US2307490A - Ventilator - Google Patents

Description

Jan. 5, 1943. M, B, CURLEY 2,307,490

VENTILATOR Filed July 19, 1940 3 Sheets-Sheet l [NI/E/YTOR MORTON B. CUELEY,

Jan. 5, 1943. M. B. CURLEY 2,307,490-

VENTILATOR Filed July 19, 1940 5 Sheets-Sheet 2 vs/vro/e MOETON B. CURLEY,

ATT'Y Patented Jan. 5, 1943 2,307,490 vEN'riLA'roR Morton B. Curley, Columbus, Ohio, assignor to. The Jeflrey Manufacturing Company, a corporation of Ohio Application July 19, 1940, Serial No. 346,350 3 Claims. (01. 120-162) This invention relates to a ventilator or fan, and an object of the invention is to provide an improved fan or ventilator having a rotor with adjustable pitch blades.

A further object of the invention is to provide a rotor or propeller particularly for a fan or ventilator in which the angle of setting of the blades can be adjusted.

A further object of the invention is toprovidean improved rotor structure for a fan.

Still another object of the invention is to provide improved mechanism for adjustingthe, angle setting of a propeller blade, particularly for a fan or ventilator.

Still another object of the inventionis to provide an improved mechanism for attaching fan blades to a hub which is particularly useful in propellers having blades which are adjustable as to angle of setting. 7

Other objects of the invention will appear here inafter, the novel features and combinations being set forth in the appended claims. In the accompanying drawings,

Fig. l is a side elevational view of a ventilator or fan comprising my invention;

Fig. 2 is a frontend view of the ventilator or fan of Fig. l;

Fig. 3 is a front view of a part of the rotor of the ventilator or fancomprising my invention;

Fig. 4 is a sectional view taken along the .line 44 of Fig. 3 looking in the direction of the arrows; and

Fig. 5 is a sectional view taken along theline 5-5 of Fig. 3 looking in the direction of the arrows. I 1

Referring particularly to Figs. 1 and 2 of the drawings, it will be seen that the ventilator or fan comprises a casing it! having a frontremovable screen H which acts as a safety feature to prevent persons or animals from entering the casing I and which is preferably provided with a door I2 so that a man may enter the casing to make adjustments or repairs. It may be stated that the fan illustrated is a very large fan so that a man can stand up inside the. casing without any difiiculty.

The discharge end of the fan is likewise provided with a screen I3 to prevent the undesired entrance of animals or persons thereinto.

The casing I0 is mounted upon a framework comprising a pair of spaced pillars l4 and a rear support l5 (see Fig. 1). Within the casing lll is a propeller l6, which is mounted ,upon a. longitudinally extending shaft I! mounted 'on roller ventilator or thrust bearings l8 and IS, the latter housed within a central stationary cowling 20 from the forward end of which extend a plurality of radial stationary guide vanes 2|, the outer ends of which are connected to the interior of the casing Ill.

Th shaft I1 is adapted to receive a drive pulley by which the propeller I6 is driven from a desired source of power, such as an electric motor.

Supporting means for the rear thrust bearing [3 includes a pair of downwardly extending legs 22 connected by a cross angle 23 and supported upon a foundation or other support 24.

Attention is now directed to. Figs. 3, 4 and 5 and to the structure of the rotor 25, which comprises a hub plate 26 rigidly attached as by welding to a cylindrical sleeve 21 which is keyed to the shaft I7 and preferably abuts a shoulder thereon. Adjacent its periphery the plate 26 is provided with a plurality of notches or cut out recesses 28 into which extend the bases 29 of propeller blades 30 which are adjustable as to angle of setting as hereinafter explained completely.

By angle of setting isjmeant an angle corresponding to the blade angle at a definite radii fromthe center of rotation, the term blade angle meaning the angle between the chord line of the airfoil section and the plane of rotation.

The base 29 of each blade 30 is provided with a peripheral or circumferential groove 3| which forms spaced shoulders 32 and 33 thereon. The bottom of the base- 29 of each blade is formed into a head 34 having a spring receiving socket 35 (see Fig. 4) therein spring 36 for a hereinafter.

Cooperating with the basis 29 of each blade 30 .is a pair of straps comprising front strap 31 and rear strap 38 which, as clearly seen in Figs. 3 and 5 of the drawings, are bolted rigidly to the rotor hub plate 26 by spaced bolts 39 cooperating with the winged portions of said straps 31 and 38.. The straps 31 and 3B are provided with tongues 40 and H, respectively, (see Fig. 4) which extend into the grooves 3| on each blade 30 and in cooperation therewith through the shoulders 32 and 33 prevent radial movement-of the blades 30 with respect to the axis of rotation of rotor 25. These tongues 40 and 4|, however, are so formed that when the straps 31 and 38 are clamped tightly against the hub plate 26, the

bases 29 of the blades 30 are free to rotate on their own longitudinal axes thereby to permit free adjustment of the angle of setting of said blades 30. This, of course, requires a somewhat loose connection between the bases 29 and the cooperatadapted to receive a coil purpose more completely explained as shown in Fig.

ing straps 31 and 38, and to prevent undesirable clattering of the blades 3|! in case the propeller I5 is rotated at a very slow speed, for example by hand when being tested by an operator, the previously described coil springs 36 are included to urge the blades 3|] radially outwardly and thus preclude such undesirable noise. In normal operation the centrifugal force on each blade 30 is quite sufficient to prevent any clattering thereof.

To provide for the adjustment of the angle of setting of each blade but extremely accurate and easily adjustable mechanism which I shall now describe.

The head 34 of each blade 30 is provided with a plurality of bores 42 which are radial with respect to the axis of the generally cylindrical shape of the head 34. The bores 42 are preferably spaced apart each from the other by a predetermined number of degrees. Purely by way of illustration and not by way of restriction, it may be stated that in the illustration given in Fig. 5 ofthe drawings, the axes of bores 42 are spaced apart 19 and seven bores 42 are illustrated. It is obvious that the number may be either increased or reduced and their angular relation may be either increased or reduced and in fact is not essentially though preferably uniform.

The strap 31 is likewise provided with a plurality of bores 43 which are preferably equal in number to the number of bores 42. The axes of bores 43 are preferably spaced at equal radial angles with respect to the head 34 and the angle between the axes of any two successive bores 43 is slightly less than the angle between the axes of any two successive bores 42.

In the illustrated embodiment of the invention of the drawings, the angle between any two successive axes of bores 43 is 17 but this angle may be either increased or decreased. It is of course necessary, however, that if the angles between successive bores 42 and 43 are uniform as illustrated in the drawings, then the angles of successive bores 43 must be different than the angles of successive bores 42 because the difference in these angles measures the amount of adjustment of the angle of setting of the blade 30 which is provided in a manner now to be described.

Each of the bores 43 is preferably threaded at and a pin 45 having a threaded head 46 and a wrench receiving socket 41 is provided which is adapted to be selectively inserted through two aligned bores 42 and 43. For example, as illustrated in Fig. 5 of the drawings, the topmost bores 42 and 43 are in alignment. and the pin 45 extends into both of them thereby locking the blade 30 in position with respect to the hub 25. A locking wire 48 threads through an opening in the head 46 and fits in a groove 49 formed in strap 31, to prevent accidental removal of the pin 45. It is evident that the cooperating bores 42 and 43 provide adjustment for the angle of setting of the blades 30. For example, with the parts in the positions illustrated in Fig. 5 of the drawings, there is one angle of setting of the blade 30. If pin 45 is removed and then inserted in the second pair of bores 42 and 43, this will necessitate adjustment of the angle of setting of the blade 30 by an amount determined by the difference between the angles between successive bores 42 and 43. In the illustration given bores 42 are 19 apart and bores 43 are 17 apart, and consequently the diiference is 2 andso a 2 rotation of the blade 30 is required to permit the 30, I provide a very simple .ticularly Fig.

insertion 6f pin 45 in the second two bores 42 and 43. In a like manner two more degrees of rotation of the blade 30 is required to insert pin 45 in the third set of bores 42 and 43 and a like increment of adjustment is required for each successive pair of bores 42, 43.

It is thus to be seen that a very simple but highly accurate method of adjusting the angle of setting of the blades 30 is provided, and this can be effected by an unskilled operator because all that is necessary is for the operator to insert the pins 45 of each of the blades 30 in the same relative bore 43.

To prevent rotation of any blade 33 beyond the desired limits of adjustment the head 34 of each is provided with a pin 50 (see Fig. 5) which works in a slot 5| formed in the strap 38, the pin 50 striking the edges of the slot 5| at the extremities of movement permitted. In fact the slot 5| is of such dimensions that anyone bore 42 may only be aligned with its one complementary bore 43, and no other bore 43.

It is manifest that the mechanism for attaching each blade 30 to the hub plate 25 is extremely simple yet very rugged and insures a strong connection therebetween yet one which permits ready removal of any blade 30 to replace it in case it becomes damaged. It also permits a free adjustment of the angle of setting of any blade 30 while at the same time insuring that the average pitch angle will be proper, by virtue of the simple expedient of placing a pin, namely the pin 45, in a desired bore 43. In shop practice the bores 42 and 43 are drilled using a fixture that obtains a definite or accurate spacing therefore if all blades are set in the sam relative settings all blades will be adjusted about their longitudinal axis exactly the same amount within very close limits.

