Abstract:
A cabinet interlocking system is disclosed for a cabinet comprising a plurality of drawers wherein the interlocking system acts to prevent more than one drawer being opened at one time. The interlocking system comprises: a) an application of wedge-shaped support members for each movable side, or on at least one side, (could also be mounted on just one side), of each drawer to support each drawer in an open and closed position, b) a set of movable interlocking spring-loaded interlocking pieces mounted on adjoining support walls of the cabinet upon which the wedge-shaped drawer slides support members applied to the sides of the cabinet drawers of the cabinet drawers remain when the drawers are in the open position, c) a locking mechanism comprising a key-operated locking bracket and a key operated locking bar, which operate to lock and unlock the set of movable interlocking spring-loaded interlocking piece to permit the movable interlocking pieces to move upon entrance of the wedge-shaped members to penetrate between the interlocking members upon opening of one cabinet drawer, to raise the interlocking support members of the other interlocking pieces of other cabinet drawers above the open drawer to prevent opening the other cabinet drawers, above the open drawer. Also, cabinet drawers are blocked from opening by a spatial constraint there being only enough space between the several spring loaded interlocking pieces to allow one and only one wedge shaped member to pass between members of one interlocking piece.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to filing cabinets, and more particularly to mechanisms designed to prevent more than one drawer in a filing cabinet from being opened. 
         [0002]    Filing cabinets and containers containing two or more drawers are used to store items, documents, heavy files, tools, supplies, and other materials. In some instances, the opening of two drawers or more in such a cabinet at the same time can cause the cabinet to tip over and possibly cause serious injury to someone or damage to the items stored in the cabinet. In order to prevent the simultaneous opening of two drawers of such a cabinet and prevent the tipping over of the cabinet, the present invention provides a systemized mechanism where space limitations are a vital concern. The present invention, cabinets, is provided with an interlocking mechanism preventing a second drawer of the cabinet from being opened after a first drawer has been opened. 
         [0003]    The present invention is also unique in that the cabinet can be designed with different sections, such as a top section with drawers and a bottom section with drawers, or left-hand side with drawers and right-hand side with drawers. The present invention then provides for the ability that each section could have a single drawer opened, while the other remaining drawers stay locked. 
         [0004]    Filing cabinets are most often equipped with locks preventing any drawers from being opened. The lock is moved to a locking or closed position. The lock overrides any system designed to allow movement in a cabinet. In the prior art interlocking systems when the lock is activated no drawers can be opened at all. In the prior art cabinets, the lock must be activated or moved to a certain position to allow a drawer to open. The prior art interlock system functions to prevent the drawers from opening or only allowing one drawer to be opened where the lock is set to a certain position. 
         [0005]    A system of locking all of the drawers and having an interlocking system that locks all but one of the drawers where space is a vital concern has not been developed until the present invention. The present invention provides for a significant number of components to be integrated and functionally combined to significantly reduce the space requirements and thereby reduce the weight of the cabinet. The present inventive cabinet combines an interlocking system with a locking mechanism so spatial constraints in the cabinet are not an impediment, and the present invention allows for the opening of a single drawer, if desired, in the cabinet without having to adjust the locking mechanism. 
         [0006]    As noted, the current methods employed in cabinets or containers utilized today do not solve the issue of space limitations. Further, the reduction in parts, and therefore the reduced cost in production, in conjunction with the integration of common elements utilized in the locking system and the interlocking system of the cabinet or container provide significant cost reductions. By utilizing common parts, the reduction in breakage in the number of components is reduced, and a reduction in the weight of the cabinet is a result. Therefore, the reduction in components provides for easier and better mobilization of the cabinet, and a greater use of the storage space in a cabinet or container than was previously available. 
         [0007]    Additionally, one of the other advantages of the present invention is a set of top drawers can be isolated or controlled from a bottom set of drawers allowing a single drawer to open from the different sections of the cabinet whether an upper or lower section of the cabinet. It should also be apparent that the present invention could be manufactured to allow for control of opening of a single drawer from a right-hand section of the cabinet or container and the opening of a single drawer from a left hand section of the cabinet or container. 
