US2742034A - Air circulating equipment for space heaters - Google Patents

Description

April 17, 1956 REsEK ErAL AIR CIRCULATING EQUIPMENT FOR SPACE HEATERS Filed April 15, 1950 3 Sheets-Sheet 1 m fi k a #1 m w um. w 7 J we; a J M :85 M x f d H M W. m M mil JK M w I ll W W M 7d \7 h 7 M 9 a lu 0 WA w IW E g g E? :EEE EEE April 1956 M. RESEK EI'AL AIR CIRCULATING EQUIPMENT FOR SPACE HEATERS Filed April 15, 1950 3 Sheets-Sheet 2 MHI H I I I HI HHU I IN HHHH N HhHHHHHHHHHH April 17, 1956 E E ETAL 2,742,034

AIR CIRCULATING EQUIPMENT FOR SPACE HEATERS Filed April 15, 1950 3 Sheets-Sheet 3 IN VEN TORS 2,742,034 AIR CIRCULATING EQUIPMENT FOR SPACE HEATERS 7 Marc Resek, Cleveland Heights, Joseph R. Kirkpatrick, South Euclid, and Karl R. Schneider, Cleveland, ()hio, assignors, by mesue assignments, to Hupp Corporation, Detroit, Mich, a corporation of Virginia Application April 175, 1950, Serial No. 156,176

' 9 Claims. (Cl. 126-110) This invention has to do with air circulating equipment for incorporation in so-called unit space heaters of the gravity circulation type, for creating a reverse or downward flow of apart of the heated air and discharging it'into the space to be heated adjacent the floor.

The primary purpose of the present invention is to provide eflicient, simple and relatively inexpensive air circulating equipment for incorporation :in unit space heaters, either at the'time of manufacture of the heaters or, as an accessory or attachment, at a later time, thus adapting the invention to installation in unit space heaters that are already in the field.

The equipment includes duct work that occupies a position inside the heater casing, and an air impeller or blower unit that is adapted forexternal mounting over' the access door or opening of the heater casing through which the lighting and clean-out opening of the com bustion apparatus is reached. Therefore, in some cases, the duct work may be built into the heaters at the time of manufacture, and at some later date, as at the time of sale, or thereafter, the purchaser may obtain the blower unit and, upon removal of the closure for the access opening, attach said unit.

Accordingly, it is another object of our invention to provide simple and inexpensive duct work that is capable of being easily and cheaply incorporated in a unit space heater, and the presence of which does not interfere with the normal thermosiphon or gravity circulation of air through the heater, nor with the customary convenient access to the lighting and cleanout opening of the combustion apparatus.

Another object of the invention is to provide air circulating equipment consisting of relatively few separable parts or units that are easy and quick of installation in existing unit space heaters without the necessity of making any changes in the heater structure, and which parts are so designed as to insure proper relation between them when installed.

A further object of the invention is to provide a substantial and durable air impeller or blower unit that is highly efiicient; that is neat and attractive of appearance; that is safe against the discharge of products of combustion into the room, and injury to persons or damage to objects by contact with the operating parts when the unit is detached from, as well as when attached to, the heater, and wherein the'motor is well protected and adequately ventilated, the construction providing a passage for an auxiliary draft about the motor without impairing the circulation of warm air through the unit.

A further object is to provide an air impeller o-r blower unit that is comparatively light of Weight, well balanced, and which is convenient of attachment to the'heater, and of handling when detached therefrom.

l The foregoing objects and advantages are attained in the embodiment of our invention illustratedin the accompanying drawings, and as we proceed to describe the invention by reference to said drawings, using like reference characters-to-designate like parts inithe several. views,

2,742,034 Patented Apr. 17, 1956 ice 4 is a rear elevational view of the blower unit, with parts broken away; and Figs. 5 and 6 are perspective views of the upper and lower sections of the duct work of our improved air circulating equipment.

