US3721276A

US3721276A - Eyelet making device for springs,to be coupled to winding machines and operating at the same output speed of the latter

Info

Publication number: US3721276A
Application number: US00050145A
Authority: US
Inventors: E Lamperti
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-06-26
Filing date: 1970-06-26
Publication date: 1973-03-20
Anticipated expiration: 1990-03-20

Abstract

The device is for forming an anchoring ring on one or both of the ends of a helical spring. It comprises: guide means for the spring, spring gripping means in the form of jaws, at least one of which is movable, means on the sides of the jaw for eyelet bending at least one end of the spring and means for shearing the surplus wire, conveyor means are provided in the form of a cradle for receiving the spring and carrying it to the deformation zone. The device is mounted at the discharge of a helical spring forming machine to finish springs with the end eyelets.

Description

United States Patent 1 Lamperti ]March 20, 1973 [54] EYELET MAKING DEVICE FOR 2,268,824 1/1942 Hicks ..140/103 SPRINGS, TO BE COUPLED TO 3,313,325 4/1967 Wells 140/103 WINDING MACHINES AND OPERATING AT THE SAME OUTPUT Primary Examiner-Lowell Larson SPEED OF THE LATTER Manley-Stephens & e

[76] Inventor: Enrico Lamperti, Via Ercole Fer- QBSTR a rario 4, Gallarate, Varese, Italy [57] CT The device is for forming an anchoring ring on one or [22] Flled June 1970 both of the ends of a helical spring. It comprises: guide [21] App]. No.: 50,145 means for the spring, spring gripping means in the form of jaws, at least one of which is movable, means 7 Y on the sides of the jaw for eyelet bending at least one [30] Forelgn Apphcatlon Pnonty Data end of the spring and means for shearing the surplus June 26 1969 Italy 18726 N69 wire, conveyor means are provided in the form of a cradle for receiving the spring and carrying it to the [52] [1.8. CI. ..140/103 deformation zone,

1f 35 02 355: Search 140/103. $3 The device 15 mounted at the discharge of a helical spring forming machine to finish springs with the end [56] References Cited eyelets UNITED STATES PATENTS 11 Claims, 16 Drawing F 8" 940,828 11/1909 Sleeper ..140/103 1,065,336 6/1913 Bigelow ..140/103 1,869,501 8/1932 Peterson ..l40/103 PATErflt-inummma 3,721,276

4 IF 7/ l v INVENTOR il -R110 LHMPERTI BYJTEPHEDDS z HQETTIG- ATTORNEYS I PATENTEDHARZOIBYS v 3,721,276 SHEET 20F 4 INVENTOR NRKO L nmPE m1 BY STEPHENS? HUETTHs- PATENTEUmzomn 3,721,276

swan u er 4 IN VE NTOR T O LAm PE RTI I BY STEPHENS HOB-1 ATTORNEYS EYELET MAKING DEVICE FOR SPRINGS, TO BE COUPLED TO WINDING MACHINES AND OPERATING AT THE SAME OUTPUT SPEED OF THE LATTER This invention relates to a device for providing on one or both of the ends of a spring the associated anchoring eyelets.

Said device is applicable to a winding machine producing the springs, and is driven by the driving means of the machine and, therefore, concurrently therewith.

The main object of the present invention is to provide' a device to be coupled to a winding machine,

whereby the springs being produced are provided with eyelets or loops on one or both of the ends, thereby avoiding the need of resorting to further processings for making such eyelets.

Particularly, the double-eyelet making device according to the present invention comprises: a member guiding the springs and holding the same in a coaxial attitude during feeding; two threaded semi-cylindrical jaws, at least one of which is movable, these jaws closing as soon as a finished sectionof spring is placed therebetween so as to be clamped thereby; said jaws having an extension below said spring; two wedges juxtaposed to a jaw in such a position as to displace the end turns of the spring and to bend them against two shaped extensions on the sides of the opposed jaw to bring said turns to a coplanar position with respect to the spring axis; two movable knives or cutters operating at the completion of the bending to shear the surplus wire from the eyelet sections; the latter being optional where closed eyelets are desired.

The eyelet forming device is driven by the cam shaft of the winding machine so that when having completed its cycle, said shaft will disengage the clutch, drive the shearing operation, and simultaneously drive the jaw pushers by the cam of the device. The eyelet forming device may be also driven by the other continuously rotating shaft of the winding machine or by an independent power source, but synchronized with the winding machine motion.

