Improvements in Lathes.
Year: 1891

page_text: [Communicated from abroad by OSCAR LE GRAND NOBLE, Boston, Massachusetts,
United States of America, Gentleman.]
Improvements in Lathes.
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 to certain improvements in that class of machines known
as lathes, cut off machines, or screw machines, wherein the well known cross feed
or tool carriage for advancing or withdrawing the tool in a plane at right angles
to the central line of the lathe is used, and wherein the material to be cut is held
by any of the well known devices and revolved against the tool. Heretofore the
speed of the revolving material has been changed as desired, by the use of cone
or step pulleys, the workman shifting the belt thereon to effect such change.
The object of the invention is to secure 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 as in the case of certain work held
by a chuck or face plate), thereby insuring the largest product possible without
depending upon the will of the workman; which result is obtained by a com-
bination of devices attached to the cross feed screw or tool carriage, and so
connecting the latter by suitable mechanism to the spindle or head stock of
the machine that the desired result is obtained, as will more fully appear in the
following description of a cut-off lathe and a common lathe, embodying the
invention.
Of the accompanying drawings forming a part of this Specification,
Figure 1 is a side elevation of a cut-off lathe, Fig. 2 a plan view, Fig. 3 an end
view, and Fig. 4 a section on line a b of Fig. 3 of the same;
Fig. 5 is a side view, Fig. 6 an end view of a lathe, and Fig. 7 a plan of the
same;
Figures 8 and 9 are front and end views respectively of the carriage C with
portions cut away so as to show the working parts.
Fig. 10 is a plan view of the cam 13 and arm working therewith.
Fig. 11 is an arrangement of belts and pulleys, instead of gears and pinions, to
effect the reverse rotary motion of the disks.
The same letters of reference indicate the same parts in all of the figures.
Referring to the lathe shown in Figures 5 to 10 inclusive, which has the usual
parts of a common lathe, riz.: a carriage, a cross feed tool carriage, a head stock
and spindle, alf old and well known but mentioned for reference, A is the bed or
frame; c, the carriage; d, the cross feed tool carriage, carrying the usual tool
post and tool as shown; 1 is the cross feed screw, threaded into the cross feed
carriage, having its bearing in carriage c and carrying pinion 2 which engages
gear 3 on shaft 4, which has a worm 5 (Figures 6 and 9) cut on its outer end,
which engages worm gear 6 fastened to shaft 7 running in bearings 8 and 81
attached to carriage e and having mounted on it gear 9 engaging intermediate
gear 10 held on a stud 10 in the end of carriage c, which in its turn engages
gear 11 which has a key and is mounted on cam-rod 12 held in bearings 14 and 14¹
on the lathe frame A, said cam-rod having a slot its whole length in which the
key of gear 11 is free to move, thus allowing the workman to move the carriage
to any position without rotating the said cam-rod; 13 is a cam or cam-rod 12, the
groove of which engages a stud roll 15ª on arm 15 attached to vertical shaft 16
carried in bearings 16 and 16". This shaft has an oscillating motion imparted to
.
11

page_text: it by the cam 13 in which a roll 15 on arm 15 runs. To the upper end of
shaft 16 is attached arm 17, connected by link 18 to shipper rod and fork 19.
The fork on the end of shipper rod 19 spans the friction wheel shaft 20 (Fig. 7)
and is fitted into a circumferential groove cut into the shaft to receive it. This
shaft is carried in a sleeve 21 and drives said sleeve by a feather 22 (Fig. 6) fitted
loosely in the sleeve and fast to the shaft 20, allowing said shaft to move endwise
and carry the friction wheel 23 to and from the centre of the friction disks 28
and 28'. On this sleeve is cut or fastened a pinion 24, which engages gear 25
that is fastened to the head stock spindle 26 to which the work is attached.
The foregoing is all driven by pulley 27 (Fig. 6) attached to driving disk 28
having mitre gear 30 attached and running loosely on shaft 29. Said mitre gear
engages intermediate gear 31 which, in turn, drives mitre gear 32 attached to
shaft 29 by key 33 (Fig. 4). Said shaft is carried in bearings 29 and 2911 and
drives disk 28' attached thereto, this arrangement of gears causing the said driving
disks to revolve in opposite directions when power is applied to pulley 27. The
disks 28 and 28 are held in contact with driving wheel 23 by the compression
of coil spring 34 between collar 35 and the hub of gear 30, best shown in Fig. 4.
