US2266009A - Ventilating device - Google Patents
Ventilating device Download PDFInfo
- Publication number
- US2266009A US2266009A US275430A US27543039A US2266009A US 2266009 A US2266009 A US 2266009A US 275430 A US275430 A US 275430A US 27543039 A US27543039 A US 27543039A US 2266009 A US2266009 A US 2266009A
- Authority
- US
- United States
- Prior art keywords
- shutters
- shutter
- movement
- levers
- link
- 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
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/72—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure
- F24F11/74—Control systems characterised by their outputs; Constructional details thereof for controlling the supply of treated air, e.g. its pressure for controlling air flow rate or air velocity
Definitions
- This invention relates generally to ventilators, but more particularly to apparatus for operating ventilators composed of a multiplicity of rotatably movable shutters.
- One object of the invention is to provide an apparatus by which said shutters may be opened and closed in a predetermined sequence to permit gradual increase or decrease in ventilation over a desired area of the ventilator structure.
- Another object of the invention is to provide a simple and inexpensive mechanism for uniformly and successively opening any desired number of shutters.
- Still another object of the invention is to provide an apparatus by which the shutters may be actuated simultaneously and opened in progressive or varied amounts to suit the required conditions of ventilation.
- Fig. 1 is a perspective and diagrammatic View showing the shutters and one type of lever mechanism in which the interconnecting links are slotted at their upper ends and connected to intermediate shutter levers by a common link pin, and a step-by-step remotely controlled shutter operating mechanism;
- Fig. 2 is a front plan View of the shutters and lever operating mechanism shown in Fig. l;
- Fig. 3 is a diagrammatic View showing the shutters and a modified form of lever operating mechanism in which the connecting links are slotted at their lower ends;
- Fig. 4 is a diagrammatic view showing the shutters and a modied form of lever operating mechanism in which the interconnecting links are slotted at their upper end and connected to intermediate shutter levers by separate pins;
- Fig. 5 is a diagrammatic view showing the shutters and a modified form of lever operating mechanism in whichvthe interconnecting links are pivotally connected to adjacent shutter levers.
- Fig. 6 is a side view showing a portion of the shutter support, a shutter, and an adjustable friction bearing.
- the ordinary ventilator or damper operates so that the shutters open or close in unison and by equal amounts, so as to allow a uniform passage of air between them, which so often causes draughts and prevents suitably modified ventilation.
- the shutters are rotated either in succession or simultaneously by varying or progressive amounts.
- the numerals I, 2 and 3 indicate shutters of a ventilator provided respectively with trunnions 4, 5 and 6, which are rotatably mounted in adjustable friction bearings attached to a frame 6I, as illustrated in Fig. 6.
- Each of said shutters I, 2 and 3 is provided respectively with lever or -crank arms l, 8 and 9 which may be of increasing lengths as shown, and each provided with link pins I0, II and I2, the lower lever 9 having an additional link pin I3.
- Links I4 and I5 are provided respectively with slots I6 and I1 for slidable engagement with the link pins I0 and II and circular openings I8 and I9 for pivotal engagement with the link pins II and I2, as shown in Figs. 1 and 2.
- the adjustable friction bearing shown in Fig. 6 comprises complementary upper and lower journal members 62 and 63 between which the shaft 64 of a shutter is rotatably mounted. The lower.
- member 63 is formed as a bracket which is attached to the shutter supporting frame 6I, and the upper journal member 62 is adjustably at.
- the link pin I3 of the lower lever 9 is pivotally engaged by the circular opening 20 in a link 2
- is also provided with another circular opening 22 by which it pivotally engages a link pin 23 located adjacent the circumference of the circular disc 50 of the step-by-step control mechanism, such as shown in the patent granted to Christian Kramer, October 29, 1912, No. 1,042,692, which may be used to control a shutter actuating motor from a remote point.
- any other step-by-step mechanism may be utilized if desirable.
- FIG. 1 shows thisV type of apparatus connected to the lever 9 by a link 2 I.
