The present invention relates to a shoulder strap, in particular, a shoulder strap for use in a harness.
Self-contained breathing apparatus (SCBA) harnesses comprise a structural support member, in the form of a back plate (or frame) to which a cylinder of breathable gas is mounted. Typically two flexible shoulder straps are each attached at a first end to an upper portion of the back plate and at a second end to a lower portion of the back plate. A flexible waist strap (or belt) is also attached to the back plate. This enables the harness to be carried on the back of a user.
It is known to use curved shoulder straps. The curved nature of the straps ensures that they can be attached to the upper and lower portion of the back plate, such that when the harness is worn by a user, the straps do not become overly twisted. This ensures that the harness is comfortable to wear. The curved straps are usually cut from a sheet of foam material and then a textile covering is applied.
Whilst these known straps are comfortable, they are expensive to manufacture and are relatively heavy. This means that they are not particularly suitable for low-cost and/or low-weight harnesses.
Embodiments of the present invention aim to address at least some of the above problems.
According to a first aspect of the invention there is provided a shoulder strap for a harness for breathing apparatus, comprising: a first elongate strap portion generally extending along a first longitudinal axis; a second strap portion attached to the first strap portion and generally extending along a second longitudinal axis that is oblique to the first axis; and a first attachment portion for attaching a first end of the shoulder strap to a harness for breathing apparatus and a second attachment portion for attaching a second end of the shoulder strap to a harness for breathing apparatus.
Preferably the first and second strap portions partially overlap. The first and second strap portions may be of the same constant width. In a particularly preferred arrangement the first and second strap portions are part of a single continuous piece of material.
In one embodiment the continuous piece of material comprises the first strap portion which is contiguous with a intermediate strap portion which itself is contiguous with the second strap portion; and the continuous piece of material comprises a first fold between the first strap portion and the intermediate strap portion and a second fold between the intermediate strap portion and the second strap portion such that the second strap portion is oblique to the first strap portion. The first and/or second fold may form a loop that is arranged such that an accessory can be attached to the strap.
In one embodiment a first edge of the shoulder strap has a first opening and the second edge of the shoulder strap has a second opening such that an accessory having first and second projections substantially facing towards each other can be detachably attached to the shoulder strap by locating the first and second flanges in the first and second openings respectively. The first and second openings may be formed between overlapping first and second portions of material. Preferably the first and second overlapping portions of material are formed by folding a continuous piece of material.
The first and second strap portions may be held in relative juxtapositions by stitching.
An end of the second strap portion not attached to the first strap portion may be provided with an attachment device to which a length-adjustment strap portion is attached. The attachment device may be a buckle. The overall length of the shoulder strap may be varied by adjusting the position at which the length-adjustment strap portion is attached to the attachment device.
The invention also concerns a harness for breathing apparatus comprising a shoulder strap according to any statement herein.
The invention may comprise any combination of the features and/or limitations referred to herein, except combinations of such features as are mutually exclusive.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
As shown in
The first strap portion 20 extends in a first direction along a first longitudinal axis and the second strap portion 30 extends in a second direction along a second longitudinal axis that is oblique to the first axis. The angle between the first and second directions is, in this embodiment, approximately 20°. However, other angles could be chosen during manufacture as will be described.
An attachment device 50 in the form of a buckle is provided at the end of the second strap portion 20. The length-adjustment strap portion 40 is attached to the second strap portion 30 using the buckle 50. The buckle 50 allows the length of the length-adjustment strap portion 40, extending from the second strap portion 30, to be varied, thus varying the overall length of the shoulder strap 10.
The first and second strap portions 20, 30 are formed from a continuous piece of strap material having a constant width. The continuous piece of strap material is folded and stitched such that the longitudinal extent, or axis, of the first strap portion 20 is oblique to that of the second strap portion 30.
The first fold 62 between the first and intermediate strap portions 20, 60 forms a first loop 63 which allows an accessory, such as a D-ring 80 (see
The fold 62 between the first and intermediate strap portions 20, 60 also forms an opening 61 at either edge of the strap. As shown in
With reference to
The length-adjusting strap 40 is attached to the end of the second strap portion 30 using the buckle. The tab 44 is passed through the first opening 56 of the buckle 50, over the sliding bar 54 and then through the second opening 58. When the looped end of the length-adjusting strap 40 is pulled, the bar 54 is caused to move downwards towards the second opening 58. This traps the strap 40 in the opening and prevents relative movement between the second strap portion 30 and the length-adjusting strap portion 40. To shorten the overall length of the shoulder strap 10, the tab 44 of the length-adjusting strap 40 is pulled which causes the strap 40 to pull through the buckle 50. To lengthen the overall length of the shoulder strap 10, the end of the D-ring 59 is lifted which allows the length-adjusting strap 40 to be pulled through the buckle 50 in the opposite direction.
As can be seen in
The tabs 44 of the length-adjusting strap portions 40 are then fed through the openings in the buckles 50 as described above. The overall length of each shoulder strap 10 is adjustable by either pulling the tab 44, so as to pull the length-adjusting strap portion 40 through the buckle 50, or by lifting the D-ring 59 of the buckle 50 so as to release a portion of the length-adjusting strap portion 40.
Since the first and second strap portions 20, 30 are formed by folding and stitching a continuous piece of material, even if in the unlikely event that the stitching were to fail, the first and second strap portions could not become detached from each other. This improves the safety of a harness comprising the shoulder strap.
Having the first and second strap portions 20, 30 oblique to one another improves the comfort of the harness. The first strap portion 20 extends from an upper portion of the back plate, across the shoulder of the wearer. The second strap portion 30 then extends from the first strap portion 20 obliquely towards the side and under the arm of the wearer. It is then coupled to the back plate either directly or via a length-adjustment portion 40. The oblique nature of the first and second strap portions 20, 30 helps to ensure that the shoulder strap 10 does not become twisted, which would make it less comfortable for the wearer.
The folds 62, 64 between the first strap portion 20, intermediate strap portion 60 and the second strap portion 30, and the stitching that secures the folds, provides convenient pockets (or openings) to which an accessory, such as a hose clip 70, can be attached.
The manufacture of the shoulder strap 10 is also particularly quick and is relatively inexpensive. This is largely due to a single piece of continuous strap being folded and stitched (or otherwise secured) to form the first and second oblique strap portions 20, 30. The loops 22, 32, 42 are also folded and stitched which allows quick manufacture.
Number | Date | Country | Kind |
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0907751.2 | May 2009 | GB | national |