WO2000070632A1 - Guide magnetique - Google Patents

Guide magnetique Download PDF

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Publication number
WO2000070632A1
WO2000070632A1 PCT/US2000/013571 US0013571W WO0070632A1 WO 2000070632 A1 WO2000070632 A1 WO 2000070632A1 US 0013571 W US0013571 W US 0013571W WO 0070632 A1 WO0070632 A1 WO 0070632A1
Authority
WO
WIPO (PCT)
Prior art keywords
reed switch
ferrous metal
magnetic
metal housing
magnet
Prior art date
Application number
PCT/US2000/013571
Other languages
English (en)
Inventor
David Tyler Posey
Raymond Lee Morgan
Original Assignee
Hermetic Switch, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US09/313,456 external-priority patent/US6126647A/en
Application filed by Hermetic Switch, Inc. filed Critical Hermetic Switch, Inc.
Priority to AU51391/00A priority Critical patent/AU5139100A/en
Publication of WO2000070632A1 publication Critical patent/WO2000070632A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/01—Introducing, guiding, advancing, emplacing or holding catheters
    • A61M25/0105—Steering means as part of the catheter or advancing means; Markers for positioning
    • A61M25/0127—Magnetic means; Magnetic markers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H36/00—Switches actuated by change of magnetic field or of electric field, e.g. by change of relative position of magnet and switch, by shielding
    • H01H36/0006—Permanent magnet actuating reed switches
    • H01H36/0013—Permanent magnet actuating reed switches characterised by the co-operation between reed switch and permanent magnet; Magnetic circuits
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H36/00—Switches actuated by change of magnetic field or of electric field, e.g. by change of relative position of magnet and switch, by shielding
    • H01H36/0006—Permanent magnet actuating reed switches
    • H01H36/0033—Mountings; Housings; Connections

