Patent Description:
A structure construction requires erection adjustment work of column members or pillar members such as steel columns after the column members or pillar members are roughly assembled and erected. The erection adjustment work adjusts column members or pillar members, so that they become upright and untilted to the horizontal plane. Regarding measuring the uprightness or tilting of column members, one of the techniques is disclosed in <CIT>, describing a system to measure the position of a pillar member by attaching a retroreflective member on the pillar and utilizing a surveying apparatus. This technique determines a tilt amount of the column member by measuring the position of the retroreflective member with the surveying apparatus.

<CIT> discloses a frame construction tool system for wood frame buildings or for metal, polymer, concrete, or composite frame buildings. A laser light unit comprises a plurality of adjustments for directing the laser light in a variety of directions, preferably for vertical, horizontal, and pivotal adjustment. The laser light unit may be used with targets, cuttings guides, and/or prism units for splitting and/or redirecting the laser beam. In one embodiment, the laser light unit is used with reflective and/or translucent/transparent targets to accurately build a "build-over roof" wherein the laser light unit maps out points and lines of an accurate connection between the roofs. In another embodiment, the laser light unit is used with one or more targets used at the top of a stud wall, to produce a straight line reference from one end/corner of a wall to another. In another embodiment, the laser light unit may be used with a cooperating cutting guide, to measure and properly cut a straight overhang for the roof or a deck and/or to measure and properly cut upending stud members in a pony wall. The preferred laser unit may be used with prism units to layout an entire building.

<CIT> discloses an optical alignment sighting device comprising a support having a V opening formed in one side thereof having <NUM>' V surfaces for the reception of a rectangular or cylindrical member therein to be aligned, means at the other side of said support opposite said V opening disposed for reflecting a line of sight extending into one end of said other Ze of said support coincident with the plane of one of 'the <NUM>' V surfaces in a direction through said other side of said support and out the other end thereof in a plane coincident with the plane of the other of the <NUM>' V surfaces.

Such a retroreflective member is assumed to be attached to targets (such as pillars) in various shapes or designs. Therefore, for attaching such a retroreflective member, different support tools are adopted in accordance with the shapes or locations of the attachment targets. This requires cumbersome management or placement works for using different support tools for various targets.

In view of the forgoing issues described, an object of the present disclosure is to provide a highly convenient target support tool.

In order to achieve the object, the present invention provides a target support tool as claimed in claim <NUM>.

The present disclosure provides a highly convenient target support tool.

A first embodiment of the present disclosure is described below with reference to the drawings. A target support tool <NUM> illustrated in <FIG> can support a retroreflector <NUM> that is a measurement target (target) usable for measuring or surveying the shape of spaces, which may be the shape of structures. The target support tool <NUM> can be used to acquire the position (spatial coordinates) of a structure as follows. The target support tool <NUM> is attached to an attachment target <NUM>. The attachment target <NUM> may be a columnar object (e.g., a steel frame) at a construction site or a corner (e.g., a projected corner or a recessed corner) between inner walls in an indoor space. The target support tool <NUM> attached to the attachment target <NUM> is then measured using a surveying device <NUM>, such as a total station. In this Description, the term "projected corner" refers to a corner, which is formed by two walls placed together to project out, and which may be referred to as an external corner in general, and the term "recessed corner" refers to a corner, which is formed by two walls placed together to recess in, and which may be referred to as internal corner in general.

The target support tool <NUM> illustrated in <FIG> and <FIG> includes a base member <NUM> and a retroreflective member <NUM>. The base member <NUM> includes a first arm 21A (<NUM>) and a second arm 21B (<NUM>) connectable to each other to form a bend part <NUM> therebetween. The retroreflective member <NUM> is placed at the outside corner of the bend part <NUM> of the base member <NUM>. The first and second arms 21A and 21B are connectable to form a right angle at the bend part <NUM>. Here, the base member <NUM> illustrated is substantially in an L-shape as a whole in a plan view (see <FIG>). In the target support tool <NUM> according to the first embodiment and target support tools 1a to 1c in other examples, which will be described later, the first and second arms 21A and 21B (first arms 41A and 51A and second arms 41B and 51B as well) are connectable to form a right angle (in other words, connectable to form a right angle).

The base member <NUM> includes a first base body <NUM> and a second base body <NUM>. The first base body <NUM> is provided with the retroreflective member <NUM>. The second base body <NUM> includes magnets M2. The magnets M2 serve as magnetic support parts to allow an attachment target to attach and detach from and to themselves. The first base body <NUM> can be detachably fixed to the second base bodies <NUM> in such a way that the outside corner of a bend part <NUM> (<NUM>) of the second base body <NUM> faces the inside corner of the first base body <NUM>. The first base body <NUM> is also detachably fixed to the second base body <NUM> (which is a magnetic body such as a metal) using magnets (i.e., magnetic support parts) M1 placed on one surfaces of the first and second arms 41A and 41B of the first base body <NUM>. The one surfaces of the first and second arms 41A and 41B may be inner surfaces <NUM> forming the inside corner of a bend part <NUM> (<NUM>) as in this embodiment.

The first base body <NUM> includes the first and second arms 41A (<NUM>) and 41B (<NUM>) connected to form a right angle at the bend part <NUM>, so as to form a substantially L-shape as a whole. As illustrated in <FIG>, the first and second arms 41A and 41B according to this embodiment are symmetric in shapes and geometries with respect to the axis A of symmetry, which passes through the bend part <NUM>. The first and second arms 41A and 41B each have a quadrangular prism shape, which has a substantially square cross- section. The bend part <NUM> has outer surfaces <NUM>, which form the outside corner. The outer surfaces <NUM> include an inner slope <NUM> and outer slopes <NUM>, respectively. The inner slope <NUM> is located on the axis A of symmetry in the plan view (see <FIG>) and forms a flat surface tilting at <NUM> degrees from the outer surfaces <NUM> of the first and second arms 41A and 41B, respectively. On the other hand, each outer slope <NUM> is interposed between the inner slope <NUM> and one of the outer surfaces <NUM> and form a flat surface chamfering the boundary of the inner slope <NUM> and the one of the outer surfaces <NUM>. The inner surface <NUM> of the first arm 41A and the inner surface <NUM> of the second arm 41B also form a right angle.

The first base body <NUM> includes the inner slope <NUM> above which the retroreflector <NUM> is located and further includes the outer slopes <NUM> on both sides of the inner slope <NUM>. This configuration provides a wider solid angle range, within which the surveying device <NUM> or any other suitable device can attain collimation with the retroreflector <NUM>.

As illustrated in <FIG>, the distal end surface <NUM> of the first arm 41A and the distal end surface <NUM> of the second arm 41B form the same plane B. The distal end surface <NUM> of the first arm 41A tilts at an acute angle of <NUM> degrees from outer surfaces <NUM> of the first arm 41A. The distal end surface <NUM> of the second arm 41B also tilts at an acute angle of <NUM> degrees from the outer surface <NUM> of the second arm 41B. That is, the distal end surfaces <NUM> tilt from the longitudinal directions (i.e., the directions of extension) of the first and second arms 41A and 41B in such a way that each distal end surface <NUM> makes an angle of <NUM> degrees with the longitudinal direction of the first and second arm 41A or 41B corresponding thereto. As illustrated in <FIG>, the first base body <NUM> includes suspension point parts <NUM> on upper surfaces <NUM> of the first and second arms 41A and 41B, respectively. The suspension point parts <NUM> each include an annular member <NUM>. The annular member <NUM> is pivotably attached to corresponding one of the upper surfaces <NUM>. The annular member <NUM> might be used to secure thereto a suspender (not illustrated), such as a carabiner or a rope-like tool to hold the first base body <NUM> or the target support tool <NUM>. This can help to prevent the first base body <NUM> or the target support tool <NUM> from falling down.

The first base body <NUM> includes a recess <NUM> at the inside corner of the bend part <NUM>. The recess <NUM> extends vertically (i.e., in the direction orthogonal to the longitudinal directions of the first and second arms 41A and 41B). The recess <NUM> has an inner surface recessed in an arc as illustrated in the plan view of <FIG>. The recess <NUM> functions as a relief for reducing the inference with the outside corner of the bend part <NUM> of the second base body <NUM> when the second base body <NUM> is placed on the inner surfaces <NUM> of the first base body <NUM>.

