Manual creasing mechanism for cartons

Abstract

The utility model discloses a manual indentation mechanism for carton belongs to carton processing equipment technical field. It mainly includes frame, and the fixed connection of frame has the pressure tank of longitudinal section V type structure, and one end of pressure tank is equipped with indentation component, and indentation component includes operating lever and rotating seat, and the bottom fixed connection of operating lever has indentation cutter matched with pressure tank, and the fixed connection of operating lever one end has the pivot, and the pivot is rotatably connected with rotating seat, and rotating seat is fixedly arranged on fixed base, and fixed base is fixedly connected with pressure tank or frame. The frame of the utility model realizes the stable connection of crossbeam, longitudinal beam and support leg through first, second connecting piece, and also can fine -tune size by virtue of long hole, and adapts to different installation scene, and central support frame avoids the droop of pressure tank, and the whole structure rigidity is strong, and is not easy to change when indentation, guarantees indentation stability.

Description

Technical Field

[0001] This utility model belongs to the technical field of cardboard box processing equipment, and more specifically, it relates to a manual creasing mechanism for cardboard boxes. Background Technology

[0002] As people's living standards improve, paper gift box packaging has become increasingly diverse and stylish, leading to a surge in market demand. Among these, handmade cardboard boxes designed for niche occasions are gaining popularity due to their uniqueness. In addition to these cardboard boxes, some printed materials and paper products often require crease treatment before completion to ensure the final product's aesthetic appeal. Based on this practical need, manual crease machines have gradually appeared on the market.

[0003] For example, patent publication number "CN221623190U" discloses a manual creasing machine, including a support platform, a support plate fixedly installed on the support platform, a creasing component slidably installed on the support plate, a fixed frame fixedly installed on the support plate, a lower pressure plate movably installed on the fixed frame, and an adjustment component at the bottom of the lower pressure plate. The adjustment component corresponds to the position of the creasing component. Pressing the lower pressure plate drives the creasing component to move downward through the adjustment component to achieve the creasing operation. An elastic component that can reset the creasing component is installed between the creasing component and the support plate. Through this setting, not only is it convenient to adjust the depth of the creasing, but the positional accuracy of the creasing on the product is also greatly improved. It adopts the lever principle, which saves time and effort, has a simple and reliable structure, is easy to maintain, greatly reduces the probability of defective products, and reduces costs.

[0004] However, the above-mentioned indentation machine still has the following problems when in use: 1. The indentation assembly relies on the guide plate and the sliding groove for positioning, and the adjustment seat transmits force through a single point of contact. It is easy to cause uneven indentation depth due to force deviation; the bearing table and the support plate are only connected by bolts without a reinforcing structure, which is easy to deform under pressure and affects the indentation accuracy; 2. The indentation depth adjustment has no quantitative scale and requires repeated test pressing to determine, without precise reference; 3. The pressure knife needs to be replaced by disassembling the clamping plate and recalibrating, and the pressure spring needs to be replaced by disassembling the fixing column, which is a cumbersome process. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a manual creasing mechanism for carton. Its frame is stably connected to the crossbeam, longitudinal beam and support leg through the first and second connecting parts. It can also be finely adjusted in size by means of the elongated hole to adapt to different installation scenarios. The middle support frame prevents the creasing groove from sagging. The overall structure is rigid and not easily deformed during creasing, thus ensuring the stability of creasing.

[0006] The aforementioned manual creasing mechanism for cartons includes a frame, on which a creasing groove with a V-shaped longitudinal section is fixedly connected. One end of the creasing groove is provided with a creasing assembly, which includes an operating lever and a rotating seat. The bottom of the operating lever is fixedly connected with a creasing knife that matches the creasing groove. One end of the operating lever is fixedly connected with a rotating shaft, which is rotatably connected to the rotating seat. The rotating seat is fixedly mounted on a fixed seat, which is fixedly connected to the creasing groove or the frame.

[0007] Preferably, a connecting rod is fixedly connected to the fixed base, and a positioning element is fixedly connected to the operating rod at a position away from the rotating base. An elastic component is connected to both the positioning element and the connecting rod.

[0008] Preferably, the frame includes at least two parallel crossbeams, with longitudinal beams at both ends of each crossbeam, and the longitudinal beams are perpendicular to the crossbeams.

