Abstract:
A multi-compartment facility having a master door which can be opened by use of a master key and, when opened, admits substantially unrestricted access to all of the mailbox compartments, the master door incorporating a plurality of pivotally-mounted, sub-doors arranged to register each with a different one of the compartments and the sub-doors being individually lockable and openable only by assigned key holders. A manually operable control determines the condition of the flaps and employs a gear and rack system which moves a cam to longitudinally displace hinge rods for the sub doors, flap locking members being carried by the hinge rods and either preventing opening of the flaps or permittting them to open depending on the displacement condition of the hinge rods. In a modified arrangement, the flaps can be selectively and individually rendered non-lockable whereby the users can opt to receive junk mail and other deliverables.

Description:
FIELD OF THE INVENTION 
   This invention concerns improvement relating to multi-compartment mailboxes such as are employed in multiple occupancy apartments and office blocks and wherein each compartment of the mailbox has a lockable door operable with a key individual to that particular compartment only. Such multi-compartment mailboxes enable mail to be delivered to a single location but separately for each occupier and with security that, barring mistakes by the mail delivering operative, each occupier will receive and have access to only his own mail. 
   BACKGROUND OF THE INVENTION 
   In a disclosure as early as 1928, the prior art GB 297 215 teaches of a multi-compartment repository for letter parcels and the like where a main door has incorporated therein small doors arranged to provide access to individual compartments. On each of these small doors is provided an insertion clot with a movable flap on the outside to the door as cover for the slot. The slots are further provided with arresting bars or steps to prevent unauthorised retrieval of delivered mail from the compartments. However, this prior art arrangement does not provide for stopping of delivery of junk mail. 
   Multi-compartment mailboxes are susceptible to misuse by persons delivering unwanted junk mail and measures have been proposed in an attempt to combat this. In particular, it has been proposed to provide an arrangement whereby the mail delivery flaps of the compartments are lockable all together and the legitimate mail delivery operative, hereinafter called the postman, has a master key which enables the mail delivery flaps to be unlocked all together so that legitimate mail can be delivered. 
   Such an anti-junk mail system is disclosed in GB-A-2289500 and has a mail delivery flap and a lockable mail collection door associated with each compartment of a multi-compartmented array, the lockable mail collection doors being operable by their respective keyholders, different occupants of the building for example, and there being a matrix array of orthogonal bars which can be moved in dependence upon the operation of a master key between positions where the horizontal bars obstruct the mail delivery flaps and thus prevent them from being opened and where the matrix array is moved bodily and permits the delivery flaps to be opened. The individual occupants of an apartment or office block are given keys for their own mailboxes and none other and can collect mail from their assigned mailboxes only, and the postman has the master key which enables the posting flaps to be collectively unlocked for delivery of mail items. 
   A problem that arises with the system of GB-A-2289500 is that the mail delivery flaps limit the size of package which can be delivered. Larger packages which will not fit through the delivery flaps may be left half in and half out of the respective flap or may be left on top of the mailbox array and in either case are not secure. Alternatively the postman has to hand carry the package to the respective apartment or office which obviates the advantages of providing a multi-compartment mail box in the first place. 
   OBJECTS AND SUMMARY OF THE INVENTION 
   In accordance with the present invention, a multi-compartment mailbox a has a master door which can be opened by use of a master key and, when opened, admits substantially unrestricted access to all of the mailbox compartments, the master door incorporating a plurality of sub-doors arranged to register each with a different one of the compartments and the sub-doors being individually lockable and being openable only by assigned key holders. 
   It is to be noted that the system of GB-A-2289500 contemplates only a two way access to the mailboxes for the postman and each occupier. However, there is a need at times for an additional access by a third party such as a building supervisor or council officials who may wish to deliver mail without using the postal system, such that even if the postman has locked his or her access to the mailbox, the third party may still deliver mail. In such cases, there would be a three-way access to the mailboxes. 
