Mechanical arm clamping device for transformer maintenance
By designing the mechanical arm clamping device for transformer maintenance, and using the adjustment mechanism and clamping mechanism, flexible disassembly and assemble the internal components of the transformer, it solves the problem that maintenance personnel have difficulty entering the narrow space for maintenance and improves maintenance efficiency.
Patent Information
- Application Number
- CN202411891950.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-02-18
AI Technical Summary
During the transformer maintenance process, it is difficult for maintenance personnel to enter the narrow space inside the transformer to disassemble and assemble parts, resulting in the need to disassemble the entire transformer as a whole, which is limited in use and inefficient.
A mechanical arm clamping device for transformer maintenance is designed. By setting up an adjustment mechanism, the clamping mechanism is connected to the extension rod. Using mechanical structures such as screws, gears and worms, the inclination angle and opening direction of the clamp are adjusted to adapt to different angles. Disassemble and assemble the parts at the location.
This device can replace the arm of the maintenance personnel to enter the transformer and disassemble and assemble parts with narrow space, avoiding the need for overall disassembly and assembly, and significantly improving maintenance efficiency.
Smart Images
Figure CN119458408A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a transformer maintenance tool, in particular to a mechanical arm clamping device for transformer maintenance. Background Art
[0002] Large power transformers and switches are extremely important parts of the power supply system, and they often generate abnormal heat during operation. Due to the complex internal structure and high height of large power equipment, and the narrow gaps between adjacent components inside the transformer, maintenance personnel often encounter inspection points that are difficult to reach with their arms. For parts in narrow spaces, maintenance personnel need to disassemble the transformer as a whole for maintenance, which has a relatively single function and large limitations in use. Summary of the invention
[0003] The object of the present invention is to provide a mechanical arm clamping device for transformer maintenance to solve the problems raised in the above-mentioned background technology.
[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a mechanical arm clamping device for transformer maintenance, comprising an installation box, the middle part of the bottom surface of the installation box is fixedly connected to the upper end of a fixed cylinder, the inner upper end of the fixed cylinder is fixedly connected to the upper end of an electric push rod, the bottom end of the electric push rod is fixedly connected to the upper end of an extension rod, the upper end of the extension rod is sleeved in the fixed cylinder, a mounting hole is provided at the bottom end of the extension rod, slots are provided on the left and right sides of the bottom end of the mounting hole, an adjustment mechanism is provided in the mounting hole, the adjustment mechanism is connected to the clamping mechanism, and the electric push rod is electrically connected to a controller.
[0005] As a preferred technical solution of the present invention, the adjustment mechanism includes a fixing plate 1, the left and right ends of which are fixedly connected to the inner wall of the mounting hole, the middle part of the fixing plate 1 is rotatably connected to the threaded cylinder through a bearing, and a gear 1 is fixedly provided on the outer side surface of the threaded cylinder, and the gear 1 is meshingly connected to the gear 2.
[0006] As a preferred technical solution of the present invention, the gear 2 is fixedly arranged on the output shaft of the motor 1, the bottom end of the motor 1 is on the upper surface of the fixed plate 1, the threaded barrel is threadedly connected to the screw, the bottom end of the screw is fixedly connected to the upper surface of the fixed frame, and the front and rear side surfaces of the bottom end of the fixed frame are respectively fixedly connected to the front and rear ends of the connecting rod.
[0007] As a preferred technical solution of the present invention, the connecting rod is sleeved in the connecting frame, the bottom end of the connecting frame is fixedly connected to the upper end of the rotating plate, the middle part of the rotating plate is rotatably connected to the middle part of the rotating shaft through a bearing, the front and rear ends of the rotating shaft are fixedly connected to the inner wall of the mounting hole, and the rotating plate is simultaneously arranged corresponding to the two notches on the left and right.
