JP7449896B2 - Radio control transmitter holding aid and radio control transmitter - Google Patents

Description

The present invention relates to a holding aid provided in the grip portion of a radio control transmitter that is easy to hold with one hand and can stably support the entire weight, and a radio control transmitter equipped with the holding aid. .

Patent Document 1 discloses an invention of a transmitter for a radio-controlled model. The radio-controlled model transmitter of the present invention includes a grip unit for holding the whole unit by grasping it in the palm of the hand, an upper body located above the grip unit, a steering unit provided on the front side of the upper body, and various extensions. The device includes an extension unit equipped with a battery, and a battery unit that stores and holds a battery. At least the parts of the grip unit, the upper body, the steering unit, and the extension unit are separable and connectable to each other. According to this invention, by freely combining the constituent members of the transmitter according to the user's preference, it is possible to customize the transmitter according to the optimal combination.

Japanese Patent Application Publication No. 2012-273

The operator holds the grip section provided at the bottom of the head section with one hand, and uses the finger of the hand holding the grip section to operate the operation section (for example, a trigger that controls the speed) on the bottom surface of the head section, A type of radio control transmitter is known in which a second operating section (for example, a wheel for controlling the direction) provided on the side surface of the head section is operated with the other hand. The transmitter shown in Patent Document 1 is also a radio control transmitter of the same type. In conventional radio control transmitters of this type, the weight of the head and grip must be supported only by holding it with one hand; It was not possible to stably support the

The present invention has been made to solve the problems of the conventional techniques described above, and provides a holding aid for a radio control transmitter that is easy to hold with one hand and can stably support the entire weight. The purpose is to

The holding aid for a radio control transmitter according to claim 1 comprises:
a grip portion to be held by an operator; a head portion provided on an upper end side of the grip portion ; and a head portion provided below the head portion and disposed in front of the grip portion for an operator to hold the grip portion. an operating section that is operated with a finger; and an operating section that is provided on the front side of the upper part of the grip section and has a shape that extends in the front and back direction on both left and right sides of the grip section and protrudes toward the front of the grip section. A holding aid for the radio control transmitter that is attached to and detached from the projection to assist the operator in holding the grip,
The left side surface is in contact with both sides of the protrusion and continues in the front-rear direction so as to fill the gap between the fingers of the operator holding the grip, and when viewed from the front with a line of sight parallel to the front-rear direction. and a right side bulge to the left and right, respectively, and have a curved shape that is convex upward when viewed from the left side or the right side with a line of sight perpendicular to the left side and the right side. a protrusion,
a front part that is in contact with the front part of the protrusion, connects the pair of protrusions together, and protrudes forward;
It is characterized by being integrally constructed of an elastic material.

The holding aid for a radio control transmitter according to claim 2 is the holding aid for a radio control transmitter according to claim 1, which includes:
The holding aid includes a first holding aid in which the protrusion on the right side and the protrusion on the left side have the same outward protrusion when the operator holding the grip part is used as a reference; a second holding aid in which the outward protrusion of the protrusion is larger than that of the right protrusion, and a third holding aid in which the outward protrusion of the right protrusion is larger than the left protrusion. It is characterized in that it can be arbitrarily selected from the group including the following and attached to the radio control transmitter.

The radio control transmitter according to claim 3 comprises:
a grip portion to be held by an operator; a head portion provided on an upper end side of the grip portion ; and a head portion provided below the head portion and disposed in front of the grip portion for an operator to hold the grip portion. an operating section that is operated with a finger; and an operating section that is provided on the front side of the upper part of the grip section and has a shape that extends in the front and back direction on both left and right sides of the grip section and protrudes toward the front of the grip section. a radio control transmitter having a continuous protrusion on the front surface of the transmitter;
The left side surface is in contact with both sides of the protrusion and continues in the front-rear direction so as to fill the gap between the fingers of the operator holding the grip, and when viewed from the front with a line of sight parallel to the front-rear direction. and a pair of protrusions whose right side bulges toward the left and right, respectively ;
a front part that is in contact with the front part of the protrusion, connects the pair of protrusions together, and protrudes forward;
It is characterized by the provision of a holding aid integrally made of an elastic material.
The holding aid for a radio control transmitter according to claim 4 is the holding aid for a radio control transmitter according to claim 2, comprising:
An engaging protrusion is provided on the inner surface of each rear part of the pair of protruding parts,
It is characterized in that engaging recesses are provided on both left and right side surfaces of the grip portion in correspondence with the arrangement of the engaging protrusions.

