A controllable time and temperature monitoring cement mixing device
By introducing timing control and temperature monitoring functions into the cement mixing device, the problem of inaccurate mixing time and temperature control was solved, improving the mixing quality and cleaning efficiency of cement-based grouting materials, and ensuring the quality of secondary grouting and the reliability of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SINOHYDRO BUREAU 11 CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-07-24
Smart Images
Figure CN224544918U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of mixing equipment technology, and in particular to a cement mixing equipment with controllable time and temperature monitoring. Background Technology
[0002] As an important component of secondary grouting, the uniformity of cement-based grouting and the temperature during mixing affect its strength. Currently, the mixing method for cement-based grouting involves mixing water and cement-based materials together, with the mixing time controlled by workers' senses and visual observation. This mixing method can lead to uneven mixing of cement-based materials and water. If the mixing time is too short, the cement-based materials are prone to clumping. Therefore, controlling the mixing time can greatly improve the uniformity of mixing.
[0003] Meanwhile, the temperature of the cement grout can affect its strength, especially at low temperatures. Therefore, it is necessary to control the temperature during mixing and the temperature at which the grout is discharged to improve the mechanical strength of the grout under the same water usage conditions. Currently, there is no cement grout mixing device suitable for temperature monitoring. Furthermore, due to variations in mixing time, some cement may settle at the bottom of the machine or damage the steel fibers in the high-strength cementitious base material. This not only seriously affects the accuracy of the water-cement ratio of the cement grout but also poses a risk to the overall quality of secondary grouting.
[0004] Existing cement slurry mixing devices, such as the cement slurry mixing device disclosed in the patent document with announcement number CN213648101U, have mixing blades that cannot be removed, which makes it impossible to clean the bottom of the tank completely and efficiently during cleaning, and hardened cement slurry easily accumulates. Utility Model Content
[0005] The purpose of this application is to provide a cement mixing device with controllable time and temperature monitoring to solve the above-mentioned problems.
[0006] To achieve the above objectives, the technical solution of this application is as follows: A cement mixing device with controllable time and temperature monitoring includes a mixing tank, a timing control switch, and a distribution box; the mixing tank is equipped with a mixing shaft, and the mixing shaft is equipped with mixing blades; the mixing tank is equipped with a temperature sensor inside, and a temperature display screen is equipped on the outside of the mixing tank, and the temperature sensor is electrically connected to the temperature display screen; the distribution box is electrically connected to the timing control switch, and the timing control switch is electrically connected to a motor that drives the mixing shaft to rotate.
[0007] Preferably, the mixing tank is provided with a limiting ring inside, and there are multiple limiting rings arranged vertically along the inner wall of the mixing tank. The sensor is located within the protective area formed by the multiple limiting rings and the inner wall of the mixing tank.
[0008] Preferably, the bottom of the mixing tank is hinged with a discharge plate, the outer side wall of the mixing tank is provided with a hinge hole, a hinge rod is rotatably provided in the hinge hole, a handle is vertically provided at the top of the hinge rod, and a limiting rod is vertically provided at the bottom of the hinge rod, the limiting rod and the handle are perpendicular to each other.
[0009] Preferably, the outer peripheral wall of the mixing tank is provided with an annular groove, a support frame is engaged in the annular groove, an adjusting rod is rotatably mounted on the support frame, and the mixing shaft and the motor are both mounted on the adjusting rod.
[0010] Preferably, the end of the adjusting rod extends outside the support frame, one end of the adjusting rod is provided with a limiting handle, a pull rod is slidably provided through the limiting handle, the pull rod is provided with two pull handles, the two pull handles are respectively located on both sides of the limiting handle, a spring is sleeved on a section of the pull rod between the limiting handle and the support frame, one end of the spring abuts against the pull handle, and the other end abuts against the limiting handle; the support frame has a plurality of insertion holes arranged circumferentially for the pull rod to be inserted.
[0011] Preferably, the stirring shaft is also provided with helical blades.
[0012] Preferably, a rotating rod is radially rotatably provided at the bottom of the stirring shaft, and a torsion spring is sleeved on the rotating rod. One end of the torsion spring is connected to the rotating rod, and the other end is connected to the stirring shaft; multiple scrapers are axially arranged on the rotating rod.
