Abstract:
A suspension device for a lowerable luggage stowage compartment has at least one spring element for assisting the movement of the compartment into a closed position against the force of gravity, and at least one damping element for damping the movement of the compartment into an opened position. A weight detector detects the weight of the compartment, and at least one additional spring element can be actuated based on the detected weight of the compartment. A retention device is provided for fixing the additional spring element. The suspension device provides a compartment that is easy to handle and easy to close even when fully loaded.

Description:
This is a nationalization of PCT/AT02/00275 filed Sep. 23, 2002 and published in German. 
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention relates to a suspension device for lowerable luggage stowage compartments comprising at least one spring element for assisting the movement of the compartment into its closed position contrary to gravity, and at least one damping element for damping the movement of the compartment into its opened position, and comprising a means for detecting the weight of the compartment and at least one additional spring element capable of being activated or switched over in dependence on the detected weight of the compartment, a retention device being provided for fixing the at least one additional spring element. 
     Furthermore, the invention relates to a lowerable luggage stowage compartment comprising such a suspension device, wherein at least one spring element is arranged between the compartment and a stationary structural element laterally of the compartment so as to assist in the movement of the compartment into its closed position contrary to gravity, and at least one damping element is arranged for damping the movement of the compartment into its opened position, a means for detecting the weight of the compartment being connected to the compartment part. 
     The present invention mainly relates to a luggage stowage compartment as is used in passenger aircraft. However, it is also applicable to luggage stowage compartments as, e.g., used in rail-borne vehicles or in other transport devices adapted for passenger transportation. 
     2. Description of the Prior Art 
     Luggage stowage compartments in passenger aircraft usually consist of cases mounted above the passengers&#39; heads and having an opening that is closable e.g. by means of a pivotable flap. To put an item of luggage into the compartment or to remove it therefrom, the passenger must open the flap and lift his/her item of luggage through the opening into the compartment or remove it therefrom. This requires a considerable effort, particularly if the items of luggage are heavy, and this may be an impediment for short or weak persons. 
     To improve the situation, particularly in very large passenger aircraft which also have a greater cabin height, luggage stowage compartments have been developed which can be pivoted downwards or lowered for the purpose of loading and unloading the same. Such pivoting or lowering mechanisms usually comprise at least one damping element which dampens the downward movement of the compartment so that the compartment will not drop down abruptly during opening of the latter and cannot cause injuries. In addition, such a mechanism comprises at least one spring element which assists the movement of the compartment contrary to gravity into its closed position and thus makes it easier for the passenger to close the loaded compartment. These damping and spring elements are adjusted such that they will provide a sufficient damping for a luggage stowage compartment bearing an average load, and will sufficiently assist the movement into its closed position. If the load of the compartment deviates from this average value to which the damping and spring elements have been adjusted, the mechanism will not function as desired. Thus, an empty compartment would be only very difficult to be moved into its open position, contrary to the action of the damping element, allowing an opening of the compartment only by exerting a relatively high tensile force. On the other hand, it would be difficult and possible only by using physical activity to move an overloaded compartment into its closed position contrary to gravity. The problem is aggravated by the fact that for future aircraft designed for ever increasing numbers of passengers, the luggage stowage containes have to be built of increasingly larger sizes and have to withstand ever increasing loads. Such luggage stowage compartments may, e.g., be designed for loads of from 0 to 60 kg. Accordingly, it is nearly impossible to design a pivoting or lowering mechanism for such a luggage stowage compartment which will be the best for all loads. 
     DE 41 30 644 A1 shows an overhead luggage stowage device whose handling will require little actuation effort and which is largely independent of the load added and the position of the movable compartment. For this purpose, the gas spring provided to assist the closing procedure is pivotably arranged so that the hinge point on the upper lever and, thus, the torque acting on the upper lever thereby assisting the closing procedure of the compartment are changeable. The weight of the movable compartment of the overhead luggage stowage device is detected by a weighing pin which acts on a weighing lever connected to the spring element. Depending on the weight of the compartment&#39;s load, the gas spring will be pivoted more or less, and thereby the weight force of the compartment will be compensated. To prevent the gas spring from being pivotable into its original position during the closing procedure of the compartment, a blocking means is provided which is actuated via a Bowden cable as soon as a pressure is exerted on the arresting plate at the lower side of the pivotable compartment so as to initiate the switching procedure. In addition, when a certain height of the lowerable compartment has been reached, the blocking device is automatically actuated so that it will also be active independently of the state of the Bowden cable. 
