JP2826473B2 - Self-propelled emergency ladder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION The present invention relates to a self-propelled emergency ladder,
In particular, it relates to a self-propelled emergency ladder that can simultaneously evacuate from each floor of a building without using electric power.

2. Description of the Related Art There are many types of conventional safety devices for evacuation, but all of them are used by doors or floors and cannot be used by many people at the same time. In addition, many of these safety devices for evacuation are temporarily attached, and when a danger occurs, circumstances may occur such that the attachment is bad or the safety device cannot be found temporarily during evacuation. Furthermore, when a large number of people use these safety devices at the same time, they may be confused and pushed with relatively weak physical strength, or the passenger may inadvertently slip and fall. An object of the present invention is to provide a self-propelled emergency ladder that enables residents on each floor of a building to simultaneously evacuate without using electric power in order to solve the above problems.

SUMMARY OF THE INVENTION A recirculation ladder, proposed to achieve the above object, comprises two rails having a U-shaped cross section. A rail device which is opposed to each other with an opening inside, and whose upper and lower ends are curved and endlessly suspended, and circulates along the inside of the U-shaped cross section of the two endless rails of the rail device; With a ring chain steer to
The ring chain steer is composed of a number of shaft bars and a flat block for interconnecting both ends of the shaft bar,
Further, rollers are attached to both ends of the shaft bar of the ring chain steer, and the rollers are loosely fitted inside the U-shaped rails of the rails arranged opposite to each other on the rail device, so that the ring chain steer is moved. A self-propelled emergency ladder configured to be able to circulate along the rails, and the rail device includes two rails that are vertically suspended in parallel with a predetermined interval, and the upper and lower ends of each rail are Each of the rails is curved in an arc shape to form an endless rail, has a U-shaped cross section, and has a relatively wide U-shaped upper and lower curved portion to smoothly circulate the ring chain steer. The self-propelled emergency ladder and the ring chain steer have a plurality of shafts each having a length shorter than a distance between the opposed rails having a U-shaped cross section and having screw portions near both ends. bar A plurality of flat blocks having shaft holes at both end portions thereof, into which extended portions provided at both end portions of the shaft bar are inserted, and the shaft bar for positioning these flat blocks on the plurality of shaft bars. A self-propelled emergency ladder comprising a plurality of nuts for tightening and fixing, and the plurality of shaft bars are formed with a middle portion having a larger diameter than a shaft hole provided in the flat block, and the flat block is It is configured not to move in the center direction of the shaft bar, and furthermore, an extending portion is protruded from both ends of the intermediate portion, and the extending portion is formed to have a smaller diameter than the shaft hole of the flat block, The length of the extending portion in the axial direction is slightly longer than the thickness of the two flat blocks so that the ends of the flat blocks overlap each other so that the flat blocks can be loosely fitted to the extending portion. The extension that protrudes from the installation part is provided with a screw part for tightening the nut. The portion extending further to both sides than the extension portion has no screw, and is slightly thinner than the screw portion so that the nut can be screwed to the screw portion of the shaft bar. A self-propelled emergency ladder provided with rollers so as to be able to be connected to each other; and two elongated flat blocks arranged in parallel on a shaft bar of the ring chain steer at predetermined intervals, and the two elongated pieces. Foot block consisting of at least one horizontal bar interposed between the flat blocks, and the horizontal bar is provided with a nut in a through hole provided to face each of the long flat blocks. The foot step is fixed to
Each of the fixed ends of the long strip-shaped flat blocks and the corresponding projecting portion of the L-shaped flat block attached to the shaft bar are tightened and fixed through holes formed in the fixed ends. A stopper protrudes obliquely above the hole of the protruding portion, and when a load is applied to the foot step, the upper edge of each fixed side end of the elongated flat block is received by the stopper, and the ring chain A self-propelled emergency ladder configured to form a step for a passenger by being held at a right angle to the steer, and two long flaky flat blocks of the footstep are formed by joining a plurality of short flaky flat blocks. It is formed or formed so that it can be easily laid by laying a plate or net on the elongated flat block, and furthermore, a hammer is provided at a predetermined distance on the shaft bar of the ring chain steer, and Corresponding to the rail A self-propelled emergency ladder that attaches a bell to one side of the device, generates a sound by hitting the bell when the mallet passes by the bell, and informs the descending altitude of the emergency