Patent Description:
Many temperature controlled commercial enclosed spaces need to be equipped with pressure relief ports or vents which are sometimes referred to as ventilators or ventilator ports. This is particularly true where the sealed space is subjected to temperature related air volume variations that must be relieved, such as a cold room.

Cold rooms typically have a neutral air pressure. To achieve the neutral air pressure the cold room is fitted with passive ports or vents. However existing passive pressure relief ports, meaning those without fans or blowers, have often permitted unwanted air migration where there is no significant pressure differential. With walk-in freezers this air intrusion may cause undesirable condensation and frosting. Frosting is a substantial problem that occurs when ambient warm air drawn into a low temperature chamber releases significant amounts of moisture relative to the change in dew point of the air at high and low temperatures. Air is drawn through the port after each door opening cycle wherein the warm air that entered the enclosure cools and contracts within the cold environment of the enclosure. If venting does not occur, a partial vacuum results within the enclosure which makes it difficult to reopen the door. In extreme cases, the enclosures can even collapse.

A temperature rise in the enclosure between cooling cycles, and especially during a defrost cycle, creates a need to vent air to the exterior to prevent pressure buildup. Again, failure to vent this pressure, with adequate relief capacity, can cause the chamber to rupture.

Passive pressure relief ports are in wide commercial use today. Large structures require the movement of a large amount of air to equalize the pressure between the interior and the exterior of the enclosure. Existing commercial use vents can be either a large sized vent or a gang of small sized vents. <CIT> discloses a cold room vent. This large amount of air movement carries with it a large amount of moisture. This moisture can condense almost immediately upon contact with the cold air and cold surfaces of the enclosure. If this occurs, a large ice block may form on the interior wall, which may eventually block the inflow of air through the port. This large ice block may also pose a potential danger to someone should it fall from the wall and strike the person. Also, the use of large vents within small rooms causes a low velocity flow of air to enter the room.

This low velocity air flow is more susceptible to freezing the moisture within the airflow upon entering the cold room.

Another problem with cold rooms is that high negative pressure may be dangerous as the warm air entering the cold room enters the cold room with the entrance of a person. The entering warm air subsequently cools and creates a negative pressure within the cold room as it condenses. This negative pressure may hold the door in a closed position until the pressure within the room normalizes. A person within the cold room may become panicked when unable to open the door. Today's vents alleviate small amounts of incoming warm air, but are inadequate to deal quickly with large volumes of warm air associated with multiple door entries or large sliding doors.

Another problem is the icing of certain valves associated with vents of cold rooms. Moisture entering the cold room may condense as ice upon the valves, thereby preventing them from functioning properly. One solution to this problem has been to simply chip the ice off the valve or remove it with the use of a heat gun. These solutions are time consuming and inadequate as it may damage the vent, cause bodily injury, and be only effective once the problem is discovered. As such, some vents have included resistive heaters. However, should the heater fail, the problem will go unresolved until the vent heater is repaired.

Yet another problem with some static valves has been that they operate and are adjusted to open at a select pressure gravitationally by adjusting the weight of a movable valve portion (poppet valve), i.e., the valves are gravitationally set and operated by their own weight, as shown in <CIT>. <CIT>, <CIT>, and <CIT> also disclose gravitationally-operated pressure relief devices. However, large air movements, such as wind or even a door closing, may cause the valve to open or flutter. This fluttering of the valve may cause it to open unnecessarily when a need for ventilation does not truly exist. The opening may also cause the valve to remain open for more time than necessary, thereby creating an icing of the valve which increases over time due to the valve remaining in an open condition.

The adjusting of the pressure by having different sized weights also increases costs associated with the vent. The different sizing of components increases the amount of inventory a supplier must carry, increase the number of components required to assemble the vent, and creates a potential for mistakenly utilizing the wrong component.

Lastly, a problem with these gravity valve devices has been that they are designed to operate in only one orientation, as they are mounted to operate with the valve positioned vertically. As such, an installer may need to inventory different models for different orientations of the valve housing based on its mounted orientation, thereby increasing expenses for the installer.

