Abstract:
An apparatus is provided for activating switches in a leading edge flap drive actuator. The apparatus comprises a mount plate having at least a first side, a second side, and an outer peripheral surface, an actuator arm rotationally coupled to the mount plate and rotationally moveable between at least an activate position and a deactivate position, and a spring arm coupled to the mount plate and extending away from the mount plate outer perpheral surface, the spring arm configured to supply a force that biases the actuator arm toward the deactivate position at least when the actuator arm is in the activate position.

Description:
FIELD OF THE INVENTION 
     The present invention generally relates to switches, and more particularly relates to an assembly for activating a switch. 
     BACKGROUND OF THE INVENTION 
     Switches are used in many different environments, including various aerospace environments, in which switches may be used with other components to accomplish certain aircraft system and/or component operations. For example, switches may be employed in the aircraft monitoring system of leading edge flap drive assemblies. In such instances, when the aircraft leading edge flaps are extended or retracted, switches are typically activated or deactivated to indicate the position of the flaps. These indications may be communicated, via a display, to the pilot. In these configurations, the switches may be activated or deactivated by switch actuators that may in turn be controlled by other components such as, for example, a cam assembly. In such instances, the switch actuators may translate the rotary motion of the cam assembly to linear motion, to activate or deactivate a switch. 
     At times, it may be preferable to replace a switch actuator. In such instances, it is preferable for the replacement switch actuator to not only have a robust design for a prolonged life, but also for the replacement to be cost efficient. 
     Accordingly, there is a need for a robust and cost efficient switch actuator. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention. 
     BRIEF SUMMARY OF THE INVENTION 
     In one embodiment of the invention, a switch actuator assembly is provided that includes a mount plate, an actuator arm and a spring arm. The mount plate includes at least a first side, a second side, and an outer peripheral surface. The actuator arm is rotationally coupled to the mount plate and rotationally moveable between at least an activate position and a deactivate position. The spring arm is coupled to the mount plate and extends away from the mount plate outer peripheral surface. The spring arm is configured to supply a force that biases the actuator arm toward the deactivate position at least when the actuator arm is in the activate position. 
     In another embodiment, a switch actuator assembly having a mount plate, a first and second actuator arm and a first and second spring arm is provided. The mount plate includes at least a first side, a second side, and an outer peripheral surface. The first and second actuator arms are each rotationally coupled to the mount plate and each rotationally and independently moveable between at least an activate position and a deactivate position. The first and second spring arms are coupled to the mount plate and each extend away from the mount plate outer peripheral surface. The first and second spring arms are each configured to supply a force that biases the first and second actuator arms toward the deactivate position, respectively, at least when the first or the second actuator arm is in the activate position. 
     In yet another embodiment, a switch actuator assembly is provided that includes a mount plate, an actuator arm, a spring arm and a switch assembly. The mount plate includes at least a first side, a second side, and an outer peripheral surface. The actuator arm is rotationally coupled to the mount plate and rotationally moveable between at least an activate position and a deactivate position. The spring arm is coupled to the mount plate and extends away from the mount plate outer peripheral surface. The spring arm is configured to supply a force that biases the actuator arm toward the deactivate position at least when the actuator arm is in the activate position. The switch assembly is disposed proximate the mount plate and includes a switch selectively moveable between a closed position and an open position in response to actuator arm movement between the activate and deactivate positions, respectively. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and 
     FIG. 1 is a cross sectional view of a switch actuator assembly in resting state, according to an exemplary embodiment of the invention; 
     FIG. 2 is a perspective view of the switch actuator of FIG. 1; 
     FIG. 3 is a cross-sectional view of switch actuator assembly of FIG. 1 taken along lines A—A showing activated switch  104 , according to an exemplary embodiment of the invention; and 
     FIG. 4 is the cross-sectional view of switch actuator assembly of FIG. 1 taken along lines B—B showing deactivated switch  104 , according to an exemplary embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. In this regard, although the switch actuator is described as being implemented in an aircraft leading edge flap actuation system, it will be appreciated that it could be implemented in numerous other systems, both in or out of the aerospace industry. 
     FIG. 1 illustrates a cross-sectional view of a controller assembly according to an exemplary embodiment as employed in an aircraft monitoring system of an aircraft leading edge flap drive assembly. The depicted controller assembly  100  includes a cam assembly  102  and a switch actuator  106  which are disposed within a housing  101 . A spacer  108  is installed between the housing  101  and the switch assembly  104 . The switch actuator assembly  100  is shown to include both an activated and a deactivated switch  104 , specifically, an activated retract switch  180  and a deactivated extend switch  182 . In this embodiment, the cam assembly  102  and switch actuator  106  work together, as will be described more fully further below, to activate or deactivate switch assembly  104 , which in turn causes a leading edge flap extend or retract position signal, respectively, to be sent to, for example, a display (not shown). It will be appreciated that the position signal may be sent to one or more displays either directly from the switch  104  or via one or more intermediate circuits. Each component of the controller assembly  100  and how they interact with one another will now be discussed. 