   In use of such an arrangement, a postman wishing to deliver mail including large packages has only to open the master door. Thereafter, the individual building occupants can open their respective sub-doors by use of their individually assigned keys to collect their mail, but cannot access anybody else&#39;s mailbox. 
   Clearly, not every mail delivery will necessarily include packages of such a size as would not fit a conventionally sized mail delivery slot. To accommodate this possibility, the present invention further contemplates the provision of a mail delivery flap associated with each compartment with all of the mail delivery flaps being commonly lockable to prevent posting of junk mail. For example, each of the sub-doors abovementioned might be provided with such a lockable mail delivery opening. For locking and unlocking such mail delivery openings, a common locking arrangement will be provided which may be operated by the same master key as is employed for operating the master door or might use a different key. 
   In accordance with a preferred embodiment of the invention which is described in detail hereinafter, an arrangement for collectively locking and unlocking mail delivery flaps provided on the compartment sub-doors makes use of vertical rods extending through the array of compartments and the same vertical rods are utilised for hingedly mounting the sub-doors of the mailing compartments. The delivery flaps are horizontally hinged with respect to the sub-doors and the vertical rods are arranged so as to be vertically movable under control of a manual operating knob which can be locked so as to be rendered inoperable until unlocked. Attached to the vertical rods at plural locations are locking elements which, in one position of the vertically displaceable rods engage with the mail delivery flaps so as to lock them in closed position and, in another position of the rods to which the rods can be moved by operation of the operating knob, are disengaged from the mail delivery flaps which then can be opened for delivery of mail. 
   In accordance with a particularly convenient arrangement the manual operating knob is rotatable, once unlocked, and has attached thereto a gear wheel which engages a rack so that upon rotation of the knob and correspondingly of the gear wheel the rack is linearly displaced. A cam surface of the rack engages an actuator aligned with an adjoining end portion of one of the aforementioned vertical rods so that displacement of the rack causes a corresponding displacement of the actuator and thereby of the respective rod and, in turn, determines the condition, locked or unlocked, of the mail delivery flaps. 
   The above and further features of the present invention are set forth in the appended claims, and together with the advantages thereof, will best be appreciated from consideration of the following detailed description of an exemplary embodiment which is illustrated in the accompanying drawings. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIGS. 1A through 1E  show, respectively, a front elevation view of the embodiment with the master door closed, a typical side sectional view, a front elevation (inside) view with the master door open, an elevation view of the rear of the master door and a plan view partly in phantom; 
       FIG. 2  shows an enlarged front elevation view, similar to  FIG. 1A , which also shows in phantom the centralised locking arrangement for the mail delivery flaps; 
       FIGS. 3A and 3B  show the centralised locking arrangement of  FIG. 2  in, respectively, locked and unlocked condition; 
       FIGS. 4A through 4D  show the centralised locking arrangement in enlarged views and in closed (locked) condition, as in  FIG. 3A ,  FIG. 4A  being a detailed elevation view and  FIGS. 4B ,  4 C and  4 D being respectively, sectional views on the lines I . . . I, II . . . II and III . . . III shown in  FIG. 4A ; 
       FIGS. 5A through 5D  are views corresponding respectively to the views of  FIGS. 4A through 4D  with the centralised locking arrangement in opened (unlocked) condition; 
       FIGS. 6A through 6C  are, respectively, front elevation, cross-sectional side elevation and exploded views of the locking control knob employed in the centralised mail delivery flap locking arrangement; and 
       FIGS. 7A through 7D  show, respectively, a detailed sectional side elevation view of the master door corresponding to the left hand side of  FIG. 1B , and enlarged sectional views showing anti-junk mail features. 
       FIGS. 8A and 8B  are partial front and side elevation views showing a modification of the mail delivery flap locking member of the abovementioned embodiment, the modification enabling the mail delivery flap to the left open at the will of the respective mailbox compartment user and the modified locking member being shown in operable condition in  FIGS. 8A and 8B ; and 
       FIGS. 9A and 9B  are views similar to those of  FIGS. 8A and 8B  but showing the modified locking member in inoperable condition. 
