A wire forming apparatus 1 comprises a rotary table 22 that is rotatably supported by a table body 21, a slide tool unit 100A that is attached to the rotary table 22 and supports a slide tool T1 capable of sliding toward a wire guide, and a tool slide mechanism 60 that is supported by the table body 21 and transmits a driving force for sliding the slide tool T1 to the slide tool unit 100A. The tool slide mechanism 60 has a single motive power transmission member 61 that is rotatably supported by the table body 21, and a driving force generated by a rotation of the motive power transmission member 61 is transmitted, in common, to a plurality of slide tools T1 attached to the rotary table 22.

A wire forming apparatus 1 comprises a rotary table 22 that is rotatably supported by a table body 21, a slide tool unit 100A that is attached to the rotary table 22 and supports a slide tool T1 capable of sliding toward a wire guide, and a tool slide mechanism 60 that is supported by the table body 21 and transmits a driving force for sliding the slide tool T1 to the slide tool unit 100A. The tool slide mechanism 60 has a single motive power transmission member 61 that is rotatably supported by the table body 21, and a driving force generated by a rotation of the motive power transmission member 61 is transmitted, in common, to a plurality of slide tools T1 attached to the rotary table 22.

In the coil spring of the present invention, a helical space defined by a space between coils has a first end region whose space is increased as it extends towards the other side in the axial direction from a first reference point where the space is zero, a reference region whose space is set at a reference value L (L>0), and a second end region whose space becomes narrow as it extends toward the other side in the axial direction and zero at a second reference point. The first end region has a first end outer part and a first end inner end. In a case where a pitch angle of the space between coils that causes the displacement of the space between coils per turn of the helical space to be L is a reference pitch angle Pa, the pitch angle in the first end outer part is set at Pa while the pitch angle in the first end inner part is set at Pb (Pb>Pa).

In the coil spring of the present invention, a helical space defined by a space between coils has a first end region whose space is increased as it extends towards the other side in the axial direction from a first reference point where the space is zero, a reference region whose space is set at a reference value L (L>0), and a second end region whose space becomes narrow as it extends toward the other side in the axial direction and zero at a second reference point. The first end region has a first end outer part and a first end inner end. In a case where a pitch angle of the space between coils that causes the displacement of the space between coils per turn of the helical space to be L is a reference pitch angle Pa, the pitch angle in the first end outer part is set at Pa while the pitch angle in the first end inner part is set at Pb (Pb>Pa).

An upholstery spring comprises a steel spring wire made of a microalloyed steel and a color indicator arranged thereon at least in some regions, the microalloyed steel containing between 0.004 to 0.015 wt.-% of one or more alloy elements. The invention further relates to a method for producing an upholstery spring, a mattress or a piece of upholstered furniture having such an upholstery spring.

An upholstery spring comprises a steel spring wire made of a microalloyed steel and a color indicator arranged thereon at least in some regions, the microalloyed steel containing between 0.004 to 0.015 wt.-% of one or more alloy elements. The invention further relates to a method for producing an upholstery spring, a mattress or a piece of upholstered furniture having such an upholstery spring.

The present invention provides a spring manufacturing machine including a wire guide member configured to guide a wire along a conveying direction to a first base point or a second base point for forming a spring, and a pair of movable assemblies configured to allow the second base point to be located between the first base point and the pair of movable assemblies. Each of the movable assemblies comprises a mounting platform configured to move close to or away from the first base point or the second base point along the conveying direction. Each mounting platform has a recess, and two mounting platforms are adjacent to each other to allow their respective recesses to surround the second base point, so that the movement of the mounting platforms do not to interfere with operation at the second base point.

The present invention provides a spring manufacturing machine including a wire guide member configured to guide a wire along a conveying direction to a first base point or a second base point for forming a spring, and a pair of movable assemblies configured to allow the second base point to be located between the first base point and the pair of movable assemblies. Each of the movable assemblies comprises a mounting platform configured to move close to or away from the first base point or the second base point along the conveying direction. Each mounting platform has a recess, and two mounting platforms are adjacent to each other to allow their respective recesses to surround the second base point, so that the movement of the mounting platforms do not to interfere with operation at the second base point.

A method of manufacturing a coil spring and a coil spring manufacturing apparatus are provided that enable precise forming of a coil spring even when various kinds of wire rods are used as a wire rod. This is based on the premise that the wire material being fed out is serially pressed against a rotating roller outer circumferential surface to form the wire rod into a coil shape. Under this premise, as the wire rod is fed out, a rotating roller is rotationally driven by a rotary drive force of a servomotor such that a portion pressed against the wire rod on the rotating roller outer circumferential surface moves toward the advancing side of the wire rod.

A method of manufacturing a coil spring and a coil spring manufacturing apparatus are provided that enable precise forming of a coil spring even when various kinds of wire rods are used as a wire rod. This is based on the premise that the wire material being fed out is serially pressed against a rotating roller outer circumferential surface to form the wire rod into a coil shape. Under this premise, as the wire rod is fed out, a rotating roller is rotationally driven by a rotary drive force of a servomotor such that a portion pressed against the wire rod on the rotating roller outer circumferential surface moves toward the advancing side of the wire rod.