Knives

• US 5,046,253 A
• Filed: 04/13/1990
• Issued: 09/10/1991
• Est. Priority Date: 03/30/1988
• Status: Expired due to Term

• Current Assignee: W A 1 Designs Limited
• Original Assignee: William A. Ireland
• Inventors: Ireland, William A.
• Primary Examiner(s): Phan, Hien H.
• Assistant Examiner(s): RADA, RINALDI I
• Application Number:
  US07/508,462
• Time in Patent Office: 515 Days
• Field of Search: 30/294, 30/290, 30/314, 30/317, 30/329, 30/291, 30/288, 30/286, 30/287, 30/289, 83/440, 83/443, 83/449, 83/450, 83/856-858
• US Class Current: 30/289
• CPC Class Codes: B26B 27/00 Hand cutting tools not provided for in the preceding groups, e.g. finger rings for cutting string, devices for cutting by means of wires
• CPC Class Codes: B26B 29/00 Guards or sheaths or guides for hand cutting tools; Arrangements for guiding hand cutting tools guards for hair clippers or dry shavers B26B19/38
• CPC Class Codes: B26B 5/00 Hand knives with one or more detachable blades

Abstract

A safety knife comprises a handle formed with an elongate narrow slot which extends transversely completely through the handle from one lateral surface thereof to the other, and extends lengthwise from a slot mouth in an outer surface of the handle to a location within the handle. The handle is formed in two halves which are clamped together by bolts, and sandwiched between the two halves is a blade having a cutting edge which extends at an acute angle across the width of the slot at a location spaced inwardly from its mouth. In use, string or similar material to be cut is passed along the slot until it meets the cutting edge of the blade, and continued pressure of the blade on the string then severs the string. Since the cutting edge is encased within the handle and is spaced from the mouth of the slot, there is little or no risk of the user being accidentally cut by the blade.

Claims

1. A knife comprising an elongate handle formed with an elongate narrow slot which extends transversely completely through the handle from one lateral surface thereof to the other, and which extends lengthwise of the handle from a slot mouth in an outer surface of the handle, adjacent one extremity thereof, to a location within the handle, therebeing encased within the handle a blade having an exposed operative cutting edge which extends across the slot at a location spaced inwardly from the mouth of the slot, one side of the slot, adjacent the mouth thereof, being defined by a longitudinal surface of a tapered tip portion of the handle which points generally longitudinally away from the rest of the handle at said one extremity thereof, the exposed operative cutting edge of the blade extending at an obtuse angle to said longitudinal surface of the tapered tip portion so as to form generally a continuation thereof, and the slot having a surface, opposite said longitudinal surface of the tapered tip portion, forming an acute angle with the exposed operative cutting edge of the blade, which surface is formed with a longitudinal groove which is wider than the thickness of the blade and into which the operative cutting edge of the blade partly extends at said acute angle, the handle being formed in two parts having means for clamping the two parts together with the blade sandwiched between them, said means for clamping the two parts of the handle together being also engageable with part of the blade so as to assist in securing the blade between the two parts of the handle.

2. A knife according to claim 1, wherein the two parts of the handle and the blade are formed with registering holes through which a clamping device passes.

3. A knife according to claim 2, wherein the clamping device is a disengageable device, so that the two parts of the handle may be separated, if required, to replace the blade.

4. A knife comprising an elongate handle formed with an elongate narrow slot which extends transversely completely through the handle from one lateral surface thereof to the other, and which extends lengthwise of the handle from a slot mouth in an outer surface of the handle, adjacent one extremity thereof, to a location within the handle, there being encased within the handle a blade having an exposed operative cutting edge which extends across the slot at a location spaced inwardly from the mouth of the slot, one side of the slot, adjacent the mouth thereof, being defined by a longitudinal surface of a tapered tip portion of the handle which points generally longitudinally away from the rest of the handle at said one extremity thereof, the exposed operative cutting edge of the blade extending at an obtuse angle to said longitudinal surface of the tapered tip portion so as to form generally a continuation thereof, and the slot having a surface, opposite said longitudinal surface of the tapered tip portion, forming an acute angle with the exposed operative cutting edge of the blade, which surface is formed with a longitudinal groove which is wider than the thickness of the blade and into which the operative cutting edge of the blade partly extends at said acute angle, said slot being generally V-shaped as viewed in cross section.

5. A knife comprising an elongate handle formed with an elongate narrow slot which extends transversely completely through the handle from one lateral surface thereof to the other, and which extends lengthwise of the handle from a slot mouth in an outer surface of the handle, adjacent one extremity thereof, to a location within the handle, there being encased within the handle a blade having an exposed operative cutting edge which extends across the slot at a location spaced inwardly from the mouth of the slot, one side of the slot, adjacent the mouth thereof, being defined by a longitudinal surface of a tapered tip portion of the handle which points generally longitudinally away from the rest of the handle at said one extremity thereof, the exposed operative cutting edge of the blade extending at an obtuse angle to said longitudinal surface of the tapered tip portion so as to form generally a continuation thereof, and the slot having a surface, opposite said longitudinal surface of the tapered tip portion, forming an acute angle with the exposed operative cutting edge of the blade, which surface is formed with a longitudinal groove into which the operative cutting edge of the blade partly extends at said acute angle, the longitudinal groove being an open groove which is wider than the thickness of the blade whereby a space is provided on each side of a part of the blade which extends into said groove.