CN109475922B

CN109475922B - Coil spring winding apparatus and method of winding coil spring

Info

Publication number: CN109475922B
Application number: CN201680079590.9A
Authority: CN
Inventors: 罗兰·凯勒
Original assignee: Spuehl AG
Current assignee: Spuehl AG
Priority date: 2016-02-03
Filing date: 2016-02-03
Publication date: 2020-04-28
Anticipated expiration: 2036-02-03
Also published as: TW201739538A; US20190039118A1; TWI654038B; CN109475922A; EP3411166A1; WO2017133766A1

Abstract

A coil spring winding apparatus (1) includes a stator and a rotor (10), the rotor (10) being supported on the stator so as to be rotatable about a rotation axis (13). The rotation axis (13) extends along a spring axis of a coil spring wound by the coil spring winding apparatus. At least one winding tool (21, 22) is supported on the rotor (10) for rotation about the axis of rotation (13) of the rotor (10) upon rotation of the rotor (10). The at least one winding tool (21, 22) is configured to bend the wire (8) to form the helical spring when the rotor (10) is rotated. The at least one winding tool (21, 22) is adjustable relative to the rotor (10).

Description

Coil spring winding apparatus and method of winding coil spring

Technical Field

Embodiments of the present invention relate to an apparatus and method of winding a coil spring. Embodiments of the present invention relate, inter alia, to an apparatus and method of winding a helical spring in which a rotor supporting one or more winding tools is mounted for rotation about an axis of rotation of the spring.

Background

Mattresses, sofas or other bedding or seating furniture may be provided with innerspring units. The innerspring unit may be formed from springs. Machines for forming innerspring units may be provided with coil spring winding apparatus operable to wind coil springs. Typically, a plurality of springs having a height matching the height of the innerspring unit are engaged with one another to form an innerspring unit. In other cases, the endless coil spring may be further processed, such as by bending, to produce an innerspring unit therefrom.

The coil spring winding apparatus may have various configurations. To illustrate, some coil spring winding apparatuses may have a rotating mandrel with the coil spring wound around an outer surface of the mandrel. This and many other kinds of coil spring winding devices output a coil spring that rotates about its spring axis while being wound. This may prevent such coil spring winding apparatus from being used with certain types of machines for forming innerspring units, for example, machines configured to receive coil springs advanced in translation to form the innerspring unit.

A coil spring winding apparatus providing a rotor rotating about an axis of rotation and having a winding tool mounted thereto may be operated in such a manner that its output advances in a translational manner along its spring axis. However, the types of springs that may be produced by such a coil spring winding apparatus may be more limited.

Disclosure of Invention

There is a continuing need in the art for a coil spring winding apparatus and method of winding a coil spring that addresses at least some of the above-mentioned needs. There is a continuing need in the art for a coil spring winding apparatus and method of winding a coil spring that can operate in a manner such that when the wound coil spring is output by the apparatus, rotation of the wound coil spring about its spring axis can be reduced or eliminated while allowing for the creation of springs of different shapes.

According to an embodiment, one or several winding tools are supported on a rotor rotatable about a rotation axis, the one or several winding tools being supported on the rotor for rotation about the rotation axis of rotation of the rotor while accommodating adjustment of the one or several winding tools relative to the rotor. This configuration allows the rotor to rotate about the spring axis of the spring being formed so that the spring advances in a translational manner from the rotor. Adjustment of the winding tool or tools relative to the rotor allows variations in the shape of the spring to be implemented, for example, by creating a spring having a conical, cylindrical or hourglass shape.

The coil spring winding apparatus according to the embodiment includes a stator and a rotor. The rotor is supported on the stator so as to be rotatable about a rotation axis. The rotational axis may extend along a spring axis of a coil spring wound by the coil spring winding apparatus. At least one winding tool is supported on the rotor for rotation about the axis of rotation of the rotor as the rotor rotates. The at least one winding tool is configured to bend a wire to form the coil spring as the rotor rotates. The at least one winding tool is adjustable relative to the rotor.

A helical spring winding apparatus having this configuration allows the rotor to rotate about the spring axis of the spring being formed so that the spring advances in translation from the rotor. The adjustment of the winding tool or tools relative to the rotor allows to implement variations in the shape of the spring.

The coil spring winding apparatus may be configured to output an endless coil spring.

The coil spring winding apparatus may be configured to output the wound coil spring in such a manner that the wound coil spring does not rotate about the spring axis while being coupled to the rotor.

The coil spring winding apparatus may be configured to output the wound coil spring in such a manner that the wound coil spring advances in translation along the axis of rotation of the rotor while being coupled to the rotor.

The pitch and/or diameter of the turns of the helical spring can be adjusted by adjusting the at least one winding tool relative to the rotor. By adjusting the at least one winding tool relative to the rotor, a helical spring can be produced having different variations in pitch and/or diameter along the spring axis.

A wire guide configured to guide the wire may be mounted on the rotor to rotate about the rotation axis when the rotor rotates. The guide may define a recess configured to guide the wire such that abutment of the wire on the at least one winding tool causes the wire to bend.

The at least one winding tool may include a first winding tool configured to bend the wire to set a diameter of a turn of the coil spring. The first winding tool may be a bending tool that bends the wire in a radial direction of the coil spring. The first winding tool may be configured to bend the wire in a plane extending transverse to the axis of rotation of the rotor.

The first winding tool may be supported on the rotor so as to be displaceable relative to the rotor in a direction transverse to the axis of rotation. The first winding tool may be supported on the rotor so as to be pivotable relative to the rotor about a pivot axis extending parallel to the axis of rotation.

The at least one winding tool may additionally or alternatively comprise a second winding tool configured to bend the wire so as to set a diameter of a turn of the helical spring. The position of the second winding tool relative to the wire guide may affect the diameter and pitch of the turns of the coil spring. The second winding tool may be a deflecting tool that bends the wire in an axial direction of the coil spring. The second winding tool may be configured to bend the wire in a direction along the rotational axis of the rotor.

The second winding tool may be supported on the rotor so as to be movable in a direction parallel to the axis of rotation of the rotor.

The wire may extend from the wire guide to the first winding tool and then to the second winding tool. The arrangement of the first winding tool and the second winding tool relative to the wire guide may define a diameter and a pitch of turns of the coil spring formed by the coil spring winding apparatus.

The coil spring winding apparatus may include a first adjustment mechanism configured to adjust a position or orientation of a first winding tool of the at least one winding tool relative to the rotor. This allows the first winding tool to be automatically adjusted relative to the rotor according to the desired shape of the helical spring.

The first adjustment mechanism may include a first motor mounted on the stator. Whereby the balancing of the rotor can be simplified.

The first adjustment mechanism may include a first slider. The first motor is configured to effect displacement of the first slider in a direction parallel to the axis of rotation of the rotor to adjust the first winding tool relative to the rotor.

The first adjustment mechanism may include a motion conversion mechanism configured to convert displacement of the first slider parallel to the axis of rotation into movement of the first winding tool transverse to the axis of rotation.

The motion conversion mechanism may comprise a wedge-shaped member supported on the rotor so as to be movable in translation relative to the rotor in a direction parallel to the axis of rotation.

The first slider may comprise an annular abutment surface abutting on an end of the wedge member to cause the wedge member to rotate with the rotor about the axis of rotation in a direction parallel to the axis of rotation to displace the wedge member.

