US3358108A - Power operated knife safety switch - Google Patents

Power operated knife safety switch Download PDF

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Publication number
US3358108A
US3358108A US526541A US52654166A US3358108A US 3358108 A US3358108 A US 3358108A US 526541 A US526541 A US 526541A US 52654166 A US52654166 A US 52654166A US 3358108 A US3358108 A US 3358108A
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US
United States
Prior art keywords
actuating member
housing
trigger
button
switch
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
US526541A
Inventor
John M Hansen
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Scovill Inc
Original Assignee
Scovill 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
Application filed by Scovill Inc filed Critical Scovill Inc
Priority to US526541A priority Critical patent/US3358108A/en
Priority to GB49237/66A priority patent/GB1136790A/en
Priority to BE689686D priority patent/BE689686A/xx
Priority to FR83591A priority patent/FR1499039A/en
Priority to ES0333378A priority patent/ES333378A1/en
Priority to CH1654466A priority patent/CH449745A/en
Priority to DES107211A priority patent/DE1285040B/en
Priority to NL6700376A priority patent/NL6700376A/xx
Application granted granted Critical
Publication of US3358108A publication Critical patent/US3358108A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
    • H01H9/02—Bases, casings, or covers
    • H01H9/06—Casing of switch constituted by a handle serving a purpose other than the actuation of the switch, e.g. by the handle of a vacuum cleaner
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
    • B26B—HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR
    • B26B7/00—Hand knives with reciprocating motor-driven blades

Definitions

  • the main object of the invention is to provide a switch closing device with means for automatically locking a switch actuating member in nondepressible position, whereby accidental bumping or pushing of the switch button cannot result in depression of the button and closing of the switch contacts.
  • Another object is to provide a switch actuating member which remains in locked position until released by manual pressure applied against a trigger portion of said actuating member, followed by manual depression of the switch actuating button while pressure on the trigger is maintained by the user of the knife or other tool.
  • the trigger part of the switch actuating member is located on the underside of the hand grip portion of the knife handle or tool for convenient manipulation by the forefinger while the thumb is used to depress the switch button located on the upper surface of the hand grip portion.
  • FIG. 1 is an elevational side view, partly in section, of the forward portion of a power operated knife embodying my safety switch, showing the switch actuating member in locked position.
  • FIG. 2 is an elevational side view, partly in section, showing the switch actuating member in unlocked position, as it appears after the trigger has been raised by applying pressure thereon.
  • FIG. 3 is a view similar to FIG. 2, showing the switch actuating member in unlocked position and the switch button depressed, as they appear when simultaneous pressure has been applied in opposite directions on said trigger and button to thereby close the switch contacts.
  • FIG. 4 is a top plan view of the switch actuating member.
  • FIG. 1 indicates a knife handle housing, as a whole, provided with hand grip portion 11, knife blades 12, and blade guards '13.
  • the housing 10 has formed therein or attached thereto a horizontal platform 14 spaced from the top wall 15, and a curved wall 16 provided with an opening 17 below the hand grip portion 11.
  • a switch button opening 18 is located in the top wall 15.
  • the safety switch of my invention comprises an actuating member 20 provided on its top with a switch button 21, a forward end 22 located in the space between the platform 14 and top wall 15, a rearwardly extending lever 23 having its trigger end 24 exposed through the opening 17, and a depending foot or contact member 25.
  • the member 25 has formed on its forward face a shoulder 26 which is complemental to, and bears upon, the shoulder surface 27 on the end of the platform 14, when the trigger 24 bears on the lower edge 28 which defines the opening 17 in the housing.
  • a leaf spring 30, generally U-shaped in form, has part of its fiat body resting on the platform 14, with the spring end 31 abutting the stop 32 on the platform.
  • the depending contact member 25 is shown as having a contact 35 directly located thereon, for making contact with a fixed contact 36 connected to conductors 37.
  • the switch contacts may be separate from the actuating member 20, and that the depending member 25 may actuate a movable contact (not shown) in place of having a contact directly mounted thereon.
  • the actuating member 20 When the knife is not in use, the actuating member 20 is in the position shown in FIG. 1, with the spring 30 urging the foiward end 22 upwardly, and theexposed trigger 24 bearing on the edge 28 of the housing wall 16. In this position, the shoulder 26 on the actuating member engages the shoulder 27 on the platform 14.
  • the switch button 21 cannot be depressed because of the stops provided by the parts 26-27 and 24-28. Therefore accidental or unintentional pressure applied to the button 21 has no eifect.
  • the user In order to actuate the switch, the user must apply pressure against the exposed trigger 24 as shown in FIG. 2, thereby raising the trigger lever and moving the shoulder 26 in a pivotal movement out of engagement with the shoulder 27. While maintaining the pressure on the trigger, the user depresses the button 21 as shown in FIG. 3, thereby moving the contact member 25 into switch closing position.
  • the surface of the shoulder 26 serves as a movable fulcrum for the trigger lever 23 when pressure is applied to the exposed end 24 to move the switch actuating member pivotally as a whole out of locked position so that the button 21 can be depressed and the contact member 25 moved into the position shown in FIG. 3.
  • a safety switch in the housing comprising (a) a manually operable switch actuating member including a trigger accessible through one of said openings in the housing and a button accessible through the other opening,
  • said actuating member being pivotally movable about said bearing surface as a non-fixed fulcrum when the trigger is depressed relatively to the housing, whereby the actuating member is moved out of support-engaging position and depression of the button is permitted while said trigger is depressed.
  • a safety switch in the housing comprising (a) a manually operable switch actuating member including a trigger accessible through the opening in the hand grip portion, and a button accessible through the opening in the housing,
  • said actuating member being pivotally movable about said bearing surface as a non-fixed fulcrum when the trigger is depressed relatively to the hand grip portion of the housing, whereby the actuating member is moved out of support-engaging position and depression of the button is permitted while said trigger is depressed.

