Heavy payload parachute ground disconnecting device
The present invention relates to a heavy payload parachute ground disconnecting device. The device comprises an actuator for keeping a holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when a force acting on the actuator is below a predetermined threshold. A latch mechanism releases a link assembly connected to the payload when itself being released from the holding mechanism. In the holding position the latch mechanism transfers a predetermined portion of a payload force for acting on the actuator within an operational range of the same. The device is highly advantageous by providing a simple, yet highly flexible, design for numerous payload ranges.
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This application claims benefit from U.S. Provisional Patent Application No. 60/723,437 filed Oct. 5, 2005 the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates generally to the field of parachute accessories, and in particular to a device for automatically disconnecting a heavy parachuted payload from a parachute upon landing.
BACKGROUND OF THE INVENTIONIn parachuting a payload from an airplane it is important that the parachuted payload is securely connected to the parachute during descent. It is also important that the payload is spontaneously disconnected from the parachute upon landing. Unless the payload is spontaneously disconnected from the parachute upon landing there is an unacceptable high risk that the payload is dragged by winds engaging the parachute, making retrieval of the parachuted payload extremely difficult and dangerous, if not impossible. Furthermore, there is a significant danger that the parachuted payload is toppled over while being dragged resulting in damage or loss of the parachuted payload such as a vehicle.
Several parachute ground disconnecting devices have been developed for automatically disconnecting a parachuted load upon landing. Such devices are designed as a coupler between the parachute and the payload for safely connecting the payload to the parachute during descent. Upon landing a payload weight dependent force acting on the parachute ground disconnecting device decreases and the device opens allowing disconnection of the payload form the parachute.
However, when designing a parachute ground disconnecting device there is a significant problem to overcome. In the first few seconds after parachute deployment transient parachute inflation phenomena generate substantial oscillations of the payload weight dependent force—or tension—acting on the parachute ground disconnecting device. Lowering the Release Load Percentage (RLP)—the ratio of the tension at the instant of disconnection to the tension during steady descent—to, for example, below 25% results in the parachute ground disconnecting device not spontaneously disconnecting upon landing, or not disconnecting at all when the parachute is caught by high winds. On the other hand, increasing the RLP to, for example, 40% to ensure spontaneous disconnecting upon landing, results in an unacceptable high risk of disconnection while the payload is still airborne.
This problem has been successfully overcome by the parachute ground disconnecting device disclosed in U.S. Pat. No. 5,687,931. Here, the parachute ground disconnecting device is kept in a locked position by a timer for a predetermined time interval during the initial portion of deployment, i.e. during the time period of the parachute inflation. After elapse of the predetermined time interval the device is set to disconnect when the tension is below a predetermined threshold or RLP. A version—GD500—operable in a payload range between 75 lbs and 500 lbs of this parachute ground disconnecting device has been successfully employed in numerous applications and under various—extreme—conditions. The GD500 has proven to be a simply operable and highly reliable parachute ground disconnecting device.
It would be advantageous to satisfy an increasing need for providing a simply operable and highly reliable parachute ground disconnecting device for heavy payload ranges between 2,000 lbs and 10,000 lbs and, ultimately, for payloads greater than 60,000 lbs.
SUMMARY OF THE INVENTIONIt is, therefore, an object of the invention to provide a parachute ground disconnecting device for heavy payloads that is simply operable and highly reliable.
It is further an object of the invention to employ the proven GD500 in the heavy payload parachute ground disconnecting device as actuator.
It is yet further an object of the invention to provide a heavy payload parachute ground disconnecting device that is simple to manufacture.
In accordance with the present invention there is provided a parachute ground disconnecting device for disconnecting a parachuted payload from a parachute upon landing comprising:
- a supporting structure comprising:
- a connecting mechanism for connecting the same to one of the parachute and the payload;
- a passage disposed such that, in a holding position, accommodation therein of a link assembly for connecting the supporting structure to one of the parachute and the payload is enabled and such that disengagement of the link assembly from the supporting structure is enabled for disconnecting the payload from the parachute;
- an actuator mounted at a first end to the supporting structure and comprising a holding mechanism at a second opposite end, the first end and the second end a predetermined variable distance therebetween, the distance being variable between a minimum and a maximum value in dependence upon a force acting on the actuator along its longitudinal axis, the actuator for keeping the holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when the force acting on the actuator is below a predetermined threshold; and,
- a latch mechanism pivotally movable mounted to the supporting structure and having an interacting structure for being accommodated in the holding mechanism, in the holding position a pivot of the latch mechanism and the interacting structure being disposed on opposite sides of the passage, the latch mechanism for retaining the link assembly in the holding position and for transferring a predetermined portion of a payload force for acting on the actuator within an operational range of the same, the latch mechanism being movable such that the predetermined distance varies in dependence upon the predetermined portion of the payload force and such that the same is moved into an open position by the link assembly upon release of the interacting structure from the holding mechanism.
