Year: 1887

page_text: I, EDWIN WARREN TUCKER, residing at the corner of Point Lobos and Eleventh
Avenues, in the city and county of San Francisco, and State of California, one of
the United States of America, Mechanical Engineer, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:—
My invention relates to improvements in those bridge-walls for furnaces which are
made hollow for the admission of air to the combustion-chamber.
•
My principal improvements consist in so constructing the bridge-wall that it may
be adjusted to regulate the space above, and also that it may be separated into
sections on the horizontal plane of the grate-bars, so that the upper and more exposed
portion can be easily renewed.
Other improvements consist in details relating to the damper controlling the
admission of air to the bridge-wall, the construction of the bridge-wall itself, and
other matters.
In the accompanying drawings, to which I refer,
Figure 1 is a vertical section of the bridge-wall, showing it in the furnace.
Figure 2 is a plan of its top.
Figure 3 is a front elevation and section.
Figure 4 is a rear elevation.
Figure 5 is a section showing the frame L.
The hollow bridge-wall A, Figures 1, and 5, consists of three castings, namely; a
base-casting a, a body-casting a, on top of a, and a top-casting a², which fits over a',
and can be raised and lowered thereon after the manner of telescopic sections, so
that the space above the bridge-wall can be accurately regulated to suit the draft-
requirements of any particular furnace.
The top-casting a² is held by bolts a³, at any given height.
Though I have here shown the vertical adjustment of the bridge-wall as effected by
means of telescopic sections, I do not confine myself to this construction, though I
deem it preferable, as being practical.
X are the grate-bars, their inner ends being supported by a ledge a', projecting
from casting a, and said bars are on a level with the top of said casting.

page_text: The base of the bridge-wall, consisting of casting a, is, therefore, below the level of
the grate, while its upper portion a¹, a², is above said level.
This latter portion is subjected to greater heat, and will not last as long as the
lower portion. But by being separable on the level of the grate-bars, the upper
portion may be renewed without having to renew the lower portion, which may still
be utilized. The bridge-wall is secured in the furnace by means of square-shanked
studs c, tapped in the sheet C, and which pass through elongated slots in a
flange B, Figures 1, and 4, on the base-casting a; nuts c', being seated on the studs.
By loosening these nuts, the flange B, may be slipped on or from the studs, their
elongated slots permitting its ready adjustment.
D is a cap, covering a hand-hole in the back wall of the casting a.
This cap is
easily placed, and can be removed readily by reason of having inclined lugs d¹ on its
back, which wedge in hook-shaped lugs d on the casting.
The casting a is secured to casting a, by bolts E, Figures 1, and 3, which pass
through lugs e on the casting a¹, and through the projecting ends of casting a,.
receiving nuts e¹ below.
The bolts E have square heads, which, from their proximity to the walls of the
casting, are thereby locked in place. They are easily dropped through the lugs e, by
inserting the hand through the hole covered by cap D, and the nuts e¹ are applied to.
the bolts from 'behind.
To the face of casting a, which is suitably grated, is applied a damper F, held to
place and guided by a stud f, passing through an elongated slot f" in each end of the
damper.
The damper is operated by a rod G, the inner end of which passes loosely through
one of its end slots, and is seated in a socket formed in a boss g in the front wall of
casting a.
The rod has a crank g' engaging a hole in the face of the damper above, so that
by turning the rod axially, its crank will move the damper sideways in order to
regulate the admission of the air to the bridge-wall. The rod G extends forwardly
to the forward end of the furnace, where it has an adjustable collar g, which, when
set up against the inner surface of the front of the furnace, holds the inner end of the
rod to its seat.
The projecting forward end of the rod passes through a bracket H, slotted on a
fixed stud, and is fixed by a set-screw. The bracket is held by a nut ², which,
when loosened, permits it to swing, whereby the rod may be turned axially to operate
the damper, and when tightened up, holds the bracket so that when the damper is
once adjusted it may be held.
Figure 2 shows the arrangement of the air-exit slots J, in the top of casting a².
They are in parallel rows and break joints with each other, thus providing for a solid
sheet of air.
K are flanges on the front of casting a², which are supports for a protecting wall of
brick.
L, Figure 5, is a vertically-movable frame within the bridge-wall. It has pins l,
which are for clearing the slots J, when they become clogged.
The frame L is moved by the rod 1, the pivoted toggle-lever 12, and the side
rods 13.
As shown at M, the inner surface of the base of casting a is made with a forward
slope, which prevents any accumulation of dirt.
Having now particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim, is-
1. A hollow hot-air bridge-wall for furnaces, made of adjustable or telescopic
sections, whereby its height may be varied for the purpose described.
2. A hollow hot-air bridge-wall for furnaces, made in sections and separable in a
horizontal plane, whereby the upper section may be renewed without disturbing the
lower section, substantially as described.

page_text: 3. A hollow hot-air bridge-wall for furnaces, made of separable castings, the base-
casting having a flange slotted over fixed studs in the sheet of the furnace, and a
hand-hole in its back covered by a removable cap, and the body-casting being secured
to the base-casting by means of bolts dropped through lugs on the interior of said
body-casting, and receiving-nuts below the ends of the base-casting, substantially as
described.
4. A hollow hot-air bridge-wall for furnaces, having discharge slots in its top,
arranged in parallel rows and breaking joints with each other, substantially as
described.
5. The projecting vertical strips on the front of the hollow bridge-wall to retain
the wall of brick, substantially as described.
6. The inner surface of the base of the hot-air bridge-wall, sloping forwardly as
described.
7. The vertically-movable frame, provided with pins and working within the hollow
bridge-wall for clearing its exit apertures, substantially as described.
8. The damper controlling the admission of air to the hollow hot-air bridge-wall,
in combination with the mechanism for operating the damper, comprising the axially
rotary rod, having a crank on its inner end, and a movable bracket on its outer end,
and adjustable collar for holding it to its seat, substantially as described.
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