[0008] As a preferred technical solution of the present invention, the bottom end of the rotating plate is fixedly connected to the upper surface of the fixed plate 2, the middle part of the bottom surface of the fixed plate 2 is rotatably connected to the upper end of the support shaft through a bearing, a worm gear is fixedly arranged on the lower side of the support shaft, the worm gear is meshingly connected to the worm, the left end of the worm is fixedly connected to the output shaft of the motor 2, and the motor 2 is fixedly connected to the bottom surface of the fixed plate 2 through a mounting seat.
[0009] As a preferred technical solution of the present invention, the upper end of the support shaft is sleeved in a sleeve, the upper end of the sleeve is fixedly connected to the bottom surface of the fixed plate 2, a conductive slip ring is fixedly provided on the outer side surface of the sleeve, and the conductive slip ring, motor 2 and motor 1 are all electrically connected to the controller.
[0010] As a preferred technical solution of the present invention, the clamping mechanism includes a support frame, the middle part of the upper surface of the support frame is fixedly connected to the bottom end of the support shaft, and the bottom ends of the left and right side surfaces of the support frame are rotatably connected to the left and right optical axes of the screw through bearings.
[0011] As a preferred technical solution of the present invention, a gear three is fixedly provided on the middle optical axis of the lead screw, the gear three is meshingly connected with the gear four, the gear four is fixedly provided on the output shaft of the motor three, the motor three is fixedly connected to the upper end of the support frame through a mounting seat, and two sections of thread grooves with opposite spiral directions are provided on the lead screw, and the two sections of the thread grooves are respectively threadedly connected to two screw holes, and the two screw holes are respectively provided in the middle of the upper ends of the two splints.
[0012] As a preferred technical solution of the present invention, two sleeve holes are provided at the upper end of each of the clamping plates, the four sleeve holes are grouped in pairs and the two groups of sleeve holes are respectively connected to two sleeve rods, the two ends of the two sleeve rods are respectively fixedly connected to the left and right sides of the support frame, and the motor three is electrically connected to the conductive slip ring.
[0013] As a preferred technical solution of the present invention, the controller is electrically connected to the battery, the controller is fixedly set on the upper surface of the installation box, the battery is fixedly set inside the installation box, the battery is also electrically connected to the charging socket, the charging socket is fixedly set at the bottom end of the right side of the installation box, and the left end of the upper surface of the installation box is fixedly connected to the bottom end of the handle.
[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention connects the clamping mechanism with the extension rod by arranging an adjusting mechanism. When the clamping mechanism is used to disassemble and overhaul the internal parts of the transformer, the lifting and lowering of the screw in the adjusting mechanism can be used to drive the rotating plate and the clamping mechanism to rotate as a whole, thereby adjusting the inclination angle of the clamping plate in the vertical plane, and the worm and worm gear in the adjusting mechanism can be used to drive the supporting shaft and the clamping mechanism to rotate as a whole, thereby adjusting the orientation of the openings of the two clamping plates so that the clamping plates correspond to the parts to be disassembled and assembled, thereby making the present device suitable for disassembling and assembling parts at different angles and positions, thereby replacing the maintenance personnel's arms entering the transformer to disassemble and assemble parts in a narrow space, avoiding the maintenance personnel's need to disassemble and assemble the transformer as a whole for overhaul, and effectively improving the maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a front view structural schematic diagram of the present invention; Figure 2 It is a front cross-sectional structural schematic diagram of the present invention; Figure 3 It is a schematic diagram of the front cross-sectional structure of the extension rod of the present invention; Figure 4 It is a schematic diagram of the structure of the regulating mechanism of the present invention; Figure 5 It is a schematic diagram of the connection frame structure of the present invention; Figure 6 It is a schematic diagram of the sleeve structure of the present invention; Figure 7 It is a schematic diagram of the structure of the clamping mechanism of the present invention.