The magnets M1 are also located on the inner surfaces <NUM> of the first and second arms 41A and 41B. The magnets M1 according to this embodiment may be, for example, magnetic members, such as a neodymium magnet. The magnets M1 are embedded in the first and second arms 41A and 41B. In this manner, the magnetic force exerted by the magnets M1 can detachably attach the first base body <NUM> to the second base body <NUM>. Note that the magnetically attached first and second base bodies <NUM> and <NUM> are easily detachable by moving the first base body <NUM> in a direction going apart from the second base body <NUM>, for example, with fingers or other means hooking the first base body <NUM> on the distal end surfaces <NUM>.

The retroreflective member <NUM> includes the retroreflector <NUM> and a support part <NUM> connected to the retroreflector <NUM>. The retroreflector <NUM> may be, for example, a prism with retroreflective characteristics. The support part <NUM> is formed in the shape of a long bar. The retroreflector <NUM> is located at the outside corner of the bend part <NUM> (<NUM>) and offset from the base member <NUM> on a bisector of an internal angle between the first and second arms 21A and 21B, the bisector being coaxial with the axis A of symmetry.

The inner slope <NUM> described above has a support hole <NUM> that is a through-hole for receiving and holding the support part <NUM> therein. The retroreflective member <NUM> is fixed to the first base body <NUM> with the support part <NUM> inserted into the support hole <NUM> at a predetermined depth.

The second base body <NUM> includes the first and second arms 51A (<NUM>) and S1B (<NUM>) connected to form a right angle at the bend part <NUM> so as to form the shape of a substantially L-shaped plate as a whole. As illustrated in <FIG>, the first and second arms 51A and 51B according to this embodiment are symmetric in shapes and geometries with respect to the axis A of symmetry. The second base body <NUM> is a plate member with a substantially uniform thickness. The outer surfaces <NUM> of the first arm and second arms 51A and 51B form a right angle. The inner surfaces <NUM> of the first arm and second arms 51A and 51B also form a right angle.

The edges of the distal ends <NUM>, <NUM> of the first arm 51A and the second arm 51B are parallel to each other on the same plane. The first and second arms 51A and 51B include a plurality of openings <NUM> that are through-holes symmetrically located with respect to the axis A of symmetry.

As illustrated in <FIG> and other figures, the first and second arms 51A and 51B each include a detachable part <NUM> at its distal end. The detachable part <NUM> includes a magnet support part <NUM>, a hole <NUM> that guides the magnet support part <NUM>, and a pivotable support part <NUM> that pivotably supports the magnet support part <NUM>.

The first and second arms 51A and 51B each include notches <NUM> recessed rectangularly in shape from both lateral edges opposite to each other in a width direction. Each pivotable support part <NUM> extends to bend in an L-shape from the inner edge corresponding to the bottom of one of these notches <NUM> beyond the corresponding outer surface <NUM>. The distal ends of the pivotable support parts <NUM> of the detachable parts <NUM> are substantially parallel to each other.

<FIG> is a perspective view of each magnet support part <NUM> and corresponding one of releasers <NUM> according to the first embodiment. The magnet support part <NUM> is formed in the shape of a long rectangular thick plate. The magnet support part <NUM> includes a proximal part <NUM> provided with a bearing 541a, and a main body <NUM> thicker than the proximal part <NUM>. The main body <NUM> includes, on one surface thereof, a long rectangular magnetic attachment surface 542a provided with the magnets M2. The magnets M2 are placed to be flush with the magnetic attachment surface 542a in this embodiment. However, the magnet(s) M2 may be embedded in the magnet support part <NUM> so that the magnet(s) M2 can have a predetermined distance (offset) from the magnetic attachment surface 542a. The magnets M2 are provided at least on the inner surfaces (i.e., the inner surfaces <NUM>) of the first and second arms 21A and 21B when the magnet support part <NUM> is pivoted in such a way that the magnetic attachment surface 542a will be located inside the hole <NUM> (see also <FIG>). In this context, the inner surfaces <NUM> are ones on the internal corner side of the bend part.

The main body <NUM> includes a taper <NUM> along the outer peripheral edge of the magnetic attachment surface 542a. The taper <NUM> is formed by tapers 543a, 543b, 543c, and 543a at each of the edge around, it is formed like a rectangular loop in a plan view as viewed from the magnetic attachment surface 542a. The tapers 543a extend along the edges of the main body <NUM> in the lateral direction (i.e., the axial direction along a pivot C) while the tapers 543b and 543c extend along the edges located in a radial direction D perpendicular to the pivot C of corresponding one of the pivotable support parts <NUM>. The tapers 543a and 543b are chamfered surfaces with substantially the same tilt angle. On the other hand, the taper 543c near the proximal part <NUM> is tilted with a concave shape.

The magnet support part <NUM> includes projections <NUM> on both sides in the direction along the pivot C. Each projection <NUM> includes a relief portion 544a and a regulating portion 544b at its outer edge away from the pivot C in the radial direction D (i.e., at the distal edge). The relief portion 544a is a concave shape in a side view, and the relief portion 544a is located closer to a handle <NUM> of the releaser <NUM> (at a pivot E). The regulating portion 544b, a part of which closer to the magnetic attachment surface 542a is adjacent to the relief portion 544a, projects toward the handle <NUM>.

The releaser <NUM> is formed substantially in a U-shape and includes the handle <NUM> and support rails <NUM>, which extend from both ends of the handle <NUM> in the same direction. The releaser <NUM> is pivotable about the pivot E with the support rails <NUM>, which are connected to the side surfaces of the main body <NUM>. Each support rail <NUM> includes a release projection 572a projecting in the shape of a semi-circular arc plate at an end opposite to the handle <NUM> with respect to the pivot E. The pivoting of the releaser <NUM> is regulated within a predetermined angle range by the release projection 572a and the regulating portion 544b abutting on each other.

Each hole <NUM> is an opening penetrating the second base body <NUM> in the thickness direction of its plate-like shape thereof, and is formed substantially in a long rectangular shape (see also <FIG>). The hole <NUM> is shaped conformably to the outer peripheral shape of the magnetic attachment surface 542a, which projects on a surface of the magnet support part <NUM>. The hole <NUM> guides the insertion and extraction of the magnet support part <NUM> in such a way that the tapers <NUM> of the magnet support part <NUM> abut or slide on an intern edge of the hole <NUM>. The corresponding pivotable support part <NUM> described above pivotably supports the magnet support part <NUM> with the magnetic attachment surface 542a, which is exposed through the hole <NUM> (see also a target support tool <NUM>-<NUM> in <FIG>).

The first and second arms 51A and 51B each include a suspendable part <NUM> formed in the shape of a substantially L-shape plate and placed near the distal end. The suspendable part <NUM> includes a substantially rectangular opening penetrating the suspendable part <NUM> in the thickness direction of its plate-like shape thereof. The suspendable part <NUM> is for securing thereto a suspender (not illustrated), such as a carabiner or a rope-like tool, to hold the first base body <NUM> or the target support tool <NUM>. This can help to prevent the target support tool <NUM> from falling down.

Here, an example use case of the target support tool <NUM> will be described. <FIG> is an enlarged schematic view of the target support tool <NUM> attached to the attachment target <NUM> in <FIG> as viewed downward from above (in a Q-direction). The attachment target <NUM> according to this embodiment has a substantially square outer shape in a cross-sectional view. Since the attachment target <NUM> has magnetic characteristics, the first arm 51A (21A) is attached to one of the outer surfaces 101a by the magnetic force of the magnets M2 (see <FIG>) placed in the detachable part <NUM>, while the second arm 51B (21B) is attached to the other outer surface 101a by the magnetic force as well.

As illustrated in the target support tool <NUM>-<NUM> in <FIG>, the target support tool <NUM> magnetically attaches to the attachment target <NUM>, of which each attachment surface 542a and one of the inner surfaces <NUM> abut on one of the outer surfaces 101a on the same surface. In this manner, the target support tool <NUM> is at least partially in surface contact with each outer surface 101a, so that the target support tool <NUM> can stably attach to the attachment target <NUM>.

