A device and method for detecting the variation of zero position of a steel tape measure

Abstract

The application relates to a device and method for detecting the zero position variation of a steel tape measure, and relates to the technical field of metrological verification devices.The device comprises a fixing table for fixing the tape body of the steel tape measure in a locked state; a sliding mechanism which is arranged at intervals from the fixing table and is used for fixing the tape hook of the steel tape measure in a locked state; and a driving measurement mechanism which is connected with the sliding mechanism, used for driving the sliding mechanism to approach or move away from the fixing table and measuring the displacement of the sliding mechanism.When the driving measurement mechanism drives the sliding mechanism to approach or move away from the fixing table to the limit position, the tape hook of the steel tape measure is in the maximum compression state or the maximum stretching state, and the zero position variation is obtained through the displacement of the sliding mechanism.The device solves the problem that in the prior art, the tape body needs to be stretched to the upper surface of the scale plate, especially when the inner size of the tape hook of the steel tape measure is limited, it is difficult to ensure that the tape hook is in the maximum compression state during the stretching process, and it is difficult to accurately measure the zero position variation of the tape hook of the steel tape measure.

Description

Technical Field

[0001] This invention relates to the field of metrological verification device technology, and specifically to a device and method for detecting the zero-point variation of a steel tape measure. Background Technology

[0002] According to the national metrological verification regulations for steel measuring tapes, the verification of the indication error of steel measuring tapes adopts the comparative method. This involves comparing the steel measuring tape to be tested with a standard tape measure, measuring the indication error at specified positions and within different ranges, and then making a composite judgment. However, in the actual production and application of steel measuring tapes, especially for those with hooks, when measuring internal and external dimensions, the outer and inner sides of the hook contact the workpiece being measured, respectively, and these are used as the starting points for measurement, i.e., the zero point of the steel measuring tape. To eliminate the influence of the thickness of the hook on the measurement results, the connection between the hook and the tape is a riveted structure and a movable connection. The hook can be stretched and compressed, with two fixed ranges for stretching and compression, thus ensuring the consistency of measurement results when measuring internal and external dimensions. Therefore, the displacement variation of the hook is one of the main sources of indication error in steel measuring tapes. This has been verified in practice during the manufacturing, production, use, and periodic inspection of steel measuring tapes. Statistics show that, even when the measuring tape is free of creases, curls, or unevenness, the main reason for out-of-tolerance readings of steel measuring tapes is that the zero-point variation of the measuring hook exceeds the preset range. Therefore, in practical applications, the conformity of steel measuring tapes can be quickly determined and screened by detecting the zero-point variation of the measuring hook. This allows for subsequent verification and use of the initially screened steel measuring tapes, thereby shortening testing time and improving testing efficiency.

[0003] In the prior art, such as the steel tape measure zero-position calibration device with patent number CN106440988A, a base plate is included. A limiting plate perpendicular to the base plate is vertically installed on one side of the upper end face of the base plate. The limiting plate has parallel and spaced-apart limit blocks for the inner dimension of the hook, the outer dimension of the hook, and the depth measuring head, which are used to limit the hook and the head of the depth measuring scale, respectively. A scribing plate is fixedly installed on the upper end face of the other side of the base plate. The upper surface of the scribing plate has multiple scribing lines evenly spaced along the same direction from the side end of the base plate where the limiting plate is installed to the other side end where the scribing plate is not installed. A microscope frame is installed on the outer edge of the base plate next to the scribing plate. A reading microscope is movably fixed in the microscope frame. The reading microscope is located above the scribing plate in the installed state.

[0004] However, in the existing technology, when limiting the inner and outer dimensions of the steel tape measure hook, the tape body needs to be stretched to the surface of the engraving plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, which makes it difficult to accurately measure the zero position change of the steel tape measure hook. Summary of the Invention

[0005] This application provides a device and method for detecting the zero-position variation of a steel tape measure. It can solve the problem that in the prior art, when limiting the inner and outer dimensions of the steel tape measure hook, the tape body needs to be stretched to the surface of the engraving plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, which makes it difficult to accurately measure the zero-position variation of the steel tape measure hook.

