Abstract:
A landing gear strut extender apparatus and its method of use adjust the length of a shock absorbing strut to facilitate the attachment of the strut between an aircraft landing gear and a snow ski. The apparatus is specifically designed for holding the strut in a desired extended (or retracted) length and is then used to attach the strut held at the desired length to an aircraft landing gear that has been fit with a snow ski.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     (1) Field of the Invention  
         [0002]     The present invention pertains to an apparatus and its method of use in adjusting and holding a length of a shock absorbing strut for attaching the strut between an aircraft landing gear and a snow ski. In particular, the present invention pertains to an apparatus specifically designed for holding the shock absorbing strut in a desired extended (or retracted) length, and the method of using the apparatus to attach the strut held at the desired length to an aircraft landing gear that has been fit with a snow ski.  
         [0003]     (2) Description of the Related Art  
         [0004]     Various different types of aircraft, including fixed-wing aircraft and rotary wing aircraft are used in all seasons and climates. When used in the winter season or in colder climates, where there is the potential for snow cover over a landing strip or landing area of the aircraft, the landing gear of the aircraft are often equipped with snow skis that support the aircraft on the surface of the snow and prevent the landing gear of the aircraft from penetrating deeply into the snow.  
         [0005]     A typical snow ski is attached to the aircraft by pivot connections at the wheel axle of the aircraft landing gear. The pivot connections enable the snow ski to pivot about the wheel axle. The typical snow ski has a length between a forward edge of the snow ski that projects forwardly of the landing gear wheel, and a rearward edge of the snow ski that projects rearwardly of the landing gear wheel. The snow ski often has a lateral width that is greater than the width of the landing gear wheel. An opening is provided through a central portion of the snow ski and the landing gear wheel is positioned in this opening when the snow ski is attached to the landing gear.  
         [0006]     With the snow ski being connected by a pivot connection to the aircraft landing gear, it is necessary that a strut be connected between the landing gear and the forward edge of the snow ski. The strut maintains the forward edge of the snow ski at a desired orientation relative to the landing gear to ensure that the snow ski forward edge is directed upwardly when the aircraft is taking off from the snow covered surface or landing on the snow covered surface. This prevents the forward edge of the snow ski from digging into the snow cover as the aircraft lands or takes off.  
         [0007]     The typical snow ski strut is comprised of a cylinder and a rod that extends into one end of the cylinder for reciprocating movement of the rod relative to the cylinder. The cylinder contains a pair of springs or other equivalent means of resisting movement of the rod from an at rest position of the rod relative to the cylinder. The end of the rod inside the cylinder is connected between the first and second springs. Pulling the rod from the cylinder compresses one of the springs and stretches the second spring. Pushing the rod into the cylinder stretches the one spring and compresses the second spring. Thus, the springs bias the rod to the at rest position relative to the cylinder. The spring bias on the rod also pulls upwardly on the forward edge of the snow ski to orient the snow ski in its upward orientation relative to the aircraft landing gear.  
         [0008]     In installing the snow ski on the aircraft landing gear with the aircraft sitting on the surface of the landing strip or landing area, the surface of the landing strip or landing area prevents the snow ski from being pivoted freely relative to the landing gear. This can prevent the forward edge of the snow ski from being positioned in its desired forward upwardly oriented position relative to the landing gear. It is therefore necessary to extend the length of the snow ski strut to connect the strut between the landing gear and the forward edge of the snow ski. This requires that the strut rod be extended from the strut cylinder against the bias of the strut springs while simultaneously attaching the strut between the landing gear and the snow ski. Performing this attachment procedure is often difficult and time consuming.  
         [0009]     An apparatus that could be used to hold the snow ski strut at its adjusted length while the strut is attached between the aircraft landing gear and the forward edge of the snow ski would facilitate the assembly of the strut to the aircraft landing gear and snow ski.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention provides an apparatus for adjusting the length of a landing gear snow ski strut from the at rest position of the strut rod and cylinder and holding the strut at the adjusted length, and a method of using the apparatus to attach the strut between an aircraft landing gear and a forward edge of a snow ski. The apparatus is comprised of a minimum number of component parts and is easily operated in holding the snow ski strut when using the apparatus to attach the strut between the aircraft landing gear and the snow ski.  
