Patent Publication Number: US-2019186572-A1

Title: Integral rod and spring for a damper

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an integral spring and control rod for use with a damper and a damper employing the same. 
     Mechanical dampers are employed in a variety of environments for damping excessive or unwanted motion. One example is a washing machine where unbalanced loads tend to cause excessive vibration. U.S. Pat. Nos. 7,445,098, 7,549,519, 5,230,229, and 5,080,204 and US Publication Nos. 2003/0183994 and 2016/0024705, the disclosures of which are incorporated herein by reference, are examples of different types of dampers and their usage in washing machines. Such dampers have a control rod with one end which is typically fixed to a frame, for example, of a washing machine. An opposite end of the control rod extends through the damper and can be attached to a movable element of the washing machine for which movement is desired to be dampened. The damper also includes a frictional damping element which interacts between the control rod and a movable part of the damper. The damping element frequently includes a polymeric pad and grease to provide the desired amount of damping action. The damper also typically includes a spring which extends between one end of the damper and a fixed end attached to the damper, such that, when movement occurs, the damper is spring returned to its at rest position under the influence of either a spring in compression or a spring in extension, depending upon the specific damper design and application. Typically, the spring is a separate component of the damper assembly and coaxially surrounds the control rod, as disclosed in the above-identified patents and publications. 
     SUMMARY OF THE INVENTION 
     This invention integrates a coil spring with extensions on opposite ends of the spring to define a control rod for a damper. Thus, the spring and control rod are integrated into a one-piece structure. This eliminates the need for two separate components, namely, a spring and a separate control rod. By integrating the coil spring and control rod, a damper can be designed using fewer parts in a unique configuration. This invention further contemplates a friction rod damper comprising a coil spring having a longitudinal axis, with the spring including a body and first and second extending ends which extend longitudinally from the body of the spring and define a control rod for the damper. The extending ends terminate in attachments, and a damper member extends coaxially through the spring and has a first end secured to the first extending end of the spring in spaced relationship to an associated attachment. The damper member includes a second end with a container surrounding the second extending end of the spring in spaced relationship to an associated attachment. The container includes a damping element engaging the second extending end of the spring, wherein the damper member allows the spring to expand and contract with its integral control rod engaged by the damping element to provide damping. 
     These and other features, objects and advantages of the present invention will become apparent upon reading the following description thereof together with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cutaway perspective view of a washing machine employing multiple dampers of the present invention; 
         FIG. 2  is a side elevational view of one of the dampers shown in  FIG. 1 ; 
         FIG. 3  is a top plan view of the damper shown in  FIG. 2 ; 
         FIG. 4  is an exploded perspective view of the damper shown in  FIGS. 2 and 3 ; 
         FIG. 5  is a vertical cross-sectional view of the damper shown in  FIG. 2 ; 
         FIG. 6  is a fragmentary perspective view of an alternative connection between the control rod and the fixing element of the damper of the present invention; 
         FIG. 7  is a fragmentary perspective view of an alternative design for the connection between the control rod and the fixing element; 
         FIG. 8  is an enlarged fragmentary perspective view of an alternative embodiment of the connection between the control rod and the fixing element; 
         FIG. 9  is a greatly enlarged top fragmentary plan view of the fixing element and control rod shown in  FIG. 8 ; 
         FIG. 10  is a vertical cross-sectional view of the control rod and fixing element shown in  FIG. 8 ; 
         FIG. 11  is a perspective view of the damper of the present invention employing yet another alternative embodiment of the connection of the control rod and fixing element; 
         FIG. 12  is a vertical cross-sectional view of the damper shown in  FIG. 11 ; 
         FIG. 13  is an enlarged fragmentary top plan view of the control rod and fixing element shown in  FIGS. 11 and 12 ; 
         FIG. 14  is a perspective view of an alternative embodiment of one of the dampers shown in  FIG. 1 ; 
         FIG. 15  is an exploded perspective view of the damper shown in  FIG. 14 ; and 
         FIG. 16  is an exploded perspective view of an alternative embodiment of the damper shown in  FIGS. 14 and 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to  FIG. 1 , there is shown a top-loading washing machine  10 , which includes a cabinet  12  and a drum  14  for receiving clothes and other items to be laundered through a hinged cover (removed) over opening  13  in the top of cabinet  12 . Drum  14  rotates and agitates the clothes during wash and spin dry cycles and is subject to vibrations during normal operation of the machine and particularly when there are unbalanced loads. Drum  14  is enclosed by an outer drum  16  supported by a frame  18  including legs and a lower ring  17  mounted on a bearing  19 . This allows both drum  14  and surrounding rotationally fixed drum  16  to move during washing cycles. In order to stabilize the drums, a plurality of dampers  20  embodying the present invention extend between outer drum  16  and anchors  15  in the floor  11  of the cabinet  12 . In  FIG. 1 , four such dampers  20  are seen, it being understood that a greater or fewer number can be employed depending on the washer design. In the washer design of  FIG. 1 , the dampers  20  act in an extension mode, however the damper design can be adapted for hanging a drum from the washer cabinet, as seen in U.S. Pat. No. 7,549,519, or in other configurations as well as in other embodiments and environments including, but not limited to, front-loading washers. 
