CN112066832A

CN112066832A - Measuring tape

Info

Publication number: CN112066832A
Application number: CN202011057524.6A
Authority: CN
Inventors: 王高鹏; 陈滨
Original assignee: Yiqixiu Information Technology Beijing Co ltd
Current assignee: Yiqixiu Information Technology Beijing Co ltd
Priority date: 2020-09-30
Filing date: 2020-09-30
Publication date: 2020-12-11

Abstract

The present disclosure provides a tape measure. The tape measure comprises a shell, a main scale and a first clamping hook, wherein an opening is formed in the shell; the main ruler comprises a plurality of ruler strips and a fixing piece, and the fixing piece is fixed at the movable end of all the ruler strips; the ruler strips are provided with a plurality of magnetic parts, when the ruler strips extend out of the openings, the parts of any two adjacent ruler strips extending out of the shell can be adsorbed together through the magnetic parts corresponding to the positions, so that the parts of all the ruler strips extending out of the shell are surrounded into a closed shape; at least one ruler strip is provided with a first scale; the first clamping hook is connected to the fixing piece and clamped outside the opening of the shell, and is used for pulling all the ruler strips to extend out of the shell and be clamped on the surface of an object to be measured. The main scale formed by combining the plurality of scale strips has certain bending strength, is suitable for measuring the length with larger size, improves the measuring range, and can also reduce the precision loss caused by self deformation.

Description

Measuring tape

Technical Field

The disclosure relates to the technical field of measuring tools, in particular to a measuring tape.

Background

The length measurement is needed in various fields of machining, engineering and the like, and the existing tools for measuring the length mainly comprise a vernier caliper, a measuring tape, a laser tracker, 3D optical measurement and the like.

The vernier caliper can realize high-precision measurement, but is heavy in weight due to the fact that the vernier caliper is mostly made of metal, is only suitable for measuring the length of a small size, and is inconvenient to operate due to too large weight if the length exceeds 1 meter. When the length exceeds 1 meter, a measuring tape is adopted for measurement, but the existing measuring tape has low strength, and can deform due to dead weight when the extending amount is long, so that the measurement precision is influenced. Large coordinate measuring instruments such as laser trackers and 3D optical measurement instruments are expensive and need to work in a thermostatic chamber to maintain their accuracy, limiting their application range.

It is to be noted that the information invented in the background section above is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

It is an object of the present disclosure to provide a tape measure that solves one or more problems with existing tape measures.

According to one aspect of the present disclosure, there is provided a tape measure comprising:

the winding drum comprises a shell, wherein a plurality of winding drums are arranged in the shell, and an opening is formed in the shell;

the main scale comprises a plurality of scale strips and a fixing piece, the fixing piece is fixed at the movable end of all the scale strips, and the main scale is positioned in the shell and can extend out of the opening; the ruler strips are provided with a plurality of magnetic parts, when the ruler strips extend out of the opening, the parts of any two adjacent ruler strips extending out of the shell can be adsorbed together through the magnetic parts corresponding to the positions, so that the parts of all the ruler strips extending out of the shell are encircled into a closed shape; at least one of the ruler strips is provided with a first scale;

the first clamping hook is connected to the fixing piece of the main ruler and clamped outside the opening of the shell, and the first clamping hook is used for simultaneously pulling all the ruler strips to extend out of the shell and be clamped on the surface of an object to be measured.

In an exemplary embodiment of the present disclosure, the number of the blade is at least three.

In an exemplary embodiment of the disclosure, the plurality of magnetic members on the blade comprises two magnetic member sets, the two magnetic member sets are respectively close to two opposite long edges of the blade, and all the magnetic members in each magnetic member set are distributed at intervals along the length direction of the blade; and the magnetic parts of the two magnetic part groups which are close to each other on the two adjacent ruler strips are in one-to-one correspondence.

In an exemplary embodiment of the disclosure, a cross section of the blade in the width direction is arc-shaped, two opposite surfaces of the blade are respectively a concave surface and a convex surface, and the convex surface of any part of the blade extending out of the housing and the convex surface of the adjacent blade are adsorbed together through the magnetic member.

In an exemplary embodiment of the disclosure, a cross section of the blade in the width direction is arc-shaped, two opposite surfaces of the blade are respectively a concave surface and a convex surface, and the convex surface of any part of the blade extending out of the housing and the concave surface of the adjacent blade are adsorbed together through the magnetic member.

In an exemplary embodiment of the present disclosure, the magnetic member comprises neodymium iron boron, and the blade is made of steel.

In an exemplary embodiment of the disclosure, the shape of the housing opening is the same as the shape of the portion of the blade extending out of the housing.

In an exemplary embodiment of the disclosure, a limiting device for limiting the extending length of the measuring tape is arranged on the inner side of the opening of the shell.

In an exemplary embodiment of the present disclosure, the first hook is rotatably disposed on the fixing member and is rotatable around an extending direction of the main scale.

In an exemplary embodiment of the present disclosure, the first hook is detachably disposed on the fixing member.

