Electric measuring tape

Abstract

The invention relates to the technical field of tool measurement, and particularly discloses an electric measuring tape which comprises a shell, one end of the interior of the shell is provided with a measuring tape containing cavity, the other end of the interior of the shell is provided with a power supply cavity, one end of the shell is further provided with an opening, and the opening is communicated with the measuring tape containing cavity; the roller is rotationally arranged in the measuring tape accommodating cavity; the motor is arranged in the cavity in the roller, the output end of the motor is connected with one end of the roller, and the other end of the motor is connected with the shell; the tape is wound on the outer wall of the roller, one end of the tape is fixedly connected with the outer wall of the roller, a rotating guide roller is arranged around the roller, and the outermost ring of the tape is bound by the rotating guide roller until the tape extends to the opening of the shell; the power supply assembly is arranged in the power supply cavity; the control circuit board is arranged in the shell; the control switch is arranged on the outer wall of the shell. According to the whole electric measuring tape, the tape band can smoothly, stably, freely and reliably zoom at a constant speed through the simplest and reasonable structure.

Description

Technical Field

[0001] The invention relates to the technical field of measuring tools, in particular to an electric measuring tape. Background Art

[0002] The demand for length measurement in human production and life has been around for a long time. In the early days, in order to meet the simple length measurement needs of industries such as construction, carpentry, and tailoring, soft tape measures and steel tape measures that were pulled by human power appeared. They have simple structures, low costs, and are easy to carry, but they have certain disadvantages. For example, when the hand pulls the tape measure, it is difficult to keep the force on the hand absolutely stable and uniform, which can easily cause the tape measure to stretch or shrink, and the pulling speed is uneven. It is also difficult to avoid hand shaking, which will lead to large errors in the measurement results and make it difficult to meet the requirements of high-precision measurement. Therefore, for some high-precision measurements, it is necessary to measure repeatedly, which will affect work efficiency. The uneven force of frequent and rapid pulling will cause fatigue, deformation, or even breakage of the spring inside the tape measure, resulting in the tape measure being unable to rewind normally. Moreover, when pulling the tape measure, if the tape pops out too fast, the edge may cut your fingers. If the tape measure flies out of your hand, it may hit yourself or others, causing certain injuries.

[0003] Later, a design combining mechanism and electronics was proposed in the Chinese patent CN94245836 multifunctional electric tape measure, in which a movement with a winding shaft and a guide shaft is built into a structurally related housing, and a permanent magnet motor with a worm is used as a power source. After power is turned on, the magnetic field generated by the permanent magnet interacts with the energized coil, so that the motor shaft drives the worm to rotate and outputs stable power. Its speed and torque can meet the requirements of the electric tape measure for winding and releasing the tape. The winding shaft sleeve of the worm gear with the tape measure and the super clutch installed between the worm gear and the winding shaft sleeve with the tape measure enable normal power transmission, realize the winding of the tape, and control the movement of the tape measure with an automatic reset button switch, which is equipped with a series battery pack. It solves the shortcomings of manually pulling out the tape measure, but has the following problems: complex structure and too many additional internal functions, resulting in a complex structure. To a certain extent, too many measuring instruments are arranged inside the housing, resulting in a decrease in the firmness and stability of the structure. The most important problem is that the transmission design of the patented electric tape measure has the biggest drawback. The extension and retraction of the tape is achieved only by the forward and reverse rotation of the motor. In actual applications, the tape cannot be smoothly released or retracted at the expected speed due to the expansion of the tape during the release process, which greatly affects the original intention of the design of the electric tape measure for user convenience, and normal use and measurement.

[0004] With the perfection of electric tape measures in all aspects, Chinese patent CN200610051847 provides an "electric tape measure", in which a tape is wound around its core, a hook at one end of the tape extends out of the scale shell through an opening on the scale shell, and the motor in the core drives the large rollers connected to the core and the tape through a transmission mechanism, wherein the motor, power supply part, and control switch are connected to form a control circuit that controls the motor to rotate forward and reverse.