     DE 43 35 151 A1 also shows an overhead luggage stowage device comprising a lowerable compartment wherein a further spring element can be activated in dependence on the loading of the compartment so as to assist in the closing procedure. If the compartment is not loaded or only slightly loaded, a supporting lever connected to the additional spring element is blocked so that the additional spring element will not exert an additional force on the compartment. If the load of the compartment exceeds a certain limiting value which is detected by the load-caused deflection of the movable compartment, the blocking of the supporting lever can be released by an active pressure from the bottom on a triggering plate on the movable compartment part, and the additional spring element will act to assist in the closing procedure. Between the triggering plate and the supporting lever, a Bowden cable is arranged to transmit the pressure onto the triggering plate on the blocking hook. Therefore, an active participation of the passenger is of necessity required for an activation of the supporting spring, and this renders an operation thereof difficult. The connection between the triggering plate and the blocking hook of the supporting gas spring required of necessity also makes mounting and maintenance more complex and makes it more susceptible to failure. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to provide a suspension device for lowerable luggage stowage compartments which will assist in the lifting of the compartment into its closed position also with the compartment being variably loaded, and which simultaneously will sufficiently dampen the movement during opening of the compartment with the compartment being variably loaded. For instance, the force required for opening the compartment in its empty state should not exceed 70 N, and the force required for closing the fully loaded compartment should not exceed 200 N. Moreover, the suspension device should be designed to be as simple, light-weight, and robust as possible, as well as maintenance-free. Furthermore, the suspension device shall ensure an easy manipulation of the lowerable luggage stowage compartment. The weight-caused activation or switching over of the at least one additional spring element shall occur automatically and without active participation by the passenger. Such a suspension device shall, e.g., withstand the stress usual and stipulated in the aircraft industry. For instance, for the actuation of such luggage stowage compartments a product life of 200,000 opening cycles is required. 
     A further object of the invention consists in providing a lowerable luggage stowage compartment which is easy to handle also for variable loads and which is constructed as simple, light-weight and robust as possible and, moreover, can be produced at low costs and is maintenance-free. 
     The first object according to the invention is achieved in that the retention device is actuatable by the means for detecting the weight of the compartment. The present invention is characterised by a direct connection between the means for detecting the compartment weight and the retention device so that if a certain weight is exceeded, one or more additional spring elements can automatically be activated or switched over, respectively. The invention is characterised by low mounting expenditures, a low amount of maintenance and a low failure rate. With this construction, a two- or multi-stage control of the spring force can be realized. As a rule, a two-stage control of the spring force will suffice for a flawless functioning of the handling of the compartment. The value of the compartment weight starting from which the additional spring element will be activated is chosen according to the respective requirements and, e.g., will be determined to be half the maximum allowable load. In case of compartment loads exceeding this limit value, the at least one additional spring element will assist in the lifting of the loaded compartment and thus will ensure an optimum handling. Thereby, an optimum handling of the lowerable luggage stowage compartment will be ensured also for varying loads. 
     To achieve the robustness required, the spring element as well as the at least one additional spring element are formed by mechanical coil springs which preferably are arranged coaxially to each other. Thus, a serial connection of at least two spring elements is formed which, due to the coaxial arrangement, have the same point of application and point of action. Of course, also a parallel arrangement of several spring elements is feasible. Moreover, coil springs arranged coaxially to each other are particularly space-saving and compact. 
     According to a further feature of the invention it is provided that the at least one additional spring element is surrounded by a sleeve which is fixable by a retention device so that the at least one additional spring element can be fixed when in its tensioned position. Thus, if the compartment is empty or if its load is below the limiting value, the at least one additional spring force of a spring element will be stored and released upon demand by actuation of the retention device. 
     The retention device may, e.g., be formed by a movable hook or the like, engaging, e.g., in a flange on the sleeve, thereby fixing the latter and the spring arranged therebelow in its tensioned position. 
     Alternatively, the retention device may also be formed by a rotatably mounted disk, wherein the rotation of the disk can be influenced by the detected weight of the compartment and by this the at least one additional spring element can be activated. By the rotatably mounted disk, the at least one additional spring element can be locked if the compartment weight is below a certain limiting value, and released, if the weight of the compartment is above a certain limiting value. If several additional spring elements are arranged, the activation of individual ones of the additional spring elements or of combinations thereof can be achieved by a respective rotation of the disk. 
