Dial protractor

Abstract

The utility model discloses a dial formula radius compasses, including the casing and the handle connected at its top, install the dial on the casing, the center rotation of dial is connected with the central shaft, and the front end of central shaft is provided with the pointer, and the lower extreme of casing is rotatively connected with the pen nib branch leg and the needle foot branch leg of symmetrical distribution respectively, and one coaxial of pen nib branch leg and needle foot branch leg is provided with the locking mechanism, and pen nib branch leg and needle foot branch leg are connected with the central shaft through transmission mechanism. The utility model need not ruler, and the operation is simplified: the synchronous linkage of branch leg and pointer is realized through transmission mechanism, and the indication value of pointer on dial directly corresponds the radius, need not the help of ruler measurement, reduces the operation step, and promotes the mapping efficiency, and the adjustment is convenient, and the operation is stable: the radius adjustment can be realized through "manual break branch leg" or "auxiliary nut fine adjustment", and the cooperation of nut and extension screw rod, the elastic clamping design of protection cap all promote the operation stability, and save the labor and not easy to slip.

Description

Technical Field

[0001] This utility model relates to the field of drawing tools, and in particular to a dial-type radius compass. Background Technology

[0002] In drafting, the compass is a commonly used tool, primarily for drawing circles or arcs. Existing compasses typically consist of two legs: one end has a pin (for fixing the center of the circle), and the other end has a pen tip (for drawing lines). The radius of the circle is changed by adjusting the angle between the two legs.

[0003] However, existing compasses have significant drawbacks when adjusting the radius: the adjustment process requires using a ruler to measure the distance between the needle and the tip to determine the radius, which is cumbersome, reduces drawing efficiency, and is prone to human error during measurement, leading to insufficient radius accuracy and affecting drawing quality. Therefore, there is an urgent need for a compass that can directly and accurately read the radius to overcome the shortcomings of existing technology. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a dial-type radius compass. This compass aims to solve the problems of existing compasses requiring a ruler for radius adjustment, being cumbersome to operate, and lacking precision. It provides a dial-type radius compass that enables intuitive reading and convenient adjustment of the radius.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A dial-type radius compass includes a housing and a handle connected to its top. A scale is mounted on the housing, and a central shaft is rotatably connected to the center of the scale. A pointer is located at the front end of the central shaft. Symmetrically distributed pen tip legs and needle feet legs are rotatably connected to the lower end of the housing. A locking mechanism is coaxially provided for one of the pen tip legs and the needle feet legs. The pen tip legs and the needle feet legs are connected to the central shaft through a transmission mechanism. The pen tip legs, the needle feet legs, the central shaft, and the pointer rotate synchronously through the transmission mechanism. The position of the pointer on the scale is the angle between the pen tip legs and the needle feet legs.

[0006] Preferably, the transmission mechanism includes two meshing sector gears, which are coaxially arranged with the rotation centers of the pen tip support leg and the needle support leg, respectively. One sector gear is coaxially connected to a sector gear, which meshes with a central gear, which is connected to a central shaft.

[0007] Preferably, a limiting pin is provided at the end of the sector gear two away from the central gear, and the limiting pin is connected to the housing.

[0008] Preferably, the needle support leg is connected to a protective cap via a pin. The protective cap is an elastic structure with an opening. The needle support leg has a protrusion corresponding to the opening. When the protrusion and the opening are engaged and overlapped, the protective cap seals the tips of the pen tip support leg and the needle support leg.

[0009] Preferably, the locking mechanism includes an extension screw coaxially connected to the pen tip support leg, the extension screw passing through the housing and threaded with a nut.

[0010] Compared with the prior art, the beneficial effects of this utility model are: No ruler needed, simplified operation: The transmission mechanism enables synchronous linkage between the support legs and the pointer. The pointer's indication on the dial directly corresponds to the radius, eliminating the need for ruler measurement, reducing operation steps, and improving drawing efficiency. Easy to adjust and stable to operate: The radius can be adjusted by "manually bending the support leg" or "fine-tuning with the auxiliary nut". The fit between the nut and the extension screw and the elastic snap-fit ​​design of the protective cap improve the stability of operation, saving effort and making it less prone to slippage. Improved accuracy and reduced error: The transmission mechanism adopts a gear meshing structure (sector gear one, sector gear two, and center gear) to ensure that the change of the support leg angle is completely synchronized with the rotation of the pointer, avoiding subjective errors in manual measurement and significantly improving drawing accuracy; High safety and easy storage: The protective cap can seal the tip of the outrigger, eliminating the risk of accidental injury during storage and carrying, while protecting the tip from impact damage and extending the tool's lifespan. Attached Figure Description

[0011] To illustrate the technical solutions in the embodiments of this utility model or the prior art more specifically and intuitively, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0012] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a front view schematic diagram of the structure proposed in this utility model; Figure 3 This is a schematic diagram of the rear view structure proposed in this utility model; Figure 4 This is a schematic diagram of the internal structure of the shell proposed in this utility model; Figure 5 for Figure 4 A partial structural diagram.

