Patent Publication Number: US-2010127606-A1

Title: Slow open slow close appliance hinge assembly

Description:
CLAIM OF PRIORITY 
     This application claims priority from and benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/117,738 filed on Nov. 25, 2008, which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     This disclosure relates to an appliance hinge assembly. More particularly, it relates to a slow open slow close appliance hinge assembly. 
     Appliances such as refrigerators, ovens and microwave ovens have hinged doors for accessing an interior compartment. For example, an oven has a body defining a cooking chamber having an opening selectively opened or closed by a door pivotably secured to the body and which pivots between a closed position and an open position. The door is pivotably connected to the body using hinge assemblies. 
     The hinge system of the present disclosure is described herein with reference to its use as an oven or stove door hinge system (the terms “oven” and “stove” may be used interchangeably herein). Those of ordinary skill in the art will appreciate, however, that a hinge system formed in accordance with the present disclosure can be used as a door hinge system for a wide variety of other appliances such as clothes washers and dryers, dishwashers and the like. 
     Appliance manufacturers continue to seek improved performance characteristics with respect to the connection of doors to the appliance body and movement of the door relative to the body. With respect to oven doors, manufacturers and consumers have expressed a desire for doors that exhibit dampened-open and/or dampened-close characteristics. In a typical configuration, the oven door must be pulled open manually until it defines an angle of about 30° with the oven body, at which time the oven door will fall under its own weight in a slow, gentle and controlled manner until it is fully open and defines an angle of 90° with the oven body. With dampened-close, the oven door is moved manually from the fully open (about 90°) position to a partially closed position (e.g., where it defines an angle of about 30° with the oven body) after which it closes the remainder of the distance in a slow, gentle and controlled manner under force of a spring or other biasing means that is part of the hinge assembly. 
     Prior attempts to provide an oven door exhibiting these dampened-open/dampened-close characteristics have been deemed sub-optimal for a wide variety of reasons. In prior arrangements, with respect to door opening, attempts have been made to reduce door-opening resistance (such as reducing counter-weight or reducing door-closing biasing force). This allows the door to open under its own weight, but has the undesired effect of increasing the speed at which the door opens which can lead to noise, vibration, damage to the oven and disruption of delicate contents of the oven such as soufflés or cakes. 
     In other prior arrangements, dampeners and/or gas-springs have been employed in tandem with conventional hinge assemblies in an effort to achieve the desired dampened-open and dampened-close effects. These dampeners and/or gas-springs have not been incorporated into the hinge assemblies. This leads to increased complexity which increases costs of manufacture and repair. Furthermore, to provide both dampened-open and dampened-close characteristics, the complexity increases even further. 
     Another problem with these hinge assemblies is that they do not provide for an effective dampening effect during opening and closing of the appliance door. Accordingly, it is desired to provide a slow open slow close appliance hinge assembly which overcomes the above-mentioned deficiencies and others while providing better and more advantageous overall results. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     This disclosure relates to a hinge for an appliance door. More particularly, it relates to a slow open slow close appliance hinge assembly. 
     In accordance with one aspect of the disclosure, a slow open slow close hinge assembly for an appliance has a first hinge assembly including a base; a tab projecting outwardly from the base in a first direction; a support projecting outwardly from the base in a second direction; a hinge arm pivotably connected to the tab via a first pivot point; a tail portion extending through an opening in the base; a slow open slow close dampener operably connected between the support at a second pivot point and the tail portion at a third pivot point; wherein a neutral position for the dampener occurs when the first, second and third pivot points are aligned substantially in a straight line. 
     In accordance with another aspect of the disclosure, an appliance includes a body; a door; first and second hinge positions for pivotably connecting the door to the body; wherein each of the first and second hinges includes a base; a tab projecting outwardly from the base in a first direction; a support projecting outwardly from the base in a second direction; a hinge arm pivotably connected to the tab via a first pivot point; a tail portion extending through an opening in the base; a slow open slow close dampener operably connected between the support at a second pivot point and the tail portion at a third pivot point; wherein a neutral position for the dampener occurs when the first, second and third pivot points are aligned substantially in the same plane. 
     In accordance with another aspect of the disclosure, a slow open slow close dampener for an appliance hinge includes a body and a rod selectively extensible from and retractable into the body, wherein when the hinge moves from a first operative position, the rod retracts into the body, the hinge moves to a neutral position and then the hinge moves to a second operative position and the rod extends out of the body. 
