Abstract: A refrigerator includes a refrigerating chamber, a damper for opening and closing a cooling air supply channel, and an actuator for displacing the damper. A spring biases the damper closed. The actuator includes a rotary knob which rotates a cam disk. Rotation of the cam disk in one direction opens the damper against the spring bias. The knob includes a plurality of recesses which are selectively engageable by an elastic pin to yieldably retain the knob in various positions of damper adjustment.

Abstract: A cold air circulating method and apparatus for an indirect-cooling type refrigerator which supplies the whole cold air from an evaporator only to a freezer compartment, discharges most of the cold air circulated within the freezer compartment into a fresh food compartment, while the rest of the cold air in a small amount is sucked into the evaporator, and returns the cold air circulated within the fresh food compartment into the evaporator. The apparatus includes an air duct for supplying the whole cold air from the evaporator only to the freezer compartment and a guide opening for discharging most of the cold air circulated within the freezer compartment into the fresh food compartment. This method and apparatus enable the effective use of the cold air and enhance freezing efficiency of the refrigerator.

Abstract: The air circulation system includes a fan unit for discharging filtered ambient air below a predetermined temperature into a walk-in cooler through a damper and exhausting warm air out of the walk-in cooler through a damper by using a discharge fan with the supply fan and discharge fan being controlled by an accustat. The fans, inlet filter and damper are incorporated into a generally rectangular housing that can be easily installed in a wall of a walk-in cooler or other similar enclosure with the air supply being ducted if desired.

Abstract: A portable refrigerating/heating apparatus comprises a heat exchanging portion and a preserving portion, which assure the cooling state and the heating state of the foodstuff and are separable from each other, in which a preserving portion for storing the storage goods in its enclosed hollow space is removably placed on the upper surface of said heat exchanging portion provided with the heat exchanging member and the blowing member, the air heat-exchanged by the heat exchanging member is forcedly blown by the blowing member into the preserving portion while being discharged through the heat exchanging means therefrom to the outside so as to cool or heat the storage goods, and then the preserving portion is separated from the heat exchanging means to be portable.

Abstract: An air flow control for a multi-port refrigerator duct that conveys cold air from the evaporator chamber to a plurality of storage chambers within the fresh food compartment. The duct has a baffle providing individual branches for each storage chamber such that each is substantially coupled directly to the evaporator chamber so that a change in air flow in one branch does not significantly affect the flow in the opposite branch. A manually operated control is mounted within the fresh food compartment and has a face plate with a vent aligned with a liner input aperture communicating with the duct. A shutter disc is captured between the face plate and the liner, and has a tear drop opening. Rotation of the shutter disc alters the location of the tear drop opening and, thus the size of the passageway through the air flow control.

Abstract: Refrigerator duct apparatus adapted for conveying cold air from the evaporator chamber within the freezer liner to a intermediate temperature storage chamber within the fresh food liner. The duct is coupled to an outlet aperture in the freezer liner using and adjustable joint that permits motion of the duct for alignment of the outlet port of the duct to an inlet aperture in the fresh food liner. Specifically, the inlet port of the duct has a mating flange with ears that are insertable through the outlet aperture in the fresh food liner in a predetermined rotational orientation. After insertion, the duct is rotated so that the ears engage peripheral portions of the outlet aperture. A dimension of the outlet aperture is larger than a corresponding dimension of the mating flange to permit the duct to be moved back and forth while the ears remain in sliding engagement on the peripheral portions to align the duct outlet port to the inlet aperture of the fresh food liner.

Abstract: The guide apparatus comprises a fan diverging evaporator cooling air into a freezing compartment and a refrigerating compartment, an intaking chamber 5 having the fan 5 mounted at center of therein and encircled part of the fan with a first outside wall and a second outside wall, an incoming passage for the refrigerating compartment and an incoming passage for the freezing compartment individually feeding cooling air into the refrigerating compartment and the freezing compartment, an inside wall formed integrally with the top end of first outside wall at top end portion of the inside wall, a shutter housing having the first outside wall of the intaking chamber encircling part of the fan and the inside wall formed integrally with the top end of the first outside wall at top end portion of the inside wall, the second outside wall facing to the first outside wall and placing the fan between the second outside wall and the first outside wall, the outside walls being flushed with one another, a shutter having a co

Abstract: A comestible storage compartment for a refrigeration unit including a drawer slidably received in a supporting frame. The drawer is molded in the form of a tub having a bottom wall, side and end walls and a front wall lip. A front wall panel is disposed in a free standing relationship on the front wall lip approximate the forward edges of the side walls. A front wall cover is disposed over the front wall panel and is secured to the forward edges of the side walls to hold the panel on the lip.A lateral flange projects outwardly from the side walls and includes a downturned lip for defining a drawer track channel. Inwardly directed ribs extend longitudinally from the drawer frame and are disposed for spaced flow interrupting relationship with the lip on the lateral flanges.

