JPS644763B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to an improved spiral spring for a spring assembly suitable for an internal spring unit of a mattress. The present invention also relates to an improved spring assembly for an internal spring unit. The assembly includes at least one pair of improved spiral coil springs.

The internal spring unit includes a plurality of spiral coil springs arranged in a plurality of generally parallel rows. The springs in each row are interconnected by a transverse helix connecting each spring to its adjacent spring. The transverse helix is a spiral coil whose cross-sectional diameter is substantially smaller than the cross-sectional diameter of the coil spring. The transverse helix extends across the array of coil springs in both the upper and lower surfaces of the unit and is connected to and around the ends or end turns of adjacent coil springs. The end turns of the coil spring are generally closed loops forming two opposed offset sections. Coil springs with offset portions are arranged within the inner spring unit such that the offset portions are adjacent to each other in each row and surrounded by a transverse helix.

Preferably, the internal spring unit conforms to the shape of the body being supported. In general, internal spring units having coil springs with offset portions are more compliant with the supported body than units having coil springs without such offset portions. This spring flexibility is provided, at least in part, by the hinge action between adjacent springs. Conventional spring offsets are U-shaped members with transverse spirals surrounding the bases of these U-shaped members. The surrounded base portions of adjacent offset portions are disposed within the circumference of the transverse spiral substantially parallel to the main axis of the transverse spiral. Although the base portions are placed very close together, a large hinge movement is allowed between the base portions. That is, the base parts can move past each other. This hinging action allows the coil springs to be compressed more or less independently of each other to conform to the shape of the body or other load being supported.

It would also be desirable to provide an internal spring unit with increased stiffness. Stiffness here is defined as the degree of compression of a coil spring in response to an applied load. The stiffness of a unit depends on many variables, such as the unit coil number (number of coils per unit surface area) and coil stiffness. Increasing the number of coils or replacing them with coil springs of greater stiffness for a given unit will reduce the degree of compression of the spring against an applied load, but the cost of manufacturing such a unit will increase. It is. Other methods of increasing the stiffness of internal spring units are described in U.S. Pat.
No. 3,653,082, the method is to crimp or compress the transverse helix around the offset of the coil spring at the longitudinal ends of the unit. The crimp portion frictionally engages the transverse helix against the enclosed offset;
It is adapted to limit hinge movement between interconnected offsets and therefore between adjacent coil springs. This method, however, reduces the degree to which the spring conforms to the shape of the supported body, which is determined by the hinge action.

It is desirable that the internal spring unit of the mattress be stiff and have great compliance with the body being supported, without significantly sacrificing other properties. It is also desirable to maximize the stiffness and body conforming properties of the internal spring unit without significantly increasing the cost of manufacturing the unit. It may also be desirable to provide different stiffnesses and body conformance to different parts of the internal spring unit, such as stiffer longitudinal ends and greater body conformance at the center or ends. . It is also desirable to provide additional stiffness in other areas of the internal spring unit, such as in the longitudinally central area of the very wide mattress.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved spiral coil spring and a spring assembly including such a coil spring which has greater stiffness than conventional spring offset units and yet has desirable body conformability. It is to be. Another object of the invention is to provide a spring assembly having an improved coil spring that provides optimum spring compliance and stiffness without appreciably increasing the cost of the unit.

These and other objects permit a predetermined degree of hinge motion between adjacent coil springs, and then transmit a portion of the pressure of the springs surrounding the offset portion upon further loading. This can be achieved by providing a spiral coil spring with an offset shape which thereby gives rise to a large resistance to the load, i.e. a large stiffness. The present invention also provides a spring assembly having at least some coil springs with an offset shape that optimizes both the compliance and stiffness properties of the springs.

Each of the improved spiral coil springs has at least one offset portion in at least one of its two end turns, the offset portion having a serpentine or serpentine shape. It has alternating protrusions.
The spring assembly of the present invention includes at least one pair of such coil springs arranged adjacent to each other such that adjacent offset protrusions substantially overlap each other. Preferably, the protrusion extends beyond the circumference of the transverse spiral surrounding the offset portion. Such offset portions are free to hinge relative to each other until the angle between the planes of the projections reaches a maximum deflection angle. This deflection angle depends on the dimensions of the projection and the inner diameter and pitch of the transverse spiral surrounding the offset section. When this maximum deflection angle is reached, the hinge movement between the springs is blocked by the transverse helices and a portion of the load pressure applied to one of the coil springs is transferred to the other coil spring. This transfer of load pressure reduces the compression of the spring against the load. Greater stiffness can therefore be provided without sacrificing the desired amount of hinge motion between the springs and the compliance characteristics of the unit.

