Double-surface back bolt for dry hanging stone curtain wall

Abstract

This application relates to double-faced back bolts for dry-hanging stone curtain walls, and pertains to the technical field of curtain wall structures. The double-faced back bolt for dry-hanging stone curtain walls includes a back bolt assembly disposed in a blind hole on the back of the stone. This assembly consists of a locking bolt, a spherical body, a backstop sleeve, and a locking nut. The locking bolt head has an inverted conical structure with two inclined facets on both sides. A locking block that cooperates with the inclined facets to prevent rotation is provided in the locking cavity at the bottom of the blind hole. The backstop sleeve is fitted over the bolt and locked inside the hole, and the spherical body is positioned between the conical surface of the head and the end face of the cavity. This application achieves high-strength pull-out resistance and anti-rotation anchoring by tightening the locking nut, which pushes the backstop sleeve axially, compressing the spherical body radially and wedging it tightly. Simultaneously, the head facets and the locking block interlock, thereby achieving high-strength pull-out resistance and anti-rotation anchoring.

Description

Technical Field

[0001] This application relates to the technical field of curtain wall structures, and in particular to double-cut back bolts for dry-hanging stone curtain walls. Background Technology

[0002] Dry-hanging stone curtain walls are a common form of building envelope, and the performance of their core connectors is crucial. Currently, the mainstream connection methods include hook-and-loop, pin-and-pin, and back-bolt connection.

[0003] Hook-and-loop fasteners require grooving the stone and using adhesives, posing a risk of contamination and being inefficient; pin-type through-hole connections are prone to stress concentration and cracking in the stone. Back-bolt technology, which involves installing through blind holes on the back of the stone, minimizes stress on the stone and is a better choice.

[0004] Currently, the most common type of back bolt is the expansion sleeve back bolt. This type of back bolt anchors anchor by tightening the bolt, which forces the expansion sleeve at the tail to expand radially, thereby compressing the stone hole wall. However, this method has significant limitations: First, its anchoring force relies on the friction between the expansion sleeve and the limited hole wall area, resulting in limited pull-out resistance and vibration fatigue resistance; second, the expansion process generates significant radial splitting stress on the stone hole wall, posing a cracking risk for natural stones with uneven strength; third, this structure generally lacks an effective anti-rotation mechanism, allowing the bolt to rotate during installation or use, affecting connection stability.

[0005] Therefore, there is an urgent need in this field for a new type of back bolt structure that can provide a more reliable and safer connection method, fundamentally overcoming the inherent defects of traditional expansion sleeve back bolts. Utility Model Content

[0006] In order to securely anchor the locking bolts within the stone and achieve strong pull-out and rotation resistance, this application provides double-cut back bolts for dry-hanging stone curtain walls.

[0007] The double-cut back bolt for dry-hanging stone curtain walls provided in this application adopts the following technical solution: A double-cut back bolt for dry-hanging stone curtain wall includes a back bolt assembly set in a blind hole on the back of the stone slab. The back bolt assembly includes a locking bolt, a ball, a back-locking sleeve, and a locking nut. The locking bolt includes an integrally formed head, a connecting part, and a threaded part. The head has an inverted conical structure near the connecting part, and the diameter of the end near the connecting part is smaller than the diameter of the end away from the connecting part. Two symmetrical inclined cut surfaces are provided on both sides of the head. The bottom of the blind hole is provided with a coaxial snap-fit ​​cavity. The snap-fit ​​cavity has a cylindrical structure and a diameter larger than that of the blind hole. Two sets of snap-fit ​​blocks are provided on the side wall of the snap-fit ​​cavity to cooperate with the inclined cut surface to prevent the head from rotating. The anti-reverse pressure sleeve is fitted on the outside of the connecting part and the threaded part and is snapped into the blind hole; The spherical body is rolled between the conical surface of the head and the end face of the snap-fit ​​cavity near the blind hole. The locking nut is threadedly connected to the threaded part and abuts against the end of the anti-reverse pressure sleeve away from the blind hole.

[0008] By adopting the above technical solution, tightening the locking nut pushes the anti-reverse pressure sleeve to move axially, squeezing the spherical body, causing the spherical body to roll radially on the conical surface of the locking bolt head, generating a wedge effect with the locking cavity, and anchoring the bolt in the stone; at the same time, the inclined cut surface of the head cooperates with the locking block in the locking cavity to firmly anchor the locking bolt in the stone, achieving strong pull-out resistance and rotation resistance.

