EP3815925A1

EP3815925A1 - Drawing compass

Info

Publication number: EP3815925A1
Application number: EP20204412.9A
Authority: EP
Inventors: Che-Chang Cheng; Hsiang-Jung Cheng; Yen-Chih Kuo; Chyi-Feng Huang
Original assignee: SDI Corp
Current assignee: SDI Corp
Priority date: 2019-11-01
Filing date: 2020-10-28
Publication date: 2021-05-05

Abstract

A drawing compass has an outer casing (40), a moving device (10), two legs (20), and an operating member (30). The moving device (10) is moveable up or down relative to the outer casing (40) and has a connecting portion (11) and two linking portions (12). An imaginary longitudinal first axis (C₁) passes through the moving device (10). The legs (20) are connected to the outer casing (40) and connected to the linking portions (12), respectively, for pivotal movement toward or away from each other. The operating member (30) is lengthwise and has a connecting end (31), an operating end (32), and a limiting portion (33). The operating member (30) can freely swing on the connecting end (31). The moving device (10) is linked up with the two legs (20) to move the operating member (30) up or down relative to the outer casing (40).

Description

This patent application claims the benefits of Taiwan patent application No. 108139727, filed on November 01, 2019 and Taiwan patent application No. 109106418, filed on February 27, 2020 , the entire contents of which are incorporated herein by references thereto.

1. Field of the Invention

The present invention relates to a drawing compass, and more particularly to a drawing compass that can be rotated stably in operation.

2. Description of Related Art

A conventional drawing compass is one of the writing stationeries for users to draw circular or arc-shaped lines. However, in general, when operating the conventional drawing compass, a user must use two fingers to hold a knob of the conventional drawing compass and make it roll between the fingers, making it difficult to strike a balance. The conventional drawing compass may easily slip off the user's fingers accidentally, causing inconvenience in use. Therefore, there were some improved structures, such as CN Pub. No. 102152694B filed in China and titled "Compasses". The compasses have a body and an operating element. The body has two legs and a center drive connected to the two legs. The operating element is pivotably connected to a supporting element that is disposed on a top end of the center drive. The body with the supporting element can be tilted to make its central axis intersect a rotation axis of the operating element. It is convenient for the user to hold the operating element and execute strength for drawing a circle or an arc without making the supporting element roll between the user's fingers, but such tilt-swing operation is only suitable for drawing a large circle or arc rather than a small circle or arc. However, when the user wants to draw a small circle or arc, it is neither easy nor convenient to hold the operating element to operate the tiltably rotatable drawing compass because the user must remove the operating element from the supporting element and then hold and make the supporting element roll between the user's fingers for drawing a circle or an arc. In this way, the user must constantly combine or remove the operating element with or from the supporting element according to the sizes of required arcs or circles without an automatic adjustment mechanism, leading to operational inconvenience.
In addition, a drawing compass has been disclosed in JP Patent No. 5620842 with an operating structure that can be held pivotally for operation. However, when the drawing compass is used to draw a circle or an arc with a small radius, the operating structure may be shaken arbitrarily, making the user unable to rotate the drawing compass steadily, so that it is thus extremely difficult to operate the drawing compass and further improvement is necessary.
The main objective of the present invention is to provide a drawing compass that can be operated stably, easily, and conveniently.
The drawing compass in accordance with the present invention has an outer casing, a moving device, two legs, and an operating member. The outer casing has a limiting hole running through a top of the outer casing. The moving device is moveable up or down relative to the outer casing and has a connecting portion and two linking portions. An imaginary longitudinal first axis passes through the moving device. The connecting portion is located at a top of the moving device. The two linking portions are located at two opposite sides beside the imaginary longitudinal first axis, respectively. The two legs can be pivotally moved toward or away from each other to define an included angle therebetween, are connected to the outer casing, and are rotatably connected to the two linking portions, respectively. The operating member is lengthwise and has a connecting end, an operating end, and a limiting portion. The connecting end and the operating end are located away from each other lengthways, the limiting portion is disposed between the connecting end and the operating end, the operating end is disposed outside the outer casing, and the connecting end is rotatably connected to the connecting portion of the moving device to enable the operating member to freely swing the connecting end serving as a fulcrum. As the two legs are pivotally moved toward or away from each other, the moving device is moved to drive the operating member to move up or down lengthways relative to the outer casing.
The drawing compass in accordance with the present invention has the following advantages.
First, parts of the operating member are selectively limited by the up-and-down movement of the operating member relative to the outer casing, so that the swing range of the operating member can be freely adjusted to draw a circle or an arc, thereby enabling users to operate the drawing compass to draw large or small circles/arcs quickly and highly maneuverably, further greatly enhancing the diversity and practicality of operations of the drawing compass.
Second, an exposed part of the operating member emerging from the limiting hole of the outer casing becomes longer as the radius of a circle or an arc to be drawn becomes larger, thereby shortening an unexposed part of the limiting portion submerging in the limiting hole, so that the swing range of the operating member is automatically adjusted to become larger accordingly. Therefore, the drawing compass of the present invention can be set according to the radius of a circle or an arc to be drawn to automatically adjust the swing range of the operating member, effectively solving the problem that the tilt-swing operating range of the conventional drawing compass cannot be adjusted. In this way, the drawing compass of the present invention can be used to freely select a required swing range of the operating member for drawing a circle or an arc, thus enabling users to quickly and highly maneuverably draw circles/arcs with a required radius, thus greatly enhancing the versatility and practicability of the drawing compass in operation.

IN THE DRAWINGS:

