Tape measure having springs module

Abstract

A measuring tape including a spring module may include a housing, a bobbin rotating within the housing, a blade wound on the winding surface of the bobbin and drawn out to the outside or retrieved to the inside through the inlet of the housing, and a spring module including a spring housing, a rotating shaft accommodated within the spring housing, and a spring connecting the spring housing and the rotating shaft, wherein the force of the spring can be transmitted to the bobbin through the rotating shaft, and the assembly and replacement of the rotating shaft and the spring are easy using the spring module.

Description

Technology Field

[0001] The present invention relates to a measuring tape, and more specifically, to a measuring tape that facilitates assembly and spring replacement by utilizing a spring module. Background Technology

[0002] A conventional measuring tape includes a housing, a bobbin, a blade wound on the outer surface of the bobbin, and a spring for restoring the bobbin or the blade. The spring is built into the housing and can restore the blade to its original position, and a hook mounted on the end of the blade can cause the end of the blade to stop at a desired position.

[0003] In a tape measure, it is difficult to reduce the length and width of the blade because it is related to the maximum measurable length and easy scale reading; therefore, a method of achieving miniaturization through a spring can be considered.

[0004] U.S. Patent No. 11,226,187 includes excluding the spring between the tape reel and the rotation axis and placing it on both sides. However, by moving the spring to both sides, the spring placed on the sides may not be able to provide sufficient force. Additionally, if the width of the spring placed on the sides is increased, the problem that the measuring tape cannot be miniaturized may resurface. The problem to be solved

[0005] The present invention provides a measuring tape capable of reinforcing the spring force while placing the spring on the side of the measuring tape.

[0006] The present invention provides a measuring tape capable of strengthening the spring force by connecting two or more springs in parallel to a single rotating shaft.

[0007] The present invention provides a compact measuring tape that efficiently utilizes the space inside the housing.

[0008] The present invention provides a measuring tape that connects two or more springs in parallel to a single rotation axis and forms a balance between the springs to prevent bias of the rotation axis. means of solving the problem

[0009] According to an exemplary embodiment of the present invention, a measuring tape may include a housing, a bobbin rotating within the housing, a blade wound on the winding surface of the bobbin and drawn out to the outside or retrieved to the inside through the inlet of the housing, and a spring module including a spring housing, a rotating shaft accommodated within the spring housing, and a spring connecting the spring housing and the rotating shaft, and the force of the spring may be transmitted to the bobbin through the rotating shaft.

[0010] Through the spring module, the rotating shaft and the spring can be assembled and disassembled together, and the rotating shaft can be mounted in the housing and connected directly to the bobbin or connected via a gear train. Unlike conventional methods, the rotating shaft and the bobbin are not connected at both ends of the spring, and the rotating shaft and the spring can be characterized by modularization.

[0011] The spring housing may include a hollow cylinder portion inserted into the interior of the bobbin and a hollow disc portion integral with the cylinder portion and located on one side of the bobbin. The spring housing may be formed using metal sheet materials, etc., and may have an overall T-shaped cross-section due to the cylinder portion and the disc portion.

[0012] In the spring housing, a rotating shaft is provided to penetrate the center of the cylinder part and the disk part in the axial direction, and one end of the rotating shaft is exposed to the outside of the cylinder part so as to be coupled with the bobbin, and one end of the spring is fixed to the spring housing, and by fixing the spring housing so that the rotating shaft cannot rotate around the center of the measuring tape housing, the effect of fixing the spring to the measuring tape housing can be achieved.

[0013] The housing may be provided using a first housing that covers one side of the bobbin and a second housing that covers the other side of the bobbin. The first housing may cover the side on which the spring and the disc portion are placed. The first housing may further include a housing cover that covers the disc portion.

[0014] In order to adjust the rotation ratio between the bobbin and the rotating shaft, a gear train may be interposed between the second housing and the bobbin, and the gear train may link the rotating shaft and the bobbin, while forming the ratio of the rotation of the bobbin to the rotation of the rotating shaft to be greater than 1.

