ELECTRIC KNIFE BLADE SECURING AND SAFETY SWITCH DEVICE

• US 3,650,029 A
• Filed: 05/04/1970
• Issued: 03/21/1972
• Est. Priority Date: 05/04/1970
• Status: Expired due to Term

• Current Assignee: Toastmaster Incorporated (Spectrum Brands Holdings, Inc.)
• Original Assignee: William F. Trelc
• Inventors: Trelc, William F.
• Primary Examiner(s): Condon, Theron E.
• Assistant Examiner(s): Peters, J. C.
• Application Number:
  US05/034,485
• Time in Patent Office: 687 Days
• Field of Search: 30/272R,272A
• US Class Current: 30/277.4
• CPC Class Codes: B23D 49/006 with contiguous, oppositely reciprocating saw blades
• CPC Class Codes: B23D 51/10 for hand-held or hand-operated devices
• CPC Class Codes: B26B 7/005 Counter reciprocating blades

Abstract

An electric knife having reciprocating carriages supporting adjacent cutting blades, a flexible blade retainer on each carriage cooperating with a blade recess for releasably holding the blade and carriage together, an on-off switch for powering the knife, and a combination blade and safety switch lock device operable in one position to cooperate with the blade retainer only to preclude blade removal while allowing switch operation and operable in a second position to cooperate with the switch only to preclude powering of the knife while allowing removal of the blades.

Claims

1. In an electric knife having a housing and blade carriage means supported to reciprocate in the housing, a blade carried by the carriage means and a carriage means tab separably cooperating with the blade for releasably uniting the blade and carriage means together, and a control including cooperating switch elements for powering the knife when the elements are closed, the combination comprising a safety control device including an element supported by the housing and having spaced extensions adjacent the tab and switch elements, where one extension in a first position of the device cooperates with the tab to preclude the removal of the blade from the carriage means and in a second position of the device is clear of the tab to permit the separation of the blade and carriage means, where the other extension in the first position of the device is clear of the switch elements to permit the powering of the knife and in the second position of the device cooperates with the switch elements to preclude the closing thereof and said device being mounted to rotate about an axis and the one and other extensions being defined in separate axially spaced planes along said axis.

2. In a knife combination according to claim 1, further including a portion of the housing spaced from but disposed adjacent the tab, and wherein the one device extension fits between and is thereby restrained by the tab and housing portion in the first position of the device.

3. In a knife combination according to claim 2, wherein a bearing unit generally used to mount the blade carriage means for reciprocation relative to the housing further provides as a part thereof said previously mentioned housing portion.

4. In a knife combination according to claim 1, further including a control button extended through an opening in the housing and having within the housing a face portion disposed adjacent one of the switch elements and adapted when depressed to move said one switch elemEnt to close the elements, said face portion further being disposed adjacent second device extension when the device is in the second position and operable by cooperation with the second extension to preclude the closing of the switch elements upon attempted depression of the control button.

5. In a knife combination according to claim 1, wherein the other device extension in the second position of the device fits between and mechanically separates the switch elements.

6. In a knife combination according to claim 1, wherein said one and other extensions each is of a semi circular shape that together extends over less than 360*.

7. In a knife combination according to claim 1, wherein each extension has a generally uniform interior or intermediate land area terminating at tapered end edges.

8. In a knife combination according to claim 1, wherein the tab is part of a flexible spring carried on the carriage means, and said tab normally separably cooperates with shoulders of the blade upon flexture of the spring.

9. In a knife combination according to claim 6, wherein the tab is part of a flexible spring carried on a carriage means, and said tab normally separably cooperating with shoulders of the blade upon flexure of the spring, further including a portion of the housing spaced from but disposed adjacent the tab, and wherein the one device extension fits between and is thereby restrained by the tab and the housing portion in the first position of the device.

10. In a knife combination according to claim 9, further including a control button extended through an opening in the housing and having within the housing a face portion disposed adjacent one of the switch elements and adapted when depressed to move said one switch element to close the elements, said face portion further being disposed adjacent second device extension when the device is in the second position and operable by cooperation with the second extension to preclude the closing of the switch elements upon attempted depression of the control button.