Patent Publication Number: US-8528998-B2

Title: Adjustable detent retention system and method

Description:
RELATED APPLICATION DATA 
     This application claims priority from Provisional Application Ser. No. 61/348,059, filed May 25, 2010, which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Aspects of the present invention relate generally to drawer systems and, more specifically, to systems and methods for adjustable and releasable retention of drawers and similar pull-out components in the closed position so as to enable selective and adjustable control of the outward pull forces of such pull-out components. 
     BACKGROUND 
     Conventional drawer slide construction generally includes a means to hold a closed drawer in position, such that the drawer does not unintentionally or inadvertently open, which could cause injury or damage. This is particularly important when drawer/cabinet structures are mobile, such as a cart, a tool box, a utility unit, furniture, etc. on wheels. Similarly, furniture, cabinets, toolboxes, racks, etc. which contain drawers supported by reciprocating slides may be placed on an uneven surface or floor. These situations could cause some tilt, sloping, or other conditions, whereby a drawer could inadvertently open by itself without any intentionally applied pull in the opening direction. 
     The conventional means to retain the drawer in the closed position, which is easily released when the drawer is pulled open, may be constituted, for example, by a frictional interface between an inner member of the slide (i.e., the drawer member) and a fixed rubber or polymer bumper located at the front or rear of the outer member of the slide (i.e., the cabinet member). These types of bumper designs are disclosed, for example, in U.S. Pat. No. 6,254,209 and U.S. Pat. No. 7,086,708. 
     These types of frictional fixed bumpers may work well when the drawer and cabinet structures are stationary or fixed in position, are on level ground, and are not mobile. Mobile applications, especially those with weight, such as tool boxes, or other rolling carts, tend to require selective detent holding forces to ensure that heavy loaded drawers remain closed when moved. One drawback of this is that, when the drawer is not heavily loaded, the high detent forces tend to require additional effort and/or cause other practical issues in opening and closing such a light-weight drawer. 
     An additional disadvantage of the frictional polymer detent interface is the consistency of the detent over time and use. Abrasion and wear of the interface (both in the opening and closing directions) tends to initially increase the pull force, then gradually subside as contact and wear may create a crease or groove in the rubber or polymer bumper. This, in turn, causes erosion and subtraction of material and contact interface from the mating interface component, which is generally a drawer member, without any means to adjust for this wear factor, and recapture the desired forces. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of the present invention mounted in a typical cabinet system. 
         FIG. 2  is an enlarged view of region “A” shown in  FIG. 1 . 
         FIG. 3  is an opposite side view of the embodiment shown in  FIG. 1 . 
         FIG. 4  is an enlarged view of region “B” shown in  FIG. 3 . 
         FIG. 5  is an exploded perspective view of an adjustable detent mechanism in accordance with an embodiment of the invention. 
         FIGS. 6A-6K  show various views of a base-and-dial combination in accordance with an embodiment of the invention. 
         FIG. 7  is an exploded view of an adjustable detent mechanism in accordance with an embodiment of the invention. 
         FIGS. 8A-8N  show various views of a base in accordance with an embodiment of the invention. 
         FIGS. 9A-9N  show various views of an adjustment dial in accordance with an embodiment of the invention. 
         FIGS. 10A-10D  show various alternatives for coupling an adjustable detent mechanism to a drawer member in accordance with embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the invention are directed to adjustable detent retention systems (and associated methods) having an adjustable detent mechanism which enables an end-user to adjust the detent—and, therefore, the holding force between the drawer and cabinet members—in consideration of the application and drawer load conditions, thereby eliminating possible damage and/or personal injury and overcoming the above-mentioned shortcomings. 
     In addition, the systems according to embodiments of the present invention are economical to manufacture and simple to adjust and use. Considerations are made for instances of selected and customized adjustment, assembly, and attachment methods, all directed towards ease of operation in providing resistance to outward pull forces through coupling of a drawer or drawers and other pull-out components supported by a drawer slide in the closed position. 
