Shoulder straps

A shoulder strap has upper and lower outer portions extending from one side edge of the strap to the other, the upper and lower portions having laterally inturned side positions at at least one side edge of the strap, and a double layer of filler strip located between the upper and lower outer portions. The upper filler strip layer has a side edge portion located between the upper outer portion and an adjacent laterally inturned side portion thereof, and the lower filler strip layer has a side edge portion located between the lower outer portion and an adjacent laterally inturned side portion thereof. Each adjacent laterally inturned side portion is short compared to the width of the strip so as to leave substantial portions of the width of the filler strip layers adjacent each other. Adjacent portions of the filler strip layers are bonded together by a strip of synthetic plastic material extending longitudinally of the strap and of such a width that the strip of synthetic plastic material terminates short of each side edge of the strap formed by adjacent laterally inturned side portions. Each pair of adjacent laterally inturned side portions is bonded together by a separate length of synthetic plastic material extending longitudinally of the strap.

This invention relates to shoulder straps for ladies' garments. 
Canadian Patent Nos. 944,502 and 944,503, which issued on Apr. 2, 1974, 
describe shoulder straps which have a seam at one or both side edges, 
there being no seams in the upper or lower surfaces of the straps. The 
exterior of the straps is formed by a suitable outer material such as 
nylon tricot, and double layers of filler strips of suitable material such 
as cotton fabric are located within the outer material. In each strap, 
portions of the layers of filler strips are bonded together, as are also 
the adjacent layers of outer material which form the side seam or seams, 
by a strip of synthetic plastic material, thereby avoiding the necessity 
of having any stitching in the strap. 
With some straps of this kind, it has been found that the strip of 
synthetic plastic material is caused to protrude out of the side seam or 
seams during the manufacturing process, which includes the application of 
heat and pressure to cause the strip of synthetic plastic material to 
effect its bonding function. This may cause the seam edge or edges of the 
strap to become hard and/or irritable to the wearer. 
The present invention accordingly provides a shoulder strap comprising 
upper and lower outer portions extending from one side of the strap to the 
other, the upper and lower portions having laterally inturned side 
portions at at least one side edge of the strap, a double layer of filler 
strip located between the upper and lower outer portions, the upper filler 
strip layer having a side edge portion located between the upper outer 
portion and an adjacent laterally inturned side portion thereof and the 
lower filler strip layer having a side edge portion located between the 
lower outer portion and an adjacent laterally inturned side portion 
thereof, each said adjacent laterally inturned side portion being short 
compared to the width of the strip so as to leave substantial portions of 
the width of the filler strip layers adjacent each other, said adjacent 
portions of the filler strip layers being bonded together by a strip of 
synthetic plastic material extending longitudinally of the strap and of 
such a width that said strip terminates short of the or each side edge of 
the strap formed by adjacent laterally inturned side portions, and the or 
each pair of adjacent laterally inturned side portions being bonded 
together by a separate length of synthetic plastic material extending 
longitudinally of the strap. 
The cross-section of the or each separate length of synthetic plastic 
material can accordingly be chosen so that the problem mentioned above is 
avoided, while at the same time effective bonding continues to be achieved 
by the strip of synthetic plastic material. 
The upper and lower outer portions may have laterally inturned side 
portions at both side edges of the strap, with adjacent laterally inturned 
side portions at each side of the strap being bonded together by separate 
lengths of synthetic plastic material extending longitudinally of the 
strap. 
The strip of synthetic plastic material may be of such a width that the 
strip also bonds together the innermost edge parts of adjacent laterally 
inturned side portions. In this case, the strip of synthetic plastic 
material may also bond the innermost edge parts of adjacent laterally 
inturned side portions to adjacent parts of the filler strips. 
The or each length of synthetic plastic material may also bond the 
laterally inturned side portions to the respective filler strip layers. 
The upper and lower outer portions may be of nylon tricot, and the filler 
strips may be of cotton flannel. The strip of synthetic plastic material 
may comprise a web of synthetic thermoplastic fibres, and the or each 
length of synthetic plastic material may comprise a mono-filament thread.

Referring to the drawing, a strap suitable for ladies' garments has an 
upper outer portion 12 and a lower outer portion 14 of nylon tricot, and 
each outer portion 12, 14 has laterally inturned side portions 16, 18 
respectively forming seams at each side edge of the strap. Each inturned 
side portion is short compared to the width of the strap so as to leave a 
gap of substantial width relative to the width of the strap between 
opposed ends of respective inturned side postions 16, 18. 
A first filler strip 20 of cotton fabric, such as cotton flannel, is 
located between the upper outer portion 12 and the inturned side portions 
16 thereof. A second filler strip 22 of similar material is located 
between the lower outer portion 14 and the inturned side portions 18 
thereof. 
Central portions of the widths of the filler strips 20, 22 are bonded 
together, through the gaps between the inturned side portions 16, 18, by a 
strip of synthetic plastic material in the form of a web of thermoplastic 
fibres 24. The web 24 is of such a width that it also bonds together the 
innermost edge parts of adjacent inturned side portions 16, 18. The web 24 
may also bond the innermost edge parts of inturned side portions 16, 18 to 
adjacent parts of the filler strips 20, 22. However, the side edges of the 
web 24 terminate well short of the side edges of the strap and, laterally 
outwardly of the web 24, adjacent inturned side portions 16, 18 are bonded 
together by separate lengths of mono-filament thermoplastic thread 26, 28. 
The threads 26, 28 may also bond the inturned side portions 16, 18 to 
adjacent parts of the filler strips 20, 22. The bonding is such that the 
filler strips 20, 22 are not bonded to the nylon tricot outer portions 12, 
14. 
The strap is manufactured in a similar manner to that described in the 
abovementioned Canadian Patent No. 944,503, except that the web 24 is 
narrower in this case, and the mono-filament threads 26, 28 are fed into 
the strap before the bonding and curing steps. With the present invention, 
the web 24 is sufficiently narrow to avoid any possibility of its side 
edges projecting from the side seams of the strap, while at the same time 
being of a sufficient size to achieve the necessary bonding. The 
mono-filament threads 26, 28 are sufficiently large to bond the adjacent 
laterally inturned portions 16, 18 together to form secure side seams, 
while at the same time being sufficiently small to avoid the likelihood of 
thermoplastic material constituting the threads 26, 28 from being forced 
out of the side seams during the bonding and curing steps. 
The above described embodiment of the present invention is an improvement 
in the double side seam strap described and claimed in Canadian Patent No. 
944,503. It will readily be understood that the present invention is 
equally applicable to the single side seam strap described and claimed in 
Canadian Patent No. 944,502. Other embodiments of the present invention 
will be clearly apparent to a person skilled in the art.