Abstract:
A device ( 15 ) for slowing the movement of a drawer ( 2 ) urged by unidirectional thrust means ( 4 ), including a casing ( 17 ) fixable to a structure (S) and defining a chamber ( 18 ) filled with a viscous fluid, and a rotor ( 31 ). The rotor ( 31 ) includes a disc portion ( 32 ) and a shaft portion ( 33 ) protruding through the lid ( 21 ) of the casing ( 17 ) in such a way as it can be associated with the door ( 2 ). The base surface ( 23   a ) of the chamber ( 18 ) has a recess ( 51 ) operable to house a pivotable arm ( 52 ). The arm ( 52 ) has a pin portion ( 54 ) protruding into the chamber ( 18 ). The lower surface ( 62 ) of the disc portion ( 32 ) of the rotor ( 31 ) has a groove ( 70 ) for engaging the pin portion ( 54 ) of the arm ( 52 ). At one end ( 73 ), the groove ( 70 ) has a cam ( 76 ) dividing it into a return path ( 75 ) and a forward path ( 74 ) for the pin portion ( 54 ) so as to define a locking position for the rotor ( 31 ) in cooperation with the thrust means ( 4 ).

Description:
This is a National Stage entry of International Application PCT/IT2003/000666, with an international filing date of Oct. 29. 2003, which was published as WO 2005/040535 A1, and the complete disclosure of which is incorporated into this application by reference. 
   BACKGROUND OF THE INVENTION 
   The present invention relates to a device for slowing the movement of a drawer or similar member which is movable with respect to a fixed structure and urged by unidirectional thrust means. 
   A device of this type is known from British Patent Application GB-A 2 062 933 and is normally used to smooth the movement of a slidable drawer caused by spring means, as used in certain types of ashtray fitted in the dashboard of motor vehicles. 
   It is also known that such drawers often have latch closure means which are released by a light pressure on the drawer, so that pressure is used to carry out both opening and closing operations. 
   The document EP-A-0 199 242 describes a device in which the latch closure means include a sphere engaged in a rectilinear groove, formed in the lateral surface of the stator, and urged by a shaped groove formed in the lateral wall of the rotor and having a cam defining a forward path and a return path for the sphere. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is a device for slowing the movement of a drawer of a compact type, having the characteristics defined in the Claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A few preferred but non-limitative embodiments of the invention will now be described with reference to the appended drawings, in which: 
       FIG. 1  is a longitudinally sectioned view of the structure of a drawer incorporating a slowing device according to the invention; 
       FIG. 2  is a longitudinally sectioned view of an embodiment of a slowing device according to the invention; 
       FIG. 3  is a plan view of a component of the device of  FIG. 2 ; 
       FIG. 4  is a plan view from below of another component of the device of  FIG. 2 ; 
       FIG. 5  is a longitudinally sectioned view of the component of  FIG. 4  taken on the line V-V of this figure; and 
       FIGS. 6 and 7  are plan views illustrating the operation of the slowing device of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With reference to  FIG. 1 , numeral reference  2  designates a drawer, for example, the drawer of an ashtray fitted in the dashboard of a motor vehicle, which can translate relative to the structure S of the dashboard along a direction defined by arrows T, while  4  schematically indicates a spring which urges the drawer into its open position. A rectilinear rack  6  is secured to the drawer  2 . A slowing device  15  of the invention is also secured to the structure S of the dashboard, with a rotatable pinion  16  arranged so as to engage the teeth of the rack  6 . 
   With reference to  FIG. 2 , the device  15  substantially includes a casing  17 , defining internally a substantially cylindrical chamber  18  open at one end, and having a pair of lateral extensions  19  provided with fixing means  19   b . In the shown embodiment, such fixing means  19   b  are represented by resilient flap portions extending upwardly. These portions  19   b  are provided for rapid engagement coupling with one of the two bodies whose relative movement needs to be slowed, for example with the structure S of the dashboard. These portions  19   b  could, of course, be of a different shape, being folded downwards, for example, or the lateral wings  19  could have fixing holes adapted to receive screws, rivets and the like for rigidly securing these extensions  19  to the structure S. 
   The open end of the cylindrical chamber  18  is adapted to be closed by a lid  21  which is fixed to the casing  17  so as to provide a fluid tight seal, for example by gluing or welding. The lid  21  has a central through-hole  22 . The base  23  of the cylindrical chamber  18 , corresponding to the base of the casing  17 , has a pin portion  24  which projects axially from the centre of the base  23  of the chamber  18  inwardly thereof. 
   The device  15  also includes a rotor  31  housed in the chamber  18 . The rotor  31  includes a disc portion  32 , rotatable inside the casing  17 , and a shaft portion  33  which extends axially from the centre of the disc portion  32  and protrudes from the lid  21  of the casing  17 , passing through the central hole  22 . The free end  33   a  of the shaft portion  33  of the rotor  31  is arranged so the pinion  16  can be mounted thereon. The rotor  31  also has a central hole  34 , formed in the base of the disc portion  32  for enabling the rotor  31  to be mounted on the pin portion  24  of the casing  17  and providing thereby an axis x of rotation for the rotor. 
   The chamber  18  filled with a highly viscous fluid of a known type, in such a way that the rotor  31  is fully immersed. The fluid tight seal at the central hole.  22  is ensured by an O-ring  41  housed in a circular seat  42  formed around the central hole  22  through the lid  21 . 