In accordance with the present invention there is further provided a parachute ground disconnecting device for disconnecting a parachuted payload from a parachute upon landing comprising:
- a supporting structure comprising:
- a connecting mechanism for connecting the same to one of the parachute and the payload;
- a passage disposed such that, in a holding position, accommodation therein of a link assembly for connecting the supporting structure to one of the parachute and the payload is enabled and such that disengagement of the link assembly from the supporting structure is enabled for disconnecting the payload from the parachute;
- a mounting structure for mounting an actuator, the actuator for being mounted at a first end to the supporting structure and comprising a holding mechanism at a second opposite end, the first end and the second end having a predetermined variable distance therebetween, the distance being variable between a minimum and a maximum value in dependence upon a force acting on the actuator along its longitudinal axis, the actuator for keeping the holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when the force acting on the actuator is below a predetermined threshold; and,
- a latch mechanism pivotally movable mounted to the supporting structure and having an interacting structure for being accommodated in a holding mechanism of the actuator, in the holding position a pivot of the latch mechanism and the interacting structure being disposed on opposite sides of the passage, the latch mechanism for retaining the link assembly in the holding position and for transferring a predetermined portion of a payload force for acting on the actuator within an operational range of the same, the latch mechanism being movable such that the predetermined distance varies in dependence upon the predetermined portion of the payload force and such that the same is moved into an open position by the link assembly upon release of the interacting structure from the holding mechanism.
In accordance with the present invention there is yet further provided a parachute ground disconnecting device for disconnecting a parachuted payload from a parachute upon landing comprising:
- a supporting structure comprising:
- a connecting mechanism for connecting the same to one of the parachute and the payload;
- a passage disposed such that, in a holding position, accommodation therein of a link assembly for connecting the supporting structure to one of the parachute and the payload is enabled and such that disengagement of the link assembly from the supporting structure is enabled for disconnecting the payload from the parachute;
- an actuator mounted at a first end to the supporting structure and comprising a holding mechanism at a second opposite end, the first end and the second end having a predetermined variable distance therebetween, the distance being variable between a minimum and a maximum value in dependence upon a force acting on the actuator along its longitudinal axis, the actuator for keeping the holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when the force acting on the actuator is below a predetermined threshold; and,
- a latch mechanism comprising:
- a first lever pivotally movable mounted to the supporting structure at a first end and having a first interacting surface at a second opposite end, in the holding position the first lever being disposed such that the first end and the second end are located on opposite sides of the passage;
- a second lever pivotally movable mounted to the supporting structure at a first end and having at a second opposite end an interacting structure for being accommodated in the holding mechanism, the second lever having a second interacting surface disposed between the first end and the second end, the second interacting surface for interacting with the first interacting surface in the holding position;
- the latch mechanism for retaining the link assembly in the holding position and for transferring a predetermined portion of a payload force for acting on the actuator within an operational range of the same, the first and the second lever of the latch mechanism being movable such that the predetermined distance varies in dependence upon the predetermined portion of the payload force and such that the first and the second lever are moved into an open position by the link assembly upon release of the interacting structure from the holding mechanism.
Exemplary embodiments of the invention will now be described in conjunction with the following drawings, in which:
FIGS. 7 to 9 are simplified block diagrams illustrating a cross-sectional view of a third, fourth, and fifth embodiment of the heavy payload parachute ground disconnecting device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION Referring to
The actuator 102 keeps the holding mechanism 128 in a locked position, as shown in
The first lever 112 of the latch mechanism retains the link assembly 110 in the holding position, as shown in
In operation, the link assembly 110 is retained in the holding position by the indentation 118 of the first lever 112 and the end portion of the passage 108. During the first portion of the descent, the holding mechanism 128 of the actuator 102 is locked for a predetermined time interval set using timer 150 and covering the time span of parachute inflation. After elapse of the predetermined time interval—during steady descent—the holding mechanism 128 is unlocked. During the phase of steady descent the latch mechanism is approximately in position I resulting in a maximum value of the distance DA. Upon landing the payload force FP is decreasing resulting in a movement from position I to position II corresponding to a minimum value of the distance DA. When the distance DA reaches the minimum value—which corresponds to the RLP—the holding mechanism 128 opens and releases the interacting structure 126, as shown in
Referring to
In the preferred embodiment the support structure 104 comprises two support plates 104A and 104B mounted together in parallel and having a predetermined distance therebetween, as shown in the perspective view of
It is noted that the various components of the heavy payload parachute ground disconnecting device 100 are designed to withstand 4G forces—encountered during the parachute inflation.
