公开(公告)号：US3576104A

公开(公告)日：1971-04-27

申请号：US3576104D

申请日：1969-09-29

Applicant: CATERPILLAR TRACTOR CO

Inventor： KOKALY JOSEPH ,  SCHEXNAYDER LAWRENCE F

IPC: F15B11/17 ,  F16H61/40 ,  F16H61/444 ,  F15B15/18

CPC classification number: F15B11/17 ,  F16H61/40 ,  F16H61/444

Abstract: A hydraulic control system for selectively operating a hydraulic motor in at least two operating speeds. The system including first and second pumps and a pilot valve having a fluid passage in communication with the first pump and the motor. First restrictive valve means provide restricted flow from the fluid passage to a first pilot flow passage and selectively communicate the fluid passage with a drain passage. Second restrictive valve means provide restricted flow from the second pump into a second pilot flow passage and selectively communicate the second pump with the fluid passage in the pilot valve and with the drain passage. The restrictive valve means are responsive to a main control valve effective to selectively communicate the first and second pilot flow passages to drain, thus providing for variable speed operation of the motor.

公开(公告)号：US3444948A

公开(公告)日：1969-05-20

申请号：US3444948D

申请日：1967-02-01

Applicant: CATERPILLAR TRACTOR CO

Inventor： BIANCHETTA DONALD L ,  JUNCK JOHN A ,  KOKALY JOSEPH

IPC: B62D5/093 ,  B62D12/00 ,  B62D5/00 ,  F15B13/16

CPC classification number: B62D12/00 ,  B62D5/093