THERMAL DOOR SYSTEM

Abstract: A thermal door system (10) is provided with a door member (11) formed as a planar laminate having a base material (42) in which are embedded corrugated sheets (43). The laminate is coated, on both planar surfaces (46, 47), with sheets (48) highly reflective of radiant thermal energy. The door material is incorporated in a system providing a rapidly acceleratable and deceleratable reel (12) and drum onto which the door material is rolled as the door is opened. The driving system (14) of the reel includes position sensing apparatus and braking apparatus. The door system also includes sensing devices (16) to detect a vehicle, a vehicle blocking device (18) to preclude impact on a closed door, and a control system to open the door and vehicle blocking device appropriately to allow the vehicle to pass through the doorway. Alternate embodiments of the door material are provided with horizontal guide bars (51) or with a security mesh (56) embedded in the door material.

Description: THERMAL DOOR SYSTEM Background of the Invention 1. Field of the Invention The present invention relates to portal closures providing a thermal barrier, and more particularly to doors that are capable of being rapidly deployed between an open and a closed position thereof while providing an improved barrier to convective, conductive, and radiant transfer of thermal energy through the doorway so closed. 2. Description of the Prior Art. In many industries, such as frozen food processing and distribution facilities, large storage rooms are provided with environmental control systems to maintain appropriate temperatures or other environmental factors within such rooms. Often, however, products being produced or stored under such controlled conditions are subject to rapid, high volume, relocation to or from processing areas, storage areas, or shipping areas, either of which can result in the need for providing frequent access to and from the controlled environment area. A typical form of transfer between such an environmentally controlled area and other locations utilizes fork lift trucks or other similar vehicles to handle palletized units of such products. The passage of such vehicles, with or without their loads, to and from the environmentally controlled area is usually facilitated by providing a portal through which such vehicles may pass. Dependent, of course, upon the degree to which the environment within the controlled area is to be maintained, closure of such portals except when absolutely necessary to permit passage of a transfer vehicle is a primary consideration of design. Several such systems are known in the art, each varying by compromise between rapidity of deployment and efficiency of isolation of the controlled area from its surroundings. One well known method of partial enclosure of such a transit portal utilizes a moving air screen to separate the controlled region from the adjacent non- controlled region. The air screen, supplied by laminar flow S HEET blowers directed across the area of the portal, generally requires movement of large volumes of air, and also usually requires a closed, high air volume, return system to prevent inordinate air currents either within the controlled area or in the adjacent region. The clear advantage exhibited by such an approach is that no obstacle is presented to impede or obstruct traffic transiting the portal. However, while the moving air screen may significantly preclude convection current transfer of thermal energy into or out of the controlled area, radiation transfer of thermal energy is not blocked. Thus, ease of passage of traffic through such a portal is obtained at the expense of compensating for radiant energy losses affecting the controlled environment in addition to the expense of operation of the blowers and exhausts establishing the air screen. A second approach observed from the industry utilizes a flexible partial enclosure of the portal, usually configured as a plurality of vertically oriented flexible strips depending from an overhead support, the strips being so disposed on the support that, when no traffic is transiting the portal, the strips depend in substantially adjacent positions to essentially fill the vertical planar area of the portal. When traffic passes through the portal, the flexibility of the strips allows such traffic to push the strips upwardly or aside until the traffic has cleared the portal. By an appropriate selection of materials used in forming such strips, some measure of thermal insulation, in a direction of traffic flow, can be provided when the strips are hanging dormantly in their respective portal closing attitudes. While such strips are generally formed to be transparent for safety purposes, some measure of blockage of radiant thermal energy transfer can be provided through selective coating of the strips. Clearly, however, when rigorous control of the environment within the controlled area is essential, a flexible strip closure is of limited utility due to the number of slits between adjacent strips, which would allow convection current transfer of thermal energy through the portal, and due to indeterminate closure of the portal arising from the flexibility of the strips allowing them to wave about their dormant positions for a period of time following transit of a vehicle through the portal. Some of the convection transfer loss can be prevented by incorporating a moving air screen adjacently parallel to the plane of the ^ strip closure. Another approach gaining acceptance in the industry utilizes a vertically rollable door mechanized to have rapid opening and closing deployment operation. The portal closing material, formed as a planar flexible sheet, is carried on a horizontally supported reel above the portal. The planar sheet has sufficient width to span the width of the portal and to include vertical edge portions riding upwardly and downwardly in channels adjacent the jambs of the portal, thereby substantially closing the portal when the door is ^ deployed to its fully closed position. An appropriately flexible lower fringe portion can be included on the door to adaptively form to the floor across the portal width to aid in sealing against convention current thermal energy transfer through the portal. In use, a vehicle seeking to transit through the portal must approach the portal, the door must appropriately operated to open the portal to allow the passage to occur, and the door must be operated to reclose the portal when the vehicle has completed its passage through the portal. Such an approach can significantly limit convection current transfer of thermal energy through the portal to such times as the door is not fully closed. Moreover, blockage of radiant thermal energy transfer through the portal can obtain by the interposition of the door closing the portal. Heretofore, however, the compromise between blockage of energy transfer through a door closing the portal and the need for rapid deployment of such a door to limit the loss of environmental control during times when the door is fully or partially open has been driven toward rapid deployment of the door rather than selection of materials for the door that would maximize resistivity to all forms of thermal energy transfer through EET the door. Indeed, the factors favoring rapid deployment appear dominant in that losses through an open portal far exceed those through a closed portal, regardless of the manner of closure of the portal. However, when traffic volume through the portal is light, such that the portal would be closed a significant portion of the total time, the losses through a closed door increase in importance. Ideally then, a system