The two-lever design of the heavy payload parachute ground disconnecting device 100 is highly advantageous by providing a relatively simple, yet highly flexible design for various payload ranges. Referring to
FD=FP×D1/D2 (1)
wherein D1 is a distance between a center of the pivot 114 and a center of the link assembly 110, and D2 is a distance between the center of the pivot 114 and the interacting point D. The force FD is transmitted at the interaction point D to the second interacting surface 120 of the second lever 122. Having regard to
FE=FD×D3/D4 (2)
wherein D3 is a distance between a center of the pivot 124 and interacting point D, and D4 is a distance between the center of the pivot 124 and a center of the interacting structure 126. The force FE is acting in vertical direction, as shown in
FA=FE×cos γ (3)
wherein γ is the angle between the line 142 and the vertical y-axis. Combining equations (1), (2), and (3) results in equation (4) describing the tension FA acting on the actuator 102 in dependence upon the payload force FP as follows:
FA=FP×D1/D2×D3/D4×cos γ. (4)
As is evident from equation (4) the design of the heavy payload parachute ground disconnecting device 100 is easily adaptable to a wide range of payloads. For example, it enables use of the GD 500 parachute disconnecting device as actuator by transforming a payload force FP in a range between 2,000 lbs to 10,000 lbs into a tension FA in a range between 75 lbs and 500 lbs, but is not limited thereto. Varying the ratios D1/D2 and D3/D4 enables design of the heavy load parachute ground disconnecting devices in various payload ranges above 10,000 lbs with ultimate payload range above 60,000 lbs. It is noted, that in order to minimize the size of the device 100 it is preferred to minimize D1 in equation (4), since there are limits to minimizing D3 in order to enable the first lever 112 to pass the second lever 122 during opening. Due to a given size of the link assembly 110 and the bolt of pivot 114 it is likely that a bent channel portion needs to be incorporated into the passage 108 to minimize D1, as shown in
Optionally, a further payload reduction is achieved by retaining, in the holding position, the link assembly 110 using the first lever 112 as well as the surface of the end portion of the passage 108, i.e. the payload force FP is distributed between the first lever 112 and the supporting structure 104 substantially depending on an angle between a contact surface of the passage 108 and a vertical y-axis. However, this embodiment is not preferred since it is difficult to ensure proper distribution of the payload force FP, which is also likely to change with time due to wear of the contact surface of the passage 108. Further, to reduce the wear of the contact surface of the passage 108 it is likely that the supporting structure 104 needs to be made of heat treated steel.
In one application, the heavy payload parachute ground disconnecting device 100 has been designed for transforming a payload range between 2,000 lbs to 10,000 lbs into a tension FA range between 75 lbs and 500 lbs for use of the GD 500 as actuator. A RLP range of the heavy load parachute ground disconnecting device 100 has been set to be between 18% and 28% of any payload in the range between 2,000 lbs to 10,000 lbs, i.e. the device 100 may disconnect at 28% of the payload and must disconnect when the payload force FP is reduced to 18% of the payload. The GD 500 allows presetting of different RLPs by the manufacturer. Further, the levers of the heavy payload parachute ground disconnecting device 100 have been designed to vary the distance DA of the actuator 102 between a maximum value of 0.375″ and a minimum value of 0.125″ as specified for the GD 500. As is evident, the design of the heavy payload parachute ground disconnecting device 100 is easily adaptable to accommodate different payload ranges, different tension FA, and values for the distance DA.