     It is noted that, in the present description, reference is made to a “drawer” and, more specifically, to a cabinet drawer. However, this is for illustrative purposes only, and not by way of restriction or limitation, and the principles of the inventions described herein may be applied to other pull-out components and/or systems that include one or more pull-out components, such as, for example, office furniture, home furniture, kitchen appliances, general cabinetry (e.g., kitchen, garage, storage, etc.), tool boxes, automotive applications, etc. Where a drawer slide equipped with the embodiments of the present invention is described as being coupled to, or engageable with, one side of a drawer or cabinet, it is understood that, in embodiments of the invention, the drawer slide may be coupled to, or engageable with, the opposite side of the drawer/cabinet, or a pair of drawer slides, equipped with the embodiments of the present invention, may be coupled to, or engageable with, both sides of the drawer/cabinet. 
     It is also noted that descriptors such as “left hand” and “right hand” are used for ease of reference only, and do not restrict the structure, means for manufacturing, or operation of, or otherwise limit, embodiments of the invention. 
     As will be described in detail below, the adjustable detent mechanism of the present invention is coupled, or otherwise disposed, adjacent the front end of a drawer slide structure. As is known, a typical slide structure may include either two members (i.e., a drawer member and a cabinet member) or three members, wherein the latter is an intermediate slide member between the drawer and cabinet members. The purpose for locating the adjustable detent mechanism at or near the front of the drawer member is to allow easy access to the mechanism, in such a manner that the drawer does not have to be opened to its fully-extended position in order for the end-user to be able to perform the adjustment activities. In addition, the various embodiments of the present invention are designed to functionally operate without using any hand tools (e.g., screwdriver, wrench, etc.) to initiate and enable the adjustment features. The mechanism is completely assembled to the slides, and pre-set to a pre-determined detent position (middle detent position, for example) which can be easily adjusted (either up or down) by a simple grasp and rotation of an adjustment dial. Thus, it is not necessary for the end-user to conduct any additional installation tasks to operate the device. 
     The adjustable detent mechanism of the instant invention, therefore, presents a much-improved solution over that of the above-mentioned polymer detents. The inventive system is advantageous as, e.g., it allows the end-user to adjust or change levels of drawer holding force depending on requirements of each drawer, provides means to maintain forces with consideration to wear and usage, allows drawer holding and pulling forces to be adjusted (either higher or lower), has adjustable interface with two mating surfaces, adjacent to each other on opposite sides of the slide assembly, and is not influenced by the orientation of the slide when installed. 
     Specifically, as shown in  FIGS. 1-4 , embodiments of the present invention are directed to a system in which a drawer  10  moves in a linear path both forward and rearward, usually within a body  20 , such as, e.g., a cabinet, using drawer slides. For purposes of the description, both the left hand and right hand slide assemblies  30  are engaged with the drawer/cabinet, the slide being exposed, with  FIGS. 1-2  showing the right hand slide assembly  30  and  FIGS. 3-4  showing the left hand slide assembly  30 . In the embodiment shown, each slide assembly  30  includes a drawer member  32 , an intermediate member  38 , and a cabinet member  39 . Coupled to the drawer member  32  is an adjustable detent mechanism  100  (see, e.g.,  FIGS. 5-7 ), which includes a base  110 , an adjustment dial  130 , and an attachment means which, in embodiments of the invention, may be a rivet  141 . It is to be understood that an identical slide is disposed on the opposite side of the cabinet structure in each figure. 
     As shown in  FIGS. 4 and 8 , integrated with the base  110  are symmetrically-disposed detent arms  112 , each of which has a forward-sloping face  113 . Each of the detent arms  112  also includes a leg  115  which points towards a base cavity  117  having a base floor  111 . The base floor  111 , in turn, defines a base aperture  119  through its central axis, a rotation restriction pin  118  on its upper surface, and a locating lug  114  on its lower (bottom) surface. The base  110  also includes an indexing pointer  116 , with the base floor  111  including a notch  111   a  opposite the indexing pointer  116 . 
     As shown in  FIGS. 5 ,  6 , and  9 , within the cavity  117 , the base  110  receives a bottom portion  132  of the adjustment dial  130 , with the ring  133  being matingly received within the base aperture  119  of the base  110 . Preferably, both the base  110  and the adjustment dial  130  are plastic or polymer injection molded components. 
