WO2009072828A2

WO2009072828A2 - Non-power apparatus for controlling descent

Info

Publication number: WO2009072828A2
Application number: PCT/KR2008/007191
Authority: WO
Inventors: Byung Chun Park
Original assignee: Byung Chun Park
Priority date: 2007-12-06
Filing date: 2008-12-05
Publication date: 2009-06-11
Also published as: KR100883838B1; WO2009072828A3

Abstract

A non-powered descent control device includes a frame installed in an elevated position. A reel unit is rotatably mounted on the frame, the reel unit having a reel and a brake drum. A rope is wound on the reel, the rope having a first end secured to the reel and a second end connected to an object to be moved from the elevated position to the ground. The device further includes a booster brake unit for producing a boosted braking force from a rotational force of the reel unit and applying the boosted braking force to the brake drum of the reel unit and a centrifugal clutch for delivering the rotational force of the reel unit to the booster brake unit and causing the booster brake unit to apply the boosted braking force to the brake drum when the reel unit rotates faster than a predetermined speed.

Description

NON-POWER APPARATUS FOR CONTROLLING DESCENT

Technical Field

[1] The present invention relates to a non-powered descent control device and, more particularly, to a non-powered descent control device capable of controlling the speed of an object moving down from an elevated position to the ground. Background Art

[2] A variety of emergency refuge facilities or escape devices have been employed in a high-rise building in order to allow people to swiftly flee from a high floor to a safe place on the ground in the event of an emergency situation, such as fire, explosion or the like. As the escape devices installed in the high-rise building, a non-powered mechanism is commercially available that does not rely on electricity in preparation for the malfunction thereof caused by a power outage.

[3] As one example of the escape devices for transporting people from the high floor of the high-rise building to the ground, a lifesaving device is disclosed in Korean Patent No. 476536. This lifesaving device includes a carrier on which a refugee can ride to flee in emergency situations and a prime mover for controlling the descent of the carrier. The carrier is connected to the prime mover through a rope which in turn is wound on the drum of the prime mover. The lifesaving device further includes a brake device designed to apply brake to the drum using the weight of both the carrier and the refugee. As the rope is unwound from the drum, the carrier begins to descend toward the ground. When the carrier reaches a position 3 meters away from the ground, four decelerating devices are operated to reduce the descending speed of the carrier.

[4] With the lifesaving device described in the above patent, it is required to control the descending speed of the carrier for safety purposes because the descending speed tends to increase in proportion to the altitude from which the carrier starts to descend. However, the lifesaving device is unable to control the descending speed of the carrier that varies with the position of the carrier, which imposes restriction on the installation altitude of the carrier. In addition, the prime mover and the decelerating devices are structurally complicated, which leads to a difficulty in installing them and an increased probability of trouble. Disclosure of Invention

Technical Problem

[5] In view of the above-noted drawbacks and other problems inherent in the prior art, it is an object of the present invention to provide a non-powered descent control device capable of safely and accurately moving down an object from an elevated position to the ground at a generally constant speed.

[6] Another object of the present invention is to provide a non-powered descent control device which is structurally simple and easy to install. Technical Solution

[7] In accordance with the present invention, there is provided a non-powered descent control device, including: a frame installed in an elevated position; a reel unit rotatably mounted on the frame, the reel unit having a reel and a brake drum; a rope wound on the reel, the rope having a first end secured to the reel and a second end connected to an object to be moved from the elevated position to the ground; a booster brake unit for producing a boosted braking force from a rotational force of the reel unit and applying the boosted braking force to the brake drum of the reel unit; and a centrifugal clutch for delivering the rotational force of the reel unit to the booster brake unit and causing the booster brake unit to apply the boosted braking force to the brake drum when the reel unit rotates faster than a predetermined speed, the centrifugal clutch including a clutch hub mounted to the frame for rotation in synchronism with the reel unit, a clutch drum provided around the clutch hub for rotation relative to the clutch hub, a plurality of clutch shoes installed on the clutch hub for rotation together with the clutch hub, the clutch shoes being radially outwardly movable by a centrifugal force to make frictional contact with the clutch drum, and a plurality of return springs for radially inwardly biasing the clutch shoes out of contact with the clutch drum. Brief Description of Drawings

[8] Fig. 1 is a front view showing a non-powered descent control device in accordance with a first embodiment of the present invention.

[9] Fig. 2 is a sectional view illustrating the non-powered descent control device in accordance with the first embodiment of the present invention.