In an exemplary embodiment of the disclosure, the fixing piece comprises a bottom support, a fixing sleeve, a spring, a connecting rod, a sliding block and a bushing, wherein the bottom support is fixed at the movable end of all the ruler strips; the fixing sleeve is sleeved outside the bottom support, a first cavity is formed between the fixing sleeve and the bottom support, and a through hole is formed in one surface, opposite to the bottom support, of the fixing sleeve in the extending direction of the ruler strip; the bushing is sleeved outside the fixed sleeve, the sliding block is positioned in the first cavity and is provided with a protruding part, and the protruding part extends out of the through hole and is fixed on the bushing; the sliding block is also provided with a guide groove, one end of the connecting rod is fixed on the bottom support, the other end of the connecting rod is slidably arranged in the guide groove and can move along the guide groove, the spring is sleeved outside the connecting rod, one end of the spring is fixed on the bottom support, and the other end of the spring is fixed on the sliding block; the first clamping hook is sleeved on the bushing.

In an exemplary embodiment of the disclosure, a plurality of winding drums are further arranged in the casing, the number of the winding drums is equal to that of the measuring tapes, and the measuring tapes are wound on the winding drums in a one-to-one correspondence manner.

In an exemplary embodiment of the present disclosure, the tape measure further comprises a vernier, the vernier being located outside the housing; the vernier scale comprises an auxiliary scale and a second clamping hook arranged on the auxiliary scale, the auxiliary scale is arranged on the main scale and can slide relative to the main scale, second scales are arranged on the auxiliary scale, and the second clamping hook is used for being clamped on the surface of an object to be measured in a matching mode with the first clamping hook.

In an exemplary embodiment of the disclosure, the auxiliary ruler is fixed on the housing, or the auxiliary ruler is slidably sleeved on the main ruler.

In an exemplary embodiment of the present disclosure, the first hook and the second hook each include a clamping surface, and the clamping surfaces of the first hook and the second hook are disposed oppositely or oppositely; or the first clamping hook and the second clamping hook both comprise hole positioning structures, and the hole positioning structures can be clamped in holes in the object to be detected.

In an exemplary embodiment of the present disclosure, the tape measure further includes a display screen and an automatic test unit, the display screen is disposed on the housing, and the automatic test unit includes:

the displacement sensor is arranged in the shell and used for measuring the length of the ruler strip of the main ruler extending out of the shell;

and the processor is arranged in the shell, is connected with the displacement sensor, and is used for calculating the length of the object to be measured according to the length data sensed by the displacement sensor and displaying the length on the display screen.

In an exemplary embodiment of the present disclosure, the automatic test unit further includes a temperature sensor disposed on the housing for sensing the ambient temperature; the processor is further used for correcting the length of the object to be detected according to the temperature data sensed by the temperature sensor, and the corrected result is used as the actual length of the object to be detected to be displayed on the display screen.

In an exemplary embodiment of the present disclosure, the automatic test unit further includes an angle sensor, which is disposed in the housing, and is configured to sense an angle between the main scale and a length direction to be measured; the processor is further used for correcting the length of the object to be detected according to the angle data sensed by the angle sensor, and the corrected result is used as the actual length of the object to be detected to be displayed on the display screen.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 is a perspective view of a tape measure according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of the construction of one blade in an exemplary embodiment;

FIG. 3 is a schematic cross-sectional view of a main scale comprised of three blade bars according to an embodiment of the present disclosure;

FIG. 4 is a schematic cross-sectional view of another main scale comprised of three blade bars according to an embodiment of the present disclosure;

FIG. 5 is a schematic cross-sectional view of a main scale comprised of four bars according to an embodiment of the present disclosure;

FIG. 6 is a cross-sectional view of another main scale comprised of four bars according to an embodiment of the present disclosure;

FIG. 7 is a schematic view of a combination of a magnetic member and a blade according to an embodiment of the disclosure;

FIG. 8 is a schematic view of the housing and main scale of FIG. 1 in the direction of extension of the main scale;

FIG. 9 is a schematic view of another opening configuration of the housing according to the disclosed embodiment;

FIG. 10 is a schematic view of the housing and main scale of FIG. 1 in a direction perpendicular to the extension of the main scale;

FIG. 11 is a schematic view of a thickness compensation structure in an embodiment of the present disclosure;

FIG. 12 is a schematic view of a tape measure with a fixed vernier in an embodiment of the disclosure;

FIG. 13 is a schematic view of a tape measure with a floating vernier in accordance with an embodiment of the present disclosure;

FIG. 14 is a schematic view of a tape measure with fixed and floating vernier in accordance with an embodiment of the present disclosure;

FIGS. 15-17 are three schematic views of the first hook and the second hook;

FIG. 18 is a schematic view of a tape measure with a handle and a housing according to an embodiment of the disclosure.

In the figure: 10. a housing; 20. a main scale; 30. a first hook; 101. a reel; 102. an opening; 210. a ruler strip; 220. a fixing member; 230. a magnetic member; 211. a first scale; 212. a through hole; 231. a metal mesh sheet; 232. neodymium iron boron; 221. a bottom support; 222. fixing a sleeve; 223. a spring; 224. a connecting rod; 225. a slider; 226. a bushing; 227. a first cavity; 228. a second cavity; 229. a guide groove; 40. a vernier scale; 41. a secondary ruler; 42. a second hook; 411. a second scale; 110. a display screen; 120. a handle; 130. a cover body; 90. an object to be measured;

