Device for building high-rise building fire emergency conveying channel based on unmanned aerial vehicle
By using drones and pulley mechanisms to create hoisting ropeways on high-rise buildings, the problem of insufficient height for fire hoses and ladders has been solved, enabling fire rescue operations in high-rise buildings.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- TANGSHAN BAICHUAN INTELLIGENT MACHINE
- Filing Date
- 2025-01-24
- Publication Date
- 2026-05-01
AI Technical Summary
Existing fire-fighting equipment is insufficient in terms of the spray height of fire hoses and the extension height of fire ladders during high-rise building fire rescues, making it impossible to effectively carry out external rescues.
Using drones to fix anchoring devices on the side walls of high-rise buildings, and forming a hoisting ropeway through pulley mechanisms and winches, fire sprinklers or transport baskets can be transported at high altitudes.
It solves the problems of insufficient water jet height and ladder extension height, increases the upper limit of drone flight altitude, adapts to different rescue scenarios, and reduces the requirements for the operating environment.
Smart Images
Figure CN224180144U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of high-rise building fire rescue technology, specifically to a device for establishing a fire emergency transport channel for high-rise buildings based on drones. Background Technology
[0002] When fires or other emergencies occur in high-rise buildings requiring rescue, fire trucks and ladders are typically used. Currently, fire hoses and water cannons can only spray up to about 50 meters. When fires occur on higher floors, these tools cannot be used for extinguishing. The only option is to utilize the building's internal fire-fighting facilities. Some fire trucks are equipped with extendable ladders for firefighters to climb and rescue trapped individuals, but these ladders can only reach heights of less than 100 meters and have strict environmental requirements for their operation. Therefore, rescue operations are significantly more difficult when fires break out in high-rise buildings. Utility Model Content
[0003] The purpose of this invention is to provide a device for establishing a fire emergency transport channel for high-rise buildings based on drones. It can set anchor points on high-rise buildings and establish a transport channel to transport rescue equipment to the floor where the fire is taking place.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] This utility model discloses a device for establishing a fire emergency transport channel for high-rise buildings based on a drone, including a drone and a winch device for being set on the ground. The drone is equipped with a first anchoring device for connecting to the side wall of the building. The first anchoring device is equipped with a first pulley mechanism. The device also includes a first rope for passing through the first pulley mechanism and connecting to the winch device to form a first hoisting rope path, and a second rope for passing through the first pulley mechanism and connecting to the winch device to form a second hoisting rope path. The second rope passes through the first pulley mechanism under the hoisting of the first hoisting rope path to form the second hoisting rope path. The weight of the first rope is less than the weight of the second rope.
[0006] Optionally, it further includes a second anchoring device for connecting to the side wall of the building, the second anchoring device reaching the anchoring position under the hoisting of the second hoisting rope path; the second anchoring device is provided with a second pulley mechanism, and also includes a third rope for passing through the second pulley mechanism and connecting to the winch device to form a third hoisting rope path.
[0007] Optionally, the first anchoring device is disposed at the bottom of the UAV, and the UAV is also provided with a rotating arm that rotates in a vertical plane. The rotating arm is provided with a third anchoring device, and when the rotating arm rotates, it drives the third anchoring device to rotate relative to the UAV.
[0008] Optionally, the rotating arm includes a first rotating arm mounted on the UAV, a second rotating arm hinged to the first rotating arm, and a drive mechanism for driving the first rotating arm to rotate relative to the second rotating arm; the third anchoring device is mounted on the second rotating arm.
[0009] Optionally, a fire sprinkler or transport basket is provided on the second hoisting rope path.
[0010] Optionally, a fire sprinkler or transport basket is provided on the third hoisting rope path.
[0011] Optionally, the second anchoring device includes a third suction cup, a nail device, or a drilling device.
[0012] Optionally, two drones are provided, each drone is provided with a first anchoring device, each first anchoring device is provided with a first pulley mechanism, and the second rope passes through the two first pulley mechanisms to form the second hoisting rope path.
[0013] Optionally, there are two drones and two second anchoring devices. Each second anchoring device is equipped with a second pulley mechanism, and the third rope passes through the two second pulley mechanisms to form the third hoisting rope path.