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  • Life Sciences & Earth Sciences (AREA)
  • Forests & Forestry (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Rotary Switch, Piano Key Switch, And Lever Switch (AREA)
  • Knives (AREA)

Description

Dec. 12, 1967 J. M. HANSEN 3,358,108
POWER OPE-RATED KNIFE SAFETY SWITCH Filed Feb. 10, 1966 INVENTOR. JOHN M. HANSEN MAaf Z 723 ATTORNEY United States Patent Connecticut Filed Feb. 10, 1966, Ser. No. 526,541 6 Claims. (Cl. 200-157) This invention rel-ates to a safety switch for power operated knives and other tools which cannot be actuated accidentally oruninten-tionally to close switch contacts and thereby produce reciprocatory movement of the knife blades or undesired movement of tool parts.
The main object of the invention is to provide a switch closing device with means for automatically locking a switch actuating member in nondepressible position, whereby accidental bumping or pushing of the switch button cannot result in depression of the button and closing of the switch contacts. Another object is to provide a switch actuating member which remains in locked position until released by manual pressure applied against a trigger portion of said actuating member, followed by manual depression of the switch actuating button while pressure on the trigger is maintained by the user of the knife or other tool.
The trigger part of the switch actuating member is located on the underside of the hand grip portion of the knife handle or tool for convenient manipulation by the forefinger while the thumb is used to depress the switch button located on the upper surface of the hand grip portion. The requirement for initial manipulation of the trigger, followed by sustained simultaneous pressure in opposite directions on the trigger and button, prevents unintentional closing of the switch contacts.
In the drawings:
FIG. 1 is an elevational side view, partly in section, of the forward portion of a power operated knife embodying my safety switch, showing the switch actuating member in locked position.
FIG. 2 is an elevational side view, partly in section, showing the switch actuating member in unlocked position, as it appears after the trigger has been raised by applying pressure thereon.
FIG. 3 is a view similar to FIG. 2, showing the switch actuating member in unlocked position and the switch button depressed, as they appear when simultaneous pressure has been applied in opposite directions on said trigger and button to thereby close the switch contacts.
FIG. 4 is a top plan view of the switch actuating member.
In that embodiment of the invention shown in the drawings, indicates a knife handle housing, as a whole, provided with hand grip portion 11, knife blades 12, and blade guards '13. The housing 10 has formed therein or attached thereto a horizontal platform 14 spaced from the top wall 15, and a curved wall 16 provided with an opening 17 below the hand grip portion 11. A switch button opening 18 is located in the top wall 15.
The safety switch of my invention comprises an actuating member 20 provided on its top with a switch button 21, a forward end 22 located in the space between the platform 14 and top wall 15, a rearwardly extending lever 23 having its trigger end 24 exposed through the opening 17, and a depending foot or contact member 25. The member 25 has formed on its forward face a shoulder 26 which is complemental to, and bears upon, the shoulder surface 27 on the end of the platform 14, when the trigger 24 bears on the lower edge 28 which defines the opening 17 in the housing.
A leaf spring 30, generally U-shaped in form, has part of its fiat body resting on the platform 14, with the spring end 31 abutting the stop 32 on the platform. The
"ice
upper part 33 of the spring extends toward the member 20 and has a small hole therein for engagement by a depending projection 34 on the forward end 22 of said member 20.
In the embodiment of the invention shown in the drawings, the depending contact member 25 is shown as having a contact 35 directly located thereon, for making contact with a fixed contact 36 connected to conductors 37. However, it is to be understood that the switch contacts may be separate from the actuating member 20, and that the depending member 25 may actuate a movable contact (not shown) in place of having a contact directly mounted thereon.