Abstract: A box member for refrigerate transportation for containing perishables therein and transporting thereby. A gas fed from a refrigerating unit flows from above to below through a gas flow path and gas flow holes of an insulating plate in the vicinity of a ceiling of the box member. A damper device for closing the gas flow path during defrosting is provided in the vicinity of an inlet of the gas flow path. An air shut-off curtain which is suspended from the ceiling and a protecting mechanism thereof are provided at the rear portion of the box member. A water tank is provided at the inside of a front corner post, and a level gauge for visually confirming the water level of the water tank and a water feed port to the water tank are provided at the outside of the front corner post. The level gauge is provided with a discharge valve and a protective net.

Abstract: A refrigerated fixture which has an opening for enabling access to the interior of the fixture, the fixture includes a pair of arcuate track members adapted to be mounted in contact with the opening and a side of the fixture, a sectional door mounted between and in the track members for sliding movement between a closed position and an open position. The fixture also includes an evaporator coil for providing refrigerated air, a fan for circulating the refrigerated air, a nozzle disposed around the opening of the fixture, and a switch which when contacted by the door operates the fan for circulating the refrigerated air to be discharged through the nozzle into the opening.

Abstract: An air conditioning system is disclosed which includes a compressor, a condenser, an evaporator, a first fan for the condenser, a second fan for the evaporator, and an oil hydraulic motor for the driving compressor. A rotation transmitting mechanism couples the first and second fans with the oil hydraulic motor to transmit rotational force from the oil hydraulic motor to the first and second fans. A hand operating mechanism is connected through a coupling to an air mix damper which is disposed between the second fan and the evaporator. The hand operating mechanism is operated to control the proportion of the air which passes through the evaporator to the air which does not pass through the evaporator.

Abstract: A refrigerator cabinet has a valve controlling the amount of cooled air flowing from a cooling chamber having an evaporator to a fresh food compartment to control the ratio of the air flow from the cooling chamber to a freezer compartment and the fresh food compartment. The valve is retained in a predetermined position at the time of assembly by a duct cover, which is forward of an evaporator cover in the freezer compartment, having a frangible key on its front wall extend through an opening in a disc of the valve. If a user deems the freezer compartment too hot or too cold, a service person breaks the frangible key with pliers, for example, after removing the duct cover and rotates the valve to one of a plurality of selected positions to change the air flow. The dics has a plurality of notches in its periphery for cooperation with a second key on the front wall of the duct cover to hold the valve in its selected position.

Abstract: An air circulation system for a refrigeration apparatus provides a controllable baffle for selectively opening or closing dual output ports. Particularly, the refrigeration apparatus includes an evaporator and an evaporator fan providing flow of refrigerated air. The fresh food compartment is to be cooled by the refrigerated air. First and second air inlet passages are provided in communication with the fan and upper and lower zones in the compartment for delivering refrigerated air in the compartment. First and second air outlet passages are provided in communication with the compartment and the fan for returning air from the compartment upper and lower zones to the fan. A baffle is mounted at the first and second air outlets and has independent open positions for each outlet allowing movement of air through its associated zone, and a closed position for each outlet preventing movement of air through such zone.

Abstract: A manual air damper control for a refrigerator is provided to convert rotary motion of a control knob disposed on a front panel in the refrigerator compartment into linear motion of an air damper disposed at the rear of the refrigerator compartment to operate the air damper in a limited space. The control includes a cam having a cam shaft on which the control knob is mounted and having a cam surface engaged by a cam following fork formed in one end of a pivot arm. The opposite end of the pivot arm engages a connecting rod which extends from the front of the refrigerator compartment to the rear thereof where the connecting rod engages the air damper to slide the air damper toward and away from the front of the refrigerator compartment.

