US2011421A - Booster fan - Google Patents

Description

Aug. 13, 1935. A. L. SEARLES BOOSTER FAN Filed Sept. 11, 1933 2 Sheets-Sheet l \nven FoY Alva-Q1 L. eafles x I M ATYbme s Aug. 13, 1935. s s 2,011,421

I BOOSTER FAN Filed Sept. 11, 193:5 2 Sheets-Sheet 2 i 9 I V a "1 "ll Patented Aug. 13, 1935 iirrso STATES ATE 'orr cr.

8 Claims.

This invention relates to a booster fan adapted to be installed in the length of a furnace warm air a pipe.

In heating buildings with warm air furnaces,

i warm air pipes lead from the enclosing casing around the radiator, combustion-chamber and firepot' of the furnace, serving to carry the warmed or heated air to different rooms in the building. It is many times desirable that the flow of heated air to a room shall be greater than what would normally fiow under the circulation caused by heating the air, and thepresent invention is directed to a novel construction which may be installed in the length of a furnace pipe and operated to draw the warm air from the furnace casing and impel it to the room to which the furnace pipe leads, whereby the room is supplied with a greater amount of heated air than it would otherwise receive. 7

A booster fan of this type or character does not need to be operating all of the time that the furnace is in operation, and one object or purpose of the present invention is to provide means for moving the fan to an inoperative position and at the same time automatically cause its cessation of movement. Other objects and purposes are to provide a simple, practical, durable and effective construction of the type noted, and one in which ready access to the fan and to the electric motor which drives the same may be had for inspection and repair. And a still further object of the invention is to provide a means for utilizing the booster fan for circulating cool air, in the warmer months of the year, drawing it from the coolerair of the basement and projecting it into the room Fig. '2 is an enlarged vertical section taken lengthwise of the-fan unit;

Fig. 3 is a vertical transverse section there-' through. I

Fig. 4 is a side elevationof said fan unit, with parts broken away, illustrating the manner in which the fan and the motor drive therefor may be rendered accessible for inspection or repair.

Fig. 5 is a rear elevation of the fan and its motor and the Venturi housing in which it is located,

and

' Fig. 6 is a fragmentary vertical elevation showing the manner in which an electricswitch for cutting the current tothe electric motor. is automatically operated upon turning the fan to a lower inoperative position. v

Like reference characters refer to like parts in the diiierent figures of the drawings. 1

The furnace may be of any conventional'cone struction,.,having an enclosing casing I from which a plurality of warm air pipes 2 are ledlat erally and upwardly, each to a' register 3 in-a room of the house which is to be heatedby the,

furnace, the register being above the floorifi as shown, though the type or character of register,-

whether it be vertical or horizontal, is of no importanceinsofar as the present invention is con-' cerned.

The booster fan unit of my invention includes inits construction a hollow casing of rectangular parallelepiped form having a top 5, parallel sides 6 and 'i andparallel front and'back B and 9, from each of the latter of which a'short pipe sleeve 1 0, having the same diameter as the diameter of the warm air pipe 2, projects. A-section of the warm air pipe 2 may be removed and the casing de scribed inserted in its place with the ends of the parts i!) in substantially abutting relationwith" the-ends or" the pipes 2. The apparatus is ,se-, cured in place by clamping bands ll which pass around and overlap the adjacent end portions of the parts 2 and i0 as shown in- Figs. 1 and 2. As shown in Fig. 2, these bands H are Welded to the sleeves Hi only'near theirbottom portions, thus permitting the sleeves to be bent or sprung outwardly easily during the installation of the apparatus.

The lower side of this casing isclosed by a bottom 12 hinged at one side by means of hinges 83 whereby the bottom maybe moved to a closed position and held therein by suitable latch means,"

or it may be turned to open position as shown in Fig. 4. It will be noted that the central axis of the pipes 2 and It is located above the 'central horizontal plane of the casing described so that there is a considerable portion of the chamber below the lower sides of the pipes 2 and I 0, the purpose of which will be hereafter described;

a A horizontal rock shaft Mextends throughthe casing adjacent the rear side 9 and below the lower side of the pipes 2.

a crank arm l5 therefor. f The fan'unit per se At one end, adjacent the :side figitis turned at right angles making is mounted on the rock shaft 14 within the hollow casing described. One end l6 of a bar I! is bent or formed into a clasping roll or eye around the rock shaft [4 and permanently secured thereto. The bar I! extends from the rock shaft l4 and is permanently secured to a second bar l8 which axis of the pipes 2 and Ill so that air may pass freely from the furnace casing through the first section of the pipe 2 and thence through'the Venturi housing tothe chamber of the casing described, and therefrom to the other section 2 which leads to the register'3.

