The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 04, 1976
Filed:
Nov. 01, 1974
Richard H Sheppard, Hanover, PA (US);
Other;
Abstract
A dual power steering system has a master and slave steering combination, valve means on the master unit, interconnecting linkage and each unit having a built-in mechanical advantage factor. The mechanical advantage of the master unit is made to be greater than the mechanical advantage of the slave unit to assure that the master always dominates the slave during operation to prevent feedback of power through the tie rod of the steering linkage and thereby prevent preemptive change in positioning of the valve means of the slave unit. This, in turn, eliminates chattering or fighting between the units that occurs especially in left-turn operation. In one embodiment, the mechanical advantage factor is defined by the angle of movement of the crank divided by the angle of movement of the steering arm (or wheel). The ratio of the master unit factor to that of the slave unit must be greater than one. The cranks on the steering units are preferably positioned beyond the position of maximum throw. In a second embodiment, the output power rating of the master unit is sufficiently greater than that of the slave unit to provide the desired mechanical advantage ratio. In either embodiment, the ratio is selected to be only slightly greater than the threshold value to maximize the output power of the steering units.