JPH0717841U - Fall prevention net into the manhole - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention provides a fall prevention net into a manhole that can prevent falling objects and flying objects from entering the manhole with a simple structure and can reduce the storage condition. The purpose is to provide. The present invention is characterized in that a semicircular formwork 4 having two mesh nets 2 stretched is connected to each other by a hinge 1 at a straight portion of the formwork 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fall prevention net that prevents falling objects and flying objects from entering a manhole.

[0002]

[Prior art]

 Conventionally, when constructing and maintaining underground equipment, the surroundings were simply surrounded by partitions or folding screens with the manhole opening open. For this reason, it was not possible to completely prevent falling objects and flying objects from entering the manhole. Therefore, there were problems in ensuring the safety of workers in the manhole and preventing equipment accidents (damage, etc.) in underground communication equipment.

[0003]

[Problems to be solved by the device]

 The present invention has been made in view of the above circumstances, and it is possible to prevent falling objects and flying objects from entering the manhole with a simple structure and to reduce the storage condition in the manhole. The purpose is to provide a fall prevention net.

[0004]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the fall prevention net into the manhole of the present invention has a structure in which a net-like net is attached to a semicircular formwork, and the straight parts of the formwork are mutually hinged. Is characterized in that.

[0005]

[Action]

 By the means described above, the fall prevention net of the present invention is stored in a folded state in a small fold with the hinge part closed before use. After the worker enters the manhole, open the hinge part and install it so that it covers the opening of the manhole to prevent falling objects and flying objects from entering the manhole. Used as a net.

[0006]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a side view of the same. Immediately, the mesh nets 2 are stretched on the two substantially D-shaped semi-circular molds 4 which are configured to have substantially the same size as the manhole iron cover. In this case, the mesh net 2 of one mold 4 is provided with an opening 3 for passing a ventilation hose or duct in the manhole. The straight parts of the two molds 4 are connected to each other by a hinge 1. Further, in the part fitted into the manhole opening of the two molds 4, that is, in the semicircular part 6 of the mold 4, the manhole is firmly fixed and the fall prevention net is stably fixed. The protrusion 5 is provided.

The mold 4 is made of a hollow member such as a rectangular pipe to make it light, and has a structure that is durable against the fall of heavy objects such as machines and measuring instruments. Incidentally, a handle or the like can be attached to a part of the mold 4 as appropriate.

As for the mesh net 2, the net 2 is made of a strong synthetic fiber such as nylon or carbon fiber, so that the net can withstand a heavy load such as a measuring instrument. By setting the mesh spacing of the net 2 to be about 15 mm, it is possible to prevent a small tool such as a driver from falling, and it is also possible to monitor the inside of the manhole. If the mesh spacing of the net 2 is narrowed, even tools smaller than the driver can be prevented from falling, but the net 2 itself becomes heavy and it becomes difficult to monitor the inside of the manhole. On the contrary, if the net spacing of the net 2 is widened, the weight of the net 2 can be reduced, but small tools such as a screwdriver will fall, so the net spacing of the net 2 is preferably about 15 mm. is there. A fishing net can be used as an example of the mesh net 2 because it is easily available and is durable. The mesh spacing of the fishing net was 15 mm, and the net thickness was 1 mm in diameter. If necessary, it is possible to provide an opening 3 for passing a hose or duct for ventilation in the manhole in a part of the mesh net 2.

Further, it is sufficient for the hinge 1 to have a structure that can withstand a heavy object that has dropped when the drop prevention net of this embodiment is used. In particular, the material, structure, and quantity are not limited.

Before use, the drop prevention net having the above-described structure was stored by folding the hinge 1 and folding it in a small fold. After the worker enters the manhole, open the hinge 1 part and install it so as to cover the opening of the manhole so as to prevent falling objects and flying objects from entering the manhole. I used it as a net. By using this fall prevention net, it was possible to secure the safety of workers in the manhole and underground communication equipment from falling objects and flying objects when the manhole was opened. It should be noted that, with the fall-prevention net installed in the manhole opening, it is also possible to move in and out workers, instruments, tools, etc. by pushing up one mold 4 of the fall-prevention net from the hinge 1 part. Is. When the work in the manhole was completed, the fall prevention net was removed from the manhole opening, hinge part 1 was closed again, and it was folded in a small fold and stored.

[0012]

[Effect of device]

 As described above, according to the present invention, it is possible to provide a drop-prevention net into a manhole that can prevent falling objects and flying objects from entering the manhole with a simple structure and can reduce the storage condition. it can.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Hinge, 2 ... Mesh net, 3 ... Opening for passing a ventilation hose or duct, 4 ... Formwork, 5 ... Projection, 6 ...
Semicircular part of the formwork 4.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masanori Nakajo 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Eiji Miyoshi 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Taizo Okaya 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Takashi Hosoda 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (1)

[Scope of utility model registration request] 1. A semicircular formwork 2 having a mesh net stretched.
A fall prevention net into a manhole, characterized in that the individual pieces are hinged to each other in a straight line portion of the form.