[0009] Preferably, the longitudinal beam and the transverse beam are fixedly connected by a first connecting member. The first connecting member includes an upper fixing member and a lower fixing member arranged vertically. One end of the upper fixing member and the lower fixing member are respectively provided with a staggered and engaging locking groove. The other end of the upper fixing member and the lower fixing member are jointly provided with a locking hole one for fixing the transverse beam. The side of the upper fixing member and the lower fixing member away from the locking hole one is jointly provided with a locking hole two for fixing the longitudinal beam.

[0010] Preferably, a central support frame is provided in the middle of the frame, a pressure groove is fixedly installed on the top of the central support frame, and a longitudinal beam near the middle of the frame is fixedly connected to the central support frame.

[0011] Preferably, two or more support legs are fixedly connected to the bottom of the longitudinal beams near both ends of the frame. The support legs, longitudinal beams and corresponding crossbeams are fixedly connected by a second connector. The second connector includes an L-shaped fixing member one and an L-shaped fixing member two arranged vertically. One end of the right-angle side of the L-shaped fixing member one and the L-shaped fixing member two is provided with an X-direction fixing hole for fixing the crossbeam. The other end of the right-angle side of the L-shaped fixing member one and the L-shaped fixing member two is provided with a Z-direction fixing hole for fixing the support leg. A Y-direction fixing hole for fixing the longitudinal beam is provided at the corner of the second connector.

[0012] Preferably, the crossbeam is provided with a positioning assembly, which includes a positioning plate. Both ends of the positioning plate are fixedly connected to the crossbeam by C-type clamps, and locking bolts are threaded onto the C-type clamps.

[0013] Preferably, the positioning plate is an L-shaped plate, and the outer vertical surface of the L-shaped plate is opposite to the pressure groove, and a handle is fixedly connected to the end of the locking bolt away from the C-shaped clamp.

[0014] Preferably, a T-shaped frame is provided between the fixed seat and the pressure groove or the frame, and the T-shaped frame is fixedly connected to the pressure groove or the frame. The fixed seat and the T-shaped frame are respectively provided with matching elongated holes. The fixed seat and the T-shaped frame are fixedly connected by fasteners and elongated holes.

[0015] Compared with the prior art, the beneficial effects of this utility model are: 1. The frame achieves a stable connection between the crossbeams, longitudinal beams and support legs through the first and second connectors, and can also be finely adjusted in size with the help of elongated holes to adapt to different installation scenarios; the middle support frame prevents the pressure groove from sagging, the overall structure is rigid and not easily deformed during indentation, ensuring the stability of indentation.

[0016] 2. The L-shaped positioning plate, together with the C-shaped clamp, can accurately position the cardboard and prevent it from shifting; the addition of the T-shaped frame and the elongated hole allows for three-dimensional micro-adjustment of the creasing knife height, which can be adapted to the creasing depth requirements of cardboard of different thicknesses and is suitable for a variety of carton processing scenarios.

[0017] 3. The operating lever, in conjunction with the rotating shaft, achieves lever-type indentation, reducing the applied force; the elastic component automatically drives the indentation knife to reset, eliminating the need for manual lifting; the design of the locking bolt handle, adjustable positioning component, etc., simplifies the operation process and improves work efficiency.

[0018] 4. Most of the components of this utility model are detachable, making maintenance and replacement convenient; it does not require a complex power unit, has low cost, and is suitable for small-batch cardboard box creasing needs of small processing plants and workshops, offering high cost performance. Attached Figure Description

[0019] Figure 1 This is a front structural diagram of Embodiment 1 of the present utility model; Figure 2 for Figure 1 A magnified view of part A in the middle; Figure 3 This is a side view of Embodiment 1 of the present utility model; Figure 4 for Figure 3 A magnified view of part B in the middle section; Figure 5 for Figure 3 A magnified view of part C in the middle; Figure 6 This is a schematic diagram of the side structure of the second connector; Figure 7 This is a schematic diagram of the rear structure of the second connector; Figure 8 This is a structural schematic diagram of the first connector; Figure 9 This is a structural schematic diagram of Embodiment 2 of the present invention. Figure 10 for Figure 9A magnified view of part D in the middle.

