[go: up one dir, main page]

US1534845A - Automatic dampee - Google Patents

Automatic dampee Download PDF

Info

Publication number
US1534845A
US1534845A US1534845DA US1534845A US 1534845 A US1534845 A US 1534845A US 1534845D A US1534845D A US 1534845DA US 1534845 A US1534845 A US 1534845A
Authority
US
United States
Prior art keywords
damper
spindle
arm
plate
weight
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Publication date
Application granted granted Critical
Publication of US1534845A publication Critical patent/US1534845A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23LSUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
    • F23L13/00Construction of valves or dampers for controlling air supply or draught
    • F23L13/02Construction of valves or dampers for controlling air supply or draught pivoted about a single axis but having not other movement
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K15/00Check valves
    • F16K15/02Check valves with guided rigid valve members
    • F16K15/03Check valves with guided rigid valve members with a hinged closure member or with a pivoted closure member
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/7722Line condition change responsive valves
    • Y10T137/7837Direct response valves [i.e., check valve type]
    • Y10T137/7898Pivoted valves
    • Y10T137/7903Weight biased
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/7722Line condition change responsive valves
    • Y10T137/7837Direct response valves [i.e., check valve type]
    • Y10T137/7904Reciprocating valves
    • Y10T137/7908Weight biased

Definitions

  • the object of the. present invention is to improve; the construction of automatic dampers andltot rovidera simple,-etiicient and inc'losing when I the draft. through the stove pipe. is. increased by the heat and products of combustion from a, fire, whereby the fire iscontrolled and a saving; of fuel. effected.
  • a furtherobject of the invention is to provide: an exceedingly sensitive automatic damperequipped with pair of weights to partially counterbalance the damper to render thesame sensitive, one of the iweights beingiadjustable whereby. the damper may be. set ina'nydesired position. i h
  • Another object of the invention is to provide'a damper which isexceedingly sensitive'and at the same time is provided with -means to Y damp out undesirablevibrations or swinging movements of the damper such 7 as. frequently accompany sensitiveness in a device-ofthis-kind.
  • FIGs-3 and 4 are enlarged detail views of a portioniofthe invention. fi
  • Fig. 5 is a section on the 2; and; f r r Fig. 6zis at fragmentary view similar. to
  • Fig. 1 showing one operative 'positionof the damper
  • the lower portion of the plate is spaced fromanddoes-not touch the adja cent innerface of thestove pipe and the upper portion is spaced a still greater dis tance from the stove pipe.
  • the main spindle 12 consists of a wire havin straight side portions 18 andan intermediate upwardly bent portion 14.
  • the side portions 13 are adapted to be hooked under the downwardly opening hooks 15 formed atthe lateral edges of the plate 10.
  • the portion 1 1 is engaged on the tongue 16 which isi formed out ofthe damper plate 10 and provided with .an upwardly opening hooked portion 17 as shown in Figs. 2 and 5.
  • the hook 17 is shallow so that the bent portion it may be readily disengaged there- T from.
  • the damper plate may be readily at tached to spindle 12 by merely engaging the side portions 13 of the spindle under the hooks 15 and then springing the bent portion 14 over the hook portion 17.
  • 21s alongitudinal sectional view of Main spindle 12 is pivoted in the walls of pipe 11 and one end thereof isbent radially to provide a short arm 18 and is then bent back on itself in a direction substantially parallel to the-short arm 18 to provide the main arm 19. Arms 18 and 19 lie in the same vertical plane, and form aloop between them designated by reference character 20.
  • auxiliary spindl 21 Passing through pipe 11 just below main spindle '12 is an auxiliary spindl 21 having a bent auxiliary arm 22 terminating in an upwardly directed hook 23 which passes through the loop as best illustrated in Figs. 1 and a.
  • spindle 21 One function of spindle 21 is to stop the damper plate 10 from movement past the vertical or open position shown at 10.
  • Spindle 21 is preferably located a slight distance forward (to the left) of the main spindle 12 so that the plate will be held slightly inclined and in such a position that there will always be a pressure on the lower side of the plate, due to the up draft, tending to move the plate towards its closed position.
  • a washer 24 and adjacent thereto is ring 25 from which is suspended an auxiliary weight 26.
  • Hook 23 of the auxiliary arm bears downwardly on the main arm 19 of loop 20 and tends to rotate the damper towards its open position.
  • weight 27 is carried on that portion of main arm 19 which is to the right of the vertical plane passing through spindle 12 and is movable along the arm 19 by means of a spiral 28 formed of wire and encircling the arm, which spiral is turnable by means of knob 29 to advance the weight along the arm in either direction.