     Another aspect of the disclosure is a hinge assembly which has a slow open slow close damper system. 
     Another aspect of the disclosure is the damper has asymmetric dampening characteristics wherein more resistance occurs during extension of a dampening rod and less resistance occurs during insertion of a dampening rod. 
     Yet another aspect of the disclosure is the damper includes a piston and rod which are extended and retracted and dampened by gas or other fluid. 
     Still another aspect of the disclosure is a damper which provides damping when the door is opened and when the door is closed. 
     Still other aspects of the disclosure will become apparent after a reading and understanding of the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure comprises various components and arrangements of components, preferred embodiments of which are illustrated in the accompanying drawings that form a part hereof and wherein; 
         FIG. 1A  is an isometric view of an oven with a door pivotably connected by a hinge assembly; 
         FIG. 1B  is a second isometric view of an oven with a door pivotably connected by a hinge assembly; 
         FIG. 2A  is a perspective view of a hinge assembly in a first operative position; 
         FIG. 2B  is a perspective view of a hinge assembly in a second operative position; 
         FIG. 3A  is a perspective view of a slow open slow close hinge assembly in a first operative position in accordance with a preferred embodiment of the present disclosure; 
         FIG. 3B  is a perspective view of a slow open slow close hinge assembly in a second operative position in accordance with a preferred embodiment of the present disclosure; 
         FIG. 4A  is a side elevational cross sectional view of a damper in an extension stroke; 
         FIG. 4B  is an enlarged side elevational view in cross section of a piston assembly of the dampener of  FIG. 4A ; 
         FIG. 4C  is a side elevational cross sectional view of a damper in a compression stroke; 
         FIG. 4D  is an enlarged side elevational view in cross section of a piston assembly of the dampener of  FIG. 4C ; 
         FIG. 5A  is a side elevational view of a slow open slow close hinge assembly in a first operative position in accordance with a preferred embodiment of the present disclosure; 
         FIG. 5B  is a side elevational view of a slow open slow close hinge assembly in an intermediate operative position in accordance with a preferred embodiment of the present disclosure; and 
         FIG. 5C  is a side elevational view of a slow open slow close hinge assembly in a second operative position in accordance with a preferred embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the drawings, which are for purposes of illustrating a preferred embodiment only and are not intended to be limiting in any way, a stove or oven O is shown in  FIGS. 1A and 1B  and includes a dampened hinge system. The oven O, apart from the dampened hinge system, is conventional and comprises a body B and a door D. The door D is movable to a closed position and an opened position as shown in  FIGS. 2A and 2B . 
     Specifically,  FIGS. 1A and 1B  are first and second isometric views of an oven O including a body B that defines a cooking chamber C having an opening CO that is selectively covered or closed by a door D pivotally secured to the body B and adapted to pivot between: (i) a closed position (not shown) where the door D is generally vertically oriented and covers the cooking chamber opening CO; and, (ii) an opened position (shown) wherein the door D is pivoted about a horizontal pivot axis away from the cooking chamber opening CO, usually to approximately a horizontal position, to allow access to the cooking chamber C. The door D is pivotally connected to the body B using first (left) and second (right) hinge assemblies HA 1  and HA 2 , respectively. According to the present disclosure, at least one or both of the hinge assemblies HA 1  and HA 2  is structured as a slow open slow close hinge assembly in accordance with the present disclosure. As described herein, the hinge assembly HA 1  is a slow open slow close hinge assembly formed in accordance with the present disclosure, while the hinge assembly HA 2  is a conventional hinge assembly. 
     In the illustrated example, the conventional hinge assembly HA 2  is constructed, e.g., as shown in  FIGS. 2A and 2B . It is not intended that the present disclosure be limited to the illustrated conventional hinge assembly HA 2  or any other particular type of conventional hinge assembly HA 2  (also, as noted above, both hinge assemblies HA 1  and HA 2  can be slow open slow closed hinge assemblies according to the present disclosure as described below with reference to  FIGS. 3A and 3B ).  FIG. 2A  shows the hinge assembly HA 2  in a first operative position corresponding to the closed position for the oven door D while  FIG. 2B  shows the hinge assembly HA 2  in a second operative position corresponding to the opened position for the oven door D. 
