Abstract: A choke assembly for use with a shotgun, the choke assembly having a collar attachable to the muzzle of the shotgun. There is a sleeve attached to the collar, the sleeve having at least one tapered bore or aperture, a ball being received in the aperture. There is a tubular slide in surrounding relationship to the sleeve and the collar, there being annular radially outwardly and radially inwardly facing recesses on the slide and collar, respectively, which cooperate to form an annular spring pocket. There is a compression spring received in the pocket, the ball having a portion extending through the tapered bore and a threadless choke received in the sleeve, the choke having an indentation in which at least a portion of the ball is received when the choke is inserted into the sleeve.

Abstract: A casing coupling has a taper which is different from the taper of a standard API Pin. The coupling has a thread pitch diameter which is increased relative to that of a standard API coupling but which still mates with a standard API pin.

Abstract: A casing coupling has a taper which is different from the taper of a standard API Pin. The coupling has a thread pitch diameter which is increased relative to that of a standard API coupling but which still mates with a standard API pin.

Abstract: A threaded connection for tubing having a pin connection with external, tapered buttress type threads, preferably with a one inch per foot thread taper, the pin threaded portion having seven threads per inch. The connection also includes a box connection having complementary internal threads threadedly engaging the pin, the box connection having a comparable pitch and thread taper.

Abstract: A threaded connection for use on oil field tubular. The connection has a dual tapered thread comprising a dual helical thread having a first, straight threaded portion and a second, angled portion, the threaded connection comprising a pin connection and a box connection both of which have thread-free sections. The thread-free section on the pin and the box are comprised of frustoconical surfaces and cylindrical surfaces. The thread-free section of the pin in addition to having a frustoconical surface and a cylindrical surface has an annular, radially outwardly radiused protrusion which, when the box and the pin connection are made-up is in interference engagement with the frustoconical surface in the box.

Abstract: A threaded connection for tubing having a pin connection with external, tapered buttress type threads, preferably with a one inch per foot thread taper, the pin threaded portion having seven threads per inch. The connection also includes a box connection having complementary internal threads threadedly engaging the pin, the box connection having a comparable pitch and thread taper.

Abstract: A threaded connection for use on oil field tubular. The connection has a dual tapered thread comprising a dual helical thread having a first, straight threaded portion and a second, angled portion, the threaded connection comprising a pin connection and a box connection both of which have thread-free sections. The thread-free section on the pin and the box are comprised of frustoconical surfaces and cylindrical surfaces. The thread-free section of the pin in addition to having a frustoconical surface and a cylindrical surface has an annular, radially outwardly radiused protrusion which, when the box and the pin connection are made-up is in interference engagement with the frustoconical surface in the box.