A dry-mix mortar transport vehicle

Abstract

The present application relates to the field of mortar transportation, in particular to a dry-mixed mortar transportation vehicle, comprising a front frame and a storage barrel fixedly installed on the front frame, further comprising a rear frame, a horizontal extruder and a vertical lifting mechanism, the dry-mixed mortar transportation vehicle can drive the storage barrel to overturn and place on the rear frame through the front frame, so that the liquid outlet pipe is located at the top of the storage barrel, when the mortar is extruded, the mortar is uniformly extruded along the liquid outlet pipe, and the extruding mechanism is pushed in this way instead of using the frame to push the extruding mechanism, the required pulling force of the lifting mechanism is reduced, and after the tires of the frame contact the ground, the worker slides the sliding clamping mechanism to be clamped with the clamping plate, then the worker drives the lifting mechanism, the lifting mechanism pulls the frame upward, the sliding clamping mechanism is driven by the frame to move upward, and the mortar is extruded along the liquid outlet pipe of the storage barrel, so that all the mortar in the storage barrel can be extruded.

Description

Technical Field

[0001] This invention relates to the field of mortar transportation, and specifically to a dry-mixed mortar transport vehicle. Background Technology

[0002] After dry-mixed mortar is mixed with water, it forms mortar. At this point, the mortar needs to be loaded into a transport vehicle and then moved to a designated location for spraying onto walls or floors. However, if a pump is used to extract the mortar during spraying, the pump may malfunction. Therefore, the traditional method is to use an extrusion mechanism to extrude the mortar. However, during horizontal extrusion, because the outlet pipe is located at the bottom front of the storage tank, a large amount of mortar is extruded at the beginning, and then less and less. When spraying onto the wall, this results in uneven spraying. Summary of the Invention

[0003] The purpose of this invention is to provide a dry-mixed mortar transport vehicle.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A dry-mixed mortar transport vehicle is provided, including a front frame and a storage bin fixedly mounted on the front frame. The storage bin is equipped with an extrusion mechanism for extruding mortar. A liquid outlet pipe is installed at the bottom front end of the storage bin. The vehicle also includes a rear frame, a horizontal extruder, and a vertical lifting mechanism. One side of the rear frame is hinged to one side of the front frame, allowing the front frame to rotate 90 degrees along the hinge. A support limiting tube is provided on the rear frame to support the rotated front frame. The horizontal extruder is fixedly mounted on the rear frame and is used to horizontally push the extrusion mechanism, causing the extrusion mechanism to extrude mortar inside the storage bin. The vertical lifting mechanism is fixedly mounted on the rear frame and is used to horizontally lift the rear frame.

[0006] Furthermore, the vertical lifting mechanism includes a frame, a first guide column, a first guide seat, and a lifting mechanism. The first guide seat is fixedly installed on the rear frame, the first guide column is slidably connected to the first guide seat, the frame is fixedly installed at the bottom of the first guide column, and the lifting mechanism is fixedly installed on the rear frame to drive the frame to perform lifting and lowering movements.

[0007] Furthermore, a sliding snap-fit ​​mechanism is provided on the frame, and a snap-fit ​​plate is provided on the extrusion mechanism to snap into the sliding snap-fit ​​mechanism. The sliding snap-fit ​​mechanism is located between the snap-fit ​​plate and the orthographic projection of the tire of the rear frame.

[0008] Furthermore, the sliding snap-fit ​​mechanism includes a snap-fit ​​tube, a slide block, and a slide rail. The slide rail is fixedly installed on the frame via an installation tube. The slide block is slidably connected to the slide rail. The snap-fit ​​tube is fixedly installed on the slide block. Limiting plates are provided on both sides of the slide rail, and the limiting plates are fixedly installed on the frame.

[0009] Furthermore, the lifting mechanism includes a first stud, a helical tube, a rotating column, a first bevel gear, and a second bevel gear. One end of the first stud is fixedly connected to the bottom of the frame. The helical tube meshes with the first stud. The helical tube is fixedly mounted on the rear frame via a swivel. The rotating column is fixedly mounted on the rear frame via a swivel. The first bevel gear is fixedly mounted on the helical tube. The second bevel gear is fixedly mounted on the rotating column. The second bevel gear meshes with the first bevel gear.

