Electricity: circuit makers and breakers – Special application
Patent
1989-10-03
1991-09-03
Scott, J. R.
Electricity: circuit makers and breakers
Special application
200 85R, 244 1713, H01H 3500, B64C 2700
Patent
active
050456490
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to aircraft weight on gear switches and, in particular, to a self-adjusting slide assembly for mounting an aircraft weight on gear switch.
BACKGROUND OF THE INVENTION
Sophisticated aircraft generally include a weight on gear switch for activating and deactivating various aircraft systems and flight controls depending upon whether the aircraft is airborne or fully supported by the landing gear on the ground. In some aircraft, such as helicopters, the weight on gear switch also provides an indication to the pilot that the aircraft is either airborne or on the ground.
Aircraft weight on gear switches, or squat switches, are typically actuated by a main landing gear strut when compressed to support the weight of the aircraft. On helicopters with skid landing gear systems, paddles or similar devices have been used to actually contact the ground surface upon landing of the helicopter. However, switches designed to contact the ground are generally unreliable because of collection of dirt and debris or damage from skid movement and objects on the ground. In addition, ground contact switches can give erroneous indications when the helicopter is landing on uneven terrain.
Other types of helicopter weight on gear switches have been based on collective stick position or engine torque. However, these types of switches generally can be overridden by the pilot so that they can indicate the aircraft is airborne when it is actually on the ground.
Another type of weight on gear switch for skid gear helicopters is mounted so as to detect deflection of a cross tube of the skid landing gear. This placement of the weight on gear switch overcomes many of the disadvantages of the ground contact or collective stick position switches. However, switches mounted to indicate deflection of the skid gear cross tube require periodic adjustment as a result of repeated cross tube deflection from normal landings and permanent deformation from harder than normal landings. Without such periodic adjustment, weight on gear switches can give erroneous indications that can affect flight safety.
Therefore, there is a need for a mounting assembly for a helicopter weight on gear switch that is self-adjusting both for normal landing deflection of the skid gear cross tube and for permanent deformation of the cross tube resulting from hard landings.
SUMMARY OF THE INVENTION
The present invention is a self-adjusting slide assembly for an aircraft weight on gear switch. A preferred embodiment of the slide assembly is particularly adapted for mounting a weight on gear switch to detect the oscillatory deflection of a skid landing gear cross tube on a helicopter.
A mounting bracket of the self-adjusting slide assembly is mounted to the underside of the helicopter fuselage in close proximity to the center of a cross tube of the skid landing gear. A back plate extends vertically downward from the mounting bracket. A pair of vertical clamp plates are attached to the back plate by fastening means so as to form a vertical channel between the clamp plates and a vertical groove between each of the clamp plates and the back plate. A slide member has a T-shaped flange along one edge thereof for slidably mounting in the channel and grooves formed by the back plate and the clamp plates. The fastening means may be tightened or loosened to adjust the force necessary to move the slide member vertically in the channel and grooves.
The slide member has a generally C-shaped configuration with upper and lower arms. The slide member is mounted so that the arms extend above and below the cross tube of the helicopter skid landing gear. During take-off and landing, the cross tube of the landing gear deflects a known distance in the vertical direction. Deflection of the cross tube causes it to contact a top bumper on the upper arm when the helicopter is airborne and to contact a bottom bumper on the lower arm when the weight of the helicopter is on the landing gear. A microswitch is mounted on the lower arm so as to extend vertically
REFERENCES:
patent: 2722587 (1955-11-01), Buzzetti et al.
patent: 2850121 (1958-09-01), Curl et al.
patent: 2887672 (1959-05-01), Morano et al.
patent: 2913072 (1959-11-01), Williams
patent: 3295795 (1967-01-01), Meek, Jr. et al.
patent: 3559204 (1971-01-01), Dashper
patent: 3634635 (1970-03-01), Ellis
patent: 3718792 (1972-05-01), Stagner
patent: 3891964 (1974-07-01), Geiger
patent: 3936622 (1974-04-01), McElroy
patent: 4007970 (1977-02-01), Romero
patent: 4172570 (1979-10-01), Leoni
patent: 4270711 (1981-06-01), Cresap et al.
patent: 4334955 (1982-06-01), Zoeke
patent: 4430533 (1981-11-01), Vatterott
patent: 4574360 (1983-04-01), Bateman
patent: 4850552 (1989-07-01), Darden et al.
Bailey George H.
Ramsey William D.
Bell Helicopter Textron Inc.
Scott J. R.
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