US3423980A

US3423980A - Spring winding machine

Info

Publication number: US3423980A
Application number: US572536A
Authority: US
Inventors: Robert L Ludwig; George Roy Rusling
Original assignee: Gulf Oil Corp
Current assignee: Gulf Oil Corp
Priority date: 1966-08-15
Filing date: 1966-08-15
Publication date: 1969-01-28
Anticipated expiration: 1986-01-28

Description

Jan. 28, 1969 "R. LUDWIG ET AL 3,423,980

SPRING WINDING MACHINE 6 E E0 v 7 v0 L m w 9 WV m a m R e a N mm wk 9% Q R Q N N 6 1 mm 3 We Jan. 28, 1969 R. L. LUDWIG ETAL 3,423,980

SPRING WINDING MACHINE Filed Aug. 15, 1966 Sheet 2 of2 I N VENTORS 4 08b??? A. LUDW/G 6. A 0) @054 ING United States Patent 6 Claims Int. Cl. 1521f 3/04, 3/10 ABSTRACT OF THE DISCLOSURE A spring winder comprising a rotating mandrel and a free moving carriage, with jaw means on the carriage to support the mandrel and to impart an adjustable pitch to the spring. The spring, as it is being formed, causes the carriage to move axially of the mandrel while maintaining pitch.

This invention pertains to machines for winding springs, particularly tension and compression springs.

As used herein, sizes refers to springs with diiferences in any or all of their parameters; namely, stock size, inside diameter, length, pitch, and the like.

The invention is directed to the problem present in many machine shops, factories, and the like, of obtaining small quantities of many different sizes of springs. The obtaining of a very small number; for example, one or two, of a particular size spring can often involve a great deal of time and money in that a highly skilled machinist, and sometimes two such workers, or other skilled workmen, must be taken from their regular work and put to producing these special springs.

Another problem solved by the present invention is the provision of a highly simplified machine of the character described. Prior machines have been characterized by the inclusion of a positive feed, such as a power driven feed screw, or equivalent element, to move the carriage along the bed. An advantage of the present invention is the elimination of such feed screws or equivalent elements, thus simplifying manufacture and use of the machine, and effecting substantial economies in its manufacture and maintenance. The function of the feed screw, imparting pitch to the spring, is carried out in the present invention by the stock guide in cooperation with the stock itself and the coils of the spring being formed, as Well as a portion of the carrier, and is done substantially automatically. The invention also permits changing the pitch while the machine is running to produce a spring having a compound pitch.

The invention accordingly comprises a machine adaptable for use by the average Worker as opposed to the highly skilled worker to produce many different sizes of springs economically, quickly, and easily, and substantially automatically after the machine is set up.

A machine embodying the invention comprises a flat, longitudinal bed having a power source mounted at one end. from which extends a longitudinal mandrel. A carriage is freely slidable on the bed and feeds the spring stock onto the mandrel, with means to impart any predetermined pitch to the spring as it is being Wound, which means are adapted to push the carriage longitudinally of the mandrel as the stock is formed into a spring.

In the accompanying drawing forming a part of this disclosure:

FIG. 1 is an overall perspective view of a machine embodying the invention;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1 showing the pitch adjustment mechanism;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 1; and

FIG. 4 is a view of the mandrel and stock guide with the stock guide cover removed showing the path of the stock therethrough.

Referring now in detail to the drawing, 10 designates a machine embodying the invention. Machine 10 comprises a bed 12 which consists of a base member 14 which is in the form of a C channel positioned with its legs up. Mounted on the ends of the legs of C channel 14 and fixed thereto by any suitable means, such as by welding,

is a top bed plate 16. Bed plate 16 comprises a flat, top,

finished surface 18 and a pair of finished, longitudinal edge surfaces 20. Finished

surfaces

18 and 20 permit easy, unrestricted motion of the carriage thereon for a reason which will appear more clearly hereinafter.

Fixedly mounted, as by welding or other suitable means, at one end of bed plate 16 are bracket means 22 on which is mounted a mandrel drive unit 24. Drive unit 24 may comprise any suitable power source, such as an air motor or an electric gearmotor, the only requisites being that, the output turn at a relatively slow speed, it have means to adjust the speed, and it have means to reverse direction. In the preferred embodiment of the invention, drive unit 24 comprises an air motor with suitable valving to adjust the speed and reverse direction, which valving is conventional and not shown.

