Lifting road pile group

Abstract

The utility model discloses a lifting road pile group, which relates to the technical field of traffic management equipment, and comprises a plurality of lifting road piles, each lifting road pile comprises an outer cylinder fixed on the ground, an inner cylinder arranged in the outer cylinder and capable of vertically ascending and descending, and a driving mechanism capable of driving the inner cylinder to ascend, and the driving mechanism is a pulley block; the traction end of the traction rope is connected with external winding and unwinding equipment, and the traction rope is connected in series through a single line and sequentially bypasses the pulley blocks of all the lifting road piles; when winding and unwinding equipment winds the traction rope, all the lifting road pile inner barrels are driven to ascend. The lifting work of the lifting road pile is driven by the traction rope, the structure is relatively simple, and the cost is low; the retractable equipment and other equipment can be arranged on the ground, and compared with the mode that the retractable equipment is arranged underground in the prior art, the retractable equipment is not prone to being affected with damp.

Description

Technical Field

[0001] This utility model relates to the field of traffic management equipment technology, specifically a rising bollard assembly. Background Technology

[0002] Rising bollards are traffic control devices used to close off designated areas of access roads for traffic, landscaping, and public parking. Chinese invention patent CN 113668428 A discloses a rising bollard for road traffic, which solves traffic safety problems in the prior art. However, because this rising bollard uses an independent drive structure, it suffers from high cost and complex maintenance. Furthermore, since the motor and other drive and control components of the bollard are located at its bottom, the bollard is prone to water ingress or moisture, causing damage to the motor and other drive and control components. Utility Model Content

[0003] The purpose of this utility model is to provide a rising bollard assembly to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] A set of rising bollards, installed on the ground in a vehicle traffic area to restrict vehicle passage, includes:

[0006] Multiple rising bollards, each rising bollard including an outer cylinder fixed to the ground, an inner cylinder disposed inside the outer cylinder that can move vertically upward and downward, and a drive mechanism that can drive the inner cylinder to rise, the drive mechanism being a pulley block;

[0007] The traction rope has its traction end connected to an external winding and unwinding device. The traction rope is a single line that passes through the pulley blocks of all the rising bollards in sequence. When the winding and unwinding device winds up the traction rope, it drives the inner cylinders of all the rising bollards to rise.

[0008] Preferably, the pulley assembly includes a fixed pulley fixedly connected to the top of the outer cylinder and a movable pulley fixedly connected to the bottom of the inner cylinder.

[0009] Preferably, the straight section of the traction rope is provided with an elastic component connected in series with the traction rope; the elastic component is configured such that when the inner cylinders of all the lifting bollards can no longer rise, the traction rope can continue to be wound up by the winding device until the elastic component is stretched to a set length by the traction rope.

[0010] Preferably, one end of the traction rope is a traction end connected to an external retraction device, and the other end is a fixed end fixed to a preset anchor point. The traction end of the traction rope starts from the anchor point, passes around all the rising bollards in sequence, and finally connects to the retraction device.

[0011] Preferably, the anchor point is located on the top side of the outer cylinder of the first lifting bollard. The driving mechanism of the first lifting bollard includes at least one pulley group consisting of a fixed pulley fixed to the top of the outer cylinder and at least one movable pulley fixed to the bottom of the inner cylinder. The remaining lifting bollards include at least one pulley group consisting of a fixed pulley fixed to the top of the outer cylinder and at least one movable pulley fixed to the bottom of the inner cylinder, as well as a reversing pulley fixed to the top of the outer cylinder. The traction end of the traction rope starts from the anchor point, passes around each pulley group of the first set of lifting bollards in sequence, and when entering the next lifting bollard, it is reversed by the reversing pulley of the lifting bollard and enters the lifting bollard. Then, it passes around the remaining lifting bollards in the same way and finally connects to the launching and retracting device.

[0012] Preferably, the anchor point is located at the bottom of the outer cylinder of the first lifting bollard. The driving mechanism of all lifting bollards includes at least one set of pulleys consisting of a fixed pulley fixed to the top of the outer cylinder and at least one movable pulley fixed to the bottom of the inner cylinder, as well as a reversing pulley fixed to the top of the outer cylinder. The traction end of the traction rope starts from the anchor point, changes direction after passing through the reversing pulley, passes around each pulley set of the lifting bollard in sequence, passes around the remaining lifting bollards in the same way, and finally connects to the launching and retracting device.

