Abstract:
An apparatus for controlling positioning of flaps in an aircraft includes a shift lever movable to each of a plurality of shift lever positions to control positioning of the flaps of the aircraft to each of a respective plurality of associated flap positions. A shift lever indexing plate includes a plurality of engagement positions associated with the plurality of shift lever positions, respectively, the shift lever being coupled to an engagement member, the engagement member moving with the shift lever and being biased to selectively engage a selected one of the plurality of the engagement positions associated with a selected one of the shift lever positions to command the aircraft flaps to the flap position associated with the selected one of the shift lever positions. The shift lever indexing plate includes a web portion which separates the engagement positions of the shift lever indexing plate, the web portion and the shift lever being shaped and the shift lever being biased such that when the shift lever is at rest and only the shift lever bias is applied to the shift lever, the engagement member must be engaged with one of the plurality of engagement positions of the shift lever indexing plate.

Description:
BACKGROUND 
     1. Technical Field 
     This disclosure relates to aircraft control systems and, more particularly, to systems used to command aircraft flap positions. 
     2. Discussion of Related Art 
     In some aircraft, it is common to control the position of wing flaps using a flap handle-command module. The module is typically located in the center pedestal in the cockpit of the aircraft. In some aircraft, the aircraft flaps can be controlled to occupy one of four possible positions from completely retracted or “UP” to completely extended or “FULL”, with the four possible positions being ordered as follows: UP-1-2-FULL. The four positions are associated with and are commanded by four respective positions of a shifter lever in the flap handle-command module. The shifter lever is connected to a flap knob, which is accessed by the pilot to position the shifter lever and, therefore, the aircraft flaps, in one of the four possible positions. 
     A drawback to conventional flap knobs and shifter levers is that they do not readily obtain one of the four possible positions. As a result, with conventional flap handle-command modules, when pilots wish to change the position of the aircraft flaps, they are required to “hunt” with the flap knob and shifter lever for the desired position. This puts undo work load on the pilots, and requires a degree of extra effort. 
     SUMMARY 
     According to one aspect, an apparatus for controlling positioning of flaps in an aircraft is provided. A shift lever is movable to each of a plurality of shift lever positions to control positioning of the flaps of the aircraft to each of a respective plurality of associated flap positions. A shift lever indexing plate includes a plurality of engagement positions associated with the plurality of shift lever positions, respectively, the shift lever being coupled to an engagement member. The engagement member moves with the shift lever and is biased to selectively engage a selected one of the plurality of the engagement positions associated with a selected one of the shift lever positions to command the aircraft flaps to the flap position associated with the selected one of the shift lever positions. The shift lever indexing plate further comprises a web portion which separates the engagement positions of the shift lever indexing plate. The web portion and the shift lever are shaped and the shift lever is biased such that when the shift lever is at rest and only the shift lever bias is applied to the shift lever, the engagement member must be engaged with one of the plurality of engagement positions of the shift lever indexing plate. 
     According to another aspect, an apparatus for controlling positioning of flaps in an aircraft is provided. A shift lever is movable to each of a plurality of shift lever positions to control positioning of the flaps of the aircraft to each of a respective plurality of associated flap positions. A shift lever indexing plate includes a plurality of engagement positions associated with the plurality of shift lever positions, respectively, the shift lever being coupled to an engagement member. The engagement member moves with the shift lever and is biased to selectively engage a selected one of the plurality of the engagement positions associated with a selected one of the shift lever positions to command the aircraft flaps to the flap position associated with the selected one of the shift lever positions. The shift lever indexing plate further comprises a web portion which separates the engagement positions of the shift lever indexing plate. The web portion of the shift lever indexing plate comprises a protrusion which interferes with the shift lever to prevent the shift lever from moving directly from a first shift lever position to a second shift lever position adjacent to the first shift lever position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other features and advantages will be apparent from the more particular description of preferred embodiments, as illustrated in the accompanying drawings, in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the preferred embodiments. In the drawings, the sizes and thicknesses of layers, regions, objects and features may be exaggerated for clarity. 
