JP2005246098A - Compass-cutter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compass-cutter which can be smoothly manipulated with simple manipulating actions. <P>SOLUTION: The compass-cutter comprises a first leg 700 which holds a needle 701 for defining a center of a circle, a second leg 800 which carries a blade 801 in a plane parallel to an axis of the needle 701, a lateral bar 900 which supports the first leg 700 and the second leg 800 so that an interval length therebetween can be slidably adjusted, and an operation portion which is slidably supported on the lateral bar 900 between the first leg 700 and the second leg 800. The rotating surface of the blade 801 can be always kept in parallel to the axis of the needle 701. As a result, the rotating surface of the blade 801 can be always kept in a nearly right angle to the object to be cut, regardless of the rotation radius. Therefore, smooth cutting operations can be done along a desired cutting line. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a compass cutter that can cut an object to be cut, such as clothing, into a circle.

  FIG. 1 shows a general compass 10 used for drawing a circle on drawing paper or the like. The compass 10 includes two leg portions 11 and 15 that can adjust the leg opening angle, and an operation portion 19 that is provided at a connecting position of the both leg portions. One leg 11 has a needle 12 at the tip, and the other leg 15 holds a pencil 16 at the tip.

  When drawing a circle, the operation unit 19 is picked with a finger around the needle 12 pierced on the drawing paper, and a rotational motion is given to the pencil 16. At this time, it is difficult to write a 360 ° circle at once without having to pick up the finger that grips the operation unit 19, so after rotating the pencil 16 halfway, once again grip the operation unit 19 and then remove the remaining circles. I often draw. This re-picking operation is troublesome and troublesome, and if this cannot be done well, the position of the needle 12 will be shifted at the time of re-picking, and an accurate circle cannot be drawn.

  In addition, if an attempt is made to write a 360 ° circle at a stretch, the position of the needle 12 stuck in the drawing paper is displaced due to the excessive force, and as a result, it is often impossible to draw an accurate circle.

  The above problems occur not only in a compass for drawing a circle but also in a compass cutter for cutting a cloth or the like into a circle.

  Therefore, a technical problem to be solved by the present invention is to provide a compass cutter that can be operated easily with a simple operation.

  The present invention has been made in order to effectively solve the above problems, and provides a compass cutter having the following features.

  The compass cutter of the present invention includes a “first leg portion that holds a needle that defines a rotation center”, a “second leg portion that holds a blade in a plane parallel to the axis of the needle”, and a “first leg portion”. And a horizontal bar that holds the distance between the first leg and the second leg so as to be slidable ”and“ an operation part that is slidably held on the horizontal bar between the first leg and the second leg ” It is characterized by comprising.

  According to the compass cutter of the present invention having the above-described configuration, the rotation surface of the blade is always maintained parallel to the axis of the needle regardless of the distance between the rotation center and the blade. For this reason, regardless of the size of the turning radius, the rotating surface of the blade can always maintain a substantially perpendicular state with respect to the object to be cut. Therefore, a smooth cutting operation along a desired cutting line is possible.

  Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. 2 to 4 show a compass cutter 20 according to an embodiment of the present invention. 2 is an overall perspective view, FIG. 3 is an exploded perspective view, and FIG. 4 is a partially broken perspective view.

  The compass cutter 20 is used to cut paper or cloth into a circle. The needle 61 is pierced at the center of the circle, the operation unit 30 is picked with a finger, and the blade 81 is moved into a circle. The operation unit 30 includes a ratchet mechanism (one-way clutch) therein.

  The ratchet mechanism transmits a rotational driving force only in one direction and is known per se. Various specific configurations of the ratchet mechanism are known, and the specific configuration of the ratchet mechanism is not limited to a specific configuration in the present invention, but with reference to FIGS. 3 and 4, One example will be described.

