Improvements in Tool Grinding or Sharpening Machines.
Year: 1890

page_text: Date of Application, 4th Mar., 1890-Accepted, 5th Apr., 1890
COMPLETE SPECIFICATION.
Improvements in Tool Grinding or Sharpening Machines.
A communication from LINN BOYD BENTON and ROBERT V. V. WALDO, of the
City and County of Milwaukee and State of Wisconsin, United States of
America, Type-founders.
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
M.I.M.E., 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:-
The objects of this invention are to accurately grind, shape or sharpen the working
edges of an engraving or other tool and in sharpening the tool to preserve its exact
original shape; also in grinding different tools to give to them, or a portion of their
cutting edges, precisely the same form and to preserve the exact original adjustment
of the tool or different tools, when ground and replaced in the machine in which it is
designed to be used.
It consists essentially of a tool holder, an oscillatory guide block, with their
attachments and connections, and of certain peculiarities of construction and arrange-
ment hereinafter specifically set forth.
In the accompanying drawing like letters designate the same parts in the several
figures. Fig. 1 is a side elevation of the machine embodying this invention; Fig. 2
is a vertical axial section of the lathe head and a portion of the bed; Fig. 3 is an
end elevation of the pulley of the lathe head seen from the right with reference to
figure 1; Fig. 4 is an end elevation seen from the left with reference to figure 1, of
a portion of the grinder guide and its support, with a cross section of the bed of the
machine; Fig. 5 is a plan view of the oscillatory grinder guide and its support;
Fig. 6 is a perspective view of the parts composing the oscillatory guide inverted ;
Figs. 7 and 8 are enlarged views of the working ends of tools illustrating the method
of grinding the same, and fig. 9 is a perspective view of the stone or grinder.
I may employ for the bed A of the machine a bed like or similar to the bed of a
watch-maker's lathe having a vertical longitudinal slot a, through which passes the
screw H securing the oscillatory guide support thereto. It is formed on the upper
side with accurately finished ways or faces, upon which the tool holder and said
guide support rest.
For the tool holder K, I employ the head stock of a watchmaker's lathe furnished
in the usual manner with a hollow spindle B, in which the tool I to be ground is
inserted and held by a chuck or jaws 2 of the ordinary construction. The hollow
spindle B is provided with the usual pulley N having around its outer end a perforated
index plate to receive the index pin k and stop and hold said spindle at the proper
intervals in its rotation to produce a tool having the desired number of faces and
cutting edges of the required angle in cross section.
The slot a in bed A has undercut grooves a¹ a¹ (shown in figs. 2 and 4) in its sides
to receive the heads k¹k of spindles which are inserted in vertical sockets in the
tool holder K. These heads are drawn snugly against the upper sides of said grooves,
and the tool holder K secured to the bed A by means of the thumb screw L and the
blocks which are inserted in a bore intersecting said sockets, and have bevelled
ends engaging bevelled notches in the spindles of heads k¹k, as shown in fig. 2.
The screw L passing through a vertical slot in the first spindle, passes through and
is threaded in the first block k² and bears at the tip against the butt of the other
block k². It operates when turned to move said blocks simultaneously in opposite
directions, and thereby to draw the heads k k towards the base of the tool holder K.
When released the heads k¹ k¹ are forced outwardly by the springs k³ ³. Any other