Fig. 1 is a perspective view of a drawing compass constructed in accordance with a first preferred embodiment of the present invention;
Fig. 2 is an exploded perspective view of the drawing compass indicated in Fig. 1;
Fig. 3 is another exploded perspective view of the drawing compass indicated in Fig. 2;
Fig. 4 is a partially sectional side view of the drawing compass indicated in Fig. 1;
Fig. 5 is a partially enlarged exploded perspective view of parts of the drawing compass indicated in Fig. 1;
Fig. 6 is a partially exploded side view of the drawing compass indicated in Fig. 1 in operation;
Fig. 7 is another partially sectional side view of the drawing compass indicated in Fig. 1 in operation;
Fig. 8 is a perspective view of a drawing compass constructed in accordance with a second preferred embodiment of the present invention;
Fig. 9 is an exploded perspective view of the drawing compass indicated in Fig. 8;
Fig. 10 is a partially sectional side view of the drawing compass indicated in Fig. 8;
Fig. 11 is a partially sectional side view of the drawing compass indicated in Fig. 8 in operation;
Fig. 12 is another partially sectional side view of the drawing compass indicated in Fig. 8;
Fig. 13 is a perspective view of a drawing compass constructed in accordance with a third preferred embodiment of the present invention;
Fig. 14 is an exploded perspective view of the drawing compass indicated in Fig. 13;
Fig. 15 is a partially sectional side view of the drawing compass indicated in Fig. 13;
Fig. 16 is a partially sectional side view of the drawing compass indicated in Fig. 13 in operation;
Fig. 17 is another partially sectional side view of the drawing compass indicated in Fig. 13 in operation;
Fig. 18 is a perspective view of a drawing compass constructed in accordance with a fourth preferred embodiment of the present invention;
Fig. 19 is an exploded perspective view of the drawing compass indicated in Fig. 18;
Fig. 20 is a side view of the drawing compass indicated in Fig. 18;
Fig. 21 is a partially sectional side view of the drawing compass indicated in Fig. 18;
Fig. 22 is a partially sectional side view of the drawing compass in Fig. 18 in operation;
Fig. 23 is another partially sectional side view of the drawing compass indicated in Fig. 18 in operation;
Fig. 24 is a partially enlarged perspective view of the drawing compass indicated in Fig. 18 in operation;
Fig. 25A is an exploded perspective view of another configuration of the drawing compass indicated in Fig. 18;
Fig. 25B is an enlarged sectional perspective view of a linking rod of the drawing compass indicated in Fig. 25A;
Fig. 26 is a partially sectional side view of the drawing compass indicated in Fig. 25A; Fig. 27 is a perspective view of a drawing compass in accordance with a fifth preferred embodiment of the present invention;
Fig. 28 is an exploded perspective view of the drawing compass indicated in Fig. 27; Fig. 29 is a partially sectional side view of the drawing compass indicated in Fig. 27; Fig. 30 is a partially sectional side view of the drawing compass indicated in Fig. 27 in operation;
Fig. 31 is another partially sectional side view of the drawing compass indicated in Fig. 27;
Fig. 32 is a perspective view of a drawing compass constructed in accordance with a sixth preferred embodiment of the present invention;
Fig. 33 is an exploded perspective view of the drawing compass indicated in Fig. 32; Fig. 34 is a partially sectional enlarged side view of the drawing compass indicated in Fig. 32;
Fig. 35 is a partially sectional side view of the drawing compass indicated in Fig. 32 in operation;
Fig. 36 is another partially sectional side view of the drawing compass in Fig. 32 in operation; and
Fig. 37 is a partially enlarged perspective view of a drawing compass constructed in accordance with a seventh preferred embodiment of the present invention in operation.

