Improvements in Machinery or Apparatus for Centring, Preparing, and Countersinking Bars, Studs, and similar articles Ready for Turning.
Year: 1892

page_text: Date of Application, 2nd June, 1892--Accepted, 10th Sept., 1892
COMPLETE SPECIFICATION.
Improvements in Machinery or Apparatus for Centring, Preparing,
and Countersinking Bars, Studs, and similar articles Ready for
Turning.
I, WILLIAM WEBSTER, of Alameda Villa, Armley, Leeds, in the County of
York, Engineer, 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 :-
The usual practice in engineering works for centring, preparing or facing the
ends and countersinking the centres of bars, previous to their being turned is
first to punch a conical indent in each end of such bar, by means of a centre punch,
then by any simple driving apparatus one end of the bar under treatment is
gripped by a chuck or otherwise caused to rotate, or it may be between centres,
one of which is what is known as a "square centre" that is having a pyramidal point,
being a tool for enlarging the said conical indentations.
Should the bar not rotate truly, lateral pressure is gradually applied thereto,
till this is attained.
After the centres have been produced in the ends of such bars, they are prepared
or faced by a hand side tool whilst rotating in the lathe, afterwards the centres
being countersunk by a brace and small drill, or by means of a fiddle drill and
bow, in some instances it is done in the drilling machine.
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My invention consists in a lathe for centring, preparing and countersinking, bars,
studs and similar articles, previous to their being turned; the fast headstock of
this lathe is provided with a hollow rotating spindle, having a suitable jaw'd chuck
on the end thereof for gripping and rotating the bars to be operated on, it is also
provided with a poppet head of the usual construction, the loose spindle of this
poppet head, carries on the end thereof a suitable chuck, provided with drills
which may be either of the "twist, or grooved" description, or the ordinary flat
spear" form; one of these drills I call the "main drill" the point of which is
used for producing the centres in the ends of the bars, this main drill is held
in the centre of the above named chuck, and is exactly in a line and opposite the
centre of the hollow rotating spindle of the fast headstock, on one side of this main
drill, on a stud carried also by the said chuck, is carried an arm or lever provided
with a small drill when this small drill is required to be used the said arm or
lever is brought into position in front of the main drill, against a projection
or stop also carried on the said chuck, the back part of the arm or lever being
somewhat clear of the point of the main drill, the said arm or lever having a
projecting piece, which bears against the face of the said chuck for taking the end
pressure whilst drilling, in this position the small drill is in the same centre line
as the main drill, and is ready for drilling the small hole or countersink" forming
the clearance bole for the point of the turning centre; when the small drill is not
in use the arm or lever is turned back out of the way.
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On one side of the main drill is provided a side or end cutter, carried also by
the said chuck in a suitable holder, the cutting edge of this side or end cutter is
fixed a certain distance back from the point of the main drill, and is used for
preparing, or facing and truing the ends of bars at the same time the operation of
centring with the main drill is being performed.
In order to insure the bar running perfectly true with the main drill, during the
operation of centring and facing, I provide a suitable rest having a slide carrying
a steel "vee piece" which bears against the rotating bar until it revolves perfectly
true, the said slide being adjustable to suit various diameters of bars.

