Abstract: A hingeless ventilator comprises a frame defining two openings surrounded by a seating rim, which is surrounded by a door recess. A pair of upright sleeves is disposed between the openings, and each upright sleeve defines an exterior track surface. A door is disposed to face the outer surface of the frame and has a main body configured to be selectively positionable to cover and uncover both of the openings and defines a lip surrounding the periphery thereof and extending generally perpendicularly to the main body. Two door struts connected to the door extend through the frame openings and hold a handle that has rollers that are biased against the exterior track surfaces of the sleeves.

Abstract: A hingeless ventilator comprises a frame defining two openings surrounded by a seating rim, which is surrounded by a door recess. A pair of upright sleeves is disposed between the openings, and each upright sleeve defines an exterior track surface. A door is disposed to face the outer surface of the frame and has a main body configured to be selectively positionable to cover and uncover both of the openings and defines a lip surrounding the periphery thereof and extending generally perpendicularly to the main body. Two door struts connected to the door extend through the frame openings and hold a handle that has rollers that are biased against the exterior track surfaces of the sleeves.

Abstract: A two-way hingeless ventilator for ventilating an enclosure through a wall thereof has a frame defining an opening therethrough. A closure member is disposed against an outer side of the frame and is alternately swingable relative to the frame between open and closed positions at opposite sides of the opening. A tensioning rod is fixed on the frame and extends between opposite sides of the opening. An actuating member extends from an inner side of the closure member through the opening and intermediate ends of the tensioning rod. A positioning slot is defined in the actuating member through which the tensioning rod passes in a tensioned condition to apply a closing force to the closure member. The positioning slot has a central position defining a closed position of the cover member and opposite side slots extending away from the central position.

Abstract: A two-way hingeless ventilator for ventilating an enclosure through a wall thereof has a frame defining an opening therethrough. A closure member is disposed against an outer side of the frame and is alternately swingable relative to the frame between open and closed positions at opposite sides of the opening. A tensioning rod is fixed on the frame and extends between opposite sides of the opening. An actuating member extends from an inner side of the closure member through the opening and intermediate ends of the tensioning rod. A positioning slot is defined in the actuating member through which the tensioning rod passes in a tensioned condition to apply a closing force to the closure member. The positioning slot has a central position defining a closed position of the cover member and opposite side slots extending away from the central position.

Abstract: A hingeless ventilator for ventilating an enclosure through a wall thereof, includes a frame, a cover, an actuating member, a handle secured to the actuating member, and a recessed chamber connected to the frame and defining a depth configured to contain the actuating member and the handle. The frame includes a border that defines an opening through the frame and a front and a back. The cover is selectively swingable relative to the frame between a closed position and open positions. The open positions place the cover intermediate the closed position and at least one of the front and back of the border that defines an opening through the frame.

Abstract: A remotely controlled powered hingeless ventilator has a cover configured on a frame on a side thereof opposite from a tension rod. The cover is variably positionable between a closed position and a fully open position relative to the frame. An actuating member connected to an underside of the cover extends through a slot in a plate member across the ventilation opening and includes an arcuate guide slot defined therein. The tension rod is disposed through this guide slot. A motor is mounted on the frame and is connectable to a power source. The motor includes a rotatable drive arm connected to the actuating member. The drive arm has a generally arcuate shape and is connected to the actuating member so that an opening and closing force is exerted by the drive arm to the actuating member along a line of force corresponding generally to an extension of the arcuate guide slot.

Abstract: A through-wall bushing defines a protected passage through a wall or similar structure, and includes a first member having an axially extending threaded portion. A second ring member is threaded onto the first member and clamps the wall structure between opposing flanges of the first member and second ring member. At least one friction inducing locking mechanism is configured on at least one of the threaded surfaces of either the first or second member, or both members. This friction inducing locking mechanism has a configuration that increases the degree of torque required to tighten and loosen the respective members upon the threads engaging the locking mechanism. The locking mechanism has a shape so that, once engaged with opposite threads, the torque required to loosen the members is greater than the torque required to further tighten the members.