[0013] Preferably, there are two rotating rods, which are symmetrically arranged; the annular area formed by the scraper on one of the rotating rods exactly overlaps with the annular area formed between two adjacent scrapers on the other rotating rod.
[0014] The cement mixing device with controllable time and temperature monitoring disclosed in this application pre-sets the mixing time via a timer control switch, avoiding the inaccuracies of workers controlling the mixing time based on feeling and visual observation, ensuring the accuracy of the mixing time, and thus improving the uniformity of the mixing. This device, by controlling the mixing time and monitoring the mixing temperature, can effectively improve the mixing quality of cement-based grouting materials, reduce grouting strength problems caused by uneven mixing or unsuitable temperature, and ensure the quality of secondary grouting. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the overall structure of this application; Figure 2 This is a top view of this application; Figure 3 for Figure 2 Sectional view of section AA; Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle; Figure 5 This is a partially enlarged schematic diagram of the limiting handle in this application; Figure 6 This is a partially enlarged schematic diagram of the connection between the stirring shaft and the rotating rod in this application.
[0016] In the picture: 1. Mixing tank; 10. Annular groove; 11. Limiting ring; 2. Mixing shaft; 20. Mixing blade; 21. Spiral blade; 3. Temperature display screen; 4. Support frame; 40. Adjusting rod; 41. Limiting handle; 42. Pull rod; 420. Pull handle; 5. Motor; 6. Hinge rod; 60. Handle lever; 61. Limiting rod; 62. Side plate; 7. Rotating rod; 70. Scraper; 71. Torsion spring; 8. Connecting frame; 80. Stop handle. Detailed Implementation
[0017] The present application will now be described in further detail with reference to the accompanying drawings. The drawings are simplified schematic diagrams, illustrating only the basic structure of the present application, and therefore only show the components relevant to the present application.
[0018] like Figure 1-6 As shown, a cement mixing device with controllable time and temperature monitoring includes a mixing tank 1, a timing control switch, and a distribution box; the mixing tank 1 is equipped with a mixing shaft 2, and the mixing shaft 2 is equipped with mixing blades 20; the mixing tank 1 is equipped with a temperature sensor inside, and a temperature display screen 3 is equipped with a temperature display screen outside the mixing tank 1, and the temperature sensor is electrically connected to the temperature display screen 3; the distribution box is electrically connected to the timing control switch, and the timing control switch is also electrically connected to the motor 5 that drives the mixing shaft 2 to rotate.
[0019] This controllable time and temperature monitoring cement mixing device mainly consists of a mixing tank 1, a timing control switch, and a distribution box.
[0020] The mixing tank 1 is the main place for mixing cement-based grouting materials. It is equipped with a mixing shaft 2, and mixing blades 20 are fixed on the mixing shaft 2. The mixing blades 20 rotate under the drive of the mixing shaft 2 to mix the cement-based materials and water in the mixing tank 1.
[0021] A temperature sensor is installed at a suitable location inside the mixing tank 1. This temperature sensor can sense the temperature of the cement slurry inside the mixing tank 1 in real time and transmit the temperature signal in the form of an electrical signal. A temperature display screen 3 is installed on the outside of the mixing tank 1. The temperature sensor and the temperature display screen 3 are electrically connected by wires. The temperature display screen 3 displays the received temperature signal in digital or other intuitive form, which makes it convenient for operators to understand the temperature of the cement slurry inside the mixing tank 1 in real time.
[0022] The distribution box is electrically connected to the timer control switch, providing power to the timer control switch. The timer control switch is electrically connected to the motor 5 that drives the stirring shaft 2 to rotate. The operator can preset the stirring time through the timer control switch. When the set stirring time is reached, the timer control switch will automatically cut off the power to the motor 5 and stop stirring.
