Hill, Van Santen, Steadman & Simpson
Coupling device
 A coupling device comprises a shaft member having a coupling ring pivotably mounted thereon, a hook, a cylindrical casing and a compression spring. The coupling ring is pivotable into a horizontal position in which the hook, the casing and the spring are removable from the shaft member and into a vertical position in which the hook is rotatable with the casing relative to the coupling ring. 
Yoshida Kogyo K.K.
Y Y B
Y10T Y10T B66C
additional additional inventional
Tomohiro
Mori