JPH064298U - Safety latch for multi-stage telescopic ladder - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To provide a safe and secure multi-stage telescopic ladder that allows easy confirmation of whether or not a safety latch has been applied. [Structure] A window hole 21 is formed in a plate member 9a on the opposite side from which a tip engaging portion 11a of a hook 11 of a housing 9 projects, and
When the tip engaging portion of the hook claw is pushed into the housing,
It is characterized in that the rear end portion 116 is formed so as to project from the window hole, and a confirmation member is provided at the rear end portion of the hook.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention is applied to, for example, a loading ladder for fire fighting, which is used for a multi-stage telescopic ladder that is indispensable for approaching and evacuation guidance at a fire site. It concerns a safety latch that prevents the ladder from shortening even if it is cut.

[0002]

[Prior art]

 Generally, a multi-stage telescopic ladder is composed of 2-3 stages of ladders, which are sequentially drawn out by a rope and extended to an appropriate length for use. In this case, each ladder is locked to the lower ladder by a safety latch attached to each ladder to keep the ladder in an extended state and even if the ladder feeding rope is cut, Has a structure that does not shorten.

2 and 3 are explanatory views showing a three-stage telescopic ladder as a multi-stage telescopic ladder. FIG. 2 shows the ladder shortened and FIG. 3 shows the ladder extended. This telescopic ladder (1) comprises a first-stage ladder (1a), a second-stage ladder (1b) and a third-stage ladder (1c) having different widths. The third stage ladder (1c) is sequentially slidably inserted into the stage ladder (1b) and the second stage ladder (1b). A pulley (2) is rotatably attached to the tip of the first stage ladder (1a), and pulleys (3) and (4) are rotatably attached to the front and rear ends of the second stage ladder (1b). Then, after the rope for feeding the ladder (5) is hooked on the pulley (2) at the tip of the first stage ladder (1a), it is hooked on the pulley (3) at the rear end of the second stage ladder (1b). Then, after further engaging with the pulley (4) at the tip of the second stage ladder (1b), the tip is fixed to the rear end of the third stage ladder (1c). In the above structure, when the rope for feeding the ladder (5) is pulled, the third stage ladder (1c) is first extended, and then the second stage ladder (1b) is extended. As a result, the ladder (1) extends. When the rope for feeding the ladder (5) is loosened, the second stage ladder (1b) is retracted by its own weight, and then the third stage ladder (1c) is retracted by its own weight. This shortens the ladder (1).

By the way, in the multi-stage telescopic ladder (1), for example, safety latches (7) are attached to the left and right parts of the first stage ladder (1a) and the third stage ladder (1c), respectively. Secure the second stage ladder (1b) and the third stage ladder (1c) to the first stage ladder (1a) and the second stage ladder (1b) by these safety latches (7) (7). Then, keep the ladder in the extended state and prevent it from being shortened even if the ladder feeding rope (5) is cut.

FIG. 4 is an explanatory view illustrating a case where the conventional structure of the safety latch (7) is attached to the first stage ladder (1a). The safety latch (7) is a casing (9) integrally fixed between the vertical bars (8) (8) of the first stage ladder (1a) by welding or the like, and a shaft in the casing (9). A hook claw (11) that is axially supported by the (10) and that engages with the vertical bar (12) of the second stage ladder (1b) when the tip engaging portion (11a) projects from the housing (9); When the tip engaging portion (11a) of the hook (11) protrudes from the housing (9), the spring (14) is urged to press the stopper (13), and when the ladder is shortened, The guide plate (15) is pushed by the vertical rail (12) of the two-stage ladder (1b) to push the hook (11) into the housing (9). The inner plate (15) is pivotally supported by a shaft (16) and rotates as shown by an imaginary line. The state in which the hook (11) has retracted into the housing (9) is also shown by an imaginary line. Here, the vertical bar (12) of the second-stage ladder (1b) moves upward in the figure when the ladder is extended, and moves downward in the figure when the ladder is shortened.

