Abstract:
A rotary damper allows for fluid bypass through the interior of the hydraulic chamber, as opposed to dampers where fluid bypass occurs only along the walls of the hydraulic chamber. Additionally, the damper accommodates bi-directional damping, by providing a universal piece and switching the position of a component in the piece.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to rotary dampers, and in particular, to rotary damping hinges for hinged structures.  
       BACKGROUND  
       [0002]     Rotary dampers are commonly used with devices whose movement in one direction is sought to be controlled, typically by being slowed. For example, rotary dampers are used for door hinges, gate hinges, such as those in doors for pick-up truck beds, toilet seat hinges, piano key covers, and the like. These dampers are typically designed to be biased in a single rotational direction. Damping in this manner is commonly referred to as one-way or uni-directional damping.  
         [0003]     This one-way damping facilitates strong damping in one rotational direction, such that movement of the object associated with the damper is slow and steady, avoiding any rapid, sudden or hard contacts, with surfaces, from rapid and uncontrolled movements. Accordingly, damping in the opposite rotational direction is minimal, allowing for rapid movement of the object associated with the damper.  
         [0004]     This one-way biasing is a drawback should damping in the opposite direction be desired. Should some significant damping in the other direction be desired, the dampers must be made from two separate sets of molds and corresponding tooling. This is wasteful of time and materials.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention overcomes the drawbacks associated with conventional rotary dampers, by providing a damper that allows for fluid bypass through the interior of the hydraulic chamber, as opposed to dampers where fluid bypass occurs only along the walls of the hydraulic chamber. Additionally, the present invention provides a single apparatus that accommodates bi-directional damping, by switching the position of a component in the apparatus. As a result, only a single piece, that forms the damping or hydraulic chamber, needs to be made, eliminating the duplicity in tooling molding and the like, required for rotary dampers that damp in different rotational directions.  
         [0006]     An embodiment of the invention is directed to a rotary damper. The damper includes, a first piece, a second piece, a rotary member, and, a flexible member. The first piece includes a cylindrical portion including oppositely disposed ends and an inner wall, lateral portions at each of the oppositely disposed ends of the cylindrical portion, the lateral portions coupled with the cylindrical portion to define a chamber. The second piece is rotationally coupled to the first piece, and includes oppositely disposed portions corresponding to the oppositely disposed ends of the cylindrical portion. The rotary member extends in the chamber and is coupled to the second piece, the rotary member extending at least proximate to the inner wall and at least proximate to the lateral portions. The rotary member at least partially (when coupled with the flexible member) divides the chamber into a first area and a second area. A flexible member extends from a point at least proximate the inner wall, to at least proximate, and typically into contact with, the rotary member. The flexible member is for moving between open and closed positions, to provide an opening between the first area and the second area.  
         [0007]     Anther embodiment of the invention is also directed to a rotary damper. The rotary damper includes, a first piece, lateral portions, a second piece, a rotary member, and, a flexible member. The first piece includes a cylindrical portion including oppositely disposed ends and an inner wall. There are lateral portions at each of the oppositely disposed ends of the cylindrical portion, the lateral portions coupled with the cylindrical portion to define a chamber, and each of the lateral portions includes a channel extending into the respective lateral portion. The second piece is rotatable with respect to the first piece and includes oppositely disposed portions corresponding to the oppositely disposed ends of the cylindrical portion. The rotary member extends in the chamber and is coupled to the second piece, with the rotary member extending at least proximate to the inner wall and at least proximate to the lateral portions. The rotary member at least partially (coupled with the flexible member) divides the chamber into a first area and a second area, and is such that the channels are closed when the rotary member is in a position beyond each channel, and that each channel is open when the rotary member moves over it. The flexible member extends from a point at least proximate to the inner wall to at least proximate the rotary member, and typically into contact therewith, the flexible member configured for moving to an open position, to provide an opening between the first area and the second area.  
