CN113666106B - High stability crucible conveying mechanical claw - Google Patents
High stability crucible conveying mechanical claw Download PDFInfo
- Publication number
- CN113666106B CN113666106B CN202110973023.0A CN202110973023A CN113666106B CN 113666106 B CN113666106 B CN 113666106B CN 202110973023 A CN202110973023 A CN 202110973023A CN 113666106 B CN113666106 B CN 113666106B
- Authority
- CN
- China
- Prior art keywords
- crucible
- hyperbolic
- radial
- claw
- roller
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G47/00—Article or material-handling devices associated with conveyors; Methods employing such devices
- B65G47/74—Feeding, transfer, or discharging devices of particular kinds or types
- B65G47/90—Devices for picking-up and depositing articles or materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G47/00—Article or material-handling devices associated with conveyors; Methods employing such devices
- B65G47/74—Feeding, transfer, or discharging devices of particular kinds or types
- B65G47/90—Devices for picking-up and depositing articles or materials
- B65G47/905—Control arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The invention discloses a high-stability crucible conveying mechanical claw, and belongs to the technical field of crucible mechanical claws. The device comprises a frame plate and a piston cylinder arranged on the frame plate; the bottom of the frame plate is provided with four claw plates in axial symmetry, the claw plates are provided with elastic rolling claws which can stretch and retract along the radial direction of the conical crucible, the end part of an output rod of the piston cylinder is provided with a sliding sleeve in a sliding way, an axial spring is arranged in the sliding sleeve, and the other end of the sliding sleeve is fixedly provided with a hyperbolic cone; the elastic rolling claw comprises a radial sliding plate, a radial spring baffle, a roller shaft and a curve roller. The crucible conveying mechanical claw has a simple and reasonable structure, and improves the crucible clamping stability by carrying out circumferential eight-point rolling friction clamping and axially pressing the end part of the conical crucible.
Description
Technical Field
The invention mainly relates to the technical field of crucible mechanical claws, in particular to a high-stability crucible conveying mechanical claw.
Background
The conical crucible is widely applied to industrial analysis, particularly the coal industry, and the automatic conveying of the conical crucible becomes a development trend along with the improvement of an automatic technology. Crucible conveying in the prior art usually has two modes, one mode is a push rod manipulator, namely the crucible is jacked up by a push rod for conveying; the other method is that a motor drives two metal sheets to form two linear contact clamping crucibles, and then the crucibles are conveyed. The crucible clamping in the prior art all leads to the following disadvantages: due to the geometrical characteristics of the conical crucible, the conical crucible is easy to vibrate in the clamping or loosening process and easy to shake in the rapid conveying process, namely the conveying stability of the conical crucible is not high. Therefore, it is highly desirable to design a crucible conveying gripper with high stability.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: aiming at the technical problems in the prior art, the invention provides the crucible conveying mechanical claw which is simple and reasonable in structure and improves the crucible clamping stability by carrying out circumferential eight-point rolling friction clamping and axially pressing the end part of the conical crucible.
In order to solve the problems, the solution proposed by the invention is as follows: a high-stability crucible conveying mechanical claw comprises a frame plate and a piston cylinder arranged on the frame plate.
And an output rod of the piston cylinder is collinear with the axis of the conical crucible.
The bottom of the frame plate is provided with four claw plates in axial symmetry, the claw plates are provided with elastic rolling claws which can stretch and retract along the radial direction of the conical crucible, the end part of an output rod of the piston cylinder is provided with a sliding sleeve in a sliding manner, an axial spring is arranged in the sliding sleeve, and the other end of the sliding sleeve is fixedly provided with a hyperbolic cone; the radius of the lower bottom surface of the hyperbolic cone is equal to the outer radius of the upper end surface of the conical crucible.
The elastic rolling claw comprises a radial sliding plate, a radial spring baffle plate, a roller shaft and a curved roller, wherein the radial sliding plate penetrates through the claw plate along the radial direction of the conical crucible, the radial spring is sleeved on the radial sliding plate, the radial spring baffle plate is fixedly arranged on one end, away from the conical crucible, of the radial sliding plate, the roller shaft is rotatably arranged on one end, close to the conical crucible, of the radial sliding plate, and the curved roller is fixedly arranged on the roller shaft.
Two ends of the radial spring are respectively connected with the radial spring baffle and the claw plate, and the radial spring is always in a stretching stress state; the curve rollers are composed of hyperbolic half rollers A and hyperbolic half rollers B which are identical in structure, and the hyperbolic half rollers A and the hyperbolic half rollers B are symmetrically arranged on two sides of the radial sliding plate; and the generatrix of a rolling surface formed by the hyperbolic half rollers A and the hyperbolic half rollers B is a hyperbolic curve.