The unit space heater, wherein we have shown our improved air circulating equipment installed, is designated, generally, by the reference numeral 10, and the casing thereof includes a front wall 12, a back wall 13, side walls 14, and a top 15. The front and side walls are provided with louvered openings 16, and the top with slots or openings 17. The front, back and side walls are suitably connected together, as by welding, along the vertical corners of the casing, and the top 15 is removably supported within a rectangular opening defined by the upper ends of the peripheral walls of the casing. Spaced inwardly from said peripheral walls, and suitably joined thereto along the vertical edges of the latter, are shields 20, 21 and 22. These shields consist of metal plates, the front and rear ones 29 and 22, respectively, being shown as having transverse flanges 24 and 25 along their lower edges.

30 designates, generally, a combustion apparatus, and in the present instance this apparatus includes a cylindrical housing or drum, closed at its upper end by a dome shaped top 31. The apparatus is shown as supported substantially centrally within the casing by a base structure 35 that is located in the lower portion of the casing. At its upper end said apparatus is held in position by a bar 36, the ends of which are suitably fastened to diagonally opposed ones of gussets 37, located within the corners of the casing; and projecting through a central opening in the bar 36 is a stud 38 that is secured to and rises from the top 31.

A substantial distance above its lower end, the housing or drum 30 is provided with a circumferential bead 40; and suitably secured to the peripheral wall of the drum immediately below said bead isthe edge flange of a ring-like element 42 that defines the bottom of a combustion chamber that is enclosed by the part of the housing 'or drum above said bead. A flue 44 leads rearwardly from the top portion of the drumthrough aligned openings in the shield 22 and back wall 30.

Situated Within the lower end of the drum is a burner bowl 50 that is supplied with liquid fuel from a suitable source (not shown) through a pipe 52. Combustion apparatus of the kind herein disclosed is well known by those familiar with the art, for which reason it will suffice to briefly explain that the burner bowl has an annular top wall'54 that is joined to the ring-like member 42 by a perforated throat structure 55. For lighting,

clean-out and inspection purposes, a large opening is made in the front side of the peripheral wall of the burner bowl, and joined to said wall about said opening is a soc alled lighter tube 56 that is enlarged at its forward end and is normally closed by a plug 57. This plug is provided with a handle 58, and is adapted to be locked in the usual way within the lighter tube. The lighter tube 'extends through a relatively large arch shaped notch 59 in the front lower portion of the drum 30, and said notch is closed by a plate 60 of approximately corresponding size and shape. The plate 60 surrounds the lighter tube 56 and is desirably welded thereto. .The front wall 12 of the heater casing is provided with an access opening that is in alignment with the lighter tube 56 and through which the handle 58 may be reached for removal of the plug 57 when it is desired to light the combustion apparatus, or to inspect or clean it. Said access opening is surrounded -by an inwardly directed flange 62, and when the heater is not equipped with our air circulating means, said access opening isnormally closed by 'a readily removable door or closure (not shown).

The air circulating equipment of the present invention comprises duct work that is adapted to be enclosed within the heater casing, and is designated generally by the reference numeral 70; and a blower unit 72, that is adapted to be applied to the exterior of the casing and encompass the access opening through which the lighter tube 56 of the combustionapparatus is accessible. The duct work 70 is desirably composed of two sheet metal parts or sections, one designated 73 and the other 7-4, and which are shown in perspective in Figs. and 6, respectively. fabricated of sheet metal, and the lower duct section 7 2- is a box-like structure that is open at front and back, as well as throughout the rear portion of its top. Said section 74 is of such size and shape that its front end fits within the flange 62 that surrounds the access opening in the front wall 12 of the casing, and a flange 7S rises from the front edge of the top wall of the duct section 74 and is adapted to be secured to the casing wall 12 by screws engaged through openings 79 of said flange. A lug 80, provided with a slot 81, is constituted of a part of a Z-shaped member that is welded or otherwise secured to the duct section 74 and rises in front of the flange 78 thereof. A U-shaped clip 84 is also carried by the section 74 adjacent its front lower edge and straddles the underlying portion of the flange 62 and holds the duct section 74 in place adjacent the bottom of the access opening of the casing. The bottom wall of the duct section 74 is shaped along its rear edge to fit the contour of the drum 30, while the side walls of said section terminate at their rear ends in flaring flanges 86 which, with said edge, are adapted to be pressed against the drum when the duct section 74 is secured to the front wall 12 in the manner described. intermediate its front and rear edges the bottom wall of said section 74 is provided with a transverse slot or opening 88.

