Foreign Material Patents (Class 460/2)
  • Patent number: 11475717
    Abstract: In one aspect, a system for detecting worn or damaged components of an agricultural machine may include first and second acoustic sensors positioned at first and second locations on the agricultural machine, respectively, with the second location being spaced apart from the first location. A controller of the system may be configured to determine a first acoustic parameter associated with the first location of the agricultural machine based on acoustic data received from the first acoustic sensor. The controller may also be configured to determine a second acoustic parameter associated with the second location of the agricultural machine based on acoustic data received from the second acoustic sensor. Furthermore, the controller may be configured to determine a component of the agricultural machine is worn or damaged when the first acoustic parameter differs from the second acoustic parameter by a predetermined amount.
    Type: Grant
    Filed: January 11, 2019
    Date of Patent: October 18, 2022
    Assignee: CNH Industrial America LLC
    Inventors: Joshua David Harmon, Huiyan Wu
  • Patent number: 11129660
    Abstract: The disclosed technology is directed to a RF power generator and feedback control system used to regulate the electrical power delivered to a cutting filament (i.e., a cutting electrode) of an electrosurgical instrument. The electrosurgical instrument uses the delivered energy to form a cutting arc for ablating a tissue mass to access a target tissue therein. The instrument forms a basket-like receptacle around the target tissue to excise the target tissue from the ablated tissue mass. As the instrument forms the receptacle, the length of exposed filament ablating the tissue changes. To this end, the RF power generator described herein is configured to vary the total power delivered during the deployment of the instrument based on a measurement of output power derived from a differential phase angle between a current sense output and a voltage sense output, in some embodiments, to maintain a uniform power density along the length of exposed filament.
    Type: Grant
    Filed: August 12, 2016
    Date of Patent: September 28, 2021
    Assignee: Covidien AG
    Inventors: Douglas M. Macarthur, John F. Vacha, Albert Solbjor, Christopher Tocci, Christian A. Moses
  • Patent number: 11109537
    Abstract: A forage harvester comprising an edge sharpness detection device for detecting a degree of edge sharpness of a cutting mechanism. The cutting mechanism comminutes a stream of harvested material, with a material inflow area being defined where the cutting blades interact with the shear bar to comminute the harvested material. The edge sharpness detection device excites one or more magnetic circuits, with the respective magnetic circuit being closed by the respective cutting blade during rotation of the cutter drum once one of the cutting blades passes the magnetic assembly. The edge sharpness detection device detects the magnetic flux in the respective magnetic circuit and, based on a detected change, determines a degree of edge sharpness of the respective cutting blade. Further, the magnetic flux of the magnetic circuit may be guided lengthwise in the cutting blade at least along a longitudinal section of the respective cutting blade.
    Type: Grant
    Filed: December 12, 2018
    Date of Patent: September 7, 2021
    Assignee: CLAAS Selbstfahrende Erntemaschinen GmbH
    Inventors: Dennis Neitemeier, Christoph Heitmann, Jochen Huster, Markus Brune, Boris Kettelhoit
  • Patent number: 9668421
    Abstract: A vibration sensor is mounted on the central shaft, such that it senses vibrations induced into the feed roll assembly in a direction transverse to the rotational axis of the feed roll.
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: June 6, 2017
    Assignee: CNH Industrial America LLC
    Inventors: Bernard E. D. Depestel, Dirk J. Desnijder, Bart M. A. Missotten, Benoit Debilde, Karel M. C. Viaene
  • Patent number: 8751115
    Abstract: Hay equipment is provided, having a plurality of unplugging devices operatively connected to the equipment. The plurality of unplugging devices are configured to move to remove a plug of material in the equipment. A controller is configured to activate substantially simultaneously the plurality of unplugging devices and to return the plurality of unplugging devices to normal operating positions once the plug of material is removed.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: June 10, 2014
    Assignee: Deere & Company
    Inventor: Daniel E. Derscheid
  • Patent number: 8635840
    Abstract: A device for detection and determination of a composition of a bulk material has an image recording unit, a control unit, a memory unit and a selection unit to enable a qualified determination to be made, during a transfer of a crop material flow into a container of an agricultural harvesting machine, of a composition of a crop during processing of the crop material. The determination enables changing of adjustment parameters of working assemblies of the agricultural harvesting machine during the processing of the crop material. The image recording unit has at least two image detectors for recording images or image series of the crop material flow.
