Automatic charging barrel clamping mechanism and automatic charging barrel clamping device
By designing an automatic clamping mechanism of the barrel including a cylinder, a tie rod and a clamping block, the problem of manual in the prior art being unable to completely fix the barrel and thread lock easily loose, and the automatic stable fixation of the barrel and long-term locking are achieved.
Patent Information
- Application Number
- CN202421883071.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-05-02
- Estimated Expiration
- 2034-08-05
AI Technical Summary
The existing barrel clamping method has the problem that the barrel cannot be fully fixed manually, and the thread locking can easily lead to loosening during long-term operations.
An automatic clamping mechanism of the barrel is designed, including a cylinder, a fixing sleeve, a pull rod, a follow-up sleeve, a locking sleeve, a spring, an upper clamping block, a lower clamping block and a hinge shaft. The pull rod is driven by the cylinder to drive the locking sleeve and the clamping block to interact to achieve automatic locking and loosening.
The automatic locking and stable fixing of the barrel is achieved, which avoids the inadequacy of manual intervention, and maintains the locking state during long-term use, preventing loose work.
Smart Images

Figure CN222820828U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of barrel clamping, in particular to an automatic barrel clamping mechanism and an automatic barrel clamping device. Background Art
[0002] When clamping the barrel, the existing lifting and mixing equipment manually pushes the barrel into place and then manually locks the barrel on the equipment with a tightening mechanism. Manual locking has the problem of not being able to completely fix the barrel on the equipment due to insufficient human strength. Most traditional locking methods are thread locking, which also has the problem of being easily loosened due to long-term operation. Utility Model Content
[0003] The purpose of the utility model is to solve the problem that the existing barrel clamping method cannot manually fix the barrel completely on the equipment, and the thread locking is prone to loosening due to long-term operation, and thus provide an automatic barrel clamping mechanism and an automatic barrel clamping device.
[0004] The technical solution of the utility model is:
[0005] A barrel automatic clamping mechanism, the barrel automatic clamping mechanism comprises a cylinder 1, a fixed sleeve 2, a pull rod 3, a follower sleeve 4, a locking sleeve 5, a tension spring 6, an upper clamping block 7, a lower clamping block 8 and two hinge shafts 9, the head end of the pull rod 3 is coaxially slidably inserted in the inner hole of the fixed sleeve 2, the head end of the fixed sleeve 2 is connected to an external device fixing frame 100, the external device fixing frame 100 is also connected to the cylinder 1, the piston rod end of the cylinder 1 is connected to the head end of the pull rod 3 Connection, the end of the fixed sleeve 2 is coaxially and slidably inserted in the inner hole of the round sleeve 300 on the side of the barrel 200, the round sleeve 300 is connected to the barrel 200 through the support ear 400, the end of the pull rod 3 is coaxially and slidably inserted in the inner hole of the follower sleeve 4, the end of the pull rod 3 is connected to the locking sleeve 5, the head ends of the upper clamping block 7 and the lower clamping block 8 are respectively hinged to the end of the follower sleeve 4 through two hinge shafts 10, and the ends of the upper clamping block 7 and the lower clamping block 8 are connected by a tension spring 6.
[0006] Furthermore, a tie rod shoulder 10 is processed in the middle of the tie rod 3 , and when the upper clamping block 7 and the lower clamping block 8 are in a closed state, the tie rod shoulder 10 contacts the end surface of the first end of the follower sleeve 4 .
[0007] Furthermore, the upper clamping block 7 and the lower clamping block 8 are both semi-cylindrical structures. The upper clamping block 7 and the lower clamping block 8 are symmetrically arranged up and down with the axis of the follower sleeve 4 as the center. When the upper clamping block 7 and the lower clamping block 8 are in a closed state, a whole cylindrical structure is formed.
[0008] Furthermore, the outer side surface of the locking sleeve 5 is processed into a conical surface, and the lower surface front side of the upper clamping block 7 and the upper surface front side of the lower clamping block 8 are both processed into conical surfaces matching the locking sleeve 5 .
