Abstract: A horizontal door assembly is provided with pivotal counter balancing spring comprising an upper cylinder and a mating lower cylinder to force the cover of the door to an open position when the door assembly is unlocked wherein the upper cylinder of the counter balancing spring is configured to reduce the forces of the spring on the pivot points of the counter balancing mechanism thereby increasing the life of the counter balancing mechanism. In a preferred embodiment, the counter balancing spring mechanism is made of plastic and has an ear at the upper end thereof with an elongated slot opening the slot having a longitudinal axis substantially parallel to the longitudinal axis of the cylinder for mating with a pin inserted in an opening in a yoke bracket attached to the lower side of the cover.

Abstract: The counter balance system for a vehicle liftgate includes a pair of gas cylinders in combination with a torsion rod. The gas cylinders urge the liftgate toward an open position but due to a short moment arm do not exert sufficient force to open the liftgate until the liftgate has pivoted about one third of the distance from the closed position toward the open position. The torsion rod also urges the liftgate toward an open position. Maximum force is exerted by the torsion rod when the liftgate is closed. As the liftgate moves toward an open position, the force exerted by the torsion rod decreases until the liftgate is midway between closed and open. The torque rod does not exert any force on the liftgate during the last portion of its movement to an open position.

Abstract: An overhead console for a vehicle or the like includes a housing defining a transmitter storage compartment for a garage door opener and an opening for permitting access to the storage compartment. A door is pivotally mounted to the housing for movement between a closed position for covering the opening and an open position for exposing the interior of the compartment through the lower opening. A hinge assembly for pivotally mounting the door to the housing includes a pair of spaced cams integrally molded to the door and a pair of spaced spring arms integrally molded to the housing. The spring arms are engageable with the cams as the door moves toward the open position from the closed position to arrest the movement of the door at an intermediate position between the closed and open positions. The spring arms are engageable and deflectable by the cam to provide frictional resistance to movement of the door only from the intermediate position to the open position.

Abstract: A portable bulk storage container having a counterweight mechanism for opening and closing a heavy lid. The container comprises a substantially gas and liquid tight tank secured inside of a frame. An opening is positioned on a front portion of a top of the tank. A lid is pivotally connected to the top of the tank for sealing the opening. A pair of fulcrums or connecting members extend from opposite sides of a rear portion of the lid. A counterweight is attached to each fulcrum. Each counterweight has an elongated lever end which extends away from the rear of the lid such that the counterweight can be used to rotate the lid between closed and open positions. Each counterweight is positioned beyond a side wall of the tank such that the counterweights can be rotated along the side wall of the tank, thereby effectively utilizing the limited amount of space available inside of the frame.

Abstract: Apparatus for aiding removal and replacement of a spa cover. The apparatus includes at least one lifting assembly secured relative to the spa tub, each having a lifting arm mounted for rotation relative to the spa tub and including a cover-engaging end coupled to the spa cover and a pivot end mounted for pivotal movement about a pivot axis. The lifting arm is rotatable through a range of motion about the pivot axis between a covering position and an uncovering position. A lifting system is provided for exerting a lifting force on the arm tending to lift the arm as the arm moves from the covering position toward the uncovering position, and for exerting a resistance force on the arm tending to resist movement of the arm from the uncovering position toward the covering position. The lifting system includes a link lever having a pivot end pivotally mounted to the lift arm at a link pivot location disposed between the arm pivot end and the cover-engaging end.

Abstract: A device for connecting a spring to a band-like or cable-like transmission apparatus. The device being easy to assemble and in which the risk of fracture of the device is greatly reduced. The device provides a connecting part to be fitted on the transmission apparatus and a hook-in part to be connected onto the spring. The connecting part then being connected to the hook-in part to connect the transmission apparatus to the spring.

Abstract: Tailgate hinge mechanism mounting the tailgate for swingable movement between closed, open and removal positions is designed to allow incorporation of a torque rod which cooperates with the hinge mechanism to assist in opening or closing the tailgate and yet is not a required portion of the hinge mechanism, but if desired may be quickly and easily installed as a unitary mechanism.

