Coil-in-coil springs and innersprings

ES 2 575 555 T3

DESCRIPTION

Springs formed by two springs, one inside the other, and a set of interior springs.

FIELD OF THE INVENTION

[0001] The present invention is framed within the general field of the design of a set of inner springs and springs, or, more specifically, in the field of sets of inner springs and springs formed by two springs, one inside the other, to mattresses and other bedding products.

BACKGROUND OF THE INVENTION

[0002] Inner mattress spring assemblies, or simply "inner spring assemblies", made of arrays or formations of a plurality of springs or wire springs, have long been used as the elastic core of mattress padding, and the upholstery is placed and fixed around the set of inner springs. Inner spring assemblies made of steel wire are mass produced by machinery that shapes the springs using steel wire stocks and joins the springs in the array arrangement. With this machinery, the attributes of the design of inner spring assemblies can be selected and modified, from the size of the wire, the design of the spring or combinations of these designs, the orientation of the spring in relation to adjacent springs in the formation of the matrix, and the way of interconnection or union of the springs.

[0003] Mattresses and other types of cushions have been constructed for decades using conventional inner spring assemblies, which, due to their symmetrical construction resulting from the use of generally symmetrical springs such as those manufactured by spring production, have two sides (as defined by the ends of the spring) that provided elastic support. Conventional inner spring assemblies typically consist of a series of hourglass shaped springs that are connected by joining convolutions at the ends with transverse helical wires. An advantage of this arrangement is that it is cheap to manufacture. However, this type of inner spring assembly provides a firm and rigid mattress surface.

[0004] Another type of spring that has been used in the construction of the mattress is the spring tucked into an individual pocket. A spring tucked into a single pocket is a spring wrapped in a cloth cover. The springs are arranged in succession and the pockets are joined by stitching to form a cohesive unit. This type of inner spring assembly provides a more comfortable mattress surface because the springs are individually relatively flexible so that each spring can be bent separately without affecting adjacent springs. However, this type of inner spring set design is more expensive to build and also more prone to sagging than conventional hourglass shaped inner spring set, not tucked into an individual pocket.

[0005] Prior art interior spring assembly designs overcome the limitations of existing interior spring assembly designs with varying heights, helical turns, and the degrees of elasticity that along with variations in placement and orientation have all been introduced. individually in an attempt to improve the interior spring assembly design or complement a particular mattress design. However, such designs and configurations typically focus on improving one aspect of mattress design, such as comfort, affordability, ease of manufacture, or durability. And the physical properties, that is, the spring characteristics, of single wire springs are restricted by the size of wire used, the height of the spring, the number and radius of turns or convolutions in a coil spring body and the end configurations.

[0006] USD579242 USD shows a coil spring with inner and outer springs for use in furniture such as mattresses. WO9825503 describes a spring unit with a plurality of springs tucked into individual pockets with one spring inside the other.

SUMMARY OF THE INVENTION

[0007] A spring formed by two springs, one inside the other, provides an alternative to the design of a set of inner springs where the advantages of several sets of existing inner springs are achieved. The spring formed in this way offers the positive aspects of having different spring heights, springs with a different number of helical turns, and springs with varying degrees of elasticity. It also fits furniture with dual capabilities, such as a sofa bed.

[0008] The present description and related inventions describe a set of inner springs for a

ES 2 575 555 T3 mattress that includes a series of "nested" springs or springs formed by two springs, one inside the other. The outer spring is greater in both height and diameter than the inner spring. The inner spring contains more helical turns or convolutions than the outer spring and thus also has a higher degree of elasticity than the outer spring. In a first embodiment, the springs formed by two springs, one inside the other, are placed in "individual pockets" before being joined in rows to form the set of interior springs. In a second embodiment, the springs formed by said springs are joined by helical tie wires that run between the rows of springs and that are wound or tied around tangential or overlapping segments of adjacent springs.