that maximizes the rapidity of deployment operations of the door, appropriately limits the open status of the door to that only essential to complete traffic passage through the portal, and minimizes losses through a closed door, is a desirable result. Unfortunately, door materials heretofore available that are compatible with or adaptable to rapid deployment systems were constrained to be of light weight, thereby limiting the resistivity to thermal energy transfer through their thickness. Additionally, such earlier materials, and the manner of their use in rapid deployment door systems, do not reasonably allow such doors to provide other beneficial results, such as fire retardation and entry security. Summary of the Invention Accordingly, it is an object of the present invention to provide a material for incorporation into a rollable portal closure that provides a significant thermal barrier to conductive and radiant thermal energy transfer across its thickness. It is another object of the present invention to provide a material for incorporation into a rollable portal closure that provides a temperature and fire barrier across its thickness. It is an additional object of the present invention to provide a material for incorporation into a rollable portal closure having resistance to penetration through its thickness. It is a further object of the present invention to provide a material for incorporation into a rollable portal closure that may be combined with a laceration resistant combination of elements to provide entry security to the portal so closed. Another object of the present invention is to provide a rollable portal closure system utilizing either of the materials provided herein. An additional object of the present invention is to provide a rollable portal closure system incorporating either of the materials provided herein in concert with a plurality of vertically spaced apart, horizontally disposed, flexure inhibiting members within layers of said materials. A further object of the present invention is to provide a rollable portal closure system including means for precluding impact on said closure by a vehicle attempting to transit said portal. Yet another object of the present invention is to provide a rollable portal closure system providing a significant fire retardation factor. Yet a further object of the present invention is to provide a rollable portal closure system providing improved security against unauthorized entry through said closure. These, and other objects, advantages, and features of the present invention that may become apparent through the hereinbelow descriptions of the principal and alternate embodiments of the present invention, are provided by a rollable doorway closure system comprising a reel mechanism, means for driving said reel mechanism, a thermal barrier door carried to roll onto and from said reel mechanism, guides for deployment of said door, means for controlling the deployment of said door, and means for impeding traffic through said doorway when said door is closed, said elements being operatively combined as indicated by the following descriptive disclosures. The door is generally comprised of a uni- directionally flexible laminate formed of materials providing a high resistivity to thermal energy conduction across the thickness of the laminate. The laminate is further formed to have its generally planar surfaces covered SHEET with reflective radiant energy barrier material, bonded thereto, such that the material, highly reflective of radiant thermal energy, is capable of flexing with the laminate in at least the preferred direction. The reel, generally disposed in a substantially horizontal orientation spanning the width of a portal or doorway, accepts the door in a rolled-up configuration to enable the portal to be in an open condition, and supports an upper horizontal end of the door when the door is deployed downwardly to close the portal. The reel is provided with a controllable drive mechanism for rapidly rotating the reel about its horizontally oriented longitudinal axis. In the principal embodiment of the invention, vertical guides are deployed adjacent each jamb of the portal, into which guides vertically oriented edges of the door are respectively engaged so as to slide vertically therewithin as the door is reeled or unreeled upwardly or downwardly during opening or closing of the portal. Control of the operation of the door, assumed to be in a normally closed position with the door unreeled from the reel so as to contact a floor of the portal, is preferrably mechanized by sensors that detect the approach of a vehicle seeking to transit through the portal, the sensors generating a signal to cause actuation of the reel driving mechanism to result in appropriate reeling of the door. The sensors also communicate completion of the passage of the vehicle through the portal to actuate closing of the door. Since the speed of a vehicle approaching or transiting through the portal can be a variable dependent on such factors as environmental conditions, load on the vehicle, traffic frequency, and vehicle operator preferences, the herein system is further provided to include means for impeding the progress of the vehicle toward the door until the door has sufficiently opened to enable the vehicle to transit the portal without impacting upon the door. Mechanization of such means can typically take the form of hydraulically or pneumatically operated skid ramps embedded into the floor of the vehicle path proximate to the portal to be level with the floor when the door is open. Such skid ramps, when deployed upwardly from the floor while the door is closed, engage lower structural surfaces of the vehicle chassis such that the continued progress of the vehicle toward a closed door will cause the vehicle to slide upwardly along the skid ramps to lift the vehicle driving wheels from contact with the floor, therby stopping the vehicle. In operation, such ramps are typically deployed to their elevated positions when the portal is closed by the thermal barrier door. As a vehicle approaches the portal for transit therethrough, the appropriate passage sensors detect the vehicle and provide a signal causing the reel driving mechanism to activate so as to roll the door upwardly onto the reel. When the door has opened sufficiently to allow the vehicle a clear passage through the portal, a position switch, incorporated on the door or on the reel, provides a signal to a control system which retracts the skid ramps to their positions level with the floor surface, thereby enabling the vehicle to progress toward and through the portal. When passage of the vehicle away from the portal is sensed, a further control signal is generated and used to actuate the reel drive mechanism to unroll the door to its closed position and also to deployed the skid ramps to their raised positions. A first alternate embodiment of the door is envisioned to include forming the door as a double thickness of the aforesaid reflective radiant barrier covered thermal barrier laminate having a substantially dead air space between the two thicknesses. A plurality of horizontally disposed guide bars are vertically spaced apart within the dead air space so as to provide the door with increased flexure stiffness across the width of the door. The guide bars are suspended from the reel supporting structure by a flexible support network that enables the guide bars to be gathered from below as the door is raised and rolled onto the reel, such gathering being accomplished in a manner that HEET the guide bars are not rolled onto the reel. A simple form of such a suspension network has a design parallel in the common