Abstract:
The invention is a guard for preventing the vandalism of a pay telephone keypad. Additionally, the invention prevents access to a pay telephone coin vault through the keypad. The inventive guard includes a plurality of attachment points. The attachment points have a shoulder raised above the exterior surface of the inventive guard. When a fastener is inserted through the attachment point, the head of the fastener will be flush or inset with respect to the top surface of the shoulder, thereby preventing leveraging against the fastener head. Additionally, a de minimus gap formed between the perimeter of the fastener head and the inner wall of the shoulder prevents insertion of a prying instrument.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Not Applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not Applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates generally to a guard that prevents the destruction and vandalism of the keypad of a pay telephone. Specifically, this invention is a keypad guard that prevents a potential vandal from damaging the pay telephone keypad and from gaining access to the pay telephone vault.  
         [0005]     Pay telephones are typically installed in isolated, unprotected locations. Over a prolonged period of time, an amount of coin money is retained within the vault of a pay telephone. Consequently, pay telephones are the subject of frequent vandalism attempts.  
         [0006]     Vandals use a variety of means to gain access to the pay telephone vault, including smashing through the pay telephone keypad or drilling through the telephone housing. The pay telephone keypad is typically positioned directly above the open-top coin vault drawer. Consequently, vandals smash through the telephone keypad in order to gain access to the pay telephone vault. Alternatively, vandals may attempt to drill through the pay telephone upper housing in order to gain access to the coin vault. The present invention is directed to preventing vandalism to the telephone keypad and preventing access to money in the pay telephone coin vault by protecting the keypad assembly. Additionally, the present invention increases security to the pay telephone by providing armor protection to the pay telephone upper housing, thereby preventing drilling of the pay telephone upper housing.  
         [0007]     Pay telephones are also the subject of frequent abuse. In addition to vandals, customers may become angry and hit the keypad. If repeated, excessive force is applied to the keypad pushbuttons, the internal springs may become damaged and ultimately inoperative. Therefore, the present invention is also directed to preventing excessive force from being applied to the keypad, thereby protecting the functionality of the pushbuttons.  
         [0008]     2. Description of the Related Art  
         [0009]     Several inventions to prevent vandalism and destruction of pay telephone keypads are known to the art. This includes single piece face plates. Prior art faceplates have typically been of light metal or heavy plastic, which affords minimal protection. Other prior art replaces the pay telephone upper housing with a stronger, more intimidating shield. Because the shield serves as a replacement for the upper housing, extensive retrofitting is required.  
         [0010]     U.S. Des. Pat. No. D353,137 issued to DeArkland on Dec. 6, 1994 discloses a face panel for a payphone. The panel comprises a faceplate with openings for the individual keys, the coin insertion slot, information signs, the coin return lever, the coin vault, etc. The faceplate is for ornamentation only and does not provide security against vandalism.  
         [0011]     U.S. Pat. No. 5,134,654 issued to McGough on Jul. 28, 1992 discloses an upper housing shield for a payphone comprising a thick metal plate formed to a “U” shape to wrap around existing payphones. Holes are formed into the housing for the lock, handset cord, coin slot, coin instruction plate, coin release mechanism, etc. The housing shield replaces the standard faceplate on a pay telephone and is attached to the payphone by welding. Thus, McGough requires retrofitting existing pay telephones by completely removing the preexisting upper housing and welding the new housing shield to the preexisting lower housing. This process is exceedingly difficult to complete in the field.  
         [0012]     U.S. Pat. No. 6,317,496 issued to White et al. on Nov. 13, 2001 discloses a guard for preventing the vandalism of a telephone. The guard is composed of an upper housing guard and keypad guard. The keypad guard is secured to the upper housing guard by high strength, visible fasteners. The upper housing guard is secured to the pay telephone&#39;s upper housing by an attachment means known in the art, such as welding or with bolts in conjunction with countersunk holes. Welding the guard can be difficult on existing pay telephones. Additionally, use of countersunk holes reduces the overall strength of the guard by providing a weakened point in the guard due to the decreased thickness of the metal at the countersunk hole.  
         [0013]     U.S. Pat. No. 4,160,136 issued to McGough on Jul. 3, 1979 discloses an anti-vandalism device for coin telephones. The invention includes a cover having a plurality of apertures, and a base having a plurality of cavities. Pushbuttons extend from the base through the cavities and finally through the,apertures. The pushbuttons are L-shaped, and a flange, interposed between the pushbuttons and the base, prevents the pushbuttons from being fully depressed, thereby alleviating any stress on the spring. The pushbuttons are adapted to replace the standard pushbuttons of a typical keypad.  
         [0014]     It would thus be beneficial to the prior art to provide a pay telephone keypad guard that deters a vandal from damaging the telephone keypad. It would further be beneficial to prevent a vandal from destructively removing the keypad to gain access to the money in the pay telephone coin vault. It would further be beneficial to protect the upper housing of the pay telephone. It would further be beneficial to provide a pay telephone keypad guard that is relatively inexpensive, simple to manufacture, and has a secure exterior appearance. Moreover, it would be beneficial that the pay telephone keypad guard be installed quickly and easily and require little retrofitting to the pay telephone.  