[0013] Preferably, both ends of the traction rope are traction ends and connected to an external retraction device. The traction ends of the traction rope start from the retraction device, pass around all the lifting bollards in sequence, and finally return to the retraction device, forming a closed-loop transmission path.

[0014] Preferably, the drive mechanism includes a pulley group consisting of at least one set of fixed pulleys fixed to the top of the outer cylinder and at least one set of movable pulleys fixed to the bottom of the inner cylinder, as well as a reversing pulley fixed to the top of the outer cylinder; the traction end of the traction rope enters the lifting bollard after being reversed by the reversing pulley, passes around each pulley group of the lifting bollard in sequence, passes around the remaining lifting bollards in the same manner, and finally connects to the take-up and take-down device.

[0015] Preferably, when the traction rope passes around the pulley block, it first passes around the movable pulley and then around the fixed pulley.

[0016] Preferably, a locking mechanism is provided between the outer cylinder and the inner cylinder. When the inner cylinder rises to its limit position, the locking mechanism locks the inner cylinder. After the locking effect is released, the winding and unwinding device releases the traction rope, and the inner cylinder descends and resets under its own gravity.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] This utility model uses a traction rope to drive the lifting and lowering of the bollards, which has a relatively simple structure and low cost. The equipment such as the deployment and retrieval devices can be set above ground, which is less likely to cause water ingress and moisture damage compared to the underground installation method in the prior art.

[0019] This invention utilizes a pulley system that connects all the driving mechanisms of the bollards in a single line via a traction rope, requiring only one launching and retracting device to achieve lifting control of multiple bollards. Compared to traditional independent drive schemes, it eliminates the cost of configuring a separate motor for each bollard, reducing equipment complexity.

[0020] This invention, through the inclusion of an elastic component, allows the traction rope to continue winding by the take-up and release device even when the inner cylinder has risen to its limit position or is blocked by external force. The winding continues until the elastic component is stretched to a set length, at which point a sensor switch signals the take-up and release device to stop operating. This protects the equipment and prevents the traction rope from breaking or the device from being overloaded due to the device continuing to wind the rope after the inner cylinder has reached its limit position. Furthermore, the elastic component provides continuous elasticity after the inner cylinder reaches its limit position, ensuring stability once the inner cylinder is in place. Attached Figure Description

[0021] Figure 1 A schematic diagram of a type of rising bollard assembly. Figure 1 .

[0022] Figure 2 A schematic diagram of a type of rising bollard assembly. Figure 2 .

[0023] Figure 3 This is a structural schematic diagram of an embodiment 1 of a rising bollard assembly.

[0024] Figure 4 This is a schematic diagram of a lifting bollard assembly embodiment 1, which has two movable pulleys at the bottom.

[0025] Figure 5 This is a structural schematic diagram of an embodiment 2 of a rising bollard assembly.

[0026] Figure 6 This is a structural schematic diagram of an embodiment 3 of a rising bollard assembly.

[0027] Figure 7 This is a schematic diagram of the locking mechanism in a type of lifting bollard assembly. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Please see Figure 1 and Figure 2 In this utility model, a type of lifting bollard assembly includes multiple lifting bollards installed on the ground in a passage area to restrict vehicle passage. Each lifting bollard includes an outer cylinder 2 fixed to the ground and an inner cylinder 1 installed inside the outer cylinder 2 and capable of being raised and lowered. A driving mechanism is provided between the outer cylinder 2 and the inner cylinder 1 to drive the inner cylinder 1 to move vertically relative to the outer cylinder 2. The driving mechanism includes a pulley group formed by a fixed pulley 6 fixedly connected to the outer cylinder 2 and a movable pulley 5 fixedly connected to the inner cylinder 1. It also includes a traction rope 3, the traction end of which is connected to an external winding and unwinding device 4. The traction rope 3 is connected in a single line and sequentially passes around the driving mechanisms of all the lifting bollards. The driving mechanisms drive the inner cylinder 1 to move vertically relative to the outer cylinder 2. The traction rope 3 passes around all the movable pulleys 5 and the fixed pulleys 6 to form a reciprocating transmission path. When the winding and unwinding device 4 winds up the traction rope 3, the traction rope 3 is tightened, driving the movable pulleys and the inner cylinder 1 to move synchronously.