[0005] The important feature of the above patented technical solution is that when the tape measure is in the release and retraction mode, the motor starts to run, and the small gear of the motor shaft transmits power to other gears. These complicated gears will gradually increase the torque to pull the tape to release and retract. In the whole process, gears of different sizes can change the transmission ratio to drive the tape to extend and retract. The complicated gears reduce the expansion and dead phenomenon of the tape (the tape is stuck), and the gear system is used to ensure smooth power transmission. However, there are certain disadvantages. First, the internal structure of the electric tape measure with gear transmission is complicated, which is why its volume and weight are relatively large, not easy to carry, and once a gear fails, it is not easy to repair. Secondly, it is susceptible to environmental influences, and the internal gear structure is susceptible to the invasion of impurities such as dust and sand. Once these impurities enter between the gears, they will increase friction, wear the gears, and may even cause the gears to get stuck, affecting the normal operation of the tape measure. Finally, the cost is high. Due to its complex structure, including multiple gears and other parts, the production cost of this electric tape measure is high, and the price is usually much more expensive than that of ordinary tape measures, which also limits its market popularity. Summary of the invention

[0006] To solve the above problems, the present invention adopts the following technical solutions.

[0007] An electric tape measure comprises a shell, wherein a tape measure accommodating cavity is provided at one end of the shell, a power supply cavity is provided at the other end, and an opening is further provided at one end of the shell, the opening being communicated with the tape measure accommodating cavity; a roller rotatably arranged in the tape measure accommodating cavity, a plurality of guide rollers are arranged around the roller, and the two ends of the guide rollers are rotatably connected to the inner wall of the shell respectively; a motor is arranged in a cavity inside the drum, the output end of the motor is connected to one end of the drum, and the other end of the motor is connected to the shell; a tape measure is wound on the outer wall of the drum, one end of the tape measure is fixedly connected to the outer wall of the drum, and the other end of the tape measure extends from the opening, and the tape measure is arranged in a space enclosed by the plurality of guide rollers; a power supply component is arranged in the power supply cavity; a control circuit board is arranged inside the shell; a control switch is arranged on the outer wall of the shell, and the control switch, the power supply component and the motor are respectively connected to the control circuit board.

[0008] Preferably, the outer shell comprises half shell one and half shell two, a cylindrical shaft is fixedly arranged on the inner wall of the half shell one, the drum is rotatably arranged on the cylindrical shaft, and the motor is arranged inside the cylindrical shaft.

[0009] Preferably, a large bearing is provided on the cylinder shaft between the cylinder and the first half shell.

[0010] Preferably, the output shaft of the motor extends out of the drum and is rotationally connected to the second half shell via a small bearing.

[0011] Preferably, a roller is rotatably arranged inside the opening, and the ruler tape is placed above the roller.

[0012] Preferably, a plurality of guide rollers are arranged around the drum, and both ends of the guide rollers are rotatably connected to the inner wall of the outer shell.

[0013] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, the guide rollers are distributed around the drum, and when the tape is discharged, the ruler will instantly expand from the inner circle to the outer circle. At this time, the outermost circle of the ruler will be tightly attached to the guide rollers. The rotation of the guide rollers can greatly resolve the friction force of the tape caused by the expansion of the ruler, effectively preventing the ruler from being twisted and stuck, and making the ruler smoother. In a real sense, a simple and reasonable structure is used to achieve quick and stable expansion and contraction of the ruler, reliable operation, low cost, easy production, easy maintenance, reasonable pricing, easy market promotion and user popularization.

[0014] In the present invention, a large friction force is generated at the outlet when the tape is extended or retracted, and the roller can allow the tape to move smoothly, thereby preventing the tape and the outlet from being damaged due to direct friction. In particular, the longer the tape is extended, the greater the friction between the tape and the outlet due to gravity. The outlet roller greatly reduces the friction and can guide the tape to ensure that the tape can be discharged or retracted in the correct direction, thereby preventing the tape from being stuck or twisted at the outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The overall structure of the present invention explodes Figure 1 ; Figure 2 The overall structure of the present invention explodes Figure 2 .