         FIG. 1  includes a schematic partially cut-away perspective view of a portion of a cockpit of an aircraft having a center pedestal in which a flap position handle-command module is located. 
         FIG. 2  includes a schematic perspective detailed view of the flap position handle-command module illustrated in  FIG. 1 , according to some exemplary embodiments. 
         FIG. 3  includes a schematic cross-sectional diagram taken along line A-A of  FIG. 2 , with the module set such that the aircraft flaps are in the UP or fully retracted position, according to some exemplary embodiments. 
         FIG. 4  includes a schematic cross-sectional diagram taken along line A-A of  FIG. 2 , with the module set such that the aircraft flaps are in the FULL or fully extended position, according to some exemplary embodiments. 
         FIG. 5  includes a schematic cross-sectional diagram taken along line A-A of  FIG. 2 , with the module in transit between positions such that the aircraft flaps are in transit to a new set position, according to some exemplary embodiments. 
         FIG. 6  includes a schematic exploded isometric view of the flap position handle-command module, according to some exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  includes a schematic partially cut-away perspective view of a portion of a cockpit  12  of an aircraft  10  having a center pedestal  14  in which a flap position handle-command module  100 , according to some exemplary embodiments, is located. Referring to  FIG. 1 , the flap position handle-command module  100  drops into center pedestal  14  as a self-contained module. 
       FIG. 2  includes a schematic perspective detailed view of the flap position handle-command module  100  illustrated in  FIG. 1 , removed from center pedestal  14 , according to some exemplary embodiments. Referring to  FIG. 2 , module  100  includes a housing  112  fixed to a flange  102 , by which module  100  is mountable in center pedestal  14 . Housing  112  is covered by a housing cover plate  114 , which is fixed to housing  112  by screws  120 . Wrap-around covers or shrouds  116  are fixed in place over housing cover plate  114  by screws  118 . 
     Module  100  is used to command the aircraft flaps to the various possible flap positions. As shown in  FIG. 2 , in these particular exemplary embodiments, there are four possible flap positions, namely, “UP” or fully retracted, “FULL” or fully extended, position “1” being the first position beyond UP or fully retracted, and position “2” being the second to last position, immediately before “FULL” or fully extended. It will be understood that the present disclosure is applicable to aircraft having any number of flap positions, not only aircraft having four flap positions. To command the flaps to the various positions, a flap knob  104  is moved within a flap knob slot  106  defined between a first flap knob slot side  108  and a second flap knob slot side  110 . The vertical opening into the interior of module  100  in the bottom of slot  106  is covered with a slot cover  107  which is carried into motion and moves with flap knob  104  as flap knob  104  moves. 
     Although not illustrated in  FIG. 2 , the motion of flap knob  104  is controlled by a detent system, as described herein in detail in connection with exemplary embodiments, such that once it is set at one of the positions, e.g., UP-1-2-FULL, it is captured at that position until moved out of that position by the user, i.e., pilot. To move flap knob  104 , the user/pilot depresses flap knob  104  down into slot  106  against a mechanical bias, such as a mechanical bias provided by a compression spring, to free flap knob  104  from its present position, then moves flap knob  104  to a new desired position, then releases flap knob  104  such that flab knob  104  reengages in accordance with the detent system according to exemplary embodiments described herein in detail, such that flap knob  104  and, therefore, the flaps of the aircraft, occupy a new stationary position. 
       FIG. 3  is a schematic cross-sectional diagram taken along line A-A of  FIG. 2 , with the module  100  set such that the aircraft flaps are in the UP or fully retracted position, according to some exemplary embodiments. Referring to  FIG. 3 , as shown, flap knob  104  is mechanically connected to a shifter lever  122  which carries an engagement pin  134 , which is stationary with respect to shifter lever  122 . Module  100  also includes a detent plate assembly  132 , which includes multiple, in this exemplary embodiment, four, engagement grooves,  136 ,  138 ,  140 ,  142 , which define the engagement positions of shifter lever  122  and, therefore, the four flap positions of the aircraft flaps. Shifter lever  122  is biased by compression spring  130 , which is attached in stationary relation between pivot pin  124  and a shift pin  128 . Compression spring  130  biases shifter lever  122  and engagement pin  134  into an engaged position, in which engagement pin  134  is forced into and held in engagement with one of engagement grooves  136 ,  138 ,  140 ,  142 . 
