockets in the push block 142 and have a sliding fit within the guide holes 146, 146 for longitudinal movement therein. The rear end of the shank 140 of the pitch tool is fastened to the push block 142 by a clamping plate 148 (FIG. 12), to which is threaded a clamping screw 150 that extends transversely through block 142 and is provided with an enlarged hand knob 152 at its outer end. In the arrangement illustrated in FIGS 1-6 and 9, the pitch tool is mounted in the upper hole 136 in the tool holder for making left-hand springs. However, where right-hand springs are to be coiled, the cutting anvil 26 and pitch tool 28 are placed in the lower mounting holes 78 and 138, respectively, as shown in FIG. 11. Semi-cylindrical grooves 151, 153 are provided in both the push block 142 and clamping plate 148 for receiving and securely holding the shank 140 of the pitch tool in either its upper or lower positions on the tool holder when the clamping screw 150 is tight. FIG. 12 shows the pitch tool located in the upper grooves 151. If desired, a blank may be placed in the lower grooves 152 of the clamp in order to prevent the plate 148 from twistmg.

Pitch tool 28 is urged into a rearward, inoperative position by a pair of coil springs 154, 154, which are compressed between tool holder 66 and the push block 142, the ends of springs 154, 154 being retained in oppositely facing recesses in these members. Disposed to the rear of push block 142 and in operative engagement therewith is a plunger head 156 that is mounted on a longitudinally reciprocable plunger 158. A bearing bracket 160 on the frame of the machine supports the plunger 158 adjacent its head 156 and a similar bearing (not shown) on a rear frame member of the machine supports the plunger 158 at its opposite end for longitudinal movement only. An upwardly extending lever 164 (FIG. 7) for actuating plunger 158 is fixed to a pivot shaft 166, that extends transversely of plunger 158 and is mounted for rotary movement in suitable bearings (not shown) on the frame of the machine. The forked upper end of lever 164 engages a rectangular lug 168 which is pivoted on plunger 158. A horizontal lever 170 is likewise fixed to pivot shaft 166, and is actuated by a cam-operated pull-rod 172 in a manner similar to that shown in the before-mentioned patent to Franks 3,009,505.

Upon downward movement of pull-rod172, lever 164 is moved clockwise, as viewed in FIG. 7, causing plunger 158 to move forward against the push block 142, thus forcing pitch tool 28 outward against the wire as it is being coiled. The wire is therefore bent axially of the spring being formed, causing its coils to be spaced from each other by the desired amount. When the pull-rod 172 is permitted to move upward, the return springs 154, 154 between the tool holder 66 and push block 142 force the latter rearward in order to retract the pitch tool 28, thereby reducing the amount of pitch in the coils. The spacing between the coils can be made uniformly open throughout the length of the spring by moving the pitch tool outward against the coil as the spring is formed and locking it in place. Or the pitch tool can be retracted so that it does not engage the coil in which event the coils of the spring are closed. On the other hand, by changing the shape of the cams that operate the pitch-control linkage, any desired variation in coil spacing can be obtained, as for example in a spring having open-spaced body coils and closed end coils.

It will be noted that vertical movement of the push block 142 with the tool holder 66 relative to plunger 158 is permitted by the abutting faces on the plunger head 156 and push block 142. Since no rigid connection is made between these members their vertical surfaces of engagement simply slide relative to each other when the tool holder is adjusted up or down in order to position the cutting anvil and pitch tool when the machine is being set up for a production run.

In setting up the machine the proper wire guide plates 15 and 16 are selected and mounted. Mounting and adjustment of the coiling point 24 is done in the same manner as for machines of conventional design, as the wire W is fed by hand. But once the diameter of the coil has been set no further adjustment for diameter is necessary in the present machine, because none of the subsequent adjustments will affect the coil diameter. The slide assembly 67 is then adjusted by means of adjusting screw 74 in order to move the anvil 26 into engagement with the coil, where it is locked in place by means of lock-screws 70'. This also brings the cutter and pitch tool 28 into correct relation with the coil so that the pitch tool engages the coil and forces it outward enough to produce the desired spacing between coils. If the coils are to be uniformly spaced the pitch tool is fixed in the position to which it is adjusted, otherwise the pitch tool controls are adjusted to vary the pitch as required. Finally, the wire is fed until the cutter is actuated by its cam 102. Adjustments for the number of coils and position of the wire ends are then made by adjusting the length of wire fed for each spring. This is done in more or less the same manner employed for conventional machines.