     The hinge assembly HA 2  comprises a base  10  adapted to be secured to the oven body B using fasteners such as rivets or screws or by welding or other suitable conventional means. The base  10  comprises a tab or ear  12  that projects outwardly therefrom. A hinge arm  20  is pivotally secured to the ear  12  using a rivet or other fastener and is adapted for pivoting movement relative to the base  10  so that the hinge arm pivots between the first and second operative positions as shown in  FIGS. 2A and 2B . The hinge arm  20  includes a door mounting portion  20   a  adapted to be secured to the oven door D by fasteners such as screws or rivets or by welding or other suitable means. The hinge arm  20  further includes a tail portion  20   b  that projects from the door mounting portion  20   a . As shown the tail portion  20   b  extends through an opening or slot defined in the base  10 . The tail  20   b  has a distal end  20   c  connected to a spring G or another suitable counter-balance mechanism. The spring G, which can be a tension spring, a compression spring, a gas-spring, or other type, can be self-contained with respect to the hinge assembly HA 2 , e.g., by having one portion connected to the base  10  and another portion connected to the tail  20   b . In the illustrated embodiment, the spring G is part of a counter-balance system  30  that is integrated into the oven O. 
     In particular, the illustrated counter-balance system  30  includes a coiled tension spring G having a first end G 1  connected to the oven body B (see also  FIG. 1B ) and a second end G 2  connected to a cable  32  that is, in turn, connected to the distal end  20   c  of the tail  20   b . The cable  32  is engaged with a pulley  34  that is connected to the base  10  of the hinge (or is connected to the oven body B). The pulley  34  routes and guides the cable  32  such that movement of the hinge arm  20  from the first operative position ( FIG. 2A ) to the second operative position ( FIG. 2B ) resiliently lengthens or extends the spring G, while movement of the hinge arm  20  from the second operative position ( FIG. 2A ) to the first operative position ( FIG. 2B ) allows the spring to contract or compress. As such, the spring G exerts a biasing force on the tail  20  of the hinge arm  20  that biases the hinge arm  20  toward or into its first operative position. 
       FIGS. 3A and 3B  are isometric views of the hinge assembly HA 1  that is a slow open slow close hinge assembly formed in accordance with the present disclosure.  FIG. 3A  shows the hinge assembly HA 1  in a first operative position corresponding to the closed position for the oven door D while  FIG. 3B  shows the hinge assembly HA 1  in a second operative position corresponding to the opened position for the oven door D. The hinge assembly HA 1  comprises a base  100  adapted to be secured to the oven body B using fasteners such as rivets or screws or by welding or other suitable conventional means. The base  100  comprises a tab or ear  112  that projects outwardly therefrom in a first or forward direction and a damper support  113  that projects outwardly therefrom in a second or rearward direction. 
     A hinge arm  200  is pivotally secured to the ear  112  at a pivot point P 1  using a rivet or other suitable fastener and is adapted for pivoting movement relative to the base  100  about a horizontal pivot axis X ( FIG. 5A ) so that the hinge arm  200  can pivot between the first and second operative positions as shown in  FIGS. 3A and 3B . The hinge arm  200  includes a door mounting portion  200   a  adapted to be secured to the oven door D by fasteners such as screws or rivets or by welding or other suitable means. The hinge arm  200  further includes a tail or tail portion  200   b  that projects from the door mounting portion  200   a . As shown the tail portion  200   b  extends through an opening or elongated slot  116  defined in the base  100 . 
     The hinge assembly HA 1  further comprises a slow open slow close damper system DS comprising a damper M operably connected between the damper support  113  and the hinge arm tail  200   b  of the hinge arm  200 . The damper M is pivotally connected to both the distal end  200   c  of the tail  200   b  and the damper support  113  at respective pivot points P 2  and P 3 . More particularly, the damper M comprises a body M 1  and a rod M 2  that is selectively extensible from and is retractable or insertable into the body M 1 , one of which (the body M 1  in the illustrated embodiment) is connected to the damper support  113  and the other of which (the rod M 2  in the illustrated embodiment) is connected to the distal end  200   c  of hinge arm tail  200   b.    
     The damper M is configured to have asymmetric dampening characteristics such that the resistance or dampening during extension of the rod M 2  out of or from the body M 1  is more than the resistance or dampening during retraction or insertion of the rod M 2  back into the body M 1 . Preferably, the damper provides little or no resistance or dampening during retraction of the rod M 2  back into the body M 1 . It is also preferred that the rod M 2  not be biased toward either its extended or retracted position by a spring or fluid pressure, i.e., the rod M 2  will be stationary in any extended or retracted position relative to the body M 1  unless acted on by other forces. For example, the damper M can be defined as a fluid spring such as a gas spring comprising a gas that is acted upon by a piston located in a cylinder bore defined in the body M 1 , wherein the piston is connected to the rod M 2  and is configured such that the gas provides or creates resistance to extension of the piston and rod M 2  but provides or creates little or no resistance to retraction or insertion of the piston and rod M 2 . Alternatively or additionally, the fluid in the damper M can comprise a hydraulic oil or other liquid. 