The upper duct section 73 is of trough or channel shape, and it is adapted to be inserted downwardly between the front shield and the opposed front portion of the drum with its open side adjacent the latter, these sheet metal parts being so proportioned and arranged that they are somewhat under tension when the duct section 73 is installed, thereby to insure said duct section being pressed firmly against the drum. The rear edges of the side walls of the duct section 73 are flared outwardly to provide flanges 90 that are substantially tangent to and engage the peripheral wall of the drum 30. The lower ends of the side walls of the duct section 73 extend below the front wall thereof and are adapted to be fastened to the side walls of the lower duct section 74 by bolts or screws engaged through slots 91 of the top duct section and through holes 92 in the side walls of the lower duct section. To facilitate assembly, nuts or fasteners 93 may be applied to the outer sides of the walls of the lower duct section in register with the holes 92 so that, after the lower duct section is emplaced, and the upper duct section is lower through the top of the heater casing between the shield 20 and the drum 30 and the lower ends of its side walls are projected between the upper ends of the side walls of the lower section, by reaching in through the access opening of the casing and into the interior of the lower duct section, the person performing the work may engage screws or bolts through the slots 91 and holes 92 and interlock them with the nuts or fasteners 93.

These sections of the duct work are When the upper and lower duct sections are thus connected, the bottom edge of the front wall of the top section extends along the rear edge of the shallow top Wall of the lower section. Now, with the duct work installed, it is only necessary to attach the blower unit 72 to complete the installation.

The blower unit 72 is a self-contained assembly that is relatively light of weight and convenient of handling. It comprises an annular shell 95 that is cylindrical for a part of its depth and is surrounded at its rear end by a flange 96. The shell curves inwardly toward its forward end where it terminates in a convergent wall or frusto-conical portion 97. Fitting within said portion and suitably secured thereto as by spot welding is the front end of a generally frusto-conical air guide 100. Attached, as by welding, to the air galide is a front grill 101 which mounts at its center a slightly dished disc 102. Secured to and extending inwardly from the cylindrical portion of the shell 95 are generally V-shaped brackets 105. These brackets are preferably made of strap metal of suitable width and thickness and their central portions 106 are arcuate and substantially concentric with the axis of the shell 95, the portions of the brackets beyond the parts 106 being substantially radial with respect to said axis. At their outer ends the radial portions of the brackets are turned laterally for engagement with the inner cylindrical surface of the shell 95 and they are shown as secured to the shell by fastening means or bolts 110. A series of wire rings 112 are attached, as by welding, in concentric relation to the shell, to the front edges of the radial portions of the brackets and constitute a rear grill.

Supported by and between the brackets 105 is a motor housing 115. This housing, according to the present construction, is drawn from sheet metal to provide front and rear cylindrical portions 116 and 117, the latter being of greater diameter than the former and joined at its forward end thereto by a shoulder 118. The portion 117 may be regarded as an extension of the motor housing, proper, and it is flared outwardly at its rear end to provide a flange 119. Punched inwardly from the extension at its rear end 117 are a plurality of tongues 120-three being shown that are equally spaced about the extension. The character of the metal from which the motor housing is formed renders these tongues resilient and they are normally displaced inwardly from the cylindrical wall of the extension. The housing 115 is closed at its forward end by a circular wall 122. Occupying the portion 116 of the housing, and fastened to said wall by studs 124, is an electric motor 125. The shaft 126 of the motor projects forwardly through a relatively large central opening of the wall 122 and has secured to it the hub of an air impeller or fan 128. With the parts constructed and assembled as described, the impeller or fan 128 is disposed within the air guide 100, between the front grill 101 and the rear grill composed of the rings 112. 'Mounted upon the shell 95, desirably on the bottom side and exteriorly thereof, is the casing of a switch 129 that is placed in circuit with the electric motor through electric cables designated 130.