    Type: Grant
    Filed: June 1, 2011
    Date of Patent: January 28, 2014
    Assignee: CLAAS Selbstfahrende Erntemaschinen GmbH
    Inventor: Willi Behnke
  • Publication number: 20130059631
    Abstract: An agricultural harvesting machine includes at least one working assembly for processing and conveying crop as well as a sensor array (9) that detects hazardous substances (18) in the crop (10) to be processed.
    Type: Application
    Filed: August 16, 2012
    Publication date: March 7, 2013
    Inventors: Frank CLAUSSEN, Thomas SURMANN
  • Publication number: 20120322519
    Abstract: An agricultural vehicle having a frame and an inlet for intaking crop mat. A hard object assembly is attached to the frame and includes transmitting antennae for transmitting microwaves and a receiver system that receives the microwaves in order to detect hard objects within the crop mat.
    Type: Application
    Filed: June 15, 2011
    Publication date: December 20, 2012
    Inventors: James E. Straeter, Calvin G. Gray, George William Slade, Daniel Leonard Orban, Timothy H. Eyerman
  • Publication number: 20120322520
    Abstract: An agricultural vehicle having a frame and an inlet for intaking crop mat. A hard object assembly is attached to the frame and includes transmitting antennae for transmitting pulsed microwaves and a receiver system that receives the microwaves in order to detect hard objects within the crop mat.
    Type: Application
    Filed: June 6, 2012
    Publication date: December 20, 2012
    Inventors: James E. Straeter, Calvin G. Gray, George William Slade, Daniel Leonard Orban
  • Patent number: 8206205
    Abstract: A method of unplugging hay and forage equipment, including the steps of identifying a plug, substantially simultaneously activating unplugging devices, unplugging the equipment, and returning the unplugging devices to position of normal operation. The identifying step includes identifying a plug in the equipment caused by the material entering the equipment. The activating step includes activating substantially simultaneously a plurality of unplugging devices. The returning step includes returning the plurality of unplugging devices to their normal operating positions.
    Type: Grant
    Filed: May 12, 2009
    Date of Patent: June 26, 2012
    Assignee: Deere & Company
    Inventor: Daniel E. Derscheid
  • Patent number: 7993187
    Abstract: A foreign object detection and removal system for an agricultural combine is provided. The system includes a controller operatively connected to a feederhouse and a chopper assembly. The feederhouse includes an acoustic element for detecting foreign objects and an actuator for opening and closing a door of the feederhouse to remove foreign objection. The chopper assembly includes an actuator to retract a knife bank to allow for the passage of foreign objects through the chopper assembly without causing damage to the chopper assembly.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: August 9, 2011
    Assignee: CNH America LLC
    Inventors: Jonathan E. Ricketts, Herb M. Farley, Bradley J. Wagner
  • Publication number: 20100048269
    Abstract: A foreign object detection and removal system for an agricultural combine is provided. The system includes a controller operatively connected to a feederhouse and a chopper assembly. The feederhouse includes an acoustic element for detecting foreign objects and an actuator for opening and closing a door of the feederhouse to remove foreign objection. The chopper assembly includes an actuator to retract a knife bank to allow for the passage of foreign objects through the chopper assembly without causing damage to the chopper assembly.
    Type: Application
    Filed: November 3, 2009
    Publication date: February 25, 2010
    Applicant: CNH AMERICA LLC
    Inventors: Jonathan E. RICKETTS, Herb M. FARLEY, Bradley J. WAGNER
  • Patent number: 7584663
    Abstract: A method of determining the content of a desired component in a stream of material including two or more types of component, includes causing or permitting a stream of a plurality of particles of material to impact a sensor member located in a path of the material thereby inducing vibration of the sensor member, analyzing vibrations of the sensor member and from the analysis determining whether individual impacts caused by the stream are one of any two or more types selected from three possible impact types, and performing an operation based on the result of the analysis.