Even if rattling (e.g., caused by a dimensional deviation from a design value) is occurred between any hole <NUM> and the inserted part (i.e., the projection having the magnetic attachment surface 542a) of the corresponding magnet support part <NUM>, the taper <NUM> allows them to stably attach each other, because the inner edge of the hole <NUM> abuts on and is supported by the magnet support part <NUM> magnetically attached and fixed to the attachment target <NUM>. This can help to prevent the base member <NUM> (i.e., the whole target support tool <NUM>) from falling down and being displaced. As a result, the retroreflector <NUM> becomes more stably fixed to the base member <NUM>, and the retroreflector <NUM> can be stably supported with respect to the attachment target <NUM>.

Referring back to <FIG>, since the attachment target <NUM> has the outer shape substantially in a regular square shape in a cross-sectional view, a distance X1 is equal to a distance Y1 (i.e., X1 = Y1), where the distance X1 is measured from the center O of the attachment target <NUM> to one of the outer surfaces 101a in a first direction (e.g., the horizontal direction in <FIG>), and the distance Y1 is measured from the center O to the other outer surface 101a in another, second direction (e.g., the vertical direction in <FIG>) orthogonal to the first direction.

On the other hand, the distance X2 between the retroreflector <NUM> of the target support tool <NUM> and one of the outer surfaces 101a of the attachment target <NUM> (i.e., the inner surface <NUM> of the second arm 51B) in the first direction (i.e., the horizontal direction in <FIG>) is a design value, which is given in advance and known. For example, the point for attaching the retroreflector <NUM> may be set by a user (i.e., an operator) of the surveying device <NUM>. The distance Y2 between the retroreflector <NUM> and the other outer surface 101a of the attachment target <NUM> (i.e., the inner surface <NUM> of the first arm 51A) in the second direction (i.e., the vertical direction in <FIG>) is a design value, which is given in advance and known. By measuring the position (i.e., the spatial coordinates) <NUM> of the retroreflector <NUM> using the surveying device <NUM> (see <FIG>), the position of the center O of the attachment target <NUM>, at which the retroreflector <NUM> is attached, can be acquired by offsetting the coordinate in the first direction from the position <NUM> by the sum of the distances X1 and X2 and offsetting the coordinate in the second direction from the position <NUM> by the sum of the distances Y1 and Y2. Note that the procedure of calculating the position of the center O is not limited to this.

In order to attach the target support tool <NUM> to the attachment target <NUM>, first, the base member <NUM> is put to abut on any corner 101b of the attachment target <NUM>, to which the target support tool <NUM> is intended to attach. Accordingly, the first arm 21A is substantially in surface contact with one of the outer surfaces 101a, while so is the second arm 21B with the other outer surface 101a. This allows the target support tool <NUM> to be placed at a temporary position easily but stably.

Next, as illustrated in the target support tool <NUM>-<NUM> in <FIG>, each detachable part <NUM> pivots about the pivot C in order to insert a part of the projection of the corresponding magnet support part <NUM> including the magnetic attachment surface 542a into the corresponding hole <NUM>. At this time, the inner edge of the hole <NUM> guides the taper <NUM> of the magnet support part <NUM> on the outer periphery of the magnetic attachment surface 542a; the detachable part <NUM> magnetically attaches to the attachment target <NUM> through the hole <NUM> at the planned attachment point at which the target support tool <NUM> is temporarily positioned, thereby stably supporting the target support tool <NUM>. As described above, using the target support tool <NUM> allows to perform, at different timings, the positioning by abutting on the attachment target <NUM> (e.g., a steel frame) and the magnetically attaching to the attachment target <NUM>, so that the retroreflector <NUM> can attach to the intended position precisely.

Next, an example operation of detaching each detachable part <NUM> will be described with reference to <FIG> and <FIG>. The target support tool <NUM>-<NUM> illustrated in <FIG> is magnetically attached to the attachment target <NUM>. In order to detach the target support tool <NUM> from the attachment target <NUM>, when the handle <NUM> of the releaser <NUM> is pivoted about pivot E in a direction away from the attachment target <NUM> by holding the handle <NUM> as illustrated in a target support tool <NUM>-<NUM>, the release projection 572a of the releaser <NUM> will abut on an abutting target 55a (illustrated in <FIG> as well), which is the outer peripheral edge (surface) of the hole <NUM>.

As illustrated in a target support tool <NUM>-<NUM> in <FIG>, by operating the handle <NUM> in the direction away from the attachment target <NUM>, the magnet support part <NUM> including the magnets M2 will be moved in the direction away from the attachment target <NUM> against the magnetic force. At this time, the point at which the release projection 572a abuts on the abutting target 55a serves as a fulcrum, the handle <NUM> serves as an effort, and the pivot E serves as a load (what is called a "second-class lever"). In other words, the releaser <NUM> includes the fulcrum part (i.e., the pivot E) supported pivotably with respect to the magnet support part <NUM>, the effort part (i.e., the handle <NUM>) on one side of the fulcrum part, and the load part (i.e., the release projection 572a) on the other side of the fulcrum part. The load part can press the abutting target 55a which is the opening edge of the hole <NUM>. The pivot E functions such that the release projection 572a receives the reaction force from the abutting target 55a and is pushed back by the reaction force, so that the magnet support part <NUM> will move in the direction away from the attachment target <NUM>.

As illustrated in a target support tool <NUM>-<NUM>, once the handle <NUM> is further pulled in the direction away from the attachment target <NUM>, the magnet support part <NUM> will pivot about the pivot C and move in the direction away from the attachment target <NUM>. In this manner, the user can easily detach the target support tool <NUM> from the attachment target <NUM> by releasing the detachable part <NUM> using the releaser <NUM> for the first arms 41A and 51A (21A) and the second arms 41B and 51B (21B).

The target support tool <NUM> according to this embodiment is configured such that the inner surfaces <NUM> formed at a right angle are abuttable on the corresponding right-angled outer surfaces 101a. Accordingly, as illustrated in <FIG>, a plurality of retroreflectors <NUM> can be attached at some positions at a predetermined corner 101b of the attachment target <NUM> while being easily aligned in the vertical direction (along the axis) of the attachment target <NUM>, without the need of performing any extra measurement. Since the retroreflectors <NUM> fixed to the same attachment target <NUM> is parallel to the axis of the center O of the attachment target <NUM>, the tilt of the attachment target <NUM> can be acquired by measuring the coordinates of the retroreflectors <NUM>.

Next, a second embodiment will be described. <FIG> is a perspective view of a target support tool 1a according to a second embodiment as viewed from the lower front, while <FIG> is a perspective view of the target support tool 1a as viewed from the upper back. In the description of the target support tool 1a according to the second embodiment, the same reference numbers and characters as those of the target support tool <NUM> are used to represent equivalent configurations, and the detailed explanation thereof will be omitted or simplified.

A base member 2a of the target support tool 1a includes a second base body 5a in place of the second base body <NUM> of the target support tool <NUM> according to the first embodiment. The first base body <NUM> has the same or similar configuration to the target support tool <NUM> according to the first embodiment.

The second base body 5a includes first and second arms 51Aa (51a) and 51Ba (51a) connected to form a right angle at the bend part <NUM>, thereby being substantially in the shape of an L-shaped plate as a whole. The distal end <NUM> of the first arm 51Aa and the distal end <NUM> of the second arm 51Ba are parallel to each other and are thus located on the same plane. The first and second arms 51Aa and 51Ba include long-rectangular openings <NUM> that are through-holes parallel to the second base body 5a at symmetric locations with respect to the axis of symmetry (corresponding to the axis A of symmetry illustrated in <FIG>) at the bend part <NUM>.

The first and second arms 51Aa and 51Ba each include, at its distal end, a detachable part 53a in place of the detachable part <NUM> illustrated in the first embodiment. Each detachable part 53a includes a magnet support part <NUM>, and a guide <NUM> that guides the magnet support part <NUM>. The magnet support part <NUM> is formed in the shape of a long rectangular thick plate. The longitudinal direction of the magnet support part <NUM> extends in the lateral directions of the first and second arms 51Aa and 51Ba.

