US2440293A

US2440293A - Rotor equipped aerial device

Info

Publication number: US2440293A
Application number: US534247A
Authority: US
Inventors: Paul H Stanley
Original assignee: Autogiro Company of America
Current assignee: Autogiro Company of America
Priority date: 1944-05-05
Filing date: 1944-05-05
Publication date: 1948-04-27
Anticipated expiration: 1965-04-27

Description

April 27, 1948. P. H. STANLEY ROTOR EQUIPPED AERIAL DEVICE 2 Sheets-Sheet 1 Filed May 5. 1944 INVENTOR. PAUL H. 'S'TANLE Y ATTORNEYS April 27, 1948. P. H. STANLEY ROTOR EQUIPPED AERIAL DEVICEv Filed May 5, 1944 2 Sheets-Sheet 2 I J 1 4 l ATTORNEYS Patented Apr. 27, 1948 delphia, Pa.,

a corporaticn of Delaware Application May 5, 1944, Serial No. 534,247

(etch-135$ 11 Claims.

This invention relates to aerial devices'andparticularly to an aerial device equipped im'th a bladed rotor arranged to provide for retarded descent of the device when it is released or launched at an elevation, for example, from an aircraft.

Broadly, a number of features of the inven tion are adaptable to many different purposes, for instance, to parachute-type devices for dropping either cargo or an occupant. Certain specific uses for which the invention is particularly Well suited are aerial flares and also aerial bombs, employed for pyrotechnic display purposes,- or for warfare.

The type of construction with which the invention is particularly concerned is one in which the rotor blades are pivotally mounted to provide' freedom for swinging movement of the blades in a direction generally transverse the mean rotative path of travel.

One of the principal objects of the invention is the provision of mechanism for controlling swinging movements of the blades under certain; circumstances and for certain purposes as will further appear. ,7 v

More specifically, the invention contemplates employment of rotor blades which are pivotally mounted to provide for decrease of rotor blade pitch angle as the blades swing upwardly. This is of importance in facilitating initiation of rotation of the rotor at the time whien the device is launched or released from an aircraft. Upon launching, the relative air flow set up by descent of the device causes the blades to swing upwardly on their pivots and thereby decrease the blade pitch angle so that the rotor starts turning, and,

as rotational speed picks up, the action of -c'entrifugal force on the blades causes them to as'- sumea path of travel defining a shallow cone.

According to the invention, provision isjmade for controlling the upward swinging movement of the blades and preferably for restricting the upper swinging movement about thepivot means which eifect decrease of blade pitch, so as'tt re strain swinging movement ofthe blades pward- 1y into positions of substantial parallelism above the body of the device. very rapid acceleration-of therotor.

In the preferred arrangement the rotor blades are constructed and positioned so as to be" ca; pable of autorotation, thereby providing for a very low rate of descent of the device.

In accordance with another aspect of the in- This aids in eilsiirin'g' vention,- pivot means are alsoprovided for the" blades, on which pivot meahsthe blades" maybe folded in order ti) facilitate compact stowage of the entire device. The blade movement control arrangements of the" invention are advantageonsly constructed to restrict excessive upward movement of the blades about the folding pivots and thereby ensurethat relatively-large angular upward swinging movements will take place about the pivot means which provides for concurrent decrease of pitch'arigle.

Still another object (if the invention is the prbvisiohof a novel means to be employed in the launching or aerial devices of the type here under consideration. According t6 this feature, releasable means are prdvided for retaining the blades 1 rowe position until after the device eenjla'unchd. I i'i'this embodiment a cable ndr iement i'sj mplbyed; which cable is automatically operative torelease' the blade holdme means hen the device has dropped sumc'i'ently to place the cable uifder tensi'on, This system or'iaunenme avoids danger of breakage of the rotor blades or damage to the aircraft, whichmigh oth rwise occur if the rotor blades unfoldedf before" the device was" entirely clear of the a r a tfrom which it launched.

