US3104857A

US3104857A - Glide parachute

Info

Publication number: US3104857A
Authority: US
Publication date: 1963-09-24
Anticipated expiration: 1980-09-24

Description

Sept 24, 1963 T. w. KNACKE ETAL 3,104,857

GLIDE PARACHU TE Filed sept. 1. 1961 4 sheets-sheet 1 'Sept 24, 1963 T. w. KNAcKE ETAL 3,104,857

GLIDE PARACHUTE Filed sept. 1, 19.61

4 Sheets-Sheet 2 -T. w. KNACKE ETAL 3,104,857

GLIDE PARACHUTE Filed sept. 1, 1961 4 sneets-sheef s 1%/ Pi? j @mlm/lm Sept- 24, 196s T. w. KNACK.; Em. 3,104,851

" `GLIDE: PARACHUTE Filed Sept. l, 1961 4 Sheets-Sheet 4 -chutes have vbeen used in .the past.

United States Patent O 35.613357 GLDE PARACHU in Theodore W. naclrc, Los Angeles, and .lohn H. McCiow,

fir., Torrance, Calii., assignors, hy mesne assignments,

to Itek Corporation, Lexington, Mass., a corporation of Delaware Filed Sept. 1, 1961, Ser. No. 135,6@3 8 Claims. (Cl. 24d-M5) The present invention relates to parachutes, and it relates more particularly to la new and improved type of parachute having the ability to glide along a determined COuISS.

Glide parachutes, per se, are known, and such parari'he wellknown types of prior art glide parachutes include those designated the Hart Paratchute, the Derrick Parachute, the Tojo Parachute, and different types of blank-gore parachutes.

The prior art glide parachutes referred to in the preceding paragraph all operate on Ithe sante principle of reaction forces. ln these prior art glide parachutes, one or more openings are provided in the canopy iof the parachute, and the air escaping through these openings creates reaction forces which propels the parachute in a direction opposite to the direction of the escaping air.

Unlike the prior Iart glide parachutes mentioned above, the glide parachute of the present invention uses the principle of lift mainly, `but combines reaction for directional control, as will be described. The glide parachute of the invention is constructed to have the shape and characteristics of an air foil, in that it is shaped to obtain a lift force on its surface from the atmosphere through which is moves.

As `is well known, lift is the for-ce which counteracts gravity, and this force is caused iby the motion of air over and under an air foil as it moves through the atmosphere. Lift is produced, as enunciated by the Bernoulli priciple, because :the air foil is shaped such that the speed 'of air over its top surface is greater than the speed of air over its lower surface. To achieve this condition, the top surface of the air foil is curved, and the air has a further path to travel over the top surface than over the lower surface. This, in accordance with Bernoullis principle, creates a condition such that the pressure `of air below the air foil is greater than the pressure of air above, and -this pressure dierential causes the air foil to rise or lift.

As is also well known, drag is the force which resists the forward motion of an object through the air. A first type of drag of an air foil section, known -as prole drag, depends largely on the shape of the air foil. Another type of drag is directly caused by the lift and is called induced drag. The total drag of the air foil is the combination of the profile drag and the induced drag.

The improved glide parachute of the present invention is constructed to have an air foil coniiguration, and the glide characteristics thereof are produced by a combination oi lift and drag, rather than by drag and reaction forces as is the case in the prior tart type Iof glide parachutes referred to above.

An object of the invention, therefore, is to provide an improved type of glide parachute which is capable of gliding along a determined glide path.V

, Another object is to provide such an improved type of glide parachute which is capable of gliding along the determined glide path with a high degree of directional stability. This object is achieved, for example, in a second embodiment of the invention yby the provision of one or more stabilizing fins.

Yet another object is to provide such an improved type 2V of glide parachute which is capable of being guided along a desired glide path. This latter object is achieved, for example, in a further embodiment by the provision of controllable vents in the canopy of the parachute, or pockets, as will be described.

Other objects and advantages will become apparent from a consideration of the following speciiicaition in conjunction with the accompanying drawings, in which:

FIGURE l is a iside sectional View of a parachute constructed in accordance with one embodiment of the invention to have an air foil configuration;

FIGURE 2 is a top View of the assembly of FIGURE 1 and illustrating the particular plane configuration of the canopy;

FIGURES 3 and 4 represent other suitable plane configurations for the canopy;

FIGURE 5 is a schematic representation of the parachute of FIGURE 1 and illustrating the forces involved in the assembly;

FIGURE 6 is a side elevational View of a parachute similar to the parachute of "FIGURE 1 and which incudes a stabilizing iin formed in the canopy of the paracute;

FIGURE 7 is a top plan View FIGURE 6;

FEGURE 8 is a top plan view of a parachute constructed in accordance with the concepts of the invention and further including controllable steering vents in the canopy;

FGURE 9 is a side View `of the parachute of FiGURE 8, substantially on the line 9--9 of FIGURE 8;

FlGURE 10 is an end view of the parachute substantially on t-he line lik-ld of FIGURE 9;

FIGURES 11 and 12 are top plan view of a parachute constructed in accordance with the concepts of the invention and further including controllable steering pockets in the canopy;

FiGURE 13 is a top plan view of a parachute constructed in accordance with the concepts of the invention and including controllable steering means; and

FIGURE 14 is a side View of the parachute of HG- URE 13.