ladder, and a plurality of axes. A speed reducer configured by combining gears is fixed to fixing means, and at least one power switching wheel is further provided in the middle of one of the gear shafts. The ring chain steer is fixed to the one gear shaft so as to be able to enter between the two shaft bars of the ring chain steer, so that the ring chain steer can be stably and smoothly run on the large gear and the U-shaped rail in cross section. The speed reducer further comprises at least one blade on a gear shaft of the speed reduction gear set, and the speed of descent of the ring chain steer is reduced by wind resistance generated on the blade during rotation. Wherein at least one blade further includes a sub-blade fixed on the blade by a spring, and when the rotation is relatively fast, the blade is widely opened due to centrifugal force and wind resistance. A self-propelled emergency ladder and a circulating ladder, wherein the lowering speed of the ring chain steer can be adjusted by the wind resistance, and the circulating ladder circulates along a rail device; A fixing means for fixing the rail device to the building, and a speed reducer attached to the fixing means for reducing the circulation speed of the ring chain steer, and at least one speed reducer is provided. And a sub-blade mounted on the blade so as to be decelerated using the wind resistance of the blade. And a self-propelled emergency ladder, wherein the sub-blade is biased to overlap with each other by a spring interposed between the sub-blade and the blade. In the self-propelled emergency ladder, the rail device includes two rails, each of which has upper and lower ends curved in an arc shape to form an endless rail, and has a U-shaped cross section. Because the U-shape of the curved portions at the upper and lower ends is relatively wide, the circulation operation of the ring chain steer is performed smoothly. Further, the ring chain steer in the self-propelled emergency ladder has a plurality of shafts each having a length slightly shorter than a horizontal distance between the rails disposed opposite to each other and having screw portions at both ends. A bar, a plurality of flat blocks having shaft holes at both ends, and fitted with the shaft bar, and a screw portion of the shaft bar tightened and fixed to position the flat blocks on the plurality of shaft bars. A plurality of nuts, and the plurality of shaft bars are formed such that the diameter of the intermediate portion is larger than the shaft hole of the flat block, so that the flat block is moved toward the center of the shaft bar. Can be stably mounted without moving. Further, the diameter of the extending portion provided at both ends of the shaft bar is formed smaller than the shaft hole of the flat block, and the length of the extending portion in the axial direction is equal to that of the flat block. Since the two flat blocks are formed longer than the thickness of the two flat blocks, when the ends of the two flat blocks are inserted into the extended portions of the shaft bar, the ends are engaged with each other. The extension portion protruding from the extension portion is provided with a screw portion for tightening a nut, and the portion further extending on both sides has no screw, and the nut is attached to both ends of the shaft bar. Since it is formed slightly thinner than the screw portion so that it can be fitted in the nut, the operation of inserting the nut is performed smoothly, and the workability is good. When assembling the ring chain steer, first, two shaft bars are set as one set (referred to as a first set), and one end of each is fitted into the shaft holes at both ends of one flat block. Again, a pair of two shaft bars (second
Set) One end of each is fitted into the shaft hole at both ends of another flat block, and the ends of the first set of shaft bars on the one side and the second set of shaft bars on the other side are connected to the third set. The flat chain is inserted into the shaft holes at both ends of the flat block, fixed by nuts and positioned. Similarly, a ring chain is formed by combining the last set of one side shaft bar and the first set of the other side shaft bar. Until the steer is formed, the ends of the shaft bar on one side of the preceding set and the bar on the other side of the subsequent set are fitted into another flat block, and fixed and positioned with a nut. Of course, the ring chain steer is applied to a high-rise building with an increased length as needed. Further, rollers are attached to both ends of the shaft bar, and the rollers are loosely fitted in rails having a U-shaped cross section, so that the circulation operation of the ring chain steer is smoothly performed. Further, the shaft bar of the ring chain steer is provided with a foot step including two elongated flat blocks and at least one horizontal bar at predetermined intervals, wherein the horizontal bar is a nut. It is fastened and fixed to a hole formed opposite to the elongated flat block. This foot step is formed by punching the fixed ends of the two elongated flat blocks and the corresponding projections of the L-shaped flat block (ring chain steer side) attached to the end of the shaft bar. It is fastened and fixed through the provided holes. A stopper is protruded diagonally above the hole of the protruding portion, and when a load is applied to the foot step, the upper edge of each fixed side end of the elongated flat block is received by the stopper. , Which is held at a right angle to the ring chain steer, and is the most stable footstep for a passenger.