The motion conversion mechanism may include a tapered surface that abuttingly engages the wedge member. The inclined surface may be provided on a member which is pivotally mounted on the rotor and which comprises or otherwise supports the first winding tool.

The coil spring winding apparatus may include a second adjustment mechanism configured to adjust at least one of a position or an orientation of a second winding tool of the at least one winding tool relative to the rotor. This allows the second winding tool to be automatically adjusted relative to the rotor according to the desired shape of the helical spring.

The second adjustment mechanism may include a hollow member attached to the rotor to rotate about the rotation axis when the rotor rotates. The hollow member may be a hollow tube. The second winding tool may be mounted to the hollow member.

The hollow member may be positioned such that the coiled coil spring extends through the hollow member. The hollow member may be positioned such that the coiled coil spring protrudes from the hollow member.

The second adjustment mechanism may include a second motor and a second slider. The second motor may be configured to displace the second slider in a direction parallel to the axis of rotation.

The second motor may be mounted on the stator.

The second slider may support the hollow member against to allow the hollow member to rotate together with the rotor while displacing the hollow member parallel to the rotation axis by displacement of the second slider. The second slider may include a roller that engages a surface of the hollow member.

The first motor and/or the second motor may each be a stepper motor.

The first adjustment mechanism may be configured to adjust the first winding tool relative to the rotor in a direction transverse to the axis of rotation.

The second adjustment mechanism may be configured to adjust the second winding tool relative to the rotor in a direction parallel to the axis of rotation.

The coil spring winding apparatus may comprise a control device configured to control adjustment of the at least one winding tool relative to the rotor.

The control device may be coupled to the first adjustment mechanism and the second adjustment mechanism. The control device may be configured to actuate the first adjustment mechanism and/or the second adjustment mechanism only when at least one of a diameter or a pitch of turns of the helical spring is to be changed.

The control device may be configured to control adjustment of the at least one winding tool relative to the rotor to effect a change in pitch and/or diameter along the spring axis. This allows complex spring shapes (e.g., spring shapes that do not end up with different portions of the coil spring) to be implemented in an automated procedure.

The control means may be configured to control the feeding of the wire in accordance with the change in pitch and/or diameter in a time-dependent manner. The control means may be configured to set the distance the wire is fed to the first and second winding tools per rotation (per rotation) of the rotor in a time-dependent manner as a function of the pitch and/or diameter.

The control means may be configured to calculate the distance that wire is fed to the first and second winding tools at each rotation of the rotor so that it is equal to the length of wire in the turn being wound in the rotation of the rotor, which length depends on the pitch and diameter of the turn.

The control means may be configured to calculate the feed of the wire as a function of the pitch and/or diameter such that the spring wound by the helical spring winding device is displaced in a translational manner.

The coil spring winding apparatus may include a wire feeding device supported on the rotor to rotate about the rotational axis when the rotor rotates. The wire may be fed to the rotating first and second winding tools by the rotating wire feeding device.

The wire feeding device may include a feeding pulley and a plurality of compression rollers configured to force the wire against the feeding pulley. Thereby a reliable control of the wire feed can be achieved.

The coil spring winding apparatus may include a wire feeder drive mechanism including a wire feed motor mounted to the stator and a transmission mechanism coupled between the wire feed motor and the feed pulley.

The wire feeder drive mechanism may include a first gear driven by the wire feed motor and rotatably mounted on the stator. The sun gear may be coupled to the first gear in a torsionally rigid manner. The sun gear may be coupled to a slew gear that rotates about the sun gear. The slewing gear can be coupled to the feed pulley in a torsionally stiff manner.

According to an embodiment, a machine for producing an innerspring unit is provided. The machine includes a coil spring winding apparatus and an innerspring unit assembly device configured to receive an endless coil spring from the coil spring winding apparatus and to produce an innerspring unit from a section of the endless coil spring, in accordance with an embodiment.

According to an embodiment, a method of winding a coil spring from a wire using a coil spring winding apparatus is provided. The coil spring winding apparatus includes a rotor. At least one winding tool is supported on the rotor so as to be rotatable about a rotation axis upon rotation of the rotor. The method includes feeding the wire to the at least one winding tool while the rotor is rotating, wherein the at least one winding tool bends the wire to form the coil spring. The method includes adjusting the at least one winding tool relative to the rotor to control the pitch and/or diameter of the coil spring.

The method may be performed using the coil spring winding apparatus according to an embodiment.

The coil spring winding apparatus according to the embodiment includes a stator and a rotor. The rotor is supported on the stator so as to be rotatable about a rotation axis. The rotational axis may extend along a spring axis of a coil spring wound by the coil spring winding apparatus. The coil spring winding apparatus may include a wire feeding device supported on the rotor to rotate about the rotational axis when the rotor rotates.

The wire feeding device may include a feed pulley and a compression mechanism configured to force the wire against the feed pulley. Thereby a reliable control of the wire feed can be achieved.

The coil spring winding apparatus and method according to the embodiments may be used to produce an endless coil spring, but are not limited thereto. The coil spring winding apparatus and method according to embodiments is operable to output a spring without rotation about its spring axis even while the spring is still connected to the rotor, which may facilitate further processing of the coil spring into an innerspring unit. The coil spring winding apparatus and method according to embodiments allow for winding of springs having different spring shapes without requiring replacement of parts of the coil spring winding apparatus.

Drawings

Embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals denote like elements.

Fig. 1 shows a schematic front view of a helical spring winding apparatus according to an embodiment.

Fig. 2 shows a partially enlarged front view of the coil spring winding device of fig. 1.

Fig. 3 shows a side view of a helical spring winding apparatus according to an embodiment.

Fig. 4 shows a side view of a helical spring winding apparatus according to an embodiment.

Fig. 5 shows a side view of the coil spring winding apparatus of fig. 1 during operation.

Fig. 6 shows a side view of the coil spring winding apparatus of fig. 1 during operation.

Fig. 7 shows a side view of the coil spring winding apparatus of fig. 1 during operation.

Fig. 8 shows a side view of the coil spring winding apparatus of fig. 1 during operation.

Fig. 9 shows a side view of the coil spring winding apparatus of fig. 1 during operation.

Fig. 10 shows a schematic front view of a helical spring winding apparatus according to an embodiment.

Fig. 11 illustrates a partial perspective view of a coil spring winding apparatus according to an embodiment.

Fig. 12 shows a schematic side view of a helical spring winding apparatus according to an embodiment.

Fig. 13 illustrates a perspective view of a coil spring winding apparatus according to an embodiment.

Fig. 14 shows a perspective detail view of the helical spring winding apparatus of fig. 13.

Fig. 15 shows a perspective detail view of the helical spring winding apparatus of fig. 13.

Fig. 16 shows a side view of the coil spring winding apparatus of fig. 13.

Fig. 17 shows a perspective detail view of a rotor of a coil spring winding apparatus according to an embodiment.

Fig. 18 illustrates a perspective view of a rotor driving mechanism of a coil spring winding apparatus according to an embodiment.

Fig. 19 shows a perspective view of an adjustment mechanism configured to adjust a winding tool supported on a rotor of a coil spring winding apparatus according to an embodiment.

Fig. 20 illustrates a perspective view of an adjustment mechanism configured to adjust a winding tool supported on a rotor of a coil spring winding apparatus according to an embodiment.

