Improvements in Rod Feeding, Centering, and Holding Devices for Lathes or the like.
Year: 1892

page_text: Date of Application, 21st June, 1892-Accepted, 23rd July, 1892
COMPLETE SPECIFICATION.
Improvements in Rod Feeding, Centering, and Holding Devices for
Lathes or the like.
A communication by CONRAD M. CONRADSON, of Madison, in the County of Dane
and State of Wisconsin, United States of America, Mechanical Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E. of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool & 6 Bank Street,
Manchester, both in the County of Lancaster, & 323 High Holborn in the
County of Middlesex, Civil Engineer, 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 lathes or screw cutting machines, and has reference
more particularly to a novel construction and arrangement of devices for feeding,
centering and holding the material operated upon.
In screw machines as ordinarily made and used, a rod is inserted through the
hollow spindle of the machine, which is provided with gripping jaws at the front
end to accurately centre the bar and support it while being operated upon.
When a screw or other article has been finished, it is cut off and the chuck jaws
opened, and another length is projected through the chuck. Where the length of
the article made is short or small in relation to the diameter, this method produces
good work, but, if the piece is slender, it springs away from the cutting tools, and
the arrangement is unsatisfactory in every way. Another disadvantage is that,
if the bar operated upon is crooked, the chuck jaws, in gripping it, will throw the
outer end away from or out of line with the centre. It therefore becomes essential
that only perfectly straight bars be used, as otherwise they will not run true after
being gripped with the chucks and in the manner referred to.
The present invention is designed to overcome these difficulties and to produce a
machine that shall allow work of any length to be operated upon, and shall also
centre both ends of the piece of material.
One form of machine for securing these results is illustrated in the accompanying
drawings, in which
:-
Figure 1 is a longitudinal vertical sectional view of a machine embodying these
improvements;
Figure 2, a vertical transverse sectional view on the line x-x of Figure 1 ;
Figure 3, a similar sectional view on the line y-y of Figure 1; and
Figure 4 a front view of the spindle-chuck with the face plate removed.
A, indicates the hollow spindle or arbor of the machine, to the end of which is
secured the chuck B. This chuck comprises a body portion C, a series of radially
moving jaws D, and a bevelled actuating band or ring E, as shown in Figures 1 and 4.
These jaws D are each bifurcated at their lower ends, and, between the ends or
arms, is pivoted a steel shoe F which is designed to adapt or adjust itself to any
irregularities in the surface or body of the bar Z to be clamped and operated
upon.
The inner end of the bar Z is centered in and clamped by a device G, which is
denominated the rod-feeding gripper, which, in the present instance, is shown
applied to the turret of a lathe.
This device comprises a flanged bushing H, screwed or otherwise secured to the
turret (or any other suitable part of the machine) in line with the axis of
the hollow spindle or arbor. Mounted within this bushing, so as to be capable of a
rotary and also a longitudinal movement therein, is a spindle I having at its outer
end a head or enlargement J, and at its inuer end one or more circumferential