page_text: suitable means may be employed for attaching the movable tool holder to the
bed A.
For the purpose of advancing the tool to the proper point for grinding, I provide
a screw 6', which works in a nut inserted in the end of the hollow spindle B
opposite the chuck 62 and bears against the shank of the tool held therein, as shown
in fig. 2.
Cis the guide support provided on the sides with standards between which the
guide block D is pivotted upon the conical tips of the screws c c. C' is a tongued
plate fitted on the upper side into a recess in the underside of the guide support C
and adapted on its underside to the bed A, to which it is secured as before explained,
by the screw H.
In a transverse groove in the underside of the oscillatory guide leaf or block D is
nicely fitted the bar E in the ends of which are formed the conical bearings for the
tips of the pivot screws c c. The guide block D is secured to the pivot bar E by
means of clamps ee and screws.e2, as shown in figs. 1 and 6, and by means of
adjusting screws el el which pass through threaded perforations in said pivot bar E
and bear at their tips against the underside of said guide block D, the upper working
face of said guide block D is set nearer to or farther from said bar E so as to cause
the working face of said guide block to describe, in oscillating on its axis, the are
of a smaller or greater circle, required to produce on the tool faces and cutting edges
of a less or greater curvature as desired.
In fig. 6 the bar E is represented as detached from the guide block D, the screws e³,
which pass through perforations in the clamps ee and engage threaded holes in said
block, having been removed. The edge of the oscillatory guide block D nearest its
axis of oscillation is cut out at h, as seen in figs. 5 and 6 to clear the tool and permit
the same to project beyond the working face of said guide block, in position to be.
operated upon by the stone O moved back and forth across it.
The pivot bar E and screws e e' also furnish means for taking up the wear on the
working face of the guide block D and preserving its exact adjustment with reference
to the axis of oscillation. This is accomplished by applying a gauge to the back of
the bar E and the upper face of the block D and moving the latter by means of the
adjusting screws ele into exactly the same position with reference to the back of bar E
and to its pivotal bearings as it originally occupied. This gauge may be permanently
attached to the device, so that the block D may be removed from time to time,
accurately faced and then replaced and set with its working face in precisely the
same position with reference to the axis on which it oscillates.
G is a screw working with a threaded perforation in the base of the guide support C
and provided with a milled rim g' and a conical head g, which bears at its apex
against the under side of the guide block D near its outer edge and gradually raises
the same on its axis, when said screw is turned up and permits it to descend when the
screw is turned down.
d d' are hooked stops pivotted to the base of the guide support C and each
arranged when turned into an upright position to limit the upward movement of the
guide block D.
One of said stops is employed in grinding tools having curved edges,
while the other is used in grinding tools having straight cutting edges or a portion of
their edges straight.
F is a stop block attached to the guide support, so as to engage with the lathe head
or tool holder and hold the same at a certain fixed distance therefrom, so that when
the lathe head is returned to the engraving or other machine in which it is employed,
after the tool has been ground or sharpened, it will occupy exactly the same position
in the machine that it did before.
The axis of oscillation of guide D is raised or lowered for the purpose of grinding
tools of different diameters or of greater or less acuteness, by inserting between
the base of the guide support C and the block C¹ a block or blocks ff of different
thicknesses.
◇ represents an oblong plane faced grinder, which may be made of any suitable

page_text: abrading substance or material, although I prefer a fine Arkansas stone for the
purpose. The guide block D is made of hardened steel or any other suitable
material that will not be abraded or easily worn by the action of the stone or grinder
upon its face.
Tools are ground, shaped or sharpened on this machine as follows:-The tool holder
or lathe head K is placed in the machine snugly against the stop F and secured to the
bed A. The tool or tool blank is then advanced by means of the screw
far enough
to permit of the necessary abrasion by the grinder O moved over the guide block D,
and then secured in place by the usual means in the hollow spindle B.
Tools of three or more faces are formed by locking the pulley N successively at
thirds, fourths, etc. of a revolution by means of the pin k. Each face is then ground
by moving the stone or grinder O back and forth across the face of the guide block D,
which is gradually swung on its axis by screw G causing said stone or grinder to
traverse an arc intersecting the axis and upper side of the tool, thereby producing the
desired curve, to the faces and cutting edges of said tool.
One face having been ground flush with the working face of the guide block while
the latter is swung as described upon its axis, the tool is turned and another face
precisely like the first is ground thereon in the same manner, the guide block D being
moved through the same are.
The operation is thus continued till all the sides and the cutting edges formed by
their intersection are ground exactly alike.
For some purposes a tool I, such as is shown in fig. 7, having the entire length of
its cutting edges formed on a curve, is desired. Such tool is produced by
gradually swinging the guide D upon its axis between the limits required to
produce the desired curvature, and grinding each of the faces of said tool from
base to point or vice versa in the manner described. Different curvatures are
given to the faces and edges of tools by changing the distance of the working
face of guide D from its axis of oscillation, and a sharper or blunter tool having
sides of the same curvature is produced by lowering or raising the guide support C
and thus changing the distance of the axis of oscillation of said guide from the
axis of the tool.
For other purposes a tool 1¹ like that shown in fig. 8, having its cutting edges
curved at the tip and straight from a point near the apex to the base, is desirable.
Such a tool is produced by moving the guide D up into engagement with the
stop d properly constructed and set to give the desired inclination to the faces of
the tool and the several faces are then ground to a plane flush with the face of
said guide to a point near the apex of the tool, and between that point and the
apex, to a curve in the manner previously described. In order that the tool may
project the same distance from the tool holder when ground or sharpened after
raising or lowering the guide support C together with the pivot screws cc, or
after changing the distance of the face of guide D from the axis on which it
turns, it is necessary to employ different stops F, by which the tool holder K
may be set at correspondingly different distances from the guide support C and
guide D.
No precise limit to the downward angular movement of guide D is necessary
since any movement in that direction beyond what is necessary to complete the
point of the tool on any side will either carry the stone out of contact with the
tool or remove waste material which would otherwise be necessarily removed in
finishing the remaining side or sides of the tool. Neither is the upper angular
movement of said guide necessarily limited with precision, in grinding tools having
curved cutting edges, but I provide for greater convenience a stop d', which limits its
movement in that direction at a point beyond which the operation of grinding would
be uselessly continued; but in grinding tools having straight cutting edges throughout,
or tools having a portion of each of their cutting edges straight as , it is necessary to
exactly limit the upward angular movement of said guide. Different stops are
provided for producing tools having faces of different inclinations.