To learn more about the technical features and practical efficacy of the present invention, and to utilize the present invention in accordance with the specification, the detailed description of the preferred embodiments as shown in the drawings is disclosed as follows.
With reference to Figs. 1 to 4, a drawing compass constructed in accordance with a first preferred embodiment of the present invention includes a moving device 10, two legs 20, an operating member 30, and an outer casing 40.
The moving device 10 is disposed in the outer casing 40 and moveable upwardly or downwardly relative to the outer casing 40. The moving device 10 has a connecting portion 11 and two linking portions 12. An imaginary longitudinal first axis C₁ passes through a center of the moving device 10. The connecting portion 11 is located at a top of the moving device 10, deviating from the imaginary longitudinal first axis C₁ of the moving device 10, and may be a concave portion or a convex portion. The two linking portions 12 are symmetrically located at two opposite sides beside the imaginary longitudinal first axis C₁ of the moving device 10, respectively, and can pivotally move toward or away from the imaginary longitudinal first axis C₁ of the moving device 10 at the same time. Furthermore, the moving device 10 has two half bodies 13 connected to each other, the connecting portion 11 is disposed between the two half bodies 13, and the two half bodies 13 are connected to each other by multiple grooves 131 and protrusions 132. Also, each of the two linking portions 12 of the moving device 10 has a swingable linking rod 14, each of which has a swing end located away from the operating member 30 and is located between the two half bodies 13.
Preferably, the moving device 10 has a guiding structure facing outwardly, and the outer casing 40 has a positioning structure facing inwardly and corresponding to the guiding structure of the moving device 10. When the moving device 10 is moved upwardly or downwardly relative to the outer casing 40, the guiding structure can move along the positioning structure to improve the stability of linear movement of the moving device 10. The linear movement of the moving device 10 is parallel to the imaginary longitudinal first axis C₁ of the moving device 10. In the first preferred embodiment of the present invention, the moving device 10 has two opposite outer sides, the guiding structure is formed of two guiding portions 15 located on the two opposite outer sides of the moving device 10, respectively, and each of the guiding portions 15 is an elongated rib located on an outer side of one of the two half bodies 13.
The two legs 20 can be pivotally moved toward or away from each other with respect to the outer casing 40 and are swingably connected to the two linking portions 12 of the moving device 10, respectively. Each of the two legs 20 has a pivotal portion 21 and a coaxial portion 22, both of which are disposed on a top thereof. Each of the pivotal portions 21 is located outside the corresponding leg 20 with respect to the corresponding coaxial portion 22 and is pivotally connected to one of the two linking portions 12 of the moving device 10. Furthermore, each of the pivotal portions 21 of the two legs 20 is pivotally connected to one of the swing ends of the two linking rods 14 of the moving device 10. The coaxial portions 22 of the two legs 20 overlap and are coaxially pivotally connected to each other to enable bottom ends of the two legs 20 to move toward or away from each other. In addition, due to the symmetrical configuration of the two linking portions 12 of the moving device 10 relative to the imaginary longitudinal first axis C₁ and the linear movement of the moving device 10, the two legs 20 can be pivotally moved toward or away from each other synchronously with respect to the imaginary longitudinal first axis C₁ more accurately. In other words, an included angle defined between the two legs 20 relative to the imaginary longitudinal first axis C₁ can keep symmetrically consistent, so that the drawing compass of the present invention can be operated stably on its center of gravity.
The operating member 30 is lengthwise and has a connecting end 31 and an operating end 32. The connecting end 31 and the operating end 32 are located away from each other lengthways. The operating member 30 further has a limiting portion 33 disposed between the connecting end 31 and the operating end 32. The operating end 32 of the operating member 30 is disposed outside the outer casing 40. The connecting end 31 of the operating member 30 is rotatably connected to the connecting portion 11 of the moving device 10, so that the operating member 30 can freely swing on the connecting end 31 serving as a fulcrum. In addition, when the connecting portion 11 is a concave portion, the connecting end 31 of the operating member 30 is a spherical body matching the connecting portion 11 in shape. The limiting portion 33 can be a tapered structure that has an outer diameter gradually increasing from the connecting end 31 to the operating end 32. Since an upper part of the limiting portion 33, adjacent to the operating end 32, is thicker than the other lower part of the limiting portion 33, higher rigidity can be provided to avoid any adverse effect on the structural strength of the operating member 30 after the drawing compass has been operated for multiple times. Also, the outer diameter of the lower part of the limiting portion 33, near the connecting end 31, is relatively smaller, so the volume of the connecting portion 11 of the moving device 10 can be reduced accordingly, thereby reducing the overall volume of the moving device 10. Preferably, the operating end 32 can be a block or a plate having a relatively larger volume for easy holding.
With reference to Fig. 4 again, the imaginary longitudinal first axis C₁ passing through the moving device 10 is parallel to the lengthwise operating member 30, an imaginary longitudinal second axis C₂ passes through the connecting end 31 and the limiting portion 33 of the operating member 30 to be parallel to the lengthwise operating member 30, and an eccentric distance E is formed between the two imaginary longitudinal axes C₁, C₂. Furthermore, one of the pivotal portions 21 of the two legs 20 is located closer to the imaginary longitudinal second axis C₂ than the imaginary longitudinal first axis C₁ and the corresponding leg 20 is defined as an eccentric side leg, and a linear distance S is defined between the pivotal portion 21 and the coaxial portion 22 of the eccentric side leg 20. Preferably, the eccentric distance E is less than or equal to the linear distance S. In detail, with reference to Figs. 4 and 5, an imaginary first extending line P₁ passes through the centers of the coaxial portions 22 of the two legs 20, being orthogonal to the imaginary longitudinal first axis C₁. An imaginary second extending line P₂ passes through the center of the pivotal portion 21 of the eccentric side leg 20. The imaginary first extending line P₁ is parallel to the imaginary second extending line P₂, and the linear distance S is a vertical distance between the imaginary first extending line P₁ and the imaginary second extending line P₂. Since the eccentric distance E is less than or equal to the linear distance S, under an ideal condition, that is, regardless of factors like shape or volume, the connecting end 31 of the operating member 30 is located right above the pivotal portion 21 of the eccentric side leg 20, making it the easiest to execute strength for drawing a circle or an arc. If the eccentric distance E is larger than the linear distance S, it will be not easy to execute strength for drawing a small circle or arc. Specifically, the two legs 20 are a pin leg and a pen leg, respectively, the connecting end 31 of the operating member 30 is connected to the connecting portion 12 corresponding to the pen leg; that is, the eccentric side leg 20 is a pen leg.
The outer casing 40 is connected to the two legs 20 and has two inner sides facing each other, a fixing member 41, and a limiting hole 42. The fixing member 41 is inserted through the coaxial portions 22 of the two legs 20 to coaxially connect the two legs 20 with the outer casing 40. The limiting hole 42 runs through a top of the outer casing 40 to enable the operating end 32 of the operating member 30 to be located outside the limiting hole 42 of the outer casing 40. The moving device 10 is moved along the imaginary longitudinal first axis C₁, while the two legs 20 are pivotally moved toward or away from each other, to drive the operating member 30 to move upwardly or downwardly lengthways relative to the outer casing 40, so that parts of the limiting portion 33 of the operating member 30 can selectively contact an inner sidewall of the limiting hole 42 of the outer casing 40 in operation. The connecting portion 11 of the moving device 10 deviates from the imaginary longitudinal first axis C₁, the imaginary longitudinal second axis C₂ passes through the connecting portion 11, and is straightly opposite to the limiting hole 42 of the outer casing 40, and the connecting portion 11 is connected to the connecting end 31 of the operating member 30.
With reference to Figs. 2 and 3, as for a configuration that the outer casing 40 has the positioning structure corresponding to the guiding structure of the moving device 10, the positioning structure is disposed on the two inner sides of the outer casing 40 and has two positioning portions 43 corresponding to the two guiding portions 15, respectively. Each of the two positioning portions 43 is connected to one of the two guiding portions 15 of the moving device 10, so that each of the two guiding portions 15 is moved along the corresponding positioning portion 43 when the moving device 10 is moved with the pivotal movement of the two legs 20, thus providing a guiding effect of up-and-down linear movement for the moving device 10. In addition, the outer casing 40 may have two half-shells 44 connected to each other, and the two half-shells 44 are coaxially connected to the coaxial portions 22 of the two legs 20 by the fixing member 41.