[0020] In the diagram: 1. Support leg; 2. Second connecting piece; 201. L-shaped fixing piece one; 202. L-shaped fixing piece two; 203. X-direction fixing hole; 204. Y-direction fixing hole; 205. Long strip hole two; 3. Positioning assembly; 301. Positioning plate; 302. C-type clamp; 303. Locking bolt; 4. Indentation groove; 5. Indentation assembly; 501. Operating lever; 502. Indentation knife; 503. Positioning piece; 504. Connecting rod; 505. Fixed seat; 506. Rotating seat; 507. T-shaped frame; 508. Long strip hole three; 6. Elastic assembly; 7. Middle support frame; 8. First connecting piece; 801. Upper fixing piece; 802. Lower fixing piece; 803. Snap-fit ​​groove; 804. Long strip hole one; 9. Crossbeam; 10. Longitudinal beam. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings: The directional terms used in the detailed description paragraphs are only for the convenience of those skilled in the art to understand the technical solutions described in this application based on the visual orientation shown in the accompanying drawings. Unless otherwise expressly specified and limited, the terms "setting," "installation," "connection," etc., should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0022] Example 1: like Figures 1 to 8 As shown, a manual creasing mechanism for cartons includes a frame, which serves as the basic support framework for the entire creasing mechanism, providing a mounting carrier for each component and ensuring the overall structural stability. A creasing groove 4 with a V-shaped longitudinal section is fixedly connected to the frame. The V-shaped creasing groove 4 provides a creasing reference surface for the carton board, and its shape cooperates with the creasing knife to form a standardized crease, providing support and limiting for the board during creasing to prevent displacement. A creasing assembly 5 is provided at one end of the creasing groove 4, such as... Figure 3 and Figure 5As shown, the creasing assembly 5 includes an operating lever 501 and a rotating base 506. The operating lever 501 provides a force application point for the operator, who manually drives the creasing knife to move. A creasing knife 502, matching the creasing groove 4, is fixedly connected to the bottom of the operating lever 501. Under the action of the operating lever 501, the creasing knife 502 cooperates with the V-shaped creasing groove 4 to apply pressure to the cardboard to form a creasing. A rotating shaft is fixedly connected to one end of the operating lever 501. The rotating shaft is rotatably connected to the rotating base 506. The cooperation between the rotating shaft and the rotating base 506 allows the operating lever 501 to rotate flexibly around the rotation point, realizing the up and down movement of the creasing knife 502. The rotating base 506 is fixedly mounted on a fixed base 505, which provides fixed support for the rotating base 506 to ensure the stability of the rotating base 506. The fixed base 505 is fixedly connected to the creasing groove 4. During installation, the fixed base 505 can also be fixed to the frame, thereby fixing the entire creasing assembly 5 to the mechanism and ensuring structural stability during creasing.

[0023] A connecting rod 504 is fixedly connected to the fixed base 505. The connecting rod 504 provides a connection fulcrum for the elastic component 6. A positioning element 503 is fixedly connected to the operating rod 501 at a position away from the rotating base 506. The positioning element 503 is used to connect the elastic component 6 and transmit the force. The elastic component 6 is connected together between the positioning element 503 and the connecting rod 504. The elastic component 6 is preferably a tension spring. The elastic component 6 stores elastic potential energy when the operating rod 501 is pressed down, and provides a restoring force after the operating rod 501 is released, so that the creasing knife 502 is automatically lifted, which facilitates the picking and placing of the cardboard.

[0024] like Figure 1 As shown, the frame includes at least two parallel crossbeams 9. In this embodiment, it is preferable that three crossbeams 9 are equally spaced. Each end of the crossbeam 9 is provided with a longitudinal beam 10, that is, the crossbeam 9 is laterally connected to the longitudinal beam 10 to enhance the lateral stability of the frame. The longitudinal beam 10 longitudinally supports the frame and forms a frame structure with the crossbeam 9. The longitudinal beam 10 is perpendicular to the crossbeam 9, thereby forming a stable rectangular frame structure and improving the overall rigidity of the frame.

