Patent ID: 12209449

DETAILED DESCRIPTION

FIG.1shows a power assist device1, which is mounted on a luggage compartment2. The luggage compartment2is in an open state. A movable end3of the power assist device1is attached to the luggage compartment2and a fixed end4is attached to a support5. The luggage compartment2rotates about a point of rotation6when being opened and closed. The power assist device1has a housing7, which is in the form of a cylinder housing and in which there is a movably mounted piston rod8.

FIG.2shows a partial longitudinal section through the power assist device1with the movable end3, the fixed end4, the housing7and the piston rod8. Also illustrated are an arresting means10in the form of a hook9and a return element12in the form of a spring11. The spring11is a compression spring13in this exemplary embodiment. An arresting means movement device60with a damping mechanism14keeps the arresting means10in its unlocked position.

FIG.3shows an enlarged view of the internal components of the power assist device1. The return element12in the form of a compression spring13is supported against the locking housing15, this constituting a counter support42fixedly connected to the housing part44, or a fixed bearing. The return element12is moreover supported against a spring disk16, this constituting a counter support43which is mounted movably in the housing part44, or a floating bearing. The locking housing15surrounds the arresting mechanism17. The spring disk16is connected to the latching element19via a connecting element59in the form of a casing tube18. The housing part44incorporates multiple components of the power assist device1, such as the housing7and the locking housing15, or encloses them.

The hook9is rotatable about a point of rotation20and can thus be brought into engagement with the latching element19in order to arrest the return element12. The hook9has a cutout21, through which the piston rod8runs. The latching element19can be arrested by the arresting means10and then extends into the locking housing15.

A movable component23with a cam24is mounted on the locking housing15so as to be rotatable about a point of rotation25. This component may be contacted by the latching element19and is thus a mating contact57with respect to the latching element19. A tension spring28is tensioned between a point26on the movable component23and a point27on the locking housing15. The pre-tensioning of the tension spring28keeps the movable component23in contact with the arresting means10.

Also shown is the damping mechanism14, which acts on the arresting means10.

FIG.4shows an enlarged illustration of the movable end3of a power assist device1according to the invention with an arresting means movement device60, which comprises the damping mechanism14, in a sectional illustration and an enlarged depiction of the damping mechanism14. The arresting means10is in the unlocking position. The damping mechanism14preferably has a hydraulic form and comprises a mechanical auxiliary return element31, in the exemplary embodiment in the form of a spring29which is a compression spring30, and a movable lifting element33in the form of a piston32. A connecting channel34forms a hydraulic damping element35. A non-return valve36, a tappet37and a seal58are also formed.

The damping mechanism14is designed such that the force of the mechanical auxiliary return element31is transmitted to the tappet37and then to the arresting means10via the movable lifting element33. The arresting means is therefore pressed into the unlocking position by the damping mechanism14and preferably held there. If a movement of the piston rod8causes the arresting means10to be brought into the arresting position, the latter presses the tappet37into the damping mechanism14. Hydraulic liquid flows through a connecting channel34and the non-return valve36into the damping mechanism14and the compression spring30is tensioned.

The compression spring30tends to relax and as a result to move the tappet37out of the damping mechanism14again, whereby the arresting means10, which is in the arresting position, is moved into its unlocking position. In the process, the hydraulic liquid that has flowed in must leave the damping mechanism14again. The movement of the piston32toward the arresting means10is greatly retarded by contrast to the reverse movement, since the non-return valve36does not open in this direction and the flow cross section for the hydraulic liquid is greatly decreased. The piston32can be referred to as timer piston on the basis of its function, since it causes retardation of the return of the arresting means10to its unlocking position. Depending on the embodiment, the limited period of time can thus be set for example in the region of 20 seconds, preferably 10 seconds, particularly preferably 5 seconds.

FIG.5shows a longitudinal section through a power assist device1according to the invention, wherein the arresting means movement device60by means of its damping mechanism14has pressed the arresting means10into its unlocking position and the latching element19is released. Since the latching element19is connected to the spring disk16via the casing tube18, the return element12can expand and provide an assistance force for the movement of the piston rod8toward its second position.