Abstract: An over-the-top type cabinet door prop unit is characterized in that it comprises a fitting case to be rigidly fitted to the inner surface of one of the lateral walls of the cabinet, a movable spring holder vertically movable relative to the fitting case containing it and urged downward by compression springs, a link arm pivotably linked at the upper end to the movable spring holder by a pivot pin and a swing arm swingable around an arm spindle located in a lower portion of the fitting case and having a base section arranged around the arm spindle and linked to the lower end of said link arm by a link pin and an arm section extending from the base section and pivotably linked at the distal end thereof by an anchor pin to an anchor pin bearing secured to the over-the-top type cabinet door and that the pivot where the link arm and the base section of the swing arm is linked by the link pin is located closer to the cabinet door relative to the vertical axial line connecting the pivot pin and the arm spindle when

Abstract: A vehicle rear lift gate hinge and counterbalance assembly (22) includes a pair of laterally spaced hinges (24) and a counterbalance (25) including a torque rod (26) for pivotally supporting and counterbalancing a vehicle rear lift gate (18) for movement between open and closed positions with respect to a rear opening (14). Each hinge (24) includes a vehicle mounted hinge member (28) and a gate mounted hinge member (30) pivotally connected to each other. The torque rod (26) has a unitary construction including a central portion (38) ends (40) that include U-shaped bight portions (42) respectively received between laterally spaced portions (34) of one of the hinge members and engageable with an engagement portion (36) of the other hinge member to provide counterbalancing adjacent the closed position of the lift gate (18).

Abstract: A device is provided for aiding in the removal and replacement of a spa cover atop a spa tub. A pair of lifting assemblies are located on opposite sides of the spa tub. Each of the lifting assemblies includes a spring having an anchored end secured relative to the spa tub and a moveable end. Each lifting assembly employs a lifting arm mounted for rotation relative to the spa tub and including a cover-engaging end attached to the spa cover, a spring-engaging end attached to the moveable end of the spring, and a fulcrum located between the lifting arm ends. The lifting arm is rotatable between extreme covering and uncovering positions in which the spring-engaging end of the lifting arm lies on opposite sides of a straight line extending between the lifting arm axis of rotation and the anchored end of the spring. The lifting arm is rotatable through an intermediate position in which the spring-engaging end of the lifting arm passes between the fulcrum and the anchored end of the spring.

Abstract: Racks (20) supported on a transfer cart (38) in a decontamination area (18) are loaded with contaminated articles. The carts are wheeled to a washer (14) into which the racks of contaminated articles are placed for washing. After washing, the racks are removed from the washer in a preparation and packing or clean room (12) and unloaded. The empty racks are moved through a rack return (28) back to the decontamination area. The rack return includes a rack supporting surface (32) on which glide strips (42) are mounted for sliding the racks from the clean room to the decontamination area. Guide strips (44) guide the racks to a pair of vertically pivoted polycarbonate doors (34) which the racks push open by engaging bumpers (58). After the rack has passed through the doors, a self-closure mechanism (60) closes the doors automatically. The rack return assembly includes stops (76, 78) on both sides for aligning a rack carrying cart of any of a plurality of sizes accurately with the rack return assembly.

Abstract: A device for closing road wells in vehicle and pedestrian zones is provided, said device comprising a support frame (2) defining an access opening (4) and a plate closing element (5) rotatably engaged with the support frame (2) about a hinging axis (6) so as to be movable between a raised open position and a lowered closed position.

Abstract: A door assembly for covering an opening (12) formed in the body (26) of an aircraft including a door (10) with two gooseneck hinge arms (28) are rotatably connected at one end to the aircraft body above the door opening and rotatably connected at their other end to the door. An actuator (30) is provided to pivot the hinge arm about its rotatable connection to the body. Two mounting panels (106) are located between the two gooseneck hinge arms. A torque tube (104) is supported by the door and rotates by turning an interior door handle (100) that is located between the two mounting panels. The door assembly further includes a latching assembly (32), hinge guide assembly (34), and frame guide assembly (36) that cooperate to give the door a desired motion. The latching, hinge guide, and frame guide assemblies each include various rollers that engage with tracks.