    Type: Grant
    Filed: March 5, 2007
    Date of Patent: September 8, 2009
    Assignee: CNH America LLC
    Inventors: Bart M. A. Missotten, Pieter W. J. Calmeyn, Bart De Ketelaere
  • Publication number: 20080234016
    Abstract: A deslugging method and system for an agricultural combine, providing several semi- and fully automated operating modes or routines for removing or dislodging a slug of crop and/or other material from the threshing system and/or a feeder of the combine for conveying crop material to the threshing system. The routines can include reciprocating, agitating and jogging routines, which can be automatically altered during execution responsive to sensed or changing conditions, as processed by a suitable filter such as a simplified Kalman type signal filter, for generating a real time estimation and prediction of the various states of the threshing system.
    Type: Application
    Filed: March 19, 2008
    Publication date: September 25, 2008
    Inventors: John E. Bundy, John G. Brome, Yun-Ren Ho, Richard E. McMillen
  • Publication number: 20080171582
    Abstract: A method and apparatus is provided for monitoring a flow path having plurality of different solid components flowing therethrough. For example, in the harvesting of a plant material, many factors surrounding the threshing, separating or cleaning of the plant material and may lead to the inadvertent inclusion of the component being selectively harvested with residual plant materials being discharged or otherwise processed. In accordance with the present invention the detection of the selectively harvested component within residual materials may include the monitoring of a flow path of such residual materials by, for example, directing an excitation signal toward of flow path of material and then detecting a signal initiated by the presence of the selectively harvested component responsive to the excitation signal. The detected signal may be used to determine the presence or absence of a selected plant component within the flow path of residual materials.
    Type: Application
    Filed: March 26, 2008
    Publication date: July 17, 2008
    Applicant: Battelle Energy Alliance, LLC
    Inventors: Reed L. Hoskinson, John M. Svoboda, William F. Bauer, Gracy Elias
  • Patent number: 7392123
    Abstract: A system and method for detecting existence of a failed or broken shear bolt supporting all or a portion of a concave of a threshing system of an agricultural combine and utilizing information relating to rates of movement and absence of movement of a concave to determine the existence and non-existence of a failed or broken shear bolt supporting the concave. More particularly, the present system and method is operable to diagnose existence of a broken shear bolt from a rapid downward movement of the concave and non-movement of the concave during operation of a driver for repositioning the concave. Also, existence of a false broken concave condition can be diagnosed by movements of the concave responsive to operation of the driver.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: June 24, 2008
    Assignee: CNH America LLC
    Inventors: David N. Heinsey, Barry E. Lehman
  • Publication number: 20070209423
    Abstract: A method of determining the content of a desired component in a stream of material including two or more types of component, comprises the steps of: causing or permitting a said stream, comprising plural particles of material, to impact a sensor member located in a path of the material thereby inducing vibration of the sensor member; analysing vibrations of the sensor member and from the analysis determining whether individual impacts caused by the stream are one of any two or more types selected from three possible impact types; and performing an operation based on the result of the analysis. The invention is of particular use in determining the content of material streams in combine harvesters.
    Type: Application
    Filed: March 5, 2007
    Publication date: September 13, 2007
    Inventors: Bart M.A. Missotten, Pieter W.J. Calmeyn, Bart De Ketelaere
  • Patent number: 7207165
    Abstract: A method and apparatus for use with a non-frangible object detection mechanism on an agricultural harvester, the detection mechanism including a sensing surface and a sensor for sensing force applied to the sensing surface that is associated with a foreign object adjacent the sensing surface, the harvester including a transport surface along which harvested materials are transported toward the sensing surface, the apparatus including at least first and second ramp members positioned between the transport surface and the sensing surface, the ramp members separated by a gap, each ramp member including a front ramp surface that extends between a front ramp end adjacent the transport surface and a ramp member apex, the ramp member apexes positioned at a location higher than the sensing surface and proximate the sensing surface, wherein, as harvested material and non-frangible objects are conveyed along the transport surface and toward the sensing surface, at least a portion of the harvested material passes betwee
    Type: Grant
    Filed: July 22, 2005
    Date of Patent: April 24, 2007
    Assignee: CNH America LLC
    Inventors: John B. Crego, Arthur George Haas, Michael Jacob Digman
  • Patent number: 7022012
    Abstract: A stone detection system of a harvester that automatically changes its sensitivity to signals from a stone sensor in response to the type of harvesting equipment connected to the harvester is provided. The stone detection system generally includes a stone sensor, a header sensor and a microprocessor. The stone sensor is configured to generate a signal indicative of the presence of a stone in the crop harvesting system. The header sensor is disposed on the crop harvesting system to sense the header type and to generate a signal indicating the header type. The microprocessor is coupled to the stone sensor and the header sensor to process the stone sensor signal based at least in part upon the header sensor signal.
