IMPROVEMENTS IN APPARATUS FOR CHARGING BLAST FURNACES
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
We, ALFRED ATTWOOD of Canal Head Foundry, and THOMAS WALTER BARBER
of No. 20, Canal Head both of Ulverston in the County of Lancaster do hereby
declare the nature of our Invention for IMPROVEMENTS IN APPARATUS FOR
CHARGING BLAST FURNACES to be as follows:-
Our improvements have been devised to simplify the mechanism employed to
lower and return the charging Bells of Blast Furnaces and to make their action
more certain and free from shocks, also to prevent the waste of gases and their
temporary stoppage when charging.
"
In carrying out our improvements we suspend the Bell from one end of a Beam
or Lever having its fulcrum near the centre of its length and having a Balance
weight fixed to the other end heavy enough to keep the Bell up to the Hopper.
Beneath the Balance weight end of the lever are suspended from it two rods, one
being connected to the piston of a double-acting air cylinder and the other, or
catch-rod" having a projection on its side. This rod passes down through a slot
hole in an iron bush piece capable of being revolved horizontally in the top of a
column or standard by a handle fixed to it. The under surface of the bush piece is
helical, similar to a single turn of a screw thread. The catch-rod with its projection
can pass freely through the slot in the bush when in one position. When the Bell
is up to the Hopper a partial turn of the Bush serves to force down the catch rod
and hold it firmly while the Bell is being loaded. To lower the charge into the
Furnace the Bush is revolve.l till the projection on the catch rod slips through the
slot. To prevent the immediate return of the Bell before the charge has been
fairly delivered into the Furnace, which sometimes causes a piece of mineral
to become nipped between the Bell and Hopper, we fix in the catch rod standard
on a spindle an eccentric cam operated by a lever whose weight keeps the cam up
to the catch rod. This cam offers no resistance to the upward movement of the
catch rod, but jams it directly it begins to descend. It is released by lifting the
lever. In case the Bell should from any cause require to be lowered again, we
employ a spur pinion fixed on a spindle in the catch rod standard, opposite the cam,
gearing into teeth cut or cast in the catch rod forming a rack. This pinion and
shaft may be revolved either by a winch handle or by a capstan head and loose
lever ou bar. The too sudden motion of the Bell, both up and down, is prevented
by the compression of the air enclosed in the air cylinder on one side of the piston

page_text: assisted by the partial vacuum at the other side. This compression and vacuum
are adjusted by means of two valves opening inwards and two small outlet valves
or petcocks, all the 4 valves having means of adjustment.
We prefer to fix these valves a short distance from each end of the cylinder, to
ensure a cushion of air to check the Bell at both ends of its travel without shock.
To prevent waste of gases we employ two Bells and Hoppers, the upper one may
be much smaller than the lower one, opens upwards and is kept open while the
lower Bell is being loaded. When the charge is lowered into the Furnace the
upper Bell closes the opening. For this purpose we prefer to make the upper Bell
as light as may be and capable of being raised and lowered independently by means
of a chain and small winch or a balance weight-so that it may be closed while the
lower Bell is being lowered and returned.
The pneumatic Brake Cylinder and catch rod are equally applicable to either
single or double Bells.

page_text: We, ALFRED ATTWOOD, Engineer of Canal Head Foundry, Ulverston in the
County of Lancaster, and THOMAS WALTER BARBER, Engineer of 20 Canal Head,
Ulverston in the County of Lancaster do hereby declare the nature of our
Invention for IMPROVEMENTS IN APPARATUS FOR CHARGING BLAST FURNACES
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Our improvements have been devised to simplify the mechanism employed to
lower and return the charging Bells of Blast Furnaces and to make their action
more certain and free from shocks; also to prevent the waste of gases from Blast
Furnaces and their temporary stoppage when charging.
In carrying out our improvements we suspend the Bell from one end of a beam
or lever having its fulcrum near the centre of its length and having a balance
weight fixed to the other end heavy enough to keep the Bell up to its hopper.
Beneath the balance weight end of the lever (see Figs. 1. 2. & 3.) are suspended
from it two rods, one connected to the piston A (Figs 2 & 3) of a double acting air
cylinder B, and the other or catch rod C, having a projection on its side. This rod
passes down through a slot hole in an iron bush piece D. capable of being revolved
horizontally in the top of a column or standard E. by a handle F fixed to it. The
under surface of the bush piece is helical similar to a single turn of a screw thread.
The catch-rod C. with its projection can pass freely through the slot in the bush D
when in one position (see Fig. 4.). When the Bell is up to the hopper, a partial
turn of the bush D serves to force down the catch rod and hold it firmly while the
Bell is being loaded. To lower the charge into the Furnace the bush D is revolved
till the projection on the catch rod C slips through the slot.
To prevent the immediate return of the Bell before the charge has been fairly
delivered into the furnace-which sometimes causes a piece of mineral to become
nipped between the Bell and Hopper, we fix in the catch-rod standard E, on a
spindle G an eccentric cam H operated by a lever I. whose weight keeps the cam
up to the catch rod C. This cam offers no resistance to the upward movement of
the catch-rod C. but jams it directly it begins to descend, and it is released by
lifting the lever I.
In case the Bell should, from any cause, require to be lowered again, we employ
a spur pinion J fixed on a spindle K in the catch rod standard E opposite the
cam H. and gearing into teeth cut or cast in the catch rod C forming a rack. This
pinion and shaft may be revolved either by a winch handle or by a capstan head L
and loose lever or bar.
The too sudden motion of the Bell both up and down, is prevented by the
compression of the air enclosed in the air-cylinder B, on one side of the piston
assisted by the partial vacuum at the other side. This compression and vacuum
are adjusted by means of two valves M. opening inwards and two small outlet
valves or pet cocks, all the four valves having means of adjustment. We prefer to
fix these valves a short distance from each end of the cylinder, to ensure a cushion
of air to check the Bell at both ends of its travel without shock.

page_text: To prevent waste of gases we employ two Bells and Hoppers (Fig. 5.) the upper
one may be much smaller than the lower one; opens upwards, and is kept open
while the lower Bell is being loaded. When the charge is lowered into the Furnace
the upper Bell closes the opening. For this purpose we prefer to make the upper
Bell as light as may be, and capable of being raised and lowered independently by
means of a chain and small winch or a balance weight, so that it may be closed
while the main Bell is being lowered and returned.
The pneumatic Brake cylinder and catch rod are equally applicable to either
single or double Bells.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is
1stly The use and application of an Air Brake Cylinder with adjustable valves, to
retard and control the descent and return of the Bell substantially as described.
2ndly The construction and mode of operating the catch rod or Locking Bar, with
its revolving bush, cam and lever for gripping it, and rack and pinion motion
substantially as described.
3rdly The application and use of a, small Bell and Hopper fixed above the large
Bell and balanced for the purpose and in the manner described.
Dated this 19th day of February 1885
ALFRED ATTWOOD.
THOMAS WALTER BARBER.