  • a spiral 28 formed of wire and encircling the arm, which spiral is turnable by means of knob 29 to advance the weight along the arm in either direction.
  • the relation of the arms and weights relatively to the spindles is such that the weights enjoy substantially rising and falling movements during motion of the damper, as distinguished from lateral swinging or pendulum movements, which latter are objectionable for the reason that they are likely to synchronize with the natural swinging movements of the damper and thereby cause violent swaying thereof and therefor uncertain regulation as well as objectionable noise.
  • the depending portion of the damper plate 10 does not come in contact with the adjacent inner surface of thepipe 11 when the damper is in its closed position. Motion of the damper towards its closed position is limited by the auxiliary arm 22 which is so shaped that it will strike the main spindle 12 at the point 30, as shown in Fig. 6.
  • a finger 31 is rigidly but adjustably secured on the spindle 12 and may be set to make contact with auxiliary spindle 21 to limit the closing movement of the damper before the arm 22 contacts with main spindle 12 at 30 as above described.
  • a damper plate in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by said arm, and weight means in frictional sliding relationship with the spindle for damping swinging movements of the damper during normal swinging movements thereof.
  • a damper plate in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by said arm, and friction means cooperating with the spindle at a point remote from its axis for damping swinging movements of the damper.
  • a damper plate in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by said arm, and means pivoted for rotation about a fixed axis and cooperating with the spindle for damping swinging movements of the damper.
  • a damper plate in combination, a damper plate, a spindle therefor, weight means for balancing the damper plate, and means for damping swinging movements of the damper, said means comprising a member extending outwardly from the spindle and adapted to turn therewith, and means frictionally resisting movement of the member.
  • a damper in combination, a damper plate, a spindle therefor, weight means for balancing the damper plate, and means for damping swinging movements of the damper,
  • said means comprising a member extending outwardly from the spindle and adapted to turn therewith, and weight 1means for resisting movement of the mem- 6.
  • said means comprising a member extending outwardly from the spindle and adapted to turn therewith, and means pivoted for rotation about a fixed axis and cooperating with the outwardly extending member for resisting movements thereof.
  • a damper plate in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending transverse to a vertical plane passing through the spindle, and spaced weights bearing on said arm to balance the damper, one of the weights being arranged to damp swinging movements of the damper plate.
  • a damper plate in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending" transverse to a vertical plane passing through the spindle, and spaced weights bearing on said arm to balance the damper, one of the weights havin slidable frictional engagement with said arm during the movement of the damper plate to effect damping of the movements of the latter.
  • a damper plate in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending transverse to a vertical plane passing through the spindle, a balance weight bearing on said arm, an auxiliary weight, an auxiliary arm supportin the auxiliary weight, said arm being ui ed for movement independently of sai first-mentioned arm and bearing on the latter.
  • a damper plate in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending transverse to a vertical plane passing through the spindle, a balance weight bearing on said arm, an auxiliary spindle having an arm connected therewith, an auxiliary weight on the auxiliary arm, sald auxiliary spindle being near said main spindle and adapted to stop the valve plate in wide open position.
  • a damper in combination, a main spindle, a damper plate mounted thereon and adapted to turn therewith, a main arm on the spindle, an auxiliary arm, and a weight carried thereby, said auxiliary arm being guided for movement independently of said main arm and having a bearing on the main arm.
  • a damper in combination, a main spindle, a damper plate mounted thereon and adapted to turn therewith, a main arm on the spindle, an auxiliary arm pivoted adjacent the main spindle, and a weight carried thereby, said auxiliary arm having a sliding bearing connection with said main arm.
  • a damper in combination, a spindle, a damper plate mounted thereon and adapted to turn therewith, means in the path of the valve plate to stop its movement in one direction, and means on the spindle and cooperating with said first-mentioned means for stopping its movement in the opposite direction.
  • a damper plate in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by the arm, and friction means associated with the spindle for damping the swinging movements of the damper during normal operation thereof.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Buildings Adapted To Withstand Abnormal External Influences (AREA)