Fig. 21 shows a front view of an assembly of an adjustment mechanism configured to adjust a winding tool supported on a rotor of a coil spring winding apparatus according to an embodiment.

Fig. 22 shows a cross-sectional view along line XXII-XXII of fig. 21.

Fig. 23 shows a perspective view of a feeding device driving mechanism of the coil spring winding apparatus according to the embodiment.

Fig. 24 is a flow diagram of a method according to an embodiment.

Fig. 25 is a flow diagram of a method according to an embodiment.

Detailed Description

Embodiments of the present invention will be described with reference to the accompanying drawings, wherein like reference numerals refer to like elements.

While embodiments of the present invention will be described in the context of particular applications of coil spring winding apparatus, it should be understood that the embodiments are not limited thereto. For purposes of illustration, while certain embodiments will be described in the context of a coil spring winding apparatus operable to output an endless coil spring, the configuration of the coil spring winding apparatus according to embodiments is not so limited, and the coil spring winding apparatus may alternatively or additionally be used to manufacture coil springs having a limited height. For further explanation, while certain embodiments will be described in the context of a coil spring winding device operable to output a coil spring, the configuration of a coil spring winding device according to embodiments is not limited thereto, even when the coil spring is still coupled to a rotor of the coil spring winding device, but does not rotate about its spring axis.

Fig. 1 shows a helical spring winding apparatus 1 according to an embodiment. Fig. 2 shows an enlarged front view of the coil spring winding device 1 of fig. 1 in a direction of view of the rotational axis of the rotor. Fig. 3 shows an enlarged side view of the helical spring winding device 1 of fig. 1 in a viewing direction transverse to the axis of rotation of the rotor.

The coil spring winding apparatus 1 includes a stator 2 and a rotor 10 rotatably supported by the stator 2. As will be explained in more detail, the rotor 10 is rotatable about a rotation axis 13. The rotation axis 13 coincides with a spring axis of the coil spring wound by the coil spring winding apparatus 1 or extends parallel to the spring axis of the coil spring wound by the coil spring winding apparatus 1.

In operation, the rotor 10 can rotate about the helical spring it generates, advancing the helical spring in translation from the rotor 10 along its axis of rotation. The rotor 10 may comprise an outer circumference 11, which may be circular, supported on the support 5 of the stator 2. The support 5 may comprise suitable bearings for rotatably supporting the rotor 10. The rotor may include a central opening 12 positioned along its axis of rotation 13. The central opening may allow the wire 8 to be supplied to one or several winding

tools

21, 22 supported on the rotor 10.

The wire 8 may be supplied to the rotor 10 in the direction of the axis of rotation 13 of the rotor 10. The wire 8 may be pulled towards the rotor 10 by a feeding device that may be supported on the rotor 10, as will be explained in more detail.

At least one winding

tool

21, 22 may be supported on the rotor 10. At least one winding

tool

21, 22 may be supported on the rotor 10 so as to rotate with the rotor 10 about the axis of rotation 13 when the rotor 10 rotates. One or several winding

tools

21, 22 may be supported on the rotor 10 so as to be adjustable relative to the rotor 10, for example in a translatory and/or pivotal manner.

One or several winding

tools

21, 22 may have different configurations. For illustration, the winding

means

21, 22 may comprise a first winding means 21, which may be used as a bending means for bending the wire 8 exiting from the wire guide 14 mounted on the rotor 10. The wire guide 14 may define a channel 15 for the wire 8.

The winding means 21, 22 may comprise second winding means 22 which may be used as deflection means for deflecting the wire 8 from the plane defined by the wire guide 14 and the first winding means 21. The second winding tool 22 may be configured to bend the wire 8 in a direction corresponding to the axial direction of the helical spring by deflecting the wire 8 away from the rotor 10, thereby setting the pitch of the turns of the helical spring. The position of the second winding tool 22 relative to the wire guide 14 also affects the diameter of the turns of the coil spring. The second winding tool 22 may be configured to perform a bending operation that deflects the wire 8 in a direction along the axis of rotation 13, thereby forming the pitch of the helical spring. The second winding tool 22 may be offset from the first winding tool 21 in a direction parallel to the axis of rotation 13 of the rotor 10.

The relative positions of the wire guide 14, the first winding tool 21 and the second winding tool 22 define the geometry, in particular the diameter and the pitch, of the turns of the helical spring wound by the helical spring winding device 1. In operation of the helical spring winding device 1, the wire guide 14, the first winding tool 21 and the second winding tool 22 abuttingly engage the wire 8 so as to bend it parallel to the plane of the rotor 10 and along the axis of rotation 13 of the rotor 10, thereby defining the diameter and the pitch of the turns of the helical spring.

As will be explained in more detail below, the helical spring winding device 1 is configured such that the helical spring wound by the helical spring winding device 1 is pushed out in translation along the axis of rotation 13 of the rotor. The coil spring winding device 1 is operable to provide a coil spring that does not rotate about its spring axis even when the coil spring is still wound and still coupled to the rotor 10.

The coil spring winding apparatus 1 is configured such that the diameter and/or pitch of the wound coil spring may vary, for example, between turns of the coil spring or from one coil spring to another. The coil spring winding apparatus 1 may be configured to control the position of the first winding tool 21 relative to the rotor 10 such that a first diameter of a first turn of a coil spring is different from a second diameter of a second turn of the same coil spring. The helical spring winding apparatus 1 may be configured to control the position of the second winding tool 22 relative to the rotor 10 such that a first pitch of a first turn of a helical spring is different from a second pitch of a second turn of the same helical spring. The position of the second winding tool 22 relative to the rotor 10 and in particular relative to the wire guide 14 may also influence the diameter of the turn. Thus, springs having a variety of different shapes, defined by variations in the diameter and/or pitch of the turns of the coil spring, may be formed without the need to pause operation of the coil spring winding apparatus 1 to replace components located on the rotor 10.

The coil spring winding device 1 may include a first adjustment mechanism configured to adjust a position of the first winding tool 21 relative to the rotor 10. The first adjustment mechanism may be configured to pivot the first winding tool 21 relative to the rotor 10 and/or to displace the first winding tool 21 relative to the rotor 10 when the rotor 10 is rotated about its axis of rotation. Thereby, a change in diameter between turns can be achieved, but without stopping the rotor 10.

The first winding tool 21 is displaceable in a direction transverse to the axis of rotation 13 of the rotor 10. The first winding tool 21 is displaceable in a plane orthogonal to the axis of rotation 13 of the rotor 10. A displacement 23 of the first winding tool in a direction transverse to the axis of rotation 13 causes a change in the diameter of the turns of the wound helical spring.

The first winding tool 21 may be mounted to the rotor 10 via a first mounting structure 25, the first mounting structure 25 allowing the first winding tool 21 to be displaced relative to the rotor 10 transverse to the axis of rotation 13 while forcing the first winding tool 21 to rotate about the axis of rotation 13 upon rotation of the rotor 10.

The first adjustment mechanism may be configured to maintain the first winding tool 21 in its position relative to the rotor 10 when the first adjustment mechanism is not actuated. For illustration, the first adjustment mechanism may comprise a first slider displaceable along the rotation axis 13 of the rotor 10 and configured to displace the wedge-shaped member in a direction parallel to the rotation axis 13. The wedge-shaped member may be supported on the rotor 10 such that it is forced to rotate with the rotor about the axis of rotation 13. The engagement of the wedge-shaped member with the cooperating inclined surface may convert a displacement of the wedge-shaped member along the rotation axis into a displacement of the first winding tool 21 in a direction 23 transverse to the rotation axis 13 of the rotor 10.

