US2682826A

US2682826A - Electrically driven fan

Info

Publication number: US2682826A
Application number: US601444A
Authority: US
Inventors: Wahlborg Karl John
Original assignee: Hjorth & Co AB
Current assignee: Hjorth & Co AB
Priority date: 1944-07-12
Filing date: 1945-06-25
Publication date: 1954-07-06
Anticipated expiration: 1971-07-06

Description

4 Sheets-Sheet 1 Filed June 25, 1945 y 6, 1954 K. J. WAHLBORG 2,682,826

' ELECTRICAL-LY DRIVEN FAN Filed June 25, 1945 4 Sheets-Sheet 2 a J 6:? a

w 29 W //M i k 52% WQW July 6, 1 4 K. J. WAHLBORG ELECTRICALLY DRIVEN FAN 4 Sheets-Sheet 4 Filed June 25, 1945 hl INVEN 0 BY? Patented July 6, 1954 7 2,682,826 ELECTRICALLY DRIVEN FAN Karl John Wahlborg, Stockholm, Sweden, as-

signor, by mesne assignments, toAktiebolaget B. A. Hjorth & 00., Stockholm, Sweden, a corporation of Sweden Application June 25, 1945, Serial No. 601,444

Claims priority, application Sweden July 12, 1944 8 Claims.

This invention relates to a ventilator unit of a type which is employed to circulate air through a duct or opening in a building wall of an enclosure.

The object of this invention is to provide an improved ventilator unit of this type which can be conveniently employed to circulate air through an existing duct in a building wall, the construction being such that the unit occupies a minimum amount of space at the inner face of the wall and a part thereof telescopically fits into the duct itself.

According to the present invention, the ventilator unit embodies a box-like casing having a rear wall adapted to be mounted on the building wall or the like so as to cover the existing air duct and an air passageway extending therethrough, and amotor-fan' unit carried by the casing, the fan being'disposed-in the air passagethe box-like casing is mounted at or'immediate ly adjacent to the inner surface of the building wall. With such an arrangement it is very easy to mount the ventilator unit on a wall of an existing air duct even when the size'of the duct does not correspond with the diameter of the passageway in which the fan: 'is positioned, and also when the duct may be rectangular in shape with its greater dimension in a vertical direction. By providing a ventilator unit having a box-like casing the rear wall thereof may be applied to ducts which vary considerably in size. Since the rearwardly extending motor telescopically fits into the duct, the casing when mounted on a building wall will project from the inner surface thereof into the enclosure a distance which is less than the overall axial distance taken up by the fan and motor, thereby providing a neat and compact-ventilator unit which is essentially disposed in its entirety within the enclosure and readily removable for inspection and cleaning.

The invention, together with the above and otherobjects and advantages thereof, will be described more fully hereinafter in connection with the accompanying drawings forming a part of this specification, and in which:

Fig. 1 is a side'view, partly in section, of a ventilator unit embodying the invention;

Fig. 2 is a side elevation of the ventilator unit shown in Fig. 1;

Fig. 3 is a front view, partly broken away and in section, of the ventilator unit shown in Figs. 1 and 2, the damper being omitted to illustrate details more clearly;

Fig. 4 is a wiring diagram for the ventilator unit shown in Figs. 1 to 3;

Fig. 10 is a front elevation of the damper'and. switch operating mechanism shown in Figs. 1.

and 3, the front member of the casing being .omitted to show details more clearly;

Fig. 11 is a top plan view of the operating mechanism illustrated in Fig. 10;

Fig. 12 is a side elevation of the operating mechanism shown in Figs. 10 and 11;

Figs. 13, 15 and 17 are fragmentary vertical views of the damper and switch operating mechanism, being similar to the details of such mechanism shown in Fig. 6 and illustrating'the different operating positions thereof;

Figs. 14, 16 and 18 are horizontal sectional views similar to Fig. 7 which correspond to the operating positions of the damper and switch operating mechanism illustrated in Figs. l3, l5 and 17, respectively, Fig. 14 being taken at line l4--l4 of Fig. 13, Fig. 16 at line iii-l6 of Fig. 15, and Fig. 18 on line l8l8 of Fig. 1'7; and

Fig. 19 is a transverse sectional view of the operating mechanism illustrated in Fig. 15.