Description

April 21, 1925. C. J. FOWLER ET AL AUTOMATIC DAMPER Filed May 8, 1923 fly. 2.
INVEHTORS CLAUDE d F'OWLEE &
dEFF'EEbOH FOWLER.
THEKE ATTORHE'Y 16 expensive amper-capable of automatically Patented Apr. 21, 1925..
UNITED STA-TEST PATENT oFFrcE.
curbs .r. Bowman; ofF max-Ens,- Ann JEFFERSON FOWLER; or RED CREEK; NEW
; YORK.
AUTOMATIC DAMPER.
Application filed, l lay 8,
B e it known, that we, CLAUDE J FOWLER and JnmnsonFownnnresiding at Yonkers; W-.:, l0 k and d Gr ek, N q s re spectively, have invented certain new and useful Improvements in Automatic: Damp ers; ofwhic h the following is-a full, clear nd-e a tdesc pt The; invention relates. to V improvements in automatic dampers for. stove pipes, cliim-. neys, smoke stacks and the like.
The object of the. present inventionis to improve; the construction of automatic dampers andltot rovidera simple,-etiicient and inc'losing when I the draft. through the stove pipe. is. increased by the heat and products of combustion from a, fire, whereby the fire iscontrolled and a saving; of fuel. effected.
A furtherobject of the invention is to provide: an exceedingly sensitive automatic damperequipped with pair of weights to partially counterbalance the damper to render thesame sensitive, one of the iweights beingiadjustable whereby. the damper may be. set ina'nydesired position. i h
Another object of the invention is to provide'a damper which isexceedingly sensitive'and at the same time is provided with -means to Y damp out undesirablevibrations or swinging movements of the damper such 7 as. frequently accompany sensitiveness in a device-ofthis-kind.
With these and other objects in view, the
. invention .consists'in the 1 construction and novel combination of parts hereinafter fully described, illustrated, in the accompanying drawing, and .pointedout in theclaims hereto appended I In the drawing I I Fig. Lisa side elevation of an automatic damper, constructed in accordance with this invention and shown applied to the stove P P e the. stove pipe showing the, damper in position; therein, certain of the. external parts of the damper being broken away;
Figs-3 and 4 are enlarged detail views of a portioniofthe invention; fi
Fig. 5 is a section on the 2; and; f r r Fig. 6zis at fragmentary view similar. to
Fig. 1 showing one operative 'positionof the damper;
line 5-5 at Fig;
1923. SeriaI No. 637,571.
.In the accompanyingdrawing, lodesignatesan-egg-shaped damper plate construct ed of sheet metal and mounted withina vertical stove pipe ll on. a horizontal spindle 12, extending across; the; damper plate. l 0= above themiddle thereof, the depending pon-- tion q-f the plate; or that portion belowthe. spindle 12beinglonger and heavier. than the: upper portion thereof-L =The-damper plate is adapted to swing from its open, positionlO} illustrated in Fig. 1 to ltSfilOSGClEPOSlt-lOII 10%- as-illustrated in Fig. Gin which position,- it will be noted, the lower portion of the plate is spaced fromanddoes-not touch the adja cent innerface of thestove pipe and the upper portion is spaced a still greater dis tance from the stove pipe. The plate 10 thus,
does not come in contact with the pipe: This construction avoids the annoyance incident to the plate 10 striking the pipe and also prevents-the accumulation of soot be tween the pipe and'the damper plate. The means for, limiting the movement of the damper plate will be hereinafter described. The main spindle 12 consists of a wire havin straight side portions 18 andan intermediate upwardly bent portion 14. The side portions 13 are adapted to be hooked under the downwardly opening hooks 15 formed atthe lateral edges of the plate 10. The portion 1 1 is engaged on the tongue 16 which isi formed out ofthe damper plate 10 and provided with .an upwardly opening hooked portion 17 as shown in Figs. 2 and 5. The hook 17 is shallow so that the bent portion it may be readily disengaged there- T from. The damper plate may be readily at tached to spindle 12 by merely engaging the side portions 13 of the spindle under the hooks 15 and then springing the bent portion 14 over the hook portion 17. This pro vides a simple means for securing the plate to the spindle and for readily attaching or detaching it. 21s alongitudinal sectional view of Main spindle 12 is pivoted in the walls of pipe 11 and one end thereof isbent radially to provide a short arm 18 and is then bent back on itself in a direction substantially parallel to the-short arm 18 to provide the main arm 19. Arms 18 and 19 lie in the same vertical plane, and form aloop between them designated by reference character 20.
Passing through pipe 11 just below main spindle '12 is an auxiliary spindl 21 having a bent auxiliary arm 22 terminating in an upwardly directed hook 23 which passes through the loop as best illustrated in Figs. 1 and a. One function of spindle 21 is to stop the damper plate 10 from movement past the vertical or open position shown at 10. Spindle 21 is preferably located a slight distance forward (to the left) of the main spindle 12 so that the plate will be held slightly inclined and in such a position that there will always be a pressure on the lower side of the plate, due to the up draft, tending to move the plate towards its closed position.
Carried on the hook 23 and adjacent to the arms 18 and 19 is a washer 24 and adjacent thereto is ring 25 from which is suspended an auxiliary weight 26. Hook 23 of the auxiliary arm bears downwardly on the main arm 19 of loop 20 and tends to rotate the damper towards its open position. The
- weight 26 offsets to some extent the main weight 27 which tends to move the damper to its closed position. As clearly shown, weight 27 is carried on that portion of main arm 19 which is to the right of the vertical plane passing through spindle 12 and is movable along the arm 19 by means of a spiral 28 formed of wire and encircling the arm, which spiral is turnable by means of knob 29 to advance the weight along the arm in either direction. By means of this spiral adjustn'ient a considerable turning movement of the knob 29 may be translated into a relatively small movement of the weight along the arm 19 thus making possible quick and acr urate adjustments of the damper.
