Improvements in and relating to Jawed Chucks.
Year: 1898

page_text: Date of Application, 8th Dec., 1898
Complete Specification Left, 1st Sept., 1899-Accepted, 28th Oct., 1899
Improvements in and relating to Jawed Chucks.
We, CHARLES TAYLOR and GEORGE BENJAMIN TAYLOR, both of Bartholomew
Street, in the City of Birmingham, Engineers, do hereby declare the nature of
this invention to be as follows:-
This invention relates to jawed chucks, and its object is to construct a chuck
in which the gripping pressure of the jaws can be accurately adjusted to a dead
set, so that the amount of pressure on the article held can be accurately guaged,
and in which the gripping pressure is applied to the jaws, or the parts carrying
the jaws, as near as possible behind the article held, and in a direct line with
the longitudinal axis of the jaw, so that the gripping surfaces of the jaws close
evenly upon the said article and not more or less on any particular part. Further-
more, the said invention comprises several improvements in the mechanism for
releasing the article held and in the general construction of the chuck's body
framing and cover plate, and in the means for operating the elements connected
with the movable jaws.
The chuck according to this invention, which may have any number of jaws
or jaw carriers sliding in suitable ways or channels upon the body part, is
characterised by a ring which is adapted to slide upon the exterior surface of
the chuck's body in line with the axis and over the jaws, and which is provided
with a number of radially disposed screwed pins having concave inner ends;
cut-away parts or slots formed within the said jaws or jaw carriers, the bottoms
of which constitute seatings; and oscillating or rocking posts or bars which inter-
vene radially between the said seatings in the jaws or jaw carriers and the con-
caved ends of the screw pins in the sliding ring, so as to communicate the sliding
movement of the said ring to the said jaws or jaw carriers at right angles, for
the purpose of closing them to grip an article between them. If the jaws or
jaw carriers are two in number, then two screw pins are provided in the sliding
ring, and two oscillating or rocking posts or bars intervene between the seatings
in the said jaws and the screw pins, one for each, but there may be more than
one oscillating post for each jaw.
The important feature in this form of chuck is the provision of the screw pins
or similar adjustable devices carried by the sliding ring, as by them the closing
of the jaws can be so adjusted in conjunction with a set traverse of the sliding
ring, as to grip upon an article with any desired pressure; thus being especially
of importance in the case of articles which are either hollow, or whose walls will
only stand a certain amount of pressure before collapsing.
In another form of this invention the jaws are operated, through oscillating
posts or rocker bars, by a frame which has a part rotating movement within the
interior of the chuck body, and which couples together the whole of the said
oscillating bars; the normal positions of the last-named being at an angle with
radial lines drawn from the chuck's centre. This frame is operated by a screw
working through the body of the chuck, which tends to move the frame so as to
force in the jaws and bring the oscillating posts or bars nearer to the radial
lines referred to, the said frame being controlled in the other direction of its part-
rotation by a suitable spring, or by springs, located in the chuck's body,
In

page_text: this form of chuck an adjustable stop is formed upon the body part adjacent to
the frame which couples the oscillating bars, in order that the said frame can
be adjusted in the amount of its movement for operating the jaws which grip
the work, so that a definite grip upon the article can be effected.
The jaws in this particular chuck are small ones which are capable of being
removed from the ways or grooves in which they work in order to replace them
by those of different radius, and to effect this the front plate of the chuck, which
encloses the whole of the moving parts, is formed with gaps adjacent to the
said ways or grooves wherethrough the said jaws can pass, but these gaps are,'
when the chuck is working, closed by a revolving plate or shutter fixed inside
the front plate, and which can be adjusted so as to cover up the said jaws and
protect their working parts from becoming clogged with dust, or uncover them
in order to remove them from their grooves or ways.
