GB1594443A

GB1594443A - Helicoptercarried rescue apparatus

Info

Publication number: GB1594443A
Application number: GB971278A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-03-11
Filing date: 1978-03-11
Publication date: 1981-07-30

Description

(54) HELICOPTER-CARRIED RESCUE APPARATUS (71) I, HARUTO OKUNIURA, a Japanese citizen of No. 1315 Oh-aza Shikatebukuro, Urawa City, Saitama prefecture, Japan. do hereby declare the invention, for which I pray that a patent may be granted to me and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to a lifesaving apparatus adapted to save lives at sites that are difficult of prompt access by ships, boats or ordinary land vehicles. More particularly, the invention is concerned with a helicopter-carried rescue apparatus which is operable as means to save shipwrecked survivors, survivors of ditched aircraft, flood victims, endangered occupants of buildings on fire, people and animals in snow storms, injured mountain climbers and so on.

Helicopters are frequently utilized to practice search and rescue works at seas, in mountains and at various other sites which are difficult of prompt access by ships, boats and ordinary land vehicles. Because, however, of the limited capabilities of conventional helicopter-carried lifesaving equipment, the search and rescue operations conducted by helicopters have been directed at search activities rather than rescue works at sites and, furthermore, the accommodation of a single piece of lifesaving equipment has been limited to an extremely small number of peop)e,say, a few persons at the most. When, on the other hand, a helicopter is in operation to rescue endangered occupants of a building on fire or mountain climbers in impending danger, the helicopter is often subjected to turbulent ascending currents of air above the building or to anabatic and katabatic winds blowing above the site in the mountain. Due to such irregular movements of air, the helicopter attempting to pick up the endangered people is compelled to stay aloft or could not approach the scene withoutout running the danger of crashing. In spite of these problems encountered in lifesaving operations to be conducted by helicopters, there is pre sently known no other means than a helicopter which is capable of promptly arriving at the scene of a disaster such as a fire of a skyscraping building, wreckage of a ship or aircraft and a mountain accident and picking up the endangered people from the air above the scene.

It is, accordingly, a prime object of the present invention to provide a new and useful helicopter-carried rescue apparatus which is capable of accommodating a great number of endangered people at a time and which can be maneuvered from a helicopter hovering or moving at a sufficiently high elevation at which the helicopter is free from the influence of irregular currents of air above the scene of a disaster.

Another object of the present invention is to provide a new and useful helicoptercarried rescue apparatus which can be hauled in a stable condition by a helicopter especially on the way to the scene of a disaster and which can be easily and with certainty maneuvered into a condition operable to accommodate endangered lives at the scene.

Still another object of the present invention is to provide a new and useful helicopter-carried rescue apparatus which is capable of safely accomodating the relieved survivors therein throughout the flight of the helicoptor on the way back from the site of a disaster.

It is, yet, another object of the present invention to provide a new and useful helicopter-carried rescue apparatus which can be installed practicallv on any existing type of helicopter by making minor modifications in the helicopter and which is economical to manufacture and to maintain.

In accordance with the present invention. these objects are accomplished in a helicopter-carried rescue apparatus which comprises a collapsible net assembly including a collapsible frame structure supporting a net and expansible and collapsible m its entirety substantially symmetrically about an axis of the net assembly between a fully collapsed condition and a fully expanded condition defining within the frame structure an open space of predetermined configuration including a floor area over which the net is stretched substantially perpendicularly to said axis when the frame structure is in the fully expanded condition, and a hoisting system including a power driven lifting mechanism for installation on a helicopter, at least one flexible hoisting line fastened to an end of the net assembly remote from its floor area, the other end of said line being fastened to said lifting mechanism for suspending the net assembly below said helicopter at a level which is variable by means of the lifting mechanism when the helicopter is in flight, and the weight of said net assembly acting to bias the same to assume an upright position having said axis in a vertical direction when the net assembly is suspended solely by said hoisting line.

More specifically, the net assembly has an upper and a lower end when the net assembly is in an upright position, the net assembly being fastened at the upper end to the above mentioned hoisting line, the aforesaid portion of the net containing the lower end of the net assembly when the net assembly in the upright position is in the fully expanded condition having the net fully stretched over the floor area. By preferance, the rescue apparatus further comprises an attitude control system capable of having the net assembly suspended below the helicopter independently of the above described hoisting system and varying the attitude of the net assembly between the aforesaid upright position and a lying position having the above mentioned axis in a substantially horizontal direction when the net assembly is suspended by means of the attitude control system. In this instance, the attitude control system may comprise a flexible suspension line which is fastened at one end to the upper end of the net assembly and which has a free tail end portion terminating at the other end of the suspension line, a suspension mechanism for installation on the helicopter and capable of having the suspension line retained thereto while allowing the net assembly to assume any position between the aforesaid upright and lying positions inclusive, suspensionline retaining means fast on the net assembly and located in the neighborhood of the lower end of the net assembly for being capable of retaining the above mentioned tail end portion of the suspension line to the net assembly, buckle means having a closed condition capable of having the tail end portion of the suspension line secured thereto and accordingly holding the tail portion to the above mentioned suspension-line retaining means on the net assembly when the net assembly is in the fully collapsed condition and an open condition allowing the tail end portion of the suspension line to be released from the buckle means and accordingly from the suspension-line retaining means, the suspension line being supported by the suspension mechanism and accordingly the net assembly being suspended from the suspension mechanism by means of the suspension line independently of the hoising system when the helicopter is in flight and the buckle means is in the above mentioned closed condition having the tail end portion of the suspension line secured to the buckle means, suspensionline release control means for installation on the helicopter, and a flexible suspensionline release line which is fastened at one end to the above mentioned release control means and at the other end to the buckle means and which is operable to allow the buckle means to be in the closed condition thereof when the release line is slackened and in the open condition thereof when the release line is taut, the aforesaid suspensionline release control means being operable to maintain the suspension-line release line slackened or to pull the release line away from the buckle means toward the control means for making the release line taut. The above mentioned suspension-line release line may have a first branch end portion fastened to the buckle means and a second branch end portion releasably anchored to the buckle means and operable to allow the buckle means to be in the closed condition thereof when the second branch end portion is slackened and in the open condition thereof when the second branch end portion is taut, the second branch end portion being slackened and tautwhen theSsuspension-line release line is slackened and taut, respectively. By preference, the suspension mechanism forming part of the attitude control system may comprise :, a pair pulleys which are capable of having the suspension line passed thereon and which are movable toward and away from each other in a predetermined direction along a portion of the fuselage of the helicopter for being capable of continuously varying the length of that portion of the suspension line which is passed between the pulleys, and drive and guide means for driving the pulleys to move toward and away from each other in the above mentioned directions. On the other hand, the collapsible net assembly of the rescue apparatus according to the present invention may further include a collapsible frame structure which is expansible and collapsiblc in its entirety about the previously mentioned axis of the net assembly between a fully collapsed condition and a fully expanded condition defining within the frame structure an open space having a predetermined configuration having an end plane at the lower end of the net assembly, the previously mentioned portion of the net being stretched on the above mentioned plane when the frame structure is in the fully expanded condition. Preferably, the frame structure as a whole is substantially symmetric and is collapsible and expansible in its entirety substantially symmetrically with respect to the axis of the net assembly and may comprise a support member located in the neighborhood of the upper end of the net assembly, substantially perpendicular to the axis of the net assembly and having an axis substantially coincident with the axis of the net assembly, a plurality of main ribs which are pivotally connected each at one end to the support member and which extend radially outwardly from the support member away from the upper end of the net assembly, the individual main ribs being pivotable around the axis of the net assembly between first angular positions closest to the axis of the net assembly and second angular positions remotest from the axis of the net assembly, the frame structure being in the fully collapsed condition thereof when the main ribs are in the above mentioned first angular positions and in the fully expanded condition when the main ribs are in the above mentioned second angular positions, an elongated, externally threaded screw rod which is rotatable about a center axis substantially coincident with the axis of the net assembly and which extends from the above mentioned support member toward the lower end of the net assembly, the screw rod having a leading end at a predetermined distance from the lower end of the net assembly, an internally threaded guide member which is in mesh with externallv threaded screw rod and which is movable on the screw rod in opposite directions parallel with the center axis of the screw rod as the screw rod is rotated in opposite directions about the center axis thereof, control ribs extending radially outwardly from the guide member and each pivotally connected at one end to the guide member and at the other end to an intermediate portion of each of the above mentioned main ribs, the individual control ribs being pivotable around the axis of the net assembly between first angular positions closest to the axis of the net assembly and second angular positions remotest from the axis of the net assembly and being in the first angular positions when the guide member is in a position closest to the aforesaid leading end of the screw rod and in the second angular positions when the guide member is in a position remotest from the leading end of the screw rod, and drive means mounted on the above mentioned support member and operatively connected to the screw rod, the drive means being operative to drive the screw rod to rotate in either direction about the center axis of the rod and accordingly drive the guide member to move in either direction along the screw rod. The main and control ribs thus forming part of the frame structure are preferably arranged substan tially symmetrically with respect to the axis of the net assembly. If desired, the rescue apparatus according to the present invention may further comprise buoyancy means attached to the net assembly, preferably to the above mentioned main ribs of the frame structure for maintaining the net assembly unsinkable when the net assembly is in water. The rescue apparatus thus provided with the buoyancy means is useful especially for the purpose of rescue operations at sea.

