The invention relates to a shoulder strap assembly for supporting a load being carried by a wearer and particularly, though not exclusively, to a shoulder strap assembly for supporting a baby carrier on both shoulders of an adult wearer.

It is known to provide backpacks and baby carriers with shoulder strap assemblies aimed at affording a greater degree of comfort to the adult wearer. For example, some of the known ergonomic features of such shoulder straps assemblies include: the provision of strategically positioned regions of cellular foam or shape memory foam padding; the provision of strategically positioned curves or contours along the length of each shoulder strap; the provision of means for individually adjusting the length of each shoulder strap; and the provision of a chest or sternum strap to link each shoulder strap and secure them on the shoulders of the wearer.

Of particular importance to parents using baby carriers is the ability for both mother and father to comfortably use the same carrier. Whilst some of the known ergonomic features mentioned above allow a degree of adjustment of a carrier's shoulder strap assembly, the overall level of adjustment is often insufficient to accommodate wide variations in body shape between different adult wearers. In particular, differences in shape and size of the shoulders, chest and bust between men and women inevitably lead to a compromise in comfort for one or both genders. Whilst it is known in the field of backpacks to provide a gender specific curved shoulder strap portion which follows the natural body curvature at the female bust, such an arrangement may provide insufficient support for larger male physiques.

A further complication arises with more versatile baby carriers which are reversible such that a baby can be supported in different positions. In particular, for baby carriers capable of supporting a child either in front or behind the adult wearer this presents additional challenges in terms of designing a shoulder strap assembly which is comfortable for the adult wearer irrespective of gender, body shape, and the manner in which the carrier is orientated on the body.

The present invention aims to overcome or at least ameliorate one or more of the aforementioned problems.

According to a first aspect of the present invention, there is provided a shoulder strap assembly for supporting a load to be carried on both shoulders of an adult wearer; the assembly comprising:

a pair of elongate flexible bands, each band having:

an elongate medial edge and an elongate lateral edge; and a length adjuster cooperable with at least a portion of one of said elongate medial edge and said elongate lateral edge so as to adjust the length of that respective edge;

wherein manipulation of the length adjuster from a first to a second configuration imparts a degree of curvature to each elongate flexible band in the medial or lateral direction.

It will be appreciated a local reduction in the length of the elongate lateral edge portion relative to the elongate medial edge portion will cause the elongate flexible band to curve in the lateral direction and vice versa.

Optionally, each band has a length adjuster cooperable with at least a portion of its respective elongate lateral edge so as to adjust the length of the lateral edge relative to the medial edge, and wherein manipulation of the length adjusters from a first to a second configuration imparts a degree of curvature to each elongate flexible band in the lateral direction.

Optionally, each length adjuster comprises a length of cord; and a guide provided at said elongate lateral edge portion for guiding the length of cord. Optionally, a single length of cord is retained within the, or each, guide such that its free ends are exposed.

In a non-limiting example, the cord may be approximately 50 cm in length.

Optionally, exposed distal ends of the cord are connected together.

Optionally, the cord is elastic. Optionally, a releasable cord lock is slidably engageable along the exposed free ends of each length of cord to restrict longitudinal movement of the cord relative to its guide.

Optionally, the guide is an enclosed U-shaped guide channel.

Optionally, the U-shaped guide channel is connected to the elongate flexible band within an elongate pocket or hem portion extending longitudinally along said elongate edge portion(s). Optionally, the elongate pocket or hem portion is generally rectangular in shape and open at only one end.

In a non-limiting example, the elongate pocket or hem portion may be approximately 17 cm in length

Optionally, individual parallel channels within the U-shaped guide channel are separated by a line of stitching.

Optionally, the line of stitching extends substantially centrally along the elongate pocket or hem portion and divides its open end into two adjacent openings. According to a second aspect of the present invention, there is provided a baby carrier comprising a shoulder strap assembly according to the first aspect.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Fig. 1A shows a first example of a prior art baby carrier having a conventional shoulder strap assembly; Fig. IB shows a second example of a prior art baby carrier having a conventional shoulder strap assembly;

Fig. 2 shows a baby carrier in accordance with the present invention in a rear carrying mode with a portion of its shoulder straps adjusted so as to curve laterally away from the mid-line of the wearer;

Fig. 3 shows a baby carrier in accordance with the present invention in a front carrying mode with its shoulder straps crossing at the back of a wearer; Fig. 4 shows a more detailed view of a shoulder strap whilst in the relaxed configuration shown in Fig. 3; and

Fig. 5 shows a more detailed view of a shoulder strap portion of Fig. 2 whilst in the asymmetrically tensioned configuration shown in Fig. 2.

Fig. 1A shows a baby carrier provided with a conventional shoulder strap assembly 10 in which the individual shoulder straps are provided with straight medial and lateral edges 12, 14. Straight shoulder straps which extend over the curve of a wearer's shoulders tend to continue over the pectoral/chest region before extending under the arms. Such an arrangement may cause discomfort to some wearers depending upon their shape, size and gender. Straight shoulder straps may cause particular discomfort for women having larger bust sizes. Attempts have been made to address this problem in the field of baby carriers by providing shoulder straps which are strategically shaped or curved so as to follow the natural body contour at the female bust. For example, Fig. IB shows a shoulder strap assembly 20 in which the individual shoulder straps are arranged so are to have curved medial and lateral edges 22, 24 which redirect the straps under the arm away from the pectoral/chest region.

