Improvements in Turning Lathes, Specially Adapted for Turning the Crank Pins of Crank Shafts.
Year: 1885

page_text: Improvements in Turning Lathes, Specially Adapted for Turning
the Crank Pins of Crank Shafts.
I, JOSEPH BARROW, of the firm of Thomas Shanks and Company of the Union
Iron Works, Johnstone in the County of Renfrew, North Britain, Engineer and
Tool Maker do hereby declare the nature of the said invention for IMPROVEMENTS
IN TURNING LATHES SPECIALLY ADAPTED FOR TURNING THE CRANK PINS OF
CRANK SHAFTS to be as follows:-
Hitherto the operation of turning the crank pins of crank shafts round and
axially parallel with the body of the shaft in the same lathe wherein the body of
the shaft has been turned, is attended with certain defects owing to the difficulty
of balancing the crank and partly due to the spring of the unsupported webs which
bitherto has frequently necessitated the employment of a special and independent
machine for the aforesaid purpose.
According to the present Invention the lathe preferably used is what is well
known as a duplex lathe, that is to say, a lathe having four tools, or in other words
two saddles each having a back and front rest. For the purpose of the present
Invention the saddle and duplex rests next the face-plate and the saddle and front
rest only are required, whilst single lathes fitted according to the present Invention
will require additions at the back of the front saddle.
The present Invention consists in the application of a large disc turned truly on
its periphery and with a hole large enough to pass through it, the coupling of the
crank to be operated upon. This disc is fitted in bearings formed upon the saddle
and back and front rests which are next the face-plate which have been bored out
by the headstock perfectly true to fit the disc. The said saddle, rests and bearings
are capable of being moved along the slide bed to any position without altering
the concentricity of the bearings so that the disc can revolve in them in coincidence
with the spindle.
The operation of using this Invention is as follows:-The coupling of the crank
is passed through the disc and then fastened to the face plate by any suitable means
at the required distance of centres or what is commonly called the throw of the
crank. The other end of the crank shaft is connected with the loose headstock by
clamp bolted to it carrying a moveable centre at a distance of centres or throw of
the crank corresponding to that attached to the fixed headstock: The exactitude

page_text: or truth of these adjustments is ascertained by well-known instruments in use for
such purpose. The flat part of the web is then bolted to the disc and is rotated by
the headstock carrying the disc with it, which disc being supported by adjustable
bearings upon the top rests and prevented from moving out of its true position
when the strain of the cut which operates upon the crank pin comes on, secures to
the work that round and axially parallel condition which is so necessary for the
correct working of cranks.
Although an ordinary overhanging tool may be used for cutting in between the
webs of the crank, and turn the crank pin, it is preferred to use a supplementary
rest fastened to the slide rest but very narrow so as to pass between the webs of
the crank and supported by abutting upon the rest or on the saddle. This supple-
mentary rest has a slide upon it with a block to which the turning tool is fastened,
the other end being fastened in the usual manner by clamps. The block and the tool
are moved upon the supplementary rest by the self-acting of the slide rest for
cutting in between the slides of the web and along the pin axially by the longi-
tudinal traverse of the lathe.