[0009] According to one aspect of the invention, there is provided a set of inner springs of a mattress comprising: a plurality of springs formed by two springs, one inside the other. Said springs carry an outer helical spring and an inner helical spring made of a continuous wire; the outer coil spring has a convolution at the upper end and a convolution at the lower end versus the convolution of the upper end, the inner coil spring has a convolution at the upper end and a convolution at the lower end versus the extreme convolution higher; characterized in that the convolution at the lower end of the inner coil spring is continuous with the convolution at the lower end of the outer coil spring; the outer helical spring has an uncompressed height of 8.25 inches (21.0 cm) and has a total of 5 helical convolutions; the inner coil spring has an uncompressed height of 14.6 cm (5.75 inches) and has a total of 7 helical convolutions; where the diameter of the convolution of the upper end of the outer coil spring is smaller than the diameter of the previous convolutions of the outer coil spring and the diameter of the convolution of the lower end of the inner coil spring is greater than the subsequent convolutions of the inner coil spring; where the wire measure of the springs that form the springs, is between 13 and 16, and said springs formed by two springs, one inside the other, are annealed twice and are individually placed in a pocket and arranged in a matrix to form the set of the inner springs of the mattress; and where the outer coil spring extends counterclockwise and the inner coil spring extends clockwise.

These and other aspects of the disclosure and related inventions are described hereinafter and in detail with reference to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS

[0011]

FIG. 1 is the perspective view of a spring formed by two springs, one inside the other.

FIG. 2 is the side view of the spring formed by two springs, one inside the other of FIG. 1.

FIG. 3 is the top view of the spring formed by two springs, one inside the other of FIG. 2 from arrows 3-3.

FIG. 4 is the enlarged side view of the outer spring of the spring formed by two springs, one inside the other of FIG. 1

FIG. 5 is the enlarged side view of the inner spring of the spring formed by two springs, one inside the other of FIG. 1

FIGS. 6 to 9 are side views of the spring formed by two springs, one inside the other of FIG. 1 in various states of compression.

FIG. 10 is the spring formed by said two springs of FIG. 1 tucked in a pocket

FIG. 11 is the cross-sectional view of the spring formed by said two springs placed in a pocket of FIG. 10 as part of a mattress assembly.

FIG. 12 is the perspective view of a set of inner mattress springs that use the springs formed by two springs, one inside the other, without a pocket, of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED AND ALTERNATIVE IMPLEMENTATION MODES

[0012] FIG. 1 is a perspective view of a spring formed by two springs, one inside the other 100 representative of the present invention. The outer spring 10 and the inner spring 20 are coaxially shaped springs and

Helical ES 2 575 555 T3 made of a single strand of spring wire or other suitable material. As shown in FIG. 2, the outer spring begins with a flat base that continues upward in a spiral forming the body of the spring. The convolution of the upper part 30 of the outer spring 10 terminates in a circular loop at the upper end of the spring. The ends are punch-formed to provide a base or support surface for the point of contact with the padding layer and upholstery. Base 40 is formed with a double circular loop where the inner loop extends upward in a spiral to form inner spring 20. As can be seen in the Figures, outer spring 10 is taller than inner spring 20. Furthermore, the diameter of the outer spring 10 is wider than the diameter of the inner spring 20, which ensures that there is no interference between the outer springs 10 and the inner ones 20. In the preferred embodiment, the outer spring has a height of approximately 21.0 cm (8.25 inches) with a diameter of about 70 mm and the inner spring is about 14.6 cm (5.75 inches) high with a diameter of about 32.8 mm. The outer spring 10 extends counterclockwise and the inner spring 20 extends clockwise. There are contiguous convolutions at opposite ends of the spring body. The convolutions of the ends of the spring are generally circular, ending in a generally flat shape that serves as a spring support structure for attachment to adjoining springs and for padding and upholstery coating application. As shown in FIG. 3, except for the upper end convolution 30, all the convolutions of the outer spring 10 have the same diameter and with the exception of the lower end convolution 50, all the convolutions of the inner spring 20 have the same diameter. In the preferred embodiment, there are 5 convolutions or twists that form the body of the outer spring 10. The diameter of the convolution of the upper end 30 of the outer spring is approximately 64 mm while the diameter of the preceding or centric convolutions 60 is approximately 70 mm. The dimension of the spring measured from the extreme edge of one convolution to the adjoining convolution is referred to herein as "pitch". The central convolutions 60 of the outer spring 10 have a pitch dimension of approximately 55.6mm. The outer spring 10 in its raw form, as shown in FIG. 4, has a free or uncompressed height of approximately 21.0 cm (8.25 inches). The independent height of the inner spring 20, as shown in FIG. 5, is about 14.6 cm (5.75 inches). The inner spring body 20 contains 7 convolutions or twists. The diameter of the convolution of the lower end 50 of the inner spring 20 is approximately 40.8 mm while the diameter of the subsequent convolutions or center convolutions 70 is approximately 32.8 mm. The central convolutions 70 of the inner spring 20 have a pitch dimension of approximately 20 mm. Alternative embodiments of the spring can be constructed with different configurations, such as different numbers of convolutions or twists and different shapes of the ends of the springs.