[0025] A central support frame 7 is provided in the middle of the frame, and the pressure groove 4 is fixedly installed on the top of the central support frame 7. The central support frame 7 provides intermediate support for the pressure groove 4, preventing the pressure groove 4 from sagging in the middle due to force, and keeping the pressure groove 4 in a horizontal and stable state. In this embodiment, the longitudinal beam 10 near the middle of the frame is fixedly connected to the central support frame 7 to further fix the central support frame 7 and enhance its support strength.

[0026] like Figure 2 , Figures 6 to 8As shown, during installation, the longitudinal beam 10 and the transverse beam 9 are fixedly connected by the first connector 8, which enables the detachable fixed connection between the longitudinal beam 10 and the transverse beam 9. The first connector 8 includes an upper fixing member 801 and a lower fixing member 802, which clamp and fix the longitudinal beam 10 and the transverse beam 9 by their upper and lower cooperation. One end of the upper fixing member 801 and the lower fixing member 802 is provided with a staggered and engaging locking groove 803. The locking grooves 803 cooperate with each other to enhance the connection strength of the upper and lower fixing members, while preventing relative sliding and improving the stability of the connection. The other end of the upper fixing member 801 and the lower fixing member 802 is provided with a locking hole 1 for fixing the transverse beam 9, and the side of the upper fixing member 801 and the lower fixing member 802 away from the locking hole 1 is provided with a locking hole 2 for fixing the longitudinal beam 10. Both the upper fixing member 801 and the lower fixing member 802 have elongated holes 804 that communicate with the snap-fit ​​hole 1. Fasteners pass sequentially through the elongated hole 804 in the lower fixing member 802, the crossbeam 9, and the elongated hole 804 in the upper fixing member 801 before being locked in place. This not only secures the crossbeam 9 but also allows for fine-tuning of its lateral position using the length allowance of the elongated hole 804. Fixing holes are provided on both sides of the elongated hole 804, which can be used to fix the crossbeam 9 and the longitudinal beam 10 respectively, improving the stability of the fixation.

[0027] Two or more support legs 1 are fixedly connected to the bottom of the longitudinal beams 10 near both ends of the frame. The support legs 1 are preferably fixed at both ends of the longitudinal beams 10, supporting the frame on the ground and maintaining a certain height for easy operation. The support legs 1, longitudinal beams 10, and corresponding crossbeams 9 are fixedly connected by a second connector 2. The second connector 2 achieves a stable connection between the three, enhancing the structural strength at the frame corners. Specifically, the second connector 2 includes an L-shaped fixing part 1 201 and an L-shaped fixing part 202 arranged vertically, using an L-shaped structure to accommodate right-angle connections at the frame corners. Both L-shaped fastener 1 201 and L-shaped fastener 202 have an X-direction fixing hole 203 at one end of their right-angle sides for fixing the crossbeam 9, which can be fixed with fasteners. The other end of the right-angle sides of both L-shaped fastener 1 201 and L-shaped fastener 202 have a Z-direction fixing hole for fixing the support leg 1, which is then fixed with fasteners. The corner of the second connector 2 has a Y-direction fixing hole 204 for fixing the longitudinal beam 10. The Y-direction fixing hole 204 is used to place the longitudinal beam 10 and is fixed with fasteners. The second connector 2 achieves three-dimensional fixing of the support leg 1, longitudinal beam 10, and crossbeam 9 at the corner. In this embodiment, elongated holes 205 are respectively formed on the two right-angle surfaces of L-shaped fastener 1 201 and L-shaped fastener 202. These elongated holes 205 can adjust the fixing position of the crossbeam 9 and the support leg 1, thereby allowing for fine-tuning of the frame height and length.

[0028] like Figure 4As shown, a positioning component 3 is provided on the crossbeam 9. The positioning component 3 is used to position the cardboard box to ensure accurate indentation. Specifically, the positioning component 3 includes a positioning plate 301, which is used to fit against the edge of the cardboard and restrict the lateral and longitudinal positions of the cardboard. Both ends of the positioning plate 301 are fixedly connected to the crossbeam 9 through C-type clamps 302. The C-type clamps 302 enable a detachable connection between the positioning plate 301 and the crossbeam 9, facilitating adjustment of the position of the positioning plate 301. A locking bolt 303 is threaded onto the C-type clamp 302. By tightening the locking bolt 303, the bottom of the C-type clamp 302 presses against the crossbeam, and at the same time, the locking bolt 303 presses against the positioning plate 301, thereby fixing the C-type clamp 302 and preventing the positioning plate 301 from moving.