The first adjustment mechanism may include a first motor 39. The first motor 39 may be mounted on the stator 2. The first motor 39 may be mounted on the base 3 or the superstructure 4 of the stator 2. This location of the first motor 39 facilitates establishing the required power connections and connections to the control device 20 while mitigating difficulties associated with positioning the motor on the rotor 10.

The control device 20 may control the adjustment of the first winding tool 21 according to the data defining the shape of the helical spring in order to reposition the first winding tool 21 with respect to the rotor 10 when the rotor 10 is rotated.

The control device 20 may further be configured to control the rotor drive motor 19, wherein the rotor drive motor 19 is operable to rotationally drive the rotor 10. The control device 20 may be configured to control the first motor 39 and the rotor drive motor 19 in a coordinated manner so as to adjust the position of the first winding tool 21 relative to the rotor 10 (which is a function of the rotational speed of the rotor 10) in a time-dependent manner.

The control device 20 may further be configured to control a second adjustment mechanism configured to adjust the second winding tool 22 with respect to the rotor 10.

The second adjustment mechanism may be configured to displace the second winding tool 22 relative to the rotor 10 as the rotor 10 rotates about its axis of rotation. Thereby, a change in pitch and optionally in diameter between turns can be achieved, but without the need to stop the rotor 10.

The second winding tool 22 is displaceable in a direction parallel to the axis of rotation 13 of the rotor 10. Displacement 24 of the second winding tool in the direction along the axis of rotation 13 causes a change in the pitch and optionally in the diameter of the turns of the wound helical spring.

The second winding tool 22 may be mounted to the rotor 10 via a second mounting structure 26, the second mounting structure 26 allowing the second winding tool 22 to be displaced relative to the rotor 10 parallel to the axis of rotation 13 while forcing the second winding tool 22 to rotate about the axis of rotation 13 when the rotor 10 is rotated.

The second adjustment mechanism may be configured to maintain the second winding tool 22 in its position relative to the rotor 10 when the second adjustment mechanism is not actuated. For illustration, the second adjustment mechanism may comprise a second slide displaceable along the rotation axis 13 of the rotor 10 and configured to displace the second winding tool 22 in a direction 24 parallel to the rotation axis 13. The second winding tool 22 may be supported on the rotor 10 such that it is forced to rotate with the rotor about the axis of rotation 13, while allowing the second winding tool 22 to be displaceable along the axis of rotation 13.

The second adjustment mechanism may include the second motor. The second motor may be mounted on the stator 2. The second motor may be mounted on the base 3 or superstructure 4 of the stator 2. This location of the second motor facilitates establishing the required power connections and connections to the control device 20 while mitigating the difficulties associated with positioning the motor on the rotor 10.

The control device 20 may control the adjustment of the second winding tool 22 according to the data defining the shape of the helical spring in order to reposition the second winding tool 22 with respect to the rotor 10 when the rotor 10 is rotated. The control device 20 may be configured to control the second motor and the rotor drive motor 19 in a coordinated manner so as to adjust the position of the second winding tool 22 relative to the rotor 10 (which is a function of the rotational speed of the rotor 10) in a time-dependent manner.

In order to vary both the diameter and the pitch of the turns of the helical spring along the spring axis, the control device 20 may be configured to control the first and second adjustment mechanisms in a coordinated manner so as to set the position of the first and second winding

tools

21, 22 with respect to the wire guide 14, depending on the data defining the shape of the helical spring to be wound.

Other configurations may be used in other embodiments. For illustration, it is not necessary that both the first winding tool 21 and the second winding tool 22 are displaceably supported on the rotor 10. The coil spring winding apparatus according to the embodiment may include only one winding tool supported on the rotor 10 so as to be displaceable relative to the rotor 10. To illustrate, in order to achieve a variation in the diameter of the turns of the helical spring, the helical spring winding device according to an embodiment may comprise a first winding tool 21, which first winding tool 21 is displaceably supported on the rotor 10 and defines the diameter of the turns of the helical spring by bending the metal wire 8 in a plane extending transversely to the axis of rotation 13 of the rotor 10.

FIG. 4 shows a side view of a coil spring winding apparatus according to another embodiment. The first winding tool 21 may be supported on the rotor 10 so as not to be displaced relative to the rotor 10. The second winding tool 22 may be displaceably supported on the rotor 10. The displacement 24 of the second winding tool 22 during the rotation of the rotor 10 effects a variation in the pitch of the turns of the helical spring and optionally influences the diameter of the turns of the helical spring.

In another embodiment, one of the first winding means 21 and the second winding means 22 may be displaceably supported on the rotor 10 so as to be displaceable simultaneously along the axis of rotation 13 and transversely to the axis of rotation 13. Thus, the variation in diameter and pitch can be achieved using a displaceable winding tool in combination with one or several wire guide elements that are stationary relative to the rotor 10.

The operation of the coil spring winding apparatus 1 will be described in more detail with reference to fig. 5 to 9.

Fig. 5 to 7 illustrate the operation of the coil spring winding apparatus 1 according to the embodiment when the coil spring winding apparatus 1 winds a coil spring. Even when the coil spring is still coupled to the rotor 10 and is still wound, the end 9 of the wire 8 wound into the coil spring advances along a straight line 51 extending parallel to the rotation axis 13.

Fig. 5 shows a side view of the helical spring winding device 1 at a certain time during operation. Both the first winding tool 21 and the second winding tool 22 rotate together with the rotor 10 about the axis of rotation 13. The position of the first and second winding

tools

21, 22 with respect to the wire guide 14 sets the diameter and the pitch of the turns of the helical spring. The end 9 of the wire 8 wound into a coil spring is positioned on the straight line 51.

Fig. 6 shows a side view of the coil spring winding device 1 after the rotor 10 has been rotated by 180 ° with respect to the state illustrated in fig. 5. The rotor 10 rotates about a rotational axis 13, which rotational axis 13 extends along the spring axis of the wound helical spring. The 180 rotation causes the coil spring to be wound a half turn. When the rotor 10 is rotated with respect to the state illustrated in fig. 5, the coil spring wound by the coil spring winding apparatus 1 is not rotated even when the coil spring is still wound. The end 9 of the wire 8 wound up as a helical spring advances in translation along a straight line 51 extending parallel to the axis of rotation 13. It will be appreciated that the straight line 51 is stationary in the world reference frame and does not rotate with the rotor 10.

Fig. 7 shows a side view of the helical spring winding device 1 after a rotation of the rotor 10 by 360 ° with respect to the state illustrated in fig. 5 and by 180 ° with respect to the state illustrated in fig. 5. The rotor 10 rotates about a rotational axis 13 extending along the spring axis of the wound coil spring. The 360 ° rotation causes the helical spring to be wound one turn compared to the state illustrated in fig. 5. When the rotor 10 rotates with respect to the state illustrated in fig. 6, the coil spring wound by the coil spring winding apparatus 1 does not rotate even when the coil spring is still wound. The end 9 of the wire 8 wound up into a helical spring also continues to advance in translation along a straight line 51 extending parallel to the axis of rotation 13.