The relation of the arms and weights relatively to the spindles is such that the weights enjoy substantially rising and falling movements during motion of the damper, as distinguished from lateral swinging or pendulum movements, which latter are objectionable for the reason that they are likely to synchronize with the natural swinging movements of the damper and thereby cause violent swaying thereof and therefor uncertain regulation as well as objectionable noise.
Additional means for damping out unnecessary vibration or swinging movement of the damper is to be found in the particular arrangement of the loop 20, the washer 2i and the weight 26. Upon reference to Fig. 4 it will be seen that hook 23 is so curved that the washer pressed by the ring 25 is urged into frictional contact with the arms 18 and 19 arried by the main spindle. .l lnough friction is thus introduced into the apparatus to damp out undesirable swinging movements of the damper without sacrificing sensitiveness of the damper as a whole to variations in draft. It will be understood that the washer 24 may be omitted or the parts modified in shape so as to reduce or increase the friction as desired.
As previously stated, the depending portion of the damper plate 10 does not come in contact with the adjacent inner surface of thepipe 11 when the damper is in its closed position. Motion of the damper towards its closed position is limited by the auxiliary arm 22 which is so shaped that it will strike the main spindle 12 at the point 30, as shown in Fig. 6. A finger 31 is rigidly but adjustably secured on the spindle 12 and may be set to make contact with auxiliary spindle 21 to limit the closing movement of the damper before the arm 22 contacts with main spindle 12 at 30 as above described.
While the form of mechanism herein shown and described constitutes a preferred embodiment of one form of invention, it is to be understood that other forms might be adopted and various changes and alterations made in the shape, size, and proportion of the elements therein without departing from the spirit and scope of the invention.
WVhat is claimed is as follows:
1. In a damper, in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by said arm, and weight means in frictional sliding relationship with the spindle for damping swinging movements of the damper during normal swinging movements thereof.
2. In a damper, in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by said arm, and friction means cooperating with the spindle at a point remote from its axis for damping swinging movements of the damper.
3. In a damper, in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by said arm, and means pivoted for rotation about a fixed axis and cooperating with the spindle for damping swinging movements of the damper.
4. In a damper, in combination, a damper plate, a spindle therefor, weight means for balancing the damper plate, and means for damping swinging movements of the damper, said means comprising a member extending outwardly from the spindle and adapted to turn therewith, and means frictionally resisting movement of the member.
5. In a damper, in combination, a damper plate, a spindle therefor, weight means for balancing the damper plate, and means for damping swinging movements of the damper,,said means comprising a member extending outwardly from the spindle and adapted to turn therewith, and weight 1means for resisting movement of the mem- 6. In a damper, in combination, a damper plate, a spindle therefor, weight means for balancing the damper plate, and means for damping swinging movements of the damper, said means comprising a member extending outwardly from the spindle and adapted to turn therewith, and means pivoted for rotation about a fixed axis and cooperating with the outwardly extending member for resisting movements thereof.
7 In a damper, in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending transverse to a vertical plane passing through the spindle, and spaced weights bearing on said arm to balance the damper, one of the weights being arranged to damp swinging movements of the damper plate.
8. In a damper, in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending" transverse to a vertical plane passing through the spindle, and spaced weights bearing on said arm to balance the damper, one of the weights havin slidable frictional engagement with said arm during the movement of the damper plate to effect damping of the movements of the latter.
9. In a damper, in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending transverse to a vertical plane passing through the spindle, a balance weight bearing on said arm, an auxiliary weight, an auxiliary arm supportin the auxiliary weight, said arm being ui ed for movement independently of sai first-mentioned arm and bearing on the latter.
10. In a damper, in combination, a damper plate, a main spindle therefor, an arm secured to the spindle and extending transverse to a vertical plane passing through the spindle, a balance weight bearing on said arm, an auxiliary spindle having an arm connected therewith, an auxiliary weight on the auxiliary arm, sald auxiliary spindle being near said main spindle and adapted to stop the valve plate in wide open position.
11. In a damper, in combination, a main spindle, a damper plate mounted thereon and adapted to turn therewith, a main arm on the spindle, an auxiliary arm, and a weight carried thereby, said auxiliary arm being guided for movement independently of said main arm and having a bearing on the main arm.
12. In a damper, in combination, a main spindle, a damper plate mounted thereon and adapted to turn therewith, a main arm on the spindle, an auxiliary arm pivoted adjacent the main spindle, and a weight carried thereby, said auxiliary arm having a sliding bearing connection with said main arm.
13. In a damper, in combination, a spindle, a damper plate mounted thereon and adapted to turn therewith, means in the path of the valve plate to stop its movement in one direction, and means on the spindle and cooperating with said first-mentioned means for stopping its movement in the opposite direction.
14. In a damper, in combination, a damper plate, a spindle therefor including an arm extending therefrom, a balance weight carried by the arm, and friction means associated with the spindle for damping the swinging movements of the damper during normal operation thereof.
In testimony whereof we hereto afiix our signatures.
CLAUDE J. FOWLER. JEFFERSON FOWLER.
Witnesses:
R. E. TERWILLIGER,
G. J. FOWLER.
US1534845D Automatic dampee Expired - Lifetime US1534845A (en)