[0016] In the figure: 1. installation box; 2. grip; 3. controller; 4. charging socket; 5. fixing cylinder; 6. extension rod; 7. adjustment mechanism; 71. fixing plate 1; 72. gear 1; 73. threaded cylinder; 74. screw; 75. fixing frame; 76. connection frame; 77. rotating plate; 78. rotating shaft; 79. fixing plate 2; 710. supporting shaft; 711. motor 1; 712. gear 2; 713. connecting rod; 714. worm; 715. conductive slip ring; 716. sleeve; 717. worm wheel; 718. motor 2; 8. clamping mechanism; 81. supporting frame; 82. lead screw; 83. gear 3; 84. gear 4; 85. motor 3; 86. screw hole; 87. sleeve hole; 88. sleeve rod; 89. clamping plate; 9. mounting hole; 10. electric push rod; 11. battery; 12. notch. DETAILED DESCRIPTION
[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0018] See also Figure 1-7 The present invention provides a technical solution of a mechanical arm clamping device for transformer maintenance: it comprises an installation box 1, the middle part of the bottom surface of the installation box 1 is fixedly connected to the upper end of a fixed cylinder 5, the inner upper end of the fixed cylinder 5 is fixedly connected to the upper end of an electric push rod 10, the bottom end of the electric push rod 10 is fixedly connected to the upper end of an extension rod 6, the upper end of the extension rod 6 is sleeved in the fixed cylinder 5, a mounting hole 9 is provided at the bottom end of the extension rod 6, and slots 12 are provided on both the left and right sides of the bottom end of the mounting hole 9, an adjusting mechanism 7 is provided in the mounting hole 9, the adjusting mechanism 7 is connected to the clamping mechanism 8, the electric push rod 10 is electrically connected to the controller 3, the extension rod 6 is connected to the fixed cylinder 5 by providing the electric push rod 10, when the device is used to assist maintenance personnel in repairing parts in a narrow position inside the transformer, the overall length of the extension rod 6 and the fixed cylinder 5 can be adjusted by extending the electric push rod 10, so as to adjust the distance between the handle 2 and the clamping mechanism 8 so that the clamping mechanism 8 can be extended into the transformer at different depths for maintenance operations.
[0019] The adjusting mechanism 7 comprises a fixing plate 71, both left and right ends of which are fixedly connected to the inner wall of the mounting hole 9, the middle portion of the fixing plate 71 is rotatably connected to a threaded tube 73 via a bearing, a gear 72 is fixedly provided on the outer side surface of the threaded tube 73, and the gear 72 is meshingly connected to the gear 2 712.
[0020] Gear 2 712 is fixedly arranged on the output shaft of motor 1 711. The bottom end of motor 1 711 is connected to the upper surface of fixing plate 1 71. Threaded barrel 73 is threadedly connected to screw rod 74. The bottom end of screw rod 74 is fixedly connected to the upper surface of fixing frame 75. The front and rear sides of the bottom end of fixing frame 75 are respectively fixedly connected to the front and rear ends of connecting rod 713. When using this device to assist maintenance personnel to repair parts in narrow positions inside the transformer, users can adjust the position and angle of the parts to be disassembled and assembled by controlling The controller 3 controls the motor 1 711 to rotate by using the gear 1 72 and the gear 2 712. When the threaded barrel 73 rotates, it drives the screw 74 to move up and down. When the screw 74 moves up and down, it drives the connecting rod 713 to slide in the connecting frame 76, and drives the rotating plate 77 to rotate along the rotating shaft 78 through the connecting rod 713 and the connecting frame 76. When the rotating plate 77 rotates, it drives the fixed plate 2 79 and the clamping mechanism 8 to rotate. When the clamping mechanism 8 rotates to a suitable angle corresponding to the parts to be disassembled, the motor 1 711 stops working.
[0021] The connecting rod 713 is sleeved in the connecting frame 76, the bottom end of the connecting frame 76 is fixedly connected to the upper end of the rotating plate 77, the middle part of the rotating plate 77 is rotatably connected to the middle part of the rotating shaft 78 through a bearing, the front and rear ends of the rotating shaft 78 are fixedly connected to the inner wall of the mounting hole 9, and the rotating plate 77 is simultaneously arranged corresponding to the two notches 12 on the left and right. By opening a notch 12 at the bottom end of the mounting hole 9 corresponding to the rotating plate 77, the rotating plate 77 is rotated to the inside of the notch 12 when the rotating plate 77 rotates around the rotating shaft 78, and the notch 12 is used to increase the rotation angle of the rotating plate 77 and the clamping mechanism 8.