     Specifically, during operation of the damper, referring now to  FIGS. 4A and 4B , on an extension stroke, a piston  308  and rod  310  travel in the direction of the arrow in  FIG. 4B , and friction between a washer  300  (such as a Teflon washer) and an inside wall  302  of a bore  304  of a damper cylindrical tube  306  keeps the washer pressed against a piston washer  307  of the piston  308  located in the bore  304 . The piston  308  is connected to rod  310 . By pressing the washer  300  against a surface of the piston washer  307 , the fluid or gas is forced to travel through small indented holes or channels  312  formed in the piston wall. The fluid travels in the opposite direction of the arrow of  FIG. 4B . In other words, the piston is configured such that gas or fluid provides resistance or dampening to the extension of the piston and rod out of the tube  306 . 
     Referring now to  FIGS. 4C and 4D , on the compression or retraction stroke, wherein the piston and rod travel in the direction of the arrow in  FIG. 4D , friction between washer  300  and inside walls  302  of bore  304  of tube  306  keeps the washer  300  pressed against a surface of the piston  308 . This allows the fluid or gas to freely pass or travel past the piston washer  307  and through four holes or channels  314  formed in the piston wall. The fluid travels in the opposite direction of the arrow of  FIG. 4D . This results in little or no resistance or dampening of insertion or retraction of the piston and rod into tube  306 . 
     Referring now to  FIGS. 5A ,  5 B and  5 C, the hinge assembly HA 1  is shown in the first and second operative positions ( FIGS. 5A and 5C ) and also an intermediate position ( FIG. 5B ). It can be seen that movement of the hinge arm  200  from the first operative (i.e. door closed) position to the intermediate position illustrated in  FIG. 5B  requires counterclockwise pivoting movement of the damper M about pivot point P 3  in a vertical plane and also retraction or insertion of the rod M 2 . The point at which projecting length of the rod M 2  is minimized (maximum retraction or insertion of the rod M 2  into body M 1 ) can be referred to as a neutral position for the damping system and for the hinge arm  200  and damper M, which will occur when the pivot points P 1 ,P 2 ,P 3  are arranged in a substantially straight line or are positioned in substantially along the same plane. Movement of the hinge arm  200  from the neutral position to its second (i.e. door opened) operative position as illustrated in  FIG. 5C  requires further counterclockwise pivoting movement of the damper M in the vertical plane about pivot point P 3  and also extension of the rod M 2 . Likewise, reverse movement of the hinge arm  200  from the second operative position ( FIG. 5C ) to the first operative position ( FIG. 5A ) through the neutral position requires initial retraction or insertion of the rod M 2  until the neutral position is reached followed by extension of the rod M 2  from the neutral position to the first operative position. As such, the hinge arm  200  and/or damper system DS can be said to go “over-center” upon movement of the hinge arm  200  through the neutral position in either direction. Both opening and closing of the oven door D include a first step of retraction or insertion of the rod M 2  followed by extension of the rod M 2 . Because of the above-described asymmetric dampening characteristics of the damper M, movement of the hinge arm  200  away from the neutral position is dampened by the damper M to a greater extent than movement of the hinge arm  200  toward the neutral position which means that, for both opening and closing of the oven door D, movement of the door D is dampened primarily (or at least to a greater extent) only after the hinge arm  200  goes over-center past the neutral position. 
     In one embodiment, the hinge assemblies HA 1  and HA 2  are configured such that the oven door D will counter-balance and remain stationary when the hinge arm  200  of the hinge assembly HA 1  is in its neutral position as required for the door to balance partially open in a broil position. The pivot point P 3  for connecting the damper M to the damper support  113  can be moved to control the position of the neutral position as measured by the angular position of the hinge arm  200  relative to a horizontal or vertical plane at the neutral position. In another embodiment, the hinge assemblies HA 1  and HA 2  are configured so that the oven door D will not counter-balance in a partially opened position, in which case the oven door D will always move to either its opened position or its closed position depending on the angular position of the hinge arm  200 . 
     The exemplary embodiment has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.