[0006] In a first aspect, embodiments of this application provide a device for detecting the zero-point variation of a steel tape measure, comprising: A fixing platform is used to secure the steel tape measure in a locked position. A sliding mechanism is provided at a distance from the fixed platform, and the sliding mechanism is used to fix the hook of the steel tape measure in the locked state; A driving measuring mechanism, connected to the sliding mechanism, is used to drive the sliding mechanism closer to or further away from the fixed platform and to measure the displacement of the sliding mechanism. When the driving measuring mechanism drives the sliding mechanism closer to or further away from the fixed platform to the limit position, the hook of the steel tape measure is in the maximum compression state or the maximum tension state, and the zero position change is obtained by the displacement of the sliding mechanism.

[0007] In one embodiment, the sliding mechanism includes: A sliding block, which is spaced apart from the fixed platform and connected to the drive measuring mechanism; A clamping assembly, disposed on the sliding block, is used to clamp the hook of the steel measuring tape.

[0008] In one embodiment, the sliding block is provided with a threaded hole, and the driving measuring mechanism includes a measuring unit and a driving screw. The driving screw passes through the measuring unit and is rotatably connected to the measuring unit. The driving screw passes through the threaded hole and drives the sliding block to move closer to or away from the fixed platform by rotation. The measuring unit is spaced apart from the sliding block, and the displacement of the sliding block is obtained by recording the number of rotations of the driving screw.

[0009] In one embodiment, the end of the drive screw is provided with a forward ratchet and a reverse ratchet. The reverse ratchet is located between the forward ratchet and the measuring unit. Both the forward and reverse ratchets are used to drive the drive screw to rotate. When the hook of the steel tape measure is in the maximum compression state or the maximum tension state, the reverse ratchet or the forward ratchet begins to slip.

[0010] In one embodiment, a fixed slide rail is further included, the slide rail being arranged along the moving direction of the sliding block, the slide rail having a T-shaped groove, and the sliding block being slidably disposed within the T-shaped groove.

[0011] In one embodiment, the clamping assembly includes: A fixing plate is disposed on the upper side of the sliding block; A movable block is spaced apart from the fixed plate. The movable block is movably disposed on the upper side of the sliding block and is used to cooperate with the fixed plate to clamp the hook of the steel tape measure. A locking screw and a locking nut are provided. The locking screw passes through the fixed plate and extends into the movable block. The locking screw is rotatably connected to the fixed plate and threadedly connected to the movable block. The locking nut is provided on the locking screw and is used to abut against the side of the fixed plate away from the movable block, so that the movable block abuts against the fixed plate.

[0012] In one embodiment, a centering mechanism is further included, the centering mechanism comprising: Two spaced-apart baffles are located on both sides of the steel tape measure. A drive assembly, which is disposed on the fixed platform and connected to the two baffles, is used to drive the two baffles to move closer or further apart from each other, so that the baffles abut against the body of the steel tape measure.

[0013] In one embodiment, the fixed platform is provided with a guide hole perpendicular to the body of the steel measuring tape. The driving assembly includes a central gear and two racks. The central gear is rotatably disposed in the fixed platform. The racks are L-shaped, with the long side of the rack meshing with the central gear. The middle part of the short side of the rack extends out of the guide hole and is connected to the baffle. When the central gear rotates, it drives the racks to move, causing the two baffles to move closer to or further away from each other.

[0014] Secondly, embodiments of this application also provide a method for detecting the zero-point variation of a steel tape measure, which is implemented using the aforementioned device for detecting the zero-point variation of a steel tape measure, and includes the following steps: After the steel measuring tape is extended to the set length, it is locked, and the body and hook of the steel measuring tape are fixed respectively. Start the drive measurement mechanism to move the sliding mechanism closer to or further away from the fixed platform to its limit position, and record the displacement of the sliding mechanism; The zero-position variation of the steel tape measure is obtained based on the displacement of the sliding mechanism.

[0015] In one embodiment, after the activation of the driving measuring mechanism, which moves the sliding mechanism closer to or further away from the fixed platform to its limit position, and records the displacement of the sliding mechanism, the method further includes: Reset the displacement of the sliding mechanism and restart the drive measuring mechanism to make the sliding mechanism move in the opposite direction, so that the sliding mechanism moves closer to or further away from the fixed platform to the limit position.