[0014] Optionally, it also includes a fire hose, on which a fire sprinkler head is provided, and on which a connecting part is provided, the connecting part being at a first preset distance from the fire sprinkler head, the connecting part being connected to the second hoisting rope, and the fire sprinkler head being connected to a drone for moving the fire sprinkler head.
[0015] In this invention, the high flight altitude of a drone is utilized to fix anchoring devices on the side walls of high-rise buildings, forming anchor points. A pulley mechanism is installed on the anchoring devices, and a winch device is set up on the ground to form a hoisting ropeway. This solves the technical problems of insufficient fire hose spray height and insufficient ladder extension height in existing technologies, which prevent the construction of rescue facilities outside buildings. The use of a first and second rope reduces the load on the drone during flight, thereby increasing its upper flight altitude. Because the drone's flight path can be flexibly selected, it has lower requirements for the operating environment and can be applied to various rescue scenarios. Attached Figure Description
[0016] Figure 1 A schematic diagram of a drone flying with the first cable attached;
[0017] Figure 2 A schematic diagram illustrating the use of a drone to establish a second hoisting ropeway;
[0018] Figure 3 A schematic diagram illustrating the establishment of a third hoisting ropeway using a drone and a second anchoring device;
[0019] Figure 4 A schematic diagram illustrating the establishment of the first hoisting ropeway using two drones;
[0020] Figure 5 A schematic diagram illustrating the establishment of a second hoisting ropeway using two drones and a first anchoring device;
[0021] Figure 6 A schematic diagram showing the hoisting of the second anchoring device via a second hoisting rope when using two drones;
[0022] Figure 7 This is a schematic diagram illustrating the connection of the third rope to the fire sprinkler when using two drones.
[0023] Figure 8 A schematic diagram illustrating the hoisting of a fire sprinkler head via a third ropeway when using two drones;
[0024] Figure 9 A diagram illustrating a drone carrying a fire sprinkler for firefighting;
[0025] Figure 10 A schematic perspective view of the drone with its rotating arm in its first state;
[0026] Figure 11 for Figure 10 A schematic diagram of a perspective view from another direction;
[0027] Figure 12 for Figure 10 A perspective view of the rotating arm in its second state;
[0028] Figure 13 A schematic diagram illustrating the process of establishing a hoisting ropeway using a drone via a first anchoring device;
[0029] Figure 14 A schematic diagram illustrating the establishment of a third hoisting rope path using a second anchoring device when utilizing a drone;
[0030] Figure 15 A schematic diagram illustrating the process of establishing a hoisting ropeway via the first anchoring device when using two drones;
[0031] Figure 16A schematic diagram illustrating the process of establishing a hoisting ropeway using two drones via a second anchoring device.
[0032] In the diagram, 1. Unmanned aerial vehicle (UAV); 2. Winching device; 3. First rope; 4. Second rope; 5. Third rope; 6. Second anchoring device; 7. Fire sprinkler head; 8. Floor where the fire occurred; 9. Fire hose; 11. First suction cup; 12. Rotating arm; 13. Second suction cup; 14. First pulley mechanism; 21. First roller; 22. Fixing part; 23. Second roller; 24. Third roller; 25. Fourth roller; 31. First connector; 41. Second connector; 51. Third connector; 61. Second pulley mechanism; 121. First rotating arm; 122. Second rotating arm. Detailed Implementation
[0033] See Figure 1-16 This utility model provides a device for establishing a fire emergency transport channel for high-rise buildings based on a drone. It includes a drone 1 and a winch device 2, which may have several winding rollers, specifically composed of several winch mechanisms. The drone 1 is equipped with a first anchoring device for connecting to the side wall of the building. The first anchoring device is equipped with a first pulley mechanism 14. It also includes a first rope 3 and a second rope 4, the weight of the first rope 3 being less than the weight of the second rope 4. The first rope 3 can be a lightweight rope used to hoist the second rope 4. The second rope 4 can be a steel wire rope used to form a second hoisting rope path, i.e., a transport channel, for transporting fire-fighting equipment or personnel. The first rope 3 passes through the first pulley mechanism 14 and is connected to the winch device 2 to form the first hoisting rope path. The second rope 4 passes through the first pulley mechanism 14 and is connected to the winch device 2 to form the second hoisting rope path. The second rope 4, under the hoisting of the first hoisting rope path, passes through the first pulley mechanism 14 to form the second hoisting rope path.