[0010] Furthermore, the horizontal extruder includes a second stud, a screw plate, a pusher, a second guide post, and a second guide seat. The second guide post is fixedly installed on the rear frame, and the second guide seat is slidably connected to the second guide post. The second stud is rotatably installed on the rear frame via a swivel, the screw plate is meshed with the second stud, and the pusher is fixedly connected to the second guide seat and the screw plate.

[0011] Furthermore, the extrusion mechanism includes an extrusion plate, a pusher, and a connecting plate. The extrusion plate is located inside the storage bin, and the outer edge of the extrusion plate is in contact with the inner edge of the storage bin. One end of the pusher is fixedly connected to the extrusion plate, and the connecting plate is fixedly installed on the other end of the pusher. A guide tube that is slidably connected to the pusher is provided on the storage bin.

[0012] Furthermore, the storage hopper includes a cylindrical body, two cylindrical covers respectively covering both ends of the cylindrical body, an arc-shaped slide rail fixedly installed on the cylindrical covers, an arc-shaped cylindrical cover and an arc-shaped sliding plate. The arc-shaped sliding plate is slidably connected to the arc-shaped slide rail, the arc-shaped cylindrical cover is fixedly installed on the inner side of the arc-shaped sliding plate, and the arc-shaped cylindrical cover covers the outer edge of the cylindrical body. An arc-shaped groove is provided on the cylindrical body for the arc-shaped cylindrical cover to close.

[0013] The beneficial effects of the present invention are as follows: The dry mortar transport vehicle can drive the storage bucket to be flipped and placed on the rear frame through the front frame, so that the liquid outlet pipe is located at the top of the storage bucket. When the mortar is extruded, the mortar is evenly extruded along the liquid outlet pipe. In this way, the extrusion mechanism is pushed instead of the frame, which reduces the pulling force required by the lifting mechanism and thus increases the service life of the lifting mechanism.

[0014] After the tires of the frame contact the ground, the worker slides the sliding clamping mechanism to engage with the clamping plate. Then, the worker drives the lifting mechanism to pull the frame upward, which in turn causes the frame to move the sliding clamping mechanism upward. The sliding clamping mechanism pushes the clamping plate upward, and the clamping plate drives the extrusion mechanism to continue to extrude the mortar inside the storage bucket. This causes the mortar to be squeezed out along the liquid outlet pipe of the storage bucket, ensuring that all the mortar inside the storage bucket can be squeezed out.

[0015] When the front and rear frames are parallel, the mortar in the storage tank can be squeezed out normally by the horizontal extruder and sprayed onto the ground. By switching between these two methods, the equipment can be easily pushed and transported when the front and rear frames are parallel. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below.

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0018] Figure 2 This is a three-dimensional structural diagram of the present invention in its changed state;

[0019] Figure 3 A three-dimensional structural diagram of the sliding latching mechanism;

[0020] Figure 4 for Figure 2 A magnified view of part A;

[0021] Figure 5 This is a three-dimensional structural diagram of a horizontal extruder;

[0022] Figure 6 This is a partial three-dimensional structural diagram of the present invention;

[0023] Figure 7 This is an exploded view of the three-dimensional structure of the storage bin;

[0024] In the diagram: 1. Front frame; 2. Rear frame; 2a. Support limiting tube; 3. Storage hopper; 3a. Cylinder; 3b. Arc-shaped cylinder cover; 3c. Arc-shaped sliding plate; 3d. Arc-shaped slide rail; 3e. Cylinder cover; 4. Extrusion mechanism; 4a. Clamping plate; 4b. Extrusion plate; 4c. Push column; 4d. Connecting plate; 5. Horizontal extruder; 5a. Second stud; 5b. Screw plate; 5c. Push frame; 5d. Second guide column; 5e. Second guide seat; 6. Vertical lifting mechanism; 6a. Frame; 6b. First guide column; 6c. First guide seat; 6d. Pulling mechanism; 6d1. First stud; 6d2. Screw tube; 6d3. Rotating column; 6d4. First bevel gear; 6d5. Second bevel gear; 6e. Sliding clamping mechanism; 6e1. Clamping tube; 6e2. Slide seat; 6e3. Slide rail. Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product.

