The described invention relates in general to a cutting devices used in pencil sharpeners and the like, and more specifically to a dual fly-away cutter-carrier assembly for use in pencil sharpeners of various types. Certain aspects of this invention may be used with electric sharpeners that are consumer products or that are intended for commercial or industrial applications.
Commercially available electric pencil sharpeners may include cutter-carriers (i.e., the cutting assembly within the pencil sharpener that actually sharpens the pencil) having single helical cutters utilizing various “fly-away” cutter designs. In such products, the sharpened pencil point typically contacts a moveable plate at the end of a conical bore that is part of the cutter-carrier, thereby causing the cutter to be moved away from the pencil in a direction out of the conical bore, thereby greatly reducing or eliminating further sharpening of the pencil. Some of these products also include a mechanical linkage to the pencil-tip plate that extends outside the cutter carrier for the purpose of triggering an electrical switch to provide motor shut-off or a visible and/or potentially audible indication that the sharpening process is complete.
Other commercially available electric pencil sharpeners with electric stop or motor shut-off capabilities provide cutter-carriers having two separate cutters, but without the fly-away feature. Such sharpeners do, however, typically include the pencil-tip moveable plate and mechanical linkage thereto that extends outside the cutter carrier. These products do not rely on the removal of the helical cutters from the conical bore that is part of the cutter-carrier for indicating that sharpening is complete, but rather on motor shut-off or a visible and/or potentially audible indicator. In such products, one of the two helical cutters is typically foreshortened to provide adequate space within the cutter-carrier assembly for the pencil-tip plate. In this arrangement, the portion of the cutter that usually sharpens the harder and more abrasive core material of the pencil is removed, leaving, as in single-cutter designs, just one helical cutter that must absorb the primary wear associated with sharpening pencils or other items. Furthermore, when two cutter systems that include a mechanical-linkage feature are used to shut off the electric motor, because the cutters are fixed in relation to the conical cavity of the carrier, the cutting edges of the cutters are usually still engaged with the pencil casing and core when sharpening stops. This often results in undesirable resistance to removing the pencil from the sharpener. Accordingly, there is an ongoing need to for a dual cutter-carrier assembly that includes the fly-away feature, but that does not suffer from the inadequacies discussed above.
The following provides a summary of certain exemplary embodiments of the present invention. This summary is not an extensive overview and is not intended to identify key or critical aspects or elements of the present invention or to delineate its scope.
In accordance with one aspect of the present invention, a first dual cutter-carrier assembly for use with pencil sharpeners is provided. This dual cutter-carrier assembly includes a rotatable carrier having a front portion, a rear portion, and a center portion, wherein the center portion defines an interior cavity that is adapted to receive a pencil to be sharpened; a first cutter pin mounted on the carrier at a predetermined angle, wherein the first cutter pin has a front portion and a rear portion, and wherein an annular groove is formed in the front portion of the first cutter pin; a first cutter rotatably and slidably mounted on the first cutter pin, wherein the first cutter extends a predetermined distance into the interior cavity for removing material from a pencil being sharpened; a second cutter pin mounted on the carrier at a predetermined angle, wherein the second cutter pin has a front portion and a rear portion, and wherein an annular groove is formed in the front portion of the second cutter pin; a second cutter rotatably and slidably mounted on the second cutter pin, wherein the second cutter extends a predetermined distance into the interior cavity for removing material from a pencil being sharpened; a contact plate mounted within the interior cavity at the rear portion of the carrier, wherein the contact plate includes a first yoke mechanically coupled to the first cutter and a second yoke mechanically coupled to the second cutter, wherein the contact plate moves in the direction of a pencil that is being sharpened when the tip of the advancing pencil touches the contact plate, wherein the first and second yokes move the first and second cutters respectively in the same direction as the moving contact plate; and wherein, as the pencil advances to a predetermined distance through the interior cavity, the first and second cutters are adapted to move outward from the interior cavity and away from the tip of the pencil being sharpened.
In accordance with another aspect of the present invention, a second dual cutter carrier assembly for use with pencil sharpeners is provided. This dual cutter-carrier assembly includes a rotatable carrier having a front portion, a rear portion, and a center portion, wherein the center portion defines an interior cavity that is adapted to receive a pencil to be sharpened; a first cutter pin mounted on the carrier at a predetermined angle, wherein the first cutter pin has a front portion and a rear portion, wherein an annular groove is formed in the front portion of the first cutter pin, and wherein a first cutter bushing having an inner bore is slidably mounted on the front portion of the first cutter pin; a first cutter rotatably and slidably mounted on the first cutter pin, wherein the first cutter is retained in a cutting position by the first cutter bushing, and wherein the first cutter extends a predetermined distance into the interior cavity for removing material from a pencil being sharpened; a first cutter gear mechanically coupled to the first cutter, wherein the first cutter gear is operative to rotate the first cutter; a second cutter pin mounted on the carrier at a predetermined angle, wherein the second cutter pin has a front portion and a rear portion, wherein an annular groove is formed in the front portion of the second cutter pin, and wherein a second cutter bushing having an inner bore is slidably mounted on the front portion of the second cutter pin; and a second cutter rotatably and slidably mounted on the second cutter pin, wherein the second cutter is retained in a cutting position by the second cutter bushing, and wherein the second cutter extends a predetermined distance into the interior cavity for removing material from a pencil being sharpened; a second cutter gear mechanically coupled to the second cutter, wherein the second cutter gear is operative to rotate the second cutter; a contact plate mounted within the interior cavity at the rear portion of the carrier, wherein the contact plate includes a first yoke mechanically coupled to the first cutter and a second yoke mechanically coupled to the second cutter, wherein the contact plate moves in the direction of a pencil that is being sharpened when the tip of the advancing pencil touches the contact plate, wherein the first and second yokes move the first and second cutters respectively in the same direction as the moving contact plate; and wherein, as the pencil advances through the interior cavity, the inner bores of the cutter bushings reach the annular grooves in the cutter pins, thereby causing the cutter bushings to no longer retain the cutters in the cutting position, whereby the cutters then move outward away from the interior cavity and away from the tip of the pencil being sharpened; and at least one spring mounted on the rear portion of the carrier, wherein the at least one spring returns the contact plate and the first and second cutters to a starting position when the pencil is removed from the interior cavity of the carrier.