As shown, for example, in FGURES 1 and 2,l the parachute of the first embodiment of the invention includes a canopy lli. The canopy lil is 'shaped to have an air foil coniiguration, as best shown in `)FIGURE 1, when the parachute is in an inflated condition. The canopy 1li achieves the air foil configuration in the embodiment of FIGURES l and 2, by appropriately shaping the canopy andl by turning in its peripheral rim portion towards the open underside of the air foil section formed thereby. v

lIt will lbe apparent fro-rn an examination of the presentation of FIGURE 1, that the cross-section through the parachute is similar to a thick air foil with a high camber and an open underside. The camber may, for example, be of the order of 10%.

The air foil shape may be maintained, [for example, by internal and external anchor lines, such as the'anchor lines 12 'od FIGURES 1 and 2 and by ,gusset-like ribs 1d, as shown in FIGURE l. The anchor lines 12 and the members 14 maintain a `desired balance between aerodynamic and stress forces. A tension line may also of the parachute of be provided at the Ilower opening to keep the proper tension on all parts of the parachute. y

A plurality of suspension :lines lo are secured to the canopy at angular positions around the periphery thereof. yIn the embodiment 'of FIGURE l, these suspension lines 16 are spaced radially outwardly from the inner peripheral edge of the turned in rirn portion, so that the 3 anchor lines 12 may maintain the canopy in its air foil shape.

The canopy It) may be self-inilarting; or it may include inflatable tubes or inilation rigging for the purpose of preventing deflation or flutter olf parts of the canopy, or to maintain the desired airfoil shape of the canopy.

The material used tor the canopy should preterably be of low porosity. However, any suitable amaterial, such as onganic textiles, synthetic textiles, plastics, glass lber, wire mesh and the like, may be used. As illustrated in FIGURE 1, an appropriate load I8 is suspended from the lower zend of the suspension lines 16.

The `embodiment of the invention shown in FIGURES 1 and 2 has a canopy lwihose plane configuration resembles an ellipse on one side of a transverse axis X--X, and a parabola on the other side, as shown in FIG- URE 2.

As shown in FIGURES 3 and 4, the canopy may have other plane rforms. For example, the canopy 10a in FIGURE 3 has a circular-shaped plane -formg and the canopy 19h of FIGURE 4 has an oval plane form. The plane torni olf the canopy may have any other appropriate comii'guration.

As shown in FIGURE 5, as the parachute of FIGURE 1 moves through the atmosphere, various forces are created. First there is the downward force, as represented by the vector Weight created by the force olf :grav-ity =on the ioad 18. The resulting motion or the parachute through the atmosphere cneates a li-ft force, due to the air (foil shape of the canopy 16. This lift tforce is represented by the vector lift in the diagram of FIGURE 5. The resultant of the two yforces weight and lift causes the assembly to move along the path designated glide pa Motion along the glide path is opposed by the drag lforce discussed above. This latrter torce is represented by the vector drag in FIG- URE 5. An examination 'of FIGURE 5 will reveal, therefore, that the glide parachute assembly of the present invention, instead of proceeding directly downwardly towards earth, is caused to move along a particular glide path during its downward descent.

rIhe parachute of FIGURES 6 and 7 is similar in most respects to the glide parachute of FIGURE l. The parachute of -FIGURE 6 includes a canopy lilo which may have a conliguration similar to any of the canopies described above. A plurality of suspension lines 16e suspend a load 18o iirom the canopy 10c. During the downward descent :of the parachute of IFIGURE 6, the parachute is caused to glide along the pat-h indicated by the arrow in FIGURE 6.

As a iurther tfeature of the embodiment of the invention shown in FIGURES 6 and 7; `one or more fins, such as the extension, or iin, 22 is formed on the canopy 10c. The iin 22 protrudes from the canopy as illustrated in FIGURES l6 and 7. This iin has a tubular configuration, and it communicates with the interior yof the canopy 10c. 'Ilhe fin 22 is inflated by the ram pressure inside the parachute. A small exit hole 22a may be provided at the end .ott the extension 22.