[0022] The bottom end of the rotating plate 77 is fixedly connected to the upper surface of the second fixed plate 79, and the middle part of the bottom surface of the second fixed plate 79 is rotatably connected to the upper end of the support shaft 710 through a bearing. A worm gear 717 is fixedly arranged on the lower side of the support shaft 710, and the worm gear 717 is meshed with the worm 714. The left end of the worm 714 is fixedly connected to the output shaft of the second motor 718, and the second motor 718 is fixedly connected to the bottom surface of the second fixed plate 79 through a mounting seat. During the maintenance process, the user can also control the operation of the second motor 718 through the controller 3 to use the worm 714 and the worm gear 717 to drive the support shaft 710, the support frame 81 and the clamping plate 89 to rotate along the support shaft 710, so that the opening direction of the two clamping plates 89 is rotated to correspond to the parts to be disassembled and assembled, so that the device can be suitable for the disassembly and assembly of parts at different angles and different positions, thereby replacing the maintenance personnel's arms entering the transformer to disassemble and assemble parts in a narrow space, avoiding the need for maintenance personnel to disassemble and assemble the transformer as a whole for maintenance, thereby effectively improving the maintenance efficiency.
[0023] The upper end of the support shaft 710 is sleeved in the sleeve 716, the upper end of the sleeve 716 is fixedly connected to the bottom surface of the fixed plate 2 79, and a conductive slip ring 715 is fixedly provided on the outer side surface of the sleeve 716. The conductive slip ring 715, the motor 2 718 and the motor 1 711 are all electrically connected to the controller 3.
[0024] The clamping mechanism 8 includes a support frame 81, the middle of the upper surface of the support frame 81 is fixedly connected to the bottom end of the support shaft 710, and the bottom ends of the left and right side surfaces of the support frame 81 are rotatably connected to the left and right optical axes of the lead screw 82 through bearings.
[0025] The middle optical axis of the screw 82 is fixedly provided with a gear three 83, which is meshed with a gear four 84, and the gear four 84 is fixedly provided on the output shaft of the motor three 85. The motor three 85 is fixedly connected to the upper end of the support frame 81 through a mounting seat. The screw 82 is provided with two sections of threaded grooves with opposite spiral directions, and the two sections of the threaded grooves are respectively threadedly connected to two screw holes 86. The two screw holes 86 are respectively provided in the middle of the upper ends of the two clamping plates 89. The user can move the device so that the end of the part to be disassembled is located between the two clamping plates 89, and control the output shaft of the motor three 85 to rotate forwardly through the controller 3 to drive the screw 82 to rotate forwardly by using the gear three 83 and the gear four 84. When the screw 82 rotates forwardly, the two clamping plates 89 are driven to approach each other through the screw holes 86. When the two clamping plates 89 are in close contact with the ends of the parts, the motor three 85 stops working, so that the parts are clamped by the clamping plates 89 for subsequent disassembly and assembly.
[0026] Two sleeve holes 87 are provided at the upper end of each clamping plate 89, and the four sleeve holes 87 are grouped in pairs and the two groups of sleeve holes 87 are respectively sleeved with two sleeve rods 88, and the two ends of the two sleeve rods 88 are respectively fixedly connected to the left and right sides of the support frame 81, and the motor three 85 is electrically connected to the conductive slip ring 715. The conductive slip ring 715 is arranged on the outside of the sleeve 716 to electrically connect with the motor three 85, so as to avoid the power cord of the motor three 85 from getting entangled and affecting the work when the support shaft 710 drives the support frame 81 to rotate.
[0027] The controller 3 is electrically connected to the battery 11, which is fixedly arranged on the upper surface of the installation box 1. The battery 11 is fixedly arranged inside the installation box 1. The battery 11 is also electrically connected to the charging socket 4, which is fixedly arranged at the bottom end of the right side surface of the installation box 1. The left end of the upper surface of the installation box 1 is fixedly connected to the bottom end of the handle 2.
