A NEW OR IMPROVED CONSTRUCTION OF BORING TOOL
Year: 1880

page_text: LETTERS PATENT to William Timms, of West Hartlepool, in the County
of Durham, Engineer, for an Invention of "A NEW OR IMPROVED
CONSTRUCTION OF BORING TOOL."
PROVISIONAL SPECIFICATION left by the said William Timms at the
Office of the Commissioners of Patents on the 20th October 1880.
WILLIAM TIMMS, of West Hartlepool, in the County of Durham, Engineer.
"A NEW OR IMPROVED CONSTRUCTION OF BORING TOOL."
This Invention relates to a new or improved construction of tool for boring and
finishing holes in metal, which is specially made capable of adjustment, so that one
size of tool may suit to cut a range of sizes of holes, whilst the wearing parts or
cutters are easily renewed at little cost. The new tool is thus more economical in
primo cost and in use than the ordinary forms of borers and reamers hitherto
employed, with which a separate tool is required for each size of hole, and which
also usually necessitate the replacing of the entire tool when the cutters are
damaged. The new or improved tool comprises a central screwed spindle having a
boss or disc at one end, and formed at the other end with a square for insertion in
the drill spindle of a drilling machine, or for being gripped in a lathe. The boss or
disc has three or more longitudinal grooves cut in it for the insertion of an equal
number of small steel cutters, which are made to fit accurately in these grooves,
and to project radially from the disc or boss to the requisite extent for the size of
hole to be bored or cut. The grooves are formed with tapered or inclined channels
or bottom parts expanding outwards, on which the cutters which are corre-
spondingly tapered on their under surfaces rest. The cutters are retained by
notches cut near their inner ends to catch on to a turned collar on the outer end of
a hollow sleeve screwed externally. This sleeve is free to slide longitudinally on
the central spindle, and thereby adjusts the cutters to the desired expanded position
by sliding them out or in on the inclined surfaces of their grooves. A screw nut
on the central spindle keeps the sleeve and cutters from sliding back, while the
cutters are pressed down and firmly held in their grooves in the disc or boss by
means of a strong screwed nut fitted on the hollow screw spindle or sleeve, and
having a turned internal bevilled surface bearing on the inner ends of the cutters,

