Improvement in Machines for Grinding or Truing Lathe Centers.
Year: 1892

page_text: Date of Application, 12th July, 1892-Accepted, 13th Aug., 1892
COMPLETE SPECIFICATION.
Improvement in Machines for Grinding or Truing Lathe Centers.
We, HERBERT ELIHU HAWES, Machinist, residence No. 232 Sixth Avenue,
City of Brooklyn, County of Kings, and State of New York, United States of
America, and WALTER DOUMAUX EDMONDS, Counsellor at Law, residence
Temple Court, No. 5 Beekman Street, City, County and State of New York,
United States of America, 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 improvements in machines for grinding or truing lathe
centers.
Figure 1 represents a perspective view of said mechanism.
Figure 2 a view partly in side elevation, partly in central vertical section
and partly broken away (to show worm) of parts of Fig. 1, all as hereinafter
described.
Figure 3, cross-section of Fig. 2, at line X. X.
Figure 4 a general perspective view of our mechanism.
23
The object of our invention is to grind lathe centers, but particularly the center
used in the "dead or "tail" spindle, and so as to obtain automatically and with
comparatively no additional trouble or expense a complete and exact alignment,
and coincidence, between points and axes of the lathe centers.
"
Heretofore as is well known such centers have been ground to the required
conical shape at their extremities by securing them separately in the usual manner
in the "live spindle socket of the lathe and revolving them against a proper
grinding surface such as an emery wheel, the axes of which during the grinding,
remained fixed relatively to the axes of revolution of the "live" spindle. By this
former process both centers were ground substantially alike, but on placing the
dead spindle center in the "dead or "tail" spindle socket it was found as a rule
that the pointed extremities of the two spindles did not coincide exactly neither
did their axes, nor did the central axes of the dead center coincide with the axes
around which was rotated the live spindle and the center carried thereby.
The difficulties of correcting this lack of alignment and coincidence, and the evil
results thereof upon the lathe work are well understood.
We accomplish the object of our invention by means of the mechanism hereinafter
described and illustrated by the drawings.
d is an ordinary grinding wheel having its periphery covered with emery or other
suitable grinding surface. It is fixed upon a hollow arbor or sleeve R and rotated
by feather / of latter engaging in longitudinal spline or groove m in wheel-shaft e.
Wheel arbor R revolves in bearings 7, 1, which constitute part of frame C which
slides back and forth upon the guides n, o, rigidly secured to frame b supported
upon base plate a fixed to tapered plug S shaped to fit the sockets S¹, S" in lathe
spindles.
Wheel arbor R is provided with collar P and threaded nut P¹, between which
wheel d is clamped. These collars and the wheel fill the space between wheel
bearings I, 1, and thus prevent longitudinal movement of arbor R. Sliding frame C
is reciprocated by means of lever g'attached to frame C by screw pin h, or otherwise
and by shouldered screw I to geared worm wheel factuated by worm k on wheel
shaft e, said attachment being so effected as to admit of pin h and screw I turning
partially in their bearings in lever g.
The geared worm wheel rotates upon a fixed central bearing screw J fixedly
secured to projection J' upon the frame b. A small corner of J₁ only is shown in
the drawing Fig. 2, the wheel concealing it and the dotted line showing the
Price 8d1

page_text: position of J. Worm wheel of rotates in engaging contact with worm k on wheel
shaft e.
The inner end of shaft e carrying the worm k revolves in suitable bearing or
lug rigidly secured to frame b.
Axes of shaft e, its said bearing and guides n, o, are parallel.
.2, 21, are lugs secured to frame and connecting latter with guides o, n,
respectively. On shaft e is fixed pulley U. Shaft e is held against endwise
movement by head or shoulder W abutting against bottom and sides of the
.counterbore or enlargement of shaft bearing in the lug b'. See Figure 2, where
a portion of the wall of 6, is broken away to show the construction.
To enable frame to be moved away from ur towards the center of revolution of
the grinding apparatus plate a is provided with feather or projection X (see Fig. 2
and dotted lines in Fig. 2) fitting into corresponding groove or depression in plate a,
plate and frame being clamped together by screws 3, 3', passing through slots
whereby, as will readily be understood, frame with its attached parts may be
moved towards and away from the center of plug S and secured by tightening the
screws at the distance therefrom desired. Part of plug S, nearest to plate a, is left
straight as bearing for double pulley T.
v, vl, are a pair of idler pulleys revolving upon bearing shaft 4.
This bearing shaft 4 is flattened and adjustably clamped to plate a by screw 4¹
sliding in slot extending radially from center of plug S.
The tapering plug S being fitted in the usual manner into the socket of the live
spindle of the lathe is rotated thereby and thus the grinding wheel is caused to
revolve in an orbit around the extremity of the lathe center to be ground thereby,
while at the same time the said grinding wheel is caused to rotate upon its own
axes as follows:
Pulleys D. D upon a countershaft E secured to tool post F, or otherwise in any
convenient manner, as, for instance, by means of the frame G, are connected, the
one, D' with the cone pulley of the lathe by belt H, the other D with double
pulley T by belt M (shown in section, Fig. 2) and the pulleys U, idler pulleys v, vl,
and double pulley T are connected by another belt U' as will be readily understood.
The rotation of the cone pulley thus rotates the pulley D' carrying thereby the
intermediate shaft E rotating in frame G and thus causes the pulley D to rotate,
which, through the belt M rotates the double pulley T, which in turn through the
belt U causes the idler pulleys ", ¹, to rotate and also the pulley U rotating
therewith the wheel shaft e, whereby the grinding wheel d is caused to rotate upon
its own axes while it is being simultaneously revolved by the rotation of the live
spindle of the lathe in an orbit concentric with the latter's axes of rotation.
The operation of our invention is as follows:
Our grinding mechanism described having been secured, as aforesaid, in the
socket of the live spindle of the lathe and the belts and intermediate shafts adjusted
a lathe center is secured in the usual way within the dead or tail spindle socket to
be ground on its exposed end to the usual cone shape. The frame is then moved
and adjusted relatively to the plate a and so as to bring the grinding edge of the
wheel d into the required contact with the end of the lathe center N which is to
be ground, the latter being advanced and adjusted by moving the tail spindle S' in
the usual manner. The idler pulleys are also moved and adjusted and fastened so
as to tighten the belt.
Power being applied in the usual way to the cone pulley the grinding wheel dis
caused to rotate and revolve, as aforesaid, and is at the same time moved longitudinally
back and forth over the surface which is being ground by the sliding of the frame C,
caused to reciprocate on its guides n, o, as aforesaid. By the latter movement a
cone surface of any desired width may be ground irrespective of the width of the
grinding wheel and undue and uneven wear of the grinding surface of the wheel is
obviated.
The rotation of the grinding wheel on its own axes produces the grinding effect
required, and its revolution in an orbit around the axis of rotation of the live