When the knife is not in use, the actuating member 20 is in the position shown in FIG. 1, with the spring 30 urging the foiward end 22 upwardly, and theexposed trigger 24 bearing on the edge 28 of the housing wall 16. In this position, the shoulder 26 on the actuating member engages the shoulder 27 on the platform 14. The switch button 21 cannot be depressed because of the stops provided by the parts 26-27 and 24-28. Therefore accidental or unintentional pressure applied to the button 21 has no eifect.
In order to actuate the switch, the user must apply pressure against the exposed trigger 24 as shown in FIG. 2, thereby raising the trigger lever and moving the shoulder 26 in a pivotal movement out of engagement with the shoulder 27. While maintaining the pressure on the trigger, the user depresses the button 21 as shown in FIG. 3, thereby moving the contact member 25 into switch closing position.
The surface of the shoulder 26 serves as a movable fulcrum for the trigger lever 23 when pressure is applied to the exposed end 24 to move the switch actuating member pivotally as a whole out of locked position so that the button 21 can be depressed and the contact member 25 moved into the position shown in FIG. 3.
As soon as pressure is withdrawn from the button and trigger, the parts are automatically restored to the position shown in FIG. 1, where the switch actuating member is again locked and actuation of the switch button 21 prevented.
Changes may be made in details of construction and arrangement of parts without departing from the scope of the inventionas defined by the appended claims.
I claim:
1. In a power operated tool provided with a housing having two spaced apart openings therein, a safety switch in the housing comprising (a) a manually operable switch actuating member including a trigger accessible through one of said openings in the housing and a button accessible through the other opening,
(b) a contact member on the actuating member,
(c) a fixed support in the housing,
(d) a bearing surface extending transversely of the actuating member for bearing on the fixed support and preventing depression of the button, and
(e) yielding means bearing on the fixed support and urging the actuating member into support-engaging position,
(f) said actuating member being pivotally movable about said bearing surface as a non-fixed fulcrum when the trigger is depressed relatively to the housing, whereby the actuating member is moved out of support-engaging position and depression of the button is permitted while said trigger is depressed.
2. The safety switch defined by claim 1, in which the transversely extending bearing surface is a shoulder on the contact member portion of the actuating member and complemental to the fixed support.
3. .In a power operated knife provided with a housing having a. hand grip portion spaced from the housing and spaced apart openings in the housing and hand grip portion, a safety switch in the housing comprising (a) a manually operable switch actuating member including a trigger accessible through the opening in the hand grip portion, and a button accessible through the opening in the housing,
(b) a contact member depending from the actuating member, a fixed support in the housing spaced from the housing wall, I
(d) a bearing surface extending transversely of the actuating member for bearing on the vfixed support and preventing depression of the button, and
(e) yielding means bearing on the fixed support and urging the actuating member into support-engaging position,
(f) said actuating member being pivotally movable about said bearing surface as a non-fixed fulcrum when the trigger is depressed relatively to the hand grip portion of the housing, whereby the actuating member is moved out of support-engaging position and depression of the button is permitted while said trigger is depressed.
4. The safety switch defined by claim 3, in which the contact member depends from the actuating member beneath said button, and the yielding means bears on the fixed support and on the forward end of the actuating member to urge the actuating member into supportengaging position.
5. The safety switch defined by claim 3, in which the actuating member has a projection on its forward end, and the yielding means is a flat spring bent into U-form with one of its arms bearing on the fixedsupport and the other of its arms .having a hole therein which is engaged by the projection on the actuating member.
6. The safety switch defined by claim 3, in which the transversely extending bearing surface is a shoulderon the contact member portion of the actuating member and complemental to the fixed support.
References Cited UNITED STATES PATENTS 2,390,846 12/1945 Obszarny 200-157 FOREIGN PATENTS 619,571 4/1961 Italy. 649,986 12/1962 Italy.
ROBERT K. SCI-IAEFER, Primary Examiner.
H. BURKE, Assistant Examiner.