For light work one disk, as 28', might be dispensed with, thus dispensing also
with the bevel gears 30, 31 and 32, but the arrangement shown is preferred as it
brings no lateral pressure on the bearings of shaft 20, as would be the case with
the use of a single disk only.
In some kinds of lathes in which a longitudinal movement of the carriage is not
required, notably for cutting off stock only, and which are frequently provided
with two tool carriages d d operated by one and the same right and left hand
screw so as to be drawn toward and from each other and the centre of the work
by the same movement of the screw, a slide rack 36 (Figures 2 and 4) is attached
to one of said cross feed carriages (in this case the rear one. Said slide rack
engaging pinion 37 on lower end of sleeve 38, to the top of which is attached
arm 17, said sleeve being held in place on stud 39 which is attached to the body
of the machine (shown by dotted line, Fig. 1) and upon which the sleeve 38 is free
to oscillate. It will be obvious that the office of sleeve 38 shown in Figures 1
2, 3 and 4, and vertical shaft 16, Figures 5 and 6, is the same, either being used as
may be found most convenient in adapting the invention to different kinds of lathes.
Fig. 7 shows an arrangement of pulleys and belt whereby the reverse rotation
of the disks is obtained, instead of by gears heretofore described, wherein a belt is
passed over the pulley 41 on the counter shaft, then down around pulley 27 to
which disk 28 is attached, thence back over idler 42 on said counter shaft and
down again in a loop around pulley 40 made fast to shaft 29. This arrangement
has the advantage of bringing the counter shaft parallel with the lathe spindle.
It is obvious that to secure to the lathe spindle a uniform increase of speed as
the tool approaches the centre line of the lathe, the friction wheel 23 must be
moved towards the circumference of the disks 28 and 28¹ at an increasing rate as
compared with the motion of the tool toward the centre; for instance, suppose
the friction wheel 23 were set three inches from the centre of the disks to work
material eight inches in diameter; when the material had been reduced to four
inches the speed should be doubled, to obtain which the friction wheel must be at
a point six inches from the centre of the disks, but a further reduction from four
to two inches should double the speed again, which would require a movement of
the friction wheel to a point twelve inches from the centre of the disks, or a
motion of six inches for one half the movement of the tool carriage, which in the
first case required only a change of three inches in the friction wheel. This is
provided for by the pitch of the cam groove in the cam 13 which is spiral with a
gaining twist. In the arrangement shown in Figures 1, 2, 3 and 4 when the rack
and pinion are used instead of the cam groove and stud, an eccentric gear or other
obvious means might be used to accomplish this result, but I prefer the arrange-
ment shown in Figures 5 to 10 for this part of the mechanism.
In operating the device the driving wheel 23 is placed as near the centre of the

page_text: driving disks 28 and 28' as will give the proper rotary speed to the material being
cut at its largest diameter, and as the tool advances toward the centre thereof the
connecting devices draw the friction driving wheel proportionately towards the
outer edge of the driving disk, thereby increasing the rotary speed of the mandrel
and hence of the material being acted upon, and maintaining substantially the same
cutting speed of the material against the tool from the largest to the smallest
diameter of the piece being cut.
The invention is not limited to the use of the discs and friction wheel as a means
of producing a variable motion to the mandrel, as it is obvious that various
equivalent devices might be used, and also other means of connecting the cross feed
of the tool post with the devices used for varying the speed of the mandrel might
be used without going beyond the invention, as it is believed that this is the first
attempt made to automatically connect the cross feed of a tool carriage with a
speed varying apparatus attached to the mandrel of a lathe, so that the speed of
the mandrel shall increase as the tool moves inward toward the centre line of the
lathe, thus maintaining an approximately regular speed of the material being
worked against the tool.
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 :-
1. In a lathe, a rotary mandrel, variable speed driving mechanism substantially
as shown, a tool carriage movable toward and from the axial line of said mandrel, a
cam mounted on a shaft rotated by the movement of said tool carriage, mechanism
connecting said cam to said driving mechanism whereby the speed of said mandrel
is increased as the tool carriage is moved toward the axial line of said mandrel,
arranged and to operate substantially as herein set forth
2. In a lathe, a rotary mandrel, variable speed driving mechanism substantially
as shown, a tool carriage operated by a cross feed screw, a cam shaft geared to said
cross feed screw and carrying a cam that by connecting mechanism substantially as
shown affects the said driving mechanism to increase the speed of said mandrel as
the tool carriage is moved toward the axial line of said mandrel, arranged and to
operate substantially as set forth..
