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Патент USA US2130370

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Sept- 20, 1938.
H. w. SPOONER
‘
2,130,370
PENCIL POINTER
Filed Nov. 23, 1935
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Patented Sept. 20, 1938
2,130,370‘
UNITED STATES PATENT OFFICE ‘7
2,130,370
PENCIL POINTER
Henry W. Spooner, Crestwood, N. Y.
Application November 23, 1935, Serial No. 51,207
6 ‘Claims. (Cl. 120-93)
This invention relates to improvements in on a vertical plane through the center line of the
pencil pointers, also frequently called pencil
hole provided to guide the pencil.
Sharpeners, and speci?cally to that type of de
Fig. 3 is a view of the top of the complete
device.
vice which is usually held in one hand while the
5, pencil is rotated by the ?ngers of‘the vother hand
against the edge of a knife held in ?xed rela
tionship to the longitudinal axis of the pencil.
In pencil pointers of this type the knife is some
times made practically an integral part of the
lOentire device, as by welding ‘to a metal body.
Various other designs'combine a body molded or
machined from plastic compounds such as phenol
resin, together with a knife of special design which.
is not readily renewable. Thus when the knife
-’ has become dulled through repeated use the en
tion of the device showing the relative positions
of the ‘blade and the pencil.
Fig. 6. is a similar section of a pencil pointer
of the usual type, shown for purposes of com
1e -
parison.
f
Fig. ‘7 is a similar section showing the im
practicability ‘of using a razor blade in a pencil
pointer of ordinary design.
‘
tire device becomes practically useless to the
Fig. 1 shows the hollow, graceful ‘lines that may 1511
be obtained in a pencil point by using this im
owner for want of some means of renewing the
proved device.
knife alone. Moreover, the usual device of this
type is so short as not to provide a proper guide
In Fig. 2, I represents the bodyof the device.
2 represents a razor blade of popular type, which
blades are usually made about .007” thiok and
20 for the body of the pencil ,thereby allowing it to
vacillate while beingrotated, resulting in the
frequent breaking of leads, either at the point,
or, by ?exure, inside the wooden envelope. If
the angle between the axis of the pencil-and the
25 edge of the knife is comparatively large, as is
frequently the case, the tapered section will be
short and the point “stubby”, necessitating fre
quent sharpenings to retain a reasonably ?ne
point.
3,0
‘Fig. 4 is an end view of the device.
Fig. 5 is a greatly enlarged section of a por
To overcome these various objections I have in
vented the pencil pointer. described below, in
which the problem of renewing the knife is solved
by the, ‘use of discarded razor blades, which the
device is built to accommodate. These blades
have been found to be amply keen for removing
‘lightshavings from wood and graphite, even after
becoming too dull to be vused comfortably for
shaving. The keenness of these blades as com
pared with the usual knife employed for this pur
4(.),_ pose permits a long, gradually tapered point to
be obtained without breakage. I obtain a
“hollow” or concave point by ?exing the blade into
the shape desired in the ?nished pencil.
The use of .this type of blade, and its ?exure
,
are therefore somewhat flexible. I utilize this
characteristic of this type of blade to obtain the
curved or hollowed pencil point by clamping the‘
blade against the concave upper surface of body
I by means of cover plate 3, which has a convex
curved surface of suitable form for the purpose.
Pressure is applied ‘to the blade 2 through cover
plate 3 by means of the milled or knurled nut 4
and screw 5 (shown in Fig. 3). In body I a
cored or drilled hole, ‘I, of a form approximat 30,1
ing that desired in the finished pencil point, is
provided vto guide the pencil and permit it to be
rotated by hand againston-e edge of blade 2. For
the removal of chips 2. slot, 8, is provided, ap
proximately the full length of blade 2 and expos
ing its edge when viewed from the‘ upper sur
face of the device. To hold the blade securely
in position dowels 6, 6 are provided as shown in
Fig. 3. ‘These dowels ?t with re'asonablesnugness
in corresponding holes or slots in the blade; or,
if desired, a tongue may be substituted for the
dowels to ?t a blade having a longitudinal slot
in place of round holes.
1
The device is. used by inserting the end of an
4;» into a curve, introduce some problems that are not.
ordinary wooden pencil in the hole l provided
readily apparent, but which will be set. forth in
therefor, pressing the pencil gently forward and
at the same time rotating it clockwise against
the following description.
