Abstract:
A slide system for an appliance is provided. The system may be used with a retractable compartment, such as a drawer, shelf or grill and may be implemented inside a cavity of the appliance having a pair of vertical walls provided with a series of ribs having a recess at their top surfaces, and a movable runner in the recess. The runner may be located over slides that delimit and guide travel of the runner to provide a longer draw-out distance for the retractable compartment, which is conducive to improving storage ability and accessibility to the retractable compartment.

Description:
RELATED APPLICATIONS 
     This application claims priority from Mexican application Serial No. MX/a/2007/008018 filed Jun. 28, 2007, which is incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention is generally directed to the field of appliances that include retractable compartments, such as shelves, racks, grills, or drawers, and devices that require a reciprocating rectilinear drawing (pull) or insertion (push) motion in operation. 
     BRIEF SUMMARY OF THE INVENTION 
     Aspects of the present invention allow for an incremental extension upon drawing retractable compartments, such as shelves, racks, grills or drawers, e.g., an extra drawn-out distance allowing improved reach to objects or items placed on shelves, racks, grills, or drawers. Most users would find desirable to have an extra drawing extension, especially if bulky objects or items are to be placed in a drawer or over a rack. 
     For example, let&#39;s think in a shelved cabinet that has a pair of folding doors on a vertical axis, and in a bulky object, which is to be deposited inside said cabinet. Normally the user would pull out the shelf towards him/her to deposit the bulky object, afterwards he/she would simply push the shelf inside the cabinet. Likewise, if we think in a cabinet with drawers, this same action may be a bit more complicated. Between shelves there is always a gap that allows access to the items placed on them, but in the case of drawers the access to their contents is usually obstructed by another drawer or a covering above it that also gets in the way when depositing objects, especially if they are bulky. 
     To gain complete access to the inside of a drawer and to avoid a partial obstruction limiting the volume of the object to be deposited inside the drawer, a fully drawn extension of the drawer is required. If the bulky object cannot be placed inside the drawer because it cannot be travel to be drawn out a sufficient total distance, the user may have to do the following: completely pull out the drawer, place the object inside, lift the drawer with the added weight of the bulky object, and attempt to reinsert the drawer into the cabinet. This invention provides a low cost solution to this problem, with a reduced number of parts which are durable and easy to manufacture, and which may work in low temperature environments such as freezers, or high temperature settings such as inside an oven. 
     By way of example, it is contemplated that features of the present invention will be substantially useful in domestic refrigerators, for both fresh food and freezer compartments. For example, there are several types of refrigerators in the market, for descriptive purposes we refer to a duplex or “side by side” refrigerator, characterized by having the fresh food compartment beside the freezer, separated by an thermal-insulating wall known as “mullion”. 
     Each compartment may have separate doors. Due to design and practical reasons, the freezer is narrower than the fresh food compartment, and its available space must be optimized at all times because it usually takes in frozen packaged products that need to be kept at low temperatures for long term conservation. Having a drawer which draws out horizontally allowing exposition of most of its contents without being obstructed by a shelf, lid or other drawer, would make the extraction of bulky and heavy packages easier and faster for evident reasons, and solve the problem set out above in the background section. Such a drawer has a pair of slides, preferably manufactured with two parallel rods, mounted on its lateral sides, which preferably are longer than the front and backsides. The travel distance of these slides depends on the length of the drawer, of the bearing brackets or ribs on the refrigerator wall that support the drawer, and the normal travel distance of the drawer; these features determine the safe extra travel distance since the weight and the cantilevered position of the drawer increases the load stress at the weight-bearing points, which can easily be overloaded causing some part of the mechanism to give way, leading to the collapse of the drawer. 
     Each slide houses a runner that travels inside the recess of the upper rib of the liner, so when the drawer is drawn out the runner reaches the limit of its travel path that is limited by the dimensions of said liner recess. When the runner reaches said limit, the runner allows the parallel slide to glide over it enabling an extra traveling distance, which extends the length the drawer can be drawn out. 
