Abstract:
A wall door stop includes a pin extending from the wall-facing surface. When installed on a wall exterior, the wall door stop may be attached by a regular or security screw to the wall. The pin engages a mating hole in the wall and inhibits unauthorized removal of the wall door stop through rotation and simultaneous pulling of the decorative ring. The pin engages the wall to prevent rotation of the decorative ring.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a wall-mounted door-stop. 
     BACKGROUND OF THE INVENTION 
     Wall door-stops also called wall bumpers are an economical method to stop the swing of a door in order to protect both the wall behind the door and the door with its associated hardware. Wall bumpers are frequently favored by architects to eliminate the tripping hazard associated with a floor mounted stop as well. A wall bumper simply includes a compliant (i.e., rubber-like) bumper component that is attached to the wall where the door knob or lever would contact the wall in the bumper&#39;s absence. Its use prevents damage to the wall and/or the door knob. For aesthetic reasons, a metal ring is usually captured between the compliant bumper component and the wall. 
     The wall bumper is typically held in place with a single threaded attachment device such as a screw or anchor bolt, which is concealed upon installation within the compliant bumper component. This mechanism serves adequately as a permanent attachment for incidental wear and tear. Unfortunately, unauthorized removal of the attachment device is easily possible by grasping the decorative metal ring that surrounds the compliant bumper component, and rotating the metal ring counter-clockwise while pulling the metal ring away from the wall. For this reason, wall bumpers are not favored in schools, prisons, and other facilities that may be exposed to a hostile clinentèle prone to casual malicious mischief out of boredom or other nonconstructive motives. Consequently, such an economical device to prevent damage to walls from door handles has been precluded from use in such facilities without a mechanism to inhibit vandalism by deliberate removal of the wall bumper. 
     SUMMARY OF THE INVENTION 
     A wall door stop includes a pin extending from the wall-facing surface. When installed on a wall exterior, the wall door stop may be attached by a regular or security screw to the wall. The pin engages a mating hole in the wall and inhibits unauthorized removal of the wall door stop through rotation and simultaneous pulling of the decorative ring. The pin engages the wall to prevent rotation of the decorative ring. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES 
     FIG. 1 is a cross-sectional side-view diagram of a wall bumper according to a presently preferred embodiment of the present invention. 
     FIG. 2 is a bottom-view diagram of a wall bumper according to a presently preferred embodiment of the present invention. 
     FIG. 3A is an isometric-view diagram of a wall bumper with an annular bumper component according to a presently preferred embodiment of the present invention. 
     FIG. 3B is an isometric-view diagram of a wall bumper with a dome bumper component according to a presently preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Those of ordinary skill in the art will realize that the following description of the present invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons after a perusal of the within disclosure. 
     The present invention is a device to obstruct removal of an installed wall-bumper. The “vandal-resistant” wall bumper incorporates a pin extending from the wall-facing surface of a frame such as a decorative ring of the bumper. This pin eliminates the ability of a mischievous person to simultaneously pull and rotate the decorative ring so as to thereby remove the wall bumper from the wall without authorization. The pin accomplishes this task in conjunction with the wall fastener by providing a structure sufficiently distant from the center of rotation so as to accept a much larger torsional moment between the wall bumper and the wall without appreciable movement. 
     A cross-sectional side-view of the present invention can be seen in FIG.  1 . The wall bumper  10  preferably includes an impactable protrusion such as a compliant bumper component  12 , a decorative ring  14 , a wall fastener such as a threaded security screw  16  with a lead shield  18  when installed, and an underside pin  20  extending from the wall-facing surface of the decorative ring  14  to inhibit rotation. The compliant bumper component  12 , composed primarily of an elastically deformable material such as rubber or an equivalent material, may have a rounded outer annulus  22  for receiving the compressive impact from a door handle slamming against it, a mesial aperture  24 , an inner interface surface  26 , a base plug  28 , and a rigid washer  30 . Such a compliant bumper component  12  as described features a concave shape. Alternatively, the compliant bumper component  12  may have an outer dome featuring a convex shape for receiving the compressive impact from a door handle. When prevention of unauthorized “thumb-turn” of the knob on the door handle is an objective, a concave shape for the compliant bumper component may be preferred. Otherwise, a convex shape may be selected. 
     The decorative ring  14 , designed to protect the compliant bumper component  12  from shear and tensile deformation, has an outer surface  32  that is typically polished or painted and includes an outer interface surface  34 , a ring opening with a radial interface surface  36 , and a wall-facing surface  38  which faces the wall on which the wall bumper is attached. A cavity region  40  may also be included in the decorative ring  14  inside the wall-facing surface  38  as a weight-reduction measure. 