The first cylindrical member 34 is fixed to the upper portion of the compass body 50 constituting the ratchet mechanism, and the compass body 50 and the first cylindrical member 34 are not allowed to rotate relative to each other. The first cylindrical member 34 has teeth formed at its upper end.
In FIG. 3, a member 33 positioned above the first cylindrical member 34 is formed by integrally forming an upper prism portion 33a and a lower second cylindrical member 33b. The member 33 is inserted into the operation portion main body 31 via a spring 32, and is urged downward toward the first cylindrical member 34 in the assembled state of FIG. At this time, the teeth formed at the lower end of the second cylindrical member 33b are engaged with the teeth formed at the upper end of the first cylindrical member 34 (see FIG. 4).
The member 33 is connected to the operation portion main body 31 at the prism portion 33a, and therefore cannot rotate relative to the operation portion main body 31. However, the member 33 is movable relative to the operation portion main body 31 in the axial direction.
The spring 32 can be omitted by using a certain amount of heavy material as the member 33. In the example of FIG. 3, the member 33 is pressed against the first cylindrical member 34 on the lower side by the spring force of the spring 32, but if the member 33 itself has a certain weight, the member 33 is not self-weighted. This is because it is pressed by the first cylindrical member 34.

Since the ratchet mechanism of the ratchet mechanism is configured as described above, when the operation unit 30 is rotated in the direction of the arrow A in FIG. 4, each of the first cylindrical member 34 and the second cylindrical member 33b is formed. The teeth mesh and the blade 81 rotates in the same direction. On the other hand, when the operation unit 30 is rotated in the direction of arrow B in FIG. 4, the teeth rotate idle without meshing, so that the blade 81 stops at that position.
Therefore, while holding the operation unit 30 with a finger and rotating it in the direction of arrow A, the blade 81 cuts paper (or cloth, etc.), and after a certain degree of advance, returns the operation unit 30 to the direction of arrow B while idling. (At this time, the blade 81 does not move and stops at that position). Then, the operation unit 30 is picked again with a finger, and the paper is cut while rotating in the direction of arrow A. By repeating the above operations, the blade 81 can be easily rotated 360 ° without forcibly moving the hand. In this case, it is necessary to re-pick the finger that grips the operation unit 30 Also disappear.

Other mechanical parts of the compass cutter 20 The characteristic structure and function of the compass cutter 20 of the present invention are as described above, and the other parts are well known and general. Briefly described is as follows.
The blade 81 is attached to one end of the horizontal bar 70 via the fixed plate 80. The blade 81 can be replaced by operating the screw member 82. The horizontal bar 70 is slidably held in the compass body 50 so as to adjust the distance between the needle 61 and the blade 81 (that is, the radius of the circle) by operating the bolt 52 and the screw member 51. It is possible. The horizontal bar 70 is provided with a scale 71 indicating this interval.
The needle 61 is positioned coaxially with the operation unit 30 and is fixed below the compass body 50 via the shaft member 60.

Modified Example of Operation Unit A modified example of the compass cutter 20 described above is shown in FIG. In this modified example, the head portion 31a of the operation portion main body 31 has a hexagonal shape. Other structures are the same as those described above, and a ratchet mechanism is built in the operation unit 30.
The hexagonal head portion 31 a engages with the spanner 100. That is, the compass cutter of FIG. 5 is operated using the spanner 100, not directly picked by hand. Such a modification is effective when the object to be cut is hard or the radius of the circle is large.
In the illustrated example, the head 31a has a hexagonal shape so as to be engaged with the spanner 100, but the shape of the head does not necessarily have to be a hexagonal shape. Any shape that can be engaged with a monkey, a wrench, etc. may be used. Furthermore, the shape that can be engaged with the tool does not need to be provided at the head of the operation unit main body 31; for example, a part of the peripheral wall of the operation unit main body 31 is cut away, for example. It may be configured to be compatible.

