JP7249132B2 - straightedge - Google Patents

Description

The present invention relates to a straightedge for drawing straight lines on paper, a whiteboard, etc., and more particularly to a ruler with a scale.

A straightedge that draws straight lines with a writing instrument has long been used as a ruler. Since such a straightedge is slippery, various ideas have been devised for the back side.

For example, in the scope of claim (3) of Jitsuzenhei 02-058995 (Patent Document 1 to be described later), "the back side of the long ruler is parallel to the front side, has a predetermined width, and is in the center of the back side. and left and right symmetrical left and right sloping portions extending from the right and left ends of the bottom portion to the left and right side wall portions in the longitudinal direction, respectively, the left and right sloping portions and the horizontal bottom portion. A non-slip ruler characterized by forming either one of on the friction surface. The specification of the publication states that "the friction surface is formed wholly or partially by applying or spraying a friction material, or by cutting the surface unevenly" (page 6, line 8 of the specification). and a side view thereof is shown in FIG. 4 of the drawings.

In addition, in claim 1 of Japanese Patent No. 3172967 (Patent Document 2 to be described later), "In a linear ruler (1) with a one-sided scale, an L-shaped cut portion is provided on the back surface (5) of the opposite surface (6) having no scale. A linear ruler (1)” is disclosed, characterized in that it is provided with A'(3). In paragraph 0025 of the same publication, "Fig. 6 shows the L-shaped cut part A (2) of the direct ruler (1) of the present invention placed on the desk (9), pressed with the middle finger (11) to make it immovable, It shows how the thumb (10) hooks the corner of the L-shaped cut portion A' (3) and picks it up easily."

However, many furniture such as desks, whiteboards, and lockers have smooth surfaces. Therefore, when trying to draw a straight line with the ruler on which paper is placed, it does not slide between the ruler and the paper, but it slides between the paper and the desk. In recent years, products such as household appliances such as refrigerators and washing machines, and daily necessities such as lunch boxes that stick together by the magnetic force of magnets are abundant around us.

On the other hand, various types of straightedges using magnets have been devised since long ago.
For example, in Japanese Utility Model Publication No. 48-020538 (Patent Document 3 to be described later), "Rubber mixed with a ferromagnetic material is adhered to all or part of one side surface 3 of the ruler body 1 with a synthetic resin sheet 4. A ruler characterized by: The specification and FIG. 4 of the same publication describe an embodiment in which a groove 2a is bored only in the central portion of the back side of the transparent ruler body 1 made of acrylic resin and a ferrite mixed rubber sheet 4b is fitted.

However, the magnets used in straightedges are permanent magnets, and the strength of the magnetic force cannot be varied like an electromagnet. That is, if a magnet with a strong magnetic force is used, it becomes difficult to shift the fixed position of the straightedge. Conversely, if the magnetic force is weakened, the straightedge will slip when drawing a straight line, although the fixing position can be shifted. Even if a straightedge with a permanent magnet can be manufactured with the optimum magnetic force, the magnetic force will eventually weaken due to changes in the magnetic force over time, and a phenomenon will occur in which the straightedge will no longer stick to iron products. Such a straight edge with weakened magnetic force tends to slip easily between the paper product and the desk surface when trying to draw a straight line on the iron desk surface or the paper product on the whiteboard.

Under these circumstances, straightedges using permanent magnets have not been able to withstand practical use, although prototypes have been marketed. That is, conventional straightedges using permanent magnets have the problem that a straight line cannot be drawn along the tip surface of the straightedge unless the straightedge is strongly pressed with one hand.

Japanese Utility Model No. 02-058995 Utility Model Registration No. 3172967 Japanese Utility Model Publication No. 48-020538

An object of the present invention is to prevent slipping between the surface of a desk and the paper surface by using a magnet with a strong magnetic force, and to prevent slipping between the surface of the paper and a straight edge by using this magnet and a flexible material. . In particular, it is an object of the present invention to provide a straightedge that is capable of both large movement/rotation and small movement/rotation.

A straightedge according to claim 1 of the present invention is a straightedge having a front sloped portion and a front flat portion on the front side and a back flat portion on the back side, wherein the back flat portion has a back rise portion and a back slope portion. , the rear end surface of the back slope portion is connected to the front flat portion, the back flat portion is a flexible material in which the solid of the magnet is partially embedded, and the back floating portion is the back surface A straight edge having a step of 0.1 mm to 1.0 mm from the surface of the flat part.

The invention according to claim 2 is characterized in that the step is 0.2 mm to 0.8 mm. The invention according to claim 3 is characterized in that the surface of the back flat portion and the rear end surface of the back slope portion have the same height. The invention of claim 4 is characterized in that the back raised portion has a gentle slope. The invention of claim 5 is characterized in that the portion other than the back flat portion is made of a non-magnetic metal, especially aluminum. The invention of claim 6 is characterized in that a plurality of concave grooves parallel to the longitudinal direction are provided in the front flat portion.