[10] Fig. 3 is a front view showing the construction of a centrifugal clutch employed in the non-powered descent control device.

[11] Fig. 4 is a sectional view illustrating the construction of the centrifugal clutch employed in the non-powered descent control device.

[12] Fig. 5 is a front view illustrating the operation of the non-powered descent control device.

[13] Fig. 6 is a front view showing a non-powered descent control device in accordance with a second embodiment of the present invention.

[14] Fig. 7 is a sectional view illustrating the construction of first and second discs of a booster brake unit employed in the non-powered descent control device of the second embodiment. Best Mode for Carrying out the Invention [15] The other objects, features, advantages of the invention will become apparent from a review of the following detailed description of the preferred embodiment taken in conjunction with the accompanying drawings.

[16] Hereinafter, certain preferred embodiments of a non-powered descent control device in accordance with the present invention will be described in detail with reference to the accompanying drawings.

[17] Referring first to Fig. 1, a non-powered descent control device in accordance with a first embodiment of the present invention is designed to control the descending movement of an object that descends from an elevated position to the ground. Examples of the object include a carrier 2 on which a refugee can ride to escape from a high-rise building and a bucket of a crane. The non-powered descent control device includes a frame 10 installed inside the high-rise building. The frame 10 may be installed, for instance, near the window of the high-rise building or on the balcony of a high-rise apartment.

[18] Referring to Figs. 1 and 2, a reel unit 20 is rotatably mounted on one side of the frame 10. The reel unit 20 includes a shaft 22, a reel 24, and a brake drum 26. The opposite ends of the shaft 22 are rotatably supported by the frame 10. The reel 24 and the brake drum 26 are coupled to the outer surface of the shaft 22 and arranged to rotate together with the shaft 22. Alternately, the shaft 22, the reel 24 and the brake drum 26 may be integrally formed into one piece. The rotation of the shaft 22 can be locked or unlocked by means of a conventional locking device. The locking device is installed within the carrier 2 where a user is able to manipulate the locking device. In the present embodiment, the opposite ends of the shaft 22 may be rotatably secured to the frame 10. The reel 24 and the brake drum 26 may be configured to rotate about the shaft 22, in which case the rotation of the reel 24 and the brake drum 26 is locked or unlocked by means of the conventional locking device.

[19] A rope 30 is wound on the outer surface of the reel 24. The first end of the rope 30 is fixedly secured to the outer surface of the reel 24 so that the rope 30 can be wound on or unwound from the reel 24. The second end of the rope 30 is connected to the carrier 2. The carrier 2 is normally located inside a high-rise building. The user may bring the carrier 2 to the outside of the building and place the same in a position ready for emergency escape. As the rope 30 is paid out from the reel 24, the carrier 2 begins to descend. A first guide pulley 32 for guiding the rope 30 unwound from the reel 24 is installed on the frame 10 between the reel 24 and the carrier 2. Although only one guide pulley 32 is illustrated in Fig. 1, the number and installation position of the guide pulley 32 may be arbitrarily changed depending on a design option.

[20] Referring to Figs. 1 through 4, the non-powered descent control device includes a centrifugal clutch 40 provided at one side of the frame 10. The centrifugal clutch is designed to deliver the rotational force of the reel unit 20 to the below-mentioned booster brake unit and causing the booster brake unit to apply a boosted braking force to the brake drum 26 of the reel unit 20 when the reel unit 20 rotates faster than a predetermined speed. The centrifugal clutch 40 includes a shaft 42, a clutch hub 44, a plurality of clutch shoes 46, a plurality of return springs 48, a pair of retainer rings 50 and a clutch drum 52.

[21] The opposite ends of the shaft 42 are rotatably supported by the frame 10. The clutch hub 44 is mounted on the outer surface of the shaft 42 and arranged to rotate in synchronism with the reel unit 20. The clutch shoes 46 are arranged on the clutch hub 44 and can be moved in both circumferential and radial directions. A lining 46a is attached to the radial outer surface of each of the clutch shoes 46. The return springs 48 are provided to interconnect the neighboring ends of the clutch shoes 46. Although two clutch shoes 46 and two return springs 48 are illustrated in Fig. 3 by way of example, the number of the clutch shoes 46 and the return springs 48 may be arbitrarily changed depending on a design option. The retainer rings 50 are mounted on the opposite sides of the clutch hub 44 to hold the clutch shoes 46 against removal. The clutch drum 52 is rotatably installed on the outer surface of the shaft 42. The clutch shoes 46 are arranged within the clutch drum 52. When the lining 46a of the clutch shoes 46 makes contact with the inner surface of the clutch drum 52, the clutch hub 44 and the clutch drum 52 rotate together with the shaft 42.