     Cam assembly  102  includes two cams, an extend cam  103  and a retract cam  105 . The cams  103 ,  105  are coupled to one another via a translating screw assembly  107  that works with the switch actuator  106  to activate and deactivate switches  180  and  182  in the switch assembly  104 , to thereby indicate, for example, different leading edge flap positions. Translating screw assembly  107  includes a splined shaft  110  which passes through cams  103 ,  105  and a translating nut  112  mounted on the shaft  110 . Cams  103 ,  105  are each threaded to an outer floating nut (not shown). When shaft  110  rotates, nut  112 , in turn, travels linearly along the shaft  110 , between cams  103  and  105 . Nut  112  engages the outer floating nut (not shown) of either the extend cam  103  or the retract cam  105 , depending on the direction of a drive force supplied to the translating screw assembly  107  from the LEFD gear drive  117 . Thus, for example, when implemented in a leading edge flap drive (LEFD) actuation system, translating screw assembly  107  is coupled to a LEFD gear drive  117 . When a pilot commands the aircraft flaps to extend or to retract, the LEFD gear drive  117  supplies a drive force in the appropriate direction, causing the shaft  110  to rotate and nut  112  to translate along the shaft  110  between the extend and retract cams  103 ,  105 . The nut  112  then engages with either the extend cam  103  or the retract cam  105 , as appropriate. When the nut  112  engages either the extend cam  103  or the retract cam  105 , the appropriate cam  103 ,  105  rotates a predetermined amount, engaging the switch actuator  106 , and thereby appropriately activating or deactivating the switch assembly  104 . 
     The extend and retract cams  103 ,  105  may be implemented in any one of nunerous known configurations, but in the depicted embodiment the cams  103 ,  105  are each generally short, cylindrically-shaped elements that have a groove  116  formed therein. It will be appreciated that the groove  116  may extend the entire length of the cams  103 ,  105 , or be formed in only a portion thereof. Moreover, in various other embodiments, instead of a groove  116 , the cams  103 ,  105  can include a protrusion. No matter the particular configuration, when either one of the cams  103 ,  105  rotates, it mechanically operates the switch actuator  106  to appropriately activate or deactivate the switch  104 . 
     The switch assembly  104  includes a switch housing  178 , and two switches, an extend switch  180  and a retract switch  182 . The switch housing  178  houses internal circuitry (not shown) that is in operable communication with, for example, a display or an aircraft instrumentation and control system (not shown). The internal circuitry is also in operable communication with the extend and retract switches  180 ,  182 . In the depicted embodiment, the extend and retract switches  180 ,  182  are implemented as button-type switches. However, it will be appreciated that this is merely exemplary of any one of numerous types of switch types that could be used. The extend  180  and retract  182  switches, as the names connote, are used to indicate that the aircraft leading edge flaps are in the extended or retracted positions, respectively. To this end, the switches  180 ,  182  cooperate with the wiring in switch housing  178  to send signals communicating the position of the leading edge flaps to the display or aircraft instrumentation and control system. 
     Turning to FIG. 2, a plan view of the switch actuator of FIG. 1 is shown. Switch actuator is mounted to the switch housing  101 , at an appropriate height and width between cam assembly  102  and switch  104 , via spacer  108 . The switch actuator  106  includes a base  117 , and one or more actuator arms. In the depicted embodiment, the base  117  includes two plates, a mount plate  118  and a spring plate  160 , and two actuator arms, an extend actuator arm  136  and a retract actuator arm  138 . The mount plate  118  and spring plate  160  are preferably spot-welded to one another, but it will be appreciated that these components could be coupled to one another via screws, adhesives, or by any one of numerous other known coupling mechanisms. 
     In the depicted embodiment, the mount plate  118  is substantially rectangular in shape and includes a pair of shorter opposing, substantially parallel sides  120 ,  122 , a pair of longer opposing, substantially parallel sides  124 ,  126 , and actuator arm attachment segments  128 ,  130 . Preferably, the mount plate  118  is machined from a single piece of material. Each of the shorter substantially parallel sides  120 ,  122  preferably includes a notch  132 ,  134  that extends toward the middle portion of the mounting plate  118 . The notches  132 ,  134 , together with screws (not shown), are used to secure the mount plate  118  and spacer  108  in the switch actuator assembly housing  110 . The longer substantially parallel sides  124 ,  126  each include one of the actuator arm attachment segment  128 ,  130 . In the depicted embodiment, the actuator arm attachment segments are diagonally positioned on opposite corners of the backing plate  118  from one another, and are substantially U-shaped. It will be appreciated, however, that this configuration and shape is merely exemplary of a particular embodiment, and that other configurations and shapes may be used, as may be suitable for other end-use systems. No matter the particular configuration or shape, the arm attachment segments  128 ,  130  are used to rotationally mount each of the actuator arms  136 ,  138  to the mount plate  118 . 
