Patent Publication Number: US-8991770-B2

Title: Helicopter control stick support assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 12/980,838, filed on Dec. 29, 2010, which claims the priority of European Patent Application No: 09425543.7, filed on Dec. 30, 2009, the subject matter of both foregoing applications of which are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a helicopter control stick support assembly. 
     Military combat helicopters normally have two seats, one for the pilot, and one for the gunner, who controls the weapons and sight movements using two sticks and the information displayed on an instrument panel. 
     The instrument panel is normally defined by a plate fitted with instruments for monitoring flight and weapon conditions, sight position, etc.; and both the instrument panel and the sticks are normally located in fixed positions in front of the gunner&#39;s seat. 
     This is an awkward solution, in that the gunner must lean slightly forward and/or reach a long way to grip the sticks. And since one of the two sticks is equipped with a force transducer to operate the sight, this awkward gripping position could affect precision control of the sight. 
     Moreover, even taking into account adjustment of the gunner&#39;s seat, the above solution allows no adjustment according to the height and build of the gunner. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a helicopter control stick support assembly designed to provide a straightforward, low-cost solution to the above problems, and which is easy to use, and comprises relatively few component parts. 
     According to the present invention, there is provided a support assembly for a helicopter control stick, the support assembly comprises a supporting structure and an instrument panel fixed to each other; and a connecting assembly for connecting the stick to the supporting structure; the connecting assembly comprising an arm elongated in a longitudinal direction and having one end supporting said stick; a guide for connecting the arm in longitudinally sliding manner to the supporting structure, to move the end to and from the supporting structure; and a rotary assembly for connecting the arm to the supporting structure in rotary manner about a horizontal axis, to adjust the height of the end, the rotary assembly having a first releasable retainer, wherein the first releasable retainer operates to lock rotation of said arm with respect to the supporting structure in a desired angular position; wherein the arm is longitudinally slidable when the first releasable retainer is operated to lock rotation of the arm; wherein the horizontal axis extends transversely between the longitudinal ends of the arm. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A non-limiting embodiment of the invention will be described by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  shows a side view of a preferred embodiment of the helicopter control stick support assembly according to the present invention; 
         FIG. 2  shows a larger-scale view, with parts removed for clarity, of the  FIG. 1  support assembly; 
         FIG. 3  shows a partly sectioned front view of the  FIGS. 1 and 2  support assembly; 
         FIG. 4  shows the same view as in  FIG. 2 , and a section of the support assembly along line IV-IV in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Number  1  in  FIG. 1  indicates as a whole a helicopter cabin defining a first seat for a pilot (not shown), and a second seat for a gunner  2 . The second seat comprises a seat  3  for gunner  2 , and a support assembly  4  supporting two control sticks  5  in front of seat  3 . 
     More specifically, one of the two sticks  5  comprises a control device (not shown) with a force transducer, for moving a sight by which to aim the weapons on the helicopter. 
     With reference to  FIGS. 2 and 3 , assembly  4  comprises a supporting structure  6 , which, viewed from the front, is substantially inverted-U-shaped, and defines the top surface and side surfaces of a passage  7  having a vertical plane of symmetry substantially coincident with the central longitudinal plane of cabin  1  and seat  3 . Here and hereinafter, the terms “front”, “rear”, “side”, etc. are intended as seen by gunner  2 , and not with reference to the travelling direction of the helicopter. 
     Structure  6  comprises two side plates  8  defining the rear end and an intermediate portion of passage  7 . 
     Plates  8  have respective pairs of arc-shaped slots  11  ( FIG. 4) and 12  ( FIG. 2 ), the centre of curvature of which coincides with the same horizontal axis  10  perpendicular to the plane of symmetry of passage  7 . Slots  11 ,  12  on each plate  8  have the same angular extension, and are spaced roughly 90° apart. 
