HELICOPTER SELF-LEVELING LANDING GEAR

• US 3,857,533 A
• Filed: 01/28/1974
• Issued: 12/31/1974
• Est. Priority Date: 01/28/1974
• Status: Expired due to Term

• Current Assignee: Samuel H. Mason
• Original Assignee: Samuel H. Mason
• Inventors: Mason, Samuel H.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Sauberer, Paul E.
• Application Number:
  US05/437,347
• Time in Patent Office: 337 Days
• Field of Search: 180/41 280/6R,6H,6.11 244/17.17,17.11,1R,12R,13R
• US Class Current: 244/17.17
• CPC Class Codes: B64C 2025/008 Comprising means for modifying their length, e.g. for kneeling, for jumping, or for leveling the aircraft
• CPC Class Codes: B64C 2025/325 specially adapted for helicopters
• CPC Class Codes: B64C 25/00 Alighting gear air-cushion alighting gear B60V3/08
• CPC Class Codes: B64C 25/52 Skis or runners

Abstract

A self-leveling landing gear for a helicopter includes two curved track members lying in parallel planes generally normal to the longitudinal axis of the helicopter. Skids are secured to the opposite downwardly extending curved ends of the curved track members. A base frame for the helicopter receives the curved track members in guide means so that the track members may move through the base member of the helicopter and thus the helicopter can remain in a level position even though one landing skid is at a higher level that the other when the helicopter lands on uneven terrain. The curved track members can be locked to the base frame of the helicopter when the helicopter is in a level position so that it will be stably supported on the uneven terrain.

Claims

1. A helicopter self-leveling landing gear including:

a. a helicopter having a lower base frame;

b. guide means on said base frame;

c. at least one curved track member of inverted U-shape having a central portion passing through said guide means and its opposite end portions curving downwardly from the central portion toward the ground, the track member lying in a plane normal to the longitudinal axis of the helicopter and being movable through the guide means to thereby vary the distance between each end and the ground;

d. landing skids extending generally parallel to the longitudinal axis of the helicopter secured respectively to the ends of the track member; and

, e. locking means on the base frame coupled to the central portion of said track member for locking the track member to the base frame in an immovable position, whereby the level of one landing skid relative to the other may vary by movement of the track member through the guide means such that said base frame and helicopter may be maintained at a level position when said landing skids engage uneven terrain during landing wherein one landing skid is at a higher level than the other, and said locking means actuated to lock the track member and thus the skids relative to the base frame after landing to maintain the base frame and helicopter level.

2. A helicopter according to claim 1 in which said locking means includes:

a curved rack following the curve of the central portion of said track member and secured to the track member for movement therewith; and

finger means pivotally mounted on said base frame for movement into and out of engagement with said rack at different points along the rack to thereby effect locking and unlocking of the track member relative to the base frame.

3. A helicopter according to claim 2 including intercoupling means between said finger means and the pitch control of the rotor blades of the helicopter whereby when the pitch is adjusted to a given value, the finger means are moved out of the rack to automatically release the track member.

4. A helicopter according to claim 2 including hydraulic control means responsive to a given weight applied to said skids to actuate said locking means whereby said locking means is automatically actuated to hold said helicopter level when the weight of the helicopter on the skids exceeds said given weight upon landing, said locking means being released when the weight of the helicopter is removed from the skids upon take-off.

5. A helicopter according to claim 4 in which said curved track member is semicircular in shape so that the weight of the helicopter when level is evenly divided on each skid regardless of the relative level Of one skid to the other.

6. A helicopter according to claim 4, in which said locking means includes first and second curved racks secured to and following the curve of the central portions of said first and second track members respectively;

and first and second pairs of finger means pivotally mounted on the base frame in first and second positions to move into and out of engagement, respectively, with said first and second racks at different points along the racks depending upon the positions of the track members in the guide means to thereby effect locking and unlocking of both track members simultaneously relative to the base frame.

7. A helicopter self-leveling landing gear comprising, in combination:

a. a helicopter;

b. a base frame secured to the lower body portion of said helicopter;

c. first and second guide means on the forward and rear portions of said base frame as measured along the longitudinal axis of said helicopter;

d. first and second curved track members of inverted U-shape having central portions passing through said first and second guide means respectively, the opposite lower end portions of each member curving downwardly from the central portion towards the ground, the track members lying in parallel planes normal to the longitudinal axis of said helicopter, said track members being movable together through the guide means to thereby vary the distance between their opposite ends and the ground;

e. landing skids extending generally parallel to the longitudinal axis of the helicopter and secured respectively to the ends of the first and second track members; and

, f. locking means on the base frame coupled to the central portions of said first and second track members for locking the track members to the base frame in an immovable position when the locking means is actuated to a first position and releasing the track members for movement through the guide means when the locking means is actuated to a second position whereby the level of one landing skid relative to the other may be varied by movement of the first and second track members through the guide means such that said base frame and helicopter may be maintained at a level position when said landing skids engage uneven terrain during landing, actuation of the locking means to its first position after landing locking the skids in their relative positions on the terrain to maintain the base frame and helicopter level.

8. A helicopter according to claim 7, in which the curved tracks are semicircular in shape so that the weight of the helicopter when level is evenly divided on each skid regardless of the relative level of one skid to the other.

9. A helicopter according to claim 7 including hydraulic control means responsive to a given weight applied to said skids to actuate said locking means whereby said locking means is automatically actuated to hold said helicopter level when the weight of the helicopter on the skids exceeds said given weight upon landing, said locking means being released when the weight of the helicopter is removed from the skids upon take-off.

10. A helicopter according to claim 9 in which said hydraulic control means is disposed between the ends of the curved tracks and the skids.