Abstract:
The present invention provides a frame having variable dimensions, comprising a plurality of telescoping legs arranged in first and second pairs, with each leg of said first pair being rotatably coupled together and each leg of said second pair being rotatably coupled together; and a scissor link mechanism coupled between the legs of said first and second pairs to vary a length of said plurality of legs in response to a distance between said first and second pairs varying. In one embodiment one end of each of said legs of said first pair is rotatably coupled together and one end of each of said legs of said second pair are rotatably coupled together. In this manner, the dimensions of the frame may be varied to accommodate support of a flexible body, such as a plastic bag, paper sack, fabric sack and the like to provide the same with a desired volume and/or an opening of the same with desired dimensions. Specifically, the length of the legs, the angle therebetween and the distance between the first and second pairs may be such as to provide a desired volume of structure support to the flexible membrane from amongst range of volumes that the flexible material can support.

Description:
BACKGROUND 
     The invention relates to adjustable frames to support flexible bodies and more particularly to adjustable frames for use supporting different shapes of flexible bodies. 
     Uses for frames having variable dimensions are manifold to support flexible material is desired to provide a system that occupies less volume when stored, as compared to the volume occupied when in use. For example, frames used to support a flexible canopy, such as a canopy fabricated from cloth, are made to be collapsible, because it is desired that the area of the canopy typically requires that the frame require a volume much greater when used than that desired to be occupied when stored. 
     U.S. Pat. Nos. 4,641,676 and 5,421,356 both to Lynch disclose portable canopy structures that may be erected from a collapsed state to an expanded state that shelters a desired surface. The canopy structure includes a dome-like covering that is held in position by a support framework having a plurality of upright support members that are interconnected by a plurality of scissor assemblies. Each upright support member slideably mounts a slide bracket, and a rigid bracket is mounted at its top. The scissor assemblies are connected to these brackets. Preferably the structure is in the form of a parallelepiped, and an internal scissor assembly extends between two facing side scissor assemblies which interconnect the upright supports. The covering extends across the tops of the supports and has side panels that depend downwardly from its perimeter, and the internal scissor assembly supports a central post that helps support the covering. A screen may be positioned around the support structure and may be connected to and be downwardly dependent from the side panels. Guide cords may be provided for the upright support members. 
     U.S. Pat. No. 5,080,237 discloses an apparatus for holding flexible material exposed to water during a washing process. To that end, at least one bag is held in an inverted position to allow the bag to be sprayed with water for cleaning and then air dried. A support base, resting on a flat surface, has a top face with a plurality of engagement slots therein. At least one frame is included, each frame having two arms, each arm being segmented into two portions pivotally joined at their ends. The support base has two clips to hold at least one frame for compact storage and portability. The ends of each arm are adapted for engagement into said engagement slots. One portion of each arm is pivotally joined to the like portion of the other arm to allow the joined portions to move in scissor-like motion. The distal ends of each arm are adjusted so that the distance between the distal ends is approximately equal to the inside dimension of the bag, the bag being placed in an inverted position over the arms. Each portion of the arms around the points of pivotal joining have a roughened surface to permit two portions to frictionally engage each other and allow the arms to maintain a set position against minor forces. Each portion of the arms has an upset surface to permit two portions to engage each other to facilitate the setting of a preferred set position. 
     Thus, there is a need to provide adjustable frames to provide support for flexible bodies in a variety of situations. 
