JPH0677754U - Hoisting device for hoisting ladder - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose of the present invention is to enable smooth and safe winding and unwinding of the ladder straps of the ladder of the hoisting type ladder. [Structure] The hoisting ladder is made of a synthetic resin knitted or woven flat belt 2 such as Tetron (trademark), and the width of the winding drum 3 of the winch 1 is made slightly larger than the width b of the belt.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a slow descending device for a hoisting ladder for promptly and safely lowering the hoisting ladder at a constant speed, and a hoisting and lowering operation of the hoisting ladder can be performed safely and smoothly. Is.

[0002]

[Prior art]

 A hanging string is connected to the lower end of the evacuation foldable ladder, the hanging string is hoisted by a hoisting device to raise the ladder, the latch of the hoisting device is released, and the ladder naturally descends. It has been publicly known that the speed is restricted by a centrifugal brake incorporated in a hoisting device so that a ladder is gently lowered (see, for example, Japanese Utility Model Laid-Open No. 56-174700). A rope such as a wire rope or a nylon rope is used as a string. According to the above-mentioned conventional technique, the lower end of the wire rope 30 is connected to the lower end of the folding ladder 31 (see FIGS. 4 and 5 and the same applies to the following in this section), and the upper end is fixed to the lid 33 of the storage box 32 by the manual hoisting device 34. The folding ladder 31 is pulled up by being wound up, and is folded and stored in the storage box 32. Although the centrifugal brake of the winding device 34 is not shown in the above publication, the winding device is actually provided with a centrifugal brake in order to prevent the ladder 31 from freely falling due to impact. 31 descends at a constant speed. A rope such as a wire rope or a nylon rope is used as a string for pulling up the ladder 31, but since the winding device is a relatively small manual winch, which is used to wind a long rope. , The rope is wound in one place in a mountain shape, and the rope wound in a mountain shape collapses, and this is repeated. As a result, winding disorder may occur, and as a result, the winding operation may not be easy, and the rope may become entangled and the unwinding operation may not be performed smoothly. Furthermore, a relatively thick rope must be used to ensure safety, but since the thick rope is stiff against bending, it has a large winding resistance, and therefore there is a problem that the ladder is heavy to pull up and fold.

[0003]

[Problems to be solved by the device]

 The present invention aims to solve the above-mentioned conventional problems, and for that purpose, to reduce the hoisting resistance of the hanging string as much as possible and devise the hanging string so that the winding and unwinding can be performed smoothly. That is the subject.

[0004]

[Means for Solving the Problems]

 Means taken to solve the above-mentioned problem is that the hanging string is made of synthetic resin such as Tetoron (trademark), or a flat belt (flat belt) made of synthetic resin, and the width of the winding drum of the winch is smaller than the width of the flat belt. It is a little larger.

[0005]

[Work]

 The synthetic resin knitted or woven flat belts such as Tetron (trade name) are strong and have a small elongation, so they are relatively thin and can sufficiently secure the necessary tensile strength, and are extremely resistant to bending. Be flexible. Therefore, the winding resistance when winding on a winding drum having a relatively small diameter is small. Also, by making the width of the winch take-up drum slightly larger than the width of the flat belt, the take-up drum can be smoothly taken up without disturbing the take-up drum. .

[0006]

