BACKGROUND OF THE INVENTION Most vehicle accidents occurring in water have a reduced survival rate compared to those occurring on the ground. In water accidents, the vehicles usually sink very rapidly, either in an upright or inverted position. Underwater, the conditions are drastically different than on the ground. Visibility is reduced. The majority of people can only see 1.5 meters underwater and 3.1 meters in the best well lit conditions; notwithstanding that most do not even like to open their eyes underwater. Survivors must depend on their breath-holding ability to make a successful escape. Generally, one's breath-holding ability is reduced 25-50% in water under 15°C. Maximum breath- holding time can be as short as 10 seconds. Survivors are disoriented due to the sudden immersion in water, loss of gravitational references, poor depth perception, water-up the nose and darkness. Most of these conditions become magnified when the vehicle is inverted. Under the latter condition, finding the lever to jettison an escape door or window, which is a simple procedure to execute in an upright position on dry land, can be a most challenging task even if the lever is only a few centimeters away from the survivor's hand.

Commonly, levers in prior art escape door or window systems are small handles, which are positioned either above, mid or below the chest, or at the shoulder, hip or knee. These various positions would not be obvious to the survivor unless he or she is familiar with the particular escape system. Most prior art mechanisms are adapted to remove the entire door or window, including the frame. This requires a complicated jettison mechanism, which is not always dependable. Furthermore, the prior art systems do not provide feedback to indicate that the door, window or hatch has been successfully jettisoned.

SUMMARY OF THE INVENTION An object of the present invention is to provide an emergency exit system of the type which includes a plurality of release means adapted to operate independently of one another to release a closure panel to provide an escape exit.

The invention, in one broad aspect, provides an emergency exit system comprising a frame defining a closeable opening and including a plurality of spaced apart locking means; a closure panel to close the opening and configured to be secured in the opening by the plurality of locking means; a release mechanism having a plurality of release means, each being independently operable; and an actuation mechanism that, upon actuation, operates to translate activation of any one of the release means to simultaneously release the plurality of locking means to release the closure panel from the frame to enable jettisoning of the closure panel.

A linking means is provided to interconnect the spaced apart locking means which are disposed in the frame peripherally thereof so that actuation of any one of the release means causes the linking means to simultaneously release each of the locking means to release the closure panel thereby to enable jettisoning of the closure panel.

Preferably, the actuation mechanism comprises a combination of coacting actuation means, which translate rotational movement of any one of the release means into movement of the locking means to simultaneously disengage each locking means from the closure panel to enable jettisoning of the closure panel.

The exit system may further comprise a plurality of spaced apart jettisoning means mounted on the frame for biasing the closure panel outwardly from the frame to permit jettisoning thereof immediately upon release of the closure panel.

In accordance with another aspect of the present invention, there is provided an emergency exit system comprising a frame defining a closeable opening and including a plurality of spaced apart locking means; a closure panel to close the opening and configured to be secured in the opening by the spaced apart locking means; an actuation mechanism for displacing the plurality of locking means from a locked position to a release position, wherein in the locked position the closure panel is releasably secured in the opening by the locking means and in the release position the closure panel is released from the frame for jettisoning ; a release mechanism having a plurality of release means, each of the release means being independently operable so that actuation of any one of the release means simultaneously disengage each locking means from the locked position to the release position; an auxiliary actuation mechanism for simultaneous actuation of each of the locking means to establish either the locked or release position, wherein the auxiliary actuation mechanism is capable of overriding the actuation mechanism; and an auxiliary release mechanism having a couple of auxiliary release means for actuation of the auxiliary mechanism to simultaneously move the plurality of locking means to either said locked or release position.

In accordance with another aspect of the present invention, there is provided an emergency exit system comprising a frame defining an opening therethrough; a closure panel releasably secured in the opening and comprising a plurality of spaced apart indentations disposed along the side edges thereof; a plurality of spaced apart locking means connected to the frame and adjacent to the indentations to releasably engage said indentation thereby to secure the closure panel in the opening in a locked position relative to the frame; an actuator means for simultaneously displacing the locking means from the locked position to a release position to release the closure panel from the frame for jettisoning of the closure panel; and a release mechanism comprising a plurality of release handles individually connected to the actuator means, wherein actuation of any one of the release handles actuates the actuator means to simultaneously disengage each locking means from the locked position to the release position.