[0009] Furthermore, the head is provided with a baffle extending along the inclined sectional direction. The baffle, the tapered surface of the head, the anti-reverse pressure sleeve, and the blind hole sidewall together form a placement cavity to prevent the spherical body from rolling off during the installation of the locking bolt.

[0010] By adopting the above technical solution, in the initial stage of installation, the baffle, anti-reverse pressure sleeve, and hole wall form a temporary cavity, which restricts the spherical body to the correct position. This solves the practical problem that multiple small balls are easy to scatter and difficult to position during installation, greatly improves the convenience and efficiency of on-site installation, and ensures the assembly quality.

[0011] Furthermore, multiple spherical bodies are provided, and the multiple spherical bodies are evenly distributed between the conical surface of the head and the end face of the snap-fit ​​cavity.

[0012] By adopting the above technical solution, multiple spherical bodies jointly bear and transmit the load, making the distribution of anchoring force more uniform, avoiding stress concentration, and significantly improving the load-bearing capacity and mechanical performance stability of the entire node.

[0013] Furthermore, the spheres are made of stainless steel or ceramic and all spheres have the same diameter.

[0014] By adopting the above technical solutions, the use of high-hardness or high-wear-resistant materials and consistent dimensions ensures uniform force transmission, guarantees the long-term durability and reliability of the anchoring system, and prevents the failure of the entire anchoring system due to premature wear or crushing of a single ball. The consistent diameter is the key to ensuring uniform force distribution and smooth installation.

[0015] Furthermore, a spring washer or a flat washer is provided between the locking nut and the anti-reverse sleeve.

[0016] By adopting the above technical solution, the spring washer provides anti-loosening function, the flat washer increases the contact area, disperses pressure, effectively prevents the lock nut from loosening under vibration environment, ensures the long-term maintenance of preload, thereby maintaining the stability of anchoring force and enhancing the safety redundancy of the entire system.

[0017] Furthermore, the back bolt assembly also includes an adapter, which is connected to the end of the locking bolt via a connecting nut.

[0018] By adopting the above technical solution, the load of the curtain wall keel system is transferred to the back bolts through the connecting nuts, thus completing the force flow transmission path design from the back bolts to the curtain wall keel and forming a complete dry-hanging connection system.

[0019] Furthermore, the adapter has an L-shaped structure and an elongated hole for adjusting the installation position.

[0020] By adopting the above technical solutions, the L-shaped structure adapts to common connection scenarios, and the elongated holes provide adjustment gaps, giving the curtain wall panels the ability to make fine adjustments in three dimensions, which facilitates on-site handling of installation errors and improves the flexibility and efficiency of construction.

[0021] Furthermore, the end of the anti-reverse pressure sleeve near the head is composed of two elastically opening semicircles, and the inner side of the semicircles is provided with a receiving groove that cooperates with the baffle.

[0022] By adopting the above technical solution, if the spherical body fails, the conical surface of the head can push the two sets of semicircular parts to open elastically, so that the anti-reverse pressure sleeve tightly supports the blind hole wall, thereby preventing the anti-reverse pressure sleeve from sliding out of the blind hole; at the same time, when the head and the anti-reverse pressure sleeve approach each other, the receiving groove accommodates and avoids the baffle.

[0023] Furthermore, the top of the baffle is inclined and the closer it is to the connecting part, the closer it is to the axis of the locking bolt. When the head and the anti-reverse sleeve approach each other, the top of the baffle slides and abuts against the bottom of the receiving groove and pushes the semi-circular part to open outward, so that the anti-reverse sleeve is locked against the inner wall of the blind hole.

[0024] By adopting the above technical solution, the baffle is inclined at the top, which pushes the semicircular part to open outward when the baffle slides in the receiving groove. This causes the anti-reverse pressure sleeve to tightly support the blind hole wall, thereby helping to anchor the locking bolt in the stone slab and improving the pull-out resistance of the locking bolt.