         [0008]    As noted above, the locking and interlocking mechanisms known in the prior art have suffered from a number of disadvantages. A particular disadvantage is that many of these systems are complicated, and require complicated assembly and parts, with significant space requirements. For example, U.S. Pat. No. 4,355,851 is directed to a file cabinet including slidably mounted drawers, provided with an interlock mechanism preventing the simultaneous opening of two drawers. The interlock mechanism includes an elongated channel having a fixed length and depth. Blocks and wedges are slidable within the channel along the length thereof. This system further includes and requires a cam means and an actuator for forcing wedges into the channel. 
         [0009]    Many systems are designed to prevent a second drawer from opening when a first drawer is already open, however, none has the added flexibility noted above of controlling sections of the drawers and allowing if desired, only a single drawer to open for that particular section. 
         [0010]    In light of the foregoing, the desirability of combining an interlocking and locking system to overcome the prior art disadvantages and space limitation can be seen in the present invention. 
       SUMMARY OF THE INVENTION 
       [0011]    The present invention provides a multi-drawer cabinet having an interlock mechanism preventing two or more drawers from being simultaneously opened. The present invention provides or allows if desired the opening of only one drawer, or if the cabinet or container is sectioned, the allowance of only a single drawer to be opened in that particular section. In addition, the following system is based on a minimal number of components of relatively easy design and assembly and employed where space is a major limitation in the cabinet housing. 
         [0012]    The cabinet interlocking system is designed for multi-drawer cabinets. The cabinet or container interlock system includes a cabinet frame, with the usual drawer housing, and a vertical support member on an inner side panel of the cabinet. The vertical support member has slots for supporting interlock pieces. The interlock pieces are vertically stacked and member portions of the piece protrude through the slots, while the remaining portion of the interlock piece serves to space the protruding member portions of other interlocking pieces. 
         [0013]    Two protruding members, attached to different spacers of different interlocking pieces are arranged in two slots, as a ‘protrusion pair’, with one protrusion of the pair resting upon the other. Each drawer has a wedge-ended member attached horizontally to a side of the drawer. The wedge-ended members are positioned to penetrate between a set of protrusions pair of interlock pieces when the drawer is opened. Only the locking interlocking members located above the opened drawer are displaced. The bottom interlocking members are not displaced on the drawers that remain closed below the opened drawer. The wedge-ended members exit from between the interlock pieces when the drawer is closed. As the wedge-ended member penetrates the vertically stacked interlock pieces, it causes only the locking members of the interlocking pieces located above the opened drawer to be displaced vertically by the width of the wedge-ended member. Thus, this system provides a spring load to cause the displaced interlocking pieces to return to a neutral position. 
         [0014]    The system load includes a spring; the spring helps in returning the interlocking piece members to the correct position. The spring constantly pushes down. Therefore the interlocking pieces are in vertical alignment, and the spatial constraints prevent them from being vertically displaced by more than by one drawer. Again, as noted above it is only the interlocking pieces located above the open drawer are displaced and keep the drawer from locking. In this way, two drawers can never be opened at the same time. As noted in a cabinet or container manufactured with specific sections the present invention allows a drawer from a designated top bank of drawers to be in the open position, while allowing a second opened drawer in a separate section of drawers from a bottom bank of drawers to be opened at the same time if desired. Any additional drawers would not be able to open. The cabinet interlock system of the present invention includes an interlocking bar in an alternative embodiment. The spring at the top of the vertical stack of interlock pieces constantly pushes down to hold the pieces in alignment and the spatial constraint of the cabinet prevents displacement of the interlock pieces by locking the interlock piece closest to the spring in a non-displaced position. A locking bar passes through the vertical support member and into a hollow in the interlock piece closest to the spring. This prevents any drawers from being opened. These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1   a : is a perspective view of a cabinet with three drawers in a closed position with wedge-ended members on each movable side, 
           [0016]      FIG. 1   b : is a perspective view of a drawer with an attached wedge-ended member on one movable side; 
           [0017]      FIG. 2   a : is a perspective view illustrating operation of the wedge-ended members and interlock pieces according to the present invention; 
           [0018]      FIG. 2   b : is a perspective view of a wedge-ended member inserted between the interlock pieces, in accordance with the present invention; 
           [0019]      FIG. 3   a : is a perspective view of the vertical support member  90  for the interlock on inner cabinet wall  21 , 
           [0020]      FIG. 3   b : illustrates T shaped slots  91 , which support interlock pieces  30  in vertical position; 
           [0021]      FIG. 3   c : is a detailed view of an interlock piece positioned mid-support within the vertical support column  90  of  FIG. 3   a;    
           [0022]      FIG. 4 : illustrates a detailed view of the spring load and lock of the present invention; 
           [0023]      FIG. 4   a : illustrates a further detailed view of the support  90  and placement of interlocking pieces  30  in T-shaped slots  91 ; 
           [0024]      FIG. 4   b : illustrates the spring load mechanism of spring  61 , 
           [0025]      FIG. 4   c : illustrates the spring upon interlocking pieces  30  load mechanism of  FIG. 4   b,    
           [0026]      FIG. 4   d : illustrates the structure of the interlocking pieces  30  as consisting of protrusions  33 ,  34 , and spacer  32 ; and 
           [0027]      FIG. 4   e : illustrates the structure of the alternative interlocking piece receiving a locking bar. 