In the preferred embodiment, the degree of elasticity of the inner spring 20 is greater than the degree of elasticity of the outer spring 10. The degree of elasticity refers to the amount of weight necessary to compress a spring by one inch. The design of two springs one inside the other provides two different degrees of elasticity during the compression of the mattress. During initial loading, only the outer spring 10 is compressed while under heavy or concentrated load, both the inner and outer springs work to support the load. This allows for comfortable compression under a light load when used for sleeping where the load is distributed over a relatively large surface area, while also maintaining comfort by supporting a heavy load concentrated in one location, when sitting on the surface of the car. mattress. The upper part or outer spring 10 is flexible enough to provide a strong and comfortable surface for sitting or sleeping and the lower part is strong enough to absorb abnormal stresses, concentrations of weight or shocks without discomfort or damage. The relative degrees of elasticity also provide a gradual transition from the outer to the inner spring at the time of compression so that the change from the first compression of the outer spring to the compression of both the outer and inner springs as load increases will not be noticed by the person sitting on the surface of the mattress. Figures 6 to 9 show the spring formed by two springs, one inside the other, 100 in various states of compression. In the preferred embodiment, the outer spring 10 must be compressed 5.72 cm (2.25 inches) before the inner spring 20 coalesces and the force required to reach the inner spring 20 is 0.51 kilograms. (1,125 pounds). The stiffness of the outer spring 10 is approximately 0.79 N / cm (0.45 pounds) and the stiffness of the inner spring 20 is approximately 3.33 N / cm (1.9 pounds) for a combined stiffness of 4, 12 N / cm (2.35 pounds).

[0014] In assembling the spring formed by two springs, one inside the other, 100 of the present invention and the related description, the spring is wound from a single wire of suitable material, such as the conventional spring wire, with a length of approximately 1930 mm. Material selection can be based on a number of factors, including temperature condition, tensile strength, modulus of elasticity, fatigue life, corrosion resistance, cost, etc. High carbon spring steels are the most commonly used of all spring materials. They are relatively cheap, easy to get, and easily worked. The spring wire used in the construction of the mattress coil spring typically has a diameter of between about 0.15 cm (0.06 inch) (16 gauge) and about 0.23 cm (0.09 inch) (13 gauge) . The exact design parameters for coil mattress springs depend on the desired firmness, which is further determined by the number of springs per unit surface area of ​​the mattress.

ES 2 575 555 T3

In the preferred embodiment, the spring wire is approximately 14 7/8 gauge.

[0015] The formation of the spring can be performed by the wire-forming machinery. Generally, the spring formers pass the wire stocks through a series of rollers to bend the wire into a generally helical configuration to form the individual springs. The radius or curvature in the springs is determined by the shapes of the cams in rolling contact with a cam follower arm. The wire reserves pass to the winder by feed rollers in a forming block. As the wire advances through a guide hole in the former block, it contacts a spring radius forming wheel connected to one end of the cam follower arm. The forming wheel moves relative to the forming block according to the shapes of the cams that the arm follows. The radius of curvature of the wire reserves is set as the wire exits the forming block. A helix is ​​formed in the wire reservoirs after they pass the forming wheel by a helix guide pin that moves in a generally linear path, generally perpendicular to the guide hole of the wire reservoirs. in the forming block in order to advance the wire along a helical path, in the opposite direction of the forming wheel. Once a sufficient amount of wire has passed through the forming block, the forming wheel and the helix guide pin, to form a full spring, a cutting tool is advanced against the forming block to cut the coil spring. wire reserves. The cut spring is then advanced via a gin mechanism to subsequent processing and forming stations. A geneva mechanism with, for example, six arms, is rotationally mounted close to the front section of the reel. Each arm of the geneva mechanism supports a gripper to grasp the spring when it is cut from the continuous wire feed into the guide block.