[0015] For example, the gear train may include a first gear that meshes directly with a rotating shaft, a second gear mounted in a second housing that meshes with the first gear, and a third gear that meshes with the second gear to transmit rotation to a bobbin, and the reduction ratio may be determined through the first to third gears. Additionally, the second gear may be fixed in the second housing, in which case it may form a gear train different from a planetary gear.

[0016] The cylinder portion of the spring housing may come into direct contact with the bobbin, but a part of the first housing may be interposed therein. Specifically, the first housing may include a hollow cylinder hub that rotatably supports the inner contact surface of the bobbin, and the cylinder portion of the spring housing may be provided in a structure that is inserted into the interior of the cylinder hub.

[0017] In addition, the spring module is directly connected to the first housing without a cylinder hub, and the cylinder part can directly and rotatably support the inner contact surface of the bobbin.

[0018] The maximum outer diameter of the spring can be set to approximately 60 to 95% of the maximum outer diameter of the bobbin to achieve a compact size of the measuring tape housing, and the ratio of the bobbin's winding diameter to the outer diameter of the rotation axis can be maintained at approximately 200 to 600%.

[0019] If the winding diameter is too small, it could actually cause damage to the blade. Therefore, it may be desirable to design the bobbin so that the winding diameter is maintained at approximately 200 to 600% relative to the axis of rotation.

[0020] When the spring is placed on the side, it may further include an additional elastic body interposed between the rotation axis and the bobbin inside the bobbin, with one end fixed to the housing and the other end fixed to the rotation axis.

[0021] The rotating shaft is rotatably mounted within the housing, and at least one spring and at least one additional elastic element can be connected in parallel to a single rotating shaft. Two types of springs can connect a single rotating shaft and the housing, and are appropriately placed in the side space and the internal space of the bobbin to minimize the spring space and contribute to the miniaturization of the measuring tape.

[0022] In this case, the winding direction of the spring and the additional elastic body, that is, the direction in which force is applied, can be the same, and they can compensate for each other's forces as they wind and unwind in the same direction.

[0023] The spring and additional elastic elements can be fixed to the housing. This means that the end of the spring is fixed to the housing, and the housing and the end of the spring can be connected directly or indirectly.

[0024] To reduce the spring space, a spring with a higher elastic modulus can be used, and by using a strong spring or a combination of springs, the number of rotations of the spring can be reduced relative to the number of rotations of the bobbin (i.e., the length of the blade). To achieve this, a gear train may be included that is interposed between the housing and the bobbin on the other side of the bobbin to link the rotation axis and the bobbin, and through the gear train, the ratio of the rotation of the bobbin to the rotation of the rotation axis can be made greater than 1.

[0025] The additional elastic element, like the spring and the pivot shaft, can be embedded in the spring module and assembled together, and the pivot shaft may include a flange that separates the space of the cylinder hub where the additional elastic element is placed from the space inside the housing cover where the spring is placed.

[0026] An additional elastic body is inserted into the interior of the cylinder part to connect the first housing and the rotation axis, and a spring is arranged between the disk part and the inside of the housing cover to connect the first housing and the rotation axis.

[0027] Structurally, a slit connecting the cylinder part and the disc part may be formed in the spring housing, and one end of an additional elastic body or spring may be connected to the slit.

[0028] When connecting additional elastic bodies and springs to the axis of rotation, the additional elastic bodies and springs can be connected at a distance of 180 degrees from each other with respect to the axis of rotation. Balance can be achieved by pulling the axis of rotation from different directions, and in the case of three springs, they can be spaced at equal intervals of 120 degrees or distributed appropriately according to the distribution of force.

[0029] It is desirable that the thickness of the spring be thicker than the thickness of the additional elastic body, and the average thickness of the spring (Ts) may be about 2 to 4 times the average thickness (Ti) of the additional elastic body.

[0030] It may be desirable for the width of the additional elastic body to be about 2 to 5 times the width of the spring. Effects of the invention

[0031] The measuring tape of the present invention can increase the pull-up force of the spring by placing a spring on the side of the bobbin, while simultaneously securing a minimum space between the bobbin and the rotation axis and placing an additional elastic body in that space. In this case, the spring can be connected to the rotation axis in parallel with the additional elastic body, or conversely, it can be connected directly or indirectly to the housing.