Also, the two long flat blocks of the foot step may be formed by joining a plurality of short flat blocks, and further, a net or a plate is provided on the step to improve the stepping condition of the passenger. Let me. Further, a hammer is provided at a predetermined distance on the shaft bar of the ring chain steer. On the other hand, a bell is provided on one side of the rail device. And the descending altitude of the emergency ladder is perceived. In the emergency ladder,
The reduction gear is composed of a combination of a plurality of shafts and gears, and is fixed to the fixing means. Further, at least one power switching wheel is provided in the middle of one of the gear shafts. Since this power switchover wheel is fixed to the one gear shaft so that each tooth plate can just enter between each shaft bar of the ring chain steer, the ring chain steer is stably and smoothly driven by the large gear. It can operate between the upper and rail devices. Also, when the number of passengers is relatively large, or when the load is relatively heavy, the descent speed of the emergency ladder may be increased and a danger may be caused. Since one blade is provided, the lowering speed of the ring chain steer is reduced by the wind resistance generated by this blade during rotation. In addition, since at least one of the blades is further provided with a sub-blade biased by a spring so as to overlap the blade with the spring, when rotation is relatively fast, centrifugal force and wind resistance act. The sub-blade opens greatly, and the lowering speed of the ring chain steer is further reduced by the wind resistance, and is appropriately adjusted to maintain safety. When the emergency ladder is not used, the sub-blade can be overlapped with the blade and reduced in space by the bias of the spring. Thus, the self-propelled emergency ladder of the present invention is also applied to a high-rise building, and it is possible to evacuate occupants on each floor simultaneously and more safely without using electric power in an emergency, and the operation is extremely simple. It is stable and smooth.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the self-propelled emergency ladder of the present invention is a rail device 1.
A ring chain steer 2 circulatingly attached to the rail device 1, and fixing means for fixing the rail device 1 and the ring chain steer 2 and circulating the ring chain steer 2 between the rail devices 1. 3 and a reduction gear 4 fixed to the fixing means 3 so as to gradually lower the ring chain steer 2. Thus, in the self-propelled emergency ladder, the rail device 1 is shown in FIG.
As shown in FIG. 5, there are symmetrical rails 5 and 5 which are opposed to each other on the left and right sides and are erected in parallel at a predetermined interval, and the upper and lower ends of the rails 5 and 5 are circular. It is curved in an arc shape and formed endlessly. The rail 5,
Each of the cross-sectional shapes 5 is formed in a U-shape as shown in FIG. 2, and the respective openings of the U-shaped cross-section are formed so as to be located inside and face each other. Furthermore,
At the curved portions at both upper and lower ends of the rails 5, 5, the U-shaped cross section is formed relatively wide so that the ring chain steer 2 is formed.
The circulation operation is smoothed. Next, the ring chain steer 2 will be described with reference to FIGS. The ring chain steer 2 includes a large number of shaft bars 6, 6,... And flat blocks 8, 8,. As shown in FIG. 3, the shaft bar 6 has a large diameter at an intermediate portion, and extending portions 11 and 11 extend outward from both ends of the intermediate portion. The extending portions 11 and 11 are formed to have a slightly smaller diameter than the intermediate portion, and further extend outward from the extending portions 11 and 11.
2 and 12 are extended, and the extended portions 12 and 12 are formed to have a slightly smaller diameter than the extended portions 11 and 11. Thus, the extending portions 11 have an axial length corresponding to two flat blocks 8, and axial holes 9 9 are provided at both ends of the flat blocks 8. As will be described later, a shaft hole 9 on one side of the flat block 8 and a shaft hole 9 on the other side of another flat block 8 are formed so as to be loosely fitted to the extending portions 11, 11. I have. Further, the extending portion 12, which is formed to have a slightly smaller diameter than the extending portion 11, 11,
12 projecting outward from each of the extending portions 11, 11, and threaded portions 7, 7 are provided at the base ends of the extending portions 12, 12.
7 is provided, and the shaft hole 9 on one side of one flat block 8 is loosely fitted to the extended portions 11, 11, and the shaft hole 9 on the other side of another flat block 8 is loosely fitted. The ends of the two flat blocks 8 and 8 are overlapped, and nuts 10 and 10 are fastened to the screw portions 7 and 7 at the respective outer portions, and the flat blocks 8 and 8 are connected to the shaft. It is configured to be positioned and fixed to the bars 6 and 6. Therefore, when assembling the flat blocks 8, 8,... To the shaft bars 6, 6,.
Extension a) provided at each end using a set a)
Shaft holes 9, 9 provided at both ends of the flat block 8 at 1, 11
Are loosely fitted, and then again another two shaft bars 6, 6 (second
Extension 1 provided at one end of each of the
Shaft holes 9 and 9 provided at both ends of another flat block 8 are loosely fitted to the flat blocks 1 and 11, respectively. Then, in FIG.