Accordingly, it is seen that a need exists for a pressure release vent that prevents the formation of ice, which is easily mounted in different orientations, and which allows for different amounts of air flow. It thus is to be provision of such a vent that the present invention is primarily directed.

A cold room vent according to the present invention is provided according to claim <NUM>.

With reference next to the drawings, there is shown a combination light and pressure relief ventilator or vent <NUM> in a preferred form of the invention, referred to hereinafter simply as vent. The vent <NUM> is used with a temperature controlled enclosure, such as a freezer, refrigerator or other cold room, all of which are referred collectively herein as cold room.

The vent <NUM> includes a mount or main housing <NUM>, a valve assembly <NUM>, and a light assembly <NUM>. The housing <NUM> includes a thermal valve body <NUM>, a port tube <NUM>, and an outside louver <NUM>. The housing <NUM> is typically mounted to the wall of the cold room with the port tube <NUM> mounted to the inside surface of the wall and the outside louver <NUM> mounted to the outside surface of the wall. The port tube <NUM> has a top wall <NUM> and a bottom wall <NUM>. The housing <NUM> is typically made of a plastic material or the like.

The housing port tube <NUM> includes a generally cylindrical valve housing portion <NUM> adjacent to a generally rectangular portion <NUM>. The port tube <NUM> also has an ancillary electrical conduit portion <NUM> adjacent the rectangular portion <NUM>. The port tube <NUM> also has an outwardly extending peripheral mounting flange <NUM> having four mounting holes <NUM> therethrough which receive mounting screws. The cylindrical portion <NUM> has a first opening <NUM> which includes an octangular receiver <NUM>, and a second opening <NUM> oppositely disposed from the first opening <NUM> to form a channel <NUM> therebetween. The cylindrical portion <NUM> is configured to telescopically house or receive the valve assembly <NUM> within the channel <NUM>, as described in more detail hereinafter.

The valve body <NUM> has a central tube portion <NUM> having an air passage opening <NUM> surrounded by an outwardly extending, octangular, peripheral mounting flange <NUM> sized and shaped to removably nest within and in register with the octangular receiver <NUM> of the housing cylindrical portion <NUM> in several orientations as described in more detail hereinafter. The valve body <NUM> defines an interior heat chamber <NUM> therein. The valve body <NUM> has a top wall <NUM> with a first low positive pressure exhaust port <NUM> therethrough, and a second high positive pressure exhaust port <NUM> therethrough. The first low positive pressure exhaust port <NUM> is the same size and shape or configuration as the second high positive pressure exhaust port <NUM>. The valve body <NUM> also has a bottom wall <NUM> with a first low negative pressure intake port <NUM> therethrough, and a second high negative pressure intake port <NUM> therethrough. The first low negative pressure intake port <NUM> is the same size and shape or configuration as the second high negative pressure intake port <NUM>. Each port <NUM>, <NUM>, <NUM> and <NUM> has a central bar <NUM> with a valve mounting hole <NUM> therein. The top wall <NUM> is removably coupled to the bottom wall <NUM> and secured thereto through manually actuated clasps or clamps <NUM>, for ease of opening and disassembling the valve assembly <NUM>.

The outside louver <NUM> has an outwardly extending mounting flange <NUM> with mounting holes <NUM> therein through which mounting screws extend to couple the louver <NUM> to the outside surface of the cold room. The louver <NUM> includes a drip deflecting hood <NUM> and a screen <NUM> therein to prevent the entrance of dirt, foreign object, insects or other pests.