     With reference to  FIG. 3 , structure  6  also comprises an inverted-Y-shaped front plate  13  defining the front end of passage  7 , i.e. the outlet end of passage  7  in front of seat  3 . Plate  13  comprises two bottom appendixes  14  on either side of passage  7 ; and a top portion  15  over passage  7  and in turn comprising an appendix  16  extending upwards. 
     As shown in  FIG. 2 , structure  6  also comprises a rear plate  17 , which has substantially the same perimeter and shape as portion  15 , defines the top of the intermediate portion of passage  7 , and is fixed by its lateral ends to respective plates  8 . 
     Plates  8 ,  13  and  17  are ribbed, in a manner not described in detail, to reinforce structure  6  and fix plates  8 ,  13 ,  17  to one another. 
     Assembly  4  also comprises an instrument panel  20  perpendicular to passage  7  ( FIG. 2 ), and which comprises a connecting portion  21  interposed between plate  13  (at the front) and plates  8  and  17  (at the rear), and tightened by bolts  26  between appendixes  14  and two corresponding front ribs  27  on plates  8 . The fastening points defined by bolts  26  are preferably also used to fix structure  6  and instrument panel  20  to the ends of two struts (not shown) fixed at the opposite ends to the walls or frame of cabin  1 . 
     Instrument panel  20  comprises a display portion  28  ( FIG. 1 ) above portion  21  and fitted with indicators and/or a display (not shown). 
     Sticks  5  are connected to structure  6  by a connecting device  30 , which comprises an arm  31  extending inside passage  7 , in a longitudinal direction  32  in the plane of symmetry of passage  7 . Sticks  5  are fitted to an end  33  of arm  31 , and are arranged side by side on a top face  34  of end  33  (so only one is visible in the  FIG. 2  side view). More specifically, sticks  5  are fitted to end  33  to rotate, with respect to arm  31 , about an axis  35  parallel to axis  10 ; and a releasable retaining device  36 , only shown partly and not described in detail, enables gunner  2  to lock sticks  5  in position about axis  35 . 
     With reference to  FIG. 3 , arm  31  comprises a top section  38  having an inverted-U-shaped cross section and two vertical lateral walls  39  with respective longitudinal slots  40  ( FIG. 2 ). Section  38  is the same width as passage  7 , so walls  39  slide on the inner lateral surfaces of passage  7 . 
     Arm  31  comprises an intermediate section  41 , which has a U-shaped cross section, comprises two lateral walls  42  inside section  38  and fixed to walls  39 , and together with section  38  defines a longitudinal cavity  43 . Section  41  comprises an intermediate bottom wall  44  fixed to a longitudinally elongated bottom body  45  with an inverted-U-shaped cross section. 
     Device  30  comprises two guides  46 ,  47  connected in angularly-fixed, longitudinally-sliding manner to arm  31 . Guide  46  is housed in cavity  43  and connected to arm  31  by pins  48 ,  49  ( FIG. 4 ) which slide inside slots  40 . Pins  49  extend along axis  10  and are fitted to plates  8  to define a hinge; whereas pins  48  are aligned with slots  11  along an axis  50  parallel to axis  10 , and slide inside slots  11  between two angular limit positions defined by the top and bottom edges of slots  11  and covering a maximum angle of 20-30°. 
     Guide  47  comprises a bottom support  52 ; and a top slide  53 , which is fixed to support  52 , is housed inside body  45 , and is fitted to the lateral walls of body  45  to slide parallel to direction  32 . Support  52  has two outer lateral faces  55  with respective arc-shaped grooves  56  ( FIG. 4 ), the centre of curvature of which coincides with axis  10 . Grooves  56  are engaged in sliding manner by respective guide projections  57  fitted to the bottom ends of plates  8  and substantially complementary in shape to grooves  56 . 