However, to the best knowledge of the applicant, no one shoulder strap assembly for baby carriers - or indeed bags, backpacks and the like - fulfils the apparently conflicting design requirements of being comfortable for an adult wearer irrespective of gender, body shape, and the manner in which the baby carrier, backpack etc. is orientated on the body. Fig. 2 shows a baby carrier configured to carry a baby on the wearer's back. The carrier is provided with a shoulder strap assembly 30 in which the individual shoulder straps are provided with medial and lateral edges 32, 34. The lateral edges 34 can be seen to be held in tension by a length adjustment means 36 which adjusts the length of a localised portion of the elongate flexible band. The consequent asymmetry in terms of the overall length of the medial and lateral edges 32, 34 causes the lateral edges to curve away from the mid-line of the wearer so as to redirect the shoulder straps under the arms in a similar manner to that illustrated in Fig. IB. Fig. 3 shows the same baby carrier as in Fig. 2 but configured to carry a baby on the wearer's front. However, in this example, the medial and lateral edges 32, 34 are in a relaxed configuration such that there is no asymmetry in terms of their overall length. Such an arrangement is appropriate for securing the shoulder straps in a crossed manner on the wearer's back.

Figs. 4 and 5 show an elongate flexible band of one of the shoulder straps in isolation from the baby carrier to which it is attached. As best seen in Fig. 4, a U- shaped guide channel 40 is formed at the lateral edge 34. In the non-limiting example illustrated, the U-shaped guide channel 40 is formed by stitching a narrow rectangular panel 42 of flexible material along a portion of the lateral edge 34. The rectangular panel 42 is secured to the lateral edge 34 of the strap by stitching along both of its longitudinal perimeter edges 46 and across one of its end perimeter edges 48. In doing so, an elongate pocket is formed having an opening at the end opposite its closed end. The elongate pocket is divided into two individual parallel channels 40 A, 40 B by a central line of stitching 50 which extends from its open perimeter edge and terminates just short of its closed perimeter edge 48.

A single length of elasticated cord 60 is located within the U-shaped guide channel 40. Exposed parts of the cord 60 are attached together at their distal ends to prevent the cord 60 from becoming detached from the U-shaped guide channel 40; and to retain a spring-actuated releasable cord lock 70 on the cord. The cord lock 70 is slidably engageable along the exposed parts of the cord 60 in a conventional manner so as to selectively restrict longitudinal movement of the cord relative to the rectangular panel 42 of the U-shaped guide channel 40.

It will be appreciated that the cord lock 70 is dimensioned to be larger than the openings through which the cord exits the parallel channels 40 A, 40 B of the U- shaped guide channel 40. Accordingly, in use, the exposed cord portions 60 can be lengthened by releasing the cord lock 70; pulling the exposed cord portions 60 away from the U-shaped guide channel 40; pushing the cord lock 70 away from the distal ends the exposed cord portions 60 so as to be urged against the openings of the U- shaped guide channel 40; and re-engaging the cord lock 70 proximate the openings of the U-shaped guide channel 40. Lengthening of the exposed cord portions 60 causes longitudinal movement of the cord relative to the rectangular panel 42 of the U-shaped guide channel 40, and hence a corresponding shortening of the cord portions 60 concealed within the U-shaped guide channel 40.

As the length of cord 60 within the U-shaped guide channel 40 reduces, the flexibility of the material from which the strap 30, and the rectangular panel 42, is constructed causes the material to locally collapse or gather in a concertina fashion to form a contoured edge as shown in Fig. 5. The cord lock 70 maintains the U- shaped guide channel 40 in this collapsed state. The degree of curvature of the contoured edge can be controlled by varying the position at which the cord lock 70 is engaged along the length of the cord 60. An opposite curvature - i.e. towards the mid-line of the wearer (not shown) - can be achieved by providing a corresponding U-shaped guide channel along a portion of the medial edge 32.

It will be appreciated that the aforementioned arrangement provides a greater degree of customisation of a shoulder strap assembly for baby carriers, or indeed bags, backpacks and the like. In particular, the ability to vary the localised curvature of a shoulder strap overcomes the aforementioned problem of comfort for an adult wearer irrespective of gender, body shape, and the manner in which the baby carrier, backpack etc. is orientated on the body.

Modifications and improvements may be made to the foregoing without departing from the scope of the accompanying claims. For example, whilst the guide as described and illustrated takes the form of an enclosed U-shaped channel, a similar outcome could instead be achieved by threading the cord through a series of exposed loops attached to the exterior edge surface of the strap.

Moreover, whilst the guide is located at the perimeter edge of the strap so as to maximise the degree of curvature imparted thereto, it would nevertheless be possible to achieve a more limited degree of curvature provided that the guide is offset from the central longitudinal axis of the strap.

Finally, whilst a single cord extending through a U-shaped guide channel and having both ends exposed is employed as the length adjustment means, an alternative solution would be to a single cord, one end of which is attached within a single guide channel.