     If the disk is non-rotationally connected to a switching lever and a switching link having at least two different switching positions that can be influenced by the weight of the compartment is arranged on the compartment, with the switching lever resting on the switching link, an activation or switching over of the at least one additional spring element can be effected in dependence on the weight. The switching link will force the switching lever into an appropriate position, whereby the disk that is non-rotationally connected to the switching lever will assume an appropriate position so that the at least one additional spring element will be released or blocked in accordance with the weight of the compartment. 
     To achieve an exact activation of the at least one spring element, the switching lever preferably is pressed against the switching link by means of a spring or the like. This may be effected by a torsion spring, e.g. 
     A simple realisation of the switching link is provided by at least two snap-in steps having different step depths, which switching link, in the opened position of the compartment, is displaceable by the weight of the latter. The maximum displacement of the compartment will determine the displacement of the switching link which will be subdivided depending on the number of switching steps. Usually, two switching steps will suffice, wherein in one switching position an additional spring element will be blocked and in the other switching position it will be released. 
     According to a further feature of the invention it is provided that the means for detecting the weight of the compartment is formed by a bearing of the compartment in its open position, which bearing can be deflected against a measurement spring. This purely mechanical construction is characterized by being particularly simple and robust. In this case, the compartment weight need not be continuously detected, it only has to be detected if a certain limiting value is exceeded. The measurement spring is dimensioned such that it can be stretched by a given deflection if the compartment is loaded in excess of the pre-determined measurement value. 
     The bearing can also be formed by an element connected to the compartment, which element, e.g. a pin, is arranged in a guide, e.g. a long hole, and is connected to the end of the measurement spring. By means of the long hole, the deflection of the compartment is limited. 
     If the element connected to the compartment is connected to one end of the Bowden cable or the like, whose other end is connected to the retention device of the at least one additional spring element so that the retention device is releasable if the compartment is deflected due to its weight, a simple, weight-controlled change of the spring force can be realized in a purely mechanical way. This is a robust and simple possibility of realizing the connection of the means for weight detection and the device for changing the spring force of the spring element. 
     To allow for an adjustment of the lowering device to the respective requirements, the limiting value of the compartment weight preferably is adjustable by an adjustable embodiment of the measurement spring. By this adjustability, also any possible signs of fatigue of the device for measuring the weight of the luggage stowage compartment can be counteracted. The adjustability of the measurement spring can be effected by changing the range of the spring or by other methods. 
     If a device for changing the spring force of the spring element and/or of the at least one additional spring element is provided, an adaptation to the respective requirements, such as, e.g., to the empty weight of the compartment, or also a re-adjustment of the spring elements can be effected. 
     In this case, the device for changing the spring force of the spring element and/or of the at least one additional spring element can be formed by a screw for changing the bias of the spring element and/or of the at least one additional spring element. In mechanical coil springs, the range of the spring and thus, the bias of the spring is adjusted by re-adjusting the screw. 
     According to a further feature of the invention, a device for maintaining the compartment in its opened position is provided, which may, e.g., be formed by a resiliently mounted sphere which engages in a corresponding snap-in depression when the compartment is in its opened position. By this, the compartment can suitably be kept in its opened position for loading and unloading, and thus, it can be manipulated more easily. In this case, the holding device must be appropriately positioned and the spring force which presses the sphere into the snap-in depression must at least be so high that it cannot be overcome by the force of the spring element. 
     Likewise, the means for detecting the weight of the compartment can be formed by an electronic sensor which detects the instantaneous weight of the luggage stowage compartment. Of course, such an electronic sensor also requires a voltage supply and the connecting lines required therefor, which are disadvantageous in contrast to the purely mechanical solution. 
     Likewise, the device for changing the spring force of the spring element can also be formed by an electronic element, e.g. an electric servo-motor or the like, which can infinitely vary the spring force of the spring element. Yet, also this realization has disadvantages when compared to a simple, mechanical construction, with regard to robustness and freedom from maintenance, and also in terms of costs and weight. 
     The second object according to the invention is achieved by a lowerable luggage stowage compartment of the indicated type in which the means for detecting the weight of the compartment is connected to a means for changing the spring force of the spring element. 