Definitions

  • the present invention relates to a magnetic guide for magnetically guiding a remote device, and more particularly, but not by way of limitation, to a ferrous metal follower which moves in response to movement of a magnetically coupled leader magnet and a shielded magnetic reed switch which actuates at the point at which a magnetic coupling is established between the ferrous metal follower and the leader magnet.
  • a follower magnet is used instead of a ferrous metal follower to further enhance the magnetic coupling.
  • the shielded magnetic reed switch provides a sensor which actuates and thereby provides an input to an electrical circuit to indicate establishment of the magnetic coupling.
  • Magnetic reed switches are well known in the art.
  • a magnetic reed switch has associated with it a specific magnetic field strength (sometimes referred to herein as magnetic flux) required to actuate the reed switch.
  • magnetic flux In the presence of a very strong permanent magnetic having a magnetic field strength of at least 300 Gauss at a distance of 4 inches from the magnet's pole face, a typical magnetic reed switch will actuate at a distance of 12-18 inches from the pole face.
  • Progress in the area of magnetic reed switches has largely involved development of ever more sensitive reed switches, i.e., reed switches requiring low magnetic field strength (low magnetic flux) for actuation.
  • the use of magnets to manipulate ferrous materials is well known in the art.
  • magnets to manipulate such diverse items as simulated ice skaters (magnets underneath a simulated ice ring, ferrous metal follower or follower magnets attached to the feet of toy skaters) and simulated dancers (magnets underneath a simulated dance floor, ferrous metal followers or follower magnets attached to the feet of toy dancers).
  • the present invention provides a ferrous metal follower guided by a leader magnet.
  • the ferrous metal follower is positioned adjacent to a magnetic reed switch disposed within a ferrous metal housing. Based on the selection of the reed switch and the architecture of the ferrous metal housing, the shielded magnetic reed switch of the present invention remains unactuated in the presence of the leader magnet until the distance between the shielded magnetic reed switch and the leader magnet matches the distance for formation of a magnetic coupling between the ferrous metal follower and the leader magnet.
  • the present invention further provides a sensor for indicating a predetermined distance between the ferrous metal follower and the leader magnet at which a magnetic coupling is established.
  • An object of the present invention is to provide a magnetic guide, wherein a ferrous metal follower (or a follower magnet) is positioned adjacent to a magnetic reed switch which, in the presence of a leader magnet having sufficient magnetic flux to actuate the magnetic reed switch, remains unactuated until the magnetic field source is within a predetermined distance from the magnetic reed switch at which predetermined distance a magnetic coupling is established between the leader magnet and the ferrous metal follower.
  • FIG. 1 is an enlarged cross-sectional view of a ferrous metal follower and a shielded magnetic reed switch for use with a leader magnet according to the present invention.
  • FIG.2 is an enlarged cross-sectional view of a second embodiment of a shielded magnetic reed switch and ferrous metal follower for use with a leader magnet according to the present invention.
  • FIG. 3 is an enlarged cross-sectional view of a third embodiment of a shielded magnetic reed switch and ferrous metal follower for use with a leader magnet according to the present invention.
  • FIG. 4 is a representation of applicants' invention showing the operation of a leader magnet in conjunction with the ferrous metal follower and shielded magnetic reed switches of FIGS. 1-3.
  • FIG. 5 is another representation of applicants' invention showing the operation of a leader magnet in conjunction with the ferrous metal follower and shielded magnetic reed switches of FIGS. 1-3.
  • FIG. 6 is an enlarged cross-sectional view of a shielded magnetic reed switch and a follower magnet for use with a leader magnet according to the present invention.
  • FIG.7 is an enlarged cross-sectional view of a second embodiment of a shielded magnetic reed switch and a follower magnet for use with a leader magnet according to the present invention.
  • FIG. 8 is an enlarged cross-sectional view of a third embodiment of a shielded magnetic reed switch and a follower magnet for use with a leader magnet according to the present invention.
  • FIG. 9 is a representation of applicants' invention showing the operation of a leader magnet in conjunction with a follower magnet and the shielded magnetic reed switches of FIGS. 6-8.
  • FIG. 10 is another representation of applicants' invention showing the operation of a leader magnet in conjunction with the follower magnet and the shielded magnetic reed switches of FIGS. 6-8.
  • FIG. 11 shows applicants' shielded magnetic reed switch of FIG.6 and a follower magnet secured within a flexible plastic tube. 5. Best Mode for Carrying Out the Invention
  • FIGS. 1-3 shown therein are three embodiments of the shielded magnetic reed switch 10 and a ferrous metal follower 38.
  • a remote device R is indicated by dashed lines.
  • a normally open magnetic reed switch 16 consisting of reeds 12, 14 sealed in a glass envelope 17, is disposed within a ferrous metal housing 30. Electrical leads 18, 20 are soldered to the portions of the reeds 12, 14, and heat shrink 22, 24 is applied as indicated.
  • the magnetic reed switch 16 is then placed within the ferrous metal housing 30 and potting compound 36 holds the reed switch 16 and leads 18, 20 in position within the ferrous metal housing 30.
  • a ferrous metal follower 38 Positioned adjacent the shielded magnetic reed switch is a ferrous metal follower 38. It will be understood to one skilled in the art that the method of attachment of the shielded magnetic reed switch 10 and the ferrous metal follower 38 to the remote device R is not critical to applicants' invention.
  • the shielded magnetic reed switch 10 and the ferrous metal follower 38 can be jointly encapsulated and incorporated into the body of the remote device R.
  • the shielded magnetic red switch 10 and the ferrous metal follower 38 may also be fastened to the remote device R by means of a suitable adhesive.
  • a ferrous metal housing 30 having a diameter of about 0.125 inch, a tubular wall 32 thickness of about 0.0125 inches, and a thickened end portion 34 of about 0.125 inches at its maximum thickness results in closure of the magnetic reed switch 16 when the permanent magnet M is within 3.5 to 5.0 inches of the magnetic reed switch 16 the adjacent ferrous metal follower 38.
  • the reeds 12, 14 of the magnetic reed switch 16 close at a distance of about 12-18 inches between the pole face P of the permanent magnet M and the magnetic reed switch 16, a distance well beyond the distance at which a magnetic coupling is created between the ferrous metal follower 38 and the permanent magnet M.
  • the permanent magnet M is also referred to as the leader magnet M.
  • FIG. 2 shown therein is another embodiment of the shielded magnetic reed switch 10 and the ferrous metal follower 38 of the present invention.