         [0011]     The apparatus is basically comprised of first and second elongate arms, with each arm having opposite proximal and distal ends. The proximal ends of the two arms are connected together by a pivot connection that holds the two arms in a general V-shaped configuration. The two arms are substantially identical, and the lengths of the two arms are reversed when connected together.  
         [0012]     A manually operable mechanism is connected between the two arms with the mechanism extending across the V-shaped configuration of the arms. Operation of the mechanism selectively pivots the arms about their pivot connection moving the distal ends of the arms away from each other, and moving the distal ends of the arms toward each other.  
         [0013]     Strut connectors are provided at the distal ends of the first and second arms. The strut connector of the first arm is adapted to be removably attached to the cylinder of the snow ski strut. The strut connector of the second arm is adapted to be removably attached to the rod of the snow ski strut.  
         [0014]     In use of the apparatus of the invention in adjusting and holding the length of the snow ski strut, the connector of the first arm is removably attached to the strut cylinder and the connector of the second arm is removably attached to the strut rod. The mechanism is then operated to cause the pair of arms to pivot about the pivot connection at the arm proximal ends causing the arms to move away from each other at the distal ends. This causes the connectors to pull the strut rod from the strut cylinder against the bias of the strut springs. The operation of the mechanism is continued, causing the arms to pivot away from each other and the strut rod to be pulled from the strut cylinder until the strut rod is extended a desired extent from the strut cylinder to enable the strut to be easily connected between the landing gear and snow ski of the aircraft. When the strut is connected to the landing gear and the snow ski, the mechanism is operated to cause the arms to pivot toward each other. This releases the connector of the first arm from the strut cylinder and releases the connector of the second arm from the strut rod end and enables removal of the apparatus from the strut. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0015]     Further features of the invention are set forth in the following detailed description of the preferred embodiment of the invention, and in the following drawing figures wherein:  
         [0016]      FIG. 1  is a side perspective view of the apparatus of the invention;  
         [0017]      FIG. 2  is a view of the apparatus similar to  FIG. 1 , showing the apparatus connected to a snow ski strut; and,  
         [0018]      FIG. 3  is a view showing the method of using the apparatus of the invention in attaching the snow ski strut between an aircraft landing gear and a snow ski. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]      FIG. 1  shows the snow ski strut extender apparatus  10  of the present invention. As shown in  FIG. 1 , the apparatus  10  is constructed of a minimum number of parts that enable the apparatus to be easily operated. The apparatus  10  is basically comprised of a pair of first and second arms  12 ,  14 , a pivot connection  16  between the arms, a mechanism  18  that extends between the arms and is used to move the arms relative to each other, and a pair of strut connectors  22 ,  24  attached to the pair of arms. In the preferred embodiment of the apparatus, each of the component parts is constructed of a rigid material, for example a metal, to enhance the strength of the apparatus. However, other equivalent materials may also be used.  
         [0020]     The first arm  12  of the pair of arms has a longitudinal length that extends between a proximal end  26  and an opposite distal end  28  of the arm. The arm proximal end  26  has a reduced lateral width compared with the lateral width of the remainder of the arm length. A plurality of oblong holes  32  extend through the arm  26  and are spatially arranged along the arm length. Coaxially aligned pivot holes  34  extend laterally through the arm and intersect one of the oblong holes  32 . A pair of fork prongs or tines  36  project outwardly from the arm distal end  28 . The prongs  36  have coaxially aligned pivot holes  38  that extend laterally through the prongs.  
