US3112091A - Automatic parachute-opening device - Google Patents

Description

Nov. 26, 1963 s. L. SNYDER 3,112,091

AUTOMATIC PARACHUTE-OPENING DEVICE Filed May 4, 1960 I5 Sheets-Sheet 1 I 5 3g 33 4O INVENTOR 'tepliemLs z lder Nov. 26, 1963 s. SNYDER 3,112,091

AUTOMATIC PARACHUTE-OPENING msvxcs Filed May 4, 1960 3 Sheets-Sheet 2 INVENTOR Nov. 26, 1963 s. 1.. SNYDER AUTOMATIC PARACHUTE-OPENING DEVICE 3 Sheets-Sheet 3 Filed May 4. 1960 um llil llllll United States Patent 3,112,091 AUTOMATIC PARACHUTE-OPENING DEVICE Stephen L. Snyder, Swarthmore, Pa. (3939 Lankenau Road, Philadelphia 31, Pa.) Filed May 4, 1960, Ser. No. 26,864 20 Claims. (Cl. 244-150) This invention relates to a device for manually or automatically opening a parachute at a predetermined altitude, and it more particularly relates to a simple and compact form of such a device which is conveniently adjustable to compensate for variations in atmospheric pressure and ground level.

The sport of sky diving has recently become quite popular and emphasized the need for a dependable and economical automatic parachute-opening device because inexperienced jumpers are prone to freeze and fail to pull the ripcord in the excitement of a drop, and even experienced sky divers have for unexplained reasons failed to release their chutes with disastrous results. One explanation I for the failure of experienced sky divers to pull the rip cord is hypnotism caused by the whirling motion during a fall, but for whatever reason they have not pulled the cord at the prescribed 2,000 foot minimum altitude, an accurate, economical and dependable automatic parachute-opening device would be a boon to them as well as to novices. Various automatic devices which are actuated by barometric pressure-sensing means have been proposed for automatically opening parachutes at predetermined altitudes. However, they are not adapted for convenient adjustment by the jumper himself to compensate for variations in ground level and atmospheric pressure, and they have been fairly bulky and complicated.

It is, therefore, an object of this invention to provide a compact, simple and economical device for automatically opening parachutes at predetermined altitudes.

Another object of this invention is to provide such a device which is readily adjustable by the jumper himself to compensate for variations in ground level and atmospheric pressure.

In accordance with this invention an extremely simple and dependable device for manually or automatically opening a parachute includes an automatically-actuable drive means mounted upon the parachute pack with its line of action disposed substantially parallel to the line of action of the ripcord pins and attached to the ripcord be tween the ripcord handle and the pins before it substantially deviates from the line of action of the pins. An altitude-sensing and signalling means is connected through an actuating circuit to the automatically-actuable drive means for causing it to open the parachute at a predetermined minimum altitude. The ripcord can also be manually pulled by the handle, and the aforementioned disposition of the drive means allows it to act directly upon the pins which minimizes the force required for absolutely dependable operation and the size and complexity of the drive means. The manually-pulled handle may, for example, be directly mounted upon the automatic drive for a front-mounted pack or connected to it for less accessible packs such as back-mounted packs.

A simple and economical altitude-sensing and signalling means for actuating the automatic drive means includes an altimeter having a visible movable altitude-indicating element and an associated visible reference element which is manually-adjustable to permit adjustment of the reference element to the ground level position of the movable element thereby compensating for atmospheric pressure variations. This device conveniently utilizes the structure of a standard barometric altimeter having a movable needle and an adjustable face with its signalling means including a switch having one of its contacts mounted in a predeice termined position relative to the face and the other of its contacts incorporated upon the needle.

Novel features and advantages of the present invention will become apparent to one skilled in the art from a reading of the following description in conjunction with the accompanying drawing wherein similar reference characters refer to similar parts and in which:

FIG. 1 is a top plan view of a parachute pack upon which one embodiment of this invention is mounted;

FIG. 2 is a rear view in elevation of the parachute pack and embodiment shown in FIG. 1;

FIG. 3 is a front view in elevation of the ripcordpulling portion of the embodiment shown in FIGS. 1 and 2;

FIG. 4 is a front view in elevation partially broken away in cross section of the portion shown in FIG. 1 in readiness for actuation;

FIG. 5 is a front view in elevation of the portion shown in FIG. 4 after it has been automatically actuated;

FIG. 6 is an enlarged cross-sectional view of the detonating portion of the embodiments shown in FIGS. 4 and 5;

FIG. 7 is a schematic diagram of electrical and mechanical elements of the altitude-sensing and signalling portion of the embodiment shown in FIG. 1 in the unarmed condition in its association with ripcord-pulling unit;

FIG. 8 is a plan view of the altitude-sensing and signalling portions shown in FIG. 7 in the armed condition;

FIG. 9 is a cross-sectional view taken through FIG. 8 along the line 9-9;

FIG. 10 is a side view in elevation of the embodiment shown in FIGS. 3-5;

FIG. 11 is a perspective view of a portion of the embodiment shown in FIG. 7; and

FIG. 12 is a schematic view of another embodiment of this invention.