[0027] Reference Figure 1 and Figure 2 The dry-mixed mortar transport vehicle shown includes a front frame 1 and a storage tank 3 fixedly mounted on the front frame 1. The storage tank 3 is equipped with an extrusion mechanism 4 for extruding mortar. A liquid outlet pipe is installed at the bottom front end of the storage tank 3. The vehicle also includes a rear frame 2, a horizontal extruder 5, and a vertical lifting mechanism 6. One side of the rear frame 2 is hinged to one side of the front frame 1, allowing the front frame 1 to rotate 90 degrees along the hinge. A support limiting tube 2a is provided on the rear frame 2 to support the rotated front frame 1. The horizontal extruder 5 is fixedly mounted on the front frame 1. The front frame 1 and rear frame 2 are fixedly mounted on the rear frame 2 and are used to horizontally push the extrusion mechanism 4, so that the extrusion mechanism 4 squeezes the mortar inside the storage bucket 3. The vertical lifting mechanism 6 is fixedly mounted on the rear frame 2 and is used to horizontally lift the rear frame 2. When lifting is required, the rear frame 2 is first rotated along the hinge, and then the vertical lifting mechanism 6 is driven to move, so that the vertical lifting mechanism 6 extends. Then, the front frame 1 and the rear frame 2 are rotated simultaneously by the worker using tools, so that the rear frame 2 is rotated from perpendicular to the ground to parallel to the ground, thus forming... Figure 2 The state.

[0028] In this invention, such as Figure 2 As shown, the vertical lifting mechanism 6 includes a frame 6a, a first guide column 6b, a first guide seat 6c, and a lifting mechanism 6d. The first guide seat 6c is fixedly mounted on the rear frame 2, the first guide column 6b is slidably connected to the first guide seat 6c, the frame 6a is fixedly mounted on the bottom of the first guide column 6b, and the lifting mechanism 6d is fixedly mounted on the rear frame 2 to drive the frame 6a to move up and down. Figure 4 As shown, the lifting mechanism 6d includes a first stud 6d1, a screw tube 6d2, a rotating column 6d3, a first bevel gear 6d4, and a second bevel gear 6d5. One end of the first stud 6d1 is fixedly connected to the bottom of the frame 6a. The screw tube 6d2 meshes with the first stud 6d1. The screw tube 6d2 is fixedly mounted on the rear frame 2 via a swivel. The rotating column 6d3 is fixedly mounted on the rear frame 2 via a swivel. The first bevel gear 6d4 is fixedly mounted on the screw tube 6d2. The second bevel gear 6d5 is fixedly mounted on the rotating column 6d3. The second bevel gear 6d5 meshes with the first bevel gear 6d4.

[0029] The rotating column 6d3 is provided with a slot for connecting to the handle. When the worker rotates the rotating column 6d3, the rotating column 6d3 will drive the second bevel gear 6d5 to rotate. The second bevel gear 6d5 will drive the first bevel gear 6d4 to rotate. The first bevel gear 6d4 will drive the solenoid 6d2 to rotate. The solenoid 6d2 will drive the first stud 6d1 to move up and down through meshing, so that the first stud 6d1 will drive the frame 6a to rise and fall.

[0030] By driving the lifting mechanism 6d to move, the lifting mechanism 6d will pull the frame 6a upward. After the frame 6a rises, the extrusion mechanism 4 will come into contact with the ground. Through gravity, the extrusion mechanism 4 will be squeezed, so that the extrusion mechanism 4 squeezes the mortar inside the storage tank 3, so that the mortar is squeezed out along the liquid outlet pipe. The extrusion mechanism 4 is driven in this way, instead of using the frame 6a to drive the extrusion mechanism 4, which reduces the pulling force required by the lifting mechanism 6d and thus increases the service life of the lifting mechanism 6d.