     The bottom portion  132  of the adjustment dial  130  includes symmetrically-disposed adjuster cams  134 ,  135 , and a slotted rotation-restriction guide  136 . Each of the adjuster cams  134 ,  135 , in turn, has cascading steps  134   a ,  135   a  around its respective periphery. With this construction, the interaction between the two legs  115  of the base  110  with the cascading steps  134   a ,  135   a  of the dial  130  causes the legs  115  to flex at their respective base points  123  which, in turn, causes the detent arms  112  to move in and out. 
     A perspective view of side face  22  of the cabinet  20  is shown in  FIGS. 3 and 4 . In  FIG. 4 , the adjustable detent mechanism  100  is shown in the closed and drawer detent holding position, with the forward sloping face  113  of detent arms  112  registered against the opposing rearward facing downward slope  41  of retention flanges (or tabs)  40  of outer member  39 . As described below, these four mating surfaces—i.e., the two faces  113  and the two faces  41 —provide the detent retention function of the present invention, with resistance to the displacement of the detent arms  112 , by means of pull force resistance of drawer  10 , being pulled by handle  23  as shown, e.g., in  FIG. 3 . The four mating surfaces, providing uniform and consistent resistance to the drawer pull forces is an advantageous improvement over devices that rely on a single interface contact for detent purposes, such as disclosed, e.g., in U.S. Pat. No. 7,229,142. 
     Each detent arm  112  is made of flexible material such that it can flex towards, and away from, a respective leg  115 . More specifically, each of the detent arms  112  is displaced inwards by collapsing a slot (or web)  121  between each respective arm  112  and corresponding leg  115  (see, e.g.,  FIGS. 4 and 8 ). Depending on the dial setting (low-high), and the displacement of the legs  115  on the cascading steps  134   a ,  135   a  as noted above, the amount of collapse of the slot  121 , i.e., the amount of flexing of the arms  112  toward the top of legs  115 , may determine the range of detent readings. 
     For example, at the lowest setting of the dial  130 , there is very little collapse of the slot  121 , and most of the resulting detent force is primarily achieved via the frictional interaction between the two surfaces  113  and  41 . As such, only a slight detent retention may exist. As the settings escalate, causing increased outward displacement of the detent arms  112 , the detent retention that is achieved is still frictional, but it is increasingly a result of the resistance of the detent arms  112  to being collapsed while being forced through the space between the faces  41  of the outer-member retention tabs  40 . 
     As the dial  130  is turned (increasing displacement), the distance between the arms  112  changes, with the displacement movement occurring at the base  123 , as described previously. The detent resistance, however, actually depends on various factors affecting the design of the web  121 , e.g., degree of flexibility of the material, thickness of the material, the web length, and so on, which may be customized during molding/manufacturing. Thus, for example, the length of the slot  121  may be reduced via an interchangeable core in the mold. Similarly, the base material may be changed, e.g., to a material that is more “stiff”, while keeping within the material family for post mold shrink purposes. In addition, the width of the tabs  40  may be changed with a slide/feature forming tool modification. 
     It is noted that, the higher the detent, the more abrasion that exists due to restrictive/frictional interaction between the face  113  of each detent arm  112  and the slope  41  of each corresponding tab  40 . Therefore, in applications where a larger degree of detent retention is desired, a plastic material—or material with similar characteristics—loaded with a lubricant (e.g., Silicon, Teflon, etc.) may be used to minimize material removal through abrasion. 
     The adjustable detent mechanism of the present invention, as described above, may be secured to drawer member  32 , sliding within intermediate member  38 , which in similar manner slides within outer member  39 . The inventive adjustable detent mechanism, however, is not restricted, nor limited, to a three-member slide structure, and can be mounted within two-member slide structures as well. The aforementioned slide members, once assembled and mated together, and supported by means of ball bearings (not shown), create a drawer slide system suitable for supporting the linear travel of pull-out components within cabinet structures and systems. 
     An exploded view of a three-member slide assembly including an embodiment of the present invention is shown in  FIG. 5 . Locating lug  114  (see, e.g.,  FIGS. 6 and 8 ) registers in an aperture  34  of drawer member  32 , with a rivet  141  piloted into, and mechanically secured through, a second aperture  36  of drawer member  32 , thereby securing the assembled base and adjustment dial to the drawer member. It is noted that, although the locating lug  114  is shown as a square protrusion on the bottom surface of the base  110 , it is to be understood that the lug, as well as the mating aperture  34  of drawer member  32 , may be of various other matching shapes. 
