Improvements in Lathes and similar Tools.
Year: 1893

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by OSCAR LE GRAND NOBLE, of 114, Lincoln Street,
Boston, Massachusetts, United States of America, Gentleman.]
Improvements in Lathes and similar Tools.
I, HENRY HARRIS LAKE of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings in the County of Middlesex, 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 particularly to the class of machines known as lathes, cut-
off machines, and screw machines, employing a cross-feed or tool-carriage, which
moves the cutting tool in a plane at right angles to the central line of the lathe, and
particularly to the type of lathe shown in United States Letters Patent granted
October 13, 1891, No. 461,401, said Patent showing an improved organization
securing approximately uniform rotary speed of the material against the cutting
tool as it passes through the material from its largest to its smallest diameter or
vice versa.
The present invention has for its object to provide certain improvements whereby
the result aimed to be secured by the invention set forth in said Patent is secured
in a more satisfactory manner and with less complication of mechanism. To these
ends the invention consists in the improvements which I will now proceed to describe
and claim.
Of the accompanying drawings, forming part of this Specification :
Figure 1 represents a side elevation of a lathe embodying my improvements, the
tail-stock and other parts of the lathe not essential in illustrating my invention,
being omitted.
Figure 2 represents a section on line 2 2, Figure 1, looking toward the left.
Figure 3 represents a side view and partial section of the mechanism shown in
Figures 1 and 2.
The same letters of reference indicate the same parts in all the figures.
In the drawings:
a represents the bed or frame of a lathe: 6 represents the head-stock spindle,
mounted to rotate in bearings on said bed, as usual: and c represents a carriage,
which is movable on the bed and supports the cross-feed slide d, the latter being
operated by the cross-feed screw d¹ and carrying the tool-post d².
The parts above mentioned are constructed and relatively arranged as usual in
machines of this class, and their operation is well-known, hence I do not here
describe it in detail.
ee represent shafts, which are journalled in bearings on the bed a, and are
arranged in line with each other and substantially at right angles with the axial
line of the spindle b. Said shafts are rotated by means of a driving-belt or bolts f,
running on pulleys g g', mounted respectively on the shafts e and e', said pulleys
being rotatively engaged with the shafts in such manner as that the shafts are
adapted to move lengthwise while being rotated by the pulleys, the connection
between the pulleys and shafts being effected in any suitable way, as by splines or
feathers on the pulleys, engaging grooves h h in the shafts. To the inner ends of
the shafts ee are affixed friction wheels i ", which are located between and are in
frictional contact with two friction disks, which are mounted upon a shaft k,
journalled in fixed bearings on the bed and arranged substantially parallel with the
spindle b. The disk ; is mounted loosely upon the shaft k, while the disk jis
affixed rigidly to said shaft.
The driving belt is arranged to rotate the pulley 9 and its shaft e and
friction wheel i in one direction, and the pulley g', the shaft e¹ and friction

