swivel from the firearm application_number US 61116590 A description fig1 shows an exemplary quick detachable security type sling swivel 10 constructed in accordance with the present invention for attaching a sling 12 to a conventional mounting base 14 which is screwed into the stock 16 of a firearm more specifically the swing swivel 10 includes a main body 18 a ring member 20 pivotably connected to the underside of the main body receiving a strap portion of the sling 12 and a pin 22 forwardly projecting from an upper extension 24 on the main body and dimensioned for sliding insertion into an opening not shown formed through the mounting base 14 a passage 26 formed in a gate 28 surrounds and closes off a forward end 29 of the pin to keep the swivel on the mounting base although the swivel 10 is shown in locked condition in fig1 after certain manipulation explained below the gate 28 can be shifted by a plunger 30 and swung away from the end 29 of the pin 22 to permit the swivel to be removed from or attached to the mounting base as shown in fig6 a security element or retainer 32 carried on the plunger 30 determines the range of operation of the plunger 30 and gate 28 and accordingly determines whether the swivel 10 can be unlocked from the mounting base 14 referring to fig2 the exemplary retainer 32 is preferably of hollow frustoconical form and includes a forward portion 34 defining an internally threaded bore 36 and a rearwardly extending skirt or sleeve portion 38 the sleeve portion 38 has.