Apparatus for sharpening crayon marking instruments to form an improved arcuate safety marking tip

A device for sharpening crayons and other soft marking instruments normally made from waxes, plastics and other soft material which includes a protective ring defining an aperture with a plurality of support members extending longitudinally therefrom. A plurality of sharpening blades extend longitudinally along the support members and are fixedly secured thereto to define a sharpening zone between the support members. Each of the sharpening blades is arcuate along its entire length extending from the protective ring to a base to which the individual support members converge. This arcuate shape is preferably of a parabolic shape to facilitate the sharpening of crayons to a blunt end shape. Debris outlets are defined between the support members and a retaining cup can be secured thereto for collecting debris. The sharpening blades are formed by blade surfaces oriented at approximately 90 degrees with respect to one another and at approximately 45 degrees with respect to the crayon marking instrument being sharpened in order to maximize sharpening and minimize any danger of accidents such as cutting of one's fingers especially by young children.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention deals with the field of sharpeners used for forming 
the end of a writing instrument into an arcuate shape to facilitate 
writing and/or marking therewith. More particularly, the present invention 
deals with means for providing a safe apparatus for sharpening crayons and 
other marking instruments made from waxes, plastics and other similar soft 
materials to facilitate marking thereof with the marking end formed into a 
blunt safety rounded configuration to facilitate common uses thereof and 
prevent injury especially to young children who tend to use such crayons. 
2. Description of the Prior Art 
Numerous patents have been granted on apparatus for sharpening and 
otherwise handling writing instruments such as crayons and the like such 
as U.S. Pat. No. 225,732 patented Mar. 23, 1880 to J. Suter on a 
"Crayon-Sharpener"; and U.S. Pat. No. 299,856 patented Jun. 3, 1884 to T. 
Schafer on a "Chalk Sharpener"; and U.S. Pat. No. 334,242 patented Jan. 
12, 1886 to W. H. Lamson on a "Pencil-Sharpener"; and U.S. Pat. No. 
355,243 patented Dec. 28, 1886 to R. Wyatt on an "Implement For Sharpening 
Tailor's Chalk"; and U.S. Pat. No. 372,315 patented Nov. 1, 1887 to H. L. 
Halverson on a "Tailor's Crayon-Sharpening Machine"; and U.S. Pat. No. 
412,401 patented Oct. 8, 1889 to G. W. Mills et al on a "Combined Crayon 
Sharpener, Cushion, And Weight"; and U.S. Pat. No. 625,878 patented May 
30, 1899 to J. J. Fraser on a "Crayon Sharpener"; and U.S. Pat. No. 
689,136 patented Jul. 23, 1901 to G. O. Anderson on a "Crayon-Sharpener"; 
and U.S. Pat. No. 691,127 patented Jan. 14, 1902 to A. T. Fox on a "Pencil 
Sharpener"; and U.S. Pat. No. 901,622 patented Oct. 20, 1908 to S. Kann on 
a "Crayon Sharpener"; and U.S. Pat. No. 941,631 patented Nov. 30, 1909 to 
R. F. George on a "Pencil-Sharpener"; and U.S. Pat. No. 1,026,671 patented 
May 21, 1912 to J. E. Hager et al on a "Pencil Sharpener"; and U.S. Pat. 
No. 1,451,163 patented Apr. 10, 1923 to A. S. Hope on a "Candle Pointer"; 
and U.S. Pat. No. 1,520,338 patented Dec. 23, 1924 to H. Dornseif on a 
"Pencil Sharpener"; and U.S. Pat. No. 1,560,291 patented Nov. 3, 1925 to 
O. E. Bork on a "Pencil Sharpener"; and U.S. Pat. No. 1,603,540 patented 
Oct. 19, 1926 to J. Holtzman and one-half assigned to Warren E. Willis on 
a "Crayon Sharpener"; and U.S. Pat. No. 1,770,062 patented Jul. 8, 1930 to 
C. H. Blomgren on a "Pencil Sharpener"; and U.S. Pat. No. 1,861,466 
patented Jun. 7, 1932 to N. Bafetti on a "Crayon Holder"; and U.S. Pat. 
