FIELD OF THE INVENTION
This invention relates to sleeping bags, and particularly to sleeping bags which utilise down and/or feathers and/or other bulk material for insulation.
BACKGROUND OF THE INVENTION
It is well known to include baffles extending between the inner skin of the bag and the outer skin of the bag for the purpose of preventing unwanted migration of the insulating material. The present invention provides a novel baffle construction which improves the loft and thermal performance of the sleeping bag.
SUMMARY OF INVENTION
The present invention provides a sleeping bag including baffles according to the following claims. Preferred features of the invention will be apparent from the dependant claims and from the following description of the preferred embodiment.
BRIEF DESCRIPTION OF DRAWINGS
The invention will now be described in a non-limiting manner with respect to preferred embodiments in which:
FIG. 1 is perspective view of a sleeping bag;
FIG. 2 is a sectioned view along line 2-2 of FIG. 1;
FIG. 3 is a sectioned view along line 3-3 of FIG. 1;
FIG. 4 is a view of a pair of prior art baffles for the canopy and floor respectively;
FIG. 5 is a view of a first embodiment of a pair of baffles for the canopy and floor respectively according to the present invention;
FIG. 6 is a view of a second embodiment of a pair of baffles for the canopy and floor respectively according to the present invention;
FIG. 7 is a view of a third embodiment of a pair of baffles for the canopy and floor respectively according to the present invention;
FIG. 8 is a view of a fourth embodiment of a pair of baffles for the canopy and floor respectively according to the present invention; and
FIG. 9 is a view of a fifth embodiment of a pair of baffles for the canopy and floor respectively according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
With reference firstly to FIG. 1, there is illustrated a down sleeping bag 10. The sleeping bag 10 has a longitudinal axis A-A and is formed in the usual manner from an outer skin 12 and an inner skin 14. The sleeping bag 10 has a lateral zipper 16 provided to facilitate entry to, and exit from, the sleeping bag 10.
Referring now to FIG. 2, there is shown a sectional view taken along line 2-2 of FIG. 1. In the sectional view shown in FIG. 2, it would readily seen that the sleeping bag combines an upper canopy portion 11, which in use is above the user, and a lower floor portion 13, which in use is below the user. Down 15 is provided intermediate inner skin 14 and outer skin 12 in the usual manner. A flap 18 is provided on the upper canopy portion 11 in order to limit the loss of body heat through the non-insulated area at and adjacent to zipper 16.
Turning now to FIG. 3, there is shown a sectional view taken along line 3-3 of FIG. 1. It will be appreciated that line 3-3 is coincident with a transverse baffle provided in the sleeping bag. It will be noted that there is an upper baffle 20 provided in the canopy portion of the sleeping bag and a lower baffle 22 provided in the floor portion 13 of the sleeping bag. The upper baffle 20 is stitched to the lower baffle 22 at the left hand side as shown in FIG. 3.
In the prior art, the upper baffle 20 and lower baffle 22 were both cut according to a straight pattern. An example of the prior art straight cut baffles is shown in FIG. 4. Typically these baffles are formed from a mesh material. It should be noted at this stage that, whilst the straight baffles of the prior art are cut according to a straight pattern as shown in FIG. 4, they nonetheless adopt a deformed or curved shape when actually in place within the sleeping bag. Hence, a distinction is drawn between the baffles being curved when in situ, and baffles which are curved from the outset when cut according to a curved pattern.
With reference now to FIG. 5 to FIG. 9, there are shown multiple embodiments of baffles cut in a curved manner according to the present invention. In each of FIGS. 5 to 9 the lower baffle 22 is straight cut as per the lower baffle of the prior art. However, in alternative embodiments (not illustrated), the lower baffle 22 could also be cut according to a curved pattern.
With reference firstly to FIG. 5, there is shown the baffle 20 which is cut according to a radial arc.
With reference to FIG. 6, the upper baffle 20 is cut according to a radial arc and the width of the baffle varies along its length with the point of maximum width midway along the length of upper baffle 20.
With reference to FIG. 7, there is shown an upper baffle 20 having a consistent width, but being of substantially U-shaped configuration.
With reference to FIG. 8, there is shown another U-shaped upper baffle 20, although in this case the upper baffle varies in width along its length.
Finally, with reference to FIG. 9, the upper baffle 20 is cut according to several straight segments, with each straight segment being angularly off set with respect to a neighbouring straight segment.
As mentioned above, both the upper and lower baffles are typically formed from a mesh-like material which has limited structural strength. Notwithstanding this limited structural strength, it has been surprisingly found that upper baffles formed according to the present invention result in the canopy portion of the sleeping bag having additional loft and hence additional thermal performance.
Whilst the invention has been described with reference to specific examples, it will of course be appreciated that many different configurations on baffle will fall within the scope of the present invention.