8 inc Howitzer manual.pdf - Replica Plans and Blueprints

9
plunger on the left side, which serves liB a reader for the recoil scale
on the cradle. A steel stop plate is attached to the front face of the
guides by four screwed rivets.
The breech ring is prepared for the reception of the breech mechanism
and provided on the underside with a lug for •he attachment of the
body of the hydraulic buffer and recuperator of the carriage. Securing
screws are provided in the breech face to prevent the breech ring from
turning when in position.
Right and left gun-metal dust covers with securing screws connect
the front and rear guides.
The chamber is cylindrical, coned at the entrance and reduced in
diameter at the front end.
· A plane for a clinometer is prepared on the right upper side of the
breech ring.
Axis lines are cut on the upper side and on the horizontal axis at
the breech and muzzle ends. Fine horizontal and vertical axis lines
are also cut on the· breech and muzzle faces.
The actual weight of the howitzer (without breech mechanism) is
engraved on top of the breech ring, and a line, denoting center of
gravity (without mechanism), is cut transversely on the upper side
of the jacket immediately in front of the rear guide ring.
The t ype, mark, register number, manufacturer's initials, and year
of manufacture are engraved on the upper portion of the breech face.
BREECH MECHANISM.
(Plato II and IIA.)
'The breechblock is worked by means of an operating lever on the
right side of the breech. On pulling the lever to the rear the breechblock
is automatically unlocked and swung into the loading position.
After loading, one thrust on the same lever inserts the breechblock
and turns it into the locked position.
The breechblock is of the interrupted screw type. It is divided
circumferentially into 12 equal parts, 4 of which are plain and the
remaining 8 screw-threaded, thus giving a two-thirds bearing surface
to the breechblock in the locked position. The threaded sectors
are of different diameters, the breech recess of the howitzer having
complementary threaded sectors to receive them. The interruptions
in the howitzer are arranged to accommodate the sectors of the block
of largest diameter ; thus, when the block is unlocked, these sectors
pass into the interruptions and tho sectors smaller in diameter unlock
into the spaces left vacant by those of the larger diameter.