Patent Publication Number: US-2013239364-A1

Title: Appliance hinge counterbalance assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. application Ser. No. 12/701,109 filed Feb. 5, 2010, now assigned U.S. Pat. No. 8,443,489, which claims priority from and benefit of the filing date of U.S. provisional patent application Ser. No. 61/150,144 filed Feb. 5, 2009, and the entire disclosure of each of said prior applications is hereby expressly incorporated by reference into the present specification. 
    
    
     BACKGROUND 
     Hinges for top-loading appliances such as washing machines and dryers must include or be operatively connected to a counterbalance assembly that provides a desired counterbalance effect such that the lid/door requires no more than a select amount of force to open, stays open without external support when fully opened, self-closes by gravity without harsh slamming against the appliance body when the lid/door is moved to a select partially closed position, and remains closed during normal operating conditions of the appliance. The counterbalance assembly must fit in a limited area and be designed to operate even after prolonged and repeated exposure to water, soap, bleach, heat, etc. A need has been identified for a new and improved appliance lid/door hinge counterbalance assembly that meets the above-noted design requirements while providing structural and functional advantages over known designs. 
     SUMMARY 
     In accordance with the present development, a counterbalance assembly for an appliance hinge includes a base including first and second spaced-apart side walls and a transverse face wall. The base includes: (i) a channel located between the first and second side walls; and, (ii) a notch comprising first and second notch portions respectively located in said first and second side walls. A rotating cam is supported on the base. The cam includes: (i) a camshaft that extends between the side walls and that is adapted for rotation about an axis of rotation, with a first end of the camshaft located in the first notch portion and a second end of the camshaft located in the second notch portion; and, (ii) a lobe that projects from the camshaft. The counterbalance assembly includes a biasing spring that comprises an inner end engaged with the base and an outer end spaced from the base. The outer end of said spring is located outside the channel. A spring rod includes an outer end operatively coupled to the spring and an inner end operatively coupled to the lobe of the cam such that the spring biases the spring rod to an extended position. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIGS. 1 and 2  are first and second isometric views of an appliance hinge counterbalance assembly formed in accordance with the present development, with the counterbalance assembly shown in a first operative position corresponding to a lid/door of the appliance being closed; 
         FIG. 3  is a bottom view of the counterbalance assembly of  FIGS. 1 and 2 ; 
         FIG. 4  is a section view as taken along view line  4 - 4  of  FIG. 3 ; 
         FIG. 4A  is similar to  FIG. 4  but shows the counterbalance assembly in a second operative position corresponding to the appliance lid/door being opened; 
         FIG. 5  is an isometric view similar to  FIG. 2 , but showing an alternative embodiment of an appliance hinge counterbalance assembly in accordance with the present development; 
         FIG. 6  is a section view taken at line  6 - 6  of  FIG. 5 ; 
         FIG. 6A  is similar to  FIG. 6  but shows the counterbalance assembly in a second operative position corresponding to the appliance lid/door being opened; 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-4A , the counterbalance assembly  10  is particularly adapted for operative connection to an associated hinge arm that pivotally secures an appliance lid/door to an appliance body. For example, the counterbalance assembly  10  is adapted for operative connection to a hinge arm used for pivotally securing a lid/door of a top-loading washing machine or dryer to the body of the washing machine or dryer. The counterbalance assembly  10  comprises a base  12  defined from a one-piece metal stamping or a multi-piece assembly of metal or other components or other like structure. The base  12  includes first and second longitudinally extending, parallel and spaced-apart side walls  12   a , 12   b  that typically lie in respective vertical planes when the counterbalance assembly  10  is operatively connected to a washer or other top-loading appliance. A channel  14  is defined between the side walls  12   a , 12   b  and is closed at one end by a transverse face wall  12   c . The base  12  also includes a top wall  12   d  that extends between the side walls  12   a , 12   b . The base  12  further includes at least one mounting tab  12   e  or other mounting structure adapted to be secured to an appliance body using one or more fasteners such as screws or rivets, or by a weld or other means. 
     A rotating cam  20  is operably supported on the base  12  and includes a cylindrical camshaft  22  that extends between the side walls  12   a , 12   b  through the channel  14  and that is adapted for rotation about its longitudinal axis of rotation X ( FIG. 3 ) that extends transverse to the side walls  12   a , 12   b . More particularly, the base  12  defines a notch  16  that opens in the top wall  12   d  and the side walls  12   a , 12   b . The notch  16  comprises first and second notch portions  16   a , 16   b  defined respectively in the first and second side walls  12   a , 12   b . First and second opposite ends  22   a , 22   b  of the camshaft  22  are rotatably supported by the first and second notch portions  16   a , 16   b , respectively. The top wall  12   d  includes a keeper tab  18  (see also  FIG. 4 ) that projects into the notch  16  so that a dwell point  16   d  for the cam shaft  22  is defined in the notch  16 . The keeper tab  18  captures the first and second camshaft ends  22   a , 22   b  respectively in the first and second notch portions  16   a , 16   b  so that when the camshaft is seated in the notch dwell point  16   d , the camshaft  22  is prevented from escaping the notch  16  during normal operation of the counterbalance assembly. 
     At least one or both opposite ends  22   a , 22   b  of the camshaft  22  are adapted to be connected to an associated wire-form or other associated appliance lid/door mounting hinge arm  30  (shown in broken lines in  FIG. 3 ) such that the hinge arm  30  and camshaft  22  rotate together on the axis of rotation X. The wire-form or other appliance lid/door mounting hinge arm  30  can alternatively be provided as part of the counterbalance assembly  10 . As shown herein, the hinge arm  30  is supplied separately (e.g., as part of the associated appliance). The hinge arm  30  is adapted for connection to an appliance lid/door using fasteners or other means. In the illustrated embodiment, the opposite ends  22   a , 22   b  of the camshaft  22  include respective non-circular recesses  23  that are adapted for close sliding insertion of a mating non-circular portion of the associated hinge arm  30  in a non-rotatable or keyed manner, but other connections between the hinge mounting arm  30  and the camshaft  22  can be used. 