The axial spring is a tension and compression spiral spring, and two ends of the axial spring are respectively connected with the output rod in the piston cylinder and the hyperbolic cone.
Further, the material of the hyperbolic cone is Teflon.
Further, the deformation amount of the axial spring in the working process of the piston cylinder is not more than one half of the radius of the curve roller.
Further, the curved roller keeps two-point contact when rolling up and down along the outer surface of the conical crucible.
Furthermore, the output rod of the piston cylinder is the longest, and when the deformation of the axial spring is zero, the curve roller is positioned in the middle of the hyperbolic cone.
Compared with the prior art, the invention has the following advantages and beneficial effects: the high-stability crucible conveying mechanical claw is provided with four elastic rolling claws, and each elastic rolling claw also comprises a curve roller consisting of a double-curve half roller A and a double-curve half roller B, so that a circumferential eight-point contact stress state is formed when the crucible conveying mechanical claw grips a conical crucible, and the stress symmetry and stability are improved; the axial spring can slightly deform, so that the axial acting force is absorbed during the initial action of extending or shortening the output rod of the piston cylinder, and the stability of grabbing and loosening the conical crucible is improved; in addition, the bottom of the hyperbolic cone is tightly pressed on the top of the conical crucible all the time in the conveying process of the conical crucible, so that the conical crucible is effectively prevented from shaking in the conveying process, and the materials in the conical crucible are prevented from being scattered. Therefore, the crucible conveying mechanical claw has a simple and reasonable structure, and improves the crucible clamping stability by carrying out circumferential eight-point rolling friction clamping and axially pressing the end part of the conical crucible.
Drawings
FIG. 1 is a schematic diagram of the structural principle of a high-stability crucible conveying mechanical claw.
Fig. 2 is a schematic plan view of four resilient rolling pawls in the present invention.
In the figure, 1-a conical crucible; 2-frame plate; 21-claw plate; 3-elastic rolling claw; 31-radial spring retainer; 32-a radial spring; 33-a radial slide plate; 34-curved rollers; 341-hyperbolic half-roller a; 342-hyperbolic half roller B; 35-roller shaft; 4-a sliding sleeve; 5-axial spring; 6, a piston cylinder; 7-hyperbolic cone.
Detailed Description
The invention will be described in further detail with reference to the following figures and specific examples.
Referring to fig. 1 and 2, the crucible conveying gripper with high stability of the invention comprises a frame plate 2 and a piston cylinder 6 arranged on the frame plate 2.
The output rod of the piston cylinder 6 is collinear with the axis of the conical crucible 1.
Four claw plates 21 are axially symmetrically arranged at the bottom of the frame plate 2, elastic rolling claws 3 which can stretch and retract along the radial direction of the conical crucible 1 are arranged on the claw plates 21, a sliding sleeve 4 is arranged at the end part of an output rod of the piston cylinder 6 in a sliding manner, an axial spring 5 is arranged in the sliding sleeve 4, and a hyperbolic cone 7 is fixedly arranged at the other end of the sliding sleeve 4. The radius of the lower bottom surface of the hyperbolic cone 7 is equal to the outer radius of the upper end surface of the conical crucible 1, so that the elastic rolling claws 3 can smoothly roll from the surface of the hyperbolic cone 7 to the surface of the conical crucible 1.
The elastic rolling jaw 3 comprises a radial sliding plate 33 passing through the jaw plate 21 along the radial direction of the conical crucible 1, a radial spring 32 sleeved on the radial sliding plate 33, a radial spring baffle plate 31 fixedly arranged on one end of the radial sliding plate 33 far away from the conical crucible 1, a roller shaft 35 rotatably arranged on one end of the radial sliding plate 33 close to the conical crucible 1, and a curve roller 34 fixedly arranged on the roller shaft 35. The cross section of the radial sliding plate 33 is rectangular, so that the radial sliding plate 33 can be effectively prevented from rotating during sliding, namely the rigidity value of the radial spring 32 cannot be changed when the radial sliding plate 33 slides; the radial sliding plate 33 is made of teflon, so that sliding friction force and sliding noise can be reduced; the curve roller 34 is made of non-metal material, and the friction coefficient of the curve roller is not less than twice of the friction coefficient of the Teflon so as to ensure that the curve roller 34 rolls on the conical crucible 1.