The several members of the device and associated variants may be as follows:

' a. The spring guiding member may be a sleeve mounted coaxially of the wire winding axis, having its receiving mouth or inlet'just after the cutting knife for the spring section and is preferably formed with at least a partial inner thread to receive the spring travelling therethrough at the output speed. Such a sleeve may' comprise an eccentric section with a longitudinal toothed element which is internally toothed and radially adjustable, or may comprise a constant diameter section with three longitudinal toothed elements which are adjustable, or may comprise a sleeve provided with a plurality of set screws arranged along a helical line and having tapered inner tips, or a simple extension of the cutting pin of the winding machine may act as a guide for the feeding spring sections instead of the sleeve.

b. A pair of jaws which may comprise a stationary element and an intermittently moving element, or both jaws may be symmetrically moving elements.

c. An operating tool mounted downstream of the jaw pushers with tools operating at right angles relative to the tools upstream of said pushers to provide the two eyelets perpendicular to each other.

d. A lever member having a spring receiving cradle to carry the spring to an operative position from the discharge of the spring winding machine.

e.v Symmetrically movable tools which are arranged vertically and a fixed sleeve coaxially of the winding machine to provide for an eyelet at only one end of the spring exiting from the sleeve.

The means by which the objects of this invention are obtained are described more fully with respect to the accompanying drawings, wherein a practical embodiment of the device accordingto the invention is shown with some variants and modified forms give by way of example only and not as limiting the disclosure and in FIG. 5 is a sectional view similar to that of FIG. 3, in

accordance with a modified embodiment relating to the position of the device with respect to the winding axis;

FIG. 6 is a view similar to FIG. 1, wherein thevariants concerning the modified embodiment are schematically shown;

FIGS. 7 and 8 are cross-sectional and longitudinal sectional views, respectively, of a sleeve;

FIGS. 9, l0, l1 and 12 are similar sectional views showing two other modified sleeves;

FIG. 13 is a sectional view according to line 13-13 of FIG. 14 showing the modified device provided with the two movable pushers;

FIG. 14 is a plan view of FIG. 13;

FIG. 15 is a front view from the outlet side showing a modified device for eyeletting and cropping one end only of the spring; and

FIG. 16 is a vertical section of FIG. 15 according to the plane through line 16-16.

From FIGS. 1, 2 and 3, it will be seen that the device comprises a supporting horizontal plate 7 on which two parallel longitudinal members are provided, namely, a stationary member 8 on the left-hand side of FIGS. 1 and 2, and a movable member 9 on the right-hand side of these figures, and acting as the jaw pusher; two fixed bars 10 forming the sliding guides for said movable longitudinal member, which are supported by said stationary longitudinal member 8 and are each provided with a spring 11 acting against said longitudinalmovable member. The movable member carries an outer roller 12 on its center line pressing against the cam 13 keyed on the shaft 14 which may be the extension of the main shaft for the winding machine, or which may be connected thereto by a universal joint 15. A stationary jaw 16 is fixed to the longitudinal member 8 and has a semi-cylindrical seat 17, on the inner periphery of which a toric thread 17' of a shape to fit the profile of spring I8 is provided to hold a spring in a correct position during operations. A shaped profile 19 and a knife or cutter 20 is secured on each side of jaw 16 for bending the last turn at each of the two ends of spring 18 and cutter 20 shearing the excess wire portion beyond the bend. The latter operation being optional and is omitted when desiring to provide closed eyelets. A movable jaw 21 is provided opposite jaw 16 and is narrower than 16 by an amount equal to two end turns of the spring. Jaw 21 is mounted on the longitudinal member 9 and is provided with a semi-cylindrical seat 17 with thread 17 Two oblique profiles 22 coupled to the two counter-blades 23, one on each side of seat 17, are capable of advancing slightly when the two jars mate for right angle bending of the two end turns against shaped abutments 19.

