A device for dampening the movement of a pivotally supported structural part, e.g. a flap in an automobile

Abstract: A device for dampening the movement of a pivotally supported structural part, e.g. a flap (10) in an automobile, comprising a pivot arm (14) attached to said structural part, a straight rack (18) linked to said pivot arm, a rotary damper having a housing (26) which is stationarily attached, a rotor rotatably supported in said housing, a viscous fluid contained in said housing and acting between said housing and said rotor, said rotor having a shaft (24), and a pinion (22) sitting on said shaft, and a linear guide means (28,30) for said rack, said guide means being supported for rotation about the axis of said rotor shaft and keeping said rack in engagement with said pinion irrespective the position of said rack.

Description: The invention refers to a device for dampening the movement of a pivotally supported structural part, e.g. a flap in an automobile according to the preamble of claim 1. It has become known to dampen pivotal movements of structural parts in the interior of an automobile, e.g. a flap for closing a glove compartment, an ashtray or the like or even a handle. To this end rotary dampers are usually used. Conventional rotary dampers include a rotor which is rotatably mounted in a housing. A brake fluid such as a silicone oil between the rotor and the housing provides for a dampening action when the rotor and the housing provides for a dampening action when the rotor is being rotated in the housing. Usually a pinion in engagement with a tooth segment is mounted to the rotor shaft. The tooth segment is of circular arc shape due to the rotary movement of the structural part to be dampened. The design of the circular arc shaped tooth segment is to be adapted to the mounting location because the radius depends on the mounting location. Furthermore guidance of the tooth segment at the pinion may cause problems, in particular noise problems. Unprecise engagement between the rack and the pinion may generate unacceptable noises. At substantial loads the pinion may slide along the rack. From FR-A 2 560 127 a device for dampening the movement of a pivotally supported flap in an automobile has become known wherein a straight rack is linked to the flap. A rotary damper has a housing which is stationarily attached, and a rotor is rotatably supported in the housing. A viscous fluid is contained in the housing acting between the housing and the rotor. The rotor has a shaft upon which a pinion is mounted. Furthermore, a pin is mounted to the housing adjacent to the pinion which cooperates with the back side of the rack opposite to the pinion for guiding purposes. From US-A-1,640,864 a sash regulating device is provided, wherein an arm is pivotally supported and operatively connected to a sash for adjusting the sash. The other end of the arm is pivotally supported by a support member. A rack is linked to the arm, and a pinion is rotatably supported on a guide member guiding the rack. The pinion can be rotated by a crank in order to displace the sash. The object of the invention is to provide a device for dampening the movement of a pivotally supported structural part, in particular a flap in an automobile, under use of a rotary damper for a satisfactory dampening of a translatory movement. This object is attained by the features of patent claim 1. In the device of the invention a pivot arm is mounted to the structural part to be dampened, with a straight rack being pivotally mounted to said pivot arm. A rotary damper is mounted to a stationary housing member, which rotary damper generally comprises a housing, a rotor and damping fluid as well as a pinion on the rotor shaft. The linear rack engages the pinion. These structure features are known. In the invention a linear guide means for the rack is provided. The guide means is a part of the damper housing and the housing is mounted for rotation about the axis of the rotor shaft upon a stationary structural part. Thus the linear guide means is supported for rotation about the axis of the rotor shaft and keeps the rack in engagement with the pinion irrespective of the position of the rack. Pivoting the structural part to be dampened will result in a combined movement of the rack in its plane, namely a rotary movement for pivoting the rack and a translatory movement. The guide means enables translatory movements of the rack within the guide and corresponding rotary movements of the pinion. Pivotal movements of the rack are accommodated by the rotating guide means. Any movement of the structural member to be dampened will result in linear movements within the guide means and a respective dampening action via the rotary damper. Accordingly circular movements become satisfactory dampened translatory movements in the device of the invention. Precise guidance of the rack avoids generation of noises, ensures respective engagement with the damper and reduces wear. According to an embodiment of the invention a bearing pin can be provided on the side of the housing opposite to the pinion, which bearing pin cooperates with a hole of a retaining member via bayonet type connection means in order to allow for limited rotation of the housing about the axis of the rotor. In a further embodiment of the invention said rack has a guide portion of T-shaped cross section, said guide portion extending in parallel spaced relationship with respect to the linear teeth of said rack. Said guide means includes a passage portion of a cross section which is complementary to that of the guide portion. This enables the guide means of the rack to be closely adjacent to the teeth, and the guide passage portion may be closely adjacent to the rotor shaft such that the total damper unit requires minimal space. The passage portion for guiding the rack is preferably provided at a radial flange which is provided at one end of the housing. The invention will be explained in more detail with reference to the accompanying drawings wherein: Fig. 1 shows schematically the device of the invention in a side elevation; Fig. 2 shows the rack of the device in Fig. 1 in a separate view; Fig. 3 is an end view of the rack in Fig. 2 in the direction of arrow 3; Fig. 4 shows the rotary damper in the same side elevation as in Fig. 1; Fig. 5 is a view of the rotary damper in Fig. 4 in the direction of arrow 5; Fig. 6 is an end view of the rotary damper in Fig. 1; Fig. 7 is a side elevation of the rotary damper in Fig. 6 in the direction of arrow 7, Fig. 1 shows a flap 10, e.g. for closing a glove compartment in an automobile. The flap 10 is mounted so as to be pivotal about a horizontal axis 12. A pivot arm 14 is integrally connected to the flap 10 on the side opposite to the pivot axis 12 and is pivotally mounted to a rack 18 via a pivot 16. The rack 18 comprises linearly arranged teeth 20 which are in engagement with a pinion 22. The pinion 22 is mounted to a shaft 24 of a not-shown rotor. The rotor is rotatably mounted within a housing 26. The housing 26 contains a brake fluid which dampens movements of the rotor when it is being rotated. The rack 18 cooperates with guide portions 28, 30 integral with a radial flange at the housing 26 on opposite sides of the pinion 22. Further details may be taken from the other Figures. As may be seen in Fig. 3 the rack 18 has a guide portion of T-shaped cross section including a flange portion 34 and a web portion 36. The web portion 36 interconnects the flange portion 34 and the portion which carries the teeth 20. A mounting gear 38 is formed at one end of the rack 18. Fig. 5 shows the shape and structure of the guiding cross section of the guide portions 28, 30. A channel 40 of a shape complementary to that of the flange portion 34 of rack 18 is arranged to linearly guide the flange portion 34, with the pinion 22 engaging the teeth 20 of the rack 18. The guide portions 28, 30 are connected to each other via a web 42 for stabilizing purposes. Furthermore the web 42 defines a further guide means for the free side of the flange portion 34 of the rack 18. A cylindrical extension 44 coaxial to the axis of the rotor shaft is provided on the side of the housing 26 opposite to that of the pinion 22. Radial projections 46 extend on opposite sides of the cylindrical extension 44 in spaced relationship to the housing 26 as may be seen in particular in Fig. 7. They are part of a bayonet-type connection and are arranged to cooperate with a respective hole in a holding member such that the housing can perform a limited rotary movement about the axis of the rotor shaft 22. Fig. 1 shows the flap 10 in a partially opened position by continuous lines. The closed position thereof is shown by dotted lines. When the flap is moved from the closed position to the opened position, the pivot arm 14 performs a pivotal movement such that the rack 18 is both pivoted and translated as may be seen from the two sketches. The guidance of the rack 18 in the guide portions 28, 30 enables the translatory movements of the rack 18 with respect to the pinion 22 such that it will be rotated in order to dampen the movement of the flap 10.

