Improvements in and relating to Pencil Sharpening Machines.
Year: 1898

page_text: Date of Application, 8th Mar.,
1898
PROVISIONAL SPECIFICATION.
Improvements in and relating to Pencil Sharpening Machines.
I, JETHRO MARSII, of 4, Wellclose Square, St. George's in the East, London,
Engineer, do hereby declare the nature of this invention to be as follows:-
"
This invention relates to machines for sharpening pencils, particularly those
formed of a core of material for marking such as graphite or
black-lead" sur-
rounded by a cylinder of wood or the like and has for its object to render such
machines suitable for use in schools and other places where a large number of
pencils are required to be sharpened quickly by children or others inexperienced
in grinding and setting the knives with which such machines are generally
provided.
For the purposes of my invention, I employ an abrading surface of sand,
powdered glass emery or the like caused to adhere in the well known manner to
a ground of cloth, paper or other suitable material. I cut or form discs of such
paper or cloth and mount them on a plate adapted to be rotated and I place the
pencil in a suitable guide so that one end of it is abraded by the rotating surface,
simultaneously rotating the pencil in the guide. By these means I obtain a
conical end to the pencil, the angle of which depends on the angle of the guide
relatively to the cutting surface while the smoothness of the point depends on the
fineness or coarseness of the said abrading or cutting surface.
In its simplest form a machine according to my invention consists of a plate
mounted on a shaft adapted to rotate in bearings and provided with means for
turning it, such as a pulley or handle. To the face of the plate is attached a
piece of the paper, cloth or the like prepared as above described. In front of the
plate and adjustable to the suitable angle with it, I provide a guide consisting of
a block having a groove in its upper side. By holding the pencil in this groove,
pressing it against the rotating abrading surface and at the same time turning
it in the guide, the sharpening is effected.
As another example of the way in which I may construct a machine in accord-
ance with this invention, I will describe one provided with means by which the
abrading surface may be renewed by inexperienced persons when worn, and with
means for automatically pressing and turning a pencil against the said abrading
surface.
I form any number of separate discs of the prepared paper, cloth or the like and
replace worn discs by new ones. To enable this replacement to be readily effected
the rotatable plate is provided with a ring adapted to screw upon its periphery.
The ring has an inwardly projecting lip adapted to force the abrading disc at its
edge against the plate when screwed up tightly, and so grip it. The discs may
be specially shaped at their edges by pressing or otherwise for this purpose. The
shaft on which the plate is mounted carries a toothed wheel in gear with a second
toothed wheel mounted on a driving shaft at one extremity of which a handle
is fixed for operating the machine. The angle of the pencil point may be varied
by pivoting the plate and its shaft below the point of engagement of the toothed
wheels or otherwise suitably.

page_text: The means for automatically rotating the pencil and pressing it against the
disc, consist of a tubular guide placed above the driving shaft at right angles
therewith. This guide is rotated from the driving shaft, preferably by worm
and worm-wheel gearing. Concentrically moving jaws within the guide are
arranged to grip the pencil when a nut surrounding it is screwed into the guide.
A spiral spring may serve to press the pencil and worm gearing for rotating it
toward the abrading surface.
The abrading disc surfaces may each be of two or more degrees of fineness so
that after grinding the pencil to the required angle on a coarse surface it may be
set to a different position for finishing. For instance, a disc may have an outer
ring of coarse, and an inner surface of fine sand.
I do not limit myself to the precise method herein described of carrying out my
invention. I may, for instance, employ two rotatable plates and discs, on opposite
sides of the pencil to be sharpened or otherwise vary the construction of the
machine without departing from the spirit of the invention.
Dated this 8th day of March 1898.
ADELEIDUITIVATION.
Improvements in and relating to Pencil Sharpening Machines.