[0032] The rotating shaft can be connected to the bobbin, either directly in a one-to-one manner or via a gear train in a reduction ratio. By reducing the rotational speed of the rotating shaft relative to the rotational speed of the bobbin, the space occupied by the spring can be kept smaller; this allows for connecting the springs in parallel while actively utilizing additional elastic elements.

[0033] In particular, the additional elastic body can connect the rotating shaft and the housing for parallel connection, rather than connecting the rotating shaft and the bobbin. In this way, the measuring tape of the present invention can strengthen the spring force by connecting two or more springs in parallel to a single rotating shaft.

[0034] The measuring tape of the present invention can form a compact size by efficiently utilizing the space inside the housing, and the springs can form a mutual balance of forces between the springs by arranging them in opposite directions or at equal intervals along the rotation axis. Brief explanation of the drawing

[0035] FIG. 1 is a drawing for explaining a measuring tape according to one embodiment of the present invention. Figure 2 is a drawing to explain the AA cross-section of the measuring tape of Figure 1. Figure 3 is a diagram illustrating the disassembled structure of the measuring tape of Figure 1. Figures 4 and 5 are drawings for explaining the spring module of the measuring tape of Figure 1. Figure 6 is a drawing for explaining the spring housing of Figure 4. FIG. 7 is a drawing for explaining a cross-section of a measuring tape according to one embodiment of the present invention. Figures 8 and 9 are drawings for explaining the spring module of the measuring tape of Figure 7. Figure 10 is a drawing for explaining the spring housing of Figure 8. FIG. 11 is a drawing illustrating the connection between a rotation axis and a spring in a measuring tape according to one embodiment of the present invention. FIG. 12 is a drawing for explaining a cross-section of a measuring tape according to one embodiment of the present invention. Figures 13 and 14 are drawings to explain the disassembled structure of the measuring tape of Figure 12. FIG. 15 is a drawing for explaining the combination of the first housing and the spring module of FIG. 13. Figure 16 is a drawing illustrating the replacement of the spring module of the measuring tape of Figure 12. FIG. 17 is a drawing for comparing the spring module of a measuring tape according to one embodiment of the present invention. Specific details for implementing the invention

[0036] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings, but the present invention is not limited or restricted by the embodiments. For reference, in this description, the same number refers to substantially the same element, and under this rule, descriptions may be made by citing content described in other drawings, and content that is deemed obvious to those skilled in the art or is repetitive may be omitted.

[0037] FIG. 1 is a drawing for explaining a measuring tape according to an embodiment of the present invention, FIG. 2 is a drawing for explaining a cross-section AA of the measuring tape of FIG. 1, FIG. 3 is a drawing for explaining the disassembled structure of the measuring tape of FIG. 1, FIG. 4 and FIG. 5 are drawings for explaining the spring module of the measuring tape of FIG. 1, and FIG. 6 is a drawing for explaining the spring housing of FIG. 4.

[0038] Referring to FIGS. 1 to 6, the measuring tape (100) according to the present embodiment may include a housing (105), a rotating shaft (150), a bobbin (140), a blade (130), a spring (170), and a gear train (190). The blade (130) is wound on the winding surface (142) of the bobbin (140) and can be wound on the outer surface of the bobbin (140) and stored by being pulled out to the outside for length measurement or pulled in for storage through the opening of the housing (105). As in the prior art, a spring may be used to pull the blade (130) into the housing (105).

[0039] The housing (105) may be provided using a first housing (110) and a second housing (120). The first housing (110) covers one side of the bobbin (140) and may cover the side where the spring (170) is placed, and the second housing (120) covers the other side of the bobbin (140) and may cover the side where the gear train (190) is placed. The first housing (110) and the second housing (120) may be combined to form a single housing (105).

[0040] The rotation axis (150) is rotatably mounted at the center of the housing (105) and is connected to a spring (170) positioned on the side along the axial direction, and the original portion (154) of the rotation axis (150) located far from the spring (170) can be coupled to the bobbin (140) via a gear train (190).

[0041] A spring (170) is provided on one side of a bobbin (140) where a first housing (110) is located, and may be interposed between the housing (105) and the bobbin (140). One end of the spring (170) is fixed to the first housing (110), and the other end may be connected to a rotation axis (150).