Abstract: An over-the-top type cabinet door prop unit is characterized in that it comprises a fitting case to be rigidly fitted to the inner surface of one of the lateral walls of the cabinet, a movable spring holder vertically movable relative to the fitting case containing it and urged downward by compression springs, a link arm pivotably linked at the upper end to the movable spring holder by a pivot pin and a swing arm swingable around an arm spindle located in a lower portion of the fitting case and having a base section arranged around the arm spindle and linked to the lower end of said link arm by a link pin and an arm section extending from the base section and pivotably linked at the distal end thereof by an anchor pin to an anchor pin bearing secured to the over-the-top type cabinet door and that the pivot where the link arm and the base section of the swing arm is linked by the link pin is located closer to the cabinet door relative to the vertical axial line connecting the pivot pin and the arm spindle when

Abstract: Disclosed is a top mounted interior door closer utilizing as a drive mechanism a yieldable actuator which is exercised during the opening and retraction which is desirably mounted in an encasement having a closing rod extending from one end. The closing rod is secured to a pair of flanking members along a vertical axis, which members, in turn, are positioned for movement in a track. The closer is sandwiched in place interiorly by having elongate slot at the top of the door means of a cover plate. The elongate slot passes a closing link pin pivotally secured to the shaft or bushing joining the rollers or blocks.

Abstract: A door hinge mechanism is easily fastened to an oven door at its top and bottom, for example, using a hook-like engagement, and providing along the length of the oven door sidewalls rigid structural members and support, and thermal isolation of the oven door sidewalls from the oven door interior.

Abstract: A door closer includes a casing fixedly fastened to a door leaf, a shaft turned in axle holes in the casing, a spiral spring mounted around the shaft within the casing and having one end fixed to the shaft and an opposite end fixed to the casing and adapted for returning the door leaf to the close position each time it is opened, a rack fixedly fastened to a door frame to which the door leaf is hinged, a bevel gear fixedly mounted on one end of the shaft and turned with it along a 90-degree arc toothed bar section of the rack, and a curved springy holding down plate fastened to the rack and adapted for holding down the bevel gear to keep the door leaf to be retained in an open position.

Abstract: The present invention is a hinge system for attaching a hinged element to a base forming a hinged unit. The hinge system includes first and second torsion rods fixed to the hinged element and to the base proximate such that the first and second torsion rods are deflected as the hinged element is rotated relative to the base producing first and second torsion forces. The first and second torsion forces prevent the hinged element from twisting as the hinged element is rotated relative to the base. A friction element is connected between the base and the hinged element for offering resistance to the relative rotation of the base and the hinged element.

Abstract: A counterbalancing mechanism for counterbalancing the weight of a door securing an opening in an enclosure. The mechanism has a pair of bearing plates mounted on the wall of the enclosure which rotatably supports a tubular shaft extending therebetween. A pair of spools, each having a cable wound thereon which is attached to the door, are mounted at the ends of the tubular shaft for rotation therewith. A pair of springs, each attached at one end to the tubular shaft and at the other end to a respective bearing plate, extend coaxially about the tubular shaft between the bearing plates to exert a counterbalancing force on the tubular shaft opposing the weight of the door which is transferred to the tubular shaft through the cables and spools. Since each of the springs generates approximately one-half of the necessary counterbalancing force, the door will remain partially counterbalanced even if one of the springs fails.

