Improvements in Draft Regulators for Chimneys, Stacks, Stove Pipes, and the like.
Year: 1891

page_text: Date of Application, 8th Sept., 1891-Accepted, 10th Oct., 1891
COMPLETE SPECIFICATION.
Improvements in Draft Regulators for Chimneys, Stacks, Stove
Pipes, and the like.
We, ALFRED FROMMHOLD, and FRANK VOIGTMANN, Manufacturers, both of
129 and 131 North Franklin Street, Chicago, Illinois, in the United States of
America, 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 :—
This invention relates to a draft regulator or damper for chimneys, stacks, stove-
pipes and the like, and more particularly to automatic draft regulators, the object
being to provide improvements in that class of draft regulators and to simplify the
construction and reduce the cost of the same.
The invention consists in the features of construction and combination of part
hereinafter fully described and specifically claimed.
In the accompanying drawings, making a part of this Specification,
Figure 1 is a vertical sectional view of a stack provided with a draft regulator
constructed with our invention and taken on the line 1-1 of Fig. 2.
Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1.
Figs. 3 and 4 are fragmentary views partly in section and in elevation, illus-
trating the indicator and set bar in two different positions.
Figs. 5 and 6 are vertical sectional views of a stack regulator of a modified form
of construction embodying our invention, and taken respectively on the lines 5-5
and 6-6 of Figs. 6 and 5.
Fig. 7 is a horizontal cross section on the line 7-7 of Fig. 5.
Figs. 8 and 9 are vertical sectional views of a stack provided with a draft
regulator of another modified form of construction embodying our invention and
taken respectively on the lines 8-8 and 9-9 of Figs. 9 and 8.
Fig. 10 is a sectional view of a portion of the damper and shows another form of
weight that can be secured thereto.
Fig. 11 is a fragmentary view on an enlarged scale of the stack and damper and
illustrates a pivotal connection for said damper.
Fig. 12 is a detail elevation on an enlarged scale, of the pivot support and
friction plate.
Figs. 13 and 14 are vertical sectional views of a stack provided with a draft
regulator of a further modified form of construction embodying our invention, and
taken respectively on the lines 13-13 and 14-14 of 14 and 13.
Fig. 15 is a fragmentary view of the damper showing still another modified form
of construction embodying our invention and
Fig. 16 is a cross sectional view of the same on the line 16-16.
In accordance with the broad idea comprised by our invention, a damper that is
heaviest below its pivotal point is pivotally supported within a draft passage, BO
that the lower portion of said damper will, by reason of the preponderance of its
weight, serve to hold the damper in an upright position. Should the draft become
excessive, it will turn said damper on its pivot to close the draft passage, and when
the draft becomes normal, said heavy end of the damper will bring said damper to
an upright position once more.
A damper could be constructed in various ways to bring its heaviest portion
below its pivot, and in Fig. 1 is shown a convenient embodiment of this idea, which
consists in locating the pivot of said damper nearer one end of the damper than the
other end.
It will be understood, that, although the damper is illustrated as rectangular in

