Abstract:
A mailbox post includes a movable joint, an elastic element connected to said post at two locations, one on each side of the joint, supportive against tension force between the two locations and connected to the post at a third location between the two locations, supportive against twisting force on the joint.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to post mounted mailbox assemblies, more particularly to an assembly that reduces the damaging effect on a mailbox and post supporting the mailbox from impact by a stick or other object applied with force against the mailbox. 
     2. Description of the Prior Art 
     Daily, mailboxes are damaged or destroyed by strikes from balls, snow, passing vehicles, vandals, sticks, or other impact sources. 
     The prior art is replete with patented designs for protecting a mailbox and mounting post from accidental or deliberate lateral force or strike against the mailbox or the post. 
     U.S. Pat. No. 5,207,377 patented May 4, 1993 by F. R. Brecht describes a mailbox container portion mounted on a bellows configured so that the upright mailbox will laterally deflect when struck by a physical object and maintain its deflected state until physically returned to the upright position. 
     U.S. Pat. No. 5,215,283 patented Jun. 1, 1993 by R. D. Gould describes a mailbox mounted on a lateral arm, offset from a tubular upper section mounted in a tubular lower section of an upright post for relative rotation about a vertical axis. A collar having an angled cam surface rotates the upper section about the vertical longitudinal axis between displaced and non-displaced positions under a normal bias of gravity. A spring attached to a transverse bolt or pin in the lower section and to a threaded follower on a vertically aligned threaded tensioning adjustment rod adds additional normal bias to the cam surface to bias the upper section toward the non-displaced position. An external spring is attached over the top of the upper section to the top of the rod and to the head of the transverse bolt. 
     U.S. Pat. No. 5,356,072 patented Oct. 18, 1994 by F. P. Thomas describes a mailbox shock mounted on a horizontal post by a plurality of anchor assemblies. Each of the plurality of anchor assemblies comprises a compression spring mounted between a side wall of the mailbox and the post on a horizontal core. The core comprises a tubular shank on a horizontal nail that passes through the sidewall of the mailbox and into the post. 
     U.S. Pat. No. 5,411,206 patented May 2, 1995 by Latham et al., describes an armor clad mailbox mounted on a horizontal arm configured so that it hangs below the arm and is rotatable about the axis of the arm. The arm is mounted on a two piece vertical pole, rotatable about the vertical axis of the pole. The vertical pole is tilted slightly from normal to the ground so that the horizontal arm will rotate back to the lowest position around the vertical axis. 
     SUMMARY OF THE INVENTION 
     It is one object of the invention to provide a mailbox that yields to lateral impact. 
     It is another object of the invention to provide a mailbox assembly that displaces from impact against the mailbox or support post from any direction about a vertical axis. 
     It is another object that the mailbox assembly automatically returns to its non-displaced position after it is displaced by impact. 
     A mailbox support includes a post, a foldable joint of the post upon which the post can fold away from the axis of the post, the foldable joint including a first face of the joint drawn toward a second face of the joint by an elastic element that is mounted in the post supportive against tensional force, passing through the first face and the second face. 
     A portion of the first face is connected to the elastic element and is configured for receiving torsion force from the elastic element for rotating the joint on the axis. The first face includes an opening configured to sufficiently fit the circumferential shape of the elastic element to receive torsion force from the elastic element for rotating the joint on the axis. 
     A portion of the second face is connected to the elastic element and is configured for receiving torsion force from the elastic element for rotating the joint on the axis. The second face is adjacent to the first face. 
     One of the first face and the second face includes a cam that rotates the face on the axis to a predetermined position on the other face when the two faces are drawn together. 
     A slot on one of the first face and the second face, and a protuberance on the other face is configured to be received by the slot when the first face is rotated on the axis relative to the second face. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the invention be more fully comprehended, it will now be described, by way of example, with reference to the accompanying drawings, in which: 
     FIG. 1 is a right side view of a mailbox on a post of the invention. 
     FIG. 2 is a top view of the mailbox, the joint of the post being shown in dotted line. The elastic element is not shown. 
     FIG. 3 is a rear view of the joint of the post, folded to a side. 
     FIG. 4 is a front view of the joint of the post, folded backward. 
     FIG. 5 is a front view of the joint of the post, folded backward slightly and rotated slightly. 
     FIG. 6 is a top view of a face of a joint of the invention, showing an elastic element in cross section. 
     FIG. 7 is a side view of another elastic element and joint of the invention. 
