Improvements in Automatic Lathe-chucks.
Year: 1899

page_text: Date of Application, 10th July, 1899-Accepted, 26th Aug.,
1899
COMPLETE. SPECIFICATION.
Improvements in Automatic Lathe-chucks.
I, ELBERT MILTON COUCH, of 17, Sumner Street, in the City of Hartford,
County of Hartford and State of Connecticut, United States of America, Mechani-
cal 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 automatically operated chucks and has for its object
the construction of a chuck of this class hating two or more radially moving
jaws automatically operated by a plunger having a longitudinal movement in
the spindle to which the chuck is secured, and provided with an interchangeable
connection between said plunger and said jaws whereby the radial movement
of the latter may be varied to adapt the chuck to a great variety of work.
A further object of the invention is the application of yielding pressure to said
jaw-operating plunger whereby said jaws may be moved in one direction for
releasing a piece of work held therebetween, or for moving said jaws into engage-
ment with the interior surface of hollow objects which are to be operated upon
by the machine, and which may be too fragile to be successfully handled by
positively operated jaws.
The invention consists in the construction hereinafter fully described and
particularly pointed out in the claims.
In the accompanying drawings,
Figure 1 shows the chuck embodying this invention applied to the spindle of
an automatic screw machine and representing the parts in longitudinal section,
and showing the chuck-jaws closed.
Figure 2 is an enlarged longitudinal section of the chuck and a portion of
the spindle on which it is carried and showing the chuck-jaws open.
Figure 3 is a face view of the chuck shown in Figure 2.
Figure 4 is an edge and face view of an interchangeable block in which are
supported the jaw-operating levers.
Figure 5 is a perspective view of the circular jaw-plate and a jaw separated
from said plate.
Figure 6 is a perspective view of a part of the jaw-operating plunger, one of
the connections between said plunger and jaw, and a pin on which said connee-
tion is pivotally supported.
In Figure 1, 2 represents a portion of the frame of a machine having the
standards 3, in which the hollow spindle is supported in suitable bearings in
the usual manner. Said spindle is provided with tight and loose driving-pulleys
located thereon between said standards. The spindle 4 has the longitudinal
passage 5 extending therethrough and the end of the spindle, opposite the chuck-
carrying end, has two oppositely located slots 6, through the wall thereof and
parallel with the axis of the spindle, through which slots certain parts to be
described, operate the chuck.
The chuck-receiving end of the spindle 4 has formed thereon, and preferably
integral therewith, the annular head 7, having a equare shoulder 8 for bearing
against the end of the bearing in which said spindle rotates. In said head is

page_text: the concentric annular cavity 9, for the reception of the circular block 10 which
is provided with the central perforation 12 for the reception and support of onc
end of the plunger 13, whose opposite end is provided with a circular head 14,
which fits closely the bore of the passage 5, in the spindle.
Said plunger moves freely in said passage, and in that part thereof lying
within the circular block 10 has suitable cuts 15 made therein at right angles
to the axis of said plunger for the reception of the ends of jaw-operating connec-
tions supported in Baid block.
Said connections 16 are substantially right-angled levers pivotally supported
in radial slots 17, in the block 10. Said slots extend from the central perfora-
tion 12 in said block to the periphery thereof, and their depth is less than the
thickness of said block, as shown by the sectional views in the drawing.
At suitable points in said blocks 10, holes 18 are bored therethrough at right
angles to said slots 17, and pins 19 located in said holes support the levers 16,
the latter swinging freely on said pins with their jaw-engaging ends projecting
from said radial slots in the block 10, and their plunger-engaging ends con-
verging towards the center of said blocks, and projecting from the inner ends
of said slots into the perforation 12, extending axially therethrough and in
"position to engage the cuts 15 above mentioned, which lie opposite the inner
ends of the said slots 17.
The location of the said slots 17, and the holes 18 for the pivot-pins, is clearly
shown in Figure 4, and Figure 2 shows the parts assembled; the section of
'the block shown is substantially on line 2-2, Figure 3, thus showing one of the
right-angled lever connections between a chuck-jaw and the plunger in operative
position.