Venetian blind. In such a method, each end of each guide bar is supported by a flexible support element from the proximate end of the guide bar disposed immediately thereabove, the flexible support elements each having an equal, non-extendable, length. When the door is unrolled from the reel to its fully closed position, the guide bars are equally vertically spaced apart, with the flexible support elements each at their maximum extent. As the door is rolled onto the reel, the lowest guide bar is first elevated by the lowermost edge of the door, collapsing accordingly the flexible support elements form which it depends from the next lowest guide bar, until the lowest guide bar has been raised into contact with the next lowest guide bar, at which elevation, the lowest and the next lowest guide bars continue to be elevated by the lowermost edge of the door, collapsing accordingly the flexible support elements by which the next lowest guide bar depends from the guide bar immediately thereabove. In a like manner, all of the guide bars are similarly gathered, in sequence from lowest to highest, until the door has been fully opened. It should be noted that this embodiment of the thermal barrier door system requires that the reel be disposed at an elevation sufficiently above the vertical clear span of the portal so that the plurality of guide bars gathered during raising of the door will remain within the dead air space of a portion of the door not rolled onto the reel at the fully open position of the door. Throughout the deployment and gathering of the guide bars, each end of each guide bar continues in engagement with a vertical guideway associated with the vertical guides adjacent the jambs of the portal. A further alternate embodiment of the door of the present invention envisions incorporating a loosely interlocked mesh, in lieu of the guide bars, within the dead air space described above. Such a mesh serves as a security barrier against laceration entry through a closed door. The mesh is generally sufficiently flexible to accomodate being rolled onto the reel with the door layers, however, it may alternately be freely suspended within the dead air space below the reel so as to be gatherable from below as the door is raised, much like the aforesaid guide bars. Such a mesh may, in the alternative, be rolled up with the outer two layers of the door. The mesh may also be formed as a plurality of spaced apart rigid elements, each extending across the door parallel to the free end of the door, this plurality of elements being linked together by multiple flexible links extending along the door orthogonally to the rigid elements. Other alternate embodiments may be readily determined by consideration . of the requirements for the several component elements and systems of the present invention. Such alternate embodiments, such as mechanizing the vehicle transit sensors as lasers or other velocity sensors, or as mere hand or foot operated switches, or as mechanizing the closed door transit impeding device as a full barrier, are envisioned to be substantially equivalent to the herein described embodiments. Additionally, it is envisioned that the approach herein disclosed for providing an improved thermal barrier, which includes fire and entry security, may be mechanized in a form having side to side opening and closing motions. The scope of the present invention shall therefore be limited only by the terms of the claims allowed therein. Brief Description of the Drawing In the accompanying drawing, wherein like reference numbers and symbols are employed to refer to like elements: FIG. 1 is a perspective view of a thermal door system in accordance with the present invention; FIG. 2 is a cross-sectional end view of a thermal door and reel mechanism in accordance with the present invention; FIG. 3 is a fragmentary perspective view of a vehicle transit impeding mechanism of the present invention; ET FIG. 4 is a fragmentary perspective cross- section of a thermal door in accordance with a principal embodiment of the present invention; FIG. 5 is a fragmentary perspective cross- section of a first alternate embodiment of a thermal door in accordance with the present invention. FIG. 6 is a cross-sectional end view of a thermal door and reel mechanism in accordance with the first alternate embodiment of the thermal door, illustrating the door deployed to three positions thereof, FIG. 6A showing the door deployed to a fully closed position, FIG. 6B showing the door deployed to a position intermediate of the fully closed position and a fully open position, and FIG. 6C showing the door deployed to the fully open position; FIG. 7 is a fragmentary perspective cross- section of a second alternate embodiment of a thermal door in accordance with the present invention; and FIG. 8 is a cross-sectional end view of a thermal door and reel mechanism in accordance with the second alternate embodiment of the thermal door, illustrating two methods for accomodating a mesh incorporated into said thermal door, FIG. 8A showing a partially open door wherein the mesh is reeled onto the reel along with the thermal door, and FIG. 8B showing a partially open door wherein the mesh is gathered upwardly from a lowermost end thereof so as to not be rolled onto the reel. Detailed Description of the Invention Referring first to FIG. 1, a rapidly deployable thermal door system is indicated generally at 10. Such a thermal door system 10 comprises, in its most essential embodiment, a deployable thermal door 11 supported from an overhead reel mechanism 12, vertical guides 13 for governing deployment of the door 11, a controllable driving mechanism 14 for operation of the reel mechanism 12, sensors 16 for detecting vehicles and the like seeking transit through a doorway 17 at which the door 11 is deployed, vehicle braking devices 18 to preclude impact of a vehicle onto a closed door 11, and means for relating signals from the sensors 16 and signals indicating the open or closed status and position of the door 11 so as to controllably operate the driving mechanism 14 and the vehicle braking devices 18 in appropriate sequence and rates to enable passage of a vehicle through the doorway 17 while maintaining the door 11 in its closed position at all times not necessary for such vehicle passage. As illustrated, the preferred utilization of the thermal door system 10 of the present invention provides for appropriately attaching the reel mechanism 12 and its associated driving mechanism 14 to a wall 19 of a structure, separating regions to be isolated by the thermal door 11, in a manner such that a longitudinal axis of the reel mechanism 12 is disposed in a substantially horizontal orientation parallel with the wall 19 spanning the width of the doorway 17. In an upwardly deployed, or open, position, the thermal door 11 is rolled substantially, but not entirely, onto the reel mechanism 12. When the door 11 is fully deployed to its closed position, a lowermost end 20 of the door 11 contacts a floor 21 across the width of the doorway 17. The so deployed door 11 includes vertical edges 22 which slidably translate vertically within the vertical guides 13 such that the door 11 is in close proximity to the wall 19 at the upper and side peripheral boundaries of the doorway 17. The combination of the close proximity of the door 11 to the peripheral boundaries of the doorway 17, the contact of the lowermost end 20 of the door 11 with the floor 21, the enclosure of the vertical edges 22 of the door 11 within the vertical guides 13, and the attachment of the reel mechanism 12 to the wall 19, provides that the doorway 17 is substantially completely closed by a door 11 so deployed to its