[0031] In this invention, such as Figure 2 As shown, a sliding engagement mechanism 6e is provided on the frame 6a, and a clamping plate 4a is provided on the extrusion mechanism 4 to engage with the sliding engagement mechanism 6e. The sliding engagement mechanism 6e is located between the clamping plate 4a and the orthographic projection of the tire of the rear frame 2. Figure 3 As shown, the sliding snap-fit ​​mechanism 6e includes a snap-fit ​​tube 6e1, a slide block 6e2, and a slide rail 6e3. The slide rail 6e3 is fixedly installed on the frame 6a through an installation tube. The slide block 6e2 is slidably connected to the slide rail 6e3. The snap-fit ​​tube 6e1 is fixedly installed on the slide block 6e2. Limiting plates are provided on both sides of the slide rail 6e3, and the limiting plates are fixedly installed on the frame 6a.

[0032] During the ascent of frame 6a, once the tires of the rear frame 2 contact the ground, the subsequent frame 6a continues to rise but cannot push the extrusion mechanism 4 by gravity. Therefore, the worker slides the sliding locking mechanism 6e to engage with the locking plate 4a.

[0033] By pushing the clamping tube 6e1, the clamping tube 6e1 is inserted into the bottom of the clamping plate 4a, thereby achieving the clamping connection. During the upward process, the friction between the clamping tube 6e1 and the clamping plate 4a prevents them from separating. In order to strengthen the support of the clamping tube 6e1, two slide rails 6e3 and slide blocks 6e2 can be set to support both ends of the clamping tube 6e1.

[0034] At this point, the worker drives the lifting mechanism 6d, which pulls the frame 6a upward. This causes the frame 6a to move the sliding locking mechanism 6e upward, which in turn pushes the pallet 4a upward. The pallet 4a then drives the extrusion mechanism 4 to continue extruding the mortar inside the storage bucket 3, causing the mortar to be squeezed out along the liquid outlet pipe of the storage bucket 3. The sliding locking mechanism 6e is positioned between the pallet 4a and the projected image of the tire of the rear frame 2 to indicate to the worker that the sliding locking mechanism 6e and the pallet 4a are not locked together. If the sliding locking mechanism 6e is not locked together with the pallet 4a, it will come into contact with the tire during the upward movement of the frame 6a, causing a problem for the worker. The frame 6a will not rise too high, allowing the worker to quickly adjust and lock the pallet 4a and the sliding locking mechanism 6e together.

[0035] In this invention, such as Figure 5 As shown, the horizontal extruder 5 includes a second stud 5a, a screw plate 5b, a pusher 5c, a second guide post 5d, and a second guide seat 5e. The second guide post 5d is fixedly mounted on the rear frame 2, and the second guide seat 5e is slidably connected to the second guide post 5d. The second stud 5a is rotatably mounted on the rear frame 2 via a swivel. The screw plate 5b is engaged with the second stud 5a, and the pusher 5c is fixedly connected to the second guide seat 5e and the screw plate 5b. A slot for connecting a handle is provided at the end of the second stud 5a. When the worker rotates the second stud 5a, the second stud 5a engages and pushes the screw plate 5b, which in turn drives the pusher 5c to move. The pusher 5c then drives the second guide seat 5e to slide on the second guide post 5d, thereby causing the pusher 5c to push the extrusion mechanism 4 to move, thus extruding the raw material in the storage bin 3 in a horizontal state.

[0036] In this invention, such as Figure 6 As shown, the extrusion mechanism 4 includes an extrusion plate 4b, a pusher 4c, and a connecting plate 4d. The extrusion plate 4b is located inside the storage bin 3, with its outer edge fitting against the inner edge of the storage bin 3. One end of the pusher 4c is fixedly connected to the extrusion plate 4b, and the connecting plate 4d is fixedly installed on the other end of the pusher 4c. The storage bin 3 is provided with a guide tube that is slidably connected to the pusher 4c. A clamping plate 4a is fixedly installed on the pusher 4c. By pushing the connecting plate 4d, the connecting plate 4d pushes the extrusion plate 4b through the pusher 4c, causing the extrusion plate 4b to squeeze the mortar inside the storage bin 3, thus extruding the mortar from the storage bin 3.

