US 3275224 A
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Description (OCR text may contain errors)
Sept. 27, 1966 E. H. BUSH VENTILATING FANS 4 Sheets-Sheet 1 Filed March 2, 1965 Sept. 27, 1966 E- H. BUSH VENTILATING mus 4 Sheets-Sheet 2 Filed March 2, 1965 P 7, 1966 E. H. BUSH 3,275,224
VENTILATING FANS Filed March 2, 1965 4 Sheets-Sheet 5 100 3, FIE-1.6.
p 7, 1966 E. H. BUSH 3,275,224
VENTILATING mus Filed March 2, 1965 4 Sheets-Sheet 4 I I I I. I I I I I I I I I I I I I I Lr I I Q I L I I I I I I I I I I I I I m lI L I: 69
1 o 9i N- --v I 3,275,224 VENTILATING FANS Edmund Helmuth Bush, Taplow, England, assignor to Firth Cleveland Limited Filed Mar. 2, 1965, Ser. No. 436,555 Claims priority, application Great Britain, Mar. 4, 1964, 9,227/64; Oct. 16, 1964, 42,379/ 64 9 Claims. (01. 230-125 This invention relates to ventilation fans of the crossflow type, i.e. comprising a bladed cylindrical rotor mounted for rotation about its axis in a predetermined direction and first and second guide walls co-operating with the rotor to induce a flow of air from a suction region through the path of the rotating blades to the interior of the rotor and thence again through the path of the rotating blades to a pressure side of the rotor, the flow taking place in planes tranverse to the rotor axis. More specifically the invention is concerned with fans of the cross flow type where the rotor and guide means are designed to set up a vortex having a core region eccentric of the rotor axis and adjacent to the first guide wall. Such a cross flow fan is described in British Specification No. 876,611.
A main object of the invention is to provide a ventilating fan of the cross-flow type fan which is readily reversible. Further objects are to provide a compact construction for such a fan, and a construction which can readily be mounted in an aperture in a window or the like.
With these objects in view the invention provides a ventilating fan comprising an outer structural unit adapted to be fixed in position; an inner structural unit mounted for rotation with respect to the outer unit about an axis fixed in relation thereto; and a motor-driven bladed cylindrical rotor mounted for rotation in predetermined direction about an axis parallel to the rotational axis of the inner unit and fixed in relation thereto; the arrangement providing openings opposite the rotor and to either side of the outer unit in both of two angularly spaced positions of the inner unit to set up a vortex having a core region eccentric of the rotor axis and adjacent the first guide wall and to thereby induce a flow of air from one opening through the path of the rotating blades of the rotor to the interior of the rotor and thence again through the path of the rotating blades to the other opening; rotation of said inner unit between said two positions changing the orientation of said guide walls relative to the rotor whereby to reverse the direction of flow between said openings; and the rotational axis of the rotor being spaced to one side of that of the inner unit with the first guide wall to the other side of the latter axrs.
The eccentric arrangement of the rotor with respect to the inner unit makes for compactness.
The outer unit can comprise a frame for attachment to a window or the like about a rectangular aperture therein, and a shroud extending outwardly to protect the unit from the weather. Preferably the construction allows the inner unit to be moved to a third position wherein flow between the two sides of the fan is totally blocked, conveniently by .a part of the inner unit and the shroud just mentioned. In preferred constructions the first guide wall forms part of the inner unit. The second may also be provided thereby but can alternatively, and preferably, form part of the outer unit.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:
FIGURE 1 is a section of one form of reversible cross-flow fan according to the invention, with the section taken transversely of the rotor axis;
United States Patent 3,275,224 Patented Sept. 27, 1966 ice FIGURE 2 is a perspective view of the fan, seen installed in a window aperture, the view being taken from inside the window;
FIGURE 3 is an exploded sectional view of a modified form of the FIGURE 1 fan;
FIGURE 4 is a transverse section showing a heatermounting cowling in conjunction with a fan as shown in FIGURE 1;
FIGURE 5 is an elevation of the FIGURE 4 cowling seen from inside the window, and
FIGURE 6 is a transverse section of a further form of reversible cross-flow fan according to the invention.
Referring to the drawings, the reversible ventilating fan shown in FIGURES 1 and 2 comprises an outer structural unit designated generally 1 comprising a main rectangular frame 2 adapted to seat upon the outside face of a pane of glass G about a rectangular aperture therein. The main frame has horizontal upper and lower members 3, 4 and vertical side members (not seen in the figures) all of which have flanges 5 on their inner edges which locate within the aperture. The side frame members are extended outwardly to form a pair of opposed parallel side cheeks 6 which are joined at their upper edges by a curved wall 7 forming an outward extension of the upper frame member 3 and called hereinafter the shutoff plate. The main frame 2 is held in position on the glass G with the aid of a second frame 8 abutting the inside face of the glass: the two frames are secured together by screws 9 and clamp the glass between them.