[0042] In this embodiment, the spring (170) is located inside the spring housing (180) of the spring module (160) and is connected to the spring housing (180), and the spring housing (180) can be fixed to the housing (105). Accordingly, the spring (170) can be indirectly fixed to the first housing (110) through the spring housing (180).

[0043] Additionally, since the blade (130) is wound from the winding surface (142), if the diameter of the winding surface (142) is too small, it may actually cause damage to the blade (130). Therefore, to protect the blade (130), it is preferable that the outer diameter of the winding surface (142) be formed to be at least twice the outer diameter of the rotation axis (150). By forming the outer diameter of the winding surface (142) to be 2 to 6 times the diameter of the rotation axis (150), a spaced-apart space may be created between the rotation axis (150) and the bobbin (140).

[0044] The spring module (160) is configured such that a spring housing (180), a rotating shaft (150) mounted inside a housing cover (116), and a spring (170) are packaged together. The spring housing (180) may be formed from a metal plate and may be formed by a hollow cylinder portion (182) and a hollow disk portion (184), and may have a T-shaped cross-section overall.

[0045] In the spring housing (180), the rotation axis (150) is positioned through the center, and the spring (170) is received in the hollow disk portion (184), with one end fixed to the rotation axis (150) and the other end fixed to the inner wall of the hollow disk portion (184).

[0046] In this embodiment, a slit (186) may be formed along the inner wall of the disc portion (184) in the screen housing (105), and the end of the spring (170) may be fixed using this slit (186).

[0047] With the spring accommodated in the screen housing (105), the housing cover (116) can cover the open side of the screen housing (105) to form a spring module (160). In this embodiment, the spring module (160) can be inserted and fixed from the outside of the first housing (110).

[0048] To this end, a hollow cylinder hub (114) protruding inward from the center can be formed in the first housing (110) into which the main body (112) and the spring module (160) can be inserted, and the inside of the cylinder hub (114) can move the rotation shaft (150) into the bobbin (140) while being in close contact with the cylinder part (182) of the spring module (160).

[0049] A through hole is formed at the end of the cylinder portion (182) in the spring housing (180) through which the original portion (154) of the rotation shaft (150) can protrude, and the original portion (154) of the rotation shaft (150) can be exposed through the through hole. As the spring module (160) is coupled to the first housing (110), the original portion (154) of the rotation shaft (150) can also pass through the hollow cylinder hub (114) and enter the interior of the first housing (110) and the second housing (120).

[0050] The rotation axis (150) may further include a flange (152) for separating the cylinder portion (182) and the disk portion (184) of the spring housing (180). By the flange (152), the space of the spring housing (180) may be divided into two spaces (183, 185).

[0051] A protrusion (188) can be formed on the outer surface of the spring housing (180), and the spring housing (180) can be fixed so that it does not rotate relative to the first housing (110) by being coupled to the first housing (110) or the housing cover (116). By fixing the spring housing (180) to the first housing (110) in this way, the spring (170) can be fixed to the housing (105).

[0052] The original portion (154) of the rotating shaft (150) can be connected to a gear train (190) provided between the second housing (120) and the bobbin (140) by passing through the cylinder hub (114) of the first housing (110). The original portion (154) of the rotating shaft (150) is formed in a non-circular shape and can be connected to a first gear (192) located at the center of the gear train (190). In the gear train (190), the first gear (192) is connected to a second gear (194) located around it, and the second gear (194) can be connected to a third gear (196) that is coupled with the bobbin (140).

[0053] In this embodiment, the third gear (196) is integrally formed on one side of the bobbin (140) to mount the bobbin (140) to the cylinder hub (114) and to be coupled with the second gear (194) while connecting the second housing (120) to the first housing (110). In this embodiment, the second gear (194) is fixed to the second housing (120) and can only rotate without changing its position.

[0054] The second housing (120) may include a gear cover (122) for protecting the first gear (192) and the second gear (194), and a hole may be formed in the center of the gear cover (122) through which the third gear (196) of the bobbin (140) and the original part (154) of the rotation shaft (150) can enter.

