Inventor

Thomas J. Langenfeld

Inventor

Sullivan, IL, US

Overview

2000–2021

Patent span

Mechanical engineering

Primary field (CPC F)

Patents· 91 as inventor

Public. Assignee & technology derived from the patent record. Each patent links to its LexDana page.

F16Hprimary

F16HGearing24%

B60KArrangement or mounting of propulsion units or of transmissions in vehicles19%

F16DCouplings for transmitting rotation9%

F15BSystems acting by means of fluids in general7%

Y10TTechnical subjects covered by former us classification6%

B62DMotor vehicles5%

B60TVehicle brake control systems or parts thereof5%

E01HStreet cleaning4%

A01DHarvesting4%

F04BPositive-displacement machines for liquids4%

PatentTitleYear

11,118,680Steerable transaxle2021 10,899,221Vent for a hydraulic drive device2021 10,876,596Electric motor with compound planetary gear drive2020 10,793,002Drive apparatus2020 10,539,163Transaxle having dual brake system2020 10,480,142Drive device2019 10,451,171Fluid expansion tank2019 10,352,421Hydrostatic transmission2019 10,337,608Steerable transaxle2019 10,166,864Drive apparatus2019 10,059,313Hydraulic motor having a dual brake system2018 9,976,640Drive assembly2018 9,914,350'Drive device'2018 9,879,671'Hydraulic motor assembly'2018 9,816,536'Transaxle having dual brake system'2017 9,802,646'Vehicle with steering mechanism'2017 9,664,270'Hydrostatic transmission'2017 9,610,840'Steerable transaxle'2017 9,598,103'Steerable transaxle'2017 9,469,191'Transaxle fluid expansion and contraction accommodation apparatus'2016 9,408,344'Three wheeled vehicle'2016 9,410,631'Valve'2016 9,371,842'Hydraulic motor having a dual brake system'2016 9,371,865'Drive device'2016 9,328,611'Return to neutral device for a hydraulic apparatus'2016 9,163,724'Transaxle having dual brake system'2015 9,139,086'Drive assembly'2015 9,109,684'Drive device'2015 9,021,799'Hydraulic motor assembly'2015 8,931,268'Transaxle fluid expansion and contraction accommodation apparatus'2015 8,919,116'Variable drive apparatus'2014 8,820,066'Steerable transaxle'2014 8,683,796'Variable drive apparatus'2014 8,636,616'Drive assembly'2014 8,628,448'Gear drive'2014 8,534,060'Drive device'2013 8,517,159'Brake actuation assembly'2013 8,499,680'Return to neutral device for a hydraulic apparatus'2013 8,479,418'Drive assembly'2013 8,465,388'Gear drive'2013 8,464,610'Drive device'2013 8,381,517'Hydraulic drive apparatus'2013 8,313,408'Drive assembly'2012 8,245,509'Zero turn transaxle'2012 8,235,858'Gear drive'2012 8,221,276'Hydraulic motor apparatus'2012 8,132,588'Valve'2012 8,057,335'Brake actuation assembly'2011 8,001,883'Return to neutral device for a hydraulic apparatus'2011 7,926,266'Hydraulic drive apparatus'2011 7,927,245'Hydraulic motor apparatus'2011 7,841,176'Zero turn transaxle'2010 7,568,497'Combined check valve and pressure relief valve'2009 7,487,636'Hydraulic drive apparatus'2009 7,476,171'Hydraulic motor apparatus including brake mechanism'2009 7,476,172'Motor apparatus including brake mechanism'2009 7,454,908'Zero turn transaxle'2008 7,412,828'Adjustable hydraulic motor apparatus'2008 7,409,890'Hydraulic motor apparatus'2008 7,396,310'Hydrostatic transaxle'2008 7,367,353'Combined check valve and pressure relief valve'2008 7,328,576'Zero turn transaxle'2008 7,308,790'Adjustable hydraulic motor apparatus'2007 7,258,134'Combination check valve and pressure rise rate valve'2007 7,234,300'Fastener and valve for a hydraulic apparatus'2007 7,225,617'Bypass mechanism for a hydraulic drive apparatus'2007 7,210,294'Hydrostatic transaxle'2007 7,134,276'Cylinder block brake for a hydrostatic drive apparatus'2006 7,127,889'Zero turn transaxle'2006 7,111,545'Return to neutral device for a hydraulic apparatus'2006 7,111,457'Diagnostic system for a hydrostatic transmission or transaxle'2006 7,081,061'Hydraulic motor apparatus'2006 7,047,736'Zero turn transaxle'2006 7,028,708'Combined check valve and pressure relief valve'2006 6,997,839'Hydraulic motor apparatus'2006 6,964,164'Return to neutral device for a hydraulic apparatus'2005 6,880,448'Pump and center section for hydrostatic transmission'2005 6,843,056'Zero turn transaxle'2005 6,840,879'Hydraulic motor apparatus'2005 6,811,510'Hydraulic motor apparatus and vehicle'2004 6,811,509'Hydraulic motor apparatus including brake mechanism'2004 6,804,958'Hydrostatic transmission bypass latch'2004 6,780,137'Differential lock mechanism'2004 6,701,825'Return to neutral device for a hydraulic apparatus'2004 6,675,696'Pump and center section for hydrostatic transmission'2004 6,672,058'Zero turn transaxle'2004 6,550,244'Axle driving apparatus having an improved hydraulic fluid bypass mechanism'2003 6,374,604'Hydrostatic transmission bypass latch'2002 6,370,876'Axle driving apparatus having an improved hydraulic fluid bypass mechanism'2002 6,253,637'Control device for hydrostatic apparatus'2001 6,122,996'Hydrostatic transmission'2000

Career & activity timeline

Assembled from patent assignee/location history and declaration credentials.

2000–2021Patents assigned to HYDRO GEAR LP (14)· patent assignee history

2000–2021Based in Sullivan, IL, US· patent location history

2001–2016Patents assigned to HYDRO GEAR LTD PARTNERSHIP (65)· patent assignee history

2011–2015Patents assigned to LANGENFELD THOMAS J (16)· patent assignee history

2013–2015Patents assigned to BONNY NATHAN W (3)· patent assignee history

2016–2017Patents assigned to HYDRO-GEAR LTD PARTNERSHIP (7)· patent assignee history

Inventor activity

Assignee and location history derived from the patent record.

Assignees

Assignee	Patents	Span
HYDRO GEAR LTD PARTNERSHIP	65	2001–2016
LANGENFELD THOMAS Jself	16	2011–2015
HYDRO GEAR LP	14	2000–2021
HYDRO-GEAR LTD PARTNERSHIP	7	2016–2017
BONNY NATHAN W	3	2013–2015

Locations

Location	Patents	Span
Sullivan, Illinois, US	91	2000–2021