Abstract:
A lock for a rural mailbox which enables normal access to the mailbox by a postal delivery person when placing mail in the box and enabling the mailbox door to be closed and locked by the postal delivery person without the use of a key or any other device to protect the mail that is in the box. The postal customer must use a key to open the lock to gain access to the protected mail.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to mailboxes having a pivotal access door such as a rural mailbox in which the door pivots at a lower edge thereof and a friction latch retains it in closed position. More specifically, the present invention relates to a novel and unique locking device associated with a mailbox which enables normal access to the mailbox by a mail delivery person when placing mail in the box and enabling the mailbox door to be closed and locked by the locking device without the use of a key to protect the mail that is in the box from theft. A key is required to open the locking device to gain access to the protected mail. 
     2. Description of the Prior Art 
     Theft of mail from mailboxes has long been a problem encountered by postal customers. Theft of checks and other important mail is especially important in rural areas where the rural mailbox alongside the road is not visible to the postal customer. Accordingly, many efforts have been made to provide a secure, theft proof mailbox including various types of locking mechanisms and other structures to prevent access to the mail once it has been deposited in the mailbox by the mail delivery person. The following U.S. patents known to Applicant disclose various types of locking devices associated with mailboxes or other containers. 
     
       
         
               
               
               
             
           
               
                   
               
             
             