[0023] When mixing cement-based grout, cement-based materials and water are added to mixing tank 1, and motor 5 is started to drive mixing shaft 2 and mixing blades 20 to rotate for mixing. Simultaneously, a temperature sensor monitors the temperature of the cement slurry in mixing tank 1 in real time and displays the temperature information on temperature display screen 3. Operators can use this information to determine whether heating or other measures are needed to control the mixing temperature. A timer control switch pre-sets the mixing time, avoiding the inaccuracies of workers relying on intuition and visual observation to control the mixing time, ensuring the accuracy of the mixing time and thus improving the uniformity of the mixing. This device, by controlling the mixing time and monitoring the mixing temperature, can effectively improve the mixing quality of cement-based grout, reduce grout strength problems caused by uneven mixing or unsuitable temperature, and ensure the quality of secondary grouting.
[0024] In some further embodiments, the mixing tank 1 is provided with a limiting ring 11 inside. There are multiple limiting rings 11, which are arranged vertically along the inner wall of the mixing tank 1. The sensor is located within the protection area formed by the multiple limiting rings 11 and the inner wall of the mixing tank 1.
[0025] Inside the mixing tank 1, multiple limiting rings 11 are arranged vertically along the inner wall of the mixing tank 1. These limiting rings 11 can be made of metal or other materials with a certain strength, and they are fixed to the inner wall of the mixing tank 1 by welding, bolting or other means.
[0026] The temperature sensor is located within the protective area formed by multiple limiting rings 11 and the inner wall of the mixing tank 1. The setting of the limiting rings 11 isolates the temperature sensor from the mixing area inside the mixing tank 1, but does not affect the temperature sensor's perception of the temperature inside the mixing tank 1.
[0027] During the mixing process, the rotation of the stirring shaft 2 and the stirring blades 20 generates a strong stirring effect on the material inside the mixing tank 1, and some material may splash. The limiting ring 11 forms a protective zone to prevent the material from directly impacting the temperature sensor during the mixing process, thus avoiding damage to the temperature sensor due to material impact. This ensures that the temperature sensor can monitor the temperature inside the mixing tank 1 normally and accurately. This structure extends the service life of the temperature sensor, improves the reliability of temperature monitoring, provides accurate data support for controlling the mixing temperature, and further guarantees the mixing quality of the cement-based grouting material.
[0028] In some further embodiments, a discharge plate is hinged to the bottom of the mixing tank 1, a hinge hole is provided on the outer side wall of the mixing tank 1, a hinge rod 6 is rotatably provided in the hinge hole, a handle 60 is vertically provided at the top of the hinge rod 6, and a limiting rod 61 is vertically provided at the bottom of the hinge rod 6. The limiting rod 61 and the handle 60 are perpendicular to each other.
[0029] The bottom of the mixing tank 1 is hinged with a discharge plate. The discharge plate can be connected to the bottom of the mixing tank 1 by means of a pin or the like, so that the discharge plate can rotate around the hinge point.
[0030] A hinge hole is provided on the outer side wall of the mixing tank 1, and a hinge rod 6 is rotatably installed in the hinge hole, allowing it to rotate freely. A handle 60 is vertically installed at the top of the hinge rod 6 for easy gripping and rotation by the operator. A limiting rod 61 is also vertically installed at the top of the hinge rod 6, perpendicular to the handle 60 at a certain angle. When it is necessary to open the discharge plate for material discharge, the operator grips the handle 60 and rotates the hinge rod 6, causing the limiting rod 61 to no longer restrict the rotation of the discharge plate, allowing the discharge plate to open under gravity or other external force for material discharge. When it is necessary to close the discharge plate, the hinge rod 6 is rotated in the opposite direction, and then the hinge rod 6 is rotated again to cause the limiting rod 61 to block and engage the discharge plate, preventing it from opening arbitrarily.
[0031] The opening and closing of the discharge plate is controlled by rotating the hinge rod 6, avoiding problems such as incomplete discharge or material leakage during the discharge process that may occur with traditional discharge methods. At the same time, the setting of the limit rod 61 ensures the stability of the discharge plate in the closed state, preventing the discharge plate from accidentally opening due to vibration or other reasons during the mixing process. This ensures the normal mixing of materials in the mixing tank 1 and the smooth progress of the discharge process, improving the overall efficiency and reliability of the mixing device.
[0032] The bottom of the mixing tank 1 is provided with a side plate 62 corresponding to the discharge plate.