     BRIEF SUMMARY 
     The present invention provides an adjustable frame comprising a plurality of telescoping legs arranged in first and second pairs, with each leg of the first pair being rotatably coupled together and each leg of the second pair being rotatably coupled together; and a scissor link mechanism coupled between the legs of the first and second pairs to provide structural support and vary a length of the plurality of legs in response to a distance between the first and second pairs varying. In one embodiment one end of each of the legs of the first pair is rotatably coupled together and one end of each of the legs of the second pair is rotatably coupled together. In this manner, the dimensions of a frame may be varied to accommodate support of a flexible body, such as a plastic bag, paper sack, fabric sack and the like to provide the same with a desired volume and/or an opening of the same with desired dimensions. Specifically, the length of the legs, the angle therebetween and the distance between the first and second pairs may be such as to provide a desired volume to the flexible membrane from amongst range of volumes that the flexible material can support. This is useful for many applications, including the washing of flexible material configured as plastic bags in a dishwasher. These and other embodiments are discussed more fully below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a frame in accordance with one embodiment in a fully extending position; 
         FIG. 2  perspective view of the frame shown in  FIG. 1  in an intermediate extended position; 
         FIG. 3  is a bottom perspective view of the frame shown in  FIG. 1 ; 
         FIG. 4  is a front view of the frame shown in  FIG. 1  in a fully extending position; 
         FIG. 5  is a front view of the frame shown in  FIG. 4  in a fully collapsed position; 
         FIG. 6  is a detailed plan view of a coupler, shown in  FIG. 1 , in accordance with an alternate embodiment; and 
         FIG. 7  is a detailed plan view of a pivot joint, shown in  FIG. 1 , in accordance with an alternate embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a frame  10  includes a plurality of telescoping legs  12 ,  14 ,  16  and  18  arranged in pairs  20  and  22 . Each of the legs  12 ,  14 ,  16  and  18  associated with one of pairs  20  and  22  are rotatably coupled together. A scissor link mechanism  24  is coupled between legs  12 ,  14 ,  16  and  18  of first and second pairs  20  and  22 . One end of each of legs  12  and  14  of pair  20  is rotatably coupled together forming a pivot joint  26 , and one end of each of the legs of pair  22  is rotatably coupled together forming a pivot joint  28 . Pivot joint  26  facilitates adjusting an angle  30  between legs  12  and  14  of pair  20 , and pivot joint  28  facilitates adjusting an angle  32  between legs  16  and  18  of pair  22 . 
     Each of legs  12 ,  14 ,  16  and  18  includes a journal and a bearing received within the journal. As shown leg  12  includes journal  34  and bearing  35 , leg  14  includes journal  36  and bearing  37 , leg  16  includes journal  38  and bearing  39  and leg  18  includes bearing  41  and journal  40 . Scissor link mechanism  24  is pivotally coupled between the bearing and journal of each leg  12 ,  14 ,  16  and  18 . 
     Referring to  FIGS. 1 and 2 , scissor link mechanism  24  includes a first pair  42  of pivotally connected couplers  43  and  44  and a second pair  46  of pivotally connected couplers  47  and  48 . Each of couplers  43 ,  44 ,  47  and  48  includes a pair of arms extending in opposing directions therefrom. Coupler  43  includes arms  49  and  50 , coupler  44  includes arms  51  and  52 , coupler  47  includes arms  53  and  54 , and coupler  48  includes arms  55  and  56 . The arrangement of the couplers in any given pair  42  and  46  is discussed with respect to coupler  42  with the understanding that the discussion applies equally to coupler pair  46 . Couplers  43  and  44  are configured to vary a magnitude of two angles formed between the two arms of coupler  43  and the two arms of coupler  44  when pair  42  rotates about an axis  57 . As shown angle  58  is formed between arm  52  and arm  49 . Angle  59  is formed between arm  52  and arm  50 . Angle  60  is formed between arm  51  and arm  49 , and angle  61  is formed between arm  51  and arm  50 . As couplers  43  and  44  rotate about axis  57  one pair of angles  58  and  61  decreases and a remaining pair of angles  59  and  60  increases and vice versa. Specifically, the magnitude of angle pair  59  and  60  is inversely proportional to the magnitude of angle pair  58  and  61  when couplers  43  and  44  rotate about axis  57 . 
