Mechanical plug with expandable seal and threaded anchor for sealing injection ports

Abstract

A plug for sealing injection ports in concrete elements comprises a fully threaded bolt, a threaded anchor adapted to engage an internal thread of the injection port and to retain the plug securely under high pressure, and an expanding rubber seal positioned between two conical washers. Tightening a nut on the bolt compresses the expanding rubber seal between the conical washers, causing the seal to expand radially against the wall of the injection port to prevent water leakage and form a watertight closure. The design allows quick installation, predictable positioning, reliable sealing even under high water pressure, and later removal for re-injection if required.

Description

[0001] Description

[0002] Title: Mechanical Plug with Expandable Seal and Threaded Anchor for Sealing Injection Ports in Concrete Elements

[0003] Field of the Invention

[0004] The present invention relates to sealing devices for injection ports, and more particularly to a plug comprising an expandable seal element, preferably made of elastomeric material, in combination with a mechanical anchoring component, such as a threaded anchor. The plug is configured to be easily mounted into an injection port, providing predictable positioning at a desired depth and reliable sealing performance under operational conditions..

[0005] Purpose of the Product

[0006] The purpose of the product is to effectively seal injection ports in concrete elements that form part of a concrete element lining in tunnels, in order to prevent water leaks from the outside of the concrete lining through the injection ports and into the tunnel.

[0007] The plug is intended for sealing leaks in tunnels where a fully or partially watertight concrete element lining is installed, with cavities between the concrete elements and the rock surface being injected with mortar, cement, or similar. When the injection of mortar, cement, or similar is performed through injection ports in the concrete elements, it is necessary to seal the injection port after the cavity has been filled to prevent leaks into the tunnel.

[0008] In cases of large water volumes, high water pressures, insufficient injection of mortar or cement, or other conditions, a plug with an expanding rubber seal and a threaded anchor will form a watertight barrier in the injection port, as the rubber seal expands against the port walls. At the same time, the plug is secured by a threaded anchor that engages the internal threads of the injection port.

[0009] Background of the Invention

[0010] Existing techniques for sealing injection ports in concrete elements used in tunnel linings are often ineffective at high water pressures. Traditional methods, such as simple gaskets or sealing compounds, do not always maintain sealing capability under high pressure.

[0011] The plug is based on the principle of mechanical expansion of a rubber seal compressed between two conical washers. The conical washers force the rubber seal against the walls of the injection port. The plug is held in place by a threaded anchor, ensuring it remains fixed even under very high water pressures.

[0012] Since there are normally a large number of injection ports to be sealed in a tunnel with a partially or fully watertight concrete element lining, it is important that the plug is quick and easy to install. The plug should also be removable in case additional injection through the port becomes necessary. Description of the Drawings

[0013] • Figure 1: Cross-section of the plug showing all components.

[0014] • Figure 2: Cross-section of the plug in the injection port before compression and expansion of the rubber seal.

[0015] • Figure 3: Cross-section of the plug in the injection port after compression and expansion of the rubber seal.

[0016] Detailed Description of the Invention

[0017] The invention consists of the following main components:

[0018] 1. Fully threaded hex bolt (1)

[0019] 2. Threaded anchor (2)

[0020] 3. Round washers (3 and 4)

[0021] 4. Hex nut (5)

[0022] 5. Rubber seal (6)

[0023] 6. Conical washers (7 and 8)

[0024] 7. Weld (9) between the innermost conical washer (7) and the fully threaded hex bolt (1)

[0025] 8. Round washer (10)

[0026] 9. Hex nut (11)

[0027] All components are mounted on the fully threaded hex bolt (1). The threaded anchor (2) is secured by two locking washers (3 and 4) tightened with a hex nut (5) so that the anchor (2) does not rotate independently of the bolt (1).

[0028] The threaded anchor (2) has external threads that match the internal threads of the injection port.

[0029] To achieve watertightness, the innermost conical washer (7) is welded (9) to the fully threaded hex bolt (1), preventing water from flowing along the bolt threads.

[0030] The rubber seal (6) has an outer diameter smaller than the internal diameter of the injection port and is positioned between the two conical washers (7 and 8).