[0009] Furthermore, the end sides of the lower surface of the upper clamping block 7 and the upper surface of the lower clamping block 8 are both processed with tension spring assembly grooves, the upper end of the tension spring 6 is inserted into the tension spring assembly groove of the upper clamping block 7 and connected to the bottom of the groove, and the lower end of the tension spring 6 is inserted into the tension spring assembly groove of the lower clamping block 8 and connected to the bottom of the groove. When the upper clamping block 7 and the lower clamping block 8 are in a closed state, the tension spring 6 is completely placed in the cavity formed by the upper and lower tension spring assembly grooves.
[0010] Furthermore, the ends of the inner hole of the circular sleeve 300 are processed into conical surfaces, and the middle part of the fixed sleeve 2 is processed into a conical surface matching the end of the inner hole of the circular sleeve 300. When the upper clamping block 7 and the lower clamping block 8 are in an open state, the side surfaces of the upper clamping block 7 and the lower clamping block 8 form a conical surface matching the end of the inner hole of the circular sleeve 300.
[0011] Furthermore, the automatic barrel clamping mechanism further comprises a locking screw 11 , and the end of the pull rod 3 is connected to the locking sleeve 5 via the locking screw 11 .
[0012] Furthermore, the automatic clamping mechanism of the barrel also includes a gasket 12 and a limit sleeve 13. The gasket 12 is coaxially and slidably sleeved on the head end of the follower sleeve 4. The end of the fixed sleeve 2 is processed with a fixed sleeve shoulder, and the head end of the follower sleeve 4 is processed with a follower sleeve shoulder. The outer diameter of the gasket 12 and the end shaft section of the fixed sleeve 2 are equal. One end of the limit sleeve 13 is coaxially sleeved on the end shaft section of the fixed sleeve 2, and the limit sleeve 13 is fixedly connected to the fixed sleeve 2. The other end of the limit sleeve 13 is coaxially sleeved on the gasket 12, and the limit sleeve 13 is fixedly connected to the gasket 12.
[0013] The present invention also provides an automatic barrel clamping device, which includes an automatic barrel clamping mechanism 500 and an equipment fixing frame 100. The number of the automatic barrel clamping mechanisms 500 is two. A horizontally arranged equipment fixing frame 100 is provided on the side of the barrel 200. Two clamping mechanism assembly holes arranged symmetrically on the left and right are opened on the equipment fixing frame 100. Two horizontally symmetrically arranged automatic barrel clamping mechanisms 500 are respectively provided on the left and right sides of the barrel 200. The two automatic barrel clamping mechanisms 500 are respectively inserted into the two clamping mechanism assembly holes.
[0014] Furthermore, the clamping mechanism assembly holes vertically penetrate the front and rear end surfaces of the equipment fixing frame 100 , and the two clamping mechanism assembly holes are arranged in left-right symmetry with the axis of the barrel 200 as the center.
[0015] Compared with the prior art, the utility model has the following effects:
[0016] 1. The barrel automatic clamping device of the utility model can automatically lock the barrel 200 without manual intervention, and can ensure that the barrel 200 is in a locked state in any state. The barrel automatic clamping mechanism can always provide a clamping force after the barrel 200 is locked with the device.
[0017] 2. The barrel automatic clamping device of the utility model can effectively lock the barrel 200. By machining a conical surface at the first and last ends of the inner hole of the circular sleeve 300 and machining a conical surface on the outer side of the locking sleeve 5, the barrel 200 is pulled to the left under the action of the cylinder 1, so that the circular sleeve 300 on the barrel 200 moves to the left and fits with the cone on the fixed sleeve 2, and at the same time, the upper clamping block 7 and the lower clamping block 8 are opened upward and downward respectively with the hinge shaft 9 as the center of the circle under the action of relative displacement, and the opened upper clamping block 7 and the lower clamping block 8 fit with the conical surface of the inner hole end of the circular sleeve 300, thereby further locking the barrel 200. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a side view of the automatic barrel clamping device of the utility model (at this time, the barrel 200 is in a clamped state, and the upper and lower clamps are in an open state);
[0019] Figure 2 It is a side view of the automatic barrel clamping device of the utility model (at this time, the barrel 200 is in a non-clamping state, and the upper and lower clamps are in a closed state);
[0020] Figure 3 It is a top view of the automatic barrel clamping device of the utility model.