When operating the holding aid for a radio control transmitter according to claim 1 and the radio control transmitter according to claim 3, the operator holds the grip part with one hand, and Place your index finger on the operating section and move your index finger to rotate the operating section. During such operations, if there is a gap between the index finger placed on the operation section and the adjacent middle finger, the operation of the index finger will become unstable. However, according to the present invention, the space between the index finger and the middle finger is filled with the protrusion, and the base of the index finger comes into contact with the protrusion, thereby stabilizing the movement of the index finger. As described above, this radio control transmitter has excellent operability due to the holding aid, is easy to hold with one hand, and is non-slip due to the elastic material, so it can be held stably.

According to the holding aid for a radio control transmitter described in claim 2, the following effects can be obtained. In other words, the user can select the first holding aid that is compatible with both left and right handed hands, regardless of the user's dominant hand, or select the second and third holding aids depending on the dominant hand. Alternatively, you can select any holding aid depending on your preference for grip feel, etc. Further, the elastic holding aid can be easily attached to and detached from the radio control transmitter as necessary.

FIG. 2 is a left side view of the radio control transmitter according to the embodiment with the holding aid removed. FIG. 2 is a perspective view of the radio control transmitter according to the embodiment, with the holding aid removed, as seen from the right side. FIG. 3 is a diagram showing the dual-purpose holding aid of the embodiment, in which part view (a) is a front view, part view (b) is a left side view, part view (c) is a right side view, and part view (d) is a plane view. Fig. 1. Part (e) is a bottom view, part (f) is a rear view, part (g) is a view taken along the cutting line of part (a) as seen from arrow g, and part (h) is part (a). ) is a view taken along arrow h along the cutting line. Partial view (a) is a view showing the right side of the radio control transmitter in the vicinity of the grip section with the dual-purpose holding aid attached, and part view (b) is a view showing the front side of the same radio control transmitter near the grip part. . FIG. 3 is a diagram showing a right-handed holding aid according to an embodiment, in which part view (a) is a front view, part view (b) is a left side view, part view (c) is a right side view, and part view (d) is a right side view. is a plan view, partial view (e) is a bottom view, partial view (f) is a rear view, and partial view (g) is a view along arrow g along the cutting line of partial view (a). FIG. 3 is a diagram showing a left-handed holding aid according to an embodiment, in which part view (a) is a front view, part view (b) is a left side view, part view (c) is a right side view, and part view (d) is a right side view. The plan view, the partial view (e) is a bottom view, the partial view (f) is a rear view, and the partial view (g) is a view in the direction of arrow g along the cutting line of the partial view (a).

Embodiments of the present invention will be described with reference to FIGS. 1 to 6.
The radio control transmitter 1 (hereinafter also simply referred to as the transmitter 1) of the embodiment shown in FIGS. 1 and 2 is used, for example, in various models (cars, motorcycles, aircraft, ships, etc.), and in industries such as drones and cranes. By using a machine as a controlled object and using a predetermined frequency band, the control signal (radio radio waves) corresponding to the operation of a rotary operation unit such as a wheel or a trigger is transmitted to the controlled object. This is a device for remotely controlling the control object. In the embodiment, it is assumed that the controlled object is a model car and that an engine is used as the power source for the controlled object, but of course the controlled object may be other than a model car, and the power source may be other than the engine. (for example, a motor).

First, the overall configuration of the transmitter 1 will be explained with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the transmitter 1 includes a casing roughly composed of a grip part 2, a base part 3, and a head part 4, and each part of the casing is made of thermoplastic resin (e.g. It is made of general-purpose plastic. The housing consisting of the grip part 2, the base part 3, and the head part 4 has a width of The grip part 2 is divided into two parts on the left and right sides, and is joined together by two connecting bolts 5 (see FIG. 2) that pass through the upper part of the grip part 2 in the width direction.

As described above, the grip section 2 has a lower end side integrated with the base section 3 and an upper end side integrated with the head section 4. The shape of the grip portion 2 in a horizontal cross section is an ellipse whose major axis gradually decreases from the base portion 3 side toward the head portion 4 side. The grip portion 2 is a portion that is held by the operator when remotely controlling the controlled object. At the upper part of the grip part 2 near the head part 4, a holding assisting structure (holding aid, etc.) is provided for the operator to securely hold the grip part 2, but the details will be explained later. Describe.

