Abstract:
An apparatus for preventing trolleys of aircraft during turbulence from leaving the floor of said aircraft includes a securing lock installed on a trolley of an aircraft for sensing the gravity on the trolley. Control is provided to prevent the action of the trolley from leaving the floor of the aircraft during turbulence. An actuation of the securing lock occurs for preventing the trolley from leaving the floor of the aircraft during turbulence. The securing lock includes a blade locking system for preventing the trolley on an aircraft during turbulence from leaving the floor of the aircraft by holding the trolley onto the seats adjacent to an aisle with extendable blades.

Description:
This application claims priority on provisional Application No. 60/205,074 filed on May 18, 2000, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF INVENTION 
     This invention relates to an apparatus and a method for securing aircraft trolleys during turbulence. 
     BACKGROUND OF THE INVENTION 
     In December 1995, a number of aircraft passengers and the crew members of the Cathay Pacific airlines were reported to have been badly injured by flying food trolleys when the aircraft met turbulence. In the early 1998, the same event also occurred on a United Airlines flight. The reasons that caused the food trolleys to fly and then fall down onto the passengers and crew members were due to the changes in the aircraft acceleration caused by turbulence. The changes of aircraft acceleration first resulted in the disappearance of gravity that holds the trolleys on the floor of aircraft and then resulted in a return of the gravity that pulled the flying trolleys back to the floor of the aircraft. For the safety of the people in aircraft, the aircraft trolleys should have a securing lock that prevents the trolleys from leaving the floor of aircraft regardless of the changes in aircraft acceleration. There has been no prior art found in this regard. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     It is the primary object of the invention to provide a method for securing aircraft trolleys during turbulence and an apparatus for performing the method. 
     According to the invention in the first aspect there is provided a method of securing aircraft trolleys during turbulence comprising the steps of preventing the trolleys from leaving the floor of aircraft during turbulence. 
     According to the invention in a second aspect there is provided a method of securing the aircraft trolleys during turbulence comprising the step of sensing the disappearance of gravity on the trolleys of the aircraft during turbulence, controlling the action of preventing the trolleys from leaving the floor of the aircraft during turbulence, and executing the action of preventing the trolleys from leaving the floor of aircraft during turbulence. 
     In a third and fourth aspect of the invention, an apparatus for preventing aircraft trolleys from leaving the floor of aircraft during turbulence is provided for performing the methods of the first and second aspects. 
     Further features of the invention may be found in the appended claims. 
     In the described embodiments of the invention, a method for securing aircraft trolleys during turbulence is disclosed. In this method, the trolleys are secured by preventing them from leaving the floor of the aircraft during turbulence. The method comprises the steps of, sensing the disappearance of gravity on aircraft trolleys during turbulence, controlling the action of preventing the trolleys from leaving the floor of the aircraft and executing the action of preventing the trolleys from leaving the floor of aircraft. A securing lock for the aircraft trolleys during turbulence is disclosed, which provides a primary function that is capable of preventing the trolley from leaving the aisle floor when the aircraft encounters turbulence. 
     The securing lock is installed on aircraft trolleys. At the instance when the aircraft meets turbulence, if the turbulence is so strong that a trolley leaves the floor of the aircraft because of the disappearance of gravity on the trolley, the securing lock will be triggered to prevent the trolley from leaving the floor. An apparatus for the securing lock is disclosed, including a blade locking system which locks a trolley of the aircraft during turbulence by holding it onto the seats adjacent to an aisle with built in blades, and a vacuum sucking system which adheres the trolley of the aircraft during turbulence to the floor of aircraft by vacuum sucking. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is a schematic view of one embodiment of the sensing unit and control unit of the blade locking system for the securing lock of the present invention; 
     FIG. 2 is a perspective view of one embodiment of the execution unit of the blade locking system for the securing lock of the present invention; 
     FIG. 3 is a schematic view of one embodiment of the sensing unit and control unit of the vacuums sucking system for the securing lock of the present invention; 
     FIG. 4 is a perspective view of one embodiment of the execution unit of the vacuum sucking system for the securing lock of the present invention; and 
     FIG. 5 is a schematic view of the one embodiment of the gravity sensing switch for sensing and controlling the vacuum sucking system for the securing lock of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Trolleys are used in aircraft for distributing goods and other purposes. An aircraft may meet air turbulence during a flight. The turbulence may cause the aircraft to accelerate in a direction such that gravity on a trolley located within an aircraft disappears and the trolley fly up from the floor of the aircraft. The present invention provides a securing lock to prevent the trolleys from flying up from the floor of aircraft during turbulence. The securing lock is installed in aircraft trolleys. It comprises a sensing unit, a control unit, and an execution unit. 