The state shown inFIG.6corresponds to an open luggage compartment2without luggage load, with the arresting means10in the arresting position and the piston rod8in an intermediate position.FIG.6shows a longitudinal section through a power assist device1according to the invention, wherein the arresting means10is latched to the latching element19, which extends into the locking housing15. This is illustrated on an enlarged scale. The latching element19is supported radially against the circumferential surface22of the locking housing15. The locking housing15can therefore take up radial forces acting on the latching element19. These radial forces can result from the arresting means10engaging in the latching element19.

An oblique region38, which can slide on a locking element39, is formed on the arresting means10. The locking element39is a contacting component40, which is in the form of a part of the latching element19. The piston rod8is guided out of the housing7until the damper piston41makes contact with the spring disk16. The engagement of the arresting means10in the latching element19keeps the compression spring30of the damping mechanism14under load via the tappet37and the piston32.

FIG.7shows a state in which, proceeding from the state shown inFIG.6, the luggage compartment2was closed without a load of luggage. The piston rod8, which is connected to the movable end3, is moved together with the damper piston41through the casing tube18and the housing7. The return element12remains arrested.

FIG.8shows a state in which, proceeding from the state shown inFIG.6, the luggage compartment2was loaded with luggage, wherein the pre-tensioning of the return element12was overcome. As more luggage is loaded into the luggage compartment, a force acts on the return element12via the movable end3, the piston rod8, the damper piston41and the spring disk16. The return element12is compressed further and the casing tube18moves the latching element19as far as the stop45and thus out of locking with the arresting means10. The arresting means10is therefore released and can be moved from the arresting position to the unlocking position by the damping mechanism14.

FIG.9shows a state in which, proceeding from the state shown inFIG.8, the arresting means10was brought into its unlocking position by the arresting means movement device60by means of its damping mechanism14. The latching element19is released and the return element12assists the closing of the luggage compartment2.

FIG.10shows a state in which, proceeding from the state shown inFIG.9, the piston rod8was already moved far enough toward its second position that the contacting component40of the latching element19makes contact with the cam24of the movable component23. Owing to the force acting on the cam24, the movable component23rotates counter-clockwise about its point of rotation25with application of load to the tension spring28and the latching element19can pass the movable component. Also illustrated is that the arresting means10does not overlap the latching element19, with the result that the return element12assists the closing of the luggage compartment2.

FIG.11shows a state in which, when the arresting means10is in the unlocking position, the piston rod8is moved from its second position or an intermediate position to its first position. This corresponds to the opening of the laden luggage compartment2. The contacting component40makes contact with the cam24of the movable component23, which rotates clockwise owing to the force which is acting. Owing to the movable component23being coupled in terms of movement to the arresting means10, the arresting means10also rotates clockwise about its point of rotation20. The arresting means10therefore rotates from the unlocking position to the arresting position. This leads on the one hand to the overlap of the arresting means10with the latching element19and on the other hand to the tappet37of the damping mechanism14being pressed in and to load being applied to the compression spring30.

FIG.12shows, proceeding from the state shown inFIG.11, the state after the rotation of the arresting means10, just before the latching element19reaches the stop45. An enlarged view illustrates that the cam24of the movable component23can slide over the latching element19into a cutout46. Therefore, the rotation of the movable component23and thus also of the arresting means10counter-clockwise is enabled again. The arresting means movement device60with the damping mechanism14can therefore move the arresting means10from the arresting position to the unlocking position. When the laden luggage compartment2is being closed, the assistance force is therefore available again.

FIG.13shows, proceeding from the state shown inFIG.11, the state after a movement of the piston rod8within the limited period of time generated by the damping mechanism14. The arresting means10has still not been completely brought from the arresting position to the unlocking position. This state corresponds to luggage being removed from the open, laden luggage compartment within the limited period of time. The force applied by the return element12exceeds the weight force of the unladen luggage compartment2and moves the piston rod8toward an intermediate position. The latching element19passes the movable component23. An enlarged view illustrates that the arresting means10still overlaps the latching element19. As the movement of the piston rod8toward an intermediate position continues, the contacting component40of the latching element19makes contact with the oblique region38of the arresting means10.