[0034] The specific working process is as follows: The winch device 2 is wound with a first rope 3 and a second rope 4. First, the first rope 3 is threaded through the first pulley mechanism 14 on the drone 1, controlling the drone 1 to fly to a certain position on the side wall of the building. During the flight of the drone 1, the winch device 2 continuously releases the first rope 3. When the drone 1 flies to the preset position, it is fixed to the side wall of the building using the first anchoring device, and the first pulley mechanism 14 is also fixed. The specific fixing method can be found below. At this time, the first rope 3, the first pulley mechanism 14 and the winch device 2 form the first hoisting rope path. One joint of the first rope 3 is untied from the winch device 2 and connected to one joint of the second rope 4. The winch device 2 is used to retrieve the first rope 3 and release the second rope 4 until the joint of the second rope 4 is threaded through the first pulley mechanism 14 and returns to the ground. The joint of the second rope 4 is then connected to the winch device 2. At this time, the second rope 4, the first pulley mechanism 14 and the winch device 2 form the second hoisting rope path. The second hoisting rope path forms a conveying channel. The items are fixed to the second rope 4, and the second rope 4 is moved clockwise or counterclockwise by the winch device 2 to transport the items.
[0035] Once the rescue is complete, the second rope 4 can be replaced with the first rope 3, the first anchoring device can be separated from the building, and the drone 1 can carry the first anchoring device back to the ground.
[0036] This invention utilizes the high flight altitude of a drone to fix anchoring devices on the side walls of high-rise buildings, forming anchor points. A pulley mechanism is installed on the anchoring devices, and a winch device is set up on the ground to form a hoisting ropeway. This solves the technical problems of insufficient water jet height and ladder extension height in existing technologies, which prevent the construction of rescue facilities outside buildings. The use of a first and second rope reduces the load on the drone during flight, thereby increasing its upper flight altitude. Because the drone's flight path can be flexibly selected, it has lower requirements for the operating environment and can be applied to various rescue scenarios.
[0037] Optionally, it also includes a second anchoring device 6, which is used to fix to the side wall of the building. The second anchoring device 6 reaches the anchoring position and is anchored at the anchoring position under the hoisting of the second hoisting rope. The second anchoring device 6 is provided with a second pulley mechanism 61, and also includes a third rope 5, which is used to pass through the second pulley mechanism 61 and is connected to the winch device 2 to form a third hoisting rope.
[0038] For certain complex rescue situations, a lifting ropeway with a stronger load-bearing capacity is required. After establishing a second lifting ropeway, the second anchoring device 6 can be fixed to the second rope 4, and the second anchoring device 6 can be transported to the anchoring position via the second lifting ropeway. Simultaneously, the third rope 5 on the winch 2 passes through the second pulley mechanism 61 on the second anchoring device 6, and the winch 2 continuously releases the third rope 5. After the second anchoring device 6 moves to the anchoring position and is anchored, the third lifting ropeway is formed. The second lifting ropeway can lift heavier and stronger second anchoring devices 6, and the anchoring point formed by the second anchoring device 6 is more secure, thus the third lifting ropeway has a stronger load-bearing capacity.
[0039] Optionally, see Figure 10-12 The first anchoring device can be located at the bottom of the drone 1. Specifically, the first anchoring device can be the second suction cup 13, or it can be a hook or other structure. The drone 1 is also provided with a rotating arm 12 that rotates in a vertical plane. The rotating arm 12 is provided with a third anchoring device, which can be a hook or the first suction cup 11, etc. When the rotating arm 12 rotates, it drives the third anchoring device to rotate relative to the drone.
[0040] Since the drone 1 needs to be in a near-horizontal attitude during flight, the first anchoring device is located at the bottom of the drone 1 to facilitate flight and load-bearing. Because the first anchoring device is located at the bottom of the drone 1, it is inconvenient to anchor it to the side wall of a building when the drone 1 is in a horizontal attitude. Therefore, a rotating arm 12 and a third anchoring device are added. Taking the first suction cup 11 as an example, the orientation of the first suction cup 11 can be adjusted by rotating the rotating arm 12. When the drone 1 flies to the preset position, the first suction cup 11 is horizontally facing the side wall of the building and is attached to it. When the drone 1 stops flying, the rotating arm 12 is controlled to rotate, and the drone rotates relative to the first suction cup 11 from a horizontal state to a vertical state. At this time, the first anchoring device is horizontally facing the side wall of the building, facilitating anchoring. The first suction cup 11 and the second suction cup 13 can be motorized suction cups.