page_text: shape, and as located in a stack yet it can be of any desired shape to correspond to
the shape of the draft passage, and can be located in any sort of a draft passage,
where it is needed.
Referring now to Figs. 1 and 2, A. indicates a stack and B an opening in the
side thereof communicating with the furnace (not shown) and through which the
products of combustion pass from the furnace to the stack. C is a damper
pivotally supported within said stack and from the walls thereof. The pivot of
said damper C consists of a bar 1, that is secured across the face of the same and
projects beyond its sides. The projecting end portions of said bar rest in V-shaped
notches of plate 2 secured to the walls of the stack as more fully described herein-
after. The said bar 1, is secured to the damper C, nearer one end than the other
end, and thereby makes the damper heavier on one side of its pivotal point than on
the other. When resting on its pivots within the stack, the heavy end of the
damper will serve to hold the damper in an upright position in an obvious
manner.
The lower end of the damper is located in front of the opening B from the
furnace, and the products of combustion issuing therefrom impinge against the said
lower end of the damper. The excess of weight of the lower end of the damper is
such that it will hold the damper in an upright position under the influence of a
normal draft impinging against the same, but will allow the said damper to turn on
its pivot to close the draft passage whenever the draft becomes excessive.
The extent to which said damper will turn and close the draft passage is
proportionate to the excess of draft, and as such excess decreases the damper will
Likewise turn on its pivot toward its upright position.
As a further and separate improvement, we have provided means whereby the
pivotal point can be shifted or moved toward either end of the damper, and
although various forms of construction could be resorted to for this purpose, we
have illustrated a convenient and simple manner of accomplishing this end. The
bar 1 is bolted to the damper and the bolts 3 pass through slots 4 in said damper,
so that by loosening said bolts, the bar can be moved as desired and then secured
again.
By this construction the preponderance of weight at the lower end of the
damper can be adjusted with great nicety.
An indicator and set bar B is connected with the damper C and extends through
an opening 5 in the stack and through a slot 6 in a plate 7 secured on the outside
of the stack. In the lower end of the slot 6 a friction roller 8 is mounted and the
indicator and set bar D runs over said roller 8. The said bar D is provided on one
side with a scale as shown in Fig. 2, by means of which the position of the damper
can be noted. The bar is also provided outside the stack with a holder 9 that
abuts against the plate and prevents the lower end of the damper from passing
towards the opening B from the upright position thereof. Near the slot 6 the
plate 7 is provided with a lug 10 having an opening or perforation 11 that registers
with a perforation 12 in the bar D when the damper is in an upright position, so
that by means of a pin 13, passed through said perforations, the damper can be
held in an upright position. It is obvious that said indicator and set bar can be
located in various other positions than the one shown without departing from our
invention.
In Figs. 11 and 12 is illustrated on an enlarged scale and in detail, the preferred
pivotal connection of the damper. In the other figures of the drawings, Figs. 1
and 2, for instance, the end of the bar 1 rests in the V-shaped notch in a plate 2
which is vertically adjustable upon a face plate 14 secured to the walls of said stack
by means of bolts 15 upon said plate 14 passing through slots 16 in said plate 2.
This construction provides a pivotal connection between said parts, but in
Figs. 11 and 12 is shown a preferable form of construction. A indicates a portion
of the stack and C a portion of the damper. A friction plate 17 is secured against
the face of the wall of the stack by means of its bent lower end 18 being driven
into the wall. A bearing plate 19 is provided with slots 20 in its lower end portion

page_text: which receive bolts 21 upon said friction plate, and by means of which said bearing
plate is secured to said friction plate.
The upper end portion 22 of the bearing plate is bent out and stands away from
the friction plate and is provided with a V-shaped notch 23, which receives the
edge of the pivot bar 1 of the damper. The friction plate extends some distance
above the bearing plate and forms an abutting surface for the end 24 of the pivot
bar 1, which is tapered, as shown to reduce the friction between the end of the bar
and said plate to a minimum. It will be noted that by reason of the adjustability
of the pivot or bearing plate 19 the damper can be hung with great precision and
accuracy.
In Figs. 5, 6 and 7 is shown another construction for shifting the pivotal point of
the damper to regulate the excess of weight below the pivotal point. In this
construction the damper C is located within a supporting frame consisting of a belt
or loop 26 and a depending stirrup or strap 27. The loop 26 is provided at its
ends with lugs 28 forming pivots that rest in the pivot plates on the walls of the
stack. The damper C is mounted loosely within said supporting frame so as to be
capable of longitudinal movement therein, and the said frame is provided with a
device for raising or lowering said damper relative thereto, which conveniently
consists of a set screw 29 passing through the lower end of the stirrup or strap 27
and bearing against the lower end of the damper. It is obvious that by turning.
the set screw the damper can be raised or lowered within the supporting frame to
adjust the preponderance of weight of the lower end portion of the damper. In
this construction stops 30 are located to engage the damper and to prevent the
lower end portion from moving toward the opening B from an upright position,
although it is plainly obvious that the set bar and indicator D (Figs. 1, 2, 3, & 4)
can be employed equally as well with this construction. The wall of the stack
towards which the lower end of the damper swings is recessed as at 31 to receive
the portion of the stirrup and strap projecting below the end of the damper, as will
be obvious.
From the foregoing description it will be seen that the damper is provided with
a counterbalancing device by making the lower end thereof heavier than the upper
end, and we have shown above one way of accomplishing this end, namely, locating
the pivotal point of the damper nearer one end of the damper than the other.
We have also shown two forms of construction for shifting the pivotal point of
the damper, whereby to obtain the desired preponderance of weight of one end
portion of the damper over the other end portion for the reasons above pointed out.
We have, however, in Figs. 8, 9, 10, 13, 14, 15 and 16 shown another way in
which to make one end portion of the damper heavier than the other end, which
consists in securing to the lower end of the damper a weight or weights. We have
also shown three different forms of construction embodying this idea, and illustrating
the different ways, comprised by our invention, in which the weighted lower end of
the damper can be made heavier or lighter to cause the damper to work accurately
and with the best results. In these forms of construction the damper is pivoted at
about its centre in the manner above described.
In Figs. 8 and 9 to the lower end portion of the damper a series of weights 32 are
secured in any desired way but preferably by means of bolts 33 that pass through
perforations 34 in said weights, and perforations along the lower end portion of the
damper. The weights 32 are forked or bifurcated to receive the lower end of the
damper, and are each provided with a series of perforations 34 by means of which
they can be secured upon the damper at variable distances from its pivotal point for
obvious reasons.
In this construction the set bar and indicator D is shown but it
will be understood that it can be dispensed with and any other stop employed.
In Fig. 10 a weight 35 of a different shape is illustrated.
In Figs. 13 and 14 the damper is shown as provided on its lower end portion
with an outwardly and downwardly projecting arm 36 upon which a weight 37 is
secured and is vertically adjustable thereon by means of its screw threaded

