Pile mechanical joint with one or more slotted protrusions for easy installation of one or more locking pins

Abstract

A pile mechanical joint having one or more grooved protrusions (3) for easy installation of one or more locking pins (7) facilitates the installation of one or more locking pins (7) even in the presence of common debris from the piling stage, or even when the dimensional tolerances of the pile's connecting plate (1) are not ideal due to manufacturing errors or external force damage. As a locking mechanism, the pile mechanical joint is inherently open or exposed, thus facilitating the removal of debris and allowing for visual inspection of any possible physical obstacles to the successful installation of one or more locking pins (7).

Description

Technical Field

[0001] This invention relates to piles for building foundations, and more particularly to pile segments and pile joints thereof. Background Technology

[0002] Precast piles are typically manufactured in segments. To enable these piles to be installed deep underground (beyond the depth of a single segment), the segments are connected using steel joints to lengthen the piles. There are two main types of steel joints: mechanical and welded.

[0003] Basically, traditional welded steel joints used for piles consist of the following steel components:

[0004] Anchor bolts (optional when used for prestressed piles)

[0005] One or more screw holes (typically used for prestressed piles)

[0006] Connecting plate

[0007] kick

[0008] Typical welded steel joints are welded along the perimeter of the connecting plate. Sometimes, welded steel connecting plates are made as male (with protruding reinforcing bars) and female (with steel pipe to accommodate the protruding reinforcing bars of the male connecting plate); sometimes, welded connecting plates are made identical (without protruding reinforcing bars or steel pipe).

[0009] Anchor bolts attached to the connecting plate are used to transfer the stress borne by the pile. However, some connecting plates used for prestressed piles do not have anchor bolts. Instead, the stress is transferred to the prestressed steel wires, steel strands, or steel bar bundles of the prestressed pile by the connecting plate.

[0010] Currently, prestressed piles are typically attached by hooking the connecting plate onto the pile using prestressed steel wires, strands, or bundles of reinforcing bars. These prestressed steel wires, strands, or bundles of reinforcing bars undergo further processes to compress and expand their ends into mushroom-shaped buttons. The expanded mushroom-shaped button ends hook onto the connecting plate to secure the connecting plate to the pile.

[0011] In the production process of prestressed piles, connecting plates are placed at both ends of the pile formwork, with steel connecting plates placed at opposite ends. The connecting plates are fully secured by fixing them to prestressed steel wires, steel strands, or steel bar bundles (for prestressed piles) or to the gate of the pile formwork (for non-prestressed piles).

[0012] Currently, significant improvements have been made to this type of pile joint used for connecting pile segments. An example of such a joint can be found in GB2363150A – “Socket-type Pile Connections,” which describes connecting pile segments by inserting a plug into a socket. The socket's internal dimensions are sufficient to allow the plug to be inserted undisturbed, thus forming a joint without introducing other materials into the socket (although hot-melt adhesive may be introduced inside the socket). However, this method is expensive and not widely used.

[0013] In WO2020094923 – “Pile Joints”, one or more pins have machined holes for inserting one or more locking pins (one or more locking pins enter the machined holes of one or more pins to prevent one or more pins from loosening). The locking pin is introduced from the outside of the pile and passes through a cylindrical cavity before contacting the one or more pins. This type of pile mechanical joint has been widely used and has fairly consistent performance; however, due to thermal strain caused by welding one or more pins to the connecting plate, a considerable thickness of the connecting plate is required. Another common problem with this type of pile mechanical joint is that the cylindrical cavity through which the locking pin passes can become clogged or blocked by concrete from the pile concrete pouring stage or debris common during the piling stage, making this type of pile mechanical joint difficult to install or even inoperable.

[0014] In WO2015026223 – “Concrete Pile End Plates”, one or more locking pins are fully hammered in to lock the pile joint along its full length (or most of its length). This type of pile mechanical joint is expensive, susceptible to debris (which can be introduced at any time during the piling stage), and requires very high levels of machining tolerances in the manufacture of the pile mechanical joint components to ensure successful operation. The high cost, the requirement for high manufacturing quality, and the sensitivity of this type of pile mechanical joint to failure due to debris or dimensional errors make it uncommon.