  • the tubular wall 32A is about 0.0125 inches thick and the thickened end portion 34A of ferrous metal housing 30 is about 0.151 inches thick.
  • the thickened end portion 34A is about 0.125 inches thick at its thickest point.
  • FIG. 3 shown therein is another embodiment of the shielded magnetic reed switch 10 and the ferrous metal follower 38 of the present invention.
  • the tubular wall 32B is about 0.025 inches thick and the ferrous metal housing is about 0.151 inches thick.
  • the thickened end portion 34B is about 0.125 inches thick at its thickest point.
  • the ferrous metal housing 30 is annealed to a full soft condition to maximize magnetic permeability.
  • FIGS. 4 and 5 the operation of the shielded magnetic reed switch 10 (much enlarged), the ferrous metal follower 38, and the leader magnet M is illustrated.
  • a distance D in FIGS. 4 and 5 defines the distance between the shielded magnetic reed switch 10 and the pole face P of leader magnet M (about 3.5 to 5. 0 inches) at which closure of the magnetic reed switch 16 occurs.
  • the leader magnet M is positioned out of range of the distance D at which closure of the magnetic reed switch 16 (see FIGS. 1-3) is desired (more specifically, the distance at which a magnetic coupling between the ferrous metal follower 38 and the leader magnet M is established).
  • the ferrous metal housing 30 absorbs the magnetic flux produced by the leader magnet M and prevents the magnetic reed switch 16 from closing.
  • the magnetic reed switch 16 connected to a generic electrical circuit by electrical leads 18, 20 remains open.
  • the leader magnet M is positioned within the distance D at which a magnetic coupling is established and the shielded magnetic reed switch 10 closes.
  • the magnetic reed switch 16 connected to the generic electrical circuit by electrical leads 18, 20 is now closed.
  • FIGS. 6-8 shown therein are three embodiments of the shielded magnetic reed switch 10 and a follower magnet 40 attached to a remote device R.
  • the structure is like that of FIGS. 1-3, respectfully, except for the substitution of a follower magnet 40 (FIGS. 6-8) for the ferrous metal follower 38 (FIGS. 1-3).
  • the magnetic coupling established between the follower magnet 40 (FIGS. 6-8) and the leader magnet M is stronger than the magnetic coupling established between the ferrous metal follower 38 (FIGS. 1-3) and the leader magnet M, thereby providing a more positive magnetic guide.
  • ferrous metal housing 30 can also perform double duty as the ferrous metal follower.
  • the size and shape of the ferrous metal follower is a design choice based on the size of the remote device R and the resistance to be encountered in its manipulation.
  • FIGS. 9 and 10 the operation of the shielded magnetic reed switch 10 (much enlarged), the follower magnet 40, and the leader magnet M is illustrated.
  • a distance D in FIGS. 9 and 10 defines the distance between the shielded magnetic reed switch 10 and the pole face P of leader magnet M (about 3.5 to 5. 0 inches) at which closure of the magnetic reed switch 16 occurs.
  • the leader magnet M is positioned out of range of the distance D at which closure of the magnetic reed switch 16 (see FIGS. 6-8) is desired (wherein the distance D corresponds to the distance at which a magnetic coupling between the follower magnet 40 and the leader magnet M is established).
  • the ferrous metal housing 30 absorbs the magnetic flux produced by the leader magnet M and prevents the magnetic reed switch 16 from closing.
  • the magnetic reed switch 16 connected to a generic electrical circuit by electrical leads 18, 20 remains open.
  • the leader magnet M is positioned within the distance D at which a magnetic coupling is established and the shielded magnetic reed switch 10 closes.
  • the magnetic reed switch 16 connected to the generic electrical circuit by electrical leads 18, 20 is now closed.
  • shielded magnetic reed switch 10 While the operation of the shielded magnetic reed switch 10 is illustrated in conjunction with a permanent magnet M, it will be understood by one skilled in the art that the shielded magnetic reed switch 10 of the present invention operates as illustrated with any magnetic field source (i.e., with either a permanent magnet or an electromagnet).
  • the shielded magnetic reed switch 10 and the follower magnet 40 of FIG. 6 are enclosed in a flexible plastic tube 42.
  • the plastic tube 42 includes a slight bulge 44 and an opening 46 through which the follower magnet 40 may be inserted.
  • An opening 48 in the flexible plastic tube 42 is available for attachment to the remote device R to be guided by applicants' invention.
  • the ferrous metal housing 30 acts as a magnetic shield to prevent the reeds 12, 14 from closing prematurely and, further, that the structure of the ferrous metal housing 30, including the thickness of the tubular wall 32, 32A, 32B and the thickness of the thickened end portion 34, 34A, 34B determine the distance D from the magnetic field source (e.g., the leader magnet M) at which the shielded magnetic reed switch 10 closes.
  • the magnetic field source e.g., the leader magnet M
  • a relatively thinner tubular wall 32, 32A, 32B will result in closure of the magnetic reed switch 16 at a relatively greater operating distance D.
  • a relatively thinner thickened end portion 34, 34A, 34B will also result in closure of the magnetic reed switch 16 at a relatively greater operating distance D.
  • Selection of the magnetic reed switch 16 also affects the operating distance D.
  • a magnetic reed switch 16 having relatively more flexible reeds results in closure of the magnetic reed switch 16 at a relatively greater operating distance D, whereas a magnetic reed switch 16 having relatively stiffer reeds effectively reduces the distance D at which the magnetic reed switch 16 closes.
  • the present invention is for apparatus involving a magnetic reed switch disposed within a ferrous housing, so that the shielded magnetic reed switch actuates at a predetermined distance from an approaching magnetic field source. In the absence of the ferrous housing, the magnetic reed switch will actuate at a distance greater than the predetermined distance.
  • While applicants' invention is illustrated herein as being a normally open magnetic reed switch 16 disposed within a ferrous metal housing 30, it will be understood to one skilled in the art that reed switches can be either normally open or normally closed.
  • a single-pole, single-throw (SPST), normally-open magnetic reed switch (also referred to by those skilled in the art as a Form "A" reed switch) is illustrated herein.
  • the magnetic guide of the present invention includes a sensor which indicates the establishment of a magnetic coupling between the leader magnet and the follower magnet.
  • the sensor provides an affirmative indication to the user that the manipulation of the leader will result in a corresponding movement of the follower magnet and any device attached thereto.
  • the magnetic guide of the present invention can be used to guide copper wires through hollow walls, manipulate fiber optic cameras in close environments such as plastic pipes, and, more generally, to create a magnetic guidance path by creating a traction force between the leader magnet and the follower magnet.
  • the sensor of the present invention actuates when the leader magnet is in the traction position with respect to the follower magnet.