Each magnet support part <NUM> includes, on one surface thereof, a long rectangular magnetic attachment surface 58a provided with a plurality of magnets (i.e., a magnetic support parts) M3. The magnets M3 are placed to be flush with the magnetic attachment surface 58a in this embodiment. However, the magnets M3 may be embedded in the magnet support part <NUM>, so that the magnet(s) is/are provided with a predetermined distance (offset) from the magnetic attachment surface 58a. The magnets M3 are provided at least on the inner surfaces (i.e., the inner surfaces <NUM>) of the first arm 21Aa (21a) and the second arm 21Ba (21a), where the inner surfaces are on the internal corner side of the bend part.

The magnet support part <NUM> is placed in the guide <NUM>, which is formed by bending a part of the corresponding arm 51a. The guide <NUM> includes a first sidewall 517a, a second sidewall 517b, and a third sidewall 517c. The first sidewall 517a is a sidewall proximal to the bend part <NUM> with respect to the magnet support part <NUM>. The second sidewall 517b faces a reverse side of the magnetic attachment surface 58a. The third sidewall 517c is an other sidewall along the width direction of the arm 51a. The first to third sidewalls 517a to 517c each have a flat surface and are substantially perpendicular to each other.

The detachable part 53a includes a releaser <NUM>. The releaser <NUM> includes a nob <NUM> and a connector <NUM>. The nob <NUM> is formed in the shape of a short cylindrical column knurled on the outer periphery. The connector <NUM>, which is slidably inserted into a through hole of the second sidewall 517b, connects the nob <NUM> and the magnet support part <NUM> with each other. The magnet support part <NUM> is thus movable, for a predetermined distance, in directions toward and away from the second sidewall 517b (i.e., in directions toward and away from the attachment target <NUM> when being attached with the target support tool 1a) (see also <FIG>). In addition, the first and third sidewalls 517a and 517c are formed close to or in sliding contact with a side surface of the magnet support part <NUM>, so that the first and third sidewalls 517a and 517c can function as a guide wall that helps to prevent from unexpected pivoting of the magnet support part <NUM>.

The first sidewall 517a includes, at one end, a suspendable part <NUM>, which has the shape of a rectangular plate and projects at the end. The suspendable part <NUM> has a substantially rectangular opening penetrating the suspendable part <NUM> in the thickness direction of its plate-like shape. The suspendable part <NUM> is for securing thereto a suspender (not illustrated), such as a carabiner or a rope-like tool, to hold the first base body <NUM> or the target support tool <NUM>. This can help to prevent the target support tool <NUM> from falling down.

The third sidewall 517c includes a brim <NUM> formed in the shape of a rectangular plate on the other side opposite to the suspendable part <NUM>. The brim <NUM> has a flat surface substantially on the same plane as the inner surface <NUM> of the second base body 5a, thereby facilitating stable support for the target support tool 1a with the brim <NUM> and the magnet support part 58a together abutting on the attachment target <NUM>.

Here, an example use case of the target support tool 1a will be described with reference to <FIG> is a cross-sectional view of a target support tool 1a-<NUM>, which has abutted on (or has attached to) the attachment target <NUM>, taken along line XII-XII in <FIG>.

Since the attachment target <NUM> has magnetically attachable, the first arm 21Aa attaches to one of the outer surfaces 101a at the corner 101b by the magnetic force of the magnets M3 of the detachable part 53a, while the second arm 21Ba (not illustrated) also attaches to the other outer surface 101a by the magnetic force of the magnets M3 of the detachable part 53a. The target support tool <NUM> magnetically attaches to the attachment target <NUM> with each magnetic attachment surface 58a, one of the inner surfaces <NUM>, and the brim <NUM> of the target support tool <NUM>, on the same plane, in surface contact with one of the outer surfaces 101a of the attachment target <NUM>. In this manner, the target support tool 1a is also at least partially in surface contact with each outer surface 101a, so that the target support tool 1a is also stably attached to the attachment target <NUM>. Each magnet support part <NUM> magnetically attached to the attachment target <NUM> is in the shape of a quadrangular short column and includes four flat outer peripheral side surfaces. One of the outer peripheral side surfaces abuts on the first sidewall 517a so as to restrict the movement of the base member 2a with respect to the attachment target <NUM> (i.e., restrict the movement to the left in <FIG>). Another one of the outer peripheral side surfaces abuts on the third sidewall 517c so as to restrict the movement of the base member 2a with respect to the attachment target <NUM> (i.e., restrict the movement to the front in <FIG>). As a result, the retroreflector <NUM> fixed to the base member 2a is prevented from positional displacement and stably supported with respect to the attachment target <NUM>.

In order to attach the target support tool 1a to the attachment target <NUM>, first, the base member 2a is put to abut on a corner 101b of the attachment target <NUM>, to which the target support tool <NUM> is to attach. At this time, the first arm 21Aa is substantially in surface contact with one of the outer surfaces 101a, while so is the other, second arm 21Ba with the other outer surface 101a. As a result of this, this allows the target support tool <NUM> to place at a temporary position easily but stably. Next, as illustrated in the target support tool 1a-<NUM> in <FIG>, each detachable part 53a is operated to move closer to the attachment target <NUM>. This allows the corresponding magnet support part <NUM> including the magnetic attachment surface 58a to abut on the outer surface 101a. Accordingly, the detachable part 53a magnetically attaches to the attachment target <NUM> so that the target support tool 1a could stably place on an intended position to be fixed from the temporary position. As described above, using the target support tool 1a allows to perform, at different timings, the positioning by abutting on the attachment target <NUM> (e.g., a steel frame) and the magnetically attaching to the attachment target <NUM>, so that the retroreflector <NUM> can attach to the intended position precisely.

In order to detach the detachable part 53a, the user releases the detachable part 53a using the releaser <NUM> for the first arms 41Aa and 51Aa (21Aa) and the second arms 41Ba and 51Ba (2lBa). The target support tool 1a-<NUM> with each magnet support part <NUM> in <FIG> abutting on the attachment target <NUM> is released in such a way that the user holds the nob <NUM> of the releaser <NUM> and moves the magnet support part <NUM> in the direction away from the attachment target <NUM> against the magnetic force. Accordingly, as illustrated in the target support tool 1a-<NUM>, the magnet support part <NUM> easily detaches from the attachment target <NUM>. Note that the movement of the magnet support part <NUM> is restricted by wider dimensional parts, which are provided on both sides (i.e., above and below the 517b in <FIG>) in the axial direction of the connector <NUM>, and which would abut on the opening edge of the through hole in the second sidewall 517b. Once the magnet support part <NUM> is away from the corresponding outer surface 101a, the target support tool 1a will easily detach from the attachment target <NUM>.

In this manner, according to the second embodiment, the detachable part 53a, can be configured with the magnets M3 so that the detachable part 53a will be easily attachable to and detachable from the attachment target <NUM>.

Next, a first variation of the present disclosure will be described. Described in the first variation is a configuration with a check mechanism <NUM>, which can be provided in the target support tool <NUM> (including the target support tool 1a) described above. <FIG> is a schematic view of the check mechanism <NUM>. The check mechanism <NUM> is placed, for example, in an arm <NUM> (one or each of the first and second arms 51A and 51B) of the second base body <NUM>. The check mechanism <NUM> allows the user to easily check whether the target support tool <NUM> surely attaches to the attachment target <NUM>. The check mechanism <NUM> is placed in such a part of the target support tool <NUM> that moves closer to the attachment target <NUM> when the target support tool <NUM> attaches to the attachment target <NUM> and moves away from the attachment target <NUM> when the target support tool <NUM> detaches from the attachment target <NUM>.

The check mechanism <NUM> includes a housing <NUM> and a movable member <NUM>. The housing <NUM> is an opening hole penetrating the second base body <NUM> in the thickness direction of its plate-like shape. The movable member <NUM> is received in the housing <NUM> movably back and forth along the plate thickness of the second base body <NUM>. The housing <NUM> includes a smaller-diameter part <NUM> on the corresponding outer surface <NUM>, and a counterbore <NUM> around the opening edge at one end of the smaller-diameter part <NUM> on the inner surface <NUM>. The movable member <NUM> includes a columnar main body <NUM> to be housed in the smaller-diameter part <NUM>, and a flange <NUM> at one end of the main body <NUM>. The movement of the movable member <NUM> toward the outer surface <NUM> is restricted with the flange <NUM> abutting on the bottom of the counterbore <NUM>, while the movement of the movable member <NUM> away from the outer surface <NUM> is also restricted, for example, with a regulating portion (not illustrated) of the housing <NUM> abutting on a regulated part (not illustrated) of the movable member <NUM>. For example, the regulated part may be a projection, and the regulating portion may be a groove that guides the projection within a movement range.