    Type: Grant
    Filed: September 2, 2004
    Date of Patent: April 4, 2006
    Assignee: CNH America LLC
    Inventors: David N. Heinsey, Michael J. Digman, Steven C. Young
  • Publication number: 20040014510
    Abstract: A rotatable drive for a feeder and a header of an agricultural combine for drivingly connecting spaced rotatable elements on the feeder and the header to a rotatable power source on a chassis of the combine, the feeder and the header being jointly mounted to the chassis for pivotal movement relative thereto about a predetermined pivotal axis through a predetermined range of harvesting positions. The drive includes a first gear box mounted on the feeder for pivotal movement therewith and including a rotatable input, a first rotatable output rotatably connected to the input and to at least one of the rotatable elements, and a second rotatable output rotatably connected to the input. The drive includes a second gear box mounted on the feeder and having a rotatable input rotatably connected by a drive shaft to the second output of the first gear box and at least one rotatable output connected to another of the rotatable elements.
    Type: Application
    Filed: July 16, 2002
    Publication date: January 22, 2004
    Inventors: Jay D. Schroeder, William C. Guske
  • Patent number: 6637179
    Abstract: A foreign object detector comprises an inertial sensor mounted for displacement with one of the displaceable rolls in the feed mechanism of a forage harvester. When a foreign object is forced through the rolls, the acceleration of the rolls' displacement exceeds a predetermined threshold and the detector stops the feed mechanism. Preferably, the detector's sensor is a microswitch having an inertially-actuable lever and which is mounted for displacement with the upper feed roll. The detector's circuitry ties into existing metal detector circuitry.
    Type: Grant
    Filed: December 20, 2001
    Date of Patent: October 28, 2003
    Assignee: Kasha Farm Supplies Ltd.
    Inventor: Wayne Duncan
  • Publication number: 20030060245
    Abstract: A combine with a throughput dependent speed control includes an angle sensor responsive to uphill, downhill and sidehill slopes. When the combine is angled from a level position, harvest speed is lowered to prevent grain losses from increasing above a target level. The control continuously learns tilt angle, loss and throughput correlation, and the speed reduction is selected based upon the learned correlation. In the preferred embodiment, throughput is estimated utilizing rotor variable drive actuator pressure (RVDAP), and a target RVDAP is modified for short periods of time in accordance with the learned correlation.
    Type: Application
    Filed: September 27, 2001
    Publication date: March 27, 2003
    Inventors: Bruce Alan Coers, Daniel James Burke, William F. Cooper, Jerry Dean Littke, Karl-Heinz O. Mertins
  • Patent number: 6430903
    Abstract: An apparatus for detecting nonmetallic debris in plant material collected with harvester equipment. As the plant material is collected, a signal generator transmits a signal capable of distinguishing the nonmetallic debris from the plant material, and a sensor receives the generator signal and produces an alarm signal when the nonmetallic debris is detected. A controller receives the alarm signal and modifies operation of the harvester in response to the alarm signal. Different signals can identify the nonmetallic debris. The signal generator and sensor can function based on energy from laser light waves, from sound waves, microwave, gamma, x-ray, or fluoroscope energy wavelengths.
