IMPROVEMENTS IN CHUCKS FOR LATHES
Year: 1885

page_text: I JOSEPH DELGER of Melson Street Luton in the County of Bedford Engineer
do hereby declare the nature of said invention for "IMPROVEMENTS IN CHUCKS
FOR LATHES" to be as follows:-
This invention relates to a peculiar construction and arrangement of adjustable
chuck for facilitating the turning of eccentric work in Lathes of all kinds and
consists of a separate boss fitted eccentrically into the ordinary chuck or mandrel
itself, and capable of being adjusted therein by a rotary adjustment so that the
axis of revolution of the said adjustable boss shall either coincide with the axis of
revolution of the mandrel or, shall be brought into a position eccentric thereto the
amount of such eccentricity being capable of the most minute adjustment by
circularly adjusting the said boss inside the ordinary chuck or mandril a graduated
scale combined or not with a vernier being employed if desired for indicating the
exact amount of eccentricity to which the boss has been adjusted.
The work to be turned is secured in any convenient or well known manner to
the circularly adjustable boss and if plain work is required the boss will remain in
its normal position that is to say eccentric to the mandril and the work fixed
thereto, approximately in line with the axis of rotation of the mandrel and then
accurately set by the rotary adjustment of the boss.
According to the degree of eccentricity required in the work the boss is circularly
adjusted to a corresponding extent. If found desirable the end of the adjustable
boss may be enlarged to any extent so as to form a circularly adjustable face plate
on which work may be chucked in the ordinary manner. By boring the adjustable
boss in the line of the axis of rotation of the mandril to receive various sized
hollow bushes therein the said bushes will be found useful as holders for ordinary
drills of any size or as holders for various kinds of work to be turned or for
receiving ordinary centres for plain turning. When drills are employed it is obvious
that they can be accurately adjusted by the aforesaid arrangement so as to run
perfectly true at the point.

page_text: I JOSEPH DELGER of Melson Street Luton in the County of Bedford Engineer do
hereby declare the nature of my invention for "IMPROVEMENTS IN CHUCKS FOR
LATHES" 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 a peculiar construction and arrangement of adjustable
chuck or holder suitable for use in turning eccentric work in Lathes and consists
in the combination with the revolving mandrel or spindle or with a removeable
block or head secured thereto of a circularly adjustable boss fitted eccentrically
therein, and capable of adjustment by being turned on its longitudinal axis.
Within this circularly adjustable boss there is in some cases formed longitudinally
a bore disposed eccentrically to the axis of the said,boss but in such a position as
to be capable of being brought by the circular adjustment of boss, in line with the
axis of rotation of the mandrel or spindle. This bore serves to hold the smaller
kinds of work to be operated upon or a drill or other like tool or an ordinary lathe
centre or which I prefer a removeable bush in which such articles can be fixed. By
suitably adjusting the said boss inside the mandrel or the holding block the work
or article carried thereby can either be brought accurately in line with the axis of
rotation. of the mandrel or spindle or when required into a position more or less
eccentric thereto the amount of eccentricity being ascertained and indicated with
the greatest accuracy by the aid of a graduated scale and index combined or not
with a vernier. The outer end of the said circularly adjustable boss may if desired
be enlarged to any extent so as to form a circularly adjustable face plate or the
face plate may be made separate and attached to the said boss. This face plate
will be found useful for carrying the larger kinds of work which may be chucked
or secured thereon in any well known or suitable manner. If plain or ordinary
turning be required the work may be secured to the adjustable boss or face plate
so as to be approximately concentric with the axis of rotation of the mandrel and
then accurately set or adjusted by the circular adjustment of the boss which may
then be fixed in its adjusted position by a set screw.
When eccentric work is to
be turned such for example as eccentrics for sewing machines and the like the
exact amount of eccentricity required is obtained by circularly adjusting the
boss to the required extent as indicated by the graduated scale and index.
using the said chuck as a holder for a drill for example, the drill can be accurately
centred or adjusted by the aforesaid circularly adjustable boss so as to run perfectly
true at the point.
In
Figure 1 of my drawings is a detached front end view of one form of my
improved chuck complete. Figure 2 is a corresponding side elevation of the same.
Figure 3 is a transverse section of the improved chuck taken along the line 1-2
in Figure 2 and showing the bore of the circularly adjustable boss in its concentric
position. Figure 4 is a longitudinal section thereof taken along the line 3-4 in
figure 3. Figure 5 is a view similar to Figure but showing the bore in the
adjustable boss adjusted to its extreme limit of eccentricity and Figure 6 is a side
elevation of the said chuck as formed with an enlarged face plate for receiving
work of various kinds to be secured thereto by screws or other well known
contrivances,