Publications (1)

Publication Number Publication Date
US1534845A true US1534845A (en) 1925-04-21

Family

ID=3408255

Family Applications (1)

Application Number Title Priority Date Filing Date
US1534845D Expired - Lifetime US1534845A (en) Automatic dampee

Country Status (1)

Country Link
US (1) US1534845A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3481265A (en) * 1968-01-15 1969-12-02 Hawley Manufacturing Corp Fumes receiver with automatic damper
US5259411A (en) * 1992-11-02 1993-11-09 The Field Controls Division Of Heico, Inc. Flow control

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3481265A (en) * 1968-01-15 1969-12-02 Hawley Manufacturing Corp Fumes receiver with automatic damper
US5259411A (en) * 1992-11-02 1993-11-09 The Field Controls Division Of Heico, Inc. Flow control

Similar Documents

Publication Publication Date Title
US2340283A (en) Flue control device
US1534845A (en) Automatic dampee
US2580797A (en) Wall box fan
US2652200A (en) Barometric draft regulator
US2295839A (en) Overhead chimney damper
US2650029A (en) Barometric draft regulator
US2620984A (en) Sealed seat draft regulator
US987946A (en) Damper for stovepipes, furnaces, smoke-stacks, chimneys, and the like.
US2687256A (en) Draft regulator for stove pipes
US1429190A (en) Dampeb
US1186303A (en) Draft-regulator.
US369161A (en) Adjustable hood for cooking-stoves
US1641875A (en) Joseph beaulieu
US2346740A (en) Draft regulator
US2291018A (en) Draft regulator
US1574711A (en) Automatic draft control
US2721705A (en) Draft regulator
US1652712A (en) Damper
US1140871A (en) Damper.
US595443A (en) Conductor-hood for stoves or ranges
US619993A (en) Dam per-regulator
US1974567A (en) Draft control
US1405871A (en) Automatic damper for stovepipes
US1067203A (en) Damper for open grates.
US1340865A (en) Draft-creating device