A tape measure

Abstract

A tape measure comprises a housing, a winding drum rotatably mounted in the housing and provided with a gear portion on the outer side, a damper fixedly arranged in the housing and located outside the winding drum, the damper being provided with a rotatable damping gear, an adapter connected with the damper and the winding drum, the adapter being provided with a first gear portion engaged with the damping gear of the damper and a second gear portion engaged with the gear portion of the winding drum, and a tape wound around the winding drum by an elastic member, the outer end of the tape extending out of the housing. The tape measure is beneficial to heat dissipation of the damper, is not easy to contaminate the tape, and is more flexible in adjusting the retraction speed of the tape.

Description

Technical Field

[0001] This utility model relates to the field of measuring tools, specifically to a measuring tape. Background Technology

[0002] Measuring tapes are common measuring tools in daily life. The reason why measuring tapes can automatically retract is because there is an elastic element inside the tape. However, traditional measuring tapes, especially steel measuring tapes, can easily cut your hand after measurement because the tape retracts too quickly.

[0003] To address the aforementioned technical problems, a measuring tape with a damping structure has emerged. For example, Japanese Patent Application Publication No. JP6577158B1 discloses a measuring tape comprising a housing, a winding drum, a measuring tape, and a damper. The measuring tape is wound around the winding drum via an elastic element. The winding drum is rotatably mounted within the housing via a support shaft. The damper is fixed to the winding drum, and the support shaft of the winding drum is connected to the rotational shaft of the damper. The damper is filled with a highly viscous fluid. Because this measuring tape connects the support shaft of the winding drum to the rotational shaft of the damper, the high-viscosity fluid in the damper reduces the rotational speed of the winding drum, thereby reducing the retraction speed of the measuring tape. This makes it less likely to cut hands and safer to use.

[0004] However, existing measuring tapes still have the following technical problems: installing the damper inside the winding drum is not conducive to the heat dissipation of the damper, which may cause the temperature to rise and the fluid viscosity to decrease, thus weakening the damping effect. On the other hand, there may be a problem that the fluid of the damper may seep into the winding drum and contaminate the tape. In addition, directly connecting the support shaft of the winding drum to the rotation shaft of the damper makes it impossible to further adjust the rotation speed of the winding drum, and the adjustment of the tape retraction speed is very limited. Summary of the Invention

[0005] The technical problem to be solved by this utility model is to provide a measuring tape that is conducive to heat dissipation of the damper, does not easily contaminate the tape, and allows for more flexible adjustment of the tape retraction speed.

[0006] The technical solution of this utility model is: a measuring tape, which includes: case; A winding drum is rotatably mounted inside the housing, and a gear section is provided on the outer side of the winding drum; A damper, which is fixed inside the housing and located outside the winding drum, is provided with a rotatable damping gear; A docking member is connected to both the damper and the winding drum. The docking member is provided with a first tooth portion that meshes with the damping gear of the damper and a second tooth portion that meshes with the gear portion of the winding drum. A measuring tape is wound around the winding drum via an elastic element, with the outer end of the measuring tape extending outside the housing.

[0007] The working principle of this utility model measuring tape is as follows: During measurement, the measuring tape is stretched outward, causing the winding drum to rotate. The elastic element converts the tension into elastic potential energy and stores it. The rotation of the winding drum causes the mating part that meshes with it to rotate, and the rotation of the mating part in turn causes the damping gear that meshes with it to rotate. After the measurement is completed, the measuring tape is released, the elastic element releases the elastic potential energy, and the winding drum rotates in the opposite direction under the action of the elastic element to retract the measuring tape. Since the rotational speed of the winding drum is restricted by the damping gear, the retraction speed of the measuring tape is relatively slow.

[0008] With the above structure, this utility model has the following advantages: This utility model of measuring tape places the damper outside the winding drum, which is more conducive to the heat dissipation of the damper and less likely to cause the temperature to rise and reduce the fluid viscosity, thus ensuring the damping effect. On the other hand, it also prevents the fluid of the damper from seeping into the winding drum and contaminating the tape. In addition, the output of the damper is not directly connected to the winding drum, but is connected through a gear transmission mechanism. Therefore, the tape retraction speed can be further adjusted by designing the transmission ratio of the gear transmission mechanism, making the tape retraction speed adjustment more flexible.

[0009] Preferably, the docking member is rotatably mounted within the housing via a first pivot. This arrangement prevents the docking member from swaying left and right under the limiting action of the damping gear and the first pivot, thereby achieving stable rotation of the docking member and ensuring reliable engagement between the docking member, the damper, and the winding drum, resulting in a more reliable and stable transmission connection.

[0010] Preferably, the outer peripheral wall of the first pivot is provided with a first annular limiting step that abuts against the top of the docking member, and the bottom of the docking member is provided with a first receiving cavity for accommodating the damping gear. The first tooth is disposed on the inner peripheral wall of the first receiving cavity, and the top of the first receiving cavity abuts against the top of the damping gear. This arrangement not only makes the connection between the damping gear and the docking member tighter, but also limits the vertical position of the docking member, further ensuring the stable rotation of the docking member and making the meshing of the docking member with the damper and the winding drum more reliable.

[0011] Preferably, the housing includes an upper housing and a lower housing. The first pivot is fixed to the upper housing, and the damper is fixed to the lower housing. The upper end of the mating member has a first shaft hole post that mates with the first pivot. When the mating member is installed on the damping gear of the damper and the upper housing is closed on the lower housing, the first pivot is inserted into the first shaft hole post, and the first annular limiting step abuts against the top of the first shaft hole post. The housing is configured as a split structure, which not only facilitates the installation of the first pivot and the first shaft hole post, but also facilitates the installation of other components inside the housing.

[0012] Preferably, a first limiting seat and a second limiting seat are respectively provided inside the housing and at the upper and lower ends of the winding cylinder. A rotating shaft structure is also connected between the first limiting seat and the second limiting seat. The winding cylinder is axially limited between the first limiting seat and the second limiting seat and is radially rotatably mounted on the rotating shaft structure. This arrangement integrates the rotating shaft structure and the axial limiting structure of the winding cylinder well, thereby simplifying the overall structure.

[0013] Preferably, the rotating shaft structure includes a second pivot disposed on one of the first limiting seat and the second limiting seat, and a second shaft hole post disposed on the other; when the winding drum is rotatably mounted on the second pivot and the upper housing is closed on the lower housing, the second pivot is inserted into the second shaft hole post. This rotating shaft structure is very simple, and the split-structure housing also facilitates the installation of the second pivot and the second shaft hole post.

[0014] Preferably, the first limiting seat is embedded in the top of the winding cylinder, and its outer peripheral wall is provided with a second annular limiting step that abuts against the top of the winding cylinder. The second limiting seat is embedded in the bottom of the winding cylinder, and its outer peripheral wall is provided with a third annular limiting step that abuts against the bottom of the winding cylinder. This arrangement makes the fit between the first and second limiting seats and the upper and lower ends of the winding cylinder more stable, and the limiting structure is relatively simple.

[0015] Preferably, the winding drum has a second receiving cavity, and the second pivot is axially inserted into the second receiving cavity. The elastic element is wound around the second pivot in the second receiving cavity, and the second pivot has a groove along its axial direction to lock the inner end of the elastic element. The measuring tape is also installed in the second receiving cavity, with its inner end connected to the outer end of the elastic element, and its outer end extending outside the winding drum. This arrangement utilizes the second receiving cavity to install the elastic element and the measuring tape, and uses the second pivot within the second receiving cavity to wind and fix the elastic element, resulting in a simple, compact, and rationally designed structure.

[0016] Preferably, the transmission ratio between the second tooth and the first tooth of the coupling member is greater than 1, and the transmission ratio between the gear portion of the winding drum and the second tooth of the coupling member is also greater than 1. This arrangement allows for a reasonable design of the transmission ratio of the gear transmission mechanism, further reducing the retraction speed of the belt. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the measuring tape of this utility model; Figure 2 This is a sectional view of the measuring tape of this utility model; Figure 3 This is a schematic diagram of the structure of the measuring tape of this utility model after the upper shell is hidden; Figure 4 This is a schematic diagram of the structure of the measuring tape after the lower housing is concealed. Figure 5 This is an exploded view of the measuring tape of this utility model; In the diagram: 1-Shell, 2-Winding cylinder, 3-Gear section, 4-Damper, 5-Damping gear, 6-Matching part, 7-First tooth, 8-Second tooth, 9-Scale, 10-Elastic element, 11-First pivot, 12-First annular limiting step, 13-First receiving cavity, 14-Upper shell, 15-Lower shell, 16-First shaft hole post, 17-First limiting seat, 18-Second limiting seat, 19-Rotating shaft structure, 20-Second pivot, 21-Second shaft hole post, 22-Second annular limiting step, 23-Third annular limiting step, 24-Second receiving cavity, 25-Slot, 26-Upper cylinder, 27-Lower cylinder seat, 28-Snap-on structure, 29-Rotating shaft, 30-Third receiving cavity, 31-First opening, 32-Second opening, 33-Guide groove. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example

[0019] like Figures 1-5 As shown, a measuring tape includes: Casing 1; The winding drum 2 is rotatably mounted inside the housing 1, and a gear part 3 is provided on the outer side of the winding drum 2; The damper 4 is fixed inside the housing 1 and located outside the winding drum 2. The damper 4 is provided with a rotatable damping gear 5. The docking part 6 is connected to both the damper 4 and the winding drum 2. The docking part 6 is provided with a first tooth 7 that meshes with the damping gear 5 of the damper 4 and a second tooth 8 that meshes with the gear part 3 of the winding drum 2. The ruler 9 is wound around the winding drum 2 via the elastic element 10, and the outer end of the ruler 9 extends out of the housing 1.

[0020] In this embodiment, the damper 4 is placed outside the winding drum 2, which is more conducive to the heat dissipation of the damper 4 and is less likely to cause the temperature to rise and reduce the fluid viscosity, thus ensuring the damping effect. On the other hand, it is also less likely for the fluid of the damper 4 to penetrate into the winding drum 2 and contaminate the tape 9. In addition, the output of the damper 4 is not directly connected to the winding drum 2, but is connected through a gear transmission mechanism. Therefore, the retraction speed of the tape 9 can be further adjusted by designing the gear ratio and other aspects of the gear transmission mechanism, so that the retraction speed adjustment of the tape 9 is more flexible.

[0021] The damper 4 is positioned below the docking member 6, the first tooth 7 is positioned at the bottom of the docking member 6, the second tooth 8 is positioned on the outer peripheral wall of the upper end of the docking member 6, and the gear 3 is positioned on the outer peripheral wall of the upper end of the winding drum 2. This arrangement is reasonable and facilitates the transmission connection between the damper 4, the docking member 6, and the winding drum 2.

[0022] The docking component 6 is rotatably mounted inside the housing 1 via the first pivot 11. In this embodiment, the upper end of the docking component 6 is rotatably mounted inside the housing 1 via the first pivot 11. This arrangement ensures that the lower end of the docking component 6 is engaged with the damping gear 5 and will not swing left or right, while the upper end is rotatably connected to the first pivot 11 of the housing 1 and will also not swing left or right. Therefore, under the limiting action of the damping gear 5 and the first pivot 11, the docking component 6 will not swing left or right as a whole, thereby achieving stable rotation of the docking component 6. This ensures reliable engagement between the docking component 6 and the damper 4 and the winding drum 2, making the transmission connection more reliable and stable.

[0023] The outer peripheral wall of the first pivot 11 is provided with a first annular limiting step 12 that abuts against the top of the docking member 6. The bottom of the docking member 6 is provided with a first receiving cavity 13 for accommodating the damping gear 5. The first tooth 7 is disposed on the inner peripheral wall of the first receiving cavity 13, and the top of the first receiving cavity 13 abuts against the top of the damping gear 5. This arrangement not only makes the connection between the damping gear 5 and the docking member 6 tighter, but also limits the vertical position of the docking member 6, further ensuring the stable rotation of the docking member 6 and making the meshing of the docking member 6 with the damper 4 and the winding drum 2 more reliable.

[0024] The housing 1 includes an upper housing 14 and a lower housing 15. A first pivot 11 is fixed to the upper housing 14, and a damper 4 is fixed to the lower housing 15. The upper end of the mating member 6 is provided with a first shaft hole post 16 that mates with the first pivot 11. When the mating member 6 is installed on the damping gear 5 of the damper 4 and the upper housing 14 is closed on the lower housing 15, the first pivot 11 is inserted into the first shaft hole post 16, and the first annular limiting step 12 abuts against the top of the first shaft hole post 16. The housing 1 is designed as a split structure, which not only facilitates the installation of the first pivot 11 and the first shaft hole post 16, but also facilitates the installation of other components inside the housing 1.

[0025] Inside the housing 1, at the upper and lower ends of the winding drum 2, there are respectively a first limiting seat 17 and a second limiting seat 18. A rotating shaft structure 19 is also connected between the first limiting seat 17 and the second limiting seat 18. The winding drum 2 is axially limited between the first limiting seat 17 and the second limiting seat 18 and is radially rotatably mounted on the rotating shaft structure 19. This arrangement integrates the rotating shaft structure 19 and the axial limiting structure of the winding drum 2 well, thereby simplifying the overall structure.

[0026] The rotating shaft structure 19 includes a second pivot 20 disposed on one of the first limiting seat 17 and the second limiting seat 18, and a second shaft hole post 21 disposed on the other. When the winding drum 2 is rotatably mounted on the second pivot 20 and the upper housing 14 is closed on the lower housing 15, the second pivot 20 is inserted into the second shaft hole post 21. This rotating shaft structure 19 is very simple, and the split structure of the housing 1 makes it very convenient to install the second pivot 20 and the second shaft hole post 21.

[0027] The first limiting seat 17 is embedded in the top of the winding cylinder 2, and the outer peripheral wall of the first limiting seat 17 is provided with a second annular limiting step 22 that abuts against the top of the winding cylinder 2. The second limiting seat 18 is embedded in the bottom of the winding cylinder 2, and the outer peripheral wall of the second limiting seat 18 is provided with a third annular limiting step 23 that abuts against the bottom of the winding cylinder 2. This arrangement makes the fit between the first limiting seat 17 and the second limiting seat 18 and the upper and lower ends of the winding cylinder 2 more stable, and the limiting structure is relatively simple.

[0028] The winding drum 2 has a second receiving cavity 24. A second pivot 20 is axially inserted into the second receiving cavity 24. An elastic element 10 is wound around the second pivot 20 within the second receiving cavity 24. The second pivot 20 has a retaining groove 25 along its axial direction to lock the inner end of the elastic element 10. A ruler 9 is also installed within the second receiving cavity 24. The inner end of the ruler 9 is connected to the outer end of the elastic element 10, and the outer end of the ruler 9 extends outside the winding drum 2. This arrangement utilizes the second receiving cavity 24 to install the elastic element 10 and the ruler 9, and uses the second pivot 20 within the second receiving cavity 24 to wind and fix the elastic element 10. The structure is simple, compact, and rationally designed.

[0029] The transmission ratio between the second tooth 8 and the first tooth 7 of the coupling member 6 is greater than 1, and the transmission ratio between the gear part 3 of the winding drum 2 and the second tooth 8 of the coupling member 6 is also greater than 1. This arrangement allows for a reasonable design of the transmission ratio of the gear transmission mechanism, further reducing the retraction speed of the tape 9.

[0030] The winding drum 2 includes an upper drum body 26 and a lower drum base 27. The bottom of the upper drum body 26 and the lower drum base 27 are connected together by a snap-fit ​​structure 28; the snap-fit ​​structure 28 can be based on existing technology. The winding drum 2 is designed as a split structure, which facilitates the installation of internal components of the winding drum 2.

[0031] In this embodiment, the elastic element 10 is a spring; the damper 4 is equipped with a rotating shaft 29, and the damping gear 5 is mounted on the rotating shaft 29. The interior of the damper 4 is filled with a high-viscosity fluid, thereby slowing down the rotation speed of the rotating shaft 29; the docking member 6, the winding cylinder 2, the first limiting seat 17, the second limiting seat 18, the first pivot 11, the second pivot 20, the first shaft hole post 16, and the second shaft hole post 21 are all columnar; the upper end of the docking member 6 is provided with a third accommodating cavity 30, and the first shaft hole post 16 is disposed in the third accommodating cavity 30; the second The pivot 20 is located at the center of the second limiting seat 18, and the second shaft hole post 21 is located at the center of the first limiting seat 17. The winding drum 2 and the housing 1 are also provided with a first opening 31 and a second opening 32 for the tape 9 to pass through. The first opening 31 of the winding drum 2 is also provided with a guide groove 33 that is adapted to the thickness of the tape 9. The tape 9 passes through the first opening 31 of the winding drum 2 and the second opening 32 of the housing 1 in sequence and extends out of the housing 1. Under the guidance of the guide groove 33, the stability of the tape 9 extraction direction is ensured.

[0032] The working principle of the measuring tape in this embodiment is as follows: During measurement, the measuring tape 9 is pulled outward, causing the winding drum 2 to rotate. The spring is tightened, thus converting the tension into stored elastic potential energy. The rotation of the winding drum 2 causes the mating part 6, which meshes with it, to rotate. The rotation of the mating part 6 then causes the damping gear 5, which meshes with it, to rotate. After the measurement is completed, the measuring tape 9 is released, the spring releases its elastic potential energy, and the winding drum 2 rotates in the opposite direction under the action of the spring to retract the measuring tape 9. Since the rotational speed of the winding drum 2 is restricted by the damping gear 5, the retraction speed of the measuring tape 9 is relatively slow.

Claims

1. A measuring tape, characterized in that it include: Shell (1); A winding cylinder (2) is rotatably installed inside the housing (1), and a gear part (3) is provided on the outer side of the winding cylinder (2). A damper (4) is fixed inside the housing (1) and located outside the winding drum (2), and the damper (4) is provided with a rotatable damping gear (5). The docking part (6) is connected to both the damper (4) and the winding drum (2). The docking part (6) is provided with a first tooth (7) that meshes with the damping gear (5) of the damper (4) and a second tooth (8) that meshes with the gear part (3) of the winding drum (2). A ruler (9) is wound around the winding cylinder (2) by an elastic element (10), and the outer end of the ruler (9) extends out of the housing (1).

2. A measuring tape according to claim 1, characterized in that: The docking member (6) is rotatably mounted inside the housing (1) via a first pivot (11).

3. A measuring tape according to claim 2, characterized in that: The outer peripheral wall of the first pivot (11) is provided with a first annular limiting step (12) that abuts against the top of the docking member (6). The bottom of the docking member (6) is provided with a first receiving cavity (13) for accommodating the damping gear (5). The first tooth (7) is provided on the inner peripheral wall of the first receiving cavity (13). The top of the first receiving cavity (13) abuts against the top of the damping gear (5).

4. A measuring tape according to claim 3, characterized in that: The housing (1) includes an upper housing (14) and a lower housing (15). The first pivot (11) is fixed on the upper housing (14), and the damper (4) is fixed on the lower housing (15). The upper end of the docking member (6) is provided with a first shaft hole post (16) that cooperates with the first pivot (11). When the docking member (6) is installed on the damping gear (5) of the damper (4) and the upper housing (14) is covered on the lower housing (15), the first pivot (11) is inserted into the first shaft hole post (16) and the first annular limiting step (12) abuts against the top of the first shaft hole post (16).

5. A measuring tape according to claim 1, characterized in that: The housing (1) is provided with a first limiting seat (17) and a second limiting seat (18) at the upper and lower ends of the winding cylinder (2), respectively. A rotating shaft structure (19) is also connected between the first limiting seat (17) and the second limiting seat (18). The winding cylinder (2) is axially limited between the first limiting seat (17) and the second limiting seat (18) and is radially rotatably mounted on the rotating shaft structure (19).

6. A measuring tape according to claim 5, characterized in that: The housing (1) includes an upper housing (14) and a lower housing (15). The rotating shaft structure (19) includes a second pivot (20) disposed on one of the first limiting seat (17) and the second limiting seat (18) and a second shaft hole post (21) disposed on the other. When the winding cylinder (2) is rotatably mounted on the second pivot (20) and the upper housing (14) covers the lower housing (15), the second pivot (20) is inserted into the second shaft hole post (21).

7. A measuring tape according to claim 5, characterized in that: The first limiting seat (17) is embedded in the top of the winding cylinder (2), and the outer peripheral wall of the first limiting seat (17) is provided with a second annular limiting step (22) that abuts against the top of the winding cylinder (2). The second limiting seat (18) is embedded in the bottom of the winding cylinder (2), and the outer peripheral wall of the second limiting seat (18) is provided with a third annular limiting step (23) that abuts against the bottom of the winding cylinder (2).

8. A measuring tape according to claim 6, characterized in that: The winding cylinder (2) is provided with a second receiving cavity (24), the second pivot (20) is axially inserted in the second receiving cavity (24), the elastic element (10) is wound around the second pivot (20) in the second receiving cavity (24), and the second pivot (20) is provided with a groove (25) in the axial direction to lock the inner end of the elastic element (10); the ruler (9) is also installed in the second receiving cavity (24), the inner end of the ruler (9) is connected to the outer end of the elastic element (10), and the outer end of the ruler (9) extends out of the winding cylinder (2).

9. A measuring tape according to claim 1, characterized in that: The transmission ratio between the second tooth (8) and the first tooth (7) of the docking member (6) is greater than 1, and the transmission ratio between the gear part (3) of the winding cylinder (2) and the second tooth (8) of the docking member (6) is also greater than 1.

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