In yet another aspect of this invention, a third dual cutter-carrier assembly for use with pencil sharpeners is provided. This dual cutter-carrier assembly includes a rotatable carrier having a front portion with first and second bearing surfaces formed therein, a rear portion, and a center portion, wherein the center portion defines an interior cavity that is adapted to receive a pencil to be sharpened; a first cutter pin slidably mounted on the carrier at a predetermined angle, wherein the first cutter pin has a front portion and a rear portion, and wherein an annular groove is formed in the front portion of the first cutter pin; a first cutter rotatably mounted on the first cutter pin, wherein the first cutter extends a predetermined distance into the interior cavity for removing material from a pencil being sharpened; a first cutter gear mechanically coupled to the first cutter, wherein the first cutter gear is operative to rotate the first cutter; a second cutter pin slidably mounted on the carrier at a predetermined angle, wherein the second cutter pin has a front portion and a rear portion, and wherein an annular groove is formed in the front portion of the second cutter pin; a second cutter rotatably mounted on the second cutter pin, wherein the second cutter extends a predetermined distance into the interior cavity for removing material from a pencil being sharpened; a second cutter gear mechanically coupled to the second cutter, wherein the second cutter gear is operative to rotate the second cutter; a contact plate mounted within the interior cavity at the rear portion of the carrier, wherein the contact plate includes a first yoke mechanically coupled to the first cutter and a second yoke mechanically coupled to the second cutter, wherein the contact plate moves in the direction of a pencil that is being sharpened when the tip of the advancing pencil touches the contact plate, wherein the first and second yokes move the first and second cutters respectively in the same direction as the moving contact plate; and wherein, as the pencil advances through the interior cavity, the annular grooves in the cutter pins reach the first and second bearing surfaces in the carrier thereby causing the cutter pins to no longer retain the cutters in the cutting position, whereby the cutters then move outward away from the interior cavity and away from the tip of the pencil being sharpened; and at least one spring mounted on the rear portion of the carrier, wherein the at least one spring returns the contact plate and the first and second cutters to a starting position when the pencil is removed from the interior cavity of the carrier.
Additional features and aspects of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the exemplary embodiments. As will be appreciated by the skilled artisan, further embodiments of the invention are possible without departing from the scope and spirit of the invention. Accordingly, the drawings and associated descriptions are to be regarded as illustrative and not restrictive in nature.
The accompanying drawings, which are incorporated into and form a part of the specification, schematically illustrate one or more exemplary embodiments of the invention and, together with the general description given above and detailed description given below, serve to explain the principles of the invention, and wherein:
Exemplary embodiments of the present invention are now described with reference to the Figures. Reference numerals are used throughout the detailed description to refer to the various elements and structures. In other instances, well-known structures and devices are shown in block diagram form for purposes of simplifying the description. Although the following detailed description contains many specifics for the purposes of illustration, a person of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the invention. Accordingly, the following embodiments of the invention are set forth without any loss of generality to, and without imposing limitations upon, the claimed invention.
The present invention provides a removable (optionally) cutter-carrier assembly for pencil sharpeners, which includes dual fly-away helical cutters. These cutters retract (i.e., move away from the pencil and out of the conical cutter-carrier bore in which the pencil has been inserted) when the pencil is fully sharpened. This retraction indicates to the user that sharpening is complete and prevents unnecessary over-sharpening and wasting of pencils or other items that are being sharpened. A mechanical linkage that extends out of the cutter-carrier assembly may also be included for triggering external devices such as visual or audible indicators. In this invention, both helical cutters are full-length and are able to remove material from the pencil tip to the outside diameter of the pencil. This aspect improves cutting speed and permits the wear caused by the pencil core to be spread across twice as many cutting edges, thereby extending the life of the cutters. In certain embodiments of this invention, both helical cutters are full-length, but the fly-away feature of the helical cutters is either optional or is not present. In such embodiments, the annular grooves formed in the cutter pins (see discussion below) are absent.
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While the present invention has been illustrated by the description of exemplary embodiments thereof, and while the embodiments have been described in certain detail, there is no intention to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to any of the specific details, representative devices and methods, and/or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the general inventive concept.
The present application is a continuation of U.S. application Ser. No. 14/988,112, filed Jan. 5, 2016, which is incorporated by reference herein in its entirety.
Number | Name | Date | Kind |
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6470929 | Fregeolle | Oct 2002 | B2 |
8205648 | Hsu | Jun 2012 | B2 |
8205649 | Yeh et al. | Jun 2012 | B2 |
8225827 | Dunlap | Jul 2012 | B2 |
8353323 | Schumacher et al. | Jan 2013 | B2 |
8505596 | Yeh et al. | Aug 2013 | B2 |
9352608 | Hsu | May 2016 | B2 |
Number | Date | Country |
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2378548 | Sep 2002 | CA |
Number | Date | Country | |
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20180222247 A1 | Aug 2018 | US |
Number | Date | Country | |
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Parent | 14988112 | Jan 2016 | US |
Child | 15937368 | US |