The features and advantages of a helicopter-carried rescue apparatus according to the present invention will be more clearly appreciated from the following description taken in conjunction with the accompanying drawings, which are given by way of example and in which: Figure I is a perspective view showing a scene on which a helicopter-carried rescue apparatus provided by the present invention is in use for a rescue operation to save endangered occupants of a skyscraper building on fire; Figure 2 is a side elevational view showing the net assembly, in a fully collapsed condition, of a preferred embodiment of a helicopter-carried rescue apparatus according to the present invention, the net assembly being shown held in an upright position; Figure 3a is a vertical section view showing the fully expanded condition of the net assembly illustrated in Figure 2; Figure 3B is a top plan view of the new assembly illustrated in Figure 3A; Figure 4 is a side elevational view showing the net assembly in a partially collapsed condition accommodating therein persons who have been relieved from a danger ; Figure 5 is a schematic perspective view showing the whole arrangement of the helicopter-carried rescue apparatus including the net assembly illustrated in Figures 2, 3A and 3B, the net assembly being shown to be suspended in the fully collapsed condition and in a lying position from a helicopter in flight; Figure 6 is a fragmentary perspective view showing, to an enlarged scalp an end portion of the net assembly in the fully collapsed condition, the end portion being a lower end portion of the net assembly when the net assembly is in the upright position illustrated in Figure 2; Figure 7a is a perspective view showing, to an enlarged scale, a buckle forming part of the attitude control system of the rescue apparatus illustrated in Figure 5, the buckle bemg shown to be in a closed condition operative to maintain the net assembly suspended from a helicopter by means of the attitude control system; Figure 7B is a perspective view showing the buckle in an open condition having the net assembly released from the attitude control system; Figure 8 is a front end view showing a helicopter equipped with the rescue apparatus embodying the present invention, the helicopter being on land with the net assembly of the rescue apparatus placed on the ground; Figure 9A is a front end view of the helicopter in flight with the net assembly of the rescue apparatus suspended in a lying position from the fuselage of the helicopter by means of the above mentioned attitude control system forming part of the rescue apparatus ; Figure 9B is a side elevational view of the helicopter illustrated in Figure 9A; Figure 10 is a side elevational view showing a condition in which the net assembly of the rescue apparatus is suspended in an upright position from the helicopter in flight by means of the above mentioned attitude control system' Figure 11 is a view similar to Figure 10 but shows condition in which the net assembly is released from the attitude control system and suspended from the fuselage of the helicopter by means of a hoisting system forming part of the rescue apparatus; Figure 12 is a side elevational view showing a condition in which the net assembly is being lowered from the helicopter ; Figure 13 is a side elevational view showing a condition in which the net assembly which has been held in the fully collapsed condition is fully expanded; Figure 14A and 14B are side elevational views each showing a condition in which the net assembly thus fully expanded is in operation to pick up survivors in the water; Figure 5a is a side elevational view showing another preferred embodiment of a helicopter-carried rescue apparatus according to the present invention, the embodiment being characterized by a modified attitude control system which is capable of having the net assembly of the apparatus in a stable condition from the fuselage of a helicopter in flight, the attitude control system being schematically illustrated to be in a condition having the net assembly in the stable condition; Figure I9B is a view similar to Figure 15A but schematically shows the attitude control system in a condition ready to have the net assembly released from the attitude control system; Figure 16A is a fragmentary side eleva tional view showing drive and guide means forming part of the attitude control system of the rescue apparatus illustrated in Figures 15A and 15B ; Figure 16B is an end view of the drive and guide means as viewed in a direction indicated by arrows B in Figure 16A; and Figure 16C is a cross-sectional view taken on line C-C of Figure 16A.

As previously noted, a helicopter-carried rescue apparatus according to the present invention is operable as means to save shipwrecked survivors, survivors of ditched aircraft, flood victims, endangered occupants of buildings on-fire, people and animals in snow storms, injured mountain climbers or, in general, lives suffering from disaster at places which are difficult to reach. Figure 1 shows a scene on which such a rescue apparatus is in use for the operation of saving endangered occupants of a skyscraper building 20 on fire. The rescue apparatus is carried by a helicopter 22 hovering above the building 20 and has a collapsible net assembly 24 which is suspended from the fuselage of the helicopter 22 by a rope 26 and which is shown landed in a fully expanded condition on the rooftop of the building 20. When accommodation of the endangered occupants of the building 20 is complete, the helicopter 22 is operated to ascend above the building with the expanded net assembly 24 suspended from the fuselage of the helicopter. The net assembly 24 thus loaded with the people relieved may be kept expanded until the helicopter 22 reaches the landing area where the net assembly 24 is to be unloaded, especially if the landing area is near the site of the fire or the helicopter must fly back to the site for relieving people still left in the building. To assure safety of fhe occupants of the net assembly, however, it is preferable that the net assembly 24 be partially collapsed to securely enclose the occupantsstherein as soon as the net assembly is lifter above the rooftop of the building. When the net assembly 24 is not in use, the net assembly is held in a fully collapsed condition suitable for being stably suspended from the fuselage of the helicopter 22, though not shown in Figure I.

The net assembly 24 of the rescue apparatus thus operative may be maneuvered directly from the helicopter 22 or, if desired, may be radio-controlled by an operator located in the neighborhood of the site.

Furthermore, the rope 26 by which the net assembly 24 is suspended from the helicopter 22 may be extended within practical limits to any desired length from the helicopter. The helicopter 22 per se can therefore be in hovering flight above the building on fire at a level where the irregular ascending currents of air produced over the building could not seriously endanger the helicopter.

While a helicopter-carried rescue apparatus proposed by the present invention will thus prove useful for the saving of the lives of persons and/or animals being endangered by fires or various other kinds of accidents and disasters, the present invention will be hereinafter described in detail as being embodied in a helicopter-carried rescue apparatus of the type which is specifically adapted to undertake operations to rescue lives being endangered in waters such as victims of floods or survivors from shipwrecks or ditched aircraft.

Referring to Figures 2,3A, 3B and 4 of the drawings, such an embodiment of the present invention is shown comprising a collapsible net assembly 30 which has a fully collapsed condition illustrated in Figure 2, a fully expanded condition illustrated in Figures 3A and 3B, and a partially collapsed condition illustrated in Figure 4. The net assembly 30 has a predetermined center axis therethrough and is in its entirety expansible and collapsible between the above mentioned fully collapsed and expanded conditions about the center axis of the net assembly 30. The net assembly 30 comprises a collapsible frame structure 32 which is expansible and collapsible in its entirety about the above mentioned center axis of the net assembly 30 between a fully collapsed condition and a fully expanded condition defining therewithin an open space having a predetermined, generally pyramidal configuration having an end plane at the above mentioned lower end of the net assembly 30. The frame structure 32 as a whole is thus collapsible and expansible substantially symmetrically with respect to the center axis of the net assembly 30. The frame structure 32 comprises four main ribs 34 which are pivotally connected each at one end to central support plate 36 located in the neighborhood of the above mentioned upper end of the net assembly 30 and substantially perpendicular to the center axis of the net assembly 30. The central support plate 36 has a center axis substantially coincident with the axis of the net assembly 30 and the pivoted ends of the individual main ribs are tocated substantially in symmetry about the center axis of the support plate 36 as will be best seen in Figure 3B. The main ribs 24 extend radially outwardly from the central support plate 36 and away from the above mentioned upper end of the net assembly and are pivotable around the center axis of the net assembly between first angular positions closest to the axis of the net assembly 30 as shown in Figure 2 and second angular positions remotest from the axis of the net assembly 30 as shown in Figure 3A, the first angular positions of the ribs 34 being substantially parallel with the center axis of the net assembly 30. The frame structure 32 as a whole is thus in the fully collapsed condition thereof when the main ribs 34 are in the above mentioned first angular positions and is in the fully expanded condition thereof when the main ribs 34 are in the above mentioned second angular positions. Each of the main ribs 34 thus arranged has a free end portion which is inwardly bent at a suitable angle which may be such that the bent end portion becomes substantially parallel with the center axis of the net assembly 30 when the frame structure 32 is in the fully expanded condition having the main ribs 34 in the second angular positions thereof as shown in Figure 3A. When the frame structure 32 is in the fully collapsed condition having the main ribs 34 in the first angular positions thereof, the respective bent end portions of the main ribs 34 have their extreme ends located in proximity to each other about the center axis of the net assembly 30 as will be seen from Figure 2. While the main ribs 34 are herein shown as being four in number, this is merely by way of example and, thus, the number of the main ribs 34 to construct the frame structure of the net assembly of an apparatus according to the present invention may be selected arbitarily subject only to an ample open space being defined by such main ribs when the frame structure is fully expanded.

The frame structure 32 shown in Figures 2,3A, 3B and 4 further comprises control ribs 38 which are disposed inwardly of the main ribs 34 substantially symmetrically with respect to the center axis of the net assembly 30, as will be best seen in Figure 3B. Each of the contro ! ribs 38 is pivotally connected at one end to each of the main ribs 34 by means of a bracket 40 which is fixedly mounted on an intermediate portion of each main rib 34 and which is located at a suitable distance from the pivoted end of the main rib. The control ribs 38 are respective (v aligned with the individual main ribs 34 in direction parallel with the center axis of the net assembly 30 and are jointlv pivoted at the other ends thereof to a guide block 42 which is located substantially centrally of the ribs 34 and 38, as will be seen from Figure 3A. The guide block 4'is formed with helical internal threads (not shown) and is in mesh with an elongated internaHy threaded screw rod 44 which is axially passed through the internallv thrcaded bore in the guide block 42 and which has a center axis substantially coincident with the center axis of the net assembly 30. The screw rod 44 is rotatable about the center axis thereof and axially extends away from the support plate 36 towards the previously mentioned lower end of the net assembly 30, having a leading end at a predetermined distance from the lower end of the net assembly 30 when the frame structure 32 is fully expanded as shown in Figure 3A.

Between the support plate 36 and the guide block 42 thus spaced apart from the support plate 36 is positioned a drive unit 46 which is mounted on the support plate 36.

Though not shown in the drawings, the drive unit 46 includes a reversible d. c. motor, a suitable reduction gear assembly and radio-controlled switch means to start and stop the motor and alter the direction of rotation of the motor and has an output shaft connected to the above described screw rod 44 by means of a coupling 48 so that the screw rod 44 is rotatable in opposite directions about the center axis thereof.

When, thus, the drive unit 46 is actuated to drive the screw rod 44 to rotate in one direction about the center axis thereof, the guide 42 which is internally meshed with the screw rod 44 is caused to move on the screw rod in one direction parallel with the center axis of the rod 44. Likewise, the guide block 42 is caused to move on the screw rod 44 in the other direction parallel with the center axis of the screw rod 44 when the screw rod 44 is driven to rotate in the other direction about the center axis thereof by means of the drive unit 46. The guide block 42 and the screw rod 44 thus constitute means to convert the rotational power output of the drive unit 46 into linear movement of the guide block 42. When the guide block 42 is moved toward the above mentioned leading end of the screw rod 44, then the control ribs 38 are caused to incline toward the center axis of the net assembly 30 about their ends pivoted to the guide block 42.

Conversely, the control ribs 38 are caused to angularly raise away from the center axis of the net assembly 30 when the guide block 42 is moved away from leading end of the screw rod 44. The switch means incorporated in the drive unit 46 is arranged in such a manner that the screw rod 44 is capable of moving the guide block 42 between prede termined limit positions on the screw rod 44 so that the control ribs 38 are pivotable around the center axis of the net assembly 30 between first angular positions closest to the center axis of the net assembly 30 as shown in Figure 2 and second angular positions remotest from the center axis of the net assembly 30 as shown in Figure 3A.

When the control rods 38 are thus moved to the first angular positions thereof, the main ribs 34 to which the control rods 38 are pivotally connected are moved to the pre viously mentioned first angular positions thereof so that the frame structure 32 as a whole assumes the fully collapsed condition illustrated in Figure 2. When the control rods 38 are moved to the second angular positions thereof, the main ribs 34 are also moved to the second angular position thereof so that the frame structure 32 as a whole assumes the fully expanded condition shown in Figures 3A and 3B. The screw rod 44 is provided with a stop member 50 at its leading end so that the guide block 42 is prevented from being disengaged from the screw rod 44 in the event the guide block 42 happens to be moved beyond the limit position close to the leading end of the rod 44. As will be understood from the illustration of Figure 3A, the stop member 50 also serves as a rest for persons who are accommodated in the net assembly 30 in the fully expanded condition.

The net assembly 30 further comprises a net 52 which is fastened to the inwardly bent end portions of the individual main ribs 34.

The net 52 consists of a generally squareshaped major portion which has four sides each spanning a neighboring two of the main nbs 34 and which is to be expanded and stretched on a plane substantially per pendicular to the center axis of the net assembly 30 when the frame structure 32 is fully expanded and four side strip portions each of which spans neighboring two of the ribs 34 and which is to be expanded and stretched substantially normally to the above mentioned plane when the frame structure 32 is fully expanded, the plane being substantially coincident with the previously mentioned end plane of the general- ly pyramidal configuration of the open space defined by the main ribs 34 when the frame structure 32 is fully expanded, as will be seen from Figures 3A and 3B. When, thus, the net assembly 30 is fully expanded in the upright position, the net 52 fully expanded and stretched between the main ribs 34 constitutes a vessel having a platform formed by the above mentioned major portion horizontally spread out at the tower end of the net assembly 30 and between the lower ends of the individual main ribs 34 and an enclosure formed by the above mentioned four side strip portions each of which is spread out between neighboring two of the ribs 34. The net 52 thus arranged is folded about the center axis of the net assembly 30 as illustrated in Figure 2. The net assembly further comprises a plank structure 54 securely fastened to the above mentioned major portion of the net 52, spherical floats 56 respectively secured to the lower ends of the main ribs 34, cylin- droid floats 58 respectively secured to lower portions of the ribs 34, and spherical floats 60 respectively secured to upper portions of the ribs 34. The plank structure 54 of constructed of a solid material floatable in water such as closed-cellular foams of synthetic resin and has major or lower and upper surfaces which are substantially perpendicular to the center axis of the net assembly-30.

The plank structure 54 is thus operable as a foothold for persons accommodated within the net 52 which is fully expanded as shown in Figure 3A or in partially collapsed condition illustrated in Figure 4. The plank structure 54 is preferably located centrally of the net 52. The floats 56, 58 anus 60 secured to the main ribs 34 are assumed to be also constructed of a material floatable in water such as closed-cellular foams of synhetic resin but, if desired, each of the floats 56, 58 and 60 may be constituted by a hollow inflatable confinement adapted to be expanded by gas under pressure which may be introduced in the confinement from an externat source or may be generated by suitable gas generating means provided within the confinement or attached to the net assembty 30 though not shown in the drawings. The specific configurations of the floats 56 58 and 60 as above described and shown in the drawings are not of critical importance and may therefore be modifie or changed as desired in consideration of the desired buoyancy of the net assembly 30 and the distribution-of the buoyancy in the net assembly 30. If. furthermore, a helicoptxr- carried rescue-apparatus according to the present invention'is to be used solely for purposes other than the saving of survivors in water, the floats 56,58 and 60 need'not be provided in íhe-net assembly ot such za rescue apparatus and the plank structure 54 need not be constructed of a floatable material although it will be preferabte to have the plank-structure be formed of a light-weightmateria).'..";,.' Turning to Figure 5 of the drawings, there is shown a condition-in which the'collapsible net assembly 30'which is constructed and arranged as hereinbefore described, is suspended in the fullv collapsed condition from a helicopter in flight, the helicopter being onlv partially and schematically shown at 68. The. helicopter 68 has formed in a bottom portion of its fuselage an opening. 70 elongated in a fore-and-aft direction of the helicopter and has suspended the net assembly 30 through the-opening 70. To have the net assembly 30 suspended therefrom, the helicopter 68 is equipped with a hoisting drum 72, a hoisting pulley 74 associated with the drum 72 and located above the elongated opening 70 in the fuselage of the helicopter 68, a pair of. control pulleys 76 and 76'which are located above the elongated opening 70 and spaced apart a fixed distance from each other in a fore-and-aft direction of the helicopter 68 and a control drum 78 located above the opening 70.

While it is important that the axes of rotation of the control. pulleys 76 and 76'be directed perpendicularly to a fore-and-aft direction of the helicopter 68, the axis of rotation of each of the drums 72 and 78 and the pulley 74 may be directed as desired. It is, however, preferable that the axes of rotation of the hoisting drum 72 and the hoisting pulley 74 be directed in parallel with each other. The hoisting drum 72 has wound thereon a lengthy flexible hoisting line which is preferably constituted by a rope 80 of preferably steel wire. The hoist ing rope 80 thus leading from the, hoisting drum 72 is passed on the hoisting pulley 74 and is fastened at its leading end to the previously mentioned. eyebolt 66 secured to the suspension structure of the net assembly 30. The hoisting drum 72 and the hoisting pulley 74 form part of a lifting mechanism which further comprises a powered drive unit including, for example, a motor, a reduction gear and a brake, though not shown in the drawings. Such a lifting mechanism constitutes in combination with the hoisting rope 80 a hoisting system of the rescue apparatus embodying the present invention. On the other hand, the control pu!)eys76.and76',form part of a suspension mechanism for suspending the net assembly 30 independently-of the above mentioned hoisting system. The suspension mechanism comprises, in addition to the control pulleys 76 and 76'., a suitable drive un, it capable of driving at least one of pulleys 76 and 76' to rotate in opposite directions about the axis or. : axes. thereof. and forms part of an attitude, contro) system of the rescue appar atus embodying the. present invention.. The attitude, controt. system is adapted to vary the attitude of the net assemb. ty 30 between the upright position having the center axis of the net assernbty. in a vertical direction a, s illustrated in Figure. 2 and a lying positiion having the center axis of the net assemblv. in an approximately horizontal direction or" more generally, substantially in parallel with a fore-and-aft direction of the helicopter 68 as shown in, Figure. 5. Such an attitude control. system, further comprises a suspen sion line which is. assumed to be constituted bya.strandedrope82ofpreterabtystee! . wire. The suspension rope 82ispassed. on the above mentiond control pullevs'6, and . 76 and extends from the two pulleys 76 and 76'. toward the net assembty 30 ttuoughjhe opening 70. in the fuselage of the helicopter 68 when the attitude control system is in a condition having the net assembly 30 sus pended from the helicopter 68 in flight. The suspension rope 82 is fastened at one end to theeyebott. 66 at the, upper, end of the net as.sembty30andhas a free tni ! end portion terminating. at the. other end of the rope 8. 2 as indicated at 82a in Figure 6. The attitude control system further comprises suspension-line retaining means which consists of fittings 84 which are securely connected to lower portions of the main ribs 34, respectively, of the frame structure 32 of the net assembly 30 in such a manner as to form a hole between each of the main ribs 34 and the fitting 84 on the rib 34 as illustrated in Figure 6. The fittings 84 are arranged substantially in parallel with a plane perpendicular to the center axis of the net assembly 30 and are located close to the inwardly bent end portions of the main ribs 34. The above mentioned tail end portion 82a of the suspension rope 82 is passed through the holes in these fittings 84 in such a manner as to form a loop girdling the individual main ribs 34 of the frame structure 32 of the net assembly 30 in the fully collapsed condition.

The tail end portion 82a of the suspension line 82 thus tightly passed in a loop form on the ribs 34 is secured to a buckle 86 forming part of the above mentioned attitude control system. Generally speaking, the buckle 86 is constructed and arranged in such a manner as to have a closed condition capable of having the tail end portion 82a of the suspension rope 82 secured thereto as illustrated in Figure 6 or more clearly in Figure 7A and an open condition allowing the tail end portion 82a of the rope 82 to be released from the buckle 86 as shown in Figure 7B.

Thus, the suspension rope 82 is retained to both the suspension mechanism incorporated in the helicopter 68 and the net assembly 30 and is therefore capable of having the net assembly 30 suspended from the suspension mechanism in the helicopter 68 when the helicopter 68 is in flight and the buckle 86 is held in the above mentioned closed condition having the tail end portion 82a of the suspension rope 82 secured thereto. Under these conditions, the net assembly 30 in the fully collapsed condition can be held in any position between the previously mentioned upright and lying positions inclusive depending upon the relationship between the respective lengths of those portions of the suspension rope 82 which extend in opposite directions from the two control pulleys 76 and 76'. If, therefore, such lengths are approximately equal to each other, the net assembly 30 is held in the above mentioned lying position as shown in Figure 5. If the previously mentioned drive unit connected to at least one of the control pulleys 76 and 76'is actuated to drive the pulley or pulleys in a direction to move the suspension rope 82 from one of the pulleys 76 and 76'to the other, that portion of the suspension rope 82 which is directed from one of the control pulleys 76 and 76'. toward the buckle 86 becomes longer than that portion of the rope 82 which is directed from the other control pulley toward the eyebolt 66 on the net assembly 30. As the former portion of the suspension rope 82 is extended and accordingly the latter portion of the rope 82 is shortened, the net assembly 30 suspended by rope 82 is gradually erected from the lying position, having the upper end of the assembly moved upwardly and the lower end of the assembly downwardly.

When the difference between those portions of the suspension rope 82 which extend from the control pulleys 76 and 76'to the upper and lower ends of the net assembly 30 reaches a certain value which depends upon the distance between the eyebolt 66 and the buckle 86 on the net assembly 30, the net assembly 30 assumes the upright position illustrated in Figure 2. If the drive unit for the control pulleys 76 and 76'is operated to move the suspension rope 86 in the opposite direction under the condition in which the net assembly 30 is thus suspended in the upright position, then the net assembly 30 is moved to have its upper end lowered and its lower end raised until the net assembly 30 resumes the initial lying position as will be readily understood. The drive unit incorporated into the suspension mechanism including the control pulleys 76 and 76'is capable of driving at least one of the control pulleys to rotate in both directions about its axis. In order to enable the suspension line to be moved more assuredly, the suspension line may comprise a chain constituting at least an intermediate portion of the line and engaging at least one sprocket wheel which is provided in lieu of the control pulleys 76 and 76', though not shown. In this instance, it is important that such a chain have a length capable of maintaining the chain in engagement with the sprocket wheel when the suspension line is in a condition suspending the net assembly 30 in a position variable between the upright and lying positions inclusive. For reduction of the weight of the suspension line as a whole'and for ease of connecting the suspension line to the net assembly 30, it is preferable that the suspension line thus having an intermediate portion constituted by a chain have opposite end portions consitituted by stranded ropes each spliced at one end to each end of the chain.

If the buckle 86 is brought into the previously mentioned open condition thereof after the net assembly 30 suspended by the suspension rope 82 from the helicopter in flight has been moved into the upright position as above described, the suspension line 82 is released and as a consequence no longer acts to suspend the net assembly 30.

The weight of the net assembly 30 is therefore totally borne by the hoisting rope 80. The control drum 78 forms part of suspension-line release control means which is adapted to release the buckle 86 from the closed condition. The control drum 78 has wound thereon a suspension-line release rope 88 leading from the drum 78 and having a first tail end portion constituted by an extension 88a of the rope 88 and a second tail end portion which is constituted by a control rope 90. The extension 88a and the control rope 90 thus constituting the first and second tail end portions, respectively, of the suspension line release rope 88 are shown spliced each at one end to the release rope 88 by means of a connector ring 92. As will be described more exactly, the control rope 90 is shorter than the extension 88a of the release rope 88.

Referring to Figures 7A and 7B of the drawings, the buckle 86 comprises a pair of rigid clamp plates 94 and 94'which are hingedly connected together along one side of the buckle 86 by a hinge pin 96 having a ring-shaped end portion projecting outwardly from the clamp plates 94 and 94'.

The hinge pin 96 has an enlarged opposite end portion also projecting from the clamp plates 94 and 94'so that the pin is prevented from being removed from the clamp plates.

The clamp plates 94 and 94'has securely attached to the respective inner faces thereof suitable thick facings 98 and 98', respectively, of a frictional material such as rubber. The clamp plates 94 and 94'are pivotable about the hinge pin 96 and thus have angular positions having the facings 98 and 98'in close contact with each other as shown in Figure 7A and therebv producing the previously mentioned closed condition of the buckle 86. The facing 98 on one clamp plate 94 is formed with spaced grooves 100 and 102 which are substantially parallel with the hinged side end of the buckle 86 and likewise the facing 98'on the other clamp plate 94'is formed with spaced grooves 100' and 102'which are also suhstantiallv parallel with the hinged side end of the buckle 96. each of the grooves 100. 102, 100'and 102' being open at both ends thereof and having a substantiallv semicircular cross section.

The grooves 100, 102, 100'and 102'are located and shaped so that the grooves 100 and 102 in one facings 98 are in registry with the grooves 100'and 102', respectively, in the other facing 98'so that two separate holes each having a substantially circular cross section are formed between the facings 98 and 98'when the clamp plates 94 and 94' are held in the above mentioned angular positions having the facings 98 and 98'in close contact with each other. The cross section of each of the grooves formed in the facings 98 and 98'is so sized that each of the holes thus formed between the facings has a diameter such that the tail end portion 82a of the suspension line 82 can be closely received in the hole. Furthermore, one clamp plate 94 has formed along its side edge opposite to the hinged side end of the buckle 86 two generally tubular portions 104 which are axially spaced apart from each other and which have axial bores substantially in line with each other in parallel with the hinged end of the buckle 86. Likewise, the other clamp plate 94'has formed at its side edge opposite to the hinged side end of the buckle 86 a generally tubular portion 104'which has an axial bore substantially parallel with the hinged side end of the buckle 86 and which has a length slightly smaller than the axial spacing between the tubular portions 104 of the clamp plate 94.

When the clamp plates 94 and 94'are in the above mentioned angular positions thereof, the tubular portion 104'of the clamp plate 94'is located between the axially aligned with the tubular portions 104 of the clamp plate 94, as seen in Figure 7A. The extension 88a of the above described suspensionline release rope 88 is fastened at its leading end to the ring-shaped end portion of the hinge pin 96 while the control rope 90 spliced at one end to the release rope 88 by the connector ring 92 is fastened at the other end to a locking pin 106 which is adapted to be inserted into the aligned axial bores in the tubular portions 104 and 104'of the clamp plates 94 and 94'when the clamp plates are in the angular positions having the facings 98 and 98'in close contact with each other. The locking pin 106 thus inserted into the aligned axial bores in the tubular portions 104 and 104'retains the clamp plates 94,94'closed together unless the pin 106 is forcibly pulled out of the bores. The suspen sion-line release control means including the control drum 78 is arranged in such a manner that the suspension-line release rope 88 can be freely paid out from the control drum 78 when the suspension rope 82 is being moved to move the net assemb. ly 30 from the Iying position towards the upright position.

When the net assembly 30 is in the fully collapsed condition as illustrated in Figures, 2,5 and 6, the tail end portion 82a of the suspension rope 82 partially passed on the main ribs 34 of the frame structure 32 of the net assembly 30 and retained in a loop form on the ribs 34 by means of the fittings 84 as best seen in Figure 6 is secured to the buckle 86 in the closed condition in such a manner that the two portions of the suspension rope 82 which adjoin the loop are tightly received in the two holes, respectively, which are formed between the facings 98 and 98'by the grooves 100 and 102 in one facing 98 and the grooves 100'and 102'in the other facing 98'In order to prevent the suspension rope 82 from being pulled out of the buckle 86 thus held in the closed condition securing the tail end portion 82a of the rope, the suspension rope 82 may be formed with a knot at or adjacent to the leading end of the tail end portion 82a, though not shown in the drawings. Furthermore, the facings 98 and 98'may have in each of the grooves 100, 102, 100'and 102'a surface which is roughened conformingly to the lay of the stranded suspension rope 82 so that the tail end portion 82a of the suspension rope 82 is more assuredly secured to the facings 98 and 98'in the buckle 86 in the closed condition.

Figure 8 shows a condition in which the helicopter 68 on land is equipped with the net assembly 30 connected to it in the fully collapsed condition. The suspension line 82 in particular is adjusted as already described to be capable of having the net assembly 30 suspended in the lying position when the helicopter 68 is in flight. When the helicopter 68 takes off and is aloft in the air, the net assembly 30 in the fully collapsed condition is suspended from the fuselage of the helicopter by the suspension rope 82 (see Figure 5) and is held in the Iying position illustrated in Figures 9A and 9B. Under these conditions, the suspension-line release rope 88 is maintained slackened between the control drum 78 and the buckle 86 as shown in Figure 5 so that the locking pin 106 is secured to the clamp plates 94 and 94'of the buckle 86 and holds the buckle 86 in the closed condition as shown in Figure 7A. The hoisting rope 80 will normally be maintained taut. With the net assembly 30 thus suspended in the lying position, the helicopter 68 rushes to the scene of a disaster which is herein assumed to be wreckage of a ship at sea. As the helicopter nears the scene, the suspension rope 82 is moved on the control pulleys 76 and 76' (Figure 5) in the previously described manner so that the net assembly 30 in the fully collapsed condition is moved into the upright position as shown in Figure 10. While the net assembly 30 is being thus moved from the lying position toward the upright position so that the buckle 86 is being moved downwardly below the helicopter 68, the suspension-line release rope 88 is continuously paid away from the control drum 78 and is maintained slackened until the net assembly 30 assumes the upright position illustrated in Figure 10.

During the flight of the helicopter 68 toward the scene or while the helicopter 68 which has reached the site is hovering above the scene, the suspension-line release rope 88 is pulled from the helicopter in a suitable manner as by driving the control drum 78 to rotate in a direction to haul in the rope. The suspension-line release rope 82 and accordingly the extension 88a of the rope 88 and the control rope 90 are therefore tensioned and, because of the fact that the control rope 90 is shorter than the extension 88a of the rope 88, the locking pin 106 tied to the control rope 90 is pulled out of the axial bores in the tubular portions 104 and 104'of the clamp plates 94 and 94'of the buckle 86 and allows the clamp plates 94 and 94'to open as illustrated in Figure 7B. The buckle 86 being thus brought into the open condition, the tail end portion 82a of the suspension rope 82 is allowed to be released from the buckle 86 and as a consequence the suspension rope 82 is disabled from bearing the weight of the net assembly 30. The net assembly 30 is thus suspended in the upright position below the helicopter 68 by the hoisting rope 80 partly leading from the hoisting drum 72 on the helicopter 68. The hoisting drum 72 is then allowed to rotate åt a controlled velocity so that the hoisting rope 80 is extended from the drum 72 and allows the net assembly 30 to lower at a controlled velocity away from the helicopter 68 as shown in Figure 11. As the net assembly 30 is thus moved downwardly away from the helicopter 68, the tail end portion 82a of the suspension rope 82 released from the buckle 86 which is now suspended from the helicopter 68 by the suspension-line release rope 88 is pulled from the net assembly 30 and is released from the fittings 84 (Figure 6) on the main ribs 34 of the frame structure 32 of the net assembly 30. The suspension rope 82 is thus freed from the net assembly 30 as shown in Figure 11 and is thereafter moved in a direction to be disengaged from the control pulleys 76 and 76' (Figure 5) on the helicop-. ter 68 as will be seen from Figure 12.

While the net assembly 30 is being thus lowered away from the helicopter 68 or when the net assembly 30 is lowered a suitable distance below the helicopter 68, the drive unit 46 provided in the net assembly 30 (Figure 2) is actuated into motion to drive the screw rod 42 to rotate about its axis in a direction to move the guide block 42 upwardly, viz., away from the stop member 50 at the leading end of the screw rod 44. As the guide block 42 is thus moved upwardly, the control ribs 38 and accordingly the main ribs 34 of the frame structure 32 of the net assembly 30 which has been held in the fully collapsed condition are caused to tilt away from the axis of the net assembly 30 until the frame structure 32 is fully expanded and as a consequence the net 52 is fully expanded and stretched between the main ribs 34, as illustrated in Figure 3A and 3B. While the net assembly 30 is being thus caused to expand in the air, the net assembly 30 still lowered away from the helicopter 68 so that the suspension rope 82 is released from the control pulleys 76 and 76'on the helicopter 68 and is allowed to dangle from the eyebolt 66 on the net assembly 30 as seen in Figure 13. After the net assembly 30 in the fully expanded condition reaches the surface of the sea in the vicinity of the shipwreck, the hoisting rope 80 may be maintained in an adequately slackened condition with the helicopter 68 hovering motionless above the scene so as to provide easy access to the net assembly 30 for swimming survivors or the survivors aboard a lifesaving boat as shown in Figure 14A or the helicopter 68 may be operated to make a horizontal flight to tow the net assembly 30 in the water for scooping survivors out of the sea as shown in Figure 14B. By the time, the net assembly 30 is lowered in the fully expanded condition to the water, the suspension-line release rope 88 may be completely hauled in to the helicopter 68 so as to recover the buckle 86 in the helicopter as will be seen from Figures 11 to 13.

Upon completion of the recovery of the surviors from the scene or when the net assembly 30 is loaded to its capacity, the net assembly 30 is raised above the surface of the water and is lifted toward the helicopter 68 by means of the hoisting rope 80. In this instance, it is apparent that, as an alternative to lifting the net assembly 30 toward the helicopter 68 in hovering flight, the helicopter per se may be lowered toward the net assembly 30 left in the water while hauling in the hoisting rope 80 toward the helicopter and thereafter moved upwardly to raise the net assembly 30 above the surface of the water, When the net assembly 30 is thus suspended in the air from the helicopter 68, the helicopter 68 may cruise back to the rescue station with the net assembly 30 maintained either in the fully expanded condition as shown in Figure 3A or in a partially collapsed condition having the occupants of the net assemble 30 enclosed in the net 52 in a partially folded condition as shown in Figure 4. The plank structure 54 secured to a central portion of the net 54 in the fully expanded and stretched condition or in the partially folded condition provides a foothold for the occupants of the net assembly 30 as will be seen from Figures 3A and 4. The plank structure 54 is constructed of a floatable material and thus contributes to maintaining the net assembly 30 afloat when the net assembly 30 stays in the water.