closed position, thereby precluding convection current thermal energy transfer through the doorway 17 or around the door 11 and its associated structure. In use, the doorway 17 is typically part of a vehicle transit path between an environmentally controlled enclosed area of a structure and surrounding or adjacent enclosed or exterior areas. The effectiveness of the ET aforesaid thermal door 11, deployed to its closed position, in precluding convective thermal energy transfer through the doorway 17 contributes significantly toward reducing energy expenditures for maintaining the environment within the enclosed controlled area. Minimizing the energy losses arising during transit access to and from the environmentally controlled enclosed area is then a primary concern requiring that the transit doorway 17 be so closed by the door 11 at all times not absolutely necessary to the accomplishment of such transit through the doorway 17. To that end, the driving mechanism 14 is directly coupled to the reel mechanism 12 such that the reel mechanism 12 may be driven to rotate about its longitudinal axis 23 at a high rotational velocity in either direction. In similar systems, deployment of the door 11 from its fully open position to its fully closed position, or vice versa, may be accomplished in a nominal period of less than five seconds. Even more rapid deployment may be achieved by coupling the drive mechanism 14 to also positively translate the lowermost end 20 of the door 11 vertically within the guides 13, and by equipping the drive mechanism 14 with a limiting brake system to avoid bounce at either end of the deployment operation thereof. While a vertically translating door 11 is described as the principal embodiment of the present invention, it may be readily noted that minor modifications to the described system 10 would enable its use in a manner wherein the door 11 is deployed to translate in a substantially horizontal direction. A smooth flow of traffic through the doorway 17, while maximizing the closed periods of the doorway 17, is enabled by the incorporation of the senors 16 at appropriate positions within the environmentally controlled area and external thereof whereat the transit of a vehicle approaching or departing the doorway 17 may be sensed and a signal generated therefrom to actuate the driving mechanism 14 to deploy the door 11 to the proper position. A typical form of a sensor 16 utilizes a photocell 24 responsive to laser rays or other forms of directed energy, which, when the path between a source 26 and the photocell 24 is interrupted by passage of a vehicle, causes the output of the photocell to drop, thus forming a signal for transmission to the driving mechanism 14. Appropriate sensing of the resumption of receipt of energy by the photocell 24 from the source 26 can be used to control closure operation of the door 11. Appropriate time delays may be incorporated in the control system to allow for completion of transit of the vehicle through the doorway 17. A more sophisticated approach to controlling the operation of the door 11 utilizes two pairs of sensors 16, one pair disposed adjacent the vehicle path external of the doorway 17 and the other pair disposed adjacent the vehicle path internal of the environmentally controlled area. Each of the sensors 16 is so oriented as to detect the passage of a vehicle toward or away fr in the doorway 17. The sequence in which the sensors 16 detect the vehicle is used to determine the direction of travel of the vehicle. The time increment between sensing by the sensors 16 of one of the pairs is used to determine the speed of the vehicle so that the control system may appropriately adjust a time delay in actuating the driving mechanism 14 so that the door 11 is opened or closed at the proper instant to minimize the period during which the door 11 is open. Other alternate embodiments of the sensors 16 can be readily envisioned to be in the form of magnetic pickup sensing coils embedded in the vehicle path so as to be responsive to magnets on the vehicle chassis, or in the form of pressure sensitive plates embedded in the floor of the vehicle path, or even in the form of a radar like transceiver installed proximate to the wall 19 adjacent the doorway 17 so as to generate signals and receive return echo signals from the vehicle. All such embodiments, including the principal embodiment herein, have the common purpose of sensing the approach of a vehicle toward the doorway 17 at an appropriate time to enable the door 11 to reach its open position just as the vehicle begins its transit through the doorway 17, and that the door 11 remain in its open position HEET no longer than necessary for the vehicle to complete its transit through the doorway 17. It is clear that in order to so minimize the time increment during which the door 11 is not in its fully closed position, to accomodate passage of a vehicle through the doorway 17, knowledge of the speed of travel of the vehicle is an essential factor. However, even in embodiments providing information about the speed of the vehicle, the speed of the vehicle may be varied by the vehicle operator to be such that the vehicle would arrive at the doorway 17 before the door 11 can open sufficiently to avoid impact of the vehicle into the door 11. To safeguard against such unintentional impacts, which could result in serious damage to the door 11 and loss of environmental control integrity of the door 11, the thermal door system 10 is provided with vehicle braking devices 18, disposed appropriately along the vehicle path both within the environmentally controlled area and external thereof. Such devices 18, as will be more fully understood from a detailed description hereinbelow, are disposed along the vehicle path appropriately removed from proximaity to the doorway 17 so that they will stop a vehicle approaching the doorway 17 before the vehicle can impact on the door 11 or enter into the doorway 17 until the door 11 is sufficiently open to allow an unimpeded transit through the doorway 17 by the vehicle. Such braking devices 18 are therefore necessarily interlocked, for their operational control, with the sensors 16 and with an indication of the vertically deployed position of the door 11. The interlocking is coupled through the control system such that the braking devices 18 remain deployed to stop vehicle progress until the indication of the vertically deployed position of the door 11 is that the door 11 is open, at which time the braking devices 18 are retracted. The braking devices 18 then remain retracted until the transiting vehicle has departed from the doorway 17, as established by the sensors 16. Referring next to FIG. 2, the principal embodiment of a door 11 and reel mechanism 12 of the present invention is shown in cross-section. The door 11 is formed as a laminate capable of readily flexing about parallel horizonal lines across the width of the door 11, normal to the plane of FIG. 2, while the laminate retains stiffness against flexure about vertical parallel lines through the door 11, in and parallel to the plane of FIG. 2. The particular construction of the principal embodiment of the door 11 will be described more fully hereinbelow. The differential flexure capability of the laminate allows the door 11 to be rolled onto the reel mechanism 12 as the door 11 is opened, while also providing a measure of stiffness across the width of the door 11. The reel mechanism 12 comprises a drum 27, journaled at either horizontally disposed end to rotate about a longitudinal axis 23 of the reel mechanism 12, in either rotational direction, under action of the driving mechanism 14 of FIG. 1. The longitudinal axis 23 of the