     FIG. 8 is a top view of the elastic element and joint of FIG. 7 taken along  8 — 8 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before explaining the invention in detail, it is to be understood that the invention is not limited in its application to the detail of construction and arrangement of parts illustrated in the drawings since the invention is capable of other embodiments and of being practiced or carried out in various ways. It is also to be understood that the phraseology or terminology employed is for the purpose of description only and not of limitation. 
     Referring to FIGS. 1 and 2, mailbox  24  includes door  26  and mail to go notification flag  32 . Mailbox  24  is mounted on post  28  which is fastened in ground  34 . The mailbox assembly has foldable joint  30  that is in about the upper ⅓ to ¼ portion of the regulation height of the mailbox from the ground. 
     Elastic  78  is stretchably mounted within post  28  by pins  36  and  38 . 
     The mailbox is aligned with axis  46 . Ball  48  is centered in groove  62 . 
     The mailbox can rotate  80  out of alignment with centerline  46  on vertical axis  70  on joint  30 . When the mailbox is rotated out of alignment with centerline  46 , groove  62  moves laterally away from ball  48 . 
     The mailbox will rotate when it is struck laterally in a direction adjacent to vertical axis  70 . 
     In FIG. 3, post  28  is folded over as a result of a blow to the mailbox along line  40  of FIG. 2 transverse to center line  46 . Center line  46  passes through ball  48  which is mounted on face  50  of joint  30 . Face  50  is generally normal to vertical axis  70  of post  28 . 
     Groove  62  in face  54  of joint  30  also coincides with center line  46  when face  54  is resting on face  50  and groove  62  receives ball  48 . 
     When the mailbox is struck, the mailbox and portion  68  of the post are thrown as one off from vertical axis  70 . 
     In FIG. 4, post  28  is folded over as a result of a blow to the mailbox along direction line  72  of FIG.  2 . Elastic element  78  is stretched when the faces  50  and  54  are moved apart by folding of the joint. The faces are pulled back together by elastic element  78  when it resiles, thus bringing post  28  in line with axis  70 . Elastic element  78  may be made of rubber, metal coil or other elastic material. 
     Referring to FIGS. 2-6, post portion  68  and the box rotate  80  when the mailbox is struck. Inward curving walls  96  of groove  62  move out of alignment with ball  48  in FIG.  5 . 
     Elastic  78  is non-circular as viewed in cross section. Central openings  84  and  88  inner walls  86  and  90  closely fit the cross section configuration of outer wall  92  of the elastic element, so that when it resiles it rotates the faces toward alignment with center line  46 . An elastic of large diameter  98  and high resilient force brings the mailbox into alignment with axis  70 . Vibration at joint  30  during movement to alignment helps overcome friction between faces  50  and  54 . Under the clamping together force of the elastic element the inward curving walls  96  of groove  62  align the groove with ball  48 , which brings groove  62  in alignment with center line  46 . Thus mailbox  24  returns into alignment with center line  46 . 
     An elastic  78  made of neoprene rubber having a durometer hardness “Shore A” 60 hardness about between tire thread and shoe heel, 1″ by 1″ square cross section will rotate a 3-6 pound mailbox assembly  102 , with mail contained, by rotational torque it applies to inner walls it contacts of openings  84  and  88  into close alignment with centerline  46  so that the mailbox is aligned for its functional use. An approximately three foot length of elastic provides sufficient stretch for the fold. Various changes may be made in materials and dimensions without departing from the spirit and scope of the invention. 
     Elastic element  78  is fastened at two spaced apart  76  fasteners  36  and  38  supportive against tension force between the fasteners and is confined at two longitudinally adjacent or close together inner walls  86  and  90  supportive against torsion or twisting force between inner walls  86  and  90 , between fastener pins  36  and  38 . 
     Referring to FIGS. 7 &amp; 8, elastic element  110  is made of spring wire. It is square in cross section and is attached to a mailbox post by spaced apart eyelets  114  and  116  respectively above and below rotatable, foldable, joint  120  so that elastic element  110  extends longitudinally under tension force. The non circular outer wall  124  of elastic element  110  is contacted by the inner walls  126  and  128  respectively of openings  134  and  136  in adjacent generally parallel faces  140  and  142  of plates  144 ,  146  so that the elastic element is twisted by the contact with walls  126  and  128  when one plate is rotated about the elastic element with respect to the other plate. 
     Although the present invention has been described with respect to details of certain embodiments thereof, it is not intended that such details be limitations upon the scope of the invention. It will be obvious to those skilled in the art that various modifications and substitutions may be made without departing from the spirit and scope of the invention as set forth in the following claims.