No. 2,013,538 patented Sep. 3, 1935 to D. Gamard on a "Device For Shaping 
Sticks Of Paint And Similar Purposes"; and U.S. Pat. No. 2,094,494 
patented Sep. 28, 1937 to V. Rago on a "Tailor's Chalk Sharpener"; and 
U.S. Pat. No. 2,151,869 patented Mar. 28, 1939 to V. Rago on a "Tailor's 
Chalk Sharpener With Replaceable Blade"; and U.S. Pat. No. 2,279,672 
patented Apr. 14, 1942 to O. L. Gerwig on a "Crayon Sharpener"; and U.S. 
Pat. No. 2,299,799 patented Oct. 27, 1942 to F. E. Correll on a "Device 
For Pointing Lead Pencils"; and U.S. Pat. No. 2,409,000 patented Oct. 8, 
1946 to A. Rubenstein on a "Crayon"; and U.S. Pat. No. 2,502,177 patented 
Mar. 28, 1950 to J. J. Sigman on a "Crayon Pencil Sharpener"; and U.S. 
Pat. No. 2,624,316 patented Jan. 6, 1953 to E. Blanco et al on a "Crayon 
Sharpener"; and U.S. Pat. No. 2,625,943 patented Jan. 20, 1953 to D. A. 
Prey on a "Lipstick Shaper"; and U.S. Pat. No. 2,642,044 patented Jun. 16, 
1953 to J. F. W. Mussguller and assigned to Klebes & Co. on a "Pencil 
Sharpener"; and U.S. Pat. No. 2,665,696 patented Jan. 12, 1954 to A. E. 
Weis on a "Combination Lipstick Applicator And Sharpener"; and U.S. Pat. 
No. 2,691,960 patented Oct. 19, 1954 to W. A. Leeds et al on a "Crayon 
Sharpener"; and U.S. Pat. No. 2,702,022 patented Feb. 15, 1955 to C. I. 
Fors on a "Pencil Sharpener"; and U.S. Pat. No. 2,857,881 patented Oct. 
28, 1958 to H. C. Beebe et al and assigned to Binney & Smith Inc. on a 
"Crayon Carton And Sharpener"; and U.S. Pat. No. 3,097,629 patented Jul. 
16, 1963 to J. F. Fleming et al and assigned to Sterling Plastics Co. on a 
"Pencil Sharpener For Cosmetic Pencils"; and U.S. Pat. No. 3,869,794 
patented Mar. 11, 1975 to J. Smith on a "Candle Shaping Apparatus"; and 
U.S. Pat. No. 4,248,283 patented Feb. 3, 1981 to L. Kaye on a "Cosmetic 
Pencil Sharpener"; and U.S. Pat. No. 4,281,698 patented Aug. 4, 1981 to W. 
Mobius on a "Pencil Sharpener"; and U.S. Pat. No. 4,402,354 patented Sep. 
6, 1983 to J. Halpern on a "Sharpener For Cosmetic Pencils"; and U.S. Pat. 
No. 4,513,798 patented Apr. 30, 1985 to W. Luttgens and assigned to A. 
Klebes GmbH & Co. K. G. Kunststoff-ung Metallwarenfabrik on a "Sharpener, 
Specifically For Cosmetic Sticks"; and U.S. Pat. No. 4,744,150 patented 
May 17, 1988 to D. Horvath on a "Container For Tape Ruler With Manual 
Pencil Sharpener"; and U.S. Pat. No. 4,755,074 patented Jul. 5, 1988 to M. 
Roberts on a "Pencil Sharpener"; and U.S. Pat. No. 4,934,057 patented Jun. 
19, 1990 to W. Chao on a "Multi-Blade Pencil-Core Sharpener"; and U.S. 
Pat. No. 4,991,299 patented Feb. 12, 1991 to C. Dietterich et al and 
assigned to Binney & Smith Inc. on a "Universal Crayon Sharpener"; and 
U.S. Pat. No. 5,002,182 patented Mar. 26, 1991 to D. McGinnis on a "Crayon 
Holder And Container"; and U.S. Pat. No. 5,046,876 patented Sep. 10, 1991 
to R. Boraca on a "Safety Tipped Pencil And Sharpener Therefor"; and U.S. 
Pat. No. 5,167,071 patented Dec. 1, 1992 to J. Eisen and assigned to 
Cosmolab, Inc. on a "Cosmetic Pencil Sharpener"; and U.S. Pat. No. 
