Machine Tool Attachment, chiefly Designed for Machining Inside Surfaces of Engineering Work, as Ports; Valve-faces; Seatings: and the like, of Locomotive, Stationary, Marine, Hydraulic and other Engines.
Year: 1889

page_text: Date of Application, 10th Dec., 1889
Complete Specification Left, 8th Sept., 1890-Accepted, 15th Nov., 1890
PROVISIONAL SPECIFICATION.
Machine Tool Attachment, chiefly Designed for Machining Inside
Surfaces of Engineering Work, as Ports; Valve-faces; Seatings:
and the like, of Locomotive, Stationary, Marine, Hydraulic and
other Engines.
WILLIAM FRANK PETTIGREW 44 Guildford Road South Lambeth London, S.W.
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to machine tools of that kind or class adapted for machining.
those parts of engines as the steam, exhaust and other ports, valve faces, valve
seatings and the like, and which parts are inaccessible for machining in the ordinary
way.
It consists of an arrangement for attaching, either by bolts, studs, set screws or
cotters, to the sliding head of vertical milling, drilling or other machines in which a
rotary motion is obtained, and it may be used for milling, tapping, drilling, slot
drilling, rymering &c. those parts of engines before specified.
In the case of a pair of inside locomotive or other cylinders, cast with the two or
more steam chests in one, it is necessary to machine the valve faces all over as well
as machining around the inside edges of steam and exhaust ports, and for such
purposes this machine tool has chiefly been designed.
According to this invention the cylinders or other parts of engineering work are
fixed to the compound slide table of a vertical milling, drilling or other machine
having a sliding head and rotary motion to its spindle. The vertical feed is thus
obtained through the sliding head onto which the machine tool constituting the
invention is fixed, whilst longitudinal, transverse and circular motions are obtained
through the intervention of the compound slide table aforesaid.
My invention consists of
(a) A casting either of iron, steel or other metal of suitable dimensions &
strength of either circular, box or other section, suitably machined by turning,
boring, facing, drilling and the like to receive a
(b) Vertical steel or other spindle, which is passed through the above casting.
One end is turned & preferably screwed to enter the vertical milling, drilling or
other machine spindle, whilst to the other end there is fixed a bevel, mitre or helical
wheel, or a worm gearing into a bevel, mitre, helical or worm wheel fixed onto a
(c) Hollow mandril or spindle forming the socket for tool, whether it be a milling
cutter, drill, rymer, tap, rosebit or other. This hollow mandril or spindle runs in
the bottom recess or box of aforesaid casting and the tool is secured in it by
means of one or more set screws passing through the mandril or spindle & securing
the tool to it.
1
In order to render the above apparatus suitable for working in arcs of or .a
complete circle as when maching the ports of a circular or piston valve, steam chest,
the casting is made in two parts and fitted with worm gearing for rotating it
through any desired angle either automatically or by hand.
Dated this 10th day of December 1880

page_text: end of spindle "B" a hole "O" is drilled through "A" and thus permite pin "L"
being inserted or taken out. The hole "P" in casting "A" is used in conjunction
with a flat formed on the collar "B" " of spindle "B." A bar placed through "P"
causes the spindle "B" to remain, stationary when being entered into or withdrawn
from the nose of spindle of machine to which my invention is to be attached or
detached as the case may be.
Having now stated the main features of my machine tool attachment I will now
proceed to describe it in operation.
The casting "A" and spindle "B" are secured to the milling or other machine
simultaneously; that is to say that whilst "A" is being entered upon the studs
(screwed into the machine) or by other attachment, the neck "B¹" of spindle "B"
also enters the nose of the machine spindle which being revolved preferably by
hand and the spindle "B" prevented from revolving by placing a bar through
the hole "P" in casting "A" and the casting "A" being prevented from revolving
owing to its being entered upon the studs or otherwise, the said studs being fixed
in the machine to which the tool attachment is to be secured or set screws may be
used in place of the before mentioned studs.
When the neck "B" is secured in the nose of machine spindle & the flange "S"
of casting "A" finally secured to the machine it will be found that motion is given
to the hollow spindle "C" in which the necessary tools are secured for operating
upon the work.
The work to be operated upon is secured to the table of the machine to which my
tool attachment is fixed & in all modern machines of the milling & drilling type
the said table is provided with compound slides giving circular transverse and
longitudinal motions whilst vertical movement is obtained through the sliding head
in the case of a milling machine to which the tool attachment is fixed or in the case
of a drilling machine & some classes of milling machines through the table to which
the work is attached & from this it will be understood that plane or circular work
may be machined by the use of my invention. The circular works being such as
ports & other openings in piston valve steam chests and such like, whilst the plane
work may be such as occurs in all classes of engineering work.
The machine tool attachment may be attached or detached from the machine it is
working in conjunction with either before or after the work to be operated upon has
been secured to machine table, and the milling cutters, taps, drills, slot drills,
rymers, rose bits & such like, all of which are suitable for use with the machine
tool attachment in question may be inserted or withdrawn from the hollow
spindle "C" at the operators convenience.
From the foregoing it is evident that I can somewhat modify the construction
of my machine tool attachment without departing from the nature of my said
invention.
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
First. In a machine-tool attachment for the purposes above specified, a hollow
spindle forming a tool holder and means for rotating the said spindle upon or about
its axis.
Second. The combination of a casting and spindle, the said spindle fitted to rotate
in the spindle of the machine to which the machine tool attachment is fixed.
Third. The improved machine tool attachment consisting of the parts constructed
and combined substantially as described with reference to the accompanying
drawing and operating substantially as and in conjunction with a machine as set
forth, and for the purpose above specified.
Dated this 3rd day of September 1890.