COIL SPRING MATTRESS CONSTRUCTION
A more versatile pocket coil mattress provides increased support in the perimeter side regions of the mattress in combination with increased support in the main sleeping area. The shape, preloading and characteristics of the pocket coil springs has changed to decrease compression per unit of force applied while still maintaining the desired user response of a pocket coiled mattress.
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The present invention is directed to pocket coil mattresses and in particular to improvements with respect to a perimeter support region and a main sleep area of the mattress.
BACKGROUND OF THE INVENTIONPocket coil mattresses are known for having extremely appealing flex properties and the ability to resiliently conform to different users thereby providing a better night's sleep. These mattresses have individual coil springs maintained in a compressed state in their own fabric pocket. Typically the fabric pockets are sewn in long strips and secured to form the mattress core.
Many pocket coil mattresses include either an edge wire around the mattress that connects to edge coil springs and provides additional stiffness for seating at the edge of the mattress or; a hard compression foam encasement to replace the edgewire, as well as between 25% and 33% of the spring core itself to prove a strengthened seating edge. The edge wire although helpful in providing this additional support, is not desirable in that the mattress can be permanently damaged if subjected to significant bending. Bending of a mattress is often necessary to allow passage of the mattress through a restricted access such as a narrow staircase or other restriction. Furthermore bending of the mattress is desirable for adjustable position leisure beds or hospital type beds. In the case of a foam encased seating edge, the end result does allow bending and does not have the sustainable performance and long term recovery level as an complete spring edge with the attached edgewire. A foam encasement seating edge is not a design that is applicable to the present invention of pocket coil spring core assembly.
In our earlier U.S. Pat. No. 6,295,676, a pocket coil mattress is disclosed that does not include an edge wire. This mattress allows bending of the mattress, however the edge of the mattress is substantially compressed when a user sits on the edge of the mattress. The ability to provide firm edge support and desirable flex for sleeping is challenging.
The present invention provides an improved pocket coil mattress that allows for the bending thereof while providing substantially improved edge support and without impacting on the uniform comfort of the balance of the mattress spring underlying its sleep surface when fully finished with upholstery padding material. These advantages are realized while still providing a main sleep area and perimeter support region that has the comfort advantages that is now expected with a pocket coil mattress.
SUMMARY OF THE INVENTIONA mattress according to the present invention, comprises a main sleep area surrounded by a perimeter support region. The main sleep area and the perimeter support region are defined by wire coil springs contained within individual fabric pockets. The wire coil springs in the main sleep area are arranged in a honeycomb offset series of rows. The wire coil springs in the perimeter support region are of a different wire construction and have different flex characteristics from the wire coil springs in the main sleep area. The wire coil springs in the perimeter support region are arranged in side by side rows and thus define a non-honeycomb arrangement. The perimeter support region has at least two side by side rows about the mattress. The perimeter support region includes four corner configurations that each have at least eight cross connected wire coil springs. These coil springs are cross connected to join coil springs of the same row and opposite rows. Between the corner configurations wire coil springs of the perimeter region are only connected across rows. The mattress is made without an edge wire about the perimeter of the mattress. The coil springs of the perimeter region cooperate to accommodate substantial resilient bending of the mattress in a length thereof while providing improved support for side seating.
According to an aspect of the invention, the wire coil springs of the perimeter support region are of a smaller coil diameter relative to the diameter of the wire coil springs of the main sleep area.
According to a further aspect of the invention, the wire coil springs of the perimeter region have a gauge of about 14.5.
In a further aspect of the invention, the wire coil springs of the main sleep area are of a gauge of about 15.5.
According to a preferred aspect of the invention, the wire coil springs of the perimeter support region are of a diameter of about 2 inches at the ends thereof and the springs taper inwardly to a narrow waist of about 50 millimeters.
In a further aspect of the invention, the perimeter support region includes at least three rows of wire coil springs of a gauge between 14 and 15.
In yet a further aspect of the invention, the perimeter support region at the top surface thereof, is connected by a flexible high-strength plastic mesh extending over the mattress. Preferably the bottom surface of the mattress is also connected a flexible high strength plastic mesh.