[0041] Optionally, see Figure 10-12 The rotating arm 12 may include a first rotating arm 121 mounted on the UAV 1, a second rotating arm 122 hinged to the first rotating arm 121, and a drive mechanism for driving the first rotating arm 121 to rotate relative to the second rotating arm 122. A third anchoring device is mounted on the second rotating arm 122. The following description uses a first suction cup 11 as an example of the third anchoring device; see [link to documentation]. Figure 11 When the first suction cup 11 needs to adhere, the drive mechanism drives the second rotating arm 122 to rotate to a horizontal position. After the first suction cup 11 adheres to the side wall of the building, see [link to relevant documentation]. Figure 9-10The drive mechanism drives the first rotating arm 121 to rotate relative to the second rotating arm 122, so that the first rotating arm 121 and the second rotating arm 122 are perpendicular. At this time, the drone 1 will be in a vertical state, and the second suction cup 13 will be horizontally facing the side wall of the building, controlling the second suction cup 13 to adhere to the side wall of the building.
[0042] Optionally, see Figure 5 The second hoisting rope path is equipped with fire sprinklers or transport baskets.
[0043] In this way, the fire sprinkler head 7 can be transported to the fire floor 8 via the second hoisting rope for fire extinguishing. The fire sprinkler head 7 is connected to the fire water pipe 9. Alternatively, a transport basket can be transported to the fire location, and trapped personnel can enter the transport basket and be transported to the ground.
[0044] Optionally, see Figure 8 The third hoisting rope path is equipped with fire sprinklers or transport baskets.
[0045] In this way, the fire sprinkler head 7 can be transported to the burning floor 8 via the third hoisting rope for fire extinguishing. The fire sprinkler head 7 is connected to the fire water pipe 9. Alternatively, a transport basket can be transported to the burning floor 8, and the trapped personnel can enter the transport basket and be transported to the ground.
[0046] Optionally, the second anchoring device may include a third suction cup, a nail device, or a drilling device.
[0047] The second anchoring device 6 can be an electric suction cup that adheres to the side wall of the building; it can be a nailing device that fires nails into the side wall of the building for fixation; or it can be a drilling device that drills holes in the side wall of the building and inserts pins or other fastening devices into the holes for fixation. Of course, it can also be other fixing structures.
[0048] Optionally, see Figure 4-5 There are two drones 1. Each drone 1 is equipped with a first anchoring device. Each first anchoring device is equipped with a first pulley mechanism 14. The second rope 4 passes through the two first pulley mechanisms 14 to form a second hoisting rope path.
[0049] Optionally, see Figure 6-8 The drone 1 is equipped with two parts, and the second anchoring device 6 is equipped with two parts. Each second anchoring device is equipped with a second pulley mechanism 61. The third rope passes through the two second pulley mechanisms 61 to form a third hoisting rope path.
[0050] When there are two drones set up, see Figure 5 and Figure 8Therefore, an anchor point can be set on each side of the fire location. This creates a second or third hoisting ropeway, which can cover a wider area, and the vertical position of the hoisted object can be controlled by coordinating the raising and lowering of the ropes on both sides. See also Figure 5 Taking the fire sprinkler head 7 as an example, the fire sprinkler head 7 is fixed by the second rope 4. The hoisting device 2 can control the raising and lowering of the second ropes 4 on both sides to move the fire sprinkler head 7 up, down, left, and right. For example, when the hoisting device 2 retracts the second ropes 4 on both sides at a constant speed, the fire sprinkler head 7 can rise; when the hoisting device 2 releases the second ropes 4 on both sides at a constant speed, the fire sprinkler head 7 can fall; when the retraction speed of the second rope 4 on the left side is greater than the retraction speed of the second rope 4 on the right side, the fire sprinkler head 7 can move to the upper left; when the retraction speed of the second rope on the left side is equal to the release speed of the second rope on the right side, the fire sprinkler head 7 can move to the left. Other control methods will not be listed one by one. Figure 8 Control principles and Figure 5 The control principle is the same.
