Improvements in Chucks having Movable Gripping Jaws.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Chucks having Movable Gripping Jaws.
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 chucks having movable gripping jaws, and has for
its object the hereinafter described improvements which render chucks much
stronger in parts than hitherto, allow of their working parts being made larger
and more durable and being better supported, and admit of their dimensions
being kept small.
One part of this invention relates to the bearings for the screws or screw pins
which traverse the jaws in their ways or grooves within the chuck face. These
bearings take the thrust of the screws consequent upon the pressure with which
the jaws grip the work. The bearing for each traversing screw is according to
this invention formed as follows:-The outer end of the screw near its head is
formed with a number of concentric sinkings or grooves separated by concentric
collars, the section of the said collars and grooves being preferably. square like
the threads of a square-thread screw. With these collars and grooves, which,
when the screw is in position within the chuck body, come inwards of the
periphery of the said body, engages a thrust block of steel, also formed with
grooves and collars similar to the ones on the screw, and which is preferably
hálf-ring shape. This thrust block is located and fitted within a similar shaped
recess or cut-away part formed in the body of the chuck adjacent to that part of
the traversing screw it engages, and it only protrudes from the said cut-away
part sufficient for its engagement with the grooves and collars of the screw, so
that the greater part, or sufficient of it, is let into the said cut away part or recess
to take a good bearing and to resist the backward thrust of the screw.
thrust block is kept in its position within the cut-away part by that part of the
traversing screw it engages, and from rotating or turning therein by a set screw,
an abutment, or a stop shoulder, fitted to or formed within the chuck's body so
as to engage it.
This
This thrust block is introduced into its seating (the recess or cut away part)
through the way in the chuck body formed for the jaw, and its semi-circular
figure (which is preferable) materially helps in its introduction into what would
otherwise be a difficult position; the said block being preferably introduced after
the screw and the jaw are in position.
The extreme outer end or head of this traversing screw (when in position) is
bounded by a clearance, which admits of putting the jaw into its way in the
chuck body, which said clearance leaves the said outer end unsupported. Accord-
ng to this invention the said head end is supported by a bush bored to the size
of the head end and of an exterior diameter to fit the clearance, which bush is

page_text: dropped over the said end into the clearance and is fixed to the chuck body by
set pins.
Another part of this invention is an improved connection means between the
head or outer end of the traversing screw and the key by which the said screw
is rotated. In this connection means the engaging facets of the two parts are
radially disposed, so that there is no twisting action to damage them as is the
case with the ordinary square post and socket connection. The end of the head
of the screw is formed with a number of sinkings of any shape but whose side
walls are preferably cut radially true with the centre of the screw, and the boss
on the key is formed with a number of teeth or projections the exact counter
part of the sinking, so that they can engage with their abutting faces radially
the full area of the screw head. An axial hole is bored in the head of the screw
adjacent to the said sinkings, and a projecting peg is centrally fitted to the boss
as aforesaid on the key, the said peg being adapted to engage the hole and
constitute a finder for the teeth to the sinkings before described.
The body-part of the chuck is according to a further part of this invention
strengthened in a particular way against the jaw ways opening out or bursting
laterally.
To effect this a steel band or ring is let into the face of the chuck at a point
which will not obstruct the movement of the jaws in their ways, the said band or
ring being preferably contracted when in position within a groove or seating
formed to receive it; or screw bolts may be passed transversely through the sides
of each of the ways so as to cross them, which will strengthen their walls against
bursting strains. In this case distance pieces of steel would be threaded onto
the said bolts to lie between the sides of the ways, so that any contraction of the
ways by the bolts is prevented.
A still further part of this invention consists in forming upon the face of the
chuck body a ring extension, or a number of ribs, which stands, or stand, out
from the said face at a point which will not interfere with the action of the
varying sized grips of the jaws but which will support the jaws in their movement
in their ways by forming extended sides to the ways. This strengthening device
is especially of importance where loose or false jaws are bolted to carrier jaws,
as it gives additional lateral support to the said false jaws.