The jaw-carrying face-plate 20 of the chuck is cup-shaped, and in the closed
end thereof is the central aperture 21. The radial slots 22 extend from said
aperture nearly to the rim of said plate. These slots receive the sliding jaws 23
and are of the same number and located in the sanie plane, relative to the axis
of the spindle, as the slots, 17 in the block 10.
Between the backside of the face-plate 20 and the forward end of the circular
block 10 is an annular cavity 24 of sufficient depth to permit the unobstructed
movement of that part of the sliding-jawa 23 lying back of said face-plate with
which the ends of the lever 16, which project beyond the face of the block 10,
engage. Said face-plate back of said' cavity 24, 'is turned out to fit closely over
the said block 10, as shown at 25, Figure 5.
When the parts are assembled, the screws 26, near the edge of said face-plate 20,
are passed through the latter into suitably tapped holes in the rim of the concave-
head 7, binding the plate thereto, and other screws 27, pass through said plate
nearer the center thereof, and enter the holes 28 shown in the block 10, in
Figure 4, to prevent the rotation of the latter in the cavity 9, and thus insuring
the contant registration of the radial slots 17, in said head, with the slots 22,
in the face-plate.
The sliding-jaws 23, are made as shown in perspective, in Figure 5, and in
front and side elevation in Figures 2 and 3, and consist of the usual L-shaped
work-grasping part 29, lying on the outer surface of the face-plate, and the
part 30, integral therewith, lying between the backside of the face of the
plate 20 and the face of the block 10, the rearmost surface of said part 30 being
close to the face of said block and having a transverse-slot 31 cut therein for
receiving the end of the lever 16 projecting from the face of said block, as
stated. Said jaws are made wider than the slots 22 in said face-plate 20, and
two parallel groovès 30" are cut in the sides thereof to form the narrow connect-
ing portion 30 between the parts 29 and 30 of said' jaws, which portion fits the
said slots 22 and leaves a bearing for the jaws on each side of the plate 20.
The form of said slot and the end of said lever 16, engaging therewith, being
substantially the, same as the teeth of a rack and pinion having the same
pitch-line.

page_text: The circular aperture 21, through the center of the face-plate 20, is of such
diameter as to admit the part 30 of the jaw for the purpose of placing said jaws
in their respective 'slots 22.
The form of the cuts 15 in the plunger 13, shown in Figure 6, is adopted only
to insure the retention of the greatest cross-sectional area possible after making
said cuts. It would serve every purpose to simply turn an 'annular groove in
the plunger at that point, instead of making the cuts of the form shown.
From the above description, it is obvious that the movement of the plunger 13
longitudinally in the hollow spindle will, 'through 'the rectangular lever connec-
tions 16, impart to the jaws of the chuck a radial movement at right angles to
the line of movement of said plunger. Means for moving said plunger consist
of a grooved collar 33, on the end of the hollow spindle 4, 'opposite to that to
which the chuck is secured, and provided with suitable feathers 34 engaging
the oppositely located slots 6 in said spindle, which permits said collar to have
a free sliding movement on said spindle while rotating with it. 'On said collar
are two oppositely located wedges $35.
On a collar 36, two rectangular levers 37, are pivotally supported, the short
ends 37° of which enter the slots'6 in the spindle for engagement with the head 14
on the plunger 13, on the side of said head nearest the chuck. The opposite
longer ends 37 of said levers have rounded extremities and the wedges 35 on
the collar 33 are adapted to move in under said ends 37b of said levers, thus
bringing the short ends thereof to bear against the head 14 of each plunger forcing
the latter back from the chuck and causing the jaws thereof to close in towards
the center of said chuck, suitable mechanism being employed to impart move-
ment "to said collar 33.
In the drawing, the mechanism shown consists of that employed on a well
Known type of automatic screw-machine, comprising a block 38 having a sliding
'movement on the-fraino of the 'machine, under said spindle, and a stud engaging
said grooved collar, and a cam-wheel 39 located near said block, and suitable
cam-strips on said cam-wheel whereby, by the rotation of said wheel, said block
may, at the proper time, be actuated to move said collar 33 back and forth on
said spindle, to operate the levers:37.