     As one of the embodiments of the securing lock system of the present invention, a blade locking system for the trolleys located within a passenger aircraft is disclosed. The sensing unit and control unit are shown in FIG.  1 . The system is installed on the trolley body  1 . The sensing unit is formed by the aisle floor  2 , the sensing wheel  3  held by the cylinder  4 , and the sensing spring  5  which links to the trolleys body and pushes constantly against the cylinder  4  together with a sensing wheel  3  against aisle floor  2 . The control unit is formed by the hole  6  having a slanted plane  7 , the rod  8  having a slanted plane  9  and the execution spring  10  pushing the rod  8  against the cylinder  4 . The execution unit of the blade locking system is shown in FIG.  2 . It is formed by the rod  8 , the blade locking transmission sets represented by  11 , and the blades represented by  12 . 
     During flying conditions without air turbulence, the blade locking system has its blades  12  retracted, i.e. the blades are kept inside the trolley body. At the moment of turbulence, if the aircraft acceleration in the direction opposite to the direction of gravity is so large that the gravity on the trolley disappears, the sensing wheel  3  will tend to be separated from the aisle floor  2 . The sensing spring S will then push the cylinder  3  together with the sensing wheel  3  outwards such that the hole  6  meets the rod  8  and the rod  8  is pushed into the hole  6  by the execution spring  10 . The blade locking action will then be trigged. The moving rod  8  will open the blades  12  through the transmission sets  11 , such that the blades  12  will be held by the passenger seats on both sides of the aisle, preventing the trolley from flying up. When the turbulence is over, gravity returns to the trolley and the force from the aisle floor  2  on the sensing wheel  3  will be large enough for the rod  8  being pushing out from the hole  6  along the slanted plane  7 . The rod  8  together with the transmission sets  11  and blades  12  will then return to their original positions. 
     The slanted angle α for both the planes  7  and  9  is designed such that on one hand of the rod  8  is able to move a long enough distance for opening the blades  12 , and on the other hand, the rod  8  can be pushed out from the hole  6  along the slanted plane  7  by the force from the floor  2  on the sensing wheel  3  when turbulence is over and gravity returns to the trolley. 
     The blades  12  and transmission sets  11  are designed in such a way that when the blades  10  are opened they are securely held by the passenger seats on both sides of the aisle. 
     As another embodiment of the securing lock of the present invention, a vacuum sucking system is disclosed. The sensing unit and control unit of the system are shown in FIG.  4 . The sensing unit is formed by the sensing wheel  13  held by the cylinder  14 , and the sensing spring  15  which links to the trolley body  1  and pushes constantly the cylinder  14  together with the wheel  13  against the floor  2 . The control unit is formed by a position switch  16  mounted on both the cylinder  14  and the body of the trolley. The execution unit of the system is shown in FIG.  5 . It is formed by the power supply  17 , the motor  18 , the pump  19 , and the vacuum sucking plate  20 . 
     During flying conditions without air turbulence, the sensing wheel  13  is pressed by the floor  2 , the position switch  16  is off, the motor  18  and pump  19  are at rest, and the vacuum sucking plate  20  is not in contact with the floor  2 . At the moment of turbulence, if the aircraft acceleration in the direction opposite to the direction of gravity is so large that the gravity on the trolley disappears, the sensing wheel  13  will tend to be separated from the floor  2 . The sensing spring  15  will then push the cylinder  14  together with the sensing wheel  13  outwards such that the position switch  16  is on. The motor  18  and pump  19  will then run so that the vacuum sucking plate  20  adheres to the floor  2 . When turbulence is over, gravity returns to the trolley and the sensing wheel  13  and cylinder  14  will be pushed back by the floor  2  so that the position switch  16  is off. The motor  18  and pump  19  will then stop, and the vacuum sucking plate  20  will leave the floor  2 . 
     In the vacuum sucking system for securing the lock of the present invention, the sensing unit can be in the form of any gravity meter that senses gravity on the trolley, and the control unit can be in the form of any control device that receives signal from the sensing unit and switches on or off the execution unit. 
     In the vacuum sucking system for the securing lock of the present invention, the sensing unit and control unit can be in the form of a sensing switch, as shown in FIG.  5 . It is formed by a sensing-connector  21  having a conductive curved face  22 , a sensing spring  23  which links the sensing-connector  21  to the trolley body  1 , and the connecting faces  24  and  25  linking to the execution unit  26 . During flying conditions without turbulence, the gravity on the sensing-connector  21  makes separates the faces  22 ,  24  and  25  and the execution unit is switched off. At turbulence, if the aircraft acceleration in the direction opposite to the direction of gravity is so large that gravity on the sensing-connector  21  disappears, the sensing-connector  21  will be pushed up by the sensing spring  23  and faces  22 ,  24  and  25  will be in contact, making on the switch for the execution unit  26 . When the turbulence is over, gravity returns to the sensing-connector  21  and pushes it down. Faces  22 ,  24  and  25  will then be separated and the execution unit  26  is switched off. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.