     As noted above, in the exemplary illustrating of  FIG. 3 , the aircraft flaps are in the FULL position. As a result, engagement pin  134  is held in engagement with engagement groove  142  of detent plate assembly  132 , since engagement groove  142  is associated with the FULL aircraft flaps position. Similarly, engagement groove  140  is associated with aircraft flaps position  2 , such that, when engagement pin  134  is in engagement with engagement groove  140 , the aircraft flaps will be commanded to flaps position 2. Similarly, engagement groove  138  is associated with aircraft flaps position 1, such that, when engagement pin  134  is in engagement with engagement groove  138 , the aircraft flaps will be commanded to flaps position 1. Similarly, engagement groove  136  is associated with aircraft flaps position UP, such that, when engagement pin  134  is in engagement with engagement groove  136 , the aircraft flaps will be commanded to flaps position UP. 
     When a releasing force is applied to flap knob  104  and flap knob  104  is sufficiently depressed against the bias force of compression spring  130 , engagement pin  134  is removed from engagement with one of engagement grooves  136 ,  138 ,  140 ,  142  such that flap knob  104  can be moved into rotation within knob slot  106  as indicated by arrow  109 . When shifter lever  122  is moved, it pivots about pivot pin  124 , carrying engagement pin  134  into motion with shifter lever  122 . When the releasing force is removed from flap knob  104 , compression spring  130  biases engagement pin  134  back into engagement with one of engagement grooves  136 ,  138 ,  140 ,  142 , depending upon the position of shifter lever  122  when the releasing force is removed. As a result, the aircraft flaps are moved to a new position commanded by the new position of shifter lever  122 . 
     The position of the shifter lever  122  is sensed to determine the flap position command to be sent to the aircraft flaps such that the aircraft flaps are set to the position commanded by the user/pilot. The position of shifter lever  122  is sensed using a combination of a beam blocker  126 , sensor mount  127 , and two pairs of sensing switches  146  (SW1),  148  (SW2),  150  (SW3), and  152  (SW4), mounted on opposite sides of sensor mount  127 , as shown. Beam blocker  126  is mechanically coupled to shifter lever  122  at shift pin  128  and pivot pin  124  and pivots about pivot pin  124  along with shifter lever  122  when flap knob  104  is moved as described above in detail. However, when flap knob  104  is depressed or released, allowing shifter lever  122  to move longitudinally, beam blocker  126  does not move with shifter lever  122  because pivot pin  124  slides within a slot  144  formed in shifter lever  122 , and shift pin  128  slides within a slot formed in beam blocker  126 . 
     Beam blocker  126  and optical sensors SW1, SW2, SW3, SW4 sense the position of shifter lever  122  and generate electrical signals used to command the aircraft flaps to the position required by the user/pilot via flap knob  104 . The electrical signals generated by switches SW1, SW2, SW3, SW4 are routed through circuit boards  145 ,  151 , cable harnesses  156 ,  154 , printed circuit board  157 , cable  159  and out of module  100  via electrical connector system  158  for further processing to develop the flap commands required to place the flaps as required by the user/pilot. 