A disc-like motor shield 133 is connected adjacent its edge to the rear side of the shoulder 118 of the motor housing; and a distance below its transverse center, said shield is deflected rearwardly and thence downwardly where an extension of the shield projects through a slot 135 in the peripheral wall of the housing extension 117. A guide member 137, which may be constructed of strap metal, occupies the top portion of the shield 95 and is shown as secured at its ends to the shell by the same fastening means or bolts 110 that connect the adjacent ends of the brackets 105 to the shell. A locking pin extends through apertures in the shell 95 and guide mem: ber 137, and is held against withdrawal from said apertures by a'stop 141 arranged to engage the inner side of the shell. When the shell is attached to the heater, the

'access opening of the casing and engage the latter over the forward end of the lighter tube 56, the tongues 120 frictionally engaging and exerting a force inwardly on said tube. When the flange 96 ofthe shell 95 contacts the front wall 12 of the heater casing, the locking pin 140 of the lug 80 to fasten the blower unit 72 to the heater casing. By connecting the terminal plug of the electric cable 130 to an outlet of the house circuit and closing the switch 129, the motor 125 will be energized to drive the impeller or fan 128. With this fan in operation, a current of air is induced downwardly and outwardly through the duct work 70 and shell 95 and projected forwardly across and adjacent the floor on which the heater stands. Assuming that the combustion apparatus is in operation, this air will be heated as it wipes down the front of the drum 30 in the zone of the enclosed combustion chamber. Simultaneously, fresh air will be drawn in through the slot 88 in the bottom wall of the lower ductsection 74 and through the slot 135 of the motor housing, and thisair will be deflected forwardly by the lower end of the shield 133 and will pass over and about the motor and out through the central opening in the front wall 122, thereby to maintain the motor relatively cool. An important additional function of the shield 133 is to prevent the action of the impeller or fan from drawing products of combustion from the burner bowl through the lighter tube 45 in case any leakage should occur at the joint between the plug and tube.

While the air circulating equipment.is operating in the manner above described, air circulates upwardly through the heater casing about the portion of the drum 30, that encloses the combustion chamber and passes out through the top of the heater, accordingto the usual thermosiphon or gravity principle of circulation which characterizes the normal operation of unit space heaters of the type shown and described.

It is apparent from the foregoing description that the blower unit '72 may beeasily and quickly removed from the heater by retracting the locking pin 140 and moving the unit forwardly until the extension 117 of the motor housing withdraws from the forward end of the lighter tube 56 and moves out through the lower duct section and the access openingof the heater casing. Obviously, the reverse operation of applying the blower unit to the heater is equally quick and easy. The facility with which this operation may be performed is an important advantage inasmuch as it affords the only opportunity of access to the combustion apparatus for lighting, cleaning and inspection purposes.

Having thus described our invention, what weclairn is:

1. Air circulating equipment for incorporation in a unit space heater of the gravity circulation type wherein a combustion apparatus is situated within a casing in spaced relation to a part thereof that is provided with an access opening leading to and substantially aligned with a manipulatable part, surrounded by a protruding part, of the apparatus; said air circulating equipment comprising, in combination with parts of the heater where- With parts of said equipment are operatively associated as herein set forth, an elongated duct work that is open at front and back adjacent its lower end and which is adapted to be disposed in a vertical position within the heater casing with the open front of its lower end in register with said access opening and aligned with said protruding part, a blower unit including a shell open on its rear side for communication with the lower pormay be projected through the opening 01' slot 81 7 tion .of the duct work at the front of the latter, means for demountably sustaining said shell exteriorly of the heater casing in a position to encompass the access opening, said shell having an air emitting opening at its front end, a part supported within and fixed to said shell and projecting rearwardly therefrom and arranged to extend through the access opening for telescoping engagement with the aforesaid protruding part of the combustion apparatus thereby to accurately position the blower-unit in operative relation to the heater, and an electric motor and an air impeller in the shell operatively connected together and operable to draw a current of air through the duct work and discharge it through the aforesaid air emitting opening of the shell.