And an extending portion 11 provided at the other end of the shaft bar 6 (referred to as c) on the right side of the second set b, and an extending portion provided at the other end of the left shaft bar 6 (referred to as d) of the second set b. After loosely fitting shaft holes 9, 9 provided at both ends of the third flat block 8 with the screw holes 7, 7 provided at both ends of the shaft bars 6, 6, 6, 6, respectively.
Nuts 10, 10, 10, 10 are fastened to 7, 7, 7, respectively, and positioned. Similarly, the last pair of right-side shaft bars 6 and the left-side shaft bar 6 of the first set a are finally connected to each other. Ring chain steer 2 by connecting and combining at flat blocks 8
Is formed, the right-hand shaft bar 6 of the previous set and the left-hand shaft bar 6 of the rear set are loosely inserted into different flat blocks 8 one after another and fastened with nuts 10 for positioning. Needless to say, the ring chain steer 2 is extended in length as required, and is also applied to a high-rise building. Also, FIG.
As shown in FIG. 1, rollers 13 are rotatably mounted on the ends 12a of the extending portions 12 on both sides of the shaft bar 6, respectively.
Reference numeral 3 denotes a C-shaped ring 12b, shown in FIG. 4, which is inserted through the opening of the cross-shaped U-shape of the opposed rails 5, 5 and is loosely fitted to the rails 5, 5. 12b
The rollers 13, 13 are fixed by the
Rolling of the rollers 13, 13 in the inside is smoothed. As shown in FIG. 5, the foot bars 1 are attached to the shaft bars 6, 6,.
4, 14,... Are provided. Thus, the foot step 14 comprises two elongated flat blocks 15, 15 arranged in parallel and facing each other, and at least one horizontal bar 16 interposed therebetween. The horizontal bar 16 is fastened and fixed with nuts outside the elongated flat blocks 15, 15. Also, in order to attach the foot steps 14, 14,... To the shaft bars 6, 6,. The fixed ends of the strip-shaped flat blocks 15 of the foot step 14 are fixed to the bolts and nuts 10 through holes 17 and 18 formed in the projecting portions of the L-shaped flat blocks 8 and 8. Tighten and fix at 10. Further, stoppers 19, 19 are provided projecting obliquely above the holes 17, 18 provided in the projecting portions, and when a load is applied to the foot step 14, the elongated flat blocks 15, 1 are provided.
The upper edge of the fixed end portion 5 is received by the stoppers 19, 19, and the foot step 14 is held at a right angle to the ring chain steer 2, and is provided to a footstep of a passenger. Further, the long strip-shaped flat block 15 of the foot step 14 can be formed by joining a plurality of short strip-shaped flat blocks. To maintain the safety of passengers. As shown in FIG. 6, a hammer 20 is provided at a predetermined distance on the shaft bar 6 of the ring chain steer 2, while a bell 21 is attached to one side of the rail device 1. Thus, when the ring chain steer 2 circulates, the hammer 20
Is configured to generate a sound by hitting the bell 21 so that the descending speed of the emergency ladder can be perceived. Also, the speed reducer 4
As shown in FIG. 7, a plurality of gear shafts 22 and a large gear 23 are combined and fixed to the fixing means 3. Further, two power switching wheels 24, 24 are arranged in parallel in the middle of one gear shaft 22 therein. These power switching vehicles 2
4 and 24 are fixed to the one gear shaft 22 so that each tooth plate can enter between the shaft bars 6 and 6 provided just opposite to the ring chain steer 2.
The ring chain steer 2 is configured to be able to stably and smoothly circulate on the large gear 23 and inside the rails 5 and 5 having a U-shaped cross section. Thus, the ladder usually penetrates the emergency ladder well, but according to the configuration of the self-propelled emergency ladder of the present invention, the emergency ladder is started as soon as a person stands on the ring chain steer 2 and the bell is driven by driving. Since 21 is generated and an alarm action is generated, intrusion of a thief can be prevented beforehand. If the number of passengers is relatively large, or if the load is relatively heavy, the descending speed of the emergency ladder may increase, which may cause danger. At this time, in the present invention, at least one blade 25 is provided on the gear shaft 22 of the large gear 23 of the reduction gear 4, and when the gear shaft 22 rotates, the resistance of the wind generated by the blade 25 causes the ring chain to rotate. The structure is such that the lowering speed of the steering wheel 2 can be delayed. Further, as shown in FIG. 7, the at least one blade 25 includes a sub-blade 26 which is fixed by being biased by a spring 27 so as to overlap the blade 25, and when the rotation is relatively fast, the centrifugal force is increased. The sub-blade 26 is greatly stretched by the resistance action of the wind pressure, and the lowering speed of the ring chain steer 2 can be adjusted by the wind resistance. When the emergency ladder is not used, the sub-blade 26 overlaps the blade 25 by the bias of the spring. According to the above configuration, the self-propelled emergency ladder of the present invention includes:
In addition to being applied to very tall buildings, it can be built inside buildings at the same time as building construction. Also, as shown in FIG. 9, the passenger can grip the axle bar 6 by hand from the upper floor and stand down on the foot step 14 to descend. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