- the numeral 30 represents the armature, and 3
- This motor is controlled from a remote point by a transmitting device 33 consisting of a plurality of contacts 34, 35, 36, 31 and 38, mounted on an insulating base 39 and a controlling contact arm 4U which is moved over the contacts by the operator.
- the receiving device 4I consists of the Vcontroller 42 driven by the motor in any suitable manner as for instance, through the shaft 43 and appropriate gears 44, 45, 46, and 41, as shown.
- the controller consists of two conducting segments 48 and 49 mounted upon a circular disc of insulating material 50 and separated from each other at their extremities ⁇ ley air spaces designated by the numerals v5I and 52, said disc being operatively connected -or rotative movement by the motor through the shaft and gearing mentioned above.
- These brushes are of less width than the space between the segments 4B and '49, so that when either of Vthe insulating spaces 5I and 52 Iarrives opposite v'any ⁇ of the brushes 34a, 35a, 38a, 31a vand 35a, the circuit will be broken through th'e fields '-31 and V32 which are connected with the segments '48 and 49 by the .brushes 53 -and 54 and the conductors 55 and 56.
- Shutters' 2 and '3 are now moving toward theirr open positions simultaneously, AWhen the Vtop or" slot 'I6 engages. pin Ill, .shutter starts V.to open SIO and then all three of the shutters are moving toward their open positions which they reach at the same time. In closing the shutters, the shutter 3 starts to close first. When the bottom of slot I1 engages pin I I, shutter 2 starts to close. Then 2 and 3 are moving toward their closed positions simultaneously. When the :bottom of slot I6 engages pin IIl, shutter I starts to close and then all three of the shutters are moving toward their closed positions and reach their closed positions at the same time.
- the modified form of the device shown 4in Fig. 4 differs from that shown in Fig. 1, in that the connecting links '
- levers in conjunction 'with their interconnecting links impart a simultaneous movement to ⁇ the shutters and effect a progressive opening and closing of the same.
- the relative amounts by which the shutters are opened and closed depend on the distances of the pivotal points of the links from the axis of rotation of the shutters. In the design shown the shutter 3c opens a greater amount than the shutter 2c, and the shutter 2c opens a greater amount than the shutter lc. If in the design of the ventilator it is necessary to increase or decrease the amount of opening of one or more of the shutters in the modified form of construction, as shown in Fig. 5, this can be accomplished by changing the points of attachment of its interconnecting links.
- a Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, levers projecting from said shutters, link pins projecting from said levers, means for restraining the free rotative movement of said shutters, and slotted overlapping links pivotally and slidably connected to the link pins of adjacent levers, whereby rotative movement imparted to one of said shutters is transmitted through said links to the next adjacent shutter in successive order after partial completion of said movement in each.
- a Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, means comprising friction bearings for restraining the free rotation of said shutters, levers projecting from said shutters, link pins projecting from said levers, means for imparting a rotative step-by-step movement to one of said levers, and longitudinally slotted links pivotally and slidably connected to the link pins of adjacent levers, whereby rotative movement imparted to one of said shutters is transmitted through said links to the next adjacent shutter in successive order after partial completion of said movement in each.
- a Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, levers of increasing lengths projecting from said shutters, link pins projecting from said levers, means for imparting a rotative step-by-step movement to one of said shutters, means comprising adjustable friction bearings for restraining the free movement of said shutters,
- a Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, means comprising adjustable friction bearings for restraining the free movement of said shutters, means for imparting a rotative step-by-step movement to one of said shutters.
- a Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, lever arms of decreasing lengths projecting from said shutters, link pins projecting from said lever arms, a link connected with a source of power and pivotally connected with the longest of said levers adapted to eiect the partial rotation of the shutter connected therewith, and longitudinally slotted connecting links pivotally connected to the link pins of the longer of adjacent levers and slidably connected to the shorter of adjacent levers adapted to transmit rotary movement thereto when the end of the slot therein contacts the link pin to which it is slidably fitted, and thereby eiect a successive movement of the shutters in opening and closing the same.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Air-Flow Control Members (AREA)
Description
- Best. l@ Q', W A. DANEELSQN I ZS@ VENTILATING DEVICE Filed May 24, 1939 ff [Us 3657.@ VZ A Patented Dec. 16, 1941 VENTILATING DEVICE Wilmot A. Danielson, Fort Knox, Ky.