[0029] During manufacturing, the positioning plate 301 is an L-shaped plate, with its outer vertical surface facing the pressure groove 4. The horizontal right-angled surface of the L-shaped structure facilitates the fixing of the C-shaped clamp 302 and the locking bolt 303, while the vertical right-angled surface facilitates positioning during cardboard creasing. A handle is fixedly connected to the end of the locking bolt 303 away from the C-shaped clamp 302. The handle increases the force application area, making it easier for operators to tighten or loosen the locking bolt.

[0030] Example 2: like Figure 9 and Figure 10 As shown, a manual creasing mechanism for cartons includes a T-shaped bracket 507 between a fixed base 505 and a creasing groove 4 or a frame. The T-shaped bracket 507 is used to adjust the position of the fixed base 505, thereby adjusting the creasing depth of the creasing assembly 5. The T-shaped bracket 507 is fixedly connected to the creasing groove 4 or the frame to ensure the stability of its own position. The fixed base 505 and the T-shaped bracket 507 are respectively provided with matching elongated holes 508. The elongated holes 508 are vertically oriented and allow the fixed base 505 to be adjusted along the direction of the elongated holes, thereby fine-tuning the height of the creasing assembly 5 and changing the distance between the creasing blade 502 and the creasing groove 4. During installation, the fixed base 505 and the T-shaped bracket 507 are fixedly connected by fasteners and the elongated holes 508, enabling the fixed base 505 to be adjusted in position, thereby adjusting the relative position of the creasing blade 502 and the creasing groove 4 to adapt to different creasing requirements. Other aspects are the same as in Embodiment 1.

[0031] Working principle: In use, this invention adjusts the positioning component 3 according to the size of the cardboard to be creasing and the required creasing position. The locking bolt 303 on the C-clamp 302 is loosened, and the C-clamp 302 and the L-shaped positioning plate 301 are pushed to slide along the crossbeam 9, so that the distance between the outer vertical surface of the positioning plate 301 and the creasing groove 4 matches the cardboard size. After adjustment, the locking bolt 303 is tightened in the opposite direction, so that the bottom of the C-clamp 302 presses against the crossbeam 9 and the locking bolt 303 presses against the positioning plate 301, thereby fixing the position of the positioning plate 301. The cardboard is then placed into the creasing groove 4, so that the edge of the cardboard fits against the vertical surface of the positioning plate 301, completing precise positioning of the cardboard and preventing displacement during creasing.

[0032] The operator holds the end of the operating lever 501 of the creasing assembly 5 furthest from the rotating shaft and applies downward pressure. The operating lever 501 rotates around the hinge point between the rotating shaft and the rotating seat 506, causing the creasing blade 502 at the bottom to move downwards synchronously until the creasing blade 502 contacts the cardboard in the creasing groove 4. The V-shaped creasing groove 4 applies pressure to the cardboard, forming a standard crease. During this process, the elastic component 6 is stretched by the positioning component 503 and the connecting rod 504, storing elastic potential energy. After creasing is complete, the operator releases the operating lever 501, and the elastic component 6 releases its elastic potential energy, pulling the operating lever 501 to rotate in the opposite direction around the hinge point. This causes the creasing blade 502 to automatically return to its original position and detach from the cardboard. The creasing cardboard is then removed from the creasing groove 4, completing one creasing operation. The above positioning and creasing steps can be repeated for batch operations.

[0033] When adjusting the creasing depth, loosen the fasteners between the fixed base 505 and the T-shaped frame 507, allowing the fixed base 505 to move up and down along the vertical direction of the elongated hole 508. This, in turn, causes the rotating base 506, the operating lever 501, and the creasing knife 502 to simultaneously make slight up and down adjustments, changing the initial distance between the creasing knife 502 and the creasing groove 4. After adjusting the distance to suit the target creasing depth, tighten the fasteners again to fix the relative position of the fixed base 505 and the T-shaped frame 507, ensuring that the creasing knife 502 can stably apply pressure to the corresponding depth in subsequent creasing operations, adapting to the creasing requirements of cardboard of different thicknesses.