The coil springs of the present invention, when interconnected by transverse helices, can be thought of as defined pair coil springs, ie springs having defined pairs of adjacent offset portions.

The offset projections are generally coplanar with the other portions of the end turns of the spring and extend in alternating and opposite directions. Adjacent offset portions are shaped so as to substantially overlap each other. When pressure is applied to the upper stacked coil spring in a defined pair, its inwardly extending offset projections are forced downwardly by the projections of the other lower coil spring. Movement is substantially impeded while the outwardly extending projections move in an upward arc until they are restricted by the transverse spirals surrounding the offset portions. Thereafter, when further load pressure is applied, a portion of the load pressure is transmitted to other coil springs, so that the degree of compression of the loaded coil springs per load decreases. A similar but opposite action occurs when pressure is applied to a coil spring with an underlying offset.

In a preferred embodiment, the end turns of the coil spring are formed with alternating projections on opposite offset portions thereof. Furthermore, both end winding portions of the coil spring may be formed in such a shape.

The present invention, its objects, features, and advantages will now be described with reference to the accompanying drawings.

The accompanying drawings, and in particular FIG. 1, illustrate a pinerest 10 embodying features of the present invention. Mattress 10 includes an internal spring unit 12 which is covered with a suitable mattress cover 14. The internal spring unit 12 includes a plurality of spiral coil springs 1.
6, and these springs 16 are arranged in a plurality of rows. Each spiral coil 16 is formed of a series of turns terminating in an end or terminal turn 20 and is interconnected to an adjacent coil spring 16 by a transverse helix 22 tied through the circumference of the end turn 20. has been done. Each end turn 20 is formed with two opposed offset portions 24 surrounded by a transverse spiral 22. This transverse helix 22 limits the movement of adjacent offset portions 24 relative to each other to a maximum angle of deflection, thereby preventing hinge action between the springs 16. A portion of the load pressure applied to one of the coil springs 16 is transferred to an adjacent coil spring 16, thereby increasing the stiffness of the unit 12. However, the hinge motion allowed between the springs 16 before reaching the maximum deflection angle satisfies the desired degree of spring compliance for the supported body.

In FIG. 2, the internal spring unit 12
The spiral coil springs 16 are arranged in a plurality of rows extending longitudinally of the internal spring unit 12. Adjacent coil springs 16 in each row have their mutually adjacent offset portions 24
are disposed close enough so that they at least partially overlap. A transverse helix 22 extends laterally of the internal spring unit 12 and connects the pairs of coil springs 16 in each row through mutually overlapping offset portions 24 to connect one longitudinal side of the internal spring unit 12. It extends from the vertical side to the other vertical side.

Each coil spring 16 has terminal turns 2 at each end.
0, the end windings 20 of which form both the upper and lower surfaces of the internal spring unit 12. The horizontal spiral body 22 is similarly connected to the unit 12.
These are connected to each other through offset portions 24 of the coil spring 16 on both upper and lower surfaces of the coil spring 16. Although only one of the opposing end turns 20 of the coil spring 16 is shown for clarity, the opposite end turn 20 is of similar construction.

As shown in FIGS. 3 and 4, the offset portion 24 of the end turn 20 is formed with alternating projections 26, at least some of which are connected to a surrounding lateral spiral. 2
It extends beyond the outer periphery of 2. Each end turn 20 with opposing offset portions 24 lies substantially in a single plane. Adjacent coil spring 16
are the adjacent protrusions 2 that are alternated.
6 are arranged at least partially overlapping, and the interconnected transverse spirals 22 partially surround the projections 26. Although other configurations are possible, each coil spring 16 has one offset portion 24 placed over the offset portion 24 of an adjacent coil spring 16, and the other offset portion 24 placed on the opposite side. Offset portion 2 of adjacent coil spring 16
It is preferable to arrange it so that it is placed under 4.

Alternate projections 26 of offset portion 24
It is preferable to configure the base portion 28, a first protrusion 30 extending inward, and a second protrusion 32 projecting outward. Therefore,
The first and second protrusions 30 and 32 extend in opposite directions. If we imagine that the offset portion 24 has a conventional U-shaped configuration, the first and second protrusions 30 and 32 are located on opposite sides of the base portion of the assumed conventional U-shaped offset.
are extended, and the form of the staggered protrusions is far from this U-shaped form. The transverse helix 22 is arranged such that the base portion 28 of the offset 24 is within the transverse helix 22 and aligned with the major axis of the transverse helix and both the first and outer portions of the circumference of the transverse helix 22. , it is desirable to surround the overlapping offset portions 24. The effects of such a structure will be explained below.