In FIGS. 1 and 2 is shown an automatic parachuteopening device 10 mounted upon a parachute pack 12 which is, for example, of the emergency type used by a sky diver. An instrument panel 14 is mounted upon the portion of the pack facing the jumper, and an altimeter 16 and stop watch 18 are customarily mounted upon this panel to inform the jumper of his altitude and duration of fall. Altimeter 16 has a movable altitude-indicating element, such as a needle, and a reference element, such as a face, which is adjustable to zero it at ground level before ascent. This type of adjustability is provided in conventional altimetcrs, and an example of it is shown in US. Letters Patent 2,465,775. An aneroid barometer type of altimeter is described in FIG. 4 of US. Letters Patent No. 2,367,034. Hooks 19 extend from pack 12 to fasten it to the body of the jumper and straps 21 facilitate its transportation.

Parachute-opening device 10 includes an automaticallyactuated drive means 11 incorporating a hollow cylinder secured to ripcord handle 22. Special switching elements are generally designated in FIG. 1 by reference numeral 24, and they are associated with altimeter 16 and electric triggering circuit wires 26 which are connected by a readily detachable coupling plug and socket 28. Cylinder 20 is mounted within a standard unmodified pocket 30 attached to the cover of pack 12, and it is connected to ripcord 32 in a manner later described in detail for automatically pulling it and its parachute-securing pins 34 out of cones 36 to release securing buckles 38 and allow the parachute to be opened by elastic bands 40. An electric battery 42, later described in detail, is connected to triggering circuit wires 26, and it is conveniently secured by clamp 44 to the rear of altimeter 16.

FIGS. 35 show the details of cylinder 20 and its manner of association with ripcord handle 22 in various phases of operation together with the mode of connection a of ripcord handle 22 and actuating cylinder 20 with ripcord 32. FIG. 3 shows the overall association of these elements in the condition where they are ready for actuation either by manual or automatic means.

Ripcord handle 22 is secured to ripcord 32 by mounting it upon automatically-actuated drive means 11 as shown in FIGS. l5 or, as shown in FIG. 12 by connecting it to drive means 11a. The disposition of the drive means between the ripcord and handle at a location before it substantially deviates from the line of action of the pins causes it to act directly upon the pins and unexpcctedly simplifies its structure. Furthermore, this permits the remarkably convenient attachment of the handle to the drive means to provide a device which is alternatively manually or automatically actuated. In FIG. 12 handle 22a is connected to drive means 11a by a cable 23a which transmits a manual pull to pins 34a and disconnects electrical coupling 280.

Details of cylinder and its associated elements are shown in FIGS. 4 and 5 respectively in the ready and actuated conditions. In FIG. 4 piston is shown in its ready condition disposed adjacent explosive unit 52. It is. for example, inherently maintained in the ready position adjacent explosive unit 52 which is, for example, a commercially available igniting and detonating unit of the type shown in FIG. 6 which includes insulated igniting wires 56 extending through screw plug 58 into its hollow chamber 60. An explosive charge 62, for example, incorporating fast-burning powder is enclosed within chamber 60 by a sea] 64, for example, made of aluminum or a suitable plastic. A thin bridge wire 66 connects igniting wires 56 within chamber 60, and a bead primer 68 is attached to bridge wire 66 for helping initiate the detonation of powder charge 62. Various other forms of detonators and powder charges may be utilized for the illustrated purpose as well as spring-powered devices. However, illustrated unit 52 is highly convenient because of its compactness and ease of reloading.

