Patent Description:
Current adjustable sharpeners include adjustable arms that have numerous drawbacks. For example, the arms are operated independently of each other. Thus, additional components in the adjustment mechanism are necessary for the arms to operate together and properly. This can also causes problems during operation if the adjustable arms are not timed correctly relative to each other. In addition, the adjustable arms are pivoted near the center of the arms, which results in the abrasive elements lacking adequate support. The adjustable arms therefore are prone to flexing under pressure during sharpening, which decreases sharpening angle accuracy.

<CIT> discloses an adjustable abrasive sharpener.

From <CIT> there is known an adjustable sharpener comprising: a body comprising a first sharpening slot, a first arm, wherein said first arm is connected to a first abrasive element, a second arm, wherein said second arm is connected to a second abrasive element, wherein said first abrasive element and said second abrasive element are positioned in said first sharpening slot, wherein said first arm is connected to said second arm, an adjuster connected to said body, wherein the adjuster includes a front portion configured to be grasped by a user, wherein said adjuster is rotatable within a recessed area of said body and an adjustment assembly connected to said adjuster and said first arm, wherein movement of said adjuster causes rotational movement of said first arm.

Aspects of the present invention seek to provide an improved adjustable sharpener.

According to an aspect of the invention, there is provided an adjustable sharpener as in claim <NUM>.

In some embodiments, said adjustment assembly comprises a rack connected to a gear.

In some embodiments, said first sharpening slot is opposite said second sharpening slot.

In some embodiments, said body comprises a plurality of feet.

In some embodiments, said body comprises a first piece and a second piece.

In some embodiments, said first arm comprises a first slot and said third arm comprises a second slot.

In some embodiments, said second arm comprises a first pin and said fourth arm comprises a second pin.

In some embodiments, said first pin is received by said first slot.

In some embodiments, said second pin is received by said second slot.

In some embodiments, at least a portion of said adjuster is positioned between said first sharpening slot and said second sharpening slot.

In some embodiments, said rack comprises a plurality of teeth and recesses.

In some embodiments, said gear comprises a plurality of teeth and recesses.

In some embodiments, said gear to connected to said first arm and said third arm.

In some embodiments, a sharpening angle is formed between said first abrasive element and said second abrasive element, wherein said rotational movement of said first arm increases or decreases said sharpening angle.

In an embodiment there is provided an adjustable sharpener including a body having two sharpening slots, a first arm connected to a first abrasive element, a second arm connected to a second abrasive element, a third arm connected to a third abrasive element, and a fourth arm connected to a fourth abrasive element. The first and second abrasive elements are positioned in said first sharpening slot forming a V-shaped sharpening angle, and the third and fourth abrasive elements are positioned in the second sharpening slot forming a V-shaped sharpening angle. The first arm is connected to the second arm via a pin in slot connection, and the third arm is connected to the fourth arm via a pin in slot connection. The adjustable sharpener also includes an adjuster connected to the body and an adjustment assembly connected to the adjuster, the first arm and the third arm. Linear movement of the adjuster causes rotational movement of the first arm and the third arm. In this regard, the adjuster allows the user to manually increase or decrease the sharpening angle between the abrasive elements in the sharpening slots. In another embodiment, the adjustable sharpener includes only one sharpening slot. In that embodiment, the adjustable sharpener requires only the first arm and the second arm and not the third arm or fourth arm.

Embodiments of the invention can provide an adjustable sharpener that is light and small (i.e. "pocket size").

Embodiments of the invention can provide an adjustable sharpener with adjustable arms that are connected to one another and pivoted from the ends of the adjustable arms to reduce the complexity of the adjustment mechanism and to ensure sharpening angle accuracy.

These and other features, objects and advantages of embodiments of the present invention will become better understood from a consideration of the following detailed description of the preferred embodiments and appended claims in conjunction with the drawings as described following:.

Embodiments of the invention are described below, by way of example only, with reference to the accompanying drawings.