     Each of the dampers  20 , shown in  FIG. 1 , can be of the type shown in the detailed drawings of  FIGS. 2-5  or their alternative embodiments in  FIGS. 6-16 . Referring now to  FIGS. 2-5 , there is shown a damper  20  which includes an integral coil spring  22  and control rod  24  extending from opposite ends of the spring body  21 . The integral coil spring  22  is made of spring music wire, such as ASCMA228 spring material, which is commercially available from a variety of sources. The integral coil spring  22  has an outside diameter of about 2-4 mm and preferably 3 mm. The spring constant “k” for spring  22  can be from 2 to 4 N/mm and, in one embodiment, is 3.25 N/mm. The control rod  24  is defined by extending ends  25  and  26  of spring body  21  and are integral with the body  21  of coil spring  22  forming one piece. The control rod  24  extends longitudinally outwardly from the spring body  21  in spaced relationship to the central longitudinal axis L of the spring  22 , as seen in  FIG. 2 . The control rod  24 , therefore, is aligned with the longitudinal axis of the spring in offset relationship and extends generally longitudinally from the outer coils at opposite ends of the spring body  21 . 
     Extending end  25  terminates in an attachment  27  in the form of a hook, while extending end  26 , which is longer than extending end  25 , also terminates in an attachment hook  28 . Other attachments may be used depending upon the environment of the damper. Hooks  27 ,  28 , as seen in  FIG. 1 , are attached to the anchor  15  on the floor  11  of cabinet  12  and the lower edge of outer drum  16  to stabilize both drums during a washing cycle. 
     Extending coaxially through the center of the longitudinal axis L of spring  22  is the damping member  30 , which is integrally molded of a polymeric material, such as ABS, polyethylene, polypropylene, or other suitable polymeric material. The damping member  30  includes a longitudinally extending leg  32  which extends coaxially through the spring  22  and has a first end  34  which terminates in a fixing member  36 . Fixing member  36  is integral with the end  34  of leg  32  and secures the first extending end  25  of control rod  24  in longitudinally spaced relationship to attachment member  27 . The leg  32  of damper member  30  is a generally U-shaped member, as best seen in  FIG. 4 , with a pair of spaced-apart legs  31  and  33 , defining a channel  39  along its length. The end of leg  32  opposite fixing member  36  is a second end  38 , which terminates in an integrally molded container  40  in spaced relationship between attachment  28  of spring  22  and body  21  of spring  22 . Container  40  includes damping elements  49  and  51 , as described below, which engage the control rod  24  and provide damping of the movement of control rod  24  through damper  20 . 
     The fixing member  36  comprises a generally rectangular block  35  having a longitudinally extending slot  37  which fixedly grips the first end  25  of spring  22  to secure the end  25  of spring  22  to the damping member  30 . The slot  37  is configured to tightly grip the end  25  of the control rod  24  against longitudinal movement and is dimensioned with respect to the diameter of the extending end  25  of spring  22  to do so. In some embodiments, a suitable bonding adhesive may be used to assist in anchoring end  25  to fixing member  36 . 