[0021] In the figure: 1. Cylinder; 2. Fixed sleeve; 3. Pull rod; 4. Follower sleeve; 5. Locking sleeve; 6. Tension spring; 7. Upper clamping block; 8. Lower clamping block; 9. Hinge shaft; 10. Pull rod shoulder; 11. Locking screw; 12. Washer ring; 13. Limit sleeve; 100. Equipment fixing frame; 200. Barrel; 300. Round sleeve; 400. Support ear; 500. Automatic clamping mechanism of barrel. DETAILED DESCRIPTION
[0022] Specific implementation method 1: Combination Figures 1 to 3The present embodiment is described. The present embodiment is an automatic barrel clamping mechanism, which includes a cylinder 1, a fixed sleeve 2, a pull rod 3, a follower sleeve 4, a locking sleeve 5, a tension spring 6, an upper clamping block 7, a lower clamping block 8 and two hinge shafts 9. The head end of the pull rod 3 is coaxially slidably inserted into the inner hole of the fixed sleeve 2. The head end of the fixed sleeve 2 is connected to an external device fixing frame 100. The external device fixing frame 100 is also connected to the cylinder 1. The piston rod end of the cylinder 1 is connected to the The front end of the pull rod 3 is connected, the rear end of the fixed sleeve 2 is coaxially and slidably inserted in the inner hole of the round sleeve 300 on the side of the barrel 200, and the round sleeve 300 is connected to the barrel 200 through the support ear 400. The rear end of the pull rod 3 is coaxially and slidably inserted in the inner hole of the follower sleeve 4, and the rear end of the pull rod 3 is connected to the locking sleeve 5. The front ends of the upper clamping block 7 and the lower clamping block 8 are respectively hinged to the rear end of the follower sleeve 4 through two hinge shafts 10, and the rear ends of the upper clamping block 7 and the lower clamping block 8 are connected through a tension spring 6.
[0023] Specific implementation method 2: Combination Figures 1 to 3 To explain this embodiment, the middle part of the tie rod 3 of this embodiment is processed with a tie rod shoulder 10. When the upper clamping block 7 and the lower clamping block 8 are in the closed state, the tie rod shoulder 10 contacts the end surface of the first end of the follower sleeve 4. In this way, by setting the tie rod shoulder 10 on the tie rod 3, after the discharge or mixing is completed, the cylinder 1 extends to drive the tie rod 3 to move to the right, and at the same time, the tie rod shoulder 10 of the tie rod 3 contacts the follower sleeve 4 to push the locking sleeve 5 to the right. The other components and connection relationships are the same as those of the first embodiment.
[0024] Specific implementation method three: Combination Figures 1 to 3 To explain this embodiment, the upper clamping block 7 and the lower clamping block 8 of this embodiment are both semi-cylindrical structures, and the upper clamping block 7 and the lower clamping block 8 are symmetrically arranged up and down with the axis of the follower sleeve 4 as the center. When the upper clamping block 7 and the lower clamping block 8 are in a closed state, a whole cylindrical structure is formed. Other components and connection relationships are the same as those of the specific embodiment 1 or 2.
[0025] Specific implementation method four: Combination Figures 1 to 3 To explain this embodiment, the locking sleeve 5 of this embodiment has its outer side processed into a conical surface, and the lower surface of the upper clamping block 7 and the upper surface of the lower clamping block 8 are both processed into conical surfaces matching the locking sleeve 5. With this arrangement, the barrel 200 is pulled leftward under the action of the cylinder 1, so that the round sleeve 300 on the barrel 200 moves leftward and fits with the cone on the fixed sleeve 2, thereby further locking the barrel 200. Other components and connection relationships are the same as those of the first, second or third embodiments.