[0016] In the figure: 1. outer shell; 2. tape measure chamber; 3. power supply chamber; 4. opening; 5. roller; 6. motor; 7. tape measure; 8. power supply assembly; 9. control circuit board; 10. control switch; 11. large bearing; 12. small bearing; 13. roller; 14. guide roller; 1-1. half shell one; 1-2. half shell two; 1-3. cylinder shaft. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0018] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0019] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0020] like Figure 1 As shown, in this embodiment, an electric tape measure includes a housing 1, a tape measure accommodating chamber 2 is provided at one end of the housing 1, a power supply chamber 3 is provided at the other end, and an opening 4 is also provided at the front end of the housing 1, the opening 4 is connected to the tape measure accommodating chamber 2, and in this example, the power supply chamber 3 is located at the gripping portion of the housing 1; The roller 5 is rotatably disposed in the tape measure accommodating chamber 2, and a plurality of guide rollers 14 are disposed around the roller 5, and both ends of the guide rollers 14 are rotatably connected to the inner wall of the housing 1; The motor 6 is arranged in the cavity inside the drum 5, the output end of the motor 6 is connected to one end of the drum 5, and the other end of the motor 6 is connected to the housing 1; The tape 7 is wound on the outer wall of the drum 5, one end of the tape 7 is fixedly connected to the outer wall of the drum 5, the tape 7 is arranged in a space surrounded by a plurality of guide rollers 14, and the outermost circle of the tape 7 is bounded by the plurality of guide rollers 14 until it extends to the opening 4 of the housing 1; A power supply component 8 is disposed in the power supply cavity 3. In this embodiment, the power supply component 8 is a dry cell battery; A control circuit board 9 is arranged inside the housing 1; The control switch 10 is arranged on the outer wall of the housing 1 , and the control switch 10 , the power supply assembly 8 and the motor 6 are respectively connected to the control circuit board 9 .

[0021] In this embodiment, the control switch 10 is designed at the front position of the upper end of the grip, which is convenient for the user to operate with one hand. The electric tape measure can be operated with one thumb. The control switch 10 is divided into a switch for controlling the tape 7 to extend and a switch for controlling the tape 7 to retract.

[0022] In this embodiment, the shell 1 includes a half shell 1-1 and a half shell 1-2, a cylindrical shaft 1-3 is fixedly arranged on the inner wall of the half shell 1-1, a roller 5 is rotatably arranged on the cylindrical shaft 1-3, and a motor 6 is arranged inside the cylindrical shaft 1-3.

[0023] In this embodiment, a large bearing 11 is provided on the cylinder shaft 1-3 between the cylinder 5 and the half shell 1-1.

[0024] In this embodiment, the output shaft of the motor 6 extends out of the drum 5 and is rotationally connected to the half shell 2 1 - 2 via a small bearing 12 .

[0025] In this embodiment, a roller 13 is rotatably disposed inside the opening 4, and the tape 7 is placed above the roller 13. The roller 13 may also be replaced by a rotatable roller with a small diameter.

[0026] In this embodiment, eight guide rollers 14 are arranged around the drum 5, and both ends of the guide rollers 14 are rotatably connected to the inner wall of the shell 1. In this embodiment, the guide rollers 14 can be set as rollers 13, and can also be replaced by rollers.

[0027] In this embodiment, the tape 7 and the roller 5 are connected by a locking connection, which can effectively prevent the tape 7 from being over-stretched or detached from the roller 5 when retracted, reduce the risk of damage to the tape 7 due to loose connection, and extend the service life of the tape measure. Compared with other connection methods, the locking connection is more stable when subjected to a large tensile force, can ensure the connection between the tape 7 and the roller 5, and make the retraction and extension of the tape 7 easy to control, which is convenient for flexible operation in different measurement scenarios.

[0028] The working principle and beneficial effects of the above technical solution are: During operation, the motor 6 is controlled by the control switch 10 to drive the roller 5 to rotate forward and reverse, thereby controlling the winding of the tape 7.

[0029] In this embodiment, the guide rollers 14 are distributed around the drum 5. When the tape 7 is discharged, the outermost circle of the tape 7 will be tightly attached to the guide rollers 14. The rotation of the guide rollers 14 can greatly resolve the friction force of the tape caused by the expansion of the tape, effectively preventing the tape 7 from being twisted and stuck, making the tape 7 smoother. In a real sense, a simple and reasonable structure is used to achieve the tape 7 to be expanded and contracted quickly and smoothly, with reliable operation, low cost, easy production, easy maintenance, reasonable pricing, easy market promotion and user popularization.