     Each actuator arm  136 ,  138  includes a first end  140 ,  142  and a second end  144 ,  146  coupled together via a middle segment  148 ,  150 , all preferably machined from a single piece of material. The first ends of the arms  140 ,  142  are disposed within the U of the arm attachment segment  128 ,  130 , and are rotationally coupled to the backing plate  118  via hinge pins  152 ,  154 . Specifically, each appendage of the U-shaped attachment segments  128 ,  130 , and the first ends of the arms  140 ,  142  each include holes that are aligned with one another to receive the hinge pins  152 ,  154 . The hinge pins  152 ,  154  are configured to rotationally secure the first ends of the actuator arms  140 ,  142  to the mount plate  118  and allow the second ends of the actuator arms  144 ,  146  to move freely in an arc-like motion. 
     The second ends of the actuator arms  144 ,  146  each include a protrusion  156 ,  158  that is preferably formed thereon or machined. Each protrusion  156 ,  158  engages the outer surface of, or fits within the groove  116  of, one of the extend or retract cams  103 ,  105  when the controller assembly  100  is actuated. In this embodiment, the protrusions  156 ,  158  have a bulb-like shape that fits and rests in the cam groove  116  (shown in FIG.  1 ), however, the protrusions  156 ,  158  may be hammer-shaped, V-shaped, or any one of numerous other solid shapes. In other embodiments, if the cams  103 ,  105  include a protrusion, instead of a groove, the actuator arms  136 ,  138  can be configured without protrusions. 
     The actuator arms  136 ,  138  and the mount plate  118  preferably comprise materials that are able to withstand frequent application of force and that does not easily fracture or break. Such materials can be polyether ether ketone, copper beryllium,  304  stainless steel or any one of numerous other known materials known in the art that possess the strength and ability to withstand frequent applications of small forces. In the case of the actuator arms  136 ,  138 , the integrity of the arms may be dependent upon dimensions and what material is used to configure to the dimensions. For instance, in this embodiment, the arms are preferably made of polyether ether ketone (e.g., PEEK). In such case, the actuator arm protrusion  156 ,  158  is preferably about three times as thick as the middle segment  148 ,  150 . 
     The spring plate  160  is coupled to the mount plate  118 , as was noted above, and is configured to restrict movement of the actuator arms  136 ,  138 , and supply a bias force to each actuator arm  136 ,  138 . Spring plate  160  is sized substantially similar to the mount plate  118 , and thus includes a pair of long substantially parallel edges  162 ,  164 , a pair of short substantially parallel edges  166 ,  168 , and two spring arms  170 ,  172 . In the depicted embodiment, the spring arms  170 ,  172  are located on opposite sides of the spring plate  160  from one another. Preferably, each spring arm  170 ,  172  extends at least to a point that it contacts the middle segment  148 ,  150  of its corresponding actuator arm  136 ,  138 . To aid in providing a spring-like property to the spring arms  170 ,  172 , each spring arm  170 ,  172  is flanked by two V-shaped cutouts. The short substantially parallel edges  166 ,  168  each include an indentation  174 ,  176  similar in shape and size to notches  132 ,  134 . Indentations  174 ,  176  are machined such that when the spring plate  160  is appropriately mounted on mount plate  118 , the indentations  174 ,  176  and notches  132 ,  134  are in alignment with one another. The spring plate  160  is preferably comprised of 17-7 pH stainless steel, however, the plate may be made of any one of numerous other materials known in the art that possess spring-like properties. 
     FIG. 3 shows a cross-section view of the controller assembly  100  taken along line A—A of FIG.  1 . In this view, the retract switch  182  of FIG. 1 is activated and the extend switch  180  is deactivated. Here, as previously described, LEFD gear drive  117  actuates translating screw assembly  107 . Once actuated, shaft  110  rotates and causes nut  112  to travel linearly along shaft  110  to engage retract cam  105 . When this occurs, further rotation of shaft  110  causes cam  105  to rotate a predetermined amount. As cam  105  rotates, actuator arm  138  moves out of groove  116  and onto cam surface  114 . Cam surface  114  in turn elevates actuator arm  138 , causing arm  138  to activate retract switch  180 , thereby sending an appropriate signal to the display or aircraft instrumentation and control system. Actuator arm  138  is biased toward the deactivate position via spring arm  172 . 
     While nut  112  is engaged with retract cam  105 , extend cam  103  is not engaged, as shown in FIG.  4 . FIG. 4 illustrates a cross-sectional view of the switch actuator assembly taken along line B—B of FIG.  1 . In this embodiment, when extend cam  103  is not engaged by nut  112 , actuator arm  136  remains within groove  116 . Thus, extend switch  180  is not activated. 
     It will be appreciated that although FIGS. 3-5 illustrate a switch actuator assembly  100  wherein the extend switch  180  is not activated and the retract switch  182  is activated, at times, the translating screw assembly  107  will engage neither the extend or retract cams  103 ,  105  and thus, neither the extend or retract switches  180 ,  182  will be activated. 
     Therefore, a robust design that is cost and space efficient has been provided. The switch actuator assembly of the invention reduces the frequency of replacing the switch actuator and reduces the costs associated with replacement. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.