David Walter Fletcher

US Patent:

7095285, Aug 22, 2006

Filed:

Jul 26, 2004

Appl. No.:

10/901416

Inventors:

David D. Heston - Dallas TX, US
John G. Heston - Murphy TX, US
Brian P. Helm - Sachse TX, US
Gordon R. Scott - Plano TX, US
Scott Mitchel Heston - Dallas TX, US
David R. Fletcher - Allen TX, US
William S. Kopp - Greensboro NC, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

H03F 3/04

US Classification:

330296

Abstract:

According to one embodiment of the present invention a method for biasing a power amplifier having at least one transistor exhibiting kink anomaly includes providing a bias circuit coupled to a gate of at least one transistor of the power amplifier. The method also includes providing, by the bias circuit, a bias voltage to the gate. The bias circuit has a load characteristic that intersects a current versus gate voltage curve for the gate at a frequency of operation of the power amplifier only once and that exhibits a low impedance at the intersection of the load characteristic with the current versus gate curve of the gate.

US Patent:

7117938, Oct 10, 2006

Filed:

May 30, 2003

Appl. No.:

10/449301

Inventors:

William R. Hamilton - Conroe TX, US
David Curtis Fletcher - Houston TX, US
Donald D. Rae - Willis TX, US

Assignee:

Gray EOT, Inc. - Willis TX

International Classification:

E21B 19/16

US Classification:

166 7753, 81 5716, 81 5724, 166 774, 175 85

Abstract:

Drilling rig apparatus for connecting and disconnecting well pipe at a drilling rig. A remotely controlled power wrench assembly is mounted on a remotely controlled lifting mechanism attached to a base spaced about the well axis on the rig floor. The wrench assembly includes upper and lower wrenches carried by the lifting mechanism. The wrench assembly includes a lower wrench for gripping a lower box coupling of a drill pipe section at the well center. An upper wrench is provided for torquing and spinning an upper pin coupling into or out of threaded engagement with the lower box coupling. A manipulator is pivotably carried on a rod supported from the wrench assembly. The manipulator captures a drill pipe section and transfers the drill pipe section between the well axis and a position at the side of the wrench assembly. A slot is provided between frame members of the base for placement of a power slip manipulator for setting and releasing slips in the rotary table.

US Patent:

20130203179, Aug 8, 2013

Filed:

Apr 8, 2011

Appl. No.:

13/640344

Inventors:

Matthew J. Vincent - Kingwood TX, US
David L. Fletcher - Kingwood TX, US
Vijay Nanda - Houston TX, US

International Classification:

G01N 25/00

US Classification:

436147

Abstract:

Disclosed is a method for determining when to replace a guard bed material used to remove one or more catalyst poisons from a feed based on a parameter change in a process. A guard bed having a guard bed material is in fluid communication with a catalyst bed having a catalyst. At least three monitors are positioned in said guard bed or said catalyst bed and at least one parameter of the guard bed or catalyst bed is monitored. A feed component comprising one or more catalyst poisons is supplied to said guard bed or said catalyst bed. The feed is contacted with said guard bed material or said catalyst to remove at least a portion of a catalyst poison and to form a product which produces an increase or a decrease in said parameter. The monitored parameters are compared to determine when to replace the guard bed material.

US Patent:

20160298356, Oct 13, 2016

Filed:

Dec 21, 2015

Appl. No.:

14/975959

Inventors:

David C. Fletcher - Burleson TX, US

International Classification:

E04H 17/14
E04H 17/16

Abstract:

A fence panel has a first fence post and a second fence post spaced from the first post, each post having a face oriented toward the other post. An upper tab and lower clip are mounted on each post. Each upper tab is fixed, and each lower clip is movable during assembly relative to the associated post between a lower position and a higher position. A top rail is assembled onto the upper tabs, a bottom rail is assembled onto the lower clips, and at least one fence picket is inserted between the rails. During assembly the bottom rail and pickets are moved upward together relative to the posts and toward the top rail to an assembled position for retaining each picket between the rails. The lower clips are moved to the higher position for retaining the bottom rail and pickets in the assembled position.

US Patent:

20160187271, Jun 30, 2016

Filed:

Mar 7, 2016

Appl. No.:

15/062965

Inventors:

- Baytown TX, US
David L. Fletcher - Kingwood TX, US
Vijay Nanda - Houston TX, US

International Classification:

G01N 25/00
C10G 45/72
C07C 2/70
C10G 45/08

Abstract:

Disclosed is a method for determining when to replace a guard bed material used to remove one or more catalyst poisons from a feed based on a parameter change in a process A guard bed having a guard bed material is in fluid communication with a catalyst bed having a catalyst. At least three monitors are positioned in said guard bed or said catalyst bed and at least one parameter of the guard bed or catalyst bed is monitored. A feed component comprising one or more catalyst poisons is supplied to said guard bed or said catalyst bed. The feed is contacted with said guard bed material or said catalyst to remove at least a portion of a catalyst poison and to form a product which produces an increase or a decrease in said parameter. The monitored parameters are compared to determine when to replace the guard bed material.