[22] Referring again to Figs. 1 and 2, the non-powered descent control device includes a power transmission unit 60 that delivers the rotational force of the reel unit 20 to the clutch hub 44. The power transmission unit 60 is formed of a gear transmission device that includes a driving gear 62 mounted on the outer surface of the brake drum 26 and a driven gear 64 mounted on the outer surface of the shaft 42. The driven gear 64 is meshed with the driving gear 62 for unitary rotation. When the driving gear 62 rotates together with the brake drum 26, the driven gear 64 engaged with the driving gear 62 are rotated together with the shaft 42 and clutch hub 44. The rotation ratio of the driving gear 62 to the driven gear 64 is set equal to, e.g., 1:4. In the alternative, the rotation ratio of the driving gear 62 to the driven gear 64 may be arbitrarily changed depending on a design option. Although the driven gear 64 is mounted on the outer surface of the shaft 42 in Fig. 2, this is for the purpose of illustration. If necessary, the driven gear 64 may be coupled with the clutch hub 44.

[23] The non-powered descent control device includes a booster brake unit 70 for producing a boosted braking force from the rotational force of the reel unit 20 and applying the boosted braking force to the brake drum 26 of the reel unit 20. The booster brake unit 70 includes a lever 72, a wire 74 and a brake band 76. The lever 72 is coupled to the frame 10 for rotation about a pivot 72a. As shown in Fig. 1, the lever 72 has a first end 72b, a second end 72c, a first extension portion extending a first span Ll from the pivot 72a to the first end 72b and a second extension portion extending a second span L2 from the pivot 72a to the second end 72c, the first span Ll being shorter than the second span L2.

[24] One end of the wire 74 is fixedly secured to the outer surface of the clutch drum 52 and the other end of the wire 74 is connected to the second end 72c of the lever 72. Wound on the outer surface of the brake drum 26 is a brake band 76 for selectively applying the boosted braking force to brake drum 26 of the reel unit 20. One end of the brake band 76 is connected to the frame 10 and the other end of the brake band 76 is connected to the first end 72b of the lever 72.

[25] A second guide pulley 34 for guiding the rope 30 is installed on the frame 10 between the pivot 72a and the first end 72b of the lever 72. The rope 30 is connected to the carrier 2 via the first and second guide pulleys 32 and 34. Alternatively, the second guide pulley 34 may be omitted, in which case the rope 30 may be connected to the carrier 2 through the first guide pulley 32. A third guide pulley 78 for guiding the wire 74 is installed on the frame 10 between the centrifugal clutch 40 and the lever 72. Although one second guide pulley 34 and one third guide pulley 78 are shown in Fig. 1, the number and location of these pulleys may be changed arbitrarily depending on a design option. The reel unit 20, the centrifugal clutch 40 and the booster brake unit 70 may be provided in plural numbers within one carrier 2 for safety purposes.

[26] Operation of the non-powered descent control device in accordance with the first embodiment of the present invention will be described hereinafter.

[27] Referring to Fig. 1, when a user wishes to flee from a high-rise building to the ground, the carrier 2 is first moved from the inside of the building to the outside and placed in a position ready for descent. Then the user rides on the carrier 2 and actuates the locking device to unlock the reel unit 20.

[28] Referring to Fig. 5, if the reel unit 20 is unlocked, the carrier 2 begins to descend by the gravity and the rope 30 is paid out from the reel 24 of the reel unit 20. As indicated by arrow "A" in Fig. 5, the reel unit 20 turns in one direction as the rope 30 is paid out. The rotational force of the reel unit 20 is transferred to the shaft 42 of the centrifugal clutch 40 through the driving gear 62 and the driven gear 64 in turn. The shaft 42 rotates together with the clutch hub 44 in the direction opposite to the rotational direction of the reel unit 20.

[29] The rope 30 thus paid out passes through the first guide pulley 32 and the second guide pulley 34, at which time the tension of the rope 30 acts against the second guide pulley 34. The tension of the rope 30 applied to the second guide pulley 34 causes the lever 72 to rotate about the pivot 72a in the direction opposite to the rotational direction of the reel unit 20 as indicated by arrow "C" in Fig. 5. Upon rotation of the lever 72, the brake band 76 applies a braking force to the outer surface of the brake drum 26, thereby reducing the rotational speed of the reel unit 20.