Fig. 8 shows a side view of the helical spring winding device 1 when the first winding tool 21 is displaced in a direction 23 transverse to the axis of rotation 13 of the rotor 10 when winding the helical spring. Thereby, a change in diameter of the turns of the coil spring can be achieved. The turns 54 of the coil spring that are wound as the rotor 10 rotates may have a diameter 55. The other turn 52 of the helical spring wound upon further rotation of the rotor 10 may have another diameter 53 different from the diameter 55.

A wide variety of spring shapes can be produced, such as barrel springs, hourglass springs, conical springs, or frusto-conical springs.

When operating the coil spring winding apparatus 1 to produce an endless coil spring which is then further processed into an innerspring unit, the control device 20 may adjust the position of the first winding tool 21 relative to the rotor 10 in a periodic manner as the first winding tool 21 and the rotor 10 rotate about the axis of rotation 13. Thereby repeating a desired pattern of different diameters along the endless helical spring.

Fig. 9 shows a side view of the helical spring winding device 1 when the second winding tool 22 is displaced in a direction 24 along the rotation axis 13 of the rotor 10 when winding the helical spring. A variation in the pitch of the turns of the helical spring is thereby achieved. The turns 58 of the coil spring wound as the rotor 10 rotates may have a pitch 59. The other turn 56 of the helical spring wound upon further rotation of the rotor 10 may have another pitch 57 different from the pitch 59. The diameter of the turns may also be varied by displacement of the second winding tool 22 relative to the wire guide 14.

The control device 20 can control the position of the second winding tool 22 with respect to the rotor 10 while the second winding tool 22 and the rotor 10 are rotated about the axis of rotation 13, thereby obtaining the desired variation in pitch of the turns along the spring axis.

When operating the coil spring winding apparatus 1 to produce an endless coil spring which is then further processed into an innerspring unit, the control device 20 may adjust the position of the second winding tool 22 relative to the rotor 10 in a periodic manner while the second winding tool 22 and the rotor 10 rotate about the axis of rotation 13. Whereby a desired pattern of different pitches can be repeated along the endless helical spring.

The variation of the diameter and the variation of the pitch can be achieved by displacing the first winding tool 21 and the second winding tool 22 while the rotor 10 is rotating.

In the coil spring winding apparatus 1 according to any of the embodiments, a feeding device that draws the wire to the rotor 10 and/or feeds the wire along the first and second winding

tools

21, 22 may be provided on the rotor 10. The feeding device may be mounted on the rotor to rotate about a rotation axis 13 when the rotor 10 rotates. The feed pulley of the feeding device may be rotatably mounted on the rotor 10. The axis of rotation of the feed pulley may be parallel to the axis of rotation 13 of the rotor 10 and may be offset from the axis of rotation 13 of the rotor 10 in a direction transverse to the axis of rotation 13 of the rotor 10.

At least the wire feed motor of the feeder driving mechanism that rotatably drives the feed pulley 61 may be mounted on the stator 2. The feeder drive mechanism may include: a rotary gear drive having an input coupled to the wire feed motor; and a rotary gear mounted to rotate about the rotational axis 13 of the rotor 10 at an angular velocity defined by the angular velocity of the rotor 10. The rotation of the rotary gear about its own axis of rotation is controlled by the output speed of the wire feed motor.

Next, the configurations of the feeding device and the feeding device driving mechanism of the coil spring apparatus according to the embodiment will be described.

Fig. 10 illustrates a front view of a coil spring winding apparatus according to an embodiment. The feeding device 60 is supported on the rotor 10. The feeding device 60 may include a feeding pulley 61. The feed pulley 61 has an outer surface configured for abutting against the wire 8. The feed pulley 61 can advance the wire 8, which abuts against the feed pulley 61 in a force-fitting manner, in particular in a friction-fitting manner.

The feed pulley 61 may extend in a plane transverse to the axis of rotation 13 of the rotor 10. The feed pulley 61 is operable to guide the wire 8 along an arc extending in a plane transverse to the axis of rotation 13 towards the wire guide 14. The feed pulley 61 may be configured to receive the wire 8 from the central opening 12, the wire 8 being guided through the rotor 10 via the central opening 12.

The deflecting rollers 16 may be rotatably supported on the rotor 10. The deflecting rollers 16 are operable to deflect the wire 8 from a direction substantially along the axis of rotation 13 to a direction transverse to the axis of rotation 13.

Fig. 11 shows a perspective view of the rotor 10 with the feeding device 60 supported thereon. The feeding device 60 may include a feeding pulley 61. The feed pulley 61 is rotatable relative to the rotor 10 about a pulley rotation axis 65. The pulley rotational axis 65 rotates about the rotational axis 13 of the rotor 10 in the operation of the coil spring winding device 1. Further, the feeding pulley 61 is rotationally driven about the pulley rotational axis 65 by the feeding device driving mechanism. The configuration of the feeder driving mechanism that can be used in the embodiments will be described in more detail below.

The feeding device 60 may be configured to urge the wire 8 against the feeding pulley 61. The feeding device 60 may include a compression mechanism 62, the compression mechanism 62 being configured to urge the wire against the feeding pulley 61. The feed pulley 61 may be rotationally driven by the feeder drive mechanism. Embodiments of the feeder drive mechanism will be described in more detail below. A control device 20 may control the operation of the feeder drive mechanism. The coil spring winding apparatus 1 may be configured such that the feeding pulley 61 is driven to advance the wire 8 by a distance corresponding to the length of the turn of the coil spring wound during each rotation of the rotor 10. The control device 10 may calculate the amount of wire that the wire 8 has to be advanced according to the diameter and pitch of the turns of the helical spring wound by the helical spring winding apparatus 1 during each rotation of the rotor 10. Alternatively, the coil spring winding apparatus 1 may be configured such that the feed pulley 61 is driven to advance the wire 8 at a constant speed, wherein the angular speed of the rotor 10 is adjusted according to the length of wire required for each turn of the coil spring.

According to a further embodiment, the configuration of the feeding device mounted on the rotor 10, as exemplarily explained with reference to fig. 10 and 11, may also be used on a helical spring winding apparatus wherein the first and/or second winding

means

21, 22 are non-adjustable with respect to the rotor 10.

Fig. 12 shows a schematic side view of the helical spring winding device 1 according to an embodiment. The coil spring winding apparatus 1 may have any one of the configurations described with reference to fig. 1 to 11 above.

The coil spring winding apparatus 1 may include a rotor driving motor 19 to drive the rotor 10. The rotor drive motor 19 may be mounted on the stator 2.

The coil spring winding device 1 may include a wire feed motor 69 to drive the feed pulley 61. The wire feed motor 69 may be mounted on the stator 2. The wire feed motor 69 may drive the input of a rotary gear drive that is coupled to the feed pulley 61 in a torsionally stiff manner.

The helical spring winding device 1 may comprise a first motor 39 controllable to adjust the position of the first winding tool 21 relative to the rotor 10. The first motor 39 may be a stepper motor. As will be explained in more detail, the first motor 39 may be coupled to the first slider to displace it in a direction parallel to the axis of rotation 13 of the rotor 10. The axial displacement of the first slide can be converted into a movement of the first winding tool 21, which is guided transversely to the axis of rotation 13 by means of a movement conversion mechanism. The motion conversion mechanism may include cooperating inclined surfaces.