[0055] The rotational speed of the bobbin (140) can be designed to rotate more than the rotational speed of the shaft (150) by means of the gear train (190). Even if the rotational speed of the shaft (150) is reduced, the weakness of the force is prevented by forming a strong parallel spring combination, and the spring space can be reduced more than conventionally by using a strong parallel spring combination.

[0056] In this embodiment, the bobbin (140) and the rotating shaft (150) may be connected without springs through a gear train (190). However, depending on the case, the bobbin and the rotating shaft may be directly connected one-to-one regardless of reduction, and the structure connecting the rotating shaft and the bobbin may also utilize various methods, such as belts, in addition to gears.

[0057] The first housing (110) can rotatably support the bobbin (140) using the cylinder hub (114), and at the same time, the spring module (160) can be inserted and fixed from the outside of the first housing (110).

[0058] Since the spring module (160) includes a rotating shaft (150) and a spring (170) in a package, if the spring function deteriorates or fails, it is easy to detach the spring module (160) from the first housing (110) to repair or replace it.

[0059] FIG. 7 is a drawing for explaining a cross-section of a measuring tape according to an embodiment of the present invention, FIG. 8 and FIG. 9 are drawings for explaining a spring module of the measuring tape of FIG. 7, and FIG. 10 is a drawing for explaining a spring housing of FIG. 8.

[0060] Referring to FIGS. 7 to 10, the measuring tape according to the present embodiment may include a housing (105), a rotating shaft (150), a bobbin (140), a blade (130), a spring (170), an additional elastic body (175), and a gear train (190).

[0061] Compared to the previous embodiment, the measuring tape of the present embodiment includes an additional elastic body (175) in the spring module (160), and the additional elastic body (175) can reinforce the restoring force of the spring (170). For a description of other similar configurations, refer to the description of the previous embodiment.

[0062] The rotation axis (150) is rotatably mounted at the center of the housing (105), connected along the axial direction to a spring (170) and an additional elastic body (175), and can be coupled to the bobbin (140) via a gear train (190).

[0063] In this embodiment, the additional elastic body (175) may be provided as a coil spring identical to the spring (170), and may also have the same winding direction to provide a restoring force together with the spring (170) in the same direction.

[0064] An additional elastic body (175) is located inside the bobbin (140) and can be interposed between the bobbin (140) and the rotation axis (150). One end of the additional elastic body (175) is fixed to the first housing (110) through a spring housing (180'), and the other end can be connected to the rotation axis (150).

[0065] In this embodiment, the spring (170) and the additional elastic body (175) are located inside the spring housing (180') of the spring module (160), are connected to the spring housing (180'), and the spring housing (180') can be fixed to the housing (105). Thus, the spring (170) and the additional elastic body (175) can be indirectly fixed to the first housing (110) through the spring housing (180').

[0066] In this embodiment, a spring (170) and an additional elastic body (175) are connected one by one to a single rotation axis (150), but in some cases, multiple identical or similar springs or additional elastic bodies may be provided. In this case, each spring and additional elastic body may be connected to the rotation axis (150) and the housing (105) in parallel, and the force of the springs may be mutually reinforced through the parallel connection.

[0067] Since the additional elastic body (175) assists the force, the width of the spring (170) can be reduced, and the internal space of the bobbin (140), which can be an empty space, can be utilized efficiently. Through the additional elastic body (175), the side space for the spring (170) and the internal space of the bobbin (140) can be utilized efficiently, and overall, it can contribute to the miniaturization of the measuring tape.

[0068] Additionally, since the blade (130) is wound from the winding surface (142), if the diameter of the winding surface (142) is too small, it may actually cause damage to the blade (130). Therefore, to protect the blade (130), it is preferable that the outer diameter of the winding surface (142) be formed to be at least twice the outer diameter of the rotation axis (150). By forming the outer diameter of the winding surface (142) to be 2 to 6 times the outer diameter of the rotation axis (150), a spaced-out space may be created between the rotation axis (150) and the bobbin (140), and by placing an additional elastic body (175) in this space, the additional elastic body (175) can assist the force that the spring (170) must handle.

[0069] In this embodiment, the spring (170) and the additional elastic body (175) can be wound in the same direction with respect to the rotation axis (150). Additionally, the winding of the rotation axis (150) is applied simultaneously to the spring (170) and the additional elastic body (175), and the entire rotation axis (150) may not move when either one is completely unwound or can no longer be wound.