An electric motor is carried on the bar I8 and on its'shaft a fan 22 is'se'cured the diameter of which isslightly lessthan the cylindrical portion 20 of the Venturi structure. It has been found essentialfor best results that the plane of rotation of the fanl 22 be located'coincident with the end of; the frustro conical section l9 of the Venturi structure or in other words that the plane of rotation of the fan and the plane in which'the cylindrical portion 20 and the frustro conical portion I9 join be coincident. This location of the fan relative to the Venturi structure reduces recirculation of the air to a minimum and causes the fan'to circulate the air most directly parallel with its axis. l V v Circuit wires 23 connect with the motor winding and pass therefrom through an opening in the conical section I9 of the Venturi housing, and thence through the side 6 of the casing to a switch box 24 which is interposed in the length of the wires 23 and secured for support to said side 6. Normally the switch within the switch-box closes automatically by spring action.

An operating finger 25 for the switch extends outwardly beyond a side of, the switch box 24 into the pathrof movementof the crank rod or handle l5. By turning thepart from its upper nearly vertical position, as shown in Fig. 1, to its lower nearly horizontal position as shown in dotted lines in Fig.1, the part 15 engages and movesthe finger 25 and automatically operates the switch to break the circuit and stop the motor from driving the'fan. V

It is evident thatby reason of the connection of the barfll'lto the rock shaft. M a turning of ,the' crank handle l5 from one position to the the lower chamber space of the casing below the 1 lower sideof the pipe sections Zand It). In

such'position the fan is automatically'stopped andair may pass from the furnace casing, I

through the pipe 2 and thence to the room, the

same vasthough the booster fan construction or: my invention. was not installed in the length'off 1 1 the pipe.

may be understood that the device may'also be installed in an inclined pipe. When installed in *1 an inclined 'pipetheVenturi structure, combined with the motor and fanlocated in operative position, will not be sufficiently inclined so that the preponderanceof weight relative to the supporting shaft I4 will retain the parts by gravity in.

such position but the center of gravity will be so positioned relative to the supporting axis as to cause downward movement of the fan structure at all times when it is free to so move;

When the device is installed in a substantially horizontal pipe, as illustrated, it will be seen that gravity tends to move the Venturi and fan and.

motor structure to inoperative position. A chain '21 is provided to raise it and maintain it in operative position and when the chain is released the device will move by gravity to its operative posi tion. The chain 21 engages holding 'means'28 as clearly shown in Fig. 1.

Thus the device may readily be operated by a person in the room to be heated by manipulating the chain 21 and when the parts are moved to operative position the crank arm l5 releases the lever 25 of the switch 24 permitting the switch to close and causing the fan motor to operate the fan which operation will continue so long as the device is in its raised operative position but when lowered by operation or the chains the crank arm I5 will reengage the switch lever andibreak,

the fan circuit causing the fan to cease operation and at the same time the fan and Venturi structurewill lie within the lowerpart of the casing 5 as illustrated in dotted lines inF ig; 2

where it will not interfere with natural circulascribed so that the Venturi housing for thefan" may be properly supported when in, its inopers ative position as shown in Fig. 2. 'It'is desirable at timesthat the fan and the housing therefor be lowered to a still lower position than that shown in Fig. 2, that is, projected partially outside of the casing. It will be noted that two'c'ot ter pins spaced apart from each other, ex-

tend through one end portion of the rock shaft [4 (see Fig. 3). When it is desired to lower the-. 1 fan and its housing to the'positionshownin position, as in Fig. 4, the fan and its motor and housing around it may be lowered through the open lower side of the casing the bottom l2ha'ving been turned to the'position in Fig. 4, Where- .upon ready examination and'access to the fan and .its motor may be had. The housing section l9 is'formed at one side"; as at 19a, to permit the longitudinal movement of shaft i4 and the attached parts. f

From the fore'goingdescription it is evident that a very practical and serviceable booster'fan con-' The ease with which the fan unit is dropped out of the air course passing through the furnace pipe so as not to obstruct thesame, coupled with the automatic stopping of the fan is a very desirable and practical feature of the present invention. The Venturi construction of the immediate fan housing aids very materially to the efficiency of the. fan, obviating back air currents and eddies. 1

This construction, while primarily of use in boosting the flow of heated air from a furnace to a room, is also very useful in the warmer months when the furnace is not operating for circulating cooler air from the basement to the rooms. This can be done by merely dropping the bottom I! to the dotted line position shown in Fig. 1, leaving the fan in its operative position, whereupon the fan will serve to siphon cool air from the basement. It is also conceived that the device may be installed and practically utilized in the cold air return pipe of the heating system and when so used it has the effect of increasing the air circulation by blowing in a direction toward the furnace jacket which results in greater heating efficiency of the furnace. The installation of the unit is simple and easy, consisting merely of removing a section of the warm air pipe 2, placing the unit in the space formerly occupied by said section and clamping it in place by use of the clamping bands H.