     Other example appliance that may benefit from aspects of the present invention may be the oven of a domestic stove. An oven has a cavity similar to that of a refrigerator, but generally tending to a square shape, that is, its width and height are almost equal. These oven cavities have a pair of lateral walls having bearing ribs that support the oven grills. These grills are racks made of rigid steel wire in a rectangular shape, whose frame is usually made from the same material and houses a series of straight wires evenly spaced to support the objects placed on the rack. This is a convenient design feature because it allows the free flow of air through the grill to surround the object placed thereon. Typically, the object is very hot when its time to extract it from the oven, thus requiring that the grill be pulled out as far as possible from the cavity of the oven, to allow a better handling of the hot object. 
     There arises the need for a mechanism made of few high temperature resistant pieces and easy to manufacture, which allows the grill to travel an extra distance so it may be completely pulled out from the oven&#39;s cavity and permit a safe placement of the items to be cooked inside de oven, without the risk of having the rack collapse, which may injure the user and damage the oven. Therefore, a grill with a pair of parallel slides at its rear lateral ends was conceived, with each slide having a runner traveling over it. This runner can travel a set distance over the recess of the bearing ribs. Once the slide reach the end of their travel when the grill is pulled out, the parallel runners are allowed to glide over the slides all the way of the travel distance, which is the extra length the grill can be pulled out. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Figure Description 
       FIG. 1  Layout scheme of traditional slides 
       FIG. 1   a  Layout scheme of traditional slides 
       FIG. 2  Travel distance of a typical drawer 
       FIG. 2   a  Travel distance of a typical drawer 
       FIG. 3  Travel distance of drawer chest where the drawer is longer than the slide 
       FIG. 3   a  Travel distance of drawer chest where the drawer is longer than the slide 
       FIG. 4  Travel distance of telescopic drawer system 
       FIG. 4   a  Travel distance of telescopic drawer system 
       FIG. 5  First combination of slide system with drawer at standstill position 
       FIG. 5   a  First combination of slide system with drawer drawn half-way 
       FIG. 5   b  First combination of slide system with fully pulled out drawer 
       FIG. 6  Isometric view of drawer with conventional slide and the drawer in the closed position 
       FIG. 6   a  Isometric view of drawer with conventional slide and the drawer in the pulled out 
       FIG. 7  Front isometric view of a refrigerator liner with drawers 
       FIG. 8  Detail of isometric front view of the refrigerator with drawers 
       FIG. 9  Left side view of the refrigerator without right liner 
       FIG. 10  Left side isometric view of the refrigerator without right liner 
       FIG. 11  Left side view of the refrigerator without right liner where the drawers can be seen completely inserted 
       FIG. 12  Isometric detail of liner ribs 
       FIG. 13  Left side isometric view showing the drawer and the liner ribs 
       FIG. 14  Isometric front view of the runner 
       FIG. 15  Isometric front view of the runner 
       FIG. 16  Left side view of the runner 
       FIG. 17  Front view of the runner 
       FIG. 18  Right side view of the runner 
       FIG. 19  Bottom view 
       FIG. 20  Top view 
       FIG. 21  Isometric detail of the runner slide system 
       FIG. 22  Isometric detail of the runner slide system with the runner at standstill position 
       FIG. 23  Isometric detail of the runner slide system with the runner in the drawn out position 
       FIG. 24  Left side view showing different positions of the drawers 
       FIG. 25  Left side isometric view showing a pulled out drawer and a drawer at standstill position 
       FIG. 26  Left side isometric view of the drawer with a rod on the rib of the liner and the drawer in closed position 
       FIG. 26   a  Left side isometric view of the drawer with a rod on the rib of the liner and the drawer in the pulled out position 
       FIG. 27  Left side isometric view of the drawer with the rack bar and pinion system, and drawer in the closed position 
       FIG. 27   a  Left side isometric view of the drawer with the rack bars and pinion system, and the drawer in the pulled out position 
     DETAILED DESCRIPTION OF THE INVENTION 
     There are several types of slides for drawers or racks/grills in general. Due to the diversity of mechanisms available in the market and for study purposes, we have classified them in six main groups.  FIGS. 1 and 1   a  show a basic slide and drawer system where the slide A houses the sliding object B; as these figures show, the useful area b is defined by the load area of the sliding object B which for practical purposes is the same as b at any given moment. The slide A requires a travel distance at least greater than b so the sliding object B can glide over it, the desirable distance being at least two times b. The extension or opening travel distance G equals b and is defined at any given moment by the equation G=a−b. 