page_text: wheel in the opposite direction, as indicated by the arrows in Figure 2; said belt,
if only one belt is employed, being disposed over a suitable system of pulleys
arranged to produce the described result. The friction wheels i i¹ are located at
opposite sides of the shaft k, and equidistant therefrom, as shown in Figure 2, hence
their rotation in opposite directions causes the simultaneous rotation of the disks jj¹
in opposite directions.. The disk j is mounted loosely upon the shaft k, and is rigidly
affixed to a bevel gear m, said gear and the disk.j rotating together in the same
direction. The disk is rigidly affixed to the shaft k, and rotates with said shaft
in the opposite direction. m² represents a bevel gear, which is affixed to the shaft k,
and is rotated thereby. n represents a vertical shaft, journalled in a fixed bearing
on the bed a and provided at its lower end with a bevel gear n¹, meshing with the
gears m m³, and at its upper end with a bevel gear n³ meshing with a bevel gear o
affixed to the head-stock spindle b. It will be seen, therefore, that the spindle 6 is
rotated by power imparted from the belt f through the shafts e e¹, friction wheels ii,
friction disks jj', gear m, shaft k, gear m', shaft n and gears n' n².
.
As already stated, the shafts e el are movable longitudinally, their arrangement
being such that each shaft, when so moved, approaches or recedes from the shaft k.
It will be seen, therefore, that the rate of motion imparted to the spindle 6 may be
varied by moving the shafts e e' simultaneously in opposite directions, the speed of
the spindle being decreased by moving the shafts e el outwardly or away from
the shaft k; and increased by moving said shafts e e¹ inwardly or toward the
shaft k.
The position of the shafts e el and friction wheels relatively to the shaft k is
determined by the position of the feed-screw d', said screw being connected with
the shafts ee through suitable intermediate mechanism adapted to move the shafts e e¹
inwardly toward the shaft k when the feed-screw d¹ is rotated to carry the cutting
tool toward the axial line of the spindle b, so that the speed of the spindle is auto-
matically increased as the tool approaches the centre of the work. The said cutting
mechanism, as here shown, is follows-
p represents a bevel gear, affixed to the feed-screw d¹. p¹ represents a vertical
shaft, journalled in a bearing on the carriage c, said shaft having at its upper end a
bevel gear, meshing with the bevel gear p, and at its lower end a worm p meshing
with the worm gear p, the hub p of which is rotatively engaged with and adapted
to move lengthwise upon a shaft p, which is journalled in fixed bearings on the bed a,
said hub and shaft being engaged by any suitable means such as by a spline or
feather on one of said parts and a groove in the other part receiving said spline.
represents an arm, rigidly affixed to the shaft p*. The upper end of said arm is
forked and engaged with two shoulders or collars 6 6 on the shaft e. p represents
a gear, affixed to the shaft and meshing with a gear p' affixed to a shaft plo which
is arranged parallel with the shaft p and is also journalled in bearings affixed to
the bed a. The shaft po has an arm p", the forked upper end of which is engaged
with two collars or shoulders 77 on the shaft e¹.
It will be seen from the foregoing that the rotation of the feed-screw d', which
adjusts the tool-carriage d and moves the tool toward and from the centre of the
work rotated by the spindle b, is accomplished by corresponding movements of the
friction wheels i toward and from the shaft k, the arrangement being such that
when the feed-screw is rotated in the direction required to move the tool toward
the axis of rotation of the work, the friction wheels i and i will be moved simul-
taneously toward the axis of the shaft k; when the feed-screw is rotated to move
the tool away from the axis of the work, the friction wheels are moved
simultaneously away from the axis of the shaft k.
From the foregoing, it will be seen that the distance between the cutting tool
and the axis of rotation of the work always corresponds to the distance between
the friction wheels and the axis of the shaft k rotated by said wheels. Hence,
when the tool is working at or near the periphery of a comparatively large piece
of work, the friction wheels i are considerably removed from the shaft k; and, as
the tool approaches the centre of the work, said friction wheels approach the

page_text: shaft at a corresponding rate. I thus directly proportion the speed and power
imparted to the spindle b to the distance of the cutting tool from the axis of
rotation of the work, the speed and power being greatest when the tool is at the
minimum distance from the axis of the work, and decreasing at a definite rate as
the tool recedes from said axis.
In the construction shown in the Patent above mentioned, the friction disks are
mounted on a shaft arranged at right angles with the spindle, and the friction
wheel which rotates in contact with the surfaces of said disks is arranged so that
when the cutting tool is at the maximum distance from the axis of the work said
friction wheel is at the minimum distance from the axis of rotation of said disks.
Hence, although the speed of the spindle is varied and has the same relation to the
portion of the tool as in the present case, the power is less when the tool is cutting
on a large diameter, the power increasing as the tool approaches the axis of the
work, this being a disadvantage which my present improvement entirely overcomes.
In said former Patent, the power is first imparted to the friction disks and from
said disks to the friction wheels, while in the present case the reverse is true, the
power being imparted to the friction wheels and from thence to the friction disks.
By this change, I am enabled to greatly simply the construction of the machine, as
will be readily seen.
The loose friction disk jis shown in Figure 3 as movable lengthwise upon the
shaft k, and pressed by a springs in the direction indicated by the arrow in
Figure 3, so that a suitable frictional connection is at all times maintained between
the disks and the friction wheels . The worm gear p* on the shaft p³ is
caused to move with the carriage c by means of arms or projections t t on the
In case my
carriage, bearing on opposite ends of the hub p' of said worm gear.
invention is applied to a cutting-off machine in which there is no necessity for a
carriage movable independently on the lathe-bed, the worm gear p¹ will not
necessarily be movable lengthwise upon the shaft p³.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent I declare that what I claim is :-
In a lathe, the combination with the head-stock spindle 6 having gear o and
cross-feed screw d¹ having bevel gear p, of the longitudinally movable shafts e e¹ in
line with each other and at a right angle to spindle b and carrying friction
wheels i, means for rotating said shafts in opposite directions, the friction disks jj¹
in contact with said wheels i i¹ and geared together and to the bevel gear o sub-
stantially as shown, the shafts pe po geared together and having arms engaging
the shafts ee, the worm gear p splined to the shaft po, and the vertical shaft p¹
journalled in bearings on the lathe carriage and having bevel gear p' meshing with
the gear p and the worm p' meshing with the gear p*, as set forth.
Dated this 24th day of January 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.