.
In the accompanying. drawing some of the
parts are shown in an enlarged scale to insure
vclearness.
Fig. 1 is a side view ‘of a pencil consisting of a
wooden envelope or body enclosing a graphlte‘or
colored core or “lead”, after being sharpened
With this device.
55.- Fig. 2 is a sectional view of theydevice, taken
the edge of the blade 2.
This removes a prac
tically'continuous chip, the ‘thickness of which
is dependentv on the position of the edge of the
blade 2 referred to the periphery'of hole '5'.
Fig. 6 represents a pencil pointerof the usual
design in this general class; In'thistype of pencil
pointer the knife, 9, is. ordinarily from four to
eight or ten times as thick asithe razor blades
45 '
2
2,130,370
which I employ. It is usually held in hori
zontal alignment by abutting its rear side against
a shoulder provided for that purpose in the body
of the device, and it is held in vertical alignment
by clamping it down against the body by means
of a small screw. The thickness and consequent
stiffness of the blade 9 is depended upon to hold
it in alignment, and the under side and edge are
invariably intended to be substantially straight.
10 This imposes a straight taper on the pencil and
precludes obtaining a hollow or concave point as
shown in Fig. 1.
In Fig. 6, e indicates the edge of a knife 9 of
ordinary type, and e—]‘ a portion of its under
15 side. This surface c—f, considered in cross sec
tion as shown, is tangent, or substantially so, to a
radius drawn from the center of pencil H) to the
edge e of knife 9. Consequently, as pencil I0 is
rotated and the chip c—g removed, the slight
reduction in the diameter of the pencil I!) per
mits it to clear the surface c—f of knife 9.
Theoretically it would touch only at edge e, which
is also the “point of tangency”.
Fig. '7 shows what would happen if‘ a razor blade
of the type in question were used in the same
manner. Because of the comparative thinness
and consequent ?exibility of blade 2 it could not
be self supporting, but must be held rigidly against
body I by means of clamp or cover plate 3. How
30 ever, these blades are invariably beveled on each
side of the central plane, the ground edge e-—d
being at an angle with the flat surface d;——-f.
incide with, or preferably to fall slightly below,
the blade surface c—d, thus insuring clearance
between the blade 2 and pencil ID as the periphery
of pencil It] leaves edge e. The combination of
the vertical and horizontal angles above men
tioned also determines the depth of feed, or thick
ness of the chip e-g, and as the axis of pencil
l0 intersects edge e at a point coinciding with
the ?nished point of the pencil, the thickness of
chip e--g varies, from any desired value at the 10
beginning of the taper down to zero, theoretically,
at the tip of the point. This results in smooth,
easy operation, a minimum of breakage, and
points of any vdegree of length and sharpness
15
desired.
It would be possible to use double-beveled
blades in this type of sharpener by inclining them
at an angle so as to insure ‘clearance between the
beveled surface c—d of blade 2 and the periphery
of pencil I0. But this would complicate’ the 20
problems of construction and make it necessary to
keep the edge of the blade nearly, if not quite,
straight. I therefore prefer to employ the con
struction above described.
While I have described my invention with great 25
particularity, especially with reference to a spe—
ci?c embodiment thereof, it is not to be construed
that I am limited to the design shown in the
drawing, for, from the information which I have
disclosed, a variety of similar devices could be 30
designed by those skilled in the art without de~
parting from the spirit of my invention as em
Repeated micrometer measurements and careful
calculations show that the angle included between
‘one beveled edge c—d and the central plane of
the blade 2 is, on the average, about 9° 42'. The
bodied in the following claims.
arc e-h, starting from the edge of blade 2, has as
its center a point lying in a vertical plane inter
secting the edge e of blade 2. Therefore the cen
tral plane of the blade is tangent to a radius
of the pencil I0 (and also a radius of the hole 1),
and any bevel on the blade 2, however slight,
lying below the central plane of blade 2 must en
croach within the periphery e-h. of hole‘ 7.
Hence the purpose of the device would be defeated,
as insertion of pencil ID in hole ‘I would merely
faces beveled along at least one side to form a
bring it in contact with ‘the protruding surface
e—-d of blade 2 rather than with its ‘cutting edge
e. Theoretically, the periphery of the pencil
would rub against blade 2 at the point on beveled
edge e—d.' which is nearest to the center of the
hole 1, thus resulting in the burnishing, rather
than the cutting of the pencil.
