IMPROVEMENTS IN APPARATUS FOR CONTROLLING THE MOVEMENTS OF THE FEEDING BELLS OF BLAST FURNACES
Year: 1883

page_text: LETTERS PATENT to Thomas Wrightson of the Teesdale Iron Works Stockton-
on-Tees in the County of Durham for an Invention of "IMPROVEMENTS IN
APPARATUS FOR CONTROLLING THE MOVEMENTS OF THE FEEDING BELLS OF
BLAST FURNACES
"
PROVISIONAL SPECIFICATION left by the said Thomas Wrightson at the
Office of the Commissioners of Patents on the 11th August 1883.
.
THOMAS WRIGHTSON of the Teesdale Iron Works Stockton-on-Tees in the County
of Durhain. "IMPROVEMENTS IN APPARATUS FOR CONTROLLING THE MOVEMENTS
OF THE FEEDING BELLS OF BLAST FURNACES.
"
This invention relates to improvements on the mechanism described in the
Specification of a former Patent granted to me N° 1803 in the year 1870.
In order to control the feeding bell of a blast furnace an hydraulic cylinder is
employed. A piston in this cylinder is connected by its rod with the further arm
of the lever from which the bell is suspended. The lever also carries a counter
weight sufficient to raise the bell and close the feed hopper. Whilst the charge is
being put into the feeding hopper around the bell the weighted end of the lever is
held down by a catch rod. When the charge has been arranged in the hopper the
catch rod is set free and the weight of the charge causes the descent of the bell.
This movement is controlled by the hydraulic cylinder as it cannot take place
without the passage of liquid from one side of the piston to the other. There is a
bye pass up in the hydraulic cylinder in which is a cock set to allow the movement
to take place at the speed desired. As a further precaution against shock a coiled
spring is provided upon the catch rod which serves as a stop when the bell has
descended the full distance. Or I may employ an elastic cushion or a plunger
forcing liquid past a loaded valve.
To prevent the immediate return of the bell which, sometimes has been found
to cause lumps of the mineral to become nipped between the bell and its seat, the
catch rod is caused to pass through a tapering recess in which is a roller connected

page_text: by links with a lever. The lever is weighted so that it tends to hold the roller
down in the recess resting against the side of the catch rod. The roller offers no
resistance to the upward movement of the catch rod but immediately the catch
rod commences to descend the roller rolls down in the recess until the rod is
jammed and unable to move further. By placing the hand upon the lever the
catch rod can be released at will and the counterpoise then raises the bell and
closes the feed hopper. The hydraulic cylinder controls the upward movement of
the bell as well as the downward.
With these arrangements it can hardly happen that portions of the charge
should get jammed by the bell in rising, but to provide for such a circumstance the
two ends of the cylinder are connected by a passage at the extremities of which
are valves which will lift to allow liquid to pass from the upper side of the piston
to the lower but close against any flow in the other direction. A solid plunger
enters by a gland into this passage and by a hand lever it can be moved to and
fro so as by a pump like action to draw liquid from the upper side of the piston
and force it beneath. The bell can thus be lowered against the action of the
counterweight. One of these valves can be set down by a hand wheel and screw
that it may not open in the ordinary working of the apparatus.
In place of the hydraulic cylinder a cylinder containing air might be used with
adjustable apertures at or near the ends of the cylinder. In this case the side
pipes would not be necessary.
The immediate return of the bell may be prevented in the manner already
described; or an eccentric mounted on an axis-may be substituted for. the roller
and incline which eccentric is released when necessary by a hand lever attached
to it.
The arrangement for liberating the catch rod is as follows:-The catch rod
passes through a sleeve having a band lever attached to it by which it can be
turned in a suitable bearing or support. The catch rod has a projection on one
side and this when the sleeve is suitably placed is able to pass through the opening
in the sleeve. By turning the sleeve however when the projection of the catch
rod is below, the catch rod becomes locked. By a like movement in the other
direction the rod is liberated. The underside of the sleeve is inclined and when
turned round draws the catch rod forcibly downwards and holds the bell close
against the rim of the feed hopper.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
'
by the said Thomas Wrightson in the Patent Office on the 11th February
1884.