Abstract: An air conditioning device comprises a refrigerant compression cycle having an electrically driven compressor, an electric motor for driving the compressor, frequency changing means for changing the frequency of a.c. power to be applied to the motor, an outlet port for blowing off conditioned air, flowing direction changing means for changing the flowing direction of the conditioned air from the outlet port, a switch which is actuated by a user when he desires to allow the conditioned air to hit himself directly, and control means for controlling the frequency changing means and the flowing direction changing means, wherein when the switch is actuated during room cooling operation, the control means outputs to the flowing direction changing means a signal for directing the conditioned air from the outlet port in a downward flowing direction.

Abstract: An integral false ceiling for a refrigerated vehicle body using a sealed ductwork, flow restriction and bleed means to provide selective transmission of refrigerated air to one or more cargo compartments in the vehicle body and return of air to an air conditioning unit, enhancing temperature control and minimizing intrusion into the cargo compartments.

Abstract: An air-conditioning system including an air conditioner incorporating a heat exchanger and a fan therein, and duct assembly connecting to the air conditioner for supplying conditioned air to a specific room equipped with the air conditioner and to another room, the duct assembly comprising an auxiliary duct removably attached to a front cover of the air conditioner and a main duct separably connected to the auxiliary duct to extend from the specific room to said another room and having air outlet portions for supplying air to the respective rooms, the auxiliary duct having an air channel for guiding the air discharged from the air outlet of the front cover into the main duct.

Abstract: A crisper humidity control including a shelf having an aperture in the front and a space between the crisper pan and the shelf at the rear to provide flow-through ventilation when both are open. The shelf further includes a laterally slidable shutter for sealing off the front passageway and a damper flap for sealing off the back passageway. A damper actuator arm is linked between the damper flap and the front shutter so that both are operated in unison from a single laterally slidable operator actuable control knob.

Abstract: An injection molded plastic air return hood for a refrigerator fresh food compartment provides an angular opening directed away from an air inlet opening for preventing short circuiting of refrigerated air in the compartment. An air return hood is prevented for each air return outlet opening in the compartment and the opening is directed towards a side wall of the compartment. Accordingly, the refrigerated air from the inlet opening must travel a more circuitous path through the refrigerator compartment, thus providing a more thorough refrigeration effect.

Abstract: A storage pan assembly for a refrigerator, having a humidity control therein, uses only four parts which are assembled together free of any fasteners. A plastic slide member snaps into place in a baffle housing to provide an adjustable baffle. The baffle in turn is held in assembled relation with a front panel, using a latching hook disposed thereon. The front panel slidably mounts on flanges located at the front of a storage pan to provide a storage pan assembly. Openings are provided through the front panel and storage pan, at the baffle, to provide an adjustable air passageway therebetween.

Abstract: A refrigerator is provided which has a compartment to be chilled below the temperature of the remainder of the main refrigerator compartment and which has an openable container therein. The container is provided with apertures therethrough near the front wall such that a stream of temperature conditioned air is caused to flow around the outer surface of the container within the compartment and to flow through the interior of the container, particularly across the inside surface of the front wall, to provide a minimal temperature gradient within the container.

Abstract: A temperature control apparatus for mounting in a transportable body includes a false ceiling having a plurality of ducts defined therethrough. The ducts extend through a single compartment or between two or more compartments when such two or more compartments are defined within the transportable body. A shutter mechanism controls the flow of temperature-treated air flowing between compartments, thereby controlling the temperature in the various compartments. To provide a flow of temperature-treated air into the apparatus, the apparatus includes an air channeling structure which can be adjusted to divert different quantities of air into the apparatus. The temperature control apparatus also includes an air return bulkhead connectible to the transportable body for channeling return air from the false ceiling directly to the unit by which the air is temperature-treated.

Abstract: An air flow system for a refrigerator having a refrigeration system including a condenser, evaporator, compressor, and thermostatic control. A freezer compartment is located at the top of the refrigerator and a fresh food compartment is located below the freezer compartment with the compartments being separated by a partition. An area above the fresh food compartment contains the evaporator and a fan for circulating air through the evaporator, which fan cycles on when the compressor is operating and off when the compressor is not operating. The air flow system includes an air duct having an upper end to receive cold air from the evaporator and a lower end having an air flow control assembly located in the fresh food compartment for discharging cold air into the fresh food compartment.

Abstract: An air conditioner comprises an outer casing containing an inner casing having a heat exchanger disposed therein and a blower so as to define jointly with the inner casing an internal air intake passage. The air conditioner further includes an air intake-discharge selector mechanism disposed in a desired position in communication with the air intake passage for taking air into and out of the air conditioner.