5,379,817 patented Jan. 10, 1995 to E. O'Neil et al on a "Sharpener For A 
Soft Element Pencil". 
SUMMARY OF THE INVENTION 
The present invention provides an improved apparatus for sharpening crayon 
marking instruments to a safe arcuate writing tip. Sharpening to a more 
rounded arcuate tip will minimize possible injury from more sharp pointed 
sharpened tips. Such marking instruments are most commonly made from 
waxes, plastics or other similar soft materials. 
Also, the sharpener preferably includes a protective ring defining an inlet 
aperture oriented laterally thereacross. This inlet aperture is adapted to 
receive a crayon marking instrument protruding therethrough to facilitate 
sharpening thereof to protect children or other persons from placing their 
fingers through the protective ring and the inlet aperture defined 
therein. The protective ring is preferably of a size no greater than 
0.5625 inches in diameter. With this size of aperture the more common 
diameters of crayons, namely, 5/16, 7/16 and 9/16 inches can be 
accommodated while at the same time utilizing the protective ring for 
preventing inadvertent accidents caused by cutting of one's fingers or the 
like by the apparatus of the present invention. 
An inlet flange is also preferably defined fixedly secured to the 
protective ring and extending laterally outward therefrom to facilitate 
mounting of the sharpening apparatus with respect to any mounting surface. 
Such mounting may commonly be in a box housing for carrying crayons or may 
be positioned within a retaining cup used with the sharpening apparatus of 
the present invention for retaining debris. 
A plurality of support members are preferably fixedly secured to the 
protective ring and extend outwardly longitudinally therefrom. These 
support members and the protective ring together define a sharpening zone 
between them which is adapted to receive a crayon marking instrument 
therein for sharpening. Each of the support members preferably includes a 
proximate end fixedly attached to the protective ring means and possibly 
integrally formed therewith. Each support member also includes a distal 
end spatially disposed from the proximate end thereof. The supports 
members preferably are defined such as to converge with the distal end 
thereof closer with respect to one another than the proximate end thereof. 
Also preferably each pair of support members cooperate together to define 
a debris outlet therebetween which allows the exiting of materials removed 
from the crayon marking instrument during sharpening thereof. 
The present invention may further include a base member positioned 
spatially disposed longitudinally from the protective ring and fixedly 
secured to each of the distal ends of the support members. Also a 
plurality of main sharpening blades are included each of which is fixedly 
secured to one of the support members and extends therealong. These main 
sharpening blades preferably define arcuate cutting edges extending 
therealong and positioned adjacent the sharpening zone to facilitate 
sharpening of a crayon marking instrument positioned therewithin to a more 
blunted curved tip to reduce the propensity for damage by users such as 
small children. This arcuate cutting edge is preferably arcuate along the 
entire length thereof and each of the arcuate cutting edges extend along 
the entire longitudinal length of the support members from the inlet 
aperture completely to the base member. This cutting blade shape has been 
found to provide a more blunted writing tip on a crayon-type writing 
instrument to minimize the danger of use thereof especially by small 
children. 
The arcuate cutting edges of each of the main sharpening blades preferably 
includes a main parabolic cutting profile which extends longitudinally 
therealong. These main sharpening blades are preferably oriented at 
approximately 45 degrees with respect to a crayon marking instrument being 
sharpened within the sharpening zone. These blade so shaped will formed 
the more blunt curved writing end on a crayon which is desirable for 
safety considerations. 
The main sharpening blades further preferably include a first blade surface 
and a second blade surface which intersect to form the arcuate cutting 
edge along the intersecting edge therebetween. The first blade surface and 
the second blade surface are preferably oriented with respect to one 
another at an angle of approximately 90 degrees. 
Multiple supplementary sharpening blades are included fixedly secured with 
respect to the base member and extending longitudinally therefrom between 
each pair of adjacent main sharpening blades in the preferred 
configuration of the present invention. In this manner sharpening will be 
facilitated at the endmost portion of the crayon marking instrument. Each 
of these supplementary sharpening blades are secured to the base member 
equally spaced from each adjacent main sharpening blade in this preferred 
configuration. Each of the supplementary sharpening blades also extends 
from the base member to an intermediate longitudinal position. Each of 
these supplementary sharpening blades preferably includes a supplemental 
parabolic cutting profile extending longitudinally therealong. 
