Glenn H Stanfield

US Patent:

7937938, May 10, 2011

Filed:

Apr 23, 2008

Appl. No.:

12/148808

Inventors:

Beau Kuipers - Minooka IL, US
Edward Mate - Manhatten IL, US
Glenn Stanfield - Plainfield IL, US

Assignee:

Caterpillar Inc. - Peoria IL

International Classification:

F16D 31/02

US Classification:

60456, 60468, 60493

Abstract:

A machine includes a hydraulic fan system for circulating cooling air through an engine compartment. Periodically, the fan rotation direction is briefly reversed in order to dislodge any material debris that may have accumulated at the inlet to the engine compartment. When a fan reversal event is initiated, the fan motor will continue to rotate due to angular momentum even after the pump output flow has been switched from a first motor port to a second motor port. During this continued rotation as the fan decelerates to zero speed, vacuum pressure levels can arise at the first motor port, and a pressure spike can develop at the second motor port. In order to alleviate these conditions, a pressure transfer valve briefly opens to facilitate fluid flow directly from the second motor port to the first motor port as the fan motor decelerates towards zero speed before reversing direction, simultaneously alleviating vacuum and pressure spike conditions.

US Patent:

20030020252, Jan 30, 2003

Filed:

Jul 26, 2001

Appl. No.:

09/915642

Inventors:

Glenn Stanfield - Plainfield IL, US

International Classification:

B60G011/26

US Classification:

280/124161, 280/005501

Abstract:

A suspension control system includes a load support member, a base member and a moveable element attached to the base member and the load support member. The load support member is moveable relative to the base member through the moveable element. A accumulator is in fluid communication with the moveable element. A locking circuit is disposed between the moveable element and the accumulator and is selectively activatable to sustain said load support member in a fixed position. The locking circuit includes a pressurized fluid supply and a flow blocking mechanism operably engaged with the pressurized fluid supply. The flow blocking mechanism is urged to block fluid communication between the moveable element and the accumulator when the locking circuit is selectively activated.