SELF-CENTERING CHUCK
Year: 1884

page_text: I, BENJAMIN WALKER BLUNT, of N° 8, Summerfield Road, Icknield Port Road,
Birmingham, in the County of Warwick, Mechanical Draughtsman, do hereby
declare the nature of said Invention for A NEW SELF-CENTERING CHUCK to be
as follows:
Two round central parts E and F form the head and body of the chuck
respectively, they are suitably attached to each other at p by being screwed
together. Externally the end of F nearest to E, forms a round guide on which
the thrust-block G is made to fit and slides. The other end of F forms a shank r,
by which to attach the chuck to the machine in connection with which it is
desired to be used. Between the aforesaid guide and shank there is an external
screw upon F, which fits into a corresponding internal screw 8 on the nut H. Also
there is a round hole v, which passes centrally through E and F to admit the
article to be fixed in the chuck. Externally the largest cylindrical part of E,
forms a guide upon which G is made to fit and slide. There is also a short cone u
formed on the outside of E through the surface of which, three round holes pass
obliquely into the centre hole v, and form guides for the three round clips L.
Each of the three guides just mentioned, is similarly situated, in relation to either
of the others, and, also in relation to the central axis a b of the chuck, or so that
each of the three centre lines cd, of the aforesaid guides for the clips, makes an
equal angle with either of the others, and also an equal acute angle O. with the
central axis a b. The clips L are made to fit into and slide in the guides above
mentioned. At one end y they are suitably formed to allow all of them at the
same time to approach the centre of the hole v, and, to grip the article to be held
by them.
Near the other end of each clip there are two grooves formed upon
opposite sides of it, into which, a suitable slide n on the thrust-block G, is made
to fit and slide for the purpose of separating the clips. The block G has three sets
of grooves in the front of it. In one of these grooves in each set, a flat hardened
steel plate K is fixed, to move in contact with the outer end of the clip, and to
cause it to move in towards the centre of the hole v. The other grooves m and n
in each of the above sets, form the slides which separate the clips. The sides of
the plates K which slide on the outer ends of the clips are so situated that the
centre lines c. d. of the guides in E. are perpendicular to them. Also each of the
three sets of grooves in G already mentioned is similarly situated in relation to

page_text: either of the others, and, in relation to the central axis a b of the chuck,
At its front end the block G fits into a conical cover J, the latter being
attached to it by three small screws. There is an external screw
-
t upon the
back end of the block G, which engages with and fits into the nut I. Internally
G has a central round hole passing lengthways through it into which the head
and body of the chuck fit. The screw t on the block G has an opposite hand
thread to that of the screw 8 on the body F. The cover J has a central
round hole of the same diameter as that of the largest part of the head E.
The nut H has a central round hole passing lengthways through it in which
there is an internal screw on the circumference of least diameter. This screw has
preferably a left hand thread, which fits on the corresponding screw 8 on the
body F. The other part of the central hole in H forms a recess into which the
nut I fits and is permanently fixed. Externally the end of H into which the nut I
is fixed is round, and the other or smaller end is hexagon. To actuate the chuck
the nuts H and I are turned together round the axis a. b. by means of a spanner
applied to the hexagonal part of H. The screw a causes the nuts to move bodily
in the direction either of a or b according to the direction in which the nuts are
made to revolve. Also according as the nuts move in the direction of a or b, the
screw t on the block G, passes farther out, or enters farther into, the nut I
respectively. Thus the block G moves along the axis a. b in the same direction as
the nuts E and I, but at an additional speed depending on the pitch of the screw t.
When G is made to move in the direction of a then the clips move towards the
axis a band when the block G is made to move in the direction of b then the clips
are separated farther apart.
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. The whole design of the chuck and also the design of each of the parts E, F,
G, H, I, J, K and L above specified.
2. The manner in which each and all of the aforesaid parts of the chuck are
applied, as explained in this my Specification and illustrated by the accompanying
Drawings.
Dated this the 7th day of January 1884.