Furthermore, the stop member 50 mounted on the screw rod 44 serves as a handhold for the occupants of the net assembly 30 when the net assembly 30 is in the fully expanded condition in the water or in the air. as will be seen from Figure 3A.

During travel of the helicopter to the site of a disaster, the net assembly 30 in the fully collapsed condition is suspended in the lying position from the helicopter as has been described. If, therefore, the helicopter must make a high-speed flight toward the site of a disaster calling for emergency, it is required for the stability of flight of the helicopter to have the net assembly suspended from the helicopter in a sufficiently stable condition.

It is, for this reason, preferable to enable the suspension rope 82 to span an increased length between the control pulleys 76 and 76'during cruise of the helicopter 68 as shown in Figure 15A and a reduced length between the pulleys 76 and 76'as shown in Figure 15B when the net assembly 30 is to be moved from the lying position to the upright position. Figures 16A to 16C show an arrangement in which the control pulleys 76 and 76'for supporting the suspension rope 82 can be moved toward and away from each other so that the length of that portion of the suspension rope 82 which spans between the control pulleys 76 and 76' is continuously variable with a certain range with the net assembly 30 kept suspended by the suspension rope 82 from the helicopter 68 in flight. The arrangement herein shown constitutes drive and guide means forming part of an attitude control system of a second embodiment of the present invention. In the description to follow, the control pulleys 76 and 76'also forming part of the attitude control system are assumed, by way of example, to be positioned forwardly and rearwardly of each other in a fore-and-aft direction of a helicopter into which the attitude control system is to be incorporated.

Referring to Figures 16A, 16B and 16C of the drawings, drive and guide means of the attitude control system of the second embodiment of the present invention comprise a generally horizontal support plate 108 having an elongated guide rail 110 securely attached to the underside of the support plate 108 by suitable fastening means such as bolts and nuts (not shown). The support plate 108 is fixedly mounted within the fuselage of a helicopter (not shown) and the guide rail 110 extends in a fore-and-aft direction of the helicopter. The guide rail 110 has cross wall portions 110a and 110b at the front and rear ends, respectively, of the guide rail 110 and an intermediate cross wall portion 110c which is located between the front and rear cross wall portions I 10a and 110b and which has opposite end faces substantially equally spaced apart from the respective inner faces of the front and rear cross wall portions 110a and 110b, as indicated by broken lines in Figure 16A. Thus, the guide rail 110 has a longitudinal middle point which is located in the intermediate cross wall portion 110c of the guide rail 110 as indicated at M in Figure 16A. Each of the longitudinal cavities thus formed in the guide rail 110 is assumed to have a rectangular cross section as shown in Figure 16C.

The guide rail 110 further has a bottom wall portion which is formed with front and rear longitudinal slots which are smaller in width than the above mentioned cavities and through which the front and rear longitudinal cavities, respectively, are open at the lower edge of the guide rail 110. Within the front longitudinal cavity is longitudinally slidably received a front pulley carrier 112 having spaced parallel lower wall portions 114 and 116 projecting downwardly from the guide rail 110 through the front longitudinal slot in the bottom wall of the guide rail 110, as illustrated in Figure 16C. Likewise, a rear pulley carrier 112'is longitudinally slidably received in the rear longitudinal cavity in the guide rail 110 and has spaced parallel lower wall portions 114'and 116' projecting downwardly from the guide rail 110 through the rear longitudinal slot in the bottom wall portion of the guide rail 110, as will be seen from Figure 16A and 16B. The lower wall portions 114 and 116 of the front pulley carrier 112 are spaced apart from each other laterally of the front half of the guide rail 110 and have the grooved front control pulley 76 mounted on a shaft 118 secured to the wall portions 114 and 116 as shown in Figure 16C so that the front control pulley 76 is rotatable about the axis of the shaft 118, viz., about an axis which is substantially perpendicular to the longitudinal direction of the guide rail 110 and which is movable together with the pulley carrier 112 longitudinally of the front half of the guide rail 110. Likewise, the lower wall portions 114'and 116'of the rear pulley carrier 112'are spaced apart from each other laterally of the rear half of the guide rail 110 and have the grooved rear control pulley 76'mounted on a shaft 118'secured to the wall portions 114'and 116', as shown in Figure 16B. The suspension rope 82 is passed on the grooved front rear control pulleys 76 and 76'thus mounted on the front and rear pulley carriers 112 and 112'as indicated by full and dots-and-dash lines in Figure 16A.

The pulley carriers 112 and 112'are formed with internally threaded axial bores 120 and 120', respectively, having respective center axes which are substantially in line with each other in a longitudinal direction of the elongated guide rail 110, as will be seen from Figure 16A. The internal helical threads thus formed in each of the pulley carriers 11'-'and 112'are such that the directions of the helices of the respective internal helical threads of the front and rear pulley carriers are opposite to each other.

Externally threaded drive shafts 122 and 122'are passed through these internally threaded axial bores 120 and 120', respectively, in the front and rear pulley carriers 112 and 112'and are in mesh with the respective internal threads of the front and rear pulley carriers 112 and 112'Thus, the directions of the helices of the external helical threads of the front and rear drive shafts 122 and 122'are also opposite to each other as indicated in part in the vicinity of the intermediate cross wall portion 110c of the guide rail 110 in Figure 16A. The drive shafts 122 and 122'are rotatable about axes which are substantially coincident with the center axes of the internally threaded axis bores 120 and 120', respectively, in the pulley carriers 110 and 110'and which are accordingly in line with each other. When, thus, the front and rear drive shafts 122 and 122'are driven to rotate as a single unit in one predetermined direction about their respective axes, the front and rear pulley carriers 112 and 112'are moved along the guide rail 110 away from the longitudinal middle point M of the-guide rail as indicated by arrows a and a', respectively, in Figure 16A. When the drive shafts 122 and 122 are driven to rotate as a single unit in the other direction about their respective axes, then the front and rear pulley carriers 112 and 112'are moved along the guide rail 110 toward the longitudinal middle point M of the guide rail as indicated by arrows b and b', respectively, in Figure 16A. The front control pulley 76 is thus movable between a position close to the front cross wall position 110a as indicated in dot-dash lines predetermined foremost and a predetermined rearmost position close to the intermediate cross wall portion 110c as indicated in full lines, while the rear control pulley 76'is movable between predetermined complementary rearmost (dot-dash lines) and foremost (full lines) positions close to the rear and intermediate cross wall portions 110b and 110c, respectively, of the guide rail 110. The front and rear drive shafts 122 and 122'are journalled at their respective outer axial ends in the front and rear cross wall portions 110a and 110-b, respectively, of the guide rail 110 and are integrally connected together at their respective inner axial-zends through an axial bore formed in the intermediate cross wall portion 110c of the guide rail 110, as shown in Figure 16A. The rear drive shaft 122'has a rearward extension projecting out of the rear cross wall portion 110b of the guide rail 110 as shown in Figures 16A and 16B. The rearward extension of the rear drive shaft 122'has fixedly mounted thereon a grooved pulley 124 which is thus rotatable about an axis which is in line with the aligned axes of rotation of the drive shafts 122 and 122'.

The drive and guide means illustrated in Figures 16A to 16C further comprises a drive unit 126 which is mounted on the upper face of the support plate 108 as shown in Figures 16A and 16B. The drive unit 126 may be composed of a reversible d. c. motor and a reduction gear assemble (not shown) and has an output shaft 128 projecting above and substantially in parallel with the above mentioned rearward extension of the rear drive shaft 122'. A grooved pulley 130 is securely connected to the output shaft 128 of the drive unit 126 and an endless belt 132 is passed round the pulleys 124 and 130 as best seen in Figure 16B.

When, thus, the drive unit 126 is operated to have its output shaft 128 rotated in one direction about the center axis thereof, such a rotational motion is transmitted by the pulley 130, endless belt 132 and pulley 124 to the rear drive shaft 122'so that the front and rear drive shafts 122 and 122'integral with each other are driven to rotate as a single unit in one predetermined direction about their respective axes and cause the front and rear pulley carriers 112 and 112'to longitudinally move along the guide rail 110 away from the longitudinal middle point M of the guide rail 110 as indicated by arrows a and a'in Figure 16A. The front and rear control pulleys 76 and 76'supported on the pulley carriers 112 and 112', respectively, are therefore moved away from each other in a longitudinal direction of the guide rail 110 untel the front and rear pulley carriers 112 and 112'reach their respective foremost and rearmost longitudinal positions on the guide rail 110 as indicated by the dots and-dash lines in Figure 16A. Figure 15A shows a condition in which the collapsible net assembly 30 forming part of the second embodiment of the present invention is suspended in a lying position by the suspension rope 82 supported by the front and rear control pulleys 76 and 76'which are held in these longitudinal positions remotest from each other on the guide rail 110 mounted on the helicopter 68 in flight toward the site of a disaster. When the helicopter 68 nears the site, the drive unit 126 of the drive and guide means illustrated in Figures 16A to 16C is operated so that the front and rear drive shafts 122 and 122'are driven to rotate in the other direction about their respective axes and cause the front and rear pulley carriers 112 and 112'to move along the guide rail 110 toward the longitudinal middle point M of the guide rail 110 as indicated by arrows b and b', respectively, in Figure 16C. As a consequence, the front and rear control pulleys 76 and 76'are moved toward each other in the longitudinal direction of the guide rail 110 until the front and rear pulley carriers 112 and 112'reach their respective rearmost and foremost longitudinal positions on the guide rail 110 as indicated by the full lines in Figure 16C.

