Patent TW-201515591-A (TW)
Title: Zipper slider of double-layered coil zipper
Inventor: WANG LIEN-CHOU
IPC: A44B19/24
Filed: 2014-01-03
Abstract: The present invention discloses a zipper slider of double-layered coil zipper. After development of Taiwanese utility model patent No. M432302, it still needs to be improved although having a tongue-shaped guiding function, and the present inventor continues to make improvement to the invention. In order to improve the double-layered coil zipper causing the expansion of clearance between coils on the outer layer at the turn while processing the turn and that the clearance between coils on the inner layer will be contracted and squeezed by each other resulting in difficult sliding due to the inconsistency of time configuration space while engaging the upper and lower layers using the same cavity zipper slider for sliding. Therefore, the lower protector is withdrawn a distance equal to the thickness of one coil layer while aligning with the center, so as to eliminate the different configuration spaces at the turn while engaging coils and thus eliminate the inconsistency of coil engagement. Besides, because the corresponding cross-sectional area of the lower protector connected to the center is reduced by about half, the tensile strength of the lower protector might be weakened. Under such a circumstance, a proper width and thickness of the lower protector respectively corresponding to both sides of the center is reserved, and a concave arc design is used to connect with the withdrawn lower protector. The present invention may achieve the effects that, by reserving a proper width and thickness at both sides of the center, providing the support as extension beam and reinforcing the tensile strength of the lower protector; in addition, the pitch between the left and right concave arcs may be used as the position-limiting expansion angle for guiding the double-layered coil zipper and may control to prevent the friction or offsetting of tongue-shaped balance guide sheet causing the guiding failure of the front section of the tongue-shaped balance guide sheet, thus making the coil engagement sliding at the turn being as smooth as at the linear portion. Particularly for zipper processing of hard shell luggage, the present invention will not be forced to straighten the zipper at the front and rear ends, and the expansion angle of left and right zipper tapes may be stabilized by the distance between two concave arcs during being forced for straightening, so as to achieve the smooth coil engagement. Moreover, for preventing the coil pitches of the left and right sides might be changed by the traction of external force as having the coil pitch at one side being kept and the coil pitch at the other side being opened and poorly engaged during twisting of the zipper, which causes the loss of coil merging or coil protrusion. The clearances at both sides of the protector are properly extended and lengthened along the side plate direction toward the top of the center, so as to increase the channel length of the upper layer zipper for the cavity hole of the zipper slider during twisting. Since the support points of coils corresponding to the side plate of the upper protector are moved forward during twisting, that is, the coil pitch is expanded to the maximum at the support point, the coil pitch will be recovered to normal while advancing to the engagement position for achieving the correction effect to prevent coil merging or coil protrusion. Furthermore, the upper and lower protectors are respectively provided with concave grooves on the upper and lower sides at both sides of the center, so as to reduce the friction for coils on single side and achieve the coil positioning during bending and the top stopping and positioning function.