[0015] Furthermore, a common problem with the welded connecting plates required for pile connection is the frequent questioning of weld quality. Given that the welding around the connecting plates is performed outdoors rather than in a factory, environmental factors can adversely affect weld quality. Moreover, weld quality directly depends on the welder's skill, which can lead to quality fluctuations and human error, potentially severely impacting the performance of the welded pile joint.

[0016] Therefore, there is a need to design a cheaper, more efficient, and sufficiently robust pile connection system that is easy to implement and can meet any load requirements while providing consistent and reliable performance. Summary of the Invention

[0017] This invention eliminates the need for a welded connection plate around the perimeter, which is essential in conventional welded joint designs that have been found to be time-consuming, where the final performance quality of the welded joint largely depends on the welder's skill.

[0018] The main components of this invention are described in detail below:

[0019] (1) One or more grooved protrusions

[0020] One or more slotted protruding heads are machined on a lathe into a mushroom shape with bolt bases or rods. The diameter of the head is larger than the diameter of the bolt base or rod. The one or more slotted protruding heads should be precisely machined on a lathe to make uniform contact with locking pins, which may have a circular cross-section, and to ensure consistent working tolerances even in the event of dimensional errors in the connecting plate, by accurately protruding from the connecting plate.

[0021] (2) For one or more threaded holes with one or more grooved protrusions

[0022] One or more slotted protrusions have bolt bases or rods. The pile connector plate shall be drilled and tapped to form threaded holes for receiving the bolt bases or rods of one or more slotted protrusions.

[0023] (3) One or more receiving cavities for accommodating one or more slotted protrusions of a connecting plate relative to a pile.

[0024] Using a flat end mill with a diameter slightly larger than the head diameter of one or more slotted protrusions, mill one or more circular cavities at a predetermined distance from one or more threaded holes. These cavities should accommodate one or more slotted protrusions of the connecting plate opposite the stud. Furthermore, a T-slot side end mill can be used to further form a notch for the lip of the one or more slotted protrusions to improve locking strength.

[0025] (4) Groove or slot used for locking pins inside pile connection plates

[0026] Using a side end mill instead of an end mill, a slot or notch is milled between one or more threaded holes and one or more receiving cavities to form a channel through which the locking pin passes. The slot or notch is machined in such a way that when the two connecting plates are assembled, the two slots or notches form a complete channel, allowing the locking pin to be inserted from the outside of the pin to contact the slotted protrusion. Essentially, each slot or notch forms half of the channel through which the locking pin will pass, and two slots or notches form a complete channel.

[0027] (5) One or more locking pins

[0028] One or more locking pins, typically cylindrical steel rods, are inserted between two slotted protrusions (one head up, the other head down) after the two pile connector plates have come into contact. The locking pins are inserted into a channel formed by the two slots or grooves in the two contacting connector plates, and after contact with the slotted protrusions, the locking pins are hammered in to lock the pile joints together.

[0029] This invention is essentially a mechanical joint locking mechanism for pile joints, comprising one or more grooved protrusions having bolt bases or rods, and corresponding one or more threaded holes in a connecting plate of the pile; one or more receiving cavities (for receiving opposing one or more protrusions of the opposite joint); one or more milled grooves or slots in the connecting plate of the pile, and the corresponding cross-sections of which can be one or more locking pins of any shape. The shape of the grooves in the one or more grooved protrusions should depend on the cross-sectional shape of the one or more locking pins. The surfaces of the one or more grooved protrusions are in partial contact with the surfaces of the one or more locking pins. Furthermore, since the one or more grooved protrusions only partially surround the periphery of the one or more locking pins, this discontinuity gives the one or more grooved protrusions a certain degree of bend, thereby facilitating the insertion of the one or more locking pins. Load transfer (e.g., tensile load) will be transferred from the upper grooved protrusion to the lower grooved protrusion, wherein the locking pins are located between the upper and lower grooved protrusions.