The improvements herein described are in whole or in part applicable to all
chucks having moving gripping jaws, irrespective of whether they are inde-
pendently or collectively operated.
Dated this 8th day of M 1800
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Patent Agents for the Applicants.
Improvements in Chucks having Movable Gripping Jaws.
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 4
described and ascertained in and by the following statement:-
This invention relates to chucks having movable gripping jaws, and has for
its object the hereinafter described improvements which render said chucks much
stronger in parts than hitherto, allow of their working parts being formed larger

page_text: and strong and being better supported, and admit of their dimensions being kept
small.
The first part of this invention relates to the bearings for the screws or screw
pins which traverse the jaws in their ways or grooves upon the chuck face.
These bearings take the thrust of the said screws consequent upon the pressure
with which the jaws grip the work. The second part of this invention is an
improved connection means between the head or outer ends of the screws or screw
pins, as aforesaid, and the key by which the said screws are rotated.
The third part of this invention effects a strengthening of the chuck body in
a particular way against its jaw-ways opening out or bursting laterally; whilst
the forth part of the invention consists in forming upon the face of the chuck-
body extensions or out-standing parts which will support the jaws in their move-
ment in the jaw-ways by forming extended sides to the said ways.
The improvements according to this invention are illustrated in the accompany-
ing sheet of drawings and will hereinafter be particularly described in connection
therewith. In these drawings the first part of the invention is shown by Figs. 1,
2, 3, 4 and 5, the first fig. being a section of half a complete chuck with
a jaw and a false jaw in position, the second fig. a top side elevation of
Fig. 1, the third fig. a section, the fourth fig. an elevation showing how
a portion of the bearing according to this part of the invention is intro-
duced into the chuck body, and the fifth fig. various views showing the forma-
tion of the head-end of the traversing screw Fig. 1. In these figs. the outer
end of the traversing screw e near its head c³ is formed with a number of con-
centric sirkings or grooves distanced by concentric collars 5, the sectional
formation of the said collars and grooves being preferably square like the threads
of a square-thread screw. With these collars and grooves which, when the
screw is in position within the chuck body a, come inward of the periphery a² of
the said body, engages a thrust block d of steel, also formed with grooves and
collars d d similar to the ones on the screw, and which is preferably half-ring
shape as shown by Figs. 3 and 4. This thrust block is located and fitted within
a like shaped recess or cut away part a³ formed in the body of the chuck adjacent
to that part of the traversing screw c it engages, and it only protrudes from the
said recess sufficient for its engagement with the grooves and collars,, of the
screw, so that the greater part, or sufficient of it, is let into the recess a³ to take
This thrust
a bearing capable of resisting the backward thrust of the screw.
block d is kept in position within the recess a³ by that part of the traversing
screw it engages, and from rotating or turning therein by a set screw e which is
fitted to the chuck-body so as to engage a part of the said thrust block which lies
within the recess and constitute a stop shoulder. The thrust block d is intro-
duced into the recess a³ through the way at in the chuck-body formed for the
jaw, and its semicircular figure materially helps its introduction into what
would otherwise be a difficult position, the said block being introduced into its
seating after the screw and the jaw f are in position, the latter being traversed
forward to its fullest extent previous to the said block's introduction. The manner
5 of introducing the thrust block d is clearly indicated by Fig. 4, and its disposition
in the recess a³ by Figs. 2 and 3.
The extreme outer end or head 3 of the traversing screw when in position is
bounded by a clearance a³ in the chuck body which is a portion of the jaw-way a',
g bored
but according to this invention the said head-end is supported by a bush
0 to the size of the head-end and of an external diameter to fit the clearance. This
bush is dropped over the end c³ of the screw c in the manner indicated by Fig. 1,
and is fixed to the chuck body so as to prevent its rotation by set pins 93.
5
h is a detachable false jaw of the ordinary construction for bolting onto the
jaw proper f, this false jaw being only shown in Fig. 1.
The second part of this invention is illustrated in the drawing by Figs. 5 and 6.