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

The tape measure provided in the embodiment of the present disclosure, as shown in fig. 1, is a schematic perspective view of a tape measure of the embodiment of the present disclosure, and includes a housing 10, a main tape 20, and a first hook 30, wherein a plurality of winding drums 101 are disposed in the housing 10, and an opening 102 is disposed on the housing 10; the main scale 20 comprises a plurality of scale strips 210 and a fixed part 220, the fixed part 220 is fixed at the movable ends of all the scale strips 210, and the main scale 20 is positioned in the shell 10 and can extend out of the opening 102; the plurality of magnetic members 230 are arranged on the ruler strips 210, when the plurality of ruler strips 210 extend out of the opening 102, the parts of any two adjacent ruler strips 210 extending out of the casing 10 can be adsorbed together through the magnetic members 230 corresponding to the positions, so that the parts of all the ruler strips 210 extending out of the casing 10 are encircled into a closed shape; at least one of the rulers 210 is provided with a first scale 211; the first hook 30 is connected to the fixing member 220 of the main scale 20 and is clamped outside the opening 102 of the casing 10, and the first hook 30 is used for simultaneously pulling all the scale strips 210 to extend out of the casing 10 and be clamped on the surface of the object to be measured.

When the tape measure is used, the first hook 30 is pulled outwards, the first hook 30 drives all the ruler strips 210 to extend out of the opening 102 of the shell 10 through the fixing piece 220, two adjacent ruler strips 210 extending out of the opening 102 are adsorbed together through the magnetic piece 230 arranged on the ruler strips 210, all the ruler strips 210 are adsorbed together to form a whole, a mutually supporting structure is formed, the first hook 30 is clamped on the surface of an object to be measured, and the length of the object to be measured can be known by reading according to the first scale 211 arranged on the main ruler 20.

The main scale 20 of the present disclosure is formed by combining a plurality of scale strips 210, which enhances the strength of the portion of the main scale 20 extending out of the housing 10, so that the main scale has a certain bending strength in a free state, and reduces the precision loss caused by self-weight deformation and bending, thereby being suitable for length measurement of larger size and improving the measurement range. On the other hand, as the rigidity of the main scale 20 is enhanced, when the external dimension of the object to be tested is tested, the precision loss of the main scale 20 caused by the self-tensile stress deformation can be reduced; when the inner dimension of the object to be measured is measured, the precision loss caused by the deformation of the inner side of the object to be measured, which is propped against the inner side of the object to be measured, can be reduced, and therefore, the measurement precision of the measuring tape is also improved.

The tape measure of the embodiments of the present disclosure is explained in detail below:

in the present application, the number of the blade 210 in the main blade is two or more. When only two rulers 210 are included, the two rulers 210 can be adsorbed back to back through the magnetic part 230, and the first scale 211 is arranged outside, so that the strength can be improved. The number of the tape 210 is preferably three or more, so that a more three-dimensional structure can be formed, and the overall strength of the main scale 20 is improved more remarkably.

As shown in fig. 2, which is a schematic structural diagram of one of the measuring tapes 210 in an exemplary embodiment, the first scale 211 provided on the measuring tape 210 may be set as millimeter scale, centimeter scale, etc. according to measurement needs, and may be provided on only one of the measuring tapes 210, or may be provided on each measuring tape 210, so as to select the most convenient measuring tape 210 for reading. To facilitate reading, the first scale 211 on the main scale 20 may comprise a fluorescent material. In the main ruler composed of a plurality of ruler strips, only one ruler strip can be provided with the first scales, and the first scales can also be arranged on all the ruler strips so as to facilitate reading from different directions.

As shown in the figure, the plurality of magnetic members 230 are disposed on the ruler strip 210, and all the magnetic members 230 are divided into two groups, namely a first magnetic member group and a second magnetic member group, and the two magnetic member groups are respectively close to two opposite long sides of the ruler strip 210, namely, the upper row of magnetic members is the first magnetic member group, and the lower row is the second magnetic member group, so that when the two ruler strips 210 are close to each other, the two magnetic member groups disposed on the long sides close to each other are more easily attracted together. Taking the main scale composed of three bars shown in fig. 3 as an example, when the lower sides of the left bar 210 and the right bar 210 in the figure approach, the magnetic attraction sets on the upper and lower sides of the two bars are nearest to each other, and similarly, when every two bars 210 approach each other, the two magnetic attraction sets on each bar 210 respectively attract the magnetic attraction sets on the adjacent bars. Obviously, the length and angle of the triangle are determined by the width of the blade 210 and the angle between adjacent blades. For example, when the included angle between the three coiled rulers 210 is 120 ° and the widths of the three rulers 210 are equal, the section of the main ruler consisting of the three rulers 210 is approximately a closed regular triangle, as shown in fig. 3. When two of the three rulers 210 are equal in width and different from the third, the main ruler 20 composed of the three rulers 210 has a closed isosceles triangle-shaped cross section, as shown in fig. 4. That is, the plurality of blades 210 may or may not have the same width. In the exemplary embodiment shown in fig. 5, the main scale includes four bars, and the four bars have equal widths, and the cross section of the main scale 20 formed by the four bars magnetically attracting each other is approximately a closed square. It will be understood by those skilled in the art that when the number of the rulers 210 is larger, the main section of the ruler composed of all the rulers is a corresponding polygon, which is not listed here.

It will be appreciated that the closer the two blade bars 210 are, the more magnetic attraction will occur. With continued reference to fig. 2, the magnetic members 230 in each magnetic member set are spaced along the length of the blade 210, and the positions of the magnetic members 230 in two adjacent magnetic member sets on two adjacent blades 210 should correspond to each other one by one, so that the two adjacent blades 210 can be attracted together at the same length, thereby forming a whole with multiple blades 210. The distance between each magnetic group and the long edge of the ruler strip 210 can be set according to actual needs, and is not limited in detail here.

