Abstract:
A hand held switch having a depressible button linked to an electromechanical two-stage switch transmits first and second type electric signals in response to a depth of the button press. A pivoting lever links the button to the switch and is designed to move the switch in response to a button press for improved tactile control.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Patent Application Ser. No. 62/363,387, filed Jul. 18, 2016, in the name of Asento et al., and entitled CONTROL SWITCH. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The subject matter disclosed herein relates to a dual-stage hand held switch. In particular, to a switch that may be used for activating radiographic imaging equipment having an x-ray tube to obtain an x-ray exposure. 
         [0003]    Current x-ray equipment often uses a wired switch to control the x-ray exposures. In one prior art design, a hand held device includes a two position switch where, in one position, it initiates a preparation of the equipment and, in the second position, it initiates the exposure. 
         [0004]    The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter. 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0005]    A hand held switch having a depressible button that is linked to an electromechanical two-stage switch transmits first and second type electric signals in response to a depth of the button press. A pivoting lever links the button to the switch and is designed move the switch about the same distance, half the distance, or less, as a depth of the button press. An advantage that may be realized in the practice of some disclosed embodiments of the control switch is improved tactile feel, stability and control. 
         [0006]    In one embodiment, a hand held switch assembly may include a rigid manually movable element and a depressible electromechanical two-stage switch which transmits a first type electric signal in response to being depressed to a first depth and a second type electric signal in response to being depressed to a second depth. A rigid pivoting lever mechanically couples the manually movable element to the two-stage switch and depresses the two-stage switch in response to a manual movement of the element. The rigid pivoting lever depresses the two-stage switch to the first depth when the manually movable element is moved about 1×, 2×, or more, of the distance of the first depth. 
         [0007]    In another embodiment, a hand held switch may include a button movable to a first button depth and to a second button depth. An electromechanical switch is mechanically coupled to the button and transmits a first type electric signal in response to the button being pressed to the first button depth. The switch transmits a second type electric signal in response to the button being pressed to the second button depth. A pivoting lever links the button to the switch and is designed move the switch about half the distance as a depth of the button movement. 
         [0008]    In another embodiment, a hand held switch assembly includes a rigid manually depressible button and a movable switch element configured to transmit a first electric signal in response to being moved to a first depth and to transmit a second electric signal in response to being moved to a second depth. A rigid pivoting lever is mechanically coupled to both the button and to the switch element, and is configured to move the switch element in response to a manual depression of the button. The pivoting lever is configured to move the switch element to the first depth when the button is depressed for a distance of about 1×, 2×, or more, of a distance of the first depth and to a second depth when the button is depressed for a distance of about 1×, 2×, or more, of a distance of the second depth. 
         [0009]    In another embodiment, a hand held switch assembly includes a button configured to move to a first position and a second position when pressed. An electromechanical switch is coupled to the button and is configured to transmit a first electric signal in response to the button being pressed to the first position and to transmit a second electric signal in response to the button being pressed to the second position. A pivoting lever provides mechanical coupling between the button and the switch. The pivoting lever is configured to move a piston in the switch to a first switch depth corresponding to the first button depth and to a second switch depth corresponding to the second button depth. 
         [0010]    This brief description of the invention is intended only to provide a brief overview of subject matter disclosed herein according to one or more illustrative embodiments, and does not serve as a guide to interpreting the claims or to define or limit the scope of the invention, which is defined only by the appended claims. This brief description is provided to introduce an illustrative selection of concepts in a simplified form that are further described below in the detailed description. This brief description is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the background. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    So that the manner in which the features of the invention can be understood, a detailed description of the invention may be had by reference to certain embodiments, some of which are illustrated in the accompanying drawings. It is to be noted, however, that the drawings illustrate only certain embodiments of this invention and are therefore not to be considered limiting of its scope, for the scope of the invention encompasses other equally effective embodiments. The drawings are not necessarily to scale, emphasis generally being placed upon illustrating the features of certain embodiments of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. Thus, for further understanding of the invention, reference can be made to the following detailed description, read in connection with the drawings in which: 
           [0012]      FIG. 1  is an image of an exterior of a generic prior art hand held switch; 
           [0013]      FIG. 2  is an image showing an interior of one exemplary embodiment of a hand held switch of the present invention; 
           [0014]      FIG. 3  is a cross section close-up view of a portion of an exemplary embodiment of a hand held switch of the present invention; and 
           [0015]      FIG. 4  is a line drawing cross-section view of one exemplary embodiment of a hand held switch of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0016]      FIG. 1  shows a prior art hand held electrical switch  100  that includes two buttons  101 ,  102  that may be separately manually depressed by an operator to initiate transmission of electrical signals through a conductive cable  103 . The signals are received at an opposite end of the cable  103  at an electrical or electromechanical device that may respond to the signals by activating (starting) or deactivating (stopping) an electrical or electromechanical function performed by the connected electrical or electromechanical device. In one embodiment, the transmitted electrical signals may be used to initiate a preparation stage of an x-ray tube such as by activating rotation of a rotating anode therein. The transmitted electrical signals may further include an activation signal used to activate a single firing or a firing sequence of the x-ray tube which emits radiographic energy (x-rays) in response thereto. 