Mounted on the output end of drive unit 24 is an adjustable chuck 26 which permits the use of various different mandrels 28. The outer end of mandrel 28 is slotted as 29 to receive the end of the spring making stock S.

Slidably mounted on bed 12 is a carriage assembly 30. Carriage 30 comprises a pair of opposed L shaped end plates 32, each having a bottom flange 34 which extends below the overhanging edge of plate 16. Each end plate 32 further comprises an upwardly extending flange 36, which extends above top surface 18 of bed plate 16. Each flange 36 carries a first pair of anti-friction rollers 38 disposed in horizontal planes and riding against finished, edge surfaces 20 of bed plate 16. Each flange 36 also carries a second pair of anti-friction rollers 40 disposed in vertical planes and riding against top finished surface 18 of bed plate 16.

Thus,

rollers

38 and 40 are the only connection be tween the carriage 30 and the bed plate 16, and therefore, carriage 30 is free to move along the plate. The carriage can be simply rolled ofi the free end of the bed plate, if desired, for adustmeuts, lubrication, and the like and removable stop means, not shown, may be provided to prevent the carriage from rolling off while the machine is in use.

Interconnecting flanges 36 between the

rollers

38 and 40 is a top slotted carriage plate 42. Adjustably mounted on carriage plate 42 are a pair of

jaws

44 and 50. law 44, in a horizontal plane, is centrally notched out to form a pair of legs 44a, which renders the jaw generally U shaped. In a vertical plane, legs 44a are notched out as at 48. Notch 48 forms a square corner, the edges of which are disposed at a 45 angle to the horizontal, and has its axis at the vertical center line of jaw 44.

J aw 44 is movably mounted on the carrier by means of a bolt 46 passing through a suitable opening in jaw 44 and extending down below plate 42 into a traveling block 53. Similarly, jaw 50 is movably mounted on the carriage by means of a bolt 52 passing through a suitable opening in jaw 50 and extending down below plate 42 into a similar traveling block 54. Perpendicular to the axes of bolts 46 and 52 is an adjusting screw 56 which passes through suitable oppositely threaded openings in the traveling block, a suitable opening 36a in flange 36 of one end plate 32, and terminates in a crank handle 58. Screw 56 comprises a first threaded portion 53a and a second oppositely threaded portion 54a, cooperating with the

blocks

53 and 54. Thus, by turning crank 58, the

blocks

53 and 54 will move together or apart from one centerline. The other end of screw 56 rides in a blind opening 57 in the opposite end plate 36 for support.

Jaw 50 is of a thickness in the direction of the axis or mandrel 28 to fit snugly between the legs 44a of jaw 44, and is notched out as at 60 with a right angle notch similar to and symmetrically disposed to notch 48 in jaw 44. Thus, the space between the notches 48 and 60 is a square in a vertical plane, and the size of this square can be adjusted by means of crank 58 to move the jaws together or apart. Mandrel 28 loosely rides in this square, and the center line of the square is made to coincide with the center line of the mandrel when the jaws and their traveling blocks are assembled onto screw 56.

For convenience, the longitudinal direction along the bed from the carrier 30 towards drive unit 24 shall be considered rearward, and the opposite direction forward.

Jaw 50 also carries means 62 to adjust the pitch of the spring as it is being formed, see FIG. 2. Pitch adjustment means 62 comprises a member 64 having a central, plain, cylindrical shank portion 66 passing through a suitable opening in jaw 50. Extending rearwardly from shank portion 66, member 64 comprises a threaded portion 68. Threadedly mounted on threaded portion 68 is a hand adjustment nut 70. law 50 comprises a plurality of rearwardly extending lugs 74 which overlap a front flange 72 on nut 70 to keep nut 70 closely adjacent the rear surface of jaw 50. Thus, turning nut 70 will move member 64 axially with respect of jaw 50. The front end of member 64 comprises a threaded stud portion 76, on which is threadedly mounted a stock guide tightening nut 78.