Abstract: A port assembly for a marine vessel, including a lens element and three concentric stainless steel rings which are superimposed upon one another. A first of the rings includes a base portion forming an outer trim ring, a second portion which is generally parallel to the base portion and a sloping riser which defines an angle of between 105.degree. and 135.degree. with a base portion. The sloping riser also connects the base portion and the second portion. A second of the stainless steel stampings also includes a stepped cross-section with two risers and an intermediate portion connecting the two risers. The second of the risers also includes a sloped portion which is welded to the sloped portion of the sloped riser. A third stainless steel stamping, or clamping ring, is bolted to the intermediate portion of the second riser and, together with the base portion of the first ring, form a clamp for securing the port assembly to the wall of the vessel.

Abstract: A self braking door slide mechanism particularly adapted for use with cabinets that have front doors that open upwardly and are retracted using the slide mechanism to a position in which the door is aligned with the top of the cabinet in either an over or under top position. A dampening cylinder extends between the top of the cabinet and the door to slow its downwardly hinging action when the door is being closed. Auxiliary brake pads are also provided on a stationary slide member which bear against the moving portion of the slide mechanism to slow the sliding action during closing due to the force of the dampening cylinder.

Abstract: A gate closer for a gate is provided. The gate closer includes a first housing which is mounted to a supporting structure of the gate. A hydraulic gate closer is installed within the first housing. A second housing is attached to the gate and an adjustable arm is installed within this second housing. The first and second housings are installed such that a rotatable shaft of the hydraulic gate closer engages the adjustable arm so that the gate closer can safely and securely close the gate.

Abstract: A torsion bar hood lift assist includes a torsion bar mounted with a free end portion positioned to engage and travel along a hood interior surface as the hood of the vehicle is opened and closed. As the hood is closed, the torsion bar bends and twists to store energy which is then transferred to the hood to assist in hood opening when the hood is lifted. The free end portion of the torsion bar supports a hood engagement member such as a roller to reduce friction between the torsion bar and hood as energy is transferred. The torsion bar is typically supported at two locations with a bearing block being used to further reduce friction. The free end of the torsion bar engages a hood reinforcing member or plate, which may comprise a hood mounting bracket, and travels against this plate during hood opening and closing.

Abstract: A sliding door shutting device includes a barrel slidably engaged in a housing and has a plug secured on one end and slidably engaged in the housing. The plug has an annular groove defined by two side walls. A spring may bias the barrel inward of the housing. The sealing ring is engaged with one side wall for allowing air to bypass the plug when the barrel is moved outward of the housing, and the sealing ring is engaged with the other side wall so as to make an air tight seal between the plug and the housing when the barrel is moved inward of the housing.

Abstract: A counterbalance mechanism (10) counters the weight of a door in an airplane. The door hingedly mounts to the fuselage of the airplane, and rotates upward and inward relative to the fuselage along a hinge axis. The counterbalance mechanism includes a housing (12) for affixing the counterbalance mechanism to the fuselage of the airplane. A guide tube (14) rotatably mounts to the housing for swinging movement about an axis of rotation generally parallel to the hinge axis of the door. The guide tube includes a rod (40) that extends outwardly from the guide tube. Compression springs (34) within the guide tube oppose outward movement of the rod. A linkage assembly that includes a bell crank (50) and a push rod (56) connects the guide tube to the door via rod (40) to assert counterbalancing force during the door opening and closing sequence of the door.

Abstract: A refrigerator door assembly is mounted on a stationary frame of a refrigeration unit and comprises a door frame integrally molded about a thermo-pane in sealing relationship therewith. The door frame is hingedly mounted on the stationary frame of the refrigeration unit by a pair of upper and lower hinge pins. A torsion bar, integrally molded within the door frame and secured to one of the hinge pins, functions to constantly apply a closing force on the door frame to move the door assembly into sealing contact with the stationary frame of the refrigeration unit.

Abstract: A device for generating a rotary return force includes a casing unit, driving and driven gear units disposed in the casing unit, and a torsion spring. The driving gear unit includes a driving axle mounted rotatably to the casing unit and a driving gear wheel mounted fixedly on the driving axle. The driving axle is adapted to be driven rotatably by a rotatable unit. The driven gear unit includes a driven axle mounted rotatably to the casing unit and a driven gear wheel mounted on the driven axle. The driven gear wheel meshes with the driving gear wheel. One of the driven and driving gear wheels is larger than the other one of the driven and driving gear wheels. The torsion spring has a first retaining end secured to the driven gear unit and a second retaining end secured to the casing unit. Rotation of the driving gear wheel in a first direction by the rotatable unit causes corresponding rotation of the driven gear wheel and winding of the torsion spring.