       
    
    
       [0028]    Referring to  FIGS. 1   a  through  4   e , the designated parts are numbered consistently throughout the figures and represent the same parts without repeating the specific designation. 
         [0029]    In  FIG. 1   a , file cabinet assembly  20  comprises  42   a ,  42   b ,  42   c ; lock bracket  13 , key hole  95 , for lock mechanism  12 .  FIG. 1   b  illustrates attachment of draw slide wedge ended member  44   b  to drawer  42   b .  FIG. 2   a  illustrates application of a key to lock mechanism  12  with lock bracket  13  which acts with upper protrusion  30   a  to lock drawer slide wedge ended member  44   a  from insertion between lower interlock protrusion  30   a  and upper protrusion  30   b .  FIG. 2   b  illustrates the structure of the invented device wherein interlock protrusion  30   a  and  30   b  inserted in wall slots engage drawer slide wedge-ended member  44   a  and wherein locking mechanism  13  is not operative.  FIG. 3   a  illustrates the construction of the vertical support inner wall  21  of cabinet  20 , drawers  42   a ,  42   b ,  42   c , spring loading  61 , spring loading plate  62 , interlock spacer  32 , vertical support member  90 .  FIG. 3   b  illustrates the T-shaped slots  91  consisting of spaces  97 ,  98 ;  93  and  94  and interlock protrusions  30 .  FIG. 3   c  details the method of inserting interlock piece  30  and interlock protrusions  33 ,  34  of interlock piece  30  through slots  91   a ,  91   b , and  91   c  in vertical support member  90  with interlock piece spacer  32 .  FIG. 4  illustrates the spring loading plate  62 , the upper and lower protrusions  33  and  34  of interlock spacer  32 , spring  61  and vertical support member  90 .  FIG. 4   a  illustrates further details of the interlock piece comprising protrusions  33  and  34  in spaces  91   a  and  91   b  in vertical column member  81  wherein inlets  92  are indicated and support screw  82 , to cabinet wall  21 .  FIG. 4   b  repeats the previous designations of previous  FIGS. 1-4   a  as does  FIGS. 4   c , and  4   d .  FIG. 4   e  illustrates an alternative embodiment of an interlock piece  30   a , which engages an inserted lock bar in hollow  92  in the upper protrusion  97  of support element  36 . 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    The present invention will now be described with reference to the accompanying drawings wherein the reference numerals in the following written description correspond to like numbered elements in the several drawings. The present invention relates to locks and interlocks used in file cabinets, tool cabinets, and other containers. A typical file cabinet  20  is depicted in  FIG. 1   a . A file cabinet assembly  20  has a series of drawers  42   a ,  42   b , and  42   c  mounted for sliding movement within a cabinet formed of an upper wall  22  (not shown), a lower wall  24  (not shown), and a pair of sidewalls  23 ,  25  (not shown). Drawer slides  44   a ,  44   b ,  44   c , (See  FIG. 2   a ) or equivalent mechanisms are interposed between drawers  42   a ,  42   b ,  42   c  and the cabinet walls  23 ,  25  for providing sliding movement of drawers  42   a ,  42   b , and  42   c  between an open position and a closed position, locking bracket  13  is shown,  FIG. 1   a . While only three drawers are illustrated in file cabinet  20 , the present invention is applicable to cabinets having any number of drawers, including cabinets designed with sections of drawers. 
         [0031]    The present invention includes a locking system with the ability to override the interlocking system. More specifically, when the locking system is activated, no drawers can be opened at any time. When the locking system is deactivated, the interlocking system is activated and the system prevents more than one drawer from being opened at a single time. The locking system may be activated by inserting a key into a keyhole  95  positioned at any suitable location on the file cabinet. The locking and interlocking systems are highly integrated so the components of the interlocking system are used in the locking system. 