The helical spring winding apparatus 1 may comprise a second motor 49 which is controllable to adjust the position of the second winding tool 22 relative to the rotor 10. The second motor 49 may be a stepper motor. As will be explained in more detail, a second motor 49 may be coupled to the second slider to displace it in a direction parallel to the axis of rotation 13 of the rotor 10. A hollow member may be coupled to the second slider so as to be displaced in a direction parallel to the rotation axis 13. The hollow member may be coupled to the rotor 10 in a torsion-resistant manner. The second winding tool 22 may protrude towards the interior of the hollow member. The coil spring winding apparatus 1 may be configured such that the winding spring extends through the interior of the hollow member.

The coil spring winding apparatus 1 may include a wire supply mechanism 80. The wire supply mechanism 80 is operable to guide the wire 8 to the rotor 10 in a direction extending along the rotational axis 13 of the rotor 10.

The wire supply mechanism 80 may include a guide member 82 (which may be a roller), around which the wire 8 is guided before it is supplied to the rotor 10.

The rotation of the rotor 10 causes the wire 8 to become twisted along the distance 81 between the guide member 82 and the rotor 10. This internal twisting of the wire 8 is advantageous because it allows a larger pitch angle in the coiled spring. This internal twisting of the wire 8 results in an internal pitch of the coil spring wound by the coil spring winding apparatus 1.

In order to control the torsion of the wire 8, which affects the pitch angle of the helical spring, the helical spring winding device may be configured such that the distance 81 along which the wire 8 is twisted is adjustable. The guide member 82 may be displaceably mounted on a support 83.

The various drive mechanisms of the coil spring winding device 1 may have various different configurations. The configurations of the rotor driving mechanism, the feeding device driving mechanism, the first adjusting mechanism to adjust the first winding tool 21, and the second adjusting mechanism to adjust the second winding tool 22 will be described with reference to fig. 13 to 23. It should be understood that alternative configurations may be implemented in other embodiments. For the sake of illustration, only some of the drive mechanisms may be configured as described with reference to fig. 13 to 23. One or several of the drive mechanisms may be omitted. For the sake of illustration, if only one of the first winding tool 21 and the second winding tool 22 is adjustable with respect to the rotor 10, only this first adjustment mechanism or only this second adjustment mechanism needs to be provided.

Fig. 13 shows a perspective view of the coil spring winding device 1 according to the embodiment. Fig. 14 and 15 show partial perspective views showing the rotor and various drive mechanisms in more detail. Fig. 16 is a partial side view. Fig. 17 is an enlarged perspective view of the rotor 10 and the components mounted thereon. Fig. 18 shows a perspective view of the rotor drive mechanism. Fig. 19 shows a perspective view of a second adjustment mechanism configured to adjust the second winding tool 22 in a direction parallel to the rotation axis 13 of the rotor 10. Fig. 20 shows a perspective view of a first adjustment mechanism configured to adjust the first winding tool 21 in a direction transverse to the axis of rotation 13 of the rotor 10. Fig. 21 is a partial front view of components of the first adjustment mechanism. Fig. 22 is a cross-sectional view along line XXII-XXII in fig. 21. Fig. 23 shows a perspective view of the feeder drive mechanism.

The configuration of the rotor driving mechanism of the coil spring winding device 1 according to the embodiment will be described with reference to fig. 13 to 18. The rotor driving mechanism is configured to rotationally drive the rotor 10. The rotor drive mechanism includes a rotor drive motor 19. The rotor drive motor 19 may be supported on the stator 2. The rotor drive motor 19 may have a gear coupled to an output shaft of the rotor drive motor 19. Which may engage a drive belt 18. The drive belt 18 may be provided with teeth which mesh with the gear on the output of the rotor drive motor 19 and with the external teeth 17 of the rotor 10.

The control device 20 may control the rotor driving motor 19 such that the rotor 10 rotates at a constant angular velocity. Alternatively, the control device 20 may control the rotor driving motor 19 such that the rotor 10 is rotated at an angular velocity depending on the diameter and pitch of the turns of the coil spring wound. This may be desirable when the feeding device 60 feeds the wire 8 at, for example, a constant speed.

The configuration of the second adjustment mechanism 40 of the coil spring winding apparatus 1 according to the embodiment will be described with reference to fig. 13 to 17 and 19. The second adjustment mechanism 40 is operable to displace the second winding tool 22 in a direction 24 parallel to the axis of rotation 13 of the rotor 10. The second adjustment mechanism 40 may be configured to adjust the position of the second winding tool 22 relative to the rotor 10 as the rotor 10 rotates, thereby adjusting the pitch of the turns of the coil spring being wound. The diameter of the turns is also affected by the position of the second winding tool 22 relative to the wire guide 14.

The second adjustment mechanism 40 includes a second motor 49. The second motor 49 may be mounted to the stator 2. The second motor 49 may have an output coupled to the second slider 41 via a rotation-to-linear motion conversion mechanism, which may include a spindle drive, a rack and pinion drive, or any other rotation-to-linear motion conversion mechanism.

The second adjustment mechanism 40 includes a second slider 41. The second slider 41 is mounted so as to be displaceable in translation along the axis of rotation 13 of the rotor 10. The second slider 41 may be coupled to the hollow member 42 in such a manner that a linear displacement of the second slider 41 displaces the hollow member 42 in a direction parallel to the rotation axis 13. The second slider 41 and the hollow member 42 may be configured such that the hollow member 42 rotates with respect to the second slider 41. One or more rollers 45 may be provided to rotatably support the hollow member 42.

The hollow member 42 is coupled to the rotor 10 in a torsion-resistant manner while being displaced relative to the rotor 10 in a direction parallel to the rotation axis 13 of the rotor 10. To this end, a rail 43 protruding from the hollow member 42 is slidably received in a mating recess of the rotor 10. The track 43 may lock the hollow member 42 to the rotor 10 in such a way that the hollow member 42 is forced to rotate together with the rotor 10 about the rotation axis 13 upon rotation of the rotor 10 while being displaced in a translational manner relative to the rotor 10 in a direction parallel to the rotation axis 13. The coiled coil spring may be supported by the support plate 91 after leaving the hollow member 42.

The hollow member 42 may be a hollow tube. The hollow member 42 may be arranged such that the central axis of the hollow member 42 is arranged along the rotation axis 13 of the rotor 10.

The second winding tool 22 may be rigidly attached to the hollow member 42. A mounting 44 may be provided, which mounting 44 mounts the second winding tool 22 such that it is supported on the rotor 10 via the rail 43, which allows the second winding tool 22 to be displaced relative to the rotor 10 in a direction parallel to the rotation axis 13.

In operation of the coil spring winding apparatus 1, the wound coil spring is output from the rotor 10 through the interior of the hollow member 42. The hollow member 42 rotates about the turns of the coil spring that have just been wound, while the coil spring is advanced in translation by rotating the hollow member 42.

