Abstract:
The application concerns a lifting device for a luggage compartment in an aircraft, wherein the luggage compartment can be moved between an open and closed position, and the lifting device includes a power generation element that exerts a lifting force on the luggage compartment. The application also concerns an aircraft with a lifting device for a luggage compartment. The power generation element is an electrical power generation element, and the lifting device has a rechargeable energy accumulator to store energy for operation of the electrical power generation element.

Description:
TECHNOLOGICAL BACKGROUND 
     DE 41 30 644 and U.S. Pat. No. 5,567,028 describe a luggage compartment with opening aids. 
     FIELD OF THE INVENTION 
     The invention relates to a lifting device for a luggage compartment in an aircraft. 
     SUMMARY OF THE INVENTION 
     According to an exemplary embodiment, the luggage compartment can be moved between an opened and closed position, and the lifting device includes a power generation element that exerts a lifting force on the luggage compartment. The invention also concerns an aircraft with a lifting device for a luggage compartment. 
     The invention, in particular, concerns movable luggage compartments arranged in commercial aircraft above the rows of seats. To move a luggage compartment from an open position to a closed position, a mechanical power generation element that supports the luggage compartment can be provided to assist the user, especially a gas-filled spring (DE 41 30 644 C2, U.S. Pat. No. 5,567,028). However, the required remaining force must be applied manually by a user. In addition, such arrangements, because of the limited lifetime of gas-filled springs, are maintenance-intensive. Depending on the weight of the load, an adjustment of the spring force can be required, which might require a weight sensor for the loading weight. 
     Pneumatic power generation elements require costly devices for compressed air generation in the aircraft. 
     Electrical power generation elements, especially electric motors, require a certain power demand for closure of the luggage compartment without outside force. With the number of luggage compartments provided in an aircraft, this can lead to extraordinary loading of the electrical system at times. The supply lines from the electrical system to the electric motors must be laid out for high current intensities and therefore have high weight. 
     To reduce these drawbacks, an electric motor with a lower power demand may be used and the remaining force for closure of the luggage compartment may be generated by means of a mechanical power generation element, especially a gas-filled spring. Such arrangements, however, are maintenance-intensive, because of the limited lifetime of the gas-filled springs. 
     An exemplary embodiment of the present invention may provide for a lifting device for a luggage compartment in an aircraft that is low-maintenance and reduces the load on the electrical system, as well as preferably has a limited weight and is user-friendly. 
     According to an exemplary embodiment of the present invention, the power generation element is an electrical power generation element, and the lifting device has a rechargeable energy accumulator to store energy for operation of the electrical power generation element. Owing to the use of an electrical power generation element, maintenance-intensive mechanical power generation devices, especially gas-filled springs, can be dispensed with. The high power required to close the luggage compartment over a short time can be taken from the energy accumulator without loading the electrical system. The energy accumulator can preferably be recharged via the electrical system after removal of the electrical power. 
     The energy accumulator is preferably charged from the electrical system of a relatively longer period with a reduced charge power or current intensity, so that the load on the electrical system is reduced. Because of the smaller charge current intensity, the connection lines between the lifting device and the electrical system can have a small cross section and therefore low weight. To charge the energy accumulator with power from the electrical system, the lifting device expediently has a corresponding charging device. The charging power of the charging device is preferably much lower than the power demand of the electrical power generation device. “Much smaller” means at least by a factor of 2, preferably smaller by at least a factor of 5. 
     The weight force support is preferably exclusively electric. The electrical power generation device allows the luggage compartment to be fully closed without outside force support, which increases user friendliness. 
     Preferably, each luggage compartment of an aircraft has its own energy accumulator. A number of decentralized energy accumulators is therefore involved. This makes it possible to keep the line length laid out for high current intensity as limited as possible. It can also be expedient for a certain number of luggage compartments to provide a common energy accumulator, in order to reduce the number of energy accumulators. Electrical storage devices for the energy accumulator are particularly simple and therefore preferred, especially one or more essentially maintenance-free capacitors. A number of capacitors can be connected in series, depending on the desired output voltage. However, rechargeable batteries are also suitable, in principle, as energy accumulator. The energy accumulator is preferably adequate for at least one, preferably at least, and more preferably at least four, operating cycles, so that in the event of repeated activation of the luggage compartment, i.e., repeated opening and closing, charging of the energy accumulator need not be waited for first. 
     The invention pertains to movable luggage compartments and is delimited on this account from fixed luggage compartments that are opened and closed by means of a flap. 
    
    
     
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       Other advantageous features are apparent from the following explanation of the invention by means of preferred variants with reference to the appended figures. In the figures: 
         FIG. 1 : shows a perspective view of a luggage compartment in the open state; 
         FIG. 2 : shows a cross-sectional view of a luggage compartment in the open state; 
         FIG. 3 : shows a cross-sectional view of a luggage compartment in the closed state; and 
         FIG. 4 : shows a schematic view of a lifting device. 
     