    Type: Grant
    Filed: July 14, 2000
    Date of Patent: August 13, 2002
    Inventors: Neil Christiansen, Dean Scrivens
  • Patent number: 6397570
    Abstract: A crop harvesting machine includes a crop transport or feed mechanism including a feed roller to which a toothed wheel is fixed. A detent in the form of a pivotally mounted lever carries a cam or tooth, the detent being pivotable between a first position wherein the cam is engaged with the toothed wheel so as to block rotation of the feed roller, and a second position wherein the cam is disengaged from the toothed wheel so as to permit free rotation of the crop feed roller. A one-way hydraulic cylinder is coupled to the detent in parallel with a tension coil spring and is controlled by a solenoid control valve, coupled in a control circuit forming part of a metal detector circuit, so as to be pressurized for moving the detent to its first, blocking position when the metal detector sensor senses an undesirable metal object in the crop, and so as to be coupled to sump so that the spring moves the detent to its second position, permitting rotation of the crop feel roller, when no metal is detected.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: June 4, 2002
    Assignee: Deere & Company
    Inventors: Stefan Bohrer, Jörg Weissig
  • Patent number: 6381932
    Abstract: A harvesting machine includes a crop intake arrangement including either a reel or a crop hold down which operate to aid in the advancement of harvested crop into the machine for further processing. In the event of a jam or the presence of metal occurring, the crop intake arrangement may be operated in reverse so as to expel the jam and/or sensed metal. An actuator is provided for moving the reel or crop hold down between non-operating and operating positions and a first sensor for sensing a jam condition and/or the presence of metal is provided which sends a signal when such a condition exists, this signal being used to effect automatic operation of said actuator so as to move the reel or hold down to a non-operating position so as not to interfere with the expulsion of the jam and/or metal. Other controls are provided and other parameters are sensed for delaying and/or overriding the automatic positioning of the reel or crop hold down in their non-operating position.
    Type: Grant
    Filed: April 17, 2000
    Date of Patent: May 7, 2002
    Assignee: Deere & Company
    Inventor: Steffen Clauss
  • Patent number: 6324822
    Abstract: A crop stream passes longitudinally at a feed velocity varying relative to a predetermined feed velocity in a harvesting machine between conveyor elements which transversely compress the stream and at least one of which is transversely deflectable. A stone in the stream is detected by continuously producing an output corresponding to the transverse deflection of the one conveyor element per unit of time, continuously monitoring the feed velocity and producing an output corresponding to actual feed velocity, and establishing for the predetermined feed velocity a predetermined threshold value for the transverse-deflection output. In addition for actual feed velocities different from the predetermined feed velocity respective threshold values are established that are equal to the predetermined threshold value multiplied by the quotient of the actual feed velocity squared divided by the predetermined feed velocity squared.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: December 4, 2001
    Assignee: Case Harvesting Systems GmbH
    Inventor: Christoph Oliva
  • Patent number: 6298641
    Abstract: The apparatus is an improvement to a feederhouse on an agricultural combine. The apparatus has a first acoustic array having a first sounding board and acoustic sensor positioned beneath the front drum and feederhouse floor. There is a second acoustic array positioned behind the front drum and between the conveyor chain encircling the front and rear drums. The second acoustic array also has a second acoustic sensor and second sounding plate. The acoustic sensor detects the impact of a stone on the sounding plates. A signal is transmitted via a controller from the sensor to a solenoid controlling a stone trap door latch. When the door opens, a sled also rotates into contact with conveyor chain. This deflects any crop flow containing stones. To close the door, the feederhouse is raise and the door rotates into contact with the latch.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: October 9, 2001
    Assignee: New Holland North America, Inc.
    Inventors: Michael J. Digman, David N. Heinsey, James A. Bennett, Yuan Cyriel Cornelius Vandergucht
  • Patent number: 6105347
    Abstract: A conveying device for material to be chopped with conveying rollers comprises a foreign body detection device and a chopper mechanism whose signals are fed to a control device which controls rapid stopping of the conveying rollers when a foreign body detection signal exceeds a predetermined threshold. Upon reversing operation of the conveying rollers, the detection device is used to end the reversing operation when the foreign body is positioned in front of the conveying rollers.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: August 22, 2000
    Assignee: Class Selbstfahrende Erntemaschinen GmbH
    Inventor: Willi Behnke
  • Patent number: 5702300
    Abstract: An over center closure apparatus for a spring latched rock door for a combine harvester includes a first, free rotating lever arm connected to rotate about the rock door pivot and a second lever arm connected to rotate with the rock door pivot. The second lever arm includes a stop positioned to engage the first lever arm as it rotates about the rock door pivot. A linkage arm extends from the first lever arm downward to a over center lever arm in an over center assembly. The over center lever arm is positioned to rotate about a pivot axis between an over center position and a free rotating position such that, when the over center lever arm is rotated to the over center position, the rock door is closed and held in the closed position by the over center position of the over center lever arm. The rock door can then be conveniently latched closed.