         [0021]     The second arm  14  is constructed in basically the same manner as the first arm  12  described above. The second arm  14  is substantially identical to the first arm, but the orientation of the second arm  14  is the reverse of that of the first arm  12  in the apparatus. With the arms  12 ,  14  reversed, the second arm  14  has a pair of prongs  42  that project outwardly from the arm proximal end  44 . A lateral spacing between the second arm proximal prongs  42  is dimensioned to receive the proximal end  26  of the first arm  12  between the prongs  42 . The second arm  14  also has a longitudinal length that extends from the arm proximal end  44  to an opposite distal end  46  of the arm. Oblong holes  48  extend through the second arm  14 . Coaxially aligned pivot holes  52  also extend laterally through the second arm  14  and intersect one of the oblong holes  48 . A pair of prongs  54  projects outwardly from the second arm distal end  46 . The second arm prongs  54  also have coaxially aligned pivot holes  56  that extend laterally through the prongs.  
         [0022]     The pivot connection  16  connects the proximal ends  26 ,  44  of the two arms, holding the two arms in a V-shaped configuration as shown in  FIG. 1 . The pivot connection  16  can be provided by a pivot pin  62  that extends through laterally aligned coaxial holes in the proximal ends  26 ,  44  of the two arms. Other equivalent means can be employed to provide the pivot connection  16  between the two arms  12 ,  14 . The pivot connection  16  enables the distal ends  28 ,  46  of the two arms  12 ,  14  to be selectively pivoted toward and away from each other.  
         [0023]     The first strut connector  22  is connected between the first arm prongs  36  for pivoting movement of the strut body connector  22  relative to the first arm  12 . The first connector  22  has a generally cylindrical exterior configuration. A pair of coaxially aligned connector pins  64  project from diametrically opposite sides of the first connector  22 . The pins  64  extend into the first arm prong pivot holes  38 , mounting the first connector  22  on the first arm distal end  28  for pivoting movement of the connector relative to the first arm  12 . A slot or opening  66  is formed into the first connector  22 . The opening  66  is configured to receive an end of the cylinder of the aircraft snow ski strut. This enables the first connector  22  and the first arm distal end  28  to be removably attached to a first portion of the snow ski strut, i.e. the cylinder or body of the snow ski strut.  
         [0024]     The second connector  24  is constructed in a similar manner to that of the first connector  22 , but at a smaller scale. The second connector  24  is also constructed with a pair of coaxially aligned connector pins  68  that project from diametrically opposite sides of the second connector. The pins  68  extend into the prong pivot holes  56  of the second arm  14 , thereby mounting the second connector  24  to the second arm distal end  46  for pivoting movement of the second connector  24  relative to the second arm  14 . A slot or opening  72  is formed into the second connector  24 . The opening  72  has a configuration that is complementary to an end of the rod of the snow ski strut. Thus, the configuration of the second opening enables the second connector  24  and the second rod distal end  46  to be removably attached to a second portion of the snow ski strut, i.e. the strut rod.  
         [0025]     The mechanism  18  that selectively pivots the first and second arms  12 ,  14  toward and away from each other about the pivot connection  16  can be anyone of various different equivalent types of mechanisms that are capable of performing this method. The mechanism  18  shown is constructed of a screw threaded rod  74  and a pair of internally screw threaded nuts  76 ,  78 .  
         [0026]     The rod  74  has a hexagonal head  82  at an intermediate position of the rod length. The head  82  is configured to be engaged by a wrench that is used to turn the rod  74  in opposite directions. The head  82  divides the rod into first  84  and second  86  rod portions that extend from opposite ends of the head  82 . The rod first portion  84  has external screw threading  88  and the rod second portion  86  has external screw threading  92 . The first portion screw threading  88  is opposite the second portion screw threading  92 . For example, the screw threading of the first portion  88  is right hand screw threading, and the screw threading of the second portion  92  is left hand screw threading.  
         [0027]     The first nut  76  of the mechanism  18  has an interior bore with internal screw threading that is complementary to the screw threading  88  of the rod first portion  84 . The rod first portion  84  is screw threaded through the interior bore of the first nut  76 . Thus, the first nut  76  is mounted on the rod first portion  84  for adjustable movement of the first nut  76  along the rod first portion  84  in response to rotation of the rod in opposite directions.  
