Joseph L Pfaff

US Patent:

6457487, Oct 1, 2002

Filed:

May 2, 2001

Appl. No.:

09/847504

Inventors:

Dwight B. Stephenson - Delafield WI
Joseph Lawrence Pfaff - Wauwatosa WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

F15B 13043

US Classification:

13759616, 91447, 91448, 91459, 91464, 13759617

Abstract:

An assembly of a pair of electrically operated bidirectional proportional control valves and a four-way direction control valve governs the flow of fluid to and from a hydraulic cylinder. The four-way direction control valve alternately connects a pump supply line to one of a pair of intermediate conduits and a tank return line to the other intermediate conduit. That connection determines the direction of movement of the cylinder piston. The intermediate conduits are coupled to chambers of the cylinder by a separate one of the proportional control valves which meters the fluid flow to or from the respective chamber. Thus the proportional control valves control the rate of piston movement.

US Patent:

6467264, Oct 22, 2002

Filed:

May 2, 2001

Appl. No.:

09/847834

Inventors:

Dwight B. Stephenson - Delafield WI
Joseph Lawrence Pfaff - Wauwatosa WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

F16D 3102

US Classification:

60460, 60368, 60494, 60484, 91454

Abstract:

A hydraulic system controls the flow of fluid to and from several functions on a machine. Each function has a valve assembly through which fluid is supplied under pressure from a source to an actuator and through which fluid returns from the actuator to a shared return line connected by a return line metering valve to the system tank. There are several regeneration modes of operation in which fluid exhausted from one port is supplied into the other port of the same actuator, which eliminates or reduces the amount of hydraulic fluid that must be supplied from the source. In some regeneration modes, input fluid for an actuator is obtained from another hydraulic function via the shared return line. In these regeneration modes an electronic controller operates the return line metering valve to restrict fluid from flowing into the tank from the shared return line, so that the fluid will be available to be supplied into an actuator port.

US Patent:

6640163, Oct 28, 2003

Filed:

Sep 30, 2002

Appl. No.:

10/260893

Inventors:

Joseph L. Pfaff - Wauwatosa WI
Robert J. Willard - Mukwonago WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

G05D 1102

US Classification:

700282, 700 11, 700203, 702 12

Abstract:

A programmable controller, for operating a machine such as one having a hydraulic system, includes a memory that stores a plurality of software function routines. A memory contains a first data file with address pointers to the function routines where the address pointers are listed in the order that the function routines may be executed. A second data file has a separate record associated with each of the address pointers and each record identifies the data variables required by the corresponding function routine. A third data file contains information about each of the variables. A code sequencer accesses the first data file and directs execution of the function routine in the order designated by the pointers. As each function routine executes, the respective record in the second data file is used to access the required variable information.

US Patent:

6705079, Mar 16, 2004

Filed:

Sep 25, 2002

Appl. No.:

10/255033

Inventors:

Keith A. Tabor - Richfield WI
Joseph L. Pfaff - Wauwatosa WI
Dwight B. Stephenson - Delafield WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

F16D 3102

US Classification:

60469, 91433

Abstract:

When a swinging boom driven by a hydraulic cylinder stops, inertia causes continued motion of the boom which increases pressure in a chamber of the hydraulic cylinder. Eventually that pressure reaches a level which causes the boom to reverse direction. Then pressure in an opposite cylinder chamber increases until reaching a level that causes the boom movement to reverse again. This oscillation continues until the motion is dampened by other forces acting on the boom. As a result, an operator has difficulty in properly positioning the boom. To reduce this oscillating effect, a sensor detects when the cylinder chamber pressure increases above a given magnitude and then a determination is made when the rate of change of that pressure is less than a defined threshold. Upon that occurrence, a control value is opened to relieve the pressure in that cylinder chamber.