Preferred embodiments of the invention are shown in the drawings wherein:
Our earlier U.S. Pat. No. 6,295,676 discloses a pocket coil mattress that does not include an edge wire and as such the mattress can bend intermediate its length. Although this structure has many advantages over existing mattresses, it has some disadvantages with respect to edge seat support. In pocket coil mattresses, the ability of the mattress to independently respond to the movement of two users and allow for significant isolation of these movements, is a primary advantage. The perimeter support region of the mattress includes two or more rows of coil springs that have different flex characteristics relative to the coil springs of the interior main sleep area. The border springs intermediate the corners, although stiffer than the coil spring of the main sleep area, still deform significantly and seating support on an edge mattress causes unwanted sidewall distortion as shown in the prior art mattress of
The mattress 2 as shown in
The perimeter support region 10 includes four corner configurations 30 and in the case of a queen or king mattress, each corner configuration is defined by 15 connected pocket coil springs. Each of these pocket coil springs are mechanically connected to adjacent pocket coil springs as indicated by the mechanical connectors 32. These mechanical connections are preferably upholstery stables located at the point of contact between adjacent pocket coil springs. With this arrangement a linked series of pocket coil springs is provided in each corner of the mattress. These connected coil springs are in contrast to the coil springs of the main sleep area that are independent. The mattress 2, with the four corner configurations 30, provide a more rigid configuration supporting the coil springs of the perimeter support region 10 between corner configurations.
The coil springs, between two corner configurations of the perimeter support region, are merely connected to adjacent pocket coil springs of the respective row or rows. As can be appreciated these connected coil spring do not move independently due to the common mechanical connection 32 but have more independent movement than the coil springs of the corner configurations.
The corner configuration 30, as shown in
The corner configuration 30 of
These corner configurations in combination with the high strength mesh, anchor and secure the remaining coil springs of the perimeter support region between the corner configurations. Each of the wire coil springs of the perimeter support region, is of a reduced overall diameter relative to the diameter of the wire coil springs of the main sleep area 50. Furthermore, the coil springs in the main sleep area 50, are in the honeycomb configuration and provide independent movement while also supporting each other as the coil springs are closely packed.
One of the problems associated with pocketed coil spring design mattresses, is that a person sitting on a side portion of a prior art mattress, as shown in
A mattress with the new corner configuration having the improved coil wire springs in the perimeter support region, undergoes less compression and less sidewall outward distortion and therefore fewer distortion ripples occur as the perimeter support region is stiffer. With this improvement there is still some distortion of the side wall of the mattress as evident at 56, however the distortion is limited and improved seat support is provided. Furthermore although the perimeter support region has been stiffened, the desirable sleeping comfort of the mattress is maintained.
Improvements with respect to the flex and shape of the wire coil springs and the relationship of the wire coil springs of the perimeter support region to the coil springs of the main area 50, can be appreciated from a review of
Wire coil spring 24 of the perimeter region, is preferably of a gauge of 14.5. The height of the spring before compression is approximately 10 to 10.5 inches and the spring end diameter is 2⅛ inches. The number of turns of the spring is six. As shown in
The new mattress with the perimeter support region of the revised shape and stronger coil springs, provides improved seat support between the anchoring corners. The improved load carrying capabilities of each spring is provided by reducing the diameter of the spring and changing the shape of the spring from a barrel shape to a tapered waist design. The length of the perimeter support region springs has been increased (preferably from 9.5 inches to 10.5) and the preload of each spring has increased and is in the range of 900 to 1000 grams whereas the prior art coil spring typically had a preload in the range of 750 to 780 grams. The diameter of the prior art spring was about 2.5 inches and the center waist diameter was 57 mm. The wire length of about 47 inches was maintained. Therefore the wire coil spring 24 has been redesigned to provide additional support in a side region of the mattress that is prone to user distortion due to a concentrated load created by sitting on a side or end of the mattress. The enhanced load carrying capabilities of the modified spring and the stiffer corner configurations cooperate and reduce sidewall distortion while maintaining independent sleep support in the main sleep area of the mattress as well as compatible sleep support in the perimeter support region. Also side seating on the mattress is improved as there is less compression.
The filler springs in the sleep central area preferably are also been modified to increase the length of the uncompressed spring to about 10 inches whereas our prior filler spring was of a length of 9 to 9.5 inches. The diameter of the spring is now preferably 2 inches whereas previously it was about 2.25 inches. The waist of its barrel shape is now 55 mm compared to the previous 58 mm. Both the new and old springs are 6 turn springs of the same 15.5 gauge that are pre-compressed and maintained in a 6.5 inch pocket. The preload of the filler spring has increased to 490 to 500 grams compared to the previous preload of about 430 grams. The changes to the filler spring cooperate with the new perimeter support region spring to provide an effective transition at the junction of the sleep central area and the perimeter support region.