         [0028]     In a like manner, the second nut  78  has an interior bore with internal screw threading that is complementary to the screw threading of the rod second end portion  86 . The rod second end portion  86  is screw threaded through the interior bore of the second nut  78 . Thus, the second nut  78  is mounted on the rod second portion  86  for adjustable movement of the second nut  76  along the rod second portion  86  in response to rotation of the rod in opposite directions.  
         [0029]     A pair of coaxial pivot pins  94  project from diametrically opposite sides of the first nut  76 . The first nut is positioned in one of the oblong holes  32  of the first arm  12  with the first nut pivot pins  94  extending into the pivot holes  34  of the first arm. This mounts the first nut  76  on the first arm  12  for pivoting movement of the first nut  76  relative to the first arm  12 .  
         [0030]     The second nut  78  is also provided with a pair of coaxial pivot pins  96  that project from diametrically opposite sides of the second nut. The second nut  78  is positioned in an oblong hole  48  of the second arm  12  with the diametrically opposite second nut pivot pins  96  extending into the pivot holes  52  of the second arm. This mounts the second nut  78  on the second arm  14  for pivoting movement of the second nut  78  relative to the second arm  14 .  
         [0031]      FIG. 3  illustrates the use of the apparatus  10  in installing a snow ski strut  102  between a snow ski  104  and a landing gear  106  of an aircraft. The apparatus  10  is used to extend or adjust the overall length of the strut  102 , and to hold the strut at its desired length for attaching opposite ends of the strut to the snow ski  104  and the landing gear  106 .  
         [0032]     In use of the apparatus  10 , the mechanism  18  is manually operated by connecting a wrench to the rod head  82  and turning the head  82  in a desired direction to increase or decrease the distance between the distal ends  28 ,  46  of the apparatus arms  12 ,  14 . This adjustment is made to position the two connectors  22 ,  24  at positions where they can be removably attached to the snow ski strut cylinder  112  and rod  108  at the positions shown in  FIG. 2 . The attachment of the apparatus  10  to the strut  102  is made with the strut rod  108  and cylinder  112  in their relative at rest positions. As shown in  FIG. 2 , the first strut connector  22  on the first arm  12  is removably attached to the strut cylinder  112  and the second strut connector  24  on the second arm  14  is removably attached to the strut rod  108 . Again, these removable connections between the apparatus  10  and the strut  102  are made while the strut rod  118  and strut cylinder  112  are at their relative at rest positions (i.e. their retracted positions).  
         [0033]     The mechanism  18  of the apparatus is then operated to cause the pair of arms  12 ,  14  to pivot about the pivot connection  16  at the arm proximal ends, causing the arms to move away from each other or toward each other. This in turn adjusts the distance between the first strut connector  22  and the second strut connector  24 , respectively increasing or decreasing the distance. The movement of the connectors  22 ,  24  adjusts the overall length of the snow ski strut  102 . The operation of the mechanism  18  is continued, causing the arms  12 ,  14  to move relative to each other and adjusting the overall length of the strut  102  by pulling the strut rod  108  from the strut cylinder  112 , or releasing the rod  108  into the cylinder  112  against the bias of the strut springs. This adjusts the overall length of the strut  102  to a desired length that enables the strut to be easily connected between the landing gear  106  and the snow ski  104  of the aircraft. The screw thread engagement between the rod ends  84 ,  86  and the arm nuts  76 ,  78  enables a continuous adjustment of the overall length of the strut  102 , as opposed to a stepwise adjustment.  
         [0034]     When the strut  102  is connected between the landing gear  106  and the snow ski  104 , the mechanism  18  is then again operated to cause the arms  12 ,  14  to pivot toward each other. This releases the strut connectors  22 ,  24  from their attachment to the strut cylinder  112  and the strut rod  108  and enables removal of the apparatus  10  from the strut  102 .  
         [0035]     Although the apparatus and its method of use of the invention have been described above by reference to a specific embodiment, it should be understood that modifications and variations could be made to the apparatus and method without departing from the intended scope of the following claims.