     The rotational movement about axis  57  is transferred to linear motion in legs  12  and  16  to vary a length thereof. To that end, arm  49  is pivotally coupled to journal  34 , and arm  50  is pivotally coupled to bearing  39 . Specifically, a pivot pin  62  is attached to both arm  49  and journal  34  and allow rotational movement therebetween. A pivot pin  64  is attached to both arm  51  and bearing  35  and allows rotation movement therebetween. In addition, translational movement between pivot pin  64  and journal  34  is facilitated by a bearing race  66  formed into journal  34 . This allows translational movement between bearing  35  and journal  34  to occur and rotational movement to both arm  51  and  49  with respect to leg  12 . To constrict unwanted movement between bearing  35  and journal  34  it is desired that the shape of journal  34  be complementary to the shape of bearing  35  and that the cross-section area of bearing  35  is proximate to the cross section area of the volume of journal  34  in which bearing  35  is received. For similar reasons the diameter of pivot pin  64  matches the width of bearing race  66 . 
     Referring to both  FIGS. 1 and 3 , to facilitate the same movement between arms  50  and  52  with respect to leg  16 , as discussed above with respect to arms  49  and  51  with respect to leg  12 , arm  50  is attached to bearing  39  via pivot pin  68 , and arm  52  is attached to journal  38  via pivot pin  70 . Pivot pin  68  moves along a bearing race  72  formed into journal  38 . The identical configuration is present with respect to coupler pair  46  and legs  14  and  18 . Specifically, arm  53  is rotatably coupled to journal  36  with pivot pin (not shown), and arm  55  is rotatably coupled to bearing  37  with another pivot pin (not shown). Arm  56  is rotatably coupled to journal  40  with a pivot pin (not shown) and arm  54  is rotatably coupled to bearing  41  with a pivot pin (not shown). Each of pivot pins coupled to bearings  37  and  41  are disposed within a bearing race  74  and  76  of journal  36  and  40 , respectively. In this manner, the same operational movement between coupler pair  46  and legs  14  and  18  may be achieved as discussed above with respect to coupler pair  42  and legs  12  and  16 . 
     Referring to both  FIGS. 1 and 4 , the dimensions of frame  10  are established to achieve a desired function. To that end, a length  80  of leg pairs  20  and  22  may be established by varying a distance  82  between pairs  20  and  22 . As shown, when angle  58  and  61  are at a maximum and angles  59  and  60  are at a minimum distance  82  and length  80  are at a maximum. It should be understood that the relative dimensions of bearings  39  and  35  and journals  34  and  38  are established so that the coupling therebetween is maintained when length  80  is maximized. When angles  59  and  60  are maximized and angles  58  and  61  minimized, distance  82  goes to zero, shown by pairs  20  and  22  touching, and length  80  is at a minimum, shown in  FIG. 5 . 
     Referring to both  FIGS. 1 and 6 , to maintain the magnitude of angles  58 - 61  one or both pair  42  and  46  of couplers  43 ,  44 ,  47  and  48  it may be desirous, but not necessary, to include a ratchet mechanism that consists of a plurality of spaced-apart recesses  110  formed in surface  112  of the coupler, shown with respect to coupler  43 . Also included on coupler  43  is a detent  116 . Detent  116  has dimensions that are complementary to the recesses (not shown) formed on coupler  44  so that the same may be received therein forming an interference fit therewith. Similarly, a detent (not shown) included in coupler  44  has dimensions that are complementary to the recesses  110  so that the same may form an interference fit therewith. In this manner, distance  82  between legs  12 ,  14  of pair  20  and legs  16  and  18  of pairs  22  may be changed by to a desired magnitude and maintained thereat vis-à-vis scissor link  24 . In this sense ratcheting hinge allows movement in two directions to incrementally change the distance between leg pairs  20  and  22 . It may be desirous, but not necessary, to maintain the magnitude of the angle between legs  12 ,  14  of pair  20  and legs  16  and  18  of pairs  22  by a ratcheting hinge. 