Two guide bars 36, fast with said longitudinal member v9, guide said jaw 21 when the latter is stationary after meeting said jaw 16 to hold a spring 35 while the longitudinal member 9 along with the profiles 22 continue to travel forward when the jaw 21 moves and returns to its normal position when the longitudinal member 9 is retracted. A spring supply sleeve 24 is arranged coaxially to the winding axis of the spring and has its upstream aperture 24' nearly adjacent the movable knife 25, which shears the wire and interrupts a formed spring section 26 almost completely. The severed spring which has entered said sleeve continues to rotate aided in the regular feeding by the partial or total torically shaped thread 27, the diameter of which slightly exceeds the outer diameter of the spring to avoid any undesired friction.

Modified forms of sleeves are shown in FIGS. 7 to 12. A modified sleeve 35 comprises a tube 35 having an eccentric section and wherein a radial slit 36 is provided longitudinally of the major width for receiving the comb-plate 37, provided on its inner edge with teeth 37' for controlling the rotational feeding of the helical spring from the winding member, said plate 37 being retained in position by at least one set screw 38 or by an adjustable resilient fastener.

In FIGS. 9 and 10 the sleeve 39 is of a constant section and three slits 36 are provided therein for three comb-plates 37 which are secured by set screws 38, or by an adjustable resilient fastener. In FIGS. 11 and 12 the constant section sleeve 40 has a plurality of set screws 41, having a tapered inner end 41, along a helical line from end to end. As to the inner thread, these sleeves are adjustable for use with difierent diameters of springs, particularly

sleeves

39 and 40. The combs could also comprise multi-sections or lengths.

As seen from the drawing, the sleeve 24 is located at a higher level than the operative axis of the device. The device and sleeve are rigidly mounted with respect to each other and to the winding machine as well by any preferred means. Fins or side guide planes with respect to said sleeve could be provided. In order that the spring 18 will fall down always in the same attitude into the lower coaxial location of the two half seats 17 for the

jaws

16 and 21, and in order to aid correct lowering of the spring, jaw 21 has a flat extension 28. A recess is provided in the other jaw (FIG. 2) corresponding to extension 28. As soon as spring 18 has fallen down, the cam 13 causes the longitudinal member 9 to advance with said jaw 21 so as to effect the clamping of said spring against the other jaw 16. The profiles 22 continue to advance, separating the end turns of the spring which, however, are held in the other jaw 16 by the inner edge of bearing or abuttments 19. Therefore, the

advancement of sides 22 will induce the turn or ring 7 half bend against the profile of bearings 19, providing the median or center eyelet 29 on the two ends of the spring. Upon immediate retraction of jaw 21, the spring 18 will fall vertically down through the slit 7'.

. If necessary, an ejector can be inserted in one of the jaws, this ejector being under the constant influence of a spring would automatically provide a bias to remove the finished spring. Consideration is now taken for the case where the eyelet can be a single completed, double completed of simple hook eyelet. The first case is that as described and shown in the drawings, considering that the knives or cutters 20-23 have been omitted. In the second case the jaw 21 is of such a width as to clear the two last turns or rings of the spring at each of its two ends and, therefor, the eyelet will in this case be a double eyelet. The third case is that as shown in the drawing with the provision of the knives or cutters 20-23 and with an eyelet as shown in FIG. 3. The end of the wire at each eyelet is cut off by cutters 20-23 to leave a simple hook eyelet.

It should still be taken into account that by varying the blades or bending profiles, offset eyelets, German eyelets, or English crank or crank eyelets can be provided, all of these forms being well known and thus not requiring any further description.

As above mentioned, the bending, abutting and cutting toolsmay vary as to shape and position according to the type of eyelet to be provided. Moreover, they can be made of hard metals or with hard metal faces as inserts.

In FIGS. 5 and 6 there is shown a variation relating to the position of the device relative to the spring feeding sleeve 24. In this variation the device is brought with the jaw axis to be coincident with that of the sleeve to provide for a direct feeding coaxial with the jaws. Therefore, to move the device away from the sleeve during the eyelet forming operation it is provided that sleeve 24 slides with its base plate 7 on two stationary guides 30 through the required distance to move the moving members of the device to prevent sleeve interference. To this end, a wide faced cam 13' is provided so that the roller 12 will contact it even at the two limit positions. On the prolongation of shaft 14 a grooved cam 31 is also provided adapted to oscillate the lever 32, pivoted at 33, to move said base plate 7 by tie rod 34 on the two slide guides 30. The remainder of the machine is the same in structure and operation as described in connection with FIGS. 1, 2 and 3.