FIG. 6 shows an example in which the compass main body and the ratchet mechanism portion are configured separately. The compass cutter 120 includes a compass main body 150 that holds a blade and an operation unit 130 that includes a ratchet mechanism. The operation unit 130 is detachably connected to the compass body 150.
In the compass cutter 120, the cylindrical portion 151 fixed to the upper part of the compass main body 150 does not include a ratchet mechanism, and only has a quadrangular prism-shaped recess 152 at the center thereof. Although the ratchet mechanism is built in the distal end portion 131 of the operation unit 130 and does not appear in FIG. 6, a square columnar protrusion that engages with the recess 152 extends downward from the distal end portion 131. ing. The object to be cut can be cut into a circular shape by engaging the protrusion (not shown) in the recess 152 and operating the handle 132.
The compass cutter 120 shown in FIG. 6 has a merit that a ratchet handle for a socket wrench, which is a general tool, can be used, and the manufacturing cost can be reduced.

Other Embodiments FIGS. 7 and 8 show another embodiment of the present invention. In the example of FIG. 7, a circular blade 85 is employed instead of the blade 81 of the compass cutter 20 of FIG. The circular blade 85 is suitable for thin cutting objects such as clothing. In the example of FIG. 8, a compass for drawing a circle is provided with a ratchet mechanism, and a pencil 88 is held by a horizontal bar instead of the blade 81 of the compass cutter 20 of FIG. Note that it is also possible to hold a needle material (not shown) on the horizontal bar instead of the blade 81 and scoring the circle.
Each of the compass cutter 220 in FIG. 7 and the compass 320 in FIG. 8 includes a ratchet mechanism similar to that of the compass cutter 20 in FIG. 2. Therefore, as a modification of the compass cutter 220 in FIG. It is also possible to configure the compass body and the operation unit including the ratchet mechanism as separate bodies as in the case described above.

Other Ratchet Mechanism Next, another example of the ratchet mechanism will be described with reference to FIG. As already described, the “ratchet mechanism” referred to in the present invention transmits a rotational driving force only in one direction, and its specific configuration is not limited to a specific one. The mechanism shown in FIG. 9 has a structure generally called a one-way clutch, which can also be considered to be included in the “ratchet mechanism” referred to in the present invention in that the rotational driving force is transmitted only in one direction. This mechanism itself is also known.

  FIG. 9 is a cross-sectional view perpendicular to the axis for schematically explaining the mechanism of the one-way clutch. The central shaft 500 and the outer cylinder 600 are arranged concentrically. The outer cylinder 600 corresponds to the operation unit main body 31 shown in FIG. 3, and the central shaft 500 is fixed to the compass main body 50 (see FIG. 3). When the outer cylinder 600 (operation unit main body) is rotated in the direction of arrow B in FIG. 9, the force is transmitted to the central shaft 500 and the compass rotates. On the other hand, when the outer cylinder 600 (operation unit main body) is rotated in the direction of arrow A in FIG. 9, the force is not transmitted to the central shaft 500, and the outer cylinder 600 rotates idle. That is, the compass stops at that position without rotating. The principle is as follows.

The outer cylinder 600 holds a plurality of cylindrical members along its inner peripheral surface by a holding mechanism (not shown). In FIG. 9, only three cylindrical members 501, 502, and 503 are illustrated, but actually, the cylindrical members are arranged over the entire circumference. Each cylindrical member is held in a gap between the central axis 500 and the outer cylinder 600 with its longitudinal axis parallel to the central axis 500 and the axis of the outer cylinder 600.
As shown in a partially enlarged view in FIG. 9, the inner peripheral surface of the outer cylinder 600 is formed with recesses for receiving individual cylindrical members, and each recess has a gentle first inclined surface 601a, 602a. 603a and steep second inclined surfaces 601b, 602b, 603b. The cylindrical members 501, 502, and 503 are biased in the direction of arrow a by a spring member (not shown) (this spring member is held on the outer cylinder 600 side).