[30] Referring to Fig. 3, the clutch shoes 46 are radially inwardly biased by the elastic force of the return springs 48 when the reel unit 20 rotates at a speed equal to or lower than a predetermined speed. The clutch hub 44 continues to receive the rotational force of the reel unit 20 through the driving gear 62 and the driven gear 64. Thus the clutch hub 44 rotates together with the reel unit 20 in the direction opposite to the rotational direction of the reel unit 20. The descending speed of the carrier 2 increases in proportion to the initial altitude thereof, while the rotational speed of the reel unit 20 is proportional to the descending speed of the carrier 2. The rotational speed of the clutch hub 44 is in proportion to the rotational speed of the reel unit 20, i.e., the descending speed of the carrier 2. In addition, the centrifugal force acting on the clutch shoes 46 increases as the rotational speed of the clutch hub 44 becomes greater.

[31] If the centrifugal force is greater than the elastic force of the return springs 48, the clutch shoes 46 move in the radial inward direction of the shaft 42, and the lining 46a of each of the clutch shoes 46 makes contact with the inner surface of the clutch drum 52 to apply a friction force thereto as indicated in a double-dotted chain line in Fig. 4. If the clutch hub 44 rotates together with the clutch drum 52 by the friction force acting therebetween, the wire 74 connected to the clutch drum 52 is pulled toward the clutch drum 52, thereby pulling down the second end 72c of the lever 72. Accordingly, the lever 72 rotates about the pivot 72a in the direction opposite to the rotational direction of the reel unit 20 as indicated by arrow "C" in Fig. 5. Upon rotation of the lever 72, the brake band 76 applies a boosted braking force against the outer surface of the brake drum 26 to reduce the rotational speed of the reel unit 20. As shown in Fig. 1, the lever 72 rotates about the pivot 72a and increases the pulling force of the wire 74 according to the ratio of the first span Ll to the second span L2, thereby boosting the braking force of the brake band 76.

[32] If the rotational speed of the reel unit 20 is reduced by the braking action of the brake band 76, the magnitude of the centrifugal force applied to the clutch shoes 46 also decreases. When the centrifugal force applied to the clutch shoes 46 is smaller than the elastic force of the return springs 48, the clutch shoes 46 move radially inwardly toward the clutch hub 44 by the elastic force of the return springs 48. The lining 46a of each of the clutch shoes 46 comes out of contact with the inner surface of the clutch drum 52, thereby releasing the clutch drum 52. If the clutch drum 52 is released, the pulling force is removed from the wire 74 that interconnects the clutch drum 52 and the lever 72. This eliminates the braking force acting between the brake drum 26 and the brake band 76. Accordingly, the reel unit 20 is allowed to rotate at a predetermined speed. In this way, the centrifugal clutch 40 enables the booster brake unit 70 to control the rotational speed of the reel unit 20, thereby ensuring that the carrier 2 is moved down at a generally constant speed in a safe and accurate manner.

[33] In case where the rope 30 is spirally wound on the reel 24 of the reel unit 20, the winding diameter of the rope 30 is gradually decreased as the carrier 2 continues to descend toward the ground. This reduces the length of the rope 30 paid out from the reel 24 per unit time. Thus the carrier 2 is allowed to descend at a reduced speed in a safe and accurate fashion under the action of the centrifugal clutch 40 and the booster brake unit 70.

[34] Referring to Figs. 6 and 7, there is shown a non-powered descent control device in accordance with a second embodiment of the present invention. The non-powered descent control device includes a reel unit 20, a rope 30, a centrifugal clutch 40, a power transmission unit 160 and a booster brake unit 170. The construction and operation of the reel unit 20, the rope 30 and the centrifugal clutch 40 of the second embodiment is substantially the same as described above in connection with the first embodiment. Therefore, no detailed description will be made in that regard.

[35] In the non-powered descent control device of the second embodiment, the other end of the rope 30 paid out from the reel 24 of the reel unit 20 is connected to the carrier 2 via the first guide pulley 32 attached to the frame 10. The power transmission unit 60 is formed of a belt transmission device that includes a driving pulley 162 mounted on the outer surface of the brake drum 26, a driven pulley 164 mounted on the outer surface of the shaft 42 and a belt 166 wound around the driving pulley 162 and the driven pulley 164 to rotate the shaft 42 and the clutch hub 44 in the same direction as the rotational direction of the reel unit 20. Alternatively, the belt transmission device may be replaced by a timing belt transmission device or a gear transmission device. The belt 166 may be wound around the driving pulley 162 and the driven pulley 164 in a crossed state so that the clutch hub 44 can be rotated in the direction opposite to the rotational direction of the reel unit 20.