Mounted on member 64 is a stock guide and tensioning assembly 80. Assembly 80 comprises a rear plate 82, which is formed integral with member 64 at the forward end of cylindrical portion 66. Rear plate 82 could also be formed as a separate member, as will be evident to one skilled in this art. Rear plate 82 comprises a forwardly extending pin 84 positioned furthest outwardly from the axis of member 64. Exetending both forwardly and rearwardly from rear plate 82 radially inwardly of pin 84 is a second stock guide pin 86. The rearwardly extending portion of pin 86 fits into any one of a plurality of holes 88 formed in jaw 50. The positioning of the rear portion of pin 86 in any one of the holes 88 determines the angular position of assembly 80 with respect to the axis of mandrel 28. This angular position is important when using heavier sizes of stock, in that such heavier stock may kink, and when using such heavier sizes, the angular position is suitably adjusted to achieve a substantially straight delivery of stock to the mandrel, depending, of course, upon the direction of rotation of the mandrel. As shown in FIG. 4, the feed stock S is fed between the two pins 84 and 86 so that it is firmly held and fed regardless of the direction of rotation of the mandrel. With exceptionally heavy stock, it may be necessary to by-pass these pins, but such large stock is stiff enough so that additional support would not be needed.

Assembly 80 further comprises a front plate 90, which is formed with three suitable openings which slidably receive pins 84 and 86 and the shank portion of member 64 between threaded portion 76 and cylindrical portion 66, respectively. Assembly 80 is removably held together by the nut 78, which also serves to tighten the plates 82 and 90 onto feed stock S. Tension is necessary on the feed stock to obtain tight, regular coils.

Operation The operation is most readily explained by way of a specific example.

It was desired to make a coil tension spring having an inside diameter of A inch, a length of 2% inches, from inch diameter carbon spring steel wire. A mandrel was selected having a diameter of inch. The mandrel diameter is somewhat smaller than the inside diameter of the spring because it is necessary to allow for the expansion of the spring after it is formed and the tension released.

The releasing of this tension is another problem solved by the present invention which is present in prior devices. This problem is the substantial danger of physical harm to the operator when releasing wound springs from mandrels that have not had the tension stored in them during their formation relieved before removal. The problem is solved in the present invention by reversing rotation of the mandrel until the tension is released, in effect unwinding the tension, and then cutting the stock to remove the finished spring. Normal finishing operations, such as flattening the ends, or the like, may be performed in the conventional manner, if desired.

The drive unit 24 was adjusted for a rotational speed of about 120 rpm. Nut 70 was turned to move member 64 carrying nut 78 and assembly 80 forwardly to make room in which to work. The nut 78 and front plate were removed. Stock S was run between pins 84 and 86 and into the mandrel slot 29. The plate 90 and nut 78 were put back into place and nut 78 tightened to put drag or tension on stock S. This drag or tension on the feed stock is required to insure tight wrapping of the wire on the mandrel and to assure uniform coils. It will be noted that once plate 90 and nut 78 are adjusted, they may be moved as a unit by rotation of nut 70. Before feeding the wire onto the mandrel, crank 58 was turned to bring

jaws

44 and 50 snugly up against mandrel 28. This enclosed mandrel 28 in the square defined by notches 48 and 60 in the jaws. The pressure applied via crank 58 is such that the mandrel is just supported, and not bound or restricted against rotation.

Nut 70 was then turned in the opposite direction to move the center line of the stock S between plates 90 and 82 rearwardly of the front face of jaw 44. It will be noted that the relative position, in a horizontal plane, between the center line of the stock S between the jaws 82 and 90 and the front vertical face of the jaw 44 determines the pitch of the completed spring, which in this case Was 7 coils per inch. To achieve this pitch, under these conditions, the spacing between the center line of the feed stock between the jaws and the front face of jaw 44 was too small to measure. The operator turns nut 70 slowly until the proper pitch is imparted. Only very slight adjustment is required.

The embodiment of the invention used to fabricate the spring of the above example is capable of winding springs having inside diameters varying from inch to more than 5 inches, using stock varying in diameter from .0126 inch to .750 inch.

It will be understood that during preparation the carriage 30 is at the front end of mandrel 28. After the machine is setup, the drive unit 24 is turned on and the spring proceeds to wind itself, with the pitch being automatically imparted to the spring by pressure of the feed stock passing from the jaw to the mandrel against the front face of jaw 44.

Referring to FIG. 2, it will be seen that moving assembly 80 to the right will result in springs having a larger pitch and moving it to the left will result in springs having a smaller pitch, with the extreme of this leftward motion being a tension or pull spring having no spaces between the coils.