[0031] The outer conical washer (8) compresses the rubber seal (6) when the hex nut (11) is tightened. Between the outer conical washer (8) and the hex nut (11) there is a round washer (10).

[0032] The fully threaded hex bolt (1), threaded anchor (2), rubber seal (6), and conical washers (7 and 8) can be adapted to different types of injection ports. Since the innermost conical washer (7) is welded to the bolt (1), the plug cannot be screwed further into the injection port once the washer (7) contacts the internally threaded section of the port. This ensures that the plug is always installed at a consistent depth.

[0033] The outer diameter of the conical washer (7) is greater than the inner diameter of the threaded section of the injection port.

[0034] Method of Use:

[0035] 1. Screw the plug into the inj ection port by hand.

[0036] 2. Once fully inserted, tighten the outer hex nut (11) with a wrench or similar tool so that the two conical washers (7 and 8) compress the rubber seal (6).

[0037] 3. The rubber seal (6) expands and presses against the walls of the injection port.

[0038] The only potential water path through the port is between the port walls and the outer side of the rubber seal (6) or between the inner side of the seal and the conical washers (7 and 8).

[0039] Water will not pass through the port as long as the water pressure does not exceed the sealing pressure between the rubber seal (6) and the conical washers (7 and 8) or between the seal and the port walls.

[0040] If the water pressure exceeds the plug’s capacity, water may pass between the rubber seal (6) and the port walls, or between the seal and the washers (7 and 8). The plug itself will still be retained by the threaded anchor (2).

[0041] The plug can be removed by loosening the outer hex nut (11).

[0042] Advantages:

[0043] The plug according to the invention offers the following advantages:

[0044] • Secure mechanical retention under high internal water pressure.

[0045] • Reliable watertight sealing through radial expansion of the rubber seal.

[0046] • Quick and simple installation using standard tools.

[0047] • Compatibility with a range of injection port designs.

[0048] • Possibility of removal and re-use for re-injection purposes.

[0049] Industrial applicability:

[0050] The invention is suitable for use in tunnel construction, dam maintenance, water treatment plants, and any concrete structure requiring high-pressure sealing of injection ports.

Claims

AMENDED CLAIMS received by the International Bureau on 22 December 2025 (22.12.2025)

1. A plug for sealing injection ports in concrete elements, comprising: a fully threaded bolt (1); a threaded anchor (2) having external threads that match the internal threads of the injection port and being adapted to engage the internal thread of the injection port to retain the plug securely within the port under high pressure; an expanding rubber seal (6) positioned between two conical washers (7, 8); wherein tightening a nut on the bolt compresses the expanding rubber seal (6) between the conical washers (7, 8), causing the seal to expand radially against the wall of the injection port to prevent water leakage and form a watertight closure.

2. The plug according to claim 1, wherein two or more of the components are formed as a single integrated component.

3. The plug according to claim 1 or 2, wherein the expanding rubber seal (6) is dimensioned to fit within the injection port.

4. The plug according to any of the preceding claims, wherein the threaded anchor (2) is dimensioned to fit within the threaded section of the injection port.

5. The plug according to any of the preceding claims, wherein the conical washers (7, 8) are dimensioned to allow compression and radial expansion of the expanding rubber seal (6).

6. The plug according to any of the preceding claims, wherein the outer diameter of at least one of the conical washers (7) is greater than the inner diameter of the threaded section of the injection port.

7. The plug according to any of the preceding claims, wherein the threaded anchor (2) and the expanding rubber seal (6) are configured to cooperate to maintain the plug in position and prevent leakage when subjected to high fluid pressure within the injection port.[0001]Statement under Article 19(1)[0002]The present amendments are filed under Article 19 PCT.[0003]Claim 1 has been amended to clarify the manner in which the threaded anchor engages the internal thread of the injection port by specifying that the threaded anchor has external threads matching the internal threads of the injection port. In addition, reference signs have been added to claim 1 for consistency with the description and the drawings, in order to address clarity and formal issues identified in the Written Opinion of the International Searching Authority.[0004]Claims 3 to 7 have been amended solely by the addition of reference signs for consistency with the description and drawings.[0005]Claim 2 remains unchanged.[0006]All amendments are fully supported by the application as originally filed, in particular page 2, lines 59-60, and do not extend the scope of protection.

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