The valve assembly <NUM> is coupled to and may be considered to be a portion of the valve body <NUM>. The valve assembly <NUM> includes a first low positive pressure exhaust valve <NUM> having a mounting stem <NUM> extending through the valve mounting hole <NUM> of the first low positive pressure exhaust port <NUM>, a second high positive pressure exhaust valve <NUM> having a mounting stem <NUM> extending through the valve mounting hole <NUM> of the second high positive pressure exhaust port <NUM>, a first low negative pressure intake valve <NUM> having a mounting stem <NUM> extending through the valve mounting hole <NUM> of the first low negative pressure intake port <NUM>, and a second high negative pressure intake valve <NUM> having a mounting stem <NUM> extending through the valve mounting hole <NUM> of the second high negative pressure intake port <NUM>. Valves <NUM>, <NUM>, <NUM> and <NUM> are all considered to be air flow control valves and all include, in addition to the stem, a conventional configuration with a head. The end of the stem of each valve <NUM>, <NUM>, <NUM> and <NUM> is coupled to one or more circular weights <NUM> through a mounting screw <NUM> which gravitationally bias each valve towards a closed position. The weight or mass of each weight <NUM> determines the pressure necessary to move the valve <NUM>, <NUM>, <NUM> and <NUM> from a closed position to an open position, illustrated by the comparison of open positioned valve <NUM> in <FIG> and closed positioned valve <NUM> in <FIG>. Each combination valve, valve mounting stem, weight and seat should be consider a valve assembly or valve sub-assembly. As used herein, the terms gravity operated, gravity biased, gravity actuated, gravitationally, gravitationally biased, or the like is intended to denote the biasing force, actuation, or movement of a valve which is generally dependent upon weight to reset the valve to a closed position, as opposed to a spring loaded valve which uses a spring biasing force to reset the valve to a closed position.

The difference in the mass or weight of the weights <NUM> allows the valves <NUM>, <NUM>, <NUM> and <NUM> to be the same construction, size, shape or configuration to aid in manufacturing, inventory and installation, yet allows for different opening pressures for each, i.e., first low positive pressure exhaust valve <NUM> and first low negative pressure intake valve <NUM> open first due to the biasing weight being less than that of the second high positive pressure exhaust valve <NUM> and second high negative pressure exhaust valve <NUM>, depending upon whether there is a positive or negative pressure change within the cold room.

The light assembly <NUM> includes a rectangular shaped LED heat sink plate or casing <NUM> which is configured to telescopically fit within the mounting flange <NUM> of the valve body <NUM>, so as to enclose and thereby form the heat chamber <NUM> through the combination of the casing <NUM>, port tube <NUM> and valve body <NUM>. The casing <NUM> is preferably made of a high thermally conductive metal, such as aluminum. The casing <NUM> is maintained in position by casing mounting screws <NUM> passing through mounting holes <NUM>. The casing <NUM> has an exterior front wall or surface <NUM>, to which is mounted an LED module <NUM> containing a plurality of LED diodes <NUM>. The front wall or surface <NUM> includes air passages, vent openings, or vents <NUM> therethrough. A gasket <NUM> is position between the casing <NUM> and the front surface port tube <NUM>. A transparent or translucent lens or lens cover <NUM> is coupled to the front surface <NUM> of the casing to cover the LED module <NUM> through lens cover mounting screws <NUM>. A lens gasket <NUM> is positioned between the lens cover <NUM> and the front surface <NUM>. An LED driver <NUM> is electrically coupled to the LED module <NUM>. The LED driver <NUM> is positioned within the housing rectangular portion <NUM> and coupled to a source of electric current, such as a conventional A.

The heat sink casing <NUM> also includes an interior or rear surface <NUM> opposite from the front surface <NUM>. The rear surface <NUM> has a large, trapezoidal or pyramid-shaped projection or projecting portion <NUM> which extends from between two adjacent vent openings <NUM> and through air passage opening <NUM> and at least partially into the heat chamber <NUM>, as specifically into the valve body <NUM>, as shown in <FIG>. The projecting portion <NUM> extends or tapers down from the heat sink casing <NUM> from the rear surface between two adjacent vent openings <NUM> to a position distal the heat sink casing <NUM>, so that airflow through the vent openings is directed onto the projecting portion <NUM>.

An electrical cover plate <NUM> is coupled to and encloses the electrical conduit portion <NUM> of the port tube <NUM> with a gasket <NUM> positioned therebetween. The cover plate <NUM> is maintained in position by mounting screws <NUM>. The cover plate <NUM> includes two conduit openings <NUM> which are fitted with removable plugs <NUM>.