     Advantageously, on either side of the compartment at least one guide rod is rotatably arranged which is hinged to the stationary structural element, and furthermore, an element is arranged for synchronising the movement of the guide rods on both sides of the compartment. By this, a synchronous movement of the compartment is achieved during the lowering procedure, and thus twistings or uneven loads acting on the suspension device are avoided. 
     In the simplest form, the synchronising element may be formed by a non-rotational tube or the like connected to the guide rods on either side of the compartment. 
     To dampen also the closing procedure of the luggage stowage compartment, a further damping means may be provided for damping the movement of the compartment into its closed position. 
     The invention will be explained in more detail by way of the accompanying drawings which show an exemplary embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Therein, 
         FIG. 1  shows a section through part of the fuselage of a passenger aircraft; 
         FIG. 2  shows an embodiment of a lowerable luggage stowage compartment in its closed position, in side view; 
         FIG. 3  shows the luggage stowage compartment according to  FIG. 2  in partially opened position; 
         FIG. 4  shows the luggage stowage compartment according to  FIG. 2  in its opened position; 
         FIG. 5  shows the luggage stowage compartment when loaded beyond a given limiting value, with the additional spring element activated; 
         FIG. 6  shows the detail VI of  FIG. 5 , in an enlarged representation; 
         FIG. 7  shows the detail VII of  FIG. 4 , in an enlarged representation; 
         FIG. 8  shows a further embodiment of a lowerable luggage stowage compartment in its closed position, in a perspective view; 
         FIG. 9  shows the lowerable luggage stowage compartment of  FIG. 8 , in its opened position; 
         FIG. 10  shows the detail X of  FIG. 9 , in an enlarged view; 
         FIGS. 11A ,  11 B, and  11 C show an embodiment of the spring element with a coaxially arranged additional spring element, when only the additional spring element is activated, in side view in a sectional representation of the spring element, and in a view on the retention device designed as a disk, and including the switching lever; 
         FIGS. 12A ,  12 B, and  12 C show the spring element according to  FIGS. 11A ,  11 B, and  11 C, in a different switching position of the switching lever; 
         FIGS. 13A ,  13 B, and  13 C show the spring element according to  FIGS. 11A ,  11 B, and  11 C in a further switching position, in which both spring elements are activated; and 
         FIGS. 14A and 14B  show a perspective view of a lowerable luggage stowage compartment according to the invention in closed ( FIG. 14A ) and opened ( FIG. 14B ) positions. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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. 
       FIG. 1  shows a section through a part of the aircraft fuselage  30 , in which the seats  31  for the passengers are arranged. Above the seats  31 , there are the luggage stowage compartments  21 , which may also be pivotably or lowerably arranged for greater ease of loading and unloading. 
       FIG. 2  shows a lowerable luggage stowage compartment  21  which is equipped with the suspension device according to the invention. Via the suspension device, the compartment  21  is connected to the stationary structural element  20  which may, e.g., be connected to the fuselage of an aircraft or the like. Preferably, the lowerable compartment  21  is designed like a trough. The suspension device preferably is arranged on both sides of the compartment, between the structural element  20  and a side wall of the compartment  21 . The suspension device consists, e.g., of an upper guide rod  4  and a lower guide rod  5 . With one of its ends (pivot point A), the upper guide rod  4  is mounted on the structural element  20  or on an element connected thereto, and with its other end (pivot point B) it is rotatably fastened to the compartment  21 . With one of its ends (pivot point D), the lower guide rod  5  is connected to the structural element  20 , and, via a damping element  2 , its other end (pivot point E) is connected to the end of the upper guide rod  4  that is connected to the compartment  21 . At the pivot point C of the upper guide rod  4 , a part  3  of a toggle lever is hinged at whose end the spring element  1  engages at pivot point H. At its other end, at pivot point G, the spring element  1  is connected to the structural element  20 . The one end of the toggle lever  3  is articulately connected to the further part  3 ′ of the toggle lever at pivot point H, whose other end, at pivot point F, is articulately connected to the compartment  21 . Toggle lever part  3 ′ causes guiding of the suspension device during lowering of the compartment  21 . In addition, a guiding link  10  may be arranged, e.g. in a wall connected to the structural element  20 , which guiding link  10  obviates a lateral deflection during