     Container  40  and the damper elements  49  and  51  are best seen in  FIGS. 4 and 5 . The container  40  includes a box-like structure formed at the second end of leg  32  and, as seen in  FIG. 4  (when opened), has a square container having side walls  42  and end walls  44  with semi-circular recesses  45  for guidably receiving control rod  24 . The container  40  half shown in  FIG. 4  is integral with the leg  32  of damper member  30  and includes a damping element  49  held in the shallow box-like half of container  40 , as seen in  FIG. 4 . This section of the container includes a pair of outwardly projecting locking tabs  46  which, as seen in  FIG. 2 , interlock with slots  47  formed in cover  50  to snap-lock the cover  50  to container  40 . The cover  50  is also generally square with a recess for receiving a second damping element  51  which engages the side of the control rod  24  opposite damping element  49  when cover  50  is snap-fit over tabs  46 . 
     The cover  50  of container  40  likewise includes semi-circular recesses  55  ( FIG. 4 ) for loosely receiving control rod  24  within the container  40  of damping member  20 . Cover  50  is a generally U-shaped member, as seen in  FIG. 4 , having a base  52  and a pair of spaced-apart legs  54  in which slots  47  are formed. The slots  47  and tabs  46  are dimensioned such that the cover  50  snap-fits over the tabs  46  in tight compressive relationship, such that damping elements  49  and  51  grip the control rod  24  with sufficient force to provide the desired damping action provided by damping member  20 . Each of the damping elements  49  and  51  are made of a foam material, such as a commercially available closed-cell foam polymeric material, such as polyurethane. The pad-like damping elements are coated with a lubricant, such as a commercially available highly temperature-stable lubricant, to provide the desired damping action once the container  40  is assembled with cover  50 . 
     The pads  49  and  51  have a selected thickness to provide the desired compression between the damping elements and the control rod  24  to provide the desired damping action. In one embodiment, the pads were about 12 mm×12 mm×4 mm. The thickness and surface area of the damper elements, as well as the container  40 , can vary as desired for a particular embodiment. In one embodiment, the width of leg  32  of the damping member was about 1.4 cm, with the legs having a height of about 0.71 cm. The overall length of one embodiment of the damper member  30  was about 16.5 cm. The length of the integral spring and control rod  24  was about 34.5 cm. These dimensions are representative of one embodiment of the invention but can be varied depending upon the application for a damper of this configuration. 
       FIG. 6  is a perspective view of an alternative embodiment of a damper  120  in which the same components as in the previously described embodiment are employed and are identified by the same reference numbers proceeded by a “1”. The container  140  is of the same construction of container  40  in the earlier embodiment, however, the fixing member  136  and spring end  125  are modified. Fixing member  136  includes, in addition to the longitudinal slot  137  for receiving end  125  of the extending leg of spring  122 , a transversely extending notch  139  which receives a coined projection  129  formed on the end  125  of control rod  124 . The interface between the coined enlargement of the outer diameter of end  125  of spring  122  fits within the notch  139  to positively anchor the control rod  124  at end  125  to damper member  130 . Damper member  130  and control rod  124 , together with the friction elements within container  140 , are otherwise identical to that described in the earlier embodiments. 
       FIG. 7  shows an alternative embodiment of the damper identified as  220  in which common elements, as in previous embodiments, include the same last two digits. In this embodiment, the damper member  230  includes a longitudinally extending slot  237  in fixing member  236  which has a zig-zag pattern, as does the end  225  of the control rod  224 , such that, when the zig-zag section  239  of end  225  of the control rod is fitted within the mating transversely offset zig-zag slot  237  of fixing member  236 , the end  225  of control rod  224  is locked against longitudinal motion. 