         [0032]    An interlock mechanism, shown generally at  12 , is interposed between the cabinet structure, sidewall  23 , and each of drawers  42   a ,  42   b , and  42   c . As will be explained, interlock mechanism  12  functions to prevent more than one of drawers  42   a ,  42   b , and  42   c  from being opened at one time. 
         [0033]      FIG. 1   b  shows drawer  42   b  and drawer slide wedge-ended member  44   b  has been attached to its side. Drawer slide wedge-ended member  44  can be of variable thickness for positioning relative to the drawer and is required to be accurately positioned relative to locking mechanism  12 . Drawer slide wedge-ended member  44   b  is attached to drawer  42   b.    
         [0034]    Referring to  FIG. 2   a , drawer slide wedge-ended members  44   a ,  44   b ,  44   c  are depicted as they would be situated were they attached to closed drawers. With regard to interlock mechanism  12 , interlock mechanism  12  includes a series of interlock pieces collectively,  30 , separately  30   a ,  30   b , and  30   c , vertically stacked. Interlock pieces are shown, but the invention is not intended to be limited to any particular number of drawers. 
         [0035]    In the  FIG. 2   a , alternative embodiment, it is noted interlock piece  30   a  comprises an upper protrusion, contact locking bracket  13 . Three interlock pieces, see  FIG. 4   d , collectively  30 , designated  30   a ,  30   b ,  30   c , consist of a spacer  32 , and two protrusion blocks, upper protrusion  33 , and lower protrusion  34 , a protrusion pair,  33 ,  34  of two interlocking pieces as shown in  FIG. 2   a . Interlock pieces are preferably formed of Delrin® (polyoxymethylene), or Nylatron® or any other suitably abrasion wear resistant material. The abrasion may be lubricated to reduce the friction caused by the movement of the components. The preferred material noted is one chosen because of ease to machine and reduction of contact friction between wedge-ended members  44   a ,  44   b ,  44   c , and interlock pieces  30   a ,  30   b ,  30   c . The present invention is not limited to this material and other materials may be utilized either in combination or separately. Each wedge-ended member  44  intersects two protrusion blocks,  33  and  34 , a protrusion pair. As an example,  FIG. 2   a , drawer slide wedge shaped member  44   b  is disposed at the point of meeting between lower protrusion block  34  of interlock piece  30   b  and upper protrusion block  33  of interlock piece  30   c . Again, the two meeting protrusions,  33  and  34 , may be termed a ‘protrusion pair’, with one protrusion of the pair resting upon the other. The vertical stack of interlock pieces can be said to be composed of a number of protrusion pairs, separated by spacers. 
         [0036]    Each drawer has a drawer slide wedge-ended member attached horizontally to a side of the drawer. The wedge-ended members, collectively  44 , individually  44   a ,  44   b , and  44   c  are positioned to penetrate between a protrusion block pair of interlock pieces, collectively  30 , individually  30   a ,  30   b , and  30   c  when the drawer is opened. Drawer slide wedge-ended members exit from between the interlock pieces when the drawer is closed. As the drawer slide wedge-ended member penetrates the vertically stacked interlock block pieces, it causes them to displace vertically by the width of the wedge-ended member. Only the pieces immediately above the drawer to be opened are displaced vertically. 
         [0037]    To help wedge-ended members  44  to penetrate between interlock pieces  30 , and to reduce friction and wear and tear, it is recommended the sections of interlock pieces  30  adjacent to the wedge-shaped members&#39; entry point be domed, or tapered. Thus, each protrusion pair consists of a higher protrusion  33 , and a lower protrusion  34 . The higher protrusion  33  of the pair consists of a flat upper profile with a tapered lower profile. The lower protrusion  34  of the pair has a flat upper profile and a tapered lower profile. A ‘tapered profile’ includes a discrete number of straight sides, or a rounded or domed profile, to promote penetration of said wedge-ended member. The protrusion pair consists of lower protrusion  34  of an interlocking piece  30  and the upper protrusion  33  of a separate interlocking piece  30  to form a protrusion pair with a higher and a lower protrusion. 
         [0038]    Drawer slide wedge-ended members  44  have a long lower edge versus a shorter upper edge, forming a prolonged triangular presentation. This provides for easier penetration of the stack of interlock pieces  30 . Prolonged lower edge of wedge-ended members  44  eases the meeting point of each protrusion pair. 