         [0017]    The following description of embodiments of the present invention is directed to  FIGS. 2-4 , whereby  FIG. 2  shows an image of the inventive hand held control switch;  FIG. 3  shows a close-up view of a portion of the inventive hand held control switch; and  FIG. 4  shows a line drawing of the inventive hand held control switch. An embodiment of a hand held electrical switch assembly  200  that may include a housing body having at least two portions, or halves,  202 ,  204 , which, when fully assembled, may be positioned to abut each other and be fixed together to define and enclose an interior space  206  within the housing. The electrical switch assembly  200  includes two buttons  208 ,  210 , at least one of which may be a rigid, manually depressible button  208 . The manually depressible button  208  may include a narrower portion such as an integrally formed shaft that is configured to travel back-and-forth parallel to (along) a linear axis, or button line,  212  within a channel  214  in the housing. The channel  214  may have a cross-section whose shape matches a shape of the cross-section of the shaft but slightly larger to allow slidable movement of the shaft therethrough. One end of the button  208  may be selectively depressed by an operator such that the button  208  (shaft) slides to one or more selectable depths (distances) into the channel  214 . One wider end of the button  208  is configured to be manually contacted and depressed by an operator, and the other end of the button (narrower shaft) is configured to engage, contact, and move, in an angular rotation direction  240 , a pivoting lever  216  as the button  208  is depressed. The narrower shaft end of the button  208  engages a slidable contact area  218  of the pivoting lever  216  as the pivoting lever  216  pivots. As the depressed button engages the pivoting lever  216  at the contact area  218 , it causes the pivoting lever  216  to pivot, or rotate, about a fixed pivot axis  220  in one of the directions  240  toward a two-stage switch  222 , for an angular distance corresponding to a depth (distance) that the button  208  (shaft) is selectively depressed. The two-stage switch  222  is a known, commercially available switch, whose operation is described herein as it pertains to the present hand held switch, and is not described in further detail. The fixed pivot axis  220  may be formed by a pin that is attached to, or is integrally formed as part of, the housing portion  204  and that extends through an opening in the pivoting lever  216 , which combination of pin and opening provides a rotatable sliding contact therebetween. 
         [0018]    As the button  208  is manually depressed, one end of the button  208  contacts the pivoting lever  216  at the contact area  218  which causes the pivoting lever  216  to simultaneously pivot about the axis  220 . The pivoting lever  216  includes another sliding contact area  226  that contacts, engages, and moves a switch element  224  toward the right, as shown in  FIG. 2 , as the pivoting lever  216  pivots about the axis  220 . The switch element  224  may be formed in the shape of a movable cylinder and may be referred to herein as a piston  224 . The switch element, or piston,  224  may be spring biased to in an outward direction toward the pivoting lever  216 . The pivoting lever  216  may include a generally planar shape, which plane is parallel to the page of  FIG. 2 , and may have a thickness that may be smaller, greater, or equal to a thickness, or diameter, of the proximate end of the shaft of the button  208 . When the button  208  is released, it causes the pivoting lever  216  to pivot, or rotate, about a fixed pivot axis  220  in one of the directions  240  away from the two-stage switch  222 , via the spring biased piston  224 . 
         [0019]    The hand held switch  200  includes a two-stage electrical switch  222  having the movable piston  224  that protrudes from a portion of the two-stage electrical switch  222  facing toward the pivoting lever  216 . As the pivoting lever  216  pivots about the pivot axis  220 , the second slidable contact area  226  of the pivoting lever  216  slidably engages the piston  224  and moves the piston  224  along a linear travel axis, or switch line,  230  into a body of the two-stage electrical switch  222 . The depressible piston  224  is configured to electrically engage a first electrical contact within the body of two-stage electrical switch  222  as the piston  224  travels a first distance into the body of the two-stage electrical switch  222  under the force of the pivoting lever  216  corresponding to a first depth that the button  208  is depressed. As the button  208  is further depressed to a second button depth or position, the piston  224  is configured to travel a second distance into the body of the two-stage electrical switch  222  under the force of the pivoting lever  216  corresponding to the second depth that the button  208  is depressed. The piston  224  then electrically engages a second electrical contact within the body of two-stage electrical switch  222  at the second distance, which is greater than the first distance. 