US Patent:

6715402, Apr 6, 2004

Filed:

Feb 26, 2002

Appl. No.:

10/082862

Inventors:

Joseph L. Pfaff - Wauwatosa WI
Dwight B. Stephenson - Delafield WI

Assignee:

HUSCO International, Inc. - Waukesha WI

International Classification:

F01B 1116

US Classification:

91526, 91530, 91531, 91533

Abstract:

A system for simultaneously operating first and second hydraulic cylinders has an inlet node for connection to a source of pressurized fluid and an outlet node for connection to a tank. A two-position, three-way primary control valve has a first port connected to the inlet node, a second port connected to the outlet node, and a common port. A first electrohydraulic proportional valve connects the common port to a first port of the first cylinder, and a second electrohydraulic proportional valve connects the common port to a first port of the second cylinder. A third electrohydraulic proportional valve connects the inlet node to a second port of the first cylinder and a second port of the second cylinder. Selectively operating the primary control valve and one of the third and fourth electrohydraulic proportional valves determines the direction in which the first and second cylinders move. Operation of the first and second electrohydraulic proportional valves meters hydraulic fluid to or from the first and second cylinders to control the rate of that movement.

US Patent:

6732512, May 11, 2004

Filed:

Sep 25, 2002

Appl. No.:

10/254427

Inventors:

Joseph L. Pfaff - Wauwatosa WI
Keith A. Tabor - Richfield WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

F16B 1308

US Classification:

60428, 60452, 60459, 91364, 91446, 91454

Abstract:

A control system for operating a hydraulic system includes a user input device which generates an input signal indicating desired movement of a hydraulic actuator. A mapping routine converts the input signal into a velocity command indicating desired actuator velocity. A valve opening routine transforms the velocity command into a flow coefficient which characterizes fluid flow through the valve assembly and from the flow coefficient produces a set of control signals designating levels of electric current to apply to valves within the valve assembly. A pressure controller regulates pressure in the supply line in response to the velocity command. When the hydraulic system has a plurality of functions, the control system adjusts each velocity command to equitably apportion fluid to each function when the aggregate flow being demanded by the functions exceeds the total flow available from a source.

US Patent:

6745992, Jun 8, 2004

Filed:

Aug 5, 2002

Appl. No.:

10/212511

Inventors:

Xiaolong Yang - Germantown WI
Michael J. Paik - Delafield WI
Joseph L. Pfaff - Wauwatosa WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

F16K 1726

US Classification:

251 3003, 25112915, 91461

Abstract:

A pilot operated valve has a main poppet that selectively controls bidirectional flow of fluid between two ports in response to pressure in a control chamber on one side of the main poppet. The main poppet has a pilot orifice that is opened and closed by a pilot poppet. A unique mechanism is provided to compensate for variation of a pressure differential on opposite sides of the pilot orifice. This mechanism has a pair of annular end members between which extends a spring formed by a plurality of helices. Multiple passages with check valves extend through the main poppet to communicate the greatest pressure among the two ports to the control chamber and the lowest pressure among the two ports to the side of the pilot orifice that is opposite the control chamber.

US Patent:

6763661, Jul 20, 2004

Filed:

May 7, 2002

Appl. No.:

10/141144

Inventors:

Keith A. Tabor - Richfield WI
Joseph L. Pfaff - Wauwatosa WI

Assignee:

Husco International, Inc. - Waukesha WI

International Classification:

F01C 2508

US Classification:

60327, 91275

Abstract:

An apparatus and method for creating vibration of an appendage of a work vehicle is disclosed. The apparatus includes a hydraulic cylinder, first and second valve assemblies, and a control element. The hydraulic cylinder is coupled between a first portion of the work vehicle and the appendage and includes a first chamber, a second chamber, and a piston. The first and second valve assemblies respectively govern whether hydraulic fluid is provided from a pump to, or to a tank from, the first and second chambers. The control element automatically causes a status of the second valve assembly to repeatedly alternate with time so that the vibration occurs at the piston and is in turn provided to the appendage.