[0051] The process of establishing the first, second, and third hoisting rope routes is described in detail below.
[0052] 1. The scenario of establishing a transport channel using a drone and a first anchoring device.
[0053] See Figure 1 , Figure 2 and Figure 13 The winch device 2 includes a first roller 21, a second roller 23, and a fixing part 22. When the UAV 1 takes off, the first rope 3 on the first roller 21 passes through the first pulley mechanism 14, and the first joint 31 is connected to the fixing part 22 of the winch device 2 on the ground. During the flight of the UAV 1, the first roller 21 releases the first rope 3. When the UAV 1 flies to the preset position, the first anchoring device is anchored to the side wall of the building. At this time, the first rope 3 forms the first hoisting rope path. The first joint 31 is untied from the fixing part 22, and the second joint 41 of the second rope 4 on the second roller 23 is connected to the first joint 31. The first roller 21 retracts the first rope 3, and the second roller 23 releases the second rope 4. When the second joint 41 reaches the first roller 21, the second joint 41 is untied from the first joint 31 and connected to the first roller 21. At this time, the first roller 21, the second roller 23, the second rope 4, and the first pulley mechanism 14 form the second hoisting rope path.
[0054] II. The scenario of establishing a transport channel using a drone and a second anchoring device.
[0055] See Figure 3 and Figure 14The hoisting device 2 also includes a third roller 24 and a fourth roller 25. After the second hoisting rope path is established, the third rope 5 passes through the second pulley mechanism 61 and its two ends are connected to the third roller 24 and the fourth roller 25 respectively. The second anchoring device 6 is fixed to the second rope 4, and the second anchoring device 6 is hoisted through the second hoisting rope path. During the ascent of the second anchoring device 6, the third roller 24 and / or the fourth roller 25 release the third rope 5. After the second anchoring device 6 moves to the preset position and is anchored, the second pulley mechanism 61, the third rope 5, the third roller 24, and the fourth roller 25 form the third hoisting rope path, which fixes the fire sprinkler head 7 or the transport basket to the third rope 5, allowing it to be hoisted.
[0056] III. The scenario of establishing a transport channel using two drones and the first anchoring device.
[0057] See Figure 4 , Figure 5 and Figure 15 The winch device 2 includes two first rollers 21 and two second rollers 23. Two drones 1 can fly to both sides of the fire location to establish two anchor points. This establishes two first hoisting ropeways. When the second joints 41 of the two second ropes 4 are pulled back to the ground by the first hoisting ropeways, both second joints 41 are untied from the two first joints 31, and then the two second joints 41 are connected. At this point, the two second rollers 23, the two first pulley mechanisms 14, and the second rope 4 form a final second hoisting ropeway. The fire sprinkler head 7 or transport basket is then secured to the second rope 4 for transport.
[0058] IV. The scenario of establishing a transport channel using two drones and a second anchoring device.
[0059] See Figure 6-8 and Figure 16 The hoisting device 2 includes two first rollers 21, two second rollers 23, and two third rollers 24.
[0060] After establishing two second hoisting ropeways, the third rope 5 on the third roller 24 passes through the second pulley mechanism 61. The third joint 51 of the third rope 5 is connected to the fixing part 22, fixing the second anchoring device 6 to the second rope 4. The second anchoring device 6 is then hoisted to the preset position via the second hoisting ropeway. Simultaneously, the third roller 24 releases the third rope 5. After the second anchoring device 6 is anchored to the preset position, the third joint 51 of the third rope 5 is untied from the fixing part 22, and the two third joints 51 are connected. Thus, the two third rollers 24, the two second pulley mechanisms 61, and the third rope 5 form a third hoisting ropeway. The fire sprinkler head 7 or transport basket is then fixed to the third rope 5 for transportation.
[0061] It should be noted that the specific structure of the winch device 2 can be set as needed, and the winch device 2 can be installed on the fire truck or on the ground.