In use, the vent <NUM> is mounted to the wall of a cold room with the port tube <NUM> mounted to the interior surface and the outside louver <NUM> mounted to the exterior surface of the cold room wall. The vent <NUM> allows for a flow of air both into and out of the cold room to ambience through dual stage venting of pressure changes within the cold room. Should the cold room door be opened and a small amount of air is introduced into the cold room (small volume) and subsequently condense to create a negative pressure, the first low negative pressure intake valve <NUM> overcomes the gravitational biasing force of its weights <NUM> to move to an open position (as shown by the valve position in <FIG>) allowing air through the first low negative pressure intake port <NUM>, through valve body opening <NUM>, and through casing air passages <NUM> into the cold room. Thus, the opening of the first low negative pressure intake valve <NUM> allows the entrance, flow, or passage of a small volume of air into the cold room to offset the condensing of the small volume of warm air which creates a negative pressure. The first low negative pressure intake valve <NUM> commences opening at a negative pressure level of at least or approximately <NUM> Pa (<NUM> inches of water). The valve allows a flow rate of <NUM><NUM>/h (<NUM> CFM) at <NUM> Pa (<NUM> inches of water).

Should the cold room door be opened and a large amount of air is introduced into the cold room (high volume), both the first low negative pressure intake valve <NUM> and the second high negative pressure intake valve <NUM> sequentially overcome the biasing forces of their weights <NUM> to each move to their open positions allowing the flow of air therethrough and subsequently through valve body opening <NUM> and casing air passages <NUM>, as shown by the arrows in <FIG>. The opening of both the first low negative pressure intake valve <NUM> and the second high negative pressure intake valve <NUM> allows the entrance or passage of a large volume of air into the cold room in a very fast manner to offset the condensing of the large volume of warm air which creates a large negative pressure. The second high negative pressure intake valve <NUM> may be thought of as a second stage valve when a large amount of air is needed to be taken in to relieve the pressure within the cold room. The process commences with the first low negative pressure intake valve <NUM> opening as previously described. With the high volume of air, the second high negative pressure intake valve <NUM> then commences opening at a negative pressure level of at least or approximately <NUM> Pa (<NUM> inches of water). The second high negative pressure intake valve <NUM> allows a flow rate of <NUM><NUM>/h (<NUM> CFM) at <NUM> Pa (<NUM> inches of water). The quick equalization of the pressure through the opening of both intake valves <NUM> and <NUM> prevents the cold room door from being stuck closed due to a large negative pressure within the cold room, which minimizes the potential of one panicking due to the inability to temporarily open the door.

As the room equalizes from the experience of the high negative pressure, the second high negative pressure intake valve <NUM> will first return to its seated position once the air pressure returns to a level below approximately <NUM> Pa (<NUM> inches of water). The air pressure within the cold room continues to rise by air passing through the first low negative pressure intake valve <NUM> until the pressure reaches approximately <NUM> Pa (<NUM> inches of water), wherein the first low negative pressure intake valve <NUM> will also move to its closed position. The end results is a cold room which is generally at a neutral pressure after the entrance of a large volume of warm air and its subsequent condensing upon cooling.

When a positive pressure occurs within the cold room, the first low positive pressure exhaust valve <NUM> overcomes the biasing force of its weights <NUM> when a small amount of positive pressure exists within the cold room (as shown by the valve position in <FIG>). The first low positive pressure exhaust valve <NUM> opens at a positive pressure level of at least or approximately <NUM> Pa (<NUM> inches of water). The first low positive pressure exhaust valve <NUM> allows a flow rate of <NUM> m3/h (<NUM> CFM) at <NUM> Pa (<NUM> inches of water). The cold room may experience positive pressure when one slams a door shut or when the air therein warms, such as when the cold room is going through a defrost mode. This positive pressure may prevent the full closing of the refrigerator door.