In order to hang the safety latches (7), first, a backing plate (17) having a second stage ladder (1b) mounted on a vertical bar (12) is attached to the hooking claw (11) and the guide plate (15). Shorten to a position where it does not hit (see Fig. 5). Next, from this state, the vertical rail (12) goes over the hook claw (11) over the second stage ladder (1b), and the backing plate (17) extends to the position where the guide plate (15) is pressed (see FIG. 6). See). Then, after that, if the second-stage ladder (1b) is shortened, the vertical cross-section (12) of the second-stage ladder (1b) projects from the housing (9), and the tip engaging portion (11a) of the hook (11). ), The safety latch (7) is completely engaged (see Fig. 7).

Next, in order to release the safety latch (7) that has been latched as described above, the vertical ladder (12) is attached to the second step ladder (1b) from the state of FIG. 7 and the hook (11) and the guide plate. When extended to a position where it does not hit (15) at all, the safety latch (7) is completely released (see Fig. 8). In this state, when the second-stage ladder (1b) is shortened, the vertical bars (12) of the second-stage ladder (1b) move the hooks (11) into the housing (9) via the guide plate (15). Push in and pass through (see Figure 9).

[0008]

[Problems to be solved by the device]

 By the way, in the conventional safety latch (7), since the front end engaging portion (11a) of the hook (11) from below is very difficult to see, the tip engaging portion (11a) of this hook (11) is very difficult to see. It is difficult to confirm whether or not the bar is hung on the vertical rail (12), and there is a safety problem.

Therefore, in order to solve this problem, conventionally, a paint which is conspicuous is applied to the tip engaging portion (11a) of the hook (11), and a safety latch (7) is applied depending on whether this paint is visible or not. It is confirmed that the paint applied to the tip engaging part (11a) of the hook claw (11) is very hard to see from below, and even if it can be seen, It is difficult to confirm whether or not the tip engaging portion (11a) of the claw (11) is hooked on the vertical rail (12).

Therefore, the present invention has been made in view of the above-mentioned problems of the related art, and an object thereof is to provide a highly safe multi-stage device capable of easily confirming whether or not a hook is hooked on a crosspiece. To provide a safety latch for a telescopic ladder.

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a housing integrally attached to a step ladder and an upper or lower step ladder when the tip engaging portion is pivotally supported by a shaft in the housing and the tip engaging portion projects from the housing. Of the hanging claw that engages with the vertical bar of the vertical hook, the spring that urges the tip engaging part of the claw to project from the housing, and the vertical bar of the upper or lower ladder when pushing down the ladder. In a safety latch of a multi-stage telescopic ladder including a guide plate that pushes the hooks into the housing, a window hole is formed in the plate material on the opposite side from which the tip engaging portion of the hooks of the housing protrudes, and The hook is formed so that the rear end projects from the window hole when the front end engaging portion is pushed into the housing.

[0012]

[Action]

 According to the safety latch of the present invention, when the tip engaging portion of the hook is hooked on the vertical rail, the rear end of the hook is not visible because the rear end of the hook is housed in the housing. When the tip engaging part of the claw is not hooked on the vertical rail, the rear end of the hooking claw appears to protrude from the window hole of the housing, so it is possible to see at a glance whether or not the safety has been hooked.

[0013]

【Example】

 FIG. 1 is a view for explaining an embodiment of a safety latch of a multi-stage telescopic ladder according to the present invention, which is the same as the conventional device of FIG. 4 except for the following points, and the same components have the same reference numerals. Is attached, and duplicate matters are omitted.

The safety latch (20) of this embodiment has a window hole (21) in a plate material (9a) on the opposite side from which the tip engaging portion (11a) of the latch claw (11) of the housing (9) projects. In addition to forming the hook claw (11), when the front end engaging portion (11a) is pushed into the housing (9), the rear end portion (11b) projects from the window hole (21). It is characterized by having done. Then, in this embodiment, a confirmation member, for example, a vermilion fluorescent tape (22) is attached to the rear end portion (11b) of the hook (11).