To adjust the pitch of the turns of the wound coil spring, the control device 20 may control the second motor 49. Actuation of the second motor 49 may displace the second slider 41. Displacement of the second slider 41 in the direction towards the rotor 10 displaces the rotating hollow member 42 towards the rotor 10, so that the second winding tool 22 is displaced towards the rotor 10, while the second winding tool 22 moves with the rotor 10 about the rotation axis 13. The pitch of the turns of the coil spring can be reduced thereby. Displacement of the second slider 41 in a direction away from the rotor 10 displaces the rotating hollow member 42 away from the rotor 10, causing the second winding tool 22 to be displaced away from the rotor 10 while the second winding tool 22 moves about the rotation axis 13 with the rotor 10. The pitch of the turns of the coil spring may be increased thereby.

The configuration of the first adjustment mechanism 30 of the coil spring winding apparatus 1 according to the embodiment will be described with reference to fig. 13 to 17 and fig. 20 to 22. The first adjustment mechanism 30 is operable to displace the first winding tool 21 in a direction 23 transverse to the axis of rotation 13 of the rotor 10. The first adjustment mechanism 30 may be configured to adjust the position of the first winding tool 21 relative to the rotor 10 as the rotor 10 rotates to thereby adjust the diameter of the turns of the coil spring being wound.

The first adjustment mechanism 30 includes a first motor 39. The first motor 39 may be mounted to the stator 2. The first motor 39 may have an output coupled to the first slider 31 via a rotation-to-linear motion conversion mechanism, which may include a spindle drive, a rack and pinion drive, or any other rotation-to-linear motion conversion mechanism.

The first adjustment mechanism 30 includes a first slider 31. The first slider 31 is mounted so as to be displaceable in translation along the axis of rotation 13 of the rotor 10.

The first slider 31 may be engaged with a motion conversion mechanism that converts displacement of the first slider 31 in a direction along the rotation axis 13 of the rotor 10 into displacement 23 of the first winding tool 21 in a direction transverse to the rotation axis 13 of the rotor 10.

The motion conversion mechanism may include a wedge member 33. The wedge member 33 may include a wedge surface 36. The wedge-shaped member 33 may be coupled to the rotor 10 in a torsionally fixed manner while being displaced with respect to the rotor 10 in a direction parallel to the rotation axis 13 of the rotor 10. To this end, the track 35 protruding from the wedge-shaped member 33 may be slidingly received in a mating recess of the rotor 10. The track 35 may lock the wedge-shaped member 33 to the rotor 10 in such a way that the wedge-shaped member 33 is forced to rotate together with the rotor 10 about the rotation axis 13 when the rotor 10 rotates, while being translationally displaceable relative to the rotor 10 in a direction parallel to the rotation axis 13.

The motion conversion mechanism may include a mating inclined surface 37 that abuttingly engages the wedge surface 36 of the wedge member 33. The inclined surface 37 may be provided on a member 38 mounted on the rotor 10 so as to be displaceable relative to the rotor 10 in a direction transverse to the axis of rotation 13 of the rotor 10. The member 38 and the wedge member 33 may be mounted such that the member 38 is displaceable in a direction perpendicular to a direction in which the wedge member 33 is displaceable relative to the rotor 10. For purposes of illustration, the member 38 may be a pivoting member mounted on the rotor so as to be pivotable about a pivot axis. The pivot axis may be parallel to the axis of rotation 13 of the rotor 10.

A biasing mechanism (not shown) may bias the member 38 into abutting engagement against the wedge surface 36 of the wedge member 33.

The first slider 31 may engage the wedge member 33 to allow the wedge member 33 to rotate relative to the first slider 31. The first slider 31 may have an annular surface on which a roller provided on the end of the wedge member 33 rolls off. The displacement of the first slider 31 in the direction parallel to the rotation axis 13 of the rotor 10 causes the wedge member 33, which rotates about the rotation axis 13 with the rotor 10, to be displaced parallel to the rotation axis 13. The wedge surface 36 of the wedge-shaped member 33 forces a member 38 rotating jointly with the rotor 10 to be displaced in a direction 23 transverse to the axis of rotation 13 of the rotor 10.

First winding tool 21 may be mounted to member 38 or may be integrally formed with member 38.

In operation of the coil spring winding apparatus 1, the wound coil spring is output from the rotor 10 through the interior of the hollow member 42. The hollow member 42 rotates about the turns of the coil spring that has just been wound, while the coil spring is advanced in translation through the rotating hollow member 42.

To adjust the diameter of the turns of the wound coil spring, the control device 20 may control the first motor 39. Actuation of the first motor 39 may displace the first slider 31. Displacement of the first slider 31 in a direction towards the rotor 10 displaces the wedge-shaped member 33 towards the rotor 10 such that the member 38 pivots with the first winding tool 21 in a first pivoting direction relative to the rotor 10. This causes the first winding tool 21 to be displaced relative to the rotor 10 in a direction 23 transverse to the axis of rotation 10. The diameter of the turns of the coil spring may be reduced thereby. When the first slider 31 is displaced in a direction away from the rotor 10, the biasing force applied by the member 38 to the wedge-shaped member 33 displaces the wedge-shaped member 33 away from the rotor 10, causing the first winding tool 21 to be displaced away from the rotor 10, pivoting the member 38 with the first winding tool 21 in a second pivoting direction relative to the rotor 10, which is opposite to the first pivoting direction. The diameter of the turns of the coil spring may be increased thereby.

The configuration of the feeding device driving mechanism 70 of the coil spring winding apparatus 1 according to the embodiment will be described with reference to fig. 23. The feeding device drive mechanism 70 is configured to rotate the feeding pulley 61 about the pulley rotational axis 65 while the pulley rotational axis 65 rotates about the rotational axis 13 of the rotor 10.

The feeder drive mechanism 70 may generally include a rotary gear drive. A rotary gear 76 (best seen in fig. 15) rotates about the axis of rotation 13 of the rotor 10 at a speed determined by the angular speed of the rotor 10. The slewing gear 76 may be attached to the feed pulley 61 in a torsionally stiff manner by a shaft 77. Rotation of the slewing gear 76 causes the feed pulley 61 to rotate about its pulley rotational axis 65 at an angular velocity corresponding to the angular velocity of the slewing gear 76.

The slewing gear 76 can be rotationally driven by a drive belt 75. The drive belt 75 meshes with the sun gear 74. The sun gear 74 is mounted in a torsionally fixed manner on the intermediate gear 73. The intermediate gear 73 may have a larger diameter than the sun gear for torque conversion. The intermediate gear 73 is rotationally driven via a drive belt 72, the drive belt 72 being connected to a gear 71 rotationally coupled to the output shaft of the wire feed motor 69.

In operation, the control device 20 controls the wire feed motor 69. The rotation of the gear 71 drives the intermediate gear 73 through the transmission belt 72. The rotation of the intermediate gear 73 forces the sun gear 74 to rotate about an axis corresponding to the rotation axis 13. Rotation of the sun gear 74 rotationally drives the slewing gear 76 through the drive belt 75. The rotation of the slewing gear 76 rotates the feeding pulley 61 via the shaft 77.

The control device 20 may be configured to control the wire feed motor 69. The control device 20 may be configured to control the wire feed motor 69 such that the feed pulley 61 rotates at a constant angular velocity. In a more preferred embodiment, the control device 20 may be configured to control the wire feed motor 69 such that the angular velocity of the feed pulley is dependent upon the pitch and diameter of the turns of the coil spring being wound. This allows the rotor 10 to rotate at a constant angular speed while the wire feed is adjusted under the control of the control device 20 so that the length of wire fed each time to the winding

tools

21, 22 corresponds exactly to the amount of wire required each time to wind a respective turn of the helical spring.