Referring to Figs. 1 to 3, l0 designates gen erally a box-shaped outer fan casing, preferably made of sheet metal, which is arranged to carry a rectangular-shaped shutter or damper H, and H denotes the wall of a cylindrical fan wheel drum defining an air passageway in which a fan I4 is disposed. The fan I4 is driven by a motor 4 .5; it which is resiliently suspended. The suspension device in the embodiments shown comprises three S-shaped clips I5, preferably made of spring steel, having their outer arms either, as in the embodiment shown in Figs. 1 to 3, extending through the rear wall 21 of the box-like casing In or, as in the embodiment shown in Figs. to 7, connected to the cylindrical wall I2 by lugs I6. The inner arms of the clips, which are encased with rubber bushings H, are secured to the motor casing by a metallic strip I8 encircling the latter.

The casing ID is formed of two wall mem.-..

bers, namely, a front wall member 20 and a rear wall member 2| held together b'yia; number of screws or bolts 22. Since the fandrum I2 is of cylindrical shape and the surrounding casing II) is essentially box-like. in character in the.

In the embodiments shown in Figs. 1 to 3 and Figs. 5 to '7 the damper or shutter is so constructed that theda'mper I I assumes a position essentially parallel to the front wall m'ember-of the casing when the-damperisin'its closed and open positions.

ment which includes arms I and:-I26"joined together' byacross piecewl2'l pivotally connected to the damper by hinges'zd. Another" pair of connected arms-lzs is-pivotally mounted to the upper part of the outer wall member 20': by

hinges 26, the lower ends of theJar'ms-iI28being arranged to slideiagainst the-inner surface of the damper I I. and I26 are pivotally connected to the pairof arms I28'at thepointslZil. Arm md terminates at point I29 while: arm I25 continues downwardly and is connected to an actuating member" or lever 21; as best shown in--Figs-.-l' and 3:'1

In" the embodiment illustrateddn Figs: l to' 4,

the switch comprises a' controlcylinder'ifi; which is actuated step by step to a: numberofdifferent positions by a pull-cord 29, aswill be described presently; the cylinder with each downward pullon the cord 29: being moved"angularly--through-= 90 in the direction indicatedby: the arrows'in- Figs; 4, ea; lbanch 40.. In this manner the brushes 3|, 32 and 33 will be successively inter--- connectedin pairs throughthe icontact segment 34. The sequence of operations on successive downward pulls ion-the cord 29; as diagrammatically indicated in Figs. 4a; id and is that: the damper is 1 first: opened while the motor re- In thenext position-seenin Fig. 4b the motor is started mains disconnected, as seen in Fig: la.

and runs at halfspeed. In the next position seen in Fig. 4c, the motor runsat. full' speed. Finally, when the switch has againmeachedthe starting position illustratedin-Figi 4, the -motoris disconnected and the damper is closed.-

The damper lI is actuated:by mechanism in cluding a cam element 35 which is arrangedonr the fan motor i3,-either at halfor full speed,-is-

effected by a'tapSI arranged on thefield winding 36 of. the motor, as diagrammatically-seenin:

Figs. 4, 4a,.4b and ic.

As seen in Figs; 1 to 3;.the damper II is supported by alazy-tongs'arranga' As :best seen in Fig; 3, therarmsi I25- As best shown in Figs. 10, 11 and 12, the cam element 35 and lever 21 form part of a damper and switch operating mechanism including a cord wheel on which the cord 29 is anchored at 290. and wound thereon in such a manner that, when the latter is pulled downward, the wheel 60 is rotated 90 in a counter-clockwise direction from the position shown in Fig. 10. Such counter-clockwise turning movement of the cord wheelfit is .stoppedby. a..member .IiIv in the form of an. elongated '.:loop whichyis; pivotally mounted at one end at 62 to the cord wheel 50. The opposite end of the member BI is looped about a bolt or stud B3 and angularly movable about. Eth c flatter.

tends-from "such: stud and: is adapted to engage" one-of"thenotchesfifi toiretain :thewstep wheel 65 in its new position each time the latteriszro tated90z While the 'step 'wheel. 6'5: is retainedzeach time the position to which it is-irotated', .the r cord wheel fill-*returns'to the-dottedline-positionshown in Fig; lobytheraction 'ofiaspring I8 when the I cord 29 is released: Theroam"discx35 andrcontrol' cylinder" 28 F' of they switchare rigidly secured to the same shaft 28a upon which thewsten-wheel S5 is mounted,- whileith-e cord. wheel fiil'z'iszireely rotatable on" such' shaft;

A cam rollerJI I is :rotatably' carriedioni an arm I2 which-is: pivotally. supported; onL thestud '68-.