[0025] In summary, this application includes at least one of the following beneficial technical effects: By tightening the nut, the head of the locking bolt is pushed closer to the anti-reverse sleeve, which in turn pushes multiple spherical bodies to roll along the conical surface of the head. Finally, the multiple spherical bodies are pressed tightly into and wedged between the conical surface of the locking bolt and the stepped surface of the locking cavity, thus firmly anchoring the locking bolt into the stone slab. During this process, the baffle pushes the two semicircles to open outward and prevents the anti-reverse sleeve from sliding in the blind hole, further assisting in anchoring the locking bolt into the stone slab. At the same time, through the interaction between the inclined cut surface and the locking block, the locking screw has a strong anti-rotation ability, thereby firmly anchoring the locking bolt into the stone and achieving strong pull-out resistance and anti-rotation ability. Attached Figure Description

[0026] Figure 1 This is a structural schematic diagram of the double-cut back bolts used in the dry-hanging stone curtain wall of this application; Figure 2 This is an exploded view of the double-section back bolt for dry-hanging stone curtain wall according to this application, in which the side wall of the stone slab is viewed in section. Figure 3 yes Figure 2 Enlarged diagram of section A in the middle; Figure 4 This is a side view of the anti-reverse pressure sleeve and the semi-circular portion of this application; Figure 5 yes Figure 4 Cross-sectional schematic diagram of BB; Figure 6 This is a half-sectional structural diagram of the double-cut back bolt for dry-hanging stone curtain wall of this application, showing the state after the locking bolt and anti-reverse pressure sleeve have been put into place; Figure 7 This is a half-sectional structural diagram of the double-cut back bolt for dry-hanging stone curtain walls according to this application, showing the state in which rotating the nut pushes the anti-reverse pressure sleeve closer to the head and pushes the spherical body to press against the step surface.

[0027] Reference numerals: 1. Stone slab; 11. Blind hole; 12. Snap-fit ​​cavity; 13. Stepped surface; 14. Snap-fit ​​block; 2. Back bolt assembly; 21. Spherical body; 22. Locking nut; 3. Locking bolt; 31. Head; 311. Inclined section; 32. Connecting part; 33. Threaded part; 4. Anti-reverse pressure sleeve; 41. Semicircular part; 411. Receiving groove; 5. Baffle; 6. Adapter hanger; 61. Oblong hole; 62. Connecting nut. Detailed Implementation

[0028] The following is in conjunction with the appendix Figures 1-7 This application will be described in further detail.

[0029] This application discloses a double-cut back bolt for dry-hanging stone curtain walls.

[0030] Reference Figure 1 and Figure 2 The double-cut back bolt for dry-hanging stone curtain wall includes a back bolt assembly 2 set in a blind hole 11 on the back of the stone slab 1. The back bolt assembly 2 includes a locking bolt 3, a ball 21, a backstop sleeve 4, and a locking nut 22.

[0031] Reference Figure 2 A blind hole 11 is pre-formed on the back of the stone slab 1. A coaxial cylindrical snap-fit ​​cavity 12 is machined at the bottom of the blind hole 11. The diameter of the snap-fit ​​cavity 12 is larger than the diameter of the blind hole 11, thereby forming a stepped surface 13 inside the hole. Two sets of inwardly protruding snap-fit ​​blocks 14 are fixedly installed on the side wall of the snap-fit ​​cavity 12. The two sets of snap-fit ​​blocks 14 are symmetrically arranged. In this embodiment, the snap-fit ​​block 14 and the stone slab 1 are integrally formed, and the structure is reserved during the processing of the snap-fit ​​cavity 12.

[0032] Reference Figure 2 and Figure 3 The locking bolt 3 is an integrally formed structure, which includes a head 31, a connecting part 32 and a threaded part 33 from its end to its tail. The head 31 is designed with an inverted conical structure near the connecting part 32. The diameter of the end near the connecting part 32 is smaller than the diameter of the end away from the connecting part 32. Two symmetrical inclined cut surfaces 311 are opened on both sides of the head 31. A baffle 5 is also provided on the head 31 along the direction of each inclined cut surface 311.

[0033] Reference Figure 4 and Figure 5 The anti-reverse sleeve 4 is sleeved on the connecting part 32 and part of the threaded part 33 of the locking bolt 3. The end of the anti-reverse sleeve 4 near the head 31 is composed of two elastic semi-circular parts 41. The roots of the two semi-circular parts 41 are connected, and their ends can be elastically deformed by external force. When the two semi-circular parts 41 do not deform, they abut against each other and form a ring. Each semi-circular part 41 has two receiving grooves 411 that cooperate with the baffle 5 on its inner side. In this embodiment, the two semi-circular parts 41 near the head 31 are provided with conical clearance holes.