[0026] Specific implementation method five: Combination Figures 1 to 3To explain this embodiment, the lower surface end side of the upper clamping block 7 and the upper surface end side of the lower clamping block 8 of this embodiment are processed with tension spring assembly grooves, the upper end of the tension spring 6 is inserted into the tension spring assembly groove of the upper clamping block 7 and connected to the bottom of the groove, and the lower end of the tension spring 6 is inserted into the tension spring assembly groove of the lower clamping block 8 and connected to the bottom of the groove. When the upper clamping block 7 and the lower clamping block 8 are in a closed state, the tension spring 6 is completely placed in the cavity formed by the upper and lower tension spring assembly grooves. With such a configuration, after the discharge or mixing is completed, the cylinder 1 extends out, driving the pull rod 3 to move to the right. Under the action of the tension spring 6, the upper clamping block 7 and the lower clamping block 8 can be closed downward and upward respectively with the hinge axis 9 as the center of the circle under the action of relative displacement. Other components and connection relationships are the same as those of the specific embodiments one, two, three or four.
[0027] Specific implementation method six: Combination Figures 1 to 3 To explain this embodiment, the inner hole of the circular sleeve 300 of this embodiment is processed into a conical surface at both ends, and the middle part of the fixed sleeve 2 is processed into a conical surface matching the inner hole of the circular sleeve 300. When the upper clamping block 7 and the lower clamping block 8 are in the open state, the side surfaces of the upper clamping block 7 and the lower clamping block 8 form a conical surface matching the inner hole of the circular sleeve 300. In this way, under the action of the cylinder 1, the barrel 200 is pulled to the left, so that the upper clamping block 7 and the lower clamping block 8 are opened upward and downward respectively with the hinge axis 9 as the center under the action of relative displacement. After opening, the upper clamping block 7 and the lower clamping block 8 fit with the conical surface of the inner hole of the circular sleeve 300, thereby further locking the barrel 200. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four or five.
[0028] Specific implementation method seven: Combination Figures 1 to 3 To explain this embodiment, the barrel automatic clamping mechanism of this embodiment further includes a locking screw 11, and the end of the pull rod 3 is connected to the locking sleeve 5 through the locking screw 11. In this way, the pull rod 3 and the locking sleeve 5 are connected by the locking screw 11, which is convenient for disassembly and installation. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five or six.
[0029] Specific implementation method eight: Combination Figures 1 to 3To explain this embodiment, the barrel automatic clamping mechanism of this embodiment further includes a backing ring 12 and a limiting sleeve 13. The backing ring 12 is coaxially and slidably sleeved on the head end of the follower sleeve 4. The end of the fixed sleeve 2 is processed with a fixed sleeve shaft shoulder, and the head end of the follower sleeve 4 is processed with a follower sleeve shaft shoulder. The outer diameter of the backing ring 12 and the end shaft section of the fixed sleeve 2 are equal. One end of the limiting sleeve 13 is coaxially sleeved on the end shaft section of the fixed sleeve 2. The limiting sleeve 13 is fixedly connected to the fixed sleeve 2. The other end of the limiting sleeve 13 is coaxially sleeved on the backing ring 12. The limiting sleeve 13 is fixedly connected to the backing ring 12. In this way, the limiting sleeve 13 is used to limit the maximum stroke of the follower sleeve 4 moving to the left. When the two ends of the limiting sleeve 13 are respectively against the fixed sleeve shaft shoulder and the follower sleeve shaft shoulder, the upper clamping block 7 and the lower clamping block 8 after opening are in contact with the conical surface of the inner hole end of the round sleeve 300, thereby further locking the barrel 200. The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth or seventh specific embodiments.
[0030] Specific implementation method nine: Combination Figures 1 to 3 The present embodiment is described. The present embodiment is an automatic barrel clamping device. The automatic barrel clamping device includes an automatic barrel clamping mechanism 500 and a device fixing frame 100. The number of the automatic barrel clamping mechanisms 500 is two. The side of the barrel 200 is provided with a horizontally arranged device fixing frame 100. The device fixing frame 100 is provided with two clamping mechanism assembly holes arranged symmetrically on the left and right sides. The left and right sides of the barrel 200 are respectively provided with two horizontally symmetrically arranged automatic barrel clamping mechanisms 500. The two automatic barrel clamping mechanisms 500 are respectively inserted into the two clamping mechanism assembly holes. With such a configuration, the automatic barrel clamping mechanisms exist on both sides of the barrel 200 at the same time, and the barrel 200 can be effectively fixed. Other components and connection relationships are the same as those of the specific embodiments one, two, three, four, five, six, seven or eight.