     The security screw  16  preferably comprises a head  42  and a threaded shaft  44 . The security screw  16  is passed through the mesial aperture  24  of the compliant bumper component  12  through the axis centerline  46  of the wall bumper  10  and may be driven into the wall through a wall aperture by means of an installation tool applied to the head  42 . As an additional security measure, the head  42  may be configured to apply torsional force in only one direction, such as clockwise for insertion into the wall aperture so as to preclude removal with a similar instrument to the installation tool. A security screw  16  is preferably inserted through the mesial aperture  24  of the compliant bumper component  12  and into a wall from the wall&#39;s outside surface  48  through an aperture in the wall. At the wall&#39;s interior surface  50  is preferably disposed a lead shield  18  or other type of conventional expansion anchor through which the security screw  16  is inserted into the wall aperture. 
     Alternatives to a security screw  16  with a lead shield  18  include use of an anchor bolt, a toggle bolt, a lag screw as well as other known fasteners. An anchor bolt has a sleeve which increases in diameter and decreases in length against the wall&#39;s interior surface  50  as the anchor bolt is turned clockwise. A toggle bolt has at least one pivotal flap that folds against the bolt shaft when inserted into the wall aperture, and pivots to present a profile larger than the wall aperture upon passing the wall&#39;s interior surface  50 . A lag screw uses a lag shield that inserts into a wall to frictionally resist removal of the lag screw through the wall aperture. The wall-mounted door stop  10  may be sold or distributed separately from the security screw  16  or other attachment mechanisms. Other means of attaching a wall bumper to a shear resistant wall will also be readily apparent to those skilled in the art. 
     The mesial aperture  24  deformably expands to receive the mounting screw such as a security screw  16 . The base plug  28  inserts into the ring opening while in contact with the radial interface surface  36 . The rigid washer  30  inhibits lateral motion between the compliant bumper component  12  and the security screw  16 . The compliant bumper component  12  restricts the movement of decorative ring  14  from moving away from the wall by the bumper&#39;s inner interface surface  26  and the ring&#39;s outer interface surface  34 . 
     A pin  20  is rigidly disposed on the decorative ring  14  on the wall-facing surface  38  and, as shown in FIG. 1, may be independent of the compliant bumper component  12 . The pin  20  is inserted into a hole in the wall that is created when the wall bumper  10  is installed on the wall outside surface  48 . As the security screw  16  is turned clockwise along the axis centerline  46 , the lead shield  18  is tightened against the wall&#39;s interior surface  50 , inhibiting nontorsional motion of the wall bumper  10  in the direction of the axis centerline  46 . When the wall bumper  10  is attached at the wall outside surface  48  by the security screw  16 , the pin  20  seated in its corresponding hole in the wall prevents the decorative ring  14  from being rotated along the axis centerline  46 . In the absence of the pin  20 , a miscreant may simultaneously apply sufficient torque to the decorative ring  14  and tension to the security screw in order to retract the wall bumper  10  from the wall. With the pin  20  embedded within a wall, the torque necessary to shear off the pin  20  is quite high. Thus, the miscreant may be prevented from removing the wall bumper  10  without appropriate tools. 
     A bottom view of the wall bumper is shown in FIG. 2, clearly showing the antirotational impediment for turning the decorative ring  14  when the pin  20 , engaged in the wall hole, presents a moment-resistance far in excess of the torsional resistance presented by the security screw  16  alone. Additional resistance may be available with the use of additional pins  20  disposed on the wall-facing surface  38  of the decorative ring  14 . While a pin  20  may appear at first to be a simple device for addressing the problem described above, a cost-effective solution has been unavailable until the present invention. 
     Isometric views of the wall bumper according to the present invention may be seen in FIGS. 3A and 3B. The wall bumper  10  featuring the concave outer annulus as the compliant bumper component  12 ′ is depicted in FIG.  3 A. The wall bumper  10  featuring the convex outer dome as the compliant bumper component  12 ″ is depicted in FIG.  3 B. Other items of the wall bumper  10  are also featured in FIGS. 3A and 3B such as the decorative ring  14  and the pin  20  on the wall-facing surface of the decorative ring  14 . Since the convex outer dome may lack an aperture to receive the wall fastener, the frame may as an alternative feature an aperture for this purpose to enable securing the wall bumper to the wall. 
     As manufactured, the pin  20  may be inserted during the production of the decorative ring  14 , which may be formed by casting and polishing. A decorative ring  14  about 2¼ inches in diameter might employ a pin  20  extending beyond the wall-facing surface  38  by a length of {fraction (3/16)} inch plus or minus {fraction (1/16)} inch (alternately between ⅛ inch and ¼ inch) with a diameter of about {fraction (1/16)} inch. Such dimensions enable a pin  20  to possess sufficient shear strength to resist unaided human-applied torsion and be sufficiently small to minimize packaging and installation complications. 
     While embodiments and applications of the invention have been shown and described, it would be apparent to those of ordinary skill in the art, after a perusal of the within disclosure, that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.