The heavy payload parachute ground disconnecting device 100 is easily rigged using, for example, the following procedure:
-
- inserting an end loop of a parachute in the connecting mechanism 106 and securing the bolt of the connecting mechanism 106;
- inserting an end loop of a payload in the link assembly 110 and securing the bolt of the link assembly 110;
- securing the actuator 102 to the support structure 104 using a bolt as pivot 130 and securing the same;
- setting the time interval by adjusting the timer 150 of the actuator 102;
- opening the first lever 112 and the second lever 122 and moving the bolt of the link assembly 110 through the passage into the holding position;
- moving the first lever 112 and the second lever 122 into the holding position; and
- locking the interacting structure 126 by closing the holding mechanism 128 of the actuator.
Referring to
Referring to
Referring to
Referring to
The heavy payload parachute ground disconnecting device and its various embodiments are highly advantageous by providing a simple, yet highly flexible, design for numerous payload ranges. Furthermore, incorporation of the GD 500 provides a heavy payload parachute ground disconnecting device based on proven and reliable technology.
Numerous other embodiments of the invention will be apparent to persons skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims
1. A parachute ground disconnecting device for disconnecting a parachuted payload from a parachute upon landing comprising:
- a supporting structure comprising: a connecting mechanism for connecting the same to one of the parachute and the payload; a passage disposed such that, in a holding position, accommodation therein of a link assembly for connecting the supporting structure to one of the parachute and the payload is enabled and such that disengagement of the link assembly from the supporting structure is enabled for disconnecting the payload from the parachute;
- an actuator mounted at a first end to the supporting structure and comprising a holding mechanism at a second opposite end, the first end and the second end having a predetermined variable distance therebetween, the distance being variable between a minimum and a maximum value in dependence upon a force acting on the actuator along its longitudinal axis, the actuator for keeping the holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when the force acting on the actuator is below a predetermined threshold; and,
- a latch mechanism pivotally movable mounted to the supporting structure and having an interacting structure for being accommodated in the holding mechanism, in the holding position a pivot of the latch mechanism and the interacting structure being disposed on opposite sides of the passage, the latch mechanism for retaining the link assembly in the holding position and for transferring a predetermined portion of a payload force for acting on the actuator within an operational range of the same, the latch mechanism being movable such that the predetermined distance varies in dependence upon the predetermined portion of the payload force and such that the same is moved into an open position by the link assembly upon release of the interacting structure from the holding mechanism.
2. A parachute ground disconnecting device as defined in claim 1 wherein the latch mechanism comprises a single lever mounted to the supporting structure at a first end and having the interacting structure at a second opposite end.
3. A parachute ground disconnecting device as defined in claim 1 wherein the latch mechanism comprises two interacting levers.
4. A parachute ground disconnecting device for disconnecting a parachuted payload from a parachute upon landing comprising:
- a supporting structure comprising: a connecting mechanism for connecting the same to one of the parachute and the payload; a passage disposed such that, in a holding position, accommodation therein of a link assembly for connecting the supporting structure to one of the parachute and the payload is enabled and such that disengagement of the link assembly from the supporting structure is enabled for disconnecting the payload from the parachute; a mounting structure for mounting an actuator, the actuator for being mounted at a first end to the supporting structure and comprising a holding mechanism at a second opposite end, the first end and the second end having a predetermined variable distance therebetween, the distance being variable between a minimum and a maximum value in dependence upon a force acting on the actuator along its longitudinal axis, the actuator for keeping the holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when the force acting on the actuator is below a predetermined threshold; and,
- a latch mechanism pivotally movable mounted to the supporting structure and having an interacting structure for being accommodated in a holding mechanism of the actuator, in the holding position a pivot of the latch mechanism and the interacting structure being disposed on opposite sides of the passage, the latch mechanism for retaining the link assembly in the holding position and for transferring a predetermined portion of a payload force for acting on the actuator within an operational range of the same, the latch mechanism being movable such that the predetermined distance varies in dependence upon the predetermined portion of the payload force and such that the same is moved into an open position by the link assembly upon release of the interacting structure from the holding mechanism.
5. A parachute ground disconnecting device as defined in claim 4 wherein the latch mechanism comprises a single lever mounted to the supporting structure at a first end and having the interacting structure at a second opposite end.
6. A parachute ground disconnecting device as defined in claim 4 wherein the latch mechanism comprises a two interacting levers.