Abstract: A hatch assembly includes a first frame member having a generally J-shaped cross-section with a longitudinal extending or upright position and a generally parallel lip portion which is separated from the longitudinal portion by a horizontal section or riser. The assembly also includes a second frame member rotatably fixed to the first frame member. The second frame member includes a pair of elastomer seals fixed thereto so that a first of the seals engages the longitudinal portion of the J-shaped frame while the second seal engages the lip. The second frame member also includes a vent or small opening between the seals and a cavity for receiving any airborne water which passes through the vent. This vent is also constructed and arranged to drain air our of the cabin. In addition, the hatch assembly includes a hidden counterweight.

Abstract: A counterweight assembly for a container lid that allows for control over the operating characteristics of the lid during opening and closing. The counterweight assembly is preferably used with a container having one or more walls, a floor, and a lid positioned on top of the walls, the lid being rotatable about a horizontal hinge axis. The counterweight assembly includes a counterweight, and a coupling arm rotatable about a counterweight axis that is located within the container. The counterweight is connected to one end of the coupling arm. The other end of the coupling arm exerts a force against the downward facing surface of the lid.

Abstract: A front panel for a magazine-loading DAT drive assembly having a tape cassette drive unit above a magazine receiving area is provided with two hinged doors. By orienting two pairs of abutments in opposite directions and positioning two springs such that they exert opposite torques on their respective pairs of abutments, the door will be biased to its closed position regardless of whether it has been swung in one direction to its loading position, or in the other direction to its unloading position.

Abstract: A skyhatch or skylight having a case to which one or more wings are pivotably attached whose opening and closing is accomplished by using a combination cable system and pneumatic spring opening and closing mechanism such that the wings can be opened to any desired position between their fully closed and fully opened position on a continuously variable basis.

Abstract: A bi-directional door for the elderly and handicapped which comprises a support assembly mounted to a floor, a swing gate pivotally mounted about a support shaft in the support assembly, and a controller assembly located within the support assembly. A first bevel gear at the base of the swing gate is positioned for rotation about the support shaft. A second bevel gear, which is controlled by the controller assembly, is coupled to the first bevel gear at a 90 degree angle. Accordingly, when the swing gate is opened and released, the controller assembly controls the rotation of the first and second bevel gears such that the swing gate returns back to a home position at a predetermined rate. In addition, the support assembly includes various ways for adjusting and fine tuning the angular position of the bi-directional door in the support assembly.

Abstract: A swingable door assembly and a hinge assembly for urging the swingable door assembly to a closed position is provided. The hinge assembly comprises a torsion spring which may be an elongate torsion rod, which may be preloaded with a predetermined amount of torsion force so that the associated swingable door assembly is urged to a closed position with respect to a casing, such as a refrigerated display case. The hinge assembly includes a ratchet pin connected to the torsion spring. First and second ratchet anchors may be mounted at a predetermined distance from each other on the ratchet pin. A fixed ratchet is secured to the ratchet between the first and second ratchet anchors.

Abstract: A fiberglass, insulated bulkhead door assembly overcomes the limitations of conventional wooden and metallic storm doors. A preassembled bulkhead door assembly is positioned atop a preexisting concrete foundation. Once in place, the bulkhead forms a liquid tight barrier. As an insulated, lockable structure, the bulkhead door assembly provides a means of ingress into and egress out of a basement of a dwelling structure. The base support and door of the bulkhead door assembly incorporate an insulative layer sandwiched between a pair of molded fiberglass panels, which are then covered by a durable gel coat finish. The combination of insulation and fiberglass maintains an effective thermal barrier between the basement of the dwelling structure and an exterior environment. A pair of pneumatic struts counterbalance the door into an upright position.

