Tracy K Clark

US Patent:

6499701, Dec 31, 2002

Filed:

Jul 3, 2000

Appl. No.:

09/609124

Inventors:

Richard D. Thornton - Concord MA
Brian M. Perreault - Stow MA
Tracy M. Clark - Bedford MA

Assignee:

MagneMotion, Inc. - Acton MA

International Classification:

B61L 100

US Classification:

246194, 246 1 C

Abstract:

Inductive transfer methods and structures combine, in a single system, at least two of the three functions of transferring power, communicating data, and sensing position with a vehicle on a guideway. A set of conductors is installed on the guideway to inductively couple a multiplicity of diverse signals with a corresponding set of conductors on the vehicle. The vehicle may be moving or stationary, and signals may be coupled in one or both directions. Coupling is effected without direct electrical contact, through a common region or gap, and the structures provide suitable and precise air gap control for the conductors effecting coupling of each signal. In addition, the windings are arranged with a topology and/or symmetry to cancel crosstalk between different signals.

US Patent:

6781524, Aug 24, 2004

Filed:

Mar 17, 2000

Appl. No.:

09/528265

Inventors:

Tracy M. Clark - Bedford MA
Brian M. Perreault - Stow MA

Assignee:

MagneMotion, Inc. - Acton MA

International Classification:

G08G 1123

US Classification:

340933, 340905, 340928, 340935, 340941, 340988, 340989, 180168, 246122 R, 246194

Abstract:

A pathway-based method, apparatus and system for tracking, sensing and communicating with an object, such as a carriage or vehicle moving on a pathway. The system includes a transmitter winding along the pathway that is energized by a transmitter and one or more sensing windings in which a signal is induced. The vehicle contains a transducer that creates a position-indicating coupling of the transmitted signal into the sensing windings. The transducer may be a passive ferromagnetic or conductive body that locally alters coupling between the windings, or a tuned coil carried on the vehicle that couples energy received from the transmitter into a sensing winding. Absolute position may be established at regular intervals using a discrete position sensor, such as a Hall Effect magnetic field sensor, and, the signal derived from the sensing windings can be monitored, by counting cycles or determining phase, to determine a precise vehicle position. With one sensing winding it is possible to determine distance to about â of a wavelength and by using two or more phased sensing windings a wayside controller determines the position within a wavelength to a smaller fraction of a wavelength. The position sensing can be accomplished without any source of power on the vehicle, and may extract power from the transducer or position sensing system to drive an electronic communication unit on the vehicle.

US Patent:

6917136, Jul 12, 2005

Filed:

Oct 1, 2002

Appl. No.:

10/262541

Inventors:

Richard D. Thornton - Concord MA, US
Tracy M. Clark - Bedford MA, US

Assignee:

MagneMotion, Inc. - Acton MA

International Classification:

H02K041/03
H02K001/06
H02K019/00

US Classification:

310254, 310 12, 310261, 310180

Abstract:

Synchronous motors according to the invention operate at higher efficiency, with lower cost, reduced mass and reduced cogging. Magnet dimensions are selected that reduce cogging forces to a negligible amount even though there are fewer slots than normal. Optionally, it is possible to use non-overlapping windings with deeper and open slots. The approach is applicable to both rotary and linear motors and motors using either permanent magnets or electromagnets in the field structure. It is particularly relevant to linear or rotary motors that have a large air gap, and to small motors that must deliver a high ratio of thrust or torque to motor mass.

US Patent:

6983701, Jan 10, 2006

Filed:

Oct 1, 2003

Appl. No.:

10/676726

Inventors:

Richard D. Thornton - Concord MA, US
Tracy M. Clark - Bedford MA, US

Assignee:

Magnemotion, Inc. - Acton MA

International Classification:

B60L 13/04

US Classification:

104282, 310 12, 310 905

Abstract:

Magnetic levitation methods and apparatus use arrays of vehicle magnets to provide three forces: suspension, guidance and propulsion. The magnets, which can be permanent magnets or superconducting magnets operating in the persistent current mode, have associated control coils that allow the magnets to provide a controllable attractive force to a laminated steel rail. The control coils adjust the gap between the magnets and the rails so as to be in stable equilibrium without requiring significant power dissipation in the control coils. These same magnets and steel rails also provide lateral guidance to keep the vehicle on the track and steer the vehicle on turns. The suspension control coils can provide lateral damping by means of offset magnets in the suspension arrays. Windings in transverse slots in the steel rails are excited with currents that react against the field produced by the vehicle magnets to create vehicle propulsion. The magnet size is adjusted to provide negligible cogging force even when there are as few as three winding slots per wavelength along the rail.