The present invention further includes a mounting collar fixedly secured to 
the protective ring and extending laterally outwardly therefrom in 
surrounding relation to the support members and the main sharpening blades 
in such a manner as to further facilitate mounting. Also a retaining cup 
may be included positioned in surrounding relationship with respect to the 
support members and the base member and in engagement with respect to the 
inlet flange to define a debris retaining chamber therewithin for 
receiving and retaining sharpening debris. The retaining cup preferably is 
detachably securable with respect to the inlet flange in such a manner as 
to facilitate the removal of sharpening debris when accumulated within the 
debris retaining chamber therewithin. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein capital costs of production is minimized. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein maintenance requirements are minimized. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein no moving parts are included. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein all parts can be easily formed of a plastic material. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein a crayon can conveniently be formed to a blunt 
bullet-nose shape. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein crayons can be sharpened of any diameter as large as 
9/16 inches in diameter. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein shaping is performed by multiple equally spaced 
continuously curved cutting blades preferably three in number. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein cutting can be easily formed into a rounded end 
configuration by utilizing cutting blades having parabolic profiles. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein the cutting edges are formed by intersecting blade 
surfaces oriented at approximately 90 degrees with respect to one another. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein the sides of the blade forming the cutting edge are 
oriented at approximately 45 degrees to the surface of the crayon marking 
instrument being cut. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein a protective collar is positioned about the inlet 
aperture to minimize the chance of inadvertent cutting of one's fingers 
especially when utilized by children. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein sharpening of the crayon marking instrument is 
performed by paring blades or scrapers rather than by cutting blades. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein continuously arcuate cutting edges form a rounded 
smooth endmost portion of the finally sharpened crayon marking instrument. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein the position of the sharpener in the side, top or 
bottom of the box of conventional crayons is easily achieved. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein use of the crayon sharpening apparatus as a separate 
operating piece is possible. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein the inclusion of a cup for collecting sharpened debris 
is optionally included. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein a writing end is formed on a crayon which is highly 
resistant to breakage due to the removal of a minimal amount of material 
therein and the formation of a blunt ended tip. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein a minimum amount of material is removed from a crayon 
during sharpening. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein sharpening can be performed without completely 
rotating of the crayon because full sharpening is provided as long as the 
crayon is moved back and forth rotationally with respect to its axis 
through at least an angle of 60-120 degrees. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein supplementary cutting means are provided in the area 
adjacent to the marking end of the crayon writing instrument to facilitate 
the removal of additional material as is normally required in this area. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein the formation of a writing instrument tip which is 
completely curved in a parabolic shape along the entire writing endmost 
portion thereof is achieved for the purposes of safety. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein the amount of material removed from a crayon during 
sharpening thereof is minimized. 
It is an object of the present invention to provide an apparatus for 
sharpening crayon marking instruments made from waxes, plastics and other 
soft materials which includes forming an improved arcuate safety marking 
end thereon wherein jamming of a crayon within a sharpener is a problem 
which is minimized due to the parabolic profile of the cutting edges.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The present invention provides an improved apparatus for sharpening crayon 
marking instruments which are commonly made from waxes, plastics and other 
similar soft materials into configurations with safe blunt writing tips 
thereon. The sharpening of such marking instruments or crayons presents 
significantly different problems than sharpening of a pencil in view of 
the fact that a pencil and the writing media contained therein are 
relatively hard. With a crayon-type instrument the material being 
sharpened is comparatively soft and a much more gentle and accurately 
controlled sharpening mechanism is required. 
In the unique apparatus of the present invention, a protective ring 12 is 
included defining an inlet aperture 14 extending laterally thereacross. 
This inlet aperture preferably is defined to receive a crayon marking 
instrument 10 extending therethrough to facilitate sharpening thereof into 
a more blunt shaped curved writing tip. A plurality of support members 22 
will extend in a longitudinal direction 18 from the protective ring 12 and 
will be fixedly secured thereto. The lateral direction 16 is defined to be 
the direction extending across the opening of the inlet aperture 14 
whereas the longitudinal direction 18 extends perpendicular to a plane 
defined by the inlet aperture 14. 
The support members 22 which extend generally longitudinally 18 away from 
the protective ring 12 are designed to generally converge with respect to 
one another and be fixedly secured with respect to a base member thereof. 