the movement of the luggage stowage compartment  21 . The guiding link  10  is configured according to the movement of the end of the spring element  1 . To dampen the movement during closing of the luggage stowage compartment  21 , an additional damping means  6  may be arranged which, e.g., acts on the lower toggle lever part  3 ′ and dampens the movement of the compartment  21  shortly before the latter is closed. The damping means  6  is arranged on structural element  20 . The damping means  6  may also act on another movable part of the suspension device. The spring element  1 , e.g., is formed by a coil spring  14  which is arranged on a rod  15  so as to prevent a lateral deflection. Over coil spring  14 , a sleeve  16  is arranged which has a flange  17  via which sleeve  16  is held in the position illustrated by means of a hook  13 . According to the invention, a means for detecting the weight of the compartment  21  is arranged on the compartment  21 . In the exemplary embodiment illustrated, a pin  18  is connected to the side wall of the compartment  21 , the pin projecting through a long hole  19  in the lower guide rod  5 . On the pin  18 , a measurement spring  7  is fastened against which a deflection of the compartment  21  in its opened position is possible. The deflection of the compartment  21  is transmitted via a Bowden cable  8  to the hook  13 , whereby a change in the spring force of spring element  1  can be achieved in dependence on the weight of the compartment  21 . The function of the means for detecting the weight of the compartment  21  and of the device for changing the spring force of the spring element  1  will be discussed in more detail further below. Usually the suspension means are arranged in mirror-inverted relationship on either side of the luggage stowage compartment  21 . A synchronisation of the movement may, e.g., be achieved via a tube  12  or the like that is non-rotationally connected to the upper guide rods  4 . 
       FIG. 3  shows the lowerable luggage stowage compartment  21  in partially opened position, wherein the compartment  21  is downwardly lowered, dampened by the damping means  2 . The lower toggle lever part  3 ′ is pivoted out of its original position about pivot point F so that the piston  22  of the damping means  6  is extended into its relaxed at-rest position. 
       FIG. 4  now shows the lowerable luggage stowage compartment in its opened position, in which the luggage comfortably can be loaded and unloaded via the opening  23  of the compartment  21 . In the opened position, the spring element  1  is completely compressed so that the spring force can exert its force when lifting the compartment  21 . In the illustrated opened position of the compartment  21 , the lower toggle lever part  3 ′ can abut on an end stop  24  which delimits its movement. The end stop  24  may also be arranged at another point of the structural element  20  and act on another element of the suspension device. Now, when the compartment  21  is loaded with items of luggage, the inventive means for detecting the weight of the compartment  21  will become active. In this context, reference is made to  FIG. 7  which shows the detail VII of  FIG. 4  in an enlarged illustration. Due to the weight of the items of luggage, the compartment  21  will sink downwards contrary to the spring force of the measurement spring  7 , the movement (distance d) being delimited by the long hole  19  in the lower guide rod  5 . Via the spring force of the measurement spring  7 , the limiting value of the weight of the compartment  21  can be adjusted starting from which a change of the spring force of the spring element  1  shall occur. The measurement spring  7  may, e.g. be adjusted via a change of the spring range, e.g. via a screw (not illustrated). To the pin  18  which projects through the long hole  19 , a Bowden cable  8  is connected which transmits the deflection of the compartment  21  to the hook  13  that retains (keeps back) the sleeve  16  of the spring element  1 . This state is illustrated in  FIG. 5 , in which the compartment  21  is lifted, whereby the spring element  1  exerts an increased spring force as a consequence of the activation of an additional spring element  25 . By the weight of the compartment  21 , the hook  13  has been moved and the sleeve  16  has been released so that the biased further spring element  25  arranged below sleeve  15  is released. By this, the additional spring element  25  which, e.g., is also formed by a coil spring, can exert its force in addition to the coil spring  14  of the spring element  1 . By this, the movement of the compartment  21  into its closed position is assisted even when fully loaded. If the luggage stowage compartment  21  is opened again and unloaded, the compartment  21  will lift upwards, and hook  13  again will retain the sleeve  16  of the spring element  1  so that the force of coil spring  25  is not effective and merely the force of coil spring  14  is active which suffices to assist in the lifting procedure of the empty or only slightly loaded compartment  21 . 
