IMPROVEMENTS IN LATHES
Year: 1879

page_text: LETTERS PATENT to Robert James Worth, of Stockton-on-Tees, in the County
of Durham, for the Invention of "IMPROVEMENTS IN LATHES."
1 1879
PROVISIONAL SPECIFICATION left by the said Robert James Worth at the
Office of the Commissioners of Patents on the 13th March 1879.
ROBERT JAMES WORTH, of Stockton-on-Tees, in the County of Durham. " IM-
PROVEMENTS IN LATHES."
My Invention has for object improvements in lathes. The fast headstock is
similar to an ordinary one, but with the bearings that usually carry the back gear
arranged at the front side. In these bearings revolves a spindle or shaft, which
for distinction I wall call A; it carries the belt cones, a spur wheel fastened to the
spindle or shaft which can be connected to the cones at pleasure, and a pinion
which for distinction I will call B, either cast with or fastened to the spur wheel,
or fastened to the spindle or shaft. The spindle or shaft A is continued through
the back bearing to drive the self acting and screwcutting gears. The main or
chuck spindle carries a sleeve with spur wheel at one end and pinion on the other,
similar to that which is used for the back gear of an ordinary lathe, and which can be
put in or out of gear with the cone pinion and spur wheel on spindle or shaft A. There
is also a spur wheel, I will call C, of a size to revolve clear of pinion B, keyed or
otherwise fastened to the main spindle. In order that pinion B shall drive the
wheel C, and with it the main spindle, a wheel I will call E is employed, of any
convenient size, placed in such a position that it can gear with both B and C;
very quick and convenient means are to be provided for throwing this wheel into
or out of gear.
In screw cutting lathes it will be convenient that the number of teeth in the
pinion on the back end of spindle or shaft A, which drives both the selfacting and
screw cutting gear, should when multiplied by the ratio of C to B, form a number
divisible by the number of threads in any multiple threaded screws the lathe may
have to cut.
This pinion drives through a reversing motion a spur wheel I will call D.
On the side of D, nearest to the lathe head, is cast or otherwise fastened a
pinion which drives through a train of wheels, the back shaft for selfacting or