[0030] This utility model uses a traction rope to drive the lifting and lowering of the bollards, which has a relatively simple structure and low cost. The launching and retraction equipment and other equipment can be set above ground, which is less likely to cause water ingress and moisture damage compared to the underground installation method in the prior art.

[0031] The straight section of the traction rope 3 in the transmission path is provided with an elastic component 13 connected in series with the traction rope 3. When the traction rope 3 is tightened, the elastic component 13 is stretched. The elastic component 13 is configured such that even after all the inner cylinders 1 of the lifting bollards can no longer rise, the traction rope 3 can continue to be wound by the winding and unwinding device 4 until the elastic component 13 is stretched to a set length by the traction rope 3. This achieves protection for the lifting bollards and prevents the winding and unwinding device 4 from continuing to wind the traction rope 3 after the inner cylinder 1 has risen to the limit position, which would cause the traction rope 3 to be directly broken or the winding and unwinding device 4 to be overloaded and damaged. Moreover, when the inner cylinder 1 rises to the limit position, the elastic component 13 can provide continuous elasticity to ensure the stability of the inner cylinder 1 after it has reached the position.

[0032] Based on the above technical solutions, this utility model can be divided into two cases. One case is that one end of the traction rope 3 is the traction end, and the other end is the fixed end, which is fixed to a preset anchor point on the first set of lifting bollards. The traction end of the traction rope 3 starts from the anchor point, passes around the drive mechanism of all the lifting bollards in sequence, and finally connects to the take-up and release device 4 (e.g., Figure 1 Another type is where both ends of the traction rope 3 are traction ends. The traction ends of the traction rope 3 start from the take-up and release device 4, pass through the drive mechanisms of all the lifting bollards in sequence, and return to the take-up and release device 4, forming a closed-loop transmission path (e.g., Figure 2 This method is more efficient in retracting and extending the traction rope 3, achieving twice the efficiency compared to the aforementioned method where one end of the traction rope 3 is the traction end. Specifically, it includes the following embodiments:

[0033] Example 1

[0034] like Figure 3 As shown, when one end of the traction rope 3 is the traction end and the other end is the fixed end, the anchor point is set on the top of one side of the outer cylinder 2 of the first lifting bollard. The driving mechanism of the first lifting bollard includes at least one set of pulleys consisting of a fixed pulley 6 and at least one movable pulley 5. In addition to including at least one set of pulleys consisting of a fixed pulley 6 and at least one movable pulley 5, the remaining lifting bollards also include a reversing pulley 61 fixed on the top of the outer cylinder 2.

[0035] When the traction rope 3 passes around each pulley block, it first passes around the movable pulley 5, then passes around the fixed pulley 6. After passing around the first lifting bollard in this way, it enters the next lifting bollard after being redirected by the reversing pulley 61. Then, it passes around the remaining lifting bollards in the same way.

[0036] In this embodiment, the more pulleys there are, the less effort is required. In this embodiment, it is preferred that there is one set of pulleys, which can reduce the workload of the traction rope 3 by half. At the same time, it will not cause the problem of complicated structure and inconvenient installation of the lifting bollard due to too many pulleys.

[0037] like Figure 4 As shown, this is an implementation method in which two movable pulleys 5 are set in a pulley group. The traction rope 3 holds the inner cylinder 1 from the bottom of the inner cylinder 1, which can improve the stability of the inner cylinder 1 during the lifting and lowering process.

[0038] Example 2

[0039] like Figure 5 As shown, when one end of the traction rope 3 is the traction end and the other end is the fixed end, the anchor point is set at the bottom of the outer cylinder 2 of the first set of lifting bollards. Unlike embodiment 1, all lifting bollard structures can be the same, including at least one set of pulley groups consisting of a fixed pulley 6 and at least one movable pulley 5, as well as a reversing pulley 61 fixed at the top of the outer cylinder 2.