It will be noted that no adjustment of the cutter stroke is required in the present machine, because the cutter is mounted on the slide assembly with the cutting anvil. This, moreover, removes any load exerted during the cutolf from the adjusting screw 74 and the lock-screws 70' for the slide assembly. In addition, the pitch tool seldom requires adjustment with respect to the anvil, since once it is adjusted for any particular anvil it needs no further adjustment. Only when the size of the anvil must be changed in order to handle either very large or very small wire sizes, is it necessary to change or readjust the pitch tool to fit the anvil. In most cases, moveover, especially in the case of the special large size anvils, the pitch tool can be rotated in its mount so that it just touches the anvil.

In any event, the same cutting anvil can be used in coiling springs with coil diameters of all but the largest and smallest sizes. Consequently only three different size cutting anvils are needed to do the jobs requiring some 50 or more different coiling arbors in previous machines. Moreover, since just one size cutting anvil can be used for almost all springs, the same cutting anvil and pitch tool can be used from one job to the next without any adjustment.

What is claimed is:

1. In a coiling machine comprising wire-guide means for positively constraining wire along a line of feed and having an arbor portion against which the wire is bent as it passes into a generally open coiling area, means for feeding wire lengthwise through said wire-guide means and projecting it into said coiling area and a coiling abutment disposed in the path of the wire as it projects from said wire-guide means for bending the wire into a coil, the combination comprising,

(a) a slide assembly disposed adjacent said coiling area for adjustment relative to said wire-guide means and coiling abutment transversely of the coiling axis,

(b) a cutting anvil fixedly mounted on said slide as sembly axially of the coil and projecting into said coiling area such that transverse adjustment of said slide assembly carries said cutting anvil toward and away from said arbor portion of said wire-guide means for positioning said cutting anvil in engagement with the inner surface of the coil once formed, and

(c) a cutter mounted on said slide assembly and movable with respect thereto into and out of wire-cutting relation with said cutting anvil in order to sever the coils from the supply of wire being fed.

2. The combination defined in claim 1, which further includes a pitch tool mounted on said slide assembly ad jacent said cutting anvil for movement therewith into operative relation with the coil simultaneously with adjustment of said cutting anvil into engagement with the coil.

3. The combination defined in claim 2, wherein said pitch tool is disposed intermediate said cutting anvil and said coiling abutment.

4. The combination defined in claim 1 wherein said cutter comprises,

(a) a cutter arm having a cutting blade adjacent one end,

(b) means for mounting said cutter arm for pivotal movement into and out of said wire-cutting relation with said anvil and for reciprocal movement along a path substantially parallel to the coiling axis such that said cutting blade is movable into and out of operative position for cutting the coil,

(c) means for pivoting said cutter arm into and out of said wire-cutting position, and

(d) means for moving said cutter arm in said reciprocal movement into and out of said operative position.

5. The combination defined in claim 4, wherein said cutter arm is movable substantially within a plane in which the coiling axis lies,

said means for pivoting said cutter arm comprising a cam follower on the other end of said cutter arm opposite said cutting blade and a cylindrical cam disposed adjacent said other end and having an annular cam surface disposed in cooperative relation with said cam follower for pivoting said cutter arm.

said means for moving said cutter arm into its operative position comprising a rocker arm mounted for engagement with said other end of said cutter arm and a second cam surface formed on the periphery of said cylindrical cam engageable with the opposite end of said rocker arm for pivoting said rocker arm and thereby moving said cutter arm into said operative position, and

means for moving said cylindrical cam about its longitudinal axis whereby said cutter arm is moved from a retracted position into said operative position and pivoted into wire-cutting relation with said cutting anvil.