Another feature is that pitch adjustment nut 70 can be turned while the spring is being formed. This permits production of springs having variable pitch, or production of a number of short springs during one run of the machine with portions of large open pitch between portions of close pitch to facilitate cutting the overall spring apart to thus effect economies in the use of material. Since the pitch can be adjusted while the machine is running, it is possible to make a spring with a very precise pitch when needed, as well as with a compound pitch.

Other variations of springs which it is possible to make include conical springs or springs having tapered ends. This is readily accomplished with the use of the embodiment of the invention as described above, except that a conical or a tapered ended, or otherwise specially formed mandrel, is substituted for mandrel 28.

It will be seen that the present invention provides simple to operate and uncomplicated means by which many diiferent sizes of springs can be made and in which the pitch is imparted to the spring automatically by the coils of the formed spring itself, which coils progressively move carriage 30 rearwardly towards power source 24 as they are formed. Reversing direction of the mandrel permits release of the stored energy within the spring to eliminate a serious safety hazard present in prior devices.

When using relatively large diameter or special mandrels it is, of course, possible to substitute a larger capacity chuck for chuck 26 shown.

While the invention has been described in some detail above, it is to be understood that the protection granted is to be limited only within the spirit of the invention and the scope of the following claims.

Therefore we claim:

1. In combination, a base member, drive means on said base member, a mandrel, means to mount said mandrel on said drive means in spaced relation to said base member for rotation of said mandrel about its axis, carriage means, means to mount said carriage means on said base member for free motion of said carriage means on said base member axially of said mandrel, said carriage means comprising means to feed spring making stock onto said mandrel, said carriage means further comprising means cooperable with said spring making stock and said feeding means to move said carriage means axially of said mandrel on said base member to impart a predetermined pitch to a spring being formed on said mandrel, said carriage means comprising a pair of jaws, means on said carriage means to adjust the relative positions of said jaws to each other and to the axis of said mandrel, one of said jaws comprising a pair of spaced legs, the other of said jaws comprising a portion receivable between said legs, said feeding means comprising a pair of plates on said other jaw, means to adjust the spacing between said plates to accommodate various sizes of spring making stock therebetween, and said cooperable means comprising means to adjust the position of said plates with said stock therebetween with respect to a portion of said one of said jaws.

2. The combination of claim 1, said feeding means further comprising means to apply tension to the spring making stock feeding between said plates to said mandrel.

3. The combination of claim 1, one of said plates comprising a pair of pins extending outwardly therefrom, the other of said plates being formed with a pair of openings adapted to slidingly receive said pins, where- :by said stock feeding between said plates to said mandrel may pass between said pins, whereby said stock is retained to feed between said plates in both directions of rotation of said mandrel.

4. In combination, a base member, drive means on said base member, a mandrel, means to mount said mandrel on said drive means in spaced relation to said base member for rotation of said mandrel about its axis, carriage means, means to mount said carriage means on said base member for free motion of said carriage means on said base member axially of said mandrel, said carriage means comprising means to feed spring making stock onto said mandrel, said carriage means further comprising means cooperable with said spring making stock and said feeding means to move said carriage means axially of said mandrel on said base member to impart a predetermined pitch to a spring being formed on said mandrel, said feeding means comprising a pair of plates, means to adjust the spacing between said plates to accommodate various sizes of spring making stock therebetween, and said cooperable means comprising means to adjust the position of said plates with said stock therebetween with respect to a portion of said one of said jaws.

5. The combination of claim 4, said feeding means further comprising means to apply tension to the spring making stock feeding between said plates to said mandrel.

6. The combination of claim 4, said plates comprising a pair of pins extending therebetween, whereby the spring making stock feeding between said plates is restrained to pass between said plates.

References Cited UNITED STATES PATENTS 963,512 7/1910 Butterworth 72-143 2,054,196 9/1936 Gogan 72144 X 2,325,462 7/1943 Arthur 72144 2,649,130 8/1953 Border 72-144 2,811,193 10/1957 Iversen 72143 FOREIGN PATENTS 585,792 10/1933 Germany.

4,400 8/1893 Sweden.

MILTON S. MEHR, Primary Examiner.

U.S. Cl. X.R. 72138