Abstract:
A pedestrian push button that discourages vandals and resists weather-related damage. The plunger is contained in a sleek, solid housing formed by a cup-shaped front cover that overlaps and substantially encloses a shallower, cup-shaped body, to protect the electrical components inside. The body is attachable from the inside to the traffic pole or other support surface, and the cover engages the body by means of a “twist-lock” connection that is hidden from view in the installed device. This reduces the appeal of the push button to vandals while at the same time making it easier for authorized personnel to open the housing for service and repair. The back of the body is contoured to conform to both flat and curved support surfaces, making the push button easy to mount securely regardless of the shape of the support surface.

Description:
This application claims the benefit of provisional application Ser. No. 60/916,343, filed May 7, 2007, entitled “Pedestrian Push Button,” the contents of which are incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention relates generally to pedestrian push buttons for traffic control devices. 
   BACKGROUND OF THE INVENTION 
   Push buttons are commonly used in high traffic areas to control traffic lights for pedestrians crossing the roadways. These buttons typically are placed about chest high on the pole supporting the light or other traffic device being controlled. Because of their position on the pole, the push button is a common target for vandals and mischievous youngsters. In addition, the button is continuously exposed to the elements, making the electrical components contained in the button housing susceptible to damage from rain and salt spray, especially in coastal areas and tropical climates. Thus, there is a need for a push button that is less inviting to vandals and this more resistant to the elements. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an intersection with a pedestrian crosswalk equipped with a traffic light and WALK and DON&#39;T WALK lights that are controlled by a push button constructed in accordance with the present invention. 
       FIG. 2  is an enlarged, fragmented perspective view of the traffic pole showing the push button installed thereon. 
       FIG. 3  is a frontal perspective view of the push button. 
       FIG. 4  is a rear perspective view of the push button. 
       FIG. 5  is a frontal perspective view of the inside of the body of the housing. 
       FIG. 6  is a rear perspective view of the inside of the cover of the housing. 
       FIG. 7  is a longitudinal sectional view of the cover of the housing. 
       FIG. 8  is a longitudinal sectional view of the plunger. 
       FIG. 9  is a longitudinal perspective, sectional view of the assembled push button. 
       FIG. 10  is an exploded view of the push button. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Turning now to the drawings in general and to  FIG. 1  in particular, there is shown therein a pedestrian push button constructed in accordance with a preferred embodiment of the present invention and designated generally by the reference numeral  10 . The push button  10  is shown installed on the side of a traffic pole  12  at a crosswalk  14 . 
   In the embodiment shown, the push button  10  controls a WALK-DON&#39;T WALK sign  16  supported on the pole  12  beneath a traffic signal light  18 . However, the push button  10  of this invention may be used to activate or control any traffic control device. As used herein, “traffic control device” includes traffic signals, lights, signs and other devices for controlling the direction, flow and safety of vehicular (motorized and non-motorized) and pedestrian traffic. 
   As best shown in  FIG. 2 , in the illustrated embodiment, the support surface on which the push button  10  is mounted is the side of the traffic pole  12 . However, the push button  10  may attached to a variety of other support surfaces, such as the flat side of a traffic control cabinet, a pedestal pole, the wall of nearby building or a retaining wall, or a wooden electrical poles. 
   With reference now to  FIGS. 3 and 4 , the push button  10  comprises a housing  22  for supporting the plunger  24  and internal components yet to be described. Preferably, the housing  22  comprises a body  28  and a cover  30 . 
   Referring now also to  FIG. 5 , the body  28  comprises a rear panel  34  and a generally cylindrical side wall  36  extending forward of the rear panel and terminating in an open front end  38 . The rear panel  34  is connectable to the traffic pole  12  ( FIGS. 1 &amp; 2 ) or other support surface from inside the side wall  36 . For this purpose, the rear panel  34  may be provided with one or more holes for use with suitable connectors. For example, the rear panel  34  has two oval bolt holes  40  and  42 , and the push button  10  may or not include a set of bolts (not shown) for connecting the body  28  to the pole  12 . For mounting on surfaces which contain no wiring conduit, an adapter plate (not shown) may be interposed between the rear panel  34  and the mounting surface. 