With reference with <FIG>, the preferred embodiments of the adjustable sharpener <NUM> of the present invention may be described. The sharpener <NUM> is comprised of a body <NUM>, one or more sharpening slots <NUM> containing abrasive elements <NUM> (e.g. carbide abrasive blades or ceramic abrasive rods) for sharpening a tool having a cutting edge (e.g. knife), and an adjuster <NUM> attached to the body <NUM> to manually change the sharpening angle between the abrasive elements <NUM>. The body <NUM> is the exterior of the sharpener <NUM> and preferably includes a first piece <NUM> (such as the front or top piece) and a second piece <NUM> (such as the back or bottom piece). Both the first piece <NUM> and the second piece <NUM> of the body <NUM> are comprised of a first section <NUM>, a second section <NUM> and an adjoining section <NUM>. In one embodiment, as shown in <FIG>, the exterior shape of the first section <NUM> is a mirror image of the exterior shape of the second section <NUM>. The first section <NUM> and the second section <NUM> are joined by the adjoining section <NUM>, which may be generally square or rectangular shaped. The two pieces <NUM>, <NUM> of the body <NUM> are roughly H-shaped because the length of the adjoining section <NUM> is less than the lengths of the first section <NUM> and the second section <NUM>. The first piece <NUM> and the second piece <NUM> of the body <NUM> are connected to each other at their ends, as shown in <FIG>. The first piece <NUM> and the second piece <NUM> of the body are preferably fastened or bonded together. Two feet <NUM> are secured between the tops of the first piece <NUM> and the second piece <NUM>, and two additional feet <NUM> are secured between the bottoms of the first piece <NUM> and the second piece <NUM>. In one embodiment shown in <FIG>, the first piece <NUM> and the second piece <NUM> of the body <NUM> include indentions to receive the four end caps <NUM>. The non-skid feet <NUM> contact a surface when the sharpener is in use and ensure that the sharpener does not slip on the surface during use.

The spaces formed between the first section <NUM>, the second section <NUM> and the adjoining section <NUM> are the sharpening slots <NUM>, as shown in <FIG> and <FIG>. A pair of abrasive elements <NUM> is positioned in each of the sharpening slots <NUM> to form a V-shaped sharpening angle. The blade of the tool is pulled across the abrasive elements <NUM> in the slots <NUM> for sharpening.

As shown in <FIG>, an adjuster <NUM> is attached to the first piece <NUM> of the body <NUM>. The adjuster allows the user of the sharpener <NUM> to manually adjust the relative positioning of the pair of abrasive elements <NUM> in each of the sharpening slots <NUM>. In other words, the adjuster <NUM> operates to adjust the sharpening angle between the pair of abrasive elements <NUM> exposed in the sharpening slots <NUM>. The adjuster <NUM> is positioned between the sharpening slots <NUM>. This orientation of the adjuster <NUM> and the sharpening slots <NUM> yields a smaller sharpener compared to current adjustable sharpeners.

The adjuster <NUM> preferably includes a front portion <NUM> and a back portion <NUM>, as shown in <FIG>. The front portion <NUM> is the portion of the adjuster <NUM> that is configured to be grasped by the user of the sharpener <NUM>. In one embodiment, the adjuster <NUM> is slidable within a recessed area <NUM> of the first piece <NUM> of the body <NUM>. The recessed area <NUM> includes a plurality of notches <NUM>, and the front portion <NUM> of the adjuster <NUM> engages one or more of the notches <NUM> as the front portion <NUM> is slid up or down within the recessed area <NUM>. In one embodiment, one of the notches <NUM> receives a lip <NUM> on the top or bottom of the front portion <NUM> of the adjuster <NUM> (as shown in <FIG>) to lock the adjuster <NUM> into place. The front portion <NUM> is connected to the back portion <NUM> of the adjuster <NUM> via a rod <NUM> that is slid through the back portion <NUM> and the front portion <NUM>. As shown in <FIG>, a spring <NUM> is positioned between the back portion <NUM> and the front portion <NUM> of the adjuster <NUM>. The back portion <NUM> of the adjuster <NUM> extends through an opening <NUM> in the front piece <NUM> of the body <NUM> into the interior of the sharpener <NUM> and contacts a rack <NUM>. In one embodiment, as shown in <FIG>, the back portion <NUM> of the adjuster <NUM> interlocks with the rack <NUM> such that the adjuster <NUM> and the rack <NUM> are engaged. The rack <NUM> is slidably connected to a track <NUM> on the inner surfaces of the first and second pieces <NUM>, <NUM> of the body <NUM>. Sliding the adjuster <NUM> up or down within the recessed area <NUM> causes the rack <NUM> connected to the track <NUM> to move in the same direction.