The two opposing offset portions 24 of one end turn 20 are formed to have mirror image shapes that are superimposed on each other. The right offset portion 24 of the coil spring 16 has a shape that matches the left offset portion 24 of the adjacent coil spring 16. Therefore, adjacent offset portions 24 are superimposed on each other.

As shown in FIGS. 5 to 8, when the coil spring 16 is under load, that is, when it is pressed, the offset portion 2 of the spring 16
4 is the offset portion 2 of the adjacent spring 16
It moves like a hinge against 4. In more detail,
The offset portions 24 overlying adjacent offset portions 24 are specifically shown beginning to rotate. The inwardly projecting protrusion or first protrusion 30 is substantially prevented from moving downward because the second protrusion or outwardly protruding protrusion 32 of the adjacent offset portion 24 is on the lower side. has been done. The second protrusion 32 is free to move upwardly in an upward arc relative to the overlying offset section 24. Offset part 2
The base portion 28 of 4 also moves in an upward arc. Although the planes of these overlapping offset portions 24 are substantially parallel when the spring 26 is unloaded, they now form an angle or deflection angle.

In a manner similar to that described above, when the coil spring 16 of the underlying offset portion 24 is compressed, the second or outwardly projecting portion 32 is compressed from the first portion of the adjacent offset portion 24.
The protruding part 30, that is, the protruding part 30 that protrudes inward, overlaps the upper side, so that it is prevented from moving upward. However, the lower overlapping offset section 24 rotates relative to the upper offset section 24. This is because the base portion 28 of the offset portion 24 and the first protrusion portion 30 overlap on the lower side.
This is because it moves in a downward arc. On the other hand, both planes of the offset portion 24 are
They move from a relatively parallel position to form a deflection angle.

One offset portion 2 relative to the adjacent offset portion 24 when the coil spring 16 is compressed
This relative movement of 4 provides a hinge action between adjacent springs 16. This hinge action compresses the springs to some degree independently, allowing the entire internal spring unit 12 to conform to the shape of the reclining body. This compliant characteristic of the internal spring unit 12 provides a desirable sense of rest to the body lying thereon. If the hinge action is global, i.e. there is no limit to the angle of deflection, the internal spring unit will be stiffer than the unit 12 according to the invention for a given number of coils and coil stiffness. becomes smaller. The coil spring 16 of the internal spring unit 12 is not capable of full hinge action, as will be explained in detail below. The hinge movement is only carried out until a predetermined maximum deflection angle is reached. If a given coil spring 16 is further compressed or loaded, adjacent coil springs 16 will be compressed together. The more coil springs are in compression for a given load, the greater the resistance to that load. That is, the stiffness of the internal spring unit 12 becomes even greater.

The inner diameter of the transverse helix 22 relative to the dimensions of the staggered projections 26 defines the maximum deflection angle. As mentioned above, based on the compression of the coil spring 16, the first or inwardly projecting protrusion 30 rotates in a downwardly directed arc or the second or outwardly projecting protrusion 30 rotates in a downwardly directed arc. A protrusion 32 protruding from the top rotates in an upward arc. The range of movement relative to adjacent offset portions 22 that overlap above or below is limited by the surrounding lateral spirals 22.
Each projection 30, 32 has a leg 34 and a tip or apex 36. The apex 36 is on the outside of the surrounding lateral spiral 22 while the leg 34 is located within the circumference of the lateral spiral 22. As the deflection angle increases based on the movement of the predetermined offset portion 24, the leg portion 34 approaches the inner surface of the surrounding transverse spiral body 22 until it contacts it, causing the offset portion 24 to move closer to the adjacent offset portion 24. Prevent it from moving any further. When the deflection angle between the offset planes is maximum,
It is virtually impossible for offset portions 24 to move relative to each other.

The internal spring unit 12 has a desirable degree of compliance with a lying body due to the hinge action between adjacent coil springs 16. Internal spring unit 12 also has a high stiffness. A similar unit without an offset section 24 formed with alternating projections 26, such as a U-shaped offset section, has substantially less stiffness. The present invention provides optimal stiffness without increasing the number of coils or the stiffness of each coil, and without sacrificing the desired spring compliance to the shape of the body being supported.