To overcome these di?iculties I employ the con
55 struction shown in Fig. 5, in which 0 represents a
point in the axis of the pencil l0, e represents the
edge of blade 2, c—e a radius intersecting the
edge e, and e--bi a line tangent to radius c—e.
Also, the line 02-0 is drawn vertically through the
60 axis of the pencil l0 and lies in a vertical plane
which coincides with. the axis ‘ of pencil l0
throughout the length of the latter. At one point
the plane represented by a—c intersects the lon
gitudinal edge e of blade 2, so that a horizontal
angle is formed between the axis of pencil I0
and edge of blade e when viewed in plan, as
in Fig. 3. In the design shown. this angle is
2° 0'. The axis of the pencil l0 and hole ‘I must
be inclined vertically also, in order‘ to produce a
70 properly tapered point. The combination of the
vertical and horizontal angles determine the posi
tion of the blade edge e relative to any point along
the axis of pencil III. This position, and the re~
sulting angle a.—c—e must be such as to permit
the line e——b, tangent to the radius c—e, to co
What I claim is:--
_
1. A pencil pointer comprising a body and 35
a replaceable blade having its upper and lower
cutting edge, said body having a longitudinally
extending concaved seat for said blade, a cover
plate having a convex surface complementary to 40
said seat effective to clamp the blade ?xedly in
position so as to shave thin chips from a pencil
when the latter is rotated against the edge of the
blade and means formed in said body to guide a
pencil so that the periphery thereof will engage 45
in a curved line contact with the extreme cutting
edge of the blade and clear the beveled lower por
tion thereof, said beveled lower portion being
positioned substantially perpendicular to the radii
connecting the axis of the pencil with the extreme 50
cutting edge of the blade.
2. A pencil pointer comprising a body and a.
blade whose upper and lower faces are both bev
eled along at least one side so as to form a cutting
edge approximately coinciding with the central 55
plane of the blade, clamping means 'coacting with
said body to ?ex the blade longitudinally so as to
give its cutting edge a curved form, means formed
in said body e?ective to guide a pencil so that it
may be rotated manually against the curved edge 60
of the blade, said clamping means and said pencil
guiding means being so relatively disposed that
the lower beveled portion of the blade is posi
tioned substantially perpendicular to radii con
necting the axis of the pencil and the extreme
cutting edge of the blade.
'
3. A pencil pointer designed to form a hollowed
or concave conical point on a pencil of the wood
encased variety, consisting of a body having a lon
gitudinally concave curved seat, ailexible blade,
an easily removable cover plate adapted to hold
said blade against said concave surface, projecr
tions to secure the blade and hold its edge in
?xed relationship to the body of the device, and
a guide adapted to receive the end of a pencil and 75
3
2,130,370
permit it to be rotated against the edge of said
blade; the said guide being so positioned that
radii drawn from points in its axis to the ‘cutting
edge of the blade will be approximately per
pendicular to the adjacent beveled surface of the
blade.
4. A device for shaping the ends of wood-en—
cased pencils, consisting of a body, a ?exible blade
ly ‘curved condition and ?xed relationship to the
axis of a pencil guiding hole formed in said body;
said axis being disposed at a compound angle
relative to the cutting edge of said blade.
6. A pencil pointer comprising a body having
a passage adapted to receive and guide the end of
a wood-encased pencil, and a double-beveled
tudinally curved cover plate adapted to ?ex the
blade longitudinally and clamp it to said body,
blade curving inwardly into said passage and. to
ward the axis thereof, for the purpose of shaping
the end of a pencil rotated therein against the 10
‘edge of said blade so that the tapered portion
means to‘ secure said cover plate to said body,
means to hold the blade against lateral move—
ment, and a guide hole in said body whose axis as
15 viewed in side elevation is inclined at an acute
angle to the plane of the blade and as viewed
lower bevel of the blade adjacent to its cutting
edge being approximately perpendicular to radii
drawn from the said cutting edge to the axis of 15
the said passage, said axis being disposed at an
with at least one double-beveled edge, a longi
in plan is disposed at an acute angle to the edge
of the blade.
5. A pencil pointer comprising a body carrying
20 a double-beve1ed-edge blade held in longitudinal
of said pencil shall have a concave contour, the
acute angle as viewed either ?atwise or edge
wise of said blade.
-
HENRY W. SPOONER.
20
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