Two ends of the radial spring 32 are respectively connected with the radial spring baffle 31 and the claw plate 21, and the radial spring 32 is always in a stretching stress state; the curved rollers 34 are composed of hyperbolic half rollers a341 and hyperbolic half rollers B342 which have the same structure, and the hyperbolic half rollers a341 and the hyperbolic half rollers B342 are symmetrically positioned on two sides of the radial sliding plate 33; the generatrix of the rolling surface formed by the hyperbolic half roller A341 and the hyperbolic half roller B342 is a hyperbola. The radial sliding plate 33 tends to move towards the tapered crucible 1 under the pulling force of the radial spring 32, and the radial pressure of the curve roller 34 on the tapered crucible 1 is in direct proportion to the deformation of the radial spring 32; when the curved roller 34 rolls up and down along the hyperbolic cone 7 or the conical crucible 1, the radial sliding plate 33 slides in the radial direction of the conical crucible 1.
The axial spring 5 is a tension and compression spiral spring, and two ends of the axial spring are respectively connected with an output rod and a hyperbolic cone 7 in the piston cylinder 6. The output rod of the piston cylinder 6 moves up and down, and drives the hyperbolic cone 7 to move up and down through the axial spring 5, so as to drive the curved roller 34 to move along the radial direction of the conical crucible 1.
Preferably, the material of the hyperbolic cone 7 is teflon, which on the one hand reduces the rolling friction between the curved roller 34 and the hyperbolic cone 7 and on the other hand eliminates rolling noise. The hyperbolic character of the hyperbolic cone 7 on the one hand helps the curvilinear roller 34 to return to the initial state of the axial spring 5 at the minimum of potential energy and on the other hand makes it possible to make the curvilinear roller 34 easily roll from the hyperbolic cone 7 onto the outer surface of the tapered crucible 1.
Preferably, the deformation amount of the axial spring 5 in the operation process of the piston cylinder 6 is not more than one half of the radius of the curve roller 34, so that the lower end face of the hyperbolic cone 7 is tightly pressed on the upper end of the conical crucible 1 when the elastic rolling claw 3 clamps the conical crucible 1, the shaking of the conical crucible 1 caused by external vibration in the transportation process of the conical crucible 1 is reduced, and the stability of the conical crucible 1 is improved.
Preferably, the curved roller 34 maintains two-point contact while rolling up and down along the outer surface of the tapered crucible 1. Therefore, when the four elastic rolling claws 3 simultaneously grip the tapered crucible 1, eight-point contact pressure can be formed to the tapered crucible 1, thereby improving the stability of the grip of the tapered crucible 1.
Preferably, the output rod of the piston cylinder 6 is the longest and the curved roller 34 is located at the middle of the hyperbolic cone 7 when the deformation amount of the axial spring 5 is zero.
The working process and the working principle of the invention are as follows: firstly, the crucible conveying mechanical claw is arranged on a mechanical arm, then the mechanical arm is adjusted to enable the mechanical claw to be positioned right above a conical crucible 1 to be conveyed, at the moment, an output rod of a piston cylinder 6 is the longest, the deformation of an axial spring 5 is zero, a curve roller 34 is just positioned in the middle of a hyperbolic cone 7, and the lower end face of the hyperbolic cone 7 is in free collision with the upper end of the conical crucible 1.
The crucible conveying mechanical claw is driven to descend by controlling the descending of the mechanical arm, meanwhile, the piston cylinder 6 is started to enable the output rod to retract slowly, the movement speed of the output rod in the piston cylinder 6 is equal to the descending speed of the mechanical claw, namely, the lower end face of the hyperbolic cone 7 always butts against the upper end of the conical crucible 1.
During the process that the output rod of the piston cylinder 6 is gradually retracted, the curve roller 34 rolls downwards along the generatrix of the hyperbolic cone 7, the radial sliding plate 33 moves towards the direction far away from the conical crucible 1, and the pressure of the radial spring 32 is gradually increased; then, the curved roller 34 rolls from the hyperbolic cone 7 to the outer surface of the conical crucible 1, and since the upper part of the conical crucible 1 is thick and the lower part is thin, when the curved roller 34 rolls on the generatrix of the conical crucible 1, the radial sliding plate 33 moves towards the direction close to the conical crucible 1, the pressure of the radial spring 32 is gradually reduced, but the curved roller 34 is still tightly pressed on the conical crucible 1.
When the output rod of the piston cylinder 6 reaches the shortest state, the curve roller 34 is positioned at the middle upper part of the conical crucible 1, and the piston cylinder 6 stops working. Because the diameter of the upper part of the conical crucible 1 is large, the diameter of the lower part of the conical crucible 1 is small, and the radial spring 32 is always in a stretching state, the curve roller 34 tends to roll downwards relative to the conical crucible 1, and at the moment, because the top of the conical crucible 1 is tightly pressed on the hyperbolic cone 7, the rolling friction force of the curve roller 34 can lock the conical crucible 1, and the axial sliding of the conical crucible 1 caused by external vibration is prevented.