[0030] This invention eliminates the need to weld one or more slotted protrusions to the connecting plate. Instead, it assembles one or more slotted protrusions onto the connecting plate itself by threading the threaded portions of the protrusions. Since welding is unnecessary, no welding-induced thermal strain is generated, eliminating the need for a thick connecting plate to distribute or withstand thermal strain. Furthermore, the absence of welding between the slotted protrusions and the connecting plate allows for some bending or lateral movement of the protrusions, facilitating the installation of the locking pin.

[0031] Furthermore, the movement of one or more locking pins and the friction with one or more slotted protrusions on the bolt base or rod generate tightening torque. This increases the prestress of the locking mechanism and also ensures the quality of proper assembly of the locking mechanism when the installation or hammering of one or more locking pins is completed. Because the slotted protrusions are threaded onto the connecting plate rather than welded to it, and because the slotted protrusions are rotatable, the locking pins are also easy to install or hammer in. The contact of each locking pin with two slotted protrusions (from each side of the opposing connecting plate, respectively) ensures that tensile loads can be withstood.

[0032] In this invention, one or more grooved protrusions are threaded onto a connecting plate of a pile and onto each grooved protrusion, wherein the one or more grooved protrusions are precisely machined on a lathe to meet operating tolerances. Inaccurate machining tolerances, damage, or deformation of the connecting plate typically lead to difficulties or even inoperability in prior art mechanical joints. However, considering that the one or more grooved protrusions themselves possess the necessary tolerances when manufactured together, the aforementioned problems do not exist with this invention. Once the one or more grooved protrusions are threaded onto the connecting plate, the protrusion amount (crucial for the operating tolerances of this invention) is always accurate due to the inherent precision of the grooved protrusions and is independent of the dimensional conditions of the connecting plate.

[0033] For this invention, a typical implementation of the operation of the pile mechanical joint involves two opposing pile joints (with grooved protrusions correctly threaded into their respective threaded holes) placed together such that the grooved protrusions are fully inserted into the receiving cavity until the connecting plates of the two piles are in complete contact. Locking of the pile joints is typically accomplished by hammering when one or more locking pins (through channels formed by a combination of two milled grooves or slots in the two opposing connecting plates) are inserted, causing one or more locking pins to contact the grooves of one or more protrusions, thereby preventing separation of the two pile joints. The one or more locking pins will be used to transmit tensile loads and also to prevent separation of the connecting plates after the one or more locking pins are installed.

[0034] The open or exposed features of one or more slotted protrusions, milled grooves or slots for one or more locking pins, and one or more receiving cavities mean that debris can be easily removed and any possible physical obstacles to the successful installation of one or more locking pins can be easily visually inspected.

[0035] The following section will detail and resolve the differences between this invention and three cited prior art pile mechanical joints:

[0036] (a) In WO2020094923 – “Pile Connector”, one or more locking pins are inserted into one or more pins with machined holes. The disadvantages of this method are high cost and the need for high machining tolerances in the components to ensure easy installation of the one or more locking pins. Typical deformation of the pile connector plate (common in typical piling operations) or out-of-tolerance machining of the components can make it difficult or even impossible to hammer in one or more locking pins. Furthermore, this type of prior art makes it difficult or even impossible to install one or more locking pins when the mechanism is contaminated with debris commonly introduced during piling operations. The present invention does not have machined holes, but instead cuts (or mills) inherently discontinuous grooves into one or more protrusions. For clarity, the machined holes in the prior art are cavities of continuously existing steel that completely surround the periphery of one or more locking pins, while the one or more grooved protrusions of the present invention do not surround the entire periphery of one or more locking pins and are therefore described as discontinuous. If the present invention has inaccurate machining tolerances, or if the connecting plate is damaged or slightly deformed due to piling operations, the discontinuity of one or more slotted protrusions in the present invention will still make it easy to hammer in or install one or more locking pins, which is not allowed in the prior art (one or more pins with machined holes). Because the present invention has the inherent ability to allow one or more slotted protrusions to bend, the presence of debris commonly encountered during the piling stage in the mechanism will not affect the present invention in the same way as it affects the prior art, thus making the present invention practically debris-proof and easy to install one or more locking pins.