The preferred deflection angle is about 0 to 15 degrees. However, the angle chosen depends on the required stiffness and unit 1.
2 and other variables that contribute to the stiffness. The preferred coil spring 16 has an offset portion extending approximately 1 to 11/4 inches (2.5 to 3.1 centimeters) end-to-end (at the datum line) from the datum line. 1/4 inch).

In the preferred embodiment shown in FIG. 9, the opposing offset portions of coil spring 42 are different. The preferred coil spring 42 has first and second offset portions 44, 46 of different lengths. The first offset portion 44 has first and second protrusions 48, 50 but is substantially free of a base portion. The second offset portion 46 is located between the first and second protrusion portions 5
2, 54 and a base portion 56. Second
The offset portion 46 is approximately
25% longer.

Although the shapes of the offset portions shown and described herein are considered preferred, it is understood that other shapes may be envisaged to provide a limited hinging action of the spring according to the invention, without being limited thereto. Of course. Additionally, the present invention describes and illustrates an internal spring unit 12 in which all of the adjacent interconnected coil springs 16 are
Both upper and lower surfaces of the unit 12 have offset portions 24 in which protrusions 26 are formed alternately.

However, this structure may be provided only in those portions of the unit 12 that require adjustment of spring compliance and stiffness. The construction of any given internal spring unit 12 can vary the maximum angle of deflection in various portions of the unit 12, thereby providing different degrees of spring compliance and stiffness to different portions of the unit 12.

It will be evident that changes may be made in details of construction, arrangement and operation without departing from the spirit of the invention, particularly as defined in the claims.

[Brief explanation of the drawing]

1 is a partially cutaway perspective view of a mattress having an internal spring unit embodying features of the present invention; FIG. 2 is a partial plan view of the internal spring unit of FIG. 1; and FIG. Enlarged partial plan view of the internal spring unit of Figure 4.
The figure is a sectional view taken along line 4-4 in Figure 3, and Figures 5 to 5.
8 is an illustrative side view of two interconnected coil springs of the internal spring unit of FIG. 1, and FIG. 9 is a plan view of a preferred spring of the internal spring unit of FIG. 10... Pine tress, 12... Internal spring unit, 14... Pine tress cover, 16...
Spiral coil spring, 20... End winding part, 22... Horizontal spiral body, 24... Offset part, 26... Projection part, 28... Base part, 3
0, 48, 52...first protrusion, 32, 50, 5
4...Second projection part, 34...Leg part, 36...Mountain part, 42...Coil spring, 44...First offset part, 46...Second offset part.

Claims (1)

Claims: 1. A spring assembly for an internal spring unit comprising a plurality of spiral coil springs arranged in a plurality of substantially parallel rows and having opposed end turns forming both upper and lower surfaces of said unit. and extending across said row of coil springs;
a plurality of transverse helices interconnecting a plurality of adjacent springs around mutually adjacent portions of the end turns of the coil spring; each of the at least one pair of adjacent portions of the end turn of the coil spring is formed as an offset portion, each of the offset portions being surrounded by a plurality of staggered protrusions and the transverse helix; a base portion, the protrusions being partially surrounded by the transverse spiral, the staggered protrusions being arranged in the plane of the distal turn in which the protrusions are formed. substantially overlapping the staggered projections of the second offset portion of the pair, and wherein the staggered projections of the first offset portion substantially overlap the staggered projections of the second offset portion of the pair; A pair of congruent staggered protrusions and the lateral spirals cooperate to provide a gap between the adjacent end turns and the inner diameter and pitch of the surrounding lateral spirals and the lateral spirals. A spring assembly for an internal spring unit, characterized in that it allows substantially unrestricted pivoting about the longitudinal axis of said base portion up to a maximum angle of deflection depending on the dimensions of said base portion. 2. Each offset portion of the pair of adjacent offset portions that is restrained has a base portion, at least a first protrusion that extends inwardly, and a second protrusion that protrudes outwardly.
a protrusion, the protrusion being adapted to extend beyond the circumference of the enclosing transverse helix when the base portion is substantially aligned with the major axis of the enclosing transverse helix; A spring assembly as claimed in claim 1. 3. The base portion of the constrained pair of offset portions and the first and second protruding portions are substantially in contact with each other and overlap each other. spring assembly. 4. The spring assembly of claim 3 further comprising a plurality of pairs of adjacent offset portions constrained within both upper and lower surfaces of the unit. 5. The spring assembly of claim 1, wherein at least one pair of said adjacent offset portions have substantially mirror image shapes. 6. The spring assembly of claim 1, wherein at least one of said base portions extends perpendicularly from a line bisecting one of said projections.