[0040] When the traction rope 3 passes around each pulley group, it first passes around the movable pulley 5, then passes around the fixed pulley 6. After passing around the first group of lifting bollards in this way, it enters the lifting bollard after being redirected by the reversing pulley 61 in the next group of lifting bollards. Then it passes around the remaining lifting bollards in the same way.

[0041] Example 3

[0042] Please see Figure 6 Both ends of the traction rope 3 are traction ends. The drive mechanism of each set of lifting bollards includes at least one set of pulleys consisting of a fixed pulley 6 and at least one movable pulley 5, as well as a reversing pulley 61 fixed on the top of the outer cylinder 2.

[0043] Please see Figure 7When the inner cylinder 1 is lifted to the preset lifting position, it is also necessary to fix the position of the inner cylinder 1. The positioning method can be to select a winch with a built-in mechanical locking structure for the launching and unloading device 4, such as the DHQZ-500 electric winch of Donghong Lifting; or a locking mechanism can be set between the outer cylinder 2 and the inner cylinder 1. When the inner cylinder 1 is lifted to the preset lifting position, the locking mechanism locks the inner cylinder 1. After the positioning effect is released, the inner cylinder 1 descends and resets under the action of gravity, or the inner cylinder 1 is pushed down quickly by other reset mechanisms. These reset mechanisms can be elastic components such as compression springs, gas springs, and hydraulic springs. Here, we only consider the automatic descent and reset of the inner cylinder 1 under the action of gravity, and the setting and selection of the reset mechanism will not be described in detail.

[0044] Please see Figure 5 The locking mechanism includes a locking tongue 7 that can be horizontally inserted into the inner cylinder 1 when the inner cylinder 1 is raised to a preset lifting position. The locking tongue 7 is slidably installed on the side wall of the top of the outer cylinder 2. A control device for driving the locking tongue 7 to insert or withdraw from the inner cylinder 1 is provided between the locking tongue 7 and the outer cylinder 2. The inner cylinder 1 is provided with a locking hole 8 corresponding to the locking tongue 7.

[0045] To ensure the stability of the locking tongue 7 during the sliding process, a groove 9 is provided on the top of the outer cylinder 2 for the locking tongue 7 to slide, and the control device is installed in the groove 9.

[0046] The control device is an electromagnetic actuator or an elastic reset mechanism, used to control the insertion or withdrawal of the locking tongue; specifically, it is a spring reset mechanism, including a spring 10 set in the slide groove 9. One end of the spring 10 is fixedly connected to the locking tongue 7, and the other end is fixed to the inner wall of the slide groove 9. In order to pull the locking tongue 7 out of the lock hole 8, a pull rope 11 is fixed to the tail end of the locking tongue 7. By pulling the rope, the locking tongue 7 can be pulled out of the lock hole 8, thereby releasing the locking effect of the locking mechanism.

[0047] The outer cylinder 2 is embedded in the ground of the passage area, and the top surface of the outer cylinder 2 is not higher than the ground. When the inner cylinder 1 is completely contained in the outer cylinder 2, it will not affect the passage of people and vehicles on the ground. Drainage holes are opened at the bottom of the outer cylinder 2 to prevent water from accumulating inside the outer cylinder.

[0048] It should be noted that the elastic component 13 in this utility model is an elastically deformable component such as an elastic rope, a double-headed tension spring with hooks, or a spring sheet. In this utility model, the preferred embodiment is a double-headed tension spring with hooks, with the hooks fixedly connected to the ends of the traction rope 3. Before the tension spring reaches its maximum extension length, the inner cylinder 1 rises and moves to a preset position. The maximum extension length of the tension spring does not exceed the maximum allowable extension length of the tension spring, i.e., the elastic limit of the tension spring. Once the extension length of the tension spring exceeds the elastic limit, plastic deformation will occur, leading to the failure of the tension spring.

[0049] When selecting the elastic component 13, it is necessary to provide sufficient elastic force to support the inner cylinder 1 to be lifted to its limit position before reaching the maximum stretch length, so as to avoid the problem that the inner cylinder 1 cannot be lifted when the elastic component 13 is stretched to its maximum length.

