Machine element or mechanism – Control lever and linkage systems – Hand operated
Reexamination Certificate
1999-12-14
2001-08-28
Green, Mary Ann (Department: 3682)
Machine element or mechanism
Control lever and linkage systems
Hand operated
C074S502000
Reexamination Certificate
active
06279416
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to an improved hydraulic lock, and in particular to a push button control for a hydraulic lock.
In U.S. Pat. No. 5,005,677 to Bucholtz et al., there is disclosed a hydraulic lock that is ideally suited for use in adjustable back seats of the type typically found on aircraft, trains, buses, and the like. The lock includes a hydraulic cylinder that is mounted between the seat back and the stationary frame of the seat. The cylinder includes a piston rod that is connected to a piston housed within the cylinder. A valving system permits fluid in the cylinder to flow across the piston under controlled conditions thereby permitting the piston rod to be extended or retracted depending on the direction of force exerted on the seat back. A push button control is generally mounted upon the arm rest of the seat which, when depressed, opens the valving system.
As further disclosed in the above noted Bucholtz et al. patent, the push button is connected to a pin slidably contained in the piston rod of the hydraulic lock. To tilt the seat back out of a full upright position, the seat occupant first depresses the button which in turn moves the pin to an operative position unseating a poppet control valve and allowing fluid to flow around the piston. Applying a slight rearward force upon the back of a seat by the occupant causes the seat back to tilt. The exchange of fluid from one side of the piston to the other continues until the back is placed in a desired position whereupon the seat occupant releases the push button closing the poppet valve locking the back in the desired position. To return the back to a full upright position, the seat occupant again depresses the button and a forward force is applied to the back.
Push button control mechanisms employed on airplane seats and the like are in almost constant use and are usually cycled a number of times each day. As a consequence, the control mechanism associated with each seat is subject to frequent maintenance and adjustment checks. It is therefore, highly desirous that the push button control can be quickly and easily removed and reassembled with the hydraulic lock without the need of tools and the like thereby minimizing the amount of down time required for periodic maintenance.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to improve hydraulic locking devices.
It is a further object of the present invention to improve push button mechanisms for controlling hydraulic locks.
A still further object of the present invention is to improve a cable operated control mechanism for use in a hydraulic lock that is used to adjust the amount of tilt afforded the back rest of a passenger seat of the type generally employed in an aircraft, train or bus.
Another object of the present invention is to provide a push button cable operated control mechanism that can be quickly installed or removed from a passenger seat equipped with a hydraulic lock actuator for adjusting the position of the seat back.
These and other objects of the present invention are attained by a control mechanism for use in a hydraulic lock for controlling the positioning of a seat back, said actuator including a hydraulic cylinder containing an extendable piston rod. The cylinder is mounted for movement between the seat back and the stationary frame of the seat. An operating rod is slidably contained within the piston rod of the cylinder and operatively connected to a valve mechanism which, when opened allows fluid to move from one side of the piston to the other under controlled conditions. The control mechanism includes a push button unit mounted on the arm of the seat and a lever arm assembly that is mounted upon the piston rod of the hydraulic lock. A cable extends from the push button unit to the lever arm assembly through a conduit so that when the push button is depressed, the lever arm causes the operating rod to open a poppet valve within the cylinder whereby fluid is permitted to flow around the piston. The distal end of the conduit is retained in the platform of the lever arm assembly. The distal end of the cable passes through the platform and is secured to a lever arm that is rotatably mounted in the platform. A locking plate is pivotally mounted on the distal end of the conduit so that the plate turns about the axial centerline of the conduit in sliding contact with the top surface of the platform. A circular cutout is formed in the locking plate that opens to one side of the plate. The cutout is adapted to mate with a circumferential groove formed in the terminal end of the piston rod to lock the hydraulic cylinder to the lever assembly. A detent is mounted in the locking plate that is arranged to engage a seat in the platform of the lever assembly to hold the locking plate in a locked position and thus prevent the plate from being prematurely displaced. The bottom of the lever arm is arranged to contact the end of the operating pin to push the pin inwardly when the push button is depressed thereby opening the poppet valve in the cylinder. A torsion spring returns the lever arm to a home position when the push button is released.
REFERENCES:
patent: 3730019 (1973-05-01), Ballard
patent: 4354398 (1982-10-01), Porter
patent: 4515034 (1985-05-01), Porter
patent: 4901594 (1990-02-01), Selzer
patent: 5005677 (1991-04-01), Bucholtz et al.
patent: 5029822 (1991-07-01), Selzer
Bucholtz Brian Charles
Daul Terrance E.
Janak John M.
Enidine Inc.
Green Mary Ann
Wall Marjama & Bilinski
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