         [0020]    When the first contact within the two-stage electrical switch  222  is electrically engaged by the movable piston  224 , the two-stage electrical switch  222  is configured to transmit a first type signal through a connected cable  228  (shown disconnected in  FIG. 2 ) downstream to control a function performed by a connected electrical or electromechanical device. As the movable piston  224  is moved further into the two-stage electrical switch  222  the second contact within the two-stage electrical switch  222  is electrically engaged by the movable piston  224 . In response, the two-stage electrical switch  222  is configured to transmit a second type signal through the connected cable  228 . The separate signals may be distinguished physically by separate conductive wires in the connected cable  228 , or the separate signals may be distinguished functionally by signal characteristics such as analog voltage level or another suitable characteristic, or by discrete digital characteristics such as by pulse code modulation or some other suitable digital intelligence. The signals may be received at another end, such as a terminal end, of the connected cable  228  directly by an electromechanical device to activate, deactivate, or change an operating mode of the device, or the signals may be received at a programmed processor that decodes digital type signals and may respond by activating or deactivating connected devices or functions according to variable program control. Such programmed processing may be included in a controller  227  within the housing of the hand held switch  200 . The controller  227  may be fabricated to include a printed circuit board having digital circuitry electrically connected to the cable  228  and may be electrically connected indirectly or directly to the two-stage switch  222  to enable the generation of voltage signals or digitally encoded signals, corresponding to the electrical engagement of the first or second contacts therein, to be transmitted through the connected cable  228 . 
         [0021]    In one embodiment, the pivoting lever  216  pivoting axis  220  is disposed to one side (offset) of the linear travel axis, or switch line,  230  of the piston  224 . The pivoting axis  220  may also be disposed to the same one side (offset) of the linear travel axis, or button line,  212  of the button  208 . The button  208  linear travel axis  212  may be said to intersect the piston  224  linear travel axis  230  at an acute angle  232  of between about 10° and 80°, more preferably between about 20° and about 50°, and even more preferably between 25° and 40°. The configuration and shape of the pivoting lever  216  relative to the button  208  and the piston  224  provides a mechanical and tactile advantage in that the travel distance of the button  208  is about twice that of the piston  224  as the button  208  is depressed by an operator—a 2× mechanical and tactile advantage that allows an operator better control over selectively transmitting the first type and second type signals. Other configurations of the pivoting lever  216  may provide more or less than the 2:1 mechanical ratio described herein. Thus, the approximate 2:1 ratio described herein is but one embodiment of the disclosed invention. The provided mechanical advantage may be understood by noting that a distance from the pivot axis  220  to the contact area  218  of the pivoting lever  216 , which contact area  218  engages the button  208 , is about twice greater than a distance from the pivot axis  220  to the contact area  226  of the pivoting lever  216 , which contact area  226  engages the piston  224 . Therefore, in another embodiment, a dimension of the pivoting lever  216  may be extended or shortened such that the relative distances between the pivot axis  220  to the contact area  218  and the pivot axis  220  to the contact area  226  may be varied to provide different mechanical ratios that may be greater or less than the  2 : 1  ratio described herein. 
         [0022]    A spring bias member  234  ( FIGS. 3, 4 ) may be used to bias the pivoting lever  216  against the piston  224 , which bias pressure is insufficient to move the piston  224 . In one embodiment, the spring bias member  234  may include a V-shaped spring having one end that abuts a fixed interior feature of the housing  204  and a second end abutting a feature on the pivoting lever  216  to bias the pivoting lever  216  against the piston  224  and thereby preload the pivoting lever  216  against the piston to avoid rattle and ensure tactile response during use of the button  208 . The piston  224  may be spring biased to return itself as well as the pivoting lever  216 , in a clockwise direction in the views of  FIGS. 3-4 , and the button  208  to starting positions after a manual release of the button  208 . Thus, the spring bias force of the piston  224  is slightly greater than a spring bias force of the V shaped spring  234 . 
         [0023]    This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.