HK40029539B - Wire coil and innerspring system - Google Patents

Description

Linear coil and built-in spring system

Technical Field

The present invention relates generally to helical springs, and particularly, but not exclusively, to helical spring systems included in mattresses.

Background Technology

As described in U.S. Patent No. 4,726,572 ('572 Patent), entitled "Spring Coil and Spring Assembly," assigned to Sealy Technology LLC, a mattress built-in spring unit is typically formed by multiple spring coils arranged in parallel rows side-by-side, wherein the parallel columns are formed orthogonal to the rows. Border wire sometimes surrounds the upper and lower perimeters of the built-in spring unit. In use, the border wire extends from the outermost spring coil and connects to a terminal convolution formed on the end of the spring coil.

The common practice is to wind the ends to form a diameter that increases relative to the diameter of the helix extending axially inward from the coil end. This allows the springs to engage with each other and makes the compression of the spring coil more stable.

The end windings of adjacent spring coils in a row typically overlap, and then a helical spring coil (called a cross helix) is wound along the row to encircle the overlapping windings. These cross helices typically include an inner diameter slightly larger than the combined diameter of the overlapping end windings. Sometimes, larger diameter helical springs are used to attach binding wire to the end windings.

The '572 patent discloses various arrangements of spring coils and cross-helices that produce built-in spring assemblies with different firmness characteristics. However, these various arrangements typically result in a fixed spring stiffness coefficient, which limits the ability to customize spring performance in different areas of a single mattress or across different mattresses within a given mattress brand.

U.S. Patent No. 7,404,223 ('223 Patent), entitled "Innerspring Coils and Innersprings with Non-Helical Segments," also assigned to Sealy Technology LLC, discloses different types of helical springs having one or more non-helical segments located between the ends of the coil and the helical body of the coil, as well as an in-line spring made from such a coil. The non-helical segments define different types of multi-tap coils, also known as "single-tap" or "multiple-tap" coils, formed from wire made of steel or alloy. The coil includes at least one non-helical segment that is combined with or adjacent to one or two of the helical coil body and the ends of the coil. A "tap" refers to a non-helical segment of the described coil that may be aligned with or coaxial with the longitudinal axis of the coil and provides height and length to the coil with less material than a coil in which the entire coil body is helical. When assembled within an internal spring, the non-helical structure and orientation of one or more taps of the coil can also be used to form a relatively stiff base for the coil that supports the coil body with helical turns (i.e., a helical coil body), and this base has a lower spring stiffness coefficient and a softer feel to the support surface of the internal spring. However, these taps add extra overall length to the spring, which limits the choice of mattress geometry.

In addition to the need for various mattress geometries, there are several common manufacturing and comfort considerations that form the basis of any mattress's built-in spring design. For example, considerable effort has been invested in developing end-wraps that facilitate the interlocking of spring coils and their connection to binding wires. End-wraps with offset portions including straight sections formed thereon have been developed, for instance. This allows the spring ends to be secured along a considerable length of the straight section, which "captures" more of the helical coil and thus provides greater stability to the individual coils. However, there is always a search for improved stability.

Another consideration in mattress design and manufacturing is the ability to create built-in spring units with varying firmness characteristics to suit different individual preferences. This can simply mean providing several mattress lines with different firmnesses, or, in more complex mattresses, providing areas of different firmness within specific mattress springs.

It is readily apparent that mattresses with varying firmness characteristics can be produced for each mattress firmness by using springs of different compressions. This is typically achieved by utilizing different raw materials or various springs made with different structures. The overall layout or construction of the built-in spring units can also be altered from one mattress firmness to another, such as by changing the coil count and coil arrangement. Using heavier raw materials, more springs, different springs, or different layouts obviously increases component production and labor costs in mattress manufacturing. Therefore, the primary consideration in manufacturing mattresses with different firmness levels is to do so in the most efficient and economical way while still achieving the desired results.

Therefore, a further improved linear coil and built-in spring system are needed.

Summary of the Invention

The purpose of this invention is to overcome and/or mitigate one or more of the aforementioned disadvantages of the prior art, or to provide consumers with a useful or commercial option.

According to one aspect, the present invention provides a wire coil for use in a built-in spring, comprising:

Multiple helical turns form a helical coil body around the longitudinal axis of the coil, and the helical turns define the radius of the helical turns;

The first coil end extends from one end of the helical coil body; and

The second coil end extends from the opposite end of the helical coil body;

Wherein, at least one of the first coil end and the second coil end includes one or more contact points, the contact points being defined by a first portion and a second portion, the first portion extending from the longitudinal axis of the coil by a distance greater than the radius of the helical turn, and the second portion extending from the longitudinal axis of the coil by a distance less than the radius of the helical turn.