Accor in t an the ft 0 th nv n n, means are provided to assist r assure unfolding f the. o r, i j es after. the, de i e s been Iaunchedi In a preferredlcon'struction a commoh' liiearis, a strip of" resilient material ise'n'lplbyd' hbtonly formthis function but also to" act as a means restraining excessive upwa'r disttin mg' movements or thebl'ades', a'sabove mentioned. I p v m new the" roregtinggdnd ther, objects and advantagfesiar dani eew u appear more fully from the follow ng descriptionreferring tothe accom- D i rawmssin.wms .s l

i e .11 asidee'lsvat n l View of O bodiuient .oit .mv nt qathe v ew a i c ing a sectional illustration of a casing in which the entire' device isfadaptedto be housed when the blades arefold'ed;

Figure? is a. :fragmentary viewv of the device ofFig'ure 1;-released fromitscasing and with th'blades unfolded andiswung' upwardly in position for initiating rotation of the rotor;"

Figure 3- is a;pla"ri*view of" a modified form of rotofblade'mountirig'for a device of the type herein disclosed; the view memdirig the inner end portionsbnlypf the rotor bladesyand ete '41saii -eivationdrview or the mechanmanat -res de c Referring nr'swsfngure 1, 1 it is assumed that in this particular embodiment the invention is adapted to an aerial flare which comprises a body 6 which, in this instance, may consist of or enclose the flare material. A fitting 1 at the upper end of the body carries a pair of apertured ears 8-8 cooperating to support a pivot pin 9, on which pivot pin a pair of links III-4|] are mounted, one for eachblade ll of thepair of blades comprising the rotor. connected with a link It] by a second pivot l2.

Blade pivots l2 provide for downward foldin of the blades to positions in which they lie adjacent to the body portion 6 and with the blades folded, the entire device is adapted to be received be open for release or discharge at the time of in a housing or casing l3, one end of which may launching by withdrawal of pin l3a. The blades may be retained in folded position Each blade I l is 4 of rotation under the influence of the air flow across the blades.

It is advantageous, however, that the upward swinging movement of the blades on the oblique pivot axis be restricted at an angular position appreciably out of parallelism with the vertical axis, and, in the arrangement of Figures 1 and 2 this is accomplished by the same elastic element l8 which is used to assist the unfolding of the blades as mentioned above. This element desirably comprises a strip of sponge rubber material, the ends of the strip being fastened to the root end portions'of the blades. This element thus constitutesacushion device restricting extreme by means of a fastening device, such as the elasv tic cord indicated at H3 in Figure 1, both ends of the cord being provided with loops,.one of which is projected through the other andithrough which said one loop, a pin 15 may be inserted so as to retain the oordaround thefolded blades and thus keep them in foldedposition. It will readily be seen that upon withdrawal of pin 15, the blades are free to swing upwardly to their operative positions, for instance, to the positions indicated in Figure 2. Release of pin I5 is preferably effected by means of. a .cable l6 which may either be held in the hand-of the operator or which, advantageously, is connected as at I! with the casing l3 for the entire unit.

With an arrangement as just described, the device is adapted to be launched byan operator who merely holds the casing in the proper position to release the device from the end'of the casing. When the devicefalls sufiiciently to place the cable l6 under tension the pin I5 is withdrawn from the loop in cor-d l4 and thereupon cord l4 drops off and the relative air flow set up by virtue of descent of the device causes the blades to swing upwardly and thereafter initiate rotation of the rotor as above mentioned.

To facilitate or assure this action, an elastic element l8, interconnects the root fittings of both blades and is in a condition of tension when the blades are folded as in Figure l.

It may here be noted that if desired the rotor may be rotatively mounted on the body portion, this arrangement being preferable formany'purposes, for instance, where the invention is applied to a device of relatively large mass or when the invention is applied to a man-carrying device. However, as is illustrated in Figures 1 and 2, various features of the invention are also adaptable to a device in which the rotor and the body portion are interconnected to rotate together.

In the embodiment of Figures 1 and 2, therefore, after the device has been launched and the blades have been caused to swing upwardly to positions such as indicated in Figure 2, the air flow across the blades initiates rotation of the entire unit, 1. e., the rotor and the body together. According to the arrangement shown, initiation of rotation of the rotor is facilitated by virtueof an angular disposition of the axis of pivot 9. The axis of this pivot, when viewed from above the rotor, forms an acute angle with the longitudinal axis of each blade at the leading side :of the ,blade axis and the outboard side of; thepivot axis.