In accordance with another aspect of the present invention, there is provided a door emergency exit system comprising a frame defining a closeable opening; a door panel hingedly mounted on the frame by a couple of selectively releasable spaced apart hinge assemblies, where each hinge assembly comprises a hinged arm disposed along one edge of the door panel releasably engaged to a release member which is mounted adjacent the hinged arm and in the frame; a plurality of spaced apart locking assemblies comprising a plurality of securing means disposed on the frame, associated locking means mounted adjacent the securing means and in the door and releaseably engageable to the securing means and means to move the locking means to engage the securing means to establish a locked condition of the door panel or to disengage from the securing means to establish an unlocked condition of the door panel during normal operation; a release mechanism having a plurality of release means that are independently operable; an actuation mechanism that, upon actuation, operates to translate activation of any one of the release means to simultaneously disengage the securing means from the locking means and the release members from the hinged arms to release the door panel from the frame to enable jettisoning of the door panel.

A linking means is provided to interconnect the plurality of securing means and release members to one another so that actuation of any one of the release means will cause the linking means to simultaneously actuate each of the securing means and release member to release the closure panel thereby, enabling jettison of the closure panel.

In accordance with another aspect of the present invention, there is provided a door emergency exit system comprising a frame defining a closeable opening. A door panel hingedly mounted on the frame by a couple of selectively releasable spaced apart hinge assemblies, where each hinge assembly comprises a hinged arm disposed along one edge of the door panel releasably engaged to a release member mounted adjacent the hinged arm and on one side of the frame. A plurality of spaced apart locking assemblies, each comprising a securing means is disposed on the opposite side of the frame. The securing means is engageable to an associated locking means, which is mounted on the opposite edge of the door. The locking assemblies further comprises means to move each of the locking means to engage with the securing means to establish a locked condition of the door panel or to disengage from the securing means to establish an unlocked condition of the door panel to enable the door panel to swing about the hinge assemblies during normal operation. A release mechanism having a plurality of independently operable release means is connected to an actuation mechanism that, upon actuation, operates to translate activation of any one of the release means to simultaneously disengage the securing means from the locking means and the release members from the hinged arms to release the door panel from the frame to enable jettisoning of the door panel. The door exit system further comprises an auxiliary release means mounted on the frame and an auxiliary actuation mechanism that, upon actuation, operates to translated activation of the auxiliary release means to simultaneously engage each of the securing means to associated the locking means and the release members to the hinged arms to releasably secure the door panel in the opening or, disengage the securing means from the locking means and the release members from the hinged arms to release the door panel from the frame to enable jettison of the door panel. The auxiliary actuation mechanism is capable of overriding the actuation mechanism.

The terms"interior","inside","inwardly"and"inner"as used herein refer to the interior or inside side of the aircraft in which the emergency exit system is mounted, and the terms"exterior","outside","outwardly"and"outer"refers to the opposite side.

DESCRIPTION OF THE DRAWINGS An embodiment of the present invention will now be described by way of examples with reference to the following drawings in which: Figure 1 is a perspective view of a window emergency exit system in accordance with one embodiment of the present invention, looking at the window from the interior side; Figure 2 is an elevation view of the exit system of Figure lwith part of the frame removed to show the actuation mechanism in the locked position, looking from the exterior side; Figure 3 is an elevation view of the exit system of Figure Iwith part of the frame removed to show the actuation mechanism in the release position, looking from the exterior side; Figure 4 is a detailed perspective view of the actuation mechanism of the exit system of Figure 1; Figure 5 is a top plan view in partial cross section along line a-a of Figure 1 showing the latch mechanism of the exit system of Figure 1; Figure 6 is an elevation view of the exit system of Figure 1 with part of the frame removed to show the emergency lighting system, looking from the interior side; Figure 7 is an elevation view of a door emergency exit system in accordance with another embodiment of the present invention, looking from the interior side; Figure 8 is an elevation view of the door exit system of Figure 7 with part of the frame removed to show the actuation mechanism; Figure 9 is a plan view along line b-b of Figure 7 the locking assembly of the door exit system of Figure 7; and Figure 10 is a side elevation view of the hinge assembly of the door exit system of Figure 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Referring to Figures lto 3, there is shown an emergency exit system 2 in accordance with one aspect of the present invention. In this case, the emergency exit system 2 is a window mountable to the fuselage of an aircraft such as a helicopter (not shown). However, it may also be a door, a hatch or any other types of exits adapted for mounting to a closed enclosure such as the body of a vehicle such as a car, bus or truck, the fuselage of an airplane or a wall of a building.

