Year: 1887

page_text: described.
In the accompanying drawing.
Figure 1 is a view in central, longitudinal section of a chuck embodying my said
improvement, the section being on the plane denoted by the dotted line --- of
figure 2.
Figure 2 is a front end view of the chuck-entire.
Figure 3 is a view of the chuck with the conical outer shell removed.
Figure 4 is a view in (partial) cross section of the parts shown in figure 3, on the
plane denoted by the dotted line y y.
Figure 5 is a side view of one of the jaws.
a denotes a screw-shaft carried by and generally integral with the pintle b, which
fits, in the ordinary manner, into the mandrel of the head-stock of a lathe or other
machine. This screw-shaft has at its front end, the conical bearing surface c. The .
parts a and c 1 denominate the screw-shaft cone.
с
d denotes what may be termed the chuck-body; the rear of which is interiorly
threaded and screws upon the thread of the screw-shaft conc.
The front part of the chuck-body d is mortised longitudinally, and carries in the
mortise the jaws e. Each jaw has a groove e' in one side; and by the side of each of
the mortises just mentioned is drilled a socket, in each of which is a spring g,
tending to press a disc h outward. These dises have, therefore, some play up-and-
down in these sockets, the outward limit of this play being defined by the stop-pins i
DI

page_text: projecting from the walls of the sockets. The said dises h, have each a peripheral
notch, permitting the passage of the disc past the stop-pin, after which, by a partial
rotation of the disc the latter is locked into the socket, below the stop-pin. The
discs, project laterally into the grooves e¹, so that the springs g, constantly tend to
press the jaws e radially outward, the co-operation of the discs and grooves el mean-
while permitting the free longitudinal movement of the jaws.
j denotes a conical shell screwing upon the front end of the chuck-body: On its
interior surface this conical shell carries an annular cam which co-operates with
the pheripheral surfaces of the jaws e. The rear ends of the jaws e bear the bevels e
which co-operate with the conical bearing surface c.
C
Now when the chuck-body is run backward in the screw-shaft a, the conical
bearing surface c bears against the bevels e" on the rear ends of the jaws, forcing the
jaws longitudinally forward and, by their peripheral contact with the annular cam j¹,
forcing them radially toward a common centre, coincident with this action there is a
lever action of the jaws, the discs h acting as elastic fulcra, the rear ends of the jaws
being forced radially outward, and the front ends being forced radially inward. This
double action makes the grip of the jaws stronger and more secure than would other-
wise be the case.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, as communicated to me by my
foreign Correspondent, 1 declare that what I claim is :-
First. In combination, in a chuck, the screw-shaft-cone
u, C, the chuck-body d, the
shell bearing the annular cam, and the jaws e bearing the bevels e", all substantially
as described and for the purpose set forth.
Second. In combination, in a chuck, the jaws e having grooves e', the chuck-body d,
the sockets f, and the discs h, all substantially as described and for the purpose set
forth.
Third. In combination, in a chuck, the jaws e having grooves e', the chuck-body d,
the sockets the springy and the discs, all substantially as described and for the
purpose set forth.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.