[0050] The maximum working load Fmax of the tension spring is determined by the working conditions of the tension spring in the mechanism, but it should not reach its limit load Flim. Usually, Fmax should be kept at 0.8Flim.

[0051] To ensure the safety of the elastic component 13, the outer cylinder 2 is provided with a limiting member 12 to limit the deformation of the elastic component 13 from being stretched to its maximum allowable stretch length. Limiting the stretch length of the elastic component 13 can effectively prevent the elastic component 13 from being stretched beyond its elastic limit and failing.

[0052] Specifically, the limiting component 12 is a baffle with a through hole in the middle. The inner diameter of the through hole is not greater than the outer diameter of the tension spring. The traction rope 3 passes through the baffle through the through hole. When the tension spring is stretched, the traction rope 3 can move freely in the through hole until the end of the tension spring touches the baffle, thereby limiting the tension spring.

[0053] Alternatively, the outer cylinder 2 may be equipped with a sensor switch 14 for detecting when the tension spring has been stretched to a set length. When the sensor switch 14 detects that the tension spring has been stretched to the set length, it will issue an alarm signal and the take-up and take-down device 5 will stop working.

[0054] When the limiting member 12 and the inductive switch 14 are both set, the inductive switch 14 is located on the outer cylinder 2 between the elastic member 13 and the limiting member 12. The inductive switch 14 acts as the first safety, limiting the extension length of the tension spring to not exceed the set length. The limiting member 12 acts as the second safety, directly blocking the end of the pull ring when the tension spring is pulled to the limiting member 12, so that the extension length of the tension spring does not exceed its maximum allowable extension length, avoiding the problem of the tension spring failing due to exceeding the elastic limit. When the traction rope 3 has two traction ends, both ends of the elastic member 13 are provided with the limiting member 12 and the inductive switch 14.

[0055] In order to detect whether the inner cylinder 1 has risen to the limit position, a second sensor switch (not shown in the figure) is also provided between the inner cylinder 1 and the outer cylinder 2. If the sensor switch 14 senses that the elastic member 13 has been stretched to the set length, but the second sensor switch does not detect that the inner cylinder 1 has risen to the limit position, an alarm will be issued to remind the staff to handle the situation.

[0056] Specifically, the inductive switch 14 and the second inductive switch can be electromagnetic proximity switches of model MC-18A in the prior art. This switch is waterproof and suitable for this equipment. In specific installation, the part that needs to be energized can be set at the limiting member 12, while the part with the permanent magnet can be fixed to the end of the tension spring.

[0057] In this utility model, the induction switch 14, the take-up and take-down device 4, and other components that require electricity are all connected to a dedicated control terminal (not shown in the figure) and are powered by the municipal power supply system. The control technology involved and the related components that need to be arranged are all existing mature technologies, and will not be described in detail here.

[0058] It should be noted that in this utility model, electrical components such as the launching and receiving devices can be installed on the ground for easy maintenance.

[0059] In addition, an auxiliary lifting mechanism (not shown in the figure) can be provided between the inner cylinder 1 and the outer cylinder 2 of this utility model to assist the inner cylinder 1 in rising, so as to offset part of the weight of the inner cylinder 1 or the friction between the inner cylinder 1 and the outer cylinder 2 or the resistance of other components during operation, thereby reducing the workload of the launching and retracting device 4.

[0060] The auxiliary lifting mechanism is preferably a spring, which is vertically disposed between the bottom of the inner cylinder 1 and the bottom of the outer cylinder 2, and provides an upward elastic force to the inner cylinder 1 when the inner cylinder 1 rises.

[0061] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Furthermore, the contents not described in detail in this specification are all prior art known to those skilled in the art.

Claims

1. A set of rising bollards, installed on the ground in a vehicle traffic area to restrict vehicle traffic, characterized in that, The utility model relates to a kind of lifting road pile and traction rope, including: Multiple lifting road piles, the lifting road pile includes the outer cylinder (2) fixed on ground, the inner cylinder (1) vertically ascending and descending movement is arranged in outer cylinder (2) and the drive mechanism that can drive inner cylinder (1) ascends, drive mechanism is pulley block; Traction rope (3), the traction end of traction rope (3) is connected with external take-up device (4), traction rope (3) single line string connection is sequentially wound around all lifting road pile pulley block;When take-up device (4) winds traction rope (3), drive all lifting road pile inner cylinder (1) ascends.