       FIGS. 8-10  disclose yet another alternative embodiment of the damper identified as  320  with corresponding elements identified by the same last two digits as in the previous embodiments. In this embodiment, the extending end  325  of spring  322  of damper member  330  has a bend  329  ( FIG. 9 ) which extends through a laterally extending slot  339  which communicates with slot  337  in fixing member  336 . When the end  325  of the integrated spring and control rod  324  is positioned within the angularly inclined introduction slot  339  and longitudinally extending slot  337 , the end  325  of control rod  324  is anchored in the fixing member  336 . The remaining components of the damper  320 , including the container at the opposite end of damper member  330 , are identical to the previously described containers and damping elements and are not shown in  FIGS. 8-10 . 
     Another embodiment of the invention is shown in  FIGS. 11-13  in which the same last two digits are used for structure corresponding to the previous embodiments. In  FIGS. 11-13 , a damper  420  is shown which includes a damper member  430  and an integrated spring with extending ends defining a control rod  424  integrally including spring  422  having a coil spring body  421  and extending ends  426  and  425 . Extending end  426  terminates in an attachment hook  428 , while end  425  terminates in an attachment hook  427 . In this embodiment, the fixing member  436  includes a longitudinally extending slot  437 , as in the first embodiment, however, the attachment hook  427  includes a polymeric cap  460  molded over hook  427  and which covers one half of the hook  427 . As best seen in  FIGS. 12 and 13 , cap  460  has an end  462  which abuts the outer wall  463  of fixing member  436  to anchor the fixing member  436  against the attachment hook  427 . As the spring  422  is expanded during operation of the damper  420 , the fixing member  436  cannot move along extending end  425  but remains immediately adjacent the cap  460  of the attachment hook  427 . The cap could be molded to encapsulate the entire end of the hook. There are a variety of matters in which the fixing member  36 ,  136 ,  236 ,  336 , and  436  or the attachments can be anchored to the extending ends of the control rod defined by the integral spring with extending ends. 
       FIGS. 14 and 15  illustrate an alternative embodiment of a damper assembly  520  of the present invention in which a fixing member  536  and container  540  are similarly structured with a snap-on cover ( 560  and  550 , respectively). In this embodiment, parts similar to the previous embodiments are identified with the same last two digits preceded by the numeral “5.” In  FIGS. 14 and 15 , the fixing member  536  comprises a pair of spread-apart legs  561  and  563  which define an inwardly tapered slot  565  between them. Extending end  525  from spring  522  of control rod  524  fits tightly within the tapered slot and, as best seen in  FIG. 14 , and is compressibly held by the cap  560 , which has legs  562 , each of which includes a slot  564  which fits over and a snap lock to tabs  566  on legs  561  and  563 . Thus, when cap  560  is in place as seen in  FIG. 14  on fixing member  536 , it compresses the legs  561 ,  563  to firmly grip and hold extending end  525  from movement during operation of the damper. 
     The container  540  is constructed in the same member as the earlier described containers with damping element  549  on one side of extending end  526  of control rod  524  and a damping element  551  positioned within the cap  560 . Cap  550  has spaced-apart legs  554  enclosing damping element  551 . Each of the legs  554  includes notches  547  which snap-over locking tabs  546  in the legs  542  of container  540 , which is generally box-shaped, enclosing end walls  541 . Thus, in the embodiment shown in  FIGS. 14 and 15 , both ends of the damping member  530  include snap-on caps for the fixing member  536  and for the container  540  for the damping elements. 
       FIG. 16  shows yet another embodiment of the invention which has the same fixing member features and container for the damping elements as the  FIGS. 14 and 15  embodiment. As a result, the corresponding elements have the same reference numbers. The caps  550  and  560  in the  FIG. 16  embodiment are joined by an interconnecting bar  570  which is an integrally molded piece  575  that includes both the cap  550  and its associated structure and cap  560  and its associated structure, as in the embodiments of  FIGS. 14 and 15 . Bar  570  is spaced outside of the spring  522  and in parallel longitudinal alignment with axis of the spring but is spaced from the spring a distance sufficient so as not to interfere with the expansion and contraction of spring  522  during operation of the damper  520 , shown in  FIG. 16 . 
     It will become apparent to those skilled in the art that various modifications to the preferred embodiment of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.