[0016] Once each spring has been formed, the springs are heat tempered and adjusted in order to incorporate a memory in the spring to increase the force of the spring as well as extend the longevity of the action of the coil spring. The geneva mechanism advances each spring to an inner spring quenching station where the spring is held at its center with a clamp and an electric current is passed through the steel wire to quench it. The heat tempering process includes heating coil springs from a temperature of approximately 260 degrees Celsius (approximately 500 degrees Fahrenheit) to approximately 316 degrees Celsius (approximately 600 degrees Fahrenheit) by applying 50 amps of current for approximately one second from a end of the pier to the other. After the inner spring has been annealed, the geneva mechanism advances the spring to the outer spring quenching station where the annealing process is repeated on the outer spring. The spring consisting of two springs, one inside the other, is annealed twice so that both the inner and outer springs are annealed and adjusted. In a serial annealing process, the outer spring is annealed in a first process followed by annealing the inner spring, or vice versa.

After the springs are heat-tempered and adjusted, they must be joined together in rows in order to form the spring assembly. In one embodiment, the springs formed by two springs, one inside the other, 100 are lined with individual pockets, as shown in FIG. 10. Each pocket 310 is defined by a top surface, a base surface, and a side wall joining the top surface and the base surface. The pockets 310 are preferably formed of a fabric formed of a material that allows the fabric to be joined or welded with heat and pressure, as in an ultrasonic welding or similar thermal welding process. For example, the fabric can be formed from a thermoplastic fiber known in the art, such as a polymer-based nonwoven fabric, polypropylene nonwoven material, or polyester nonwoven material. Or, the pockets 310 can be joined by stitching, metal staples, or other convenient methods. In this case, a wide variety of textile fabrics or other sheet material can be used. The fabric is normally folded in half and joined at the top surface and side edges to form, or define, a pocket. Each pocket spring 300 is arranged in a succession of chains, after which each of the chains are joined side by side. FIG. eleven shows a cross-sectional view of a mattress assembly 400 containing a series of springs formed by two springs, one inside the other, tucked into pockets 300. The interconnection of the chains can be done by welding or glue. Such interconnection, however, may alternatively be accomplished by means of Velcro clamps or fasteners, or in some other convenient manner.

[0018] When the springs formed by two springs, one inside the other, 100 of the present description are placed in the individual pockets, the outer spring 10 is preferably in a slightly compressed state in which for example the total nominal height of the spring Exterior 10 is reduced by approximately 4.45 cm (1.75 inches) or to a total nominal height of approximately 16.5 cm (6.5 inches). This decreases the differential from the outer spring to the inner spring to approximately 0.75 inches. To compress the outer spring 10 in the pocket, a representative force of 0.3572 kilograms (0.7875 pounds) is required.

[0019] In a further example, shown in FIG. 12, the springs formed by two springs, one within the other, are joined or wired in a series using the helical tie wires 510 that run between the rows of springs and that are wrapped around tangential or overlapping segments of springs contiguous.

ES 2 575 555 T3

The helical tie wire 510 extends transversely between the rows of springs to form the set of inner springs 500 with a thickness equal to the axial length of the springs.

[0020] The springs formed by two springs, one within the other, 100 of the present invention and related descriptions can be packaged. The act of packing refers to the process where the inner spring units are compressed along the spring axes to a small fraction of the uncompressed height in order to reduce the shipping volume. This is necessary for shipping the inner spring assemblies from one manufacturing facility to a different finished product manufacturing facility, such as a mattress plant. The act of packing referred to herein includes packing the bulk of at least several sets of inner springs stacked together, separated by a sheet of material such as thick paper and compressed in the bulk packer, as is common practice. in the industry. The springs are designed to be compressed on their axis under the packing pressure required to simultaneously pack multiple inner spring assemblies.

[0021] It will be appreciated by persons skilled in the art that numerous variations and / or modifications can be made to the invention thus shown in the specific embodiments without departing from the scope of the invention as defined in the claim. The present embodiments should, therefore, be considered in all respects as illustrative and not restrictive. Other features and aspects of this invention will be appreciated by those skilled in the art when reading and understanding the description. Such features, aspects, as well as the expected variations and modifications of the described results and examples are clearly within the scope of the invention where the invention is limited only by the scope of the following claims.