[0037] The aforementioned prior art requires welding one or more pins to the connecting plate and does not utilize the one or more slotted bolt bases or rods of the present invention, which do not require welding and generate some tightening torque and increase prestress when one or more locking pins are fully installed. The weld-free nature of the present invention allows for additional bending in the one or more slotted protrusions, thereby facilitating the installation of one or more locking pins.

[0038] (b) In the second type of prior art, WO2015026223 – “Endplates of Concrete Piles”, the entire length (or most of the length) of one or more locking pins is required to engage with or be used in the locking mechanism. The problem with this type of prior art is the need for high machining tolerances and the requirement for most or all of the length of one or more locking pins to be wedged into the locking mechanism. Machining errors, deformation, or damage caused by piling operations can make it extremely difficult or even impossible to hammer in or install one or more locking pins. This is not to say that one or more locking pins in this prior art are difficult to insert in all cases; sometimes one or more locking pins are easy to insert, but the likelihood of one or more locking pins being difficult to insert in this prior art is much greater compared to the present invention. The presence of common debris introduced during the piling stage makes it extremely difficult or even impossible to install one or more locking pins in the prior art. The present invention does not require wedging most of the length of one or more locking pins into place as in the prior art. The present invention only requires contact between a small portion of one or more locking pins and one or more grooved protrusions, whereas in the prior art, this requires most of the length of one or more locking pins to be used directly for force transmission in the locking mechanism. In this invention, one or more locking pins do not need to have any contact with the connecting plate at all, because one or more grooved protrusions directly transmit tension or bending force to the one or more locking pins without the involvement or influence of the connecting plate. This differs from the prior art, where the connecting plate not only contacts one or more locking pins, but the tension or bending force is actually transmitted directly from the connecting plate to the one or more locking pins. The partial contact method of this invention makes it practically chip-proof and facilitates the insertion of one or more locking pins.

[0039] The prior art of the above type does not use the bolt base or rod with one or more grooved protrusions of the present invention, which does not require welding and can generate some tightening torque and additional prestress when one or more locking pins are fully installed, and allows one or more grooved protrusions to bend, making one or more locking pins easy to install.

[0040] The main objective of this invention is to provide a mechanical pile connector that facilitates the installation of one or more locking pins due to the discontinuous nature of one or more grooved protrusions and the partial contact between one or more locking pins and one or more grooved protrusions. Furthermore, the installation of one or more locking pins is made easier because it is not necessary to wed most of the one or more locking pins into place so that the mechanical locking of the pile connection plate can function fully.

[0041] Another object of the present invention is to create a mechanical joint for piles that is inherently simple and, due to its inherent simplicity, will provide or produce consistent performance.

[0042] A further objective of this invention is to create an economical mechanical pile connector that, while being economical, does not compromise its performance.

[0043] The above and other objects, features and advantages of the present invention can be more clearly understood by reading the following description in conjunction with the accompanying drawings. Attached Figure Description

[0044] Figure 1 The simplified typical square pile and the simplified typical hollow cylindrical pipe pile are shown in the standard welded connection plate.

[0045] Figure 2 The invention is shown on a typical pipe pile connection plate on a typical pipe pile.

[0046] Figure 3 A typical embodiment of the invention is shown, wherein the locking pin has a square cross-sectional shape.

[0047] Figure 4 A typical embodiment of the invention is shown, wherein the locking pin has a circular cross-sectional shape.

[0048] Figure 5 A typical embodiment of the invention is shown, wherein the grooved protrusion is on the left side and the locking pin is on the right side. Detailed Implementation

[0049] Figure 1 The present invention illustrates the conventional welded connecting plate (1) used to replace, for both simplified typical square piles and simplified typical hollow cylindrical pipe piles. The upper left is a plan view of a typical pipe pile connecting plate (1), the upper right is a plan view of a typical square pile connecting plate (1), the lower left is a side view of a typical pipe pile connecting plate (1), and the lower right is a side view of a typical square pile connecting plate (1). The connecting plate (1) is cast or installed at the end of the precast pile. When a deeper driving penetration depth is required, the connecting plate (1) is welded along the entire perimeter of the contact connecting plate (1), thereby extending the length of each part of the precast pile.