[0034] Finally, although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A manual creasing mechanism for cartons comprising a frame characterised in that: A V-shaped groove (4) with longitudinal cross section is fixedly connected to the frame. An indentation assembly (5) is provided at one end of the groove (4). The indentation assembly (5) includes an operating lever (501) and a rotating seat (506). An indentation knife (502) matching the groove (4) is fixedly connected to the bottom of the operating lever (501). A rotating shaft is fixedly connected to one end of the operating lever (501). The rotating shaft is rotatably connected to the rotating seat (506). The rotating seat (506) is fixedly set on the fixed seat (505). The fixed seat (505) is fixedly connected to the groove (4) or the frame.

2. The manual creasing mechanism for cardboard boxes according to claim 1, characterized in that: A connecting rod (504) is fixedly connected to the fixed base (505), and a positioning element (503) is fixedly connected to the operating rod (501) away from the rotating base (506). An elastic component (6) is connected between the positioning element (503) and the connecting rod (504).

3. The manual creasing mechanism for cardboard boxes according to claim 1, characterized in that: The frame includes at least two parallel crossbeams (9), and longitudinal beams (10) are provided at both ends of the crossbeams (9), with the longitudinal beams (10) being perpendicular to the crossbeams (9).

4. The manual creasing mechanism for cardboard boxes according to claim 3, characterized in that: The longitudinal beam (10) and the transverse beam (9) are fixedly connected by a first connector (8). The first connector (8) includes an upper fixing member (801) and a lower fixing member (802) arranged vertically. One end of the upper fixing member (801) and the lower fixing member (802) is provided with a snap-fit ​​groove (803) that is staggered and engages with each other. The other end of the upper fixing member (801) and the lower fixing member (802) is provided with a snap-fit ​​hole 1 for fixing the transverse beam (9). The side of the upper fixing member (801) and the lower fixing member (802) away from the snap-fit ​​hole 1 is provided with a snap-fit ​​hole 2 for fixing the longitudinal beam (10).

5. The manual creasing mechanism for cardboard boxes according to claim 4, characterized in that: The frame has a central support frame (7) in the middle, and the pressure groove (4) is fixedly installed on the top of the central support frame (7). The longitudinal beam (10) near the middle of the frame is fixedly connected to the central support frame (7).

6. The manual creasing mechanism for cardboard boxes according to claim 3, characterized in that: Two or more support legs (1) are fixedly connected to the bottom of the longitudinal beams (10) near both ends of the frame. The support legs (1), longitudinal beams (10) and corresponding crossbeams (9) are fixedly connected by a second connector (2). The second connector (2) includes an L-shaped fixing part one (201) and an L-shaped fixing part two (202) arranged vertically. One end of the right angle side of the L-shaped fixing part one (201) and the L-shaped fixing part two (202) are provided with an X-direction fixing hole (203) for fixing the crossbeam (9). The other end of the right angle side of the L-shaped fixing part one (201) and the L-shaped fixing part two (202) are provided with a Z-direction fixing hole for fixing the support leg (1). A Y-direction fixing hole (204) for fixing the longitudinal beam (10) is provided at the corner of the second connector (2).

7. The manual creasing mechanism for cardboard boxes according to claim 3, characterized in that: The crossbeam (9) is provided with a positioning component (3), which includes a positioning plate (301). Both ends of the positioning plate (301) are fixedly connected to the crossbeam (9) through C-type clamps (302). The C-type clamps (302) are threaded with locking bolts (303).

8. The manual creasing mechanism for cardboard boxes according to claim 7, characterized in that: The positioning plate (301) is an L-shaped plate, and the outer vertical surface of the L-shaped plate is opposite to the pressure groove (4). The end of the locking bolt (303) away from the C-shaped clamp (302) is fixedly connected to a handle.

9. The manual creasing mechanism for cartons according to any one of claims 1 to 8, characterized in that: A T-shaped frame (507) is provided between the fixed base (505) and the pressure groove (4) or the frame. The T-shaped frame (507) is fixedly connected to the pressure groove (4) or the frame. The fixed base (505) and the T-shaped frame (507) are respectively provided with matching elongated holes (508). The fixed base (505) and the T-shaped frame (507) are fixedly connected by fasteners and elongated holes (508).

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