[36] Referring to Figs. 6 and 7, the booster brake unit 170 includes a shaft 172, a first disc

174, a second disc 176, a first wire 178, a brake band 180 and a second wire 182. The opposite ends of the shaft 172 are rotatably supported by the frame 10. The first and second discs 174 and 176 are mounted on the outer surface of the shaft 172 and can be rotated together with the shaft 172. The second disc 176 has a diameter D2 greater than the diameter Dl of the first disc 174. The shaft 172 may be integrally formed with the first and second discs 174 and 176. Additionally, the opposite ends of the shaft 172 may be fixedly secured to the frame 10, in which case the first and second discs 174 and 176 are constructed to rotate about the shaft 172.

[37] One end of the first wire 178 is fixedly secured to the outer surface of the clutch drum 52, and the other end of the first wire 178 is connected to the outer edge of the second disc 176. A second guide pulley 184 for guiding the first wire 178 is installed on the frame 10 between the clutch drum 52 and the second disc 176. The brake band 180 is wound around the outer surface of the brake drum 26, thereby applying a boosted braking force to the brake drum 26. One end of the brake band 180 is secured to the frame 10, while the other end of the brake band 180 is connected to one end of the second wire 182. The other end of the second wire 182 is secured to the outer surface of the first disc 174. A third guide pulley 186 for guiding the second wire 182 is installed on the frame 10 between the brake drum 26 and the first disc 174.

[38] In the non-powered descent control device of the second embodiment, the rope 30 is paid out from the reel 24 of the reel unit 20 as the carrier 2 descends with the reel unit 20 unlocked. As indicated by arrow "A" in Fig. 6, the reel unit 20 turns in one direction as the rope 30 is paid out from the reel 24. The rotational force of the reel unit 20 is transferred to the shaft 42 of the centrifugal clutch 40 through the driving gear 162, the driven gear 164 and the belt 166.

[39] As indicated by arrow "D" in Fig. 6, the shaft 42 and the clutch hub 44 rotate in the same direction as the rotational direction of the reel unit 20. The clutch shoes 46 are radially inwardly biased toward the outer surface of the clutch hub 44 by the elastic force of the return springs 48 and rotate together with the clutch hub 44. If the centrifugal force applied to the clutch shoes 46 by the rotation of the clutch hub 44 becomes greater than the elastic force of the return springs 48, the clutch shoes 46 are moved radially outwardly from the shaft 42. Consequently, the lining 46a of each of the clutch shoes 46 makes contact with the inner surface of the clutch drum 52 to apply a friction force thereto. If the clutch hub 44 rotates together with the clutch drum 52 by the friction force acting therebetween, the first wire 178 connected to the clutch drum 52 is pulled toward the clutch drum 52.

[40] As indicated by arrow "E" in Fig. 6, the second disc 176 connected to the first wire

178 rotates in the direction opposite to the rotational direction of the clutch drum 52. The first disc 174 rotates together with the second disc 176. The brake band 180 connected to the first disc 174 through the second wire 182 is pulled toward the third guide pulley 186, thereby applying a boosted braking force to the outer surface of the brake drum 26 to reduce the rotational speed of the reel unit 20. As shown in Fig. 7, the first and second discs 174 and 176 are rotated about the shaft 172 to increase the pulling force of the second wire 182 according to the ratio of the first diameter Dl to the second diameter D2, thereby boosting the braking force of the brake band 76.

[41] If the rotational speed of the reel unit 20 is reduced, the magnitude of the centrifugal force applied to the clutch shoes 46 is also decreased. If the centrifugal force applied to the clutch shoes 46 becomes smaller than the elastic force of the return springs 48, the clutch shoes 46 are moved toward the clutch hub 44 by the elastic force of the return springs 48. The lining 46 of each of the clutch shoes 46 comes out of contact with the inner surface of the clutch drum 52, thus releasing the clutch drum 52. The pulling force of the first wire 178 imparted by the rotation of the clutch drum 52 is then removed. Accordingly, the brake band 76 removes the braking force applied to the reel unit 20. This ensures that the carrier 2 can be moved down at a generally constant speed in a safe and accurate manner.

