Improvements in Turning, Planing, and like Tools, and in Holders therefor.
Year: 1892

page_text: Date of Application, 30th Jan., 1892
Complete Specification Left, 7th Apr., 1892-Accepted, 7th May, 1892
PROVISIONAL SPECIFICATION.
Improvements in Turning, Planing, and like Tools, and in Holders
therefor.
I, THOMAS BLEARS, of 56, Freme Street, Chorlton-on-Medlock, in the County
of Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an improved turning tool and an improved tool holder,
so arranged as to enable accurate and steady adjustment to be made and maintained.
My improved tool is applicable with various modifications of the holder, to the
purposes of turning, planing, slotting, screwing, and boring, and other modifications
of metal cutting and finishing.
In carrying the invention into effect as applied for turning purposes I arrange a
circular steel disc, the circumference of which is turned all round, of the
configuration required in a turning tool. I grind into the edge of this disc a
recess, leaving a cutting edge with the necessary angle from front to back. I
drill one or more holes in the disc; preferably, however, I drill three holes equally
disposed round the centre and close to it.
This disc with the cut in recess, forms my cutting tool, and I mount it in a tool
holder between two jaws, and I clip the disc cutting tool between the jaws by a
bolt passed through it.
The tool stem is preferably forged solid with the jaws and is so placed that its
general axis is below the centre of the disc as held in the jaws. I drill out this tool
stem and insert therein a thrust pin, which thrust pin I screw home by means of a
forcing screw inserted in the end of the stem. The thrust pin is of sufficient length
to pass completely through the stem and come into contact with a part of the
cutting disc circumference below the centre, round which it rotates, and between
the gripping jaws. When the forcing screw is screwed home the action is
thus communicated by the thrust pin to the cutting disc, and the said cutting
disc is rotated about the centre from which it swivels or is secured. The
cutting edge, formed by the recess or gap in the front edge, is thus caused to
move forward or rise higher or towards the line of the centre round which it
rotates. I am thereby enabled to adjust the said cutting edge either to raise or
lower it.
As the tool wears it is sharpened by grinding round the circumference of the
disc, and the position of the cutting edge is conveniently adjusted by the aid of
the forcing screw to suit the alteration caused by grinding. To enable the whole
edge or circumference of the cutting disc to be utilized, I prefer to drill three
holes in it disposed equally round the centre, and these holes enable me to
follow up the disc by the thrust pin, so as to rotate completely round the
circle.
When the thrust pin has followed the disc through a third of a circle, or so
far beyond a third as may be convenient, I withdraw the bolt from the jaws and
rotate the disc to bring the next hole opposite the holes in the jaws, I then
insert the bolt and screw up the jaws again, at the same time withdrawing the
thrust pin to give a fresh start. In this manner I am enabled to rotate the cutting
disc round the complete circle and utilize the whole of the circumference for
cutting purposes. My new tool holder, by aid of the jaws and clipping bolt firmly
holds the disc tool without vibration; while the thrust pin takes the full pressure
of the cut without any possibility of shift on the part of the tool during action,
by slipping. At the same time the thrust piece and forcing screw permit of
the greatest possible accuracy in setting the tool and also allow a tool to

page_text: be readily set for different heights of centres relatively to the slide rest in different
lathes, without resorting to packing up or other temporary expedients.
The tool may be made with two or more slots or sets of jaws to carry two or more
cutting discs, and so dises may be set to take different cuts in succession, a rough
heavy cut for example may be followed by a light or finishing out, and so tools may
be combined to finish, or almost finish the turning operation at one traverse of the
slide rest. Screw cutting tools may also be applied and a finishing comb cutter may
be applied to follow a screw cutting cutter.
By my device several cutters may readily be thus applied to operate in immediate
succession.
My straight tool holder may be readily applied to planing, shaping and like
purposes with similar advantage.
In applying my tool holder and cutter to boring purposes I arrange the front part
of the holder stem at right angles or at an angle to the main stem, and I carry my
circular cutter in jaws at such angles. I then apply the thrust pin through a hole
drilled in line with the jaws, and insert the forcing screw in a projection from the
stem of the tool holder, through its side. Or a double thrust pin may be
applied adjusted from the outer end.
Dated this 29th day of January 1892.
CLERK & MARKS,
13, Temple Street, Birmingham, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Turning, Planing, and like Tools, and in Holders
therefor.
I, THOMAS BLEARS, of 56, Freme Street, Chorlton-on-Medlock, in the County of
Lancaster, 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:-
My invention relates to an improved turning tool and an improved tool holder
so arranged as to enable accurate and steady adjustment to be made and maintained.
My improved tool is applicable with various modifications of the holder to the
purposes of turning, planing, slotting, screwing and boring and other modifications
of metal cutting and finishing.
Referring to the accompanying sheet of drawings in which Figures 1, 2, 3 and 4
illustrate my invention carried into effect as applied for turning purposes; I arrange
a circular steel disc A, the circumference of which is turned all round, of the
configuration required in a turning tool. I grind into the edge of this disc a
recess A leaving a cutting edge A with the necessary angle from front to back.
1 drill one or more holes in the disc; preferably, however, I drill three holes
equally disposed round the centre and close to it as shown in Figures 1 and 3.
This disc A with the cut in recess A' forms my cutting tool, and I mount it in a
tool holder B between two jaws B1, B2, and I clip the disc cutting tool between the
jaws by a screw bolt C passed through it. The tool stem B is preferably forged
solid with the jaws B1, B2 and is so placed that its general axis is below the centre
of the disc A as held in the jaws. I drill out this tool stem and insert therein a
thrust pin D, which thrust pin 1 screw home by means of a forcing screw E
inserted in the end of the stem. The thrust pin D is of sufficient length to pass
completely through the stem and come in contact with a part of the cutting dise
circumference below the centre C round which it rotates and between the gripping
jaws. When the forcing screw E is screwed home the action is thus communicated
by the thrust pin D to the cutting disc, and the said cutting disc is rotated about
the centre C from which it swivels, or is secured. The cutting edge A2 formed by
the recess or gap A' in the front edge, is thus caused to move forward or rise higher

