Improvements in Drills and Cutters for Undercutting in Iron, Wood, Stone, and other Kindred Materials.
Year: 1891

page_text: Date of Application, 2nd Jan., 1891
Complete Specification Left, 12th May, 1891-Accepted, 18th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in Drills and Cutters for Undercutting in Iron, Wood,
Stone, and other Kindred Materials.
JAMES ALFRED DERHAM Number 77 Wellfield Road Preston, in the County
of Lancashire Boiler Maker, I do hereby declare the nature of this invention to be
as follows:-
My invention consists of two angle cutters hinged from one centre, which admits
of the cutter expanding, and thereby allowing the cutters to undercut, or enlarge
any hole wider at the bottom than the top.
The sides of cutter being any other than a right angle, admits of their cutting
sides being reversed, by simply changing their relative positions on the centre
which allows of one set of cutters being used for boring two different sized holes.
This invention is adaptable for undercutting holes in weights, for the reception,
and retention, of lead, for balancing purposes.
January 1st 1801
JAMES ALFRED DERHAM.
COMPLETE SPECIFICATION.
Improvements in Drills and Cutters for Undercutting in Iron, Wood,
Stone, and other Kindred Materials.
JAMES ALFRED DERHAM, Number 77 Wellfield Road Preston in the County
of Lancashire, Boiler Maker 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 consists of two angle cutters hinged from one centre which admits
of the cutters expanding and thereby allowing the cutters to undercut or enlarge
any hole wider at the bottom than top, the sides of cutter being any other than a
right angle admits of their cutting sides being reversed by simply changing their
relative positions on the centre which allows of one set of cutters being used for
boreing or undercuting two different sized holes.
This invention is adaptable for undercutting holes in weights for the reception
and retention of lead for balancing purposes.
This invention also consists of a round steel spindle of any given dia. Fig. 1 ou
drawing one end made to fit into the socket of a drilling machine the other end of
spindle as a jaw cut into it for holding the two cutters Fig. 2 (on drawing) the
cutters lap over each other in the jaw of the spindle, are held in position by a round
pin slightly taper passing through the jaw and cutters Fig. 2 on drawing. A
moveable sleive Fig. 3 and 4 on drawing is placed on a round steel spindle with
slots cut in both ends to support the cutters. The external dia. of half length of
moveable sleive must be a little smaller than the hole which as to be undercut.
The external dia. of the other half of moveable sleive must be smaller as per
Fig. 3 and 4 on drawing. The cutters Fig. 2, and the moveable sleive Fig. 3 and 4
are driven by a stationery pin Fig. 5 on drawing which passes through the spindle
and projects out about inch from each side of spindle. This driveing pin fits into
the slots of the moveable sleive Fig. 3 and 4 on drawing.
The cutters which are about 66 degrees of an angle and longer on one side than
the other allows the same cutters being used for one or more different sized holes
by simply reversing the cutters and moveable sleive end for end.
The mode of working the above mentioned is as follows place one end of

page_text: the round steel spindle Fig. 1 into the socket of a drilling machine put the
other end of the spindle as well as the cutters into the hole which as to be undercut.
The moveable sleive must be pushed down to the cutters into the hole. The
cutters will then be firmly supported by the moveable sleive and slot which fits to
the driving pin mentioned above. Apply presure to the drilling machine spindle
and the cutters will then immediatly and gradualy expand and undercut the holes
larger at bottom than top. If a larger or smaller hole is desired to be undercut
the cutters and moveable sleive must be reversed. The drawings are full size
throught.
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 as features of novelty are as follows
1st. I claim as features of novelty the shape of cutters Fig. 2 on drawing..
2nd. The mode of fixing the cutters in the jaw of spindle one cutter overlaping
the other.
3rd. The moveable sleive Fig. 3 and 4 on drawing.
4th. The mode of undercuting one or more size of holes with the same cutters as
per drawings.
Dated this 9th day of May 1891.
JAMES ALFRED DERHAM.