[0033] In some further embodiments, the outer peripheral wall of the mixing tank 1 is provided with an annular groove 10, a support frame 4 is engaged in the annular groove 10, an adjusting rod 40 is rotatably mounted on the support frame 4, and the mixing shaft 2 and the motor 5 are both mounted on the adjusting rod 40.
[0034] The outer peripheral wall of the mixing tank is provided with an annular groove 10. The support frame 4 can be snapped into the annular groove 10 to connect with the mixing tank 1, which facilitates the subsequent removal of the entire mixing shaft 2 and mixing blades 20 for better cleaning of the mixing tank 1.
[0035] In some other embodiments, rubber pads can be provided on the sidewalls of the annular slot 10, and the locking plates provided on both sides of the support frame 4 can be correspondingly locked in the annular slot 10 to ensure the stability of the locking.
[0036] The annular slot 10 facilitates the snap-fit of the support frame 4, allowing it to snap-fit smoothly at any angle without the need to specifically search for or align the snap-fit position.
[0037] An adjusting rod 40 is rotatably mounted on the support frame 4, allowing it to rotate around a specific axis. Both the stirring shaft 2 and the motor 5 are mounted on the adjusting rod 40. The motor 5 drives the stirring shaft 2 to rotate, thereby causing the stirring blades 20 to stir the material inside the mixing tank 1. By rotating the adjusting rod 40, the positions of the stirring shaft 2 and the stirring blades 20 within the mixing tank 1 can be adjusted to meet different stirring requirements.
[0038] The structural design of this support frame 4 and adjusting rod 40 allows for flexible adjustment of the positions of the mixing shaft 2 and mixing blades 20. During the mixing process, based on the mixing conditions of the materials and the spatial distribution within the mixing tank 1, the operator can rotate the adjusting rod 40 to change the positions of the mixing shaft 2 and mixing blades 20, making the mixing more uniform and efficient. For example, when the material distribution within the mixing tank 1 is uneven, the positions of the mixing shaft 2 and mixing blades 20 can be adjusted to reach deeper into areas with more material accumulation, improving the mixing effect. This adjustable structure increases the applicability and flexibility of the mixing device, better meeting the needs of different mixing scenarios and improving the mixing quality of cement-based grouting materials.
[0039] In some further embodiments, the end of the adjusting rod 40 extends outside the support frame 4. One end of the adjusting rod 40 is provided with a limiting handle 41. A pull rod 42 is slidably provided through the limiting handle 41. The pull rod 42 is provided with two pull handles 420, which are located on both sides of the limiting handle 41. A spring is sleeved on a section between the limiting handle 41 and the support frame 4. One end of the spring abuts against the pull handle 420, and the other end abuts against the limiting handle 41. The support frame 4 has a plurality of insertion holes arranged circumferentially for the pull rod 42 to be inserted.
[0040] The adjusting rod 40 is horizontally positioned. One end of the adjusting rod 40 extends beyond the support frame 4. A limiting handle 41 is provided at the end of the adjusting rod 40 extending beyond the support frame 4. The limiting handle 41 can be a metal block or other component with sufficient strength, fixed to the adjusting rod 40 by welding or other means. A pull rod 42 slides through the limiting handle 41, freely sliding within a hole on the limiting handle 41. The pull rod 42 has two handles 420, located on either side of the limiting handle 41, facilitating gripping and pulling by the operator. A spring is fitted onto a section of the pull rod 42 between the limiting handle 41 and the support frame 4. One end of the spring abuts against the handle 420, and the other end abuts against the limiting handle 41. The support frame 4 has multiple insertion holes arranged circumferentially for the pull rod 42 to be inserted. When the adjusting rod 40 is rotated to the appropriate position, the pull rod 42 is inserted into the corresponding insertion hole to fix the position of the adjusting rod 40.
[0041] When the position of the stirring shaft 2 and the stirring blade 20 needs to be adjusted, the operator holds the handle 420 and pulls the lever 42 outward, causing the lever 42 to be pulled out of the insertion hole. At this time, the spring is compressed. Then, the adjusting rod 40 is rotated to the desired position, and the handle 420 is released. Under the action of the spring, the lever 42 will automatically insert into the corresponding insertion hole, fixing the adjusting rod 40 in that position. This structure makes the position adjustment of the adjusting rod 40 more convenient and accurate. Through the cooperation of the spring and the lever 42, it can be ensured that the adjusting rod 40 can be stably fixed in the desired position after adjustment, preventing the position of the adjusting rod 40 from changing due to vibration or other reasons during the stirring process. This ensures the stability of the position of the stirring shaft 2 and the stirring blade 20, and improves the reliability and stirring quality of the stirring device.
