1192

THE COLLIERY GUARDIAN.

Juke 6, 1913.

does not take harm through being exposed to the heat
of the gases while no steam is passing through it. The
sectional slab dampers which we illustrate fulfil these
conditions. When the superheater is in action, the
slab dampers are stored in any convenient place ; not
being exposed to the heat of the furnace, no deteriora-
tion takes place. The openings through which the
slab dampers are placed in position are sealed

Sectional View of Header
or Superheater.

that in this drill the valve action is in principle that of
the “ Hardy-Simplex,” i.e., air pressure is suddenly
reduced at one end of the valve when the piston
uncovers the main exhaust ports, and the full pressure
acting on the opposite end causes the valve to travel to
the other side of the valve box, and thereby change the
direction of the motive fluid and reverse the piston or
hammer. Thus this valve does not depend on compression
set up by the piston in order to accomplish its reversal,
and is not, like other types, dependent on a tight piston
and cylinder. Further, it is unique in moving only
in. in order to cut off the main air supply, but it has
a further considerable travel before readmitting air.

“ Hardy-Simplex” Hammer Drill.”
(Hardy Patent Pick Company Limited)

possible. As a matter of fact, this B6 machine uses
40 per cent, less air than the original “ Hardy-Simplex. ’
and has a higher boring speed than the original
“ Simplex ” by some 10 to 15 per cent. This supports
the claim made by the makers that the new valve action
has given us the most economical and powerful hammer
drill of its weight (27 lb.) ever placed on the market. In
previous types of “Hardy-Simplex” the valve piston
was semi-cylindric, the unbalanced exhaust area com-
pensating wear to valve and valve seat. The makers
have now succeeded, by providing end contact joints
instead of surface joints, in preserving the feature of
great durability of the “ Simplex ’ without the disad-

STEAM OUTLET

STEAM INLET

Standard Superheater with Patent Sectional Slab
Dampers.

''







Single-header Superheater.



with light covers. When the slab dampers are in use
as shown, the superheatei is perfectly isolated •
the boiler can continue working, and inspection Or
repairs of the superheater can be carried out at any
convenient time, and without the difficulty expert need
otherwise in carrying out such work due to the heat of
the furnace gases and the inconvenience caused by tie
inrush of air when the flue is opened out. The slab
dampers are made in sections for the convenience of
handling. As these slab dampers are only used for
emergencies, it will be evident that one set of slabs will
suffice for a group of boilers. The slab dampers are not
only applicable to the “ Standard ” design of super-
heater (as shown in the illustration), but also to other
types of superheaters manufactured by Messrs. T.
Sugden, Limited.

Messrs. T. Sugden Limited also show models of
their single header superheater which they have been
supplying lately. Many collieries and other works had
so far to abandon the idea of working with superheated
steam, as the downtakes of their boilers, due to their
narrowness, did not permit of superheaters being
adopted without running the risk of reducing the
draught. We illustrate the single header super-
heater manufactured by Messrs. T. Sugden Limited.
Although it possesses practically all the advantages of
their well-known “ Standard ” superheater, it is possible
to fix same in boiler downtakes, however limited the
space may be. The arrangement leaves ample space
for inspection and cleaning without practically any
diminution of the draught. Quite a number of this
special type of superheater are already at work and
giving excellent results.

THE HARDY PATENT PICK CO. LIMITED.

This well-known Sheffield firm show examples of their
new patent “ Hardy-Simplex ” air hammer rock drill
with automatic rotation (type B6). It may be recalled

(Messrs. T. Sugden Limited).

"Hardy Puncher” Arranged for Cutting near Floor.
(Hardy Patent Pick Company Limited.)

Therefore, on the one hand, all valve losses are practi-
cally eliminated, and on the other hand the delay in
readmitting air in quantity for the reversal of the piston
diminishes internal resistance, and gives a very powerful
blow, with an air consumption reduced to a point beyond
which it is difficult to imagine any serious economy

vantage of the slight friction on the valve seating,
caused by the unbalanced exhaust area. A most impor-
tant feature of the new design is its great rigidity,
ensuring the machine being constantly in line, and
thereby giving maximum output in spite of wear and
tear. The whole of the parts are enclosed, and from the