Slope landing compensator system

• US 4,062,507 A
• Filed: 02/03/1977
• Issued: 12/13/1977
• Est. Priority Date: 02/03/1977
• Status: Expired due to Term

• Current Assignee: Donald W. Felder
• Original Assignee: Donald W. Felder
• Inventors: Felder, Donald W.
• Primary Examiner(s): Kelmachter, Barry L.
• Application Number:
  US05/765,196
• Time in Patent Office: 313 Days
• Field of Search: 244/17.17, 244/104 R, 244/104 FP, 244/102 SS, 244/102 R, 244/100 R, 280/6 H, 280/6.11, 180/41, 267/65 D, 267/DIG. 2, 137/461, 137/462, 137/517
• 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 25/00 Alighting gear air-cushion alighting gear B60V3/08

Abstract

A slope landing compensator system for allowing helicopters with air/oil strut type landing gear to land on inclined surfaces while maintaining the air frame in a more upright attitude, comprising two pressure responsive valves, an interconnecting line with a conventional on/off valve between the two valves. A pressure responsive valve is mounted to each of the main landing gear struts with an interconnecting line between the two so that during landing on an inclined surface, as the up slope gear touches the surface and as the strut compresses the internal pressure travels across to the down slope strut until the up slope strut has compressed to a predetermined pressure at which time pressure is sufficient to close the pressure responsive valve of the up slope strut to give firm support and so that all the pressure is not transmitted to the down slope strut and allow the up slope strut to bottom out. The down slope strut now has a higher pressure and will compress less than normal, allowing both main landing gears of the helicopter to be firmly in contact with the surface while maintaining the air frame in a more upright attitude.

Claims

1. A slope landing compensator system for allowing helicopters to land on an inclined surface while maintaining the airframe of the helicopter in a more upright attitude comprising:

a main landing gear strut on each side of said airframe;

each of said struts containing a fluid and pneumatic shock absorbing system including a piston and fluid and air;

one of said pistons being compressed to a greater extent than the other of said pistons when said helicopter has landed on said inclind surface;

said strut with said piston compressed to a greater extent forming an up slope strut and said other strut forming a down slope strut;

said fluid and air in said up slope strut having a higher internal pressure than the fluid and air in said down slope strut;

valve means for transferring the air from said up slope strut to said down slope strut so that said down slope strut may be extended more than said up slope strut;

said valve means including a pressure responsive valve associated with a service valve receptacle on each of said struts and a pilot operated valve connecting said pressure responsive valves;

each said pressure responsive valve including a valve housing, a movable working member in said housing for movement in one direction by air pressure in an amount and at a rate proportional to said air pressure to a closed position, and for movement in an opposite direction to an open position, biassing means for continuously biassing said working member in said opposite direction, means defining a valve inlet passageway, means defining a valve outlet passageway, means defining a communicating passageway between said inlet and outlet passageway means when said working member is in said open position, said working member forming a second passageway for continuous communication between said inlet passageway means and the top of the working member and a service valve receptacle in the upper portion of the valve housing, said working member having a valve position indicator pin extending from its bottom surface and being of sufficient length to extend through a bore in a biassing adjustment plug in said housing when the working member is in said closed position, said bore providing sufficient clearance between the pin and the walls of the bore to permit air to pass therethrough, guide means for said working member comprising a guide pin in said housing and a slot in said working member for providing up and down stops and radial alignment means, sealing means around the lower portion of said working member and a dust seal located in said housing adjacent said adjustment plug;

said inlet passageway means of each of said pressure responsive valves communicating with one of said strut service valve receptacles through a threaded connection; and

said outlet passageway means of the pressure responsive valves directly communicating with each other through said pilot operated valve for permitting said air in said up slope strut to be transferred to said down slope strut in response to the higher air and fluid pressure in said up slope strut until sufficient pressure is created to activate the pressure responsive valve associated with said up slope strut to said closed position.