The:lever21.- connected-tothe armzIZfw-of the? damper operating mechanism; described above, is:operatively:,associatedrwiththe arm,='d2.. Thev lever '21 is-formed from a==length of resilient rodhaving. a portion-21 wound about. the-hub of'the arm-12, and the left-hand. endshownin v Fig.-- 10 is clamped: in :a hooked: portion-..'I3:of' the arm. 222' The arm I2; lever-211 and-:roller =-'I I form anonseparable unit during-z-normalioperation of the control mecha-"nis-m being:described;v In the event the=-dampenItI is accidentally pushed to its closed position iwhenzthe. operating mechanism is act ing .to i-maintainthe' damper open, thelever 2'3: yields due to its resiliency ,so i that: parts of: the

the-lever 21 imparts upward movement to' the arm- I 25. ofthe damper operating mechanism to effect openingeof" the damper? I I. I When the cam disc-35sis subsequently moved to its dottedline positioninFig; 10,-the rol1er- II is urged downwardly by the action of the damper closing springaill: shown-id Fig. 3; Such downward movementof therroller- 'II- can then-:take place inasmuch as the inwardly curved portion of the camdisc 35 is then directed upwardly, as best shownin.Fig.3.-- The advantage of-the regulating mechanismabove described-is that only a draw. cord; chain orithe likeiis required to actuate the motor switch and: shutten oridamper- I I I In the embodiment shown in Figs. 5 to '7 and 13 to 19 the common actuating member for the motor switch and damper comprises mechanism including a plate 38 which is reciprocably carried in an extension 39 which is fixed to the casing and serves as a guide. Movement of the plate 38 is effected exteriorly of the casing by two cords 4| which pass over guide rolls 48 and are connected to opposite ends of the plate, the cords passing through openings in the casing and freely hanging outside the latter. The plate 38 is formed with a curved cam-groove 42 arranged to receive a lever 210. which corresponds to the lever 21 in the embodiment of Figs. 1 to 3, the lever 21a being connected to the arm H511 to guide the latter and impart vertical movement thereto.

The plate 38 is also provided with a tongue 43 which is mounted in an insulated manner thereon and adapted to cooperate with a switch, as will be described presently. To hold the plate in a' number of different operating positions, it is formed with a number of openings 44 located according to such operating positions, the openings being adapted to be engaged by a ratchet spring 45 connected to the extension 39. As best seen in Fig. 7, the switching provisions comprise two pairs of laminated contact springs 46 and 41 which are mounted on a contact member 48 formed of insulating material and connected to the casing.

In operating the embodiment of Figs. 5, 6 and 7, a pull on the left-hand cord 4| in Fig. 6 will move the plate 38 from the position shown in Figs. 6 and 7 to that shown in Figs. 13 and 14 to displace the lever 21 upwards, so that the damper willbe opened. A further pull on the cord will move the plate 38 from the position shown in Figs. 13 and 14 to that shown in Figs. 15, 16 and 19' to cause the tongue 43 to bear against the pair of springs 46, with the result that the motor will be started up and be driven at full speed. Another pull on the'same left-hand cord 4| will move the plate 38 from the position shown in Figs. 15 and 16 to thats hown in Figs. 1'7 and 18 to cause the tongue 43 to bear against the pair of springs 41, which efiects switching of the motor to half speed operation. When the right-hand cord 4| in Fig. 6 is pulled, themotor will again be switched to full speed operation and a furtherpull on the right-hand cord 'will disconnect the motor at which time the damper also will be closed.

In the control mechanism just described, it is possible to switch the motor any desired number of times between half and full speed operation simply by pulling on either the right-hand or left-hand cord without actuating the damper operating mechanism. For the purpose of quickly ascertaining the operation of the ventilator unit, the reciprocable plate 38 is provided with an indicating device 49 which is visible through an aperture 381 or window in the base of the casing, such device 49 being in the form of a tongue which may indicate, as by its color, for example, whether the fan motor is disconnected or is being operated at full speed orat half speed. An indicating device of a similar type may also be provided in the embodiment illustrated in Figs. 1 to 3.