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  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biophysics (AREA)
  • Pulmonology (AREA)
  • Engineering & Computer Science (AREA)
  • Anesthesiology (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Hematology (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Switches That Are Operated By Magnetic Or Electric Fields (AREA)

Abstract

L'invention concerne un guide magnétique qui comporte un suiveur métallique ferreux (38) et un aimant entraîneur (40). Le flux magnétique associé à cet aimant (40) envahit le suiveur (38) et induit un couplage magnétique entre le suiveur (38) et l'aimant (40), si bien que le suiveur (38) se déplace en réaction au mouvement de l'aimant (40). Un commutateur à lames magnétique blindé (16) adjacent au suiveur (38) active une distance prédéterminée à laquelle le couplage magnétique est établi.
PCT/US2000/013571 1999-05-17 2000-05-17 Guide magnetique WO2000070632A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU51391/00A AU5139100A (en) 1999-05-17 2000-05-17 Magnetic guide

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US09/313,456 US6126647A (en) 1999-05-17 1999-05-17 Magnetically guided catheter with sensor
US09/313,456 1999-05-17
US53469100A 2000-03-24 2000-03-24
US09/534,691 2000-03-24

Publications (1)

Publication Number Publication Date
WO2000070632A1 true WO2000070632A1 (fr) 2000-11-23

Family

ID=26978891

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/013571 WO2000070632A1 (fr) 1999-05-17 2000-05-17 Guide magnetique

Country Status (2)

Country Link
AU (1) AU5139100A (fr)
WO (1) WO2000070632A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3711749A (en) * 1971-10-07 1973-01-16 M Koblents Reed switch
US3720894A (en) * 1971-11-03 1973-03-13 Westinghouse Electric Corp Current monitoring means
US6018130A (en) * 1998-05-20 2000-01-25 Breed Automotive Technology, Inc. Roll-over sensor with pendulum mounted magnet

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3711749A (en) * 1971-10-07 1973-01-16 M Koblents Reed switch
US3720894A (en) * 1971-11-03 1973-03-13 Westinghouse Electric Corp Current monitoring means
US6018130A (en) * 1998-05-20 2000-01-25 Breed Automotive Technology, Inc. Roll-over sensor with pendulum mounted magnet

Also Published As

Publication number Publication date
AU5139100A (en) 2000-12-05

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