Preferably, the contact points are located at the ends of the first coil and the second coil.

Preferably, the contact points are spaced apart around the entire circumference of the helical coil body to provide uniform support around the entire circumference of the helical coil body. Preferably, the first coil end is approximately located in a plane perpendicular to the longitudinal axis of the coil.

Preferably, the end of the second coil is approximately located in a plane perpendicular to the longitudinal axis of the coil.

Preferably, the point on the longitudinal axis of the coil is centrally located within the contour of the first coil end and the second coil end.

Preferably, the first coil end includes two approximately straight end segments.

Preferably, the two end segments are approximately parallel to each other.

Preferably, the two end segments are spaced approximately 180 degrees apart around the longitudinal axis of the coil and around the body of the helical coil.

Preferably, the first coil end includes two end segments, and the second coil end includes two end segments that overlap with the two end segments of the first coil end in a direction parallel to the longitudinal axis of the coil.

Preferably, the coil is formed into a built-in spring system using various feasible methods, including but not limited to: a pocket made of textile material, a helical lacing wire, or another method of connecting the coil.

Preferably, the upper part of the helical coil body includes turns that are more tightly wound than the lower part of the helical coil body.

Preferably, as each of the six different contact points contacts the coil body, the spring stiffness coefficient of the linear coil increases sequentially in the six stages during compression.

According to another aspect, the present invention provides a built-in spring system comprising a plurality of the above-described coils.

Preferably, the longitudinal axis of each of the multiple linear coils is centered to prevent uneven coil spacing in the alternating units of the linear coils.

Preferably, the rows or columns of linear coils are rotated 180 degrees around their longitudinal axis and relative to other linear coils to improve system stability.

Attached Figure Description

To aid in understanding the present invention and to enable those skilled in the art to practice it, preferred embodiments of the invention are described below by way of example only with reference to the accompanying drawings, in which:

Figure 1 is a side perspective view of a linear coil used in a built-in spring system according to an embodiment of the present invention;

Figure 2 is a top view of the linear coil in Figure 1, showing only the end of the first coil and the first turn of the helical coil body;

Figure 3 is a bottom view of the linear coil in Figure 1, showing only the end of the second coil and the first turn of the helical coil body;

Figure 4 is another top view of the linear coil of Figure 1, showing the end of the first coil overlapping with the end of the second coil and the body of the helical coil;

Figure 5 is a front view of the linear coil in Figure 1;

Figure 6 is a right-side view of the linear coil in Figure 1;

Figure 7 is a side view of the built-in spring system according to an embodiment of the present invention; and

Figure 8 is a top view of the built-in spring system in Figure 7.

Similar reference numerals in the various figures indicate similar elements.

Detailed Implementation

This invention relates to a linear coil and a built-in spring system. The elements of the invention are shown in concise outline form in the accompanying drawings, illustrating only those specific details necessary for understanding embodiments of the invention, without obscuring this disclosure with excessive detail, which will be readily apparent to those skilled in the art based on this specification.

In this patent specification, adjectives such as first and second, left and right, top and bottom, upper and lower, rear, front and side, etc., are used only to define one element or method step in relation to another, without necessarily requiring a specific relative position or order described by the adjective. Words such as "comprising" or "including" are not used to define an exclusive set of elements or method steps. Rather, these words define only the minimum set of elements or method steps included in a particular embodiment of the invention.

According to one aspect, the invention is defined as a linear coil for use in a built-in spring, the linear coil comprising: a plurality of helical turns forming a helical coil body around a longitudinal axis of the coil, the helical turns defining a helical turn radius; a first coil end extending from one end of the helical coil body; and a second coil end extending from an opposite end of the helical coil body; wherein at least one of the first coil end and the second coil end includes one or more contact points defined by a first portion and a second portion, the first portion extending from the longitudinal axis of the coil by a distance greater than the helical turn radius, and the second portion extending from the longitudinal axis of the coil by a distance less than the helical turn radius.