page_text: A is a cylindrical or other shaped block or head forming the main body of. the
chuck which block is shown at Figure 4 as adapted for being screwed to the nose
of a lathe mandrel or other rotary spindle although it may obviously be secured
thereto in various other ways or may even form the end of the mandrel or spindle
itself if desired. In a longitudinal bore made eccentrically in the said block or
removeable head there is fitted the circularly adjustable cylindrical boss B fixed
securely therein in its adjusted position by a set screw C or other well known means.
D is the longitudinal bore in the adjustable boss also situate eccentrically therein
for the purpose of receiving a bush E (one of which is shown by way of example
only in front view and side elevation detached at Figure 7) said bush serving as a
holder. for small work such as the spindles and eccentrics employed in sewing
machines one of which is illustrated (by way of example only) at Figure 8 or it
may be used as a holder for a drill or a lathe centre as hereinbefore stated. F is
the index shown in figure 1 as secured to the adjustable boss and G is a divided or
graduated scale on the end of the block or mandrel A for facilitating the setting
of the work or article carried by the boss B either concentrically with the axis of
the mandrel or to any given amount of eccentricity. In order to protect the scale
and index from injury I prefer that they should be sunk or recessed more or less
in the end of the block or mandrel as shown in figure 1. This figure also shows
the circularly adjustable boss and scale so arranged that when the index is at zero
on the scale the axis of the bore D will coincide with the axis of revolution of the
mandrel as illustrated by the dotted circle d but by circularly adjusting the boss B
inside the block or mandrel A within a range of a half revolution various inter-
mediate degrees of eccentricity can obviously be obtained. In my drawing
(figure 1) I have shown the bore D as adjusted to about 3/10 ths (three tenths) of
its extreme range of adjustability. H is a set screw for fixing the work or the
bush or holder E in the bore D a hole being made in the side of the bush (see
figure 7) for the entrance of the end of the set screw. I is a slot or groove made
transversely across the mandrel or block A to admit of the screw H being brought
to any desired position when circularly adjusting the boss B. Figures 3 and 5
show the said screw in its two extreme positions. If desired the end of the boss B
may be made to project sufficiently beyond the block A to carry the screw Hin
which case the slot I will not be required but I prefer the arrangement shown in
my drawings. In figure 6 K represents an enlarged face plate here shown as
formed in one piece with the circularly adjustable boss and L, L, are screws or other
suitable contrivances for fixing the work on the said face plate. In this arrange-
ment which will be found useful when operating upon the larger kinds of work,
the index F may be fitted to the block A and the scale formed on the back of the
face plate or the scale may be formed round the cylindrical surface of the block A
and the index be fixed to the back of the face plate K, but in all essential
particulars the chuck will be substantially of the same construction as that
described with reference to figure 1.
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 adjustable chucks or holders suitable for use in turning eccentric work in
lathes the combination with the mandrel or spindle or with a removeable head or
block secured thereto of an eccentrically disposed and circularly adjustable boss
provided or not with a face plate and serving as the holder of the work to be
operated upon or of drills lathe centres or other like tools or appliances substantially
as herein before described.
2. Forming the aforesaid circularly adjustable boss with a longitudinally and
eccentrically disposed bore or recess for the reception of the work or a bush for
holding the work to be operated upon or a drill, or other tool or a lathe centre
substantially as hereinbefore described.

page_text: 3. The combination with the aforesaid circularly adjustable boss of a face plate
to which the work may be fixed in any ordinary or suitable manner substantially
as herein before described.
'
4. The use in combination with the aforesaid eccentrically disposed and circularly
adjustable boss whether provided or not with a face plate, of an index and divided
scale for facilitating the accurate setting of the article carried thereby to any given
amount of eccentricity substantially as herein before described.