[0028] The operating steps of the present invention are: When using the device to assist maintenance personnel in repairing parts in narrow positions inside the transformer, the user can hold the handle 2 to extend the clamping mechanism 8 into the transformer, and control the electric push rod 10 to extend through the controller 3 to push the extension rod 6 out of the fixed tube 5. When the extension rod 6 drives the clamping mechanism 8 to move to correspond to the parts to be disassembled, the electric push rod 10 stops extending. Then, according to the position and angle of the parts to be disassembled, the user can control the motor 1 711 through the controller 3 to drive the threaded tube 73 to rotate by using the gear 1 72 and the gear 2 712. When the threaded tube 73 rotates, it drives the screw rod 74 to move up and down. When the screw rod 74 moves up and down, it drives the connecting rod 713 to slide in the connecting frame 76, and the connecting rod 713 and the connecting frame 76 drive the rotating plate 77 to rotate along the rotating shaft 78; When the rotating plate 77 rotates, it drives the fixed plate 2 79 and the clamping mechanism 8 to rotate. When the clamping mechanism 8 rotates to a suitable angle corresponding to the parts to be disassembled, the motor 1 711 stops working. At this time, the user can control the motor 2 718 to work through the controller 3 and use the worm 714 and the worm gear 717 to drive the support shaft 710, the support frame 81 and the clamping plate 89 to rotate along the support shaft 710, so that the opening direction of the two clamping plates 89 rotates to correspond to the parts to be disassembled. At this time, the user can move the device so that the end of the parts to be disassembled is The motor 3 85 is between the two clamping plates 89, and the controller 3 controls the output shaft of the motor 3 85 to rotate forward, and the gear 3 83 and the gear 4 84 drive the screw 82 to rotate forward. When the screw 82 rotates forward, the two clamping plates 89 are driven to approach each other through the screw hole 86. When the two clamping plates 89 are in close contact with the ends of the parts, the motor 3 85 is stopped. Then the user can pull the device to move horizontally to drive the parts to move horizontally for plugging, unplugging, disassembling and assembling, and can also control the motor 2 718 to drive the two clamping plates 89 to rotate to perform rotational disassembly and assembly of the parts.
[0029] In the description of the present invention, it is necessary to understand that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.
[0030] In the present invention, unless otherwise clearly stipulated and limited, for example, it can be a fixed connection, a detachable connection, or an integrated one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.
[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A mechanical arm clamping device for transformer maintenance, comprising a mounting box (1), characterized in that: The middle part of the bottom surface of the installation box (1) is fixedly connected to the upper end of the fixed cylinder (5), the inner upper end of the fixed cylinder (5) is fixedly connected to the upper end of the electric push rod (10), the bottom end of the electric push rod (10) is fixedly connected to the upper end of the extension rod (6), the upper end of the extension rod (6) is sleeved in the fixed cylinder (5), the bottom end of the extension rod (6) is provided with a mounting hole (9), the bottom end of the mounting hole (9) is provided with notches (12) on both sides, the mounting hole (9) is provided with an adjustment mechanism (7), the adjustment mechanism (7) is connected to the clamping mechanism (8), and the electric push rod (10) is electrically connected to the controller (3).
2. The mechanical arm clamping device for transformer maintenance according to claim 1 is characterized in that: The adjustment mechanism (7) comprises a fixing plate 1 (71), the left and right ends of the fixing plate 1 (71) are fixedly connected to the inner wall of the mounting hole (9), the middle part of the fixing plate 1 (71) is rotatably connected to the threaded tube (73) via a bearing, and the outer side surface of the threaded tube (73) is fixedly provided with a gear 1 (72), and the gear 1 (72) is meshingly connected with a gear 2 (712).