Advantages of some embodiments of the invention include a linear coil with improved support and reduced deformation during compression when the first effective turn of the coil body contacts the coil end at one or more deliberat contact points. Furthermore, the contact points gradually close the end portion of the coil, providing the opportunity for a variable spring stiffness coefficient without the need for additional springs, where the spring stiffness coefficient increases, and thus the coil becomes more robust as it is compressed. The contact points also help reduce noise from the linear coil. Additionally, the end profile increases the overlap of the coil body on the end profile, preventing the coil body from being pushed through the end profile under compression and getting stuck when the coil is released. Moreover, when the linear coil is assembled in a built-in spring system, the central longitudinal axis of the coil creates a more uniform space between the coil bodies in alternating coil unit assemblies, reducing the chance of collisions between adjacent linear coils, regardless of coil orientation. Various coil assembly methods can be used, including, for example, pocket coils, spiral ties, etc.

Those skilled in the art will understand that not all the above-described advantages will be achieved through all possible embodiments of the invention. The following figures depict a specific embodiment of the invention, which provides three intentional contact points at each end of the coil. Those skilled in the art will understand that different embodiments of the invention may have different contact points formed by alternative coil end shapes, and may also have different coil end profiles at each end of the coil. It is also possible for two end segments to be oriented differently relative to each other.

Figure 1 is a side perspective view of a linear coil 100 for use in a built-in spring system according to an embodiment of the present invention. The coil 100 includes a plurality of helical turns 105, which form a helical coil body 110 around a longitudinal axis 115 of the coil 100. The helical turns 105 define a helical turn radius 120.

The first coil end 125 extends from the first end 130 of the spiral coil body 110. The second coil end 135 extends from the opposite end 140 of the spiral coil body 110.

Figure 2 is a top view of the linear coil 100, showing only the first coil end 125 and the first turn of the helical coil body 110. Contact points 200, 215, and 220 are locations in the end view where portions of the first coil end 125 extend across the helical coil body 110, and therefore are locations where the first coil end 125 will contact the coil body 110 when the linear coil 100 is compressed. For example, the second contact point 215 is defined by both a first portion 202 and a second portion 207 of the first coil end 125, the first portion 202 extending from the longitudinal axis 115 of the coil 100 by a distance 205 greater than the helical turn radius 120, and the second portion 207 extending from the longitudinal axis 115 of the coil 100 by a distance 210 less than the helical turn radius 120. The first contact point 200 and the third contact point 220 are similarly defined.

Therefore, the first coil end 125 crosses over the first turn of the spiral coil body 110 at each contact point 200, 215 and 220.

During the compression of the linear coil 100, the first contact point 200 contacts the first turn of the helical coil body 110 at a point directly below the first contact point 200 (in a direction parallel to the longitudinal axis 115). After the first contact point 200 contacts the first turn of the helical coil body 110, during further compression of the coil 100, the end portion of the coil body 110 between the first contact point 200 and the first coil end 125 no longer affects the spring stiffness coefficient of the coil 100. Therefore, during this further compression, the spring stiffness coefficient of the coil 100 increases.

Subsequently, during further compression of the coil 100, and after the second contact point 215 contacts the first turn of the spiral coil body 110, the end portion of the coil body 110 between the second contact point 215 and the first coil end 125 no longer affects the spring stiffness coefficient of the coil 100. Therefore, the spring stiffness coefficient of the coil 100 further increases. This process continues through the second contact point 215 and reaches the third contact point 220, which closes off another portion of the coil 100 between contact points 215 and 220, thereby further affecting the spring stiffness coefficient of the coil 100.

Contact points 200, 215, and 220 also provide improved support and stability for the coil body 110 and reduce lateral forces when the coil 100 is compressed.

According to some embodiments, the coil end profiles and contact points 200, 215, 220 allow the top and bottom of the longitudinal axis 115 of the helical coil body 110 to be positioned as close as possible to the center point of the coil end profile, thereby minimizing any tilt or directional bias and maximizing stability when compressing the coil 100.

Figure 3 is a bottom view of the linear coil 100, showing only the second coil end 135 and the first turn of the helical coil body 110. The second coil end 135 extends from the opposite end 140 of the helical coil body 110. Similar to the first coil end 125, the second coil end 135 also includes contact points 300, 310, and 315. Furthermore, the second coil end 135 includes two end segments 320 and 325, which are approximately straight, approximately parallel to each other, and approximately 180 degrees apart as measured around the longitudinal axis 115 of the coil 100 and around the helical coil body 110.

Figure 4 is another top view of the linear coil 100, showing the first coil end 125 overlapping with the second coil end 135 and the helical coil body 110. The end segments 420, 425 of the first coil end 125 are located directly above the end segments 320, 325 of the second coil end 135.

The two end segments 420, 425 are also approximately straight, approximately parallel to each other, and approximately 180 degrees apart, measured around the longitudinal axis 115 of the coil 100 and around the helical coil body 110.

Figure 5 is a front view of the linear coil 100.