reel mechanism 12 is supported from the adjacent wall 19 by attachment of a reel housing 29 thereto such that the longitudinal axis 23 and the drum 27 are sufficiently horizontally spaced apart from the wall 19 to allow freedom of rotation of the drum 27, even when multiple layers of the laminate forming the door 11 are rolled onto the drum 27 as the door 11 is fully opened. The housing 29 is provided with a generally downwardly directed guiding opening 30 through which the door 11 progresses as it is unrolled from the drum 27, said opening 30 being substantially adjacent the wall 19. Referring next to FIG. 3, the vehicle braking device is shown in greater detail to comprise, in a principal embodiment thereof, a hydraulic cylinder 31, having a longitudinal axis, pivotably coupled at a first end 32 thereof, to a bracket 33 securely anchored to a lower surface 34 of a hole 36 formed in the floor 21 of the vehicle transit pathway, a piston 37 extending along the longitudinal axis 28 from a second end of the cylinder 31 obverse to the first end 32 thereof, to be pivotably coupled proximate to a first end 38 of a plate 39 . A second end of the plate 39 is hinged about an axis 40 disposed ET substantially coplanar with the surface of the floor 21. Hydraulic supply lines 41 couple the cylinder 31 to a controllable pressurized hydraulic supply (not illustrated) . The piston 37 and cylinder 31 are in their most extended mutual positions when the door 11 is not sufficiently open to allow vehicle transit through the doorway 17. The extension of the piston 37 from the cylinder 31 causes the plate 39 to assume a pivoted position about the hinge axis 40 such that the first end 38 of the plate 39 is elevated above the surface of the floor 21 sufficiently to form a ramp which will engage lower surfaces of the undercarriage of a vehicle attempting to progress toward the doorway 17, thereby causing the vehicle to be raised as it climbs along the ramp formed by the plate 39 until the drive wheels of the vehicle are lifted from contact with the floor 21, precluding further progress of the vehicle. When the door 11 is in an open position sufficient to allow passage of the vehicle through the doorway 17, appropriate control signals generated by the sensors 16 and the door position are provided to the controllable hydraulic supply to actuate the cylinder 31 so as to retract the piston 37 therewithin, pivoting the plate 39 downwardly about the hinge axis 40 until the plate 39 is substantially coplanar with the floor 21, concurrently lowering the vehicle drive wheels into contact with the floor 21 so that transit of the vehicle through the doorway 17 may continue. Completion of passage of the vehicle through the doorway 17 provides a further control signal to the hydraulic supply so as to cause actuation of the cylinder 31 and piston 37 to redeploy the plate 39 to its ramp forming upwardly pivoted position. In a normal operation of transiting vehicles through the doorway 17 at appropriate vehicle speeds, the door 11 is opened and the plate 39 is accordingly retracted without impeding vehicle progress. Referring next to FIG. 4, construction of a principal embodiment of the thermal door 11 is shown by the illustrated fragmentary perspective cross-section thereof. The door 11 is, as stated earlier herein, a laminate. The primary rigidity of the door 11 results from a laminated material, shown in the enlarged fragmentary view (FIG. 4B) of door 11, comprising a generally resinous base material 42 having a plurality of corrugated flexible sheets 43 embedded therein such that their respective corrugations are substantially mutually parallel to extend across the width of the laminate in a direction indicated by arrows 44. These corrugations provide strength of the laminate to inhibit flexure about axes in the plane of the door 11 normal to the arrows 44, while allowing flexure of the laminate about axes in the plane of the door 11 parallel to the directions indicated by the arrows 44. The materials chosen to form the laminate are further constrained to be such that provide substantial thermal resistivity to conduction of thermal energy across the thickness of the laminate, from a first planar surface 46 thereof to an obverse, second planar surface 47 thereof, and vice versa. The aforesaid laminate is additionally provided with thermal energy reflective sheets 48 appropriately bonded to both planar surfaces 46, 47 of the laminate, thereby significantly limiting radiative thermal energy transfer across the thickness of the door 11. The inclusion of the thermal energy reflective sheets 48, by inhibiting radiative thermal energy transfer from a source thereof external to one side of the door 11, provides an added benefit in enhancing the use of the door 11 as a fire barrier protecting the area to the side of the door 11 obverse to the source of thermal energy. The nature of the reflective sheets 48 is such that each surface of each sheet 48 reflects at least ninety five percent of the radiant thermal energy incident thereon, with a result that no more than 0.000625 percent of radiant thermal energy from a source thereof incident on the door 11 will be radiated outwardly from the obverse surface of the door 11. Referring next to FIG. 5, a first alternate embodiment of a thermal door in accordance with the present invention is indicated generally at 49. The door 49 generally comprises a pair of reflectively covered laminates HEET separated by a dead air space 50 in which are deployed a plurality of horizontally disposed bars 51. Each of the reflectively covered laminates of the pair is, in all respects of construction, identical with the door 11 of FIG. 4. In particular, in progressing through a thickness of the door 49, the laminate layers encountered are, sequentially, a thermal energy reflective sheet 48, a laminate of the base material 42 and a plurality of corrugated sheets 43 bounded by planar surface 46, 47, a second thermal energy reflective sheet 48, the dead air space 50 which may include a bar 51, a third thermal energy reflective sheet 48, a second laminate of the base material 42 and a plurality of corrugated sheets 43 bounded by planar surfaces 46, 47, and a fourth thermal energy reflective sheet 48. The lowermost ends 20 of each of the pair are joined together across the width of the doorway 17. The preferred manner of joining the lowermost ends 20 together is to form the pair as a single continuous laminate looped at the lowermost end 20. The plurality of bars 51 depends from the reel mechanism 12 independently of the door 49. The bars 51 are vertically spaced apart by substantially equal distances when the door 49 is deployed to its fully closed position. The bars 51 each extend fully across the width of the doorway 17 to extend outwardly, at each end of their respective extent, from the vertical edges of the door 49, to engage separate vertically disposed guideways (not illustrated) . When the door 49 is fully closed, the bars 51 provide additional rigidity against impact and side-to-side flexure of the door 49. Referring next to FIG. 6, the manner in which the bars 51 of the door 49 are suspended, and their disposition relative to the reel mechanism 12 during differing stages of deployment of the door 49, is indicated with reference to three deployment positions of the door 49: FIG. 6A illustrating the door 49 in its fully open position; FIG. 6B illustrating the door 49 deployed to a position intermediate between its fully open and its fully closed positions; and FIG. 6C illustrating the door 49 in its fully closed position. When the door 49 is in its fully open position, the pair of laminate combinations are both rolled up onto