[0031] Specific implementation method ten: Combination Figures 1 to 3 To explain this embodiment, the clamping mechanism assembly holes of this embodiment vertically penetrate the front and rear end surfaces of the equipment fixing frame 100, and the two clamping mechanism assembly holes are arranged symmetrically with the axis of the barrel 200 as the center. Other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth embodiment.
[0032] How it works
[0033] Combination Figures 1 to 3 The working principle of the automatic barrel clamping device of the utility model is described as follows:
[0034] After placing the barrel 200 on the support rod, Figure 2As shown, at this time, the barrel 200 is in a non-clamping state, and the upper and lower clamps are in a closed state. After the barrel 200 is in place, the cylinder 1 contracts and drives the pull rod 3 to move to the left. At the same time, the pull rod 3 and the fixed sleeve 2 are on the same axis. At the same time, the pull rod 3 pulls the locking sleeve 5 to move to the left. Under the relative displacement of the locking sleeve 5 and the upper clamping block 7 and the lower clamping block 8, they open upward and downward with the hinge axis 9 as the center of the circle. The upper clamping block 7 and the lower clamping block 8 are opened to support the circular sleeve 300 on the barrel 200, as shown in FIG. Figure 1 As shown, the barrel 200 is in a clamped state, and the upper and lower clamps are in an open state. Under the action of the cylinder 1, the barrel 200 is pulled to the left at the same time, so that the round sleeve 300 on the barrel 200 moves to the left and fits with the cone on the fixed sleeve 2, further locking the barrel 200. The barrel automatic clamping mechanism exists on both sides of the barrel 200 at the same time, which can effectively fix the barrel 200.
[0035] When the discharge or mixing is completed, the cylinder 1 extends, driving the pull rod 3 to move to the right. At the same time, the pull rod 3 and the fixed sleeve 2 are on the same axis. At the same time, the pull rod shoulder 10 of the pull rod 3 contacts the follower sleeve 4 and pushes the locking sleeve 5 to the right. In this case, the locking sleeve 5 has a relative displacement with the upper clamping block 7 and the lower clamping block 8, and closes downward and upward respectively with the hinge axis 9 as the center under the action of the tension spring 6, ensuring that the size after closing is smaller than the fixed sleeve 2, so that the barrel 200 can be further pushed out from the barrel automatic clamping mechanism. Figure 2 As shown, at this time, the barrel 200 is in a non-clamping state, and the upper and lower clamps are in a closed state, and the barrel 200 can be easily disengaged from the barrel automatic clamping mechanism.
[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A barrel automatic clamping mechanism, characterized in that: The automatic barrel clamping mechanism comprises a cylinder (1), a fixed sleeve (2), a pull rod (3), a follower sleeve (4), a locking sleeve (5), a tension spring (6), an upper clamping block (7), a lower clamping block (8) and two hinge shafts (9). The head end of the pull rod (3) is coaxially and slidably inserted into the inner hole of the fixed sleeve (2). The head end of the fixed sleeve (2) is connected to an external device fixing frame (100). The external device fixing frame (100) is also connected to the cylinder (1). The piston rod end of the cylinder (1) is connected to the head end of the pull rod (3). The end of the fixed sleeve (2) is coaxially and slidably inserted into the inner hole of the round sleeve (300) on the side of the barrel (200), and the round sleeve (300) is connected to the barrel (200) through the support ear (400). The end of the pull rod (3) is coaxially and slidably inserted into the inner hole of the follower sleeve (4), and the end of the pull rod (3) is connected to the locking sleeve (5). The head ends of the upper clamping block (7) and the lower clamping block (8) are respectively hinged to the end of the follower sleeve (4) through two hinge shafts (9), and the ends of the upper clamping block (7) and the lower clamping block (8) are connected by a tension spring (6).