Now, when the outer cylinder 600 is rotated in the same direction as the urging direction by the spring (arrow A direction), the rotational torque acting on the outer cylinder 600 is not transmitted to the central shaft 500, and therefore the outer cylinder 600 is idling. To do. Then, the cylindrical members 501, 502, and 503 move following the first inclined surfaces 601a, 602a, and 603a by the urging force of the spring member, respectively.
On the other hand, when the outer cylinder 600 is rotated in the direction opposite to the biasing direction by the spring (in the direction of arrow B), the cylindrical members 501, 502, and 503 have the first inclined surfaces 601a and 602a, respectively, by the biasing force by the spring. , 603a. Since the diameter of each cylindrical member is set to be larger than the gap width between the central shaft 500 and the outer cylinder 600, the cylindrical member is in contact with the first inclined surface, so that the cylindrical member is in the first inclined direction. As a result, the rotational torque acting on the outer cylinder 600 is transmitted to the central shaft 500 through the cylindrical member, and the entire compass rotates.

Compass cutter in which the operation unit can always be arranged in the middle between the rotation center and the blade . FIG. 10 shows a compass cutter according to another embodiment of the present invention. The compass cutter operation unit 960 includes a ratchet mechanism similar to that in the compass shown in FIGS. 2 to 4 and is fixed to the compass body 950.
However, in the example of FIG. 10, the needle 701 that defines the rotation center of the compass is not fixed to the compass body 950. The needle 701 is fixed to the tip of a shaft member (first leg) 700 extending from the lower side of a slide member 750 different from the compass body 950. Both the compass body 950 and the slide member 750 can be slid and moved along a horizontal bar (horizontal bar) 900 by operating the screw members 951 and 751 and fixed at an arbitrary position. The mechanism is the same as that of the embodiment shown in FIG.

In the compass cutter of FIG. 10, by adjusting the positions of the compass body 950 and the slide member 750, the operation unit 960 is always rotated regardless of the distance between the rotation center (position of the needle 701) and the blade 801. The center (position of the needle 701) and the center of the blade 801 can be arranged. Furthermore, by rotating the slide member 750 along the horizontal bar 900, the rotation radius of the blade 801 fixed to the fixed plate (second leg) 800 can be changed. It is always maintained parallel to the axis of the needle 701.
Such a structure is particularly useful in a compass cutter that uses a blade to cut an object into a circle. This will be described below.

As shown in FIG. 1, it is assumed that the blade is fixed to one leg portion of a compass that adjusts the radius of rotation according to the open leg angle of the two leg portions 11 and 15. In that case, as the rotation radius is changed, the angle formed by the axis of the needle 12 and the rotation surface of the blade also changes. This means that the relative angle of the blade rotation surface relative to the surface of the object to be cut (such as a piece of cloth) changes. Depending on the relative angle (that is, depending on the size of the turning radius), the desired cutting line This means that smooth cutting work that is perfect for this is hindered.
On the other hand, in the configuration of FIG. 10 (the same applies to FIGS. 3 and 7), the rotational surface of the blade 801 is independent of the distance between the center of rotation (position of the needle 701) and the blade 801. It is always maintained parallel to the axis of the needle 701. For this reason, the rotating surface of the blade 801 can always maintain a substantially right angle with respect to the object to be cut regardless of the size of the turning radius. In addition, since the position of the operation unit 960 can always be arranged at the center between the rotation center (position of the needle 701) and the blade 801, the pressing force transmitted from the operator's hand to the compass is applied to the needle 701 and the blade 801. It is possible to distribute almost evenly to both. In FIG. 10, the same applies when a fixed blade 81 as shown in FIG.

  As described above, also in the compass cutter having the configuration shown in FIG. 10, the cutting operation can be performed without difficulty with a simple operation. Even if the compass cutter does not include a ratchet mechanism in the operation unit, the same advantages as those described with reference to FIG. 10 can be obtained. For example, a mechanism as shown in FIG. 13 and FIG. 14 may be adopted as the operation unit in addition to the ratchet mechanism.