The rack <NUM> includes teeth <NUM> that engage the recesses <NUM> of a rotatable gear <NUM>, as shown in <FIG>. The recesses <NUM> are positioned between teeth of the gear <NUM>. The recesses <NUM> of the gear <NUM> also engage the teeth <NUM> of a first arm <NUM> and a third arm <NUM>, as shown in <FIG>. The teeth of the first arm <NUM> and the third arm <NUM> are preferably located at one end of the arms <NUM>, <NUM>. The track <NUM>, rack <NUM> and gear <NUM> may collectively be referred to as an adjustment assembly in one embodiment. As shown in <FIG>, the first arm <NUM> is connected to the second arm <NUM>, and the third arm <NUM> is connected to a fourth arm <NUM>. In one embodiment, the first arm <NUM> includes a slot <NUM> that receives a pin <NUM> attached to the second arm <NUM>. Similarly, the third arm <NUM> includes a slot <NUM> that receives a pin <NUM> attached to the fourth arm <NUM>. The first arm <NUM> and the second arm, and the third arm <NUM> and the fourth arm <NUM>, may also be hinged to one another. One corner of each of the arms <NUM>, <NUM>, <NUM>, <NUM> is preferably fastened to the second piece <NUM> of the body of the sharpener. The point of connection between the arms and the second piece of the body is a pivot point for the arms <NUM>, <NUM>, <NUM>, <NUM>. Each of the arms <NUM>, <NUM>, <NUM>, <NUM> is joined to an abrasive element <NUM> for sharpening.

In one embodiment, sliding the adjuster <NUM> upward causes clockwise rotation of the gear <NUM> via its engagement with rack <NUM>. The clockwise rotation of the gear <NUM> causes counter-clockwise rotation (or pivot) of the first arm <NUM> and the third arm <NUM> at their pivot points <NUM>, as shown in <FIG>. Because of the connection between the slot <NUM> of the first arm <NUM> and the pin <NUM> of the second arm <NUM>, the counter-clockwise rotation of first arm <NUM> causes the second arm <NUM> to rotate (or pivot) clockwise at its pivot point <NUM>. The first arm <NUM> can be rotated counter-clockwise until the pin <NUM> of the second arm <NUM> contacts the left side wall of the slot <NUM> of the first arm <NUM>, as shown in <FIG>. Similarly, the counter-clockwise rotation of the third arm <NUM> causes the clockwise rotation (or pivot) of the fourth arm <NUM> at its pivot point <NUM>. The third arm <NUM> can be rotated counter-clockwise until the pin <NUM> of the fourth arm <NUM> contacts the left side wall of the slot <NUM> of the third arm <NUM> when considering the pin <NUM> and slot <NUM> to be at the bottom of the arms <NUM>, <NUM>, as shown in <FIG>. As a result of the counter-clockwise rotation of the first arm <NUM> and the third arm <NUM>, the sharpening angle formed between the abrasive elements <NUM> attached to the first arm <NUM> and the second arm <NUM> becomes smaller, and the sharpening angle formed between the abrasive elements <NUM> attached to the third arm <NUM> and the fourth arm <NUM> also becomes smaller. Thus, the adjuster <NUM> allows the user to manually decrease the sharpening angle between the abrasive elements in the sharpening slots <NUM>. In addition, the distance between the top (or open end) of the sharpening slot <NUM> and the intersection between the abrasive elements <NUM> in the sharpening slot <NUM> becomes greater.