In FIG. 5, piston 50 is shown in its extremity of ripcord-pulling travel after explosive unit 52 has released its gas charge. Piston 59 has, through ripcord cable 48 connected to it, withdrawn pins 34 from cones 36 thereby permitting buckles 38 to be released and permit the parachute to open. At its terminal extremity of travel one end of piston 50' has contacted elastic buffer 70 made of hard fibre which absorbs its remaining energy whose dissipation is facilitated by the connection of chamber 72 within cylinder 20 to atmospheric pressure through slot 74 which allows the expanding gases to dissipate into the air when the end 76 of piston 50 exposed to the gases uncovers slot 74. The end of ripcord cable 48 is conveniently connected in operative position to piston 50 by inserting it through a slanted aperture 77 in the side of piston 59 and securing its end 75 which is enlarged by attached ring 79 within a cavity 81 in the end of piston 50. This substantially straight mode of connection keeps piston 50 adjacent explosive unit 52 as long as pins 34 are inserted within cones 36. In FIG. 10 cable 48 is shown inclined at an angle to the vertical along the slot 74 which is turned toward the path of action of ripcord pins 34 to minimize frictional resistance. The base 49 of handle 22 is bent away from pack 12 to make it more accessible.

FIGS. 7-9 show details of actuating circuit 78 and interconnected portions of cylinder 20, altimeter 16 and various electrical switching elements which are now described in detail. Electrical circuit 78 includes wires 26 connecting battery 42, represented schematically in FIG. 7, with arming and switching element movably mounted adjacent altimeter face 82 and altimeter needle 84. \Vires 26 are connected through detachable coupling 28 in the previously described manner with explosive unit 52 fastened in the end of cylinder 20. These wires also connect battery 42 with a stationary contact 86 secured to altimeter face 82 through a wire 88 passing under face 82, and the other side of the circuit is connected through a grounding wire 9i) to the metal mechanism of altimeter 16- and through it to altimeter needle 84. Battery 42 is, for example, a mercury cell of the type providing 1.3 volts and 0.2 ampere. This type of cell is light and compact as well as having a long shelf life, and its aforementioned voltage and amperage are quite sutficient for igniting an explosive unit 52 incorporating an igniter and detonator of the type described which consistently detonates when actuated by the aforementioned voltage and current.

Switching and signalling element 80 is, for example, sector shaped and pivoted concentrically with needle 84 and attached to a manually-operable knob 92. It includes a foot 94 which is engagcable as shown in FIG. 9 under stationary spring contact 86 to arm the triggering circuit. The armed" condition is indicated as shown in FIG. 8 to the parachute jumper by display of the Word armed" through elongated slot 98 in switching element 80 when foot 9 4 is engaged under spring contact 86. The off" position is shown in FIG. 7 Where foot 94 is engaged under spring clip 87 which is for convenience made similar in structure to contact 86 although it has no electrical function. These structures are shown in detail in FIG. 11 which shows dual spring fingers 89 and 91 which respectively engage the fiat of foot 94 and the space 93 between split toes 95 and 97. This structure insures firm engagement and electrical contact. A contact is mounted in the form of a pin extending from the surface of switching element 80 adjacent altimeter face 82 in the path of movement of altimeter needle 84. Contact I09 is arranged to be engaged by needle 84 at the onethousand foot altitude when foot 94 is engaged with fixed Contact 86-. This detonates explosive unit 52 to automatically open the parachute at the one-thousand foot altitude if it has not been opened sooner by a manual pull of the ripcord. A manual pull of the ripcord disarms the triggering circuit 78 by the opening of wire coupling 28 to prevent explosion of the charge after the ripcord has been manually pulled.

Operation At the ground level switching element 80 is maintained in the unarmed position shown in FIG. 7 providing an open triggering circuit 78, and the altimeter face is zeroed through knob 102 shown in FIG. 1 and actuating gears 104 and 106 shown in FIG. 7 to cause needle 84 to indicate a zero altitude at ground level regardless of the atmospheric pressure on a given day. This sets the contact on the sector when moved to the armed position at a point which will be contacted by the needle at the exact altitude to which it is set, and it insures that the parachute will open consistently at the one-thousand foot altitude above starting ground level regardless of the existing atmospheric pressure on the day of the jump.

After the jumper has reached an altitude above the one-thousand foot level and there is no danger of premature detonation, switching element 80 is moved from the Off" position shown in FIG. 7 to the Armed position shown in FIG. 8 to complete the triggering circuit. This condition of readiness is indicated to the jumper by display of the word Armed through slot 98 as shown in FIG. 8, and security in the Otf" position is demonstrated when the word Off is visible along the side of the sector as shown in FIG. 7.

On the way down the jumper should pull the ripcord at two thousand feet; however, if for some reason he fails to do so, the chute will be automatically opened at one thousand feet in the manner previously described when needle 34 engages contact 100 on the underside of switch 80 as shown in FIG. 8 to complete the triggering circuit and detonate the charge.