         [0008]     Another embodiment of the invention is directed to a rotary damper. The rotary damper includes, a chamber, a moveable member, and a flexible member. The chamber is for holding fluid, such as grease or other hydraulic fluid, is typically cylindrical and of a circular cross section, and includes at least one interior wall and oppositely disposed lateral walls. The movable member is rotatably mounted in the interior of the chamber, with the mounting such that the moveable member is in frictional contact with the at least one interior wall and the oppositely disposed lateral walls. The flexible member is in a cooperative arrangement with the moveable member, and the flexible member extends from at least proximate the at least one inner wall into operative communication with the moveable member, to divide the chamber into a first area and a second area. The flexible member is biased so as to be moveable in a first direction to allow for fluid bypass through the interior of the chamber upon rotation of the moveable member.  
         [0009]     Another embodiment of the invention is further directed to a rotary damper. The rotary damper includes a chamber, a moveable member and a flexible member. The chamber includes at least one interior wall and oppositely disposed lateral walls. It is designed for holding fluid, and at least one of the oppositely disposed lateral walls includes a channel for fluid transport extending into the at least one lateral wall. The moveable member is rotatably mounted in the chamber, and in frictional contact with the at least one interior wall and the oppositely disposed lateral walls. The movable member is disposed such that when beyond the channel, the channel is closed, and when moved along the channel, the channel is open, to allow for fluid bypass along the sides or walls of the chamber. The flexible member is cooperatively arranged with respect to the moveable member, and it extends from at least proximate the at least one inner wall, typically into contact with the moveable member, to divide the chamber into a first area and a second area. The flexible member is biased so as to be moveable in a first direction to allow for fluid bypass through the interior of the chamber upon rotation of the moveable member.  
         [0010]     Another embodiment of the invention is directed to a rotary damper member for supporting bi-directional damping. The member includes, a cylindrical portion including at least one interior wall, and defining an interior chamber, and, a finger extending from the interior wall into the chamber, the finger extending at least substantially the length of the cylindrical portion. There is also a first stub and a second stub, disposed on opposite sides of the finger, with the first stub and the second stub extending at least substantially the length of the cylindrical portion. The first stub and the second stub are positioned from the finger, to define a first slot and a second slot, each slot capable for receiving and retaining a flexible member, depending on the directionality of the damping desired. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Attention is now directed to the drawing figures, where like numerals or characters indicate corresponding or like components. In the drawings:  
         [0012]      FIG. 1  is a perspective view of the apparatus in accordance with an embodiment of the invention in a first position;  
         [0013]      FIG. 2  is a top view of the apparatus of  FIG. 1 ;  
         [0014]      FIG. 3  is a rear view of the apparatus of  FIG. 1 ;  
         [0015]      FIG. 4  is a side view showing the apparatus of  FIG. 1  in an exemplary rotation, to a second position;  
         [0016]      FIG. 5  is a cross section of the apparatus of  FIG. 2 , taken along line  5 - 5 ;  
         [0017]      FIG. 6  is a cross section of the apparatus of  FIG. 2  taken along line  6 - 6 ; and  
         [0018]      FIG. 7  is a front perspective view of the inner side of an end cap of the apparatus.  
     
    
     DETAILED DESCRIPTION  
       [0019]     The present invention is directed to a rotary damper, that damps by providing for fluid bypass along the walls of an internal hydraulic or other fluid filled chamber, as well as through the interior of the chamber. The present invention is also directed to a universal member for bi-directional damping, that accommodates damping in the desired direction, based on the placement of a flexible member in interior of the universal member.  
         [0020]      FIGS. 1-3  show the apparatus  20  of the invention in a first or extended position, while  FIG. 4  shows the apparatus  20  of the invention in a second or rotated position. The apparatus  20  is a rotary damper, for example, a hinge, typically formed of a first piece  22 , attached to a second piece  24 . This rotational attachment allows the rotation of either of the pieces  22 ,  24  with respect to the other piece. These pieces  22 ,  24  are typically made of metal, plastic, or other non-porous materials. Both pieces  22 ,  24  may include openings  22   a ,  24   a , to accommodate, screws, nails, joints or other fasteners, or the like, allowing the apparatus to be attached or joined to various objects.  