The base portion 3 is a substantially rectangular portion provided at the lower end side of the grip portion 2 . The base part 3 regulates the lower limit position of the hand that grips the grip part 2, and prevents the hand from slipping off from the grip part 2, and also allows the transmitter 1 to be placed upright on the ground, for example, when not in use. It also functions as a leg part. Although not shown, the base portion 3 has a built-in battery.

The head section 4 is provided on the upper end side of the grip section 2, and includes a wheel 6 that is a rotary operation section and a trigger 7 that is a rotation operation section.

The wheel 6 is an operation unit that functions as a steering wheel for controlling the direction of movement of the steered object. As shown in FIG. 1, the wheel 6 is rotatably supported by the head portion 4 by a rotating shaft whose axis coincides with the center of the approximately disk shape and which extends perpendicularly to the plane of the paper. By rotating the wheel 6 counterclockwise and clockwise from a predetermined reference position, the traveling direction of the steered object, for example, a model car, can be controlled. The wheel 6 can be selectively attached to either the right side or the left side of the head section 4 depending on the dominant hand of the operator.

The trigger 7 is an operation unit for controlling the power source of the steered object, for example, the engine of a model car, and adjusting the moving speed of the steered object. The trigger 7 has a trigger shape as shown in FIGS. 1 and 2, and includes two levers: a throttle lever 7a for accelerating the steered object and a brake lever 7b for decelerating the steered object. .

In a typical operating position of the radio control transmitter 1, the operator is positioned on the left side of the transmitter 1 facing right in FIG. The trigger 7 is operated with some fingers of the hand, and the wheel 6 is rotated with the fingers of the dominant hand. The transmitter 1 shown in FIGS. 1 and 2 is for right-handed users, and if the operator stands on the left side of FIG. By operating the robot, you can precisely control the direction of movement of the model car that is being operated.

Next, a holding assist structure for enabling the operator to grip the grip portion 2 reliably will be described with reference to FIGS. 1 to 4.
In explaining the holding auxiliary structure, first, definitions are given to terms such as positions and directions such as front, rear, left and right, or front, rear, and side surfaces (right side and left side) of the transmitter 1 or the grip portion 2, etc. That is, when viewed from the side of the operator holding the transmitter 1, the back side where the trigger 7 is located (the right side in FIG. 1, the left side in FIG. 2) is the front (front, front, front side, etc.), and the trigger 7 is The front side or the operator side (the left side in FIG. 1, the right side in FIG. 2), which is the side opposite to the side where it is present, is the rear (rear, rear surface, rear side, etc.). In the right-handed transmitter 1 shown in FIGS. 1 and 2, the side where the wheel is provided is the right side, and the opposite side is the left side.

As shown in FIGS. 1 and 2, a protrusion 10 is provided as a part of the housing in the upper part of the grip part 2 near the head part 4, that is, in the part where the main connecting bolt 5 passes through the grip part 2. Molded. This protrusion 10 becomes an attachment part for a holding aid 20, which will be described later. The protrusion 10 is continuous in the front-rear direction on both left and right side surfaces of the grip section 2, and is continuous on the front surface of the grip section 2. As shown in FIG. 1, the protrusion 10 has a curved shape convex upward on both the left and right side surfaces of the grip 2, and has a pointed tip protruding forward and slightly downward on the front surface of the grip 2. There is.

As shown in FIGS. 1 and 2, the protrusion 10 of the grip part 2 is provided with a holding aid, which is an auxiliary part that allows the operator to hold the transmitter 1 stably by firmly gripping the grip part 2. Tool 20 is attached. The installed state is shown in FIG. As explained below, the holding aid 20 is a part with a shape, structure, and material that can be easily attached to and detached from the protrusion 10 of the grip part 2, and can be used for right-handed, left-handed, or both-handed users depending on the dominant hand of the operator. You can arbitrarily select from three types that can be used for both purposes. First, a dual-purpose holding aid 20 (hereinafter also simply referred to as holding aid 20) as a first holding aid that can be used by both right-handed and left-handed users will be described.