A rod 981 is fixed to the operation unit compass main body 950 of FIG. A screw portion 982 formed at the tip of the rod 981 is passed through a hole 991 formed in the top wall of the cylindrical body 990, and a nut 983 is engaged with the screw portion 982. Thereby, the cylindrical body 990 can freely rotate with respect to the rod 981 in both the left and right directions.
When such an operation unit is employed, the cutting operation by the rotary blade 801 is performed by revolving the hand holding the cylindrical body 990 around the needle 701. When such an operation unit is provided, the ratchet mechanism is capable of cutting in both the left and right rotation directions, and the cutting operation is easy regardless of whether the user is right-handed or left-handed. As compared with the case of adopting the above, there is an advantage that the structure of the operation unit is simplified.
In the case where the operation unit shown in FIG. 13 is employed, the cutting work is easier when the compass body 950 is fixed on the side closer to the blade 801.

The operation unit is configured by a single rod 995 that is fixedly fixed to the operation unit compass body 950 of FIG. In this case, although workability is inferior to the example of FIG. 13, there is an advantage that the structure is further simplified.

  In the example of FIGS. 13 and 14, it is naturally possible to use the blade 81 as shown in FIG. 2 or the pencil 88 as shown in FIG. 8 instead of the rotary blade 801.

FIG. 11 and FIG. 12 show a modified example of the compass cutter shown in FIG. 10 in which the operation unit is positioned at the center between the rotation center and the blade . Each of the modifications includes a mechanism that makes it easy to position the operation unit (center positioning) at a center position between the rotation center and the blade.

The compass cutter in FIG. 11 performs center positioning of the operation unit 960 using springs 965 and 966. The springs 965 and 966 are accommodated in a long hole 901 formed along the longitudinal direction of the horizontal bar 900. One end 965a of the spring (second spring) 965 is fixed to the left end 901a of the elongated hole, and the other end 965b is fixed to a fixing pin 955 provided on the compass body 950. On the other hand, one end 966 a of the spring (first spring) 966 is fixed to a fixing pin 955, and the other end 966 b is fixed to a fixing pin 755 provided on the slide member 750.
The spring constants of the two springs 965 and 966 are equal, and when the screw member 951 is fastened and the position of the slide member 750 is fixed, the screw member 951 is loosened to make the compass body 950 slidable. By this action, the operation unit 960 automatically comes to a position between the center of rotation (position of the needle 701) and the blade 801. Finally, the screw member 951 is fastened to fix the position of the compass body 950.
In the example shown in FIG. 11, the fixing plate (first leg) 800 is directly fixed to the horizontal bar 900, and one end 965a of the spring 965 is fixed to the horizontal bar itself. Therefore, as a result, the operation unit 960 and the fixed plate 800 are connected by the spring 965. As shown in the example of FIG. 12, the fixing plate 800 may be slidable with respect to the horizontal bar 900, and the one end 965a of the spring 965 may be fixed to the fixing plate 800.

The compass cutter shown in FIG. 12 uses the screw member 970 to center the operation unit 960. The screw member 970 includes a central operation dial portion 971, and a left screw portion 972 and a right screw portion 973 that protrude coaxially toward both sides from the operation dial portion 971. The screw member 970 is positioned in a long hole 902 formed along the longitudinal direction of the horizontal bar 900, and the operation dial portion 971 is exposed to the outside from a slit portion formed in the compass body 950a.
The fixed plate 800 that holds the blade 801 is fixed to the slide member 800a, and is engaged with the left screw portion 972 via the fixed member 800a. That is, the slide member 800 a includes a screw portion (not shown) inside, and the screw portion is engaged with the left screw portion 972. The slide member 750a that holds the needle 701 includes a screw portion (not shown) inside, and the screw portion is engaged with the right screw portion 973.
Since the left screw portion 972 and the right screw portion 973 have the same pitch, when the operation dial portion 971 exposed from the side surface of the compass body 950a is rotated with a finger, the blade 801 and the needle 701 are always in contact with each other. With the operation unit 960 positioned in the center, they move away from each other or approach each other.

