JP5847348B1 - Distance measuring instrument - Google Patents

Abstract

Provided is a distance measuring device that can be easily handled during distance measurement on a wall surface or a ceiling surface and can measure a distance without stress. A distance measuring instrument 1 includes an operating rod 2 gripped by a measurer P, a support member 3 that is rotatably mounted around a tip of the operating rod 2 with a rod-shaped member 2 as a rotating shaft, The rotating shaft 40 is supported by the support member 3, and includes a measuring wheel 4 that is offset so as not to overlap an extension line of the axis of the rod-shaped member 2, and a rotary encoder 5 that measures a moving distance from the rotation of the measuring wheel 4. . The axial direction of the rotation axis of the measurement wheel 4 of the distance measuring device 1 coincides with the tangential direction of the circular locus drawn by the center of the measurement wheel 2 when the measurement wheel 4 rotates together with the support member 3. [Selection] Figure 1

Description

  The present invention relates to a distance measuring device that measures a distance between two desired points.

  In order to measure a desired distance between two points mainly on the ground, a road, a track or the like, a wheel type distance measuring device called a road measure, a wheel counter, or the like is widely used. In general, such a wheel-type distance measuring device has a configuration in which a measuring wheel is attached to the tip of a rod-shaped operation rod provided with a gripping portion at one end. By rolling while walking between the two points, the distance between the two points is calculated from the rotating operation of the wheel, and the distance is displayed in an analog or digital manner. Patent Document 1 discloses a road measure in which a handshake handle is attached to the upper end of an operating rod and a measuring wheel is attached to the lower end side, and the moving distance of the wheel is measured using magnetism and digitally displayed.

  By the way, such a wheel-type distance measuring device can be applied not only to measuring the distance on the ground but also on a wall surface or a ceiling surface. For example, a concrete structure such as a building or a bridge girder may crack on the wall surface or ceiling surface due to deterioration over time. For repairing the crack, specify the position of the crack and measure the length of the crack. There is. Patent Document 2 discloses a wheel-type crack measuring instrument that measures the length of a crack generated in such a wall or ceiling.

JP-A-61-026816 JP 2009-174950 A

  When measuring the distance on the ground, the measurer measures the distance by rolling the wheel while walking along the measurement target location, so the positional relationship between the measurer and the measuring instrument is basically almost constant and does not change. In addition, since the positional relationship between the measuring instrument and the measurement target location is almost constant and does not change, measurement can be performed without paying much attention to the movement of the measuring instrument. On the other hand, unlike the measurement of the distance on the ground, when the distance is measured on the wall surface or the ceiling surface, the measurer cannot walk along the measurement target location.

  For example, when measuring the length of a crack on a wall surface or a ceiling surface using a crack measuring instrument disclosed in Patent Document 2, the measurer lifts the measuring instrument by hand, and the wheel portion becomes a measurement target location. It is necessary to move the measuring instrument while moving the measuring instrument itself by hand so that it rolls along. The cracks that occur on the wall and ceiling are not straight but often occur with irregular bending, so it is necessary to change the direction of the wheel in detail, especially near the boundary between the wall and the ground (floor) or on the wall When measuring the length of a crack that occurs near the boundary between the ceiling and the ceiling surface, the measuring instrument is required to have good handling so that the direction of the wheel can be changed in a narrow place.

  The present invention has been made in view of the above points, and provides a distance measuring device that can be easily handled during distance measurement on a wall surface or a ceiling surface and can measure a distance without stress. Objective.

  In order to achieve the above object, the present invention provides a rod-shaped member to be gripped by a measurer, a support member that is pivotally attached to the vicinity of the tip of the rod-shaped member with the rod-shaped member as a rotation shaft, A measuring wheel that is supported by a support member so that the rotating shaft is supported and that is offset so as not to overlap an extension line of the axis of the rod-shaped member; and a distance measuring unit that measures a moving distance from the rotation of the measuring wheel. Provided is a distance measuring device in which an axial direction of the rotating shaft of a wheel coincides with a tangential direction of a circular locus drawn by a center of the measuring wheel when the measuring wheel rotates together with the support member (Invention 1). .

  According to the above invention (Invention 1), the measuring wheel is rotatably attached around the rod-like member via the support member, so that the distance measuring device can trace the measurement target portion at the tip of the rod-like member. When the measurer moves, the measurement wheel rolls along the measurement target area so as to follow the movement of the tip of the rod-like member. Can be measured.

  In the said invention (invention 1), it is preferable that the relative position of the said measurement wheel with respect to the front-end | tip part of the said rod-shaped member is comprised so that it may vary using an elastic member (invention 2).