[0050] Figure 2 The mechanical joint of the pile on the pipe pile connection plate (1) of the present invention is shown. Figure 2In the present invention, the connecting plate (1) of the pipe pile has threaded holes (2), which were originally used in the pipe pile manufacturing process to apply prestress to the prestressed steel wire, steel strand or steel bar bundle of the pipe pile, and also to fix the connecting plate (1) to the pile formwork. The present invention will use these same threaded holes (2) to install the grooved protrusion (3), the receiving cavity (4) is used to receive the grooved protrusion (3) of the top pipe pile (5) relative to the connecting plate (1), and when the milled groove or slot (6) of the top connecting plate (1) and the bottom connecting plate (1) are in full contact, a complete channel for the locking pin (7) will be formed, which will be installed to complete the locking process of the connecting plate (1) and realize the connection between the top pile connecting plate (1) and the bottom pile connecting plate (1). A single milled groove or slot (6) forms half of a complete channel for a locking pin (7), and when the top connecting plate (1) and the bottom connecting plate (1) are in full contact, the two contacting milled grooves or slots (6) of the top connecting plate (1) and the bottom connecting plate (1) form a complete channel for a locking pin (7) to the slotted protrusion (3). Figure 2 As shown, the top pile (5) and the bottom pile (8) are connected after one or more of their locking pins (7) are fully installed.

[0051] Figure 3 A typical embodiment of the invention is shown, wherein the locking pin (7) has a square cross-sectional shape. The upper figure shows the unassembled locking mechanism of the invention, wherein the top connecting plate (1) and the bottom connecting plate (1) each have a grooved protrusion (3), a receiving cavity (4) for receiving the opposing grooved protrusion (3), and a milled groove or slot (6). The lower figure shows the invention, with only the locking pin (7) not installed for better understanding of the complexity of the invention. The lower figure shows the contacting top connecting plate (1) and bottom connecting plate (1), each of which has a grooved protrusion (3) located in its respective receiving cavity (4), and the remaining operation is to install the locking pin (7) into the channel formed by the two milled grooves or slots (6). The installation of the locking pin (7) will prevent the two grooved protrusions (3) from disengaging, as the locking pin (7) blocks the disengagement channel of the grooved protrusions (3), thereby locking the two stud connecting plates (1) together.

[0052] Figure 4A typical embodiment of the invention is shown, wherein the locking pin (7) has a circular cross-sectional shape. The upper figure shows the unassembled locking mechanism of the invention, wherein the top connecting plate (1) and the bottom connecting plate (1) each have a grooved protrusion (3), a receiving cavity (4) for accommodating the opposing grooved protrusions (3), and a milled groove or slot (6). The lower figure shows the invention, with only the locking pin (7) not installed for better understanding of the complexity of the invention. The lower figure shows the top connecting plate (1) and the bottom connecting plate (1) in contact, with the grooved protrusions (3) of the top pile (5) and the bottom connecting plate (1) respectively located in their respective receiving cavities (4), and the remaining operation is to install the locking pin (7) into the channel formed by the two milled grooves or slots (6). The installation of the locking pin (7) will prevent the two grooved protrusions (3) from disengaging, as the locking pin (7) blocks the disengagement channel of the grooved protrusions (3), thereby locking the two pile connecting plates (1) together.

[0053] Figure 5 A typical embodiment of the invention is shown, wherein the grooved protrusion (3) is on the left side and the locking pin (7) is on the right side.

[0054] Preferred embodiments of the invention have been shown and described in this disclosure, and various alternatives and modifications have been proposed. It should be understood that these are not intended to be exhaustive, and other changes and modifications can be made within the scope of the invention. These suggestions selected and included herein are for illustrative purposes so that others skilled in the art can fully understand the invention and its principles and be able to modify it, each of which may be best suited to specific conditions.