2. Air circulating equipment for incorporation in a unit space heater of the gravity circulation type wherein a combustion apparatus having a lighter tube is situated within a casing in spaced relation to a part of the latter provided with an access opening substantially aligned with said lighter tube; .said air circulating equipment comprising, in combination with parts of the heater whercwith parts of said equipment are operatively associated as herein set forth, an elongated duct Work that is open at front and back adjacent its lower end and which is adapted to be disposed in a vertical position within the heater casing with the open front of its lower end in register with said access opening and aligned with said lighter tube, a blower unit including a shell open on its rear side for communication with the lower portion of the duct work at the front of the latter, means for demountably sustainingv said shell exteriorly of the heater casing in a position to encompass the access opening, said shell having an air emitting opening at its front.

end, a motor housing of lesser cross sectional area than said access opening supported substantially centrally Within the shell and having a rearward extension inside the ductwork adapted to be engaged over the aforesaid lighter tube, an electric motor sustained within the front portion of said housing in spaced relation to the surrounding part thereof, the housing having an air admitting opening on its underside in the region of said extension and provided with an outlet opening at its forward end, a motor shield disposed within and transversely of the housing adjacent the rear end of the motor and having its lower edge adjacent to the rear edge of said air admitting opening, the front of the motor housing being spaced a substantial distance rearwardly of the front of the shell, and an air impeller in the shell forwardly of the motor housing for impelling air admitted to the duct work from the interior of the heater casing outwardly through said air emitting openin Said impeller having operative connection with the motor.

3. Air circulating equipment according to claim 2, wherein the motor housing is fabricated of sheet metal that is inherently resilient and said rearward extension comprises a wall that surrounds the lighter tube, and tongues partially severed from said wall of the extension of the housing and deflected inwardly for engagement with the lighter tube.

4. Air circulating equipment for incorporation in a unit space heater of the gravity circulation type wherein a combustion apparatus is situated within a casing in spaced relation to a part thereof that is provided with an access opening leading to a manipulatable part of the apparatus; said air circulating equipment comprising an elongated duct work that is open at front and back adjacent its lower end and which is adapted to be disposed in a vertical position within the heater casing with its lower end in register with said access opening, a blower unit ends and the plane of which is substantially normal to the axis of the housing, the housing being of greater diameter rearwardly of said shoulder than forwardly thereof, tongues partially severed from the enlarged portion of the housing and deflected inwardly for engagement with a part of the combustion apparatus surrounding the aforesaid manipulatable part, the housing having a central opening at its front end, a motor located within the front portion of the housing and secured thereto, the motor including a shaft projecting forwardly through the opening in the front end of the housing, an air impeller mounted upon the motor shaft forwardly of the housing, the housing having an air admitting opening on its lower side rearwardly of said shoulder, the motor being spaced from the surrounding portion of the housing and from the front end of the latter to provide an air passage about the motor, and a motor shield having a generally circular body portion disposed transversely of the housing with its peripheral portion engaged with and secured to said shoulder and having a bottom extension whose lower edge is disposed adjacent the rear edge of said air admitting opening, the duct work having a bottom opening in the region of the air admitting opening of the motor housing.