I, JETHRO MARSH, of 4, Wellclose Square, St. George's in the East, London,
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:-
This invention relates to machines for sharpening pencils, particularly those
formed of a core of material for marking, such as graphite or
black-lead" sur-
rounded by a cylinder of wood or the like, and has for its chief object machines
suitable for use in schools and other places where many pencils are required to
be sharpened quickly by children or others inexperienced in grinding and setting
the knives with which such machines are generally provided.
For the purpose of my invention I prefer to employ an abrading surface of
powdered glass, sand, emery, or the like, caused to adhere in the well-known'
manner to a ground of paper, cloth, or other suitable material. I cut or form a
disc of such glass-paper or the like, and mount it on a plate adapted to be rotated
and I place the pencil in a suitable guide or holder so that one end of it is pointed
by the rotating abrading surface, simultaneously rotating the pencil in the guide
or holder.
By these means I obtain a conical end to the pencil the containing angle of
which depends on the angle of the axis of the guide or holder relatively to the
plane of the cutting or abrading surface, while the smoothness of the point varies
with the size of the grains forming the said surface.
A simple form of machine according to this invention consists of a plate
mounted on a shaft adapted to rotate in bearings and provided with a means for
turning it, such as a handle. To the face of the plate and adjustable to the
suitable angle with it I provide a guide or holder.
this guide and pressing it axially against the rotating abrading surface and at the
By holding the pencil in
same time turning it in the guide the sharpening is effected.
I replace worn abrading or cutting discs by new ones, and to enable the replace-
ment to be readily effected the rotatable plate is provided with a ring to screw
upon its periphery. The ring has an inwardly projecting lip adapted to press
the disc at its edge against the plate when screwed up tightly, and so grip it.
The discs may be specially shaped at their edges for this purpose.

page_text: According to another form of my invention, the shaft on which the plate is
mounted carries a toothed wheel in gear with a second toothed wheel mounted on
a driving shaft, at one extremity of which is fixed a handle for operating the
machine. The angle of the pencil point may be varied by shifting the plate and
its shaft about a pivot placed below the point of intersection, and in a plane of
the toothed wheels.
A tubular guide is carried on the driving shaft the axis of which it crosses in
this case.
The guide is rotated from the driving shaft preferably by worm or
screw gearing. Radially moving jaws are arranged to grip the pencil when a
nut surrounding it is screwed into the guide. A spiral spring may press the
guide and pencil toward the cutting or abrading surface.
Each disc face may be divided into two or more portions, which differ by the size
of the grains of abrading or cutting material. For instance, a disc may have an
outer ring of coarse, and a central surface of fine sand, so that after the pencil
is ground to the required angle on a coarse surface it may be finished on a
smoother surface.
In order that my invention may be better understood I will describe two pencil
sharpening machines, by way of example, constructed in accordance therewith.
In the accompanying drawings which illustrate the description, Fig. 1 is a side
view, partly in section, of a machine in which the pencil is pressed axially against
the abrading disc, and Fig. 2 is a plan thereof, also partly in section. Fig. 3 is a
front view of a disc having its face divided into two concentric portions composed
of differently sized grains of abrading material. Fig. 4 is a side view partly in
section of a machine in which the pencil approaches the cutting disc in a direction
at right angles with its face, and Fig. 5 is a plan thereof also partly in section.
Like reference letters or symbols refer to like parts in each of the figures.
Referring first to Figures 1 and 2, A is an abrading dise of glass-paper or the
like, mounted on a plate B which is fast on a shaft or spindle C, rotatable in its
bearing D.
For mounting the pointing disc here shown the plate B is furnished with a screw
threaded ring m having a lip or flange n, and milled edge. A backing of rough
face is preferably attached to the plate B by gluing or otherwise, the disc A is
placed next the backing, the ring m being finally screwed up tightly so as to grip
the disc A, and backing between the flange n and plate B. The plate B is in one
piece with a bevil pinion E which meshes with a spur bevil F, fast on the driving
shaft G provided at its opposite end with a crank handle H.
is mounted on the driving shaft G, so as to slide freely along it, and a pinion J
A pencil guide I
in the guide I rotates with the shaft G, being provided with a feather adapted to
slide in a keyway in the usual manner. The guide I carries a chuck or pencil
holder K, having fixed upon it a spur wheel L, which engages the pinion J.