THOMAS WRIGHTSON of the Teesdale Iron Works Stockton-on-Tees in the County
of Durban "IMPROVEMENTS IN APPARATUS FOR CONTROLLING THE MOVEMENTS
OF THE FEEDING BELLS OF BLAST FURNACES "
This Invention relates to improvements on the mechanism described in the
Specification of a former Patent granted to me N° 1803 in the year 1870.
In order to control the feeding bell of a blast furnace an hydraulic cylinder is
employed. A piston in this cylinder is connected by its rod with the further arm
of the lever from which the bell is suspended. The lever also carries a counter-
weight sufficient to raise the bell and close the feed hopper. Whilst the charge is
being put into the feeding hopper around the bell the weighted end of the lever is
held down by a catch rod. When the charge has been arranged in the hopper the
catch rod is set free and the weight of the charge causes the descent of the bell.
This movement is controlled by the hydraulic cylinder as it cannot take place
without the passage of liquid from one side of the piston to the other. There is a
bye pass upon the hydraulic cylinder in which is a cock set to allow the movement
to take place at the speed desired. As a further precaution against shock a coiled
spring is provided upon the catch rod which serves as a stop when the bell has
descended the full distance. Or I may employ an elastic cushion, or a plunger
forcing liquid past a loaded valve.
To prevent the immediate return of the bell which sometimes has been found to
cause lumps of the mineral to become nipped between the bell and its seat the
catch rod is caused to pass through a tapering recess in which is a roller. connected
by links with a lever. The lever is weighted so that it tends to hold the roller
down in the recess resting against the site of the catch rod. The roller offers no
re-istance to the upward movement of the catch rod but immediately the catch rod
commences to descend the roller rulls down in the recess until the rod is jammed
and unable to move further. By placing the hand upon the lever the catch rod
can be released at will and the counterpoise then raises the bell and closes the fred
hopper. The hydraulic cylinder controls the upward movement of the bell as well
as the downward.
With these arrangements it can hardly happen that portions of the charge should
get jammed by the bell in rising, but to provide for such a circumstance the two
ends of the cylinder are connected by a passage at the extremities of which aro
valves which will lift to allow liquid to pass from the upper side of the piston to
the lower but close against any flow in the other direction. A solid plunger enters
by a gland into this passage and by a hand lever it can be moved to and fro so as
by a pump like action to draw liquid from the upper side of the piston and force it
beneath. The bell can thus be lowered against the action of the counterweight.
One of these valves can be set down by a hand wheel and screw that it may not
open in the ordinary working of the apparatus.
In order that my said Invention may be most fully understood and readily
carried into effect I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS
Figure is a vertical section of the hydraulic controlling cylinder with some
parts in connection therewith represented in side elevation.
Figures 2. 3, 4 and 5 show details of the arrangement and Figures 6 and 7.aro
respectively a side elevation and a plan and illustrate a modification affecting a
portion of the
"

page_text: In Figure 1 A is part of the rocking beam from which the feeding bell of the
furnace is suspended. This beam is mounted preferably upon knife edges so that
it may rock freely. The beam carries a sufficient counterpoise A' to raise the bell
when unloaded and close the feeding hopper. B is the hydraulic controlling
cylinder, it contains a piston C which by the rod D is connected with the beam A.
The cylinder B is mounted upon trunnions so that it, and all the parts attached
to it are free to move about a centre at B¹. B' is a passage connecting the upper
with the lower end of the cylinder B, and in this passage there is a cock E which
can be so set as to retard to any desired extent the flow of the water or liquid
which the cylinder contains from one side of the piston to the other.
By setting this cock the rapidity with which the hell descends and ascends can
be regulated and moderated so as to avoid shock to the mechanism.
Bs is a small tank on the top of the cylinder covering the stuffing box through
which the piston rod passes. This tank is kept full of water or liquid to
ensure that air shall not enter the cylinder by the gland which need not be packed
tightly.
F is another passage connecting the two ends of the cylinder B.
At each end of the passage F a valve is provided, one valve is free to open to
allow water to pass out from the upper end of the cylinder, and prevents its return,
and the other valve is arranged to allow water to enter the cylinder at its lower
end, and to close to prevent the passage out.
