Flexible lifting loop for concrete articles

Abstract

The invention relates to building, and more particularly to flexible lifting loops for lifting concrete and reinforced concrete articles. A flexible lifting loop is formed from a two-ply fabric strap and comprises, at one end, a lifting part and, at the other end, an anchor with an eyelet formed by a bend in the two-ply fabric strap, which are connected to one another by a straight anchor section formed from the two-play fabric strap. The plies of the two-ply fabric strap have a wire frame arranged therebetween. The two-ply fabric strap has a seam region situated on the lifting part and / or on the anchor section. The technical result is that of increasing the lifting capacity of the flexible lifting loop and eliminating the cause of chips and cracks in the body of the concrete.

Description

[0001] FLEXIBLE MOUNTING LOOP FOR CONCRETE PRODUCTS

[0002] DESCRIPTION OF THE INVENTION

[0003] AREA OF TECHNOLOGY

[0004] The invention relates to construction, namely to flexible mounting loops for slinging concrete and reinforced concrete products.

[0005] LEVEL OF TECHNOLOGY

[0006] Resource conservation is currently rapidly developing, which involves the production of thin-walled concrete structures. Anchoring such concrete and reinforced concrete structures requires the use of reliable anchoring systems.

[0007] There are a number of Russian Federation patents for the design of a flexible mounting loop: No. 194846, E04G 21 / 14, published 25.12.2019; 2681970, E04G 21 / 14, published.

[0008] 14.03.2019; 2764008, E04G 21 / 14, published 12.01.2022; 2778954, B65G 7 / 12, published

[0009] 29.08.2022; 213703, E04G 21 / 14, published 23.09.2022; 2810368, E04G 21 / 14, published

[0010] December 27, 2023.

[0011] They all share common features: the loop consists of two parts—a sling section and an anchor section. The anchor section is made of a double-stitched polyester strap, with an anchor eye at one end and a curved end at the edge of the concrete. The anchor section contains a stitched area of ​​the double-stitched polyester strap, up to 250 mm long, adjacent to the eye.

[0012] Common disadvantages include insufficient strength of the anchor section and low load-bearing capacity of the lifting loop.

[0013] A technical solution is known under Russian patent No. 2778954, E65G7 / 12 (prototype), published on September 29, 2022, in which the flexible mounting loop is a double textile tape, which is equipped with a protective cuff located at the point where the mounting loop exits the concrete product so that part of the protective cuff is located in the body of the concrete product, and the other part is above the surface of the concrete product, and the protective cuff is located with the possibility of covering the anchor eye of the A-shaped anchor, the slinging unit at the bending point is made with a protective lining located on its inner surface.

[0014] A disadvantage of the design according to Russian Federation Patent No. 2778954 is the formation of chips and cracks in the concrete body at the location of the anchor section during lifting operations. In FIG. 2 (Russian Federation Patent No. 2778954) it is clearly visible that the stitching zone with a length of 200-250 mm of the textile tape of the anchor section (length 350-450 mm), containing three layers of textile tape, is larger in cross-section than the rest of the double textile tape located above, containing two layers of tape. During lifting operations, the flexible mounting loop stretches, the textile tape, having a low modulus of elasticity (for polyester tape - 12-16 MPa) elongates up to 5-10%, proportionally decreasing in cross-section, and the anchor section 3 is partially pulled out of the channel in the concrete. The presence of a cross-linked zone, which has a larger cross-section than the concrete channel formed by the two-layer textile tape, prevents the anchor section from extending further. Thus, only part of the load is transferred to the anchor, while the rest is supported by the cross-linked zone.

[0015] This leads to the stitching zone, as it moves upward, breaking (splitting) the concrete body, causing chips and cracks. Due to its larger cross-section (3 layers of textile tape), it cannot pass through the rectangular channel (2 layers of textile tape) in the concrete formed by the two-layer textile tape during the casting of the concrete slab. The anchor section also loses strength, as the stitching zone, especially its upper portion, is compressed by the channel walls and abrades against the concrete layer as it moves through the narrow concrete channel, thereby losing strength.

[0016] However, the presence of a protective cuff does not eliminate this drawback, since when exposed to a load, the cuff is pulled out of the concrete body, being part of the anchor section, therefore its presence does not in any way affect the strength of the anchor section, since the cuff does not bear any functional load.

[0017] DISCLOSURE OF THE ESSENCE OF THE INVENTION

[0018] The technical result of the invention is to increase the load-bearing capacity of a flexible lifting loop and eliminate the causes of chipping and cracking in the concrete body. In the first embodiment, the technical result is achieved in that a flexible lifting loop for a concrete product, composed of a double textile tape with a slinging part, includes a stitching zone at one end, and an anchor with an eye formed by bending the double textile tape at the other, connected to each other by a straight anchor section made of a double textile tape and a wire frame located between them.