Abstract: An apparatus for controlling the position of a door suitable for use in association with door closing piston assemblies having a spring-biased reciprocable door closing piston rod and a latch plate transversely slidable along the length of the piston rod. By use of the present invention, a momentary initial rotational bias may be imparted to the latch plate automatically and electronically, thereby causing it to shift the latch plate towards a rotated angle while the door is closing, and to facilitate pre-positioning the latch plate to set into a locking hold-open orientation without any subsequent manual adjustment.

Abstract: The present invention relates to a two way animal door adapted to be installed in an existing door to allow two way travel of household pets. More specifically, the present invention pertains to a frame which is inserted into a rectangular aperture formed within an existing door. The frame carries a centrally located post which serves to divide the frame into two equal portions. Within the frame are position a first and a second door. The first door is openable only in one direction, while the second door is openable only the opposite direction. Each of the doors is mounted to the surrounding frame by way of adjustable spring biased hinges. The various components of the present invention and the manner in which they interrelate will be described in greater detail hereinafter.

Abstract: A refrigerator includes a door hinged to a housing, and a door opening/closing assist device which aids in opening and closing the door. The device includes a spring-biased roller carried by the door and a guide plate carried by the housing. The guide plate forms a guide curvature against which the roller is elastically biased. The guide curvature is shaped so that during an initial stage of a door opening (or closing) movement the roller is displaced by the guide curvature to cause the spring to store energy, and so that during a final stage of the door opening (or closing) movement, the spring releases energy and forces the door to assist the performance of the final stage.

Abstract: A skylight has a sash, a casement and [spring-loaded.revreaction. carrier arms which are mounted at one end to the casement and at the other end on a pivot bearing on the sash side rail. The sash has spindles cooperating with a U-shaped runner on the side member of the casement. A cover plate borders the channel of the runner and overlaps the spindles when the sash is in the swinging position. When the sash is in the closed position [and the swinging position], the spindles is outside the working range of the cover plate. When the sash is opened and the carrier arm is coupled thereto, it tilts on the pivot bearing. When opened with the sash uncoupled from the carrier arms, the spindle move in the grooves of the runner toward the lower edge of the casement, and the pivot bearing on the casement is lifted off and the sash swings open. The spindles are positioned on the side rail of the sash and move longitudinally when they are seated in individual settings by movement of the handle on the sash cross member.

Abstract: A spa cover lifting apparatus which can be adjusted to accommodate spa covers of different sizes and which can be attached to the spa cover without damaging said spa cover or requiring special fastening means. The spa cover lifting apparatus mounts on the spa frame and raises the spa cover from its horizontal engagement position to a vertical position freeing the spa for use. The lifting action of the apparatus being assisted by a telescoping gas strut.

Abstract: An automated window system and method for a building utilizes a pair of gas springs to bias a window panel outward from a corresponding frame. A force opposing the gas springs is supplied by a motor driven spindle selectively winding and unwinding a cord coupled to the window panel sash adjacent the jamb portion of the frame and window. The cord is slidably retained to the jamb portion of the window sash through a pair of threadable pulls in order to equalize the forces supplied opposing the gas springs in the event of uneven winding of the cord due to buffeting or other forces while the window panel is being moved between an "open" to a "closed" position thereof.

Abstract: A cabinet for displaying objects, consists of a plurality of sides, of which one side is in the form of a door and bears in the closed state on the end surfaces of the two adjoining sides, wherein its outer edges are aligned with the outsides of these sides. The cabinet comprises two hinges arranged one above the other, each consisting of a door hinge part fixed to the door and a housing hinge part, which are rotatably connected together by a pin. Each housing hinge part is fitted on the end of a rod which is movable axially and perpendicular to the closing plane of the door in a bearing body fixed on a lower sheet metal frame located in the lower part of the cabinet or a bearing body fixed on an upper sheet metal frame located in the upper part. In the region of the lower part of the cabinet a gas pressure spring is fitted horizontally in the region of the lower part of the cabinet between the lower sheet metal frame and the door.