page_text: which are correspondingly bevilled immediately over their retaining notches. This
screw nut and bevilled cap may be tightened up by a screw key, and held fixed by
a jam nut behind it, and the nut on the central spindle retaining the sleeve and
cutters in position may also be fixed by a jam nut. The cutters are made nearly
rectangular in cross section with a cutting edge parallel or nearly so to the longi-
tudinal centre of the tool, and they are shifted longitudinally on the inclined
surfaces of their retaining grooves to expand or contract the radial position of the
cutting edges, and thus adjust them with precision to cut any size of hole within
the range or limits to which the size of tool is adapted.
The improved tool may either be fitted in the drill spindle of a vertical boring 1
machine to revolve in cutting or boring, or be held stationary in a lathe with the
work fixed on the revolving chuck.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Timms in the Great Seal Patent Office on the 16th April
1881.
WILLIAM TIMMS, of West Hartlepool, in the County of Durham, Engineer.
"A NEW OR IMPROVED CONSTRUCTION OF BORING TOOL."
My said Invention relates to a new or improved construction of tool for boring
and finishing holes in metal, which is specially made capable of adjustment, so that
one size of tool may suit to cut a range of sizes of holes, whilst the wearing parts
or cutters are easily renewed at little cost. The new tool is thus more economical
in prime cost and in use than the ordinary forms of borers and reamers hitherto
employed, with which a separate tool is required for each size of hole, and which
also usually necessitate the replacing of the entire tool when the cutters are
damaged.
My improved boring tool is illustrated in the accompanying Drawings, of which
Figures 1 and 2 are respectively a side and end elevation; Figures 3 and 4 are a
longitudinal and transverse section respectively taken as at the lines 1--1 and 2--2
on each other; and Figures 5 and 6 are a detached elevation and plan of the cutters
used in the improved tool.
Referring to these Drawings the new or improved tool comprises a central
screwed or partially screwed spindle A, having a boss or disc A' screwed on or
otherwise fixed at one end, and formed at the other end with a square A³ for
insertion in the drill spindle of a drilling machine, or for being gripped in a lathe.
The boss or disc A' has three or more longitudinal grooves a cut in it for the
insertion of an equal number of small steel cutters B, which are made to fit
accurately in these grooves a, and to project radially from the disc or boss A¹ to
the requisite extent for the size of hole to be bored or cut. The grooves a are
formed with tapered or inclined channels or bottom parts extending outwards at a¹,
on which the cutters B, which are correspondingly tapered at 6 on their under
surfaces, rest. The cutters are retained by notches b¹ cut near their inner ends to
catch on to a turned collar c on the outer end of a hollow sleeve C screwed
externally. This sleeve C is fitted free to slide longitudinally on the central spindle,
and thereby adjusts the cutters to the desired expanded position to suit the size of
hole to be bored by sliding them out or in on the inclined surfaces of their grooves.
The screw sleeve Ŏ is kept from turning by means of a groove C² in it, and a
feather on the spindle A, which at that part is reduced in diameter, and is not
screwed. A screw nut D on the screwed part of the central spindle keeps the
sleeve C and cutters B from sliding back, while the cutters B are pressed down and
firmly held in their grooves in the disc or boss by means of a strong screwed nut
or cap E fitted on the hollow screw spindle or sleeve C, and having a turned
internal bevilled surface & bearing on the inner ends of the cutters B, which are
correspondingly bevilled outside at 6², immediately over their retaining notches b'.
This screw nut and bevilled cap E may be tightened up by a screw key, and held
fixed by a jam nut E¹ behind it, and the nut D on the central spindle A retaining
the sleeve C and cutters B in position may also be fixed by a jam nut, as shown
dotted at D. The cutters B are made nearly rectangular in cross section with a
forward projecting cutting edge 63 parallel, or nearly so, to the longitudinal centre
of the tool, and they are shifted longitudinally on the inclined surfaces of their
retaining grooves a outwards or inwards to expand or contract the radial position
of the cutting edges 63, and thus adjust them with precision to cut any size of hole
within the range or limits to which the size of tool is adapted, such as, for example,
any size between two and two and a half inches. The notches b' of the cutters B

page_text: are cut with a tapered surface to bear on a corresponding bevilled or conical edge
of the collar c, so that as the cutters B are moved outwards to suit a larger size of
hole to be bored, the inner ends of the cutters may be raised, and their bevilled
bearing surface b may rest flat on the bottom surface of the grooves a.
The improved tool may either be fitted in the drill spindle of a vertical boring
machine to revolve in cutting or boring, or be held stationary in a lathe with the
work fixed on the revolving chuck.
Having thus described the nature of my said Invention, and the manner of
performing the same, I have to state that what I consider novel and original, and
therefore claim as the Invention secured to me by the hereinbefore in part recited
Letters Patent is,―
First. The construction, arrangement, and combination of the parts of a tool for
boring or finishing holes in metal, in which the cutters are fitted on bevilled
bearings, and are capable of adjustment to cut or bore different sizes of holes,
substantially as herein described and shown in the accompanying Drawings.
Second. The construction and fitting of tools for boring or finishing holes in
metal with movable cutters held in bevilled groove bearings, and adjusted by means
of a hollow sleeve and screw nuts on the tool spindle to adapt such tools for cutting
different sizes of holes, substantially as herein described in reference to the
accompanying Drawings.
In witness whereof, I, the said William Timis, bave hereunto set my hand
and seal, this Fifteenth day of April, in the year of our Lord One thousand
eight hundred and eighty one.
Witness,
WALLACE FAIRWEATHER, C.E.,
of W. R. M. Thomson & Co.,
Patent Agents,
Glasgow,
WILLIAM TIMMS. (L.S.)