the drum 27 of the reel mechanism 12 such that the dead air space 50 is substantially collapsed and the surfaces of the laminate combinations are in mutual contact. The bars 51, having been gathered by the lowermost end 20 of the door 49, are disposed in substantially mutual contact within a residual portion of the dead air space 50 between the pair of laminate combinations at a residual lower portion thereof depending below the guide opening 30 of the reel housing 29. It should be noted hereat that the reel housing 29 and the guide opening 30 are to be appropriately enlarged from those of the principal embodiment so that they may accomodate the doubled thickness of laminate combinations forming the door 49. As the door 49 is deployed from its fully open position of FIG. 6A, the bars 51 are, as a group, lowered with the lowermost end 20 of the door 49 until a flexible bar suspending element 52, having a fixed length from its support on the reel housing 29 to the uppermost bar 51, reaches its substantially non-extendable length, thereby precluding further downward movement of the uppermost bar 51. As the door 49 continues therefrom in its downward deployment toward its closed position, all of the bars 51 except the uppermost bar 51, continue to progress downwardly along with the lowermost end 20 of the door 49 until a second bar suspending element 53, extending from the uppermost bar 51 to the next proximately lower bar 51, reaches its extended length, whereat the second bar 51 becomes suspended at its intended fixed elevation. As indicated by FIG. 6B, this process of deploying the bars 51 continues from the top of the door 49 downwardly, with any intermediate position of the 'door 49 providing for a number of bars 51 being disposed at their intended elevations and the remainder of the bars 51 continuing to rest in mutual sequential contact supported by the lowermost end 20 of the door 49. Each succeedingly lower bar 51 is coupled to the bar 51 disposed next proximately higher thereto by a bar EET suspending element 53. In the usual manner of suspending the bars 51, each end of each bar is provided with the appropriate suspending elements 53. When the door 49 has reached its fully closed position as shown in FIG. 6C, all of the flexible bar suspending elements 53 have reached their respective extended lengths and the bars 51 are deployed to their respective vertically spaced apart elevations. In most configurations of the door 49, it is generally desirable that the lowest bar 51 be proximate to the lowermost end 20 of the door 49 when the door 49 is in its fully closed position, as will be further explained later herein. Referring next to FIG. 7, a second alternate embodiment of a thermal door in accordance with the present invention is indicated generally at 54. As can be observed from the fragmentary perspective cross-section of FIG. 7A, the door 54 appears quite similar to the door 49 of FIG. 5, except that the bars 51 of the door 49 are replaced by a mesh element 56 in the door 54. The mesh element 56 shown in the enlarged fragmentary view (FIG. 7B) of door 54 is formed as a loosely interlocked plurality of ringlets 57 such that when the door 54 is deployed to its fully closed position, the ringlets 57 are substantially uniformly distributed within the dead air space 50 between the pair of laminate combinations forming the door 54 so as to fully cover the planar area of the door 54. The ringlets 57, by being interlocked to each other in all planar directions of the door 54, provide for security against entry through the door 54 which may be attempted by using a technique of penetration and laceration of the laminate combinations. If the material chosen for the ringlets 57 is sufficiently durable, laceration of the door 54 sufficient to provide an opening necessary for unauthorized entry through the door 54 is precluded by the mesh element 56. The mesh element 56 may alternately be formed as a plurality of spaced apart, substantially rigid, wires extending across a width of the door so as to be substantially parallel to the free end of the door. These wires are linked together by a number of flexible members extending along the length of the door so as to retain the rigid wires in their respective positions. Referring lastly to FIG. 8, deployment of a thermal door of the type illustrated in FIG. 7 as the door 54, to include a mesh element 56, is accomplished by rolling the door 54 onto and from an appropriately configured drum 27 of a reel mechanism 12 in an appropriately sized housing 29, as has been heretofore described. However, the inclusion of the mesh element 56 provides that two alternative methods of rolling the door 54 onto the drum 27 are feasible. A first method, as shown in FIG. 8A, wherein the door 54 is illustrated to be in an intermediately deployed position, utilizes the looseness of the interlocking of the ringlets 57 to enable the mesh element 56 to be rolled onto the drum 27 along with the laminate combinations forming the door 54. The looseness of the interlocking of the ringlets 57 forming the mesh element 56 is such that the mesh element 56 does not substantially increase the resistance to flexure of the door 54 in either direction along the planar surfaces of the door 54. A second method, shown in FIG. 8B, provides for the utilization of a smaller configuration of the drum 27, reel housing 29, and guide opening 30 by independently supporting an uppermost end of the mesh element 56 from the reel housing 29 such that the looseness of the interlocking between the ringlets 57 allows gathering of the mesh element 56 from the lowermost end 20 of the door 54 as the door 54 is raised from its closed position, much in the manner that the bars 51 of the door 49 of FIG. 5 and FIG. 6 are gathered. The fully gathered mesh element 56 is, in this method, stored in a residual dead air space between the laminate combinations depending below the reel housing 29 when the door 54 is at its fully open position. With reference to the drawing in general, in either of the embodiments described, the lowermost end 20 of the door may be driven along with operation of the reel HEET mechanism 12 by the inclusion of appropriate pulley, cable, and spring components within the vertical guides 13. Such further mechanization of the operation of the thermal door enhances the capability for rapid deployment thereof despite any random flexure in the deployment direction inherent in the laminate combination used to form the door. Accomplishment of this added feature require that the lowermost end 20 of the door be provided with a substantially rigid member extending across the width of the doorway 17, such member being firmly coupled to the lowermost end 20 of the door. Such a rigid member spanning the lowermost end 20 of the door 54 of FIG. 7 and FIG. 8 will also provide a lowermost anchoring member for the mesh element 56 to prevent unauthorized entry by a laceration of the lower end 20 and a subsequent gathering of the mesh element 56 upwardly therefrom. While the foregoing has presented detailed descriptions of a preferred and alternate embodiments of a thermal door system in accordance with the present invention, it is envisioned that such descriptions have also revealed further alternate embodiments comprised of permutations of the features and component elements of the embodiments explicitly set forth. Moreover, it is clear that reasonable substantially equivalent mechanizations accomplishing the purposes herein in like manner will be evident to those knowledgable in the art. Each of such further embodiments is to be construed as being within the scope of the present invention, as limited only by the appended claims.