Claims: A device for dampening the movement of a pivotally supported structural part, e.g. a flap in an automobile, comprising a pivot arm (14) attached to said structural part (10), a straight rack (18) linked to the pivot arm (14), a rotary damper having a housing (26) which is stationarily attached, a rotor rotatably supported in the housing (26), a viscous fluid being contained in the housing (26) and acting between the housing (26) and the rotor, the rotor having a shaft (24) and a pinion (22) mounted on said shaft (24), and guide means mounted on the housing (26), characterized in that a linear guide means is provided for the rack (18), and the housing (26) is supported for rotation about the axis of the rotor shaft maintaining the rack (18) in engagement with the pinion (22) a irrespective of the positional orientation of the pivotally supported structural part (14). The device of claim 1, wherein the rack (18) has a guide portion (34, 36) T-shaped in cross section and extending in parallel spaced relationship with respect to the linear teeth (20) of the rack (18) with which the pinion (22) is enmeshed and the guide means includes a passage portion (28, 30) having a cross section configuration which is complementary to the T-shaped guide portion of the rack (18). The device of claim 2, wherein passage portions (28, 30) are located on both sides of the pinion (22) for guiding the rack (18). The device of claim 1, wherein the housing (26) has a bearing pin on the side thereof which is opposite to the side upon which the pinion (22) is mounted to cooperate with a hole of a retaining member through a bajonet connection means to allow limited rotation of the housing (26). The device of claim 2, wherein a radial flange is formed upon the housing (26) and the passage portions (28, 30) are formed upon the flange.

Inventors: MUELLER HANS-GUENTHER, VILLBRANDT UTE, MUELLER, HANS-GUENTHER, VILLBRANDT, UTE, Müller, Hans-Günther
Applicants: ITW ATECO GMBH, ITW-ATECO GMBH
Application year: 1997
Main classification: F16F9
IPC codes: E05F3, F16F9, B60R7