Coil Spring Assembly

Abstract

A coil spring assembly includes at least one row of coil springs, frame members at opposite ends of the row, and an anchor wire extending along the row adjacent one end of the springs. The anchor wire is shaped to provide a series of U-shaped hooks, one for each spring, extending laterally of the direction of the row and having a lateral dimension corresponding to the thickness of the wire of the spring. Each hook is engaged with a turn at the end of the spring, and the anchor wire has opposite ends secured to the frame member to thereby tightly engage the hooks with the springs.

Description

This invention relates to coil spring assemblies, such as are used for example in mattresses or seats.

Such coil spring assemblies include a series of coil springs secured at their opposite ends to other parts of the assembly. The coil springs and frequently other parts of the assembly are made of metal wire, and sometimes metal clips are also used. It is desirable that the coil spring assembly should be as noiseless as possible in use, long-lasting, and comfortable. Another more recent requirement in the case of coil spring assemblies for mattresses is that the coil spring assembly should transmit forces evenly, because in hotels and motels for example it is becoming increasingly popular to attach a vibratory device to beds, and it is necessary that the motion produced by such a device be transmitted through the mattress in an even manner to provide comfortable motion to a person lying thereon.

It is therefore an object of the invention to provide an improved coil spring assembly which satisfies the above-mentioned requirements.

According to the invention, at least one end of the springs in each row in a coil spring assembly is secured to an anchor wire extending along the row adjacent the ends of the springs. The anchor wire is bent to provide a series of U-shaped hooks, one for each spring, extending laterally of the direction of the row and having a lateral dimension corresponding to the thickness of the wire of the springs. Each hook is engaged with a turn at the end of the spring, and the anchor wire has opposite ends secured to the frame members to thereby tightly engage the hooks with the springs.

For ease of manufacture, and repair when necessary, each anchor wire, when detached from the frame members, may be engageable with the springs and disengageable therefrom by rotation of the wire about its longitudinal axis.

Preferably the hooks are positioned on the outside of the turns, with adjacent straight portions of the anchor wire being positioned on the inside of the turns. Also, the anchor wires may be secured to the frame members so as to be in torsion in a direction more tightly engage each hook with the respective spring, and also such that compression of the spring increases the tension.

Two anchor wires may extend along opposite sides of each row, such that their hooks engage the springs at diametrically opposite positions. Also, the springs in each row are preferably laterally aligned to provide further rows extending perpendicularly to the first-mentioned rows, there being further anchor wires extending perpendicularly to the first-mentioned anchor wires and secured at diametrically opposite positions on the springs intermediate the previously mentioned diametrically opposite positions.

The opposite ends of each anchor wire may be shaped as catch portions, with the frame members being wires with which the catch portions are engaged to secure the anchor wires thereto.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a plan view of a coil spring assembly, the lower portions thereof being omitted for clarity,

FIG. 2 is an enlarged detail view of parts of the assembly of FIG. 1,

FIG. 3 is a detail view similar to FIG. 2, but showing a modified lower portion,

FIG. 4 is an upper perspective view of part of the coil assembly showing a clip, and

FIG. 5 is a lower perspective view of the part shown in FIG. 4.

Referring first to FIGS. 1 and 2, a coil spring assembly includes an upper rectangular wire framework having sides 1, 2, 3, 4. A first set of anchor wires 5 extend between the sides 1, 3 parallel to the sides 2, 4 and a second set of anchor wires 6 extend between the sides 2, 4 parallel to the sides 1, 3. A series of coil springs 7 have a tapering diameter from top to bottom, and are arranged in laterally aligned rows.

Each anchor wire 5, 6 is bent to provide U-shaped hooks 8, one for each spring 7 in a row, which extend laterally of the length of the wire and have a lateral dimension corresponding to the thickness of the wire of the springs 7. Each anchor wire 5, 6 extends straight towards each spring 7 across the top of the last turn thereof on the inside of the turn, then into a loop 8 which extends downwardly on the inside of the turn, radially outwardly underneath the turn, up on the outside of the turn, through a short length parallel to the direction of the general length of the main portion of the wire, downwardly and radially inwardly and then upwardly on the inside of the turn, to form the opposite end of the loop 8, which then extends into the next straight portion of the anchor wires 5, 6.