If a flexible material in which a strong magnet is entirely or partly built is used for the back flat portion, the straightedge is firmly attached to a desk, whiteboard, etc. by the magnetic force of the magnet. However, when the rear end surface of the front flat portion is pressed with a finger, the magnet can be easily separated from the desk or the like by a known principle of leverage, and the back slope portion contacts the desk or the like. Then, the magnetic force of the magnet is weakened, and the straightedge can be easily removed from the desk or the like. That is, the straight edge ruler of the present invention can be moved and rotated to a large extent like the straight edge rulers of the past.

On the other hand, in the straight edge ruler of the present invention, both small movement and rotation are possible by providing a step on the back side. That is, when the tip surface side of the front inclined portion is pressed with a finger, the back flat portion is slightly lifted by the step between the back raised portion and the back flat portion. As a result, the magnetic force of the magnet is slightly weakened, and the straightedge can be moved and rotated in small steps.

The reason why the step distance is set to 0.1 mm to 1.0 mm is that the attractive force of the magnetic force depends on the distance between the straightedge and the desk or the like. That is, when the lower limit of 0.1 mm is not reached, the attractive force of the strong magnet becomes too strong to allow small movements and rotations. If the upper limit of 1.0 mm is exceeded, the attractive force of the strong magnet becomes weak, and it becomes possible to move and rotate significantly.

The reason why the distance between the steps is preferably 0.2 mm to 0.8 mm is that the flexible material can be slightly deformed when the straightedge is pressed down with a finger. That is, the shape of a straightedge is almost fixed, and its length is generally 150mm to 2000mm or 120mm to 600mm. Also, its thickness is generally 0.5 mm to 2.0 mm or 1.0 mm to 5.0 mm. Then, the distance of the steps is also inevitably limited. Therefore, it is preferable that the step distance is 0.2 mm to 0.8 mm.

Here, the step means the difference between the depth from the surface of the front flat portion to the starting end face of the rear raised portion and the depth from the surface of the front flat portion to the surface of the rear flat portion. If the portion other than the back flat portion is made of non-magnetic metal, the flexible material can be wrapped from three directions with metal or alloy tapes such as aluminum, titanium, brass, or brass by metal press working. Alternatively, the flexible material can be stretched and fitted. If the part other than the back flat part is made of non-magnetic metal, for convenience, the depth from the surface of the front flat part to the start surface of the back raised part and the distance from the surface of the front flat part to the end surface of the back slope part The depth difference can be substituted.

The flexible material that serves as the fulcrum of the lever can be made of rubber, elastomer, synthetic resin, or the like. Even with small movements and rotations, the flexible material does not smudge or erase what is written on the whiteboard. Also, the magnet is generally a ferrite magnet, but a rare earth magnet or the like can also be used. These magnets can be made into powder and kneaded with flexible materials, made into filaments or tapes and arranged in stripes between flexible materials, or made into strips or discs and spotted into flexible materials. can be built into

If the flat part of the back rising part is gently sloped with respect to the back flat part, that is, if a gentle slope is provided, the horizontal component of the pressing force will be applied to the flexible material when the tip surface of the front slope part is pressed with a finger. transmitted. Also, the distance that the magnet separates from the desk or the like is slightly increased by the depth of the gentle slope.

In addition, since the step made of the flexible material changes depending on the pressing force of the front slope portion, pressing the central portion of the front slope portion strongly with a finger shortens the step distance and increases the magnetic force of the magnet. In this case, even if the straightedge is long, it is possible to draw a straight line on the whiteboard or paper while holding it with a plurality of fingers of one hand. If the tip surface side of the oblique portion has a semicircular cross section, even when writing with a fountain pen or ballpoint pen, excess ink or the like will not bleed onto the paper or whiteboard due to capillary action. In addition, even if the magnet weakens due to deterioration over time, the flexible material of the back flat portion does not slip easily against paper, whiteboards, etc., so it can be used in the same way as conventional straightedges.

According to the straightedge of the present invention, not only can the straightedge be moved and rotated to a large extent, but even if a magnet with a strong magnetic force is used, it can be moved and rotated slightly depending on the position and pressing force of the finger that presses the front inclined portion. It has the effect of rotating. In addition, since the position of the straight ruler of the present invention is fixed by the magnetic force of the magnet, when drawing a line on paper with a fountain pen, ballpoint pen, etc., it is possible to draw a straight line without bleeding the ink with the raised back portion raised. When drawing a line on paper with a pencil, mechanical pencil, or the like, a straight line can be drawn with the tip surface as a reference by pressing the front inclined portion.

In addition, if the straight edge of the present invention has a gentle slope on the back floating portion, the step distance can be increased by the depth of the gentle slope, so that the strong magnetic force of the magnet can be finely adjusted. can. Conversely, even if the magnetic force of the magnet deteriorates over time, there is an effect that the straight edge can be moved and rotated slightly depending on the position and pressing force of the pressing finger. Further, if a plurality of grooves parallel to the longitudinal direction are provided in the front flat portion, fingertips do not slip when pressed. Also, if the portion other than the back flat portion is made of non-magnetic metal, the straightedge can be easily press-formed.