       BRIEF SUMMARY OF THE INVENTION  
       [0015]     Accordingly, it is an object of the present invention to provide a new and improved telephone keypad guard that: 
        Protects the telephone keypad from striking blows or other vandalism;     Prevents a vandal from destructively removing the keypad to gain access to money in the coin vault;     Protects the upper housing from drilling or other vandalism;     Is relatively inexpensive and simple to manufacture;     Requires little retrofitting to the pay telephone; and     Can be installed easily and quickly.        
 
         [0022]     To achieve such improvements, the present invention is a pay telephone keypad guard that prevents vandalism of the pay telephone keypad. The objectives are accomplished by the structure and method of installation of the inventive keypad guard.  
         [0023]     A critical feature of the keypad guard is its thickness, which reinforces the strength of the upper housing and protects the functionality of the keypad when struck by excessive force. The thickness of the invention provides reinforced strength to the guard, preventing striking blows from destroying the pay telephone upper housing. Additionally, the keypad guard is installed on top of the existing faceplate of the pay telephone, which increases the overall thickness.  
         [0024]     A further critical feature of the vault guard is the construction of the keypad guard, which surrounds the non-mounting sides of the pay telephone, and which, by virtue of raised shoulders surrounding the attachment points, prevents the application of a tortion about the attachment means.  
         [0025]     A further critical feature of the invention is the use of impact rivets, or equivalent single-use attachment means. The impact rivets may be applied entirely externally, thereby avoiding the need to disassemble, even partly, the pay telephone.  
         [0026]     A further critical feature of the keypad guard is the attachment passages. The attachment passages are configured to prevent a vandal from gaining the leverage necessary to pry off the fasteners used to attach the keypad guard to the pay telephone upper housing.  
         [0027]     Other objects of the invention will become apparent from time to time throughout the specification hereinafter disclosed. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]      FIG. 1  is an explosion view of the preferred embodiment and a pay telephone.  
         [0029]      FIG. 2  is a perspective view of the preferred embodiment of the invention.  
         [0030]      FIG. 3  is an isometric view of the second side plate. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0031]     The keypad guard is shown generally in  FIGS. 1-3  as keypad guard  100 .  
         [0032]      FIG. 1  illustrates keypad guard  100  attached to pay telephone  600 . The attachment portion of keypad guard  100  is generally C-shaped and has internal dimensions nearly identical, absent tolerances, as the exterior surface of pay telephone upper housing  610 , such that keypad guard  100  is superposed about pay telephone upper housing  610 . Keypad guard  100  is preferably high strength metal, with sufficient strength and thickness to protect against drilling and heavy striking blows from vandals.  
         [0033]     Keypad guard  100  includes a plurality of component openings  124 , which permit access to common functional components of pay telephone  600 . Common functional components include handset cradle  650 , dialing information panel  660 , advertisement  665 , coin slot  680 , coin return lever  670 , handset cord  690 , etc, seen in  FIG. 1 . Keypad guard  100  also includes a plurality of push button cavities  126 , typically twelve in number, aligned in four rows of three each. Push button cavities  126  align with and receive a plurality of keypad push buttons  632 .  
         [0034]     Keypad guard  100  is shown separately in  FIG. 2 . Keypad guard  100  is formed by face plate  120 , first side plate  140 , and second side plate  160 . Face plate  120 , first side plate  140  and second side plate  160  are of high strength and uniform thickness. First side plate  140  is joined rearwardly perpendicular to face plate  120  at junction  150 , forming longitudinal edge  152 . Second side plate  130  is likewise joined rearwardly perpendicular to face plate  110  at junction  170 , forming longitudinal edge  172 . Junctions  150  and  170  may be formed by welding or by bending of a single metal plate. Longitudinal edges  152  and  172  may be beveled with respect to first side plate  140  and face plate  120  and with respect to second side plate  160  and face plate  120 , respectively. Beveling of longitudinal edges  152  and  172  permits keypad guard  100  to contour to the exterior of pay telephone upper housing  610 , reducing potential space between keypad guard  100  and pay telephone upper housing  610 , which may be used as a point of leverage. Alternatively, junctions  150  and  170  may be radiused to reduce potential space.  
         [0035]     Keypad guard  100  is preferably high strength metal, with sufficient strength and thickness to protect against heavy striking blows from vandals. Keypad guard  100  should be sufficiently thick to prevent damage to pushbuttons  632  when heavy blows depress pushbuttons  632 . Each pushbutton  632  of the keypad  630  has a throw distance (not shown), defined as the distance required to depress the keypad push button until an associated electrical switch is engaged, thus completing the electrical circuit signaling the entry of the number or function associated with the keypad pushbutton  632 . In the present invention, the thickness of the keypad guard  100  is such that the keypad pushbutton  632  is inset with respect to the surface plane of face plate  120  after keypad pushbutton  632  traverses the throw distance. This prevents damage to the keypad push buttons  632  and their associated electrical switches when struck by excessive force.  