     Referring to both  FIGS. 1 and 7 , the ratchet hinge is discussed with respect to pivot joint  28  and applies equally to pivot joint  26 . Specifically, ratcheting hinge allows incrementally adjusting the position between legs  12 ,  14  of pair  20  and legs  16  and  18  of pair  22 . To that end, ratcheting hinge includes a plurality of spaced-apart recesses  120  formed into a surface  122  of leg  18  and a detent  126  extending therefrom. Detent  126  has dimensions that are complementary to the recesses (not shown) formed on leg  16  so that the same may be received therein forming an interference fit therewith. Similarly, a detent (not shown) included in leg  16  has dimensions that are complementary to the recesses  120  so that the same may form an interference fit therewith. In this manner, the relative angular positions between legs  12  and  14  of pair  20  and legs  16  and  18  of pairs  22  may be changed by pivot joints  26  and  28 , respectively. In this sense ratcheting hinge allows movement in two directions to incrementally change the angular position between legs  12  and  14  of pair  20  and leg  16  and  18  of pair  22 . 
     The magnitudes of angles  30 ,  32  and  58 - 61  establish a volume space occupied by frame  10 . This facilitates multiple volume dimensions and uses of frame  10  and enables storage of the same by minimizing the volume occupied by the same when not is use. In a storage configuration angles  30 ,  32 ,  58  and  61  are minimized thereby providing the frame with the smallest volume. 
     In operation establishing angles  30  and  32  and  58 - 61  to have a desired magnitude, frame  10  may be used as a support for different sizes and shapes of flexible bodies. In accordance with one embodiment frame  10  is suitable for use as a means for making flexible bodies suitable for re-use, such as the washing of bags used for storage and transporting of foodstuffs, e.g., plastic sandwich bags and zipper storage bags such as the type sold under the trademark ZIPLOC®. One manner in which to wash bags would be using frame in an automatic washing system (AWS) (not shown), commonly referred to as a dishwasher. In this example, frame  10  would be placed in an AWS (not shown) such that the journals  34 ,  36 ,  38  and  40  would attach to a bottom or top AWS rack (not shown) or surface thereof from whence water and detergent would be injected by the AWS (not shown). As a result, water from the AWS (not shown) typically is projected toward pivot joints  26  and  28 . Angles  30  and  32  are typically established to ensure that a distance between journals  34  and  36  and a distance between journals  38  and  40  is sufficient to maximize the area of the opening of bag. In addition to angles  30  and  32 , angles  58 - 61  are also established to provide length  80  and width  82  of sufficient magnitude to provide rigid internal support to varying size of volumes of plastic bags; thus, increasing the probability that the area of the inner surface of the bag is exposed to water and detergent during the normal AWS wash-cycles. 
     One concern with respect to use of frame in an AWS (not shown) is securely fastening the bag, in an inverted position, to frame  10 . To that end, each journal  34 ,  36 ,  38  and  40  includes a bag keeper, shown as  88 ,  90 ,  92  and  94 . Each bag keeper  88 ,  90 ,  92  and  94  is integrally formed with bearing  34 ,  36 ,  38  and  40 , respectively with one end forming a clamp  89 ,  91 ,  93  and  95 . Each clamp  89 ,  91 ,  93  and  95  is resilient biased against one of journal  34 ,  36 ,  38  and  40 , respectively. In this manner, a portion of the bag may be disposed between one of the clamps and journal member with the clamp forming interference fit therewith securely affixing the bag to frame  10 . To increase the force per unit area applied to the bag one or more of clamps  89 ,  91 ,  93  and  95  include a projection that extends across each journal  34 ,  36 ,  38  and  40 . This is shown as projection  97  and  99  extending across bearing  36  and  40 , respectively. Each projection  97  and  99  is positioned proximate to clamp  91  and  95 , respectively, so that the bag may be wedged therebetween. Projections  96  and  98  facilitate the same for clamps  89  and  93 , located on bearings  34  and  38 , respectively. 
