# US 11,109,886 B2 · Surgical knife safety handle having user operable lock > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,109,886 B2 - Document ID: US11109886B2 - Status: Granted - Kind: B2 - Application number: 16/515,571 - Filed: 2019-07-18 - Published: 2019-11-07 - Granted: 2021-09-07 - Earliest claimed: 2004-10-20 - Assignees: Beaver-Visitec International (US), Inc. - Applicants: Beaver-Visitec International (US), Inc. - Inventors: Dana Cote; Brian Rapp; Paul Karnafel; Xiaoyu Zhang - Web page: https://patentgrep.com/patent/US11109886B2 ## CPC - A61B 17/3211: Surgical scalpels, knives; Accessories therefor - A61F 9/007: Methods or devices for eye surgery - A61B 2017/32113: {with extendable or retractable guard or blade} - A61B 2090/0801: {Prevention of accidental cutting or pricking} - A61F 9/00754: {for cutting or perforating the anterior lens capsule, e.g. capsulotomes} - A61F 9/0133: {Knives or scalpels specially adapted therefor} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract A surgical knife safety device having a handle, a blade connected to the handle, and a guard carried by the handle for sliding movement between a retracted position in which the blade is exposed for use, and an extended position for covering the sharp cutting edge of the blade. A spring, such as leaf spring or a cantilever beam, and a pair of detents or slots are provided to fix the guard in the extended or retracted position and to provide resistance during movement between the two positions. ## Claims ### Claim 1 A method for shielding a knife blade in a safety handle having a handle body with a distal end, a proximal end and a slot extending along a portion of a longitudinal handle body axis and having at least one detent adjacent to the slot, the safety handle also having a knife holder for carrying the knife blade, and a guard positioning mechanism movably disposed within the handle body, the guard positioning mechanism having a guard portion, the method comprising the steps of: depressing a user control mechanism disposed upon a cantilever, wherein the cantilever is secured only at its proximal end to the guard positioning mechanism, the user control mechanism extending outwardly from the handle body via the slot; wherein the cantilever releasably engages the detent to releasably secure at least one of the knife holder and the guard portion at a position with respect to the handle body, and depressing the user control mechanism releases the cantilever from the detent to allow relative movement between the guard positioning mechanism and the handle body; and moving the user control mechanism along the slot to selectively cover or expose the knife blade relative to the guard portion. ### Claim 2 (depends on 1) A method for shielding a knife blade in a safety handle as claimed in claim 1, wherein the cantilever is resiliently biased toward the slot when the user control mechanism is depressed. ### Claim 3 (depends on 1) A method for shielding a knife blade in a safety handle as claimed in claim 1, wherein the cantilever comprises a projection for engagement with the detent to substantially secure the user control mechanism in one of a fully extended position and a fully retracted position. ### Claim 4 (depends on 1) A method for shielding a knife blade in a safety handle as claimed in claim 1, wherein the detent comprises at least one of a recess, a cavity, a notch or an opening in the handle body. ### Claim 5 (depends on 1) A method for shielding a knife blade in a safety handle as claimed in claim 1, wherein the guard portion is constructed of a transparent material. ### Claim 6 (depends on 1) A method for shielding a knife blade in a safety handle as claimed in claim 1, wherein the guard portion is constructed of an opaque material. ### Claim 7 A method for shielding a knife blade in a safety handle having a handle body with a distal end, a proximal end and an opening in a portion of the handle body and having at least one detent in the handle body, the safety handle also having a knife holder for carrying the knife blade, and a guard positioning mechanism movably disposed within the handle body, the guard positioning mechanism having a guard portion, the method comprising the steps of: depressing a user control mechanism disposed upon a cantilever, wherein the cantilever is secured only at its proximal end to the guard positioning mechanism, the user control mechanism extending outwardly from the handle body via the opening; wherein the cantilever releasably engages the detent to releasably secure at least one of the knife holder and the guard portion at a position with respect to the handle body, and depressing the user control mechanism releases the cantilever from the detent to allow relative movement between the guard positioning mechanism and the handle body; and moving the user control mechanism to selectively cover or expose the knife blade relative to the guard portion. ### Claim 8 (depends on 7) A method for shielding a knife blade in a safety handle as claimed in claim 7, wherein the cantilever is resiliently biased toward the opening when the user control mechanism is depressed. ### Claim 9 (depends on 7) A method for shielding a knife blade in a safety handle as claimed in claim 7, wherein the cantilever comprises a projection for engagement with the detent to substantially secure the user control mechanism in one of a fully extended position and a fully retracted position. ### Claim 10 (depends on 7) A method for shielding a knife blade in a safety handle as claimed in claim 7, wherein the detent comprises at least one of a recess, a cavity, a notch or an opening in the handle body.