The variation shown in FIGS. 13 and 14 relates to jaws 41, which are bothv symmetrically movable. Jaws 41 are mounted by a pair of sleeves 42 on the fixed bars 43, on which they can slide under the action of earns 44, the movement of which is made conjoint by the two bevel gears 45 and shaft 45' coupling the same. The springs 43' compressed between the opposite pairs of sleeves 42 retain the pressure of jaws 41 against the associated cams 44. One of the two shafts 46, on which the cam 44 and a tappered hub of gear 45 are keyed, is directly driven by the mainshaft of the machine (not shown). A second cam 47 is keyed onto shaft 46. A cam follower 48 bears on cam 47 and is mounted on the shaped lever 49, pivoted on a fixed pivot at 49' and carrying at its opposite end a rod 50 extending at right angles thereto to take a vertical position at the beginning of its operation (FIG. 13). At its upper end a cradle seat 50' is provided for receiving the spring coming out of the sleeve M. The cam 47 causes the cradle 50' to take three positions; a spring receiving position (full lines in FIG. 13); a second lowered position bringing the spring to the level of the two jaws 41 for the eyelet forming operation (dashed lines); and a third position of spring release (dashed lines) so that the completely eyeletted spring will fall out of the machine.

Any ejector assuring that the spring will fall down may be used. In order to secure the spring on the cradle 50', it is contemplated that during the time said spring has to retain the spring the lever adjacent cradle 50' will be magnetized by an electromagnet which is intermittently operated by a microswitch controlled by said cam 47 or the like. Such holding could also be provided by mechanical or leaf means. The novelty of the two symmetrically moving jaws 41 will enable to provide the so-called English or crank eyelets, when duly changing the tools.

The same device shown in FIGS. 13 and 14 can provide two eyelets at right angles to each other. To this end, it is only required to remove the downstream tools of the two jaws 41, and to key a cam onto the shaft 46 to operate a rocking lever controlling a vertical slide, the stationary guides of which are fast with the apparatus. The end of said slide being configured so as to form a tool bending the downstream eyelet of the spring in a horizontal direction, that is, perpendicular to the direction of the eyelets at the other end.

In some instances, springs having an eyelet at only one end thereof are required. A simplified device may be provided for obtaining springs having only one eyelet, said device having the same features as described above. Thisdevice is shown in FIGS. 15 and 16 and provides a vertical plate 52 made fast to the bedplate of the winding machine, which carries the guide sleeve M, which, therefore, is fast therewith. Two opposed slides 53 are provided to carry the tools 53 for forming the eyelet 0 with the last turn of the spring and to simultaneously crop the wire end. The two slides 53 are simultaneously driven by a pair or rocking levers 54, pivoted on plate 52 at 54' and are driven by a pair of cams 55 keyed on a driving shaft 56, said cams being arranged so as to move said levers symmetrically.

Both the sleeve M and slides 53, the pivots 54' and cams 55 are mounted by members enabling an accurate setting up thereof. The slides 53 are constantly maintained in contact with the associated levers 54 by expansion springs (not shown). It is apparent that this simplified device is suitable to be mounted coaxially of the winding machine as its operation rate is synchronized with that of the winding machine. In any case, it should be taken into account that the described devices carry out simultaneously the eyelet forming and the cropping operation. In the last case above described, this is done directly at the winding machine outlet.

It should also be noted that the devices, as shown in FIGS. 1, 6 and 14, are also applicable in combination with winding machines particularly, but not exclusively for manufacturing eyelet tension springs. Thus, by approaching the devices so that the jaw axis will be at the exact lower level with respect to the winding axis, they may be supplied by means of lever 49, excluding the loading guide sleeve, by suitable registering systems taking care of the mutual positions for the several members in connection with the diameter and length of the spring to be provided with eyelets.

. Also, in the normal operation of the described devices, it is possible to replace the sleeve by providing the cutting pin of the winding machine with an extension, said extension having a length which is multiple of the spring length and which may be of any material.

The members directly contacting the spring sections coming out of the winding machine will have to be changed whenever said spring section changes, either as-to the spring diameter or the wire diameter from which it is formed and the element length. Furthermore, part of said member will need to be changed when changing the type of eyelet to be provided.

Other variations can be made to parts or members in order to improve the structure and/or operation. However, all of such variations will be within the covering scope of the present invention.