As shown in FIGS. 1 to 3, the holding aid 20 has a pair of left and right protrusions 21, 21, and a front part 22 that integrally connects the fronts of the pair of protrusions 21, 21. The pair of left and right protrusions 21, 21 are continuous in the front-rear direction, and contact the protrusions 10 on both left and right side surfaces of the grip portion 2 when worn. A front portion 22 connecting the pair of left and right protrusions 21, 21 protrudes forward, and comes into contact with the front portion of the protrusion 10 of the grip portion 2 when worn. As shown in FIGS. 3(d) and 3(e), the holding aid 20 as a whole has an approximately U-shaped external shape in plan view, with the free ends of the pair of left and right protrusions 21, 21 at the rear being slightly narrower. are doing.

To explain the shape in more detail, the pair of left and right protrusions 21, 21 of the holding aid 20 swell outward like the pair of left and right protrusions 10, 10 of the grip part 2 (particularly in FIGS. 2 and 3). (a), (f)), when viewed from a line of sight perpendicular to the left and right side surfaces of the grip part 2, it has a curved shape that is convex upward, similar to the pair of left and right protrusions 10, 10 of the grip part 2. (See especially FIG. 1 and FIGS. 3(b) and (c)). Further, the front part 22 of the holding aid 20 has a shape that protrudes forward and slightly downward, similar to the front part 10a of the projection part 10 of the grip part 2 (see FIGS. 1 and 2). In this way, since the holding aid 20 and the protrusion 10 of the grip portion 2 have similar shapes, the holding aid 20 can be attached with the inner surface of the protrusion 10 in close contact with the outer surface thereof.

As described above, the holding aid 20 shown in FIG. 3 is a dual-purpose holding aid 20 that can be used by both right-handed and left-handed operators. Therefore, this holding aid 20 is designed so that the grip part 2 can be held in the same manner whether a right-handed operator holds it with the left hand or a left-handed operator holds it with the right hand. As shown in the figure, it has a symmetrical shape with respect to a center line that is parallel to the front-rear direction.

In addition, as shown in FIGS. 3(g), (h), and (e) in particular, approximately three engaging protrusions 23 are provided on the inner surfaces of the rear parts of the left and right protrusions 21 of the holding aid 20, respectively. They are arranged vertically. Furthermore, as shown in FIGS. 1 and 2, three engaging recesses 24 are provided on each rear side of both left and right side surfaces of the grip portion 2 of the transmitter 1, corresponding to the arrangement of these engaging protrusions 23. They are generally arranged in a vertical direction. Note that a part of the engagement recess 24 is a hole through which one of the two connecting bolts 5 is inserted. The shapes of the engaging protrusions 23 and the engaging recesses 24 only need to be the same in the corresponding sets, and the shapes of the three sets do not need to be the same.

The holding aid 20 is made of an elastomer having appropriate frictional properties and elasticity, and is integrally molded with the above-described shape and structure by injection molding or the like. To give an example of the physical properties of an elastomer that can be used, the Young's modulus is about 0.1 to 10 MPa, but if olefin santoprene is used, for example, the Young's modulus is about 1 to 3 MPa.

As shown in FIG. 1 or 2, when the rear part (opening side) of the holding aid 20 is directed toward the front part 10a of the protrusion 10 of the grip part 2 and the holding aid 20 is pushed into the protrusion 10, the holding aid 20 is elastically deformed to accept the protrusion 10, and then returns to its original shape, resulting in the mounted state shown in FIGS. 4(a) and 4(b). That is, the protrusion 21 of the holding aid 20 shown in FIGS. 1 to 3 comes into close contact with the protrusion 10 shown in FIGS. 1 and 2, and each engagement protrusion 23 shown in FIG. The front part 22 of the holding aid 20 which is engaged with each engagement recess 24 shown in FIG. 2 and has substantially the same shape is fitted into the front part 10a of the protrusion 10. In this way, the approximately U-shaped holding aid 20 is inserted into the grip part 2 in a state in which it is slightly deformed in the opening direction, and when the deformation returns, the engagement protrusion 23 and the engagement recess 24 engage with each other with a moderate click feeling. Since they fit together, they are securely attached to the protrusion 10.