6. In a coiling machine having wire coiling tools, means for feeding wire lengthwise along a line of feed and into engagement with said coiling tools in order to form the wire into coils and a cutting anvil disposed for engagement with an inner portion of a coil thus formed, a cutter for severing said coils from the supply of wire being fed which comprises,

(a) cutter arm mounted for pivotal movement into and out of wire-cutting relation with said cutting anvil, said cutter arm being disposed for such movement within a plane substantially perpendicular to the plane in which said coil is formed,

(b) said cutter arm having a cutting blade adjacent one end,

(c) means for mounting said cutter arm for pivotal movement into and out of said wire-cutting relation with said anvil and for reciprocal movement 13 along a path substantially parallel to the coiling axis such that said cutting blade is movable into and out of an operative position for cutting the coil,

(d) means for pivoting said cutter arm into and out of said wire cutting position, and

(e) means for moving said cutter arm into and out of said operative position.

7. In a spring coiling machine having wire coiling tools, means for feeding wire lengthwise along a line of feed and into engagement with said coiling tools in order to coil the wire into springs and a cutting anvil disposed for engagement with an inner portion of the coil thus formed, a cutter for severing a coiled spring from the supply of wire being fed, which comprises,

(a) a cutter arm mounted for pivotal movement in a plane substantially perpendicular to the line of feed of the wire,

(b) said cutter arm having a cutting blade adjacent one end movable into and out of wire-cutting relation with said cutting anvil upon pivotal movement of said cutter arm,

(c) means for mounting said cutter arm for both linear and pivotal movement and for confining such linear movement to a path substantially parallel to the longitudinal axis of the spring being coiled, such that said cutting blade is movable into an operative position for cutting the coil and retracted into an inoperative position,

((1) a cam follower on the other end of said cutter arm,

(e) a cylindrical cam disposed adjacent said other end of said cutter arm having an annular cam surface disposed in cooperative relation with said cam follower for pivoting said cutter arm into and out of cutting position,

(f) a rocker arm mounted for engagement of one end with the other end of said cutter arm for moving said cutting blade into its operative position with respect to the spring coil,

(g) a second cam surface formed on the periphery of said cylindrical cam engageable with said opposite end of said rocker arm for pivoting said rocker arm and thereby moving said cutter arm into said operative position, and

(11) means for rotating said cylindrical cam about its longitudinal axis whereby said cutter arm is moved from a retracted position into said operative position and pivoted into cutting relation with said cutting anvil.

8. In a cyclically operable spring coiling machine, having means for longitudinally feeding wire to a predetermined extent during each cycle and for interrupting the feed near the end of each cycle, a coiling abutment having an inoperative position spaced from the path of wire feed and having an operative position in said path in which said coiling abutment serves to deflect the longitudinally fed wire from its path into a coil and a cam shaft rotatable about a fixed axis having a cam for moving said coiling abutment to and from its operative position, linkage means interconnecting said cam and coiling abutment comprising in combination,

(a) a lever pivoted at a fixed pivot point,

(b) a cam follower disposed at one end of said lever for engagement with said cam,

(c) a rod pivotally connectable at one end to said lever at a first connection point located a predetermined distance from said pivot point on one side thereof relative to said cam follower, said rod being alternatively connectable to said lever at a second connection point located an equal distance from, and on the opposite of, said pivot point from said first connection point,

( d) means for pivotally connecting the other end of said rod with said coiling abutment, said means including a pivot pin at said other end of said rod located at equal distances from said first and second connection points on said lever, whereby the same amount of movement is imparted to said coiling abutment by said cam when said rod is connected to either of said first and second connection points, but in opposite directions depending on which of said connection points said rod is connected to.

References Cited UNITED STATES PATENTS 1,250,584 12/1917 Jensen 72-132 1,762,556 6/1930 Marshall 72132 1,774,495 8/1930 Laiferty et a1 72138 X 2,073,343 3/1937 Heilman 72138 2,119,002 5/1938 Bergevin et al. 72132 2,175,426 10/1939 Blount et al. 72138 X 2,925,115 2/1960 Franks 72135 X 3,009,505 11/1961 Franks 72132 X 3,010,491 11/1961 Pearson 72132 3,342,052 9/1967 Boy 72138 MILTON S. MEHR, Primary Examiner U.S. Cl. X.R. 72138

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