    
    
     Luggage compartments are arranged in a longitudinal frame  11  above the rows of seats of an aircraft. A luggage compartment  10  is arranged pivotable by means of a support arm  12  relative to longitudinal frame  11  around hinge  13 . In the open position depicted in  FIGS. 1 and 2 , the luggage compartment  10  can be loaded and unloaded through opening  14 . In the closed position depicted in  FIG. 3 , the bottom wall  15  of luggage compartment  10  is sealed off flush with the longitudinal frame  11 , in order to securely stow the luggage contained in the luggage compartment  10 . 
     In order to move the luggage compartment  10  from the open to the closed position, a lifting device  20  is provided. The lifting device  20  comprises an electric motor  21  with a gear mechanism to drive a cable roller  22 . A drive cable  23  runs around cable roller  22  via deflection rollers  24 ,  25  and is fastened on its end away from the motor on the top wall  18  of luggage compartment  10 . The electric motor  21  is driven by means of electrical power stored in an electrical storage unit  28  and controlled by means of a control device  27 . The control device  27  is supplied with a feed voltage Ui, produced, for example, by a converter  29 . The converter  29  is connected to the electrical system via lines  33 . Electric motor  21 , control device  27 , storage unit  28  and converter  29  are expediently connected to the longitudinal frame  11 , for example, on a rear wall  16  of the longitudinal frame  11  behind a rear wall  17  of the luggage compartment  10 . The electric motor  21  can have lines  32  for temperature monitoring for certain applications. 
     The luggage compartment  10  or each luggage compartment  10  has a storage unit  28 . However, this is not necessarily the case; for example, one storage unit  28  could also be allocated to two or more adjacent luggage compartments. In this case, the dimensioning of the storage unit  28  would be correspondingly larger relative to the values stated below. 
     A switch  26  is provided on the luggage compartment  10 , for example, on the bottom wall  15  or on the longitudinal frame  11 . If, starting from the open position depicted in  FIG. 2 , the switch  26  is operated by a user, a corresponding signal is sent to the control device  27 . The control device  27  optionally checks the charge status of the electrical storage unit  28 . It is assumed that the charge status of the storage unit  28  is sufficient for one operating cycle of the luggage compartment  10 . The control device  27  then connects the electric motor  21  to storage unit  28 , in order to rotate the electric motor  21  and therefore cable roller  22  clockwise, and pull the luggage compartment  10  by means of the drive cable  23  upward into the closed position depicted in  FIG. 3 . In the closed position, the luggage compartment  10  can be locked by means of a lock (not shown). The switch  26  can preferably be designed as a pushbutton, which can be laid out as a simple, small and therefore inexpensive membrane switch. 
     Both the electric motor  21  and the storage unit  28  are dimensioned sufficiently to reliably execute the closure process without outside force support up to a maximum loading weight for the luggage compartment  10 . Support of the luggage compartment  10  by the user is not required. For some applications, the electric motor  21  preferably has a power demand of more than 50 W, for example, about 80 W. Since the rotational speed or power demand of the electric motor  21  is approximately constant, i.e., independent of the loading state of the luggage compartment  10 , a weight sensor for power adjustment of the electric motor  21  is unnecessary. 
     The storage unit  28  is dimensioned sufficiently to be able to close the luggage compartment at least five times in sequence. The electrical storage unit  28  includes one or more capacitors connected in series, set up to take off sufficiently high currents. So-called Ultra-Caps can be involved. For some applications, the capacitance of the storage unit  28 , overall, is at least 50 F, for example, in the range of 100 F. The lines  30 ,  31  between the storage unit  28  and the electric motor  21  must have sufficient current conductance, especially a sufficient line cross section with respect to the maximum flowing current. 
     After unloading, the electric storage unit  28  is recharged by the control device  27 , which simultaneously serves as charging device. The charging current is taken from the electrical system via lines  33 . The control device  27  takes a charging current from the electrical system that is much smaller than the withdrawal current from the storage unit  28  for operation of electric motor  21 . In order to reduce the load on the electrical system, the charging power is preferably, at most, 15 W, more preferably, at most, 10 W, and even more preferably, at most, 8 W. Because of this relatively limited power, no special requirements need be imposed on the dimensioning of lines  33 ,  34  between the electric system and control device  27 , so that these can have a relatively limited line cross section and therefore relatively low weight. The same applies for dimensioning of the converter  29 , which can have a correspondingly small maximum power demand. The charging power is sufficient to permit charging of the storage  28  within a limited charging period in the range of less than 600 s, preferably less than 300 s. 
     If the pushbutton  26  in the closed position depicted in  FIG. 3  is operated by a user, a corresponding signal is sent to the control device  27 . The control device  27  unlocks the luggage compartment lock, if this is preferably electrically operable. Otherwise, unlocking of the luggage compartment lock can be required instead, in addition or in combination with operation of pushbutton  26 . The control device  27  then connects the electric motor  21  to storage unit  28 , in order to rotate the electric motor  21  and therefore the cable roller  22  and to move the luggage compartment  10  downward by means of drive cable  23  to the open position depicted in  FIG. 3 . The electric motor  21  then expediently acts as a motor brake, in order to prevent return or abrupt lowering of the luggage compartment  10 . 
     Via signal line  35  and a corresponding interface, the control device  27  can optionally be connected to a central control unit of the aircraft, for example, by an available data bus. This makes it possible to operate the luggage compartment centrally. For example, in certain phases of the flight, it can be useful to centrally close all luggage compartments of an aircraft and keep them locked, so that operation of any provided individual pushbutton  26  does not trigger an opening process of the corresponding luggage compartment  10 . In addition, fully automatic control of luggage compartments  10  can occur via the central control unit, during which a user need no longer carry out activity on an individual luggage compartment for opening or closing, i.e., need no longer operate the individual pushbuttons  26 . Expediently, the luggage compartment locks are therefore operable from the central control unit of the aircraft for fully automatic opening of the luggage compartments. An electromechanical, for example, electromagnetic, luggage compartment lock is preferably involved. Operation of the luggage compartments via the central control unit is also advantageous for test operation.