Patent ID: 8782859

Claim:
A concealed slide fastener comprising: a pair of fastener tapes; a pair of fastener element rows respectively provided on bent edges which are formed by bending opposing tape side edges of the pair of fastener tapes along a longitudinal direction thereof into substantially U-shape, the pair of fastener element rows each having a plurality of continuous fastener elements; a slider configured to insert the pair of fastener element rows therethrough and configured to engage and disengage the pair of fastener element rows with and from each other; a box pin and a box body which are provided at one end of one of the pair of fastener tapes in a longitudinal direction of the pair of fastener element rows; and an insert pin provided at one end of another of the pair of fastener tapes in the longitudinal direction of the pair of fastener element rows, the insert pin being insertable into the box body, wherein the insert pin comprises: an insert portion configured to be inserted into a space formed in the box body; and an engagement portion formed on a side surface of the insert portion, which faces the box pin and configured to be engaged with a lowermost one of the fastener elements of one of the fastener element rows which is close to the box pin, and wherein a length of the engagement portion in the longitudinal direction of the pair of fastener element rows is set to be at least twice an interval between a first fastener element and a second fastener element adjacent to the first fastener element of one of the fastener element rows in the longitudinal direction of the pair of fastener element rows, wherein the interval is defined between a lower edge of the first fastener element and an upper edge of the second fastener element.