The coupling frame of the oscillating bars may be operated by a sliding part
similar to the ring described in the first chuck, through the medium of two or
more bell-crank levers or similar devices, which will combine to give the said
frame a part-rotating movement; or the said frame may be operated by a ring
screw threaded upon the body of the chuck, and which is held momentarily by
friction-grips while the chuck is revolving until the frame has been given the
necessary part-rotation; this last form being also applicable to the first-described
chuck with the ring sliding in the direction of the chuck's axis for operating
the oscillating bars.
The construction of the oscillating bars may be either in the form of a short
rod or pin, or of a short bar of a determined breadth, and their ends may be
either semi-circular, or spherical, or dumb-bell shaped, and the seatings or
grooves in the jaws and rings or frames they engage may either conform to their
shape or be made angular, so that very little friction is obtained between the
contact parts.
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1300
We, CHARLES TAYLOR and GEORGE BENJAMIN TAYLOR, both of Bartholomew
Street, in the City of Birmingham, Engineers, 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 jawed chucks, or chucks having movable jaws, and
is an amplification of the inprovements described and set forth in an application
for Letters Patent dated the 10th of September 1898 and numbered 19268. The
object of the present invention is to construct a chuck in which the gripping
pressure of the jaws can be accurately adjusted to a dead set to nicely guage
the amount of pressure upon the article held, the said adjusted pressure being
applied to the jaws or the jaw carriers as near as possible behind the point
of nip of the article held, and in a direct line, or as nearly so as possible,
with the longitudinal axis of the jaw; the result being that the gripping
surfaces of the jaws close evenly upon the article held and not more or
less upon any particular part. Furthermore, the said invention comprises
several improvements in the mechanism for releasing the article held, in
the general construction of the chuck's body framing and cover plate, and in
the means for operating the elements connected with the movable jaws.
In the patent application herein before cited, jaws with slots or cut-away parts

page_text: machined in them are described as operated by short rods or posts and a sliding
ring or its equivalent, the latter having a backward and forward reciprocating
movement over the body of the chuck, and the short rods or posts an oscillating
or rocking movement between seatings in the ring and in the slots or cut-away
parts of the jaws or the jaw carriers.
The chuck according to the present invention is in one form (as shown in
Fig. 1 of the annexed sheets of drawings) almost identical in construction with
the first one described in the patent application cited, it having jaws or jaw
carriers c, slots or cut-away parts c³ in said jaws, a back and forth sliding ring i
moving over the body a of the chuck and over the jaws in line with the chuck's
axis, and oscillating rods or rocking posts 9 working between seatings in the
jaws or jaw carriers and the ring in exactly the manner as described in the
application cited, but in addition to these parts, and also an adjustable stop and
projection marked m, m², as forming the important feature in this form of chuck
is the provision of screw pins h or similar adjustable devices upon the sliding
ring i, as by them the closing of the jaws or jaw carriers c can be so adjusted in
conjunction with a set traverse of the sliding ring i as to grip upon an article
with any desired pressure; this latter being especially of importance in the case
of holding in the chuck articles which are either hollow or whose walls will
only stand a certain amount of pressure before collapsing. The screw pins h
engage radially-disposed screw boxes in the front part of the ring, and within
their inner ends are formed seatings go for the ends g of the rocking posts g
to engage.
The screw pins h, when adjusted, can be locked in any suitable
manner, but in the drawing, Fig. 1, the outer ends are split and tightly fit
the screw boxes h².
By the provision of screw devices such as h a chuck constructed, say, for
holding one inch diameter articles, could be made, if desired, without change of
jaws to grip an article slightly larger or smaller than this size, say, for example,
one inch and an eight diameter, or seven eights diameter only, to do which it
would be only necessary to either unscrew or screw up the said pins; it being
understood that in every case the grip of the jaws upon the article is the greatest
and best distributed when the oscillating posts or rocker bars are in a direct
longitudinal line with the jaws.
y is a lever or bar for screwing the chuck upon the end of the spindle of a
lathe or the like.