[0042] In some further embodiments, the stirring shaft 2 is also provided with helical blades 21.
[0043] A spiral blade 21 is also provided on the stirring shaft 2. The spiral blade 21 can be fixed to the stirring shaft 2 by welding, bolting or other means. The shape and size of the spiral blade 21 are designed according to the size of the mixing tank 1 and the stirring requirements. Its spiral direction and pitch and other parameters can effectively promote the up-and-down tumbling and mixing of materials in the mixing tank 1.
[0044] When the mixing shaft 2 rotates, the spiral blades 21 also rotate. The rotation of the spiral blades 21 lifts the material at the bottom of the mixing tank 1 upwards and pushes the material at the top downwards, forming an up-and-down circulating flow of materials. This up-and-down mixing method increases the contact area and mixing degree between materials, allowing cement-based materials and water to mix more thoroughly and improving the uniformity of mixing. Compared with the traditional mixing blades 20, the spiral blades 21 can better solve the problem of material settling at the bottom of the machine during mixing, reduce the deviation of the water-cement ratio of cement slurry, and improve the overall quality of secondary grouting.
[0045] In some further embodiments, a rotating rod 7 is provided at the bottom of the stirring shaft 2 for radial rotation, and a torsion spring 71 is sleeved on the rotating rod 7. One end of the torsion spring 71 is connected to the rotating rod 7, and the other end is connected to the stirring shaft 2; a plurality of scrapers 70 are arranged axially on the rotating rod 7.
[0046] A rotating rod 7 is provided at the bottom of the stirring shaft 2, which rotates radially. A connecting frame 8 can be provided at the bottom of the stirring shaft 2. A through hole is provided on one side of the connecting frame 8 that is parallel to the stirring shaft 2. One end of the rotating rod 7 passes through the through hole, and a bolt can be screwed onto the end of the rod to limit its movement. A stop 80 can be provided on the part of the rod that does not pass through the hole to form a limit.
[0047] A torsion spring 71 is fitted onto the rotating rod 7, with one end connected to the rotating rod 7 and the other end connected to the stirring shaft 2. Under the action of the torsion spring 71, the rotating rod 7 has a certain initial rotational tendency. Multiple scrapers 70 are axially arranged on the rotating rod 7. The scrapers 70 can be made of metal or other materials with a certain degree of hardness and wear resistance. The shape and size of the scrapers 70 can be adapted to the bottom of the mixing tank 1 to scrape off cement slurry that may accumulate at the bottom of the mixing tank 1.
[0048] During the mixing process, the mixing shaft 2 drives the rotating rod 7 and scraper 70 to rotate. When material accumulates at the bottom of the mixing tank 1, the scraper 70 scrapes up the accumulated material during rotation, allowing it to re-enter the mixing process and preventing the material from settling at the bottom. Simultaneously, the torsion spring 71 allows the scraper 70 to undergo elastic deformation when encountering significant resistance, preventing damage due to excessive resistance. This structure of the rotating rod 7 and scraper 70 with the torsion spring 71 effectively cleans the bottom of the mixing tank 1, ensuring the cleanliness of the tank's interior, improving mixing quality, reducing cement slurry water-cement ratio deviations caused by bottom material accumulation, and guaranteeing the quality of secondary grouting.
[0049] In some further embodiments, there are two rotating rods 7, which are symmetrically arranged; the annular area formed by the scraper 70 on one of the rotating rods 7 exactly overlaps with the annular area formed between two adjacent scrapers 70 on the other rotating rod 7.
[0050] There are two rotating rods 7, symmetrically arranged at the bottom of the stirring shaft 2. The annular area formed by the scraper 70 on one rotating rod 7 exactly overlaps with the annular area formed between two adjacent scrapers 70 on the other rotating rod 7. This overlapping arrangement allows the scrapers 70 on the two rotating rods 7 to cover more of the bottom area of the mixing tank 1 during rotation, improving the efficiency of scraping off the bottom material.