2. The lift post set of claim 1, wherein, The pulley block includes the fixed pulley (6) fixedly connected with the top of the outer cylinder (2) and the movable pulley (5) fixedly connected with the bottom of the inner cylinder (1).

3. The lift post set of claim 1, wherein, The straight line section of the traction rope (3) is provided with an elastic component (13) connected with the traction rope (3) in series; The elastic component (13) is configured to continue to be wound by the take-up device (4) when the inner cylinder (1) of all lifting road piles cannot ascend, until the elastic component (13) is stretched to a set length by the traction rope (3).

4. The lift post set of claim 1, wherein, One end of the traction rope (3) is the traction end and is connected with the external take-up device (4), and the other end is the fixed end and is fixed in the preset anchor point. The traction end of the traction rope (3) starts from the anchor point, sequentially passes through all the lifting road piles, and finally connects to the take-up device (4).

5. The lift post set of claim 4, wherein, The anchor point is arranged on one side of the top of the outer cylinder (2) of the first lifting road pile. The drive mechanism of the first lifting road pile includes at least one pulley block composed of a fixed pulley (6) fixed on the top of the outer cylinder (2) and at least one movable pulley (5) fixed on the bottom of the inner cylinder (1). The remaining lifting road piles include at least one pulley block composed of a fixed pulley (6) fixed on the top of the outer cylinder (2) and at least one movable pulley (5) fixed on the bottom of the inner cylinder (1), and a deflection pulley (61) fixed on the top of the outer cylinder (2). The traction end of the traction rope (3) starts from the anchor point, sequentially passes through each pulley block of the first group of lifting road piles, changes direction through the deflection pulley (61) of the next lifting road pile when entering the next lifting road pile, enters the next lifting road pile, and sequentially passes through the remaining lifting road piles in the same way, and finally connects to the take-up device (4).

6. The lift post set of claim 4, wherein, The anchor point is arranged on the bottom of the outer cylinder (2) of the first lifting road pile. The drive mechanism of all the lifting road piles includes at least one pulley block composed of a fixed pulley (6) fixed on the top of the outer cylinder (2) and at least one movable pulley (5) fixed on the bottom of the inner cylinder (1), and a deflection pulley (61) arranged on the top of the outer cylinder (2). The traction end of the traction rope (3) starts from the anchor point, changes direction through the deflection pulley (61), sequentially passes through each pulley block of the lifting road pile, sequentially passes through the remaining lifting road piles in the same way, and finally connects to the take-up device (4).

7. The lift post set of claim 1, wherein, Both ends of the traction rope (3) are traction ends and are connected with the external take-up device (4). The traction end of the traction rope (3) starts from the take-up device (4), sequentially passes through all the lifting road piles, and finally returns to the take-up device (4), forming a closed-loop transmission path.

8. The lift post set of claim 7, wherein, The driving mechanism comprises at least one set of pulley blocks composed of fixed pulleys (6) at the top of the outer cylinder (2) and at least one movable pulley (5) at the bottom of the inner cylinder (1), and a change direction pulley (61) fixed at the top of the outer cylinder (2); the traction end of the traction rope (3) changes direction through the change direction pulley (61) and then enters the lifting column, sequentially passes through each pulley block of the lifting column, and then sequentially passes through the remaining lifting columns in the same way, and finally is connected to the winding and unwinding device (4).

9. The lift post set of claim 5 or 6 or 8, wherein, When the traction rope (3) passes through the pulley block, it first passes through the movable pulley (5) and then passes through the fixed pulley (6).

10. The lift post set of claim 1, wherein, The locking mechanism is arranged between the outer cylinder (2) and the inner cylinder (1), and the inner cylinder (1) is locked by the locking mechanism when it rises to the limit position; after the locking effect is released, the winding and unwinding device (4) unwinds the traction rope (3), and the inner cylinder (1) can be lowered and reset under the action of its own gravity.

Images