Patent Application
20130299760
The present invention relates to an aircraft jack for lifting aircraft. In a preferred embodiment, the jack is a collapsible, two stage, twenty ton tripod jack.
This invention relates generally to aircraft jacks and, more particularly, to a jack for raising an airplane above ground level during manufacture and for many other maintenance and repair operations. The jacking of an airplane is extremely critical due to airplane flexibility, high gross weights, and numerous other precautionary measures required.
A common device used to lift aircraft is a tripod jack. Tripod jacks generally include a single aircraft interface point extending above a three legged base. Use of traditional tripod jacks for lifting aircraft has drawbacks. One drawback is the amount of time and energy required to lift the aircraft. Another is variant jacking conditions. A need exists for a single jack solution to address all variant conditions.
This invention is a tripod jack of a “single solution” jack designed for lifting and supporting variant aircraft. The criteria for a single solution jack (set of 3 jacks per aircraft) will meet all jacking conditions for each variant aircraft and several other aircraft. Single jack design is used on any of the three variant aircraft and several other aircraft at any of the five jacking locations: front (one location), inboard wing (two locations) or outboard wing (two locations). The jacks are designed for the typical landing gear retraction check or landing gear removal and installation. In addition, they are designed to operate on an aircraft carrier while in a sea state 6 condition. They also may support an aircraft in the sea state 8 condition. The jacks themselves are collapsible and can be containerized in restricted space for long term storage or deployment.
The two-stage jack apparatus comprises a tripod base having three legs; with a welded floor pad at the end of each leg, a hydraulic cylinder with telescoping rams with an integrated threaded mechanical extension, a weldment ring which the cylinder is threaded in the center and three mounting holes equally spaced on the outside diameter to attach the tripod base legs; lower support linkage for the legs; base support plate to connecting support linkages and to mount an air driven hydraulic pump and manual dual speed high/low hydraulic hand pump; transparent hydraulic reservoir mounted to the hydraulic cylinder.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings.
The following is a preferred embodiment of the invention.
Dual speed hydraulic hand pump: Highly resistant to corrosion. Built with stainless steel 303 series parts and plated per MIL-C-26074, class 1, grade C specification. Two pumps are featured: high volume low pressure pump for quick ram actuation to the jack point and a low volume high pressure pump used to actuate rams without the air driven hydraulic pump. The hand pump handle will not exceed 50 lbs of force to operate by hand. The pump features a pressure release ball to allow fluid to return quickly back to reservoir from the cylinder.
Air driven hydraulic pump: Marine grade, ⅓hp pump that operates on common ship air supply of 90 psi.
Polyethylene Reservoir: Tank material is cross linked polyethylene material. Has a high resistance to puncture, stress cracking, thermal resistance and notch failure. The material is transparent which provides simple reservoir fluid level detection. The vent is leak proof for storage or deployment.
Spring loaded casters: Highly resistant to corrosion. Caster wheels are built with a glass reinforced nylon that will resist wear on aircraft decking.
Hardware components: All hardware components are built with corrosion resistant stainless steel material or plated per MIL-C-26074, class 1, grade C.
1. Place jack on a hard, level surface.
2. Open reservoir vent screw (counterclockwise)
3. Hydraulic rams must be completely retracted before operating the jack.
4. Raise mechanical extension as close to aircraft jack pad as possible.
5. Close pump release valve and operate either hand pump or air pump.
6. Hydraulic rams must extend in order from largest to smallest diameter.
7. Large diameter hydraulic ram must fully extend before the next stage ram begins to raise.
8. Lower mechanical ram locknut(s) while extending rams. Keep within 1 inch of bottom of extending ram.
9. Do not continue to operate air pump after all rams have fully extended.
1. Lower all jacks simultaneously.
2. If ram locking collar(s) is tight, raise jack slightly to release collar(s) ¼ from tripod.
3. Ensure proper staging as aircraft is being lowered: loosen ram locking collar nut
1. Utilize a flexible 1 inch wide strap, secure entire jack with strap under weldment ring and lift vertically.
2. Remove quick disconnect pin in leg linkage and fold leg in and re-secure with pin. Repeat for each leg.
3. Lower collapse jack to the ground and lay jack on open side (without reservoir and pumps).
4. Remove flexible strap.
The above detailed description of the present invention is given for explanatory purposes. It will be apparent to those skilled in the art that numerous changes and modifications can be made without departing from the scope of the invention. Accordingly, the whole of the foregoing description is to be construed in an illustrative and not a limitative sense, the scope of the invention being defined solely by the appended claims.
The present patent application is based upon and claims the benefit of provisional patent application No. 61/645,695, filed on May 11, 2012.
| Number | Date | Country | |
|---|---|---|---|
| 61645695 | May 2012 | US |