What is claimed is:

l. A device for opening a parachute pack secured by pins attached to a ripcord and inserted into cones comprising an electrically-actuated drive means including a movable clement mounted within a stationary portion, an altitudesensing means for providing a signal at a predetermined altitude, an actuating circuit connecting said sensing means to said drive means for causing it to propel said movable element in response to said signal, coupling means connecting said movable element with said ripcord to permit said ripcord to be pulled, pocket means upon said pack having an opening disposed in a position remote from said cones, said pocket means being substantially closed in a position adjacent said cones for securing said drive means against movement towards said cones, said pocket means being mounted upon a portion of said pack closely adjacent to said pins with a line of action extending through said opening aligned with the line of action of said pins, said drive means being inserted within said pocket which disposes its line of action in line with that of said pins with said opening in said pocket, and a handle being directly connected to said stationary portion of said drive means to permit said ripcord to be manually pulled through said coupling which connects said movable element of said drive means to said ripcord.

2. A device as set forth in claim 1 wherein said drive means is disposed immediately adjacent said pin means, and said handle is connected to said stationary portion of said drive means by a cable.

3. A device as set forth in claim 1 wherein said handle is rigidly mounted upon said stationary portion of said drive means.

4. A device as set forth in claim 1 wherein said drive means includes a piston disposed within a cylinder, and coupling means connects said piston to said ripcord.

5. A device as set forth in claim 4 wherein said coupling means is a portion of said ripcord which connects said piston to said pin means.

6. A device as set forth in claim 4 wherein an explosive means is attached to the end of said cylinder remote from said handle.

7. A device as set forth in claim 6 wherein a longitudinal slot extends through the side of said cylinder along the path of travel of said piston, and said coupling means extends through said slot from said piston to said ripcord.

8. A device as set forth in claim 6 wherein a longitudinal slot extends through the side of said cylinder along the terminal portion of travel of said piston, and said slot being slightly longer than said piston to exhaust said cylinder to the atmosphere at the terminal portion of travel of said piston for minimizing the shock of said piston when it impinges upon the terminal end of said cylinder.

9. A device as set forth in claim 3 wherein said drive means includes a piston disposed within a cylinder, an explosive means is attached to the end of said cylinder, igniting wires are connected to said explosive means, and a detachable coupling is inserted within said igniting wires for disconnecting said igniting wires from said explosive means to disarm said drive means when said handle is manually pulled.

it). A device as set forth in claim 3 wherein said connected handle and drive means are both installed within said pocket.

11. A device as set forth in claim 7 wherein said handle is mounted upon said cylinder, and said longitudinal slot is substantially aligned with a plane including said ripcord and the longitudinal centerline of said cylinder to minimize the frictional resistance imposed upon said coupling means.

12. A device for opening a parachute pack secured by pins attached to a ripcord comprising an automaticallyactuable drive means having movable and stationary portions, an altitude-sensing means for providing a signal at a predetermined altitude, an actuating circuit connecting said sensing means to said drive means for causing it to operate at a predetermined altitude, coupling means connecting a movable portion of said drive means with said ripcord for pulling said cord, a handle being connected to said automatically-actuable drive means to permit said ripcord to be manually pulled, pocket means upon said pack having an opening disposed in a position remote from said cones, said pocket means being substantially closed in a position adjacent said cones for securing said drive means against movement towards said cones, said pocket means being mounted upon a portion of said pack closely adjacent to said pins with a line of action extending through said opening aligned with the line of action of said pins, said drive means being inserted within said pocket which disposes its line of action in line with that of said pins and with said opening in said pocket, a detachable coupling being connected in said actuating circuit, one end of said detachable coupling being connected to said automatically-actuable drive means, and the other end of said detachable coupling attached to said pack for disarming said circuit when said ripcord is manually pulled.

13. An automatic device for opening a parachute at a predetermined altitude comprising drive means for providing an electrically-actuated thrust, an altimeter means incorporating a visible movable altitude-indicating element and an associated direct-reading visible reference element arranged to directly denote altitude in cooperation with each other, manually-adjustable means connected to said reference element for adjusting it with reference to the ground level position of said movable element to indicate a zero altitude at ground level, signalling means mounted upon said reference element for providing a signal when said moving element assumes a predetermined relationship with said reference element at said predetermined altitude, and an actuating circuit connecting said signalling means with said drive means for causing it to provide a parachute pack opening thrust at said predetermined altitude.