         [0036]     Keypad guard  100  provides protection for keypad  630  through the mating of keypad guard  100  to pay telephone upper housing  610 . As seen in  FIG. 1 , pay telephone upper housing  610  includes face member  612 , first side wall  614 , and second side wall  616 . Keypad guard  100  is properly aligned and superposed about pay telephone upper housing  610 .  
         [0037]     Keypad guard  100  is secured to upper housing  610  through a plurality of attachment receivers  200 . Referring to  FIG. 2 , two attachment receivers  200  are located on first side plate  140 . Similarly, two attachment receivers  200  are located on second side plate  160 .  
         [0038]     As seen in  FIG. 2 , attachment receiver  200  is comprised of receiver rim  210 , receiver base  212 , and bolt hole  220 . Bolt hole  220  provides communication between keypad guard  100  and pay telephone upper housing  610 . Receiver base  212  is at least the same thickness as first side plate  140 , second side plate  160 , and face plate  120 . Bolt hole  220  extends through receiver base  212 . Receiver rim  210  is concentric with bolt hole  220 . As shown in  FIG. 3 , receiver rim  210  is raised a rim distance  211  above receiver base  212 . Rim distance  211  is of sufficient height such that it alters the leverage point of a pry bar (not shown), preventing a vandal from prying off attachment bolt  240 .  
         [0039]     Referring to  FIGS. 2-3 , receiver rim  210  has inner diameter  214  and outer diameter  216 , with inner diameter  214  larger than bolt hole diameter  222 . Attachment bolt  240  may be used to fasten keypad guard  100  to upper housing  610 . Attachment bolt  240  may be a rivet, or other similar securing means. Referring to  FIG. 3 , attachment bolt  240  comprises bolt head  242  and bolt shaft  244 . Bolt head  242  has a -bolt head diameter  241  sized to fit within inner diameter  214 . Bolt shaft  244  is partitioned into a plurality of shaft fingers  246 , which are positioned about shaft axis member  248 . Shaft axis member  248  communicates with bolt tip  243 , such that when force is applied to bolt tip  243 , bolt tip  243  and shaft axis member  248  are projected forward, causing shaft fingers  246  to expand radially, thus mushrooming within pay telephone upper housing  610 . Alternatively, any externally-applied connector, such as a moly bolt with a detactable head, may be used so long as once applied, no point of leverage exists.  
         [0040]     Referring to  FIG. 3 , after attachment bolt  240  is forcibly driven through bolt hole  220 , the resulting space between inner diameter  214  and bolt head  242  is bolt gap  250 . Bolt gap  250  should be less than one millimeter, such that it prevents the insertion of a pry bar or similar tool between inner diameter  214  and bolt head  242 . Preventing insertion of a pry bar greatly decreases the ability of removing attachment bolt  240 . When attachment bolt  240  is forcibly driven through bolt hole  220 , bolt head tip  243  can be inset, flush, or outset with respect to receiver rim  210 . Rim distance  211  must be sufficient to eliminate the prying surface created by the base of bolt head  242 . Therefore, in the preferred embodiment, rim distance  211  is at least one-half of bolt head height  245 . Once attachment bolt  240  is properly installed, bolt head  242  should have no wrenching surfaces.  
         [0041]     Bolt head  242  may also be of any shape, so long as bolt gap  250  is less than 1 millimeter and rim distance  211  is at least one-half of bolt head height  245 . Attachment bolt  240  should be of high strength and remain externally visible to convey an appearance of structural substance in order to deter vandalism.  
         [0042]     In practice, housing holes  620  are drilled into first side wall  614  and second side wall  616  of upper housing  610 , as seen in  FIG. 1 . Housing hole  620  has housing hole diameter  622  that is substantially similar in diameter to bolt hole diameter  222 . Additionally, housing holes  620  are aligned with bolt holes  220 . Bolt shaft  244  is sized to be received within bolt hole  220  and housing hole  620 . When attachment bolt  240 , bolt hole  220 , and housing hole  620  are aligned, force is exerted onto bolt head  242  and bolt head tip  243 , thereby thrusting bolt shaft  244  through bolt hole  220  and housing hole  620 , thereby joining keypad guard  100  and pay telephone upper housing  610 . This method of installation allows keypad guard  100  to be quickly and easily secured to pay telephone upper housing  610  without necessitating removal of parts. Additionally, the installation method permits installation of the keypad guard  100  onto a pay telephone  600  already existing in the field.  
         [0043]     The foregoing description of the invention illustrates a preferred embodiment thereof. Various changes may be made in the details of the illustrated construction within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the claims and their equivalents.