Patent ID: 11898675
Assignee: SHANGHAI VISION MECHANICAL JOINT CO., LTD
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 13:
14. A coupling method for coupling two pipe elements by a pipe element coupler, comprising the following steps:
(A) sleeving a first coupling end portion of said pipe element coupler on an enlarged coupling end portion of a first pipe element of the two pipe elements, and inserting an enlarged coupling end portion of a second pipe element of the two pipe elements into a second coupling end portion of said pipe element coupler in such a manner that engaging keys of a plurality of coupling members are respectively aligned with the corresponding grooves of the first and second pipe elements, sandwiching a plurality of protrusions of a gasket between the two enlarged coupling end portions of the pipe elements, wherein said engaging surface of each of said engaging keys has varying radiuses of curvature, wherein a gap is defined between said engaging surface and a corresponding groove circumference at a bottom of the groove; and
(B) reducing said gap between said engaging surface and the corresponding groove circumference by fastening two fastening end portions of said coupling members through said fastening element, so as to retain said engaging keys at the corresponding grooves; each of said engaging surfaces defines a logarithmic spiral curve having an equation of ρ=eθ, wherein ρ denotes a radius of curvature of the engaging surface, θ denotes a center angle between said distal end point and said proximate end point and Sp denotes a dimension of the pipe element;
wherein when Sρ=60.3 mm, θ has a range of 0-169.88°;
wherein when Sρ=73.0 mm, θ has a range of 0-170.67°;
wherein when Sρ=76.1 mm, θ has a range of 0-171.23°;
wherein when Sρ=88.9 mm, θ has a range of 0-172.46°;
wherein when Sρ=108.0 mm, θ has a range of 0-173.53°;
wherein when Sρ=114.3 mm, θ has a range of 0-173.92°;
wherein when Sρ=133.0 mm, θ has a range of 0-174.84°;
wherein when Sρ=139.7 mm, θ has a range of 0-175.02°;
wherein when Sρ=141.3 mm, θ has a range of 0-175.05°;
wherein when Sρ=159.0 mm, θ has a range of 0-175.57°;
wherein when Sρ=165.1 mm, θ has a range of 0-175.68°;
wherein when Sρ=168.3 mm, θ has a range of 0-175.76°;
wherein when Sρ=216.3 mm, θ has a range of 0-175.42°;
wherein when Sρ=219.1 mm, θ has a range of 0-175.47°.