   Referring still to  FIGS. 4 and 5 , the rear panel  34  preferably includes a wire opening  46  through the internal electrical components described below may be connected to the wiring in the pole  12 . More preferably, the rear panel  34  comprises a tubular extension  48  extending outwardly or rearwardly from the back of the rear panel. This tubular extension  48  will serve as a cable or wire guide during installation of the push button  10 . 
   As used herein, “forward” and “forwardly” and “frontal” refer to the end of the housing  22  supporting the plunger  24  and farthest from the traffic pole  12 . “Rearward,” “rearwardly,” and “back” refer the opposite end of the housing  22  nearest the pole  12  or other support surface. “Inward” and “inwardly” refers to the inside of the housing  22 , and “outward” and “outwardly” refer to the outside the housing. 
   For a reason that will become apparent, at least one and preferably a plurality of projections or lugs  50  are formed on the outer surface  52  of the side wall  36  of the body  28 . In the embodiment shown three lugs, which are designated collectively by the reference numeral  50 , are spaced around the side wall  36 . 
   Referring still to  FIGS. 3 and 4  and now also to  FIGS. 6 and 7 , the cover  30  will be further described. The cover  30  comprises a front face  54  and a side wall  56  that extends rearwardly from the front face and terminates in an open rear end  58 . In its preferred form, the side wall  56  is generally cylindrical and substantially solid. As used herein, “substantially solid” denotes a smooth, seamless side wall uninterrupted by visible openings for connectors, such as screws or bolts, commonly used to attach pedestrian push button devices. 
   More preferably, the side wall  56  is integrally formed, as by machining or molding, from a solid piece of material. In the embodiment shown, the only interruption in the integrity of the side wall  56  is a small opening  60  for a set screw  62  ( FIG. 4 ), which is positioned to be on the bottom of the housing  22  in the assembled device. Most preferably, the face  54  and the side wall  56  are together integrally formed and substantially solid (except to the opening for the plunger  24 ). Such a “connector-free” appearance reduces the likelihood that pranksters or vandals will attempt to disassemble the device. 
   The side wall  56  of the cover  30  is sized and shaped to receive the open front end  38  of the side wall  36  of the body  28  in a telescoping fashion. Provided on the inside surface  64  of the side wall  56  are lug-receiving recesses, such as the grooves  66 . The number of grooves  66 , which in this embodiment is three, preferably corresponds to the number of lugs  50  on the outer surface  52  of the side wall  36  of the body  28 . 
   The grooves  66  are sized to snugly receive the lugs  50 . More particularly, as best seen in  FIG. 7 , each of the grooves  66  includes an open portion  70  and a terminal portion  72 . The open portion  70  is continuous with the open rear end  58  of the cover  30  and extends generally longitudinally, that is, in a directional generally parallel to the long axis of the cover  30 . The terminal portion  72  is a closed-ended groove that extends a distance circumferentially from the open portion  70 , thereby forming an L-shaped groove. Though the lug-receiving recesses could take the form of slots that extend entirely through the side wall  56  of the cover  30 , the grooved form is preferred for reasons that will become apparent. 
   As best seen in  FIG. 6 , a pair of internally threaded screw bores  68  are formed on the inside of the front face  54  of the cover  30 . These bores  68  serve as an attachment point for mounting the switch assembly yet to be described. 
   The open portions  70  are positioned around the open rear end  58  so that the lugs  50  can be aligned with them. Once the lugs  50  are aligned, the cover  30  can be advanced further over the body  28  until the lugs abut the end of the open portions  70 . At this point, the cover  30  can be rotated about a quarter-turn on the body  28  so that the lugs  50  slide to the blind ends of the terminal portions  72 . Thus, the side wall  36  of the body  28  and the side wall  56  of the cover  30  are cooperatively configured to form a twist lock engagement therebetween. 