         [0039]    The various interlock pieces, collectively  30 , are not joined to one another but are stacked and held in vertical alignment. Spring loading means  61 ,  62  is attached to the top of the vertical stack. Spring loading means  61 ,  62  can alternatively be attached to the base of the stack, or to the middle of the vertical stack of interlock pieces  30   a ,  30   b ,  30   c . Spring loading means  61 ,  62  helps in returning the stack to the neutral or closed position, and the stack of interlock pieces  30   a , 30   b , and  30   c  only requires a small displacement accordingly, substantially equal to the width of wedge-ended member  44   a ,  44   b , or  44   c , so one wedge-ended member  44   a ,  44   b , or  44   c  penetrates through the stack. The limited displacement effectively means two different drawers cannot be simultaneously opened, and a second drawer cannot be opened if a different one is already open. 
         [0040]    In an alternate embodiment, top interlock piece  36  is unique in  FIG. 4   b . It is closest to the spring load means  61 ,  62 . It does not include an upper protrusion  33  positioned opposite a wedge-ended member  44 , since its lower protrusion  30   a  is positioned opposite the top most drawer wedge-ended member  44   a . However, top interlock piece  36  may include instead a key-locking mechanism bar locking mechanism. In an alternate embodiment, the locking mechanism is in the form of a hollow  92  in interlock  36  allowing the insertion of a locking bar from the side or front wall of the cabinet. Bottom interlock piece  30  may also be manufactured slightly differently from the other interlock pieces  30  depending on design considerations; for example, it may not require its lower protrusion  34 , other than to wedge into position. Therefore, in a further embodiment, bottom interlock piece  34  may be fixedly attached into position. 
         [0041]    In a preferred embodiment,  FIG. 2   b  shows locking system  12  with wedge-ended member  44   a  inserted amidst the stack of interlock pieces  30   a ,  30   b ,  30   c , indicating the first drawer has been opened. As may be seen, interlock piece  30   a  above wedge-ended member  44   a  has been displaced upwards against the spring loading mechanism  61 ,  62 , which is fully compressed. Interlock pieces below member  44   a  have not moved at all. 
         [0042]    With reference now to  FIG. 3   a , a vertical support member  90  for the interlock system  12  is depicted. A vertical support member is part of or attached to inner wall  21  of cabinet  20 , the same wall as outer wall  23 . The vertical support member provides guiding support for the vertical stack of interlock pieces, and in a preferred embodiment incorporates T shaped slots  91  to support the interlock pieces. The invention is not limited to T shaped slots  91  slots of different shapes and sizes may be utilized. T shaped slot  91  shown in  FIG. 3   b  is depicted as divided into two distinct and mutually exclusive sections, horizontal sections  97  and  93 , and vertical sections  98 , and  94 . In reality, T shaped slot  91  is not divided at all, but for clarity they are described as if they contain several sections. The benefit of the T shaped slot(s)  91  is the interlock pieces may be inserted into the horizontal section  97  of the T shaped slot(s)  91 , and then dropped down to a narrow vertical lower section  98 . In vertical section  98 , the interlock piece cannot move from side to side. In addition, vertical section  98  is high enough that even at maximum displacement of operational usage, the interlock pieces will not rise high enough to reach horizontal section  97 , thus they remain properly confined. Hence, the spatial restraint of the interior of the cabinet frame helps in channeling the displacement of the interlocking mechanism, and provides for allowing only one drawer to be opened in a cabinet or section of a cabinet if so desired. Although the slots are referred to as T shaped, this description is intended to include the possibility that the horizontal section of the T shaped slots may be rounded. Again, the T configuration is not the only available configuration to provide the necessary support and configuration for locking the appropriate component. 
         [0043]      FIG. 3   c  depicts an inserted sample interlock piece  30  as it would appear once inserted into T shaped slots  91   a  and  91   b . To insert sample interlock piece  30  into the T shaped slots, sample interlock piece  30  is held from behind vertical support member  90 . Upper protrusion  33  is inserted towards the viewer into the horizontal section of the T shaped slot  91   a  whilst lower protrusion  34  is inserted into the horizontal section of T shaped slot  91   b . Sample interlock piece  30  is then allowed to drop down, so that upper protrusion  33  hangs from the base of the vertical section of T shaped slot  91   a , while lower protrusion  34  does not reach the base of the horizontal section of T shaped slot  91   b . It would instead rest on a lower interlock piece. To set up interlock device  12  it is recommended to start with the lowest interlock piece  30 , and then insert all of them, finishing with the spring load at the top. Spacer  32  is shown indistinctly because much of it is behind vertical support member  90 , although part of it is visible behind T shaped slot  91   b.    