US Patent:

7448327, Nov 11, 2008

Filed:

Jan 9, 2006

Appl. No.:

11/327998

Inventors:

Richard D. Thornton - Concord MA, US
Tracy M. Clark - Bedford MA, US

Assignee:

Magnemotion, Inc. - Acton MA

International Classification:

B60L 13/04
H02K 41/02

US Classification:

104282, 310 12, 310 905

Abstract:

Magnetic levitation methods and apparatus use arrays of vehicle magnets to provide three forces: suspension, guidance and propulsion. The magnets, which can be permanent magnets or superconducting magnets operating in the persistent current mode, have associated control coils that allow the magnets to provide a controllable attractive force to a laminated steel rail. The control coils adjust the gap between the magnets and the rails so as to be in stable equilibrium without requiring significant power dissipation in the control coils. These same magnets and steel rails also provide lateral guidance to keep the vehicle on the track and steer the vehicle on turns. The suspension control coils can provide lateral damping by means of offset magnets in the suspension arrays. Windings in transverse slots in the steel rails are excited with currents that react against the field produced by the vehicle magnets to create vehicle propulsion. The magnet size is adjusted to provide negligible cogging force even when there are as few as three winding slots per wavelength along the rail.

US Patent:

7538469, May 26, 2009

Filed:

Jun 30, 2005

Appl. No.:

11/172006

Inventors:

Richard D. Thornton - Concord MA, US
Tracy M. Clark - Bedford MA, US

Assignee:

MagneMotion, Inc. - Devens MA

International Classification:

H02K 1/06
H02K 41/03
H02K 19/00

US Classification:

310254, 310 12, 310180, 310261, 31015645, 310166

Abstract:

Synchronous motors according to the invention operate at higher efficiency, with lower cost, reduced mass and reduced cogging. Magnet dimensions are selected that reduce cogging forces to a negligible amount even though there are fewer slots than normal. Optionally, it is possible to use non-overlapping windings with deeper and open slots. The approach is applicable to both rotary and linear motors and motors using either permanent magnets or electromagnets in the field structure. It is particularly relevant to linear or rotary motors that have a large air gap, and to small motors that must deliver a high ratio of thrust or torque to motor mass.

US Patent:

8616134, Dec 31, 2013

Filed:

Jan 23, 2009

Appl. No.:

12/359022

Inventors:

Nathanael N. King - Somerville MA, US
Brian M. Perreault - Stow MA, US
Tracy M. Clark - Bedford MA, US
Richard D. Thornton - Concord MA, US
Jason Young - Marlboro MA, US
Michael W. Bottasso - Maynard MA, US

Assignee:

Magnemotion, Inc. - Devens MA

International Classification:

B60L 13/06
B60L 1/00

US Classification:

104284, 191 6

Abstract:

Aspects of the invention provide a transport system powered by short block Linear Synchronous Motors (LSMs). The use of short blocks allows vehicles to move under precise control even when they are in close proximity to each other. The design allows the vehicles to be propelled and guided while negotiating sharp turns and negotiating merge and diverge switches. A coreless LSM can be used to create propulsive force without attractive force so as to allow a relatively high drag vehicle suspension, such as a vehicle sliding on a smooth surface.

US Patent:

20070044676, Mar 1, 2007

Filed:

Jul 19, 2006

Appl. No.:

11/490516

Inventors:

Tracy Clark - Bedford MA, US
Jesse Mendenhall - Medford MA, US
Richard Thornton - Concord MA, US

Assignee:

MagneMotion Inc. - Acton MA

International Classification:

B61B 13/08

US Classification:

104130020

Abstract:

A system for switching a transport vehicle comprising: a guideway, a vehicle that moves along the guideway, and a magnetic field source that creates a force on the vehicle to affect motion in a desired direction at a switch. Once the vehicle has started motion through the switch the guidance can be continued by use of permanent magnets until the normal guidance system is effective. The switching scheme can work with any suspension scheme, including wheels and maglev, and can work with any lateral guidance scheme, including horizontal guide wheels and magnetic guidance. The system can be used with very closely spaced vehicles, such as with Personal Rapid Transit, material handling, and elevators with multiple cabs in the same shaft.