Inasmuch as the pitch angle of the leading face of each airfoil blade 30 may vary progressively from the inner end to the outer end thereof, reference has been made above to adjustment of the angle of setting of the blade but it should be understood that it is very important that the setting of each blade in this respect shall be exactly the same as the setting of all the other blades. Such exact setting of all the propeller blades to secure the same pitch angle at any given sections of the blades is predetermined by the construction shown in the drawings, par- 5. The attendant is precluded from making any errors, since the pin and slot structure 50, 5| necessitates pairing of the borings 42, 43 individually. For instance, by removing the pin 45 from the uppermost bores 42, 43 and inserting such pin in the fourth bore 43 from the top for each propeller blade, the latter will necessarily be shifted 6 because the pin can be inserted only into the fourth bore .42 from the top on account of the abutment mechanism 50, 5|, 38 shown in Fig. 5. Each blade may be adjusted separately and independently and then secured in adjusted position, with the assurance that when the adjustments have been completed each airfoil blade will be in exactly the same position relative to the rotor.

While the clamping straps may be so proportioned with respect to the base 29 of each fan blade as to enable each fan'blade to be adjusted independently of the others by loosening the bolts 39 before each adjustment and tightening them again after adjustment, without the use of the pin 45, I prefer the arrangement above described wherein the base 29 is loosely mounted 2,807,490 between the straps 31, 38 so that when the bolts 39 have once been tightened they need never be loosened again for any adjustments of any of the airfoil blades 30. In other words, it is preferred to use the tongue and groove connections between the clamping straps 31, 38 and the base 29 merely as an annular bearing which prevents the blade from being pulled out or having its outer tip end from abutting against the inner cylindrical wall of the casing l0. Also it is preferred to include the pin 45 insertable in registering bores 42, 43 as shown in Fig. 5, to hold the blade in adjusted position relative to the rotor particularly since the base 29 is free to be turned manually by grasping the blade 30 when the pin 45 is released, without first loosening any of the bolts 39.

To reduce wind lossage a plate 52 extends between the sleeve 21 of the hub plate'26 and successive straps 38, the plate 52 being held in place by bolts 53 which extend through hub plate 26. In addition the forward end of the rotor l6 carries a oowling 54 which is preferably attached to rotate with the propeller l6 but if desired may be made stationary and attached to the casing Hi.

It should also be noted that the clamping straps 31 each has an extension 55 in the form of a segment of a cylinder. The extensions 55 are arranged circumferentially end to end to form a complete cylinder with its peripheral surface flush with the rear outer surface of the oowling 54 as shown in Fig. 5. Such cylindrical extension 55, 55 also assists in supporting the rear end of the oowling 54 when the latter rotates with the fan unit but when the oowling 54. is stationary a slight space is left between the oowling 54 and the cylindrical extension 55, 55. v

' The clamping straps 38 may also be provided with extensions 56 each in the form of a segment of a cylinder and arranged end to end to form a complete cylinder with its outer surface flush with the front end of the oowling 20. The cylindrical sufaces 55 and 56 are located on opposite sides of the rotor plate 26, the periphery of which is approximately flush with the cylindrical surfaces and 56. The streamlining of the cowling 54 and 20 is therefore maintained as much as possible.

Obviously those skilled in the art may-make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and I therefore wish not to be restricted to the precise construction herein disclosed. I

Having thus described and shown an embodiment of my invention, what I desire to secure by Letters Patent of the United States is:

1. In a rotary fan, the combination with a rotor, of a fan blade adjustably attached thereto for adjustment of its blade angle, means attaching said blade to said rotor asv aforesaid com prising a base on said blade and a co-operating attaching member on said rotor, means for predetermining the angle of adjustment of said blade comprising a plurality of bores in said base extending along radial axes with respect thereto, a plurality of bores in said attaching member extending along radial axes with respect to said blade base and adapted to be aligned with selected ones of said bores in said blade base, pin means for connecting selected pairs of bores in the attaching member and the base, and limit stop mechanism for the base to prevent any selected bore in the attaching member from being connected to any more than one bore in the base.

2. In a device of the class described, the combination with a rotor, of a fan blade adjustably attached thereto for adjustment of its pitch angle, means attaching said blade to said rotor as aforesaid comprising a base on said blade Y and a cooperating attaching member on said rotor, means for adjustably determining the angle of adjustment of said blade comprising a plurality of bores in said base extending along radial axes with respect thereto, a plurality of bores in said attaching member extending along radial axes with respect to said blade base and adapted to 'be aligned with selected ones of said bores in said blade base, pin means adapted to extend selectively into abore in said blade base and an aligned bore in said attaching member, and abutment means for preventing any more than one bore in the attaching member from being aligned with any more than one bore in the base at any one time.

3. A fan or ventilator comprising the combination with a rotor including a fiat plate, of a plurality of fan blades, mechanism journaling each of said blades to said rotor plate on a radial axis, said journaling mechanism comprising straps detachably secured to said rotor plate, and extensions from said straps arranged end to end to form cylindrical surfaces adapted to be arranged flush with the surfaces of associated streamlining oowling.

MORTON B. CURLEY.

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