[0070] The spring module (160) is configured to include a spring housing (180'), a rotating shaft (150) mounted inside the housing cover (116), an additional elastic body (175), and a spring (170). The spring housing (180') may be formed from a metal plate and may be formed by a hollow cylinder portion (182) and a hollow disk portion (184), and may have a T-shaped cross-section overall.

[0071] In the spring housing (180'), the rotation axis (150) is positioned through the center, and an additional elastic body (175) is received in the hollow cylinder portion (182), so that one end is fixed to the rotation axis (150) and the other end is fixed to the inner wall of the hollow cylinder portion (182). Additionally, the spring (170) is received in the hollow disk portion (184), one end is fixed to the rotation axis (150), and the other end is fixed to the inner wall of the hollow disk portion (184).

[0072] In this embodiment, a slit (186') passing through the entire cylinder portion (182) and disk portion (184) may be formed along the inner wall of the screen housing (105), and the ends of an additional elastic body (175) and a spring (170) may be fixed using this slit (186').

[0073] The first housing (110) can rotatably support the bobbin (140) using the cylinder hub (114), while the spring module (160) can be inserted and fixed from the outside of the first housing (110). Additionally, a spring housing (180') is provided separately so that an additional elastic body (175) can be fixed to the first housing (110) through the spring housing (180').

[0074] Since the spring module (160) includes a rotating shaft (150), an additional elastic body (175), and a spring (170) in a package, it is easy to detach the spring module (160) from the first housing (110) to repair or replace it if the spring function deteriorates or fails.

[0075] FIG. 11 is a drawing illustrating the connection between a rotation axis and a spring in a measuring tape according to one embodiment of the present invention.

[0076] Looking at FIG. 11, an additional elastic body (175) on the rotation axis (150) can be fixed to the side with the original end (154) centered on the flange (152), and a spring (170) can be fixed to the side with the original end centered on the flange (152).

[0077] And the average thickness (Ts) of the spring (170) can be formed to be thicker than the average thickness (Ti) of the additional elastic body (175). The width (Wi) of the additional elastic body (175) can be formed to be 2 to 5 times the width (Ws) of the spring (170).

[0078] The spring (170) and the additional elastic body (175) may be connected to the same side with respect to the center of the rotation axis (150) (a), but the spring (170) and the additional elastic body (175) may be connected to the rotation axis (150) in opposite directions (b). If there are three springs or additional elastic bodies, they may be appropriately positioned so that the force from the spring is distributed evenly according to the distribution of about 120 degrees.

[0079] In this embodiment, the spring (170) can generate sufficient force, with the maximum outer diameter (Ds) being about 60 to 95% of the maximum outer diameter (Db) of the bobbin (140), and to this end, the width (Ws) and thickness (Ts) of the spring (170) can be appropriately adjusted. Through this process, there is no need to expand the outer diameter of the spring (170) to be equal to the outer diameter of the bobbin, and to this end, an additional elastic body (175) can provide a condition in which the outer diameter of the spring (170) does not need to be expanded more than necessary.

[0080] In addition, by forming the outer diameter (Ds) of the spring (170) smaller than the outer diameter (Db) of the bobbin (140), the housing design can be made thicker in the center than in the periphery, making it easier for a worker to grip with their hand.

[0081] In this embodiment, the ratio of the diameter of the winding surface (142) of the bobbin (140) and the winding diameter (Dw) to the outer diameter (Dx) of the rotation axis (150) can be maintained at approximately 200 to 600%. This allows for the formation of a spaced-apart space between the winding surface (142) and the rotation axis (150), thereby preventing damage to the blade and providing the effect of spring reinforcement through the additional elastic body (175).

[0082] FIG. 12 is a drawing for explaining a cross-section of a measuring tape according to an embodiment of the present invention, FIG. 13 and FIG. 14 are drawings for explaining the disassembled structure of the measuring tape of FIG. 12, FIG. 15 is a drawing for explaining the combination of the first housing and the spring module of FIG. 13, and FIG. 16 is a drawing for explaining the replacement of the spring module of the measuring tape of FIG. 12.