The transmitter 1 shown in FIG. 4 is a right-handed transmitter 1 in which a wheel 6 is provided on the right side of the head portion 4 (the front side in FIG. 4), and the holding aid 20 is of a dual-purpose type. Consider a case where a right-handed operator holds the transmitter 1 in his left hand and operates the wheel 6 with his right hand. When operating the radio control transmitter 1, the operator holds the grip part 2 with his left hand, hooks the index finger of his left hand on the trigger 7, and moves the index finger to rotate the trigger 7. During such an operation, if there is a gap between the index finger placed on the trigger 7 and the adjacent middle finger, the index finger will move without support, making the operation unstable. However, according to the transmitter 1 of the embodiment, the space between the index finger and the middle finger is filled by the protrusion 21 of the holding aid 20 extending in the longitudinal direction of the finger, and the base of the index finger is Since it contacts the front part 22, the movement of the index finger is stable.
Although the description has been made assuming that a right-handed pilot holds the right-handed transmitter 1 shown in FIG. The transmitter 1 may be held in the right hand, or, although not shown, a left-handed pilot may hold the left-handed transmitter 1 in the left hand.

As described above, the radio control transmitter 1 equipped with the holding aid 20 has excellent operability of the trigger 7 with the fingers of the grasping hand, and can also be grasped with one hand. Cheap. Furthermore, since it is made from an elastic material such as rubber, it does not slip easily, so you can hold it stably without losing your balance during maneuvering, and you will not get tired even if you hold it for a long time.

As described above, the main body of the transmitter 1 is a casing that is divided into left and right halves, which are connected by connecting bolts 5. Therefore, in the pointed front part 10a of the protrusion 10, a crack (dividing line, PL line) of the housing runs vertically in the center of the width direction. If the holding aid 20 is not attached to the protrusion 10, when the operator grasps the grip part 2, the parting line of the casing will hit the tip of the finger, making the operator feel uncomfortable with the fingertip, which may impede operation. There is sex. However, as described above, the holding aid 20 is formed by injection molding or the like, and is constructed as a whole including the pointed front part 22, so there are cracks (partition lines) on the surface of the front part 22. etc. do not exist. Therefore, according to the transmitter 1 equipped with the holding aid 20, the crack in the pointed front part 10a of the protrusion 10 is hidden, so there is an advantage that the contact with the fingers is improved.

Further, as described above, the main body of the transmitter 1 has a structure in which the housing is divided into two parts on the left and right sides and joined together with the connecting bolt 5. Therefore, as shown in FIG. There is a hole through which the connecting bolt 5 is inserted. If the holding aid 20 is not attached to the protrusion 10, this hole or the connecting bolt 5 in the hole will be exposed, and if the operator's fingers while gripping the grip part 2 touch it, the operator will feel discomfort in his fingertips. It is possible to remember. However, if the holding aid 20 is attached, these holes and the heads of the connecting bolts 5 can be hidden.

Next, compared to the dual-purpose holding aid 20 shown in FIG. 3, a right-handed holding aid 20R (hereinafter also simply referred to as the holding aid 20R) is a second holding aid that is easier for right-handed operators to use. will be explained with reference to FIG. Note that the description will focus on features specific to the right-handed holding aid 20R, and in FIG. 5, parts corresponding to those in FIG. 3 are designated by the same reference numerals as in FIG. 3, and the description thereof will be omitted.

FIG. 5(g) is a view taken along the line gg in FIG. 5(a) in the direction of arrow g. As can be seen from this cross-sectional view, the left and right protrusions 21 of the holding aid 20R are not symmetrical, and the left side protrudes outward higher than the right side, in other words, is thicker. Since the right-handed operator holds the transmitter 1 with his left hand, the fingers of his left hand touch the left side of the holding aid 20R attached to the grip part 2. Therefore, if the left protrusion 21 of the holding aid 20R is made larger than the right side, the grip part 2 can be held more securely and stably by the left hand.

Next, regarding a left-handed holding aid 20L (hereinafter also simply referred to as holding aid 20L) as a third holding aid that is easier for left-handed operators to use than the dual-purpose holding aid 20 shown in FIG. This will be explained with reference to FIG. Note that the description will focus on features specific to the left-handed holding aid 20L, and in FIG. 6, parts corresponding to those in FIG. 3 are designated by the same reference numerals as in FIG. 3, and the description thereof will be omitted.