Consequently the chuck is turned when the shaft G is rotated.
Instead of the spur L and pinion J, two sprocket wheels and a chain may be
employed, or an intermediate wheel placed between the spur and pinion: then the
direction of rotation of the chuck will be reversed.
The chuck K shown is provided with radially moving jaws which grip the
pencil when the nut M is screwed up in the manner hereinafter described with
reference to Fig. 4, but it may be of any suitable construction. A stop N is pro-
vided on the guide I to serve as a gauge in placing the pencil in the chuck.
The pencil is drawn axially toward the pointing disc A, by a spiral spring 0
attached at one end to the bed of the machine, and at the other end to a lug P
fast on the guide. The pencil is withdrawn from the disc by means of the lever Q
connected by a link R to the lug P.
chuck from the disc and allow of the insertion or removal of a pencil.
A stop S is suitably placed to withold the
The length of the conical pencil point may be varied by turning the plate
shaft bearing D about its pivot T and setting it in position by means of the
screw U. The dust particles or cuttings removed from the pencil by the disc are
prevented by a hood V from mixing with the air surrounding the machine, being

page_text: caused to pass into a removable drawer W beneath, through a slot X in the, bed
plate. In order to permit of substituting new discs for worn ones readily,, the
hood is so arranged that it may be swung out of the way about its pivot V.
It is retained in place when the machine is being operated by any suitable means;
in Fig. 1 its movement is prevented by a stop Z on one side and a swing "button"
on the other..
a
The mode of operation is as follows: The lever Q being engaged by the stop S
so that the guide I is witheld from the disc A, a pencil is pushed into the chuck K
until its forward end reaches the stop N, then the nut M is screwed up so as to
close the jaws and grip the pencil. The lever Q is then raised slightly to disen-
gage it from the stop S and to allow the spring ( to act and draw the guide I
toward the disc A. The handle H is then turned and the disc rotated through
the shaft G and bevil wheels F and E. The chuck K is also rotated through the
pinion and spur J and L, and the pencil abraded uniformly round its end until
it receives a sharp conical point, then it may be drawn out of contact with the
disc by means of the lever Q and released from the chuck K by unscrewing the
nut M
Fig. 3 illustrates an abrading disc having its face divided into two concentric
portions, each composed of differently sized grains of abrading material, and well
adapted for use in the machine above descrbed. The ring b is of coarse, and the
central face c, of finer grains, so that the pencil moving in the direction of the
arrow, and first coming in contact with the part b, has there the greater part of
superfluous material removed, and later, reaching the part e is there finished with
a smooth point.
In the modification represented by. Figs. and 5, the pencil is caused to
approach the pointing disc A¹ in a direction at right angles to its face. The
disc A¹ may be mounted on the plate B in the manner above described, but is
here shown attached to it by means of a nut d engaging a screw formed on the
end of the shaft C¹. A washer interposed between the nut d, and disc A¹ transmits
the pressure from the nut to the disc when the former is screwed up. Preferably
a disc of rough material is attached to the disc so that the pressure of the pencil
against the disc tends to prevent slipping.
Where discs coated with abrading material on both faces are used, I prefer to
attach a disc of impressionable material to the plate B for the same purpose.
Excepting for the screw at its end, the shaft C¹ is similar to that above described,
as is also the bearing D. A toothed pinion E' is carried by the plate B and
engages a spur wheel F¹ fast on the driving shaft G which as in the foregoing
example is provided with a handle H. The guide I¹ is mounted on the shaft G,
the axis of the chuck K mounted therein, crossing it at an angle suitable for the
required pencil point. The chuck K has fast on it a screw or worm wheel L¹
which engages a screw wheel on the shaft G, along which it is free to slide but
with which it is caused to turn by means of a feather and keyway as before
mentioned.