Application May 24, 1939, Serial No. 275,430
(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 O. G. 757) Claims.
This invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.
This invention relates generally to ventilators, but more particularly to apparatus for operating ventilators composed of a multiplicity of rotatably movable shutters.
One object of the invention is to provide an apparatus by which said shutters may be opened and closed in a predetermined sequence to permit gradual increase or decrease in ventilation over a desired area of the ventilator structure.
Another object of the invention is to provide a simple and inexpensive mechanism for uniformly and successively opening any desired number of shutters.
Still another object of the invention is to provide an apparatus by which the shutters may be actuated simultaneously and opened in progressive or varied amounts to suit the required conditions of ventilation.
Other objects relating to the details of construction, combination and arrangement of parts, will hereinafter appear in the description to follow.
Referring more particularly to the accompanying drawing in which corresponding parts are indicated by similar reference characters:
Fig. 1 is a perspective and diagrammatic View showing the shutters and one type of lever mechanism in which the interconnecting links are slotted at their upper ends and connected to intermediate shutter levers by a common link pin, and a step-by-step remotely controlled shutter operating mechanism;
Fig. 2 is a front plan View of the shutters and lever operating mechanism shown in Fig. l;
Fig. 3 is a diagrammatic View showing the shutters and a modified form of lever operating mechanism in which the connecting links are slotted at their lower ends;
Fig. 4 is a diagrammatic view showing the shutters and a modied form of lever operating mechanism in which the interconnecting links are slotted at their upper end and connected to intermediate shutter levers by separate pins; and
Fig. 5 is a diagrammatic view showing the shutters and a modified form of lever operating mechanism in whichvthe interconnecting links are pivotally connected to adjacent shutter levers.
Fig. 6 is a side view showing a portion of the shutter support, a shutter, and an adjustable friction bearing.
The ordinary ventilator or damper operates so that the shutters open or close in unison and by equal amounts, so as to allow a uniform passage of air between them, which so often causes draughts and prevents suitably modified ventilation.
In the Ventilating apparatus which forms the subject matter of this invention, the shutters are rotated either in succession or simultaneously by varying or progressive amounts.
Referring to Fig. 1, the numerals I, 2 and 3 indicate shutters of a ventilator provided respectively with trunnions 4, 5 and 6, which are rotatably mounted in adjustable friction bearings attached to a frame 6I, as illustrated in Fig. 6. Each of said shutters I, 2 and 3 is provided respectively with lever or -crank arms l, 8 and 9 which may be of increasing lengths as shown, and each provided with link pins I0, II and I2, the lower lever 9 having an additional link pin I3.
Links I4 and I5 are provided respectively with slots I6 and I1 for slidable engagement with the link pins I0 and II and circular openings I8 and I9 for pivotal engagement with the link pins II and I2, as shown in Figs. 1 and 2.
' The adjustable friction bearing shown in Fig. 6, comprises complementary upper and lower journal members 62 and 63 between which the shaft 64 of a shutter is rotatably mounted. The lower.
tached to the lower member by means of theV screws 65. The adjustment of the screws 65 controls' the degree of friction and resistance to rotary movement of the journaled shaft 64.