The magnetic members 230 in a magnetic member group on the blade 210 can be equally spaced, which is advantageous to avoid dislocation and deformation when magnetic attraction is performed after the blade is extended. The magnetic members 230 within a set of magnetic members may also be spaced at unequal intervals to avoid magnetic attraction of the magnetic members 230 between the layers of the tape 210 wound on the reel 101. In addition, the two magnetic groups on the same ruler 210 may be distributed in the same manner or in different manners, that is, the distribution manner of the magnetic members 230 in the first magnetic group and the distribution manner of the magnetic members 230 in the second magnetic group may be the same or different, and as long as the magnetic members 230 in any magnetic group and the magnetic member 230 in the other magnetic group matched with the magnetic group are distributed in the same manner, the magnetic properties corresponding to each other can be achieved. Preferably, the spacing between the magnetic members 230 in each set is 5 to 10 times the width of the blade 210.

With continued reference to fig. 3-5, as a further improvement, the cross-section of the blade 210 in the width direction is provided in an arc shape, such that the opposing faces of the blade 210 are concave and convex, respectively. There are two ways to magnetically attract two adjacent rulers 210. As shown in fig. 3-5, the magnetic attraction manner is one of the magnetic attraction manner, in which the convex surface of the portion of one blade 210 extending out of the housing 10 and the convex surface of the adjacent blade 210 are attracted together by the magnetic member 230. That is, when two adjacent strips 210 are magnetically attracted together, the convex surfaces of the two strips 210 are attached together, and the arc-shaped openings 102 of all the strips 210 are outward as a whole, thereby forming the shape as shown in the figure. As shown in fig. 6, as another magnetic attraction manner, in this manner, for example, a main scale composed of four bars, a convex surface of a portion of one bar 210 extending out of the housing 10 and a concave surface of an adjacent bar 210 are attracted together by a magnetic member 230. That is, when two adjacent strips 210 are magnetically attracted together, the convex surface of one strip 210 fits the concave surface of the other strip 210, and the arcuate openings 102 of all the strips 210 face inward, forming a quadrilateral shape as shown. The cross section of the ruler strip 210 is designed into an arc shape, so that two adjacent ruler strips 210 can be conveniently combined together.

In this application, the stronger the magnetism of magnetic part 230, the more easily adjacent chi strip 210 takes place magnetism and inhales, and the stability after the actuation is better moreover, helps keeping stronger rigidity. The magnetic member 230 is preferably made of neodymium iron boron, which has extremely high magnetic energy and coercive force, and high energy density, and can play an ideal magnetic attraction role. The material of the blade 210 needs to be selected to have a certain bending property, elasticity and rigidity, and should be a non-magnetic material. The ruler can be made of plastic sheets, alloy materials and the like, preferably stainless steel strips, and the stainless steel ruler strip 210 is light in weight and convenient to carry and use. The surface of the blade 210 may be provided with a self-lubricating wear-resistant coating to reduce the damage to the first scale 211 due to the friction when the adjacent blades 210 are magnetically attracted together.

The particular means of securing the magnetic member 230 and the blade 210 may be conventional in a variety of ways. For example, as shown in fig. 7, which is a schematic view of a combination structure of a magnetic member 230 and a ruler strip 210, a through hole may be formed on the ruler strip 210, the magnetic member 230 is formed by a metal mesh 231 and flexible ndfeb 232, and may be manufactured in batch by performing, and the magnetic member 230 has the same shape and thickness as the through hole formed on the ruler strip 210. The magnetic part 230 is embedded into the through hole, the metal ring on the periphery of the metal mesh 231 is welded with the edge of the through hole of the ruler strip 210, the metal mesh 231 plays a role in fixing and supporting, and reliable connection of the flexible neodymium iron boron 232 and the ruler strip 210 can be guaranteed. In addition, the magnetic member 230 can be fixed in the through hole by other mechanical means, and even made into a thin sheet to be wrapped inside the blade 210. The present application is not limited to the fixing method of the two.

Fig. 8 is a schematic diagram of the housing 10 and the main scale 20 in fig. 1 (the fixing member and the first hook are not shown in the figure) in the extending direction of the main scale, in this exemplary embodiment, three reels 101 are arranged in the housing 10, the main scale comprises three bars 210, and the three bars 210 are respectively wound on the three reels 101. As seen from the top view, one sides of the extending ends of the three coiled rulers 210 wound on the winding drum 101 are close to each other, and a certain included angle is formed between two adjacent rulers 210, and the three coiled rulers 210 are arranged in a radial shape as a whole. Since the protruding ends of the three rulers 210 are close to each other, the three rulers 210 can be smoothly integrated into a whole by magnetic attraction after protruding out of the casing 10. When the measuring tape 210 is retracted into the housing 10, the three measuring tapes 210 are pulled apart from each other and wound on the winding drum 101 independently of each other due to the different directions of arrangement of the winding drum 101.