When the mechanical arm drives the crucible conveying mechanical claw to convey the conical crucible 1 to a destination, namely the bottom surface of the conical crucible 1 is in a supporting state, for example, the bottom surface of the conical crucible 1 contacts a table top, the mechanical arm drives the crucible of the invention to move upwards, meanwhile, an output rod of the piston cylinder 6 extends outwards gradually, the speeds of the mechanical claw and the piston cylinder are the same, namely, the lower end surface of the hyperbolic cone 7 always butts against the upper end of the conical crucible 1.
During the process that the output rod of the piston cylinder 6 is gradually extended, the curve roller 34 rolls upwards along the conical crucible 1 until the curve roller rolls to the middle part of the hyperbolic cone 7, namely the output rod reaches the longest state. Thereby completing the conveyance of the tapered crucible 1.
In the conveying process of the conical crucible 1, although the mechanical arm moves, the conical crucible 1 is stressed at eight points on the same circumference, and the lower end face of the hyperbolic cone 7 is always pressed against the upper end of the conical crucible 1 under the action of the axial spring 5, so that the conical crucible 1 cannot shake, and the scattering of materials in the conical crucible 1 is avoided. When the crucible conveying mechanical claw is in a non-working state, the curve roller 34 is just positioned in the middle of the hyperbolic cone 7; the axial spring 5 respectively generates tensile deformation and compression deformation in the up-and-down movement process of an output rod of the piston cylinder 6, so that the surplus energy of the conical crucible 1 during grabbing and releasing placement can be absorbed, and the stability during grabbing or releasing is improved.
The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that are not thought of through creative efforts should fall within the scope of the present invention.
Claims (3)
1. The utility model provides a high stability crucible conveying mechanical gripper, includes frame plate (2) and installs piston cylinder (6) on frame plate (2), its characterized in that:
the output rod of the piston cylinder (6) is collinear with the axis of the conical crucible (1);
four claw plates (21) are axially symmetrically arranged at the bottom of the frame plate (2), elastic rolling claws (3) which can stretch and retract along the radial direction of the conical crucible (1) are arranged on the claw plates (21), a sliding sleeve (4) is arranged at the end part of an output rod of the piston cylinder (6) in a sliding manner, an axial spring (5) is arranged in the sliding sleeve (4), and a hyperbolic cone (7) is fixedly arranged at the other end of the sliding sleeve (4); the radius of the lower bottom surface of the hyperbolic cone (7) is equal to the outer radius of the upper end surface of the conical crucible (1);
the elastic rolling claw (3) comprises a radial sliding plate (33) which penetrates through the claw plate (21) along the radial direction of the conical crucible (1), a radial spring (32) sleeved on the radial sliding plate (33), a radial spring baffle plate (31) fixedly arranged on one end, far away from the conical crucible (1), of the radial sliding plate (33), a roller shaft (35) rotatably arranged on one end, close to the conical crucible (1), of the radial sliding plate (33), and a curved roller (34) fixedly arranged on the roller shaft (35);
two ends of the radial spring (32) are respectively connected with the radial spring baffle (31) and the claw plate (21), and the radial spring (32) is always in a stretching stress state; the curved rollers (34) are composed of hyperbolic half rollers A (341) and hyperbolic half rollers B (342) which are identical in structure, and the hyperbolic half rollers A (341) and the hyperbolic half rollers B (342) are symmetrically arranged on two sides of the radial sliding plate (33); the generatrix of a rolling surface formed by the hyperbolic half roller A (341) and the hyperbolic half roller B (342) is a hyperbolic curve;
the axial spring (5) is a tension and compression spiral spring, and two ends of the axial spring are respectively connected with an output rod in the piston cylinder (6) and the hyperbolic cone (7);
the curved roller (34) keeps two-point contact when rolling up and down along the outer surface of the conical crucible (1); the output rod of the piston cylinder (6) is the longest, and when the deformation of the axial spring (5) is zero, the curve roller (34) is positioned in the middle of the hyperbolic cone (7).
2. The high-stability crucible conveying mechanical claw as claimed in claim 1, wherein: the hyperbolic cone (7) is made of Teflon.
