HK1031202B - Braking device - Google Patents

Description

Brake device

The present invention relates generally to vertically descending life saving devices and more particularly to a brake device for a vertically descending life saving device which uses a solid pourable material which generates a braking force when a centrifugal force is applied to the material.

Vertical descent lifesaving devices are known, which basically comprise some type of chair or safety belt for supporting the human body, which is connected to a drum on which a cable is wound, in the event of a critical situation requiring a rapid evacuation of a high-rise building, a person fixes himself to the chair or safety belt and hooks one end of the cable to a solid position of the building, and then the person jumps away from the building, a braking mechanism reducing the speed of rotation of the drum with the cable as the person descends, so that the person descends to the ground at a safe speed.

An example of such a device is described in dutch patent 9401422 to Boon Safety CV, which describes a self-evacuating portable unit for use in high-rise buildings, comprising a spool with a cord wound in two directions and having braking means limiting the speed of the cord, which acts on the cord, which is made of aramid material, like TWARON and KEVLAR.

Soviet union patent 1430031 describes a life saving device for descent comprising a support hat fitted with a brake disc and an adjustable emergency brake shoe.

Brazilian patent 8701130 describes an automatic gravity rescue device which includes a system having a spooled safety belt for falling from a high rise building and an automatic belt rewinding mechanism.

Portugal patent 77995 describes a rescue apparatus for people trapped in a building that includes a safety belt mounted on a pair of rollers and a plurality of suspended cable sets.

The soviet patent 1005798 describes a centrifugal braking mechanism for a load-lowering device, which mechanism comprises a plurality of springs of different strengths.

Soviet union patent 3372230 describes a centrifugally braked lifesaving mechanism having a drum including a brake disc disposed in an inner cavity of a brake cylinder having brake shoes therein, the mechanism having a plurality of springs of different strengths for urging the brake shoes against the brake disc, the end of the cable moving downwardly and rotating the drum when a person being rescued descends, the moment from the drum being transmitted to a flywheel of the centrifugally braked mechanism through a cam clutch and planetary gear reducer, the brake shoes rising to the inner surface of the drum due to the centrifugal force against the spring force of the springs and urging against the brake disc.

Dutch patent 8004667 describes a building emergency lifesaving cable drum which is stopped or braked during the paying out of the cable by the tension of the cable, at least once per revolution, in order to limit the speed of the paying out.

German patent document 2748904 describes a rope drum for life saving equipment having a brake mechanism that engages and disengages the brake by rotating a crank handle.

Us patent 4448284 describes a life saving device with a centrifugally powered brake that is pressed by centrifugal force against a brake drum when a rescue line is paid out from the rotating drum.

One disadvantage of the prior art devices is that the braking movement generates a significant amount of heat during descent, which can result in the descent speed being above the safe speed limit, or worse, in catastrophic failure of the braking mechanism.

The present invention seeks to provide an improved vertically descending rescue apparatus which is safe and reliable and is not affected by the heat generated by the brake.

There is thus provided in accordance with a preferred embodiment of the present invention a brake including a chamber rotatably mounted on a shaft, the chamber defining an interior chamber in which is mounted a disc having opposed surfaces extending outwardly from said shaft, a solid pourable material being disposed in said interior chamber, rotation of the chamber being sufficient to cause said material to generate centrifugal forces which wedge said material between the interior surface of the chamber and the opposed surfaces to apply a braking force to the disc.

According to a preferred embodiment of the invention, the apparatus further comprises a roller mounted on said shaft and connected to the chamber, wherein rotation of the roller rotates the chamber.

Further in accordance with a preferred embodiment of the present invention the drum is connected to the chamber by a gear train, preferably causing the speed of rotation of the chamber relative to the drum to be increased.

Additionally in accordance with a preferred embodiment of the present invention, the apparatus further includes a cable wound around the drum.

In accordance with a preferred embodiment of the present invention, the apparatus further comprises a support ring fixedly attached to the end of the cable.

Further in accordance with a preferred embodiment of the present invention, the apparatus further includes a housing connected to the shaft, the chamber being disposed within the housing.

Further in accordance with a preferred embodiment of the present invention, at least one handle is attached to an outer surface of the housing.

In accordance with a preferred embodiment of the present invention, at least one body support means is attached to the outer surface of the housing.

Further in accordance with a preferred embodiment of the present invention, the solid pourable material may comprise: sand, powdered material or granular material.

Further in accordance with a preferred embodiment of the present invention there is provided a brake apparatus including a chamber rotatably mounted on a shaft, the chamber defining an interior chamber, a disc mounted on the shaft in the interior chamber, the disc having opposed surfaces extending outwardly from said shaft, a wedge disposed in said interior chamber, the chamber being rotatable sufficiently to cause said wedge to generate a centrifugal force to wedge said wedge between the interior surface of the interior chamber and at least one of the opposed surfaces to apply a braking force to the disc.

According to a preferred embodiment of the invention, the wedge pair has a catch and preferably also the opposite surface.

The invention will be understood and appreciated more fully from the following drawings and detailed description.

FIG. 1 is a simplified cross-sectional view of a brake apparatus constructed and operative in accordance with a preferred embodiment of the present invention;

FIG. 2 is a simplified schematic illustration of a life saving device constructed and operative in accordance with a preferred embodiment of the present invention, including the brake device of FIG. 1;

fig. 3 is a simplified cross-sectional view of a brake apparatus constructed and operative in accordance with another preferred embodiment of the present invention.

Referring now to fig. 1, fig. 1 illustrates a brake apparatus 10 constructed and operative in accordance with a preferred embodiment of the present invention.

The brake apparatus 10 includes a chamber 12, the chamber 12 being rotatably mounted on a shaft 14, the chamber 12 being formed of two halves 12A and 12B, but it will be appreciated that any other configuration may be used. The chamber 12 has an inner cavity 16 which in the illustrated embodiment has an end portion that is approximately parabolic in shape, but any other shape may be used.

The disc 18 is mounted on the shaft 14 within the cavity 16. the disc 18 preferably has two opposed surfaces 20 and 22 extending outwardly from the shaft 14.

The solid pourable material 24 is arranged in the inner cavity, the solid pourable material 24 may be any kind of powdery or granular material, and the best mode of carrying out the invention comprises using sand as the solid pourable material 24. Sand can withstand the tremendous heat generated during braking without significant changes in the material properties. The shape imparted to the solid pourable material 24 during rotation by the chamber 12 is shown in fig. 1, as will be described below. Of course, it should be understood that the solid pourable material 24 is only located within the chamber 12 when the chamber 12 is in a quiescent state. One or more sealing strips 25 may be provided in the inner cavity 16 to seal the solid pourable material 24.

The roller 26 is preferably movably mounted on the shaft 14 and is connected to the chamber 12, for example by mechanical fasteners 27 at reference lines, the roller 26 is preferably connected to the chamber 12 by a gear train 28, the gear train 28 comprising one or more reduction gears, the roller 26 rotating about the shaft 14 to rotate the chamber 12, the gear train 28 preferably providing the chamber 12 with a higher rotational speed than the roller 26, for example, the gear ratio may be selected such that the rotational speed of the chamber 12 is 5 times the rotational speed of the roller 26. The cable 30 comprises a plurality of flexible steel cords, preferably in the amount required for safety, and the cable 30 is preferably wound around the outside 32 of the drum 26.

The shaft 14 is preferably pivotally mounted within the housing 34, the chamber 12 is within the housing 34, and the gears of the gear set 28 are also preferably pivotally mounted within the housing 34, the combination of the chamber 12, the disc 18, the shaft 14, the solid pourable material 24, the housing 34 and the cable 30 forming the life saving device 35.

Referring now to fig. 2, fig. 2 shows a person 36 falling from a high-rise building 38 using the life saving device 35. Preferably, the cable 30 has a support ring 40 secured to one end thereof, and optionally one end of the cable 30 is connected to an elastic band 42, in which case one support ring 40 is secured to one end of the elastic band 42.

When the life saving device 35 is in use, the support ring 40 is attached to a hook 44 or other structure that is securely anchored to the building 38, and the life saving device 35 preferably has one or more body support devices 46, such as a harness 48. One or more armrests 50 are preferably attached to the outer surface of the housing 34. Alternatively, instead of grasping the life saving device 35, the person 36 may attach the life saving device 35 to the hook 44 and the cable 30 to the body support 46 to descend with the cable 30.

Additionally, referring to FIG. 1, as the person 36 descends, the cable 30 is paid out from the drum 26 and the drum 26 is then caused to rotate, the rotation of the drum 26 causes the chamber 12 to rotate more rapidly through the gear train 28, the rotation of the chamber 12 causes the solid pourable material 24 to generate centrifugal forces and wedge the solid pourable material 24 between the inner surface of the cavity 16 and the opposed surfaces 20 and 22 to generate a braking force against the disc 18, whereby the solid pourable material 24 acts more like a brake pad pressing against the disc 18 to brake, as described above, the solid pourable material 24 having the shape shown in FIG. 1 during rotation of the chamber 12.

Tests have shown that the rescue apparatus 35 allows rescue weights to be reached from 1-1000kg of people to a safe descent speed of less than 2.5 m/s. The solid pourable material 24 may reach very high temperatures, which may be well above 1000 c, for example, during a descent of a few hundred meters, the sand used as the solid pourable material 24 may effectively polish the surfaces 20 and 22 and the sand may become powdery, and nevertheless, the sand may effectively and safely brake the disc 18. The above values are of course merely exemplary and the invention is not limited to these values.

Referring now to fig. 3, fig. 3 illustrates a brake 60 constructed and operative in accordance with another preferred embodiment of the present invention. The brake 60 is substantially identical to the brake 10 and like numerals are used to designate like parts, and the brake 60 differs from the brake 10 in that the brake 60 does not include a solid pourable material, but rather includes one or more wedges 62 freely disposed in the interior cavity, the wedges 62 preferably being aligned with corresponding brake pads 64 and the disc 18 preferably being aligned with corresponding brake pads 66.

Fig. 3 shows one wedge 62 (on the right side of the disc 18) prior to rotation of the drum 26 and chamber 12 and the other wedge 62 (on the left side of the disc 18) during rotation of the drum 26 and chamber 12, as described above with respect to the life saving device 35, as shown in fig. 2, as the person 36 descends, the cable 30 is paid out from the drum 26 and then the drum 26 is rotated, rotation of the drum 26 causes the chamber 12 to rotate faster through the gear train 28, rotation of the chamber 12 causes the wedge 62 to generate centrifugal force and wedge the wedge between the inner surface of the cavity 16 and the catch 66 of the opposing surfaces 20 and 22 so that the catch 64 of the wedge 62 generates a braking force on the disc 18. It will be appreciated that the wedge 62 may have any shape that conforms to the shape of the inner surface of the cavity 16.

It will be understood by those skilled in the art that the foregoing detailed disclosure and description are not intended to limit the invention, but on the contrary, the intention is to cover both combinations and subcombinations of the features described hereinabove as well as variations and modifications thereof which would occur to persons skilled in the art upon reading the foregoing description and which are not in the prior art.

Claims (13)

1. A brake apparatus comprising:

a chamber rotatably mounted on the shaft, said chamber defining an interior cavity;

a disk mounted on said shaft within said cavity, said disk having opposite surfaces extending outwardly from said shaft;

a solid pourable material disposed in said cavity, rotation of said cavity causing said material to generate centrifugal forces and wedge said material between said inner surface of said cavity and said opposing surface to generate a braking force against said disc.

2. The brake apparatus of claim 1, further comprising a roller mounted on said shaft and connected to said chamber, wherein rotation of said roller rotates said chamber.

3. The brake of claim 2, wherein said roller is connected to said chamber by a gear train.

4. A braking apparatus as claimed in claim 3, wherein the gear train causes the chamber to rotate at a higher speed than the drum.

5. The brake apparatus of claim 2, further comprising a cable wound around said drum.

6. The brake apparatus of claim 5, further comprising a support ring secured to one end of said cable.

7. The brake apparatus of claim 1 further comprising a housing connected to said shaft, said chamber being disposed within said housing.

8. The brake of claim 7, wherein at least one handle is attached to an outer surface of said housing.

9. The brake of claim 7, wherein at least one body support is associated with an outer surface of said housing.

10. The brake apparatus of claim 1, wherein said solid pourable material is selected from the group consisting of: sand, powdered material or granular material.

11. A brake apparatus comprising:

a chamber rotatably mounted on the shaft, said chamber defining an interior cavity;

a disk mounted on said shaft within said cavity, said disk having opposite surfaces extending outwardly from said shaft;

a wedge disposed in said cavity, rotation of said chamber causing said wedge to generate centrifugal force to wedge said wedge between an inner surface of said cavity and at least one of said opposing surfaces to generate a braking force against said disc.

12. The braking device of claim 11, wherein the pair of wedges has a brake pad.

13. The brake apparatus of claim 11 wherein said opposed surfaces are tapered.