[0034] Reference Figure 6 Multiple spherical bodies 21 are stainless steel or ceramic balls of the same diameter. The multiple spherical bodies 21 are evenly placed in a temporary placement cavity formed by the conical surface of the head 31 of the locking bolt 3, the baffle 5, the end face of the anti-reverse pressure sleeve 4, and the side wall of the blind hole 11. This is to facilitate the installation of the locking bolt 3 and the anti-reverse pressure sleeve 4 and prevent the multiple spherical bodies 21 from rolling off, thereby affecting the subsequent installation.

[0035] Reference Figure 2The locking nut 22 is threaded onto the threaded portion 33 of the locking bolt 3. An elastic washer or flat washer can also be provided between the locking nut and the end face of the anti-loosening sleeve 4 to enhance the anti-loosening effect. After being locked by the locking nut 22, the distance between the head 31 and the end face of the anti-loosening sleeve 4 can only decrease and cannot increase.

[0036] Reference Figure 2 The back bolt assembly 2 also includes an adapter 6, which has an L-shaped structure. The adapter 6 is connected to the threaded end 33 of the locking bolt 3 via a connecting nut 62. At the same time, the adapter 6 has an elongated hole 61, which can be connected to the vertical frame or horizontal beam of the curtain wall via a bolt assembly. The design of the elongated hole 61 allows for adjustment of the installation position of the stone slab 1 within a certain range.

[0037] Reference Figures 1-7 Specifically, the installation process of its back bolt assembly 2 is as follows: First, the anti-reverse sleeve 4 is put onto the locking bolt 3. Then, the assembled locking bolt 3 and anti-reverse sleeve 4 are inserted together into the blind hole 11 on the back of the stone slab 1. Before the head 31 enters the blind hole 11 and the anti-reverse sleeve 4 enters the blind hole 11, the operator puts multiple spherical bodies 21 between the baffle 5 and the conical surface, and pushes the locking bolt 3 and anti-reverse sleeve 4 into the blind hole 11, forming a placement cavity for storing multiple spherical bodies 21. The spherical bodies 21 are temporarily restricted behind the baffle 5 and will not roll into the inclined cut surface 311 area.

[0038] Then continue pushing the locking bolt 3 and the anti-reverse sleeve 4 so that the head 31 enters the locking cavity 12. Before the head 31 enters the locking cavity 12, the operator can freely rotate the locking screw. After the angle of the locking bolt 3 is adjusted, its head 31 enters the locking cavity 12 and the inclined surface 311 is aligned with the locking block 14. At this time, under the action of the inclined surface 311 and the side wall of the locking block 14 abutting against each other, the locking bolt 3 is only allowed to slide in the locking cavity 12 and cannot rotate, thereby effectively preventing the locking bolt 3 from rotating and realizing the anti-torsion function.

[0039] The locking nut 22 is then inserted into the threaded portion 33 of the locking bolt 3 and tightened using a tool. The locking nut 22 applies axial pressure to the anti-reverse sleeve 4 through the spring washer, forcing the anti-reverse sleeve 4 to move into the blind hole 11. The end face of the anti-reverse sleeve 4 then pushes the spherical body 21. The spherical body 213 rolls on the tapered surface of the head 3121 in a direction that gradually increases in diameter, generating a huge radial expansion force. This force causes the spherical body 21 to be tightly pressed into and wedged between the tapered surface of the locking bolt 3 and the stepped surface 13 of the locking cavity 12, thereby firmly anchoring the locking bolt 3 within the stone and achieving strong pull-out resistance.

[0040] Meanwhile, as the distance between the anti-reverse sleeve 4 and the head 31 decreases, the baffle 5 slides in the receiving groove 411 and continuously squeezes the semicircular part 41, forcing the two semicircular parts 41 to elastically open outward, thereby tightly supporting the inner wall of the blind hole 11, and thus assisting the spherical body 21 in preventing the locking bolt and the anti-reverse sleeve 4 from sliding out of the blind hole 11 as a whole, thereby improving its stability.

[0041] Finally, the adapter 6 is installed onto the protruding end of the locking bolt 3 using the connecting nut 62, which facilitates the subsequent fixing of the other end of the adapter 6 to the curtain wall keel using the bolt assembly, thus completing the dry-hanging installation of the entire stone panel.