Figure 6 is a right-side view of the linear coil 100. As shown, the upper part of the helical coil body 110 includes more tightly wound turns than the lower part of the helical coil body 110. This results in contact points 200, 215, 220, 300, 310, and 315 making sequential contact with the coil body 110 during compression of the coil 100. For example, contact point 200 may contact the coil body 110 first, followed by contact point 215, then contact points 200, 300, and 310, and finally contact point 315. Therefore, as each contact point 200, 215, 220, 300, 310, and 315 contacts the coil body 110, the spring stiffness coefficient of the coil 100 increases sequentially in six stages during compression.

In view of this disclosure, those skilled in the art will understand that alternative embodiments of the invention may include different coil end profiles having, for example, different numbers and locations of contact points and coil body turns with different pitches and radii, thereby forming different variable responsivity as needed.

Figure 7 is a side view of a built-in spring system 700 according to an embodiment of the present invention. A spiral strap 705 connects end segments 320, 420 to adjacent end segments 325, 425 of adjacent linear coils 100, respectively, to form the built-in spring system 700.

Centering the longitudinal axis 115 of each linear coil 100 prevents uneven coil spacing in alternating units of the linear coils 100 within the built-in spring system 700, wherein rows or columns of coils 100 can be rotated 180 degrees to improve unit stability. This design also prevents the formation of large and small spaces between rows or columns, thereby reducing the likelihood of adjacent coils 100 contacting each other.

Figure 8 is a top view of the built-in spring system 700, and also shows the alternating units of the linear coil 100.

Those skilled in the art will understand that various embodiments of the present invention can be made of various materials or combinations thereof, including steel, metal alloys, or high-strength plastics or composite materials.

Those skilled in the art will also recognize that the alternating pattern of the coil can take many different forms as needed to achieve the desired final product. The coil can be rotated at different rotation angles throughout the spring unit in an alternating pattern through columns, rows, checkerboards, or any combination or combination thereof to obtain the desired effect, feel, or stability in the unit.

For purposes of description, the above description of various embodiments of the invention has been provided to those skilled in the art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. Many alternatives and variations of the invention will be apparent to those skilled in the art upon receiving the above teachings. Therefore, although some alternative embodiments have been specifically discussed, other embodiments will be apparent or relatively readily developed by those skilled in the art. Accordingly, this specification is intended to cover all alternatives, modifications, and variations of the invention discussed herein, as well as other embodiments falling within the spirit and scope of the above-described invention.

Claims (12)

1. A linear coil for use in a built-in spring, comprising: Multiple helical turns form a helical coil body around the longitudinal axis of the coil, and the multiple helical turns define a helical turn radius; A first coil end, which extends from one end of the helical coil body; and The second coil end extends from the opposite end of the helical coil body; Wherein, at least one of the first coil end and the second coil end includes one or more contact points defined by a first portion and a second portion, the first portion extending from the longitudinal axis of the coil by a distance greater than the helical turn radius, the second portion extending from the longitudinal axis of the coil by a distance less than the helical turn radius, and at least one first coil end and the second coil end are not fixed and terminate at a distance from the longitudinal axis less than the helical turn radius. 2. The linear coil according to claim 1, wherein the contact point is included at the first coil end and the second coil end. 3. The linear coil according to claim 1, wherein the contact points are spaced apart around the entire circumference of the helical coil body to provide uniform support around the entire circumference of the helical coil body. 4. The linear coil according to claim 1, wherein the end of the first coil is approximately located in a plane perpendicular to the longitudinal axis of the coil. 5. The linear coil according to claim 1, wherein the end of the second coil is approximately located in a plane perpendicular to the longitudinal axis of the coil. 6. The linear coil according to claim 1, wherein a point on the longitudinal axis of the coil is centrally located within the contours of the first coil end and the second coil end. 7. The linear coil according to claim 1, wherein the first coil end comprises two approximately straight end segments. 8. The linear coil according to claim 7, wherein the two end segments are approximately parallel to each other. 9. The linear coil of claim 1, wherein the first coil end comprises two end segments, and the second coil end comprises two end segments that overlap with the two end segments of the first coil end in a direction parallel to the longitudinal axis of the coil. 10. The linear coil according to claim 1, wherein the upper portion of the helical coil body includes turns that are more tightly wound than the lower portion of the helical coil body. 11. The linear coil of claim 10, wherein, as each of the six different contact points contacts the coil body, the spring stiffness coefficient of the linear coil increases sequentially in six stages during compression. 12. A built-in spring system comprising a plurality of linear coils as claimed in claim 1.