Fire escape – ladder – or scaffold – Means maintaining platform level on angularly movable support – Swingable support
Patent
1976-11-08
1978-10-24
Machado, Reinaldo P.
Fire escape, ladder, or scaffold
Means maintaining platform level on angularly movable support
Swingable support
60433, B66F 1104
Patent
active
041216873
ABSTRACT:
A control system for hydraulic lifts is characterized by a low pressure air circuit for controlling a high pressure closed center hydraulic circuit for operating hydraulic cylinders of the lift.
In the disclosed embodiment the control system is for operating a hydraulic bucket lift, and the air circuit has a plurality of air switches which are actuable to provide compressed air at outlets from the circuit. The hydraulic circuit includes fluid valves operated by the compressed air at the outlets from the air circuit, and a fluid pump which operates only upon actuation of the circuit to move the cylinder, yet which maintains full hydraulic pressure at all other times for rapid system response. Adjustable metering valves control the volume flow of fluid to the cylinders to smooth and control the speed of operation thereof, and therefore of the lift.
As a consequence of the hydraulic circuit being of the closed center type, a plurality of lift functions may be simultaneously performed without a loss of operating speed, and since the pump operates only upon system actuation, it is efficient to run and system wear is minimized. Further, as the switches for controlling operation of the lift are low pressure air switches, rupture of a switch or an air supply line does not present a hazard to an operator of the lift.
REFERENCES:
patent: 3132718 (1964-05-01), Pierce
patent: 3566903 (1971-03-01), Honeycutt
patent: 3616940 (1971-11-01), Milner
patent: 3860088 (1975-01-01), Gellatly
patent: 3962871 (1976-06-01), Blaha
patent: 3991846 (1976-11-01), Chichester
Society of Automotive Eng. Inc., Dale A. Knutson, pamphlet 730070.
Engel Gerard
Ulrich, II Roy E.
Machado Reinaldo P.
Ulrich Supply Company, Inc.
LandOfFree
Control system for hydraulic lifts does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control system for hydraulic lifts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control system for hydraulic lifts will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2333590