The link pin I3 of the lower lever 9 is pivotally engaged by the circular opening 20 in a link 2|. The link 2| is also provided with another circular opening 22 by which it pivotally engages a link pin 23 located adjacent the circumference of the circular disc 50 of the step-by-step control mechanism, such as shown in the patent granted to Christian Kramer, October 29, 1912, No. 1,042,692, which may be used to control a shutter actuating motor from a remote point. In this connection it is to be understood that any other step-by-step mechanism may be utilized if desirable. Fig. 1Y
shows thisV type of apparatus connected to the lever 9 by a link 2 I. In this figure, in which the remote control apparatus is shown diagrammatically, the numeral 30 represents the armature, and 3| and 32 vthe twov elds of motor (not shown), either one of which may be in circuit to drive the motor in the forward or reverse direc-V tion. This motor is controlled from a remote point by a transmitting device 33 consisting of a plurality of contacts 34, 35, 36, 31 and 38, mounted on an insulating base 39 and a controlling contact arm 4U which is moved over the contacts by the operator. The receiving device 4I consists of the Vcontroller 42 driven by the motor in any suitable manner as for instance, through the shaft 43 and appropriate gears 44, 45, 46, and 41, as shown. The controller consists of two conducting segments 48 and 49 mounted upon a circular disc of insulating material 50 and separated from each other at their extremities `ley air spaces designated by the numerals v5I and 52, said disc being operatively connected -or rotative movement by the motor through the shaft and gearing mentioned above. Cooperating with these conducting segments are ifa `plum-lity of brushes 34a, 35a, 33a, 31a and 38a connected respectively by conductors 34h, 35h, 36o, 31o and 38o with the contacts on the transmitting device having corresponding reference characters, 'and brushes 53 and 54 whichr are connected respectively -through conductors-55 and 56 to the fields 3i vand 32 of the motor. These brushes are of less width than the space between the segments 4B and '49, so that when either of Vthe insulating spaces 5I and 52 Iarrives opposite v'any `of the brushes 34a, 35a, 38a, 31a vand 35a, the circuit will be broken through th'e fields '-31 and V32 which are connected with the segments '48 and 49 by the .brushes 53 -and 54 and the conductors 55 and 56.
It will be seen -that with-the parts in the vposition shown, no current can lflow 'to the fields of the motor, since the contact 34a is in-oi position. Ii however, the arm 40 ofthe transmitting device 33 is moved to Ycontact 35 then the circuit lwill be completed from the positive side vof the line through -the'contact arm 40, contact '35, conductor 35o, brush 35a, segment `4I), brush 54, conductorf56 vand thence to eld 32,"motor armature .39 and to the negative 'side of the line. "This will cause the motor to rotate the controller disc 5U and sectors 48 and j49 in a 'direction vindicated by the arrow, -until the Ainsulating `space '5I .is opposite the brush 35a, whereupon the motor will stop. In like xmanner if thecontact arm '4B 'is moved to the contact 36 vthe Acontroller will be rotated by the motor until the space `5I between the segments is opposite the brush 36a and the circuit is opened. If now'the contact arm is moved in a 'counter-clockwise direction .into engagement with the contact 35 'or 34 the controller will be moved in the opposite direction by the energization 'of the field 3l. 'It will .be observed that in this device only 'live positions or stopping points in the movement ofithe controller are available. The number of such stopping points depends on the number of contacts on the transmitter and brushes on the controller, which may be increased or decreased .in the design of the apparatus to suit the purpose for which it 'isused In -the operation of the 'formof lever mechanism 'shown `in Figs. 1 and 2, when disc 5B imparts a rotary clockwise Vmo'vementlto the shutter 3' through the link 2I and shutterflever 9, the shutter 3 starts to open, and after opening a distance sufficient to allow the top 1of the. slot I1 to engage the pin II, Yshutterf'2 starts to open.
Shutters' 2 and '3 are now moving toward theirr open positions simultaneously, AWhen the Vtop or" slot 'I6 engages. pin Ill, .shutter starts V.to open SIO and then all three of the shutters are moving toward their open positions which they reach at the same time. In closing the shutters, the shutter 3 starts to close first. When the bottom of slot I1 engages pin I I, shutter 2 starts to close. Then 2 and 3 are moving toward their closed positions simultaneously. When the :bottom of slot I6 engages pin IIl, shutter I starts to close and then all three of the shutters are moving toward their closed positions and reach their closed positions at the same time.