[0016] The beneficial effects of the technical solutions provided in this application include: When using this device for detecting the zero-point variation of a steel tape measure, a fixed platform is used to fix the tape measure body in a locked state. A sliding mechanism is spaced apart from the fixed platform and used to fix the hook of the locked steel tape measure. A drive measuring mechanism is connected to the sliding mechanism and is used to drive the sliding mechanism closer to or further away from the fixed platform, measuring the displacement of the sliding mechanism. When the drive measuring mechanism drives the sliding mechanism closer to or further away from the fixed platform to its limit position, the hook of the steel tape measure is in a state of maximum compression or maximum tension. The zero-point variation is obtained from the displacement of the sliding mechanism. After the steel tape measure is pulled out to a set length and locked, the tape measure body and hook are fixed respectively. The drive measuring mechanism is then activated, causing the sliding mechanism to move closer to or further away from the fixed platform to its limit position, and the displacement of the sliding mechanism is recorded. The zero-point variation of the steel tape measure is obtained based on the displacement of the sliding mechanism. Since the steel tape measure is locked when the driving measuring mechanism moves the sliding mechanism closer to or away from the fixed platform, the displacement of the sliding mechanism is essentially the relative movement between the hook and the body of the tape measure. This reduces the influence of other factors, such as the extension and retraction of the steel tape measure. Therefore, when the hook of the steel tape measure moves from the maximum compression state to the maximum extension state, or from the maximum extension state to the maximum compression state, the displacement of the sliding mechanism is the zero-position change of the steel tape measure. The measured zero-position change is highly accurate, and the measurement process is simple and convenient. This solves the problem in the existing technology that when limiting the inner and outer dimensions of the steel tape measure hook, the body of the tape measure needs to be stretched to the surface of the engraving plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, which makes it difficult to accurately measure the zero-position change of the steel tape measure hook. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of an embodiment of a device for detecting the zero-position variation of a steel tape measure according to the present invention.

[0019] Figure 2 This is a top view schematic diagram of an embodiment of a device for detecting the zero-position variation of a steel tape measure according to the present invention.

[0020] Figure 3 This is a schematic cross-sectional view of an embodiment of a device for detecting the zero-position variation of a steel tape measure according to the present invention.

[0021] Figure 4 This is a schematic diagram of the drive component in an embodiment of a device for detecting the zero-position variation of a steel tape measure according to the present invention.

[0022] In the diagram: 1. Fixed platform; 11. Bracket; 12. Clamping mechanism; 121. Clamping block; 122. Clamping screw; 2. Steel tape measure; 3. Sliding mechanism; 31. Sliding block; 32. Clamping assembly; 321. Fixed plate; 322. Moving block; 323. Locking screw; 324. Locking nut; 33. Mounting plate; 4. Drive measuring mechanism; 41. Measuring unit; 42. Drive screw; 421. Forward ratchet; 422. Reverse ratchet; 43. Differential drum; 44. Fixed sleeve; 5. Slide rail; 6. Centering mechanism; 61. Baffle; 62. Drive assembly; 621. Central gear; 622. Rack; 7. Guide hole; 8. Base. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0024] This application provides an apparatus and method for detecting the zero-position variation of a steel tape measure. It solves the problem in the prior art that when limiting the inner and outer dimensions of the steel tape measure hook, the tape measure body needs to be stretched to the surface of the engraving plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, which makes it difficult to accurately measure the zero-position variation of the steel tape measure hook.

[0025] like Figure 1 and Figure 2 As shown, this application provides an apparatus for detecting the zero-point variation of a steel tape measure, comprising: Fixing platform 1, which is used to fix the body of the steel tape measure 2 in the locked state; The sliding mechanism 3 is spaced apart from the fixed platform 1. The sliding mechanism 3 is used to fix the hook of the steel tape measure 2 in the locked state. The driving measuring mechanism 4 is connected to the sliding mechanism 3 and is used to drive the sliding mechanism 3 to approach or move away from the fixed platform 1 and measure the displacement of the sliding mechanism 3. When the driving measuring mechanism 4 drives the sliding mechanism 3 to approach or move away from the fixed platform 1 to the limit position, the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, and the zero position change is obtained by the displacement of the sliding mechanism 3.