Generally, the emergency exit system 2 comprises a frame 4 defining a central opening 6; a closure panel 8 such as a metallic frame releasably secured in the opening 6 by a plurality of locking means 10 extending from the frame 4; an actuation mechanism 12 (Figures 2 and 3) disposed within the interior of the frame 4 and a release mechanism mounted on the inside side of the frame 4 and includes a plurality of release means 14, which are independently operable to simultaneously displace the plurality of locking means 10 to enable jettisoning of the closure panel 8 to provide an emergency exit.

The window exit system 2 will now be described in detail with reference to Figures lto 6.

The frame 4 and the opening 6, both have a generally rectangular shape; however, they may assume other types of shapes. The frame 4 consists of an exterior and interior panels 16 and 18 joined to one another. The interior panel 18 has a thickness sufficient to incorporate the actuation mechanism 12 therein (Figures 2 or 3).

Looking from the interior side, the frame 4 further includes four closed compartments 20 extending inwardly into the interior of the helicopter from each corner thereof to define four recessed portions for receiving the release means 14. These compartments hold part of the actuation mechanism 12 and an emergency lighting system 24 (Figure 6), both of which will be described in detail below.

In contrast to prior art emergency exit systems, the exit system 2 of the present invention is provided with a release mechanism, which includes a plurality of release means 14. These release means 14 are mounted in obvious locations, i. e. they span along the interior horizontal and longitudinal sides 30,32 of the frame 4, so that they can be easily located and accessed, thus significantly improving the chances of escape and survival of the trapped survivors. Each release means 14 consists of an elongated cylindrical handle 26 fixed, at each end thereof, to press fitted arm levers 28 and 28'.

The release means 14 are individually connected to the actuation mechanism 12 in such a manner as to be independently operable from one another. Therefore, actuation of any one of the release means 14 will simultaneously disengage the locking means 10 to permit release of the closure panel 8 from the frame 4, without concurrently actuating the remaining release means 14. This minimizes the number of operations and amount of energy required from the survivor to release the closure panel 8. All the energy provided by the operator will be applied to the release of the closure panel 8 rather then for actuation of the remaining release means 14. Also, if one release means 14 malfunctions another may be used to serve the same function. The closure panel 8 is jettisoned by pulling anyone of the release means 14 towards the operator and away from the frame 4.

The release means 14 are rotatably mounted on the frame 4 between a first limit position and a second limit position. In the first limit position, the closure panel 8 is secured in the opening 6. In the second limit position, the closure panel 8 is released from the frame 4.

The actuation mechanism 12 includes in general terms a plurality of sets of actuation means 34. Each set is connected to one release means 14 and the total number of sets corresponds to the total number of release means 14. Referring to Figures 2 to 4, rotation of one release means 14 is transmitted to its corresponding set of actuation means 34 and then to the plurality of locking means 10 to simultaneously retract each locking means 10 inwardly into the frame 4 to release the closure panel 8. The actuation mechanism 12 is switchable between a locked position, seen in Figure 2, wherein the locking means 10 extend away from the frame 4 and centrally toward the opening 6, and a release position, seen in Figure 3, wherein the locking means are retracted into the frame 4.

Referring to Figure 4, each set of actuation means 34 comprises a combination of first, second, third and fourth actuation means 38,40,60 and 62 respectively, connected to one another in such a way as to translate rotational movement from the actuation means 14 into movement for disengagement of the locking means 10. The first and second actuation means 38 and 40 are mounted at opposite ends of a first gear shaft 42, which in turn is mounted on an L-shape support structure 44. Preferably, the first actuation means 38 is a helical gear and the second actuation means 40 is a spur gear.

The first gear shaft 42 consists of a wide base portion 46 which abuts a ball bearing mounted in the horizontal portion of the support structure 44. A retaining block 50 containing a ball bearing helps to support the shaft 42 in a generally upright position.

At its upper end, the shaft 42 is fixed to the first actuation means 38. A second gear shaft 54 is provided to connect the first actuation means 38 to the arm lever 28. At its lower end, the first gear shaft 42 extends through an opening in the horizontal portion 48 and is fixed to the second actuation means 40 by means of nut 56 and a key (not shown). The second actuation means 40 is engaged to the third actuation means 60, which is further connected to the fourth actuation means 62 by linking means. The linking means comprises a cable or line 58 running within a channel (not shown) spanning the inside perimeter of the frame 4. The cable 58 interconnects the third actuation means 60 to the fourth actuation means 62 so that linear movement of any one of the third actuation means 60 causes the each of the fourth actuation means 62 to simultaneously pivot (Figures 2 and 3).