page_text: connection with said arm 36. The indicator and set bar is shown also in this
connection but it will be understood that it can be omitted if desired so long as
stops are arranged to prevent the lower end of the damper from approaching the
opening B from an upright position.
In Figs. 15 and 16 a weight 38 is shown having hooked ends 40 that embrace the
side edges of the damper as shown and said weight is secured upon the damper by
thumb screws 41, that pass through the weight and bear against said damper. The
said weight 38 can be moved vertically upon the damper for obvious reasons, and a
plurality of such weights 38 can be used if desired.
It is obvious that various changes, variations and substitutions can be made in
the constructions illustrated without departing from our invention, and it will be
understood that except in the claims for the specific construction we do not limit
ourselves to the precise construction herein shown, but contemplate making any
changes and substitutions not departing from the spirit of our invention. It will
be noted that this invention is also applicable to draft passages wherein the opening
from the furnace or fire is below the damper. It will be further understood that
the relative dimensions of the several parts can be varied as desired, for instance,
the space between the side edges of the damper and the walls of the stack can be
changed as found convenient.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
:-
1. A draft regulator consisting of a freely pivoted damper having a weighted
lower end portion.
2. A draft regulator consisting of a freely pivoted damper, the portion of said
damper below its pivotal point being heavier than the portion above the same
whereby said damper is normally held in a substantially upright position.
3. A draft regulator consisting of a freely pivoted damper, the portion of said
damper below its pivotal point being heavier than the portion above the same
whereby said damper is normally held in a substantially upright position, and devices
substantially as described for varying the preponderance of weight of the lower
portion of said damper.
4. A draft regulator consisting of a freely pivoted damper, the portion of said
damper below its pivotal point being heavier than the portion above the same
whereby said damper is normally held in a substantially upright position, and
devices substantially as described for varying the weight of the lower portion of
Baid damper.
5. A draft regulator consisting of a freely pivoted damper having its pivot
located above its middle.
6. A draft regulator consisting of a freely pivoted damper having its pivot
located above its middle and devices substantially as described for changing the
relative location of said pivot and damper.
7. A draft regulator consisting of a freely pivoted damper having a shifting
pivot normally located above the middle of the said damper.
8. A draft regulator consisting of a freely pivoted damper, said damper having
longitudinal slots to which the pivots of said damper are removably secured.
9. A draft regulator consisting of a freely pivoted damper having longitudinal
slots, and a pivot bar removably secured within said slots.
10. The combination, substantially as hereinbefore set forth, of a damper pivotally
supported within a chimney or other draft passage, and an indicator bar connected
with said damper and projecting outside of said chimney or draft passage.
11. A draft regulator consisting of a freely pivoted damper having a weighted
lower end portion, and a stop located to engage and arrest said damper when it is
in a substantially upright position.
12. The combination, substantially as herein before set forth of a damper pivotally

page_text: supported within a chimney or other draft passage, a bar connected with said damper
and projecting outside of said casing and provided with devices for holding said bar
and damper immovable.
13. The combination, substantially as hereinbefore set forth, of a damper pivotally
supported within a chimney or other draft passage, an indicator bar connected with
said damper and projecting outside of said chimney or draft passage, and a friction
roller located beneath said bar.
14. The combination substantially as hereinbefore set forth of a damper and an
adjustable pivot plate for supporting the same.
15. The combination, substantially as bereinbefore set forth, of a damper and a
vertically adjustable pivot plate for supporting the same.
16. The combination, substantially as hereinbefore set forth of a damper, a pivot
plate for the same having slots, and bolts secured to the wall of a draft passage and
removably secured within said slots.
17. The combination substantially as hereinbefore set forth of a friction plate
secured to the wall of a draft passage, a pivot plate and a damper having laterally
projecting tapered pivots resting upon said pivot plate.
Dated this 8th day of September 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.