[0026] When using this device for detecting the zero-point variation of a steel tape measure, a fixed platform 1 is used to fix the body of the steel tape measure 2 in a locked state. A sliding mechanism 3 is spaced apart from the fixed platform 1 and is used to fix the hook of the steel tape measure 2 in a locked state. A drive measuring mechanism 4 is connected to the sliding mechanism 3 and is used to drive the sliding mechanism 3 closer to or further away from the fixed platform 1, and to measure the displacement of the sliding mechanism 3. When the drive measuring mechanism 4 drives the sliding mechanism 3 closer to or further away from the fixed platform 1 to its limit position, the hook of the steel tape measure 2 is in a state of maximum compression or maximum tension. The zero-point variation is obtained from the displacement of the sliding mechanism 3. After the steel tape measure 2 is pulled out to a set length and locked, the body and hook of the steel tape measure 2 are fixed respectively. The drive measuring mechanism 4 is then activated, causing the sliding mechanism 3 to move closer to or further away from the fixed platform 1 to its limit position, and the displacement of the sliding mechanism 3 is recorded. The zero-point variation of the steel tape measure 2 is obtained based on the displacement of the sliding mechanism 3. Since the steel tape measure 2 is locked when the driving measuring mechanism 4 drives the sliding mechanism 3 to approach or move away from the fixed platform 1, the displacement of the sliding mechanism 3 is essentially the relative movement between the hook and the body, reducing the influence of other factors, such as the extension and retraction of the steel tape measure 2. Therefore, when the hook of the steel tape measure 2 moves from the maximum compression state to the maximum extension state, or from the maximum extension state to the maximum compression state, the displacement of the sliding mechanism 3 obtained is the zero-position change of the steel tape measure 2. The measured zero-position change has high accuracy, and the measurement process is simple and convenient. It solves the problem in the prior art that when limiting the inner and outer dimensions of the steel tape measure hook, the body needs to be stretched to the surface of the engraving plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, which makes it difficult to accurately measure the zero-position change of the steel tape measure hook.

[0027] In this example, the fixed platform 1 includes a bracket 11 and a clamping mechanism 12. The clamping mechanism 12 is mounted on the bracket 11 and includes a clamping block 121 and a clamping screw 122. The clamping screw 122 passes through the clamping block 121 and extends into the bracket 11. By rotating the clamping screw 122, the clamping block 121 is pressed against the upper surface of the bracket 11, and the steel tape measure 2 is fixed by the clamping block 121.

[0028] In this example, the base 8 is also included, and the fixed platform 1, the sliding mechanism 3 and the driving measuring mechanism 4 are all mounted on the base 8.

[0029] like Figure 1 and Figure 2 As shown, in some optional embodiments, the sliding mechanism 3 includes: The sliding block 31 is spaced apart from the fixed platform 1 and connected to the drive measuring mechanism 4; The clamping assembly 32 is disposed on the sliding block 31 and is used to clamp the hook of the steel tape measure 2.

[0030] In this embodiment, the structure of the sliding mechanism 3 is specifically described. The sliding mechanism 3 includes a sliding block 31 and a clamping assembly 32. The sliding block 31 is spaced apart from the fixed platform 1 and connected to the driving measuring mechanism 4. The clamping assembly 32 is disposed on the sliding block 31 and is used to clamp the hook of the steel tape measure 2. The structure is simple and easy to manufacture.

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, in some optional embodiments, the sliding block 31 is provided with a threaded hole, and the driving measuring mechanism 4 includes a measuring unit 41 and a driving screw 42. The driving screw 42 passes through the measuring unit 41 and is rotatably connected to the measuring unit 41. The driving screw 42 passes through the threaded hole and drives the sliding block 31 to move closer to or away from the fixed platform 1 by rotation. The measuring unit 41 and the sliding block 31 are spaced apart, and the displacement of the sliding block 31 is obtained by recording the number of rotations of the driving screw 42.

[0032] In this embodiment, a threaded hole is provided on the sliding block 31. The driving measuring mechanism 4 includes a measuring unit 41 and a driving screw 42. The driving screw 42 passes through the measuring unit 41 and is rotatably connected to the measuring unit 41. The driving screw 42 passes through the threaded hole and drives the sliding block 31 to move closer to or away from the fixed platform 1 by rotation. The measuring unit 41 and the sliding block 31 are spaced apart. The displacement of the sliding block 31 is obtained by recording the number of rotations of the driving screw 42, and a specific driving method is given. The driving process is stable and it is convenient to record the displacement of the sliding block 31.

[0033] In this example, the system also includes a differential cylinder 43 and a fixed sleeve 44, both of which are fitted onto the drive screw 42. The fixed sleeve 44 has graduations on its bottom, allowing for visual reading of the integer portion of the measurement value. The fixed sleeve 44 has an internal thread with a pitch of 0.5 mm, which engages with the external thread on the drive screw 42 to form a threaded pair. The graduations on the differential cylinder 43 are used for fine visual readings, accurate to 0.01 mm and estimable to 0.001 mm. When the differential cylinder 43 rotates one revolution, the drive screw 42 advances or retracts by one pitch, typically 0.5 mm. The graduations on the differential cylinder 43 divide its circumference into 50 equal parts. For every 1 / 50th revolution of the differential cylinder 43, the drive screw 42 moves 0.01 mm. For visual readings, the measurement result is obtained by adding the main graduation on the fixed sleeve 44 to the decimal portion of the differential cylinder 43.

[0034] like Figure 1 and Figure 2As shown, in some optional embodiments, the end of the drive screw 42 is provided with a forward ratchet 421 and a reverse ratchet 422. The reverse ratchet 422 is located between the forward ratchet 421 and the measuring unit 41. Both the forward ratchet 421 and the reverse ratchet 422 are used to drive the drive screw 42 to rotate. When the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, the reverse ratchet 422 or the forward ratchet 421 begins to slip.

[0035] In this embodiment, a forward ratchet 421 and a reverse ratchet 422 are provided at the end of the drive screw 42. The reverse ratchet 422 is located between the forward ratchet 421 and the measuring unit 41. Both the forward ratchet 421 and the reverse ratchet 422 are used to drive the drive screw 42 to rotate. When the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, the reverse ratchet 422 or the forward ratchet 421 begins to slip. The forward ratchet 421 drives the drive screw 42 to rotate in the forward direction, and the reverse ratchet 422 drives the drive screw 42 to rotate in the reverse direction. When the hook of the steel tape measure 2 is in the maximum compression state or the maximum tension state, the reverse ratchet 422 or the forward ratchet 421 begins to slip, so that excessive rotation will not cause damage between the hook and the tape of the steel tape measure 2.

[0036] In this example, when the ratchet exceeds the preset measuring force, an audible alarm is triggered and the ratchet begins to slip, informing the user that the measuring force has reached the preset value, ensuring that the same torque is used during the measurement process to obtain more accurate measurement results.

[0037] like Figure 1 and Figure 3 As shown, in some optional embodiments, a fixed slide rail 5 is also included. The slide rail 5 is arranged along the moving direction of the sliding block 31. A T-shaped groove is provided in the slide rail 5, and the sliding block 31 is slidably arranged in the T-shaped groove.

[0038] In this embodiment, the device for detecting the zero-position variation of a steel tape measure also includes a fixed slide rail 5. The slide rail 5 is arranged along the moving direction of the sliding block 31. The slide rail 5 is provided with a T-shaped groove. The sliding block 31 is slidably arranged in the T-shaped groove. The sliding method is given. The sliding block 31 is realized by the cooperation of the drive screw 42, the sliding block 31 and the slide rail 5.

[0039] In this example, the sliding block 31 is partially engaged within the slide rail 5, allowing the sliding block 31 to move along the slide rail 5 under the action of the drive screw 42.

[0040] like Figure 1 and Figure 2 As shown, in some optional embodiments, the clamping assembly 32 includes: A fixing plate 321 is disposed on the upper side of the sliding block 31; The movable block 322 is spaced apart from the fixed plate 321. The movable block 322 is movably disposed on the upper side of the sliding block 31 and is used to cooperate with the fixed plate 321 to clamp the hook of the steel tape measure 2. The locking screw 323 passes through the fixed plate 321 and extends into the movable block 322. The locking screw 323 is rotatably connected to the fixed plate 321 and threadedly connected to the movable block 322. The locking screw 324 is provided on the locking screw 323 and is used to abut against the side of the fixed plate 321 away from the movable block 322, so that the movable block 322 abuts against the fixed plate 321.

[0041] In this embodiment, the structure of the clamping assembly 32 is specifically described. The clamping assembly 32 includes a fixed plate 321, a movable block 322, a locking screw 323, and a locking nut 324. The fixed plate 321 is disposed on the upper side of the sliding block 31, and the movable block 322 is spaced apart from the fixed plate 321. The movable block 322 is movably disposed on the upper side of the sliding block 31 and is used to cooperate with the fixed plate 321 to clamp the hook of the steel tape measure 2. The locking screw 323 passes through the fixed plate 321 and extends into the movable block 322. The locking screw 323 is rotatably connected to the fixed plate 321 and threadedly connected to the movable block 322. The locking nut 324 is disposed on the locking screw 323 and is used to abut against the side of the fixed plate 321 away from the movable block 322, so that the movable block 322 abuts against the fixed plate 321. The clamping or releasing process is achieved by adjusting the position of the locking nut 324 on the locking screw 323.

[0042] In this example, the movable block 322 is slidably mounted on the upper side of the sliding block 31 via a guide rail. A mounting plate 33 is also included, which is fixedly mounted on the sliding block 31 and located on the side of the fixed plate 321 away from the movable block 322. A locking screw 323 passes through the mounting plate 33, and a locking nut 324 is located between the fixed plate 321 and the mounting plate 33, improving the stability of the locking screw 323.

[0043] like Figure 1 and Figure 2 As shown, in some optional embodiments, a centering mechanism 6 is also included, which includes: Two spaced baffles 61 are located on both sides of the steel tape measure 2; The drive assembly 62 is mounted on the fixed platform 1 and connected to two baffles 61. It is used to drive the two baffles 61 to move closer or further apart, so that the baffles 61 abut against the body of the steel tape measure 2.

[0044] In this embodiment, the device for detecting the zero-position variation of a steel tape measure further includes a centering mechanism 6. The centering mechanism 6 includes a drive assembly 62 and two spaced baffles 61. The two baffles 61 are located on both sides of the steel tape measure 2. The drive assembly 62 is mounted on the fixed platform 1 and connected to the two baffles 61. It drives the two baffles 61 to move closer or further away from each other, so that the baffles 61 abut against the steel tape measure 2 to fix the lateral direction of the steel tape measure 2, prevent the steel tape measure 2 from moving during the detection process and affecting the inspection results, and also facilitate the positioning of the steel tape measure 2.

[0045] like Figure 1 , Figure 2 and Figure 4 As shown, in some optional embodiments, the fixed platform 1 is provided with a guide hole 7 perpendicular to the body of the steel tape measure 2. The drive assembly 62 includes a central gear 621 and two racks 622. The central gear 621 is rotatably disposed in the fixed platform 1. The racks 622 are L-shaped. The long side of the racks 622 meshes with the central gear 621. The middle part of the short side of the racks 622 extends out of the guide hole 7 and is connected to the baffle 61. When the central gear 621 rotates, it drives the racks 622 to move, so that the two baffles 61 move closer or further apart.

[0046] In this embodiment, a guide hole 7 perpendicular to the body of the steel measuring tape 2 is provided on the fixed platform 1. The drive assembly 62 includes a central gear 621 and two racks 622. The racks 622 are L-shaped. The central gear 621 is rotatably mounted in the fixed platform 1. The long side of the racks 622 meshes with the central gear 621. The middle of the short side of the racks 622 extends out of the guide hole 7 and is connected to the baffle 61. When the central gear 621 rotates, it drives the racks 622 to move, causing the two baffles 61 to move closer or further apart. Since the guide hole 7 restricts the direction of movement of the racks 622, the rotation of the central gear 621 drives the racks 622 to move, thereby causing the two baffles 61 to move closer or further apart. The structure is simple and easy to implement.

[0047] like Figure 1 and Figure 2 As shown, on the other hand, this application also provides a method for detecting the zero-point variation of a steel tape measure, which is implemented using the aforementioned device for detecting the zero-point variation of a steel tape measure, and includes the following steps: After extending the steel measuring tape 2 to the set length, lock it in place and fix the tape body and hook of the steel measuring tape 2 respectively; Start the drive measuring mechanism 4 to move the sliding mechanism 3 closer to or further away from the fixed platform 1 to the limit position, and record the displacement of the sliding mechanism 3; Based on the displacement of the sliding mechanism 3, the zero-position change of the steel tape measure 2 is obtained.

[0048] When using this device for detecting the zero-point variation of a steel tape measure, a fixed platform 1 is used to fix the body of the steel tape measure 2 in a locked state. A sliding mechanism 3 is spaced apart from the fixed platform 1 and is used to fix the hook of the steel tape measure 2 in a locked state. A drive measuring mechanism 4 is connected to the sliding mechanism 3 and is used to drive the sliding mechanism 3 closer to or further away from the fixed platform 1, and to measure the displacement of the sliding mechanism 3. When the drive measuring mechanism 4 drives the sliding mechanism 3 closer to or further away from the fixed platform 1 to its limit position, the hook of the steel tape measure 2 is in a state of maximum compression or maximum tension. The zero-point variation is obtained from the displacement of the sliding mechanism 3. After the steel tape measure 2 is pulled out to a set length and locked, the body and hook of the steel tape measure 2 are fixed respectively. The drive measuring mechanism 4 is then activated, causing the sliding mechanism 3 to move closer to or further away from the fixed platform 1 to its limit position, and the displacement of the sliding mechanism 3 is recorded. The zero-point variation of the steel tape measure 2 is obtained based on the displacement of the sliding mechanism 3. Since the steel tape measure 2 is locked when the driving measuring mechanism 4 drives the sliding mechanism 3 to approach or move away from the fixed platform 1, the displacement of the sliding mechanism 3 is essentially the relative movement between the hook and the body, reducing the influence of other factors, such as the extension and retraction of the steel tape measure 2. Therefore, when the hook of the steel tape measure 2 moves from the maximum compression state to the maximum extension state, or from the maximum extension state to the maximum compression state, the displacement of the sliding mechanism 3 obtained is the zero-position change of the steel tape measure 2. The measured zero-position change has high accuracy, and the measurement process is simple and convenient. It solves the problem in the prior art that when limiting the inner and outer dimensions of the steel tape measure hook, the body needs to be stretched to the surface of the engraving plate. In particular, when limiting the inner dimension of the steel tape measure hook, it is difficult to ensure that the hook is in the maximum compression state during the stretching process, which makes it difficult to accurately measure the zero-position change of the steel tape measure hook.

[0049] like Figure 1 and Figure 2 As shown, in some optional embodiments, after the activation of the driving measuring mechanism 4, which moves the sliding mechanism 3 closer to or further away from the fixed platform 1 to its limit position, and the displacement of the sliding mechanism 3 is recorded, the method further includes: Reset the displacement of the sliding mechanism 3 and restart the drive measuring mechanism 4 to make the sliding mechanism 3 move in the opposite direction, so that the sliding mechanism 3 moves closer to or further away from the fixed table 1 to the limit position.

[0050] In this embodiment, after the drive measuring mechanism 4 is activated, the sliding mechanism 3 is moved closer to or further away from the fixed platform 1 to its limit position, and the displacement of the sliding mechanism 3 is recorded, the displacement of the sliding mechanism 3 is reset, and the drive measuring mechanism 4 is restarted, causing the sliding mechanism 3 to move in the opposite direction, moving closer to or further away from the fixed platform 1 to its limit position. This eliminates the influence of the initial relative position of the ruler and the hook on the measurement results, and it is not necessary to ensure that the initial relative position of the ruler and the hook is at its limit position, thus making it more applicable.

[0051] In this example, this step can be repeated to obtain two sets of data: the zero displacement of tension and the zero displacement of thrust, and calculate their average value as the final measurement result. The two measurement results are then compared with the standard displacement of the hook specified in the steel tape measure manufacturing standard. The difference is the zero displacement of the hook when subjected to tension and thrust.

[0052] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0053] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A device for detecting the zero-position variation of a steel tape measure, characterized in that, include: A fixing platform (1) is used to fix the steel tape measure (2) in a locked state; A sliding mechanism (3) is provided at a distance from the fixed platform (1). The sliding mechanism (3) is used to fix the hook of the steel tape measure (2) in the locked state. A driving measuring mechanism (4) is connected to the sliding mechanism (3) to drive the sliding mechanism (3) to approach or move away from the fixed platform (1) and to measure the displacement of the sliding mechanism (3). When the driving measuring mechanism (4) drives the sliding mechanism (3) to approach or move away from the fixed platform (1) to the limit position, the hook of the steel tape measure (2) is in the maximum compression state or the maximum tension state. The zero position change is obtained by the displacement of the sliding mechanism (3). The sliding mechanism (3) includes: A sliding block (31) is spaced apart from the fixed platform (1) and connected to the driving measuring mechanism (4); A clamping assembly (32) is disposed on the sliding block (31) for clamping the hook of the steel tape measure (2); The sliding block (31) is provided with a threaded hole. The driving measuring mechanism (4) includes a measuring unit (41) and a driving screw (42). The driving screw (42) passes through the measuring unit (41) and is rotatably connected to the measuring unit (41). The driving screw (42) passes through the threaded hole and drives the sliding block (31) to move closer to or away from the fixed platform (1) by rotation. The measuring unit (41) is spaced apart from the sliding block (31), and the displacement of the sliding block (31) is obtained by recording the number of rotations of the driving screw (42). The end of the drive screw (42) is provided with a forward ratchet (421) and a reverse ratchet (422). The reverse ratchet (422) is located between the forward ratchet (421) and the measuring unit (41). Both the forward ratchet (421) and the reverse ratchet (422) are used to drive the drive screw (42) to rotate. When the hook of the steel tape measure (2) is in the maximum compression state or the maximum tension state, the reverse ratchet (422) or the forward ratchet (421) begins to slip.

2. The device for detecting the zero-position variation of a steel measuring tape as described in claim 1, characterized in that, It also includes a fixed slide rail (5), which is arranged along the moving direction of the sliding block (31). The slide rail (5) is provided with a T-shaped groove, and the sliding block (31) is slidably arranged in the T-shaped groove.

3. The device for detecting the zero-position variation of a steel tape measure as described in claim 1, characterized in that, The clamping assembly (32) includes: A fixing plate (321) is disposed on the upper side of the sliding block (31); A movable block (322) is spaced apart from the fixed plate (321). The movable block (322) is movably disposed on the upper side of the sliding block (31) and is used to cooperate with the fixed plate (321) to clamp the hook of the steel tape measure (2). A locking screw (323) and a locking nut (324) are provided. The locking screw (323) passes through the fixed plate (321) and extends into the movable block (322). The locking screw (323) is rotatably connected to the fixed plate (321) and threadedly connected to the movable block (322). The locking nut (324) is provided on the locking screw (323) and is used to abut against the side of the fixed plate (321) away from the movable block (322) so that the movable block (322) abuts against the fixed plate (321).

4. The device for detecting the zero-position variation of a steel measuring tape as described in claim 1, characterized in that, It also includes a centering mechanism (6), which comprises: Two spaced baffles (61) are located on both sides of the steel tape measure (2); A drive assembly (62) is disposed on the fixed platform (1) and connected to the two baffles (61) for driving the two baffles (61) to move closer or further away from each other, so that the baffles (61) abut against the body of the steel tape measure (2).

5. The device for detecting the zero-position variation of a steel measuring tape as described in claim 4, characterized in that, The fixed platform (1) is provided with a guide hole (7) perpendicular to the body of the steel measuring tape (2). The drive assembly (62) includes a central gear (621) and two racks (622). The central gear (621) is rotatably disposed in the fixed platform (1). The racks (622) are L-shaped. The long side of the racks (622) meshes with the central gear (621). The middle part of the short side of the racks (622) extends out of the guide hole (7) and is connected to the baffle (61). When the central gear (621) rotates, it drives the racks (622) to move, so that the two baffles (61) move closer or further away from each other.

6. A method for detecting the zero-position variation of a steel tape measure, characterized in that, The method of using the apparatus for detecting the zero-point variation of a steel measuring tape as described in any one of claims 1-5 includes the following steps: After the steel tape measure (2) is pulled out to the set length, it is locked and the body and hook of the steel tape measure (2) are fixed respectively. Start the drive measuring mechanism (4) to move the sliding mechanism (3) closer to or further away from the fixed platform (1) to the limit position, and record the displacement of the sliding mechanism (3); The zero-position variation of the steel tape measure (2) is obtained based on the displacement of the sliding mechanism (3).

7. The method for detecting the zero-position variation of a steel measuring tape as described in claim 6, characterized in that, After the aforementioned start-up drive measuring mechanism (4) moves the sliding mechanism (3) closer to or further away from the fixed platform (1) to its limit position and records the displacement of the sliding mechanism (3), the process further includes: Reset the displacement of the sliding mechanism (3) and restart the drive measuring mechanism (4) to make the sliding mechanism (3) move in the opposite direction, so that the sliding mechanism (3) moves closer to or further away from the fixed platform (1) to the limit position.

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