3. The high-stability crucible conveying mechanical claw as claimed in claim 1, wherein: the deformation of the axial spring (5) in the working process of the piston cylinder (6) does not exceed one half of the radius of the curve roller (34).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110973023.0A CN113666106B (en) | 2021-08-24 | 2021-08-24 | High stability crucible conveying mechanical claw |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110973023.0A CN113666106B (en) | 2021-08-24 | 2021-08-24 | High stability crucible conveying mechanical claw |
Publications (2)
Publication Number | Publication Date |
---|---|
CN113666106A CN113666106A (en) | 2021-11-19 |
CN113666106B true CN113666106B (en) | 2022-11-08 |
Family
ID=78545408
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110973023.0A Active CN113666106B (en) | 2021-08-24 | 2021-08-24 | High stability crucible conveying mechanical claw |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113666106B (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114633271B (en) * | 2022-03-10 | 2024-04-16 | 常州大学 | Flexible clamping manipulator with gear self-locking function |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107932532A (en) * | 2017-12-05 | 2018-04-20 | 常州大学 | A kind of crucible available for high temperature furnace clamps special manipulator |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10194660A (en) * | 1997-01-14 | 1998-07-28 | Ginan Shatai Kogyo:Kk | Separation device of article |
JP6509937B2 (en) * | 2017-04-28 | 2019-05-08 | 昭和電工株式会社 | Cylindrical body holding method |
CN108526981B (en) * | 2018-05-21 | 2024-06-04 | 杭州职业技术学院 | Mechanical claw opening and closing mechanism |
CN209193043U (en) * | 2018-12-11 | 2019-08-02 | 宁夏富乐德石英材料有限公司 | Quartz glass crucibles clamp device |
CN109799198B (en) * | 2018-12-19 | 2021-08-03 | 江阴秋毫检测有限公司 | Soil heavy metal detection process |
CN110328681B (en) * | 2019-07-29 | 2020-04-14 | 南京涵铭置智能科技有限公司 | Clamping device and clamping method for industrial robot |
CN210791020U (en) * | 2019-08-28 | 2020-06-19 | 山东科技大学 | Industrial robot's centre gripping hand claw |
CN211217937U (en) * | 2019-09-03 | 2020-08-11 | 保山隆基硅材料有限公司 | Crucible loading and unloading device and crucible cleaning line |
CN112010027A (en) * | 2020-09-11 | 2020-12-01 | 天津环博科技有限责任公司 | Crucible carrying clamping jaw mechanism |
-
2021
- 2021-08-24 CN CN202110973023.0A patent/CN113666106B/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN107932532A (en) * | 2017-12-05 | 2018-04-20 | 常州大学 | A kind of crucible available for high temperature furnace clamps special manipulator |
Non-Patent Citations (1)
Title |
---|
一种新型铝锭码垛机械手的研究设计;马占义等;《新技术新工艺》;20090825(第08期);全文 * |
Also Published As
Publication number | Publication date |
---|---|
CN113666106A (en) | 2021-11-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN113666106B (en) | High stability crucible conveying mechanical claw | |
CN106271741B (en) | A kind of intelligent grip device of adaptive Workpiece length | |
CN205520347U (en) | Jump ring push in device | |
CN101372776B (en) | Improved structure of drafting device in ribbon lap machine | |
CN106272501B (en) | Toggle slide bar adaptive robot finger apparatus | |
CN207057339U (en) | Veneer reeling machine | |
CN206981647U (en) | A kind of reinforcing bar apparatus for correcting | |
CN206782754U (en) | One kind buffering conveying pressing wheel device | |
CN206633490U (en) | A kind of corrugated paper board paper-feeding mechanism | |
CN205952442U (en) | Automatic tin seamer accurate to heart is put to jar position | |
CN101117196B (en) | Hanger with steel-reel damage-proof function | |
CN106378763A (en) | Attachable core-driven double-head powder shaft sleeve pickup | |
CN208584232U (en) | A kind of fixed device of presser type for machining | |
CN208162125U (en) | A kind of machine driving chain cleaning device | |
CN106985032A (en) | A kind of structure-improved of the upper clamped beam of glass edge-grinding machine | |
JPS607868Y2 (en) | Advance intermittent feeding device for strip material | |
CN209565191U (en) | A kind of two-sided coating machine air lifter | |
CN213197201U (en) | Fixing device is used in processing of packagine machine sliding plate | |
CN213950337U (en) | Convenient to use's metallurgical hoist | |
CN221110582U (en) | Rubber roll sleeve retreating all-in-one machine | |
CN214418861U (en) | Finger for three-jaw cylinder and spinning paper tube matched with finger | |
CN216710826U (en) | Lifting device | |
CN208249470U (en) | A kind of automobile packing case holds bud device in the month with die-cutting machine | |
CN220316937U (en) | Full Bao Zhu slip ring | |
CN218753526U (en) | Transfer tool |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |