Abstract:
The present invention comprises a system for determining and adjusting the angle at which an escape slide is oriented. The system comprises an inflatable slide having a primary inflatable slide segment and at least one additional slide segments attached to the primary slide segment. Additionally, a state sensor configured to determine the attitude of the slide when inflated is attached to the slide or to structure surrounding the slide. Further, the system includes an inflation gas source coupled to the primary and at least one additional inflatable slide segments and an inflation controller in communication with the inflation gas source and the state sensor. The gas source and the state sensor operate to cause the gas source to adjust the at least one additional slide segments as a function of the attitude measured by the state sensor.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to emergency escape slides and, more specifically, to an adjustable escape slide that adapts to adverse airplane attitudes or other conditions that affect the slide angle. 
     BACKGROUND OF THE INVENTION 
     Aircraft evacuation slides are designed to accommodate an apriori sill height and be of an appropriate length to provide an appropriate slide angle under normal conditions. When a commercial airplane lands in certain adverse conditions, such as an engine coming off in conjunction with certain gear-out conditions, the resulting airplane altitude can render existing escape slides unusable at some doors. The angle of the slide must be within a certain allowable ranges to be effective. Outside of these ranges the slide angle is either too shallow to allow sufficient speed, or too steep to allow a safe egress. 
     Moreover, the escape slides are made of an appropriate length that is also dependent upon the size or model of aircraft the escape slides is used on. This may result in escape slides that are limited only for use on specific fleet airplanes and/or door locations. Ultimately, this leads to market deficiencies because not only are markets required to make additional escape slide variations in part numbers, and designs but also it increases the amount of certifications required. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a system for determining and adjusting the angle at which an escape slide is oriented. The system comprises an inflatable slide having a primary inflatable slide segment and at least one additional slide segments attached to the primary slide segment. Additionally, a state sensor configured to determine the attitude of the slide when inflated is attached to the slide or to structure surrounding the slide. Further, the system includes an inflation gas source coupled to the primary and at least one additional inflatable slide segments and an inflation controller in communication with the inflation gas source and the state sensor. The gas source and the state sensor operate to cause the gas source to adjust the at least one additional slide segments as a function of the attitude measured by the state sensor. 
     The present invention further comprises a method for employing an inflatable escape slide wherein the angle of the escape slide is measured or predicted then subsequently adjusted to place the slide in an optimal slide geometry, regardless of aircraft orientation. The method includes deploying a primary inflatable slide segment by releasing the slide segment and inflating, at substantially the same time activating a timing device or pressure sensor. Upon passage of a predetermined amount of time or achieving a desired slide pressure the slide angle is measured or the slide angle is predicted relative to vertical. Next, a determination is made whether the slide angle is within operating tolerances or not. If the slide is within operating tolerances, slide use may begin. However, if the slide use is not within allowable operating tolerances then an at least one additional slide segment attached to the primary slide segment is inflated or deflated to achieve proper slide geometry. Once proper slide geometry is achieved, slide use may commence. 
     As will be readily appreciated from the foregoing summary, the invention provides and efficient system and method for orienting an escape slide such that optimal slide geometry is achieved regardless of aircraft attitude, size or model. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings. 
     FIG. 1 is a frontal view of the invention; 
     FIG. 2 is a top view of the state sensor; 
     FIG. 3 is a frontal view of the contact sensor; and, 
     FIG. 4 is a flowchart of the process employed in accordance with the present invention 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 depicts an evacuation slide deployment  20 . The slide deployment  20  includes a slide  23  employable to slidably transfer people, animals, or inanimate objects from an elevated position to a lower position. In a presently preferred embodiment, the slide deployment  20  is attached to an aircraft  22  and is an evacuation slide. However, other employment environments are considered within the scope of this invention. More specifically, maritime vessels, amusement devices, buildings, large construction or mining equipment, or any other environment in which a temporary need exists to transfer people or property from a position of height to a lower position. 
     The slide  23  includes a primary inflatable slide segment  24  having a first end  25  and a second end  27  and at least one additional slide segment  26  attached to the second end  27  of the primary slide segment  24 . The first end  25  of the primary slide segment  24  is attached to an aircraft  22  at an access point, for example, a doorway. At least one vertical slide support segment  28  can be attached to a bottom surface of the slide  23 . When deployed, the slide  23  forms a slide angle  31  relative to a reference plane  29 . In a preferred embodiment, the reference plane  29  is a vertical plane passing. However, any plane of reference is considered within the scope of this invention. 
     The primary slide segment  24 , additional slide segments  26 , vertical slide support segment  28  are all in fluid communication with one another and with a gas source  37 . The gas source can be attached to the slide  23 , or it can be attached to the aircraft  22 . In a preferred embodiment, the gas source  37  is a compressed gas chamber wherein upon activation of a valve the compressed gas is introduced into the inflatable slide  23 . However, any other gas source is considered within the scope of this invention, for example, an oxidizing process. 
     The slide deployment  20  includes a state sensor  30 . In a preferred embodiment, as depicted in FIG. 1, the state sensor is located on an external surface of the primary slide segment  24 . However, the state sensor can be located at any location on the slide  23 , either internally or externally. Alternatively, the state sensor  30  can be attached to aircraft  22 . Regardless of location, the state sensor is in communication with the slide  23  and the gas source  37 . 
     A deployment attitude sensor  35  is also employable with this invention. The deployment attitude sensor  35  measures the attitude of the deployment site prior to deployment of the slide. More specifically, the sensor  35  measures an angle, relative to a predetermined reference point, and determines the number of additional slide segments  26  that must be employed in order to deploy the slide  23  such that the slide angle  31  is within a optimal operating range. The deployment sensor  35  can be employed singularly, or in conjunction with any other sensor arrangement. 
     FIG. 2 depicts the state sensor  30 . The sensor  30  includes a housing  33  having a plurality of electrical components contained within. In a preferred embodiment, the housing  33  contains a power source  40 , a position sensor  32 , a programmable position decoder  34 , a timer and/or pressure sensor  36  and an inflation device or trigger  38 . However, any variety of electrical components can be included within the state sensor without exceeding the scope of this invention. 
     In a preferred embodiment, each sensor, or electrical component of the state sensor  30 , can be in communication with sensory devices located outside of the housing  33  (not shown). Thus, the state sensor  30  can receive data from areas remote from the state sensor  30 . Conversely, the state sensor  30  can contain all of the sensory devices and electrical components within the housing  33 . In this manner, external connections are not necessary. For example, the power source  40  can be a battery or other local power source. 
     The position sensor can take a variety of forms. In a preferred embodiment, the position sensor is an electrolytic inclination sensor. However, any other position sensor is considered within the scope of the invention. For example, FIG. 3 depicts a contact switch sensor  30  arrangement. More specifically, a portion of a semi-rigid sensor arm  43  is attached to the primary slide segment  24  such that the attitude of the slide segment  24  is transferred to the sensor arm  43 . The sensor arm  43  is pivoted about a point  45 . As the sensor arm  43  pivots, the sensor arm  43  engages at least one contact switch  47 , or contact switch array  47  thereby indicating the attitude of the slide  23 . Likewise, optical sensors, electronic inclination sensors, mercury tilt switches and other sensory devices are considered within the scope of this invention. 
     FIG. 4 depicts a preferred embodiment of the slide deployment sequence  50 . More specifically, the deployment sequence  50  depicts a general process, which when preformed, yields a consistent, reliable, and optimally configured slide geometry regardless of aircraft attitude. 
     Step  52  initiates the deployment sequence  50 . The initiation can be a manual or automatic process. However, in a preferred embodiment, the initiation is a manual removal of an aircraft access point cover, for example, a door, and the manual initiation of the slide deployment  50 . 
     Following step  52  is a slide deployment, step  54 . Deployment step  54  includes the initial inflation of the slide  23  and at substantially the same moment, the activation of either a timer  36 , a pressure sensor  32  (see FIG. 2) or both. The inflation device  38  controls inflation of the slide  23 . The timer  36  and the pressure sensor  32  both serve the same initial purpose. More specifically, the elements allow the slide to inflate enough to allow for an accurate initial slide angle measurement. Thus, the slide measurement can be made at any time during the deployment. In the instance where the slide is not fully deployed, the slide angle  31  may be predicted based upon the slide geometry when the time ore pressure reading is taken. 
     The initial measurement of the slide angle is indicated by step  56 . The position sensor  32  performs the slide angle  31  measurement. The slide angle  31  is preferably measured relative to a vertical plane passing through the aircraft access point. However, measuring the slide angle  31  relative to any other plane is considered with the scope of the invention 
     After the initial measurement or prediction of the initial slide angle, a determination is made whether the slide angle  31  is within an optimal operating range, as indicated by step  58 . The programmable position decoder  34  preferably makes this determination. If the slide angle  31  is within a optimal operating range the slide can be used as indicated by the step  60  until the evacuation deployment sequence  50  is complete, step  64 . 
     When the slide angle  31  is not within a proper operating range the slide angle must be adjusted, step  62 . More specifically, the position decoder must make a determination whether the angle is too steep or too shallow. In the instance where the angle  31  is too steep, a signal is passed to the inflation device  38  to allow the gas source  37  to further inflate the additional slide segment  26  thereby increasing the slide length. Conversely, if the angle  31  is too shallow, the additional segment can be deflated in order to shorten the slide length and increase the slide gradient. The deflation can be performed in a variety of ways. For example, in a preferred embodiment a squib (not shown) may be detonated, forming a hole in the at least one additional slide segment  26  thereby deflating the segment  26 . The position sensor  32  monitors the slide angle  31  and when the position decoder  34  determines that an adequate slide angle  31  is obtained the adjustment ceases. Upon obtaining the adequate slide angle  31 , the slide  23  may be used and ultimately the evacuation sequence can terminate, step  64 . 
     While the preferred embodiments of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, initially the slide may fully inflate all segments and subsequently deflate some or all of the additional segments as necessary. Additionally, the slide may initially only inflate the primary slide segment with additional slide segments deployed as necessary, or any combination of the above description. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the scope of the invention should be determined entirely by reference to the claims that follow.