   With reference also to  FIGS. 3 ,  6  and  7  (for the sake of clarity, in  FIG. 3  the casing  17  is shown without the lid  21  and the rotor  31 ), the base surface  23   a  of the chamber  18  has a recess  51  with an arm element  52  (shown in  FIGS. 6 and 7 ) housed therein, mounted pivotably on a pin  53  formed in one piece with the base of the recess  51 . The arm element  52  includes an integrally formed elongate body  52   a , with a thickness along the length of the device  15  less than or equal to the depth of the recess  51 . One end  52   b  of the body  52   a  of the arm element  52  is pivoted on the pin  53 , while the other end  52   c  has a pin portion  54  projecting from the base surface  23   a  inwardly of the cylindrical chamber  18 . Due to this configuration, the arm element  52  is able to oscillate in the bottom of the recess  51 , in a plane parallel to the base surface  23   a . The shape of the recess  51  can be different from that shown in  FIG. 3  but it must be able to allow the arm element  52  to pivot sufficiently in order for the device to operate, as will be described later. 
     FIG. 4  is a plan view from below just of the rotor  31 . An elongate groove  70 , which extends spirally around the centre C of the disc portion  32  of the rotor  31 , is formed in the lower surface  62  of the disc portion  32 , that is the surface opposite the base surface  23   a . More in particular, this groove  70  begins from its end portion  71  arranged near the centre C of the disc portion  32 , then progressively moves away in radial direction from the centre C as it proceeds along its extension direction s, in such a way to approach the edge of the disc portion  32 . The groove  70  ends at a second end portion  73 , which extends so as to approximately form a ring, with forward and return branches  74 ,  75 , respectively, and a cam portion  76  interposed between them. 
   A recess  77  is formed in the cam portion  76 , in front of which a cuspid branch  78  is extended which interconnects the two branches  74 ,  75  of the groove  70 . The cuspid branch  78  defines two sharp bends  79 ,  81  at its ends, substantially opposite the recess  77  of the cam portion  76 . 
   The groove  70  is engageable by the pin portion  54  of the arm element  51 , which moves along the groove when the rotor  31  is rotated relative to the casing  17 . After passing the entire groove  70  beginning from the end portion  71 , the pin portion  54  engages in succession the branches  75  and  74  of the groove  70 , accompanied by the movement of the arm element  52 , thereby accomplishing locking and release operations in the manner of the pressure latch system described with reference to the prior art. 
   With reference to  FIGS. 6 and 7  the operation of the device according to the invention will now be described. For the sake of clarity, the lid  21  is rendered in transparency and the groove  70  is rendered in dash-dotted line. 
   From the latched position, in which the pin portion  54  engages the recess  77  of the cam portion  76 , pressure applied on the drawer  2  causes a slight anti-clockwise rotation of the rotor  31 , by means of the rack  6  engaged with the pinion  16 , thereby causing the pin portion of the arm to be moved away from the recess until it reaches the bend  79 , beyond which anti-clockwise rotation is prevented. The arm element  52  pivots slightly clockwise, following the movement of the pin portion  54  induced by the rotor  31 . 
   When pressure on the drawer  2  is released, the spring  4  urges it until it is fully open. The movement transmitted to the rotor  31  causes it to rotate clockwise, whereby the pin portion  54  passes along the forward branch  74  and the rest of the groove  70  until it reaches the end of travel position defined by the end portion  71  of the groove  70  (see  FIG. 6 ). During such movement of the rotor  31 , which is slowed down by the friction with the viscous fluid, the arm element  52  follows the pin portion  54  thus pivoting clockwise, and reaches its position of maximum travel in such direction (see  FIG. 6 ). 
   If pressure continues to be exerted on the drawer  2 , the rotor  31  rotates anti-clockwise and the pin portion  54  returns along the groove  70  until it is diverted by the cam portion  76  into the return branch  75 , whereby the arm element  52  reaches its position of maximum anti-clockwise travel (see  FIG. 7 ). 
   If pressure on the drawer  2  is continued, the rotor  31  rotates until the pin portion  54  engages the bend  81  of the return branch  75 , which prevents further rotation. 
   If pressure is released, the action of the spring  4  causes the rotor  31  to rotate slightly clockwise and, thanks to the configuration of the cuspid branch  78 , the pin portion  54  is guided to the recess  77  of the cam portion  76 , once again locking the rotor  31  into the starting latched position. 
   It will be appreciated that, although it has internal latch means, the slowing device according to the first embodiment of the invention has a structure which is more compact and is simpler to manufacture than the prior art, wherein the axial depth of the casing can be of only a few millimeters, while maintaining the high reliability of the device. In particular, the Applicant has made the portion  73  of the groove  70  with an angular extent of around 20-30° in a device with a diameter of around 2 cm. In this way, by fitting this device with the rack  6 , it is possible to activate the release mechanism with a longitudinal movement of the drawer  2  of the order of one millimeter. 
   Further, it is possible to adapt the diameter of the rotor  31  and/or the number of the coils of the groove  70  to the required travel of the drawer  2 . 
   It is understood that the invention is not limited to the embodiments described and illustrated here, but that the shape and arrangements of parts, construction and operating details can be modified. In the first embodiment, for example, the arm element could be mounted on the disc portion of the rotor, while the groove could be formed in the base of the chamber itself. Alternatively, it is possible to arrange these latch means between the upper surface of the disc portion and the lower surface of the casing lid, or on both sides of the disc portion. 
   The groove  70  can of course be orientated as a mirror image of that described, thereby causing the device to be locked or released by rotation in the opposite sense to that described above. Further, the end portion of the groove provided with the cam portion could be arranged at the end of the groove which is radially closer to the centre of the disc portion of the rotor. 
   In addition, it is not necessary that the arm element and the groove be arranged inside the chamber of the casing, but rather it is possible to provide for extensions of the casing and the rotor, respectively, the extensions being rotatable one relative to the other, and being arranged in such a way to form a pair of opposing surfaces for supporting the arm portion and the groove, respectively.