Abstract: A simulated wrought iron fence gate is disclosed, the gate comprising a gate frame, post structure, hinge mechanisms, a gate return mechanism, and a latch mechanism.

Abstract: A support for holding a closed element, such as a flap or lid in a closed or open position relative to a container has a first and second arm. One of the arms is connected to the container by a first pivot bearing and the other arm is connected to the closing element by a second pivot bearing. The two arms are connected to one another by a third pivot bearing and by a pressure spring operational between the arms. The two arms are supported relative to one another in a first arm position, which corresponds to the closed position, where the pivot bearings are close to one another, or in a second position, which corresponds to the open position, where the pivot bearings are positioned remote from one another.

Abstract: A method of increasing the range of controlled movement of a door opened by a treadle operated door opening assembly is described, along with a treadle operated door opening assembly constructed in accordance with the teachings of the method. The method includes the step of mounting a contact member which projects from the first face of the door adjacent to the hinge edge and the bottom edge. With this modification when a person treads upon a radially extending pedal a shaft rotates causing a point of contact between the arm and the door to move sequentially from a first position substantially parallel to the first face of the door to a second position engaging the contact member substantially perpendicular to the first face of the door.

Abstract: A hinge is provided with a tubular hinge pin. This allows the use of a torsion rod, inserted through the tubular hinge pin, of any desired diameter smaller than that of the interior of the hinge pin, thereby permitting easy adaptation of the resistance provided by the torque rod.

Abstract: A cover assembly for manholes and the like has a hinged cover which is urged closed by gravity and open by an opposing bias force acting between the cover and cover base in such manner as to reduce the force required to open a relatively heavy cover whose weight exceeds the maximum single person lifting weight permitted by OSHA and union regulations to a value equal to or less than such maximum lifting weight. A manually releasable latch prevents uncontrolled closure of the cover by gravity in the event of failure of the bias force.

Abstract: A cabinet housing electronic equipment which utilizes a door mounted to hydraulic lifts and a door stay to keep the door from closing if the lifts fail. Special troughs are also provided to protect craftspeople during a rainstorm and to keep water from electronic equipment and areas where it might cause the door to freeze shut.

Abstract: A closure apparatus for a subsurface pit for servicing an aircraft located beneath an aircraft servicing surface across which aircraft travel is provided with an improved spring biasing arrangement. The system employs separate springs interposed between the hollow body of the pit and the lid so as to urge the pit lid from its horizontal seated position toward a fully raised position. Obstructions are provided for separately intercepting and disengaging the springs from acting against the pit lid as the pit lid is opened through intermediate angular positions between the horizontal seated position and the fully raised position. By sequentially isolating the pit lid from the action of each of the springs, one at a time, the moment of spring force opposing closure of the lid more closely follows the moment of the force of gravity tending to close the lid. This substantially reduces the maximum manual force that is thereby required to overcome gravity in opening the pit lid.

Abstract: A counterbalanced window operator includes a housing in which a rotatable lead screw, rotated by a crank handle or electric power unit, cooperates with a non-rotatable nut member to axially displace the nut member and move pivoting arms to open and close the window.

Abstract: A port assembly for a marine vessel, including a lens element and three concentric stainless steel rings which are superimposed upon one another. A first of the rings includes a base portion forming an outer trim ring, a second portion which is generally parallel to the base portion and a sloping riser which defines an angle of between 105.degree. and 135.degree. with a base portion. The sloping riser also connects the base portion and the second portion. A second of the stainless steel stampings also includes a stepped cross-section with two risers and an intermediate potion connecting the two risers. The second of the risers also includes a sloped portion which is welded to the sloped portion of the sloped riser. A third stainless steel stamping, or clamping ring, is bolted to the intermediate portion of the second riser and, together with the base portion of the first ring, form a clamp for securing the port assembly to the wall of the vessel.