October 2, 1914.

THE COLLIERY GUARDIAN.

701

Points of Superiority

in

___

____

____

_	__

Hammer O Drills.

MECO FLAP VALVE is the simplest on the market.
It has the least wear of any, as it floats on air. Any
wear does not affect the efficiency of the hammer drill
owing to the valve’s self seating properties. We have
never yet seen a	broken valve, their

life is practically un-	limited. Freezing up

is unknown with a flap valve, and it is very difficult to
choke. It operates satisfactorily at any pressure from
20 to 120 lbs. per square inch. A valve which has stood
the test of time and is still unapproached for reliability.

MECO RECOIL COLLAR. One of the reasons

why Meco Hammer Drills last longer than others is due
to our fitting between the front end and the cylinder a
recoil collar. This takes up all the shock from those
blows of the piston which do not hit the drill
steel instead of	'	injuring the

front • cylinder	cover, with con-

sequent longer life to the piston,_________
longer life to the	front ei^d of the

machine, and less vibration. With a patent arrangement
on the recoil collar the amount of exhaust air available
for flushing can be suitably regulated to suit any con-
ditions. The use of the Recoil Collar shortens the
length of the front cylinder cover, making the machine
more rigid and reducing the vibration.

PISTON. Made from one solid steel forging, so care-
fully hardened and tempered that it will withstand the
roughest use ____ - without un...
due wear. We aban______
doned the	use of bored

out pistons some years ago owing to their inefficiency
and short life.

RATCHET. Made from a single solid steel forging,
the teeth being ground	to the correct angle

_____

of contact with the	pawls, thus ensuring

positive rotation with	practically no wear.

CYLINDER. Forged out of solid steel, is tempered
glass hard on the internal wearing surface, and is left
soft on the exterior to prevent fracture when subjected
to rough handling.

All other parts
thousandth part
gauges.

are ground to the
of an inch to limit

We have recently considerably strengthened up several
parts of our machines without unduly increasing their
weights.

Let us send you, entirely at our own expense, one of these hammer
drills for you to try. Our expert will accompany it, and his
experience and services are at your disposal free of cost and obligation.

___

= Mining Engineering Co. Ld.

. Meco Works, Moorfields, SHEFFIELD. .

Telegrams : “ Meco, Sheffield.’

Telephone: 4530 Central, 2 lines.