By-suitable proportionment relative to the decrease in thelength of the lever arms of the successively moved shutters, their initial rotative movement .can :bemade to equal substantially the same arcuate distance.
It will be noted that the construction shown -in Fig. 3, `the `interconnecting slotted links effect an initial and lfinal movement in opening or closing all but the end shutters. .Rotary movement is not transmitted to the intermediate rshutters until after a predetermined movement of the lowermost shutter. The uppermost shutter opens or closes only with the ysimultaneous movement of vall the other shutters.
Throughout the modified forms, 'shown inFigs. 3, '4 and 5, all of Ywhich have the general construction to the form shown in Figs. 1 and'Z, like elements to those 'described in Figs. 1 and '2 are indicated by similar reference Vcharacters which are differentiated bythe -sublet'ters a, b, .and c.
In the modication shown in ".Eig. 3, the 'construction 'differs from that :shown 'in Fig. 1, "1n that the shutters open by movement 'in a counter-clockwise direction, the links 14a and I5a are provided with slots at their lower extremities and are coupled to the intermediate .lever .Baby separate `link pins I1Ia and"21a.
uIn the `operation of this form of the device, after the `shutter 3a has been opened a predetermined amount by 'action of the motor operated link 2Ia on the lever 9a, 'the pin -12a reaches the top 'of the slot `I`1a in the'link 'I-5a `and .transmits movement -of lever '9a through the'flink `I5a to the lever 3a to open shutter '2a. The link I4a transmits movement of the lever 8a to the shutter Ia in the same manner.
It will thus be .seen 'that the -successive lopening and closing of the shutters depend Aon the movement of the slotted interconnecting links as in the type shown iin Figs. 1 and 2.
The modified form of the device shown 4in Fig. 4 differs from that shown in Fig. 1, in that the connecting links '|412 and 15b' are connected to separate link pins I'Ib and 21h located on the intermediate lever 8b.
The operation of .this 'form of the device .'is practically the same as that shown'in Figs. 1 .and 2, with the exception that a lower link has a greater movement 'than "the lirik .immediately above it, which is due to the greater .distance-of their pivotal .points on the intermediate .shutter levers, fromfthe fulcrum or axiallline of the shu'tter 'operated loysaid levers. 'This feature is also found in the type illustratedin Fig. '3, in which'it will lbe noted that pin -I "lfb is further from thev In this type of construction .as illustrated, .the
levers in conjunction 'with their interconnecting links impart a simultaneous movement to `the shutters and effect a progressive opening and closing of the same. The relative amounts by which the shutters are opened and closed depend on the distances of the pivotal points of the links from the axis of rotation of the shutters. In the design shown the shutter 3c opens a greater amount than the shutter 2c, and the shutter 2c opens a greater amount than the shutter lc. If in the design of the ventilator it is necessary to increase or decrease the amount of opening of one or more of the shutters in the modified form of construction, as shown in Fig. 5, this can be accomplished by changing the points of attachment of its interconnecting links.
Having described my invention, what I claim as new and wish to secure by Letters Patent is:
1. A Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, levers projecting from said shutters, link pins projecting from said levers, means for restraining the free rotative movement of said shutters, and slotted overlapping links pivotally and slidably connected to the link pins of adjacent levers, whereby rotative movement imparted to one of said shutters is transmitted through said links to the next adjacent shutter in successive order after partial completion of said movement in each.
2. A Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, means comprising friction bearings for restraining the free rotation of said shutters, levers projecting from said shutters, link pins projecting from said levers, means for imparting a rotative step-by-step movement to one of said levers, and longitudinally slotted links pivotally and slidably connected to the link pins of adjacent levers, whereby rotative movement imparted to one of said shutters is transmitted through said links to the next adjacent shutter in successive order after partial completion of said movement in each.