In that same embodiment, sliding the adjuster <NUM> downward causes counter-clockwise rotation of the gear <NUM> via its engagement with rack <NUM>. The counter-clockwise rotation of the gear <NUM> causes the clockwise rotation (or pivot) of the first arm <NUM> and the third arm <NUM> at their pivot points <NUM>, as shown in <FIG> and <FIG>. Because of the connection between the slot <NUM> of the first arm <NUM> and the pin <NUM> of the second arm, the clockwise rotation of first arm <NUM> causes the counter-clockwise rotation (or pivot) of the second arm <NUM> at its pivot point <NUM>. The first arm <NUM> can be rotated clockwise until the pin <NUM> of the second arm <NUM> contacts the right side wall of the slot <NUM> of the first arm <NUM>. Similarly, the clockwise rotation of the third arm <NUM> causes the counter-clockwise rotation (or pivot) of the fourth arm <NUM> at its pivot point <NUM>. The third arm <NUM> can be rotated clockwise until the pin <NUM> of the fourth arm <NUM> contacts the right side wall of the slot <NUM> of the third arm <NUM> when considering the pin <NUM> and slot <NUM> to be at the bottom of the arms <NUM>, <NUM>. As a result of the clockwise rotation of the first arm <NUM> and the third arm <NUM>, the sharpening angle between the abrasive elements <NUM> attached to the first arm <NUM> and the second arm <NUM> becomes greater and the sharpening angle between the abrasive elements <NUM> of the third arm <NUM> and the fourth arm <NUM> also becomes greater. Thus, the adjuster <NUM> allows the user to manually increase or decrease the sharpening angle between the abrasive elements <NUM> in the sharpening slots <NUM>. In addition, the distance between the top (or open end) of the sharpening slot <NUM> and the intersection between the abrasive elements <NUM> in the sharpening slot <NUM> is reduced.

In another embodiment or depending on whether the sharpener is being viewed from the front or the back, sliding the adjuster <NUM> upward causes counter-clockwise rotation of the gear and sliding the adjuster downward causes clockwise rotation of the gear. In that embodiment, the movements of the various components are opposite of the movements of those components described above.

As shown in <FIG>, the body <NUM> of the sharpener <NUM> also include an opening <NUM> that extends through the first piece <NUM> and the second piece <NUM>. A lanyard (not shown) may be attached to the opening <NUM>. A cover <NUM> is attached to the first and second sections <NUM>, <NUM> of each of the first piece <NUM> and the second piece of the body <NUM> to aid the user in safely gripping the sharpener <NUM> during use.

While the adjustable sharpener of embodiments of the present invention has been described with reference to four arms <NUM>, <NUM>, <NUM>, <NUM> and two sharpening slots <NUM>, the present invention is not so limited. In another embodiment, the adjustable sharpener includes only two arms <NUM>, <NUM> and one sharpening slot <NUM> (as shown in <FIG>), but the sharpener operates in the same manner as described above.

In another embodiment, the adjuster <NUM> is capable of being rotated to adjust the sharpening angle. In that particular embodiment, the rotational movement of the adjuster <NUM> causes the rack <NUM> to move up or down on the track <NUM>. The sharpening angle is then adjusted in the same manner as described above.

It is to be appreciated that some of the features of the appearance of the sharpener shown in <FIG> are selected for aesthetic rather than technical reasons. For example, the rounded sides of the body <NUM> and the overall shape and surface decoration of the sharpener shown provide an aesthetic appearance. In addition, the choice of pattern on the front portion <NUM> of the adjuster and the cover <NUM>, and the location of the opening <NUM> for the lanyard, are governed at least partially by aesthetic considerations.

Claim 1:
An adjustable sharpener comprising:
a body (<NUM>) comprising a first sharpening slot (<NUM>);
a first arm, wherein said first arm is connected to a first abrasive element;
a second arm, wherein said second arm is connected to a second abrasive element, wherein said first abrasive element and said second abrasive element are positioned in said first sharpening slot, wherein said first arm is connected to said second arm;
an adjuster (<NUM>) connected to said body, wherein the adjuster includes a front portion (<NUM>) configured to be grasped by a user, wherein said adjuster (<NUM>) is slidable within a recessed area (<NUM>) of said body (<NUM>), wherein the recessed area (<NUM>) includes a plurality of notches (<NUM>) and the front portion (<NUM>) of the adjuster (<NUM>) engages one or more of the notches (<NUM>) as the front portion (<NUM>) is slid up or down within the recessed area (<NUM>); and
an adjustment assembly connected to said adjuster (<NUM>) and said first arm,
wherein linear movement of said adjuster causes rotational movement of said first arm.