page_text: It will be observed that the pivot bar E is formed at the ends with upturned pro-
jections e³ e³, in which are formed the bearings for the pivot screws cc. By this
construction the axis of oscillation may be brought very close to the working face of
the guide D without encroaching upon the material allowed for wear or weakening
said guide or causing the pivot screw supports to project in the way of working the
grinder O.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents 1 declare that what I claim is
--
1. The combination in a tool sharpening device of a tool holder, a grinder guide
capable of swinging on an axis transverse to the axis of the tool held in said holder,
and a grinder adapted to be moved upon said guide, substantially as and for the
purposes set forth."
2. The combination in a tool sharpening device of a tool holder and an oscillatory
grinder guide, having adjustable pivot bearings whereby the working face of said
guide is adjusted with reference to its axis of oscillation, substantially as and for the
purposes set forth.
3. The combination in a tool sharpening device of a tool holder, a guide support,
a grinder guide pivotted in said guide support and capable of oscillation on an axis
transverse to the axis of the tool holder and a device arranged to swing said guide on
its axis and to hold the same at the desired inclination to the tool, substantially as and
for the purposes set forth.
4. The combination in a tool sharpening device of a rotary tool holder provided
with a stop for securing it at different points in its rotation, a grinder guide arranged
to swing on an axis transverse to the axis of the tool held in said holder, and a
grinder adapted to be moved upon said guide, substantially as and for the purposes
set forth.
5. The combination in a tool sharpening device with a supporting bed, of a rotary
tool holder attachable to said bed, an oscillatory grinder guide and a stop by which
the tool holder and grinder guide are exactly set at a determinate distance apart,
substantially as and for the purposes set forth.
6. The combination in a tool sharpening device of a tool holder, a grinder guide
capable of turning on an axis transverse to that of the tool held in said holder
an adjustable guido support whereby the axis on which said guide swings may be
moved towards or from the axis of the tool, and a grinder adapted to be moved upon
said guide, substantially as and for the purposes set forth.
7. The combination in a tool sharpening device of a tool holder, a grinder guide
capable of turning on an axis transverse to that of the tool held in said holder, a stop
by which the angular movement of said guide is limited and a grinder adapted to be
moved upon said guide, substantially as and for the purposes set forth.
8. The combination in a tool sharpening device of a head provided with a rotary
tool holder, a guide support provided with an oscillatory guide recessed to receive the
end of the tool, a device arranged to swing said guide on its axis, and a bed to which
said head and guide are attachable, substantially as and for the purposes set
forth.
9. The combination in a tool sharpening device of a suitable bed, a removable
tool holder attachable thereto, a grinder guide capable of swinging on an axis trans-
verse to the holder and a grinder adapted to be moved upon the working face of said
guide, substantially as and for the purposes set forth.
10. The combination in a tool sharpening device of a tool holder, a grinder guide
capable of swinging on an axis transverse to the axis of the tool held in said holder,
and provided with a movable wearing block, and a grinder adapted to be moved upon
the working face of said wearing block, substantially as and for the purposes set
forth.
11. The combination in a tool sharpening device of a rotary tool holder, a stop

page_text: arranged to secure said tool holder at intervals in its rotation, an adjustable plane
faced guide, and a plane faced grinder arranged to work with said guide, substantially
as and for the purposes set forth.
12. The combination in a tool sharpening device of a tool holder, a plane faced
grinder and an oscillatory grinder guide, a pivot bar secured thereto and offset at the
ends, in which are formed the pivot bearings, whereby the axis of oscillation may be
brought close to the working face of said guide, substantially as and for the purposes
set forth.
13. The combination in a tool sharpening device of a tool holder furnished with a
clamping device and with an adjusting screw arranged to advance the tool in said
holder, a plane faced grinder and a plane faced oscillatory grinder guide, substantially.
as and for the purposes set forth.
41
11000
W. P. THOMPSON & BOULT,
Agents for the Applicant.