The housing 10 of the tape measure may be shaped to match the shape of the coiled plurality of measuring tapes 210. With continued reference to fig. 1 and 8, the housing 10 has a radial profile that matches the three coiled blades 210, thereby creating a space constraint on the coiled blades 210 that prevents the blades 210 from unraveling. The housing 10 has an opening 102 for the blade 210 to extend out, so the opening 102 should correspond to the movable end of the blade 210. The shape of the opening 102 in this embodiment is the same as the triangular shape formed by three rulers 210 extending out of the casing 10, i.e. the triangular shape, so that when the three rulers 210 extend out, certain restrictions are formed on the positions and angles of the rulers 210, and two adjacent rulers 210 are convenient to approach and magnetically attract together. When the rulers 210 are pulled outwards, the magnetic attraction process of the adjacent rulers 210 can be performed after the adjacent rulers 210 extend out of the shell 10, or can be performed in the shell 10, and the specific way is related to the space of the shell 10, the distance between the rulers 210, the magnetic force of the magnetic part 230 and other factors.

In other embodiments, as shown in fig. 9, which is another schematic view of the opening structure, the openings may be provided as three separate strip-shaped openings 102, the three strip-shaped openings 102 are arranged in a triangular shape formed by the ruler strips 210 extending out of the housing 10, and each ruler strip 210 extends out of the corresponding strip-shaped opening 102. The separate openings 102 help to separate the retracted blade 210, but the magnetic attraction of the blade 210 as it extends outwardly occurs after it has been extended out of the housing 10. When the blade 210 is of an arcuate configuration, the shape of the strip opening 102 may also be arcuate to match the shape of the blade 210, thereby facilitating the movement of the blade 210 in and out.

It is understood that when the number of the measuring tape 210 is other, the housing 10 may be provided with a corresponding shape, and the housing 10 may be provided with an opening 102 with a corresponding shape, as in the above embodiment, so as to facilitate the storage and extension of the measuring tape 210. This is not further enumerated here.

In this application, the casing 10 can be provided with a coiled elastic member to realize the retraction of the ruler strip 210, one end of the elastic member is fixed on the winding drum 101, the other end of the elastic member is fixed on a fixed shaft, when the ruler strip 210 is stretched, the winding drum 101 rotates to drive the elastic member to compress and rotate, when the external force is removed, the elastic member retracts to drive the winding drum 101 to rotate reversely, and the ruler strip 210 is automatically retracted. Of course, the main scale 20 may be automatically retracted by a structure, which is not particularly limited in the present application.

As a further improvement, the inner side of the opening 102 of the casing 10 can be provided with a limiting device for limiting the extending length of the blade 210, namely, after the blade 210 is extended, the blade 210 can be fixed for reading. The limiting device can be a pressing sliding block, the pressing sliding block is used for pressing the ruler strip 210 to one side along the thickness direction of the ruler strip to be locked, at the moment, the ruler strip 210 cannot be rolled in or rolled out, and the pressing sliding block is prevented from being rolled in or rolled out relative to the shell 10 unintentionally during measurement. On the other hand, when the object to be measured is high or low, the sight line of the measuring person is difficult to be kept horizontal with the other edge of the object to be measured, the main scale 20, and reading deviation is easily caused by sight line deviation. The main ruler 20 is locked through the limiting device, so that the tape can be read after leaving an object to be measured, and measurement is convenient. The number of the limiting devices may be multiple, and only one limiting device may be arranged at the position of the corresponding ruler strip 210, so that all the ruler strips 210 are limited simultaneously. The wound elastic member and the position-limiting means are not shown in the drawings since they can be implemented using existing structures.

In this application, the securing members 220 in the main scale 20 are used to secure the free ends of all the blades 210 together so that all the blades 210 are extended or retracted simultaneously. Referring to fig. 1 and 10, fig. 10 is a schematic view of the housing and the main scale in fig. 1, in a direction perpendicular to the extending direction of the main scale, and the fixing member 220 may include a cylindrical structure, which is sleeved on the outer portion of the movable end of the multiple-scale strip 210 and fixed by riveting, welding, bolting, and the like.

In the present application, the shape of the first hook 30 can be selected according to the characteristics of the object to be measured, for example, when the first hook 30 needs to be fixed on the inner surface or the outer surface of the object to be measured, the first hook 30 has a fastening surface, and the fastening surface can face the housing 10 or face away from the housing 10. When it is desired to fix the first hook 30 in the hole of the object to be measured, the first hook 30 may include a hole-positioning structure, such as a column protruding along the width direction of the ruler strip 210, and the hole-positioning structure may extend into the hole of the object to be measured, so as to measure the length of the hole-positioning structure.

In an exemplary embodiment, the first hook 30 is rotatably disposed on the fixing member 220 such that it can rotate around the extending direction of the main scale 20 (i.e., the horizontal direction in fig. 10) so as to be rotated to the most suitable position to be caught on the surface of the object to be measured. Further, the first hook 30 is detachably disposed on the fixing member 220, so as to facilitate replacement.

When measuring the size by using the measuring tape, different measuring methods can be selected according to the condition of the object to be measured, such as hanging on the object or propping against the object. The difference between the two measures is the thickness of the first hook 30 at the head of the tape measure. In order to prevent the thickness of the first hook 30 from affecting the measurement accuracy, a thickness compensation structure may be provided on the fixing member 220 of the main scale 20.

Referring to fig. 11, which is a schematic view of a thickness compensation structure, the fixing member includes a shoe 221, a fixing sleeve 222, a spring 223, a link 224, a sliding block 225 and a bushing 226, and the shoe 221 is fixed on the movable ends of all the blades 210 for fixing the blades 210 together. The fixing sleeve 222 is sleeved outside the bottom support 221, a first cavity 227 is formed between the fixing sleeve 222 and the bottom support 221, and a through hole is formed in the fixing sleeve 222 on the surface opposite to the bottom support 221 in the extending direction of the ruler strip. The bushing 226 is sleeved outside the fixing sleeve 222. The sliding block 225 is located in the first cavity 227 between the fixing sleeve 222 and the bottom bracket 221, and the sliding block 225 has a protrusion which extends through the through hole of the fixing sleeve 222 and is fixed on the bushing 226, thereby connecting the fixing sleeve 222 and the bushing 226 together. The slide block 225 is also provided with a heart-shaped guide slot 229 as shown. One end of the link 224 is fixed on the bottom bracket 221, the other end is slidably disposed in the guide slot 229 and can move along the guide slot 229, the spring 223 is sleeved outside the link 224, one end is fixed on the bottom bracket 221, and the other end is fixed on the sliding block 225. The first hook 30 is disposed on the sleeve 226 and can rotate around the sleeve 226.

When the first hook 30 is required to be abutted against the object to be tested, the first hook 30 is moved leftward relative to the fixing member 220, the first hook 30 drives the bushing 226 and the sliding block 225 to move leftward until the movable end of the connecting rod 224 slides in the guide groove 229 to the rightmost limit position, at this time, the spring 223 is in a compressed state, and the second cavity 228 between the bushing 226 and the fixing sleeve 222 disappears, so that the two are attached together. At this time, the reading is the actual length of the object to be measured. When the first hook 30 needs to be hung on an object to be measured, the first hook 30 is pulled rightwards relative to the fixing member 220, the first hook 30 drives the bushing 226 and the sliding block 225 to move rightwards until the movable end of the connecting rod 224 slides in the guide groove 229 to the leftmost limit position, at this time, the spring 223 is in a stretching state, a second cavity 228 is formed between the bushing 226 and the fixing sleeve 222, and the width of the second cavity 228 in the length direction of the ruler 210 is equal to the thickness of the ruler 210. At this time, the reading is the actual length of the object to be measured. Therefore, the horizontal movement range of the first hook 30 at the left and right extreme positions is equal to the width of the cavity in the length direction of the blade 210, i.e. the thickness d of the blade 210. Thereby, errors due to different measuring modes and the thickness of the first hook 30 can be compensated. The structure shown in fig. 11 is merely an example, and in other embodiments, other structures may be used to achieve thickness compensation.

In order to achieve more accurate measurement, referring to fig. 12 to 14, the tape measure of the present embodiment may further include a vernier 40, the vernier 40 is located outside the housing 10 and includes a secondary ruler 41 and a second hook 42 disposed on the secondary ruler 41, the secondary ruler 41 is disposed on the main ruler 20 and is slidable relative to the main ruler 20, and is provided with a second scale, and the second hook 42 is configured to cooperate with the first hook 30 to be clamped on the surface of the object to be measured.

In an exemplary embodiment, the vernier 40 is a fixed vernier, and as shown in fig. 12, which is a schematic view of a tape measure with a fixed vernier, the secondary ruler 41 of the vernier 40 is fixed on the housing 10 and located at the opening of the housing 10, and the second hook 42 is also always in a fixed position. After the main scale 20 is extended out, the accurate size of the object to be measured can be obtained through the first scale 211 on the main scale 20 and the second scale 411 on the auxiliary scale 41. One length datum is read accurately in one measurement by the fixed vernier 40.

In an exemplary embodiment, referring to fig. 13, the vernier scale 40 is a floating vernier scale, that is, the secondary scale 41 of the vernier scale 40 slidably fits over the main scale 20, and the second hook 42 can slide on the main scale 20 along with the secondary scale 41. Because the floating vernier can move, length data at a plurality of different positions can be read in one measurement, and the measurement efficiency is improved. A plurality of floating vernier scales 40 may be provided on a single tape measure. The surface of the floating vernier 40 that contacts the main scale 20 may be provided with a self-lubricating wear-resistant coating to reduce the friction when the floating vernier 40 and the main scale 20 slide with each other, reducing the damage to the first scale 211.

In yet another exemplary embodiment, referring to fig. 14, the tape measure may be provided with a fixed vernier 40 and a floating vernier/s 40. When the main scale 20 retracts into the housing 10, the first hook 30 may be caught at the outside of the vernier 40 since the vernier 40 may occupy a certain space.

Whether the vernier scale is a fixed vernier scale or a floating vernier scale, the second hook 42 should be matched with the first hook 30, that is, the clamping surface of the second hook 42 and the clamping surface of the first hook 30 may be oppositely arranged to be hung on the outer surface of the object to be measured 90, as shown in fig. 15, or the clamping surface of the second hook 42 and the clamping surface of the first hook 30 are oppositely propped against the inside of the object to be measured 90, as shown in fig. 16; or the first hook 30 and the second hook 42 both include hole positioning structures, and the two hole positioning structures can be clamped in holes of the object to be measured 90 to measure the distance between the two holes, as shown in fig. 17. Therefore, the second hook 42 may also be provided as a detachable structure for replacement.