       FIGS. 2 and 2   a  show a typical drawer mechanism. A is the slide delimited on its lateral sides by a pair of stops or bulges, that will limit the travel of the sliding object B which in this case is fitted with an appendix b′ fixed to the structure of the sliding object B and that travels within the limits set in A.  FIG. 2  shows the mechanism at a standstill position, the useful area b is almost equal to the surface of the sliding object B. In this position no item can be introduced into or deposited over the sliding object B, so  FIG. 2   a  shows the sliding object B drawn out and allowing us to discern how b′ glides over the slide A up to its opposite end and produces an extension or opening travel distance G defined at any given moment by the equation G=a−b′. As  FIGS. 2 and 2   a  and the above equation show, the useful area b is not equal to G. This is not desirable when bulky or inflexible objects are to be deposited in the drawer, because a useful loading area or volume is wasted. 
       FIGS. 3 and 3   a  are a variation of the mechanism shown in  FIGS. 2 and 2   a . The main difference is that the travel distance “a” is smaller than the useful area “b” while in  FIGS. 2 and 2   a  “a” and “b” are equal. 
       FIGS. 4 and 4   a  show an example telescopic mechanism with at least two sets of slides. This mechanism is of interest because it can produce a extension or opening travel distance “G” greater than in the above examples. Slide “A” is overlapped by slide “B” which also has an appendix “b′” which travels the distance “aa”. Slide “B” is overlapped by the sliding object “C” which also has an appendix “c′” attached thereto which travels the distance “b” to produce a extension or opening travel distance G defined by the equation G=a−b′+b−c′; considering that appendixes b′ and c′ are of equal size, then G=a+b− 2   c ′. As  FIG. 4   a  shows, the useful area c is closer in size to the sliding object “C”, providing a greater extension or opening travel distance of sliding object “C” from its standstill position. 
       FIGS. 5 ,  5   a  and  5   b  show a combination of example slide systems used in accordance with aspects of the present invention. Slide “A” with a distance “a” is overlapped by the sliding object “C” which can be a runner that can glide horizontally within two combined paths determined by the dimensions “a” and b″. When the sliding object “B” glides horizontally it travels over the distance b″ which makes the opening “Go” equal to b″. As the sliding object “B” continues to be pulled out because the travel over dimension “a” is still possible as shown in  FIG. 5   b , the total extension or opening travel distance “G” is defined by the equation G=a+b−2C. This produces almost the complete extraction of the useful area “b” leaving a covered and inaccessible dimension “2C” which for practical purposes is very small. 
     Aspects of present invention may be suitable for the design of drawers for “duplex” or “side-by-side” refrigerators, therefore, the description of the invention will refer to such devices. It will be understood, however, that the present invention can be implemented in any type of cabinet or cavity, not limited to a refrigerator drawer, it can also be adapted to a grill or rack, one difference difference being that the dimension representing the depth of a drawer is absent or small in the case of a grill or rack. 
