Deere + Company

Stanley M Gregerson

Robert E Haight

Timothy J Mattson

A seal arrangement for providing a reliable seal between a shaft and an opening through which the shaft passes where the shaft undergoes both rotary and axial movement relative to the opening. The seal assembly consists of a seal suitable for relative rotary motion between the gasket surface and the surface to be sealed, a sleeve, and a seal suitable for sealing when there is relative axial movement between the seal and the sealed surface. The sleeve is used to isolate the rotary and axial motion of the shaft into two components so that each seal will only see one type of motion. In order to accomplish this, the sleeve is restrained from axial motion relative to the opening and has synchronous rotary motion with the shaft. This seal arrangement is particularly useful in pivotable drive assemblies where the use of a simple universal joint will impose a reciprocating motion on a drive axle.

Seal assembly for rotary and reciprocating motion

A control system for preventing engagement of a transmisson when its power source is started with the transmission in gear. The system uses a control valve, an engagement override valve, a check valve and a relief valve to interrupt fluid flow to clutch or brake elements during initial startup unless the transmission is in neutral or park. Unwanted triggering of the override system upon a reduction of hydraulic pressure is avoided in this control system. The control valve of this system may be made responsive to clutch pedal or shift lever movement.

Control system for transmission engagement

A hydrostatic drive tractor having a hydraulically lowerable and raisable hitch to lower and raise an associated implement to respectively increase or decrease draft load includes a draft control system sensing increases and decreases in the hydrostatic drive pressure which are proportional to draft load as sensed by the drive wheels to activate valving to respectively raise and lower the hitch.

Growing community of inventors

Cedar Falls, IA, United States of America

Stanley M Gregerson