When the included angle of the two legs 20 of the drawing compass of the first preferred embodiment of the present invention is zero degree, the limiting portion 33 of the operating member 30 fully submerges in the limiting hole 42 of the outer casing 40. With reference to Figs. 1 and 6, when a user makes the two legs 20 pivotally move away from each other, the moving device 10 is linked up with the two legs 20 to move along the lengthwise operating member 30 relative to the outer casing 40 to further move the operating member 30 upwardly. In the meantime, the limiting portion 33 of the operating member 30 gradually emerges upwardly from the limiting hole 42 of the outer casing 40, and a swing range of the operating member 30 is positively correlated with the included angle of the two legs 20. In other words, an exposed part of the operating member 30 emerging from the limiting hole 42 of the outer casing 40 becomes longer as the radius of a circle or an arc to be drawn becomes larger, thereby shortening an unexposed part of the limiting portion 33 submerging in the limiting hole 42, so that the swing range of the operating member 30 is automatically adjusted to become larger accordingly. Therefore, the drawing compass of the present invention can be set according to the radius of a circle or an arc to be drawn to automatically adjust the swing range of the operating member 30, effectively solving the problem that the tilt-swing operating range of the conventional drawing compass cannot be adjusted. In this way, the drawing compass of the present invention can be used to freely select a required swing range of the operating member for drawing a circle or an arc, thus enabling users to quickly and highly maneuverably draw a circle or an arc with a required radius, thus greatly enhancing the versatility and practicability of the drawing compass in operation.
As for the operation of the drawing compass of the first preferred embodiment of the present invention, when the two legs 20 are pivotally moved away from each other to make the included angle therebetween smaller as shown in Fig. 6, the unexposed part of the operating member 30 submerging in the outer casing 40 is major and the exposed part of the same is minor, so that a very small swing range can be made. In this way, a user can hold the operating member 30 to draw a circle or an arc with a smaller radius. Referring to Fig. 7, when the included angle of the two legs 20 is set larger, the two linking rods 14 are linked up with the two legs 20 to move the moving device 10 upwardly along the outer casing 40, and each of the two guiding portions 15 of the moving device 10 can move upwardly along the corresponding positioning portions 43 as shown in Figs. 2 and 3, thereby driving the operating member 30 to move upwardly relative to the outer casing 40. In the meantime, the exposed part of the limiting portion 33 of the operating member 30 emerging from the limiting hole 42 of the outer casing 40 becomes longer, and the swing range of the operating member 30 becomes larger and the operating member 30 can be operated to tilt and swing freely with respect to the imaginary longitudinal first axis C₁, so that the user can hold the operating member 30 of the drawing compass of the present invention to draw a circle or an arc with a larger radius. In addition, when the user intends to draw a smaller circle or arc, the user can also choose to hold the two half-shells 44 instead of the outer casing 40. Therefore, the drawing compass of the first preferred embodiment of the present invention can be used to draw large or small circles/arcs having various radiuses quickly and highly maneuverably, thus providing users with diversified operation methods and effectively enhancing the practicability of the drawing compass.
As for the operation of the drawing compass of the first preferred embodiment of the present invention, despite that the radius of a circle or an arc to be drawn is small as shown in Fig. 6 or is large as shown in Fig. 7, the eccentric distance E is formed between the imaginary longitudinal second axis C₂ and the imaginary longitudinal first axis C₁, so that a force arm of the drawing compass of the present invention is increased and the torque of rotation in the process of drawing a circle or an arc is also increased, thus further enabling the user to draw circles or arcs more smoothly, especially for large or small circles/arcs that can be drawn quickly and highly maneuverably.
With reference to Figs. 8 to 10, a drawing compass constructed in accordance with a second preferred embodiment of the present invention is substantially the same as that of the first preferred embodiment except for the following features. In the second preferred embodiment of the drawing compass, the moving device 10A does not have the two linking rods 14 and is an elastic C-like structure. Alternatively, the moving device 10A can be shaped like another geometric figure (e.g. triangle, quadrilateral, or polygon) having an opening. Each of the two linking portions 12A of the moving device 10A, located away from the operating member 30A, is a swing end, and top ends of the two legs 20A are rotatably connected to the swing ends of the two linking portions 12A, respectively. For example, the moving device 10A is a flexible C-like clamp structure, each of the swing ends of the moving device 10A has a clamping portion 16A, and the top ends of the two legs 20A are pivotally connected to the clamping portions 16A of the two linking portions 12A of the moving device 10A, respectively.
As regards the operation of the drawing compass of the second preferred embodiment of the present invention, when the included angle of the two legs 20A is set smaller as shown in Fig. 11, the unexposed part of the limiting portion 33A of the operating member 30 submerging in the limiting hole 42A of the outer casing 40A is major and the exposed part of the same is minor, so that a very small swing range can be made. In this way, the user can hold the operating member 30A to draw a circle or an arc with a smaller radius. Referring to Fig. 12, the included angle of the two legs 20 is set large, the operating member 30A is linked up with the two legs 20 to move the moving device 10A upwardly relative to the outer casing 40, the exposed part of the limiting portion 33A of the operating member 30A emerging from the limiting hole 42A of the outer casing 40A becomes longer to make the unexposed part of the same shorter, so that the operating member 30A can be operated to tilt and swing freely with respect to the imaginary longitudinal first axis C₁. In this way, the user can hold the operating member 30A of the drawing compass of the second preferred embodiment of the present invention to draw a circle or an arc with a larger radius, thus providing users with diversified operation methods and effectively enhancing the practicability of the drawing compass.
With reference to Figs. 13 to 15, a drawing compass constructed in accordance with a third preferred embodiment of the present invention is substantially the same as that of the first preferred embodiment except for the following features. In the third preferred embodiment of the drawing compass, the outer casing 40B has a holding portion 45B formed on the top of the outer casing 40B and protruding along the lengthwise operating member 30B. The holding portion 45B can be used to limit the free swing of the operating member 30B relative to the outer casing 40B, and the holding portion 45B can be integrally formed with one of the two half-shells 44B. The limiting hole 42B is formed inside the holding portion 45B, and the operating end 32B of the operating member 30B is located outside the holding portion 45B to enable parts of the limiting portion 33B of the operating member 30B to selectively contact the inner sidewall of the limiting hole 42B. In addition, the drawing compass further has a cap 50B, and the cap 50B is selectively connected to a bottom of one or the other of the two legs 20B or the operating end 32B of the operating member 30B.
When the included angle of the two legs 20B of the drawing compass of the third preferred embodiment of the present invention is zero degree, the limiting portion 33B of the operating member 30B is fully moved into the limiting hole 42B of the outer casing 40B. With reference to Figs. 13 and 16, when a user makes the two legs 20B pivotally move away from each other, the two legs 20B will force the moving device 10B to move along the lengthwise operating member 30B relative to the outer casing 40B to drive the operating member 30B to move upwardly. In the meantime, the limiting portion 33B of the operating member 30B gradually emerges upward from the limiting hole 42B of the outer casing 40B, and the swing range of the operating member 30B is positively correlated to the included angle of the two legs 20B. In other words, the exposed part of the operating member 30B emerging from the limiting hole 42B of the outer casing 40B becomes longer as the radius of a circle or an arc to be drawn becomes larger, so that the swing range of the operating member 30B is automatically adjusted and increased accordingly. Therefore, the drawing compass of the present invention can be set according to the radius of the circle/arc to automatically adjust the swing range of the operating member 30B.
As for the operation of the drawing compass of the third preferred embodiment of the present invention, when the included angle is set smaller as shown in Fig. 16, the unexposed part of the limiting portion 33B of the operating member 30B submerging in the holding portion 45B of the outer casing 40B is major and the exposed part of the same is minor, so that a very small swing range can be made. In this way, the user can hold the operating member 30B to draw a circle or an arc with a smaller radius. Referring to Fig. 17, when the included angle of the two legs 20B is set larger, the two linking rods 14B are linked up with the two legs 20B to move the moving device 10B upwardly relative to the outer casing 40B, and meanwhile each of the two guiding portions 15B of the moving device 10B moves upwardly along the corresponding positioning portion 43B as shown in Fig. 14, thereby driving the operating member 30B to move upwardly relative to the outer casing 40B. In the meantime, the exposed part of the limiting portion 33B of the operating member 30B emerging from the holding portion 45B of the outer casing 40B becomes longer, and the swing range of the operating member 30B becomes larger and the operating member 30B can be operated to tilt and swing freely with respect to the imaginary longitudinal first axis C₁, so that the user can hold the operating member 30B of the drawing compass of the present invention to draw a circle or an arc with a larger radius.