The method of joining the upper and lower parts of the guide permits them to
turn relatively one to the other and allows of a slight variation in the angle the
pencil makes with the disc face. As will be seen in Fig. 4, these parts are joined
by screws which clip the upper flange to the lower when screwed up. The
screws pass through slots in the upper flange and engage screwed holes in the
lower flange.
The pencil is gripped in the chuck by radial jaws e, pressed inwardly by screw-
ing up the nut M which bears on a ring f, that by sliding upon the inclined
part of the jaws e, forces them toward the pencil. When the pressure is removed
from the ring f by unscrewing the nut M, a circular spring i opens the jaws; so
causing the ring f to slide backward and release the pencil. The jaws are pre-
vented from twisting or turning in the chuck, as they work in gaps j, formed in
the shell of the chuck K and ring f, which latter carries a pin g working in a
slot h

page_text: The pencil is fed toward the disc by a spiral spring 04, which, seated at one end
upon a bearing k, tends to force the pencil against the disc A', from which it may
be withdrawn and witheld by the lever Q and link R as above described.
It will be obvious that a spiral spring in compression around the shaft G may
be employed instead of the spring O in the former machine; while a spiral spring
in tension, attached to the lug and the bed-plate could be equally well applied
in the present example.
The pencil stop or gauge N is in this case attached to the hood V, and the
mode of operating the machine is similar to that above described for the former
machine.
I do not limit myself to the precise method herein described of carrying out my
invention, I may for example in some cases provide the plate B with a knife or
knives in the well-known manner, or otherwise vary the construction of the
machines without departing from the spirit of the invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
:―
1. In a pencil sharpening machine, the combination of a pointing disc or plate,
a toothed wheel adapted to turn with the disc or plate, a second toothed wheel
meshing with the first toothed wheel, and mounted on and turned by a driving
shaft, a pencil guide and holder arranged to slide along said driving shaft, means
for pressing the pencil guide and holder toward, and withdrawing them from the
sharpening disc or plate, gearing for transmitting rotation from the driving
wheel shaft to the pencil holder, and means for rotating the driving shaft sub-
stantially as described, for the purpose set forth.
2. In a pencil sharpening machine, the combination of a pointing disc or plate,
means for rotating it, a pencil holder or chuck adapted to slide to or from the
disc or plate, a spiral spring arranged to force the chuck or holder toward the said
dise or plate, substantially as described for the purpose set forth.
3. In a pencil sharpening machine, a plate having a screw thread at its periphery
and a screw threaded radially flanged ring adapted to engage the screw thread on
the plate, substantially as described, in combination with a sharpening disc, means
for rotating the said plate and disc and for holding a pencil in contact with the disc
for the purpose set forth.
4. In a pencil sharpening machine in which a pencil is rotated in contact with
a rotating pointing disc or plate, the means substantially as described for varying
the angle between the face of the disc or plate, and the axis of the pencil for the
purpose set forth.
5. For use in a pencil sharpening machine of the kind in which a pencil is
pointed by contact with a rotating sharpening disc or plate, an abrading or cutting
disc or plate having its working face divided, each portion being composed of
grains of abrading or cutting material differing in size from the grains of another
portion substantially as described for the purpose set forth.
6. In a pencil sharpening machine, the combination with a pointing device and
a guide, of a chuck or pencil holder having radially movable jaws, a ring and
shell grooved to receive the jaws, the ring adapted when pushed forward to close
the said jaws, a nut for forcing the ring axially forward, and a circular spring
adapted to open said jaws, substantially as described for the purpose set forth.
7. A pencil sharpening machine constructed substantially as described with
reference to Figures 1 and 2, or Figures 4 and 5 of the accompanying drawings.
8. Am abrading or cutting disc prepared substantially as described with
reference to Figure 3 of the accompanying drawings for the purpose set forth.
Dated this 8th day of December 1898.
JETHRO MARSH.