Claims: Claims 1. A thermal door system for enclosing a vehicle passage doorway comprising: a thermal door configured substantially as a planar laminate having radiant thermal energy reflective layers affixed to its planar surfaces, said thermal door laminate having a preferred direction of flexibility, said planar laminate having planar dimensions appropriate to overlappingly span a vertical height and horizontal width of the doorway to be enclosed by the thermal door; a reel or rolling mechanism onto which the thermal door laminate may, from an end thereof attached to said reel, be rolled in its preferred direction of flexibility to open the doorway and from which the thermal door laminate may, from a free end thereof obverse to said attached end, be unrolled to close the doorway; and means for controllably driving the reel mechanism to appropriately rapidly open or close the thermal door. 2. The thermal door system of claim 1 including means for sensing deployment positions of the thermal door to sense at least a fully open position thereof, a fully closed position thereof, and an intermediate deployed position thereof wherein the door is sufficiently open to allow free passage of a vehicle. 3. The thermal door system of claim 2 including means for controllably braking the reel driving mechanism to preclude overdeployment and bounce of the thermal door upon reaching its open or closed deployment positions, and means for guiding said free end of said thermal door between its open and closed deployment positions, said means also providing environmental enclosure of edges of the laminate extending between said free end and said attached end of said thermal door. 4. The thermal door system of claim 2 including means, deployed in a path of the vehicle approaching the thermal door, for precluding progress of the vehicle toward the doorway unless the door is deployed to an open position sufficient to allow free passage of the vehicle through the doorway, said means being controllably operable to be in SHEET either a status precluding progress of the vehicle or a status allowing progress of the vehicle; means, disposed proximate to the vehicle path of approach to the doorway, for sensing the approach of a vehicle attempting to pass through the doorway, said means generating an appropriate signal upon the approach of a vehicle toward the doorway; and means, responsive to said signal from the means for sensing the approach of a vehicle, for controllably operating the reel driving mechanism and the vehicle blocking device such that sensing the approach of the vehicle will cause the door to be opened and the vehicle blocking device to assume its non-impeding status when the door has opened sufficiently, said means further providing controllable operation of the reel driving mechanism and the vehicle blocking device so as to close the thermal door and place the vehicle blocking device in its impeding status upon completion of the passage of the vehicle through the doorway. 5. The thermal door system of claim 1, wherein said laminate forming said thermal door is constructed to comprise: a substantially fused base material; a plurality of planar sheets, embedded within said base material such that said planar sheets are substantially congruently parallelly equidistantly spaced apart through a thickness of said base material normal to said planar sheets, said sheets being formed to include a plurality of parallelly spaced apart corrugations, said sheets being so oriented within said base material that all said corrugations are mutually parallel, said corrugations determining said direction of preferred flexibility to be orthogonal to their respective extent defining a first door panel; and a pair of radiant thermal energy reflective layers, each formed as a thin planar element having opposed planar surfaces, highly reflective of radiant thermal energy, said layers having planar areas congruent with said laminate, said pairs of layers being appropriately bonded to respective planar surfaces of said laminate. 6. The thermal door system of claim 5, further comprising: a second door panel consisting of said laminate and said reflective layers, said second panel being disposed in a congruently parallel manner with respect to the first such panel; an internal dead air space, formed, when the door is deployed to its fully closed position, as a substantially planar slab volume congruent between the first and second door panels; means for joining the free end of the first door panel to the free end of the second door panel; a plurality of guide bars, disposed within said dead air space to be mutually parallel with the free ends of the panels, said guide bars each having an extent greater than the span of the door between opposed edges thereof running between the free ends of the door panels and the opposed ends thereof attached to the reel mechanism, said extending ends of said guide bars engaging the means for guiding the free end of the door during opening and closing thereof; and means for supporting said plurality of guide bars, when said door is deployed to its fully closed position, to be mutually parallelly equidistantly spaced apart along the extent of the door between its free end and its attached end, said means for supporting said guide bars being further formed to allow the guide bars to be gathered at the free end of the door as the door is opened, thereby precluding the guide bars from engaging onto the reel mechanism. 7. The thermal door system of claim 5, further comprising: a second door panel consisting of said laminate and said reflective layers, said second panel being disposed in a congruently parallel manner with respect to the first such panel; an internal dead air space, formed, when the door is deployed to its fully closed position, as a substantially planar slab volume congruent between the first and second door panels; means for joining the free end of the first door panel to the free end of the second door panel; a mesh element, formed of a plurality of loosely interlocking rings arrayed so as to be deployable over a planar area equivalent to the surface area of the door, said mesh element being disposed within said dead air space and TESHEET coupled to the free end of the door; and means for independently supporting said mesh element within said dead air space such that, when said door is deployed to its fully closed position, said mesh element is substantially uniformly distributed over the planar area of the door, said means for supporting said mesh element being further capable of enabling the mesh element to collapsably gather against the free end of the door as the door is deployed toward its open position. 8. The thermal door system of claim 5, further comprising: a second door panel consisting of said laminate and said reflective layers, said second panel being disposed in a congruently parallel manner with respect to the first such panel; an internal dead air space, formed, when the door is deployed to its fully closed position, as a substantially planar slab volume congruent between the first and second door panels; means for joining the free end of the first door panel to the free end of the second door panel; a mesh element, formed of a plurality of loosely interlocking rings arrayed so as to be deployable over a planar area equivalent to the surface area of the door, said mesh element being disposed within said dead air space and coupled to the free end of the door; and means for supporting said mesh element in said dead air space in a manner such that, when said door is deployed to its fully closed position, said mesh element is substantially uniformly distributed over the planar area of the door, said mesh element being further constrained to remain so distributed relative to the door panels throughout deployment of the door onto and from the reel mechanism. 9. The thermal door system of claim 1, wherein said laminated door is deployable in a vertical direction from said reel mechanism mounted to a wall of a structure having a vehicle doorway therethrough, said mounting of said reel mechanism being such that the longitudinal axis of the reel mechanism being such that the longitudinal axis of the reel mechanism is substantially horizontally disposed to span a width of the doorway, transverse to the direction of travel of the vehicle, at an elevation above the clear vertical opening of the doorway, said laminated door having an extent, in the direction from the free end thereof to the opposed end thereof attached to the reel mechanism, sufficient to extend from the reel mechanism to the floor surface of the vehicle pathway through the doorway when the laminated door is deployed to its fully closed position. 