page_text: spindle insures the grinding down of the lathe center into a cone whose apex and
axis are exactly coincident with said axis of rotation of the live spindle.
"
To grind or "true the lathe center which is to be used in the live spindle
socket, we secure the plug S in the socket of the dead or tail spindle, re-adjust the
belts after moving the pulley D to the required position upon the intermediate
shaft F and secure within the socket of the live or head spindle the center which
is to be ground.
The latter is, of course, caused to rotate by the rotation of the live spindle
and the grinding wheel being adjusted as aforesaid so as to make the required
contact is simultaneously rotated and moved backwards and forwards longitudinally
as described, thus effecting the grinding.
In this case, however, it will, of course, be understood that the grinding wheel d
does not revolve, this being rendered unnecessary by the rotation of the center
which is being ground.
Figure 4 of the drawings shows the application of our mechanism to an ordinary
lathe, the grinding mechanism being shown in position within the socket of the live
spindle, and brought down by adjustment so as to apply the edge of the grinding
wheel to the extremity of the center N.
By means of our said mechanism and method of grinding the centers, both
centers are automatically and necessarily ground so that their apexes will exactly
meet in the very center of the longitudinal axis of rotation of the live spindle of
the lathe, and this irrespective of any bend through defect in the dead center or
dead spindle socket, or inaccurate alignment of the lathe sockets or of the centers
themselves.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The combination of the live spindle of a lathe with a grinding wheel revolving
in an orbit concentric with the axes of rotation of said live spindle, substantially as
and for the purpose described.
2. The combination of the live spindle of a lathe with a rotating grinding wheel
revolving in an orbit concentric with the axes of rotation of said live spindle,
substantially as and for the purpose described.
3. The combination of the live spindle of a lathe with a rotating and simul-
taneously reciprocating grinding wheel revolving simultaneously in
an orbit
concentric with the axes of rotation of said live spindle, substantially as and for
the purpose described.
4. The combination with the live spindle of revolving and rotating grinding
wheel thereby revolved in orbit concentric with said spindle's axes of rotation,
substantially as and for the purpose described.
5. The combination of live lathe spindle, actuating pulley T, both having same axes
of rotation and rotating and revolving grinding wheel revolving in orbit concentric
with said axes, substantially as and for the purpose described.
6. The combination of live lathe spindle, actuating pulley T, both having same axes
of rotation and rotating, revolving, and reciprocating grinding wheel, revolving in
orbit concentric with said axes, substantially as and for the purpose described.
7. The combination of plug S, pulley T, frame b, shaft e, wheel d, pulleys v, vl,
pulley U, all connected together, substantially as and for the purpose described.
8. The combination of plug S, pulley T, frame b, shaft e, wheel d, pulleys v, v¹,
pulley U, arbor R, all connected together, substantially as and for the purpose
described.
9. The combination of plug S, pulley T, frame b, shaft e, wheel d, pulleys v, vl,
pulley U, arbor R, hearings l, l', worm k, worm wheel f, connecting rod g, sliding
frame C, spline m, feather 1, all connected together, substantially as and for the
purpose described.
10. The combination of plug S, pulley T, frame b, shaft e, wheel d, pulleys v, v²,

page_text: pulley U, arbor R, bearings 1, 1, worm k, worm wheel f, guide rods n, o, all connected
together, substantially as and for the purpose described.
11. The combination of plug S, pulley T, frame b, shaft worm k, worm wheelf,
connecting rod g, sliding frame C, and wheel d, pulleys v, v¹, and U, substantially
as and for the purpose described.
12. The combination of plug S, pulley T, frame b, base plate a, shaft e,
pulleys, v, U, and wheel d, substantially as and for the purpose described.
13. The combination of lathe cone pulley Y, countershaft E, pulleys D, D', live
spindle S¹, plug S, pulley T, frame b, shaft e, wheel d, all connected together,
substantially as and for the purpose described.
14. The combination of lathe cone pulley Y, countershaft E, pulleys D, D',
live spindle S¹, plug S, pulley T, frame b, shaft e, wheel d, worm k, worm wheelf,
connecting rod 9, sliding frame C, and guides n, o, all connected together,
substantially as and for the purpose described.
Dated this 11th dor of July 1800
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicants.