A pay-off mechanism for a packaging machine
By designing an unwinding mechanism in the packaging machine that includes a pressure roller and a damping adjustment component, the problem of loose film was solved, and the tightness of the film could be adjusted according to its characteristics, thereby improving the packaging quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANTOU XINQISHUN MECHANICAL DESIGN CO LTD
- Filing Date
- 2026-04-29
- Publication Date
- 2026-06-02
AI Technical Summary
The clamping devices of existing packaging machines are unable to adjust the tightness of the pulled film according to the characteristics of the film, resulting in loose film and affecting packaging quality.
Design an unwinding mechanism including a pressure roller and a damping adjustment assembly. The tightness of the film pull-out is controlled by adjusting the damping of the contact roller. The damping adjustment assembly includes a pressure pad, a compression spring, an adjusting nut, and a bearing. Tightening or loosening the adjusting nut adjusts the damping to ensure that the film remains tight during pull-out.
It enables the adjustment of the film's pull-out state based on the film's characteristics, ensuring the film remains tight and does not loosen, thereby improving the secure binding of packaged items and enhancing packaging quality.
Smart Images
Figure CN224312922U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of packaging machines, and in particular to an unwinding mechanism for a packaging machine. Background Technology
[0002] In the packaging industry, rotary strapping machines are widely used for strapping various items due to their efficient rotary packaging method. To achieve continuous packaging and effectively improve efficiency, eliminating the need for manual fixing of the film's starting end to the item each time it is wrapped, some existing packaging machines can pre-define the film's starting end. For example, a strapping packaging machine disclosed on August 12, 2025, with publication number CN223212581U, eliminates the need for manual pulling out and pre-fixing or wrapping the film to the item each time, enabling continuous packaging and effectively improving efficiency. Meanwhile, this type of strapping and packaging machine is also equipped with a pressing device and a tensioning device to maintain the tension of the unwound film. However, its pressing device is only equipped with a pressing wheel that can keep the film roll close under the action of the first tension spring. This type of pressing wheel is difficult to apply enough pressure to the film during rapid winding, which can easily lead to the pulled-out film being relatively loose, resulting in insufficient tightness of the packaged items and affecting the packaging quality. At the same time, it cannot make adaptive adjustments according to the characteristics of films with different tensions. Utility Model Content
[0003] The technical problem to be solved by this utility model is to provide an unwinding mechanism for a packaging machine. This unwinding mechanism can adjust the difficulty of pulling out the film according to the characteristics of different films, so that the pulled-out film can remain tight and not loose, thus ensuring packaging quality.
[0004] To solve the above technical problems, the following technical solution is adopted:
[0005] A packaging machine's unwinding mechanism includes an unwinding frame, a film unwinding shaft, and a pressing device. The film unwinding shaft is mounted on the unwinding frame. The pressing device includes a pressing wheel and a pressing mechanism, which is mounted on the unwinding frame. The pressing wheel comprises a fixed shaft, a contact roller, and a damping adjustment assembly capable of adjusting the damping magnitude of the contact roller's rotation. The fixed shaft is fixedly mounted on the pressing mechanism, and the contact roller is rotatably mounted on the fixed shaft. The contact roller is positioned and parallel to the film unwinding shaft. The damping adjustment assembly is disposed between the fixed shaft and the contact roller.
[0006] Typically, when the packaging machine uses a strapping packaging machine like the one with patent CN223212581U, the unwinding frame is the winding ring on the packaging machine.
[0007] In operation, the film roll is threaded onto the unwinding shaft, and the contact rollers on the pressure rollers press against the film roll, rotating as the film is fed out. To ensure the film remains taut and secure during unwinding, the damping of the contact rollers can be adjusted using a damping adjustment component. Increasing the damping makes unwinding more difficult, ensuring the film remains taut and secure, thus improving the tightness of the packaged items. For films with lower tensile strength, the damping can be reduced, allowing the film to be smoothly unwound while maintaining a taut state. This unwinding mechanism allows for adjustment of the contact roller damping based on the characteristics of different films or packaging requirements, thereby regulating the tightness of the film during unwinding and effectively ensuring packaging quality.
[0008] In a preferred embodiment, the damping adjustment assembly includes a clamping washer, a compression spring, an adjusting nut, and at least one bearing. The contact roller has an axially extending through hole with an annular step at the center. The fixed shaft includes a front adjustment section and a rear mounting section. The diameter of the rear mounting section is larger than the inner diameter of the annular step, and the inner diameter of the annular step is larger than the diameter of the front adjustment section. The fixed shaft passes through the through hole from back to front, and the front adjustment section extends out of the contact roller through the annular step. The clamping washer and the compression spring are sequentially fitted onto the front adjustment section, with the clamping washer in contact with the annular step. The side wall of the front adjustment section has an external thread matching the adjusting nut, and the adjusting nut is threadedly connected to the front adjustment section. One end of the compression spring is in close contact with the clamping washer, and the other end of the compression spring is in close contact with the adjusting nut. The rear mounting section is mounted on the pressure application mechanism, and the side wall of the rear mounting section is connected to the inner wall of the through hole via a bearing. The specific method for adjusting the damping of the contact roller during rotation is as follows: by tightening the adjusting nut, the compression spring is compressed, which increases the pressure of the compression spring on the pressure washer, thereby increasing the pressure of the pressure washer on the annular step. This increases the friction between the contact roller and the pressure washer, thus increasing the damping of the contact roller during rotation. This makes it less likely for the film to drive the contact roller to rotate and be released, ensuring that the unwound film will not loosen and improving the tightness of the packaging. Conversely, loosening the adjusting nut will reduce the damping of the contact roller during rotation.
[0009] In a further preferred embodiment, the damping adjustment assembly further includes multiple retaining rings. At least one first annular groove is formed on the outer wall of the rear mounting section, located on one side of the bearing. At least one second annular groove is formed on the inner wall of the rear portion of the through hole, located on the other side of the bearing. Each retaining ring is respectively engaged in the first or second annular groove. The retaining rings limit the movement of the bearing and contact roller, preventing displacement of the bearing and contact roller during damping adjustment or film unwinding. Typically, when there are multiple bearings, each bearing has a first annular groove and a second annular groove on its front and rear sides, respectively.
[0010] In a further preferred embodiment, the clamping roller further includes a cover plate, which is fixedly installed at the front end of the contact roller. The rear end of the cover plate has an annular protrusion, the diameter of which is larger than that of the contact roller. The cover plate has a through hole corresponding to the through hole, and the adjusting nut, the front adjusting section, and part of the compression spring are located in the through hole and covered by the cover plate. The annular protrusion of the cover plate can limit the film, preventing it from displacing from the surface of the contact roller. At the same time, the cover plate can also block the adjusting nut, the front adjusting section, and part of the compression spring, preventing the adjusting nut from being accidentally activated.
[0011] In a further preferred embodiment, the pressure applying mechanism includes a first swing arm and a first tension spring. The middle portion of the first swing arm is rotatably mounted on the unwinding frame via a pin. The rear mounting section of the fixed shaft is fixedly mounted on one end of the first swing arm. One end of the first tension spring is connected to the other end of the first swing arm, and the other end of the first tension spring is connected to the unwinding frame. Under the action of the first tension spring, the first swing arm ensures that the contact roller remains in close contact with the surface of the film roll during the unwinding process.
[0012] In a preferred embodiment, the unwinding mechanism further includes a tensioning device, which comprises a second swing arm, a tensioning roller, and a second tension spring. The middle portion of the second swing arm is rotatably mounted on the unwinding frame via a pin. The tensioning roller is rotatably mounted on one end of the second swing arm. One end of the second tension spring is connected to the other end of the second swing arm, and the other end of the second tension spring is connected to the unwinding frame. Under the action of the second tension spring, the second swing arm enables the tensioning roller to tension the film, which, in conjunction with the pressing device, maintains tension on the unwound film.
[0013] The beneficial effects of this invention are as follows: This unwinding mechanism can adjust the difficulty of pulling out the film according to the characteristics of different films, so that the pulled-out film can remain tight and not loose, thus ensuring packaging quality. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the unwinding mechanism in an embodiment of the present invention;
[0015] Figure 2 This is a schematic diagram of the structure of the pressure wheel in an embodiment of this utility model;
[0016] Figure 3 This is a cross-sectional view of the pressure wheel in an embodiment of this utility model. Detailed Implementation
[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:
[0018] like Figure 1-3 The unwinding mechanism of a packaging machine shown includes an unwinding frame 1, a film unwinding shaft 2, and a pressing device 3. The film unwinding shaft 2 is mounted on the unwinding frame 1. The pressing device 3 includes a pressing wheel 301 and a pressing mechanism 302, with the pressing mechanism 302 mounted on the unwinding frame 1. The pressing wheel 301 includes a fixed shaft 3011, a contact roller 3012, and a damping adjustment component 3013 that can adjust the damping magnitude when the contact roller 3012 rotates. The fixed shaft 3011 is fixedly mounted on the pressing mechanism 302, and the contact roller 3012 is rotatably mounted on the fixed shaft 3011. The contact roller 3012 is matched with and parallel to the position of the film unwinding shaft 2. The damping adjustment component 3013 is disposed between the fixed shaft 3011 and the contact roller 3012.
[0019] The packaging machine uses the same strapping packaging machine as patent CN223212581U, and the unwinding frame 1 is the winding ring on the packaging machine.
[0020] In use, the unwinding mechanism described above has the film roll threaded onto the film unwinding shaft 2. The contact roller 3012 on the pressure roller 301 presses against the film roll and rotates as the film is fed out. To ensure the film remains tight and secure when pulled out, the damping of the contact roller 3012 during rotation can be adjusted using the damping adjustment component 3013. Increasing the damping of the contact roller 3012 makes it more difficult to pull out the film, thus ensuring the pulled-out film remains tight and secure, improving the strength of the packaging. For films with poor tensile strength, the damping of the contact roller 3012 can be reduced, allowing the film to be pulled out smoothly while maintaining a tight state. This unwinding mechanism can adjust the damping of the contact roller 3012 during rotation according to the characteristics of different films or different packaging requirements, thereby adjusting the tightness of the film during pull-out and effectively ensuring packaging quality.
[0021] The damping adjustment assembly 3013 includes a clamping pad 30131, a compression spring 30132, an adjusting nut 30133, and two bearings 30134. The contact roller 3012 has an axially extending through hole 30121, with an annular step 30122 at the center of the through hole 30121. The fixed shaft 3011 includes a front adjusting section 30111 and a rear mounting section 30112. The diameter of the rear mounting section 30112 is larger than the inner diameter of the annular step 30122, and the inner diameter of the annular step 30122 is larger than the diameter of the front adjusting section 30111. The fixed shaft 3011 passes through the through hole 30121 from rear to front, and the front adjusting section 30111 extends from the annular step 30122 to the contact roller 30134. 2. Externally, a clamping washer 30131 and a compression spring 30132 are sequentially fitted onto the front adjusting section 30111, and the clamping washer 30131 contacts the annular step 30122; the side wall of the front adjusting section 30111 has an external thread 301111 that matches the adjusting nut 30133, and the adjusting nut 30133 is threadedly connected to the front adjusting section 30111; one end of the compression spring 30132 is in close contact with the clamping washer 30131, and the other end of the compression spring 30132 is in close contact with the adjusting nut 30133; the rear mounting section 30112 is mounted on the pressure applying mechanism 302, and the side wall of the rear mounting section 30112 is connected to the inner wall of the through hole 30121 through the bearing 30134. The specific method for adjusting the damping of the contact roller 3012 during rotation is as follows: by tightening the adjusting nut 30133, the compression spring 30132 is compressed, which increases the pressure of the compression spring 30132 on the pressure pad 30131, thereby increasing the pressure of the pressure pad 30131 on the annular step 30122. This increases the friction between the contact roller 3012 and the pressure pad 30131, thus increasing the damping of the contact roller 3012 during rotation. This makes it less likely for the film to drive the contact roller 3012 to rotate and be released, ensuring that the unwound film will not loosen and improving the tightness of the packaging. Conversely, by loosening the adjusting nut 30133, the damping of the contact roller 3012 during rotation can be reduced.
[0022] The damping adjustment assembly 3013 also includes multiple retaining rings 30135. A first annular groove 301121 is formed on the outer wall of the rear mounting section 30112, located on one side of the bearing 30134. A second annular groove 301211 is formed on the inner wall of the rear part of the through hole 30121, located on the other side of the bearing 30134. Each retaining ring 30135 is respectively engaged in the first annular groove 301121 or the second annular groove 301211. The retaining rings 30135 limit the movement of the bearing 30134 and the contact roller 3012, preventing displacement of the bearing 30134 and the contact roller 3012 during damping adjustment or film unwinding.
[0023] The pressure roller 301 also includes a cover plate 3014, which is fixedly installed at the front end of the contact roller 3012. The rear end of the cover plate 3014 has an annular protrusion 30141, the diameter of which is larger than that of the contact roller 3012. The cover plate 3014 has a through hole corresponding to the through hole 30121. The adjusting nut 30133, the front adjusting section 30111, and a portion of the compression spring 30132 are located in the through hole and covered by the cover plate 3014. The annular protrusion 30141 of the cover plate 3014 can limit the film, preventing it from shifting away from the surface of the contact roller 3012. At the same time, the cover plate 3014 can also block the adjusting nut 30133, the front adjusting section 30111, and a portion of the compression spring 30132, preventing the adjusting nut 30133 from being accidentally touched.
[0024] The pressure applying mechanism 302 includes a first swing arm 3021 and a first tension spring 3022. The middle part of the first swing arm 3021 is rotatably mounted on the unwinding frame 1 via a pin. The rear mounting section 30112 of the fixed shaft 3011 is fixedly mounted on one end of the first swing arm 3021. One end of the first tension spring 3022 is connected to the other end of the first swing arm 3021, and the other end of the first tension spring 3022 is connected to the unwinding frame 1. Under the action of the first tension spring 3022, the first swing arm 3021 can keep the contact roller 3012 in close contact with the surface of the film roll during the unwinding process.
[0025] The unwinding mechanism also includes a tensioning device 4, which comprises a second swing arm 401, a tensioning roller 402, and a second tension spring 403. The middle part of the second swing arm 401 is rotatably mounted on the unwinding frame 1 via a pin. The tensioning roller 402 is rotatably mounted on one end of the second swing arm 401. One end of the second tension spring 403 is connected to the other end of the second swing arm 401, and the other end of the second tension spring 403 is connected to the unwinding frame 1. Under the action of the second tension spring 403, the second swing arm 401 enables the tensioning roller 402 to tension the film, which, in conjunction with the pressing device 3, maintains tension on the unwound film.
Claims
1. An unwinding mechanism for a packaging machine, comprising an unwinding frame, a film unwinding shaft, and a pressing device, wherein the film unwinding shaft is mounted on the unwinding frame; the pressing device comprises a pressing wheel and a pressing mechanism, wherein the pressing mechanism is mounted on the unwinding frame, characterized in that: The pressing roller includes a fixed shaft, a contact roller, and a damping adjustment assembly that can adjust the damping magnitude when the contact roller rotates. The fixed shaft is fixedly installed on the pressure application mechanism, and the contact roller is rotatably mounted on the fixed shaft. The position of the contact roller matches and is parallel to that of the film unwinding shaft. The damping adjustment assembly is disposed between the fixed shaft and the contact roller.
2. The unwinding mechanism of a packaging machine as described in claim 1, characterized in that: The damping adjustment assembly includes a clamping washer, a compression spring, an adjusting nut, and at least one bearing. The contact roller has an axially extending through hole with an annular step at the center. The fixed shaft includes a front adjustment section and a rear mounting section. The diameter of the rear mounting section is larger than the inner diameter of the annular step, and the inner diameter of the annular step is larger than the diameter of the front adjustment section. The fixed shaft passes through the through hole from back to front, and the front adjustment section extends out of the contact roller through the annular step. The clamping washer and the compression spring are sequentially fitted onto the front adjustment section, with the clamping washer in contact with the annular step. The side wall of the front adjustment section has an external thread matching the adjusting nut, and the adjusting nut is threadedly connected to the front adjustment section. One end of the compression spring is in close contact with the clamping washer, and the other end of the compression spring is in close contact with the adjusting nut. The rear mounting section is mounted on the pressure application mechanism, and the side wall of the rear mounting section is connected to the inner wall of the through hole via a bearing.
3. The unwinding mechanism of a packaging machine as described in claim 2, characterized in that: The damping adjustment assembly also includes multiple retaining rings. At least one first annular groove is opened on the outer wall of the rear mounting section, located on one side of the bearing. At least one second annular groove is opened on the inner wall of the rear part of the through hole, located on the other side of the bearing. Each retaining ring is respectively engaged in the first annular groove or the second annular groove.
4. The unwinding mechanism of a packaging machine as described in claim 2, characterized in that: The clamping roller also includes a cover plate, which is fixedly installed at the front end of the contact roller. The rear end of the cover plate is provided with an annular protrusion, the diameter of which is larger than that of the contact roller. The cover plate has a through hole corresponding to the through hole. The adjusting nut, the front adjusting section, and part of the compression spring are located in the through hole and covered by the cover plate.
5. The unwinding mechanism of a packaging machine as described in claim 2, characterized in that: The pressure applying mechanism includes a first swing arm and a first tension spring. The middle part of the first swing arm is rotatably mounted on the unwinding frame via a pin. The rear mounting section of the fixed shaft is fixedly mounted on one end of the first swing arm. One end of the first tension spring is connected to the other end of the first swing arm, and the other end of the first tension spring is connected to the unwinding frame.
6. The unwinding mechanism of a packaging machine as described in claim 1, characterized in that: The unwinding mechanism also includes a tensioning device, which includes a second swing arm, a tensioning roller, and a second tension spring. The middle part of the second swing arm is rotatably mounted on the unwinding frame via a pin. The tensioning roller is rotatably mounted on one end of the second swing arm. One end of the second tension spring is connected to the other end of the second swing arm, and the other end of the second tension spring is connected to the unwinding frame.