     One embodiment of the spring element  1  according to the invention is represented in  FIG. 6 , which shows the detail VI of  FIG. 5  in a sectional illustration. The spring element  1  consists of a coil spring  14  which is arranged over a rod  15 . The one end of the spring element  1  is connected to the structural element  20  at pivot point G, while the other end of the spring element  1  is connected to the compartment  21  via pivot point H. Thus, the coil spring  14  exerts a force from pivot point G in the direction of pivot point H. A sleeve  26  is arranged over the coil spring  14 , which sleeve has a length corresponding to the stroke of the spring element  1 . Above sleeve  26 , the additional coil spring  25  is arranged which is covered by sleeve  16 . The coil spring  25  is maintained in compressed state by the end  27  of sleeve  16  as long as the hook  13  retains the sleeve  16  via flange  17 . After actuation of the hook  13 , the sleeve  16  is pressed against the end of the spring element  1 , and the coil spring  25  can unfold its force in the direction of the pivot point H. To prevent the end  27  of sleeve  16  from moving beyond pivot point H, an enlarged flange  40  is arranged on rod  15 . When opening the luggage stowage compartment  21 , the spring element  1  is compressed, whereupon the flange  17  of sleeve  16  will again be pressed behind the hook  13  which, in case of an empty or slightly loaded compartment  21 , will again retain the sleeve  16 . For this purpose, the hook  13  must be biased, e.g. by means of a coil spring  28 . Even though the illustrated coaxial, two-step arrangement of the spring element  1  has advantages, also a parallel arrangement of two or more spring elements may serve to achieve the object according to the invention. 
       FIG. 8  shows a perspective view of a further embodiment of the overhead luggage stowage compartment  21  in its closed position. There, the stationary structural element  20  has been illustrated without side walls for a better view on the suspension device. In this alternative embodiment, the damping element  2  is connected between the upper guide rod  4  and an element for connection to the fuselage of the aircraft or the like. Just as in the embodiment according to  FIGS. 2 to 5 , the suspension device consists of an upper guide rod  4  and a lower guide rod  5 , with a damping element  2  arranged between the ends thereof (pivot points D and E). In contrast to the embodiment according to  FIGS. 2 to 5 , not a toggle lever is arranged at the pivot point C of the upper guide rod  4 , but rather a rigid lever  29  whose other end is articulately connected at pivot point F to the side wall  33  of the stationary structural element  20 . At pivot point H of the lever  29 , the one end of the spring element  1  engages which, with its other end, is connected at pivot point G to the side wall  33  of the structural element  20 . According to the invention, a switching link  34  is arranged at the side wall of the compartment  21 , which switching link, in the opened position of the luggage stowage compartment  21  according to  FIG. 9 , cooperates with a switching lever  35  of the spring element  1  and causes switching of the spring element  1  in dependence on the weight of the compartment  21 . For this purpose, the movable compartment  21  in its opened position is arranged to be displaceable in its position against the spring force of a measurement spring, whereby the weight of the compartment  21  can be detected. According to  FIG. 7 , the displaceability of the compartment  21  in dependence on the weight of its load can be effected by movement of a pin  18  in a long hole  13  of the guide rod  5 . The weight-caused change of the position of the compartment  21  within pre-determined limits may, however, also be realized in a different manner. 
       FIG. 10  shows the detail X according to  FIG. 9  in an enlarged illustration. In accordance with the weight-caused change of the position of the compartment  21 , the switching link  34  fastened to the side wall of the compartment  21  is moved, the direction of this movement being determined, e.g., by the guidance of the pin  18  in the long hole  19  in the lower guide rod  5 . The end of the switching lever  35  rests on the switching link  34  and is pressed towards the switching link  34 , preferably by a spring not illustrated, e.g. a torsion spring. A disk  36  is non-rotationally connected to the switching lever  35 , which disk has appropriately configured recesses  37  via which, upon rotation of the disk  36 , the at least one additional spring element  25  can be retained or released, and switching between the spring elements  1  and  25  may be effected, respectively. In the exemplary embodiment illustrated, this is achieved by a sleeve  16  arranged about the additional spring element  25 , the projection of the sleeve  16  projecting through the recess  37  of the disk  36  and being retained or released at an appropriate angular position of the disk  36 . The function of the spring element  1  in combination with the additional spring element  25  will be explained in more detail by way of  FIGS. 11 to 13 . 