3. The mechanical arm clamping device for transformer maintenance according to claim 2 is characterized in that: The gear 2 (712) is fixedly arranged on the output shaft of the motor 1 (711); the bottom end of the motor 1 (711) is connected to the upper surface of the fixing plate 1 (71); the threaded tube (73) is threadedly connected to the screw rod (74); the bottom end of the screw rod (74) is fixedly connected to the upper surface of the fixing frame (75); the front and rear side surfaces of the bottom end of the fixing frame (75) are respectively fixedly connected to the front and rear ends of the connecting rod (713).
4. The mechanical arm clamping device for transformer maintenance according to claim 3 is characterized in that: The connecting rod (713) is sleeved in the connecting frame (76); the bottom end of the connecting frame (76) is fixedly connected to the upper end of the rotating plate (77); the middle part of the rotating plate (77) is rotatably connected to the middle part of the rotating shaft (78) via a bearing; the front and rear ends of the rotating shaft (78) are fixedly connected to the inner wall of the mounting hole (9); and the rotating plate (77) is simultaneously arranged correspondingly to the two notches (12) on the left and right.
5. The mechanical arm clamping device for transformer maintenance according to claim 4 is characterized in that: The bottom end of the rotating plate (77) is fixedly connected to the upper surface of the second fixed plate (79); the middle part of the bottom surface of the second fixed plate (79) is rotatably connected to the upper end of the support shaft (710) via a bearing; a worm gear (717) is fixedly arranged on the lower side of the support shaft (710); the worm gear (717) is meshingly connected to the worm (714); the left end of the worm (714) is fixedly connected to the output shaft of the second motor (718); and the second motor (718) is fixedly connected to the bottom surface of the second fixed plate (79) via a mounting seat.
6. A mechanical arm clamping device for transformer maintenance according to claim 5, characterized in that: The upper end of the support shaft (710) is sleeved in a sleeve (716), the upper end of the sleeve (716) is fixedly connected to the bottom surface of the second fixing plate (79), and a conductive slip ring (715) is fixedly provided on the outer side surface of the sleeve (716), and the conductive slip ring (715), the second motor (718) and the first motor (711) are all electrically connected to the controller (3).
7. The mechanical arm clamping device for transformer maintenance according to claim 1 is characterized in that: The clamping mechanism (8) comprises a support frame (81), the middle portion of the upper surface of the support frame (81) being fixedly connected to the bottom end of the support shaft (710), and the bottom ends of the left and right side surfaces of the support frame (81) being rotatably connected to the left and right optical axes of the lead screw (82) respectively via bearings.
8. The mechanical arm clamping device for transformer maintenance according to claim 7 is characterized in that: A gear three (83) is fixedly arranged on the middle optical axis of the lead screw (82), the gear three (83) is meshingly connected with a gear four (84), the gear four (84) is fixedly arranged on the output shaft of a motor three (85), the motor three (85) is fixedly connected to the upper end of the support frame (81) through a mounting seat, the lead screw (82) is provided with two sections of thread grooves with opposite spiral directions, and the two sections of the thread grooves are respectively threadedly connected to two screw holes (86), and the two screw holes (86) are respectively arranged in the middle of the upper ends of the two clamping plates (89).
9. A mechanical arm clamping device for transformer maintenance according to claim 8, characterized in that: Two sleeve holes (87) are provided at the upper end of each clamping plate (89), the four sleeve holes (87) are arranged in groups of two, and the two groups of sleeve holes (87) are respectively sleeved with two sleeve rods (88), the two ends of the two sleeve rods (88) are respectively fixedly connected to the left and right side surfaces of the support frame (81), and the motor three (85) is electrically connected to the conductive slip ring (715).
10. The mechanical arm clamping device for transformer maintenance according to claim 1, characterized in that: The controller (3) is electrically connected to the battery (11), the controller (3) is fixedly arranged on the upper surface of the installation box (1), the battery (11) is fixedly arranged inside the installation box (1), the battery (11) is also electrically connected to the charging socket (4), the charging socket (4) is fixedly arranged at the bottom end of the right side surface of the installation box (1), and the left end of the upper surface of the installation box (1) is fixedly connected to the bottom end of the handle (2).