page_text: the screw in case the selfacting gear is worked off the screw; one pinion or wheel
in this train may be made changeable so as to vary the rate of self-action. On the
other side of wheel D is a boss to which any of the change wheels may be attached
which are used to drive the screw through carrier wheels on a quadrant in the
ordinary manner. This wheel D with its attachments is made to slide along the
stud on which it revolves, so that either the pinion on the side next the lathe
drives the selfacting train and the change wheels for screw cutting are out of gear,
or the pinion for selfacting is out of gear and the change wheels in gear; the teeth
of the wheels in the reversing motion being made sufficiently broad to allow of D
always remaining in gear with them in either case.
These improvements are applicable to self-acting and screw cutting lathes, or to
lathes not screw cutting, by omitting those which have reference to the screw
cutting gear, and the improvements in gearing for fast headstock may be used with
or without the improvements in the self-acting and screw cutting gear; or the self-
acting and screw cutting gear may be modified to suit ordinary headstocks, in
which case this pinion is placed on the end of the main spindle in the usual manner,
and the number of teeth in this pinion should be divisible by the number of threads
in any multiple threaded screws the lathe may have to cut.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert James Worth in the Great Seal Patent Office on the 12th
September 1879.
BOBERT JAMES WORTH, of Stockton-on-Tees, in the County of Durham. "IM-
PROVEMENTS IN LATHES."
My Invention has for object improvements in lathes, and is illustrated in the
accompanying Sheet of Drawings, wherein,
Fig. 1 shews in front elevation part of a lathe embodying my improvements.
Fig. 2 is a plan.
Figs. 3 and 4 are views at right angles to Fig. 1.
According to this Invention I use a fast headstock H, similar to an ordinary one
but with the bearings (similar to those used to carry the back gear in an ordinary
headstock) arranged at the front side. In these bearings F revolves the first motion
spindle or shaft A, which carries the belt cones G with the usual pinion attached,
a spur wheel J fastened to the spindle or shaft A, which can be connected to the
cones at pleasure, and a pinion B either cast with or fastened to the spur wheel J
or fastened to the first motion spindle or shaft A. The spindle or 'shaft A is
continued through the back bearing to drive the self-acting and screw-cutting
gears. The main or chuck spindle S carries a sleeve with a spur wheel K at one
end and a pinion L at the other, which pinion and spur wheel can be put into or
out of gear with the cone pinion and spur wheel J on the spindle or shaft A, sub-
stantially as shewn in the Drawing. There is also a spur wheel C of a size to
revolve clear of the pinion B, keyed or otherwise fastened to the main spindle S.
In order that pinion B shall drive the wheel C, and with it the main spindle, I
employ an idle wheel E, of any convenient size, placed in such a position that it
can gear with both B and C. This wheel E may be made to run loose upon a stud,
along which it can also be traversed by a convenient handle, as shewn in the
Drawing, so as to put B into or out of connection with C at pleasure. Instead of
sliding the wheel E along a stud it may be mounted on an eccentric, which is
capable of being turned through a portion of a revolution, and by this means
connect or disconnect B and C as required. When, as in large lathes, greater power
is required than will be given by this arrangement, the wheel E while serving to
connect B and C, as before described, may also be used as the spur wheel of the
ordinary triple gear, being keyed on to a shaft revolving in suitable bearings,
which shaft carries on the end nearest to the chuck a pinion which gears, when
required, with an external wheel cast with or otherwise fastened to the back of the
chuck. On the back end of A is the pinion M, which drives both the self-acting
and screw-cutting gears (see Fig. 3). I prefer to make the number of teeth in this
pinion multiplied by the ratio of C to B form a number divisible by the number
of threads in any multiple threaded screws the lathe may usually have to cut.
This pinion drives through a reversing motion a spur wheel D. On the side of D,
nearest to the lathe head, is cast or otherwise fastened a pinion N, which drives
through a train of wheels the back shaft for self-acting, or drives the screw, as shewn
in the Drawing, in case the self-acting gear be worked off the screw; one pinion
or wheel in this train may be made changeable so as to vary the rate of self-action.
On the other side of the wheel D is a boss O, to which any of the change wheels
may be attached, which are used to drive the screw for screw-cutting in the ordinary
manner. This wheel D with its attachments is made to slide along the stud on
which it revolves, so that either the pinion N is in gear with and drives the self-
acting wheels, or pinion N is out of gear and the screw-cutting wheels are in gear,
the teeth of the wheels in the reversing motion being made sufficiently broad to
allow of D remaining in gear with them in either case, as shewn in the Drawing.
Instead of sliding D along its stud the same end may be attained by mounting

page_text: each train of wheels on a separate quadrant, and the wheels on either quadrant
may be put into or out of gear in the manner now usual in ordinary screw-cutting
lathes. When this latter arrangement is employed it will not be needful to make
the teeth of the wheels in the reversing motion any broader than those in M and D.
If a backshaft be used the pinion N may be dispensed with and the selfact train
of wheels worked from the teeth of D itself, or in place of the train of wheels either
the wheel D or the pinion N may drive a spur wheel attached to belt cones which
drive the back shaft in the ordinary manner.
These improvements are applicable to self-acting and screw-cutting lathes, or to
lathes not screw-cutting, by omitting those which have reference to the screw-
cutting gear.
Having described the nature of my said Invention, and explained in what manner
the same is to be or may be performed or carried into practical effect, I would have
it understood that what I consider to be novel and original, and therefore claim as
the Invention secured to me under the Letters Patent hereinbefore in part recited
is,-
1. The use or employment in the fast headstock of a lathe of additional gear for
driving the main spindle from the first motion shaft, such additional gear con-
sisting of a pinion and wheel connected by an idle wheel, substantially as
described.
2. The method, substantially as herein before described, of driving the self-acting
and screw-cutting gears from the first motion shaft instead of from the main.
spindle.
3. The combination of parts constituting the improved. lathe headstock,
mechanism, constructed, arranged, and operating substantially as shewn in and
described with reference to the accompanying Sheet of Drawings.
In 'witness whereof, I, the said Robert James Worth, have hereunto set my.
hand and seal, this Tenth day of September, in the year of our Lord.
One thousand eight hundred and seventy nine.
ROBERT JAMES WORTH. (L.S.)
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