Improvements in and relating to sleeping bags

Abstract

 A sleeping bag (10) has a top layer (18) and a bottom layer (20), the top layer extending laterally around a greater portion of the perimeter of the bag than the bottom layer.

Description

[0001] This invention concerns improvements in and relating to sleeping bags, especially sleeping bags for use in extreme weather conditions, where body heat retention is vital.

[0002] Sleeping bags generally comprise two layers of fabric with insulating material sandwiched in between. Sleeping bags for use in extreme weather conditions are usually shaped to fit more closely to a user's body, e.g. are narrower at the feet and wider at the shoulders. In addition, long lengths of zip fasteners are avoided compared to conventional sleeping bags as these are areas through which heat can be lost.

[0003] For sleeping bags usable in extreme weather conditions, there are two main requirements. The first is that areas through which heat loss can occur need to be at a minimum and the second requirement is that the weight of the sleeping bag should be kept as low as possible without adversely affecting the heat loss requirement.

[0004] A first object of the invention is to provide a sleeping bag capable of meeting the above-mentioned first requirement.

[0005] A second object of the invention is to provide a sleeping bag capable of meeting the above-mentioned second requirement.

[0006] According to a first aspect of this invention there is provided a sleeping bag having a top part and a bottom part wherein the top part extends laterally around a greater portion of the perimeter of the bag than the bottom part.

[0007] By having the top part extending effectively partially underneath the user of the bag, there is created a wrap-around effect that helps to keep the user's body warm.

[0008] The bottom part of the bag may in these circumstances include a thinner layer of insulating material than the top part. In that way the weight of the bag may be kept down.

[0009] The preferred sleeping bag of the invention has additional insulation material in areas of the bag that surround parts of the body from which heat loss is greatest, typically the feet, chest and head. Generally two layers of insulation material will be provided in the top part of the sleeping bag with three layers in the feet, chest and head areas of the bag.

[0010] Preferred sleeping bags of the invention will be shaped to fit a user's body, typically by being narrower at the feet and wider at the shoulders.

[0011] This invention will now be further described, by way of example only, with reference to the accompanying drawings, in which:-

Figure 1 shows a sleeping bag of the invention; and

Figure 2 is a section on line AA of Figure 1.

[0012] Referring to the accompanying drawings, a sleeping abg 10 is shown designed for extreme conditions i.e. for experienced campers, mountaineers and expedition members. The sleeping bag 10 is shaped to fit closely to the body shape i.e. is narrower at the feet and Wider at the shoulders. The bag 10 generally has an inner layer 12 and an outer layer 14 between which are on or more layers of insulating material 16.

[0013] The sleeping bag 10 has a top part 18 and a bottom part 20. The top part 18 is sized and arranged to cover a greater area than the bottom part. In other words the top part 18 extends around the bag so that its edges will extend partially under a user's body. This creates a wrap-around effect on the top layer to reduce potential heat loss, hence keeping the user's body warmer.

[0014] The thickness of insulating material in the bottom part is less than that provided in the top part. That is done in order to keep the weight of the bag down.

[0015] In areas of the bag surrounding a user's feet, chest and head (22, 23 and 24 respectively), extra thickness of insulation material is provided. These areas are where most heat loss occurs, so that chances of keeping warm in very severe weather conditions are improved.

Claims

1. A sleeping bag having a top layer and a bottom layer, wherein the top layer extends laterally around a greater portion of the perimeter of the bag than the bottom layer.

2. A sleeping bag as claimed in claim 1, wherein the bottom layer includes a thinner layer of insulating material than the top layer.

3. A sleeping bag as claimed in claim 1 or 2, wherein additional insulating material is provided in those areas of the bag intended to surround a user's body parts from which heat loss is greater.

4. A sleeping bag as claimed in claim 3, wherein additional insulation material is provided in areas of the bag intended to surround a user's feet.

5. A sleeping bag as claimed in claim 3 or 4, wherein additional insulation material is provided in areas of the bag intended to surround a user's chest.

6. A sleeping bag as claimed in claim 3, 4 or 5, wherein additional insulation material is provided in areas of the bag intended to surround a user's head.

7. A sleeping bag as claimed in any one of claims 1 to 6, shaped to a user's body by being narrower at the feet end and wider in the shoulder region.

8. A sleeping bag as claimed in any one of claims 4 to 7, wherein the top layer of the bag has two layers of insulation material and three layers of insulation material are provided in the feet, head and chest areas of the bag.

Drawing