     As shown in  FIG. 3 , a releasable locking device  60  frictionally locks rotation of guide  47  about the hinge defined by axis  10 , and comprises: two nut screws  61  fixed with respect to faces  55 , located above grooves  56 , and aligned with slots  12  along an axis  59  parallel to axis  10 ; and two threaded members  62  screwed inside respective nut screws  61 , and which move inside slots  12  between two angular limit positions defined by the right and left edges of slots  12  and corresponding to the angular limit positions of pins  48 . Device  60  also comprises a lever  63  to rotate threaded members  62  together about axis  59 , and grip their ends axially against the outer lateral faces of plates  8  to frictionally lock rotation of guide  47 . 
     With reference to  FIGS. 2 and 4 , pins  48  are threaded and form part of a releasable locking device  64  for gripping walls  39  between guide  46  and plates  8  to frictionally lock both rotation and slide of arm  31 . Device  64  is independent of device  60 , and comprises two levers  65  for respectively screwing/unscrewing pins  48  inside respective nut screws  66  fixed in relation to respective lateral walls of guide  46 . 
     When frictional locking device  64  is released, arm  31  can slide, with respect to guides  46 ,  47  and pins  48 ,  49 , which also perform a guide function, into a fully withdrawn position, in which end  33  and sticks  5  are positioned close to the front of instrument panel  20  to allow gunner  2  to move freely in and out of his seat. Once settled in seat  3 , gunner  2  can pull arm  31  longitudinally to draw sticks  5  horizontally away from the instrument panel and into the best position to grip sticks  5  (as shown by the dash line in  FIG. 1 ). At the same time, by releasing device  60 , the height of sticks  5  can also be adjusted by rotating arm  31  about axis  10 . When so doing, guides  46 ,  47  rotate together with arm  31 . 
     For example, arm  31  may be slid and rotated to rest end  33  on or between the knees. Once set to the required position, arm  31  is preferably locked in place using device  64 . 
     If arm  31  is subjected to vibration transmitted by structure  6 , however, locking devices  60 ,  64  may be loosened slightly or completely, to prevent vibration being transmitted. 
     When locking device  64  is released, the angle of arm  31  about axis  10  locked by device  60  remains unchanged, so that the same gunner occupying the seat need only set the angle of arm  31  once, and only operate device  64  to lock/release the arm in direction  32 , i.e. to adjust sticks  5  with respect to control panel  20 . 
     To leave the seat quickly, in the event of an emergency, arm  31 , even when locked by device  64 , can be pushed by gunner  2  towards instrument panel  20  forcefully enough to overcome the friction exerted by device  64  on arm  31 , and so slide the arm in to permit easy exit from seat  3 . 
     By fitting sticks  5  to an arm  31  that can be extended or extracted from support  6 , gunner  2  obviously need no longer lean or reach forward to grip sticks  5 . Assembly  4  also provides for relatively wide adjustment of both the height and longitudinal position of sticks  5 , to enable gunner  2  to adjust the position of the sticks to his own height and build, and to the set position of seat  3 . 
     Another advantageous adjustment is permitted by rotation about axis  35  and by device  36 , which provide for adjusting sticks  5  with respect to the forearms of gunner  2 . 
     Ergonomically positioning sticks  5  makes for more accurate sight control as compared with known solutions allowing no stick position adjustment. 
     Moreover, axis  10  being located between the ends of arm  31  and extending across arm  31 , structure  6  is compact, while allowing ample freedom of adjustment. 
     As stated, devices  60  and  64  operate independently, so arm  31  can be slid longitudinally with no change in the angle of arm  31 . 
     Clearly, changes may be made to support assembly  4  as described herein without, however, departing from the scope of the present invention as defined in the accompanying Claims. 
     In particular, assembly  4  may be applied to adjust the position of sticks other than the weapon control sticks described. 
     Guide  46  may be located outside arm  31 , possibly connected to structure  6  by a hinge system other than the one described; and/or arm  31  may feature guide members other than slots  40  and pins  48 ,  49 , or be telescopic; and/or guide  47 , body  45 , device  60 , and projections  57  as a whole may be eliminated, and only device  64  used to lock arm  31 ; and/or instrument panel  20  may be fixed to a supporting structure in a different manner from the one described by way of example.