With reference to Fig. 14, in the third preferred embodiment of the drawing compass of the present invention, the bottom of one of the two legs 20B has a first engaging structure 24B, the operating member 30B has a second engaging structure 34B formed on an external surface of the exposed part of the operating element 30 B and located close to an opening of the holding portion 45B, and the cap 50B has a third engaging structure 51B. The third engaging structure 51B selectively engages with the first engaging structure 24B or the second engaging structure 34B to connect the cap 50B with the two legs 20B or the operating member 30B. In this way, in addition to holding the operating end 32B of the operating member 30B, the user can also hold the cap 50B to draw a circle or an arc via the engagement between the third engaging structure 51B and the second engaging structure 34B and further integral coordination between the cap 50B and the operating member 30B. Consequently, the cap 50B not only increases the holding stability during circle/arc drawing, but also provides a protective effect for the drawing compass by covering the bottoms of the two legs 20B when the drawing compass is not in use.
With reference to Figs. 18 to 21, a drawing compass constructed in accordance with a fourth preferred embodiment of the present invention is substantially the same as the third preferred embodiment except for the following features. In the fourth preferred embodiment of the drawing compass, there is no eccentric distance between the moving device 10C and the connecting end 31C of the operating member 30C. In other words, the imaginary longitudinal first axis C₁ and the imaginary longitudinal second axis C₂ fully overlap each other. Furthermore, the two half bodies 13C of the moving device 10C are connected to each other by a concavo-convex configuration formed of multiple grooves 131C, 131C' and multiple protrusions 1321,32C', and the two half-shells 44C of the outer casing 40C are connected to each other by multiple connecting holes 441C and multiple connecting rods 442C. In addition, each of the two half-shells 44C has an arc-shaped limiting section 443C formed on a lower segment of the half-shell 44C. When the outer casing 40C is connected to the two legs 20C, the two limiting sections 443C can jointly define a limiting space for limiting the included angle of the two legs 20C relative to the outer casing 40C.
Furthermore, with reference to Figs. 18 and 21, in the fourth preferred embodiment of the present invention, the limiting portion 33C of the operating member 30C has a first length L₁, the holding portion 45C has a second length L₂, and the moving device 10C has a maximum displacement D. The first length L₁ is not less than the sum of the second length L₂ and the maximum displacement D, that is, L₁ ≧ L₂ +D. Furthermore, a gap is formed between the limiting portion 33C of the operating member 30C and an inner sidewall of the holding portion 45C. Preferably, the gap is not less than 0.05 millimeters.
When the included angle of the two legs 20C of the drawing compass of the fourth preferred embodiment of the present invention is zero degree, the limiting portion 33C of the operating member 30C fully submerges in the limiting hole 42C of the outer casing 40C. With reference to Figs. 18 and 22, when the two legs 20C are pivotally moved away from each other, the moving device 10C is linked up with the two legs 20C to move the operating member 30C upwardly lengthways relative to the outer casing 40C. In the meantime, the limiting portion 33C of the operating member 30C gradually emerges upwardly from the limiting hole 42C of the outer casing 40C. The swing range of the operating member 30C is positively correlated with the opening angle of the two legs 20C; that is, the exposed part of the operating member 30C emerging from the limiting hole 42C of the outer casing 40C becomes longer as the radius of a circle or an arc to be drawn becomes larger, so that the swing range of the operating member 30C is automatically adjusted and increased accordingly. Therefore, the drawing compass of the present invention can be set according to the radius of the circle/arc to automatically adjust the swing range of the operating member 30C, effectively solving the problem that the tilt-swing operating range of the conventional drawing compass cannot be adjusted. In this way, the drawing compass of the present invention can enable users to quickly and highly maneuverably draw a circle or an arc with a required radius, thus greatly enhancing the versatility and practicability of operation of the drawing compass.
With reference to Figs. 21 to 23, taking the gap between the limiting portion 33C of the operating member 30C and a top edge of the limiting hole 42C being 0.05 millimeters as an example to illustrate that as a lifting distance of the operating member 30C is longer, the swing range of the operating member 30C becomes larger. For example, when the operating member 30C is lifted by 2 millimeters, the operating member 30C can be tilted for an angle of 1.36 degrees relative to an imaginary central axis of the limiting hole 42C, and when the operating member 30C is lifted by 9 millimeters, the operating member 30C can be tilted for an angle of 2.05 degrees relative to the central axis of the limiting hole 42C.
Regarding the operation of the drawing compass of the fourth preferred embodiment of the present invention, when the included angle of the two legs 20C is set smaller as shown in Fig. 22, the unexposed part of the operating member 30C submerging in the holding portion 45C of the outer casing 40C is major and the exposed part of the same is minor, so that a very small swing range can be made. In this way, the user can hold the operating member 30C to draw a circle or an arc with a smaller radius. Referring to Figs. 23 and 24, when the included angle of the two legs 20C is set larger, the two linking rods 14C are linked up with the two legs 20C to move the moving device 10C upwardly relative to the outer casing 40C, and each of the two guiding portions 15C of the moving device 10C moves upwardly along the corresponding positioning portion 43C as shown in Fig. 19, thereby driving the operating member 30C to move upwardly relative to the outer casing 40C. In the meantime, the exposed part of the limiting portion 33C of the operating member 30C emerging from the limiting hole 42C of the outer casing 40C becomes longer, so that the swing range of the operating member 30C becomes larger and the operating member 30C can be operated to tilt and swing freely with respect to the outer casing 40C and the user can hold the operating member 30C of the drawing compass of the present invention to draw a circle or an arc with a larger radius. When the user intends to draw a smaller circle, the user can choose to hold the holding portion 45C. Therefore, the drawing compass of the fourth preferred embodiment of the present invention can draw large or small circles/arcs of various radiuses quickly and highly maneuverably, providing users with diversified operation methods and effectively enhancing the practicability of the drawing compass.
As for the operation of the fourth preferred embodiment of the present invention in use, with reference to Figs. 23 and 24, the limiting space defined between the limiting sections 443C of the two half-shells 44C of the outer casing 40C can be used to limit the included angle of the two legs 20C relative to the outer casing 40C, thus effectively keeping the included angle of the two legs 20C within an appropriate range.
In addition, when the user holds the operating member 30C to rotate the drawing compass, the two legs 20C are symmetrically connected to the moving device 10C by the two linking rods 14C, so that the drawing compass of the present invention can be rotated on its center of gravity without deviating from the rotation and slipping off the user's fingers, and the user can rotate the drawing compass steadily.
With reference to Figs. 25A and 26, in the fourth preferred embodiment of the present invention, the limiting portion 33C of the operating member 30C has an engagement structure 33C' disposed on an external surface of the limiting portion 33C adjacent to the operating end 32C, and an outer diameter of the engagement structure 33C' is larger than either of those of other parts of the limiting portion 33C. The engagement structure 33C' can be shaped like a triangle, a polygon, a tooth, or a groove, and the top end of the limiting hole 42C' of the outer casing 40C has an inner peripheral surface that matches the engagement structure 33C' of the operating member 30C in shape, so that parts of the limiting portion 33C of the operating member 30C can selectively engage with the limiting hole 42C' of the outer casing 40C. When the included angle of the two legs 20C is smaller or zero degree, the engagement structure 33C' of the limiting portion 33C engages with the limiting hole 42C' to enable the user to draw a smaller circle or an arc, thus disabling the operating member 30C from free swing. The operating member 30C can be automatically enabled for free swing while the operating member 30C is lifted upwardly to enable the engagement structure 33C' of the limiting portion 33C to escape from the limiting hole 42C'. In addition, the outer diameter of the limiting portion 33C keeps uniform from a lower end of the engagement structure 33C' toward the connecting end 31C.
In addition, an end of each of the two linking rods 14C' of the moving device 10C that is pivotally connected to the corresponding leg 20C is an elastically deformable engaging structure. With reference to Figs. 25B and 26, each of the linking rods 14C' has a first pivotal end 141C' and an elastic second pivotal end 142C', both of which are located away from each other, each of the first pivotal ends 141C' has a through hole running therethrough, each of the second pivotal ends 142C' has a slot 143C', and each second pivotal end 142C' has two columns protruding from two opposite outer surfaces of the second pivotal end 142C', respectively. The first pivotal ends 141C' of the two linking rods 14C' are rotatably clamped between the two half bodies 13C of the moving device 10C. The protrusions 132C' of the two half bodies 13C are inserted through the through holes of the two first pivotal ends 141C' and then into the grooves 131C' and, further coaxially interconnecting the protrusions 132C' and the grooves 131C'. The two second pivotal ends 142C' of the two linking rods 14C' are elastically deformably engaged with the pivotal portions 21C on the tops of the two legs 20C, respectively. In the meantime, the two columns of each second pivotal end 142C' are mounted in two pivot holes of the pivotal portion 21C of the corresponding leg 20, respectively, to pivotally connect the linking rod 14C with the corresponding leg 20C without any pivot pin, thus reducing the overall number of components and further decreasing the manufacturing cost.