Each of the third actuation means 60 consists of a hollow elongated rack having a set of teeth at the upper edge thereof for engagement with those of the spur gear 40, as best seen in Figure 4. The cable 58 is passed through the hollow space and can move freely therein. In the locked position (Figure 2), the rack 60 abuts a cable stop 64 affixed to the cable 58. As the spur gear 40 rotates, the rack 60 moves in the counterclockwise direction as shown by the arrows and pushes the cable stop 64 forward. The forward movement of the cable stop 64 in turn, moves the cable 58 forward to pivot each of the fourth actuation means 62 to simultaneously displace each of the locking means 10 to disengage the closure panel 8 from the frame 4 for jettisoning (Figure 3).

The fourth actuation means 62 are pivotally mounted on the frame 4 by way of a pivot mount 66. Each fourth actuation means 62 comprises a toothed head portion for engagement with the locking means 10 and a C-shaped tail portion. A cable pin 74 is captured in the C-shaped portion and is fixed to the cable 58 so that linear motion of the cable 58 pivots the fourth actuation means 62 to either the locked position to secure the closure panel 8 in the opening 6 or to the release position to free the closure panel 8 from the frame 4. For each locking means 10 there is a corresponding fourth actuation means 62.

The actuation mechanism 12 further comprises several idler pulleys 73 situated at the corners of the frame 4 and a conventional cable tensioner 75 to maintain the cable 58 at a desired tension.

Each locking means 10 includes an elongated cylindrical body extending into a relatively narrow head. The body consists of a set of teeth extending along its length for engagement with those of the fourth actuation means 62. Pivotal movement of the fourth actuation means 62 either retracts the locking means 10 into the frame 4 to the release position as shown in Figure 3, or extend the locking means 10 away from the frame 4 and towards the opening 6 to the locked position as shown in Figure 2. In the locked position, the locking means 10 engage corresponding indentations 77 (Figure 2), which are located along the side edges of the closure panel 8 and adjacent the locking means 10 to releasably secure the closure panel 8 in the opening 6. The locking means 10 may be a pin or any type of means capable of securing the closure panel 8 to the frame 4. In this case, four locking pins 10 are provided; however, there may be more or less.

Referring to Figure 5, a latch mechanism comprising a plurality of latch assemblies 82 is provided. The number of latch assemblies 82 corresponds to the number of release means 14. Each latch assembly 82 is connected to the arm lever 28' at one end of a release means 14 and particularly at the end, which is opposite to that of the gear arrangement. The latch assemblies 82 retain the release means 14 in the second limit position, as shown by the broken lines in Figure 5. Each latch assembly 82 includes a pivotal drive link 84 connected to an L-shaped support 44', which in turn is connected to the arm lever 28'. A housing 88 is provided at the lower end of the drive link 84 to receive a detent pin 90. The housing 88 is loaded with a compression spring 92 acting in the longitudinal direction of the housing 88 and resting between the base of the housing and the detent pin 90. In the first limit position, the detent pin 90 engages a slight coned-shaped hole 86 in the support structure 44'. As the release means 14 is rotated from its initial limit position to its second limit position, the detent pin 90 concurrently rotates until it reaches a drilled hole 94 into which it fits to lock the release means 14 in the second limit position, as shown by the broken lines in Figure 5.

Referring to Figures 2 and 3, a plurality of spaced apart jettisoning means 96 are mounted on the frame 4. Each jettisoning means 96 comprises a spring loaded plunger, which serves to bias the closure panel 8 outwardly from the frame 4, immediately upon release of thereof to clear the opening 6 and provide an escape exit.

In operation, one (or more) release means 14 is pulled towards the operator and away from the frame 4 from the first limit position to the second limit position.

Rotational movement of the release means 14 is transmitted through the arm lever 28 to rotate the first actuation means 38 (Figure 4). Rotation of the first actuation means 38 is further transmitted to the second actuation means 40 for rotation thereof via rotation of the first gear shaft 42. As the second actuation means 40 rotates, it moves the third actuation means 60 forward for translational motion and pushes onto the cable stop 64 to move the cable 58 forward in the counterclockwise direction, as indicated by the arrows in Figure 2, and to concurrently move the cable pins 74 forward. The translational motion of the cable pins 74 causes the corresponding fourth actuation means 62 to pivot and coact with their corresponding locking means 10 to retract the locking means 10 into the frame 4 to release the closure panel 8, which is immediately biased outwardly for jettisoning from the frame 4 by the spring loaded plungers 96.

