Patent ID: 7520032

Claim:
A linear slide fastener in which a linear fastener element fixed to a side edge of a fastener tape with a fixing thread, wherein a concave portion for accommodating the fixing thread is formed on a top face of an upper leg portion of the linear fastener element, and when heights from a bottom face of a lower leg portion up to the top face of the upper leg portion on a side of a coupling head, at the concave portion and on a side of an inverted portion are assumed to be H 1 , H 2 and H 3 respectively, a condition of H 1 >H 3 >H 2 is provided, a convex portion projecting toward a top face of the lower leg portion is formed on a bottom face of the upper leg portion, when heights from the bottom face of the upper leg portion to the top face of the lower leg portion on the side of the coupling head and at the convex portion are assumed to be H 4 and H 5 respectively, a condition of H 4 >H 5 is provided, and wherein a width from an end of the concave portion on the side of the coupling head to a deepest portion of the concave portion formed on the top face of the upper leg portion is smaller than a width from an end of the concave portion on the side of the inverted portion to the deepest portion of the concave portion, wherein a core thread is inserted through the convex portion and the side of the inverted portion in a gap portion formed between the upper leg portion and the lower leg portion of the linear fastener element, and wherein a gradient of slope from an end of the concave portion on the side of coupling head to the deepest portion of the concave portion formed on the top face of the upper leg portion is sharper than a gradient of slope from an end of the of the concave portion on the side of the inverted portion to the deepest portion of the concave portion.