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Publication numberUS3571544 A
Publication typeGrant
Publication dateMar 23, 1971
Filing dateOct 21, 1968
Priority dateOct 21, 1968
Publication numberUS 3571544 A, US 3571544A, US-A-3571544, US3571544 A, US3571544A
InventorsHilary William Sheehan
Original AssigneeHilary William Sheehan
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Magnetic key operated switch for electrically operated hand tools
US 3571544 A
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Description  (OCR text may contain errors)

United States Patent Inventor Hilary William Sheehan 1408 Leneva Lane, Pasadena, Tex. 77502 769,189

Oct. 21, 1968 Mar. 23, 1971 Appl. No. Filed Patented MAGNETIC KEY OPERATED SWITCH FOR ELECTRICALLY OPERATED HAND TOOLS 2 Claims, 5 Drawing Figs.

References Cited UNITED STATES PATENTS 3/1916 Meriwether 2,625,630 1/1953 Eckles 200/164 2,735,908 2/1956 Peretti et al. 200/157 2,767,278 10/1956 Collins 335/302X FOREIGN PATENTS 1,140,952 12/1 962 Germany ZOO/61.58

1,138,123 12/1968 Great Britain 335/205 Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorney-Ranseler O. Wyatt ABSTRACT: This invention relates to a switch for electrically operated hand tools, and the like, wherein the contact points of the switch are normally maintained yieldably separated,

and one arm of said points is movable, and a ring is provided,

for the user of the device having a magnetized key, shaped to fit the particular key opening of the tool, so that when the key, mounted on a ring worn on a finger of the user, is inserted into the key opening, the movable arm will be moved into closed position, completing an electrical circuit through the motor of the tool, and upon removal of the key, for any reason, the tool will be immediately deactivated.

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/ w I I I 1a 0 1111] 6 .1 I 11111 1111. j I I l MAGNETIC KEY OPERATED SWITCH FOR ELECTRICALLY OPERATED HAND TOOLS SUMMARY OF THE INVENTION A switch for electrically operated hand tools comprising a fixed and a movable contact arm, contact points mounted on the extended ends of said arms, a key, opening in the housing of the hand tool and a magnetized key, having the same contour as the key opening, mounted on a finger ring and adapted to be inserted into said key opening to move said movable arm and to move said contact points into contact with each other and to maintain said contact until said key is removed from said key opening.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the key mounted on a ring and showing a finger to receive said ring in dotted lines.

FIG. 2 is a side elevational view of the ring key.

FIG. 3 is a side elevational view, insection, showing the switch mounted in a housing and showing the key in the key opening in dotted lines.

FIG. 4 is an elevational perspective view of a hand tool having the key opening to receive the magnetized key.

FIG. 5 is an electrical diagramillustrating the circuit employed.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the numeral l designates a tool housing such as the handle of an electric drill in which a key opening 2 is formed of a particular, selected contour. A block of mag netized metal, contoured to exactly fit the contour of the opening 2, forms the key 3, which is mounted on a finger ring.

In the housing 1 is mounted the electric circuit control plange 4 and the spring loaded movable contact arm 5. A control arm 6 is mounted on the extended end of the contact arm 5, and is formed of a metal responsive to the magnetic force of the magnetized key 3, the extended end of the control arm 6 being positioned opposite the key opening 2. A fixed contact arm 7.is mounted in the housing 1 as the contact terminal 9. Mounted on the arm 5 is the pivotal contact member 8 which is yieldably urged in one direction by the spring 13 to provide a wiping action as the contact members 8, 9 are brought together and separated. An electric cord, as 10, extends through the housing 1 and the wires thereof are connected to the respective contact arms. The circuit is carried through the plate 4 to the motor 14.

The ring 11 on which the key 3 is mounted may be worn on the finger of the user, or expanded to be worn over the glove 12 of the user. When the key 3 is inserted in the opening 2, the control arm 6 will be drawn to the key 3 and the arm 5 pivoted to place the contact point 8 into contact with the point 9, thus completing the circuit through the motor and activating the tool. In the event the user drops the tool, or it becomes disengaged from his hand in any manner, the key 3 will be removed from the opening 2, and the arm 5 will move the point 8 out of contact with the point 9, and the motor of the tool will be deactivated.

lclaim:

I. In a switch for electrically operated hand tools, a switch housing, a spring mounted movable arm and a fixed arm, said arms being mounted in said housing and connected into an electrical circuit from a source of power through an electrically operated motor, contact points on said arms, a control arm on said movable arm formed of magnetic responsive metal, an opening in said housing adjacent said control arm and a magnetized key insertable into said opening to move said movable arm into contact with said fixed arm, the said key being mounted on a finger ring to be worn by the user.