         [0044]      FIG. 4  shows locking spring  61  and interlock spaces  32 .  FIG. 4   a  shows a locking bar interlock, system  12  attached to cabinet wall  21 . Interlock pieces  33  and  34 ,  30   c  are visible through T shaped slots  91   a  and  91   b .  FIG. 4   a  shows an additional vertical column member  81  removably attached, by screws  82  or other equivalent mechanisms onto cabinet wall  21 . Vertical column member  81  serves to protect interlock pieces  30  from being thrust towards cabinet wall  21 . The vertical column member prevents internal slippage of interlock pieces  30  if the filing cabinet is improperly handled. A further alternate embodiment of the present invention is provided in  FIG. 4   e , a locking bar is inserted into hollow  92 . 
         [0045]      FIG. 4   b  shows further details of  FIG. 4   a  with regard to spring loading  61 ,  62  and interlock piece  30   a . Spring  61  is compressed against plate  62  as interlock piece  30   a  is raised. The interlock system  12  could equally well work upside down, if spring loading  61 ,  62  were to be alternatively placed under the lowest interlock piece  30 . For clarity, the present disclosure was limited to descriptions utilizing upward displacement. Downward displacement is equally anticipated. 
         [0046]      FIG. 4   c  depicts further details of the alternate locking bar system, which could use any locking mechanism known in the art. In an alternative embodiment,  FIG. 4   e , the top section  36  of topmost interlock piece  30   a  is formed as a block containing a hollow  92 , into which locking bar  94  (not shown) is inserted when it is desired to deactivate the spring and prevent any displacement of the interlock pieces  30 . This effectively stops all the drawers from opening. This locking procedure can only be effective if done when all the drawers are initially closed. The locking bar  94  prevents the spring  61  from being compressed and therefore wedge-ended members are prevented from penetrating the series of interlock pieces  30 . Since they cannot penetrate, the drawers are unable to open. 
         [0047]      FIG. 4   e  depicts the locking bar.  FIG. 4   e  further depicts an alternative locking bar top section  36  of topmost interlock piece  30   a  containing a rectangular receptacle for a rectangular shaped locking bar. 
         [0048]    The locking system alternatively includes a keyhole and a key, in which the key is operationally connected to the locking device, such as locking bracket  13 . The turning of the key in the keyhole causes the locking mechanism to be activated, such as inserting locking bracket  13  over protrusion block  33  of interlock  33   a . The present invention further provides a method for building the cabinet of the present invention, in which no more than one drawer can be opened at any given time. 
         [0049]    A number of stages are involved: 
         [0050]    Providing a filing cabinet frame with a vertical member on an inner side surface of the filing cabinet; 
         [0000]    i) attaching a wedge-ended horizontal bar to each of the drawers;
 
ii) producing T shaped slots on a face of the vertical member facing the drawers;
 
iii) inserting the top end of a first interlock piece and the bottom end of a second interlock piece into each T shaped slot from behind the slot so protrusions of the interlock pieces protrude towards the drawer spacers of the interlock pieces remain behind the vertical member;
 
iv) spring loading the interlock pieces so there is a constant downward push to substantially the width of a single wedge-ended horizontal bar;
 
v) positioning the slots so all the interlock pieces are arranged in a vertically contacting pile so when a drawer is opened, a wedge-ended horizontal bar displaces the molded interlock pieces between the horizontal bar by the width of the horizontal bar; optionally
 
vi) locking the cabinet by inserting a locking bar into the interlocking pieces closest to the spring load whilst the spring load is fully extended in an alternate locking procedure;
 
vii) locking the cabinet by turning a key in a keyhole, the key connected to a locking bracket, which on being turned over protrusion  33  of interlock piece  30  a locks the locking system in an alternate locking procedure.
 
While the present invention has been described in terms of the preferred embodiments depicted in the drawings and discussed in the above specification, it will be understood by one skilled in the art that the present invention is not limited to these particular preferred embodiments, but includes any and all such modifications that are within the spirit and scope of the present invention as defined in the following claims.