Should the cold room door be slammed or defrost mode activated so as to create a large positive pressure within the cold room (high volume), both the first low positive pressure exhaust valve <NUM> and the second high positive pressure exhaust valve <NUM> sequentially overcome the biasing forces of their weights <NUM> to each move to their open positions allowing the flow of air through casing air passages <NUM>, valve body opening <NUM>, exhaust valves and out louver <NUM>, as shown by the arrows in <FIG>. The opening of both the first low positive pressure exhaust valve <NUM> and the second high positive pressure exhaust valve <NUM> allows the exit or exhausting of a large volume of air from the cold room in a very fast manner to offset the introduction or expansion of the large volume of air which creates a large positive pressure. The second high positive pressure exhaust valve <NUM> may be thought of as a second stage valve when a large amount of air is needed to be exhausted relieve the positive pressure within the cold room. The process commences with the first low positive pressure exhaust valve <NUM> opening as previously described. With the high volume of air, the second high positive pressure exhaust valve <NUM> then commences opening at a positive pressure level of at least or approximately <NUM> Pa (<NUM> inches of water). The second high positive pressure exhaust valve <NUM> allows a flow rate of <NUM> m3/h (<NUM> CFM) at <NUM> Pa (<NUM> inches of water). The quick equalization of the pressure through the opening of both exhaust valves <NUM> and <NUM> allows the cold room door to close properly by eliminating the positive pressure within the cold room.

As the room equalizes from the experience of the high positive pressure, the second high positive pressure exhaust valve <NUM> will first return to its seated position once the air pressure returns to a level of approximately <NUM> Pa (<NUM> inches of water). The air pressure within the cold room continues to drop by air passing through the first low positive pressure exhaust valve <NUM> until the pressure reaches approximately <NUM> Pa (<NUM> inches of water). wherein the first low positive pressure exhaust valve <NUM> will also move to its closed position. The end results is a cold room which is generally at a neutral pressure after the entrance of a large volume of air or expansion of air within the cold room.

Thus, the flow or venting of air into the cold room is controlled by at least two negative pressure intake valves while the flow of air out of the cold room is controlled by two positive pressure exhaust valves.

The vent is preferably designed so that the LED module <NUM> is always energized to provide constant light within the cold room. The use of LED lights facilitates this due to their low power consumption. The heat generated by the constantly illuminated LED module <NUM> thermally passes through the heat sink casing <NUM>, i.e., the LED module is in thermal communication with the LED heat sink casing <NUM>. This heating of the LED heat sink casing <NUM> constantly warms the air within the interior heat chamber <NUM> of the port tube <NUM>, and specifically within the valve body <NUM>, and thus warms the exhaust valves <NUM> and <NUM> and intake valves <NUM> and <NUM>. The warming of the valves prevents the formation of ice upon the valves which would prevent them from properly opening or closing, i.e., prevents the valves from freezing in place within their respective ports. It should be noted that this heating is economical as the cold room should be constantly illuminated regardless.

The projecting portion <NUM> extends into the interior heat chamber <NUM> and specifically into the valve body <NUM> through valve body opening <NUM> to warm the air to a higher degree, as the air passes over a larger warmed surface area of the heat sink casing <NUM>.

The octangular shape of the valve body mounting flange <NUM> allows the valve body <NUM> to be positioned or repositioned within the octangular receiver <NUM> in any of the eight positions (radial or angular orientations) in which the mounting flange <NUM> fits or is register within the receiver <NUM>. These eight positions are eight different radial orientations relative to the octangular receiver, port tube, or main house, as the valve body may be rotated about an axis extending longitudinally along the center of the valve body, i.e., set at different radial or angular orientations. This flexibility in mounting the valve body <NUM> relative to the port tube <NUM> allows the port tube <NUM> to be mounted in a variety of different radial or angular orientations or positions while still allowing the valve assembly <NUM> to properly gravitationally actuate by positioning the valve body <NUM> in a horizontal position depicted in the drawings. For example, the port tube <NUM> may be positioned horizontally with the top wall <NUM> facing upwardly as shown in the drawings. Alternatively, the port tube <NUM> may be positioned horizontally with the top wall <NUM> facing downwardly (inverted from the depiction in the drawings), here the housing <NUM> would be mounted in an inverted position compared to the drawings, so that the valve body actually has the top wall positioned on the top, as shown in the drawings, which is also true of the other orientations describer hereinafter. Alternatively, the port tube <NUM> may be positioned vertically with the top wall <NUM> oriented vertically and facing to the right (turned <NUM> degrees counterclockwise from the depiction in the drawings). Alternatively, the port tube <NUM> may be positioned vertically with the top wall <NUM> oriented vertically and facing to the left (turned <NUM> degrees clockwise from the depiction in the drawings. Also, the port tube <NUM> or may be positioned to any of the four positioned between these horizontal or vertical positions (turned at <NUM> degree angles from the just described four positions). With each of the eight positions (angular orientations) of the port tube mounting flange <NUM>, the port tube mounting flange <NUM> is still positioned to be nested within the octangular receiver <NUM> with the valve body <NUM> oriented horizontally, as depicted in the drawings, so that the gravitational valves are still oriented vertically for proper gravitational actuation upon a change in air pressure.

