OPENING SPRING FOR MULTIPLE FOLD AUTOMATIC OPEN-CLOSE UNBRELLA

摘要

An opening spring for multiple fold automatic open-close umbrellas is revealed. The opening spring is disposed in a shaft to provide power for extending the shaft while opening the umbrella. The opening spring is formed by a wound wire with a constant wire diameter and having a plurality segments of coils with different outer diameters. A gradually changing part is disposed between two adjacent segments of coils. The coil outer diameter of the gradually changing part is reduced from top to bottom along the axial direction.

主权项

1. An opening spring used for multiple fold automatic open-close umbrellas and disposed in a shaft of a multiple fold automatic open-close umbrella to provide power for extending the shaft while opening the multiple fold automatic open-close umbrella comprising: a plurality of segments of coils with different coil outer diameters formed by a wound wire with a constant wire diameter; and a gradually changing part arranged between two adjacent segments of coils;
wherein an outer diameter of an upper segment of coils of the two adjacent segments of coils is larger than an outer diameter of a lower segment of coils of the two adjacent segments of coils; wherein an outer diameter of each coil of the gradually changing part is decreased axially from top to bottom.