[0037] In this invention, such as Figure 7As shown, the storage bin 3 includes a cylindrical body 3a, two cylindrical covers 3e respectively covering both ends of the cylindrical body 3a, an arc-shaped slide rail 3d fixedly installed on the cylindrical covers 3e, an arc-shaped cylindrical cover 3b, and an arc-shaped sliding plate 3c. The arc-shaped sliding plate 3c is slidably connected to the arc-shaped slide rail 3d. The arc-shaped cylindrical cover 3b is fixedly installed on the inner side of the arc-shaped sliding plate 3c and covers the outer edge of the cylindrical body 3a. An arc-shaped groove is provided on the cylindrical body 3a for the arc-shaped cylindrical cover 3b to close. There can be two arc-shaped cylindrical covers 3b. By setting the two arc-shaped cylindrical covers 3b to move inward at the same time, more mortar can be stored inside the storage bin 3. After the mortar is full, the two arc-shaped cylindrical covers 3b are fixedly connected by using a clamp.

[0038] Implementation principle: The spray pipe is connected to the liquid outlet pipe, and another worker connects the handle to the end of the second stud 5a. When the worker rotates the handle, the second stud 5a will drive the screw plate 5b to move through the meshing. The screw plate 5b drives the pusher 5c to move, so that the pusher 5c drives the second guide seat 5e to slide on the second guide post 5d. This causes the pusher 5c to push the connecting plate 4d to move, which in turn pushes the extrusion plate 4b through the pusher 4c. The extrusion plate 4b then extrudes the mortar inside the storage tank 3, squeezing out the mortar. The extruded mortar is then squeezed out along the liquid outlet pipe, allowing the mortar to be sprayed onto the wall or the ground.

[0039] However, the above method can generally only be used on the ground. When spraying mortar on walls, as the mortar in storage bucket 3 gradually decreases, more mortar will be squeezed out at the beginning, and then less and less will be squeezed out, resulting in uneven spraying of the wall. Therefore:

[0040] The rotating column 6d3 is equipped with a slot for connecting to a handle. When the worker rotates the rotating column 6d3, the rotating column 6d3 will drive the second bevel gear 6d5 to rotate, the second bevel gear 6d5 will drive the first bevel gear 6d4 to rotate, the first bevel gear 6d4 will drive the screw tube 6d2 to rotate, and the screw tube 6d2 will drive the first stud 6d1 to move up and down through meshing. This causes the first stud 6d1 to drive the frame 6a to rise and fall. During the process of the frame 6a rising, the extrusion mechanism 4 will come into contact with the ground. Through gravity, the extrusion mechanism 4 will be squeezed, which will squeeze the mortar inside the storage tank 3 and cause the mortar to be squeezed out along the liquid outlet pipe. The extrusion mechanism 4 is driven in this way instead of by the frame 6a, which reduces the pulling force required by the lifting mechanism 6d, thereby increasing the service life of the lifting mechanism 6d, and making the amount of extruded mortar uniform, thus ensuring that it is uniform when sprayed onto the wall.

[0041] After the tires of the rear frame 2 contact the ground, the subsequent frame 6a continues to rise and cannot push the extrusion mechanism 4 by gravity. Therefore, the worker slides the sliding locking mechanism 6e to lock with the clamping plate 4a. Then, the worker drives the lifting mechanism 6d to pull the frame 6a upward, which in turn causes the frame 6a to move the sliding locking mechanism 6e upward. The sliding locking mechanism 6e will push the clamping plate 4a upward, and the clamping plate 4a will drive the extrusion mechanism 4 to continue to squeeze the mortar inside the storage tank 3, so that the mortar is squeezed out along the liquid outlet pipe of the storage tank 3.