  When measuring the distance on the wall or ceiling surface, the positional relationship between the measurer and the distance measuring device changes during the measurement, and the positional relationship between the distance measuring device and the measurement object also changes. It is difficult to measure the measurement target location while maintaining a constant angle so that both measurement wheels are in contact with the wall surface and the ceiling surface. According to the above invention (Invention 2), even if the angle of the distance measuring device with respect to the measurement target location is changed, the relative position of the measuring wheel with respect to the tip of the rod-like member varies, so the rod-like member of the distance measuring device and the measurement are always performed. The distance measuring device can be moved so that both wheels touch the wall or ceiling surface.

  In the said invention (invention 2), the relative position of the said measurement wheel with respect to the front-end | tip part of the said rod-shaped member may fluctuate by changing the position of the said measurement wheel by the said elastic member (invention 3), The relative position of the measurement wheel with respect to the distal end portion of the rod-shaped member may vary by the position of the distal end portion of the rod-shaped member being varied by the elastic member (invention 4).

  In the said invention (invention 1-4), it is preferable that the marking mechanism is provided in the front-end | tip part of the said rod-shaped member (invention 5).

  According to the said invention (invention 5), the measurement object location can also be marked simultaneously with the measurement of the distance by tracing the measurement object location with the tip of the rod-shaped member.

  The distance measuring instrument of the present invention can be easily handled even when measuring the distance on the wall surface or ceiling surface, and can measure the distance without stress.

It is the schematic which shows the structure of the whole distance measuring device which concerns on 1st embodiment. It is a fragmentary sectional view which shows the structure of the operating rod tip part of the distance measuring device which concerns on the same embodiment. It is the schematic which shows the structure of the measurement wheel and support member of the distance measuring device which concerns on the same embodiment. It is explanatory drawing which shows a mode that distance measurement is carried out with the distance measuring device which concerns on the same embodiment. It is explanatory drawing which shows a mode that distance measurement is performed in the state in which the operating rod of the distance measuring device which concerns on the same embodiment inclined. It is explanatory drawing which shows a mode that the distance measurement of the curved ceiling surface is performed with the distance measuring device which concerns on the same embodiment. It is a partial schematic diagram which shows the structure of the front-end | tip part of the distance measuring device which concerns on 2nd embodiment. It is a partial schematic diagram which shows the structure of the front-end | tip part of the distance measuring device which concerns on 3rd embodiment. It is the schematic which shows the structure of the measurement wheel and support member of the distance measuring device which concerns on the same embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, in this application, it demonstrates on the assumption that the length of the crack which arose on the wall surface and ceiling surface of concrete buildings, such as a building and a bridge girder, and the crack itself used as this measuring object is called a measuring object part. However, a region where the crack is generated (a region including the crack and the periphery of the crack) may be referred to as a measurement target location.

[First embodiment]
FIG. 1 is a schematic diagram showing the overall configuration of a distance measuring device 1 according to the first embodiment of the present invention. The distance measuring instrument 1 according to the first embodiment of the present invention is attached to a rod-shaped operation rod 2 gripped by the measurer P and to the vicinity of the tip of the operation rod 2 so as to be rotatable about the operation rod 2 as a rotation axis. The support member 3, the rotation shaft 40 supported by the support member 3, and the measurement wheel 4 that is offset so as not to overlap the extension of the axis of the operating rod 2, and the rotational displacement amount of the measurement wheel 4 is an electrical signal. And a display / operation unit 6 for performing measurement operations such as starting and ending distance measurement and displaying measurement results. In the present embodiment, the rotary encoder 5 is used as a distance measuring means for measuring the moving distance from the rotation of the measuring wheel 4.

  The operation rod 2 is a cylindrical pipe-like rod-like member, and a resin grip 21 for the measurer P to hold is attached to one end of the operation rod main body 20. In the vicinity of the other end portion, an attachment portion 22 having a diameter smaller than that of the operation rod main body 20 is provided in order to attach the support member 3 in a freely rotatable manner. A choke 23 is attached as a marking mechanism for marking.

  As shown in FIG. 2, the vicinity of the distal end portion of the operation rod 2 includes a choke 23, a holding member 24, a cap member 25, and a coil spring 26, and the choke 23 is connected to the operation rod main body 20 via the holding member 24. It is mounted on the shaft center. In addition, a columnar cavity 201 is formed in the distal end portion of the operating rod main body 20 with the distal end side of the operating rod main body 20 being opened. The coil spring 26 is housed in the cavity 201 in a state where both ends are in contact with a part of the holding member 24 holding the choke 23, the bottom surface 241 of the holding member 24, and the bottom 202 of the cavity 201. A cap member 25 having an opening 251 at the center is attached to the distal end portion of the operating rod body 20, and the side of the holding member 24 that holds the choke 23 protrudes from the opening 251 of the cap member 25 together with the choke 23.