The movable member <NUM> is biased toward the inner surface <NUM> by an elastic member (not illustrated), such as a spring. When the target support tool <NUM> is unattached to the attachment target <NUM>, the movable member <NUM> will project beyond the inner surface <NUM> with a predetermined amount of projection (see a movable member <NUM>-<NUM>).

On the other hand, when the target support tool <NUM> is attached to the attachment target <NUM> (i.e., when each inner surface <NUM> abuts on the attachment target <NUM>), the movable member <NUM> is pressed from the inner surface <NUM> toward the housing <NUM> to move against the elastic force of the elastic member. The flange <NUM> of the movable member <NUM> moved into the housing <NUM> is received in the counterbore <NUM>, and then the movable member <NUM> dose not project beyond the inner surface <NUM>. When moving into the housing <NUM>, the movable member <NUM> moves toward the outer surface <NUM> of the second base body <NUM>, so that the distal end of the main body <NUM> will become substantially flush with the outer surface <NUM>. Accordingly, this configuration allows the user to check whether the movable member <NUM> is flush with the outer surface visually by seeing the outer surface <NUM>, or tactually by touching the outer surface <NUM>, so that the user can easily determine whether the target support tool <NUM> surely attaches to the attachment target <NUM>, or not.

In this manner, the check mechanism <NUM> changes in state in accordance with the attachment and detachment of the base member <NUM> to and from the attachment target <NUM> to allow to check of the attachment and detachment of the base member <NUM> using one or both of the visual and tactile senses. Accordingly, this configuration makes it possible for the user to easily check the attachment of the target support tool <NUM>. Note that the check mechanism <NUM> may be placed in the target support tool 1a or any arm <NUM> of the first base body <NUM>. One or more check mechanisms <NUM> may be provided.

Next, a second variation of the present disclosure will be described. The target support tools <NUM> and 1a described above in the first and second embodiments may be modified to measure using the first base body <NUM> alone. <FIG> illustrates a target support tool 1b including a base member <NUM> with the first base body <NUM>, but without the second base body <NUM>, 5a. The target support tool 1b includes first and second arms 21A and 21B, and which are configured shorter for the total length of the each arm than those in the target support tool <NUM> including the second base body <NUM>, 5a. This second variation is suitable for, for example, a case where the attachment target <NUM> has a relatively small curvature radius at the corner 101b, a wider contact area can be secured between each inner surface <NUM> and the corresponding outer surface 101a can be secured. Accordingly, the target support tool 1b stably magnetically can attach to the attachment target <NUM> despite having no second base body <NUM>, 5a.

The retroreflector <NUM> of the target support tool 1b and one of the outer surfaces 101a of the attachment target <NUM> (i.e., the inner surface <NUM> of the second arm 41B) are placed at a distance X3 in-between in the first direction (i.e., the horizontal direction in <FIG>), while the distance Y3 is between the retroreflector <NUM> and the other outer surface 101a of the attachment target <NUM> (i.e., the inner surface <NUM> of the first arm 41A) in the second direction (i.e., the vertical direction in <FIG>). The distances X3 and Y3 each are a design value, which have been given in advance and known. By utilizing the known design values, the position of the center O of the attachment target <NUM>, at which the retroreflector <NUM> is attached, can be worked out by measuring the position (i.e., in the spatial coordinates) <NUM> of the retroreflector <NUM> with the surveying device <NUM>, and offsetting the coordinate in the first direction from the position <NUM> by the sum of the distances X1 and X3 and offsetting the coordinate in the second direction from the position <NUM> by the sum of the distances Y1 and Y3. See <FIG> for the positional relationship between the center O and the distances X1 and Y1.

The target support tool 1b illustrated in <FIG> is easily moved away from the attachment target <NUM>, for example, with a hand holding the respective distal end surfaces <NUM> of the first and second arms 41A and 41B. That is, each distal end surface <NUM> also functions as a releaser.

As illustrated in <FIG>, the target support tool 1b can also measure the position of the attachment target <NUM> by attaching the respective distal end surfaces <NUM> of the first and second arms 41A and 41B to the outer surfaces 101a of the attachment target <NUM> in face-to-face relationship. The target support tool 1b can magnetically attach to the attachment target <NUM> by the magnetic force of the magnets M1 with each distal end surface (one surface) <NUM> thereof on the attachment target <NUM>, each distal end surface <NUM> serving as a magnetic attachment surface with the magnets M1.

The distance R1 between the retroreflector <NUM> of the target support tool 1b and the same plane B including the distal end surface <NUM> is given as a design value in advance. The distance (e.g., the distance X1 or Y1 in <FIG>) between the center O of the attachment target <NUM> (not illustrated in <FIG>) to the outer surface 101a is given in advance from design information. The direction F from the retroreflector <NUM> to the center O of the attachment target <NUM> can be set in advance based on the design information. By measuring the position (i.e., the spatial coordinates) <NUM> of the retroreflector <NUM> by using the surveying device <NUM> (see <FIG>), the position of the center O of the attachment target <NUM> can be acquired, at which the retroreflector <NUM> is attached.

<FIG> illustrates another example use case of the target support tool 1b. This figure is a side view of the attachment target <NUM> in the normal line of the outer surfaces 101a. Two lines are drawn on the outer surfaces 101a as a guide index G, working as a guide to place the attachment target <NUM>, which will be described in the following paragraphs. The guide index G in this figure are illustrated as being drawn with two straight lines intersecting each other at a right angle, which form an L-shape.

When the target support tool 1b is being placed on the attachment target <NUM>, it will be placed at a position, for example, a place at which a reference position 412a would coincide with a reference point g1, where the reference position 412a is the imaginary intersection between the inner surfaces <NUM>, and the reference point g1 is the intersection between the guide indexes G. In the example in <FIG>, the guide index G are straight lines forming a right angle. Referring to the guide index G, the inner surfaces <NUM> of the first base body <NUM> (i.e., the base member 2b) are adjusted to be along the two lines of the guide index G, so that the reference position 412a and the reference point g1 will coincide with each other.

The target support tool 1b is widely open around the reference position 412a with the recess <NUM>, which will allow the user to easily see the positions of the guide index G and the relative positions between the target support tool 1b and the guide index G. Accordingly, the recess <NUM> can function as a relief to allow to see the guide index G, the intersection (i.e., the corner 101b) of the lines drawn on the attachment target <NUM>, this will allow the user to easily check where the target support tool 1b should be placed on with respect to the attachment target <NUM>. With the recess <NUM> to see the guide indexes G, the target support tool 1b (i.e., the relative position of the retroreflector <NUM> with respect to the attachment target <NUM>) can easily be attached at the same position as before, even when the target support tool <NUM> is repeatedly attached to and detached from the attachment target <NUM>.

A target support tool 1c-<NUM> illustrated in <FIG> is an example configuration in which the retroreflector <NUM> is located at a position where the center position <NUM> in a plan view from the inside of the bend part <NUM> (<NUM>) and the upper surfaces <NUM> will coincide with the reference position 412a (i.e., the imaginary intersection between the inner surfaces <NUM>). The retroreflector <NUM> of the target support tool 1c-<NUM>, for example, may form in a pyramid shape (i.e., a regular quadrangular pyramid) which is a half of a regular octahedron, and may be provided to be seeable at least in a direction of one of the upper surfaces <NUM>.

An example attachment of the target support tool 1c-<NUM> to the attachment target <NUM> will be described: First, abut the lower surfaces <NUM> (see also <FIG>) of the target support tool 1c-<NUM> on the outer surfaces 101a of the attachment target <NUM>. At this time, by adjusting the inner surfaces <NUM> to be along the two lines of the guide index G respectively, the center position <NUM> of the retroreflector <NUM> can automatically coincide with the reference point g1. Thus, the user can easily position the retroreflector <NUM> on the target support tool 1c-<NUM> by checking whether the center position <NUM> of the retroreflector <NUM> overlaps with the guide index G (i.e., whether the center position <NUM> of the retroreflector <NUM> overlaps the normal line of the outer surfaces 101a at the reference point g1).

As long as the position of the reference point g1 is determined, the guide index G may be drawn with an obtuse or acute angle, and the reference point g1 may be indicated with a point or a dot, or a tilted line or lines. Alternatively, the guide index G may be drawn with lines intersecting each other into a cross shape. The retroreflector <NUM> is transparent or translucent enough to see the reference point g1 on the outer surfaces 101a through; Although the target support tool 1c is leaningly attached to the outer surfaces 101a at a tilt, the retroreflector <NUM> will be easily and highly accurately re-attached to the attachment target <NUM> at a planned attachment point.

Next, a third variation of the present disclosure will be described. <FIG> illustrates an example use case of the target support tool 1c according to the third variation. The target support tool 1c includes the retroreflector <NUM> at the internal corner (i.e., the inside or recessed corner) of the bend part <NUM> of the base member <NUM> (i.e., the first base body <NUM>), where the bend part <NUM> form in an L-shape. The retroreflective member <NUM> is attached to the first base body <NUM> with the support part <NUM> engaged to the support hole <NUM> of the first base body <NUM> (see <FIG>) from the inner side. The target support tool 1c can attach to the attachment target <NUM> by attaching to a recessed corner of inner walls in an indoor space, or a recessed corner of building materials at a construction, etc..

The retroreflector <NUM> of the target support tool 1c and one of the outer surfaces 101a of the attachment target <NUM> (i.e., the outer surface <NUM> of the second arm 41B) are placed at a distance X4 in-between in the first direction (i.e., the horizontal direction in <FIG>), while the distance Y4 is between the retroreflector <NUM> and the other outer surface 101a of the attachment target <NUM> (i.e., the outer surface <NUM> of the first arm 41A) in the second direction (i.e., the vertical direction in <FIG>). The distances X4 and Y4 each are a design value, which have been given in advance and known. By utilizing the known design values, the position of the corner 101e of the attachment target <NUM>, at which the retroreflector <NUM> is attached, can be worked out by measuring the position (i.e., the spatial coordinates) <NUM> of the retroreflector <NUM> with the surveying device <NUM> (see <FIG>).

While such an example described above so far is such that the base member <NUM> of the target support tool 1c in <FIG> includes the first base body <NUM> alone, the base member <NUM> may include the first base body <NUM> and the second base body <NUM>, 5a as in the first and second embodiments. In this case, the first base body <NUM> may be provided on the outer surfaces <NUM> or the inner surfaces <NUM> of the second base body <NUM>, 5a.

When the first base body <NUM> is located on the outer surfaces <NUM> of the second base body <NUM>, 5a, for example, the bend part <NUM> of the second base body <NUM>, 5a has an opening that has a common axis with the support hole <NUM> of the first base body <NUM> (see <FIG>) and that allows the support part <NUM> of the retroreflective member <NUM> to insert and extract from the inner side. Accordingly, this enables the retroreflector <NUM> to be placed at the internal corner of the bend part of the base member <NUM> including the first base body <NUM> and the second base body <NUM>, 5a. The second base body <NUM>, 5a may be magnetically attached to the attachment target <NUM> by the magnets M1 on the first base body <NUM>. As an alternative, the second base body <NUM>, 5a may be magnetically attached to the attachment target <NUM> by the magnets M2, M3 on the second base body <NUM>, 5a, with the configuration of each detachable part <NUM>, 53a exchanged between the outer and inner surfaces <NUM> and <NUM>.

When the first base body <NUM> is located on the inner surfaces <NUM> of the second base body <NUM>, 5a, the second base body <NUM>, 5a may be magnetically attached to the attachment target <NUM> by the magnets M2, M3 on the second base body <NUM>, 5a, with the configurations of each detachable part <NUM>, 53a exchanged between the outer and inner surfaces <NUM> and <NUM>.

Next, a third embodiment of the present disclosure will be described. <FIG> is a perspective view of a target support tool 1d according to a third embodiment. In the target support tool 1d according to the third embodiment, the first and second arms 21A and 21B of the base member <NUM> described in the first and other embodiments connects to form various angles including a right angle with a hinge <NUM>, which is a pivotable bend part in place of the bend part <NUM>, which is provided in the first and the second embodiments. The first and second arms 21A and 21B are configured to pivot on the hinge <NUM>, for example, within an angle range of <NUM>° from +<NUM>° to -<NUM>°. For example, in an indoor space <NUM> in <FIG>, the target support tool 1d can be used to measure the position of a corner formed by wall surfaces with any of various angles, including a recessed corner 101a1 or a projected corner 101a2, as an attachment target <NUM>.

The retroreflector <NUM> of the target support tool 1d is placed at the pivot center of the hinge <NUM>. An example measurement of the attachment target <NUM> using the target support tool 1d will be described: First, measure the positions of the retroreflectors <NUM> attached to three or more corners (e.g., the projected corner 101a2 in a section S and the recessed corners 101a1 adjacent to the projected corner 101a2 on both sides in the example in <FIG>). Measured three points each at the three corners can be connected to draw two imaginary straight lines L, which are parallel to the outer surfaces 101a of the attachment target <NUM>. The imaginary straight lines L will also form an angle with both sides of the inner measurement point (at the position <NUM> in an enlarged view of the section S). By measuring the angle between the imaginary straight lines L, an angle of the projected corner 101a2 can determined. Since the angle of the projected corner 101a2 is equal to the sum of the angles of the first and second arms 21A and 21B, and a distance R2 between the imaginary straight lines L and the inner surface <NUM> is a known value, which is used as an offset between the projected corner 101a2 and the position of the retroreflector <NUM>, then the position of the projected corner 101a2 can be calculated.

Note that the retroreflector <NUM> may be placed at a position with an offset in the direction of the pivot axis of the hinge <NUM> (which is the upward or backward direction with respect to the target support tool 1d) by a predetermined distance in order to allow easy positional checking performed with the surveying device <NUM>. While the configurations described above so far are such that the target support tool 1d includes the first base body <NUM> alone, the target support tool 1d may include the first base body <NUM> and the second base body <NUM>, 5a that are pivotable by the hinge <NUM>.

Next, a fourth embodiment of the present disclosure will be described. <FIG> is a schematic view showing a configuration of a target support tool 1e according to a fourth embodiment. In the description of the target support tool 1e, the same reference characters as those of the target support tool <NUM> are used to represent equivalent configurations, and the detailed explanation thereof will be omitted or simplified. <FIG> illustrates a configuration of a second base body 5e but no first base body <NUM>.

In the target support tool <NUM> described above, each pivotable support part <NUM> supporting the corresponding magnet support part <NUM> proximal to the bend part <NUM>. In the target support tool 1e according to this embodiment, each pivotable support part <NUM> supporting the corresponding magnet support part <NUM> is located at one end (on the left in <FIG>). Specifically, the pivotable support part <NUM> of one of the magnet support parts <NUM> corresponding to the first arm 51A is located distally from the bend part <NUM>, while the pivotable support part <NUM> of the other magnet support part <NUM> corresponding to the second arm 51B is located proximally to the bend part <NUM>.

The target support tool 1e includes a string link member <NUM> connecting the magnet support part <NUM> on the first arm 51A and the magnet support part <NUM> on the second arm 51B. The string link member <NUM> is a long flexible string article, such as a wire. The string link member <NUM> is connected to a connector <NUM> located at the pivotable end of each magnet support part <NUM>. The string link member <NUM> passes through the outside corner (the projection) of the bend part <NUM>.

With the configuration of the target support tool 1e, for example, once the magnet support part <NUM> on the second arm 51B is operated in the closing direction, the string link member <NUM> operates the magnet support part <NUM> on the first arm 51A in the closing direction (i.e., the state of a target support tool 1e-<NUM>). Similarly, once the magnet support part <NUM> on the first arm 51A is operated in the opening direction, the string link member <NUM> operates the magnet support part <NUM> on the second arm 51B in the opening direction (i.e., the state of a target support tool 1e-<NUM>). In this manner, the target support tool 1e is configured such that the magnets M2 (i.e., the magnetic support part) on the first arm 51A and the magnets M2 (i.e., the magnetic support part) on the second arm 51B are attached and detached in coordination with each other.