page_text: With such a lathe as above described, the centring, preparing and countersinking
is performed in the following manner, one end of the bar to be operated on, is
placed in the said moveable jaw'd chuck on the end of the hollow spindle of the
fast headstock and properly secured therein, when it is caused to rotate, the steel
vee piece of the rest is then brought to bear against outer end of the rotating bar until
it revolves accurately true, then the spindle of the poppet head carrying the centring
chuck is caused to advance toward the outer end of the bar the "main drill " point
entering the end of such revolving bar for a certain distance when the side or end
facing cutter begins to face or end such bar, the said spindle is advanced still further
until the end is sufficiently faced, the spindle is then withdrawn for a certain distance,
and the arm or lever carrying the small drill is brought into position, and the spindle
again advanced for a certain distance, so drilling the countersink hole, for the clearance
of the turning centre, the lathe is now stopped and the bar taken out and reversed
in the lathe, the same operations being performed on the contrary end, when this
has been done, it is taken out of the lathe and is ready for turning.
The centring and facing may be performed by another chuck in a similar manner,
this chuck I mount in or on the loose spindle of the poppet head of an ordinary
lathe.
For general use I make the shank of the said chuck to fit the taper hole usually
provided in the loose spindle of any poppet head, the projecting head of the chuck
being of a suitable diameter and length, through the centre of such chuck.
I carry
a straight grooved drill the point of which projects, and in the head of the chuck
on one side of the centre, I make a groove a certain distance deep from the end,
for carrying a facing or ending cutter, on this ending cutter is formed a shank,
the outside of such shank being made to fit the hollow groove of the drill whilst
the reverse side of the shank is rounded to fit the side of the hole in the chuck
for the reception of the straight grooved drill, this shank serves the place of a die
for the set screw to pinch against so fixing both the facing cutter and the grooved
drill in the proper position.
In the accompanying sheet of explanatory drawings, in which similar letters of
reference indicate like parts,
Fig. 1 is a front elevation of a lathe according to my invention,
Fig. 2 is a front view of the jaw'd chuck,
Fig. 3 is a front elevation of the steadying rest,
Fig. 4 is an enlarged plan of the centring preparing and countersinking chuck,
Fig. 5 is a side elevation of same,
Fig. 6 is an end view of same,
Fig. 7 is a plan of a centring and preparing chuck as used in an ordinary lathe.
Fig. 8 is a side elevation, whilst Fig. 9 is a plan of same.
In Fig. 1; the bed A of the machine is carried on standards which are only
partially shown, on bed A is fixed the fast headstock B fitted with the hollow rotating
spindle C carrying the moveable jaw'd chuck D for gripping and revolving the
work, the moveable jaws E and F being actuated by the right and left hand
screw G; His the adjustable rest with moveable slide I carrying the vee piece J on
arm K the moveable slide I being adjustable vertically by screw Land hand
wheel M to suit different diameters of bars to be operated on N is the loose poppet
head fitted with the movable spindle O actuated by the screw P and handwheel Q
in the usual manner, on the end of the moveable spindle O, is fitted the centring
preparing and countersinking chuck R, shown in enlarged drawing Figs. 4. 5 and 6
this chuck being fixed to the spindle O by screw S, the main drill T in the centre
of the chuck R is held in position by the lockbolt U; on the stud V held in
position by set screw W, is carried 'the arm or lever X having the small drill Y,
fixed in position by the pinch screw Z closing the slit A' on the boss of this arm
or lever X, is the heel piece B, which rests against the stop piece C¹ when the
arm or lever is thrown back, as shown on drawing; when the arm is in position for
drilling, the rest piece D' comes against the stop piece C₁ whilst the block E¹
rests against the face of the chuck to take the pressure whilst drilling, on one side

page_text: of the chuck R, is fixed in a suitable holder the preparing or end facing cutter F¹
held in position by set screw G¹.
In Figures 7. 8 and 9; H¹ is a chuck for centring and preparing only, through
the centre of this chuck is carried the straight grooved drill I', the preparing or
end cutter J', having a shank K' on one side thereof, and held in position by the
set screw L'
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is-
1. The construction of a lathe having a fast headstock provided with a hollow
rotating spindle, with a moveable jaw'd chuck on the end thereof, for holding the
articles, an adjustable steady rest, and a loose poppet head the loose spindle of
which carries on the end thereof the centring, preparing and countersinking chuck,
substantially as described and shown.
2. The centring, preparing and countersinking chuck Figs. 4. 5 and 6 substantially
as arranged and described.
3. The centring and preparing chuck Figs. 7. 8 and 9 having a preparing or end
facing cutter with a shank on one side thereof, for the purpose specified, substantially
as described and shown.
4. The use of the point of a twist, grooved or spear shaped drill, for the purpose
of centring, bars, studs and similar articles such articles rotating during the
operation substantially as described.
5. The steady rest having a moveable carriage capable of vertical adjustment
and carrying on an overhanging arm a vee piece, substantially as described and
shown.
1
T
1000
THOS. E. CRAVEN,
For the Applicant.