     Bearing in mind the foregoing considerations, the freezer compartment of a “duplex” or “side-by-side” refrigerator will be an example environment to describe an example embodiment of the invention.  FIGS. 6 and 6   a  show the traditional shortcomings of a refrigerator drawer. Said drawer  22  has a pair of brackets  28  which horizontally protrude from its lateral sides. Said brackets  28  extend across the length of drawer  22  and at some longitudinal point they have a fixed stop  17 . Said fixed stop  17  travels forwards and backwards inside recess  14 , and its travel is limited by stops  16  and  15 , respectively. As shown in  FIGS. 2 ,  2   a ,  3 , and  3   a , which are an schematic representation of the mechanism described by  FIGS. 6 and 6   a , the draw-out distance of the drawer at all times depends on the length of recess  14 , which limits the draw-out distance of drawer  22  due to design limitations, such as the inability to modify the geometry of liner  10 , which would entail higher development and costs. Other design consideration is the available space, which needs to be fully usable in account of the needs of the user. There is a need to maximize the distance the drawer  22  can be pulled out to allow placing objects and packages of considerable size.  FIGS. 2 ,  2   a ,  3 , and  3   a  show a typical slide mechanism for drawer  22  that consists of a slide “A” overlapped by the sliding object “B” having an appendix b′ that prevents reaching the maximum draw-out distance “G”. It is to be noted that slide “A” acts sometimes as the recess  14 , as shown in  FIGS. 6 and 6   a , and this limits the dimensions of both the slide “A” and the recess  14  to less than the length of the drawer  22 ; this makes possible to draw out the drawer  22  almost its entire length, which would be ideal in terms of  FIGS. 2 and 2   a  as the maximum draw-out distance “G” should be as close as possible to dimension b. 
       FIG. 7  shows an isometric view of the cavity of the freezer compartment of a “duplex” or “side-by-side” refrigerator; said cavity is manufactured of some thermoformed plastic and is called a liner  10 . Said liner  10  houses the drawers  22  (not shown) which are fitted with a faceplate  20 . A series of ribs  11 ,  12 , and  13  are embossed in the vertical lateral walls of liner  10  so the basket frame  27  can slide over them and be pulled out. In a standstill position said ribs  11 ,  12 , and  13  bear the weight of the drawer  22  and its contents. 
       FIG. 8  shows a detail of the arrangement of the drawers  22  inside the bottom part of the freezer cavity; the arrangement of the ribs  11 ,  12 , and  13 , and the upper shelf  23  which sometimes is also the lid for the upper drawer  22 . 
       FIGS. 9 and 10  show a left cross-sectional view and a isometric view of said cross-section, respectively, of the freezer cavity  21  showing a vertical wall of the liner  10  with ribs  11 ,  12 , and  13  and their spatial location inside the freezer cavity  21 . Said location is determined by design parameters and by the dimensions of the drawers  22 , the ease of opening and reach of the users, as well as the habits of the users, which in some way define the size of the drawer for storing products the user acquires and require freezing. It is evident that any modification to the ribs  11 ,  12 , and  13 , and the liner  10  itself entails a considerable investment in design, structural tests, tooling, etc., therefore any modification of said ribs  11 ,  12 , and  13  and the liner  10  is not desirable. The present invention discloses a slide system that do not imply any modifications to the structure of the liner  10  and the ribs  11 ,  12  and  13 , by providing the drawer  22  with a longer travel distance upon opening. 
       FIG. 11  shows a lateral view of the cavity of the freezer  21  having one of the vertical walls of liner  10  removed, allowing a view of the interior. This figure shows the space occupied by the drawers  22 , which may be manufactured with wire mesh, to facilitate the passage of cold air to better cool the objects contained in the drawer  22 . This structural feature is not meant to be limiting since it does not preclude that said drawer may be built of different materials such as plastic or metal, either with solid, perforated or slotted walls, but to better illustrate the operation of the present invention the drawers  22  may be manufactured with wire mesh. The figure also shows frame  27  placed over rib  13 , however, the user may opt to place it over rib  12  if he/she prefers to modify the placement height of drawers  22  inside the cavity of the freezer  21 . Also shown are the runners  30  that glide over the slides  25  and  26  (not shown) and the location of the C-guide  24  in the backside of the drawer  22 , the C-guide  24  clings to the rib  13  (or rib  12  depending on the location of the drawer  22 ) when the drawer  22  is pulled out, thereby stopping the drawer from falling down due to the weight of its contents by leaning the bottom part of the C-guide  24  on the bottom side of the rib  13  (or rib  12  if applicable). The front side of the drawer  22  consists in a faceplate  20 , which aesthetically enhances the appearance of the cavity of the freezer  21 , however, in terms of functionality the drawer  22  can do without this faceplate and be replaced with wire mesh or a wall. 