[0083] Referring to FIGS. 12 to 16, the measuring tape (200) according to the present embodiment may include a housing (210, 220), a rotating shaft (250), a bobbin (240), a blade (230), a spring (270), an additional elastic body (275), and a gear train (290). The blade (230) is wound on the winding surface (242) of the bobbin (240) and can be drawn out or retrieved to the outside through the opening of the housing.

[0084] The housing is provided using a first housing (210) and a second housing (220), and a spring module (260) can be mounted on the first housing (210). When the spring module (260) is mounted, the rotation axis (250) is rotatably mounted at the center of the housing and is simultaneously connected to a spring (270) and an additional elastic body (275) along the axial direction. The original portion (254) of the rotation axis (250) can be coupled to the bobbin (240) via a gear train (290) so as to be interlocked.

[0085] In this embodiment, the spring module (260) is directly coupled to the first housing (210) without a cylinder hub and can rotatably support the inner contact surface of the bobbin (240). That is, the spring housing (280) serves as the housing of the spring module (260) and acts as a medium for fixing the additional elastic body (275) and the spring (270) to the first housing (210), and can itself serve as a center for the rotation of the bobbin (240).

[0086] As shown in FIG. 13, the cylinder portion (282) of the spring module (260) of the present embodiment may have a relatively larger diameter than the cylinder portion (182) of the previous embodiment, which may help to further reinforce the additional elastic body (275) or, conversely, to form a smaller additional elastic body space and overall tape measure size.

[0087] An additional elastic body (275) can assist with greater force, further reduce the width of the spring (270), and utilize the internal space of the bobbin (240), which can be an empty space, more efficiently.

[0088] As shown in FIG. 9, the first housing (210) and the spring housing (280) may be provided in a state where they are integrally combined during the initial assembly, and the assembly of the measuring tape can be simply completed by combining the first housing (210) and the second housing (220) around the bobbin (240) on which the blade (230) is wound.

[0089] And while assembling the first housing (210) and the second housing (220), if the end portion of the rotating shaft (250) exposed at the center of the housing cover (216) is tightened with a wrench or the like, assembly is also possible with the spring in a tensioned state. In some cases, if the spring becomes loose, the housing can be separated and the rotating shaft (250) can be rotated in the tightening direction to reinforce the loosened force.

[0090] The spring module (260) may be provided as a package including a spring housing (280), a rotating shaft (250), an additional elastic body (275), a spring (270), and a housing cover (216), and a specific description may be provided by referring to the description of the previous embodiment.

[0091] In the spring housing (280), the rotation axis (250) is positioned through the center, an additional elastic body (275) is received in the hollow cylinder portion (282), the spring (270) is received in the hollow disk portion (284), and the outer end can be bent and fixed through the slit (286).

[0092] To this end, the first housing (210) is formed with a hole (212) through which a spring module (260) can enter without a cylinder hub, and an additional elastic body (275) and a rotation axis (250) can enter into the bobbin (240) together with the spring module (260).

[0093] The original end of the rotating shaft (250) protrudes from the end of the cylinder portion (282) of the spring housing (280), and the original end of the rotating shaft (250) can pass through the bobbin (240) and be connected to the gear train (290) of the second housing (220).

[0094] A protrusion (288) or a bend may be formed on the outer surface of the spring housing (280), and the spring housing (280) may be coupled to the first housing (210) or the housing cover (216). By fixing the spring housing (280) to the first housing (210), the spring (270) and the additional elastic body (275) may be fixed to the housing.

[0095] The original part (254) of the rotating shaft (250) is connected to the gear train (290) of the second housing (220), and the rotating shaft (250) and the bobbin (240) can be coupled without springs through the first gear (292), the second gear (294), and the third gear (296).

[0096] The rotational speed of the bobbin (240) can be designed to rotate much more than the rotational speed of the shaft (250) by means of the gear train (290). Even if the rotational speed of the shaft (250) is reduced, the weakness of the force is prevented by forming a strong parallel spring combination, and the spring space can be reduced more than conventionally by using a strong parallel spring combination.