Because of this'obliquity of the pivot axis the pitch angle of the blades is decreased to a-ne ative value when the blades swing upwardly and this decrease in pitch angle facilitates initiation -as shown in Figure 2. The cushion also serves to absorb shocks at the time of launching the device; when the blades swing upwardly under the action of the air flow. Beyond the foregoing the, arrangement of the cushion tends to spread the blades from their uppermost positions and thus aids; in bringing-the blades downwardly toward their normal operativev positions, as rotation commences. 1

Turning now to the arrangement of Figures 3 and 4, it is here assumed that the. invention is adapted to a device for carrying either an occupant, cargo, or an explosive, for instance an aerial bomb. Only the upper end portion of the body is illustrated at .20 in Figure 4. A rotor mounting structure 2| is connected with the upper end of the body portion 20 and serves to house and mount bearings 22-42 which cooperate with a rotative rotor spindle 23 projecting upwardly from the mounting structure 2|, to carry a pair of apertured lugs 24-24 which serve to mount a pivot pin 25 on which a'pair of blade mounting links 26-26 are adapted to'swing upwardly and downwardly. j In Figures 3 and 4 the root end portions of a pair of blades are indicated at 21-41, the direction of rotation being indicated by the arrow B. Each blade 21 is connected with a link 26 by means of a pivot 28. 7 Attention is now called to the fact that, as in the embodiment'of Figures 1 and 2, each bladeis mounted for upward and downward swinging'movement about two pivot axes. Moreover, as before, the outboard pivot axis (28) is preferably arranged perpendicular to the longitudinal axis of the associated blade in order to provide for folding of the blades downwardly to positions adjacent side walls of the elongated body portion, for compact stowage. In Figures 3 and 4 it is also contemplated that the axis of pivot 25, onwhich both of the blades of the pair are mounted, is obliquely inclined with respect to the longitudinal axis of the blades in the, same sense as. above described with reference to Figures 1 and 2, to facilitate initiation of rotation.

Blade movement control devices are provided in the embodiment of Figures 3 and 4, including for each blade, complementary cooperating stops 29-30 which act to restrict upward swinging movement of the-blade about pivot'28 to a position just a little abovethe horizontal (when the connecting link 26 is also in horizontalposition). Because of the stops 2930, extensive upward swinging movement of each blade must take place about the oblique pivot axis125. p

Control means are also'provided' to influence swinging movement about-the axis of pivot 25. This mechanism includes linkageconstraining the two links 26 to move inun'ison. For uiisrur p'o'se, pairs of pivoted links-3l interconnect each blade mounting'link 2fiwith a transversepin :32,

site blades, as above described, when the blades swing upwardly through a large angle, they move together, the upward movement being limited by engagement "of pin 3'2with the'upper ends of slots 33. In this uppermost position, in which the pin 32 takes the position indicated at 32a and in which links 3| and blades 2! take the positions indicated at 3m and 21a, the blade axes extend upwardly and outwardly at angles in the neighborhood of the mid-position between horizontal and vertical.

The foregoing construction thus also provides for restricted upward swinging movement of a pair of blades about an oblique pivot axis, whereby to ensure rapid initiation of rotation of the rotor.

In addition to the above the arrangement of Figures 3 and 4 provides freedom for downward swinging movement of the blades 21 to folded positions in which the blades lie parallel to and closely adjacent sides of the elongated body as indicated at 211).

With respect to the blade pitch angle to be employed, it may be said that appreciable variation is ermissible. An appropriate autorotative setting found suitable for the purpose is about 4 or 5 degrees above the no-lift setting with reference toa plane perpendicular to the axis of rotation.