   Moreover, since the grooves  66  do not extend through the side wall  56  of the cover  30 , once the cover is connected to the body  28 , both the grooves  66  and the lugs  50  are hidden in the assembled push button  10 , as is best illustrated in  FIG. 3 . Though, the open portions  70  of the grooves  66  are visible from the back of the push button  10  ( FIG. 4 ), these are not readily visible when the push button is attached to the pole  12  or other supporting surface, as seen in  FIG. 2 . For this reason, in most instances, it will be desirable to size the side wall  56  of the cover  30  so that, when the push button  10  is assembled, the side wall of the cover will substantially cover or overlap the side wall  36  of the body  28 ; this will place the open rear end  58  as near as possible to the pole  12  or other mounting surface. 
   In the embodiment shown and described herein, the lugs  50  are formed on the outer surface  52  of the side wall  36  of the body  28 , and the grooves  66  are formed on the inside surface  64  of the side wall  56  of the cover  30 . It will be appreciated that the placement of these elements could be reversed, that is, the lugs or projections  50  could be placed on the inside  64  of the cover  30  and the recesses  66  formed on the outer surface  52  of the body&#39;s side wall  36 . The present invention contemplates either arrangement. 
   Also formed on the inside of the front face  54  of the cover  30  are internally threaded bores  68  for receiving screws that attach a mounting plate to be described later. 
   Returning to  FIG. 4 , yet another feature of the present invention is shown. The rear panel  34  of the body  28  may be shaped to conform to the shape of the intended support surface. Thus, where the intended support surface is the side of a traffic pole  12 , which is curved ( FIG. 2 ), the rear panel  34  preferably has a first section  76  that is curved. Alternately, the push button  10  may be mounted on a flat panel of some sort, in which case it is advantageous to provide the rear panel  34  with a flat surface, such as the second flat section  78 . 
   Most preferably, the rear panel  34  is provided with both shapes, that is, with both a curved section  76  and a flat section  78  in a manner that permits the rear panel to conform alternately to either support surface, as in the preferred embodiment. To use the flat section  78 , the body  28  would be positioned as shown in  FIG. 4 , with the holes  40  aligned horizontally. To use the curved section  76 , the body  28  would be rotated about 90 degrees from the position shown in  FIG. 4 , so that the holes  40  are aligned vertically. 
   With continuous reference to  FIGS. 3 ,  6 , and  7 , and turning also to  FIGS. 9 and 10 , a preferred switch assembly  84  will be explained. The switch assembly  84  is operable between an ON position and an OFF position. The switch assembly  84  is operatively connectable to the WALK—DON&#39;T WALK signs  16  or the signal  18 , or both, or other traffic control devices, so that in the ON position the switch activates the traffic control devices, and so that in OFF position the switch does not activate the devices. In most instances, the switch assembly  84  will be biased in the OFF position. In this way, the traffic control devices will be affected only when a pedestrian is present at the crosswalk  14  to operate the push button  10  manually. 
   The type of switch mechanism may vary. For example, in some instances, a piezoelectric element may be employed. However, in a presently preferred embodiment, best seen in  FIGS. 9 and 10 , the preferred switch assembly  84  comprises a switch  86  usually including a movable member or button  88 , which will close the circuit (not shown) when pressed. As shown, the switch housing  86  is mounted on the inside of the cover  30  so that operation of the plunger  24  will press the switch button  88 , in a manner set for the hereinafter in more detail. 
   A terminal block  90  usually also is included for electrically connecting the pushbutton  10  to the supply wires, although wire nuts can be used instead. The terminal block  90  is conveniently attached by screws  92  or in any suitable manner to the rear panel  34  of the body  28  or in any appropriate location inside the body. During installation, the lead wires (not shown) from the switch housing  86  are connected to the terminal block  90 , as described elsewhere. 
   The preferred configuration and mounting of the plunger  24 , identified earlier, now will be described. The plunger  24  is mounted in the housing  22  for movement between a resting position and a pressed position. As seen in  FIG. 8 , the plunger  24  generally comprises a domed or disk-shaped head  94  and a switch-engaging member, such as the stem  96 , extending rearwardly from the head. 
   The front face  54  of the cover  30  defines a plunger recess  100 , which varies with the shape and type of push button  24  that is utilized. As best seen in  FIGS. 8-10 , the plunger recess  100  preferably comprises an annular shelf  102  surrounding a plunger opening  104  that is continuous with a tubular shaft  106  extending rearwardly of the face  54 . The plunger recess  100  is shaped to receive the plunger  24 . More specifically, the annular shelf  102  is sized to receive the disk-shaped head  94  of the plunger  24 , and the tubular shaft  106  is sized to receive the stem  96 . In this way, the plunger  24  is movably mounted in the face  54 . 