3. The combination of the mandrel 26, driving disks 28 and 28' and friction
wheel 23 with the tool carriage d and means whereby said wheel is moved towards
the circumference of said disks as the said tool carriage is moved inwards towards
the axial line of the mandrel, substantially as set forth.
4. In a lathe, a mandrel, a friction driving wheel, as 23, geared thereto, disks
as 28 and 28' adapted to drive said wheel at a varying speed according to its
distance from the centre of said disks, a tool carriage movable in a plane at right
angles to the axial line of said mandrel, and mechanism connecting said tool
carriage and friction wheel, adapted to move said wheel 23 toward or from the
circumference of said disks as the tool carriage is moved toward or from the axial
line of said mandrel, arranged and to operate substantially as specified.
5. In a lathe, the shaft 12, means for connecting it to the cross feed screw 1 of
the tool carriage d so as to be rotated thereby, the cam 13 on said shaft, upright
shaft 16 carrying arm 15 provided with a stud and roll 15 operated by said cam 13,
arm 17 connecting rod 18, shipper rod and fork 19, shaft 20 carrying friction
wheel 23 and geared to the mandrel 26, and the driving disks 28 and 28' adapted
to be revolved in opposite directions, arranged and to operate substantially as
described.
6. In a lathe, the combination with a cross feed screw; of a horizontal shaft
connected thereto with intermediate gearing, a cam upon said shaft, an upright
shaft carrying two horizontally projecting arms, the lower arm carrying a stud
operated by said cam to partially rotate the said upright shaft, a horizontal shaft
carrying a friction wheel, said last mentioned shaft being movable longitudinally in
its bearings by a shipper rod and fork operated by a link connected to the upper

page_text: arm on said upright shaft and connected by gearing to the mandrel of the lathe,
and friction disks adapted to drive said friction wheel, substantially as herein
specified.
7. In an apparatus for giving a variable motion to a lathe mandrel, the com-
bination with a shaft and a friction disk fastened thereto, of another disk loose upon
said shaft but fast to a driving pulley upon the same shaft, a bevel gear also loose
upon said shaft and fast to said pulley, another gear fast upon said shaft and
connected to said first mentioned gear by an intermediate gear whereby power
applied to said pulley causes said friction disks to revolve in opposite directions,
substantially as herein set forth.
8. In a lathe, the cross feed screw 1, gear 2 thereon, gear 3 and worm 5 on
shaft 4, worm gear 6, shaft 7, gears 9 and 11 connected by intermediate gear 10,
shaft 12, cam 13 thereon, upright shaft 16, arm 15 carrying stud and roll 15ª
engaging with cam 13, arm 17 connecting link 18, forked shipping rod 19, shaft 20,
sleeve 21, friction wheel 23, disks 28 and 28' on shaft 29 with mechanism adapted
to rotate said disks in opposite directions, gears 24 and 25 and mandrel 26, all
arranged and to operate substantially as set forth.
9. In an apparatus for rotating a lathe mandrel at a varying speed, the com-
bination with such mandrel, of a rotatable sleeve connected thereto by gears so as
to revolve therewith, a shaft movable longitudinally within said sleeve but 60
connected thereto as to rotate with it, a friction wheel mounted on said shaft,
friction disks adapted to be revolved so as to rotate said friction wheel by contact
with its periphery, and means for moving said friction wheel toward or from the
centre or centres of said friction disks and thereby cause its speed of rotation to be
diminished or increased accordingly, substantially as herein set forth.
10. In an apparatus for connecting the cross feed of a lathe with a speed varying
apparatus attached to its mandrel, a shaft at right angles to the axial line of said
mandrel, but not in the same plane therewith, two arms projecting from said shaft
and fastened thereto, a cam adapted to be rotated by the rotation of the cross feed
screw, said cam being arranged to operate a stud connected to one arm on said
shaft so as to partially rotate it, the other arm of said shaft being connected with
a friction wheel so as to move it along its axial line as said shaft is partially rotated
and thus vary its speed, substantially as and for the purpose herein set forth.
Dated this 23rd day of October 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.