The second scale 411 on the vernier may be divided into ten divisions, twenty divisions, fifty divisions, etc., and the vernier 40 and the main scale 20 cooperate to perform more accurate measurement. For example, the first scale 211 of the main scale 20 is in millimeters (mm), the second scale 411 of the vernier scale 40 is in the size of 50 divisions of 49mm, each approximately 1mm scale on the vernier scale 40 is actually 0.98mm in length, one indicator mark is marked on the vernier scale 40 every 5 divisions, and the corresponding reading on the vernier scale 40 is 0.1 mm. One side that corresponds the main scale 20 scale on the vernier scale 40 can set up the rectangle window, and the window department covers the transparent sheet that is equipped with second scale 411 to in direct see through transparent sheet from the window of measurement personnel see "0" scale on the main scale 20 of second scale 411, and see which scale aligns on vernier scale 40 and the main scale 20. The vernier 40 may be made of an aluminum alloy to achieve light weight. In order to facilitate the comparison between the vernier scale 40 and the scale on the main scale 20, the first scale 211 on the main scale 20 includes a fluorescent material, and the corresponding light leaking scale groove on the vernier scale 40 irradiates the first scale 211 on the main scale 20, so that the corresponding scales of the second scale 411 on the vernier scale 40 and the first scale 211 on the main scale 20 are aligned and can be displayed differently from other scales, so as to facilitate prompting. Alternatively, the lines on the main scale 20 are blue, and the vernier scale 40 is made of a transparent material and yellow semi-transparent lines, so that the scales are green when corresponding. Of course, other ways such as integrating a photoelectric sensor on the fixed vernier 40 for signal acquisition, processing and display can be used as the special indication.

In order to improve the convenience of measurement and reading in the present disclosure, in an exemplary embodiment, the tape measure further includes a display screen 110, the display screen 110 is disposed on the housing 10, and an automatic test unit for automatically reading the length data and displaying the data on the display screen 110, so that a measurer can directly read the data. The automatic test unit comprises a displacement sensor and a processor, wherein the displacement sensor is arranged in the shell 10 and is used for measuring the length of the ruler strip 210 of the main ruler 20 extending out of the shell 10; the processor is also disposed in the housing 10, connected to the displacement sensor, and configured to calculate the length of the object to be measured according to the length data sensed by the displacement sensor and display the length on the display screen 110. The displacement sensor can be of various types such as strain type, inductive type, differential transformer type (LVDT), eddy current type, Hall sensor and the like. In one embodiment, the displacement sensor may calculate the protrusion length according to the number of the protruded magnetic members 230.

In the case of the blade 210 using steel, since steel has the property of expanding with heat and contracting with cold, the measurement accuracy is susceptible to temperature during the process of realizing precise measurement. According to the requirements of metrological verification regulations of JJG 4-1999 Steel tape, the precision grade of the steel tape is divided into two grades I and II, and the allowable error delta between any two lines is as follows: Δ i ═ ± (0.1+0.1L) mm; Δ ii ═ ± (0.3+0.2L) mm; wherein L is the length of testing, and the unit is meter, when measuring 3 meters long degree actual dimensions promptly, I level precision allowable error is 0.4mm, II level precision allowable error is 1 mm. The allowable error range is within 0.8mm and 2mm, and even if a qualified measuring tape is adopted, the accuracy of the measuring tape cannot meet the relative position accuracy required by assembly.

In this regard, in an exemplary embodiment, the automatic test unit further comprises a temperature sensor disposed on the housing 10 for sensing the ambient temperature in which the tape measure is located. The processor may also correct the length data of the object to be measured calculated by the displacement sensor according to the temperature data sensed by the temperature sensor, and display the corrected result on the display screen 110 as the actual length of the object to be measured. In one embodiment, the processor corrects the length of the object to be measured according to the following equation:

L_t＝L+ΔL+α·L(t-t₀)

wherein L is_tThe actual length of the object to be measured at the temperature t; l is the standard temperature t of the displacement sensor₀A number of time uncorrected measurements; Δ L is the temperature as the standard temperature t₀Deviation between the actual length of the lower object to be measured and the test length of the displacement sensor; α is the coefficient of thermal expansion of the blade 210.

Wherein, α. L (t-t)₀) The deviation due to thermal expansion at temperature t. For the measuring tape which is subjected to self-checking calibration, alpha.L (t-t) can be calculated by measuring the temperature t during operation and the rough length L of the extending measuring tape₀). When L is calculated by the number of magnetic members 230, Δ L is a function of the number of magnetic members 230, and α L (t-t)₀) The number of the magnetic members 230 and t₀As a function of (c). The data L corrected by the method_tI.e. a highly accurate and reliable length measurement.

Preferably, the automatic test unit further includes an angle sensor disposed in the housing 10 for sensing an angle between the main scale 20 and the length direction to be measured. The processor is further configured to correct the length of the object to be measured calculated by the displacement sensor according to the angle data sensed by the angle sensor, and display the corrected result on the display screen 110 as the actual length of the object to be measured. This can avoid the problem that the accuracy of the measured data is affected by the presence of a certain angle when the main scale 20 is extended. The angle sensor may employ a micro gyroscope.

Further, additional functions may be provided on the housing 10 for the measurement personnel to use, such as setting a dedicated key or the like to set the offset to zero for fast self-test calibration. Special keys can be arranged to store the measured sizes and deviations in a numbering mode or call the measured sizes and the deviations out for displaying again.

Further, referring to fig. 18, a handle 120 may be disposed on the housing 10 for carrying and handling. The handle 120 may also be used to house a battery or the like.

Further, referring to fig. 18, a foldable cover 130 is disposed on the housing 10, and a side edge of the cover 130 is fixed on the housing 10, and when the main scale 20 is retracted back into the housing 10, the cover 130 can be extended along the side edge and cover the opening 102 on the housing 10, so that a cavity is formed between the cover 130 and the housing 10, and the first hook 30 is located in the cavity. The cover 130 can protect the first hook 30. When main scale 20 needs to be extended out of housing 10 for measurement, foldable cover 130 is simply opened. The housing 10 may further be provided with an auxiliary structure such as a handle.