The cross-section of the tubular iin 22 may be circular, oval, polygonal, or `other suitable shape. One or more ot the lns, such as the iins 22 in FIGURES 6 fand 7 may be provided. These ns extend irom the rear of the canopy in a direction opposite to the direction of ight. The purpose of the tins is to provide the rglide parachute with directional stability, and hold its glide path in the direction ot the wind.

The parachute illustrated in FIGURES S-lO is sirnilar in most respects to the parachute embodiments described above. The latter parachute includes a canopy 10d ot any desired plane form and coniigured as an air toil in accordance with the teachings of the invention.

'Ille parachute of FIGURES 8-l0 includes a plurality of suspension lines 16d. -In this embodiment, the suspension lines are shown as attached to the turned-in A inner rim of the canopy. The canopy itself is cut and coniigured to have its air foil shape when inated.

The parachute of FIGURES 8 10 4is provided with a pair of

vents

36 and 32. These vents are positioned on opposite sides o the canopy 10d, as shown. The vents 3d and 32 function as a steering means Ifor the parachute to cause it to glide down along a desined path.

'llhe steering vent 39 is provided with a control line 34 which extends down through a ring 36 to a position where it can be manipulated by a person suspended trom the parachute. 'Ilhe steering vent 32 is, likewise, provided with a control line 38 which extends down through a ring 4G .to a position Where it also can be manipulated by the person.

The manipulation of the

control lines

34 and 38 causes the cowl portions of cthe vents 30 and 32 to be moved in and out with respect to the canopy. This, in turn, controls the cross-section area of the vents and the amount of air passing therethrough. 'Ihis control of the air passage controls the reaction forces so that effective steering olf the parachute may be realized.

The parachute of yFIGURES 11 and l2 is pro/vided with controllable air-brake pockets for steering purposes. 'Ihese pockets are designated 50 and 52 in FIGURES 1l and l2. The pockets are positioned on opposite sides of the canopy 19e of the parachute, and they open in the `direction of lglide, as shown. The pockets inflate as the parachute proceeds along its glide path; and act as air brakes.

The amount of opening of the individual pockets is controlled by

lines

54 and 56. 'Ihese lines, like the

lines

34 and 38 in FIGURES 8, 9 and 10, run through appropriately positioned rings 58 and 60 and down to a position in which they can be manipulated by the person suspended from .the parachute. The pockets 50 and 52 in FIGURE ll are shown in the open, inflated position. The pockets in FIGURE 12 are shown closed, under the control tof the

lines

54 and 56. Y

When the left pocket 50 alone is opened, the parachute will be caused to turn to the left. On the other hand, when the righ-t pocket 52 alone is opened, the parachute will be caused to turn to the right. Opening both pockets 50 land 52 will air brake the forward motion of the parachute and change its glide slope. A n

The parachute of FIGURES 13 and 14 `includes a canopy 107 which has an airfoil configuration in accordance with the teachings of the invention. The parachute of FIGURES 13 and 14 also includes a plurality of suspension lines 66.

A first group 62 of the suspension lines 60 is connected` to a riser 64. A second group 66 of the suspension lines 60 isfconnected to a riser 68. A third group 70 of thev suspension lines is connected to a riser 72. A zfourth group 74 of the suspension lines is connected to a riser 76, not shown.

Additional fixed risers may be used for Aother groups of the suspension lines, if so desired. The

risers

64, 68, 72, 76, however, are controllable in that they may be lengthened or shortened. If the riser 68, for example, is lengthened and the riser 76 is shortened, the canopy 10i will execute a right hand bank and the parachute will turn right.

Likewise, if the riser 68 is shortened and the riser 76 is lengthened, the canoyp 10f will execute a left bank and the parachute will turn left. On the other hand, if the riser 72 is lengthened and the riser 64 is shortened, or vice versa, the pitch of the canopy will change and a glide path control is provided.

The risers illustrated in FIGURE 14 provide, there- Y of the invention is advantageous in that it is constructed to glide with a high degree of directional stability along a glide path in its descent to earth, and which in some of its embodiments is capable of ya full convenient attitude control.

While particular embodiments of the invention have been shown and described, it is evident that modifications may .be made. The present invention is intended to cover all such modiiicat-i'ons as fall within the spirit and scope of the invention.