With this configuration, when the safety latch (20) is engaged, the latch claw (11) projects the tip engaging portion (11a) from the housing (9) as shown by the solid line in FIG. Since the end portion (11b) is inserted into the housing (9), the vermilion fluorescent tape (22) attached to the rear end portion (11b) cannot be seen.

Further, when the safety latch (20) is not latched, the latch claw (11) allows the tip engaging portion (11a) to enter the housing (9) as shown by the chain double-dashed line in FIG. Since the rear end (11b) is projected from the window hole (21), the vermilion fluorescent tape (22) attached to the rear end (11b) can be seen.

Therefore, whether or not the safety latch (20) is applied can be easily confirmed at a glance, and the multi-stage telescopic ladder (1) can be used more safely.

In the above embodiment, the vermilion fluorescent tape (22) is attached to the rear end portion (11b) of the hook (11) as a confirmation member, but the present invention is not limited to this. However, fluorescent tape or ordinary tape of a color other than vermilion that is easily noticeable may be attached, and paint other than this, which is easily noticeable, may be applied, or other checking members may be removed. You may attach it.

[0019]

[Effect of device]

 According to the present invention, as described above, it is possible to see at a glance whether or not the safety latch is applied depending on whether the rear end of the hook is protruding from the window hole of the housing or not. The child can safely and surely perform the expansion and contraction operation of the ladder.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a safety latch of a multistage telescopic ladder according to the present invention.

[Fig. 2] Fig. 2 shows the shortening of the ladder of the multi-stage telescopic ladder.
(A) is a front view and (B) is a side view.

[Fig. 3] Fig. 3 is a view showing a multi-stage telescopic ladder when the ladder is extended,
(A) is a front view and (B) is a side view.

FIG. 4 is a configuration diagram showing a conventional structure of a safety latch.

FIG. 5 is a view for explaining how to hang a safety latch, and is a drawing showing a state in which a backing plate having a second-stage ladder attached to its vertical crosspiece is shortened to a position where it does not contact the latch of the safety latch and the guide plate. Is.

FIG. 6 is a view for explaining how to hang a safety latch, and is a drawing in which a second step ladder is extended to a position where a guide plate of the safety latch is pushed in.

FIG. 7 is a view for explaining how to apply a safety latch, and is a drawing in a state where the safety latch is applied.

FIG. 8 is for explaining a method of releasing the safety latch,
It is a drawing of a state where the vertical runner of the second step ladder is extended to a position where it does not contact the hooks of the safety latch and the guide plate.

FIG. 9 is a view showing a state of a safety latch when the ladder of the multistage telescopic ladder is shortened.

[Explanation of symbols]

 1 Multi-stage telescopic ladder 1a 1st stage ladder 1b 2nd stage ladder 1c 3rd stage ladder 9 Enclosure 11 Engagement 14 Spring 15 Guide plate 17 Contact plate 20 Safety latch 21 Window hole 22 Vermilion fluorescent tape

Claims (1)

[Scope of utility model registration request] 1. A housing integrally attached to a step ladder, and when it is pivotally supported by a shaft in the housing and a tip engaging portion projects from the case, it engages a vertical rung of the upper or lower step ladder. With hanging nails,
A spring that urges the tip engaging portion of the hook to protrude from the housing, and a guide that pushes the hook into the housing when pushed down by the vertical rail of the upper or lower ladder when the ladder is shortened. In a safety latch of a multi-stage telescopic ladder including a plate, a window hole is formed in a plate material on the opposite side from which the tip engaging portion of the hook of the case projects, and the tip engaging portion of the hook is placed in the case. A safety latch for a multi-stage telescopic ladder, characterized in that when it is pushed in, the rear end portion is formed so as to project from the window hole.