Patent Publication Number: US-10312029-B2

Title: Illuminated vandal-resistant pushbutton switch

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
     Not applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates generally to pushbutton switch devices and, more particularly, to pushbutton switch devices in which electrical contact is made in a control circuit when the switch plunger is advanced. The switch provides a momentary signal in a circuit that initiates an action which continues after the momentary push of the button has been released. Many coordinated switches may be mounted in a panel array with corresponding pushbuttons such as in elevator controls and, specifically, the switch devices of the invention feature full illumination with a vandal-resistant construction. 
     II. Related Art 
     A variety of pushbutton switch devices have been developed in which a target pushbutton is connected to a central plunger system that is longitudinally moveable in a button body to contact, momentarily connect and thereby activate a control circuit upon depressing the plunger against a return compression spring and in which contact is broken upon release and retraction of the pushbutton and plunger. Such switches initiate an action which continues after a momentary push of the button has been released. Such a sequence is well known. For example, in elevator controls where pushbuttons associated with each floor are used to log in and activate the operation of the elevator accordingly. 
     Pushbutton switches are known which include illumination aspects. Such devices are shown, for example, in U.S. Pat. No. 5,434,377 to Martin et al in which LED illuminating devices are used, and U.S. Pat. No. 8,829,375 to Hogan et al. It is also known to provide switches with a rugged or vandal-resistant construction in locations where they may be subject to abuse. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to embodiments of a pushbutton switch assembly having a pushbutton element designed to be depressed and released, the button springing back to a normal position immediately after release. A momentary signal to a circuit provided by the pushbutton is designed to initiate a remote action such as the operation of an elevator rather than just a local result. The pushbutton switch assemblies of the invention combine full illumination with a vandal-resistant construction. 
     A preferred embodiment includes a base that contains an illuminating LED array and one or more microswitches, a button body housing which may or may not include an illuminated halo is provided with a fixed hollow central barrel and a pushbutton target system is mounted in and operable within the button body housing, the pushbutton being spring biased and longitudinally moveable relative to the housing or button body. A symmetrical compression return spring is mounted in the button body that causes the pushbutton, when depressed and released, to return to an outward or normal position. The button body housing is designed to be mounted in a pushbutton panel and may come with or without a halo aspect. 
     Illumination is provided by an LED array located in the base of the assembly containing a plurality of LED devices. Light from the LEDs is projected straight up along a centerline to illuminate the pushbutton target and at an angle to illuminate a halo. In this manner, both the target and the halo (if present) may be fully illuminated. 
     A vandal-resistant or “vandal-proof” aspect is also provided in the design. The pushbutton target system is surrounded by a ring portion of the button body housing with only a narrow gap therebetween such that when the pushbutton target system is depressed, its travel is limited by the ring to just enough to enable contact with the corresponding microswitches. Both the target body and the ring portion are preferably made of stainless steel for added strength. If excessive force is applied to the pushbutton, it is distributed through the stainless steel components and the mounting panel leaving the signaling aspect unaffected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, wherein like numerals designate like parts throughout the same: 
         FIG. 1  is an exploded perspective view of a pushbutton switch assembly in accordance with the invention; 
         FIG. 2A  is an exploded side elevational view of the embodiment of  FIG. 1 ; 
         FIG. 2B  is a top view of the embodiment of  FIG. 2A ; 
         FIG. 3A  is an assembled pushbutton switch assembly embodiment similar to that of  FIG. 1  with an alternative button body; 
         FIG. 3B  is a sectional elevational view of the embodiment of  FIG. 3A ; 
         FIG. 3C  is a partial exploded view of upper components in  FIG. 3B . 
         FIG. 4  is a perspective view of an assembled pushbutton switch assembly similar to that shown in  FIGS. 3A and 3B ; 
         FIG. 5  is a side elevational view of an embodiment with a domed button body; and 
         FIG. 6  is a partial schematic partially exploded side view of a pushbutton switch assembly showing an illumination pattern. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description is intended to present certain exemplary preferred embodiments that illustrate the concepts of the present invention. The embodiments are intended by way of example and are not intended to limit the scope of the invention in any respect. It is further recognized and understood that one skilled in the art might make modifications which remain in keeping with the inventive concepts. 
       FIG. 1  depicts an exploded perspective view of a pushbutton switch assembly embodiment in accordance with the invention. An exploded side elevational view appears in  FIG. 2A  and a top view appears in  FIG. 2B . The embodiment, shown generally at  10 , includes an LED and microswitch-containing base  12 , a threaded button body housing  14  with illuminated halo at  16 . A button body housing nut is shown at  18  and a cylindrical button return compression spring is shown at  20 . A pushbutton target system  22  includes a flush domed button  24  with rings  26  and indicator  28  with an indicator jewel  30 . A typical panel segment with cutout is shown at  32  illustrating the mounting mode. The cylindrical compression spring  20  is preferably symmetrical so that it can be installed in either direction in the spring seat to avoid any binding issues during an actuating or return stroke. 
       FIGS. 3A, 3B, and 3C  depict elevational, sectional, and partial exploded views of an embodiment of the pushbutton switch assembly similar to that of  FIGS. 1, 2A and 2B  with an alternative button body housing and pushbutton target system. A plurality of push-in or plug-in wire connectors are shown at  40 . An LED illuminating array is shown at  42 . A pair of microswitches  44  and  46  with actuator contact points  48  and  50  are also mounted in the base. A flat or concave pushbutton target is shown at  52  and a button body housing at  54 . 
     The outer surface  56  of the pushbutton target system includes an inclined aspect  56 A that is surrounded by a ring member of the button body housing  58  that includes a matching inclined surface  58 A. Both of these members are close to each other with only a narrow gap therebetween. In this manner, the travel of the pushbutton target system is limited as it is stopped by or “bottoms out” on the matching surface ring  58  when it is fully depressed such that surface  56 A contacts surface  58 A. The members  56  and  58  are preferably made of stainless steel to better give the pushbutton assembly a vandal-resistant aspect which is important to the design. Thus, when the target body is fully depressed, the bottom of the target shaft contacts the mating actuator components only to the extent necessary to actuate the microswitch component and this prevents additional force from affecting switch operation. Excessive force applied to the target is distributed and dissipated through the extended contact area of the matching inclined surfaces of the stainless steel components and the mounting panel. The button assembly remains fastened to the panel. 
     A slightly different arrangement is shown at  60  in  FIGS. 4 and 5  and includes a flush domed target  62  with rings  64  and a halo  66 . 
     A partial schematic partially exploded side elevational view of the pushbutton switch assembly in  FIG. 6  diagrams the illumination pattern for a completely illuminated embodiment. An LED array is shown at  70  which contains three or more LED members (not shown). Light is projected straight up to illuminate the target along a center line at  72  and at an angle along lines as at  74  to illuminate a halo at  76 . Microswitches with contact points are shown at  78  and  80 . 
     The design of the pushbutton switch assembly allows for the entire surface of the button target to be illuminated as well as an optional outer halo ring while preserving stainless on stainless vandal-resistant aspects in switch operation. 
     This invention has been described herein in considerable detail in order to comply with the patent statutes and to provide those skilled in the art with the information needed to apply the novel principles and to construct and use embodiments of the example as required. However, it is to be understood that the invention can be carried out by specifically different devices and that various modifications can be accomplished without departing from the scope of the invention itself.