Figs. 8 and 9 show a modified damper construction in which the damper II is inclined to the front side of the casing in its open position and parallel to such front side or face in its closed position. As best seen in Fig. 9, such damper operation is efiected by providing a torsion spring 58a between the arm |25a and the inside face of the damper, the spring being arranged so that it always will tend to maintain the damper in the inclined position indicated by full lines in Fig. 8. When the arms of the lazy tongs assume a folded position, the damper is automatically moved to a position which is parallel to the casing, by reason of the fact that its upper edge, as indicated by dotted lines in Fig. 8, will first be moved against the front wall of the casing.

If it is desired to cause the damper to be inclined to the vertical in its open position without employing the torsion spring 58a in the manner just described, an arrangement can be adopted which is shown in Fig. 8 in which a chain 5| or the like is connected to the upper edge of the damper and to the casing, the extent of the inclination being varied by adjusting the length of the chain. The provision of the chain 5| may also be of advantage even when the torsion spring 58a is employed because it tends to prevent rattling of the damper in its open position. In the embodiment shown in Figs. 1 to 3, the torsion springs are arranged to cause the damper II to bear resiliently against the arms I25 and I26.

Although I haveillustrated and described particular embodiments of my invention, I do not desire to be limited to the particular arrangements set forth, and I intend in the following claims to cover all modifications which do not depart from the spirit and scope of my invention.

What is claimed is:

1. In a ventilating unit for circulating air through an existing air duct in a building wall of an enclosure having spaced apart inner and outer surfaces, such unit comprising a box-like casing including spaced apart first and second wall members constituting front and rear walls, respectively, each of the wall members being formed with an opening, an air passageway forming member extending between the first and second wall members and terminating atthe openings therein, another member which is spaced from the passageway forming member and connects the first and second wall members to form a substantially closed outer chamber exteriorly of the passageway, an electric motor, a fan carried by the motor and driven by the latter, the fan and motor together taking up a'definite overall distance in the direction of the axes of such parts, damper means for the'passageway, means for mounting the damper means on the casing for movement thereon between an open position and. a shut position at the first wall member or front wall of the'casing, electric switching means for controlling the motor, means for adjusting the position of the damper means, the electric switching means and damper adjusting means including parts'disposed in the closed outer chamber of the casing, means for mounting the casing on the building wall with the second wall member or rear Wall thereof at the inner surface of the building wall with the opening in such second wall member communicating with the duct, means for carrying the motor on the casing with the fan disposed in the air passageway between the first and second wall members and the motor projecting exteriorly of the casing from the second wall member or rear wall thereof so that the duct will constitute a housing for the motor when the easing is mounted at the inner surface of the building wall, the casing when mounted on the building wall projecting from the inner surface thereof into the enclosure a distance which is less than the overall axial distance taken up by the fan andunotor, andtherdamperymeans: in itsp-shut' position OlOSiIlQthGOPGDlIlEQlIl the firstwall member or::front wall of: the;casing,,

2.. The combination- :defined in claim :1 comprising; structure incl-uding 'the' electric switching means'xfor. operating-the motoratfullspeed or a reduced speed; the casing having a window, and

indicating means. in theouter closed chamber whiohis visible through thewindow'to indicate the position of the switching-'m'eans'and determine whether-the:motordsstopped or-being operatediatifu'll or: reduced speed.

3:;The' combination-defined'inclaim l in which then'electricswitching means includes a movable elementfor controllingsthe motor, and the damperv adjusting means comprises mechanism includingrcam means and. a: cam-follower operable re sponsive-to'movementof the'element for adjustingzthedamper means, .the camzmeans constituting one of the: parts disposediwithin the casing in thesclosed outer chamberiithereof.

4:;The combination defined'in claim 1 in which thesda'mper' means zincludes ,:a vertically disposed plate movable. totand froma shut position overlying theopening in the first wall member or front wall. of the casing and the means for mounting. the damper means on the casing includes. spaced: apart vertically extending arms pivotally connected. at their upper-ends to the plater at' a region thereof which is located above the .centerpf gravity of the, plate, said mounting means being so constructed-and arranged that thearms' are essentially. parallel to the first wall member orfront wall of the casing when the damper means-isin "its shut position and the plate overliesthe-opening inthe first wall member-andvthe armsare at an-acute-angle to the first wall member when the-damper means is-in,

itsopen position and theiplate is removed from theopening of. the-firstwall member, and the damper adjusting means including structureoperativelyconnected'to the arms for; moving the latter.