   

   DETAILED DESCRIPTION OF THE EMBODIMENTS 
   Referring to FIG.  1 A and the corresponding enlarged views of  FIG. 2 , the multi-compartment mail box  1  of the embodiment has two columns each of nine compartments  2 . A master door  3  is hinged on the right hand side of  FIGS. 1A and 2  and has an associated key operated master lock  4  and a pull handle  5 . When the master door  3  is opened, as shown in  FIG. 1C , the inner compartments  2  of the mailbox are fully accessible for placement of packages up to substantially the full size of the compartment. When the master door  3  is closed and locked, access to the compartments  2  is enabled by provision of sub-doors  6  individually associated with and in registry with respective ones of the compartments  2 , the sub-doors  6  being mounted in the master door  3  so that when the master door is unlocked and opened, all the sub-doors  6  move with it. See in this connection  FIG. 1E  which shows the master door  3  in closed condition with the sub-doors  6  in open condition in phantom. The sub-doors  6  each incorporate a lock  7  openable with a key which will not open any of the other sub-door locks and also each has a mail delivery flap  8  and, as described below, the plural mail delivery flaps  8  in the mailbox  1  are all commonly lockable and unlockable by a common arrangement including a manually operable knob handle  9  which, as can be seen from  FIGS. 1A and 2 , is provided on the front of the mailbox  1 . 
     FIG. 2  shows the basic principles of the mail delivery flap common locking and unlocking arrangement. The control knob  9  is a lockable and unlockable rotary knob which, when unlocked enables a gear wheel  10  to be turned. The gear wheel  10  meshes with two rack members  11  and  12  so that when the gear wheel is rotated the rack members translate horizontally. End portions  13  of respective rack members  11 ,  12  are wedge-shaped and locate between a roller  14  fixed to the mailbox chassis and a roller  15  attached to the upper end of a spring biased actuator  35  which is aligned with a spring biased vertical rod  16  which extends downwards throughout the extent of the master door  3  and provides hinged mounting for respective ones of sub-doors  6 . In the embodiment shown, the vertical rod  16  associated with rack member  11  serves to mount the sub-doors  6  of one column of mailbox compartments, and the vertical rod  16  associated with the other rack member  12  serves to mount the sub-doors  6  of the other column of mailbox compartments. 
   Rotation of the knob handle  9  and the gear wheel  10  causes horizontal translation of the wedge-shaped end portions  13  of the rack members  11 ,  12  between the rollers  14  and  15  which in turn causes the actuators  35  to be displaced so as to displace the vertical rods  16 . Affixed to the rods  16  are locking members  17  which, as shown schematically in  FIGS. 3A and 3B , interfere with the opening movement of respective ones of the mail delivery flaps  8  when the rods  16  are in their uppermost positions ( FIG. 3A ) and prevent opening of the respective flaps, and when the rods  16  are displaced downwardly ( FIG. 3B ) move out of engagement with the flaps  8  so as to permit them to be opened. 
     FIGS. 4A through 4D  show the centralized mail delivery flap locking arrangement in full detail in its closed (locked) condition. Referring first to  FIG. 4A  which shows the locking arrangement as viewed from the inside of the mailbox, namely from the back of the master door, the manually operable knob handle  9  can be seen in phantom and its attached gear wheel  10  engaging the racks  11 ,  12  can be seen in full line. The wedge-shaped ends  13  of the racks engage as shown between the rollers  14  and  15  which are affixed, respectively to the mailbox chassis and to the upper ends of the spring biased actuators  35  so that turning of the knob handle  9  in a direction such as to advance the racks  11 , 12  between the rollers  14 , 15  causes the actuators  35  to project through openings formed in the underside of the top of the master door frame. With the master door closed the lower ends of the actuators  35  project into openings provided in the top edge of the master door and engage and depress against spring bias the upper ends of the vertical rods  16 . When the knob handle  9  is subsequently returned to its original position, the racks  11 , 12  withdraw from between the rollers  14 , 15  which permits the actuators  35  to resile upwards and, in turn, permits the rods  16  to resile upwards. Note that the rods  16  are always contained within the fabric of the master door, their extent of permitted movement being limited, and that the master door cannot be opened if the actuators  35  are depressed. To ensure that the knob handle  9  is not left in an unlocked position accidentally thereby preventing the master door from being opened, it is provided that the key to operate the knob handle  9  cannot be withdrawn from the lock if it is in an open position. 