               
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     While the above patents disclose various types of security measures for mailboxes and the like, they do not disclose a relatively simple structure that can be easily installed on a conventional rural mailbox without substantial modification of the mailbox and which will provide unobstructed access to the mailbox by a mail delivery person when inserting mail into the box and which is quickly and easily locked by merely turning a lock device, without the use of a key or any other tool, once the mail has been placed in the mailbox thus securely locking the mailbox and preventing access thereto by anyone that does not utilize an appropriate key. 
     SUMMARY OF THE INVENTION 
     The mailbox lock constructed in accordance with the present invention includes a hasp constructed of three segments which are pivotally connected. One of the segments of the hasp is secured to the top area of the mailbox adjacent the open end thereof. The second or intermediate segment of the hasp overlies the first segment to prevent access to the structure which fastens the first segment to the mailbox and extends beyond the first segment into overlying relation to an upper edge portion of the mailbox door. The third segment extends downwardly from the outer end of the second segment and extends downwardly in front of an upper portion of the mailbox door. The third segment which overlies the portion of the outer surface of the upper end portion of the mailbox door is provided with an opening therein having a unique asymmetrical configuration which enables the third segment to move inwardly of a rotatable lock member having the same configuration as the opening to a position that enables the lock member to be rotated a quarter turn to engage the outer surface of the third segment laterally of the opening to secure the third segment in locked position inwardly of the rotatable lock member. The lock member is rotatably affixed to a post that is attached to the upper end portion of the door thereby maintaining the door in closed position. The rotatable lock member and post include a key operated lock which is effective to enable the lock member to rotate from an unlocked position to a locked position without using a key but requiring a key to rotate the lock member from a locked position back to an unlocked position. 
     This structure enables all segments of the hasp to be positioned in a generally straight alignment against the upper surface of the mailbox so that the mailbox door can be opened without any impediment from the hasp. After mail has been placed in the mailbox and the door closed, the second and third segments of the hasp are swung upwardly and forwardly and the third segment of the hasp swung downwardly with the lock member on the door passing through the opening in the third segment and being partially rotated by a mail delivery person to a locking position transversely of the opening without use of a key. The mailbox is then securely locked and in order to gain access to the interior of the mailbox, it is necessary for a key to operate the key operated lock to return the rotatable lock member to unlocked position. 
     Accordingly, an object of the present invention is to provide a locking device for a rural-type mailbox or similar container utilizing a sturdy but yet simply constructed hasp which can be easily attached to a mailbox by using readily available tools and easily manipulated fastening devices and requiring a minimum modification of the mailbox structure. 
     Another object of the invention is to provide a mailbox lock utilizing a three segment hasp mounted on the mailbox on an upper surface area thereof adjacent the open end of the mailbox and a rotatable lock member mounted on a post fixedly mounted on the mailbox door adjacent an upper end thereof with the segments of the hasp overlying fastening devices which secure the hasp and post to the mailbox when the third segment of the hasp is in locking engagement with the lock member mounted on the post on the door. 
     A further object of the invention is to provide a lock for mailboxes in accordance with the preceding objects in which the third segment of the hasp includes an asymmetrical opening through which a rotatable lock member having a configuration corresponding to the shape of the opening extends when the third segment of the hasp is in vertical position outwardly of the door. Rotational movement of the lock member results in portions of the lock member overlying outer surfaces of the third segment of the hasp with such rotational movement to a locking position requiring only that the lock member be manually rotated a partial revolution without requiring the use of any key or other device. 
     A still further object of the invention is to provide a mailbox lock in which the lock member, when rotated to a locked position by a mail delivery person will automatically become locked in locked position to securely protect the mail within the box with a key being required for a postal customer to move the lock member from the locked position back to an unlocked position to enable access to the mail in the box. 
     Yet another object of this invention to be specifically enumerated herein is to provide a mailbox lock in accordance with the preceding objects and which will conform to conventional forms of manufacture, be of simple construction and easy to use so as to provide a device that will be economically feasible, long lasting and relatively trouble free in operation. 
     These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a rural mailbox with the lock of the present invention mounted thereon and illustrating the limited rotational movement of the rotatable lock member between locked and unlocked positions. 
     FIG. 2 is a perspective view of the mailbox lock with the three segments of the hasp oriented against the upper surface of the top portion of the mailbox and the lock member mounted on the upper front portion of the mailbox door being in unlocked position. 
     FIG. 3 is an exploded group perspective view of the anchor plate, post and rotatable lock member that is secured to the front surface of the mailbox door. 
     FIG. 4 is a perspective view of the structure of FIG. 3 illustrating the components in assembled position. 
     FIG. 5 is an exploded elevational view of the components of the lock illustrating their manner of assembly. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Although only one preferred embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the preferred embodiment, specific terminology will be resorted to for the sake of clarity. It is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. 
     Referring now to the drawings, the mailbox lock of the present invention is generally designated by reference numeral  10  and is illustrated in installed relation on a conventional rural-type mailbox generally designated by reference numeral  12  in FIG.  1 . 
     The mailbox  12  includes a longitudinally extending peripheral wall  14  having an arcuately curved upper portion  16  and an open front having a correspondingly shaped door  18  pivotally connected to the lower edges thereof by pin structures  20  to enable the mailbox door  18  to be pivoted downwardly to a generally horizontal or downwardly depending relation to the mailbox  12  to provide access to the interior of a mailbox in a manner well known. The mailbox also includes a signal flag  21  mounted thereon and the mailbox can be supported by a suitable post or other structure alongside a roadway to enable a mail delivery person in a vehicle to place mail in the mailbox in a well known manner. 
     The mailbox lock  10  includes a hasp generally designated by reference numeral  20  that is attached to the upper curved portion  16  of the mailbox  12  adjacent the door  18 . The lock  10  also includes a locking device generally designated by reference numeral  22  which is secured to the front surface of the door  18  adjacent the upper curved edge thereof. 