In another form of chuck according to this invention, illustrated in Figs. 2, 3,
and 4, by two front elevations and a cross section (the first view with the front
plate of the chuck removed, and the last view with the front plate on) the
jaws c, c, c, are operated through oscillating parts or rocker bars 9, 9, 9 by
a frame i, which has a part-rotating movement within the interior of the chuck's
body a, and which couples the whole of the oscillating posts; the normal posi-
tions of the last-named being at an angle with radial lines drawn from the chuck's
centre. The frame is mostly of triangular form as shown for strength, but
it has circular parts upon it where it takes a bearing on the chuck's body. The
said frame is operated in one direction by a screw working through the body
of the chuck against an extension of said frame which, on screwing in, rotates
the said frame so as to force inwards the jaws in their ways, and bring the
oscillating posts or bars nearer to the radial lines referred to; the movement
of the frame i being controlled in the other direction of its part rotation, after
the screw is screwed out, by a spring located between an abutment of the
chuck body and an extension of the frame i. The oscillating posts or rocker
bars have suitable seatings within the jaws c and the part-rotating frame i
(preferably bulbous seatings g², g³, as shown), the ends of the said posts or bars
being balled.
In this last described form of chuck an adjustable stop m is formed upon the
body part a adjacent to the frame i, coupling the oscillating posts, in order that
the movements of the said frame can be limited or extended for giving a definite

page_text: grip upon the article held. Further the jaws c, c, c, are small ones capable of
removal from the ways in order to replace them by those of a different gripping
radius, and to effect this the front plate a² of the chuck, which encloses the
whole of the moving parts, is formed with gaps adjacent to said ways, where-
through the said jaws can pass, but these gaps are, when the chuck is complete
for working, closed by a revolving plate or shutter. 03 located inside the fixed
front plate a, the said shutter having gaps 03 and intervening solid parts o*
within and as part of it, which respectively open and close the jaws to the gaps o,
and effectively cover and keep the said jaws dust proof when working.
The coupling frame i of the oscillating bars (Figs. 2 to 4) may be operated by
a sliding part similar to the ring i, Fig. 1, through the medium of a bell-crank
lever or similar device, which will give the said frame a part-rotating movement.
Such a method is shown in Figs. 5, 6, and 7, the first of these figs. being a part
face elevation with the cover plate removed, the second a transverse section, part
elevation, and the third a back face elevation. In these illustrations s is the bell-
crank lever jointed to the chuck frame, and 2 is one of its arms acted upon
by the sliding ring i, and the other of its arms acting upon an extension
of the coupling frame ; the last named being constructed, and working, in a
similar manner to the frame in Figs. 2 to 4.
The oscillating bars may be either in the form of short rods or pins, or of
short bars of a determined breadth, and their ends may be either semicircular,
spherical, or dumb-bell shaped, and the seatings or grooves in the jaws and rings
or frames they engage may either conform to their shape or be made angular.
Having now particularly described and ascertained the nature of our
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
First. In jawed chucks, the combination with the body part a and jaws or
jaw carriers c having cut-away parts within them, of a sliding ring i working
upon said chuck body and over the jaws and carrying screw adjusting devices
such as h, and oscillating posts or rocker bars y disposed in seatings between
parts c and, for the purpose substantially as described in Fig. 1.
Second. The general construction, arrangement, and fitting of the parts of
jawed chucks as described and set forth in Fig. 1.
Third. In jawed chucks, the combination with the body parts a, jaws c work-
ing in ways, and oscillating posts or rocker bars g, of a part-rotating frame i, and
screw and spring devices for operating the latter, substantially as described and
set forth in Figs. 2 to 4.
Fourth. In jawed chucks, the method herein described and illustrated in Fig. 3
and 4 for replacing the jaws c and rendering them dust-proof.
Fifth. The general construction and arrangement of the parts in combination
as described and set forth in Fig. 2.
Sixth. In jawed chucks, the means substantially as described and set forth
in Figs. 5 to 7 for operating the coupling frame, the same comprising essen-
tially a sliding ring i and a bell crank lever s.
Dated this 1st day of September 1899.
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also of Liverpool, London, and Manchester,
Patent Agents for the Applicant.