Year: 1886

page_text: Date of Application, 18th Mar., 1886.
Complete Left, 16th Dec., 1886.
Complete Accepted, 25th Jan., 1887.
nature of this invention to be as follows:-
My invention relates to Compound Drill for Bore Rods, as used for boring
long holes in Colliories, Mines & other places, & is especially suitable in connection
with my patent Bore Rod D 6907.
"85
The drills at present in use make a hole full size of Rod, which is bound to be of
sufficient size to get strength to drill long holes or even shorter ones in hard substances
this size generally about 24 inches (varying with circumstances) is found to be
inconvenient and even dangerous in most cases where there are heavy pressures of
water &c., it being difficult to get a plug in against the pressure in that area of hole.
I propose to remedy this by a Compound Drill, having proceeding cutting part like
an ordinary drill of small diameter, say 1 inch or other size that might be suitable,
and say 18 or 20 inches long (more or less) as might be required, & the other part
being in the same piece swelled out to size of Rod & commencing with cutters
projecting out at each side to suit same.
The result being that the small part of drill would pierce or enter the water or gas &c.
and area being of inch 7854 and Rod part 24 inches, area 3.978 with a pressure of say
200 lbs. per squ. inch of water in old workings-makes a tremendous difference in the
plugging of hole.
Thus my invention makes a small hole in water or gas &c. & still leaving rods of
sufficient size to give ample strengths for the longest holes.
What I claim for my invention is the drill having 2 sets of cutters (more if
required) the smaller set preceeding the larger in the form of an ordinary drill by
18 or 20 inches more or less as might be required, & then having side cutters formed
out, making size of rods to follow, thereby always making the small hole preceeding
larger part & consequently would always hole the smaller area.

page_text: ROBERT WILSON Railway Forge Bishop Auckland Engineer I do hereby declare
the nature of my invention for COMPOUND DRILL 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 a drill making two or three sizes of hole, or Compound drill,
for Bore Rods as used for boring long holes in Collieries, Mines & other places, and
is specially suitable in connection with my patent Bore Rod D 6907.
85
The drills at present in use make a hole full size of Rod, which is bound to be of
sufficient size to get strength to drill long holes, and to allow size of web to clear out
the cuttings, this size being generally 24" dia. (varying with circumstances) is found
to be inconvenient and dangerous in some cases, where there are heavy pressures of
water, it being difficult to get a plug in against the pressure in the area of hole.
I propose to remedy this by a Compound drill having preceeding cutting part like
an ordinary drill of small diameter A1 say 1 inch or other size that might be suitable,
and say 10 or 12 inches long, that then swelling out to say 13" by two cutters at the
side A 2, keeping this size for about 8 inches or as might be required, & then other two
cutters A 3 at side bringing hole to same size as the Rods that follow, namely about
21" dia., the result being that the small part of drill would pierce or enter the water,
and the area of inch being 7854 and rod part 24"-3.978 area, against a pressure of
say 200 lbs per squ. inch of water in old workings, makes a tremendous difference in
plugging of holes.
Bringing the size of drill from 1" dia. to 24" or might be required, by three sets of
cutters instead of two, as in provisional specification, has the advantage that the drill is
not so liable to choke in bringing out cuttings.
Thus my invention makes a small hole in water or gas etc., still leaving the Rods of
sufficient size to bore the longest holes.
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 is
The drill having two or three sets of cutters, formed on and in one piece with the
drill, for the purpose of drilling long try holes, with the small part of drill piercing,
thus exposing a small area to the pressure, as against the old system.