Abstract: A horizontal door assembly is provided using a gas spring as a lifting mechanism for the door leaf. A special bracket having a number of pivot pin openings is employed to rotatably couple the gas spring to the door frame, whereby different lifting forces can be applied to the door by the user of the door by adjusting the position of the gas spring in the bracket. A brace is also provided to support the bracket and gas spring to enhance operation of the door. A resilient material such as EPDM is used to decelerate movement of the door leaf to the open position and provide a stable door leaf when in the open position. Sections of the door assembly are provided with screw studs to facilitate on-site construction and packaging and shipping of the door assembly.

Abstract: A roof scuttle is provided which is adapted to be easily installed on any curb on a roof which curb may be existing, pre-formed or formed on the roof at the time of installation. The roof scuttle has a rectangular frame with an outwardly extending drip flange and the bottom of the frame is placed flat on the curb and the inside wall of the frame of the roof scuttle secured to the curb. This eliminates any external fastening of the roof scuttle to the roof which can cause leakage problems and also provides a more secure and safe installation. One embodiment of the roof scuttle uses a wood frame supplied with the roof scuttle which frame is useful for transportation of the roof scuttle and also for installations requiring a wood frame curb. The roof scuttle may be installed over irregular shaped openings, existing roof scuttles, and wide or narrow concrete, wood or metal curbs.

Abstract: A gas operated auto loading shotgun having an axially elongate magazine tube and a gas operated piston/cylinder coaxially surrounding the magazine tube includes a gas pressure relief mechanism at the forward end of the gas cylinder for venting gases of combustion in a forward direction toward the muzzle end of the gun when gas pressure within the gas cylinder exceeds a predetermined magnitude. The pressure relief mechanism includes two angularly spaced apart vent ports communicating with the interior of the gas cylinder and terminating at valve seats at the forward end of the gas cylinder. Spherical valve elements seated on the valve seats are biased toward the valve seats by an annular flat spring member secured in fixed on the gas cylinder by a single fastener and surrounding an associated portion of the magazine tube.

Abstract: A shotgun barrel assembly for producing a prematurely enlarged shot pattern has an axially position on barrel and a barrel extension mounted in fixed position on the forward end of the barrel. The barrel defines a shell chamber and a bore which communicates with and extends forwardly of the shell chamber and opens through the forward end of the barrel. A portion of the bore forward of the shell chamber is generally cylindrical and terminates at a conically tapered forwardly diverging portion which opens through the forward end of the barrel and has an axial length at least equal to eight times the diameter of the cylindrical portion. The barrel extension defines an expansion portion which forms an extension of the bore and which has a diameter greater than the major diameter of the conically tapered portion. Compensating slots may be formed in the barrel extension portion.