Each support member preferably defines a proximate end 26 which is fixedly 
secured to the protective ring 12 adjacent the inlet aperture 14. Also 
each support member 22 preferably includes a distal end 28 which is 
fixedly secured with respect to the base member 32 at a location spatially 
distant from the proximate end 26 thereof. 
A plurality of main sharpening blades 34 are includes with one of each such 
blade fixedly secured with respect to each of the support members 22 
extending longitudinally. These main sharpening blades preferably include 
an arcuate cutting edge 36 to facilitate forming of the more blunted 
writing tip preferable for use by children for the purposes of increased 
safety. The cutting edge 36 extends completely from the protective ring 12 
to the base member 32 and is arcuate at all points along that complete 
distance. As such, main sharpening blades 34 provide an arcuate contour 
along the complete length thereof. Preferably this arcuate contour or 
profile is parabolic and, as such, presents a main parabolic cutting 
profile 38 as shown best in FIG. 2. 
The parabolic shape of this profile allows the formation of a smooth curved 
surface along the outside of the writing end of the crayon marking 
instrument 10 after sharpening thereof. This allow for a crayon writing 
tip which is more blunted and safer for use by children and others. 
As shown best in FIGS. 4 and 9, the main sharpening blade 34 will 
preferably include a first blade surface 42 and a second blade surface 44. 
Blade surfaces 42 and 44 meet to form the arcuate cutting edge 36. 
Preferably first blade surface 42 and second blade surface 44 are oriented 
at approximately a 90 degree blade surface cutting angle shown by 
reference 46. Also as seen particularly in FIG. 9, the first blade surface 
42 as well as the second blade surface 44 will both be oriented at 
approximately 45 degrees with respect to the crayon marking instrument 10 
and in particular with respect to a tangent along the external circular 
surface of the crayon marking instrument 10 taken at the point of contact 
of the arcuate cutting edge 36 therewith. 
When sharpening of such soft materials most of the material is removed from 
the endmost portion 50 of the crayon marking instrument 10 to help in 
removing the additional material. A plurality of supplementary sharpening 
blades 48 can be included. Each of these sharpening blades preferably is 
secured directly to the base member 32 and extends upwardly therefrom to 
an intermediate longitudinal position 52 similar distant from the 
protective ring 12. Preferably one of these supplementary sharpening 
blades 48 will be positioned between each adjacent pair of main sharpening 
blades 34. In the configuration as shown in FIGS. 1 and 2 with exactly 
three main sharpening blades 34 being utilized as well as three support 
members 22, the supplementary sharpening blades 48 will also be three in 
number. They will extend upwardly from the base as shown in FIG. 1 to the 
intermediate longitudinal position 52 and will be equally spaced between 
each adjacent pair of main sharpening blades 34. Preferably these 
supplementary sharpening blades 48 will also provide a truncated 
supplemental parabolic cutting profile 54 along the truncated distance 
thereof. 
To further facilitate mounting of the sharpening apparatus of the present 
invention with respect to surrounding structure, a mounting collar 56 may 
be included. This mounting collar preferably will provide a means for 
facilitating mounting of the crayon sharpener apparatus of the present 
invention with respect to a surface such as the external surface of a 
crayon box or the external surface of a debris retaining chamber. The 
mounting collar 56 can be detachably secured with respect to a retaining 
cup 58 in such a manner as to define a debris retaining chamber 62 
therebetween which is adapted to receive and retain debris therein. Such 
debris is normally expelled through the debris outlets 30 defined between 
each adjacent pair of support members 22. 
An inlet flange 20 may also extend laterally outwardly from the inlet 
aperture 14 in such a manner as to provide a wide surface to further 
facilitate mounting of the apparatus of the present invention with respect 
to a crayon box or other surface. The inlet flange 20 may also be 
engageable with respect to the retaining cup 58 to provide a detachable 
securement therewith for selectively defining a debris retaining chamber 
62 defined therebetween. To facilitate grasping of the inlet flange 20 and 
the retaining cup 58 a plurality of dimples 60 may be positioned in the 
upper surface of the inlet flange 20 as shown best in FIGS. 5, 6 and 7. 
These dimples 60 provide an area wherein the user can exert pressure 
against the inlet flange 20 to facilitate retaining thereof during 
sharpening of a crayon marking instrument 10. 