     To assemble the detent mechanism, the adjustment dial  130  is positioned within cavity  117  of base  110 , such that rotation restriction pin  118  is aligned with slotted rotation restriction guide  136  of dial  130 . The two displacement legs  115  of base  110  come in contact with the cascading steps  134   a ,  135   a  of the dial to initially position the assembly. The cascading steps  134   a ,  135   a  are designed to displace the detent arms  112  into an interference contact with the rearward facing slopes  41  of the retention tabs  40  on outer member  39 . 
     The indexing pointer  116  of base  110  registers in indentations (e.g., U-shaped or V-shaped notches)  137  of dial  130  to create a positive registration of the dial and its selected position. The positive registration is identifiable not only visibly, but also audibly, due to the registration “click” when moved to the desired and selected position. Corresponding graduated sized indicators  138 , molded to the upper surface of dial  130 , are positioned adjacent the indentations  137  to provide visual recognition to the end-user of the various (e.g., six) detent positions provided by embodiments of the present invention. It is to be understood that, when an end-user turns the dial  130  via the protrusions  139  such that the indexing pointer  116  is registered into one of the indentations  137 , the smallest indicator alignment results in the lowest detent setting, with the largest indicator  138  aligned so as to result in the highest detent setting. The graduated sized indicators  138 , shown in the figures as rectangular projections, may be substituted with circular “bubbles”, ascending numbers, or sequential letters of the alphabet, and by no means limit or restrict the use of visual identifying characters for the positioning of the adjustable detent of the present invention. The graduated sized indicator set points segmented between the highest and lowest settings provide for customized selection of detent forces for the adjustable detent mechanism. At any given setting, the adjustment dial  130  is releasably “locked” into position via the interaction between the indexing pointer  116  and one of the indentations  137 . 
     In operation, the inventive detent mechanism is coupled or secured to the drawer member  32  of the slide assembly, which travels a pre-determined length. When the slide is almost completely closed, detent arms  112  contact the retention tabs  40  of the cabinet slide member  39 . Being flexible (e.g., made of plastic), the detent arms  112  deflect and bypass the tabs  40 . The force to overcome the interference during the closing activity is less than the force to overcome the interference in the opening activity. This is due to the sloped angle differences of the detent arms. The angle is less in one direction of travel and greater in the other direction. Once the slide is fully retracted, and the drawer is fully closed, the detent arms (now on the inner side of the tabs) resist opening of the drawer  10 , without a purposeful pull. The interference provided by the detent arms, aligned with the deflection restriction of the adjustment dial  130 , when positioned provide the detent function intended of the invention, with the added capability of being adjustable to an upper and lower end of pull force. As described above, rotation of the adjustment dial  130  causes the arms  112  to move in and out via the interaction between the adjuster cams  134 ,  135  and the legs  115 . The range of rotation of the dial  130 , in turn, is defined by the interaction between the rotation restriction pin  118  and the slotted rotation restriction guide  136 . 
     A simplified version of the exploded view of  FIG. 5  is shown in  FIGS. 7 and 10A , where a rivet  141  is used to couple the detent mechanism  100  to the drawer member  32 . However, other fastening means may also be used. Thus,  FIG. 10B  shows an “E” style lock ring  142  that snaps on to a standing grooved pin  37   a  secured to the drawer member  32 . The “E” style lock ring may be taken apart and reassembled very quickly with a pair of pliers and/or a flat screwdriver. 
     In  FIG. 10C , a self-clinching threaded stud  37   b  is secured to the drawer member  32  and a lock nut  143  is used to hold the components in position for use. The nut  143  can be removed and re-assembled as many times as needed. In an alternative embodiment, as shown in  FIG. 10D , a self-clinching nut  37   c  may be secured to, or integral with, the drawer member  32 , and a shoulder screw  144  may be used to hold and position the components against the drawer member for use. 
     The above options allow for field replacement of components (e.g., the plastic components) in the event of damage or excessive wear. This type of field replacement does not require the user to remove the slide from either the drawer or cabinet. 
     While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit and scope thereof. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive. In addition, it is understood that one or more of the components described herein in connection with a specific embodiment may be used in conjunction with one or more of the components described in connection with a different specific embodiment.