Each anchor wire 5, 6 is assembled with the spring 7 in a row by rotation about the longitudinal axis of the wire. The opposite ends of each anchor wire 5, 6 has a catch portion 9 securable to the adjacent side 1, 2, 3, 4, of the rectangular framework. Each catch portion 9 extends from a straight portion of the anchor wire 5, 6 below the respective framework side to the outside of the framework, then upwardly and over the top of the framework side to position the free end within the framwork. The upward section of the catch portion 9 is inclined laterally of the straight portion of the anchor wire 5, 6 to position the catch portion on the same side of the straight portion as the hooks 8.

Each catch portion 9 is formed at an angular disposition to the hooks 8 so that the anchor wire 5, 6 has to be torsioned to engage the catch portion with the respective side 1, 2, 3, 4. The direction of torsioning is in the direction of rotation for attachment, so that the torsion causes tight engagement of each hook 8 with the respective spring 7 and also tight engagement of the catch portion 9 with the framework sides. Also, compression of the springs 7 tends to increase the torsion.

The location of the spring 7 and the anchor wire 5, 6 in the framework 1, 2, 3, 4 is such that each spring is secured to an anchor wire 5, 6 or is adjacent a framework side at four 90.degree. positions. In those cases where the spring 7 is adjacent the framework side, the upper turn of the spring is tightly secured to the side by a metal clip 10. Also, the free end 11 at the larger end of the spring 7 is tightly connected to the adjacent turn by being tightly wound therearound.

The lower narrower end of each spring is secured to a pair of mutually perpendicular bottom wires 12, 13 which are members of two series of mutually perpendicular wires, the wire 12 extends across the top of the lowermost turn, and the wire 13 extends below the lowermost turn but above the wire 12, the two wires 12, 13 being slightly distorted to achieve this connection.

The coil spring assembly described above transmits forces in an even manner, is substantially free from noise, has tight connections everwhere, resists sway, possesses substantially constant compression characteristics from place to place over the top of the assembly, and the top tends to remain planar and rectangular. Since each spring 7 is secured to the top at four places, the full and uniform compression resistance of each spring is utilized. Also, relatively few different parts are required, and each anchor wire is directly connected to each spring, without any further connecting parts being required. The described assembly is intended for manufacture with relatively heavy, tempered wire.

FIG. 3 shows a useful modification of the bottom of the spring assembly. Instead of the bottom wires 12, 13, and anchor wire 14 similar to the anchor wires 5, 6 is used, the lower free end 15 of the spring 7 having been bent to extend diametrically for engagement with a loop 16 of the anchor wire 14. The anchor wire 14 may be provided with catch portions (not shown) similar to the catch portions 9 for attachment to framework sides.

FIGS. 4 and 5 show enlarged views of an upper boundary part of the coil assembly showing how the clip 10 tightly secures the upper turn of a spring 7 to an adjacent framework side 2.

Claims

We claim:

1. A coil spring assembly including a rectangular wire peripheral frame, a first set of spaced, parallel anchor wires extending between one pair of opposite sides of the frame and a second set of spaced, parallel anchor wires extending between the other pair of opposite sides of the frame to form a grid having rectangular segments formed by the anchor wires or by the anchor wires and one or two sides of the frame, a series of coil springs, each spaced from one another, extending perpendicularly to the plane of the grid and each having an end turn adjacent a rectangular segment with the sides of the segment being adjacent and substantially tangential to portions of the end turn, each anchor wire being shaped to provide a series of U-shaped hooks, one for each spring adjacent the wire, extending laterally of the length of the wire and having a lateral dimension corresponding to the thickness of the turn of the spring, each hook being engaged with the end turn of the respective spring, each anchor wire having bent ends engaging the respective wire sides of the peripheral frame with the anchor wire in torsion to tightly engage each hook with the respective spring, each anchor wire when detached from a peripheral frame being removable from engagement with the respective springs and engageable therewith by rotation of the wire about its longitudinal axis, and the portions of the end turns of the springs adjacent a side of the peripheral frame being tightly secured thereto.