Patent · US Expired

Tractor-drawn plow with hitch and furrow wheel hydraulic motors connected in series

US4410047A · kind A · utility

2Cited by
7References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJun 22, 1981
Grant dateOct 18, 1983
Priority date
Expiry dateJun 22, 2001

Classification

  • Technology area (CPC A)Human Necessities
  • CPC primaryA01B3/26
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A tractor-drawn plow is carried at its left front end on a tractor via vertically shiftable hitch means and at its right front end on a furrow wheel linkage means providing for raising and lowering of the frame among transport, open-up plowing and normal plowing positions. The hitch means and furrow wheel linkage include separate hydraulic motors of the two-way type, and these are connected hydraulically in series, with provision for re-phasing, to insure substantial leveling of the frame during raising and lowering movement of the frame. Provision is made in the connection of the hitch motor to the hitch means for enabling limited retrograde movement of the hitch motor piston to a position covering the re-phase port after the hitch motor has extended to fully raise the frame. Further provision is made in the furrow wheel linkage enabling lowering of the frame to either open-up plowing position or normal plowing position by retraction strokes of the same length of the furrow wheel motor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.