page_text: grooves a a¹ as shown in Figure 1. In the flange 6 of the bushing is formed a
socket c in which is mounted a spring-pressed pin d, the inner rounded end of which
is designed to enter either of the grooves a a' in the spindle, the engagement being
such that, while the spindle is prevented from accidentally moving lengthwise, it
may be so moved by hand by exerting sufficient force to cause the rounded end of
the pin to ride back into the socket and out of the groove.
The head or enlargement J of the spindle I is slotted to receive two gripping
levers K, which are pivoted therein at right angles to the axis of the spindle as
shown in Figures 1, 2 and 3. These levers are each provided with a tail or
extension e designed to rest upon a collar or sleeve f carried by the bushing H, as
shown in Figure 1. a spring g, secured to the head or enlargement J and bearing
upon the tail of the lever, serving to hold the gripping faces of the levers away
from each other.
The outer ends of the levers K are each provided with a gripping jaw / having
a semicircular seat to receive and bear upon the rod Z, and a stem which enters a
socket formed in the end of the lever.
These jaws are adjusted toward each other by means of screws ; and are held
in their adjusted position by means of set screws k as shown in Figures 1 and 3.
Surrounding the bushing H, in advance of the sleeve or collar f, is a second
collar having a smaller diameter than that of collar f, the edge of the collar f
next to collar being bevelled as shown in Figure 1 so as to allow the tails of the
levers K-which, by the way, are rounded-to ride easily on to and off the collar f
as the spindle I and attached parts are moved lengthwise with relation to the
bushing H.
The operation is as follows:-
The bar or rod Z is first passed through the hollow spindle or arbor A with the
end projecting beyond the face of the chuck. The spindle I, with attached parts,
should be now moved outward longitudinally with reference to its bushing, as
indicated by the dotted lines in Figure 1, whereupon the rounded tails or ends of
the levers K will be found resting upon the small collar 1, the pin d engaging
the groove a¹ of the spindle, and the jaws of the levers K being separated or
opened.
The gripping devices are now moved up toward the rod Z, and the jaws h pass
upon the end of the bar until arrested by the bar coming into contact with the
spindle I. Continuing the movement alluded to, the spindle will be pushed into the
bushing, and the tails of the levers riding up the inclined edge of the collar f will
force the jaws firmly against the rod or bar Z so as to clamp the latter. By the
time that the levers K clamp the rod firmly, the groove a of the spindle will pass
under the spring pin d, which immediately locks the spindle and bushing against
further independent longitudinal movement.
When this has been accomplished, the gripping devices and the turret, or other
part to which they are secured, are moved backward bodily, drawing with them
the rod or bar Z. During these operations, the bar remains unclamped within the
chuck on the hollow arbor, but, when a sufficient length of the rod has been fed
through the arbor and chuck, the jaws of the latter are so actuated as to cause them
also to clamp the rod.
Work may now be done upon the rod or bar Z while held at both ends, or, if
desired, the turret may be moved backward still further so as to release the levers
and jaws, and the rod operated upon while held only by the chuck jaws.
When work is done upon the bar or rod Z while held by the jaws h, the latter
turn or rotate with the work, the spindle 1, to which the levers K and attendant
parts are attached, turning or rotating within the bushing H.
The gripping devices may be applied to the end of the bar or rod Z while the
latter is turning, if desired. The spindle I is preferably provided with a central
stud or projection m against which the end of the bar Z shall strike when the
gripping devices are brought up against the bar, instead of allowing the latter to
bear directly against the spindle.

page_text: While the invention has been shown applied to a turret lathe, it is to be under-
stood that it may be applied to other styles of lathes or to other parts of such
lathes or machines. Nor is it to be understood as limited to the precise construction
herein shown, as the present invention comprises a gripper movable and acting
as described regardless of its details.
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 or machine having a hollow arbor through which the material is
fed, the combination, with such hollow arbor, of a chuck applied thereto, and a
rod-gripping device mounted upon a part of the lathe which is movable toward and
from the face of the chuck, said rod-gripping device being adapted to take hold of
the rod and draw or feed it through the hollow arbor, substantially as shown and
described.
2. In combination with the hollow arbor and its chuck, a gripping device movable
toward and from the face of the chuck and having its gripping jaws arranged to
rotate with the work, substantially as shown and described.
3. In combination with the hollow arbor and its chuck, a combined rod-gripping
and centering device substantially such as shown and described, movable toward
and from the face of the chuck and adapted to take hold of the rod, draw it through
the hollow arbor and centre it.
4. In combination with the hollow arbor and its chuck, a tool post or turret
movable toward and from the face of the chuck, and rod-gripping devices mounted
upon the tool post or turret, to take hold of the rod and draw it through the hollow
arbor and chuck.
5. In combination with the hollow arbor and its chuck, the rod-gripping device G
having the jaws K; said gripping device comprising two parts H and I, adapted
to move lengthwise one in relation to the other, and thereby actuate the gripper
jaws, all substantially as shown and described.
6. In combination with the hollow arbor and its chuck, the rod-gripping device G
having the jaws K; said gripping device comprising two parts H and I, one of
which is adapted to move lengthwise and to rotate relatively to the other, all
substantially as shown and described.
7. In combination with a turret, a bushing H mounted therein and provided with
an inclined face or collar f, and spindle I, provided with head J and gripping
levers K and moving longitudinally within the bushing, all substantially as shown
and described.
8. In combination with bushing H having pin d and collars fl, spindle I provided
with grooves a a¹, and pivoted gripping levers K.
9. In combination with the hollow arbor and its chuck, a tool post or turret
movable toward and from the face of the chuck, a rod-gripping mechanism carried
by the said tool post or turret, and provided with gripping jaws which are auto-
matically thrown into and out of action by the longitudinal movement of said jaws
relatively to the tool post or turret.
Dated this 20th day of June 1892.
WM. P. THOMPSON & Co.,
Agents for the Applicant.