[0030] In this embodiment, a large friction force will be generated at the outlet when the tape 7 is extended and retracted. The roller 13 can allow the tape 7 to move smoothly, avoiding damage to the tape 7 and the outlet due to direct friction. In particular, the longer the tape 7 is extended, the greater the friction between the tape 7 and the outlet due to gravity. The outlet roller 13 greatly reduces the friction and can guide the tape 7 to ensure that the tape 7 can be discharged and retracted in the correct direction, preventing the tape 7 from getting stuck or twisted at the outlet.

[0031] In this embodiment, the drum 5 is made into a hollow drum 5, and the motor 6 is arranged inside the drum 5. The motor 6 as the power part is installed in the hollow drum 5, so that the overall design structure is compact, space is saved, the layout is reasonable, the motor is protected, the risk of collision is reduced, dust and moisture are prevented, and the measurement accuracy is improved in terms of performance. Because the distance between the motor 6 and the reel is short, the transmission path is short, and the energy transfer efficiency is high, the influence of energy loss and mechanical errors in the transmission process on the measurement accuracy is reduced, and the retraction and release of the tape 7 is more accurate.

[0032] In this embodiment, the left and right ends of the drum 5 adopt a double bearing structure. The friction when the reel rotates is effectively reduced, the friction resistance is reduced, and the support at both ends of the drum 5 allows the drum 5 to rotate more flexibly, making the retraction and extension of the tape 7 smoother and more fluent, avoiding the jamming phenomenon, enhancing the stability to a greater extent, keeping the drum 5 balanced, and being able to evenly bear the weight of the drum 5 and the tape 7. Moreover, this structure is more adaptable to large-sized tapes 7. For some electric tape measures that need to use large-sized and thick tapes 7, the double bearing structure can better support and drive the retraction and extension of the tape 7.

[0033] The above are only preferred specific implementations of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and improved concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An electric measuring tape, characterized in that: include, A housing (1), wherein a tape measure accommodating cavity (2) is provided at one end of the housing (1), and a power supply cavity (3) is provided at the other end; an opening (4) is also provided at one end of the housing (1), and the opening (4) is connected to the tape measure accommodating cavity (2); A roller (5) is rotatably disposed in the tape measure accommodating chamber (2), wherein a plurality of guide rollers (14) are disposed around the roller (5), and both ends of the guide rollers (14) are rotatably connected to the inner wall of the outer shell (1); The motor (6) is arranged in a cavity inside the drum (5), the output end of the motor (6) is connected to one end of the drum (5), and the other end of the motor (6) is connected to the housing (1); A tape ruler (7) is wound on the outer wall of the drum (5), one end of the tape ruler (7) is fixedly connected to the outer wall of the drum (5), the other end of the tape ruler (7) extends out from the opening (4), and the tape ruler (7) is arranged in a space enclosed by a plurality of guide rollers (14); A power supply component (8) is arranged in the power supply cavity (3); A control circuit board (9) is arranged inside the housing (1); A control switch (10) is arranged on the outer wall of the housing (1); the control switch (10), the power supply component (8) and the motor (6) are respectively connected to a control circuit board (9).

2. An electric measuring tape according to claim 1, characterized in that: The outer shell (1) comprises a half shell one (1-1) and a half shell two (1-2); a cylindrical shaft (1-3) is fixedly arranged on the inner wall of the half shell one (1-1); a roller (5) is rotatably arranged on the cylindrical shaft (1-3); and a motor (6) is arranged inside the cylindrical shaft (1-3).

3. An electric measuring tape according to claim 2, characterized in that: A large bearing (11) is provided on the cylinder shaft (1-3) between the cylinder (5) and the first half shell (1-1).

4. The electric measuring tape according to claim 1, characterized in that: The output shaft of the motor (6) extends out of the drum (5) and is rotationally connected to the second half shell (1-2) via a small bearing (12).

5. The electric measuring tape according to claim 1, characterized in that: A roller (13) is rotatably arranged inside the opening (4), and the ruler (7) is placed above the roller (13).

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