page_text: or towards the line of the centre round which it rotates.
adjust the said cutting edge either to raise or lower it.
I am thereby enabled to
As the tool wears it is sharpened by grinding round the circumference of the
disc, and the position of the cutting edge is conveniently adjusted by the aid of
the forcing screw E to suit the alteration caused by grinding. "To enable the whole
edge or circumference of the cutting disc A to be utilized, I prefer to drill three
holes in it, disposed equally round the centre, and these holes enable me to
follow up the disc by the thrust pin D so as to rotate completely round the
circle.
When the thrust pin D has followed the disc A through a third of a circle,
or so far beyond a third as may be convenient, I withdraw the bolt C from the
jaws and rotate the disc to bring the next hole opposite the holes in the jaws B1, B2,
I then insert the bolt C and screw up the jaws, again at the same time withdrawing
the thrust pin D to give a fresh start. In this manner I am enabled to rotate the
cutting disc round the complete circle and utilize the whole of the circumference
for cutting purposes. The dotted circles marked F in Figures 1 and 3 indicate
the line of grinding, and nearly the whole circumference of the disc may be ground
away to the line before a new disc is required. My new tool holder, by aid of
the jaws and clipping bolt firmly holds the disc tool A without vibration, while the
thrust pin D takes the full pressure of the cut without any possibility of shift by
slipping on the part of the tool during action. At the same time the thrust pin or
piece D and forcing screw E permit of the greatest possible accuracy in setting the
tool, and also allow a tool to be readily set for different heights of centres relatively
to the slide rest in different lathes, without resorting to packing up or other temporary
expedients.
The tool may be made with two or more slots or sets of jaws to carry two or
more cutting discs, and so dises may be set to take different cuts in succession, a
rough heavy cut for example may be followed by a light or finishing cut and so
tools may be combined to finish, or almost finish the turning operation at one traverse
of the slide rest. Screw cutting tools may also be applied and a finishing comb
cutter may be applied to follow a screw cutting cutter.
By my device several cutters may readily be thus applied to operate in immediate
succession.
My straight tool holder may be readily applied to planing, shaping and like
purposes with similar advantage.
Figure 1 is a section of my straight tool holder and figure 2 is a plan.
In applying my tool holder and cutter to boring purposes I arrange the front
part of the holder stem or jaws B1, B2 at right angles or at an angle as shown in
Figures 3 and 4 to the main stem B and I carry my circular cutter A in the jaws
at such angles. I then apply the thrust pin D through a hole drilled in line with
the jaws and insert the forcing screw in a projection from the stem of the tool
holder through its side. Or a double thrust pin may be applied adjusted from the
outer end. I prefer however to operate the circular cutter A by means of a screw
bolt and nut G (Figures 3 and 4) and the wedge piece G. When the bolt G is
screwed up by its nut the wedge or incline surface Grotates the circular cutter A
about the centre C, and the screw H is adopted to adjust the play of the incline
piece G. This bolt C is shifted to the next hole when the cutter A has moved out
of range, and so the cutter is completely rotated till the whole cutting surface has
been entirely utilized.
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. A turning, planing or like tool which consists of a circular disc having
its circumference of the configuration desired in a cutting or screwing tool, the
cutting edge being formed by means of a notch or recess in the circumference and

page_text: the disc being rotated on a pin or bolt passed through it, at a position out of its
centre, substantially as and for the purposes hereinbefore described.
2. A tool holder carrying a disc cutting tool in jaws; the said disc cutting tool
being adjusted, rotated and held against its work by a thrust pin or wedge piece
acting on a part of its circumference at one side of the centre substantially as herein-
before described and as illustrated in the accompanying drawings.
3. A tool holder as claimed in Claim 2 combined with a disc cutting tool in which
three holes are arranged round the centre to enable the said disc to be completely
rotated by the thrust pin or wedge piece in order to utilize the whole circumference
for cutting, substantially as hereinbefore described and illustrated.
4. The tool holders liereinbefore described as illustrated at Figures 1, 2, 3 and 4
of the accompanying drawings.
Dated this 6th day of April 1892.
CLERK & MARKS,
13, Temple Street, Birmingham, Agents for the Applicant.