5. Air circulating equipment for incorporation in a unit space heater of the gravity circulation type wherein a combustion apparatus is situated within a casing in spaced relation to a part thereof that is provided with an access opening leading to and substantially aligned with a manipulatable part of the apparatus; said air circulating equipment comprising, in combination with parts of the heater wherewith parts of said equipment are operatively associated as herein set forth, an upper duct section in the form of a channel adapted to be positioned within the heater casing with its open side adjacent the combustion apparatus and its lower end in about the region of the top of the access opening of the casing, a lower box-like duct section that is open at front and back, the same being partly open at the top for communicative connection with the upper duct section, the lower duct section being adapted to be'supported within the casing in register with the access opening so that said manipulatable part of the combustion apparatus is capable of being reached through said opening and through the lower duct section, means adjacent the bottom front portion of the lower duct section for engagement with the casing at the bottom of the access opening, means adapted to connect the lower duct section to the casing adjacent the top of said opening, a lug carried by and extending from the lower duct section at the top of the access opening, a

blower unit including a shell that is open on its rear side and adapted'to be engaged with the exterior of the heater casing and to encompass the access opening, said shell having an air emitting opening at its front end, holding means carried by the shell for cooperation with the aforesaid lug to removably attach the shell to the heater casing, an electric motor housed within the shell, and an air impeller in the shell operatively connected to the motor.

6. Air circulating equipment according to claim 5, wherein said holding means consists of a pin carried by and guided within the top portion of the shell, said lug extending generally forwardly and having an aperture for the reception of the lower end of said pin.

7. Air circulating equipment for incorporation in a unit space heater of the gravity circulation type wherein a combustion apparatus is situated within a casing in spaced relation to a part thereof that is provided with an access opening leading to and substantially aligned with a manipulatable part of the apparatus; said air circulating equipment comprising, in combination with parts of the heater wherewith parts of said equipment are operatively associated as herein set forth, an elongated duct work that is open at front and back adjacent its lower end and which is adapted to be disposed in a vertical position within the heater casing with the open front of its lower end in register with said access opening, a blower unit including a shell that is open at front and back for communication on its rear side with the lower portion of the duct work at the front of the latter, means for demountably sustaining said shell exteriorly of the heater casing in a position to encompass the access opening of the latter, said shell being cylindrical adjacent its rear end, brackets located inside the shell within the zone of the cylindrical part thereof and arranged in opposed relation to each other, each bracket being made of an elongated piece of material having its ends turned laterally for connection with the cylindrical portion of the shell at points spaced circumferentially of the latter, the adjacent portions of said piece being disposed substantially radially of the surrounding portion of the shell and at an angle of approximately 90 to each other and the central part of the bracket being arcuate and coextensive with said angle and substantially concentric to said surrounding portion, a cylindrical motor housing supported by and between the arcuate parts of the opposed brackets, a motor occupying said motor housing, and an air impeller within the shell and operatively connected to the motor.

8. The combination and arrangement of elements set forth in claim 7, and, in addition thereto, a grill comprising a series of ring-like elements secured to said radially disposed portions of said brackets.

9. The combination and arrangement of elements set forth in claim 7, and, in addition thereto, a guide member constructed of an elongate piece of material disposed transversely of the top interior portion of the shell and having its ends attached to the shell in the region of the adjacent ends of the opposed brackets, the central portion of said guide member and the shell having substantially radially aligned apertures, a locking pin slidably engaged through said apertures, abutment means on the pin for limiting its longitudinal movement, and an apertured lug carried by a part of the duct work that is adapted to be disposed adjacent the top of the access opening of the casing for holding engagement with the lower end of said pin.

References Cited in the file of this patent UNITED STATES PATENTS 2,156,101 Willett Apr. 25, 1939 2,228,201 Cotes Jan. 7, 1941 2,241,025 Wedderspoon May 6, 1941 2,279,974 Evans Apr. 14, 1942 2,279,975 Evans Apr. 14, 1942 2,332,583 Lonergan Oct. 26, 1943 2,457,818 Heiman Jan. 4, 1949 2,473,810 Miller June 21, 1949

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