2. The automatic barrel clamping mechanism according to claim 1 is characterized in that: A pull rod shoulder (10) is machined in the middle of the pull rod (3). When the upper clamping block (7) and the lower clamping block (8) are in a closed state, the pull rod shoulder (10) contacts the end surface of the first end of the follower sleeve (4).
3. The automatic barrel clamping mechanism according to claim 2 is characterized in that: The upper clamping block (7) and the lower clamping block (8) are both semi-cylindrical structures. The upper clamping block (7) and the lower clamping block (8) are symmetrically arranged up and down with the axis of the follower sleeve (4) as the center. When the upper clamping block (7) and the lower clamping block (8) are in a closed state, a whole cylindrical structure is formed.
4. The automatic barrel clamping mechanism according to claim 3 is characterized in that: The outer side surface of the locking sleeve (5) is processed into a conical surface, and the lower surface front side of the upper clamping block (7) and the upper surface front side of the lower clamping block (8) are both processed into conical surfaces matching the locking sleeve (5).
5. The automatic barrel clamping mechanism according to claim 4 is characterized in that: The end of the lower surface of the upper clamping block (7) and the end of the upper surface of the lower clamping block (8) are both processed with tension spring assembly grooves, the upper end of the tension spring (6) is inserted into the tension spring assembly groove of the upper clamping block (7) and connected to the bottom of the groove, and the lower end of the tension spring (6) is inserted into the tension spring assembly groove of the lower clamping block (8) and connected to the bottom of the groove. When the upper clamping block (7) and the lower clamping block (8) are in a closed state, the tension spring (6) is completely placed in a cavity formed by the upper and lower tension spring assembly grooves.
6. The automatic barrel clamping mechanism according to claim 5, characterized in that: The inner hole of the circular sleeve (300) is processed into conical surfaces at both ends, and the middle part of the fixed sleeve (2) is processed into a conical surface matching the inner hole of the circular sleeve (300). When the upper clamping block (7) and the lower clamping block (8) are in an open state, the side surfaces of the upper clamping block (7) and the lower clamping block (8) form a conical surface matching the inner hole of the circular sleeve (300).
7. The automatic barrel clamping mechanism according to claim 6, characterized in that: The automatic barrel clamping mechanism also includes a locking screw (11), and the end of the pull rod (3) is connected to the locking sleeve (5) through the locking screw (11).
8. The automatic barrel clamping mechanism according to claim 7, characterized in that: The automatic barrel clamping mechanism also includes a gasket (12) and a limiting sleeve (13). The gasket (12) is coaxially and slidably sleeved on the head end of the follower sleeve (4). The end of the fixed sleeve (2) is processed with a fixed sleeve shaft shoulder, and the head end of the follower sleeve (4) is processed with a follower sleeve shaft shoulder. The outer diameters of the gasket (12) and the end shaft sections of the fixed sleeve (2) are equal. One end of the limiting sleeve (13) is coaxially sleeved on the end shaft section of the fixed sleeve (2). The limiting sleeve (13) is fixedly connected to the fixed sleeve (2). The other end of the limiting sleeve (13) is coaxially sleeved on the gasket (12). The limiting sleeve (13) is fixedly connected to the gasket (12).
9. An automatic barrel clamping device, characterized in that: The automatic barrel clamping device comprises the automatic barrel clamping mechanism (500) and the equipment fixing frame (100) according to any one of claims 1 to 8, wherein the number of the automatic barrel clamping mechanisms (500) is two, and a horizontally arranged equipment fixing frame (100) is provided on the side of the barrel (200), and two clamping mechanism assembly holes arranged symmetrically on the left and right are opened on the equipment fixing frame (100), and two horizontally symmetrically arranged automatic barrel clamping mechanisms (500) are respectively provided on the left and right sides of the barrel (200), and the two automatic barrel clamping mechanisms (500) are respectively inserted into the two clamping mechanism assembly holes.
10. The automatic barrel clamping device according to claim 9, characterized in that: The clamping mechanism assembly hole vertically penetrates the front and rear end surfaces of the equipment fixing frame (100), and the two clamping mechanism assembly holes are arranged in left-right symmetry with the axis of the barrel (200) as the center.