When said levers are actuated to move said plunger, as described, away from
the chuck on the opposite end of the spindle, said plunger moves against the
tension of a coiled spring 40, in the hollow-spindle 4, one end. of said spring
abutting against the head 14 on said plunger. The opposite end of the spring
abuts against a disk 41 which fits the bore of the spindle and is provided with
ears 42, thereon for engagement with 'the slots 6 in said spindle and thereby
kept from turning therein.
'On 'the end of the spindle is screwed a cap 43 having a hole central therein
through which the head of a screw 44 may project, which screw 'has a threaded
engagement with said disk 41, and is provided with a collar 45 near its head
which bears on the inside of the cap 43. The tension of the spring will hold
the said collar on said screw against said cap and by turning said screw, said
tension may be increased or diminished by the movement imparted to the
disk 41, in the spindle.
The function of the spring applied, as above described, is to impart movement
to the plunger 13 in the direction of the chuck after the collar 33 has been moved
back to release the levers 37 from engagement' with the wedges 35, which move-
ment of the plunger moves the chuck-jaws away from the center of the said
chuck.
Only a slight degree of tension need be put on said spring to accomplish the
unchucking movement above described:
"
If it is desired to use the chuck to grasp hollow pieces by outward movement
of the jaws, the tension of the spring 40 may be increased to any required
degree by means of the disk 41, operated by the screw 44, as described.
The collar 33 will then be timed to move forwards towards the chuck to force

page_text: the plunger 13 backward and release the article in the chuck, thus compressing
the spring 40, and to move in the opposite direction and release the levers 37
from their bearing on the wedges 35, thus leaving the spring 40 free to move
the plunger for effecting the engagement of the chuck-jaws, as stated, with the
interior surface of any hollow article.
The amount of force under which the chuck-jaws will be forced into engagement
with a piece of work, as aliovo stated, can be regulated at will, thus permitting
the device to be used in turning up articles of delicate structure which would
frequently be broken by positively working jaws.
By substituting for the block 10, herein described, a similar block having the
jaw-operating levers 16 of proportions different from those of the levers shown
herein, a different degree of movement may be imparted to said jaws by a given
movement of the plunger, and thus a chuck adapted to handle all kinds of work
may be constructed by means of the invention herein described, riz.,-a chuck
whose jaws for a given movement of the actuating plunger, may either have a
wide range of movement and comparatively small power, or one having a smaller
range of movement and proportionately greater power.
In either case the jaws may be used for grasping an object by positive move-
ment towards the center of the chuck, or by a yielding expansive movement away.
from said center, in the manner above described.
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:-
1. In a chuck having radially moving jaws, a suitably supported jaw-actuating
plunger having a line of movement transverse to the radial movement of said
jaws, connections between said plunger and said jaws whereby movement of
said plunger actuates said jaws, and plunger moving mechanism consisting of
oppositely located, pivoted elbow-levers, one end of which engages said plunger,
movable wedges for separating the opposite ends of said levers whereby said
plunger is moved in one direction, a spring bearing on said plunger for moving
the latter in the opposite direction, and means for regulating the tension of said
spring, substantially as described..
2. The combination with a suitably supported chuck having radially moving
jaws and an axially supported endwise movable jaw-actuating member, of a
spring for moving said member in one direction for releasing or clamping a
piece of work, and mechanism for moving said member in an opposite direction
positively, and means for varying the tension of said spring, substantially as
described.
3. An automatic chuck comprising a hollow spindle, an endwise movable
member axially supported therein, radially movable chuck-jaws, elbow-levers
engaging said jaws and said endwise movable member, a block supported remov-
ably in the head of said spindle in which said elbow-levers are hung, means for
moving said member endwise positively in one direction, a spring in said spindle
against which said member moves, a disk in said hollow spindle, and a screw
supported on the latter for moving said disk to compress said spring, substantially
as described.
Dated this 2nd day of June 1899.
ELBERT MILTON COUCH.
Haseltine, Lake & Co.,
45, Southampton Buildings, Loudon, W.C.,
Agents for the Applicant.