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US5144749A Expired / Lapsed US ⏱️ 0.0 years remaining

Utility knife

Assignee: Individual
•
Filing: 1992-03-30
•
Granted: 1992-09-08
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Expires: 2012-03-30
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Abstract

Abstract A utility knife has a bolster formed at a downward angle from a body which receives a blade shield and a circular blade. A channel is formed in the body at the bolster and has an upper pair of notches and a lower pair of notches. The blade shield has a circular portion which has a diameter greater than that of the blade and a pair of resilient arms each with a tab. When the tabs are engaged with the lower pair of notches, the blade shield shields the blade, and when the tabs are engaged with the upper pair of notches, the blade is exposed.

Inventors

  • 👤 Chien-Tang Chen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 19:14
CPC Classifications
B; B26; B26B; B26B5/00; B26B5/001; B26B25/00; B26B25/005; B26B29/00; B26B29/02; B26B29/06

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 257 words
A utility knife comprising: a body which serves as a handle for manipulation; a bolster protruding from a front portion of said body, extending at an angle downward therefrom; a channel being formed in said front portion of said body and an angle corresponding to that of said bolster and having an upper pair of notches and a lower pair of notches formed therein, said upper pair of notches being defined as further away from an end of said bolster; and a blade shield comprising a substantially circular portion and engaging means, said circular porting having a slot formed therein, said engaging means being slidably received in said channel and comprising a pair of resilient arms each having a tab formed on an outside end thereof and a projection, said tabs being engageable with said notches; and a circular blade having a diameter smaller than that of said circular portion of said blade shield; fastening means such as a screw and a nut fastening said blade shield to said bolster in a slidable manner and fasten said blade to said bolster in a rotatable manner; whereby when said utility knife is not in use, said tabs are engaged with said lower pair of notches, thereby said circular portion of said blade shield shields said blade; and when it is desired to use said utility knife, a user pushes on said projection, urging said tabs out of said lower pair of notches into said upper pair of notches, thereby moving said blade shield upward and exposing said blade.
Claim 2
Dependent Claim 257 words
A utility knife comprising: a body which serves as a handle for manipulation; a bolster protruding from a front portion of said body, extending at an angle downward therefrom; a channel being formed in said front portion of said body and an angle corresponding to that of said bolster and having an upper pair of notches and a lower pair of notches formed therein, said upper pair of notches being defined as further away from an end of said bolster; and a blade shield comprising a substantially circular portion and engaging means, said circular porting having a slot formed therein, said engaging means being slidably received in said channel and comprising a pair of resilient arms each having a tab formed on an outside end thereof and a projection, said tabs being engageable with said notches; and a circular blade having a diameter smaller than that of said circular portion of said blade shield; fastening means such as a screw and a nut fastening said blade shield to said bolster in a slidable manner and fasten said blade to said bolster in a rotatable manner; whereby when said utility knife is not in use, said tabs are engaged with said lower pair of notches, thereby said circular portion of said blade shield shields said blade; and when it is desired to use said utility knife, a user pushes on said projection, urging said tabs out of said lower pair of notches into said upper pair of notches, thereby moving said blade shield upward and exposing said blade.

References Cited (Backward Citations)

US1358973A Cited
US3802080A Cited
US4432137A Cited
US4884342A Cited
US5101564A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-09-08 1996-03-09 1996-09-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-09-08 2000-03-09 2000-09-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-09-08 2004-03-09 2004-09-08 $7700.00 Window Closed / Lapsed

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