FIG.14shows, proceeding from the state shown inFIG.13, that the contacting component40of the latching element19slides on the oblique region38of the arresting means10as the movement of the piston rod8continues toward an intermediate position. As a result, the arresting means10rotates clockwise and is brought from an intermediate position between the arresting position and the unlocking position back to the arresting position. At the same time, the arresting means movement device60and the damping mechanism14are repositioned and the limited period of time starts anew after a movement of the piston rod8to the first position, for example owing to the luggage compartment2being loaded with luggage.

FIG.15shows a further exemplary embodiment according to the invention. Components and functional units which are similar or identical to the preceding exemplary embodiments in terms of function and/or design are denoted by the same reference signs and are not described separately again. The statements made relating toFIGS.1to14therefore correspondingly apply toFIG.15. In this exemplary embodiment, the positions of the point of rotation25of the movable component23and the point of rotation20of the arresting means10coincide. The design of the arresting means10, of the movable component23with the cam24and of the latching element19, and also of the locking housing15are matched to the exemplary embodiment shown inFIGS.1to14, and therefore all the functional features can be implemented. The arresting means movement device60and the damping mechanism14are outside the locking housing15and are coupled in terms of movement to the arresting means10via a bearing piece47. The return element12in the form of a compression spring13is inside the latching element19and is supported against the locking housing15and the latching element19.

FIG.16shows a further exemplary embodiment according to the invention. Components and functional units which are similar or identical to the preceding exemplary embodiments in terms of function and/or design are denoted by the same reference signs and are not described separately again. The statements made relating toFIGS.1to15therefore correspondingly apply toFIG.16. In this exemplary embodiment, the latching element19is arrested by means of a hydraulic mechanism. The latching element39is a valve48in this case. In this case, the power assist device1comprises two fluid chambers49,50, which are filled with a hydraulic liquid and are connected to one another by the valve48. The two fluid chambers49,50are separated from one another by the spring disk16. A fluid chamber49extends between the valve48and the spring disk16and contains the return element12. A further fluid chamber50extends between the spring disk16and the valve48via a connecting channel51. The position of the spring disk16and therefore also the length52of the return element12in this way establish the volume of the two fluid chambers49,50and their volume ratio. A movement of the spring disk16is then only possible when the valve48is open. A non-return valve53, which is illustrated on an enlarged scale and enables a movement of the spring disk16in one direction when the valve48is closed, is additionally attached to the spring plate16. The valve48in the open state forms the unlocked state and in the closed state forms the arrested state. A loaded compression spring13is therefore arrested when the valve48is closed. A compression spring13that is relieved of load can be subjected to load owing to the non-return valve53when the valve48is closed, and is then arrested. Moreover, an arresting means movement device60with a damping mechanism14like in the preceding exemplary embodiments is present, wherein in this case the tappet37is coupled in terms of movement to an actuator54, which has an inclined plane55in contact with the valve48.

FIG.17shows an enlarged view of the region around the damping mechanism14and the valve48of the power assist device1fromFIG.16in an arrested state. The valve48is closed. The pretension of the compression spring13that acts on the spring disk16leads to an increase in the hydraulic pressure on that side of the spring disk16that faces away from the return element12. The hydraulic pressure acts via the connecting channel51on the valve48, which remains in its closed position and keeps the valve channel56closed. Therefore, when the luggage compartment is unladen, a pressure differential can build up, which keeps the valve48in the closed position by itself. The force acting on the valve48owing to the pressure differential is greater than the opening force acting on the valve48from the loaded compression spring30of the damping mechanism14, with the result that the valve48remains closed. In the state which is shown, the latching element19is against the stop22, as is the case when the luggage compartment2is laden, when the pre-tensioning of the return element12is overcome. The return element12exerts no pressure on the spring disk16and thus on the valve48. Therefore, the damping mechanism14is able to open the valve48.

FIG.18shows the enlarged view fromFIG.17after the valve48has been opened by the damping mechanism14. The valve48was contacted and opened by the inclined plane55of the actuator54. Hydraulic liquid can flow through the valve channel56. Therefore, a movement of the spring disk16and thus also the action of the assistance force of the return element12on the piston rod8is possible. During this movement, the latching element12can rotate the movable component23counter-clockwise about its point of rotation25and pass it.