page_text: improvements in Turning Lathes, specially Adapted for Turning
the Crank Pins of Crank Shafts.
I, JOSEPH BARROW, of the firm of Thomas Shanks and Company of the Union
Iron Works, Johnstone in the County of Renfrew, North Britain, Engineer and
Tool Maker do hereby declare the nature of my said invention for IMPROVEMENTS
IN TURNING LATHES SPECIALLY ADAPTED FOR TURNING THE CRANK PINS OF CRANK
SHAFTS and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :--
Hitherto the operation of turning the crank pins of crank shafts round and
axially parallel with the body of the shaft in the same lathe wherein the body of
the shaft has been turned, is attended with certain defects owing to the difficulty
of balancing the crank and partly due to the spring of the unsupported webs which
hitherto bas frequently necessitated the employment of a special and independent
machine for the aforesaid purpose.
According to the present invention the lathe preferably used is what is well
known as a duplex lathe, with four tools, or in other words two saddles each having
a back and front rest. For the purpose of the present Invention, the saddle and
duplex rests next the face-plate and the saddle and front rest only are required,
whilst simple lathes that is to say lathes which are not duplex, fitted according
to the present Invention, will require additions at the back of the front saddle.
the
The present Invention consists in the application of a large disc turned truly on
its periphery and formed with a hole or recess large enough to pass through
coupling of the crank to be operated upon. This disc is fitted in bearings formed
upon the saddle, and back and front rests which are next the face-plate which
bearings are bored out by the headstock perfectly true to fit the disc. The said
saddle, rests and bearings are capable of being moved along the slide bed to any
position without altering the concentricity of the bearings so that the disc can
revolve in them in coincidence with the spindle.
The operation of using this Invention is as follows:-The coupling of the crank
is passed through the disc and then fastened to the face plate by any suitable means
at the required distance of centres or what is commonly called the throw of the
crank. The other end of the crank shaft is connected with the loose headstock by
a clamp bolted to it carrying a moveable centre at a distance of centres or throw of
the crank corresponding to that attached to the fixed headstock. The exactitude
or truth of these adjustments is ascertained by well-known instruments in use for
such purpose. The fat part of the web is then bolted to the disc and is rotated
by the headstock carrying the disc with it, which disc, being supported by adjust-
able bearings upon the top rests and prevented from moving out of its true position
when the strain of the cut which operates upon the crank pin comes on, secures to
the work that round and axially parallel condition which is so necessary for the
correct working of cranks.
Although an ordinary overhanging tool may be used for cutting in between the
webs of the crank, and turning the crank pin, it is preferred to use a supplementary
rest fastened to the slide rest but very narrow so as to pass between the webs of
the crank and supported by abutting upon the rest or on the saddle. This supple-
mentary rest has a slide upon it with a block to which the turning tool is fastened,

page_text: the other end being fastened in the usual manner by clamps. The block and the
tool are moved upon the supplementary rest by the self-acting of the slide rest for
cutting in between the sides of the web and along the pin axially by the longi-
tudinal traverse of the lathe.
In order that my said Invention may be properly understood and readily carried
into effect, I will now proceed to describe the drawings hereunto annexed.
Figure 1, is a plan of part of a duplex lathe constructed according to my present
Invention.
Figure 2, is a front elevation of the same.
Figure is a transverse section of the same shewing the means of securing the
crank-shaft to the disc as hereinafter more particularly described.
Figure 4, is a transverse section of the same shewing in side elevation, the sup-
plementary slide rest employed to support the tool and all constructed according to
my present Invention.
My present Invention consists in the application to a duplex or other lathe of
the large disc A which is turned truly on its periphery and so constructed as to
admit of the coupling a, of the crank shaft being passed through it and to be
secured to the face-plate B. This may be provided for by a large hole formed
through the disc A, but I prefer for this purpose that a recess be made in the edge
of the said disc, that is to say in the manner indicated at Figures 3 and 4 of the
annexed drawings. After the crank shaft C, has been placed in position within
this recess the curved bar b, (Figure 3) is secured by the bolts c, or their equivalents
and thereby maintains true and unbroken the continuity of the periphery of the
disc A. The said disc A is supported in and upon bearings formed by the
saddles D and E, and by the projections c¹, cast in one with their respective
front and back rests F, and G, previously bored out by the fixed head stock
so as to be concentric with the spindle and to the diameter of the disc A.
The blocks c², are bolted to the top rest by screws and nuts and are provided
with the brackets d, which carry the rollers e, at their end. It will be seen
that these blocks c³, can be set up against the disc A so as to form a steady
bearing within which the disc A, revolves and at its lower part the disc A, is held
down upon the saddles D and E, by the curved bracket plate f, (Figures 1 and 2).
The rollers e, bear upon and rotate in contact with the inner surface of the annular
projection g, of the disc A, as shewn more particularly at Figure 1 of the annexed
drawings. By this arrangement, the disc A, with its bearings is capable of being
moved along the slide or lathe bed I, to any required position without altering the
concentricity of the said bearings so that the disc A, can at all times revolve in
them in coincidence with the lathe spindle h.
After the crank shaft C, has, in the manner herein before explained, been passed
through the disc A, the coupling a, thereof is secured to the face-plate B, at the
required distance of centres, or what is commonly called the throw of the crank.
The coupling a, of the crank shaft may be secured to the face plate B, in any of
the well-known ways, but I prefer to effect this by means of the chuck i, which is
secured to the said face plate and the jaws j, of which are screwed tightly against
the periphery of the coupling a, in the ordinary manner.-The second coupling k, of
the crank shaft is secured by the bolts and nuts l, and m, or their equivalents, to the
clamp or arm n, and the said coupling k, is prevented from moving longitudinally
thereon by means of the projection o, and the bracket p, (Figure 1) the latter of
which is so arranged as to support the bolt m, against the weight of the crank
shaft, that is to say at that time when the clamp or arm n, is in a vertical or
nearly vertical position. The exactitude or truth of the adjustment of the crank
shaft C, within the lathe, is or may be ascertained by well-known instruments in
use for such purposes, such an instrument for example as that indicated in dotted
lines at Figure 2.-This instrument carries the centre q, and, which, when the base
thereof is standing on the lathe bed, and before the crank shaft has been placed in
position, is adjusted to the height of the centre 7, (Figures 2 and 4). This centre r,
is secured in the chuck i, and the before mentioned adjustment is preferably made