As described above, the self-propelled emergency ladder of the present invention is applied to a very tall building, so that residents on each floor can be evacuated at the same time without using electric power in an emergency. There is no chance of slipping and falling during evacuation. In addition, since the descending speed of the ring chain steer can be adjusted by installing the speed reducer according to the present invention, the emergency ladder can be operated stably and smoothly.

[Brief description of the drawings]

FIG. 1 is a perspective view of a preferred embodiment of the present invention.

FIG. 2 is an inverted U-shaped cross section rail according to an embodiment of the present invention;
The sketch of a shaft bar and a flat block.

FIG. 3 is a schematic view of a shaft bar according to the embodiment of the present invention.

FIG. 4 is a schematic view of a combination of a ring chain steer according to the embodiment of the present invention.

FIG. 5 is a composition sketch of a foot step in an example of the present invention.

FIG. 6 is a sketch of a bell and a mallet according to the embodiment of the present invention.

FIGS. 7A and 7B are schematic views of a reduction gear transmission according to an embodiment of the present invention.

FIG. 8 is a schematic view of a blade according to the embodiment of the present invention.

FIG. 9 is a perspective view showing a mode of use of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rail apparatus 2 Ring chain steer 3 Fixing means 4 Reduction gear 5 Rail 6 Shaft bar 7 Screw part 8 Flat block 9 Shaft hole 10 Nut 11 Extension part 12 Extension part 13 Roller 14 Footstep 15 Slender flat block 16 Side Bar 17, 18 Hole 19 Stopper 20 Hammer 21 Bell 22 Gear Shaft 23 Large Gear 24 Power Switching Wheel 25 Blade 26 Sub-blade 27 Spring

Claims (8)