       FIG. 12  shows a detail of the ribs  12  and  13 ; said ribs  12  and  13  consist of a recess  14  delimited by a pair of stops  16  and  15  at the front and the back, respectively. Also shown is the upper side acting as a loading surface  19 , which is in contact with the basket frame  27  and bears its weight allowing it to slide in a reciprocating movement forward and backwards. The recess  14  houses the runner  30  while it moves, and limits its travel distance. The ribs  12  and  13  form a channel  18 , which allows a supplementary draw-out distance by allowing the runner  30  to fit between the three walls formed by the bottom side of the rib  12 , the wall of liner  10 , and the loading surface  19  of the rib  13 ; the runner makes contact with these three walls at the first inclined plane  34 , the vertical plane  36  and the horizontal plane  37 , respectively, thanks to the adequate camber  38  the runner can occupy the space of the recess  14  and get inside the channel  18 . For the runner  30  to get into the channel  18  there should be an adequate coupling angle  31  ranging from 15 to 65 degrees, allowing it to jump over stop  16  when the user pulls out the drawer  22 . 
       FIG. 13  shows the drawer  22  at standstill position, that is, completely inside the cavity of the freezer  21 . The frame  27  is supported by the loading surface  19  of the rib  13 . Notice the location of the runners  30 , the slides  25  and  26  in the backside of the lateral sides of the frame  27 , ending just where the C-guide  24  is located. 
       FIGS. 14 ,  15 ,  16 ,  17 ,  18 ,  19 , and  20  show the different components of the runner  30 . Said parts are the C-rail  32  connected to the bottom slide  26  to glide over it. Considering that said bottom slide  26  is a round rod, the runner  30  would tend to rotate, to prevent this a C-rail  32  was devised, thereby allowing only a horizontal rectilinear movement over the slides (a single freedom degree movement). The camber  38  is sized to fit the space formed by the recess  14  of the ribs  12  or  13 , as well as to fit in the C-channel  18  formed by said ribs  12  and  13 . Said camber also consists of a pair of coupling angles  31 , which make contact with the stops  16  and  15  at the end of the travel of recess  14 ; the second inclined plane allows the runner  30  to fit between the slides  25  and  26 . 
       FIG. 21  shows the assembly of the runner  30  in the slides  26  and  25 , the C-rail  32  houses the bottom slide  26  allowing the runner to glide over. To prevent the rotation of runner  30  around the longitudinal axis of the bottom slide  26 , the runner  30  is provided with a guiding slot  33  that is connected with the upper slide  25 ; this also puts the camber  38 , vertical plane  36 , and horizontal plane  37  in an adequate position to interact with the recess  14  of the ribs  12  or  13 . Meanwhile, the C-guide  24  clings to either the rib  12  or rib  13  (depending on the position), preventing the drawer from falling down while being pulled out. 
       FIGS. 22 and 23  show the interaction of the runner  30 , slides  25  and  26 , and the frame  27  with the ribs  12  and  13 .  FIG. 22  in particular shows the drawer at standstill position. In this position the C-guide is not in use, that is, is not in contact with either one of the ribs  12  or  13 . The runner  30  is also at standstill position, placed between the back stop  15  and the travel end curve of the upper slide  25 .  FIG. 23  shows the drawer  22  in a completely pulled out position, so the runner  30  is located between the front stop  16  and the frame  27 , however, if the drawer  22  is further pulled out the runner  30  gets into the channel  18 , thereby producing an extra length of the opening distance. Also noteworthy is the C-guide  24  which clings to the rib  13  making contact with its bottom rib which prevents the drawer  22  from “turning sidewise” or spilling its contents. 
       FIG. 24  shows three different positions of the drawer  22  in relation to the freezer cavity  21 . The top drawer  22  is fully pulled out, the middle drawer  22  is at halfway and the bottom drawer  22  is at standstill position. In one example embodiment, a stop  35  may be disposed in a bottom side of at least one of the ribs to limit travel of the C-guide  24 . On the other hand,  FIG. 25  shows an isometric view of two drawers  22  inside the freezer cavity  21 . The top drawer is fully pulled out while the bottom drawer is at standstill position. This figure is particularly useful to show the extra opening distance obtained by implementing the present invention, maximizing the opening extension and giving the user a better solution for storing bulky objects with ease by means of a low-maintenance, reliable mechanism made up of few pieces, easy to manufacture and apt for use under extreme conditions. 