FIG. 6(g) is a view taken along the line gg in FIG. 6(a) in the direction of arrow g. As can be seen from this cross-sectional view, the left and right protrusions 21 of the holding aid 20L are not symmetrical, and the right side protrudes outward higher than the left side, in other words, is thicker. Since the left-handed operator holds the transmitter 1 with his right hand, the fingers of his right hand come into contact with the right side of the holding aid 20L attached to the grip section 2. Therefore, if the right side protrusion 21 of the holding aid 20L is made larger than the left side, the right hand can hold the grip part 2 more reliably and stably.

According to the radio control transmitter of this embodiment described above, the holding aid according to the operator's dominant hand can be selected from three types of holding aids 20, 20R, and 20L: right-handed, left-handed, and both-handed. It is also easy to replace the holding aid 20 every time the operator changes.
It should be noted that the usage of right-handed and left-handed holding aids explained above is a general case, and right-handed operators do not necessarily prefer right-handed holding aids, and left-handed operators do not necessarily prefer right-handed holding aids. The same holds true for right-handed operators. In that case, for example, the grip may be gripped by pressing the larger protrusion with the thumb of the hand that grips the grip.

1...Radio control transmitter (transmitter)
2...Grip part 3...Base part 4...Head part 5...Connecting bolt 6...Wheel as an operating part 7...Trigger as an operating part 10...Protrusion part of the grip part 10a...Front part of the protrusion part 20...Third auxiliary holding Dual-purpose holding aid as a tool 20R...Right-handed holding aid as a first auxiliary holding tool 20L...Left-handed holding aid as a second auxiliary holding tool 23...Engagement protrusion 24...Engagement recess

Claims (4)

a grip portion to be held by an operator; a head portion provided on an upper end side of the grip portion ; and a head portion provided below the head portion and disposed in front of the grip portion for an operator to hold the grip portion. an operating section that is operated with a finger; and an operating section that is provided on the front side of the upper part of the grip section and has a shape that extends in the front and back direction on both left and right sides of the grip section and protrudes toward the front of the grip section. A holding aid for the radio control transmitter that is attached to and detached from the projection to assist the operator in holding the grip,
The left side surface is in contact with both sides of the protrusion and continues in the front-rear direction so as to fill the gap between the fingers of the operator holding the grip, and when viewed from the front with a line of sight parallel to the front-rear direction. and a right side bulge to the left and right, respectively, and have a curved shape that is convex upward when viewed from the left side or the right side with a line of sight perpendicular to the left side and the right side. a protrusion,
a front part that is in contact with the front part of the protrusion, connects the pair of protrusions together, and protrudes forward;
A holding aid for a radio control transmitter, characterized in that it is integrally made of an elastic material. The holding aid includes a first holding aid in which the protrusion on the right side and the protrusion on the left side have the same outward protrusion when the operator holding the grip part is used as a reference; a second holding aid in which the outward protrusion of the protrusion is larger than that of the right protrusion, and a third holding aid in which the outward protrusion of the right protrusion is larger than the left protrusion. 2. The holding aid for a radio control transmitter according to claim 1, wherein the holding aid for a radio control transmitter can be arbitrarily selected from the group consisting of: and attached to the radio control transmitter. a grip portion to be held by an operator; a head portion provided on an upper end side of the grip portion ; and a head portion provided below the head portion and disposed in front of the grip portion for an operator to hold the grip portion. an operating section that is operated with a finger; and an operating section that is provided on the front side of the upper part of the grip section and has a shape that extends in the front and back direction on both left and right sides of the grip section and protrudes toward the front of the grip section. a radio control transmitter having a continuous protrusion on the front surface of the transmitter;
The left side surface is in contact with both sides of the protrusion and continues in the front-rear direction so as to fill the gap between the fingers of the operator holding the grip, and when viewed from the front with a line of sight parallel to the front-rear direction. and a pair of protrusions whose right side bulges toward the left and right, respectively ;
a front part that is in contact with the front part of the protrusion, connects the pair of protrusions together, and protrudes forward;
1. A radio control transmitter, characterized in that a holding aid is integrally made of an elastic material. An engaging protrusion is provided on the inner surface of each rear part of the pair of protruding parts,
3. The holding aid for a radio control transmitter according to claim 2, wherein engaging recesses are provided on both left and right side surfaces of the grip portion in correspondence with the arrangement of the engaging protrusions.

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