page_text: I, BENJAMIN WALKER BLUNT, of 257 Nechells Park Road, Birmingham in the
County of Warwick, Mechanical Draughtsman, do hereby declare the nature of
my Invention for "NEW SELF-CENTERING CHUCK," and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
Two round central parts E and F form the head and body of the chuck
respectively. They are suitably attached to each other at P by being screwed
together. Externally the end of F nearest to E, forms a round guide on which
the block G is made to fit and slide. The other end of F forms a shank R, by
which to attach the chuck to the machine in connection with which it is desired.
to be used. Between the aforesaid guide and shank there is upon F an external
screw S, which fits into a corresponding internal screw S on the nut H. There is
also a round hole V, which passes centrally through E and F to admit the article
to be fixed in the chuck. Externally the cylindrical part of E of largest diameter,
forms a guide upon which G is made to fit and slide. There is also a short
cone U formed on the outside of E, through the surface of which, three round
holes pass obliquely into the centre hole V, and form guides for the three round
clips L. Each of the three guides last mentioned, is similarly situated in relation
to either of the others, and also in relation to the central axis A. B of the chuck,
or so, that each of the three center lines C. D. of the aforesaid guides for the clips,
makes an equal angle with either of the others, and also an equal acute angle O
with the central axis A. B. The clips L are made to fit into and slide in the
guides above mentioned. At one end Y they are suitably formed to allow all of
them at the same time to approach the centre of the hole V, and to grip the
article to be held by them. Near the other end of each clip there are two
grooves X formed upon opposite sides of it, into which, a suitable slide N on the
block G, is made to fit and slide for the purpose of separating the clips. The
block G has three sets of grooves on the front of it. In one of these grooves in
each set, a flat hardened steel plate K is fixed, to move in contact with the outer
end of the clip, and to cause it to move in towards the centre of the hole V.
other grooves M and N in each of the above sets form the slides which separate
the clips.
The
The sides of the plates K which slide on the outer ends of the clips, are so
situated, that the centre line C. D. of the guides in E are perpendicular to them.
Also each of the three sets of grooves in G already mentioned is similarly situated
in relation to either of the others, and, in relation to the central axis A. B of the
chuck. At its front end the block G fits into a conical cover J, the latter being
attached to it by three small screws.
There is an external screw T upon the back end of the block G which engages
with and fits into the nut I. Internally G has a central round hole passing
lengthways through it, into which the head and body of the chuck fit. The
cover J has a central round hole of the same diameter as that of the largest part
of E. The nut H has a central round hole passing lengthways through it, in
which there is an internal screw on the circumference of least diameter.
This screw has preferably a left hand thread, which tits on the corresponding
screw S on the body F. The other part of the central hole in H forms a recess
into which the nut I fits and is rigidly fixed. Externally the end of H into which
the nut I is fixed is round and the other or smaller end is hexagonal.

page_text: To actuate the chuck the nuts H and I are turned together round the axis A. B.
by means of a spanner applied to the hexagonal part of H.
The screw S causes the nuts to move bodily in the direction either of A or B
according to the direction in which the nuts are made to revolve. Also according
as the nuts move in the direction of A or B, the screw T on the block G passes
farther out or enters farther into the nut I respectively.
Thus the block G moves along the axis A. B in the same direction as the nuts H
and I but at an additional speed depending on the pitch of the screw T. When G
is made to move in the direction of A, then the clips move towards the axis A. B,
and when the block G is made to move in the direction of B, then the clips are
separated farther apart.
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 The whole design of the chuck and also the design of each of the parts E. F.
G. H. I. J. K and L above specified.
2nd The manner in which cach and all of the aforesaid parts of the chuck are
applied, as explained in this my Specification, and illustrated by the accompanying
Drawings.
Dated this the 6th day of September 1884.