Alternatively, the closure panel 8 can also be jettisoned by actuating an auxiliary actuation mechanism 98 (Figures 2 and 3). The auxiliary actuation mechanism 98 is capable of overriding the actuation mechanism 12 and comprises a pulley member 100 having a slot therein to receive a release pin 102, which is attached to the cable 58. An auxiliary release mechanism is provided and includes a couple of auxiliary release means 104 connected to the pulley member 100 on the inside (Figure 1) and outside (not shown) sides of the lower corner of the frame 4. Rotation of either auxiliary release means 104 rotates the pulley member 100 for movement of the locking means 10 to either the locked (Figure 2) or release (Figure 3) position.

It will be appreciated by one skilled in the art that although the actuation mechanism 12 described herein includes a specific gear arrangement, a variety of gear combinations can be implemented to obtain the same result as long as such combinations translate the rotational movement of the release means 14 arising from actuation thereof by a user to disengagement movement of the locking means 10 to disengage the locking means 10 from the closure panel 8 for release thereof. It will also be readily recognized that the actuation mechanism of the present invention can include electrically operated means in addition to, or instead of mechanically operated means.

For example, any of the gear elements can be powered by a small electric motor.

Similarly, the auxiliary actuation mechanism 98 is not limited to the pulley system disclosed and may include variations therefrom.

Referring to Figure 1, the closure panel 8 may consists of a window frame 101 and a window pane 103 secured thereto by a rubber molding 106. The window pane 103 can be manually forced out of the window frame 101 in a traditional manner by removing the rubber molding 106 to provide an emergency exit. The molding 106 is made of resilient material and provides an airtight sealing between the window pane 103 and the window frame 101.

Once removed, the closure panel 8 may be secured back into the opening 6 by placing the closure panel 8 into the opening 6 and pushing it toward the frame 4 as far as possible to compress the spring loaded plungers 96. The detent pins 90 are then be manually removed out of the housing 88 and the release means 14 are rotated to the first limit position. Finally, the window pane 8 is secured in the opening by rotating either of the auxiliary handles 104 to bring the locking means 10 from the release position (Figure 3) to the locked position (Figure 2).

Turning to Figure 6, the emergency lighting system 24 is used to illuminate the opening 6 and to indicate to the operator whether the closure panel 8 is secured in the opening 6 or jettisoned. The latter is achieved by changing the status of the lighting. In this case, a steady lighting indicates that the closure panel 8 is in the locked position, whereas a strobe lighting indicates that the closure panel 8 has been jettisoned. The lighting system 108 is incorporated into the frame 4 and consists mainly of a plurality of high intensity light emitting diode (LEDs) 110 disposed on the release means 14 and the auxiliary release means 104; a strobe switch 112 mounted on the frame 4 to indicate when the closure panel 8 has been jettisoned; lighting activation means (not shown) for activating the lighting system 24 and a power pack 114 mounted externally and separately from the exit system 2.

The lighting activation means includes an immersion sensor, an impact sensor, a roll-over sensor and a pilot switch. The sensors may be mounted on the fuselage of the aircraft or incorporated in the power pack 114. The immersion sensor is triggered when the helicopter is submerged in water. The impact sensor is triggered when a desired preset impact force is exceeded. The roll-over sensor is triggered when the helicopter is rolled over. Typically, the pilot switch is mounted on the console of the aircraft and can be manually controlled by the pilot to activate the lighting system 108. In this case, the impact sensor, immersion, roll-over sensors and pilot switch are connected in parallel between the power pack 114 and the LEDs 110 so that any one of those will activate the emergency lighting system 24.

The power pack 114 is connected to the lighting system 24 by means of a power cable 122, and includes therein a microprocessor (not shown) to control the lighting system 24.

Upon activation of the lighting system 24 by any one of the lighting activation means, the plurality of LEDs 110 will be activated simultaneously to illuminate the release means 14 and auxiliary handles 104. The release means and handles 14 and 104 will remain steadily illuminated until the lighting activation means are deactivated or one (or more) of the release means 14 is rotated to its second limit position to release the closure panel 8. In the latter case, the status of the light will change from steady light to strobe light. The strobe light is activated by one of the spring-loaded plunger 96, which activates the strobe switch 112. The strobe light will remain activated as long as the closure panel 8 is removed from the frame 4.

Referring to Figures 7 to 10, there is shown a door emergency exit system 200 in accordance with another embodiment of the present invention.