1 is a sectional view of a straightedge showing an embodiment of the present invention; FIG.

Preferred embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the embodiments described below do not limit the content of the present invention described in the claims. Moreover, not all the configurations described below are essential requirements of the present invention.

Embodiment 1 of the present invention will be described with reference to the drawings. The outline of the straightedge 1 is 150 mm long, 30 mm wide and 4 mm thick. A straightedge 1 has a front sloped portion 2 and a front flat portion 3 on the front side, and a rear rising portion 4, a rear flat portion 5 and a rear sloped portion 6 on the back side. The front inclined portion 2 is graduated in units of 1 cm, and sub-scales in units of 1 mm are engraved. 16 grooves are formed in the front flat portion 3 in the longitudinal direction.

The rear raised portion 4 has a gentle slope surface 8 formed from a start end surface 7 and continues to the front inclined portion 2 via a tip end surface 9 having a semicircular cross section. On the other hand, the back sloped portion 6 has a terminal end face 10 and a rear end face 11 , and the rear end face 11 continues to the front flat portion 3 .

The back flat portion 5 is made of an elastomer rubber material, and has three built-in magnets 12 with a diameter of 8 mm at both ends in the longitudinal direction of the straightedge 1 and near the center. The back flat portion 5 is surrounded by aluminum metal and has a structure closed in three directions.

The step 13 is the difference between the depth from the surface of the front flat portion 3 to the starting end surface 7 of the rear raised portion 4 and the depth from the surface of the front flat portion 3 to the surface of the rear flat portion 5 . Since the elastomer rubber material of the flat back portion 5 has elasticity, if the surface of the flat back portion 5 is used as the terminal surface 10 of the back slope portion 6 for convenience, the step 13 is 0.3 mm. The depth of the gentle slope surface 8 from the starting end face 7 to the tip end face 9 is 0.1 mm. On the other hand, the depth from the rear end face 11 to the terminal end face 10 of the back slope portion 6 is 0.8 mm. The height from the reference surface such as the paper surface to the front end surface of the front inclined portion 2 is less than half the height from the reference surface such as the paper surface to the rear end surface 11 of the back slope portion 6 in order to maintain a weak magnetic force.

When the terminal surface side of the front flat part 3 is pressed with the middle finger, the back slope part 6 easily contacts the plane of the office desk by the principle of leverage, so that the straightedge 1 can be separated from the desk using the thumb.

When the tip side of the oblique portion 2 is pressed with the middle finger, the gently sloping surface 8 easily comes into contact with the flat surface of the office desk due to the principle of leverage. However, even if the 0.3 mm of the step 13 and the 0.1 mm of the depth of the gently sloping surface 8 are combined, the straightedge 1 is only 0.4 mm away from the office desk. For this reason, two fingers, an index finger and a middle finger, are required to move in parallel on an office desk with one hand. Further, when rotating the straightedge 1, it is necessary to hold the front inclined portion 2 with one hand and press the rear end face 11 with the other finger.

The present invention is not limited to this embodiment, and various modifications can be made within the scope of the present invention. For example, the tip surface may be linear. This is because when the front sloped portion is pressed with a finger, the tip surface slopes inward due to a step or the like, creating a space where the writing instrument hits, thereby preventing ink bleeding. Further, the flexible material may be synthetic resin having good slipperiness, contrary to the embodiment. Memo sheets can be sandwiched between them as field notes in the field.

1 Straightedge 2 Front sloped portion 3 Front flat portion 4 Back raised portion 5 Back flat portion 6 Back sloped portion 7 Start end surface 8 Gentle slope surface 9 Front end surface 10 End surface 11 Rear end surface 12 Magnet 13 Step

Claims (6)

The front side has a front inclined portion and a front flat portion, and the back side has a back raised portion, a back flat portion and a back sloped portion , and the gentle slope surface of the back raised portion passes through the tip surface to the front slope. In the straightedge where the back sloped part continues to the front flat part through the rear end face , the back flat part is a flexible material with a solid magnet embedded in a part , The height from the reference surface of the paper surface to the front end surface is lower than the height of the rear end surface, and the rear raised portion has a step of 0.1 mm to 1.0 mm from the surface of the rear flat portion. Characterized straight edge. 2. The straight edge ruler according to claim 1, wherein the height to said tip end face is less than half the height of said rear end face. 2. The straightedge according to claim 1, wherein the step is 0.2 mm to 0.8 mm. 2. The straightedge according to claim 1, wherein the surface of said flat back portion and the rear end surface of said sloped back portion have the same height. 2. The straight edge ruler according to claim 1, wherein the portion other than the back flat portion is made of non-magnetic metal. 2. The straight edge ruler according to claim 1, wherein a plurality of concave grooves parallel to the longitudinal direction are provided on the front flat portion.

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