       FIGS. 11A ,  11 B, and  11 C show the embodiment in which the luggage compartment  21  is empty or only slightly loaded and thus will not be pressed downwards by the weight of its load. Thus, the switching lever  35  will be on the uppermost step of the switching link  34 . In this angular position, the disk  36  which is non-rotationally connected to the switching lever  35  will release the sleeve  16  around the spring element  25  so that the latter can exert its force to assist in the movement of the compartment  21  into its closed position. This is effected by the end of the sleeve  16  which projects through the recess  37  in disk  36  being released, and being moved away from disk  36  by the spring force of spring  25 . This can be recognized from the  FIG. 11A  sectional illustration of the spring elements  1 ,  25 . The spring element  1  which is arranged coaxially relative to the spring element  25  is retained via connections to the plate  38  by the position of the disk  36  so that it cannot exert a pressure force. Taken all together, thus only the pressure force of the smaller spring element  25  will be effective. 
       FIGS. 12A ,  12 B, and  12 C show the case of a compartment  21  with an average load, the compartment being moved downwards in its position, contrary to the force of a measurement spring not illustrated. By this, also the switching link  34  carries out a corresponding movement so that the switching lever  35  will come to lie on the lower step of the switching link  34  (see  FIGS. 12B and 12C ) and by this will cause a rotational movement of the disk  36  connected to the switching lever  35 . Due to this rotational movement of the disk  36  which, in the exemplary embodiment illustrated, is approximately 25° in clockwise direction, the sleeve  16  about the spring element  25  is held tightly so that the spring element  25  cannot exert any force. Instead, in accordance with the angular position of the disk  36 , the spring element  1  will be released and can thus exert its force. In case of this average load of the compartment  21 , thus, only the larger spring element  1  will be active. 
       FIGS. 13A ,  13 B, and  13 C show the state of a fully loaded compartment  21  in which the switching link  34  is moved for an even farther distance, so that the switching lever  35  will come to lie on the lowermost step of the switching link (see  FIGS. 13B and 13C ), so that the disk  36  will carry out a further rotational movement in clockwise direction. As compared to the position according to  FIGS. 11A ,  11 B, and  11 C, in the exemplary embodiment illustrated, the disk  36  has been rotated by about 50° in clockwise direction. In this position, corresponding recesses  37  are provided on disk  36  which will release both the sleeve  16  of the spring element  25  and the respective retention elements of the spring element  1  so that both spring elements  1 ,  25  can exert their force. In this fully loaded state of the compartment  21 , thus, the full force will be unfolded to assist the closing movement. Of course, instead of the three-step construction illustrated in FIGS.  9  to  13 A- 13 C, also a two-step or multi-step arrangement can be realized. It is also not important whether the spring element  1  is arranged about the spring element  25 , or vice versa. Switching between the individual steps always can only be effected in the opened state of the compartment  21 , in which all the retention devices of the spring elements  1  and  25  project through the openings  37  in disk  36  and, thus, a locking or release of the spring elements  1  or  25  is allowable. 
     Finally,  FIGS. 14A and 14B  show the luggage stowage compartment  21  which has been provided with the suspension device according to the invention so as to make it lowerable. In  FIG. 14A , the compartment  21  is shown in its closed position, in which it is pressed against the structural element  20  and fixed via a closing means  32 . The suspension devices are arranged between a side wall  33  of the stationary structural element  20  and the side wall of the compartment  21 . The upper guide rods  4  arranged on both sides are visible. To synchronize the lowering movement, the guide rods  4  are non-rotationally interconnected via a tube  12  or the like.  FIG. 14B  shows the lowered compartment  21 , whereby the opening  23  for loading and unloading the compartment  21  with items of luggage is cleared. The lower guide rod  5  and a part of the damping element  2  are visible. 
     Because it is robust and maintenance-free, a purely mechanical solution is preferred. Yet it should be noted that also an electronic device for detecting the weight of the compartment  21  and also an electronic device for changing the spring force of the spring element  1  could be provided. However, for an electronic solution, a voltage supply is required, on the one hand, and wiring of the elements, on the other hand, with the consequence of an increased weight and also of increased maintenance and installation requirements. Furthermore, it should be noted that in principle, the most varying spring elements may be used, with coil springs, however, being preferred because they are simple and robust. Pneumatic spring cylinders have the disadvantage that they react to temperature changes and thus, the effect of their force is temperature-dependent which may be disadvantageous particularly in aircraft which are subjected to high temperature fluctuations. The elements of the suspension device illustrated may be made of light metal, such as aluminium or magnesium, or also of plastics, preferably of fiber-reinforced plastics. 
     The invention being thus described, it will be apparent 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 recognized by one skilled in the art are intended to be included within the scope of the following claims.