The inward facing surfaces of the upper and lower members 8a, 8b of the second frame 8, together with the inward facing surfaces of the corresponding members 3, 4 of the main frame 2 and the interior surface of the shutoff plate 7, define portions of a common cylinder: the interior surface of the shut-off plate 7 and of the upper frame members 3, &2, together account for an arc of some of the common cylinder, while the interior surfaces of the lower frame members account together for some 20 of the cylinder.
The fan further comprises an inner structural unit designated generally 10 and including end walls 11 interconnected by a pair of opposed walls 12, 13 forming parts of a common cylinder; the walls 12, 13 each extend over an arc of about and define between their edges 12a, 13a, 12b, 13b inlet and outlet openings 14, 15 extending over about 75 and 45 respectively. A series of protective ribs 14a extend across the inlet opening 14, and similar ribs may be provided also at the outlet opening 15. The inner structural unit 10' is a clearance fit within the outer structural unit 1 and is mounted thereon for rotation about its axis 16.
A bladed cylindrical rotor 17 is mounted for rotation within the inner structural unit 10 about an axis 18 which is parallel to but spaced from the axis 16 of that unit, such that its nearest approach to the cylinder defined by the walls 12, 13 is at the edge 13a of the wall 13, the rotor being spaced therefrom by about half the radial blade depth. The rotor 17 comprises a series of similar blades 19 mounted between end discs 20 and being concave and forwardly curved having regard to the direction of rotation shown by the arrow 21. One rotor end disc 20 is supported on and driven by an electric motor (not shown) adjacent to and mounted on one of the end walls 11 of the inner unit '10, and the other rotor end disc is bearingmounted on the other end wall 11. A guide wall structure designated generally 22 is mounted on the inside ofthe part-cylindrical wall 12 and presents to the rotor 17 a main guide wall portion 23 converging therewith towards a nose 24 about diametrically opposite the edge 13a and spaced therefrom about half the radial blade depth; a lead-in'wall portion 25 extends from the wall 12 to the nose 24, while remote therefrom the main tion 26 at a further nose27, the wall portion 26 terminating at the edge of 12b of the wall 12.
In FIGURE 1 the inner structural unit 10 is shown positioned for extraction of air from a 'room.' On rotation of the rotor 17 in the direction of the arrow 21, the rotor together with the guide means formed by the guide wall structure 22 on one side of the rotor and the interior surface of the wall 13 on the other set up a vortex of Rankine type having a core interpenetrating the path of the blades 19: air is induced to flow from the inlet opening 14 twice through the path of the rotating blades 19 of the rotor to the outlet opening 15. The general pattern of air flow is'shown by the flow lines F while the vortex core is indicated at V.
For intake of air into the room the inner structural unit is rotated by 180; the rotor 17 and guide means cooperate as before, but because .of the changed orienta- .tion of the guide means the general direction of flow is reversed.
If it is desired simply to close the aperture 111 the glass,
the inner unit 10 is rotated by some 90 from the position illustrated to present the inlet or outlet opening 14, 15 to the shut-off plate 7.
It will be seen that in any orientation of the inner unit 10, the'shut-off plate 7 prevents rain from entering the room while the clearance between the inner and outer units 10, 1 and the overlaps of their cylindrical surfaces provide a sufficient sealing against draughts.
The fan may be controlled by a cord C (FIGURE 2) by which the inner structural unit is rotated between its extraction, intake and shut-off positions. The cord C may constitute a power supply cable for the fan'motor and may have a switch S therein. Alternatively the fan motor may be supplied by a flexible cable separate from the cord C and controlled by micro-switches on one .structural member which are actuated by contact with projections on the other structural unit, as the inner such unit is rotated by the cord. In this way it can be ensured that the fan motor is on when the inner unit is in its shut-off position. Stops may be provided to prevent continuous rotation of the inner unit in one direction such as would strain the flexible cable; the stops together with the micro-switches can be such as to locate the inner unit precisely in any selected one of its three positions.
FIGURE 3 shows a modification of the fan of FIG- URES 1 and 2; similar parts are given the same reference numerals and will not need further description. The chief difierences between the fan of FIGURE 3 and that previously described lies in the shut-off plate 7 being formed as an outward continuation of the upper member 8a of the inner frame 8. This plate 7 terminates in a gutter 50 discharging clear of the opening 15 at the sides of the fan and thereby preventing ingress of water drips into or through the fan.