If the pivotable support parts <NUM> are located at opposite sides of the magnet support parts <NUM>, the coordinate operation in the opening or closing direction can be controlled reversely. Each magnet support part <NUM> includes a releaser (e.g., the releaser <NUM>) that causes the magnet support part <NUM> to pivot in the opening direction against the magnetic force of the magnets M2 (the details are not illustrated).

As described above, the target support tool 1e according to the fourth embodiment is also magnetically attached by causing the second base body 5e to abut on the attachment target <NUM> at a planned attachment point and then causing each magnet support part <NUM> to pivot. Using the target support tool 1e allows to perform, at different timings, the positioning by abutting on the attachment target <NUM> and the magnetically attaching to the attachment target <NUM>, so that the retroreflector <NUM> can attach to the intended position precisely.

Next, a fifth embodiment of the present disclosure will be described. <FIG> is a schematic view showing a configuration of a target support tool 1f according to a fifth embodiment. In the description of the target support tool 1f, the same reference characters as those of the target support tool <NUM> are used to represent equivalent configurations, and the detailed explanation thereof will be omitted or simplified. <FIG> illustrates a configuration of a second base body 5f but no first base body <NUM>.

The target support tool 1f includes link members <NUM> and an operatable part <NUM>. Each link member <NUM> is in the shape of a long bar and is pivotably connected to one of the first arm 51A or the second arm 51B. The operatable part <NUM> can press and operate one end of the link member <NUM>. The link member <NUM> is pivotably connected to and supported by a support part <NUM> on each of the first and second arms 51A and 51B of the second base body 5f. The operatable part <NUM> is located near the bend part <NUM> and is movable in a direction toward and away from the second base body 5f by a guide (not illustrated). Note that the operatable part <NUM> according to this embodiment is biased in a direction away from the second base body 5f by a bias member (not illustrated) (e.g., a coil spring). The operatable part <NUM> is connected to (abuts on in the example in <FIG>) one end (closer to the bend part <NUM>) of each link member <NUM> at a point closer to the second base body 5f.

The other end (i.e., distal from the bend part <NUM>) of the link member <NUM> is engaged with an engageable part (e.g., a groove or an inside corner) <NUM> of each magnet support part <NUM>. The magnet support part <NUM> moves in the opening or closing direction in accordance with the position of the link member <NUM> engaged with the engageable part <NUM>. Note that the detailed configuration of each engageable part <NUM> is not illustrated.

With the configuration of the target support tool 1f, for example, once the operatable part <NUM> is pressed toward the second base body 5f, one end of the link member <NUM> moves toward the bend part <NUM> and the link member <NUM> pivots. The other end of the link member <NUM> then operates the corresponding magnet support part <NUM> in the opening direction (i.e., the state of a target support tool 1f-<NUM>). Once the pressing on the operatable part <NUM> is loosened, the biasing member biasing the operatable part <NUM> moves the operatable part <NUM> in the direction away from the second base body 5f. The pressing on the link member <NUM> is then loosened so that each magnet support part <NUM> is pivotable in the closing direction. When the second base body 5f abuts on the attachment target <NUM>, each magnet support part <NUM> pivots in the closing direction by the magnetic force of the magnets M2 acting onto the attachment target <NUM> (i.e., the state of a target support tool 1f-<NUM>).

Note that the operatable part <NUM> described above may be able to operate one end of each link member <NUM> by pulling. The operatable part <NUM> and each link member <NUM> may be configured such that one end of the link member <NUM> moves in a direction away from the second base body 5f in accordance with the movement of the operatable part <NUM>. The target support tool 1f may be configured such that each link member <NUM> and the operatable part <NUM>, and the link member <NUM> and each magnet support part <NUM> are connected by hinges using bearings with long holes and shaft cores.

The present disclosure is not limited to the configurations that have been described above. The operatable part <NUM> may be biased toward the second base body 5f by a bias member (not illustrated). In this case, with no external force applied, each magnet support part <NUM> is moved in the opening direction by the corresponding link member <NUM> (i.e., the state of the target support tool 1f-<NUM>). By operating (pressing or pulling) the operatable part <NUM> in a direction away from the second base body 5f, the magnet support part <NUM> is operated in the closing direction toward the attachment target <NUM> (the state of the target support tool <NUM> f-<NUM>).

Therefore, once the operatable part <NUM> moves each link member <NUM>, the other end of the link member <NUM> then operates the corresponding magnet support part <NUM> in the opening or closing direction. This provides such an effect that the magnets M2 (i.e., the magnetic support part) on the first arm 51A and the magnets M2 (i.e., the magnetic support part) on the second arm 51B can be attached and detached in coordination with each other.

As described above, the target support tool 1f according to the fifth embodiment is also magnetically attached by causing the second base body 5f to abut on the attachment target <NUM> at a planned attachment point and then causing each magnet support part <NUM> to pivot. Using the target support tool 1f allows to perform, at different timings, the positioning by abutting on the attachment target (e.g., a steel frame) <NUM> and the magnetically attaching to the attachment target <NUM>, so that the retroreflector <NUM> can attach to the intended position precisely.

Next, a sixth embodiment of the present disclosure will be described. <FIG> illustrates an example use case of a target support tool <NUM> attached to the attachment target <NUM> using arm members <NUM>. <FIG> illustrates the arm members <NUM> of the target support tool <NUM> according to the sixth embodiment. In the description of the target support tool <NUM>, the same reference numbers and characters as those of the target support tool <NUM> are used to represent equivalent configurations, and the detailed explanation thereof will be omitted or simplified.

The target support tool <NUM> includes the arm members <NUM> (i.e., a first arm member 9A and a second arm member 9B) instead of the second base body <NUM> according to the first embodiment. The arm members <NUM> are extension members (i.e., a third base body) that interpose between the first base body <NUM> and the attachment target <NUM>, and attach the first base body <NUM> to the attachment target <NUM> in a fixed manner. That is, a base member <NUM> includes the first base body <NUM> and the arm members (i.e., the third base body) <NUM>.

As illustrated in a plan view and a front view of <FIG>, each arm member <NUM> is formed in the shape of a substantially rectangular flat surface, and includes a first flat surface 9a and a second flat surface 9b opposite to the first flat surface 9a. Each arm member <NUM> is made of a magnetic material. The first and second flat surfaces 9a and 9b are parallel to each other. The distance (thickness of the plate-like shape) R3 between the first and second flat surfaces 9a and 9b is given in advance and known. Each arm member <NUM> includes a plurality of magnets (a magnetic support part) M4 on the second flat surface 9b. Each arm member <NUM> includes an operatable part <NUM> substantially in a U-shape at each long side edge.

Referring back to <FIG>, an example use case of the target support tool <NUM> using the arm members <NUM> will be described. First, the arm members <NUM> are attached to different adjacent outer surfaces 101a of the attachment target <NUM> by the magnetic force of the magnets M4, where each outer surface 101a faces the second flat surface 9b corresponding thereto. The arm members <NUM> are placed to form a substantially right angle. Accordingly, each outer surface 101a of the attachment target <NUM> will be extended by the corresponding first flat surface 9a at the corner 101b.

After that, the first base body <NUM> is attached to the first flat surface 9a of each arm member <NUM> by the magnetic force of the magnet M1 with the first flat surface 9a facing the corresponding inner surface <NUM>. Accordingly, the arm member <NUM> located on the first arm 41A of the first base body <NUM> functions as the first arm member 9A that is the first arm, while the arm member <NUM> located on the second arm 41B of the first base body <NUM> functions as the second arm member 9B that is the second arm. The base member <NUM> includes the first and second arms 21A and 21B indirectly connected via the first base body <NUM> to form the bend part <NUM> at which the retroreflector <NUM> can be placed. In this regard, base member <NUM> is different from the base member <NUM> etc. including the first and second arms 21A and 21B integrally and directly connected by the second base body <NUM>.