[0051] During the mixing process, the two rotating rods 7 drive their respective scrapers 70 to rotate. Because the annular areas formed by the scrapers 70 overlap, the scrapers 70 on the two rotating rods 7 can complement each other during rotation, ensuring that no area is missed at the bottom of the mixing tank 1. This overlapping arrangement greatly improves the thoroughness of scraping off the bottom material, more effectively preventing material from settling and accumulating at the bottom of the mixing tank 1, reducing deviations in the water-cement ratio of the cement slurry, improving the mixing quality of the cement-based grout, and ensuring the smooth progress of secondary grouting projects.
[0052] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.
Claims
1. A cement mixing device with controllable time and temperature monitoring, characterized in that, It includes a mixing tank (1), a timing control switch and a power distribution box; the mixing tank (1) is equipped with a stirring shaft (2) and stirring blades (20) on the stirring shaft (2); the mixing tank (1) is equipped with a temperature sensor inside and a temperature display screen (3) is equipped on the outside of the mixing tank (1), and the temperature sensor is electrically connected to the temperature display screen (3); the power distribution box is electrically connected to the timing control switch and the timing control switch is electrically connected to the motor (5) that drives the stirring shaft (2) to rotate.
2. The cement mixing device with controllable time and temperature monitoring according to claim 1, characterized in that, The mixing tank (1) is provided with a limiting ring (11) inside. There are multiple limiting rings (11), which are arranged vertically along the inner wall of the mixing tank (1). The sensor is located in the protective area formed by the multiple limiting rings (11) and the inner wall of the mixing tank (1).
3. The cement mixing device with controllable time and temperature monitoring according to claim 1, characterized in that, The bottom of the mixing tank (1) is hinged with a discharge plate. The outer side wall of the mixing tank (1) is provided with a hinge hole. A hinge rod (6) is rotatably provided in the hinge hole. A handle rod (60) is vertically provided at the top of the hinge rod (6). A limiting rod (61) is vertically provided at the bottom of the hinge rod (6). The limiting rod (61) and the handle rod (60) are perpendicular to each other.
4. The cement mixing device with controllable time and temperature monitoring according to claim 1, characterized in that, The outer peripheral wall of the mixing tank (1) is provided with an annular groove (10), and a support frame (4) is engaged in the annular groove (10). An adjusting rod (40) is rotatably mounted on the support frame (4). The mixing shaft (2) and the motor (5) are both mounted on the adjusting rod (40).
5. The cement mixing device with controllable time and temperature monitoring according to claim 4, characterized in that, The end of the adjusting rod (40) extends outside the support frame (4). One end of the adjusting rod (40) is provided with a limiting handle (41). A pull rod (42) is slidably provided through the limiting handle (41). Two pull handles (420) are provided on the pull rod (42). The two pull handles (420) are located on both sides of the limiting handle (41). A spring is sleeved on a section of the pull rod (42) between the limiting handle (41) and the support frame (4). One end of the spring abuts against the pull handle (420), and the other end abuts against the limiting handle (41). The support frame (4) has a plurality of insertion holes arranged circumferentially for the pull rod (42) to be inserted.
6. The cement mixing device with controllable time and temperature monitoring according to claim 1, characterized in that, The stirring shaft (2) is also provided with spiral blades (21).
7. The cement mixing device with controllable time and temperature monitoring according to claim 1, characterized in that, The bottom of the stirring shaft (2) is provided with a rotating rod (7) that rotates radially. A torsion spring (71) is sleeved on the rotating rod (7). One end of the torsion spring (71) is connected to the rotating rod (7), and the other end is connected to the stirring shaft (2). Multiple scrapers (70) are arranged axially on the rotating rod (7).
8. The cement mixing device with controllable time and temperature monitoring according to claim 7, characterized in that, There are two rotating rods (7), and the two rotating rods (7) are symmetrically arranged; the annular area formed by the scraper (70) on one of the rotating rods (7) exactly overlaps with the annular area formed between two adjacent scrapers (70) on the other rotating rod (7).