2. The device defined in claim 1 wherein the key is mounted on a finger ring which may be adjusted to be mounted on the gloved finger of the user.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1174887 *Nov 23, 1915Mar 7, 1916Vincent R BriceMagnetic nail-holding device.
US2625630 *Jan 10, 1949Jan 13, 1953Emerson Electric Mfg CompanySwitch
US2735908 *Sep 19, 1952Feb 21, 1956 Power tools
US2767278 *Jun 29, 1951Oct 16, 1956Douglas CollinsMagnetic lock switch for starter and ignition circuits
DE1140952B *Oct 27, 1958Dec 13, 1962Olivetti & Co SpaSicherheitseinrichtung an elektrischen Schreib- und aehnlichen Maschinen
GB1138123A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3713056 *Nov 15, 1971Jan 23, 1973Surva Seikosha KkElectromagnetic switch assembly
US3750062 *Aug 16, 1971Jul 31, 1973Suwa Seikosha KkThin-type switchboard
US3801767 *Dec 11, 1972Apr 2, 1974R MarksPull-apart safety switch with magnetic means for machines
US3979052 *May 6, 1974Sep 7, 1976United Technologies CorporationHigh security lock
US4105885 *Jun 22, 1976Aug 8, 1978Consumer Concepts, Inc.Hand operated instruments having non-magnetic safety switch
US4232819 *Jul 10, 1978Nov 11, 1980Sentry Controls, Inc.Control system for environmental apparatus
US4531029 *Aug 8, 1983Jul 23, 1985Currillies TrimbleCricket switch
US6936789Oct 31, 2002Aug 30, 2005Illinois Tool Works Inc.Triggerless welding implement and method of operating same
US7007712May 10, 2005Mar 7, 2006Gary AndersonPneumatic tool lock
US7024717Sep 15, 2003Apr 11, 2006Braun GmbhMethod and device for cleaning teeth
US7086111Mar 16, 2001Aug 8, 2006Braun GmbhElectric dental cleaning device
US7207080Sep 10, 2002Apr 24, 2007Braun GmbhDental cleaning device
US7317263May 10, 2005Jan 8, 2008Gary AndersonPower tool lockdown device
US7621015Oct 24, 2005Nov 24, 2009Braun GmbhMethod and device for cleaning teeth
US7624467Jun 18, 2004Dec 1, 2009Braun GmbhDental cleaning device
US7661172Jul 31, 2007Feb 16, 2010Braun GmbhDental cleaning device
US7673360Jul 31, 2007Mar 9, 2010Braun GmbhDental cleaning device
US7750509Dec 27, 2007Jul 6, 2010Gary AndersonPower tool lockdown device
US7751898 *Aug 4, 2004Jul 6, 2010Cochlear LimitedMedical device with magnetically-responsive control switch
US7770251Jun 18, 2004Aug 10, 2010Braun GmbhMethod and device for cleaning teeth
US7774886Aug 3, 2007Aug 17, 2010Braun GmbhMethod and device for cleaning teeth
US7861349Aug 1, 2007Jan 4, 2011Braun GmbhMethod and device for cleaning teeth
US7979939Nov 30, 2009Jul 19, 2011Braun GmbhDental cleaning device
US8181301Feb 4, 2010May 22, 2012Braun GmbhDental cleaning device
US8218711Dec 16, 2005Jul 10, 2012Braun GmbhReplaceable accessory for a small electrical appliance and method of monitoring the usage of the accessory
US8276280 *Aug 11, 2009Oct 2, 2012Republic Of Korea (Management: Rural Development Administration)Electromotion trim scissors
US8443476Apr 19, 2012May 21, 2013Braun GmbhDental cleaning device
US8558430Aug 19, 2011Oct 15, 2013Braun GmbhResonant motor unit and electric device with resonant motor unit
US8631532Jul 25, 2012Jan 21, 2014Braun GmbhOral hygiene device
US8671493Jun 22, 2011Mar 18, 2014Braun GmbhDental cleaning device
US8683637May 2, 2013Apr 1, 2014Braun GmbhDental cleaning device
US20100064527 *Aug 11, 2009Mar 18, 2010Lee Kyung SukElectromotion trim scissors
EP1619569A2 *Jun 30, 2005Jan 25, 2006Lacroix Electronique SRLThermostat with modifiable operating modes and method for modifying said operating modes
EP1764757A1 *Jul 3, 2006Mar 21, 2007Robert Bosch GmbhAnti-theft device for electric power tool machines and electric power tool machine with anti-theft device
EP2395527A1 *Apr 2, 2011Dec 14, 2011Festool GmbHManually operated machine tool with an electric switch
WO2004041471A1 *Sep 26, 2003May 21, 2004Illinois Tool WorksTriggerless welding implement and method of operating the same, a magnetic operator and a glove
Classifications
U.S. Classification335/205, 335/302, 70/413, 200/52.00R
International ClassificationH01H9/06, H01H36/00
Cooperative ClassificationH01H2009/0221, H01H36/0066, H01H36/00, H01H9/06
European ClassificationH01H9/06, H01H36/00, H01H36/00B14