With this configuration the actual sharpening zone 24 will be defined 
between the individual support members 22 and between the main sharpening 
blades 38 defined thereon. The sharpening zone 24 will also be defined to 
be longitudinal from the inlet aperture 14 and actually positioned between 
the protective ring 12 and the base member 32. 
With the configuration of the present invention preferably the protective 
ring 12 will be equally to or greater than 9/16 inches (0.5625 inches) in 
order to accommodate those different sizes of crayon marking instruments. 
Such crayon marking instruments are commonly available in multiple sizes, 
the largest of which is 9/16 of an inch. The most common sizes currently 
are 5/16 inch, 7/16 inch and 9/16 inch in diameter. In an aperture 14 of 
0.5625 inches or greater, all of these commonly utilized sizes are 
accommodated. Also because of the unique arcuate and preferably parabolic 
shape of the cutting blades utilized in the present invention, the crayons 
of these various sizes will not get wedged or otherwise improperly 
captured within the sharpening zone 24. In fact, a full continuous 
rotation of the crayon marking instrument 10 within the sharpening zone 24 
is not necessary to achieve full and complete sharpening. Due to the fact 
that the preferred configuration shown in FIGS. 1 and 2 includes three 
main sharpening blades 34 as well as three supplementary sharpening blades 
48 positioned therebetween, it is apparent that the six blades will allow 
complete sharpening with a rotation of as small as 60 degrees total. Thus 
the back and forth rotary pivoting rather than full rotational movement of 
the crayon marking instrument 10 is necessary in order to achieve full 
sharpening thereof. 
Many of the prior art devices have used very sharp blades and even razor 
blades to achieve proper shaping or sculpting of soft crayon material. 
Such is not needed and presents unnecessary dangers to the users of such 
sharpeners which are often young children. The present invention provides 
a means for providing full sharpening without requiring any slicing or 
cutting of the soft crayon material. The present invention merely provides 
a means for grinding or abrading the exterior surface of the crayon for 
sharpening thereof. This is achieved by the use of the first blade surface 
42 and the second blade surface 44 in a relative orientation of as great 
as 90 degrees with respect to one another. This is also achieved by 
orienting these blade surfaces 42 and 44 at approximately 45 degrees with 
respect to the surface being cut of the soft crayon writing instrument. 
Thus the sharpening apparatus of the present invention is safer for use by 
children, but also the curved cutting blades impart a more blunted and 
less sharp marking tip on the crayon marking instrument thus affording 
even more safety when used by youngsters. 
One of the primary advantages of the present invention is that a minimum 
amount of material is removed from the crayon during sharpening. This 
minimum amount of material is removed to the unique arcuate and preferably 
parabolic shape of the cutting edges. In this manner the crayons will last 
significantly longer because the tip will take on a flatly rounded 
bull-nose shape. Conventional crayon sharpeners have always sharpened the 
crayon almost to a point which removes a significant amount of material 
and the point of the crayon is quickly worn down thereby necessitating 
re-sharpening more often than when sharpening is performed with the 
sharpener of the present invention. 
The wide cutting angles of as great as 90 degrees of the present invention 
are particularly responsible for the greatly reduced chance of cutting 
one's fingers when compared with metal blade sharpeners or sharpeners 
utilizing more severe angles. Also the preferably integrally molded 
protective ring 12 extending about the inlet aperture 14 provides a 
protection against the insertion of fingers into the sharpening zone 24 
especially by children who commonly use crayons and crayon sharpening 
equipment. 
By the use of arcuate and preferably parabolic cutting blades the blunt end 
of the crayon marking instrument will be formed into a bull-nose or 
arcuate shape which also is much more resistant to breakage during rough 
crayon use and is much safer than the more sharp writing points placed on 
crayons by currently used crayon sharpeners. Such rough crayon use is 
common among children and the tips of the crayons tend to break very 
easily whenever sharpened with conventional equipment. The present 
invention provides means for leaving a significant amount of additional 
material on the crayon after sharpening thereof thereby minimizing the 
breakage problem. 
While particular embodiments of this invention have been shown in the 
drawings and described above, it will be apparent, that many changes may 
be made in the form, arrangement and positioning of the various elements 
of the combination. In consideration thereof it should be understood that 
preferred embodiments of this invention disclosed herein are intended to 
be illustrative only and not intended to limit the scope of the invention.