Abstract: A refrigerator having a cold air meat keeper that is adjustable to a plurality of alternate vertical positions. The cold air is introduced into the refrigerated food compartment through a port in the back wall of the liner. The meat keeper, which is suspended below a height-adjustable cantileverly-supported shelf, has an elastic conduit extending rearwardly therefrom. The conduit has an enlarged rear chamber that seals against the liner wall around the port in a plurality of elevational positions. The conduit is compressed in an interference fit to provide a positive sealing force against the liner surface.

Abstract: A shelf unit (3, FIG. 1) for a refrigerator cabinet includes an air flow passageway (6) connectible to a duct (1) located at the rear of the refrigerator. The flow of air through the passageway (6) is regulated by a flap whose movement is controlled by a thermostat (9) also mounted upon the shelf. The shelf unit, when in position in a refrigerator, enables a user to preset the temperature of the zone in the refrigerator cabinet beneath the unit.

Abstract: A refrigerating apparatus is disclosed. The apparatus comprises a housing having at least one food storage compartment. A fan and an evaporator are provided for generating a stream of chilled air. A delivery duct carries the chilled air to a delivery vent opening in the food storage compartment and an air return duct carries air from a return vent opening in the food storage compartment back to the fan and evaporator. A food storage drawer is mounted in the food storage compartment and is slidably movable between an open and closed position. The drawer has inlet and outlet vent openings to positions adjacent the delivery and return vent openings when the drawer is in its closed position. Movable dampers are mounted adjacent each vent opening and are biased toward a closed position blocking the vent openings.

Abstract: The invention relates to a refrigerated counter unit having a counter bed below a storage compartment, wherein a current of recirculated air is deliverd by a blower, following cooling by a heat sink and humidification, to the storage compartment, and from there back to the heat sink. The blower, the heat sink, and a humidifying unit are mounted in a housing outside the counter bed, preferably in a separate subassembly housing of the counter bed. To simplify the construction and improve efficiency, the invention provides that the cooled and humidified current of recirculated air is delivered by inlet air supply ducts to the longitudinal sections of the counter of the storage compartment air is supplied from the housing that receives the blower, the heat sink, and the humidifying unit by means of a plurality of air supply ducts that are separated from one another and extend throughout at least a fraction of the length of the counter bed.

Abstract: The present invention is related to a switching device for selectively controlling the flow of cooling air in a central cooling air duct of a refrigerator of the type having a cold storage space and a freezing storage space. In preferred embodiments, the switching apparatus includes a pivotal flap member disposed in a cooling air duct leading to both the freezing and cold storage spaces. A manually operable control lever is pivotably mounted at a housing attached to the cooling air duct and is interconnected to pivot the control flap valve by means of a connecting pin having one end connected to the control lever and the other end connected to a working lever which is in rotatably fixed with the pivot axis of the control flap.

Abstract: Disclosed is a refrigerator comprising a freezing compartment and a refrigerating compartment in which the freezing compartment can be used as a refrigerating compartment. The two compartments are in close proximity. Means are provided in a cooling-air passage to supply cooling air generated from an evaporator into both of the compartments or selectively only into one compartment.

Abstract: A refrigerator comprising side-by-side freezer and fresh food storage compartments cooled to their respective low and high operating temperatures by the circulation of streams of below-freezing air thereto includes a storage chamber in the fresh food compartment door maintained at an intermediate temperature by conducting air from the freezer compartment through the chamber.

Abstract: A refrigerator having a crisper pan with a back passageway that is always open and a front passageway that is adjustable so that the operator can adjust the amount of flow through ventilation to control the humidity in the pan. The lid for the pan also functions as a refrigerator shelf and the back passageway is defined by a gap between the lid and the back of the pan. The front passageway is defined by a front lid plenum having a floor with a plurality of ports. A slide gate positioned in the plenum has a plurality of windows which, by sliding laterally in the plenum, can be made to respectively align with the ports to enable flow through ventilation. Full or partial sealing of the ports is provided by sliding the slide gate laterally to alter the alignment of the windows with the ports.

Abstract: A refrigerator having a reversible cold air meat keeper for providing convenient access thereto regardless of the side of the refrigerator that the doors are hinged. The cold air is channeled into a plenum behind the back wall of the refrigerator compartment and there are at least two spaced ports communicating from the plenum into the chamber. The cold air meat keeper has a conduit extending from the rear wall thereof. In one predetermined mounting position of the meat keeper, the conduit removably couples with one of the ports for receiving cold air from the plenum. In the alternate predetermined mounting position of the meat keeper, the conduit removably couples with the other port for receiving cold air.