Figure 15B illustrates the condition in which the collapsible net assembly 30 is suspended in a lying position by the suspension rope 82 supported by the front and rear control pulleys 76 and 76'which are thus held in the positions closest on the guide rail 110.

While the drive shafts 122 and 122'of the drive and guide means illustrated in Figures 16A to 16C have been described to be integrally connected together and driven by a single drive unit which is operatively connected to the unitary construction of the shafts 122 and 122', the front and rear drive shafts may be constructed to be separate and dependent from one another and driven by two separate drive units each of which is exclusively associated with only one of the drive shafts, the drive units being arranged to operate either in synchronism with each other or independently of each other. In this instance, the internal threads of the pulley carriers and accordingly the external threads of the drive shafts may be formed so that the respective internal threads of the front and rear pulley carriers and accordingly the respective external threads of the front and rear drive shafts are helically turned either in opposite directions or in the same directions. For varying the distance between the front and rear pulley carriers mounted on the drive shafts having the external threads which are thus helically turned in the directions opposite to each other, the drive respective drive units for the drive shafts should be operated to drive the shafts to simultaneously rotate in the same direction as in arrangement of Figures 16A to 16C.

Where, however, the external threads of the front and rear drive shafts are helically turned in the same directions, the distance between the front and rear pulley carriers on such drive shafts is varied by operating the respective drive units for the shafts in such a manner as to drive the shafts to simultaneously rotate in the directions opposite to each other. If, furthermore, the front and rear drive shafts which are constructed separately of each other are driven to rotate in such a manner that both of the front and rear pulley carriers are simul- taneously move in the same direction viz., forwardly or rearwardly relative to the helicopter on which the drive shafts are installed, the net assembly suspended from the helicopter can be moved in a fore-andaft direction relative to the helicopter in flight. The arrangement using the separate front and rear drive shafts is, thus, operable not only for the purpose of varying the distance between the front and rear control pulleys without varying the fore-and-aft position of the net assembly relative to the helicopter but for the purpose of moving the net assembly forwardly or rearwardly relative to the helicopter.

Claims

WHAT I CLAIM IS: 1. A helicopter-carried rescue apparatus comprising a collapsible net assembly including a collapsible frame structure supporting a net and expansible and collapsible in its entirety substantially symmetrically about an axis of the net assembly between a fully collapsed condition and a full expanded condition defining within the frame structure an open space of predetermined configuration including a floor area over which the net is stretched substantially perpendicularly to said axis when the frame structure is in the fully expanded condition, and a hoisting system including a power driven lifting mechanism for installation on a helicopter, at least one flexible hoisting line fastened to an end of the net assembly remote from its floor area, the other end of said line being fastened to said lifting mechanism for suspending the net assembly below said helicopter at a level which is variable by means of the lifting mechanism when the helicopter is in flight, and the weight of said net assembly acting to bias the same to assume an upright position having said axis in a vertical direction when the net assembly is suspended solely by said hoisting line.

2. A helicopter-carried rescue apparatus as claimed in Claim 1, in which said frame structure comprises a support member located in the neighborhood of the hoisting line end of the net assembly, substantially perpendicular to the axis of the net assembly and, itself having an axis substantially coincident with said net assembly axis, a plurality of main ribs which are pivotally connected each at one end to said support member and which extend radially outwardly from the support member and away from said upper end of the net assembly, the individual main ribs being pivotable around the net assembly axis between first angular positions closest to the net assembly axis and second angular positions remotest from said net assembly axis, the frame structure being in the fully collapsed condition thereof when said main ribs are in said first angular positions and in the fully expanded condition when the main ribs are in said second angular positions, an elongated, externally threaded screw rod which is rotatable about a center axis substantially coincident with said axis of the net assembly and which extends axially away from said support member toward the floor area end of the net assembly, said screw rod having a leading end at a predetermined distance from said floor area end of the net assembly when the frame structure is in the fully expanded condition thereof, an internally threaded guide member which is in mesh with said screw rod and which is movable on the screw rod in opposite directions parallel with the center axis of the screw rod as the screw rod is rotated in opposite directions about the center axis thereof, control ribs extending radially outwardly from said guide member and each pivotally connected at one end to the guide member and at the other end to an intermediate portion of each of said main ribs, the individual control ribs being pivotable around the axis of the net assembly and having first angular positions closest to said axis of the net assembly and second angular positions remotest from the axis of the net assembly and being in the first angular positions thereof when the guide member is in a position closest to said leading end of the screw rod and in the second angular positions thereof when the guide member is in a position remotest from the leading end of the screw rod, and drive means mounted on said support member and operatively connected to said screw rod, the drive means being operative to drive the screw rod to rotate in either direction about the center axis of the rod and accordingly drive said guide member-to move in either direction along the screw rod.

3. A helicopter-carried rescue apparatus as claimed in Claim 1 or Claim 2 in which said net assembly further comprises buoyancy means secured to said net assembly for maintaining the net assembly unsinkable in water.

4. A helicopter-carried rescue apparatus as claimed in Claim 3, in which said buoyancy means comprises a plurality of floats which are secured to said frame structure and to said net.

5. A helicopter-carried rescue apparatus as claimed in Claim 4, in which said floats are arranged substantially symmetrically with respect to said axis of the net assembly.

6. A helicopter-carried rescue apparatus as claimed in any one of Claims 1 to 5, in which said net assembly further comprises a plank structure secured to the floor area portion of the net and having substantially flat major surfaces which are substantially perpendicular to the axis of the net assembly when the net is fully expanded and stretched.

7. A helicopter ; carried rescue apparatus as claimed in Claim 6, in which said plank structure is constructed of a material floatable in water.

8. A helicopter-carried rescue,, apparatus as claimed in any one of Claims 1 to 7, further comprising an attitude control system capable of having said net assembly suspended below said helicopter indepen dently of said hoisting system and varying the attitude of the net assembly between said upright position and a lying position having said axis of the net assembly in a substantially horizontal direction when the net assembly is suspended by means of the attitude control system.

9. A helicopter-carried rescue apparatus as claimed in Claim 10, in which said attitude control system comprises a flexible suspension line which is fastened at one end and has an output shaft 128 projecting above and substantially in parallel with the above mentioned rearward extension of the rear drive shaft 122'. A grooved pulley 130 is securely connected to the output shaft 128 of the drive unit 126 and an endless belt 132 is passed round the pulleys 124 and 130 as best seen in Figure 16B.

When, thus, the drive unit 126 is operated to have its output shaft 128 rotated in one direction about the center axis thereof, such a rotational motion is transmitted by the pulley 130, endless belt 132 and pulley 124 to the rear drive shaft 122'so that the front and rear drive shafts 122 and 122'integral with each other are driven to rotate as a single unit in one predetermined direction about their respective axes and cause the front and rear pulley carriers 112 and 112'to longitudinally move along the guide rail 110 away from the longitudinal middle point M of the guide rail 110 as indicated by arrows a and a'in Figure 16A. The front and rear control pulleys 76 and 76'supported on the pulley carriers 112 and 112', respectively, are therefore moved away from each other in a longitudinal direction of the guide rail 110 until the front and rear pulley carriers 112 and 112'reach their respective foremost and rearmost longitudinal positions on the guide rail 110 as indicated by the dots and-dash lines in Figure 16A. Figure 15A shows a condition in which the collapsible net assembly 30 forming part of the second embodiment of the present invention is suspended in a lying position by the suspension rope 82 supported by the front and rear control pulleys 76 and 76'which are held in these longitudinal positions remotest from each other on the guide rail 110 mounted on the helicopter 68 in flight toward the site of a disaster. When the helicopter 68 nears the site, the drive unit 126 of the drive and guide means illustrated in Figures 16A to 16C is operated so that the front and rear drive shafts 122 and 122'are driven to rotate in the other direction about their respective axes and cause the front and rear pulley carriers 112 and 112'to move along the guide rail 110 toward the longitudinal middle point NT of the guide rail 110 as indicated by arrows b and b', respectively, in Figure 16C. As a consequence, the front and rear control pulleys 76 and 76'are moved toward each other in the longitudinal direction of the guide rail 110 until the front and rear pulley carriers 112 and 112'reach their respective rearmost and foremost longitudinal positions on the guide rail 110 as indicated by the full lines in Figure 16C.