[42] The embodiments set forth hereinabove have been presented for illustrative purpose only and, therefore, the present invention is not limited to these embodiments. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the invention defined in the claims. Industrial Applicability

[43] With the non-powered descent control device described hereinabove, it is possible to safely and accurately move down an object, such as a carrier of an escape device, a bucket of a crane or the like, from an elevated position to the ground at a generally constant speed. In addition, the reel unit, the centrifugal clutch and the booster brake unit are structurally simple and easy to install.

Claims

[1] A non-powered descent control device, comprising: a frame installed in an elevated position; a reel unit rotatably mounted on the frame, the reel unit having a reel and a brake drum; a rope wound on the reel, the rope having a first end secured to the reel and a second end connected to an object to be moved from the elevated position to the ground; a booster brake unit for producing a boosted braking force from a rotational force of the reel unit and applying the boosted braking force to the brake drum of the reel unit; and a centrifugal clutch for delivering the rotational force of the reel unit to the booster brake unit and causing the booster brake unit to apply the boosted braking force to the brake drum when the reel unit rotates faster than a predetermined speed, the centrifugal clutch including a clutch hub mounted to the frame for rotation in synchronism with the reel unit, a clutch drum provided around the clutch hub for rotation relative to the clutch hub, a plurality of clutch shoes installed on the clutch hub for rotation together with the clutch hub, the clutch shoes being radially outwardly movable by a centrifugal force to make frictional contact with the clutch drum, and a plurality of return springs for radially inwardly biasing the clutch shoes out of contact with the clutch drum.

[2] The non-powered descent control device as recited in claim 1, wherein the booster brake unit including: a lever coupled to the frame for rotation about a pivot, the lever having a first end, a second end, a first extension portion extending a first span from the pivot to the first end of the lever and a second extension portion extending a second span from the pivot to the second end of the lever, the first span being shorter than the second span; a wire having a first end secured to the clutch drum and a second end connected to the second end of the lever; and a brake band wound on the brake drum of the reel unit for selectively making frictional contact with the brake drum, the brake band having a first end secured to the frame and a second end connected to the first end of the lever.

[3] The non-powered descent control device as recited in claim 2, further comprising a power transmission unit including a driving gear rotatable together with the reel unit and a driven gear rotatable together with the clutch hub, the driven gear engaged with the driving gear.

[4] The non-powered descent control device as recited in claim 2, further comprising a power transmission unit including a driving pulley rotatable together with the reel unit, a driven pulley rotatable together with the clutch hub and a belt wound around the driving pulley and the driven pulley.

[5] The non-powered descent control device as recited in claim 2, wherein the object includes a carrier on which a user can ride, and further comprising a first guide pulley attached to the frame for guiding the rope extending between the reel unit and the carrier.

[6] The non-powered descent control device as recited in claim 5, further comprising a second guide pulley attached to the second extension portion of the lever for guiding the rope extending between the reel unit and the carrier, the rope being connected to the carrier via the first guide pulley and the second guide pulley, and a third guide pulley attached to the frame for guiding the wire extending between the centrifugal clutch and the lever.

[7] The non-powered descent control device as recited in claim 1, wherein the booster brake unit including: a shaft rotatably mounted to the frame; first and second discs coaxially mounted on the shaft, the second disc having a diameter greater than that of the first disc; a first wire having a first end fixed to the clutch drum and a second end connected to the second disc; a second wire having a first end and a second end connected to the first disc; and a brake band wound on the brake drum of the reel unit for selectively making frictional contact with the brake drum, the brake band having a first end secured to the frame and a second end connected to the first end of the second wire.

[8] The non-powered descent control device as recited in claim 7, further comprising a power transmission unit including a driving gear rotatable together with the reel unit and a driven gear rotatable together with the clutch hub, the driven gear engaged with the driving gear.

[9] The non-powered descent control device as recited in claim 7, further comprising a power transmission unit including a driving pulley rotatable together with the reel unit, a driven pulley rotatable together with the clutch hub and a belt wound around the driving pulley and the driven pulley.

[10] The non-powered descent control device as recited in claim 7, wherein the object includes a carrier on which a user can ride, and further comprising a first guide pulley attached to the frame for guiding the rope extending between the reel unit and the carrier, a second guide pulley attached to the second extension portion of the lever for guiding the first wire extending between the clutch drum and the second disc and a third guide pulley attached to the frame for guiding the second wire extending between the brake drum and the first disc.