       FIGS. 26 and 26   a  show an example alternate embodiment of the invention, where the slides  25  and  26  are not positioned on the back lateral end of the drawer  22 . Instead there is a rod  29  placed between the stops  16  and  15  across the recess  14 , which is in turn placed over the upper side of the support  46 . The runner  30  runs backwards and forwards over said rod  29 , its travel distance is limited by the length of the recess  14  and the stops  16  and  15 . When the drawer  22  is pulled out, the drawer seat  28  slides over the supports  46 . Said supports  46  may not be molded or thermoformed on the liner  10  such as the ribs  11 ,  12  or  13 , instead they may be manufactured from assorted materials, preferably an injected plastic. They are placed over the vertical walls of the freezer cavity  21  by means of, including but not limited to, screws, adhesive, rivets, snap assembly, retainers, etc. Said drawer seats  28  are connected respectively to the vertical lateral walls of the drawer  22 . This structure bears the weight of the drawer  22  and its contents. Said drawer seats  28  must be provided with a drawer seat recess  39  over the bottom side of said drawer seats  28 , limited by a front stop  40  and a back stop  41 . The runner  30  travels across the length delimited by the drawer seat recess  39  and the stops  40  and  41 , producing a longer opening distance. It is evident that other support (not shown) placed in the liner  10  wall is necessary to stop the drawer  22  from falling down when it is being pulled out. Said support may be thermoformed or molded on the vertical walls of the liner  10  or an assorted piece is overlapped in the vertical walls of liner  10 . This embodiment may have a C-guide  25 , which clings to the rib  12  or  13  (depending on the position) or the support  46  and prevents the drawer  22  from falling down when being pulled out. 
     Other example alternative embodiment of the present invention is shown in  FIGS. 27 and 27   a . In said embodiment the drawer  22  is provided with a rack bar and pinion system in the outer side of its vertical lateral walls. Now the drawer seat  28  has its bottom side provided with a rack bar  43  and the support  46  is provided with a pinion  42  on its top side, over support  46  a pinion  44  travels guided over the slot  45 , whose extent depends on the length of racks  42  and  43 . The travel distance of said pinion  44  may be delimited by the extent of the slot  45  or the length of the rack bars  42  or  43 , which preferably have the same number of teeth. In this embodiments it is evident that the stops at the end of the travel of the recess  14  are unnecessary, since the pinion  44  can only engage the rack bars  42  and  43 . When the drawer  22  is pulled out, the drawer seat  28  slides over the pinion  44  and in turn this slides over the support  46 . This piece may not be molded or thermoformed on the liner  10  like the ribs  11 ,  12  or  13 , but instead is manufactured from assorted materials, preferably an injected plastic, and is placed over the vertical walls of the freezer cavity  21  by means of, including but not limited to, screws, adhesive, rivets, snap assembly, retainers, etc. Thanks to the rack bars  43  and  42  respectively, the pinion  44  may have a protruded bulge extruded at its axial axis (not shown). Said bulge enters into the slot  45  which will guide the travel of pinion  44 ; hence this mechanism also allows the drawer  22  to be pulled out smoothly and uniformly a greater distance, because this mechanism has the advantage of minimizing friction between pieces. Since unsafe positions of the drawer  22 , which may cause it to fall down or get out of position inadvertently, are avoided, the appealing by the user is also improved. It is evident that other support (not shown) placed in the liner  10  wall is necessary to stop the drawer  22  from falling down when it is being pulled out. Said support may be thermoformed or molded on the vertical walls of the liner  10  or an assorted piece is overlapped in the vertical walls of liner  10 . This embodiment may have a C-guide  25 , which clings to the rib  12  or  13  (depending on the position) or the support  46  and prevents the drawer  22  from falling down when being pulled out. 
     Having described the invention in sufficient detail, it is considered that the same is sufficiently innovative, and without limiting the scope of the invention disclosed herein, any modification to the same, no matter how subtle, may fall within the scope of protection sought according to the following claims.