[0097] As described above, although the present invention has been explained with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0098] 100 : Measuring tape 110 : First housing 114 : Cylinder hub 116 : Housing cover 120 : 2nd Housing 130 : Blade 140 : Bobbin 150 : Rotating shaft 160 : Spring Module 170 : Spring 175: Additional elastic element 180: Spring housing 190 : Gear train

Claims

Claim 1 A measuring tape characterized by: a housing; a bobbin rotating within the housing; a blade wound on the winding surface of the bobbin and drawn out to the outside or retrieved to the inside through the inlet of the housing; and a spring module including a spring housing, a rotating shaft accommodated within the spring housing, and a spring connecting the spring housing and the rotating shaft; wherein the force of the spring is transmitted to the bobbin through the rotating shaft, and the spring housing includes a hollow cylinder portion inserted into the interior of the bobbin and a hollow disk portion integral with the cylinder portion and located on one side of the bobbin, and the rotating shaft penetrates the cylinder portion and the disk portion of the spring housing axially to interlock with the bobbin, and the spring connects the spring housing and the rotating shaft at the disk portion, and the spring housing is fixed so as not to rotate around the center of the rotating shaft relative to the housing, and a spaced-apart space is formed between the cylinder portion and the rotating shaft, and the ratio of the winding diameter of the bobbin to the outer diameter of the rotating shaft is 200 to 600%. Claim 2 A measuring tape comprising: a housing; a bobbin rotating within the housing; a blade wound on the winding surface of the bobbin and drawn out to the outside or retrieved to the inside through the inlet of the housing; and a spring module including a spring housing, a rotating shaft accommodated within the spring housing, and a spring connecting the spring housing and the rotating shaft; wherein the force of the spring is transmitted to the bobbin through the rotating shaft, the spring housing includes a hollow cylinder portion inserted into the interior of the bobbin and a hollow disk portion integral with the cylinder portion and located on one side of the bobbin, the rotating shaft penetrates the cylinder portion and the disk portion of the spring housing axially and interlocks with the bobbin, the spring connects the spring housing and the rotating shaft at the disk portion, the spring housing is fixed so as not to rotate around the center of the rotating shaft relative to the housing, a spaced-apart space is formed between the cylinder portion and the rotating shaft, and further includes an additional elastic body connecting the cylinder portion and the rotating shaft, wherein the spring and the additional elastic body have the same winding direction. Claim 3 A measuring tape according to claim 1 or 2, wherein the housing is provided using a first housing covering one side of the bobbin where the disk portion is located and a second housing covering the other side of the bobbin, and the first housing includes a housing cover covering the disk portion. Claim 4 A measuring tape according to claim 3, comprising a gear train interposed between the second housing and the bobbin to link the rotation axis and the bobbin, wherein the ratio of the rotation of the bobbin to the rotation of the rotation axis by the gear train is greater than 1. Claim 5 In claim 4, the gear train comprises a first gear that meshes directly with the rotation axis, a second gear mounted in the second housing that meshes with the first gear, and a third gear that meshes with the second gear to transmit rotation to the bobbin, wherein the second gear is fixed to the second housing. Claim 6 A measuring tape according to claim 1 or 2, characterized in that the cylinder portion rotatably supports the inner contact surface of the bobbin. Claim 7 A measuring tape according to paragraph 3, wherein the first housing comprises a hollow cylinder hub that rotatably supports the inner contact surface of the bobbin, and the cylinder portion is inserted into the interior of the cylinder hub. Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 A measuring tape characterized in that, in paragraph 2, the thickness of the spring is thicker than the thickness of the additional elastic body. Claim 12 A measuring tape according to claim 11, characterized in that the thickness of the spring is 2 to 4 times the thickness (Ti) of the additional elastic body. Claim 13 A measuring tape according to paragraph 2, characterized in that the width of the additional elastic body is 2 to 5 times wider than the width of the spring. Claim 14 A measuring tape according to claim 1 or 2, characterized in that the maximum outer diameter of the disk portion is 60 to 95% of the maximum outer diameter of the bobbin. Claim 15 A measuring tape according to claim 1 or 2, characterized in that the rotating shaft includes a flange separating the cylinder portion and the disk portion. Claim 16 A measuring tape according to claim 1 or 2, wherein the spring housing includes a slit formed on the side of the disk portion, and one end of the spring is connected to the slit.

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