When the measuring tape disclosed by the invention is used for measuring, some auxiliary appliances can be matched to improve the measuring comfort and the measuring efficiency. Such as a length scale, which may be a three edged structure, may be used as a self-checking calibration for the tape measure of the present disclosure. The length scale can adopt the aluminium alloy to make to realize lightweight design, can also arrange the lightening hole under the circumstances of assurance intensity. For example, the positioning tool is used for fixing or supporting the first clamping hook of the main scale or the middle part of the main scale during operation by one person, so that the deformation of the main scale due to self weight is reduced, and the measurement precision is improved. The positioning tool can be a sucker, a magnetic suction device and a double-sided easy-to-pull adhesive tape device so as to adsorb the tape measure on an object to be measured.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A tape measure, comprising:

the shell is provided with an opening;

2. A tape measure according to claim 1, wherein the number of blades is at least three.

3. A tape measure according to claim 2, wherein the plurality of magnetic members on the blade comprises two sets of magnetic members, the two sets of magnetic members being located adjacent respective opposite long edges of the blade, all of the magnetic members in each set being spaced apart along the length of the blade; and the magnetic parts of the two magnetic part groups which are close to each other on the two adjacent ruler strips are in one-to-one correspondence.

4. A tape measure according to claim 3, wherein the blade is arcuate in cross-section in the width direction so that the opposite faces of the blade are concave and convex, respectively, and the convex face of any blade projecting outside the housing is attracted to the convex face of an adjacent blade by the magnetic means.

5. A tape measure according to claim 3, wherein the blade is arcuate in cross-section in the width direction so that opposite faces of the blade are concave and convex, respectively, the convex face of any blade projecting beyond the housing being attracted to the concave face of an adjacent blade by the magnetic means.

6. A tape measure according to claim 1, wherein the magnetic member comprises neodymium iron boron and the blade comprises steel.

7. A tape measure according to claim 1, wherein the housing opening is shaped to correspond to the shape of the portion of the blade extending out of the housing.

8. A tape measure according to claim 7, wherein the inside of the housing opening is provided with a stop means for limiting the extent to which the blade extends.

9. A tape measure according to claim 1, wherein the first hook is rotatably mounted on the fixing member so as to be rotatable about the direction of extension of the main tape.

10. A tape measure according to claim 9, wherein the first catch is removably arranged on the fixing member.

11. The tape measure of claim 1, wherein the fixing member comprises a shoe, a fixing sleeve, a spring, a connecting rod, a sliding block and a bushing, wherein the shoe is fixed to the movable ends of all the blades; the fixing sleeve is sleeved outside the bottom support, a first cavity is formed between the fixing sleeve and the bottom support, and a through hole is formed in one surface, opposite to the bottom support, of the fixing sleeve in the extending direction of the ruler strip; the bushing is sleeved outside the fixed sleeve, the sliding block is positioned in the first cavity and is provided with a protruding part, and the protruding part extends out of the through hole and is fixed on the bushing; the sliding block is also provided with a guide groove, one end of the connecting rod is fixed on the bottom support, the other end of the connecting rod is slidably arranged in the guide groove and can move along the guide groove, the spring is sleeved outside the connecting rod, one end of the spring is fixed on the bottom support, and the other end of the spring is fixed on the sliding block; the first clamping hook is sleeved on the bushing.

12. The tape measure of claim 1, wherein a plurality of winding drums are further provided in the case, the number of the winding drums is equal to the number of the measuring tapes, and the plurality of measuring tapes are wound around the plurality of winding drums in a one-to-one correspondence.

13. The tape measure of claim 1, further comprising:

a vernier scale located outside the housing; the vernier scale comprises an auxiliary scale and a second clamping hook arranged on the auxiliary scale, the auxiliary scale is arranged on the main scale and can slide relative to the main scale, second scales are arranged on the auxiliary scale, and the second clamping hook is used for being clamped on the surface of an object to be measured in a matching mode with the first clamping hook.

14. A tape measure according to claim 13, wherein the secondary tape is fixed to the housing or the secondary tape is slidably mounted on the primary tape.

15. The tape measure of claim 14, wherein the first hook and the second hook each comprise a clamping surface, and the clamping surfaces of the first hook and the second hook are disposed oppositely or oppositely; or the first clamping hook and the second clamping hook both comprise hole positioning structures, and the hole positioning structures can be clamped in holes in the object to be detected.

16. A tape measure according to any one of claims 1 to 15, further comprising a display screen provided on the housing and an automatic test unit comprising:

17. The tape measure of claim 16, wherein the automatic test unit further comprises:

the temperature sensor is arranged on the shell and used for sensing the ambient temperature;

the processor is further used for correcting the length of the object to be detected according to the temperature data sensed by the temperature sensor, and the corrected result is used as the actual length of the object to be detected to be displayed on the display screen.

18. The tape measure of claim 16, wherein the automatic test unit further comprises:

the angle sensor is arranged in the shell and used for sensing the angle between the main scale and the length direction to be measured;

the processor is further used for correcting the length of the object to be detected according to the angle data sensed by the angle sensor, and the corrected result is used as the actual length of the object to be detected to be displayed on the display screen.