Abstract: A meat keeper compartment includes an adjustable air duct assembly which supplies cold air flow from the evaporator compartment of a top freezer type refrigerator into a meat keeper receptacle slidably mounted on a shelf which may be positioned at different levels or on different sides of the fresh food compartment of the refrigerator. The air duct assembly consists of an air deflector which receives cold air from the freezer through a slot in the partition between the freezer and fresh food compartment, a cold air outlet to deliver cold air into the meat keeper receptacle, an upper air duct having the back wall of the refrigerator form the back wall of the duct, a lower air duct which telescopes with the upper air duct for adjustment of the cold air outlet, and an adjustable air damper for regulation of the amount of cold air flow.

Abstract: Apparatus for controlling the temperature and humidity of air to be conditioned are disclosed. A fan coil unit incorporates a heat exchanger and a bypass area. The bypass area includes a damper assembly for apportioning the air flow between the bypass area and the heat exchanger such that humidity control of the air flowing therethrough may be obtained.

Abstract: An air conditioner system for an automotive vehicle is provided with a main and an auxiliary cooling unit for discharging cooling air to respective front and rear portions of the vehicle compartment. The main and auxiliary cooling units operate to control air flow amounts independently of each other. A main control switch for controlling the amount of cooling air from the main cooling unit cooperates with a pair of auxiliary cooling unit switches to control the auxiliary cooling unit. One member of the pair of auxiliary cooling unit switches is provided adjacent the driver's seat and the other adjacent the rear seat for turning the auxiliary cooling unit on and off. The auxiliary cooling unit can be controlled by either one of the pair of switches as long as the main control switch is on.

Abstract: An air circulation apparatus provided with a plurality of outlet nozzles separating the air flowing from the air circulation apparatus into a plurality of diverging air jet streams. The air circulation apparatus may take the form of a recirculation blower, an air space heater, or a room air conditioner.

Abstract: A refrigerator wherein, in order to prevent cold air within the refrigerator body from flowing out while the door is opened, and air curtain will be formed in the opening of the body when the door is opened but will be removed when the door is closed.

Abstract: A refrigerator having a freezer compartment on top and a fresh food compartment below with an air duct connecting the two compartments. A temperature control system and method of controlling is provided and includes a temperature sensing element located at the top of the fresh food compartment and shielded from the stream of cold air being directed into the fresh food compartment. The temperature sensing element changes the temperature in both the freezer and fresh food compartments without changing the constant ratio of those respective compartment temperatures. An air flow assembly divides the cold air entering the fresh food compartment through the connecting air duct between the top of the compartment and the bottom. The air flow control assembly is arranged to divide the cold air stream such that the ratio of the difference in the freezer and fresh food compartment temperatures is changed.

Abstract: A low cost control regulates air flow between the freezer and food compartments of a side-by-side refrigerator and cooperates with a freezer thermostat to form a system which regulates operation of the refrigerator compressor in an energy efficient manner. A spiral coil spring of thermostat metal material has its inner end secured to a damper shaft to bias damper movement between positions opening and closing a control housing orifice in response to changes in temperature. A cylinder fitted around and secured to the outer end of the spring coil rotates to adjust the spring bias for selectively changing the temperature setting of the control. A control arm has a split sleeve at one end releasably clamped to the cylinder at a selected angle for initially calibrating the control and system, the opposite arm end being slidable on the control housing to rotate the arm for selectively varying the spring bias.

Abstract: A refrigerated display case having a display section within a cabinet and movable door covering the access opening to such display section. The cabinet has top, bottom, rear and side walls with an access opening in its front, which opening is covered by the door. An air conduit extends along the top, bottom and rear walls of the cabinet. The air conduit has an outlet opening and an inlet opening at opposing ends thereof with the openings being in alignment so that air leaving the outlet opening will be directed towards and received by the inlet opening thereby forming an air curtain across the front opening of the cabinet along the path inside the door. During a refrigeration cycle of operation of the display case, refrigerated air is circulated through the air conduit and a refrigeration mechanism arranged within the conduit by a positive pressure air flow so as to establish a refrigerated air band and a refrigerated air curtain across the front opening in the cabinet.