With reference to Figs. 27 to 29, a drawing compass constructed in accordance with a fifth preferred embodiment of the present invention is substantially the same as that of the fourth preferred embodiment except for the following features. In the fifth preferred embodiment of the drawing compass, the outer casing 40D does not have the holding portion 45C as the outer casing 40C of the fourth preferred embodiment of the drawing compass, the limiting portion 33D of the operating member 30 has two parts, one of which defines an engagement structure located adjacent to the operating end 32D and having an outer diameter larger than that of the other part of the limiting portion 33D. Furthermore, the engagement structure has a polygonal external surface. Preferably, the engagement structure is a hexagonal column and has a regular hexagonal cross-section perpendicular to the lengthwise operating member 30D. In addition, the other part of the limiting portion 33D can be hexagonal tapered. The limiting hole 42D runs through the top of the outer casing 40D and has an inner peripheral surface that matches the engagement structure of the operating member 30D in shape. In this way, the limiting portion 33D of the operating member 30D can selectively engage with the limiting hole 42D of the outer casing 40D as the operating member 30D moves up or down.
When the included angle of the two legs 20D of the drawing compass of the fifth preferred embodiment of the present invention is set zero or smaller as shown in Figs. 29 and 30, the limiting portion 33D of the operating member 30D engages with the limiting hole 42D of the outer casing 40D, so that the operating member 30D submerges in the limiting hole 42D of the outer casing 40D without free swing relative to the outer casing 40D and a user can draw a circle or an arc with a smaller radius. Furthermore, with reference to Fig. 31, the user can also set the included angle of the two legs 20D larger, so that the two linking rods 14D are linked up with the two legs 20D to move the two half bodies 13D upward with respect to the outer casing 40D. With reference to Fig. 28, each of the two guiding portions 15D of the moving device 10D can move upwardly along the corresponding positioning portion 43D, thereby driving the operating member 30D to stably move upwardly relative to the outer casing 40D, so that the engagement structure of the limiting portion 33D of the operating member 30D disengages from the limiting hole 42D of the outer casing 40D. In the meantime, the operating member 30D can be operated to tilt and swing freely relative to the outer casing 40D, and the user can hold the operating member 30D and to draw a circle or an arc with a larger radius, thereby providing users with diversified operation methods and effectively enhancing the practicability of the drawing compass.
With reference to Figs. 32 to 34, a drawing compass constructed in accordance a sixth preferred embodiment of the present invention is substantially the same as that of the fourth preferred embodiment except for the following features. In the sixth preferred embodiment of the drawing compass, the moving device 10E does not have the two linking rods 14C of the moving device 10C of the fourth preferred embodiment, and the moving device 10E is an elastic C-like clamping structure. Alternatively, the moving device 10E can be another geometric figure (e.g. triangle, quadrilateral or polygon) having an opening, each of the two linking portions 12E of the moving device 10E has a clamping portion 16E, and each of the clamping portions 16E has two clamping cylindrical protrusions spaced from each other. The top ends of the two legs 20E are pivotally connected to each other and are connected to the clamping portions 16E of the two linking portions 12E of the moving device 10E, respectively, and each of the two legs 20E has a mounting post 23E mounted between the two cylindrical protrusions of one of the two clamping portions 16E to engage with the clamping portion 16E of the corresponding linking portion 12E of the moving device 10E. Furthermore, the limiting portion 33E of the operating member 30E has a polygonal engagement structure, and the limiting hole 42E runs through the top of the holding portion 45E and has an inner peripheral surface that matches the engagement structure of the operating member 30E in shape. In this way, the limiting portion 33E of the operating member 30E can be selectively engaged with the limiting hole 42E of the outer casing 40E.
When the included angle of the two legs 20E of the drawing compass of the sixth preferred embodiment of the present invention is set zero or smaller as shown in Fig. 35, the limiting portion 33E of the operating member 30E engages with the limiting hole 42E of the outer casing 40E, and the operating member 30E submerges in the limiting hole 42E of the outer casing 40E without free swing relative to the outer casing 40E, so that a user can hold the operating member 30E to draw a circle or an arc with a smaller radius. Furthermore, with reference to Fig. 36, when the user sets the included angle of the two legs 20E larger, the operating member 30E is linked up with the two legs 20E and to move the moving device 10E upwardly relative to the outer casing 40E, so that the engagement structure of the limiting portion 33E of the operating member 30E is disengaged from the limiting hole 42E of the outer casing 40E. In this way, the operating member 30E can be operated to tilt and swing freely relative to the outer casing 40E, and the user can hold the operating member 30E to draw a circle or an arc with a larger radius, thereby providing users with diversified operation methods and effectively enhancing the practicability of the drawing compass.
With reference to Fig. 37, a drawing compass constructed in accordance with a seventh preferred embodiment of the present invention is substantially the same as that of the fifth preferred embodiment except for the following features. In the seventh preferred embodiment of the drawing compass, the engagement structure of the limiting portion 33F of the operating member 30F has multiple teeth arranged annularly, and the limiting hole 42F of the outer casing 40F has a toothed profile that matches the engagement structure of the limiting portion 33F in shape. In this way, the operating member 30F can be fixed or operated to freely swing relative to the outer casing 40F while the limiting portion 33F engages with or disengages from the limiting hole 42F, so that a user can selectively draw a smaller or larger circle/arc, thus providing users with different and diversified operation methods and effectively enhancing the practicability of the drawing compass.
According to the above-mentioned features and structural relationships, in the drawing compass of the present invention, parts of the operating member 30, 30A, 30B, 30C, 30D, 30E, 30F are selectively limited by the up-and-down movement of the operating member 30, 30A, 30B, 30C, 30D, 30E, 30F relative to the outer casing 40, 40A, 40B, 40C, 40D, 40E, 40F, so that the swing range of the operating member 30, 30A, 30B, 30C, 30D, 30E, 30F can be freely adjusted to draw a circle or an arc, thereby enabling users to operate the drawing compass to draw large or small circles/arcs quickly and highly maneuverably, further greatly enhancing the diversity and practicality of operations of the drawing compass. In addition, as the two legs 20, 20A, 20B, 20C, 20D, 20E are pivotally moved away from each other, the swing range can be automatically adjusted according to the radius of a circle or an arc to be drawn, so that the users can easily draw circles/arcs having different radiuses according to the users' needs.
Further, the symmetrically connecting structure between the moving device 10, 10B, 10C, 10D, 10E and the two legs 20, 20B, 20C, 20D, 20E and the linear movement of the moving device 10, 10B, 10C, 10D, 10E are adopted in the preferred embodiments of the present invention. For example, the two linking rods 14, 14B, 14C, 14C', 14D are symmetrically connected to each other, or the moving device 10A, 10E has a C-like clamping structure, so that the two legs 20, 20A, 20B, 20C, 20D, 20E can be pivotally moved toward or away from each other more accurately and synchronously relative to the imaginary longitudinal first axis C₁. In this way, the drawing compass of the present invention can be rotated on its center of gravity during use, thus providing a stable rotation effect for the drawing compass. Furthermore, the eccentric setting of the operating members 30, 30A, 30B can increase the force arm of rotation of the drawing compass to increase the torque of rotation, and the user can perform the circle drawing more smoothly, so that large or small circles/arcs can be quickly and highly maneuverably drawn. Preferably, the structural relationships between the limiting space defined by the limiting sections 443C, 443D of the two half- shells 44C, 44D can prevent the users from making mistakes or accidently damaging the drawing compass.
The imaginary longitudinal first axis C₁ and the imaginary longitudinal second axis C₂ of the present invention respectively refer to that each of the moving device10, 10A, 10B, 10C, 10D, 10E and the operating member 30, 30A, 30B, 30C, 30D, 30E, 30F has a virtual reference line for defining the relative positions of related components without restricting whether the overall shape of each of the moving device 10, 10A, 10B, 10C, 10D, 10E and the operating member 30, 30A, 30B, 30C, 30D, 30E, 30F itself is completely symmetrical or not. For example, in the third preferred embodiment of the present invention, in order to strengthen the simultaneous pivotal movement of the two legs 20B, the two linking rods 14B of the moving device 10B are arranged symmetrically with respect to the imaginary longitudinal first axis C₁, and an upper segment of the moving device 10B that is connected to the operating member 30B is not symmetrical with respect to the imaginary longitudinal first axis C₁.