Similarly to the window exit system 2, the door exit system 200 comprises a frame 4 defining an opening 6. A door panel 8 is provided to close the opening 6. The door panel 8 comprises a main body portion 202 and a door flange portion 204, which overlaps with the fuselage of the helicopter for closure of the door panel 8. The door panel 8 also includes a window 206 and an inner door latch 208 operatively connected to a plurality of locking assemblies 210 to effect closure of the door 8 during normal operation. A pair of spaced apart hinge assemblies 212 are disposed on one edge of the outside side of the door panel 8 to hingedly mount the door panel 8 to the frame 4. The exit system 200 further includes an actuation mechanism 12 mounted inside the frame 4 and a release mechanism consisting of a plurality of release means 14. Each release means 14 operates independently of one another to release the door panel 8 from the frame 4 for jettisoning of the door panel 8.

The release means 14 are connected to the actuation mechanism 12 in the same manner as described above. However, in this case, actuation of any one of the release means 14 simultaneously disengages, both, the plurality of locking means 10 and the hinge assemblies 212 to release the door panel 8 from the frame 4 for jettisoning thereof.

The plurality of locking assemblies 210 are interconnect to one another by the cable 58, which in this case, runs at two levels along the inside perimeter of the frame 4.

Each locking assembly 210 includes a securing means 214 pivotally mounted on the frame 4 to secure the door panel 8 in the opening 6, and an associated locking means 10 mounted on the door panel 8 adjacent and engageable to the securing means 214 to enable locking and unlocking of the door panel 8 during normal operation. More specifically, during normal operation, the door panel 8 is locked by rotating the inner door latch 208 counterclockwise to extend the locking means 10 away from the door panel 8 for engagement with their corresponding securing means 214. The locking means 10 is engaged on the inner side of the securing means 214, as best seen in Figures 7 and 9. Alternatively, the door latch 208 can be rotated in the reverse direction to retract the locking means 10 into the door panel 8 to disengage the locking means 10 from the securing means 214 to unlock the door panel 8 permitting the door panel 8 to swing about the hinge assemblies 212.

The securing means 214 consists of a tab 216 fixed to a rotating gear 218 which is rotatably mounted on the frame 4. Upon actuation of any one of the release means 14, the plurality securing means 214 are simultaneously rotated by about 45 degree via translational movement of the fourth actuation means 62 to selectively move the securing means 214 into the frame 4 and hence, disengage the securing means 214 from the locking means 10 to release the door panel 8 for jettisoning thereof. Preferably, the locking means 10 are rolling pins.

Referring to Figure 10, each hinge assembly 212 comprises a mounting bracket 220 having a series of apertures 222 to accept bolts (not shown) to attach the bracket 220 to the outside side of the door panel 8 (not shown). The bracket 220 extends at one end thereof into a yoke 224, which is hingedly linked to an arm 226 by a standard hinge pin 228. The arm 226 includes a hinge post 230 which comprises a tapered portion 232 having a first shoulder 234, a central portion 236 having a second shoulder 238 and a flange portion 240. The first and second shoulders 234 and 238 define a retainer portion 242. The hinge assembly 212 further comprises a release member or slotted plate 244 mounted in the frame 4 (Figure 8) to releasably engage with the hinge post 230. The slot in the plate 244 is key-shaped to enable the door 8 to be hingedly mounted to the frame 4 when the retainer portion 242 of the hinge post 230 is seated in the small diameter slot (Figure 8), or to be released when the hinge post 230 is in the large diameter slot.

To release the door 8 for jettisoning, any one of the release means 14 can be pulled. This will actuate the actuation mechanism 12 in a similar manner as described in the window version of the invention to drive the cable 58 in a counterclockwise direction, as shown by the arrows in Figure 8. Translational movement of the cable 58 is transmitted into translational movement of the fourth actuation means 62, which in turn, is transmitted into pivotal movement of each of the tab 216 into the frame 4.

Movement of the cable 58 also results in linear movement of each of the slotted plate 244 in the counterclockwise direction to disengage the hinge post 230 from the small diameter slot into the large diameter slot of the plate 244 to enable the door panel 8 to be released from the frame 4 for jettisoning.

Similarly to the window version, the door emergency exit system 200 also includes an auxiliary actuation mechanism 98 (Figure 8). This mechanism can be used to override the actuation mechanism 12 to release the door panel 8 from the frame 4 or to hingedly mount the door panel 8 back on the frame 4 after it has been released.

While the foregoing embodiment of the invention have been described and shown, it is understood that all alternatives and modifications may be made thereto and fall within the scope of the invention.