I claim:

1. A machine for forming eyelets on at least one end of a succession of coiled wire springs from a winding machine, said eyelet forming machine comprising a driving shaft, a guide member having its axis coaxial of successive springs as they are discharged from a spring winding machine, clamping means to receive and hold successive springs comprising a pair of jaws, at least one of which is movable, at least one pair of tool elements closely adjacent an end of said jaws and movable upon clamping of a spring in said jaws for bending at least one end turn of the spring to form an eyelet the plane of operation of said jaws and said tool elements being parallel to but below the axis of said guide member.

2. The eyelet forming machine of claim 1, in which a cradle is mounted for movement from an elevated position to receive each successive spring from the guide member to an intermediate position to hold such spring in position to be engaged by said jaws, and to a lowest discharge position to discharge successive springs after the eyelet has been formed.

3. The eyelet forming machine of claim 2, in which electric means are provided to magnetize said cradle when it isin its elevated position, whereby, the successive springs will be securely held by said cradle as it moves to its intermediate position.

4. An eyelet forming device according to claim 1, in which said guide member for the springs coming out of the winding machine comprises a horizontal extension of the cutting pin of the winding machine, the length of which is a multiple of that of the spring.

5. An eyelet forming device for springs according to claim 1, in which said guide member for the springs comprises a cylindrical sleeve coaxial with the winding machine axis, having its inlet adjacent the cutting knives of the formed spring section and having at least a partial inner toric thread to fit the spring travelling through it and rotating at the output rate.

6. An eyelet forming device for springs according to claim 5, in which said sleeve has at least one longitudinal slit for accomodating at least one radially adjustable comb-plate which is clamped in place by screws at right angles thereto.

7. An eyelet forming device for springs according to claim 5, characterized in that said sleeve is provided with a plurality of grub screws extending therethrough arranged according to an eliptical line and having tapered inner ends.

8. An eyelet forming device for springs according to claim 1, in which the receiving and clamping seat for each spring comprises two jaws, one of which is stationary and each of which has on its clamping face a semi-cylindrical seat with a toric thread matching that of the spring, the moving jaw being shorter by at least two turns of the spring and at least one at each end, the stationary jaw extending the full length of the spring.

9. An eyelet forming device for springs according to claim 8, including a movable member supporting one of said jaws, said tool elements lying at each end of said movable jaw and mounted on said movable member, a

cam operative to positively move said movable.

member, the movable jaw being slidable in said movable member, whereby, when said two jaws contact, said tool holder will advance further for causing said tool elements to bend the end turns of said spring to form an eyelet, said movable jaw being biased by a spring to move it back to normal position upon return of the entire movable member.

10. An eyelet forming device for springs according to claim 1, in which a base plate is mounted on two stationary guides, a wide cam face is provided so that the movable clamping means will constantly contact it, and a second cam is provided in the form of a grooved cam, and a lever, which is connected by a tie rod to move the whole device relative to said guide members, is pivoted to said base plate, and is provided with an end engaging the groove of said grooved cam.

11. An eyelet forming device according to claim 1, said device comprising a vertical plate. fast with the machine and carrying the guide member; two coaxial and symmetrically moving slides, tools for forming an

Claims

3. The eyelet forming machine of claim 2, in which electric means are provided to magnetize said cradle when it is in its elevated position, whereby, the successive springs will be securely held by said cradle as it moves to its intermediate position.

9. An eyelet forming device for springs according to claim 8, including a movable member supporting one of said jaws, said tool elements lying at each end of said movable jaw and mounted on said movable member, a cam operative to positively move said movable member, the movable jaw being slidable in said movable member, whereby, when said two jaws contact, said tool holder will advance further for causing said tool elements to bend the end turns of said spring to form an eyelet, said movable jaw being biased by a spring to move it back to normal position upon return of the entire movable member.

11. An eyelet forming device according to claim 1, said device comprising a vertical plate fast with the machine and carrying the guide member; two coaxial and symmetrically moving slides, tools for forming an eyelet of the last turn of the spring and simultaneously cropping the wire end carried by said slides, said guide member being coaxial with the winding machine discharge, a pair of cams, a pair of rocking levers controlled by said pair of cams keyed on the driving shaft; said cams being arranged so as to move said levers simultaneously.