It should be understood that other shapes of flanges and receivers may also be designed which may provide more or less multi-radial varied positions. For example, a square flange and receiver would provide four multi-radial orientations for the mounting of the port tube <NUM> and consequently relative mounting multi-radial positions of the valve body <NUM>. Thus, the receiver <NUM> and mounting flange <NUM> may be considered to have a multi-radial symmetrically shape as they each have a shape which allows for different radial angles or different radial nesting therebetween.

The first low positive pressure exhaust valve <NUM>, the second high positive pressure exhaust valve <NUM>, the first low negative pressure intake valve <NUM>, and the second high negative pressure intake valve <NUM> all have the same size and shape or configuration so that any valve may be fitted to any related port <NUM>, <NUM>, <NUM> and <NUM>. This reduces inventory needs, reduces the cost of manufacturing, and eases the maintenance of the vent <NUM>. It should be understood that as an alternative, the flange receiver <NUM> and corresponding mounting flange <NUM> may be of a shape, such as circular, to allow the flange <NUM> to be rotated relative to the receiver <NUM> and maintained in its relative radial position be a screw or other coupler.

It should be understood that the combination of a light and vent also reduces cost and labor as both features are achieved through the mounting of a single unit which includes both functions.

It should also be understood that the light assembly is considered to be a heat assembly, as the light assembly creates heat. However, as an alternative to the LED light source shown in the preferred embodiment, the vent may include other types of commonly known heat assemblies, such as an electrically resistive element or non-LED light sources.

It should be understood that the projection <NUM> and the removable feature of the valve body with the receiver <NUM> and flange <NUM> of the present invention may be used with non-gravitational actuated valves.

Claim 1:
A cold room vent (<NUM>) comprising:
a housing (<NUM>) mountable to a cold room structure, said housing (<NUM>) having a first pressure exhaust port (<NUM>) and a second pressure exhaust port (<NUM>);
a gravity biased first pressure exhaust valve (<NUM>) mounted to said first pressure exhaust port (<NUM>) having a first weight which allows the opening of said gravity biased first pressure exhaust valve (<NUM>) at a first air pressure level, the first pressure exhaust valve (<NUM>) comprising a first mounting stem (<NUM>) extending through a valve mounting hole (<NUM>) of the first pressure exhaust port (<NUM>), the first pressure exhaust valve (<NUM>) further comprising a head, the first weight comprising one or more weights (<NUM>) coupled to the end of the first mounting stem (<NUM>), wherein the one or more weights (<NUM>) gravitationally bias said first pressure valve towards a closed position; and
characterized by
a gravity biased second pressure exhaust valve (<NUM>) mounted to said second pressure exhaust port (<NUM>) having a second weight which allows the opening of said gravity biased second pressure exhaust valve (<NUM>) at a second air pressure level greater than said first air pressure level, the second pressure exhaust valve (<NUM>) comprising a second mounting stem (<NUM>) extending through a valve mounting hole (<NUM>) of the second pressure exhaust port (<NUM>), the second pressure exhaust valve (<NUM>) further comprising a head, the second weight comprising one or more weights (<NUM>) coupled to the end of the second mounting stem (<NUM>), wherein the one or more weights (<NUM>) gravitationally bias said second pressure exhaust valve (<NUM>) towards a closed position,
whereby the gravity biased first pressure exhaust valve (<NUM>) opens the first pressure exhaust port (<NUM>) at the first air pressure level and the gravity biased second pressure exhaust valve (<NUM>) opens the second pressure exhaust port (<NUM>) at the second air pressure level.