     To facilitate use in an AWS, frame  10  is typically fabricated from a polymer compound, such as injection molded plastic. The simplicity of the design makes frame cost efficient for manufacture, because bearings  35  and  39 ,  37  and  41  have identical shapes. All journal members  34 ,  36 ,  38  and  40  have identical shapes and all couplers  43 ,  44 ,  47  and  48  have identical shapes. Thus, the mold (not shown) employed to fabricate frame need not be complicated. 
     Referring to  FIGS. 1 ,  2  and  4 , as an alternative, a plurality of magnetic bodies may be embedded in various parts of frame  10 . The magnetic bodies may be placed virtually any where on frame  10 . However, it is desired that the magnetic bodies be placed so as to facilitate affixing frame  10  to a metal surface when in a storage configuration. To that end, each journal  34 ,  36 ,  38  and  40  includes a magnetic body mounted on a surface of journal  34 ,  36 ,  38  and  40  facing away from an adjacent journal  34 ,  36 ,  38  and  40  attached to a common coupler pair  42  and  46 . This is shown by magnetic bodies  100 ,  102  and  103  attached to journals  34 ,  36  and  38 , respectively. A magnetic body may also be attached to journal  40 . It is desired that magnetic bodies be flush with or slight recessed within the portion of surface of journals  34 ,  36 ,  38  and  40 . In one example, a storage plate (not shown) may be employed to facilitate storing of frame  10 . The storage plate (not shown) may be a circular thin gauge magnetically responsive metal disc (not shown) having adhesive backing. The adhesive may be used to attach the plate (not shown) to a surface and frame  10  magnetically adhered thereto. 
     Magnetic bodies may also be present on one end of bag keeper  88 ,  90 ,  92  and  94 , shown as  104 - 107  in  FIG. 3 . The magnetic bodies are placed so as to facilitate affixing frame  10 , with attached soiled flexible body, to either the top or bottom AWS (not shown) rack or attach to any other magnetically responsive material. Magnetic bodies  104 - 107  are in place to facilitate the secure attachment and positioning of frame  10  in the AWS (not shown). Secure attachment and upright positioning of frame  10  is desired to achieve an appropriate wash and desired wash while avoiding undesirable movement of frame  10  and/or flexible body attached to frame  10 , i.e., being tossed-about the AWS. Magnetic bodies  104 - 107  and keepers  88 ,  90 ,  92  and  94  are positioned so as to securely hold a soiled flexible body in an inverted position to allow the same to be fully sprayed with water and detergent for cleaning and then server as a rack for air drying either inside or outside the AWS. Magnetic bodies serve as easy coupling mechanisms to facilitate easy placement and removal from ASW (not shown). Frame  10  is not necessarily permanently or semi-permanently attached to the AWS. 
     Another example for the use of frame would be to support different garments for advertising, such as shirts, blouses, trousers and the like. By adjusting angles  26  and  28 , as well as length  80  and width  82 , frame  10  may be suitable for displaying garments of different sizes and to provide different appearances, such as full-figure, slim and intermediate, dependent upon the volume to which the flexible material is expanded by frame  10 . To that end, flexible material is typically fitted over frame  10  with the journals  34 ,  36 ,  38  and  40  forming a base of frame and pivot joints  26  and  28  forming a top of frame  10  over which the flexible material is placed. Of course such use of frame would obviate an advantage to fabricate the same from water resistant material and could vitiate the need to have bag keepers  88 ,  90 ,  92  and  94 . 
     While the invention has been described by way of example and in terms of the specific embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. For example, a ratcheting mechanism and ratcheting hinge are discussed with respect to maintaining the relative position between different components of the invention. However, it may be that the ratcheting mechanism and/or the ratcheting hinge may be replaced by abrogating the detents and merely providing roughened surfaces in place thereof. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.