[0019] In the second embodiment, the technical result is achieved in that a flexible mounting loop for a concrete product, made of a double textile tape with a slinging part at one end and an anchor with an eye formed by bending the double textile tape at the other, are connected to each other by a straight anchor section made of a double textile tape with a stitching zone adjacent to the slinging part and a wire frame located between the layers of the double textile tape.

[0020] In the third embodiment, the technical result is achieved in that a flexible mounting loop for a concrete product, made of a double textile tape with an anchor with an eye formed by bending the double textile tape at one end and a slinging part at the other, are connected to each other by a straight anchor section made of a double textile tape with a wire frame between its layers and with a stitching zone located partly on the anchor section and partly on the slinging part.

[0021] In some embodiments, the end sections of the anchor are bent.

[0022] In some embodiments, the double textile tape may be provided with a heat-shrinkable film coating.

[0023] BRIEF DESCRIPTION OF DRAWINGS

[0024] The essence of the technical solution is explained by drawings.

[0025] FIG. 1 - flexible mounting loop, front view, the stitching area is located on the slinging part.

[0026] FIG. 2 - flexible mounting loop, side view, the stitching area is located on the slinging part.

[0027] FIG. 3. - flexible mounting loop, front view, the stitching zone is located on the anchor section and is adjacent to the slinging part. FIG. 4. - flexible mounting loop, the stitching zone is located on the slinging part (side view).

[0028] FIG. 5 - flexible mounting area, front view, the stitching area is located simultaneously partly on the anchor section and partly on the slinging part.

[0029] FIG. 6 - flexible mounting zone, side view, the stitching zone is located simultaneously partly on the anchor section and partly on the slinging part.

[0030] DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0031] In FIG. 1 and FIG. 2, a flexible mounting loop is shown, mounted in a concrete product, and is a double textile tape 1, consisting of a slinging part 2 with a stitching zone 3 and an anchor section 4, having an eye 5 with a metal or composite anchor 6 at the end. The eye 5 is formed by a bend of the double textile tape, fastened with metal staples (not shown). In order for the anchor section 4 and the anchor 5 to be located in the same plane, a metal frame 7 is located between the layers of the double textile tape 1. In this case, the stitching zone of the double mounting tape 1 is located on the slinging part 2 of the mounting loop.

[0032] The difference between FIG. 3 and FIG. 4 and FIG. 1 and FIG. 2 is that the stitching zone 3 of the double mounting tape 1 is located on the anchor section 4 and is adjacent to the slinging part 2.

[0033] The difference between FIG 5 and FIG 6 and the previous figures is that the stitching zone 3 of the double mounting tape 1 is located partly on the anchor section 4 and partly on the slinging part 2.

[0034] The production of flexible mounting loops and their subsequent installation in a concrete product is shown in examples 1-3.

[0035] The ends of a single textile tape are sewn together into a ring and folded to form a double textile tape 1. An anchor 6 is placed on one end of the double textile tape 1, securely fastened with metal staples, forming an eye 5, and an auxiliary metal rod (not shown) is placed on the other.

[0036] The double textile strap can be coated with heat-shrinkable film. This protects the textile strap from damage and abrasion when in contact with concrete and formwork elements, helping to maintain the strap's strength and increase the load-bearing capacity of the flexible lifting loop.

[0037] Example 1. Wire frame 7, 400-450 mm long and with a width close to the width of the textile tape (for example, 30 mm) is placed between anchor 6 and the upper end of anchor section 4 adjacent to slinging part 2. By manually pulling double textile tape 1 with a force of 5 to 20 N, wire frame 7 is secured inside it with metal staples (not shown). In this case, stitching zone 3 is located on slinging part 4 of FIG. 1. Subsequently, the resulting mounting loop is mounted in a concrete product, while anchor section 4 is located in the concrete layer, and slinging part 2 serves to carry out lifting operations (Option 1).

[0038] As shown in FIGURE 6, the ends of anchor 6 are curved. This design improves the anchor's secure attachment to the concrete and ensures a more uniform transfer of tensile force to the anchor, thereby further reducing the likelihood of chipping and cracking in the concrete structure during lifting operations.

[0039] During lifting operations, the flexible lifting loop stretches and extends along its entire length. The tensile force from slinging part 2 is transferred without limitation (in the prototype, the tensile force is limited by three-layer stitching) to anchor 6. Upon completion of lifting operations, the flexible lifting loop returns to its original length (FIG. 2). In this case, it is undesirable for the stitching zone to be located in the flexure area of ​​slinging part 2. Therefore, the placement of stitching zone 3 in slinging part 2 is only possible if its length is greater than 500 mm; otherwise, damage to stitching zone 3 is possible.

[0040] This version of anchor section 4 can be used in flexible mounting loops for three-layer sandwich panels.

[0041] Compared to the prototype, the lifting capacity of the flexible mounting loop is increased by 2 or more times, and during lifting operations, no chips or cracks are formed in the body of the concrete panel.