3. A Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, levers of increasing lengths projecting from said shutters, link pins projecting from said levers, means for imparting a rotative step-by-step movement to one of said shutters, means comprising adjustable friction bearings for restraining the free movement of said shutters,
and links provided with a central longitudinal slot pivotally and slidably connected to the link pins of adjacent levers to permit a limited independent movement of said links, whereby rotative movement imparted to one of said shutters is transmitted through the connecting links to the next adjacent shutter in successive order after partial completion of said movement in each.
4. A Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, means comprising adjustable friction bearings for restraining the free movement of said shutters, means for imparting a rotative step-by-step movement to one of said shutters.- levers of decreasing lengths projecting from said shutters for eiecting a relative increase in velocity in the rotative movement of said shutters, and links having longitudinally extending slots pivotally and slidably connected to adjacent levers to permit a limited independent movement therebetween, whereby rotative movement imparted to one of said shutters is transmitted through the connecting links to the next'adjacent shutter in successive order throughout the series, after the partial completion of said movement in each.
5. A Ventilating mechanism comprising a series of pivotally mounted parallelly arranged overlapping shutters, lever arms of decreasing lengths projecting from said shutters, link pins projecting from said lever arms, a link connected with a source of power and pivotally connected with the longest of said levers adapted to eiect the partial rotation of the shutter connected therewith, and longitudinally slotted connecting links pivotally connected to the link pins of the longer of adjacent levers and slidably connected to the shorter of adjacent levers adapted to transmit rotary movement thereto when the end of the slot therein contacts the link pin to which it is slidably fitted, and thereby eiect a successive movement of the shutters in opening and closing the same.
WILMOT A. DANIELSON.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US275430A US2266009A (en) | 1939-05-24 | 1939-05-24 | Ventilating device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US275430A US2266009A (en) | 1939-05-24 | 1939-05-24 | Ventilating device |
Publications (1)
Publication Number | Publication Date |
---|---|
US2266009A true US2266009A (en) | 1941-12-16 |
Family
ID=23052254
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US275430A Expired - Lifetime US2266009A (en) | 1939-05-24 | 1939-05-24 | Ventilating device |
Country Status (1)
Country | Link |
---|---|
US (1) | US2266009A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2976884A (en) * | 1958-05-19 | 1961-03-28 | Anemostat Corp America | Valve structures |
US20130240157A1 (en) * | 2012-03-16 | 2013-09-19 | Oma Automation Enterprise Co., Ltd. | Electric window blinds |
-
1939
- 1939-05-24 US US275430A patent/US2266009A/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2976884A (en) * | 1958-05-19 | 1961-03-28 | Anemostat Corp America | Valve structures |
US20130240157A1 (en) * | 2012-03-16 | 2013-09-19 | Oma Automation Enterprise Co., Ltd. | Electric window blinds |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2293065A (en) | Air flow control damper | |
US2266009A (en) | Ventilating device | |
US1655246A (en) | Air and oil equalizing means for oil burners | |
US2571374A (en) | Ventilating fan | |
US3640455A (en) | Air temperature control system | |
US2331758A (en) | Louver damper | |
US2479243A (en) | Automatic greenhouse venilator | |
US2309984A (en) | Overhead door operating means | |
US1820764A (en) | Skylight | |
US1015204A (en) | Automatic temperature-regulator. | |
US1779050A (en) | Reversible fan | |
US2528855A (en) | Apparatus for use in association with two picture projector machines | |
DE3908511C2 (en) | Wall fan | |
US2441726A (en) | Electric air circulating heater | |
US2616356A (en) | Heating and ventilating apparatus | |
US3282557A (en) | Electrically actuated unidirectional rotary drive having adjustable stops for damper control and the like | |
US1467901A (en) | Ventilator | |
US2163692A (en) | Method and means for conditioning the air in an enclosure | |
US1837923A (en) | Automatic fuel | |
US1440171A (en) | Electric heater | |
US2485356A (en) | Ventilating apparatus | |
US2054071A (en) | Temperature control system | |
US2623251A (en) | Adjustable louver for venetian blinds | |
US1776777A (en) | Forced-draft-producing device | |
US2060671A (en) | Fan switch |