[0013] In the diagram: 1. Housing; 2. Dial; 3. Handle; 4. Pen tip support leg; 5. Needle support leg; 6. Pointer; 7. Central shaft; 8. Protective cap; 9. Opening; 10. Protrusion; 11. Pin; 12. Nut; 13. Sector gear one; 14. Sector gear two; 15. Limit pin; 16. Central gear. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0015] Reference Figure 1-5 A dial-type radius compass includes a housing 1 and a handle 3 connected to its top. A scale 2 is mounted on the housing 1. A central shaft 7 is rotatably connected to the center of the scale 2. A pointer 6 is provided at the front end of the central shaft 7. A symmetrically distributed pen tip support leg 4 and needle support leg 5 are rotatably connected to the lower end of the housing 1. A locking mechanism is provided on one of the pen tip support leg 4 and the needle support leg 5 on the same axis. The pen tip support leg 4 and the needle support leg 5 are connected to the central shaft 7 through a transmission mechanism. The pen tip support leg 4, the needle support leg 5, the central shaft 7 and the pointer 6 rotate synchronously through the transmission mechanism. The position of the pointer 6 on the scale 2 is the angle between the pen tip support leg 4 and the needle support leg 5.

[0016] In this embodiment, the transmission mechanism includes two meshing sector gears 13. The two sector gears 13 are coaxially arranged with the rotation centers of the pen tip support leg 4 and the needle support leg 5, respectively. One of the sector gears 13 is coaxially connected to a sector gear 14, which meshes with a central gear 16. The central gear 16 is connected to the central shaft 7.

[0017] In this embodiment, a limiting pin 15 is provided at the end of sector gear 2 14 away from the central gear 16, and the limiting pin 15 is connected to the housing 1.

[0018] In this embodiment, the needle support leg 5 is connected to a protective cap 8 via a pin 11. The protective cap 8 is an elastic structure and has an opening 9. The needle support leg 5 has a protrusion 10 corresponding to the opening 9. When the protrusion 10 and the opening 9 are engaged and overlapped, the protective cap 8 closes the tips of the pen tip support leg 4 and the needle support leg 5. The locking mechanism includes an extension screw coaxially connected to the pen tip support leg 4. The extension screw passes through the housing 1 and is threadedly connected to a nut 12. When the nut 12 is manually rotated, the nut 12 moves along the extension screw and presses against the housing 1. The friction between the two locks the pen tip support leg 4.

[0019] Work process: In the initial state, pointer 6 coincides with the zero mark on dial 2. Adjusting the radius can be done in two ways: Manually move the pen tip support leg 4. The pen tip support leg 4 drives the coaxial sector gear 13 to rotate. This sector gear 13 meshes with and drives another sector gear 13 to rotate, thereby causing the needle support leg 5 to rotate synchronously and change the included angle between the two. At the same time, the sector gear 13, which is coaxial with the pen tip support leg 4, drives the sector gear 2 14 to rotate. The sector gear 2 14 meshes with and drives the central gear 16 and the central shaft 7 to rotate. The central shaft 7 drives the pointer 6 to rotate. The position of the pointer 6 on the scale 2 corresponds to the current distance between the pen tip and the needle, i.e., the radius.

[0020] After the radius is determined, keep the pen tip support leg 4 and the needle support leg 5 stationary, manually rotate the nut 12, and the nut 12 moves along the extension screw connected to it and presses on the housing 1. The friction between the two locks the pen tip support leg 4, thereby ensuring that the included angle between the pen tip support leg 4 and the needle support leg 5 remains unchanged. After locking, the two legs can be firmly fixed by drawing circles.

[0021] After use, snap the opening 9 of the protective cap 8 into the protrusion 10 of the pin leg 5 to seal the tip of the leg and complete the storage.

[0022] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A dial-type radius compass, comprising a housing (1) and a handle (3) connected to its top, characterized in that, A dial (2) is mounted on the housing (1). A central shaft (7) is rotatably connected to the center of the dial (2). A pointer (6) is provided at the front end of the central shaft (7). A symmetrically distributed pen tip support leg (4) and needle support leg (5) are rotatably connected to the lower end of the housing (1). A locking mechanism is provided on one coaxial part of the pen tip support leg (4) and the needle support leg (5). The pen tip support leg (4) and the needle support leg (5) are connected to the central shaft (7) through a transmission mechanism. The pen tip support leg (4), the needle support leg (5), the central shaft (7) and the pointer (6) rotate synchronously through the transmission mechanism. The position of the pointer (6) on the dial (2) is the angle between the pen tip support leg (4) and the needle support leg (5).

2. A dial-type radius compass according to claim 1, characterized in that, The transmission mechanism includes two meshing sector gears (13), which are coaxially arranged with the rotation centers of the pen tip support leg (4) and the needle support leg (5), respectively. One of the sector gears (13) is coaxially connected to a sector gear (14), which meshes with a central gear (16), which is connected to a central shaft (7).

3. A dial-type radius compass according to claim 2, characterized in that, The sector gear 2 (14) is provided with a limit pin (15) at the end away from the central gear (16), and the limit pin (15) is connected to the housing (1).

4. A dial-type radius compass according to claim 3, characterized in that, The needle support leg (5) is connected to a protective cap (8) via a pin (11). The protective cap (8) is an elastic structure. The protective cap (8) has an opening (9). The needle support leg (5) has a protrusion (10) corresponding to the opening (9). When the protrusion (10) and the opening (9) are engaged and overlapped, the protective cap (8) closes the tip of the pen tip support leg (4) and the needle support leg (5).

5. A dial-type radius compass according to claim 4, characterized in that, The locking mechanism includes an extension screw coaxially connected to the pen tip support leg (4), the extension screw passing through the housing (1) and threaded with a nut (12).

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