page_text: when such centre is in its lowermost position.-The crank shaft C, having been
placed in position in the disc A its opposite end is raised or lowered until such
time as, by the application of the before described centre block, it is ascertained
that the countersunk centre s, (Figure 2) is in line with the centre r, at which time
the coupling, of the said crank shaft is secured to the clamp or arm n, at a
distance between its centres corresponding to the distance between the centres of
the fixed headstock. The longitudinal rigidity between the fixed and the moveable
centres of the lathe is secured by the bars t, the length of which is adjustable by their
being formed in two parts which are capable of being screwed one within the other
to a greater or less extent.-One of these bars t, is secured to the clamp or arm n,
and the other to the disc A. The crank shaft C, is secured to the disc A, by means
of the jaws u, which, as represented more particularly at Figure 3, of the annexed
drawings, are capable of being screwed by the screws v, against the edges or
surfaces of the web w, and thereby cause the said crank-shaft C, and disc A to
rotate as one.
Although an ordinary overhanging tool may be used for cutting in between the
webs w, and x, of the crank shaft and turning the crank pin y, thereof I prefer to
use a supplementary rest such as that represented at a¹, upon the annexed
drawings. This rest a¹, as shewn more particularly at Figure 1, is of very narrow
width 80 as to enable it to pass between the webs of the crank, and the said rest a¹,
is supported upon and secured by the screwed bolts h¹, or their equivalents to the
front slide rest J.-This supplementary rest a', has the slide b¹, formed upon it,
along which the block d', is free to be moved longitudinally. To this block d', as
indicated more particularly at Figure 4 of the annexed drawings, the turning
tool e¹, is secured by the screws f¹, and the other end of the tool e', is fastened in
the usual manner to the ordinary tool rest K, that is to say by means of the
clamps g-The block d¹, and the tool e¹, for cutting in between the sides of the
webs w, and x, are moved inwards or outwards upon the supplementary rest a³, by
the tool rest K, being operated by hand in the ordinary well-known manner; or
the said block d', and tool e¹, may be so operated transversely by the ordinary
self-acting transverse motion as imparted to the slide rest J, while for cutting in
between the sides of the webs and along the pin axially, the rests J, and K, and
the tool e, along with the saddle upon which they are carried are operated by the
self-acting longitudinal traverse of the lathe in the ordinary well-known manner.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what
I claim is
First. The improvements in turning lathes specially adapted for turning the
crank pins of crank shafts consisting of the disc A, the curved bar b, thereof,
projections c¹, blocks c², brackets d, rollers e, bracket plate f, clamp or arm n,
bracket P, bars t, jaws u, and the screws v, and their attachments all substantially
as and operating in the manner herein before set forth with reference to the
annexed drawings or the mechanical equivalents of all or any of such parts.
Second. The improvements in turning lathes specially adapted for turning the
crank pins of crank shafts consisting of a supplementary slide rest a¹, with its
block d¹, all operating substantially as hereinbefore described with reference to the
annexed drawings in combination with the apparatus claimed in the preceding
claiming clause.
IL: 1 1
T
J. H. JOHNSON, DAY & JOHNSON,
Applicant's Agents.