         [0021]     The first piece  22  includes a flat portion  30  and a cylindrical portion  32 . The flat portion  30  terminates in an end  34 , that extends under the cylindrical portion  32 , typically to a distance corresponding to at least approximately the mid-point of the circular cross- section of the cylindrical portion  32  (as shown in  FIG. 6 ). The cylindrical portion  32  includes oppositely disposed open ends  38 ,  39 .  
         [0022]     The second piece  24  includes a flat portion  40 , with flanges  42 ,  43 , that fit over the respective open ends  38 ,  39  of the cylindrical portion  32 . The flanges  42 ,  43  are typically shaped to cover the open ends  38 ,  39  of the cylindrical portion  32 . The flanges  42 ,  43  include openings  42   a  ( FIG. 5 ),  43   a , that accommodate screws  44  ( FIG. 5 ),  45  that are received in a central member  70  in the respective bores  73   a ,  73   b  (the screws  44 ,  45  and central member  70  defining a transverse axis TX extending through the cylindrical portion  32 , as shown in  FIG. 5  and detailed below), allowing for rotation of the pieces  22 ,  24  with respect to each other, between the first position ( FIGS. 1-3 ) and the second position ( FIG. 4 ), and all positions therebetween. The second piece  24  is connected to the central member  70 , via the screws  44 ,  45 , whereby rotation of the second piece  24 , rotates the central member  70 .  
         [0023]     The flat portion  40  terminates  30  in an end  46  ( FIG. 6 ), that extends under the cylindrical portion  32 , typically to a distance proximate to the mid-point of the circular cross-section of the cylindrical portion  32 , and a curved portion  48  ( FIG. 6 ). The curved portion  48  is of a radius of curvature slightly larger than the radius of curvature of the cylindrical portion  32 , allowing the second piece  24  to move over the cylindrical portion  32  of the first piece  22 , without obstruction.  
         [0024]     The ends  34 ,  46 , are in close proximity to each other (typically with a gap therebetween), typically allowing for the surface  22   b  of the first piece  22  and the surface  24   b  of the second piece  24  to be flush, as both pieces  22 ,  24  are along a plane P ( FIGS. 4 and 6 ). The positioning of these ends  34 ,  46  typically allows for a small amount of over rotation of both pieces  22 ,  24  (for example, approximately  2 - 3  degrees), and this positioning serves to limit travel for both pieces  22 ,  24  (as the ends  34 ,  46  may abut if over rotated). This arrangement, of the pieces  22 ,  24  and the gap between their respective ends  34 ,  46 , also allows for manufacturing variations.  
         [0025]     For example, as shown in  FIG. 4 , the second piece  24 , at the flat portion  40 , has been rotated (for example, counterclockwise) with respect to the first piece  22 , in the direction of the arrow  50 , for example, to a position shown by the broken line flat portion  40 ′, and indicated by the angle θ, that may be, for example, approximately 22 degrees. The second piece  24  can be returned to the first or flat position by being rotated (for example, clockwise) in the direction of the arrow  51 .  
         [0026]     Turning also to  FIGS. 5 and 6 , the interior  60  of the cylindrical portion  32  is shown in detail. The interior  60  is formed by the inner walls  62  of the cylindrical portion  32 . The interior  60 , at the inner walls  62 , is typically of a constant diameter (cross-sectional diameter) and accordingly, of a circular cross section in shape. End caps  64 ,  65  are received in cut outs  62   a  of the inner walls  62  in a frictionally snug and fixed engagement. The end caps  64 ,  65  may be further secured to the inner walls  62  (in the cut outs  62   a ) by adhesives, mechanical fasteners, corresponding protrusions and indents, and the like. The end caps  64 ,  65  are in a rotational relationship with the flanges  42 ,  43 , and central member  70 , such that the end caps  64 ,  65  remain stationary, when either, or both of the first  22  or second  24  pieces are moved. Coupled with the end caps  64 ,  65 , the inner walls  62  of the interior  60 , form a chamber  66 , that is typically filled with grease or other fluid  67  (shown in broken lines), allowing the apparatus  20  to hydraulically damp. The inner sides  64   a ,  65   a  of the end caps  64 ,  65  define the sides or side walls of the chamber  66 , while the space between the inner sides  64   a ,  65   a  of the end caps  64 ,  65  and the inner wall  62  defines the interior of the chamber  66 .  