Diameters of both edge (border) coil and sleep central area (filler) coil, despite the difference in wire gauge are close in size so as not to distort the final assembled core in terms of resilient performance and responsive compliance across the core surface that translates above and below in the finished mattress. This describes desirable, uniform performance and compliance across the finished (upholstered and covered) mattress from side to side and head to foot. The springs cooperate to provide a proportional balance between the perimeter edge and the sleep central subassemblies placed in the final pocket spring core assembly.
Surprisingly, the additional pre-compression and changes to the perimeter coil springs, support the load of a person sitting on the side of the mattress with less compression of the mattress sidewall. These changes in combination with the increased load carrying capability of the main sleep area springs per unit of compression, provides a pocket coil mattress with the known desired sensation of pressure relief, great support and fast response to the user's movement. The modified perimeter and main sleep area springs have greater load carrying capability per unit of compression while still providing the desired response and without a load ridge at the junction of the perimeter support springs and the main sleep area springs. Both types of springs have a higher rate of recovery without impacting the user's perception of great support and appropriate response to user movement.
The extent of side edge compression of the mattress due to a user sitting thereon, has substantially decreased from 3 to 4 inches for example to preferably 1 to 2.5 inches. This change provides the additional support and allows the mattress able to meet the need of various bed applications without using a border edge wire. Furthermore the springs are less likely to fatigue over the life of the mattress due to the higher strength.
The applicant has found, that improvements to pocket coil mattresses can be realized by providing additional support created by the connected corner configurations. Further improvements in the characteristics of the side edge of the mattress can be realized by changing the shape and load carrying capacity of the wire coil springs used in the perimeter support region. Further improvements can be realized by utilizing wire coil springs in the main sleep region that are of reduced diameter and of greater load carrying capabilities relative to the prior art mattresses.
Although the invention has been described herein in detail appreciated the variations may be made thereto without departing from the attached claims. The detailed description has focused on applicant's preferred embodiments however the attached claims define the applicant's invention.
Claims
1. A mattress comprising a main sleep area surrounded by perimeter support region with both the main sleep area and the perimeter support region being defined by wire coil springs contained within fabric pockets; the wire coil springs in the main sleep area are arranged in honeycomb offset rows; the wire coil springs in the perimeter support region are of a different wire construction having different flex characteristics relative to the wire coil springs in the main sleep area; said wire coil springs in said perimeter support region are arranged to define at least two side by side rows about the mattress; and wherein said wire coil springs of said perimeter support region define four corner regions of the mattress with each corner region including at least 8 wire coil springs cross connected and joining adjacent wire coil springs of the respective row and adjacent wire coil springs of opposite rows; said wire coil springs of the perimeter region cooperating to allow said wire coil springs between said corner regions to accommodate substantial resilient bending of said mattress in a length thereof.
2. A mattress as claimed in claim 1 wherein said wire coil springs of said perimeter region are of a smaller spring coil diameter relative to the diameter of the wire coil springs of said main sleep area.
3. A mattress as claimed in claim 2 wherein said wire coil springs of said perimeter region have a gauge of about 14.5.
4. A mattress as claimed in claim 3 wherein said wire coil springs of said main sleep area have a gauge of about 15.5.
5. A mattress as claimed in claim 3 wherein said wire coil springs of said perimeter region are of a diameter of about 2 inches at the ends thereof and taper inwardly to a narrow waist of about 50 mm.
6. A mattress as claimed in claim 2 wherein said perimeter support region includes at least 3 rows of wire coil springs and said wire coil springs are of a gauge of between 14 and 15.
7. A mattress as claimed in claim 6 wherein said wire coil springs of said perimeter region are connected at both ends of said coil springs.
8. A mattress as claimed in claim 7 wherein said perimeter support region on a top surface and a bottom surface is connected by a flexible high strength mesh.
9. A mattress as claimed in claim 1 wherein the wire coil springs in said perimeter support region have a preload force of at least 970 grams.
10. A mattress as claimed in claim 9 wherein the wire coil springs in said main sleep area have a preload force of at least 490 grams.
11. A mattress as claimed in claim 10 wherein the wire coil springs in said perimeter support region have a preload force in the range of 970 to 1000 grams.
12. A mattress as claimed in claim 11 wherein the wire coil springs in said main sleep area have a preload force in the range of 490 to 520 grams.
Type: Application
Filed: Jan 20, 2020
Publication Date: Jul 23, 2020
Applicant: MARSHALL VENTILATED MATTRESS COMPANY LIMITED (Toronto)
Inventor: Brad Warner (Toronto)
Application Number: 16/747,158