In these figs. is shown a connection means between the head of the traversing
screw e and the key by which the said screw is rotated, the said means being one

page_text: which will prevent a twisting action upon the engaging faces, which is so frequent
in the ordinary square post and socket connection. According to this part of
the invention the end of the head of the screw is formed with a number of
sinkings whose sides are cut radially true with the centre of the screw c,
and a boss m² on the key end m (Fig. 6) is formed with a number of teeth or
projections m³ of the exact counter part of the sinkings i, so that they can engage
with their abutting faces radially the full area of the screw head. A axial hole n
(Fig. 5) is bored in the head of the screw c adjacent to the said sinking, and a
projecting peg m* (Fig. 6) is centrally fitted to the boss, as aforesaid, in the key,
the said peg and axial hole to constitute a finder for the teeth of the key to the
sinkings of the screw.
The third part of this invention is illustrated in the drawings by Figs. 7, 8;
9, and 10. In these figs. the jaw-ways are strengthened in a particular way
against opening out. In Figs. 9 and 10 a steel band or ring o is let into the
face o of the chuck-body at a point which will not obstruct the traversing move-
ment of the jaws, the said band or ring being preferably contracted when in
position within a groove or seating o³ formed in the chuck-body to receive it. In
Figs. 7 and 8 a screw bolt s is passed transversally through the sides of the jaw
ways in the chuck body so as to cross it and pull and hold the said sides together
to strengthen them against bursting strains. In this case a distance pieces of
steel is threaded upon the bolts to lie between the sides of the way, so that any
contraction of the latter by the bolt being screwed up is prevented.
The fourth part of this invention is set forth in the drawings in Figs. 11 and 12.
This consists in forming upon the face a² of the chuck body a a number of
ribs ³, which stand out from the said face at a point which will not interfere
with the action of the varying sized. grips of the jaws, but which will support the
said jaws in their travel in the ways by forming extended sides to the said ways.
These ribs are preferably cast in one piece with the chuck-body as shown by
Fig. 12, and constitutes a strengthening device which is of particular importance
where loose or false jaws are bolted to the carrier jaws, as additional lateral
support is given to the said false jaws. This part of the invention is indicated
in Fig. 1, the rubs a³, shown in dotted, supporting the false jaw h on each side.
The improvements herein described are in whole or in part applicable to all
chucks having moving gripping jaws irrespective of whether they are indepen-
dently or collectively operated.
Having now particularly described and ascertained the nature of our 'said
invention, and in what manner the same is to be performed, we declare that what
.we claim is:
-
First. In jawed chucks, the use of a thrust block such as d let into a recess in
the chuck-body and engaging the traversing screws or screw pins c in the manner
substantially as described.
Second. In jawed chucks, the combination of a traversing screw or screw pin c
having grooves and collars c, upon it, a thrust block d let into a recess in the
body of the chuck and engaging the said grooves and collars, and a bush g fitted
upon the end of the screw c substantially as described and set forth in Figs: 1 to 5.
Third. A thrust block for the traversing screws of jawed chucks constructed
and introduced into a recess in the chuck body in the manner described and
illustrated in Figs. 1 to 4.
Fourth. A connection means between the traversing screws of jawed chucks
and a key for operating them, characterised by teeth or projections and sinkings
whose engaging facets are formed radially true to the centre of the screw and key
boss formed on the parts substantially as set forth.
Fifth. In jawed chucks, the method described and set forth in Figs. 9 and 10
for strengthening the jaw ways against opening out.
Sixth. In jawed chucks, the method described in Figs. 7 and 8 for strengthen-
ing the jaw ways against bursting or opening on.

page_text: Seventh. In jawed chucks, forming upon the face of the chuck body ribs such
as a for better supporting the jaws in their movement by extending the sides of
the jaw ways.
Eight. In jawed chucks, the particular construction arrangement, and fitting
of the traversing screw bearing as set forth in Figs. 1 to 5.
Dated this in uay
Για αυ
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Also at Liverpool, London, and Manchester,
Patent Agents for the Applicants.