Firefighting Apparatus

Abstract

A firefighting bucket carried by a helicopter has flexible walls and a collapsible frame facilitating transportation and storage. Slide fasteners in the flexible walls may be opened to reduce the capacity of the bucket. Doors in the bottom of the bucket are operated by a fluid-operated ram which is connected to a pressurized fluid source in the aircraft. The ram may be laid flat when the frame is collapsed.

Description

This invention relates to an aircraft-borne firefighting bucket. The principal use envisioned for this apparatus is in the fighting of forest fires -- a task which is frequently performed by a highly mobile group of firefighters who move substantial distances between fire sites.

In recent years, valuable techniques have been developed for fighting fires with rotary-wing helicopter aircraft. One such technique involves the use of a water bucket which is a vessel having a capacity of several hundred gallons. Doors in lower portions of the bucket are opened to permit filling and emptying. Filling is usually accomplished simply by opening the doors and flying the helicopter to immerse the bucket in a lake or other relatively calm body of water. The doors are closed and the filled bucket is flown to the fire site where the doors are opened to discharge the water. The flight techniques used by the pilot enable him to drop the load on individual targets such as burning snags or stumps, or he may regionalize the load to supress fire lines "jumps" or grass and brush fires.

Prior to this invention, all modern firefighting buckets were rigid vessels formed of metal or reinforced plastic. Some were provided with water-discharging holes selectively closed by plugs in order to vary the capacity of the vessel. Some of these prior devices were provided with a door-opening mechanism which included an electric motor which turned a door-opening screw. Disadvantages of this arrangement are that loss or severe damage to the bucket is costly since all of the significant mechanical elements are on the bucket. Another disadvantage is that such mechanisms operate relatively slowly, taking 2 or 3 seconds. In emergency situations where a pilot wishes to jettison the entire load instantaneously, the slowly opening doors are quite undesirable.

A prior design attributable to the present inventor involved the use of a pneumatic ram involving a cylinder and piston which opened doors in the bottom of a rigid firefighting bucket; however, this arrangement also had its shortcomings, especially when the firefighting buckets had to be transported for excessive distances. Particularly, it was found that the wind resistance provided by the bucket itself made it extremely impractical to carry the bucket beneath the helicopter for substantial distances. Instead, fixed wing aircraft were used to transport the buckets to an airport near the fire site. This form of transportation is, of course, both expensive and time consuming.

In order to overcome some of the disadvantages attributable to prior firefighting buckets, this invention contemplates the use of a bucket formed of a collapsible frame with flexible sidewalls so that the space occupied by the bucket may be minimized during periods of storage and transportation. This enables the bucket to be stored at strategic ground stations ready for instant use, carried inside the cockpit of a helicopter, carried beneath the fuselage of the helicopter in a transport rack or, if desired, carried with other firefighting supplies in conventional aircraft.

According to the disclosed and preferred embodiment of the invention, the collapsible frame includes upper and lower peripheral frame elements which are maintained at a constant maximum spacing by means of braces pivotally connected therebetween. The braces are movable to collapsed positions to permit the upper and lower peripheral frame elements to move toward each other and reduce the volume occupied by the bucket. It is also preferred that the doors in the bucket be operated by a fluid-operated ram which is movable to a collapsed position where it lies flat when the frame is in its collapsed position.

Another aspect of this invention involves the provision of slide fasteners and flexible side walls in a firefighting bucket, with the slide fasteners being openable to permit liquid to escape from the bucket in order to control the effective capacity of the bucket.

The preferred form of firefighting bucket according to this invention has been found to be relatively inexpensive to manufacture, easily transportable, relatively light and otherwise extremely useful and reliable when performing its task of extinguishing fires. The satisfaction of these and other objects will be apparent from a study of the preferred embodiment thereof described in the specification and shown in the accompanying drawings wherein:

FIG. 1 is a view showing an operational firefighting bucket suspended from a helicopter.

FIG. 2 is an elevational view of the water bucket, partially in cross-section.

FIG. 3 is a plan view of the apparatus.

FIG. 4 is a detail of one suitable means for locking the frame braces in position.

FIG. 5 is a view similar to FIG. 2 but showing the device in its collapsed position.

FIG. 6 is a schematic view of the pneumatic system used in connection with the apparatus.

As seen in FIG. 1, the bucket generally designated 2 is suspended from the usual sling hook on a helicopter 8 by means of a sling 4 which is attached to four equally-spaced points on the frame of the bucket 2. Air lines 6 extend from a pressure source in the cockpit of the helicopter 8 to the door-operating ram located in the bucket 2 and described in a later portion of this specification.

The normal use of the device when suspended from a helicopter as shown in FIG. 1 involves the filling of the bucket 2 by flying to a large body of water such as a lake. The doors in the bottom of the bucket 2 are opened, and the pilot reduces his altitude until the bucket 2 is immersed. The bucket doors are closed and the pilot increases his altitude to withdraw the filled bucket from the body of water. The pilot then flies to the fire and, when properly positioned, he opens the doors in the bucket to discharge its contents on the fire.

Details of the bucket will be seen in FIG. 2. The bucket is formed of a collapsible frame which supports the flexible side walls. The frame includes an upper peripheral frame element 10 connected to a lower peripheral frame element 12 by means of four braces 14.

The braces 14 serve as connector means which hold the frame elements 10 and 12 at a fixed spaced apart distance. The braces are pivotally connected to the frame elements 10 and 12 by pivot pins 16 and 18, the axes of which are substantially horizontal and lie about 45.degree. with respect to a vertical plane which passes through the center of the bucket and through the respective brace. The mid-portion of the brace 14 includes a hinged connection with a pivot pin 20, the axis of which lies parallel to the pins 16 and 18.

Experience has shown that the bucket flies better when its sidewalls are tapered upwardly and outwardly. Accordingly, the horizontal dimensions of the upper peripheral frame element 10 are greater than those of the lower frame element 12. In order to enable these elements to collapse to the maximum extent when the device is not in use, the pivot pin 20 is located closer to the pin 18 than to the pin 16.

The bottom wall of the bucket is rigid, but the sidewalls are flexible in order to permit collapsing of the frame. The sidewalls are formed of canvas 22 which has a seam at its upper edge for retaining a metal strap 24. Blind rivets pass through openings in the strap 24 and through the wall of the tubular upper peripheral frame element 10, in order to hold the upper edge of the flexible sidewalls in position. The lower edge of the canvas 22 is folded inwardly where it rests upon a horizontal deck 26 of the bucket bottom. An annular member 28 is provided with holes which receive rivets 30. These rivets pass through the member 28 and the deck 26 to hold the canvas in position. A conventional plastic sealant may be used to prevent leakage of water between the plate 26 and the lower edge of the canvas 22.

While various means such as an over-center locking arrangement may be used to hold the brace in its upright position, the preferred mechanism is shown in FIG. 4 where it will be seen that a locking member 15 is axially slidable in the two segments 14a and 14b of the brace. A compression spring 17 operates between the locking member 15 and a stationary pin 19 in order to urge the locking member 15 upwardly as viewed in FIG. 4. An actuating element 21 extends through slot 23 in the brace portion 14b and may be depressed in order to withdraw the member 15 and permit the brace portions to move relatively about the pivot pin 20 of the brace hinge.

The construction of the doors in the bottom of the bucket is best seen in FIGS. 2 and 3. The bottom frame of the bucket includes the peripheral frame element 12, the steel deck 26 and a pair of spanning tubular bars 36. The deck 26 covers the entirety of the area within the peripheral frame element 12 with the exception of a pair of rectangular openings located beneath the doors 38. The doors 38 are supported on piano hinges 40 which have one leaf attached to the deck 26 above the tubular bars 36 and the other leaf attached to the door itself. The peripheral edges of the doors 38 rest on the deck members 26 where there may be soft rubber seals or gaskets to minimize or prevent leakage.

The means for moving the doors from their illustrated closed position to the open water-discharging position includes a double acting pneumatic ram 42 which has a conventional cylinder and piston construction. When the bucket is operational, the ram 42 is, as illustrated in FIGS. 2 and 3, upright with respect to the bottom of the bucket. The lower end of the ram is attached to the bottom of the bucket frame by means of a pair of upstanding brackets 46 which support a pin 48. Spaced apart eyes 50 on the lower end of ram 42 surround the pin 48 to provide a pivotal connection between the pin 48 and the ram 42.

The other end of the ram 42 includes an extensible rod 52 which is raised and lowered by the air acting upon the piston within the ram 42. An eye 54 at the upper end of the rod carries a pair of members 56, the outer ends of which are pivotally connected by pins 58 and 60 to eyes located at the uppermost ends of the adjustable length door actuating rods 62 and 64. The lower ends of the rods 62 and 64 are bifurcated to carry bolts 66 and 68 which are pivotally received in link members 70 and 72. The link members 70 and 72 are connected, respectively, by pins 74 and 76 to the upstanding pairs of brackets 78 and 80 on the two doors 38.

During normal operations, the pneumatic ram 42 is maintained in its upright position by means of the brace member 82 best shown in FIG. 3. The brace member 82 is pivotally connected by a quick-release pin 84 to the spaced apart ears 86 on the housing of the ram 42. The lower end of the brace 82 includes a sleeve 88 connected by a bolt 90 to upstanding brackets 92 on the deck 26. When it is desired to collapse the bucket, it is a simple task to remove the quick pin 84, rotate the ram 42 about the pivotal connection formed by the pin 48, and similarly tilting the door actuating rods 62 and 64 about the pivot pins 66 and 68. Collapsing of the frame of the bucket therefore simply involves collapsing the braces to enable the peripheral frame elements 10 and 12 to move toward each other. The quick pin 84 is removed from the brace for the pneumatic ram 42, and the ram assembly is laid sideways against the bottom of the bucket.

FIG. 6 is a diagrammatic showing of one suitable arrangement for actuating the doors of the bucket. This arrangement includes a compressor 94 and a pressure vessel 96 which serve as a source of pressurized fluid to the door-operating ram 42. A valve 98 in the cockpit is provided with two stages which are selectively moved to open or close the doors. When in its illustrated position, the valve introduces high pressure air to the conduit 100 which urges the piston and the door actuating rod 52 upwardly. At the same time, the area above the piston is vented through the conduit 102 to the atmosphere. Movement of the valve 98 to a position where its other stage is operative will cause the high pressure air to flow into the conduit 102, forcing the piston and the rod 52 downwardly and venting the conduit 100 to the atmosphere. While there is nothing critical about the particular nature of the elements shown in FIG. 6, it has been found desirable to provide air at a pressure of 250 psi, generated by a compressor operated by the electrical system of the aircraft. One suitable compressor is the Corneilus compressor of the type used as gunchargers in World War II fighter aircraft.

Variations in flying conditions and in aircraft lift capabilities makes it desirable to provide variations in the capacities of the bucket. This may be done by providing different sized buckets, but it is also possible to do this by using a zipper or other suitable slide fastener in the flexible sidewall of the bucket. When the zipper fasteners are open, the bucket will retain water only up to their elevation, thereby giving the pilot some control over the magnitude of the load which he is carrying.

As shown in FIG. 2, a zipper 32 has its conventional attaching tapes sewn to opposite sides of a horizontal slot in the canvas sidewall 22. A canvas flap 34 lies over the opening in order to prevent excessive seepage through the zipper and to prevent the application of too much pressure on the zipper. In order to maximize the discharge rate of excessive water, it is preferred that a series of zippers be provided so that the total circumferential extent of the openings will be between 20 and 50 percent of the circumference of the canvas 22 at the elevation of the zippers.

It will become apparent to persons skilled in the art that this invention may be used in diverse forms of firefighting buckets having significant physical disimilarities from the illustrated and preferred embodiment of the invention. Therefore, it is emphasized that the invention is not to be construed as limited to the preferred and disclosed embodiment, but is intended to encompass all devices which fall within the spirit of the claims which follow.

Claims

I claim:

1. Firefighting apparatus comprising

a bucket for fire-extinguishing material,

means for suspending the bucket from an aircraft,

said bucket having a bottom with two doors openable to discharge gravitationally the contents of the bucket,

means for opening the doors including a fluid-operated ram located between the doors,

said bucket being formed of a collapsible frame having flexible sidewalls, thereby permitting reduction of the volume occupied by the bucket when being stored or transported, one portion of the ram being connected to the frame and another portion of the ram being connected to both said doors.

2. Apparatus according to claim 1 having disengageable means for holding the ram erect with respect to the bottom of the bucket during normal use of the bucket, said ram being movable upon disengagement of the disengageable means to a position where it lies flat when the frame is in its collapsed position.

3. Apparatus according to claim 2 in combination with an aircraft.

4. Apparatus according to claim 3 having a source of pressurized fluid in the aircraft, a fluid passage connecting the source and the ram, and valve means in the fluid passage which permits controlled operation of the ram.

5. Apparatus according to claim 1 wherein the frame includes upper and lower peripheral frame elements which have constant dimensions regardless of the collapsed or erected state of the bucket, connector means holding the peripheral frame elements at a fixed spaced apart distance when the bucket is in its erected position, means for disabling said connector means to permit the peripheral frame elements to move toward each other.

6. Apparatus according to claim 5 wherein the connector means are a plurality of braces pivotally connected at their opposite ends to each of the peripheral frame elements, and the means for disabling the connector means are lockable pivotal joints located between the opposite ends of each of the braces.

7. Apparatus according to claim 6 wherein the upper peripheral frame element is larger horizontally than the lower peripheral frame element so as to improve the aerodynamic and immersibility characteristics of the bucket, and the lockable pivotal joints are located closer to the lower peripheral frame element than to the upper peripheral frame element.

8. Firefighting apparatus for use with aircraft comprising

a bucket for fire-extinguishing material,

means for suspending the bucket from an aircraft,

said bucket having a door in a lower portion thereof openable to discharge gravitationally the content of the bucket,

means for opening the door,

said apparatus being characterized in that the sidewalls of the bucket is formed of a flexible sheet material,

slide fasteners in the sidewalls below the upper edge thereof, whereby the slide fasteners may be opened to permit liquid to escape therefrom in order to control variably the capacity of the bucket.

9. Firefighting apparatus comprising

a bucket for fire-extinguishing material,

means for suspending the bucket from an aircraft,

said bucket having a door in a lower portion thereof openable to discharge gravitationally the contents of the bucket,

means for opening the door,

said apparatus being characterized in that the bucket is formed of a collapsible frame having flexible sidewalls, thereby permitting reduction of the volume occupied by the bucket when being stored or transported and,

said sidewalls having openings below the upper edge thereof closed by slide fasteners, whereby the slide fasteners may be opened to permit liquid to escape therefrom in order to control variably the capacity of the bucket.

10. Firefighting apparatus comprising

a bucket for fire-extinguishing material,

means for suspending the bucket from an aircraft,

said bucket having a door in a lower portion thereof openable to discharge gravitationally the contents of the bucket,

means for opening the door,

said bucket being formed of a collapsible frame having flexible sidewalls, thereby permitting reduction of the volume occupied by the bucket when being stored or transported,

said collapsible frame includes upper and lower peripheral frame elements which have constant dimensions regardless of the collapsed or erected state of the bucket, said upper peripheral frame element being larger horizontally than the lower peripheral frame element so as to improve the aerodynamic and immersibility characteristics of the bucket,

a plurality of braces pivotally connected at their opposite ends to each of the peripheral frame elements to hold peripheral frame elements at a fixed spaced apart distance when the bucket is in its erected position, lockable pivotal joints located between the opposite ends of each of the braces and closer to the lower peripheral frame element than to the upper peripheral frame element to permit the peripheral frame elements to move toward each other, each said brace having the pivotal axis of its lockable pivotal joint and the pivotal axis of its connections to the frame elements lying horizontal and at about 45.degree. with respect to a vertical plane which passes through the center of the bucket and through the respective brace when erected.

11. Firefighting apparatus comprising

a bucket for fire-extinguishing material,

means for suspending the bucket from an aircraft,

said bucket having a door in a lower portion thereof openable to discharge gravitationally the contents of the bucket,

means for opening the door,

said bucket being formed of a collapsible frame having flexible sidewalls, thereby permitting reduction of the volume occupied by the bucket when being stored or transported, a door-actuating fluid operated ram having one portion connected to the frame and another portion connected to the door, and

disengageable means for holding the ram erect with respect to the bottom of the bucket during normal use of the bucket, said ram being movable upon disengagement of the disengageable means to a position where it lies flat when the frame is in its collapsed position.