Claims

A drawing compass, characterized in that the drawing compass comprises:
an outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F) having a limiting hole (42, 42A, 42B, 42C, 42C', 42D, 42E, 42F) running through a top of the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F);

a moving device (10, 10A, 10B, 10C, 10D, 10E) moveable up or down relative to the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F), an imaginary longitudinal first axis (C₁) passing through the moving device (10, 10A, 10B, 10C, 10D, 10E), and the moving device (10, 10A, 10B, 10C, 10D, 10E) having
a connecting portion (11, 11D) located at a top of the moving device (10, 10A, 10B, 10C, 10D, 10E); and

two linking portions (12, 12A, 12D, 12E) located at two opposite sides beside the imaginary longitudinal first axis (C₁), respectively;

two legs (20, 20A, 20V, 20C, 20D, 20E) pivotally movable toward or away from each other, connected to the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F), and rotatably connected to the two linking portions (12, 12A, 12D, 12E) of the moving device (10, 10A, 10B, 10C, 10D, 10E), respectively; and

a lengthwise operating member (30, 30A, 30B, 30C, 30D, 30E, 30F) having a connecting end (31, 31C, 31D), an operating end (32, 32B, 32C, 32D), and a limiting portion (33, 33A, 33B, 33C, 33D, 33E, 33F);