     The hasp  20  includes a first rectangular segment  24  secured to the upper curved surface  16  closely adjacent the open end thereof and closely adjacent the door when the door is closed. A plurality of fasteners  26  extend through the first segment  24  of the hasp  22  and through the curved top surface  16  of the mailbox  12 . Retaining nuts may be provided on the inner end of the fasteners  26  or alternatively, the first segment may be permanently secured to the mailbox by welding, epoxy or other fastening means. Pivotally attached to the first segment  24  of the hasp  20  is a second or intermediate segment  28  connected to the first segment  24  by a hinge structure  30  which defines a hinge axis transverse of the hasp and is a conventional pin and barrel hinge. Attached to the outer end of the second segment  28  of the hasp  20  is a third segment  32  of the hasp which is connected to the second segment  28  by a hinge  34  defining a hinge axis transverse of the hasp  20 . The third segment of the hasp  20  includes an asymmetrical opening  36  extending therethrough in which the lengthwise dimension of the opening is longer than the transverse dimension of the opening and may be provided with straight inner and outer end edges  38  in parallel relation to each other and inclined side edges portions  40  in order to provide a uniquely shaped opening to move over a correspondingly shaped rotatable lock member  50  forming a part of the locking device  22  when the hasp is positioned in locked position. 
     FIG. 2 illustrates the arrangement of all of the segments of the hasp when the door  18  is unlocked and unimpeded access can be gained to the interior of the mailbox  12  by a mail delivery person when all segments of the hasp are oriented in horizontal position against the upper surface of the mailbox. After the mail has been placed in the mailbox by the delivery person and the door  18  is closed, the second and third hasp segments  28  and  32  can be pivoted forwardly until the second segment  28  overlies the first segment  24  and the third segment  32  is pivoted downwardly toward a generally vertical position. The rotatable lock member  50  moves through opening  36  to the position illustrated in FIG.  1 . In this position, the second segment  28  overlies the first segment  24  and protects the fastening devices  26  securing the first segment  24  to the mailbox  12  from access by tools or the like which could possibly be used to separate the hasp  20  from the mailbox  12 . This arrangement makes removal of the hasp  20  from mailbox  12  difficult in the event someone wishes to gain access to the interior of the mailbox. 
     The locking device  22  includes a mounting plate  42  mounted on the exterior surface of the door  18  adjacent the upper edge by fasteners  44  or other securing devices such as epoxy, welding or the like. As illustrated in FIGS. 3-5, the locking device  22  also includes an asymmetrical projection  46  on the outer surface of the mounting plate  42  which corresponds to the configuration of the opening  36  in the third segment  32  of the hasp  20  so that the opening  36  in hasp segment  32  can be positioned in enclosing relation to the peripheral edge of the projection  46  and positioned adjacent the outer surface of the mounting plate  42  to conceal and protect fasteners  44  which secure mounting plate  42  to door  18 . Projecting outwardly from the projection  46  is a generally cylindrical post  48  rotatably supporting the lock member  50  which also has the same shape, configuration and peripheral dimensions as the projection  46  as illustrated in FIG.  4  and as the opening  36  in the third segment  32  of the hasp  20 . 
     The lock member  50  is rotatable in relation to the post  48  and when in the unlocked position as illustrated in FIGS. 1 and 4, the peripheral surfaces of the lock member  50  are in alignment with the peripheral surfaces of the projection  46 . In this position, the lock member  50  can extend through the opening  36  in the third segment  32  of the hasp  20  when the third segment  32  is pivoted downwardly to a vertical position over the lock member  50  and projection  46  so that the external surface of the third segment  32  is positioned slightly inwardly of the inner surface of the lock member  50 . This enables the lock member  50  to rotate ¼ of a turn to a perpendicular relation to opening  36  and projection  46  and transversely of the third segment  32  of the hasp. In this position, the end portions of the lock member  50  will overlie and engage portions of both side edges of the opening  36  thereby retaining the third segment  32  of the hasp  20  against the mounting plate  42  with the periphery of the opening  36  aligned with the external surface of the projection  46 . 
     The post  48  includes a laterally opening arcuate recess  52  for receiving a set screw  54 , such as an Allen head screw, extending through a side wall of the lock member  50  to enable the lock member  50  to be removed. The recess  52  extends 90° to enable the lock member  50  to rotate ¼ turn in relation to post  48  between locked and unlocked positions. Also, the lock member  50  includes an upward projection  56  telescopically receiving post  48 . A lock cylinder  58  rigid with projection  56  has a slot  60  therein receiving a key  62  enabling the lock member  50  to rotate ¼ turn in relation to post  48  from a locked position to an unlocked position. The lock cylinder  58  and the lock member  50  can rotate from an unlocked position to a locked position without the key  62  being inserted into the key slot  60  of locking cylinder  58 . When the lock member  50  is moved to the locked position, the locking cylinder  58  locks the lock member  50  in the locked position so that it cannot be returned to an unlocked position without inserting and manipulating the key  62  in a well known manner. 
     The lock member  50  and post  48  are telescopically and rotatably related and the lock cylinder  58  in lock member  50  is rotatable in post  48 . The lock cylinder  58  and post  48  include spring biased pins and tumblers as utilized in a conventional lock which are actuated by the key  62  in a well known manner to enable the lock cylinder  58  and the lock member  50  to rotate when the key  62  is inserted to move the lock member  50  from a locked to an unlocked position. When a mail delivery person approaches the mailbox with the hasp  20  in the position of FIG. 2, the door  18  can be opened by grasping and pulling handle  64 . After mail is inserted and the door closed, the mail delivery person can then move the hasp  20  to the position of FIG.  1 . The mail delivery person can then rotate lock member  50  ¼ turn since the pins and tumblers are misaligned in unlocked position and the key has been removed. When the lock member  50  is rotated ¼ turn, the pins and tumblers become aligned and the springs cause the pins and tumblers to extend across the shear line between the lock cylinder  58  and post  48  to prevent movement of lock cylinder  58  and lock member  50  to unlocked position until the key is inserted. The specific lock structure is not shown since it is conventional and well known. 
     If the hasp  20  and lock member  50  are mounted in a position where the normal spring friction latch is provided, a pull handle  64  may be attached to the door at any position alongside of or adjacent the lock member  50  in order to pivot the door between open and closed positions. If the hasp and lock member are mounted offset from the top edge of the mailbox and door, the conventional spring latch structure may be utilized to move the door between open and closed positions when the lock member is in unlocked position and the hasp is positioned along the outer surface of the mailbox. 
     The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.