   The vertical rods  16  extend downwards through respective ones of the two columns of mailbox sub-doors  6  and, as previously mentioned, provide for the hinged mounting of the sub-doors. The rods  16  are spring biased upwardly by means of springs  18 ,  19  provided at appropriate locations and abutments  20  provided on the rods cooperate with portions of the frame of master door  3  (see  FIG. 4B ) to determine the range of upwards and downwards movement permitted to the rods. Affixed to the rods  16  at the locations of the abutments  20  are plates  21  which carry at their edge opposite to the abutment respective ones of the locking members  17  which are in the form of elongate rod-like fingers extending parallel to the vertical rods  16 . 
   The mail delivery flaps  8  can be seen in cross-section in FIG.  4 C and are horizontally pivoted with respect to respective ones of the sub-doors  6  along their upper edges. A lip  22  at the lower edges of the mail delivery flaps  8  interferes with the front face of the sub-doors  6  to ensure that the flaps can only pivot inwardly, and a counterweight  23  ensures that the flaps return to closed condition once an item of mail has been inserted. 
   When the mail delivery flaps locking arrangement is in the condition shown in  FIG. 4A , the rods  16  are in their uppermost positions and the locking fingers  17  are so positioned that their upper ends locate behind the flaps  8  (see  FIG. 4C ) to prevent them being opened. When, as shown in  FIG. 5A , the knob handle  9  is turned to unlock the flaps  8  by translation of the racks  11 ,  12  and corresponding downwards movement of the actuators  35  and thus of the rods  16 , the upper ends of the locking fingers  17  move clear of the flaps (see  FIG. 5C ) so that the flaps  8  can be opened. Regardless of the condition of the flaps  8 , that is to say regardless of whether they are collectively locked or collectively unlocked, the individual sub-doors  6  can still be opened. 
     FIGS. 6A ,  6 B and  6 C show the form of the manual control that is associated with the above described centralised flap locking arrangement, and illustrate how such control can itself be locked so as to be inoperable and unlocked for operation. The control comprises a knob handle  9  as abovementioned which is rotatable relative to a knob base  24  in dependence upon the condition of a lock  25  which is bonded with the knob handle  9 . When the control lock  25  is unlocked, the knob handle  9  can be rotated, and when the control lock  25  is locked a part  26  engages with the base  24  to prevent the knob handle  9  being turned. The control lock  25  has a rectangular section shank  27  with a screw-threaded end portion  28  and, as shown in  FIG. 6B , this enables the gear wheel  10  to be affixed to the knob handle  9  for rotation therewith when the knob handle is unlocked and turned.  FIG. 6C  shows the parts of the flap locking arrangement in exploded view, reference numerals  29  and  30  in this view designating Nylon™ washers, reference number  31  designating an end washer, reference number  32  designating a circlip serving to retain the knob handle  9  and control lock  25  to the mailbox chassis  1 , and reference numeral  33  designating a screw threaded fastening nut. As a precautionary measure to avoid the lock being left in an unlocked state unintentionally, it is provided that the key used with the control lock  25  cannot be withdrawn if the control lock  25  is not in a locked position. The user would therefore be alerted to the fact that the lock is still open as he or she would not be able to withdraw the key. 
   The arrangement thus described provides, amongst other features, a master door which the postman can open in order to deliver packages which are too large to fit the mail delivery flaps that are provided in the individual sub-doors. The mail delivery flaps can be accessed for delivery of small mail items and to guard against insertion of junk mail into the mailboxes, the mail delivery flaps can be commonly locked and unlocked. The same key as locks and unlocks the master door could be used to lock and unlock the mail delivery flaps, but it is preferred to provide different keys for this purpose since keys for locking and unlocking the mail delivery flaps may advantageously be given to other persons, such as the building supervisor or to council officials for example, who desirably should not have a key to the master door. 