wherein the connecting end (31, 31C, 31D) and the operating end (32, 32B, 32C, 32D) are located away from each other lengthways, the limiting portion (33, 33A, 33B, 33C, 33D, 33E, 33F) is disposed between the connecting end (31, 31C, 31D) and the operating end (32, 32B, 32C, 32D), the operating end (32, 32B, 32C, 32D) is disposed outside the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F), the connecting end (31, 31C, 31D) is rotatably connected to the connecting portion (11, 11D) of the moving device (10, 10A, 10B, 10C, 10D, 10E) to enable the operating member (30, 30A, 30B, 30C, 30D, 30E, 30F) to freely swing on the connecting end (31, 31C, 31D), and the moving device (10, 10A, 10B, 10C, 10D, 10E) is linked up with the two legs (20, 20A, 20B, 20C, 20D, 20E) to move the operating member (30, 30A, 30B, 30C, 30D, 30E, 30F) up or down relative to the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F) lengthways.
The drawing compass as claimed in claim 1, wherein the two linking portions (12, 12A, 12D, 12E) of the moving device (10, 10A, 10D, 10E) are symmetrically arranged with respect to the imaginary longitudinal first axis (C₁).
The drawing compass as claimed in claim 1, wherein
the moving device (10, 10A, 10B, 10C, 10D, 10E) further comprises a guiding structure facing outwardly; and
the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F) further comprises a positioning structure facing inwardly and corresponding to the guiding structure of the moving device (10, 10A, 10B, 10C, 10D, 10E); and
when the moving device (10, 10A, 10B, 10C, 10D, 10E) is moved upwardly or downwardly relative to the outer casing (40, 40A, 40B, 40C, 40D, 40E, 40F), the guiding structure is moved along the positioning structure.
The drawing compass as claimed in claim 1, wherein the limiting position (33, 33C, 33D, 33E, 33F) of the operating member (30, 30C, 30D, 30E, 30F) is tapered to comprise an outer diameter gradually increasing from the connecting end (31, 31C, 31D) to the operating end (32, 32B, 32C, 32D).
The drawing compass as claimed in claim 1, wherein
the outer casing (40B, 40C, 40E) further comprises a holding portion (45B, 45C, 45E) formed on the top of the outer casing (40B, 40C, 40E) and protruding outward along the lengthwise operating member (30B, 30C, 30E) for limiting a swing range of the operating member (30B, 30C, 30E) relative to the outer casing (40B, 40C, 40E);
the limiting hole (42B, 42C, 42E) is formed in the holding portion (45B, 45C, 45E); and
the operating end (32B, 32C) of the operating member (30B, 30C, 30E) is located outside the holding portion (45B, 45C, 45E).
The drawing compass as claimed in claim 5, wherein
the limiting portion (33C) of the operating member (30C) further comprises a first length (L₁);
the holding portion (45C) further comprises a second length (L₂);
the moving device (10C) further comprises a maximum displacement (D); and
the first length (L₁) is not less than a sum of the second length (L₂) and the maximum displacement (D).
The drawing compass as claimed in claim 5, wherein a gap is formed between an outer sidewall of the limiting portion (33C) of the operating member (30C) and an inner sidewall of the holding portion (45C) and is not less than 0.05 millimeters.
The drawing compass as claimed in claim 1, wherein
the limiting portion (33C) of the operating member (30C) further comprises an engagement structure (33C') formed on an external surface of the limiting portion (33C);
the limiting hole (42C') of the outer casing (40C) further comprises an inner peripheral surface matching the engagement structure (33C') of the operating member (30C) in shape; and
parts of the limiting portion (33C) of the operating member (30C) selectively engage with the limiting hole (42C') of the outer casing (40C).
The drawing compass as claimed in claim 8, wherein the engagement structure (33C') of the limiting portion (33C) is shaped like a triangle, a polygon, a tooth, or a groove.
The drawing compass as claimed in claim 1, wherein
the outer casing (40, 40B, 40C, 40D) further comprises two half-shells (44, 44B, 44C, 44D) connected to each other;
each of the two half-shells (44C, 44D) of the outer casing (40C, 40D) further comprises a limiting section (443C, 443D) formed on a lower segment of the corresponding half-shell (44C, 44D); and
the two limiting sections (443C, 443D) of the two half-shells (44C, 44D) jointly define a limiting space therebetween for limiting an included angle defined between the two legs (20C, 20D) relative to the outer casing (40C, 40D).
The drawing compass as claimed in claim 1, wherein the two linking portions (12, 12A, 12D, 12E) of the moving device (10, 10A, 10B, 10C, 10D, 10E) are swingable toward or away from each other with respect to the imaginary longitudinal first axis (C₁).
The drawing compass as claimed in claim 11, wherein
each of the two linking portions (12, 12A, 12D, 12E) of the moving device (10, 10A, 10B, 10C, 10D, 10E) further comprises a swingable linking rod (14, 14B, 14C, 14C', 14D);
each said linking rod (14, 14B, 14C, 14C', 14D) further comprises a swing end located away from the operating member (30, 30B, 30C, 30D); and
a top of each of the two legs (20, 20B, 20C, 20D) is connected to the corresponding swing end of the linking rod (14, 14B, 14C, 14C', 14D) of the linking portion (12, 12A, 12D, 12E).
The drawing compass as claimed in claim 12, wherein
each of the linking rods (14C') of the moving device (10C) further comprises a first pivotal end (141C') and a second pivotal end (142C'), both of which are located away from each other; and
each of the two second pivotal ends (142C') comprises a slot (143C') such that the second pivotal ends (142C') are elastically deformable and pivotally connected with the tops of the two legs (20C), respectively.
The drawing compass as claimed in claim 11, wherein
the moving device (10A, 10E) is an elastic structure;
each of the two linking portions (12A) of the moving device (10A) further comprises a swing end located away from the operating member (30A); and
top ends of the two legs (20A) are rotatably connected to the swing ends of the two linking portions (12A), respectively.
The drawing compass as claimed in claim 1, wherein the drawing compass further comprises a cap (50B) selectively connected to a bottom of one or the other of the two legs (20B) or the operating end (32B) of the operating member (30B).
The drawing compass as claimed in one of claims 1 to 15, wherein
a longitudinal imaginary second axis (C₂) passes through the connecting end (31) of the operating member (30, 30A, 30B) and is parallel to the lengthwise operating member (30, 30A, 30B); and
an eccentric distance (E) is formed between the imaginary longitudinal first axis (C₁) and the imaginary longitudinal second axis (C₂).
The drawing compass as claimed in claim 16, wherein the connecting portion (11) deviates from the imaginary longitudinal first axis (C₁) of the moving device (10, 10A, 10B) and is connected to the operating end (31) of the operating member (30, 30A, 30B), the imaginary longitudinal second axis (C₂) passing through the connecting portion (11) and the limiting hole (42, 42A, 42B) of the outer casing (40, 40A, 40B).
The drawing compass as claimed in claim 16, wherein
each of the two legs (20, 20B, 20C, 20D) further comprises a pivotal portion (21) and a coaxial portion (22) on a top thereof;
the pivotal portion (21) of each said leg (20, 20B, 20C, 20D) is located outside the corresponding leg (20, 20B, 20C, 20D) relative to the coaxial portion (22) and is pivotally connected to one of the two linking portions (12, 12D) of the moving device (10, 10B, 10C, 10D);
the coaxial portions (22) of the two legs (20, 20B, 20C, 20D) overlap and are connected to each other such that an imaginary first extending line (P₁) that is orthogonal to the imaginary longitudinal first axis (C₁) passes through a center of each said coaxial portion (22);
the pivotal portion (21) of one of the two legs (20, 20B, 20C, 20D) is located closer to the imaginary longitudinal second axis (C₂) than the imaginary longitudinal first axis (C₁) and said one leg (20, 20B, 20C, 20D) is defined as an eccentric side leg;
a linear distance (S) is defined between the pivotal portion (21) and the coaxial portion (22) of the eccentric side leg (20, 20B, 20C, 20D); and
the eccentric distance (E) is less than or equal to the linear distance (S).
The drawing compass as claimed in claim 17, wherein the two legs (20, 20A, 20B, 20C, 20D, 20E) are a pin leg and a pen leg, respectively, and the connecting end (31) of the operating member (30, 30A, 30B) is connected to the connecting portion (12, 12D) corresponding to the pen leg.
The drawing compass as claimed in claim 1, wherein
each of the two legs (20, 20B, 20C, 20D) comprises a pivotal portion (21) and a coaxial portion (22), both of which are provided on a top of the leg (20, 20B, 20C, 20D);
each of the pivotal portions (21) of the two legs (20, 20B, 20C, 20D) is located outside the corresponding leg (20, 20B, 20C, 20D) with respect to the corresponding coaxial portion (22) and is pivotally connected to one of the two linking portions (12, 12D) of the moving device (10, 10A, 10B, 10C, 10D); and
the coaxial portions (22) of the two legs (20, 20B, 20C, 20D) overlap and are coaxially connected to each other.