         [0027]     The end caps  64 ,  65 , include bores  68 ,  69 , through their centers, through which the screws  44 ,  45  extend. Each of the bores  68 ,  69  extends from an indent  68   a ,  69   a , in the inner side  64   a ,  65   a  of each end cap  64 ,  65 , to an indent  68   b ,  69   b  in the outer side  64   b ,  65   b  (typically cylindrical) of each end cap  64 ,  65 .  
         [0028]     The screws  44 ,  45 , push against O-rings  44   a ,  45   a , as the screws  44 ,  45  and O-ring  44   a ,  45   a  seat in the indents  68   b ,  69   b  in the outer sides  64   b ,  65   b  of the end caps  64 ,  65 . The O-Rings  44   a ,  45   a  are formed of elastomers or other resilient materials, and seal the end caps  64 ,  65 , keeping fluid in the chamber  66 .  
         [0029]     The end caps  64 ,  65  are fixed in their position and contact a central member  70  (or rotary member), at its head  71 , at the respective ends  71   a ,  71   b . The ends  71   a ,  71   b  of the head  71  seat in the indents  68   a ,  69   a  of the inner sides  64   a ,  65   a  of the end caps  64 ,  65  in a rotational engagement. A tail  72  extends outward from the head  71  of the central member  70 . The head  71  of the central member extends beyond the tail  72  of the central member  70 , and the tail  72  extends (along the transverse axis TX) to the surfaces  64   a ′,  65   a ′ of the inner  64   a ,  65   a , and into an abutting contact with the respective surfaces  64   a ′,  65   a ′ of the end caps  64 ,  65 .  
         [0030]     The receipt is such that the openings  42   a ,  43   a  in the flanges  42 ,  43 , align with the bores  68 ,  69  in the end caps and bores  73   a ,  73   b  in the central member  70 , to receive the respective screws  44 ,  45 . This receipt, coupled with the wiping or frictional contact of the tail  72  of the central member  70 , with the respective end caps  64 ,  65 , allows for rotation (movement) of the central member  70 , when the second piece  24  is rotated with respect to the first piece  22 , and vice versa (for example, as shown in  FIG. 4 , and described herein). During this rotation of the central member  70 , the end caps  64 ,  65  remain stationary.  
         [0031]     The O-rings  76 ,  77 , formed of elastomers or other resilient materials, seat in circumferential slots  78 ,  79 , respectively, on the outer sides  64   b ,  65   b  of the end caps  64 ,  65 , to facilitate rotation of the first piece  22  and the second piece  24 , with respect to each other, and serving as a seal, to keep fluid, for example, grease (functioning as a hydraulic fluid, e.g., Class 3 vacuum grease), oil (e.g., 90 weight motor oil) or other hydraulic fluid within the interior  60  (the chamber  66 ) of the cylindrical portion  32 .  
         [0032]     Turning also to  FIG. 7 , channels or metering paths  82 ,  83  extend into the inner sides  64   a ,  65   a , of the end caps  64 ,  65 , and these channels or metering paths  82 ,  83  are typically symmetric. (A portion of the channel  82  is shown in broken lines in  FIG. 6 ). The channels or metering paths  82 ,  83  facilitate the flow of fluid, also known as fluid bypass, along the sides (side walls) of the chamber  66 , and around the central member  70 , upon rotation of one or both of the pieces  22 ,  24 . The channels or metering paths  82 ,  83  are typically “C” shaped (typically, the “C” shape is symmetric), extend as arcs or arc-like into the respective inner sides  64   a ,  65   a , and typically originate at a point beyond (above) the tail  72  of the central member  70 , so as to be opened for fluid bypass around the central member  70 , when the central member  70  is moved (by movement of the second piece  24  or if the first piece  22  is moved, or combinations thereof) so as to be along the channels or metering paths  82 ,  83 .  