Figure 15B illustrates the condition in which the collapsible net assembly 30 is suspended in a lying position by the suspension rope 82 supported by the front and rear control pulleys 76 and 76'which are thus held in the positions closest on the guide rail 110.

While the drive shafts 122 and 122'of the drive and guide means illustrated in Figures 16A to 16C have been described to be integrally connected together and driven by a single drive unit which is operatively connected to the unitary construction of the shafts 122 and 122', the front and rear drive shafts may be constructed to be separate and dependent from one another and driven by two separate drive units each of which is exclusively associated with only one of the drive shafts, the drive units being arranged to operate either in synchronism with each other or independently of each other. In this instance, the internal threads of the pulley carriers and accordingly the external threads of the drive shafts may be formed so that the respective internal threads of the front and rear pulley carriers and accordingly the respective external threads of the front and rear drive shafts are helically turned either in opposite directions or in the same directions. For varying the distance between the front and rear pulley carriers mounted on the drive shafts having the external threads which are thus helically turned in the directions opposite to each other, the drive respective drive units for the drive shafts should be operated to drive the shafts to simultaneously rotate in the same direction as in arrangement of Figures 16A to 16C.

Where, however, the external threads of the front and rear drive shafts are helically turned in the same directions, the distance between the front and rear pulley carriers on such drive shafts is varied by operating the respective drive units for the shafts in such a manner as to drive the shafts to simultaneously rotate in the directions opposite to each other. If, furthermore, the front and rear drive shafts which are constructed separately of each other are driven to rotate in such a manner that both of the front and rear pulley carriers are simul- taneously move in the same direction viz., forwardly or rearwardly relative to the helicopter on which the drive shafts are installed, the net assembly suspended from the helicopter can be moved in a fore-andaft direction relative to the helicopter in flight. The arrangement using the separate front and rear drive shafts is, thus, operable not only for the purpose of varying the distance between the front and rear control pulleys without varying the fore-and-aft position of the net assembly relative to the helicopter but for the purpose of moving the net assembly forwardly or rearwardly relative to the helicopter.

WHAT I CLAIM IS: 1. A helicopter-carried rescue apparatus comprising a collapsible net assembly including a collapsible frame structure supporting a net and expansible and collapsible in its entirety substantially symmetrically about an axis of the net assembly between a fully collapsed condition and a fully expanded condition defining within the frame structure an open space of predetermined configuration including a floor area over which the net is stretched substantially perpendicularly to said axis when the frame structure is in the fully expanded condition, and a hoisting system including a power driven lifting mechanism for installation on a helicopter, at least one flexible hoisting line fastened to an end of the net assembly remote from its floor area, the other end of said line being fastened to said lifting mechanism for suspending the net assembly below said helicopter at a level which is variable by means of the lifting mechanism when the helicopter is in flight, and the weight of said net assembly acting to bias the same to assume an upright position having said axis in a vertical direction when the net assembly is suspended solely by said hoisting line.

2. A helicopter-carried rescue apparatus as claimed in Claim 1, in which said frame structure comprises a support member located in the neighborhood of the hoisting line end of the net assembly, substantially perpendicular to the axis of the net assembly and, itself having an axis substantially coincident with said net assembly axis, a plurality of main ribs which are pivotally connected each at one end to said support member and which extend radially outwardly from the support member and away from said upper end of the net assembly, the individual main ribs being pivotable around the net assembly axis between first angular positions closest to the net assembly axis and second angular positions remotest from said net assembly axis, the frame structure being in the fully collapsed condition thereof when said main ribs are in said first angular positions and in the fully expanded condition when the main ribs are in said second angular positions, an elongated, externally threaded screw rod which is rotatable about a center axis substantially coincident with said axis of the net assembly and which extends axially away from said support member toward the floor area end of the net assembly, said screw rod having a leading end at a predetermined distance from said floor area end of the net assembly when the frame structure is in the fully expanded condition thereof, an internally threaded guide member which is in mesh with said screw rod and which is movable on the screw rod in opposite directions parallel with the center axis of the screw rod as the screw rod is rotated in opposite directions about the center axis thereof, control ribs extending radially outwardly from said guide member and each pivotally connected at one end to the guide member and at the other end to an intermediate portion of each of said main ribs, the individual control ribs being pivotable around the axis of the net assembly and having first angular positions closest to said axis of the net assembly and second angular positions remotest from the axis of the net assembly and being in the first angular positions thereof when the guide member is in a position closest to said leading end of the screw rod and in the second angular positions thereof when the guide member is in a position remotest from the leading end of the screw rod, and drive means mounted on said support member and operatively connected to said screw rod, the drive means being operative to drive the screw rod to rotate in either direction about the center axis of the'rod and accordingly drive said guide member to move in either direction along the screw rod.

3. A helicopter-carried rescue apparatus as claimed in Claim 1 or Claim 2 in which said net assembly further comprises buoyancy means secured to said net assembly for maintaining the net assembly unsinkable in water.

4. A helicopter-carried rescue apparatus as claimed in Claim 3, in which said buoyancv means comprises a plurality of floats which are secured to said frame structure and to said net.

5. A helicopter-carried rescue apparatus. as claimed in Claim 4, in which said floats are arranged substantially symmetrically with respect to said axis of the net assembly.

6. A helicopter-carried rescue apparatus as claimed in any one of Claims I to 5, in which said net assembly further comprises a plank structure secured to the floor area portion of the net and having substantially flat major surfaces which are substantially perpendicular to the axis of the net assembly when the net is fully expanded and stretched.

7. A helicopter-carried rescue apparatus as claimed in Claim 6, in which said plank structure is constructed of a material floatable in water.

8. A helicopter-carried rescue apparatus as claimed in any one of Claims I to 7, further comprising an attitude control system capable of having said net assembly suspended below said helicopter independently of said hoisting system and varying the attitude of the net assembly between said upright position and a lying position having said axis of the net assembly in a substantially horizontal direction when the net assembly is suspended by means of the attitude control system.

9. A helicopter-carried rescue apparatus as claimed in Claim 10, in which said attitude control system comprises a flexible suspension line which is fastened at one end assembly and being in the first angular positions thereof when the guide member is in a position closes to said leading end of the screw rod and in the second angular positions thereof when the guide member is in a position remotest from the leading end of the screw rod, and drive means mounted on said support member and operatively connected to said screw rod, the drive means being operative to drive the screw rod to rotate in either direction about the center axis of the rod and accordingly drive said guide member to move in either direction along the screw rod.

22. A helicopter-carried rescue apparatus as claimed in Claim 21, in which said net assembly further includes buoyancy means secured to said frame structure for maintaining the net assembly unsinkable in water.

23. A helicopter-carried rescue apparatus as claimed m Claim 22, in which said buoyancy means comprises a plurality of floats which are secured to the main ribs.

24. A helicopter-carried rescue apparatus as claimed m Claim 23, in which said floats are arranged substantially in symmetry with respect to said axis of said net assembly.

25. A helicopter-carried rescue apparatus as claimed in Claim 23 or 24, in which each of said floats is constructed of a solid block of closed-cellular foams of synthetic resin.

26. A helicopter-carried rescue apparatus as claimed in Claim 23 or 24, in which each of said floats is constructed of a hollow inflatable container.

27. A helicopter-carried rescue apparatus as claimed in any one of Claims 23 to 26, in which said net assembly further includes a plank structure secured to the floor area portion of said net and having substantially flat major surfaces which are substantially perpendicular to said axis of the net assembly when the net is fully stretched.

28. A helicopter-carried rescue apparatus as claimed m Claim 27, in which said plank structure has a major portion constructed of a floatable material.

29. A helicopter-carried rescue apparatus as claimed in Claim 28, in which said floatable material consists of closed cellular foams of svthetic resin.

30. A helicopter-carried rescue apparatus as claimed in Claim 28 or 29, in which said plank structure is located substantiallv centrally of the floor area portion of said net.

31. A helicopter-carried rescue apparatus as claimed in any one of Claims 21 to 30, in which said net assembly further includes a stop member secured to said screw rod in proximity to the leading end of the screw rod.

32. A helicopter-carried rescue apparatus as claimed in any one of Claims 9 to 31, in which said suspension line has a roller chain constituting at least an intermediate portion of the suspension line and in which said suspension mechanism comrpises at least one sprocket wheel with which said roller chain is engageable, said roller chain having a length capable of maintaining the roller chain in engagement with said sprocket wheel when said suspension line is in a condition suspending said net assembly in a position variable between said upright and lying positions inclusive.

36. A helicopter-carried rescue apparatus constructed and arranged substantially as described with reference to and as illustrated in the accompanying drawings.