   It is to be noted that the system of GB-A-2289500 contemplates only two way access to the mailboxes for the postman and each occupier. However, there is a need at times for an additional access by a third party such as a building supervisor or council officials who may wish to deliver mail without using the postal system, such that even if the postman has locked his or her access to the mailbox, the third party may still deliver mail. The above-described embodiment meets this need by providing three-way access to the mailboxes. 
   Referring now to  FIGS. 7A ,  7 B,  7 C and  7 D, these show features built into the mailbox structure to ensure that thin sheets of paper cannot be slipped into the mailboxes when the mail delivery flaps are locked.  FIG. 7A  shows a sectional view through a master door which closely shows details of the mail delivery flaps  8  and of the sub-doors  6  and  FIGS. 7B ,  7 C and  7 D are enlarged showing of details. As can be seen from  FIGS. 7B ,  7 C and  7 D the upper edges of the mail delivery flaps  8  engage with complementarily shaped edges of the sub-doors  6  with a convoluted section and the same is the case for the edges of the sub-doors where they fit into the frame of the master door  3  and for the master door where it fits into its frame. These convoluted profiles effectively prevent the insertion of thin sheets into the mailboxes. 
   Referring now to  FIGS. 8A and 8B  and  FIGS. 9A and 9B , these show a modification of the above-described embodiment which enables the mail delivery flaps  8  of the individual compartments to be selectively left unlocked if the user of the respective compartment is happy to receive junk mail and other materials. Comparing the arrangement shown to the arrangement in  FIG. 4A , it can be seen that the locking finger  17  of  FIG. 4A  is modified so as to be selectively adjustable within a tubular edge portion of the plate  21  much in the manner of a door bolt. The tubular edge portion is designated  210  in  FIGS. 8A and 8B  and in  FIGS. 9A and 9B , the adjustable locking finger is designated  170  and has attached thereto an operating member  171  which can move in an L-shaped opening  211  in the side wall of the tubular portion  210 . 
   In the condition shown in  FIGS. 8A and 8B , the locking finger  170  is advanced so that its upper end can interfere with the movement of the mail delivery flap  8  so as to prevent it from being opened. With the locking finger  170  in this position, the system operates as in the embodiment above-described. In the condition shown in  FIGS. 9A and 9B , however, it can be seen that the locking finger  170  has been adjusted relative to the tubular portion  210  so that it is retracted from the location of the mail delivery flap  8  and cannot interfere with its movement. It is a simple matter for the user of the respective compartment to elect whether or not his mailbox should be capable of receiving junk mail or other deliverable material merely by selective adjustment of the operating member  171  and correspondingly of the position of the locking finger  170  relative to the tubular portion  210 . An indication of the condition of the locking finger  170 , visible from the front of the mailbox, could for example be provided by provision of sight glasses or windows (small boxes) in the compartment doors which enable coloured or other distinctive indicia provided on the fingers  170  to be observed. 
   Having described the present invention in the foregoing by reference to a particular embodiment and a modification thereof, it is to be appreciated that the embodiments are in all respects exemplary and that modifications and variations thereto are possible without departure from the spirit and scope of the invention as set forth in appended claims. Thus, for example, whilst the invention has been described by reference to multi-compartment mailboxes, the teaching of the invention could be applicable to other multi-compartment situations. Furthermore, the invention is applicable to retrofit applications where a master door as herein described is fitted to an already existing mailbox array. This is a significant advantage over the system of GB-A-2289500 which is not readily adaptable to retrofit applications since installation of the matrix array of orthogonal bars cannot simply be achieved by fitting the existing structure of a multicompartment mailbox with a new door. The various locks in the embodiments are key operated, but one or more or all could be replaced by corresponding combination locks and the references herein to operation of a lock by a key are intended to be interpreted accordingly.