         [0033]     In each inner side  64   a ,  65   a  of each end cap  64 ,  65  is a canal  86 , that is typically “L-shaped” (only one shown). This canal  86  (only one shown) extends along the indent  68   a , from the bore  68  to the surface  64   a ′,  65   a ′ of the inner side  64   a ,  65   a . Each indent  68   a ,  69   a  includes a rounded portion  68   a ′,  69   a ′, for receiving the ends  71   a ,  71   b  of head  71  of the central member  70  in a rotatable engagement, and, a tail portion  68   b ′ (only one shown), corresponding to the shape of the tail  72  of the central member  70 , extending radially outward, to a point proximate to the edge  64   e ,  65   e  of the end cap  64 ,  65 . The tail indent  68   b ′ holds fluid, allowing for a smooth wiping contact of the tail  72  (at its ends) of the central member  70  against the surfaces  64   a ′,  65   a ′ of the inner sides  64   a ,  65   a  of the end caps  64 ,  65 .  
         [0034]     The canal  86  in indented, so as to extend beyond the head  71  of the central member. This canal  86  allows for fluid bypass over the central member  70 , when the apparatus  20  is being assembled and the interior  60  (chamber  66 ) is being filled with fluid. Once the screws  44 ,  45  have been attached, and the O-rings  44   a ,  45   a , seal the end caps  64 ,  65 , the canal  86  is no longer used for fluid bypass.  
         [0035]     While the end cap  64  at its inner side  64   a  has been described and shown in  FIG. 7 , the inner side  65   a  of the end cap  65  is symmetric. Accordingly, the description for the inner side  64   a  of the end cap  64  is equally applicable to the inner side  65   a  and its surface  65   a ′ of the opposite end cap  65 .  
         [0036]     The central member  70 , is typically of a “key” shaped cross section. It includes the head  71 , that is rounded, for positioning centrally in the interior  60  (this head  71  includes the bores  73   a ,  73   b ), with the tail  72 , extending from the head  71 , radially outward, toward the inner wall  62  of the cylindrical portion  32 . A contact piece  96 , typically of a flexible material such as an elastomer or the like, is typically frictionally fitted into a slot  97  at the outer end of the tail  72 . The contact piece  96  typically is dimensioned for maintaining contact, with the inner wall  62  of the cylindrical portion  32 , typically by a wiping action or other frictional type contact, as the central member  70  rotates in the chamber  66  (interior  60 ).  
         [0037]     A finger  100 , extends from the inner wall  62 , to an edge  100   a , and is aligned with the head  71  of the central member  70 . Stubs  104 ,  105  also protrude from the inner wall  62 , and are typically spaced equidistant from the finger  100 . The spacing between the finger  100 , and the respective stubs  104 ,  105  creates slots  106 ,  107 , that are typically L-shaped and symmetric, due to the indentations  104   a ,  105   a  in the stubs  104 ,  105 , and the equidistant positioning of the stubs  104 ,  105  with respect to the finger  100 .  
         [0038]     A flexible member  110 , is designed to seat in either of the slots  106 ,  107 , depending on the desired biasing of the apparatus  20 . The flexible member  110 , terminates in a tip  110   a , at a point at least proximate to the head  71  of the central member  70 , and is typically in contact with the head  71  of the central member  70 . For example, as shown here, the flexible member  110  is seated in the slot  106 . The stubs  104 ,  105 , are typically of a lower elevation than the finger  100 , in order to facilitate bending of the flexible member  110  during fluid bypass, in the direction of the stubs  104 ,  105 , in a damping operation, one such operation with bending toward the stub  104  detailed below.  
         [0039]     The flexible member  110  is typically L-shaped and universally sized, to seat in either of the slots  106 ,  107 , and as shown in  FIG. 6 , remains locked in position, as a portion of the flexible member  110  remains anchored in the indentation  104   a , of the stub  104 . (If the apparatus was configured oppositely, for damping in the opposite direction, the flexible member  110  would remain anchored in the indentation  105   a , of the stub  105 ).  