   To prevent the plunger  24  from being pulled completely out of the housing  22 , the stem  96  is provided with an internally threaded blind bore  110  to receive a bolt  112 , which captures a washer  114  therebetween. The bolt and washer  112  and  114  engage the end of the shaft  106 , preventing the stem  96  from pulling further out of the shaft. 
   To provide contact between the switch button  88  of the switch assembly  84  inside the housing  22  with the moving plunger  24 , an opening  118  sized to receive the switch button is provided in the annular shelf  102  of the plunger recess  100 . See  FIGS. 6 and 7 . Thus, as the head  94  of the plunger  24  moves in and out of the plunger recess  100 , the switch button  88  will be moved from the off position to the on position. 
   As indicated, it is preferable for the plunger  24  to be biased in the resting position. To that end, a coil spring  122  may be interposed between the head  94  and the annular shelf  102  around the stem  96 . The spring  122  is compressed when the head  94  of the plunger  24  is pressed, but returns to the extended position when pressure on the head is released. 
   The repetitive movements of the stem  96  inside the tubular shaft  106  may cause friction. This interface is also susceptible to encroachment by moisture and salt. To reduce the damage associated with these problems, the push button  10  preferably comprises a bushing  124  made of a suitable wear-resistant, friction-reducing material. In one preferred embodiment, the bushing  124  is formed of oil-impregnated bronze. This provides a low friction bearing surface between the stem  96  and the shaft  106  that is self-lubricating. Other suitable materials include Teflon coated metal, plastic, or other metals, such as stainless steel or aluminum. 
   Referring still to  FIG. 10 , the preferred mounting for the switch  84  is shown. A switch mounting plate  126  if formed to fit over the body of the switch  84 . The plate  126  includes ears  128  with openings  130  to receive screws  132  with washers  134 . The stems of the screws  132  are received in the bores  68  ( FIG. 6 ) described previously. 
   In the preferred embodiment, the body  28 , the cover  30 , and the plunger  24  all are integrally formed of stainless steel. This provides a corrosion resistant finish and eliminates the need for painting. 
   Having described the preferred structure of the push button  10 , its manner of use will be explained. First, the intended support structure, such as the traffic pole  12  is selected, and the shape—curved or flat—is determined. Next, a wire opening (not shown) in the pole  12  is made at the level at which the push button is to be mounted. Or, if the mounting surface has no wiring conduit, an external conduit may be used with an adapter plate (not shown). 
   The housing  22  is opened, that is, the body  28  is separated from the cover by opening the twist lock engagement. Wires from the pole  12  are connected to the wires (not shown) from the terminal block  90  extending out through the tubular extension  48  on the back of the rear panel  34  of the body  28  (or directly to the wires using wire nuts). Then, the body  28  is bolted to the pole  12 , or attached to the pole in some other suitable manner. 
   Having attached the body  28  to the pole  12 , the leads (not shown) from the switch housing  86  are connected to the terminal block  90 . Then the cover  30  is connected to the body  28  using the twist lock. Finally, the set screw  62  is inserted into the set screw opening  60  on the bottom of the housing  22  to secure the cover  30 . The push button now is operational. 
   Now it will be appreciated that the pedestrian push button of the present invention provides a seamless, solid housing without visible screw heads or other connectors. This makes a weather resistant enclosure which does not tempt would-be vandals. 
   The embodiments shown and described above are exemplary. Many details are often found in the art and, therefore, many such details are neither shown nor described. It is not claimed that all of the details, parts, elements, or steps described and shown were invented herein. Even though numerous characteristics and advantages of the present invention have been described in the drawings and accompanying text, the description is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of the parts within the principles of the invention to the full extent indicated by the broad meaning of the terms of the attached claims. The description and drawings of the specific embodiments herein do not point out what an infringement of this patent would be, but rather provide an example of how to use and make the inventions. The limits of the inventions and the bounds of the patent protection are measured by and defined in the following claims.