The fans of FIGURES 1 and 2, and FIGURE 3, may be modified to discharge from or into a duct, if desired.
FIGURES 4 and show a detachable cowling (designated generally 30) which can be used with the fan of FIGURES 1 and 2 when it is desired to heat the air entering the room. The cowling 30 comprises upper and lower walls 31, 32 and end walls 33 which mate against the upper, lower and side members respectively of the main frame 2 and extend inwardly into the room, enclosing the room side of the fan and terminating in an outlet 34 protected by a grille 35: the upper wall 31 has a downturned flange 36 adjacent the upper main frame member 3 which simply hooks into a groove 37 formed in the latter to receive it. The upper wall 31 of the cowling 30 is longer than the lower wall 32 and downwardly curved, and the outlet 34 is directed downwardly. Heating means 38 extend the length of the cowling 30 opposite the fan rotor 17. Such means comprise plate-like insulating supports 39 spaced at intervals and presenting their edges to the air flow and carrying electric resistor .seen in transverse section.
wires (not shown). The supports 39 are fitted into a connected by top and bottom walls 41. By reason of the cowling 30, and heating means 38 therein air entering the room is heated and caused to flow downwardly.
Where the fan is controlled by a cord and microswitches, as previously mentioned, a further micro-switch may be provided to control the heating means 38: thus intake of .cold air may be associated with one angular position and air intake combined with heater operations may be associated with another angular position close to the first and defined with the aid of the further microswitch.
FIGURE 6 illustrates a further form of fan according to the invention installed in a 'rectanguler aperture in a window W of a room R. The fan illustrated comprises an outer structural unit in the form of a pair of walls 102, 103 interconnecting disc-like end members 104 and each forming about a 90 arc of a common cylinder as The walls 102, 103 define a pair of openings 105, 106 each subtending about 90 at the axis of the cylinder, the opening 105 facing upwardly into the room R and the opening 106 facing downwardly towards the outside. The 'walls 102, 103 carry di ametrally opposed flanges 107, 108, formed with grooves 109, 110, which receive upper and lower edges of the window aperture and thus hold the fan in place. Flanges (not shown) on the end members 104 provide weather sealing against the room side of the glass, An outwardly extending lip 111 along the lower edge of the wall'102 forms a gutter for endwise discharge of rainwater and thereby to avoid entry of water into the opening 106.
The end member 104 of the outer structural unit 100 mount for rotation about its axis 101a an inner structural unit comprising a guide wall 115; The inner unit mounts a cylindrical bladed rotor 116 and an electric motor (not shown) to drive it in the direction of the arrow 117, the rotor axis being eccentric of the axis of the inner unit. The inner unit is rotatable 'with 'the rotor 116, between the position illustrated and a second position 180 there- .from. The inner unit may also rotate to an intermediate position where the guide wall 115 substantially blocks air flow through the outer unit 100.
The guide wall 115 includes a main guide wall portion 118 subtending a small angle at the rotor axis and converging therewith in the direction of rotor rotation to a nose 119 forming the nearest approach of the guide wall to the rotor being distant therefrom by about half the radial depth of the blades of the rotor 116. The guide wall 115 also includes a lead-in portion 120 which is concave to the rotor and extends from adjacent the inside surface of the wall 102 of the outer unit 100 up to the nose 119; remote from the nose 119 the main guide wall portion merges, at a further nose 121, with an outlet wall portion 122.
In the position of the inner unit illustrated, the guide wall 115 and the interior surface of the wall 103 of the outer structural unit 100 co-operate with the rotor 116 on rotation thereof to set up a vortex of Rankine type having a core region eccentric of the rotor axis; by reason of the vortex air is caused to enter the opening 105, flow twice through the path of the rotating blades of the rotor 116, and leave the fan through the opening 106. The flow lines are indicated diagrammatically and approximately by the chain lines, the core region being designated V.
In the second position of the inner unit, the guide wall 115 and the interior surface of the wall 102 co-operate with the rotor 116 on rotation thereof to induce, in the same general manner as just described, a flow of air from the opening 106 to the opening 105.
It will thus be seen that the fan can operate as an extractor fian (in the position illustrated) or to induce a fresh air flow into the room: the inner structural unit may also be positioned to substantially block air flow.
It is to be appreciated that the openings 105, 106 extend over the length of the rotor 116; the outer structural unit has an imperforate end portion surrounding the motor. Complete sealing of the guide wall 115 to the inside of the outer unit 100 has been found unnecessary, but a flexible sealing strip can be provided if desired on the inlet end of the guide wall without involving closer manufacturing tolerances.