[0042] Example 2. Wire frame 7, 400-450 mm long, is placed on anchor section 4, limited by anchor 6 and the end of stitching zone 3, coinciding with the end of anchor section 4 adjacent to slinging part 2 (FIG. 3). By manually pulling double textile tape 1 with a force of 5 to 20 N, wire frame 7 is secured inside it with metal staples (not shown). Subsequently, the resulting lifting loop is mounted in a concrete product, while anchor section 4, including stitching zone 3, is located in the concrete body, and slinging part 2 serves for lifting operations (Option 2).

[0043] As shown in FIG. 3, the end sections of anchor 6 are curved. During lifting operations, the flexible lifting loop stretches and extends along its entire length. Under tensile stress, stitching zone 3 partially extends beyond anchor section 4, and the tensile stress is transmitted unimpeded (unlike in the prototype) through the double textile tape to anchor 6. Upon completion of lifting operations, in the absence of tensile stress, stitching zone 3 returns to anchor section 4, i.e., to its original position (FIG. 4). Therefore, with a short length of slinging portion 2 (less than 300 mm), it is preferable to place the stitching zone on anchor section 4. This arrangement is convenient for horizontal casting of a concrete product, when the "soft" slinging portion 2 is located to the side of the product being cast.During molding, the soft slinging part 2 easily bends to the side, and the presence of a rigid wire frame 7 and the rigidity of the stitching zone 3 make it possible to accurately localize the location of the slinging part 2 on the concrete product.

[0044] Compared to the prototype, the lifting capacity of the flexible mounting loop is increased by 2 or more times; during lifting operations, no chips or cracks form in the body of the concrete panel.

[0045] Example 3. The stitching zone 3 is located simultaneously partially on the anchor section 4 and partially on the slinging part 2. The wire frame 7, 400-550 mm long, is placed between the anchor 6 and the stitching zone 3 (FIG. 5). By manually stretching the double textile tape 1 with a force of 5 to 20 N, the wire frame 7 is secured inside it with metal staples (not shown). Subsequently, the resulting lifting loop is mounted in a concrete product, wherein the anchor section 4, partially including the stitching zone 3 and the wire frame 7, is located in the concrete body, and the slinging part 2, used for carrying out lifting operations, also partially including the stitching zone 3 and the wire frame 7, is located perpendicular to the surface of the concrete body. As shown in FIG. 5, the anchor is made straight and has no bends.

[0046] During lifting operations, the flexible lifting loop is stretched and extended along its entire length. Under tensile stress, part of the stitching zone 3, which was partially located on the anchor section 4, leaves the concrete body and the tensile force is transmitted unhindered (unlike in the prototype) through the double textile tape 1 to the anchor 6. After the lifting operations are completed, in the absence of tensile stress, part of the stitching zone 3 returns to the anchor section 4, i.e., to its original position (FIG. 6), while the slinging part 2 always assumes a perpendicular position with respect to the surface of the concrete product due to the wire frame 7 and the stitching zone 3. This variant of using the lifting loop is preferable for vertical molding, when the slinging part 2 is located on top of the product being molded, which is convenient for lifting operations (Option 3).

[0047] Compared to the prototype, the lifting capacity of the flexible mounting loop is increased by 2 or more times; during lifting operations, no chips or cracks form in the body of the concrete panel.

[0048] Thus, the flexible lifting loop, manufactured in all three design variants, ensures its unimpeded movement within a rectangular concrete channel. This increases the lifting capacity of the flexible lifting loop by two or more times compared to the prototype, eliminating the possibility of chipping and cracking in the concrete structure (e.g., a thin-walled concrete structure). Furthermore, during lifting operations, the load is transferred directly to the anchor, not to the stitching area, eliminating the potential for cracking and chipping.

[0049] INDUSTRIAL APPLICABILITY

[0050] The production of the proposed design of flexible mounting loops is possible using existing technological equipment.

[0051] The tests conducted demonstrated the operability and industrial applicability of three flexible mounting loop design options.

[0052] Thus, the stated technical result was achieved: the load-bearing capacity of the flexible mounting loop was increased, and the causes of the formation of chips and cracks in concrete were eliminated.

Claims

CLAUSES OF THE INVENTION 1. A flexible mounting loop for a concrete product, made of a double textile tape with a slinging part at one end and an anchor with an eye formed by bending the double textile tape at the other end, connected to each other by a straight anchor section made of a double textile tape, wherein a wire frame is located between the layers of the double textile tape, and the double textile tape contains a stitching zone located on the slinging part and / or on the anchor section.

2. A flexible mounting loop according to paragraph 1, characterized in that the stitching zone is located on the slinging part.

3. A flexible mounting loop according to claim 1, characterized in that the stitching zone is located on the anchor section and is adjacent to the slinging part.

4. A flexible mounting loop according to claim 1, characterized in that the stitching zone is located partly on the anchor section and partly on the slinging part.

5. A flexible mounting loop according to claim 1, characterized in that the end sections of the anchor are bent.

6. A flexible mounting loop according to claim 1, characterized in that the double textile tape is provided with a coating of heat-shrinkable film.

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