Fig. 24 is a flow diagram of a method 110 according to an embodiment. The method 110 may be performed by a helical spring winding apparatus 1 according to any of the embodiments described with reference to fig. 1 to 23. The method 110 may be performed under the control of the control device 20.

At 111, the rotor drive mechanism is activated. The rotor drive motor 19 is operable to rotate the rotor 10 at a constant or time-dependent angular velocity.

At 112, the position of one or several winding

tools

21, 22 supported on the rotor 10 is adjusted relative to the rotor 10. The first winding tool 21 is displaceable in a plane transverse to the axis of rotation 13 of the rotor 10, and when the rotor 10 rotates, it rotates about the axis of rotation 13 to thereby adjust the diameter of the turns of the helical spring being wound. Alternatively or additionally, the second winding tool 22 may be displaced in a direction along the rotational axis 13 of the rotor 10 to thereby adjust the pitch of the turns of the helical spring being wound. The displacement of the second winding tool 22 may also affect the diameter of the turns of the helical spring.

Adjusting the position of one or several winding

tools

21, 22 supported on the rotor 10 may comprise: determining whether to change a diameter and/or pitch on a turn of the coil spring being wound; and actuates the motors of the adjustment mechanisms associated with the winding

tools

21, 22 that need to be repositioned with respect to the rotor 10 to change the diameter and/or pitch.

Adjusting the position of one or several winding

tools

21, 22 supported on the rotor 10 may comprise: the motors of the adjustment mechanisms associated with the winding

tools

21, 22 that need to be repositioned with respect to the rotor 10 to change the diameter and/or pitch (only when they need to be changed).

Fig. 25 is a flow diagram of a method 120 according to an embodiment. The method 120 may be performed by a helical spring winding apparatus 1 according to any of the embodiments described with reference to fig. 1 to 23. The method 120 may be performed under the control of the control device 20.

At 121, information regarding the shape of the coil spring to be wound may be obtained. This information may be retrieved from a storage medium or memory that stores instructions along the diameter and pitch defining the coil spring along the spring axis. The helical spring winding device 1 may comprise an input interface configured to allow the user to define the shape of the helical spring to be wound. Information about the shape of the coil spring may be obtained from the user interface or from data generated based on user input.

At 122, the rotor drive mechanism 19 is activated. The rotor drive mechanism 19 is operable to rotate the rotor 10 at a constant angular velocity.

At 123, the position of one or several winding

tools

21, 22 supported on the rotor 10 is adjusted relative to the rotor 10. Step 123 may be implemented as described above for step 112.

At 124, as the rotor 10 rotates, the feeder drive mechanism 70 may be controlled according to the pitch and diameter of the turns being wound. The wire feed motor 69 may be controlled so that the angular velocity of the feed pulley 61 is dependent on the pitch and diameter of the turns of the coil spring being wound. This allows the rotor 10 to be rotated at a constant angular speed while the wire feed is adjusted under the control of the control device 20 so that the length of wire fed each time to the winding

tools

Although the embodiments of the present invention have been described with reference to the accompanying drawings, various modifications may be implemented in other embodiments. For illustration, it is not required to mount a plurality of adjustable winding tools on the rotor. A helical spring winding apparatus according to embodiments may be configured to output a helical spring having a constant diameter along its spring axis but a variable pitch, in which case it may only be necessary to provide a winding tool 22 displaceable along the axis of rotation 13. A helical spring winding device according to embodiments may be configured to output a helical spring having a constant pitch along its spring axis but a variable diameter, in which case it may only be necessary to provide a winding tool 21 displaceable transversely to the axis of rotation 13.

Although the embodiment has been described in which the coil spring winding apparatus is configured to manufacture an endless coil spring from a metal wire, the coil spring winding apparatus may also be configured to cut a series of turns output from the rotor 10 into a coil spring having a limited height.

The coil spring winding apparatus and method according to embodiments of the present invention may be used to manufacture innerspring units for mattresses, sofas, armchairs or other bedding or seating furniture, but is not so limited.

Claims

1. A helical spring winding apparatus (1) comprising:

a stator (2);

a rotor (10) supported on the stator (2) so as to be rotatable about a rotational axis (13), the rotational axis (13) extending along a spring axis of a coil spring wound by the coil spring winding apparatus (1);

a rotor drive motor (19) for rotationally driving the rotor (10);

at least one winding tool (21); and

a first adjustment mechanism (30) configured to adjust the position of a first winding tool (21) of the at least one winding tool (21, 22) relative to the rotor (10) during rotation of the rotor (10) about its axis of rotation, the first adjustment mechanism (30) comprising a motor (39) mounted on the stator (2);

wherein the at least one winding tool (21, 22) is supported on the rotor (10) for rotation about the rotation axis (13) of the rotor (10) upon rotation of the rotor (10), the at least one winding tool (21, 22) being configured to bend a wire (8) to form the helical spring upon rotation of the rotor (10), the at least one winding tool (21, 22) being adjustable relative to the rotor (10); and

wherein a control device (20) is provided to control the rotor drive motor (19) and the motor (39) of the first adjustment mechanism (30) in a coordinated manner to adjust the position of the first winding tool (21) of the at least one winding tool (21, 22) relative to the rotor (10) in a time-dependent manner, thereby adjusting the diameter (53, 55) of the turns of the helical spring.

2. The coil spring winding apparatus according to claim 1,

the first adjustment mechanism (30) comprises a slider (31), a motor (39) of the first adjustment mechanism (30) being configured to effect a displacement of the slider (31) in a direction parallel to the axis of rotation (13) of the rotor (10) to adjust the first winding tool (21) relative to the rotor (10).

3. The coil spring winding apparatus of claim 1, further comprising:

a second adjustment mechanism (40) configured to adjust a position of a second winding tool (22) of the at least one winding tool (21, 22) relative to the rotor (10).

4. The coil spring winding apparatus according to claim 3,

wherein the first adjustment mechanism (30) is configured to adjust the first winding tool (21) relative to the rotor (10) in a direction (23) transverse to the axis of rotation (13), and

wherein the second adjustment mechanism (40) is configured to adjust the second winding tool (22) relative to the rotor (10) in a direction (24) parallel to the rotation axis (13).

5. The coil spring winding apparatus according to claim 3 or 4,

the control device (20) is configured to control the feeding of the wire (8) according to variations in pitch (57, 59) and/or diameter (53, 55) in a time-dependent manner.

6. The coil spring winding apparatus according to claim 5,

the control device (20) is configured to calculate the feed of the wire (8) as a function of the pitch (57, 59) and/or the diameter (53, 55) so that the spring wound by the helical spring winding apparatus (1) moves in translation.

7. The coil spring winding apparatus of claim 1, further comprising:

a wire feeding device (60) supported on the rotor (10) for rotation about the axis of rotation (13) upon rotation of the rotor (10).

8. The coil spring winding apparatus according to claim 7,

the wire feeding device (60) comprises a feeding pulley (61) and a compression mechanism (62), the compression mechanism (62) being configured to force the wire (8) against the feeding pulley (61).

9. The coil spring winding apparatus of claim 8, further comprising:

a wire feeder drive mechanism (70) comprising a wire feed motor (69) mounted to the stator (2) and a transmission mechanism (71-77) coupled between the wire feed motor (69) and the feed pulley (61).