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

1. A construction of the class described adapted to be interposed in the length of a' furnace warm air pipe comprising, a casing having a top, vertical sides and a vertical front and back, a bottom hingedly connected to said casing to close the lower side thereof, sleeves connected to the front and back and extending therefrom in axial alinement, a horizontal rock shaft passing through the sides of said casing, a Venturi fan housing secured to said rock shaft and comprisinga frustro-conical section and a short cylindrical section, an electric motor mounted within said housing, a fan driven by said motor within the housing, and a releasable latch for the housing carried by the front of said casing, whereby the housing with the attached motor and fan may be turned to a lower horizontal position and supported by said latch or may be turned to a still lower position and projected partially outside of said casing on release of the latch and opening said bottom, as specified. V

2. A construction containing the elements in combination defined in claim 1, combined with manually operable means for turning the fan, motor and housing to upper operative or lower inoperative positions, and means for automatically stopping the motor when turned to lower position and for starting it when turned to upper position.

3. A construction of the class described adapted to be interposed in the length of a furnace warm air pipe comprising, a casing having a bottom hingedly connected to said casing to close the lower sidethereof, a horizontal rock shaft passing through said casing, a Venturi fan housing secured to said rock shaft and comprising a frustro-conical section and a short cylindrical section, an electric motor mounted within said housing, a fan driven by said motor within the housing, and a releasable latch for the housing carried by the said casing, whereby the housing with the attached motor and fan maybe turned to a lower horizontal position and supported by said latch or may be turned to a still lower position and projected partially outside of said casing on :a

release of the latch and opening said bottom, as

specified.

4. In combination with a furnacepipe adapted to extend from a furnace casing, of a casing having a lateral extension and an opening leading into said lateral extension, a cover for saidopening, said casing being. interposed in the length of the pipe, a fanmounted for change of position and provided with supporting means for one position in which it is located in alinement with the furnace pipe, another in which it is in the lateral extension and below the lower side of said pipe, and a third in which it is swung partly through the opening in said casing, and meansfor manually moving the fan to any of said positions.

5. A construction of the class described adapted to be interposed in the length of a furnace 1 pipe comprising, a casing having a bottom hingedly connected to said casing to close the lower side thereof, a horizontal rock shaft passing through said casing, a housing secured to said rock shaft and open at both ends, an electric motor mounted on said housing, a fan driven by said motor Within the housing, and releasable means for the housing carried by the said casing, whereby the housing with the attached motor and fan may be turned to a lower horizontal position and supported by said releasable means or may be turned to a still lower position and projected partially outside of said casing on release of the releasable means and opening said bottom, as specified.

6. In a construction of the classdescribed, an enclosing casing provided with ducts at opposite sides for connecting the same to sections of a furnace warm air pipe, thereby disposing the easing in the length of said pipe, a rock shaft slidably extending through the casing and adapted for axial movement to two predetermined positions, an electric motor and a fan driven thereby carried on and supported by the rock shaft whereby it may be positioned substantially between the said ducts and substantially at right angles to the axis of one duct and also swung downwardly, an arm extending from the rock shaft, an electric circuit for the motor, a switch in said circuit, and 1 to be interposed in the length of a furnace pipe comprising, a casing having a bottom hingedly connected to said casing to close the lower side thereof, a horizontal rock shaft passing through said casing, a housing secured to said rock shaft and open at both ends, an electric motor mounted on said housing, a fan driven by said motor within the housing, and means for supporting the fan in alinement with the axis of the furnace pipe, said housing with the attached motor and fan being rotatable to a position wherein they are projected partially outside of said casing when the said bottom is opened.

8. 'A construction of the class described adapted to 'be interposed in the length of a furnacepipe comprising, a casing-,scylindrical sleeves secured to and extending from said casing 'in substantially axial alinement, said cylindrical sleeves being located near the top of the casing, a pivoted rock shaft passing through the said casing below the lowermost point of the cylindrical sleeves, a fan, an electric motor connected to and driving the fan, and a support for the electric motor connected with said rock shaft, said rock shaft being movable through an arc of substantially 90, whereby said shaft may be turned to position the 'fan in alinement with said sleeves or moved to a unobstructed passage is haddirectly through the casing, releasable means for positively maintaining the fan in alinement with said sleeves, means for supporting the fan in its lower positionand door means in the casing adjacent the fan when the'fan is in its lower position, said door means being capable of being' opened regardless of the position of the said fan, and'said fan being operable in its lower position to induce a flow of air into the pipe when said door is opened.

- l ALVAH L. SEARLES.

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