Claims

1. A mechanical joint for piles, characterized in that, Includes one or more slotted protrusions (3) with bolt bases or rods and corresponding one or more threaded holes (2) in the connecting plate (1) of the pile; one or more receiving cavities (4); one or more milled grooves or slots (6) in the connecting plate (1) of the pile and corresponding one or more locking pins (7) whose cross-sections can be of any shape, wherein the shape of the groove in the one or more slotted protrusions (3) should depend on the cross-sectional shape of the one or more locking pins (7), characterized in that the one or more slotted protrusions (3) are in partial contact with the surface of the one or more locking pins (7), and thus, since the one or more slotted protrusions (3) only partially surround the periphery of the one or more locking pins (7), this discontinuous manner allows the one or more slotted protrusions (3) to have a certain degree of bending, thereby facilitating the insertion of the one or more locking pins (7).

2. The pile mechanical joint as described in claim 1, wherein, The one or more grooved protrusions (3) that contact a small portion of the one or more locking pins (7) make the one or more locking pins (7) easy to install, even when the pile mechanical joint, which serves as the locking mechanism, is contaminated with common debris introduced during the piling stage.

3. The pile mechanical joint as described in claim 1, wherein, The one or more grooved protrusions (3) are precisely machined on a lathe to form bolt bases or rods that are threaded to the threaded holes (2) of the connecting plate (1) and ensure that the head of the one or more grooved protrusions (3) extends accurately from the connecting plate (1), thereby ensuring accurate operating tolerances so that the one or more locking pins (7) can be easily installed even if the connecting plate (1) is slightly deformed, damaged and / or has inaccurate manufacturing tolerances.

4. The pile mechanical joint as described in claim 1, wherein, When manufactured separately from the connecting plate (1), one end of the one or more grooved protrusions (3) is threaded and the other end is a grooved protrusion head, so that when the one or more locking pins (7) are installed, the one or more grooved protrusions (3) rotate due to the movement of the one or more locking pins (7) and the frictional contact between the one or more locking pins (7) and the one or more grooved protrusions (3).

5. The pile mechanical joint as described in claim 1, wherein, When manufactured separately from the connecting plate (1), one or more grooved protrusions (3) are threaded at one end and have a grooved protrusion head at the other end. Since the one or more grooved protrusions (3) are not welded to the connecting plate (1), some bending or lateral movement will be allowed in the one or more grooved protrusions (3), thereby making the one or more locking pins (7) easy to install.

6. The pile mechanical joint as described in claim 1, wherein, Separation of the two opposing connecting plates (1) is prevented by wedging the one or more locking pins (7) into the appropriate positions between the one or more grooved protrusions (3).

7. The pile mechanical joint as described in claim 1, wherein, Any tensile load is transferred between the two opposing slotted protrusions (3) by wedging the one or more locking pins (7) into place between the slotted protrusions (3).

8. The pile mechanical joint as described in claim 1, wherein, When the pile mechanical joint is fully assembled, the milled grooves or slots (6) of the one or more locking pins (7) for the top connecting plate (1) and the bottom connecting plate (1) will form a complete channel for the one or more locking pins (7) to contact the one or more slotted protrusions (3).

9. The pile mechanical joint as described in claim 1, wherein, The pile mechanical joint includes one or more slotted protrusions (3), milled grooves or slots (6), and one or more receiving cavities (4) that are essentially open or exposed, thus facilitating the removal of debris and the visual inspection of any possible physical obstructions to the successful installation of one or more locking pins (7).

10. The pile mechanical joint as described in claim 1, wherein, By using a T-slot side milling cutter, a lip is formed on the one or more receiving cavities (4) for placing the one or more slotted protrusions (3) to improve locking strength.

11. A method for connecting segmented piles together using a pile mechanical joint through the following steps, the pile mechanical joint comprising one or more grooved protrusions (3) for locking the mechanical joint when their respective one or more locking pins (7) are installed, wherein a connecting plate (1) has one or more lathe-machined grooved protrusions (3) having bolt bases or rods threaded to threaded holes (2) of the connecting plate (1) for threaded connection, and also having milled slots or grooves (6) for the respective one or more locking pins (7), and one or more receiving cavities (4): (i) Place the top pile (5) and bottom pile (8) having one or more grooved protrusions (3) fully assembled in their respective threaded holes (2) together such that the connecting plates (1) are in contact; (ii) Place the one or more locking pins (7) into the channel formed by the milled groove or slot (6); (iii) The process is complete when the one or more locking pins (7) are fully installed or hammered in.

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