Abstract: A refrigerator having a humidity controlled pan assembly which includes a storage pan having an open top and a stationary cover inside the refrigerator for receiving the pan. A cover panel within the stationary cover is movable back and forth along the top of the pan by a movable control mechanism and linkage between the control mechanism and the cover panel that moves the cover panel back and forth along the top of the pan in response to movement of the control mechanism. With this arrangement, the user of the refrigerator may move the control mechanism to increase or decrease the amount of ventilation and, thus, control the humidity inside the pan.

Abstract: An air flow control assembly in a refrigerator having a freezer compartment on top and a fresh food compartment on the bottom separated by a partition and interconnected by an air duct located at the rear of the compartments. The air duct has an air inlet opening in the freezer compartment and an air outlet opening in the fresh food compartment. A movable damper opens and closes the air duct outlet opening and a storage pan is located in air flow communication with the air duct outlet opening. The storage pan has a stationary cover. There is a movable control mechanism located at the front of the storage pan, a push rod linkage member cooperating at one end with the damper to open and close the air duct outlet opening upon movement of the push rod linkage member and the other end is connected to the control mechanism for moving the push rod linkage member.

Abstract: A heat sink (50), on which is mounted heat producing elements, such as transistors (40-43), is contained entirely within a cabinet (10) provided with openings (20, 27) positioned directly below and above the heat sink. The heat sink includes a rectangular plate (52) with the transistors mounted on one side and a plurality of integrally formed parallel fins (60) projecting laterally from the plate on the other side and extending diagonally thereacross. The heat sink may be convection cooled by air entering the openings (22) in the bottom of the cabinet and exiting through openings (27) in the top, or the heat sink may be forced air cooled by means of a fan (75) mounted the rear panel (16) which draws air through the openings (22) and across the fins (60).

Abstract: A refrigerator having a freezer compartment on top and a fresh food compartment below with an air duct connecting the two compartments. A temperature control system and method of controlling is provided and includes a temperature sensing element located at the top of the fresh food compartment and shielded from the stream of cold air being directed into the fresh food compartment. The temperature sensing element changes the temperature in both the freezer and fresh food compartments without changing the constant ratio of those respective compartment temperatures. An air flow assembly divides the cold air entering the fresh food compartment through the connecting air duct between the top of the compartment and the bottom. The air flow control assembly is arranged to divide the cold air stream such that the ratio of the difference in the freezer and fresh food compartment temperatures is changed.

Abstract: A horizontal supply conveyor carrying a board with a number of loaves of cheese thereon is mounted for vertical adjustment in front of the open ends of a multiplicity of horizontal guideways disposed in superimposed and in juxtaposed relationship. By selective adjustment and selective operation of the conveyor the board is moved into registry with a selected one of said guideways whereupon a pushing device pushes the board from the conveyor and into the guideway in which similar loaded boards are stored the last one of which is thus discharged from the rear of the selected guideway onto another conveyor to be moved back to the first conveyor by transporting means which include a device for turning over the loaf. The walls separating adjacent units constitute ducts for the supply and discharge of air to the guideways accommodating the loaves of cheese.

Abstract: An airflow moisture control for use with a refrigerator food storage hydrator drawer cover and guide that enables the user to vary the amount of moisture therein by adjustable side vents. The manual control includes a damper and integral hinge pin with cooperating flexible arcuate fingers extending through the vents having surfaces thereon for engaging the edge portions of their associated vents so as to impart positioned stability for selectively rotating the damper in any one of a plurality of angularly related positions. The dampers are interchangeable for hingedly engaging the cover for either left or right side operation.

Abstract: The present invention includes a ventilator for use in equalizing pressures within and without an enclosure, such as a coldroom or the like. A heated valve assembly is situated within an enclosure wall opening such that it is freely exposed to both environmental and internal fluid air pressures. A fluid impervious wall formed with inlet and outlet ports therethrough is partially covered by inner and outer closure members, both of which are supported and keyed by a common rod or shaft. These closure members are each biased by a common helical spring toward sealed and closed positions in which the inlet and outlet ports are covered. Pressure differentials are equalized by displacement of at least one of said closure members, thereby permitting air flow through one of the respective ports. By preselecting the spring rate of the helical spring, the minimum forces required to displace the closure members are controlled and predetermined.

Abstract: A lever for operating a damper door of an air conditioner includes a rotatable shaft extending through an orifice of a wall in the air conditioner, the shaft having a pair of spaced collars for receiving therebetween the edges of the wall which define a slot receiving the lever. One collar is slightly bowed and has a tooth which engages an edge of the orifice to hold the lever in place in the wall when the shaft has been positioned in the slot.