     The counterbalance assembly  10  further comprises a biasing spring  40  operatively connected/coupled to the rotating cam  20  for controlling rotational movement of the cam. In the illustrated embodiment, the spring  40  is a helical coil spring having an outer end  40   a  spaced from the base face wall  12   c , external to the channel  14 , and an opposite inner end  40   b  operably abutted or otherwise engaged with the face wall  12   c  or other part of the base  12  (via direct abutment or indirect abutment through a thrust washer or the like). A spring rod  42  extends coaxially through the spring  40 , and an outer end  42   a  of the spring rod is operatively engaged/coupled to the outer end of the spring  40   a , e.g., by deforming the outer end  42   a  of the spring rod and/or by including a washer or other enlarged member or portion on the outer end  42   a  of the spring rod  42 , so that the outer end  42   a  cannot pass through the hollow core region or inside diameter of the spring  40 . The spring rod  42  also extends through an opening in the face wall  12   c  of the base  12  such that an inner end  42   b  of the spring rod is located in the channel  14 . The inner end  42   b  of the spring rod is operatively coupled to the rotating cam  20  through a connecting link  50 . As shown in  FIG. 4 , rotation of the cam  20  about its axis X in first and second angular directions A 1 ,A 2  results in corresponding linear translation of the spring rod in corresponding first and second linear directions L 1 ,L 2 . 
     With continuing reference to  FIGS. 3 and 4 , the rotating cam  20  includes a radially projecting tab or lobe  24  located in the channel  14  between the base side walls  12   a , 12   b . The inner end  42   b  of the spring rod  42  is operatively coupled to the lobe  24  of the cam  20  by the connecting link  50  that has a first end  50   a  pivotally connected to the cam lobe  24  a second end  50   b  pivotally connected to the inner end  42   b  of the spring rod  42 . The pivoting connections between the connecting link  50  and the arm  24  and spring rod  42  can be made using rivets or other fasteners or by other means such as direct engagement between mating portions of the components. The spring  40  biases the spring rod  42  to an extended position in which the outer end  42   a  of the spring rod  42  is spaced a maximum distance from the face wall  12   c  of the base  12 . 
     Referring to  FIGS. 4 and 4A , rotational movement of the cam  20  about its longitudinal axis X in the first angular direction Al (in response to closing movement of the appliance lid/door to which the mounting hinge arm  30  is connected) will induce inward sliding translation of the spring rod  42  in the direction L 1  into the channel  14  against the biasing force of the spring  40  so that the outer end  42   a  of the spring rod  42  is moved toward the transverse wall  12   c  and compresses the coils of spring  40 , which corresponds to a first operative position of the counterbalance assembly  10  as shown in  FIG. 4 . Rotational movement of the cam  20  in an opposite angular direction A 2  during opening of the appliance lid/door to which the lid/door mounting hinge arm  30  is connected will be aided by the resilient biasing force of the spring  40  which assists sliding translational movement of the spring rod  42  in the direction L 2  to its extended position where the outer end  42   a  of the spring rod is spaced a maximum distance from the transverse wall  12   c , which corresponds to a second operative position of the counterbalance assembly  10  as shown in  FIG. 4A . As such, the resilient elongation of the spring  40  assists opening movement of the associated appliance lid/door connected to the hinge arm  30  and the resilient compression of the spring  40  dampens closing movement of the associated lid/door. 
     In the illustrated embodiment, the inner end  42   b  of the spring rod is pivotally connected to the end  50   b  of the connecting link  50  by a rivet or other pivot fastener  54 . The first and second body side walls  12   a , 12   b  include respective first and second elongated slots  13   a , 13   b  that are aligned with each other, and the pivot fastener  54  is slidably engaged in at least one and preferably both of the slots  13   a , 13   b . As shown, the pivot fastener  54  includes opposite first and second ends that are respectively slidably engaged with the first and second elongated slots  13   a , 13   b . The sliding engagement of the fastener  54  in the slots  13   a , 13   b  serves to stabilize and control movement of the spring rod  42  and cam  20  and limits the maximum inward and outward sliding movement of the spring rod  42  in the directions L 1  and L 2  (and thus limits the angular rotation of the cam  20  in the directions A 1  and A 2 ). 
       FIGS. 5 ,  6  and  6 A illustrate and alternative embodiment counterbalance assembly  110  that is the same as the counterbalance assembly  10  except as otherwise shown and/or described herein. As such, like components are identified with like reference numbers that are  100  greater than those used above in relation to  FIGS. 1-4  and are not described further here. In the counterbalance assembly  110 , the lobe  124  of the cam  120  includes an elongated curved or arcuate slot  125 , and the inner end  142   b  of the spring rod  142  is directly slidably connected to the lobe  124  with a sliding engagement between the spring rod inner end  142   b  and the slot  125 , e.g., using a rivet  126  or other slide fastener. The slots  13   a , 13   b  of the base  12  from  FIGS. 1-4  are not required because the elongated arcuate slot  125  of the cam lobe  124  limits travel of the spring rod  142  in the directions L 1 ,L 2 .  FIG. 6  shows a first operative position of the counterbalance assembly  110 , which corresponds to the appliance lid/door being closed.  FIG. 6A  shows a second operative position of the counterbalance assembly  110 , which corresponds to the appliance lid/door being opened. 
     The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.