I claim:

1. An aerial device comprising a body portion, a bladed rotor connected with the body portion providing for retarded descent of the device, said rotor incorporating a plurality of blades pivotally mounted for upward and downward swinging movement through a range extending above and below a plane perpendicular to their autorotational axis, and mechanism for controlling upward swinging movements of the blades including resilient means interconnecting the blades and normally urging them toward positions approximately perpendicular to the axis of rotation of the rotor.

2. A device in accordance with claim 1 in which each blade is of aeroform section adapted for autorotation and mounted for pivotal swinging movement about an axis providing for decrease of blade pitch as the blade swings upwardly, whereby to facilitate initiation of autorotation of the rotor when the device is launched.

3. An aerial device comprising an elongated body portion, a multi-bladed rotor connected with the body portion at an end thereof and providing for retarded descent of the device, blade mounting pivot means providing for upward and downward blade swinging movement in a direction generally transverse the rotative path, the range of upward movement including a position in which the blades approach parallelism with their rotational axis, and means for restricting the upward movement just short of substantial parallelism.

4. A device in accordance with claim 3 in which said last means comprises a resilient element and adapted to limit extreme upward movement thereof.

5. A device in accordance with claim 3 in which said last means comprises a resilient element interconnecting the blades and adapted to limit extreme upward movement thereof.

6. An aerial device comprising an elongated body portion, a bladed rotor incorporating a pair of blades, the rotor being mounted on an end of the body portion and providing for retarded descent of the device, pivot means for the blades providing for the downward folding movement of the two blades at the opposite sides of the elongated body and means limiting upward pivotal movement of the blades about said pivot means, the limiting means being arranged to permit the blades to swing upwardly above a position perpendicular to their rotational axis to a position just short of parallelism, but to prevent the blades from swinging into positions of substantial parallelism above the body portion.

'7. A device in accordance with claim 6 and further including second pivot means for the blades providing for decrease of blade pitch angle when the blades swing upwardly.

8. A device in accordance with claim 6 and further including second pivot means for the blades providing for decrease of blade pitch angle when the blades swing upwardly, and means constraining the blades of the pair to swing upwardly to the same extent about said second pivot means.

9. An aerial device comprising a body portion, a bladed rotor comprising a pair of pivotally mounted rotor blades mounted on the body portion and providing for retarded descent of the device, the blade mounting pivots including, for each blade, two radially spaced pivot axes providing for upward and downward swinging movement of the blade in a direction generally transverse the mean rotative path of travel thereof, the inboard pivot axis being positioned to provide for decrease of blade pitch with upward swinging movement of the blade, and stop means operative with respect to swinging movement about the outboard pivot axis, said stop means being arranged to inter-engage upon upward swinging movement of the blade beyond a small angle from the horizontal, whereby to ensure that extensive upward swinging movement of the blad will take place about the inboard pivot axis.

10. An aerial device comprising an elongated body portion, a bladed rotor mounted at one end of the body portion with its rotational axis approximately coinciding with the longitudinal axis of the body portion to provide for retarded descent of the device, a blade of the rotor being mounted for swinging movement in a direction transverse the mean rotative path through a range extending above and below a plane perpendicular to their rotational axis, and yielding means for restraining the blade as against excessive upward swinging movement.

11. An aerial device having a sustaining rotor blade adapted to be air rotated when the device is dropped from a height, means providing for locating said blade in a downwardly folded position, and means urging the blade upwardly from folded position toward a position normal to the rotational axis when the device is dropped, wherein both means permit further upward movement of the blade responsive to relative air flow, and the means urging the blade from folded to its operative position also resists extreme upward movement of the blade.

PAUL H. STANLEY.

(References on following page) REFERENCES 011111) file of this patent; V

UNITED STATES PATENTS Number Name Date Ziegenfuss Sept. 12, 1911 Wiley June 26, 1934 10 Tiling Oct. 4, 1932 Nelson Sept. 14, 1943 Number Nufmber 8 A Name Dat Focke .i. Oct. 8, 1940 Raio Nov. 9, 1943 Bennett- Mar. 5, 1940 Cierva, Oct. 25, 1932 Frazer July 13, 1943 Upson Nov. 19, 1935 Chupp Nov. 28, 1939 FOREIGN PATENTS Country Date Great Britain 1913