    Type: Grant
    Filed: April 18, 1996
    Date of Patent: December 30, 1997
    Assignee: AGCO Corporation
    Inventor: Ronald E. Wilson
  • Patent number: 5444966
    Abstract: An agricultural harvesting machine having feed rolls for feeding crop material along a feed path to a cutterhead which chops the crop material is provided with a metal detector for detecting ferrous metal objects passing along the feed path. The metal detector comprises a plurality of magnets and a plurality of generally planar Hall effect sensing elements. The magnets collectively produce a detection field which extends into the crop feed path. Each sensing element is disposed such that the magnetic field produced by two adjacent magnets is normal to the plane of the sensing element. In addition the sensing elements are disposed in a plurality of planes all normal to the crop feed path. However, the sensing elements are disposed in planes oriented at different angles relative to the direction of crop feed.
    Type: Grant
    Filed: February 3, 1994
    Date of Patent: August 29, 1995
    Assignee: New Holland North America, Inc.
    Inventors: Richard P. Strosser, Marvin G. Weaver, Jr., Mark K. Chow
  • Patent number: 5343676
    Abstract: In a device for recognizing ferromagnetic foreign bodies, for protecting the working members of a harvesting machine, having a magnetic field generating device (9), the lines of flux of which run transversely to the direction of transport, and having assigned pick-up coils (15; 16; 17), it is intended to improve the recognition range across the entire width of the feed system, whilst keeping costs low. At the same time, it is intended better to suppress disturbance signals. For this purpose, the magnetic field generating device (9) comprises an odd number of magnetic poles (12; 13; 14), the two outer magnetic poles (13; 14) possessing the same polarity. At least every second magnetic pole (12) is enclosed by a pick-up coil (15). Expediently, three magnetic poles (12; 13; 14) are present, which are all enclosed by a pick-up coil (15; 16; 17) each. The pick-up coils (15; 16; 17) are connected up such that the induced voltages are added together.
    Type: Grant
    Filed: December 10, 1992
    Date of Patent: September 6, 1994
    Assignee: Claas Saulgau GmbH
    Inventor: Burkhard Weiss
  • Patent number: 5092818
    Abstract: A forage harvester having a feed mechanism for transporting crop material along a feed path to a rotating cutterhead is provided with a first detector for detecting metal objects in the crop material and a second detector for detecting hard objects. The feed mechanism includes a hollow feed roll rotatable about a fixed shaft and both detectors are supported by the fixed shaft inside the feed roll. The first detector is a metal detector mounted inside a housing supported by the fixed shaft. The second detector is a thin film microphone for sensing air-borne sound waves produced when hard objects impact the feed roll. The second detector may be mounted on the housing or, alternatively, mounted on a support member attached to the fixed shaft. In either arrangement, a vibration-absorbing pad is provided to isolate the microphone from mechanical vibrations occurring in its supporting structure.
    Type: Grant
    Filed: October 26, 1990
    Date of Patent: March 3, 1992
    Assignee: Ford New Holland, Inc.
    Inventors: Carl E. Bohman, Howard A. Winey, Gilbert W. Linde
  • Patent number: 5078645
    Abstract: A thin film highly directional audible sound sensor is mounted within a rotatable feed roll of a forage harvester to detect the presence of stones and other hard foreign objects in a crop material being fed past the feed roll to a cutter mechanism. Air-borne sound waves produced by the impact of foreign objects on metal parts of the harvester are detected by the sensor which produces a signal for stopping the crop feed mechanism before the foreign objects reach the cutter mechanism. The sensor is mounted on a stationary support within the rotatable feed roll. Output signals from the sensor control a stop mechanism for the crop feed mechanism via conductors extending through a stationary support shaft for the feed roll, thereby avoiding the need to commutate output signals from the detector.
    Type: Grant
    Filed: October 26, 1990
    Date of Patent: January 7, 1992
    Assignee: Ford New Holland, Inc.
    Inventors: Carl E. Bohman, Howard A. Winey, Richard P. Strosser