[0062] Optionally, see Figure 9 It also includes a fire hose 9, on which a fire sprinkler head 7 is installed. A connecting part is provided on the fire hose 9, and the connecting part is at a first preset distance from the fire sprinkler head 7. This first preset distance can be specifically determined as needed. The connecting part is connected to a hoisting rope, which can be a second or third hoisting rope. Figure 9 The diagram shows the connection point attached to the third hoisting rope, and the fire sprinkler 7 is also connected to a drone for moving the fire sprinkler 7.
[0063] Thus, when the fire floor 8 is located at the top of the building, the first anchoring device or the second anchoring device 6 can be anchored below the fire floor 8. The hoisting rope is connected to the connection of the fire water pipe 9. The hoisting rope is used to support the weight of the part below the connection of the fire water pipe 9. The drone carries the fire sprinkler 7 to the fire floor 8 to extinguish the fire. The drone only carries the weight of the fire water pipe from the fire sprinkler 7 to the connection.
[0064] The above embodiments are merely illustrative of the present invention and not limiting. Under the concept of the present invention, technical solutions without substantial changes are still within the protection scope of the present invention.
Claims
1. A device for establishing fire emergency transport channels in high-rise buildings based on unmanned aerial vehicles (UAVs), characterized in that, The device includes a drone and a winch for installation on the ground. The drone is equipped with a first anchoring device for connection to the side wall of a building. The first anchoring device is equipped with a first pulley mechanism. The device also includes a first rope for passing through the first pulley mechanism and connecting to the winch to form a first hoisting rope path, and a second rope for passing through the first pulley mechanism and connecting to the winch to form a second hoisting rope path. The second rope passes through the first pulley mechanism to form the second hoisting rope path under the hoisting of the first hoisting rope path. The weight of the first rope is less than the weight of the second rope. It also includes a second anchoring device for connecting to the side wall of the building, the second anchoring device reaching the anchoring position under the hoisting of the second hoisting rope path; the second anchoring device is provided with a second pulley mechanism, and also includes a third rope for passing through the second pulley mechanism and connecting to the winch device to form a third hoisting rope path.
2. The device for establishing fire emergency transport channels in high-rise buildings based on unmanned aerial vehicles as described in claim 1, characterized in that, The first anchoring device is located at the bottom of the UAV. The UAV is also equipped with a rotating arm that rotates in a vertical plane. The rotating arm is equipped with a third anchoring device. When the rotating arm rotates, it causes the third anchoring device to rotate relative to the UAV. 3.The device for establishing an emergency delivery channel for a high-rise building fire based on a UAV according to claim 2, wherein, The rotating arm includes a first rotating arm mounted on the UAV, a second rotating arm hinged to the first rotating arm, and a drive mechanism that drives the first rotating arm to rotate relative to the second rotating arm; the third anchoring device is mounted on the second rotating arm.
4. The device for establishing an emergency delivery passage for a high-rise building fire based on a UAV according to claim 1, characterized in that, Fire sprinklers or transport baskets are installed on the second hoisting rope path.
5. The device for establishing fire emergency transport channels in high-rise buildings based on unmanned aerial vehicles as described in claim 1, characterized in that, Fire sprinklers or transport baskets are installed on the third hoisting rope path.
6. The device for establishing fire emergency transport channels in high-rise buildings based on unmanned aerial vehicles as described in claim 1, characterized in that, The second anchoring device includes a third suction cup, a nail device, or a drilling device.
7. The device for establishing fire emergency transport channels in high-rise buildings based on unmanned aerial vehicles as described in claim 1, characterized in that, Two drones are provided, each drone is equipped with a first anchoring device, and each first anchoring device is equipped with a first pulley mechanism. The second rope passes through the two first pulley mechanisms to form the second hoisting rope path. 8.The device for establishing an emergency delivery passage for a high-rise building fire based on a UAV according to claim 1, wherein, The drone is provided in two locations, and the second anchoring device is provided in two locations. Each second anchoring device is provided with a second pulley mechanism, and the third rope passes through the two second pulley mechanisms to form the third hoisting rope path. 9.The device for establishing an emergency delivery passage for a high-rise building fire based on a UAV according to claim 1 or 7, characterized in that, It also includes a fire hose, on which a fire sprinkler head is installed. A connecting part is provided on the fire hose, and the connecting part is at a first preset distance from the fire sprinkler head. The connecting part is connected to the second hoisting rope. The fire sprinkler head is also connected to a drone for moving the fire sprinkler head.