         [0040]     The flexible member  110  is typically of a material, such as an elastomer, that is resilient, yet allows for bending and flexing. Moreover, as a result of the slots  106 ,  107  being symmetric, coupled with the universal sizing of the flexible member  110 , the flexible member  110  can be fitted into either of the slots  106 ,  107 . Accordingly, only a single piece  22  needs to be manufactured (machined and tooled), as it can facilitate damping in any desired rotational direction (for example, clockwise or counterclockwise). Accordingly, with the flexible member  110  in the desired slot  107 , damping is in the opposite direction, to that shown in  FIGS. 5 and 6 .  
         [0041]     The finger  100 , stubs  104 ,  105  (and corresponding indents  104   a ,  105   a ), slots  106 ,  107  and flexible member  110 , are designed to extend in the interior  60  of the cylindrical portion  32  (transversely, in the direction of the transverse axis TX), between the end caps  64 ,  65 .  
         [0042]     The central member  70 , coupled with the finger  100  and flexible member  110 , divides the chamber  66  into areas  120 ,  121 . For example, in the arrangement of components as shown in  FIGS. 5 and 6 , there are two areas, a high-pressure area  120  and a low-pressure area  121 .  
         [0043]     There may also be a volume compensator  125 , that, as shown, seats in the low-pressure area  121 . The volume compensator  125  is, for example, a solid or fluid filled member that extends at least approximately the length of the chamber  66  (transversely, in the direction of the transverse axis TX, between the end caps  64 ,  65 ).  
         [0044]     Exemplary operations will now be detailed with reference to  FIGS. 1-7 . For example purposes, the flexible member  110  is in the slot  106 , as shown in  FIG. 6 .  
         [0045]     When the second piece  24  is rotated counterclockwise (in the direction of the arrow  50  of  FIG. 4 ), from the first or flat position to the second or rotated position shown in  FIG. 4 , rotation to the position (orientation), as shown in  FIG. 4 , is slow. The counterclockwise moving central member  70  causes high damping forces, resulting from grease flowing mainly through the metering paths  82 ,  83  absent any bypass through the interior of the chamber  66 .  
         [0046]     This is because there is not any flow, or an extremely limited flow of fluid between the head  71  of the central member  70  and the flexible member  110 , as the flexible member  110 , due to its biasing, is forced against the finger  100 . This biasing results in a slight, if any, opening between the tip  110   a  of the flexible member  110  and the head  71  of the central member  70 . Accordingly, absent any significant opening through the interior of the chamber  66 , fluid flow between the low pressure area  121  and the high pressure area  120  (through the opening between the edge  100   a  of the finger  100  and the head  71  of the central member  70 ), is slow, resulting in slow and typically controlled and regulated damping, upon the counterclockwise rotation of the second piece  24  (and accordingly, the central member  70 ), with respect to the first piece  22 .  
         [0047]     When the second piece  24  is rotated clockwise, in the direction of the arrow  51 , from second or rotated position to the first or flat position, as shown in  FIGS. 1-3 , rotation is faster due to lower damping forces. This is because the clockwise moving central member  70  causes fluid flow through the channels or metering paths  82 ,  83 , as well as through an opening between the flexible member  110  (at the tip  110   a  of the flexible member  110 ) and the finger  100  (at the edge  100   a  of the finger  100 ), and the head  71  of the central member  70 . The biasing of the flexible member  110 , results in its flexing or bending over the stub  104 , creating the aforementioned opening for fluid flow. This allows for rapid fluid flow or fluid bypass into the low-pressure area  121 , from the high-pressure area  120 , aforementioned opening, through the interior of the chamber  66  in addition to through the channels or metering paths  82 ,  83 . Damping, and movement of the pieces  22 ,  24  to the original position is faster in the clockwise direction, when compared to the counterclockwise direction, as detailed above.  
         [0048]     In the orientation shown, and when the fluid that fills the chamber  66  is, grease or oil, as detailed above, or any other fluid of a viscosity to function as hydraulic fluid (also as detailed above), there are pressure differentials between the high-pressure area  120  and the low-pressure area  121 . Pressure differentials may be as great as 1500 pounds per square inch (psi).  
         [0049]     While preferred embodiments of the present invention have been described, so as to enable one of skill in the art to practice the present invention, the preceding description is intended to be exemplary only. It should not be used to limit the scope of the invention, which should be determined by reference to the following claims.