10. The thermal door system of claim 1, wherein said laminated door is deployable in a horizontal direction from said reel mechanism mounted to a wall of a structure having a vehicle doorway therethrough, said mounting of said reel mechanism being such that the longitudinal axis of the reel mechanism is substantially vertically disposed to span a clear vertical opening of the doorway, and sufficiently proximate to one side jamb of the doorway such that the laminated door, having a sufficient extent in the direction from the free end thereof to the opposed end thereof attached to the reel mechanism, is deployable, when deployed to its fully closed position, to span the clear horizontal opening of the doorway to the jamb opposite that supporting said reel mechanism. 11. The thermal door system of claim 1, further comprising a second laminated door, a second reel mechanism, and a second means for driving said second reel mechanism, each substantially identical with the first such components of the system; said first and said second laminated doors being deployable in a substantially horizontal direction; said first and said second reel mechanisms being respectively mounted to jambs of the doorway on opposed sides of the clear horizontal span of the doorway, said reel mechanisms being oriented in their respective mounted positions such that their respective longitudinal axes are substantially vertical; said first laminated door having an extent from the free end thereof to the opposed end thereof attached to the first reel mechanism sufficient to extend from the first reel mechanism to a vertical line through the doorway located substantially at the middle of the clear horizontal opening of the doorway; said second laminated EET door having an extent from the free end thereof to the opposed end thereof attached to the second reel mechanism sufficient to extend from the second reel mechanism to a vertical line through the doorway located substantially at the middle of the clear horizontal opening of the doorway; said first and said second means for respectively driving said first and said second reel mechanisms being appropriately controlled to cooperatively operate such that, when said door is to be deployed from its fully closed position to its fully open position, said first laminated door is deployed onto said first reel mechanism while, concurrently, said second laminated door is deployed onto said second reel mechanism, closure of said doorway being accomplished in a reverse manner by simultaneously deploying said first and said second laminated doors respectively from said first and said second reel mechanisms such that the respective free ends of the first and second laminated doors are placed in mutually parallel abutment when the door is deployed to its fully closed position. 12. A rapidly deployable thermal door deployable between a closed position wherein said door is deployed to cover the area of a doorway, and an open position thereof, allowing transit through the doorway, and the reverse, said thermal door comprising: a substantially fused base material, configured as a substantially planar slab having a width between side edges thereof and a length extending appropriately from a free end thereof; and a pair of radiant thermal energy reflective layers, each formed as a thin planar element having opposed planar surfaces, highly reflective of radiant thermal energy, said layers having planar areas congruent with said laminate, said pair of layers being appropriately bonded to respective planar surfaces of said laminate. 13. The thermal door of claim 12 wherein said base material has a plurality of elements embedded therewithin in a substantially uniform distribution, said elements being so arranged therein as to determine a preferred direction of flexibility to extend from the free end of said base material along its length, said elements providing reduced flexibility in the width direction of said planar slab of base material, said direction of preferred flexibility being in a direction of deployment of said thermal door between open and closed positions thereof. 14. The thermal door of claim 12 including a plurality of planar sheets, embedded within said base material such that said planar sheets are substantially congruently parallelly equidistantly spaced apart through a thickness of said base material normal to said planar sheets, said sheets being formed to include a plurality of parallelly spaced apart corrugations, said sheets being so oriented within said base material that all said corrugations are mutually parallel, said corrugations determining a direction of preferred flexibility to be orthogonal to their respective extent, said direction of preferred flexibility being in a direction of deployment of said thermal door between open and closed positions thereof. 15. The thermal door of claim 14, as defining a first door panel, further comprising a second panel constructed from said base material, said sheets including corrugations, and said radiant thermal energy reflective layers, said second panel having a planar area congruently parallel with that of said first panel and separated therefrom by a substantially dead air volume, free ends of said first and said second pahels being joined together, and ends thereof opposed to said free ends being mutually coupled to means for deploying said panels between open and closed positions thereof to enclose a doorway. 16. The improvement as claimed in claim 15, further comprising: a plurality of guide bars, disposed within said dead air space to be mutually parallel with the free ends of the panels and substantially parallel with said corrugations, said guide bars each having an extent greater than the span of the door between opposed edges thereof; and means for supporting said plurality of guide bars, when said door is deployed to its fully closed position, to be mutually parallelly equidistantly spaced apart along the SHEE extent of the door between its free end and its attached end, said means for supporting said guide bars being further adapted to allow the guide bars to be gathered at the free end of the door as the door is opened. 17. The improvement as claimed in claim 15, further comprising: a mesh element, formed of a plurality of loosely interlocking rings arrayed so as to be deployable over a planar area equivalent to the surface area of the door, said mesh element being disposed within said dead air space and coupled to the free end of the door; and means for independently supporting said mesh element within said dead air space such that, when said door is deployed to its fully closed position, said mesh element is substantially uniformly distributed over the planar area of the door, said means for supporting said mesh element being further capable of enabling the mesh element to collapsably gather against the free end of the door as the door is deployed toward its open position. 18. The improvement as claimed in claim 15, further comprising: a mesh element, formed of a plurality of loosely interlocking rings arrayed so as to be deployable over a planar area equivalent to the surface area of the door, said mesh element being disposed within said dead air space and coupled to the free end of the door; and means for supporting said mesh element in said dead air space in a manner such that, when said door is deployed to its fully closed position, said mesh element is substantially uniformly distributed over the planar area of the door, said mesh element being further constrained to remain so distributed relative to the door panels throughout deployment of the door. 19. The improvement as claimed in claim 15, further comprising: a mesh element, formed of a plurality of substantially rigid members disposed to be mutually parallel with the free end of the door and arrayed in an equidistantly spaced apart manner throughout the extent of the door from said free end thereof to the opposed end thereof, and a plurality of durably flexible members T extending, in a mutually parallel spaced apart manner, from said free end of the door to the opposed end thereof, each of said flexible members being rigidly coupled to each of said rigid members at each of their respective crossing intersections, said mesh element being deployed over a planar area equivalent to the surface area of the door, said mesh element being disposed within said dead air space and coupled to, at least, the free end of the door; and means for supporting said mesh element in said dead air space in a manner such that, when said door is deployed to its fully closed position, said mesh element is substantially uniformly distributed over the planar area of the door, said mesh element being further constrained to remain so distributed relative to the door panels throughout deployment of the door. ESHEET

Inventors: BARKO CHARLES R, BARKO JOHN A, BARKO RICHARD L, SCHILLINGER HARALD, BARKO, CHARLES, R., BARKO, JOHN, A., BARKO, RICHARD, L., SCHILLINGER, HARALD
Applicants: FROMMELT IND INC, FROMMELT INDUSTRIES, INC.
Application year: 1991
Main classification: E06B9
IPC codes: E06B9