(57) [Claims] 1. A circulating ladder, wherein the circulating ladder comprises:
A rail device in which two rails having a U-shaped cross section are opposed to each other with the U-shaped opening inside, and upper and lower ends are curved and endlessly provided; A ring chain steer circulating along the inside of the cross section of the endless rails, the ring chain steer comprising a number of shaft bars and a flat block for interconnecting both ends of the shaft bars. Further, rollers are attached to both ends of the shaft bar of the ring chain steer, and the rollers are loosely fitted inside the U-shaped rails of the rail devices arranged opposite to each other, so that the ring chain steer is provided. A self-propelled emergency ladder characterized by being configured to circulate along said rail. 2. The rail device according to claim 1, wherein the rail device comprises two rails vertically extending in parallel at a predetermined interval, and upper and lower ends of each rail are respectively curved in an arc shape to form an endless rail. 2. A self-propelled emergency ladder according to claim 1, wherein the cross-sectional shape is a U-shape, and the U-shaped upper and lower curved portions of the rail are made relatively wide to smoothly circulate the ring chain steer. 3. A plurality of shaft bars each having a length shorter than a distance between the opposed U-shaped rails and having threaded portions near both ends. A plurality of flat blocks having shaft holes at both end portions thereof, into which extended portions provided at both end portions of the shaft bar are inserted, and the shaft bar for positioning these flat blocks on the plurality of shaft bars. The self-propelled emergency ladder according to claim 1, further comprising a plurality of nuts for tightening and fixing the emergency ladder. 4. The plurality of shaft bars are formed such that an intermediate portion has a larger diameter than a shaft hole provided in the flat block so that the flat block does not move in the center direction of the shaft bar.
Further, extending portions protrude from both ends of the intermediate portion, the extending portions are formed to have a smaller diameter than the shaft hole of the flat block, and the length of the extending portions in the axial direction is reduced by the flattening. It is formed slightly longer than the two thicknesses of the blocks so that the ends of each flat block can be overlapped so that they can be loosely fitted to the extending portion. Further, the extending portion projecting from the extending portion has A screw portion for tightening the nut is provided, and the portion extending further to both sides from the extension portion has no screw, and is slightly more than the screw portion so that the nut can be screwed to the screw portion of the shaft bar. 4. The self-propelled emergency ladder according to claim 3, wherein the both ends are provided with rollers for smooth movement. 5. The shaft bar of the ring chain steer includes two elongated flat blocks arranged in parallel at a predetermined distance, and at least a plurality of elongated flat blocks interposed between the two elongated flat blocks. A foot bar comprising a single horizontal bar, wherein the horizontal bar is fastened and fixed to a through hole provided in each of the long piece-shaped flat blocks by a nut. Are the fixed ends of the two elongated flat blocks and the L correspondingly attached to the shaft bar.
It is tightened and fixed through a hole formed in the projecting portion of the mold flat block, and further, a stopper is protruded diagonally above the hole of the projecting portion to apply a load to the foot step. 4. The step according to claim 3, wherein an upper edge of each fixed-side end of said elongated flat block is received by said stopper, and is held at a right angle to said ring chain steer to form a footstep for a passenger. Self-propelled emergency ladder. 6. The two long flaky flat blocks of the foot step are formed by joining a plurality of short flaky flat blocks, or a plate or net is laid on the long flaky flat blocks to stand. Further, a hammer is provided at a predetermined distance on the shaft bar of the ring chain steer, and a bell is attached to one side of the rail device correspondingly, and the hammer is connected to the side of the bell. 6. The self-propelled emergency ladder according to claim 5, wherein the bell hits the bell when the vehicle passes, and generates a sound to notify the descending altitude of the emergency ladder. 7. A speed reducer configured by combining a plurality of shafts and gears is fixed to a fixing means, and at least one power switching wheel is further provided in the middle of one of the gear shafts. Each tooth plate of the power switch wheel is fixed to the one gear shaft so as to be able to enter between two shaft bars of the ring chain steer, whereby the ring chain steer is stably and smoothly formed on the large gear and the cross section. Further, the speed reducer is provided with at least one blade on a gear shaft of one of the speed reduction gear sets, and the speed reduction device has a wind resistance generated by the blade during rotation. The lowering speed of the ring chain steer is reduced, wherein at least one blade further includes a sub-blade fixed on the blade by a spring, and the rotation is relatively small. 2. The self-propelled emergency ladder according to claim 1, wherein at high speed, the blade is greatly opened due to centrifugal force and wind resistance, whereby the lowering speed of the ring chain steer can be adjusted by the wind resistance. 8. A recirculating ladder, wherein the circulating ladder circulates along a rail device, a fixing means for fixing the rail device to a building, and a circulating ladder. A speed reducer mounted on said fixing means for reducing the circulation speed, said speed reducer having at least one blade and a sub-blade mounted on said blade; The sub-blade can be decelerated by using wind resistance of the blade, and the sub-blades are urged to overlap each other by a spring interposed between the sub-blade and the blade. Or the self-propelled emergency ladder according to 7.