【Example】

 Next, examples will be described. This embodiment is an example in which the present invention is applied to an evacuation ladder attached to a veranda or the like of a normal high-rise building. The length of the ladder when it is extended is 4,175 m and is wound by a winding drum 3 of a manual winch 1. The total length of the Tetoron (trademark) plain weave flat belt (flat belt) 2 to be taken is 4,200 m. The winding drum 3 is fixed to a shaft 7, and both ends of the shaft 7 are supported by the support bracket 6 via bearings. A well-known centrifugal brake 5 is provided outside the flange 4 of the winding drum 3. Since various structures of the centrifugal brake are known, detailed description thereof will be omitted, but the outline of the centrifugal brake 5 in this embodiment is as shown in FIG. That is, the brake drum 5a is fixed to a winch support bracket 6, and a pair of centrifugal brake shoes 5c are pivotally supported by a member 5d fixed to a shaft 7 by a pin 5b. Normally, the pair of centrifugal brake shoes 5c are pulled inward in the radial direction by a suitable return spring (not shown) and separated from the braking surface of the brake drum 5a. When the rotation speed of the shaft 7 becomes equal to or higher than a certain value, the brake shoe 5c spreads radially outward against the return spring due to the centrifugal force and presses against the braking surface of the brake drum 5a to brake it. When the rotation speed of the shaft 7 decreases, the centrifugal force decreases and the braking force weakens, and when it increases, the centrifugal force increases and the braking force increases. The rotation speed of the shaft 7 is controlled to a predetermined speed by the change of the braking force in response to this rotation speed. The Tetoron woven flat belt 2 has a width b of 14 mm, a thickness t of 1 and 2 mm, and a tensile strength of about 700 kg. The take-up drum 2 has a drum diameter of 90 mm, and the width B between the left and right flanges is 16 mm, and this width B is 2 mm larger than the width b of the Tetoron woven flat belt 2. The handle 8 is attached to the shaft 7, and thereby the winding drum 3 is driven to wind up the Tetron woven flat belt 2 and the ladder is pulled up and folded. The winch function and other storage structures for the ladder are conventional. Since there is no difference with the ladder of, the description of these is omitted. As in the prior art, when the winch latch mechanism that holds the ladder folded is removed, the ladder drops and extends, and the Tetoron woven flat belt is unwound from the winding drum of the winch 1 in accordance with this. . This winding operation causes the winding drum to rotate, and as described above, the centrifugal brake 5 automatically controls the rotation speed to a substantially predetermined speed. Therefore, the feeding speed of the Tetoron woven flat belt is controlled to be substantially constant, and the ladder is prevented from freely falling at an impact speed. When wound on a take-up drum, the Tetoron woven flat belt is bent into a cylindrical shape which is approximately equal to the outer diameter of the take-up drum. Great flexibility. Therefore, the winding resistance of the small diameter winding drum is extremely smaller than that of the conventional rope. In addition, since the linear flat belt is easily returned when unreeling, the unreeling operation is also smooth.

[0007]

[Effect]

 A device that solves the above problems of the present invention is not yet known. Therefore, solving the problems described above and solving the problems of the prior art is the effect peculiar to the present invention. That is, it is possible to minimize the winding resistance when winding the hanging string of the folding ladder around the winding drum of a relatively small diameter, and to smoothly and reliably wind and unwind the hanging string. Is something that can be done. In addition, in order to solve the above problems caused by the rope being a rope, that is, the problem of collapse during winding and the problem of unwinding uncertainty due to the entanglement of the rope due to collapse, Can be solved by using a thin steel flat belt, but if the sling that extends close to the extended ladder is a flat metal belt, the person who hurriedly gets off the ladder in an emergency can use a flat metal belt. Although there is a risk of being touched and scratched, the hanging strap of the present invention is a Teflon woven flat belt, so there is no risk of injury if a person who hurriedly descends the ladder contacts it in an emergency. It is extremely safe. Furthermore, when the hanging strap is a flat metal belt, wire rope, etc., and the hanging strap lacks flexibility in bending, the unwinding from the take-up drum is not smooth and the unwinding speed of the take-up drum is high. Fluctuates, which causes unstable operation of the centrifugal brake, resulting in unstable and uncertain control of the ladder descending speed by the centrifugal brake. However, since the knitted or woven flat belt made of synthetic resin such as Tetron (trademark) of the present invention is extremely flexible in the bending direction, its unreeling is extremely smooth, and therefore, the rotation of the take-up drum during unwinding is extremely low. It is also a great advantage of the present invention that the operation of the centrifugal brake is stable for this reason, and that the descending speed is controlled smoothly and reliably by this centrifugal brake.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment.

FIG. 2 is a front view of a winch centrifugal brake.

FIG. 3 is a front view of a folding ladder equipped with the winding device of the present invention.

FIG. 4 is a front view of a conventional technique.

FIG. 5 is a side view of FIG.

[Explanation of symbols]

 1 ... Manual winch 2 ... Tetoron woven flat belt (flat belt) 3 ... Winding drum 4 ... Flange 5 ... Centrifugal brake 5a ... Brake drum 5b ... Pin 5c ... Centrifugal brake shoe 5d ... A member fixed to the shaft 6 ... Support bracket 7 ... Shaft 8 ... Handle 30 ... Wire rope 31 ... Folding ladder 32 ... Storage box 33・ ・ ・ Lid 34 ・ ・ ・ Manual winding device b ・ ・ ・ Flat belt width t ・ ・ ・ Flat belt thickness B ・ ・ ・ Width between the left and right flanges 4 and 4

Claims (1)

[Scope of utility model registration request] 1. A method for connecting a hanging string to the lower end of a folding ladder or in the vicinity thereof, hoisting the hanging string with a hoisting device to raise the ladder, and releasing the latch of the hoisting device to naturally descend the ladder. , The descent speed is limited by the centrifugal brake built into the hoisting device,
A hoisting type in which the ladder is gently lowered, the hanging string is a synthetic resin knitted or woven flat belt such as Tetron (trade name), and the width of the winch winding drum is slightly larger than the width of the belt. Ladder lowering device.