     As described above, module  100  also includes a detent plate assembly  132 , which includes multiple, in this exemplary embodiment, four, engagement grooves,  136 ,  138 ,  140 ,  142 , which define the engagement positions of shifter lever  122  and, therefore, the four flap positions of the aircraft flaps. Detent plate assembly  132  is held in position by screws and nuts  156  and  158 . It includes a web portion  154  and an opening portion  137 . The opening portion defines engagement grooves  136 ,  138 ,  140 ,  142  at which engagement pin  134  engages to hold shifter lever  122  in one of the four possible positions. The web portion  154  defines the portions of detent plate assembly surrounding and between the engagement grooves  136 ,  138 ,  140 ,  142 , including a flat section opposite engagement grooves  136 ,  138 . It will be noted that, according to exemplary embodiments, web portion  154  includes pointed and sloped portions  160 ,  162  and  164  between engagement grooves  136 ,  138 ,  140 ,  142 . As a result, when releasing force is removed from flap knob  104  such that compression spring  130  applies biasing force to shifter lever  122 , engagement pin  134  is forced into one of engagement grooves  136 ,  138 ,  140 ,  142 , without the need for any further action by the user/pilot. That is, the combination of the pointed and sloped shape of web portion of detent plate assembly  132  between grooves  136 ,  138 ,  140 ,  142  and the bias force supplied by compression spring  130  ensures that engagement pin  134  will engage one of engagement grooves  136 ,  138 ,  140 ,  142 , such that flap knob  104  and shifter lever  122  will automatically center on one of the flap positions, i.e., one of the aircraft flap positions is automatically commanded, without the need for the user/pilot to “hunt” for a shifter lever position to drop into. 
     Web portion  154  of detent plate assembly  132  also includes a safety protrusion  117 , which prevents the user/pilot from moving directly into the FULL position without first stopping at the 2 position. This is a safety feature which prevents the aircraft flaps from being placed in the fully extended position from any position other than the position immediately adjacent to the fully extended position. 
       FIG. 4  is a schematic cross-sectional diagram taken along line A-A of  FIG. 2 , with the module set such that the aircraft flaps are in the FULL or fully extended position, according to some exemplary embodiments. All of the elements of  FIG. 4  are the same as those of  FIG. 3 , as indicted by the like reference numerals. Accordingly, detailed description of those like elements will not be repeated. 
     Referring to  FIG. 4 , engagement pin  134  is in engagement with engagement groove  142 , which, as described above, is associated with aircraft flaps FULL position. As a result, with flap position handle-command module  100  in this configuration, the aircraft flaps will be commanded to FULL for the fully extended positio 
       FIG. 5  is a schematic cross-sectional diagram taken along line A-A of  FIG. 2 , with the module  100  in transit between positions such that the aircraft flaps are in transit to a new set position, according to some exemplary embodiments. All of the elements of  FIG. 5  are the same as those of  FIGS. 3 and 4 , as indicted by the like reference numerals. Accordingly, detailed description of those like elements will not be repeated. 
     Referring to  FIG. 5 , because shifter lever  122  is in transit between positions, engagement pin  134  is not in engagement with any of engagement grooves  136 ,  138 ,  140 , 142 . As a result, flap knob  104  and shifter lever  122  are depressed against the bias of compression spring  130 , as illustrated by the reduced amount of flap knob  104  exposed above slot side  110  and the increased amount of distal end  122   a  of shifter lever  122  exposed beyond detent plate assembly  132 . However, in accordance with the exemplary embodiments, when any releasing force applied to flap knob  104  is removed such that module  104  is allowed to return to a rest quiescent state, compression spring  130  and the pointed and sloped side  160  of engagement groove  138  will force engagement pin  134  into engagement with engagement groove  138 . As a result, the aircraft flaps will be commanded to flap position 1. This self-centering and self-engagement of the exemplary embodiments will occur automatically with no external intervention other than removal of any releasing force which may be presently applied against the biasing force of compression spring  130 . That is, the user/pilot will not need to move or “hunt” with flap knob  104  to find flap position 1. According to the self-centering action of the exemplary embodiments, that will be accomplished automatically. 
       FIG. 6  includes a schematic exploded isometric view of the flap position handle-command module, according to some exemplary embodiments. Most of the elements of  FIG. 6  are the same as those of  FIGS. 3, 4 and 5  as indicated by the like reference numerals. Accordingly, detailed description of those like elements will not be repeated. Referring to  FIG. 6 , shifter lever  122  is fixedly attached to flap knob  104  by a set screw  105 , which is applied to a flat portion  109  at a proximal end  122   b  of shifter lever  122 . 
     While the present disclosure has shown and described exemplary embodiments, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure, as defined by the following claims.