In this embodiment, a configuration has been described where the separate arm members <NUM> are used for the first and second arms 21A and 21B. With this configuration, even if one of the arm members <NUM> is leaningly attached to the corresponding outer surface 101a of the attachment target <NUM> at a tilt, the first flat surfaces 9a extend orthogonally to each other at the corner 101b without being influenced by the tilt. Depending on the curvature radius of the corner 101b of the attachment target <NUM>, the first and second arms 41A and 41B of the first base body <NUM> can or cannot abut on sufficient areas of the outer surfaces 101a. Even in the case where the first and second arms 41A and 41B of the first base body <NUM> cannot abut on sufficient areas of the outer surfaces 101a due to a large curvature radius of the corner 101b, using the arm members <NUM> as extension members allows the target support tool <NUM> (i.e., the retroreflector <NUM>) to be fixed at an intended position at the corner 101b with such a large curvature radius.

In this embodiment, since the base member <NUM> of the target support tool <NUM> includes the first base body <NUM> and the plurality of arm members <NUM>, the target support tool <NUM> can be compact as a whole.

The position of the center O of the attachment target <NUM> can be calculated as follows. In <FIG>, the retroreflector <NUM> of the target support tool <NUM> and the inner surface <NUM> of the second arm 41B (i.e., the first flat surface 9a) place at a distance X3 in-between in the first direction (i.e., the horizontal direction in <FIG>), while a distance Y3 is between the retroreflector <NUM> and the outer surface <NUM> of the first arm 41A (i.e., the first flat surface 9a) in the second direction (i.e., the vertical direction in <FIG>). The distances X3 and Y3 each are a design value, which has been given in advance and known. In addition, a distance R3 corresponds to the thickness of the plate-like shape of each arm member <NUM>, between the first and second flat surfaces 9a and 9b. The distance R3 is also a design value, which is given and known. By utilizing these known design values, the position of the center O of the attachment target <NUM> can be determined by measuring the position (i.e., in the spatial coordinates) <NUM> of the retroreflector <NUM> with the surveying device <NUM> (see <FIG>), and offsetting the coordinate in the first direction is offset from the position <NUM> by the sum of the distances X1, R3, and X3 and offsetting the coordinate in the second direction is offset from the position <NUM> by the sum of the distances Y1, R3, and Y3.

Next, a target support tool according to a seventh embodiment will be described. The target support tool according to the seventh embodiment includes, instead of the magnets M1 to M4, electromagnets as magnetic support parts magnetically attachable to the attachment target <NUM> in the first to six embodiments and the first to third variations. Some certain kinds of the electromagnets lose their magnetic force when powered on (when a current flows), and generate magnetic force when powered off. When these kinds of the electromagnets are applied in place of the magnets M1 to M4, each member may include a power source such as a battery, a driver that controls the power supply to the electromagnets, and a receiver that receives a control instruction to the driver.

Accordingly, the electromagnets (i.e., the magnetic support part) on the first arm 21A (41A, S1A, 51Aa) and the electromagnets (i.e., the magnetic support part) on the second arm 21B (41B, 51B, 51Ba) are electrically controllable to be attached and detached in coordinate with each other.

When the electromagnets are used as the magnetic support parts, the pivotable mechanism of the magnet support parts <NUM> can be excluded or omitted, which will simplify the configuration of the target support tool.

As described above, the target support tools <NUM> and 1a to <NUM> according to the present disclosure each include the base member <NUM> including the first and second arms 21A and 21B connectable to each other to form the bend part <NUM> therebetween; the magnetic support part (i.e., the magnets M1 to M4 or the electromagnets) on at least the first arm 21A; and the retroreflector <NUM> at the bend part <NUM> (or the hinge <NUM>) of the base member <NUM>. In addition, the configurations of the target support tools <NUM> and 1a to <NUM> have been described, each of which includes: the base member <NUM>, 2a, <NUM> including the first and second arms 21A and 21B directly or indirectly connected to form the bend part <NUM> at which the retroreflector <NUM> can be placed; and the magnetic support parts (i.e., the magnets M1 to M4 or electromagnets) on the first and second arms 21A and 21B. Accordingly, the retroreflector <NUM> is stably attachable to and detachable from any attachment target <NUM> using the magnetic support part(s). As a result, highly convenient target support tools <NUM> and 1a to 1d can be configured.

While the embodiments of the present disclosure have been described above as such, the aspects of the present disclosure are not limited to the embodiments.

For example, in the description of the embodiments, the distal ends <NUM> of the first and second arms 51A and 51B of the second base body <NUM> may bend to tilt the inner surfaces <NUM>. As an alternative, the distal ends <NUM> each may form a flat surface on the distal end with area large enough to stably abut on the flat surfaces of the attachment target <NUM>, as well as the distal ends <NUM> form flat on the same plane.

While the configurations described above so far are such that the first and second base bodies <NUM> and <NUM>, 5a of the target support tools <NUM> and 1a according to the first and second embodiments are attachable and detachable, the first and second base bodies <NUM> and <NUM>, 5a may be configured inseparably and integrally as a whole.

Each check mechanism <NUM> according to the first variation may have the following configuration: Once the target support tool <NUM> is attached to the attachment target <NUM>, the main body <NUM> of the movable member <NUM> will project beyond the corresponding outer surface <NUM>. Once the target support tool <NUM> is detached from the attachment target <NUM>, the movable member <NUM> will become substantially flush with the outer surface <NUM> or will enter and go into the housing <NUM>.

Each check mechanism <NUM> may include an electrical mechanism to detect the attachment target <NUM> attaching the target support tools <NUM> and 1a to 1d, and then perform notification electrically, such as light turning-on or illumination and slight electric shocks. In this case, the target support tools <NUM> and 1a to 1d may include a power source (e.g., a battery or a solar panel).

While the configurations described above in the embodiments so far are such that the magnets M1 to M3 are placed on each of the first and second arms 21A and 21B, the magnets M1 to M3 may be on at least either one of the first or second arms 21A or 21B. In this sense, the one with the magnets M1 to M3 may be defined as the first arm 21A.

While the first and second arms 21A and 21B have been described in different names for the sake of convenience, the configurations and names may be exchangeable between the first and second arms 21A and 21B in each of the target support tools <NUM> and 1a to 1d.

While the configuration examples described above so far are such that the first and second arms 21A and 21B are the linear bars, each arm may partially or fully include a curve. That is, the first and second arms 21A and 21B each may form in other shapes, which are suitable to be attachable in accordance with the corresponding outer surface 101a of the attachment target <NUM>. For example, if the outer surfaces 101a of the attachment target <NUM> curve like the side surface of a cylindrical columnar body, the inner surfaces of the first and second arms 21A and 21B each may include a curved arc region.

In each of the target support tools <NUM> and 1a, 1b, 1c, 1e, 1f, and <NUM>, the retroreflector <NUM> may include the position <NUM>, which is the measurement point, at the intersection between the center lines (i.e., the imaginary straight lines L) of the first and second arms 21A and 21B as illustrated in the target support tool 1d in <FIG>.

While the configurations described so far in the embodiments are such that the first and second base bodies <NUM> and <NUM>, 5a are attachable and detachable by the magnets M1, each base body may be attachable and detachable by other attachment and detachment mechanisms, such as screw fastening, recess-and-protrusion mating, or an engagement and disengagement mechanism using engagement claws.

Claim 1:
A target support tool (<NUM>, 1a to <NUM>) attachable to an attachment target (<NUM>) of a structure and configured to support a measurement target useable for measuring or surveying the structure, the target support tool comprising:
a base member (<NUM>, 2a, <NUM>) including a first arm (21A, 21Aa) and a second arm (21B, 21Ba) connected to each other to form a bend part (<NUM>) therebetween and allowing the measurement target to be placed at an external or internal corner of the bend part (<NUM>); and
a magnetic support part (M2) at least on the first arm (21A, 21Aa), the magnetic support part (M2) allowing attachment and detachment of the target support tool to the attachment target (<NUM>),
characterised in that
a distal end surface (<NUM>) of the first arm (21A, 21Aa) and a distal end surface (<NUM>) of the second arm (21B, 21Ba) form a same plane (B).