[0042] The working principle of this application embodiment is as follows: The locking nut 22 pushes the head 31 of the locking bolt and the anti-reverse sleeve 4 closer together, thereby pushing multiple spherical bodies 21 to roll along the conical surface of the head 31. Finally, the multiple spherical bodies 21 are pressed tightly into and wedged between the conical surface of the locking bolt 3 and the stepped surface 13 of the snap-fit ​​cavity 12, thus firmly anchoring the locking bolt 3 in the stone slab 1. During this process, the baffle 5 pushes the two semicircular parts 41 to open outward and prevents the anti-reverse sleeve 4 from sliding in the blind hole 11, further assisting in anchoring the locking bolt 3 in the stone slab 1. At the same time, through the interaction between the inclined cut surface 311 and the snap-fit ​​block 14, the locking screw has a strong anti-rotation ability, thereby firmly anchoring the locking bolt 3 in the stone, achieving strong pull-out resistance and anti-rotation ability.

[0043] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A double-sided back bolt for dry-hanging stone curtain walls, comprising a back bolt assembly (2) disposed in a blind hole (11) on the back of a stone slab (1), characterized in that: The back bolt assembly (2) includes a locking bolt (3), a ball (21), a backstop sleeve (4), and a locking nut (22). The locking bolt (3) includes an integrally formed head (31), a connecting part (32) and a threaded part (33). The head (31) has an inverted conical structure at the end near the connecting part (32) and the diameter at the end near the connecting part (32) is smaller than the diameter at the end away from the connecting part (32). The head (31) has two symmetrical inclined cut surfaces (311) on both sides. The bottom of the blind hole (11) is provided with a coaxial snap-fit ​​cavity (12). The snap-fit ​​cavity (12) has a cylindrical structure and a diameter larger than that of the blind hole (11). Two sets of snap-fit ​​blocks (14) are provided on the side wall of the snap-fit ​​cavity (12) to cooperate with the inclined cut surface (311) to prevent the head (31) from rotating. The anti-reverse pressure sleeve (4) is sleeved on the outside of the connecting part (32) and the threaded part (33) and is snapped into the blind hole (11); The spherical body (21) is rolled between the conical surface of the head (31) and the end face of the snap cavity (12) near the blind hole (11). The locking nut (22) is threaded to the threaded part (33) and abuts against the end of the anti-reverse pressure sleeve (4) away from the blind hole (11).

2. The double-cut back bolt for dry-hanging stone curtain walls according to claim 1, characterized in that: The head (31) is provided with a baffle (5) extending along the inclined cut surface (311). The baffle (5), the conical surface of the head (31), the anti-reverse pressure sleeve (4), and the side wall of the blind hole (11) together form a placement cavity to prevent the spherical body (21) from rolling off when the locking bolt (3) is installed.

3. The double-cut back bolt for dry-hanging stone curtain walls according to claim 1, characterized in that: Multiple spheres (21) are provided, and the multiple spheres (21) are evenly distributed between the conical surface of the head (31) and the end face of the snap-fit ​​cavity (12).

4. The double-cut back bolt for dry-hanging stone curtain walls according to claim 3, characterized in that: The spheres (21) are made of stainless steel or ceramic and all spheres (21) have the same diameter.

5. The double-cut back bolt for dry-hanging stone curtain walls according to claim 1, characterized in that: A spring washer or a flat washer is provided between the locking nut (22) and the anti-reverse sleeve (4).

6. The double-cut back bolt for dry-hanging stone curtain walls according to claim 1, characterized in that: The back bolt assembly (2) also includes an adapter (6), which is connected to the end of the locking bolt (3) via a connecting nut (62).

7. The double-cut back bolt for dry-hanging stone curtain walls according to claim 6, characterized in that: The adapter (6) has an L-shaped structure and an elongated hole (61) is provided on the adapter (6) for adjusting the installation position.

8. The double-cut back bolt for dry-hanging stone curtain walls according to claim 2, characterized in that: The anti-reverse pressure sleeve (4) is composed of two elastically openable semicircular parts (41) at one end near the head (31), and the inner side of the semicircular part (41) is provided with a receiving groove (411) that cooperates with the baffle (5).

9. The dual-split-face back-up bolt for dry-hanging stone curtain walls according to claim 8, characterized in that: The top of the baffle (5) is inclined and the closer it is to the connection part (32), the closer it is to the axis of the locking bolt (3). When the head (31) and the anti-reverse pressure sleeve (4) approach each other, the top of the baffle (5) slides and abuts against the bottom of the receiving groove (411) and pushes the semi-circular part (41) to open outward, so that the anti-reverse pressure sleeve (4) is locked in the inner wall of the blind hole (11).

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