Claims

1. A dry-mixed mortar transport vehicle, comprising a front frame (1) and a storage bin (3) fixedly mounted on the front frame (1), wherein the storage bin (3) is equipped with an extrusion mechanism (4) for extruding mortar, and a liquid outlet pipe is installed at the bottom front end of the storage bin (3), characterized in that, It also includes a rear frame (2), a horizontal extruder (5) and a vertical lifting mechanism (6). One side of the rear frame (2) is hinged to one side of the front frame (1), so that the front frame (1) can be rotated ninety degrees along the hinge. The rear frame (2) is provided with a support limiting tube (2a) for supporting the rotated front frame (1). The horizontal extruder (5) is fixedly installed on the rear frame (2) for horizontally pushing the extrusion mechanism (4) so ​​that the extrusion mechanism (4) extrudes the mortar inside the storage bucket (3). The vertical lifting mechanism (6) is fixedly installed on the rear frame (2) for horizontally lifting the rear frame (2). The vertical lifting mechanism (6) includes a frame (6a), a first guide column (6b), a first guide seat (6c), and a lifting mechanism (6d). The first guide seat (6c) is fixedly installed on the rear frame (2). The first guide column (6b) is slidably connected to the first guide seat (6c). The frame (6a) is fixedly installed at the bottom of the first guide column (6b). The lifting mechanism (6d) is fixedly installed on the rear frame (2) and is used to drive the frame (6a) to perform lifting and lowering movements. A sliding snap-fit ​​mechanism (6e) is provided on the frame (6a), and a snap-fit ​​plate (4a) is provided on the extrusion mechanism (4) to snap-fit ​​the sliding snap-fit ​​mechanism (6e). The sliding snap-fit ​​mechanism (6e) is located between the snap-fit ​​plate (4a) and the orthographic projection of the tire of the rear frame (2).

2. The dry-mixed mortar transport vehicle according to claim 1, characterized in that, The sliding snap-fit ​​mechanism (6e) includes a snap-fit ​​tube (6e1), a slide block (6e2), and a slide rail (6e3). The slide rail (6e3) is fixedly installed on the frame (6a) through the mounting tube. The slide block (6e2) is slidably connected to the slide rail (6e3). The snap-fit ​​tube (6e1) is fixedly installed on the slide block (6e2). Limiting plates are provided on both sides of the slide rail (6e3), and the limiting plates are fixedly installed on the frame (6a).

3. A dry-mixed mortar transport vehicle according to claim 2, characterized in that, The lifting mechanism (6d) includes a first stud (6d1), a helical tube (6d2), a rotating column (6d3), a first bevel gear (6d4), and a second bevel gear (6d5). One end of the first stud (6d1) is fixedly connected to the bottom of the frame (6a). The helical tube (6d2) meshes with the first stud (6d1). The helical tube (6d2) is fixedly mounted on the rear frame (2) via a swivel. The rotating column (6d3) is fixedly mounted on the rear frame (2) via a swivel. The first bevel gear (6d4) is fixedly mounted on the helical tube (6d2). The second bevel gear (6d5) is fixedly mounted on the rotating column (6d3). The second bevel gear (6d5) meshes with the first bevel gear (6d4).

4. A dry-mixed mortar transport vehicle according to claim 3, characterized in that, The horizontal extruder (5) includes a second stud (5a), a screw plate (5b), a pusher (5c), a second guide post (5d), and a second guide seat (5e). The second guide post (5d) is fixedly installed on the rear frame (2). The second guide seat (5e) is slidably connected to the second guide post (5d). The second stud (5a) is rotatably installed on the rear frame (2) through a swivel. The screw plate (5b) is meshed with the second stud (5a). The pusher (5c) is fixedly connected to the second guide seat (5e) and the screw plate (5b).

5. A dry-mixed mortar transport vehicle according to claim 4, characterized in that, The extrusion mechanism (4) includes an extrusion plate (4b), a pusher (4c), and a connecting plate (4d). The extrusion plate (4b) is located inside the storage bin (3). The outer edge of the extrusion plate (4b) is in contact with the inner edge of the storage bin (3). One end of the pusher (4c) is fixedly connected to the extrusion plate (4b). The connecting plate (4d) is fixedly installed on the other end of the pusher (4c). The storage bin (3) is provided with a guide tube that is slidably connected to the pusher (4c).

6. A dry-mixed mortar transport vehicle according to claim 5, characterized in that, The storage bin (3) includes a cylinder (3a), two cylinder covers (3e) respectively covering both ends of the cylinder (3a), an arc-shaped slide rail (3d) fixedly installed on the cylinder cover (3e), an arc-shaped cylinder cover (3b) and an arc-shaped slide plate (3c). The arc-shaped slide plate (3c) is slidably connected to the arc-shaped slide rail (3d). The arc-shaped cylinder cover (3b) is fixedly installed on the inner side of the arc-shaped slide plate (3c) and covers the outer edge of the cylinder (3a). An arc-shaped groove is provided on the cylinder (3a) for the arc-shaped cylinder cover (3b) to be closed.

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