5. The combination defined in .claim 1 in which the electric switchingmeans comprises a member which is movable back and forth ina straight line and-a switch unit having a movable partin the'path ofmovement of themember which is actuated by themember in one-position thereof, mechanism operatively connectedto the damper means and to the member for. governing the posi. tion of theolamper meansaccordingtothe position of themember in its straight lineof movement, and manually operable means accessible exteriorly of the casing to impart movement back and forth inastraightline to the. member.

6..In a ventilator unit capable of circulating air through diiferent size air ducts in building walls of enclosures having spaced apart inner and outer. surfaces,- such unit comprising a boxlike casing including spaced apart first and sec ond wall members constituting front and. rear walls, respectively, each of the wall members being formed with an opening, an air passageway forming member extending between the first and second wall members and terminating at the openings therein, another member which is spaced from the passageway forming member andconnects the first and second wall members to form a housing exteriorly of the passageway, an electric motor, a fan carried by the motor and driven by the latter, the fan and motor together taking up av definite overall distance in the direction of the axes of such parts, a shutter for the passageway, means for mounting the shutter on I the casing for; movement lthereon: between trolling the motor, the control. mechanism including arts disposedin the housing and a-man ually operable part accessible exteriorly of; the.- casing, means for mounting the casing on a build ing wall having a duct with the second wall meme her or rear wall thereof at the inner'surfacerof the building wall with the openinginsuchsec- 0nd wall member communicating' with therduct;

means for mounting-the motorron the casing with the fan disposed in the .air. passageway between the first and second wall members and the motor projecting exteriorly of the casing from thesesond wall memberor .rea1"\.vall.ithereof so that'the duct will constitute; a housingfor the motor when the casing. is mounted: atgthe 'inner'surface' of the building'wall; thecasing when mounted on the building wallprojecting'from: the inner surface thereof into: the-enclosure a. distance which is less than the overall axial distance taken up by the fan and'motor; the shutterinxits .shut position closing the. opening in the first wall member or front wallaofi the casing,andl the means-for mounting'thez motor being' so constructed and arranged that, when: the. second wall member or rear wall of'l'theecasing. overlies a duct, the ventilator unit will be operablefiwhen the motor projects intmductsrof :different size, the maximum size ductiintoi. which: the motor can project being dependenti'upon the size of the casing and the ability'to..:position the; latter so that the rear wall thereof 'overlies'the duct;

'7 A: ventilator unit. as set forth in claim 1 in which theelectric switching means comprises a member which is movable back: and. forth in a straight line :and aswitchunit having 'a movable part in; the'path of movement of the member whichris actuaterlzby'the member in' one position thereof, mechanism.operatively connected to the damper means: and tothe member for governing the positionrofi the damper means according to the" position. of the member in its-straight line ofunovement, and. manually operable means in cluding pull cords: accessible exteriorly" of the casing torimpart movement back and-forth in a straight line; to: the. member-,the member and mechanism. operatively.:connected thereto and switch unit being.so=constructedvand arrangedthat, when movement is imparted to the member in one: direction: by one: of the pull cords, the dampermeans initia'llywill be opened and thereafter upon further movement'of the-rnember-to the one position the movable part of the switch unit will bezactuatedto start the motor and'the damper means will remain open.

8. A ventilator unitasset'forth-in claim-1'7 in which the-electric switching-means includes the first mentioned switch unit anda second switch unit also having a movablepart' inithe pathof movement of the member which is actuated by the member in another position thereof,. the member and. mechanism operatively. connected, thereto and. first. and. second switch'units being so constructed. and .arrangedthat, when movement isimparted to the member in'such one direction by theone pull cord; themotorwill .be operated'at one speed when-the movable'part of the first switch unit is. actuated by thememberand. operatedat a different speed. when the-movable part of the second switchis-thereafter actuated by the member and the damper means will be open at both motor speeds.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Roth Aug. 15, 1922 Frank et a1 June 28, 1927 Van Zile June 3, 1930 Morse Aug. 28, 1934 Ross Aug. 28, 1934 Ferris June 18, 1935 Ross Aug. 13, 1935 PI umber Name Date McLaughlin May 5, 1936 Melin Jan. 19, 1937 Hueglin June 22, 1937 Morse Dec. 17, 1940 Benson Jan. 7, 1941 Kidney June 2, 1942 Spear Apr. 13, 1943 Morrison Sept. 18, 1945 FOREIGN PATENTS Country Date Germany Apr. 21, 1933 France Jan. 9, 1937