FIG.19shows a further exemplary embodiment according to the invention. Components and functional units which are similar or identical to the preceding exemplary embodiments in terms of function and/or design are denoted by the same reference signs and are not described separately again. The statements made relating toFIGS.1to18therefore correspondingly apply toFIG.19. In this exemplary embodiment, the power assist device1comprises two return elements12in the form of compression springs13. These enclose not the piston rod8, but a respective guide rod61,62. A sleeve-shaped housing7, inside which is the piston rod8, is formed between the return elements12. The arresting means movement device60with the damping mechanism14is formed on the outside in relation to the parallel guide rods61,62and the piston rod8inside the housing44. The housing44extends toward the fixed end4. The other end of the power assist device1is designated by the movable end3. There can also be a further housing7around the housing7and/or the housing44.

FIG.20shows a further side view of the power assist device1fromFIG.19. The visible elements are the same as inFIG.19.

FIG.21shows the power assist device1fromFIG.20with the housing44illustrated as partially open. This portion is moreover illustrated on an enlarged scale. In the enlarged view, it can be seen that the return elements12in the form of compression springs13slide on the guide rods61,62. The compression springs13are supported against a spring plate16formed on the latching element19. The piston rod8is inside the housing7. The arresting means10is illustrated with line hatching and can be rotated about a point of rotation20. The point of rotation20coincides with the point of rotation25of a component23with a cam24. In this exemplary embodiment, the arresting means10comprises the locking element39, whereas the oblique region38is formed on the latching element19. The contacting component40is moreover formed on the latching element19. Instead of a tension spring28, a leg spring63is used to keep the component23with the cam24in contact with the arresting means10. The arresting means10is connected to the tappet37of the arresting means movement device60with damping mechanism14via a bearing piece47. Moreover illustrated is the locking housing15, which is part of the housing44. The mode of operation of bringing the arresting means10into the arresting position by bringing the cam24into contact with the contacting component40with pressing of the tappet37into the arresting means movement device60is in this respect the same as the other exemplary embodiments. In the arresting position of the arresting means10, there is the option of latching the latching element19to the locking element39.

FIG.22shows a sectional view through the power assist device1fromFIG.21in the same state as inFIG.21and with an enlarged view of the region around the arresting means10. In addition, damper pistons41are illustrated.

FIG.23shows a perspective illustration of the power assist device fromFIG.22without a housing44. It can be seen that the arresting means10consists of two interconnected parts64,65, between which is the bearing piece47with the spring29and the tappet37of the arresting means movement device60. Moreover, the movable component23with the cam24is attached between the parts64,65, the movable component being held under loading by means of the leg spring63.

What is therefore proposed is to design a power assist device1comprising a piston rod8, which is mounted so as to be able to move in a housing7and has a first position and a second position, and a preferably elastic return element12, which can be arrested by means of a positionally variable arresting means10, by means of which an assistance force can be transmitted to the piston rod8in the unlocked state, and which in the arrested state is decoupled in terms of force by the piston rod8, such that, in the unlocked state, a movement of the piston rod8to the first position moves the arresting means10from an unlocking position to an arresting position, which enables arresting of the return element12only within a limited period of time.

LIST OF REFERENCE SIGNS

1Power assist device2Luggage compartment3Movable end4Fixed end5Support6Point of rotation7Housing8Piston rod9Hook10Arresting means11Spring12Return element13Compression spring14Damping mechanism15Locking housing16Spring disk17Arresting mechanism18Casing tube19Latching element20Point of rotation21Cutout22Circumferential surface23Component24Cam25Point of rotation26Point27Point28Tension spring29Spring30Compression spring31Auxiliary return element32Piston33Lifting element34Connecting channel35Damping element36Non-return valve37Tappet38Oblique region39Locking element40Contacting component41Damper piston42Fixedly connected counter support43Movably mounted counter support44Housing45Stop46Cutout47Bearing piece48Valve49Fluid chamber50Fluid chamber51Connecting channel52Length53Non-return valve54Actuator55Inclined plane56Valve channel57Mating contact58Seal59Connecting element60Arresting means movement device61Guide rod62Guide rod63Leg spring64Part65Part