Claims (1)

1. IN A POWER OPERATED TOOL PROVIDED WITH A HOUSING HAVING TWO SPACED APART OPENINGS THEREIN, A SAFETY SWITCH IN THE HOUSING COMPRISING (A) A MANUALLY OPERABLE SWITCH ACTUATING MEMBER INCLUDING A TRIGGER ACCESSIBLE THROUGH ONE OF SAID OPENINGS IN THE HOUSING AND A BUTTON ACCESSIBLE THROUGH THE OTHER OPENING, (B) A CONTACT MEMBER ON THE ACTUATING MEMBER, (C) A FIXED SUPPORT IN THE HOUSING, (D) A BEARING SURFACE EXTENDING TRANSVERSELY OF THE ACTUATING MEMBER FOR BEARING ON THE FIXED SUPPORT AND PREVENTING DEPRESSION OF THE BUTTON, AND (E) YIELDING MEANS BEARING ON THE FIXED SUPPORT-ENGAGING URGING THE ACTUATING MEMBER INTO SUPPORT-ENGAGING POSITION, (F) SAID ACTUATING MEMBER BEING PIVOTALLY MOVABLE ABOUT SAID BEARING SURFACE AS A NON-FIXED FULCRUM WHEN THE TRIGGER IS DEPRESSED RELATIVELY TO THE HOUSING, WHEREBY THE ACTUATING MEMBER IS MOVED OUT OF SUPPORT-ENGAGING POSITION AND DEPRESSION OF THE BUTTON IS PERMITTED WHILE SAID TRIGGER IS DEPRESSED.
US526541A 1966-02-10 1966-02-10 Power operated knife safety switch Expired - Lifetime US3358108A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US526541A US3358108A (en) 1966-02-10 1966-02-10 Power operated knife safety switch
GB49237/66A GB1136790A (en) 1966-02-10 1966-11-02 Improvements in or relating to a safety switch for a power operated knife or tool
BE689686D BE689686A (en) 1966-02-10 1966-11-14
ES0333378A ES333378A1 (en) 1966-02-10 1966-11-15 A security switch device. (Machine-translation by Google Translate, not legally binding)
FR83591A FR1499039A (en) 1966-02-10 1966-11-15 Safety switch for knife or motor operated tool
CH1654466A CH449745A (en) 1966-02-10 1966-11-17 Motor operated tool safety switch
DES107211A DE1285040B (en) 1966-02-10 1966-12-01 Safety switch for electrical tools that can be activated by pressure
NL6700376A NL6700376A (en) 1966-02-10 1967-01-11

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US526541A US3358108A (en) 1966-02-10 1966-02-10 Power operated knife safety switch

Publications (1)

Publication Number Publication Date
US3358108A true US3358108A (en) 1967-12-12

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US526541A Expired - Lifetime US3358108A (en) 1966-02-10 1966-02-10 Power operated knife safety switch

Country Status (8)

Country Link
US (1) US3358108A (en)
BE (1) BE689686A (en)
CH (1) CH449745A (en)
DE (1) DE1285040B (en)
ES (1) ES333378A1 (en)
FR (1) FR1499039A (en)
GB (1) GB1136790A (en)
NL (1) NL6700376A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3694604A (en) * 1971-04-09 1972-09-26 Gen Electric Switch for electric knife with wiping action contact shorting bar
US4032128A (en) * 1975-10-16 1977-06-28 Danfoss A/S Pivotal bearing for an omega spring
US4122320A (en) * 1976-08-16 1978-10-24 Disston, Inc. Hand-operated double-acting trigger switch
US4289070A (en) * 1979-06-26 1981-09-15 Cosco Industries, Inc. Rubber stamp
US6185826B1 (en) 1999-05-13 2001-02-13 Scott Lutz Electric slicing knife with switch guard

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2390846A (en) * 1943-11-29 1945-12-11 Guardian Electric Mfg Co Handgrip control switch

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2916572A (en) * 1958-05-23 1959-12-08 Ulanet George Electric switch responsive to the movements of the human body during sleep
US3132227A (en) * 1961-08-28 1964-05-05 Black & Decker Mfg Co Trigger switch with lock for tool or appliance

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2390846A (en) * 1943-11-29 1945-12-11 Guardian Electric Mfg Co Handgrip control switch

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3694604A (en) * 1971-04-09 1972-09-26 Gen Electric Switch for electric knife with wiping action contact shorting bar
US4032128A (en) * 1975-10-16 1977-06-28 Danfoss A/S Pivotal bearing for an omega spring
US4122320A (en) * 1976-08-16 1978-10-24 Disston, Inc. Hand-operated double-acting trigger switch
US4289070A (en) * 1979-06-26 1981-09-15 Cosco Industries, Inc. Rubber stamp
US6185826B1 (en) 1999-05-13 2001-02-13 Scott Lutz Electric slicing knife with switch guard

Also Published As

Publication number Publication date
ES333378A1 (en) 1967-08-01
CH449745A (en) 1968-01-15
NL6700376A (en) 1967-08-11
BE689686A (en) 1967-05-16
DE1285040B (en) 1968-12-12
GB1136790A (en) 1968-12-18
FR1499039A (en) 1967-10-20

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