CA2017968A1 - Duvet construction - Google Patents

Abstract

Abstract of the Disclosure An improved form of construction for a duvet, sleeping bag, comforter or the like is described wherein, by means of internal baffles, the interior space of the structure is divided up into a plurality of substantially square box-like lofted spaces each of which contains a feather-based insulating material, such as down.
This construction both allows the down to move and to circulate within the substantially square box-like spaces. Consequently it will provide essentially even insulation throughout the duvet, or the like, and substantially avoids the formation of cold spots.

Description

~ 1'7131 This invention relates to insulated items generally used for sleeping or similar purposes, such as duvets. Sleeping bags and comforters, wherein the primary insulation material is down or feathers.

A conventional down-filled duvet or sleeping bag comprises essentially an outer case, which is made of a substantially feather-proof fabric, and which is d;vided up internally to provide a plurality of three dimensional or lofted spaces. The required insulation is provided by packing loosely into these spaces either down as such, or feathers of some sort. In the conventional form of construction these lofted spaces are created simply by stitching through the two outer case face layers, to provide a channel or tube rimming either the length or width of the ;tem. Whilst this permits the feathers to be loosely packed and to move about (which is necessary for good insulation), nevertheless it also provides uninsulated cold areas at the seams forming the channels. Further, due to the length of the channels, it is possible for the down fill to congregate at one end or the other, which again results in a cold spot.

Various more complex constructions have been proposed whereby these cold spots may be eliminated. Examples are the complex channel constructions described in U.S. 2,179,424 and 4,783,703, and in Canadian 437,121 and 486,108. Although these methods appear to be successful in relatively small items such as a jacket, they do not solve the problems of eliminating cold spots from a relatively large item such as a duvet, sleeping bag, or comforters. The difficulty appears to be that when these methods are used in large items, for example a duvet, the channels are of such a size and length that the down can congregate at certain points, typically the ends of the channels. This results both in uneven insulation, and in the formation of cold spots.
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A further complication with a large item is that these cold spots cannot be avoided by simply cramming the channels full of down i, ~; :

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I This will cause feather breakdown and loss of ;nsulation and will -I hinder movement of the down, which is needed in order to get maximum insulation.

This invention seeks to provide a duvet or other large j feather insulated item in which cold spots are effectively eliminated~ and yet in which the insulation has freedom to move. This is ! provided, in essence, by stitched box form of construction, in which j the spaces containing the insulation comprise a plural~ty of lofted ~1 I box-like shapes sharing common walls, and within which the insulation ~ -I is free to move about. f~
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f Thus in its broadest embodiment this invention provides anI insulated down filled structure, particularly a duvet, sleeping bag, or comforter, comprising in combination:
a substantially feather impermeable fabric outer casing f consisting of an upper and a lower casing sheet joined together at 3 their edges by a wall member;
a plurality of substantially linear baffle members of substantially the same height as the wall member placed between the upper and lower casing sheets and dividing the space contained within ~
the outer casing into a plurality of substantially square box-shaped ;
lofted spaces; and Z a quantity of loosely packed feather or down insulation in ¦ each of the lofted spaces, the quantity being sufficient to provide the required level of insulation, and insufficient to prevent f adequate movement of the insulation within the lofted space.
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Preferably both the internal baffles forming the box shaped lofted spaces and the wall are from about 1.5 cm to 6 cm in height.
Preferably each box shaped lofted space is from about lO cm square to about 50 cm square. More preferably, these spaces are from about 20 f cm to about 30 cm square, and most preferably are about 25 cm (10 inches) square.
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The invention will now be described by way of reference to the attached f;gure, which shows a duvet, partly in section. In this figure the various seam constructions, which are conventional, are -~
not shown.

The duvet, 1, comprises an upper casing sheet 2, a lower casing sheet 3, and a wall member 4 joining them together around the outside edge. The upper and lower casing sheets are generally of the same dimensions and will range upwardly from a size suitable for a child's bed or cradle to a size suitable for a king size bed, at least. It is noted that a similar range of sizes would also apply in the case of a sleeping bag or a comforter. Generally a duvet is ~, substantially rectangular, but other shapes are commonly used for -i sleeping bags, such as the so-called "mummy" type.

~ The interior of the duvet is divided up into a plurality of I substantially square box-shaped lofted spaces, for example as at 6, ¦ by the baffles, as at 7 and 8~ each of which run for the length and width of the duvet. The stitch seam lines for these are shown ~ batched at 7A and 8A. Each of these lofted spaces contains -¦ insulating material, such as at 9.

The internal dimensions of these lofted spaces are of some ~ ~5 ~ importance. On the one hand, they need to be large enough in height, ¦ length, and width to permit the down to circulate to some degree in I order to obtain the best insulation. On the other hand, they should ¦ not be so large that the down can congregate preferentially in one place, such as a corner. In practice, the following dimension ranges have been found to be suitable~
for the wall and baffles: a height of from 1.5 cm to 5 cm; ~ ~ 1 for the lofted spaces: smallest: about 10 cm square;
largest: about 50 cm square;
preferred: 20 to 30 cm square;
most preferred: about 25 cm square.
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In the preceding discussion, the lofted space containing the down is described as being square. Although it is preferred that they are substantially square, some variation from truly square is practical. For example, an oblong shape can be used in order to obtain an integral number of lofted box-like shapes along each dimesnion of the article. Furthermore, squares are not the only shapes which will pack together in the required manner: this is also possible with triangles and hexagons which will therefore also serve to provide a base shape for the lofted box-like shapes required for this invention. Construction of a device based on a shape other than -~ -substantially square, although theoretically possible, would be far more difficult. It would also potentially lead to a lowered level of insulation at the edges of an inherently rectangular item, such as a duvet or comforter.

The duvet is constructed from conventional materials. A
suitable outer casing is a 233 thread count cotton fabric. The ~1 insulation will be down as such, or other feather based material generally known as "down".

For a comforter, a single layer construction similar to a duvet is used. For a sleeping bag, a two-layer construction is used, incorporating, if desired, head protection. ;

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Claims (8)

1. An insulated down filled structure comprising in combination:
a substantially feather impermeable fabric outer casing consisting essentially of an upper and a lower casing sheet joined together at their edges by a wall member;
a plurality of substantially linear baffle members, of substantially the same height as the wall member placed between the upper and the lower casing sheets and dividing the space within the outer casing into a plurality of substantially square box-shaped lofted spaces; and a quantity of loosely packed feather or down insulation in each of the lofted spaces, the quantity of insulation being sufficient to provide the required level of insulation, and insufficient to prevent adequate movement of the insulation within the lofted space.

2. A structure according to claim 1 which is a single layer duvet or comforter.

3. A structure according to claim 1 which is a double layer sleeping bag.

4. A structure according to claim 1 wherein the insulation is down.

5. A structure according to claim 1 wherein both the wall and the baffles are from about 1.5 cm to about 6 cm in height.

6. A structure according to claim 1 wherein the lofted spaces are from about 10 cm to about 50 cm square.

7. A structure according to claim 6 wherein the lofted spaces are from about 20 cm to about 30 cm square.

8. A structure according to claim 7 wherein the lofted spaces are about 25 cm square.