Gis a solid plunger entering by a stuffing box into the passage F, and by means
of a hand lever it can be moved to and fro in the ordinary manner of working a
pump. This apparatus comes into use only in case the bell in ascending should nip
lump of the ore or material passing into the furnace and consequently should be
unable to properly close the feeding hopper.
When this happens the cock E is closed; then as the plunger ascends in the
passage Fits place is occupied by water and when the plunger-next descends this
water is forced through the lower valve into the part of the cylinder beneath the
piston. Consequently the piston ascends, and the bell suspended at the other end
of the beam A is lowered and the lump of ore or fuel which previously prevented
the bell from closing is able to fall away.
HH is a catch rod attached at its upper end to the beam A; it is
divided into two parts an upper and a lower which are connected with a screw
coupling H³.
By turning this coupling by a handle provided upon it the length of the catch
rod can be adjusted.
The lower part H₁ of the catch rod for a portion of its length is made to a
rectangular formn and this portion of the rod works through a socket I at the
upper end of a standard I* which is carried upon the same bed with tho
cylinder B.
When the bell has closed the feed hopper of the furnace the catch rod H is in
its lowest position and the portion of the rod which is rectangular has then passed
out on the under side of the socket I.
The lower section H' of the rod is then free to be turned by means of the
handle H³ provided for the purpose; and when it is so turned the shoulder at the
upper end of the rectangular part of the rod passes beneath the under face of the
socket, and so prevents the rod rising.
The bell is thus locked in a closed position.
When the furnace requires feeding and the charge has been deposited in the
feeding hopper, the catch rod is liberated by again turning the handle H. The
feeding bell then by the aid of the load resting upon it preponderates over the
counterpoise A' and the bell with the charge descends at a speed regulated by the
position of the cock E in the passage B³.
K is a volute spring provided around the lower end of the catch bar; this spring
also aids in checking the descent of the bell as it reaches its lowest position. A
ring or washer supported by the spring then coming in contact with the under side

page_text: of the socket I. In order to prevent the immediate return of the bell from its
lowest position a taper recess I is provided within the socket I on one side, and
in this recess a roller L is lodged. It is connected by a pair of links, one on either
side with the inner end of a hand lever M having its fulcrum at M' and carrying
a weight M. This weight presses the roller L down towards the lower end of the
taper recess I' and keeps it firmly in contact with the wall of the recess on one
side, and with the flat surface of the catch rod H' on the other side.
The roller L opposes but little resistance to the rise of the catch bar, but when
the catch bar tends to descend, the roller is drawn down into the recess until it
becomes tightly nipped sufficiently to prevent a further descent of the catch bar
until the roller L has been removed. This is effected at the pleasure of the
attendant by pressure upon the band lever M. Consequently in feeding the furnace
the bell can be retained near its lowest position with the feed hopper open as long
as the workman may judge to be necessary to admit of the whole charge entering
the furnace for the feed hopper does not close until the attendant permits it
to do so.
In Figures 6 and 7 I show an arrangement for attaining the same end in a
somewhat different manner.
In this case the catch bar has ratchet teeth formed in it with which a pawl O
engages. On the axis of the pawl is the weighted hand lever P.
The pawl allows the catch bar to rise and the feeding hopper to open, but it
prevents the return of the parts by dropping in between the teeth on the catch
bar and as before, the return does not take place until the catch rod is liberated by
the workman lifting the handle on the lever P.
Having thus described the nature of my said Invention and the manner
of performing the same I would have it understood that I claim as my
improvements in apparatus for controlling the movements of the feeding bells of
blast furnaces.
First. The use in combination with the hydraulic controlling cylinder and
catch rod of apparatus by which the catch rod is retained after the descent of the
feeding bell and the feeding hopper kept open until released by the workinan.
Second. The arrangement of apparatus as herein described by which the feeding
bell is rendered less liable to jam and remain open and in such cases is more
readily liberated.
In witness whereof I the said Thomas Wrightson have bereunto set my hand
and seal this eighth day of February in the year of our Lord One thousand eight
hundred and eighty four.
THOMAS WRIGHTSON. (L.S.)