14. An automatic device for electrically actuating a power-operated parachute-opening drive means to open a parachute at a predetermined altitude comprising an altimeter incorporating a movable indicating element and an adjustable face which cooperate to directly denote altitude to a viewer, manually-adjustable means connected to said adjustable face for adjusting it with reference to said indicating element at ground level to indicate a zero altitude at ground level, an actuating means connecting said movable indicating element with said drive means for actuating said drive means to provide a parachuteopening thrust at said predetermined altitude, said actuating means including a switch means having one of its contacts mounted upon said movable indicating element and the other of its contacts mounted upon said face in a disposition relative to said face to be engaged by said one contact upon said needle at a predetermined position corresponding to said predetermined altitude, said actuating means including an actuating circuit connecting said switch means with said drive means, and an arming means operativcly connected with said actuating means for inactivating it until said indicating element moves upwardly past said predetermined position and for activating said actuating means upon the downward movement of said movable indicating element to said predetermined position whereby said actuating circuit is completed when said one of said contacts upon said movable indicating element is engaged with said other of said contacts.

15. A device as set forth in claim 14 wherein said movable indicating element comprises a needle, a movable sector is concentrically mounted about said needle, said other contact means which is mounted in a predetermined position relative to said face is mounted upon said sector, and said arming means comprises a stationary energized contact means which is engageable by a portion of said sector.

16. A device as set forth in claim 15 wherein said actuating circuit is grounded to a conductive portion of the mechanism of said altimeter for electrically connecting it to said needle.

17. A device as set forth in claim 15 wherein said sector is made of conductive material, said sector includes a foot which engages said energizing contact to arm said actuating circuit, and a pin extends from said sector toward said face for engaging said needle.

18. A device as set forth in claim 17 wherein a radially directed slot is provided in said sector for providing a visual indication of the portion of said face with which it is aligned when said foot is engaged with said energizing contact, and indicia are provided upon said face in line with said slot for indicating the armed condition.

19. A device as set forth in claim 17 wherein a clamp is provided for holding said sector out of engagement with said energizing contact.

20. A device as set forth in claim 19 wherein said clamp and said energizing contact comprise dual spring fingers, and said foot includes spaced toes which interlock with one of said fingers upon said clamp and energizing contact means.

References Cited in the file of this patent UNITED STATES PATENTS McCabe Jan. 9, White Mar. 29, McCabe May 3, Ogden et al. Apr. 18, Quilter May 2, Johnson June 5, Hatfield Apr. 27, Gaylord May 1, Moy et al. July 28,

FOREIGN PATENTS France Dec. 29, France Apr. 1, France July 28,

Claims (1)

1. A DEVICE FOR OPENING A PARACHUTE PACK SECURED BY PINS ATTACHED TO A RIPCORD AND INSERTED INTO CONES COMPRISING AN ELECTRICALLY-ACTUATED DRIVE MEANS INCLUDING A MOVABLE ELEMENT MOUNTED WITHIN A STATIONARY PORTION, AN ALTITUDE-SENSING MEANS FOR PROVIDING A SIGNAL AT A PREDETERMINED ALTITUDE, AN ACTUATING CIRCUIT CONNECTING SAID SENSING MEANS TO SAID DRIVE MEANS FOR CAUSING IT TO PROPEL SAID MOVABLE ELEMENT IN RESPONSE TO SAID SIGNAL, COUPLING MEANS CONNECTING SAID MOVABLE ELEMENT WITH SAID RIPCORD TO PERMIT SAID RIPCORD TO BE PULLED, POCKET MEANS UPON SAID PACK HAVING AN OPENING DISPOSED IN A POSITION REMOTE FROM SAID CONES, SAID POCKET MEANS BEING SUBSTANTIALLY CLOSED IN A POSITION ADJACENT SAID CONES FOR SECURING SAID DRIVE MEANS AGAINST MOVEMENT TOWARDS SAID CONES, SAID POCKET MEANS BEING MOUNTED UPON A PORTION OF SAID PACK CLOSELY ADJACENT TO SAID PINS WITH A LINE OF ACTION EXTENDING THROUGH SAID OPENING ALIGNED WITH THE LINE OF ACTION OF SAID PINS, SAID DRIVE MEANS BEING INSERTED WITHIN SAID POCKET WHICH DISPOSES ITS LINE OF ACTION IN LINE WITH THAT OF SAID PINS WITH SAID OPENING IN SAID POCKET, AND A HANDLE BEING DIRECTLY CONNECTED TO SAID STATIONARY PORTION OF SAID DRIVE MEANS TO PERMIT SAID RIPCORD TO BE MANUALLY PULLED THROUGH SAID COUPLING WHICH CONNECTS SAID MOVABLE ELEMENT OF SAID DRIVE MEANS TO SAID RIPCORD.

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