Patent ID: 6293099
Filing Date: 2001-09-25
Classification: B66F,F15B

Abstract:
A hydraulic circuit for supplying an oil from an oil tank to at least a lift cylinder for lifting a fork for lifting, comprising:a first route extending from the oil tank to the lift cylinder;a first hydraulic pump disposed on said first route;a first electric motor on-off controlled for driving said first hydraulic pump;a first check valve disposed on said first route downstream of said first hydraulic pump for allowing only an oil-flow from the oil tank to the lift cylinder;a second route extending from the oil tank to the lift cylinder;a second hydraulic pump disposed on said second route;a second electric motor PWM controlled for driving said second hydraulic pump;a flow controlling valve disposed on said second route down stream of said second hydraulic pump and including an electro-magnetic valve operated associating with the chopper-controlling of said second hydraulic motor; andseparating means for hydraulically separating said check valve and said electro-magnetic valve of said flow controlling valve.