JPH0221673Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Technical field of invention] The present invention relates to a pipe mouth waterproofing device.

[Technical background of the invention and its problems] Conventional general pipe entrance waterproofing devices have either putty-like waterproofing mixture interposed between the cable and the pipe opening, or a packing made of rubber etc. It is something that However, when a single-core power cable is installed in a conduit, the cable expands and contracts due to changes in load and other factors.

In particular, plastic cables such as CV cables expand and contract significantly, reaching 100 to 150 mm. During this thermal expansion and contraction, the cable will slide against the pipe entrance waterproofing device, but if the amount of sliding is large, in the case of a pipe opening waterproofing device with a waterproofing compound interposed, the cable will slide against the waterproofing compound. is extruded,
This will result in loss of watertightness. On the other hand, in pipe entrance waterproofing devices that use rubber packing, the tightening force of the packing is determined by taking into consideration the sheath of plastic cables that do not have metal sheaths, creep of insulators, deformation of metal shielding, etc. It is not possible to obtain water stopping power.

As a conduit mouth waterproofing device that does not lose its watertightness even when the cable slides, a cable holding tube is airtightly attached to the conduit entrance through a flexible bellows in the direction of the conduit axis, and the cable is attached to this through packing. However, in the case of a plastic cable, it is not only extremely expensive, but also has the same problems as the use of rubber packing itself.

[Purpose of the invention] The present invention was made based on the above circumstances, and is a pipe mouth waterproofing device that does not lose its water-stopping properties due to cable sliding and can provide sufficient water-stopping properties even for plastic cables. I will provide a.

[Summary of the invention] The pipe mouth waterproofing device of the invention includes a plurality of annular packings made of a soft elastic material, and a laminate of packings made of hard rubber etc. that is in contact with both end surfaces of the laminate of these packings. an annular spacer concentrically provided with a cylindrical portion protruding outward in the axial direction of the spacer, an annular fastening fitting abutting one spacer, and an annular fastening fitting abutting the other spacer and said fastening fitting Similarly, a fixing metal fitting including a ring-shaped part, a projecting piece that protrudes in the axial direction and has a wall at its tip, and has a tapered surface on the radially outer surface that descends toward the base of the wall, and the tightening metal fitting. The present invention is characterized in that it includes a tightening screw extending from an annular portion to an annular portion, a wedge engaged with the tapered surface, and a wedge adjustment screw screwed into the wall.

[Embodiment of the invention] Fig. 1 is a side view showing a part of an embodiment of the invention in cross section, and Fig. 2 is a front view thereof. It is made of soft rubber, synthetic resin, foamed rubber or synthetic resin (hereinafter referred to as soft elastic material), and is made of multiple annular packings 1.
are laminated, and on both end faces of the laminate, spacers 2 made of hard rubber or the like are arranged in an annular shape and have a thin cylindrical part concentrically along the inner peripheral surface on one side, with the thin cylindrical part facing outward. It's in contact.

Furthermore, a packing fastening fitting 3 having a two-part structure divided by an L-shaped dividing line is in contact with one of the spacers, and a fixing fitting 4 having the configuration described below is in contact with the other spacer. has been done.

The fixing fitting 4 has an annular portion 4a which is divided into two parts similarly to the packing tightening fitting 3, and each of the divided portions is located at both diametrical ends of the annular ring and protrudes in the axial direction. and a projecting piece 4b having a wall body 4c projecting outward in the direction.

A tapered surface 4d descending toward the base of the wall 4c and side walls 4e on both sides of the tapered surface are provided on the radially outer surface of the projecting piece 4b. A long hole 4f in the axial direction is provided in the side wall 4e, and a guide pin 5a of the wedge 5 is engaged with this long hole.

Incidentally, a tightening force is applied to the packing 1 by a tightening bolt 6 that penetrates from the packing tightening fitting 3 to the annular portion 4a of the fixing fitting.

Further, a reinforcing plate 7 having a two-part structure is attached to the wall body 4c, and a wedge adjustment screw 8 is screwed into the reinforcing plate 7.

The device of the present invention having the above configuration is used in the following manner. First, a plurality of packings 1 are engaged with the spacer 2 and the cable C, and the packing fastening fittings 3 and fixing fittings 4 are fixed to the spacers at both ends of the stack. Next, the cable C is shifted and the stacked body of the packing 1 is put into the pipe T, and the wall 4c of the fixture 4 is engaged with the pipe opening. Here, the nut 6a screwed onto the tightening bolt 6 is rotated to apply a necessary tightening force to the packing 1, and the packing 1 is crimped onto the cable C and the inner periphery of the conduit. Next, the wedge adjusting screw 8 is rotated to advance the wedge 5 and fix the fixing fitting 4, and hence the device of the present invention, to the pipe opening.

As mentioned above, in the device of the present invention, the packing is made of a soft elastic material, so even if the packing is tightened to obtain water-stopping properties,
There is no risk of damage to the cable. Further, even if the packing is made of a soft elastic material, the cable is mechanically supported by the spacer, the fastening metal fittings, and the fixing metal fittings, so that the cable does not become unstable. Furthermore, when the cable undergoes thermal expansion and contraction, the cable can slide freely against the packing without losing its watertight properties as in devices using waterproofing compounds. In addition, the device is fixed to the pipe port with 2
Since the rotation of the nut 6a is effected by the protruding piece 4b, the rotation of the nut 6a can be easily performed using a long box spanner. Furthermore, since the walls 4c at the tips of the protruding pieces 4b are connected by the reinforcing plate 7, there is no fear that the protruding pieces 4b will be deformed when the wedge is pushed forward by the wedge adjustment screw 8.

[Effects of the Invention] The conduit mouth waterproofing device of the present invention is useful because there is no risk of losing water-stopping properties due to thermal expansion and contraction of the cable, and it can be supplied at a lower cost than conventional devices using Perose.

[Brief explanation of drawings]

FIG. 1 is a side view showing a part of an embodiment of the present invention in cross section, and FIG. 2 is a front view thereof. 1... Packing, 2... Spacer, 3... Tightening metal fitting, 4... Fixing metal fitting, 4a... Annular part, 4b... Protruding piece, 4c... Wall, 4d... Tapered surface, 5 ...Wedge, 6...Tightening screw, 8...Wedge adjustment screw.

Claims (1)

[Scope of utility model registration request] An annular packing made of a soft elastic material, an annular spacer abutting both end faces of the packing, an annular fastening fitting abutting one of the spacers, and an annular fastening fitting abutting the other spacer. A fixing metal fitting including a similar annular part to the fastening metal fitting, a projection protruding from the annular part in the axial direction, having a wall at the tip, and having a tapered surface on the radially outer surface that descends toward the base of the wall; A conduit opening prevention device comprising: a tightening screw extending from the tightening fitting to an annular portion; a wedge engaged with the tapered surface; and a wedge adjustment screw screwed into the wall.