7. A parachute ground disconnecting device as defined in claim 6 wherein the latch mechanism comprises:
- a first lever pivotally movable mounted to the supporting structure at a first end and having a first interacting surface at a second opposite end, in the holding position the first lever being disposed such that the first end and the second end are located on opposite sides of the passage; and,
- a second lever pivotally movable mounted to the supporting structure at a first end and having at a second opposite end an interacting structure for being accommodated in the holding mechanism, the second lever having a second interacting surface disposed between the first end and the second end, the second interacting surface for interacting with the first interacting surface in the holding position;
8. A parachute ground disconnecting device for disconnecting a parachuted payload from a parachute upon landing comprising:
- a supporting structure comprising: a connecting mechanism for connecting the same to one of the parachute and the payload; a passage disposed such that, in a holding position, accommodation therein of a link assembly for connecting the supporting structure to one of the parachute and the payload is enabled and such that disengagement of the link assembly from the supporting structure is enabled for disconnecting the payload from the parachute;
- an actuator mounted at a first end to the supporting structure and comprising a holding mechanism at a second opposite end, the first end and the second end having a predetermined variable distance therebetween, the distance being variable between a minimum and a maximum value in dependence upon a force acting on the actuator along its longitudinal axis, the actuator for keeping the holding mechanism in a locked position during a predetermined time interval and after elapse of the predetermined time interval for releasing the holding mechanism when the force acting on the actuator is below a predetermined threshold; and,
- a latch mechanism comprising: a first lever pivotally movable mounted to the supporting structure at a first end and having a first interacting surface at a second opposite end, in the holding position the first lever being disposed such that the first end and the second end are located on opposite sides of the passage; a second lever pivotally movable mounted to the supporting structure at a first end and having at a second opposite end an interacting structure for being accommodated in the holding mechanism, the second lever having a second interacting surface disposed between the first end and the second end, the second interacting surface for interacting with the first interacting surface in the holding position;
- the latch mechanism for retaining the link assembly in the holding position and for transferring a predetermined portion of a payload force for acting on the actuator within an operational range of the same, the first and the second lever of the latch mechanism being movable such that the predetermined distance varies in dependence upon the predetermined portion of the payload force and such that the first and the second lever are moved into an open position by the link assembly upon release of the interacting structure from the holding mechanism.
9. A parachute ground disconnecting device as defined in claim 8 wherein the actuator is pivotally movable.
10. A parachute ground disconnecting device as defined in claim 8 wherein the passage comprises a substantially straight channel oriented substantially parallel to a line connecting the connecting mechanism and the link assembly in the holding position.
11. A parachute ground disconnecting device as defined in claim 10 wherein the channel comprises an angled portion.
12. A parachute ground disconnecting device as defined in claim 8 wherein the first lever comprises an indentation for retaining a portion of the link assembly therein.
13. A parachute ground disconnecting device as defined in claim 12 wherein an end portion of the passage and the indentation substantially form a bore such that movement of the first lever between a position corresponding to a maximum value of the predetermined distance and a position corresponding to a minimum value of the predetermined distance is enabled and such that the link assembly is securely retained in the indentation during parachute inflation.
14. A parachute ground disconnecting device as defined in claim 8 wherein the first interacting surface is a curved surface having a predetermined radius.
15. A parachute ground disconnecting device as defined in claim 8 wherein the second surface is a flat surface oriented substantially perpendicular to the line connecting the connecting mechanism and the link assembly in the holding position.
16. A parachute ground disconnecting device as defined in claim 8 wherein the second lever comprises two parallel lever sections disposed at a predetermined distance and having the interacting structure and an interacting element interposed therebetween, the interacting element comprising the second interacting surface.
17. A parachute ground disconnecting device as defined in claim 16 wherein each of the two lever sections comprises a bore for separately mounting each of the two lever sections to the supporting structure.
18. A parachute ground disconnecting device as defined in claim 16 wherein a portion of the first lever comprising the first interacting surface has a width to fit between the two lever sections.
19. A parachute ground disconnecting device as defined in claim 8 wherein the support structure comprises two parallel plates mounted together having a predetermined distance therebetween.
20. A parachute ground disconnecting device as defined in claim 19 wherein the actuator and the latch mechanism are disposed between the two plates.
21. A parachute ground disconnecting device as defined in claim 8 comprising a first stop pin for stopping the first lever in an open position and a second stop pin for stopping the second lever in an open position.
22. A parachute ground disconnecting device as defined in claim 21 wherein the first lever and the second lever are spring loaded.
Type: Application
Filed: Oct 5, 2006
Publication Date: Apr 12, 2007
Applicant: Irvin Aerospace Canada Limited (Belleville)
Inventor: Nedeljko Miljic (Belleville)
Application Number: 11/543,099
International Classification: B64D 17/02 (20060101);