  As described above, in the compass cutter shown in FIGS. 11 and 12, the operation unit 960 can be positioned easily and reliably at the middle position between the rotation center and the blade.

It is a front view explaining the conventional compass used for drawing a circle. It is a perspective view explaining the compass cutter concerning one embodiment of the present invention. It is a disassembled perspective view explaining the compass cutter of FIG. It is a partially broken perspective view explaining the compass cutter of FIG. It is a perspective view explaining the modification provided with the hexagonal head which can be engaged with a spanner. It is a perspective view explaining the example which constituted the compass main part and the ratchet mechanism as separate bodies. It is a perspective view explaining other embodiment which employ | adopted the circular blade. It is a perspective view explaining other embodiment which applied the present invention to the compass which draws a circle. It is a schematic diagram explaining the principle of the other ratchet mechanism employable in this invention. It is a perspective view explaining other embodiment which can always arrange | position the operation part of a compass cutter to the center of a rotation center and a braid | blade. FIG. 11 is an explanatory view showing a modified example of the compass cutter of FIG. FIG. 11 is an explanatory view showing still another modified example of the compass cutter of FIG. It is a perspective view explaining another example of the operation part of a compass cutter. It is a perspective view explaining the further another example of the operation part of a compass cutter.

Explanation of symbols

10 Compass
11, 15 legs
12 stitches
16 pencil
19 Operation unit
20, 120, 220 Compass cutter
30, 130 Operation unit
31 Control unit body
31a head
32 Spring
33 parts
33a prismatic part
33b Second cylindrical member
34 First cylindrical member
50, 150 compass body
51 Screw member
52 volts
60 shaft member
61 needles
70 horizontal bar
71 scale
80 Fixed plate
81 blades
82 Screw member
85 Circular blade (rotary blade)
88 pencil
100 spanner
131 Tip
132 Handle
151 Cylindrical part
152 Square columnar recess
320 compass
500 center axis
501, 502, 503 Cylindrical member
600 outer cylinder
700 Shaft member (1st leg)
701 needle
800 Fixed plate (2nd leg)
801 Rotary blade
900 Horizontal bar
965, 966 Spring
960 operation unit
970 Screw member
971 Operation dial section
972 Left-hand thread
973 Right-hand thread
981 Rod
990 cylinder
995 rod

Claims (3)

A first leg (700) that holds a needle (701) that defines a center of rotation;
A second leg (800) holding the blade (801) in a plane parallel to the axis of the needle (701);
A horizontal bar (900) that holds the first leg (700) and the second leg (800) in such a manner that the distance between them can be adjusted by sliding;
A compass cutter comprising: an operation unit slidably held on a horizontal bar (900) between a first leg (700) and a second leg (800). The operation part (960) and the first leg part (700) are connected by a first spring (966), and the operation part (960) and the second leg part (800) are connected by a second spring (965). The compass cutter according to claim 1,
The spring constants of the first spring (966) and the second spring (965) are substantially equal,
When the positions of the first leg and the second leg are fixed and the operation part (960) is slid free along the horizontal bar (900), the urging force of both springs (965, 966) The compass cutter is characterized in that the operation unit (960) is urged to a central position between the needle (701) held on both legs (700, 800) and the blade (801). A screw member (970) having a central operation dial part (971), and a left screw part (972) and a right screw part (973) projecting coaxially from both ends to the opposite side. The compass cutter according to Item 1,
The pitch of the left thread (972) and right thread (973) is equal to each other,
The first leg (700) and the second leg (800) are respectively engaged with either the left-hand thread (972) or the right-hand thread (973).
When the operation dial part (971) is rotated, the needle (701) and blade (801) held on both legs (700, 800) are always in the state where the operation part (960) is located at the center between them. A compass cutter, characterized by moving away from and approaching each other.

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