What is claimed is:

1. A deployable glide parachute assembly comprising:

an upper exible inilated canopy member having a circumferential edge;

a lower, dish shaped member, partially enclosing the underside of the canopy member, having an inner peripheral edge deiining an aperture and having `an outer peripheral edge attached t-o the circumferential edge ofthe canopy member;

when deployed, the parachute assembly generating an air foil conguration with leading and trailing edges having a predetermined camber line in a pl'ane lof symmetry extending between the leading and trailing edges;

the distance between the canopy member and the lower member normal to the camber line land in the plane of symmetry continuously increasing at a first rate from the leading edge to a maximum intermediate the leading and trailing edges and thereafter decreasing at a second rate -to the trailing edge;

means extending between the inner peripheral edge :of the lower member and the canopy to maintain the air ifoil conguration when the parachute is deployed; and

a plurality |of suspension lines secured to the canopy at spaced angular positions disposed about the perimeter of the canopy for supporting a load.

2. The parachute assembly of claim 1 wherein the means for maintaining the air foil configuration further comprises gusset-like ribs, one end of which is connected to the lower member and the other end of which is oonnected to the load bearing suspension lines.

3. The parachute assembly of claim 1 wherein the canopy further comprises at least one extension projecting therefrom rfor providing directional stability along the glide path ofthe parachute.

4. The parachute assembly iof claim 3 wherein the ex-Y tension has a tubular iin-like configuration and is initiated by the ram pressure inside the canopy.

5. The parachute assembly of claim 1 wherein the canopy member further comprises at least one vent formed therein to control the movement Kof the parachute along its glide path.

6. The parachute assembly of claim 5 wherein the canopy has at least a pair of vents formed therein to control the movement of the parachute -along its glide path;

each of the vents having la cowl associated therewith;

land

a corresponding pair of control lines attached to respective ones of the oowls to control the passage of air through the vents thereby controlling the movement of the parachute along its glide path.

7. "Bhe parachute assembly of claim 1 wherein the canopy further comprises at least a pair of pockets attached thereto at diametrically yopposite positions and opening in the Adirection of movement of the parachute to control the movement lort the parachute along its glide path.

8. The parachute assembly of claim 7 further including a -pair of [control lines attached to respective ones Of the pockets to control :the amount of opening of the pockets.

References Cited in the file of this patent UNITED STATES PATENTS 1,270,419 Kendig June 25, 1918 1,780,190 Hoffman Nov. 4, 1930 2,318,674 Coleman May 11, 1943 2,562,799 Kowalski July 31, 1951 2,804,276 Hutson Aug. 27, 1957 2,941,765 Feldman June 21, 1960 2,993,668 Gold July 25, 1961 3,013,753 Hughes et al. Dec. 19, 1961 FOREIGN PATENTS 144,792 Great Britain yJune 17, l1920 585,513 France Dec. 10, 1924 240,341 Switzerland Apr. 16, 1946 9,948 Germany Aug. 21, 1956 756,139 Great Britain Aug. 29, 1956 OTHER REFERENCES Aviation Week Magazine, pages 57, 59, 63, Sept. 19, 1960.

Claims

1. A DEPLOYABLE GLIDE PARACHUTE ASSEMBLY COMPRISING: AN UPPER FLEXIBLE INFLATED CANOPY MEMBER HAVING A CIRCUMFERENTIAL EDGE; A LOWER, DISH SHAPED MEMBER, PARTIALLY ENCLOSING THE UNDERSIDE OF THE CANOPY MEMBER, HAVING AN INNER PERIPHERAL EDGE DEFINING AN APERTURE AND HAVING AN OUTER PERIPHERAL EDGE ATTACHED TO THE CIRCUMFERENTIAL EDGE OF THE CANOPY MEMBER; WHEN DEPLOYED, THE PARACHUTE ASSEMBLY GENERATING AN AIR FOIL CONFIGURATION WITH LEADING AND TRAILING EDGES HAVING A PREDETERMINED CAMBER LINE IN A PLANE OF SYMMETRY EXTENDING BETWEEN THE LEADING AND TRAILING EDGES; THE DISTANCE BETWEEN THE CANOPY MEMBER AND THE LOWER MEMBER NORMAL TO THE CAMBER LINE AND IN THE PLANE OF SYMMETRY CONTINUOUSLY INCREASING AT A FIRST RATE FROM THE LEADING EDGE TO A MAXIMUM INTERMEDIATE THE LEADING AND TRAILING EDGES AND THEREAFTER DECREASING AT A SECOND RATE TO THE TRAILING EDGE; MEANS EXTENDING BETWEEN THE INNER PERIPHERAL EDGE OF THE LOWER MEMBER AND THE CANOPY TO MAINTAIN THE AIR FOIL CONFIGURATION WHEN THE PARACHUTE IS DEPLOYED; AND A PLURALITY OF SUSPENSION LINES SECURED TO THE CANOPY AT SPACED ANGULAR POSITIONS DISPOSED ABOUT THE PERIMETER OF THE CANOPY FOR SUPPORTING A LOAD.