It is to be appreciated that, in all embodiments described, the eccentric mounting of the rotor minimizes the overall diameter of the tan. Using the outer structural unit to provide part of the guide means, as in the FIG- URE 6 embodiment simplifies construction and reduces material costs.
It is to be appreciated that the heater of FIGURES 3 and 4 can be used with the FIGURE 6 fan, as can also the control arrangements specifically described with reference to FIGURES l and 2.
1. A ventilating fan of the cross-flow type comprising an outer structural unit adapted to be fixed in position; an inner structural unit mounted for rotation with respect to the outer unit about an axis fixed in relation thereto; and a motor-driven bladed cylindrical cross-flow rotor mounted for rotation in predetermined direction about an axis parallel to and spaced from the rotational axis of the inner unit and fixed in relation thereto; said units providing openings opposite the rotor and to either side of the outer unit in both of a first and a second angularly spaced position of the inner unit, first and second guide walls extending the length of the rotor; rotor and guide walls co-operating in each of said positions of the inner unit to set up a vortex having a core region eccentric of the rotor axis and adjacent the first guide wall and to thereby induce a flow of air from one opening through the path of the rotating blades of the rotor to the interior of the rotor and thence again through the path of the rotating blades to the other opening; rotation of said inner unit between said two positions changing the orientation of said guide walls relative to the rotor whereby to reverse the direction of flow between said openings; and the rotational axis of the rotor being spaced to one side of that of the inner unit with the first guide wall to the other side of the latter axis.
2. A fan as claimed in claim 1, wherein the outer unit comprises a frame for mounting the fan within an aperture in a window or the like.
3. A fan as claimed in claim 1 wherein the outer unit comprises a shut-ofl? plate, the inner unit being rotatable to a third position wherein the inner unit and said shutoff plate co-operate to prevent air flow from one side of the fan to the other.
4. A :fan as claimed in claim 1 wherein the inner unit comprises a pair of outer walls each a portion of a common cylinder, centered on the rotational axis of the first unit, one outer wall carrying said first guide wall and the other outer wall forming said second guide wall.
5. A fan as claimed in claim 1 wherein the inner unit comprises an outer wall carrying 0r forming the first guide Wall and the outer unit comprises a pair of outer walls each a portion of a common cylinder centered on the rotational axis of the inner unit and each providing said second guide wall in one of said positions of the inner unit.
6. A fan as claimed in claim 1 including a shroud attached to the outer unit over one of said openings and mounting a heating element to extend over the length of said opening.
7. A fan as claimed in claim 1 wherein the inner unit is rotatable between stops defining said two positions by means of a flex for the motor driving said rotor.
8. A fan as claimed in claim 7 wherein the motor is controlled by micro-switches actuated on notation of the inner unit to said two positions.
9. A ventilating fan of the cross-flow type comprising an outer structural unit providing a rectangular frame to be mounted within a window aperture, end plates on the short sides of the rectangle, a shroud plate and a second plate extending between the end plates for location on outside and inside of the window aperture respectively, said shroud and second plates forming spaced portions of a common cylinder having its axis parallel to and between the long sides of the rectangle, and defining a pair of openings directed to the outside and inside respectively of said window aperture; an inner structural unit mounted for rotation about the axis of said cylinder and including a main wall extending longitudinally thereof; and a motor-driven bladed cylindrical cross-flow rotor mounted for rotation in predetermined direction about an axis parallel to and spaced from the rotational axis of the inner unit and fixed in relation thereto; said units providing openings opposite the rotor and to either side of the outer unit in both of a first and a second angularly spaced position of the inner unit, and the :main Wall of the inner unit and one of said shroud and second plates of the outer unit substantially preventing flow in a third position of the inner unit; the rotor is the first said angular position of the inner unit cooperating with the main wall thereof and the shroud plate to induce a flow of air between said openings in one direction and the rotor is the second of said angular positions of the inner unit cooperating with the main wall thereof and the second plate of the outer unit to induce a flow of air between the said opening in the other direction.
References Cited by the Examiner UNITED STATES PATENTS 2,337,325 12/ 1943 Hach et al. 23042 2,659,294 l1/ 1953 Hersperger 9894 3,065,553 11/1962 Olin 230-42 3,116,011 12/1963 Laing 23045 3,150,821 9/1964 Laing 9894 FOREIGN PATENTS 596,328 1/ 1948 Great Britain.
MARK NEWMAN, Primary Examiner.
H. F. RADUAZO, Assistant Examiner.