  In the present embodiment, when a force that pushes the choke 23 toward the operating rod body 20 is applied, the choke 23 moves into the operating rod body 20 together with the holding member 24, and when the pushing force is released, the coil spring 26 is restored. The choke 23 and the holding member 24 are configured to return to their original positions by force.

  In addition, by providing a marking mechanism such as the choke 23 at the tip of the operation rod 2, the measurement target location can be marked simultaneously with the distance measurement by tracing the measurement target location with the tip of the operation rod 2. Can do. As the marking mechanism, in addition to the chalk 23, a pen tip that bleeds out ink, paint, or the like may be used, or a spray nozzle that discharges paint may be used.

  As shown in FIG. 3, the support member 3 includes a base portion 30 provided with an attachment hole 301 that fits into the attachment portion 22 of the operating rod main body 20, and an arm portion for supporting the rotating shaft 40 of the measurement wheel 4. 31a and 31b. The arm portions 31a and 31b extend symmetrically and in parallel from the base portion 30, and the rotation shaft 40 of the measurement wheel 4 is passed and supported between the end portions of the arm portion 31a and the arm portion 31b. The inner diameter of the mounting hole 301 is slightly larger than the outer diameter of the mounting portion 22 of the operating rod main body 20, and the support member 3 can freely rotate about the operating rod 2 as a rotating shaft.

  The support member 3 is attached to the operation rod 2 with the cap member 25 detached from the operation rod main body 20 and first the fitting hole 301 of the base 30 of the support member 3 is fitted to the attachment portion 22 of the operation rod main body 20. In this state, the cap member 25 is fitted into the distal end portion of the operating rod main body 20 and fixed. The means for fixing the cap member 25 to the operation rod main body 20 is not particularly limited, such as welding or an adhesive. For example, the inner surface of the cap member 25 and the outer surface of the distal end portion of the operation rod main body 20 are threaded. It is preferable to adopt a screw cap method or the like, and to be configured so that the cap member 25 can be removed depending on the situation.

  The measurement wheel 4 is a disk-shaped wheel member whose outer peripheral surface in contact with the measurement target portion is made of rubber. The structure of the measuring wheel 4 is not particularly limited as long as the measuring wheel 4 has a disk shape that can rotate around the rotating shaft 40. For example, the measuring wheel 4 may be one in which the rotating shaft 40 is only attached to the center of a disk-shaped rubber member. Alternatively, a tire-like rubber member may be attached to the outer periphery of a stainless steel or aluminum wheel, and the rotating shaft 40 may be attached to the center of the wheel.

  The rotary encoder 5 converts the rotational displacement amount of the measuring wheel 4 into an electrical signal, and a known rotary encoder can be appropriately employed while taking into consideration the size and weight of the distance measuring device itself. One end of the rotating shaft 40 of the measuring wheel 4 is coupled to the rotary encoder 5, and a pulse signal is output according to the amount of rotational displacement of the rotating shaft 40. The pulse signal is processed to determine the moving distance of the measuring wheel 4. Desired. The obtained movement distance data of the measuring wheel 4 is transmitted to the transmission / reception unit (not shown) of the display / operation unit 6 via the transmission / reception unit (not shown) of the rotary encoder 5. For example, a known short-range wireless communication technology such as Bluetooth (registered trademark) can be used.

  The display / operation unit 6 includes a power switch 60 for turning on / off the power, a display 61 for displaying the measured distance, a measurement start button 62 to be pressed when starting the measurement, and a measurement to be pressed when ending the measurement. An end button 63, an integration button 64 that is pressed when integrating measured distances, and a clear button 65 that is pressed when resetting measured distance data are provided. The display 61 displays the distance in two stages, the upper part displays the distance measured by one measurement, and the lower part displays the total distance accumulated by pressing the integration button.

  The distance measuring instrument 1 according to the present embodiment has the above-described configuration, so that the axial direction of the rotating shaft 40 of the measuring wheel 4 is operated with the measuring wheel 4 together with the support member 3 and the operating rod 2 as a rotating shaft. This means that the center of the measurement wheel 4 coincides with the tangential direction of the circular locus drawn when rotating around the cage 2. That is, the measurement wheel 4 is rotatably attached around the operation rod 2 via the support member 3, but the measurement wheel 4 always rotates toward the operation rod 2. With this configuration, when the measurer P moves the distance measuring device 1 so as to trace the measurement target portion with the tip portion (that is, the choke 23) of the operation rod 2, the measurement wheel 4 moves to the tip of the operation rod 2. Since it rolls along the measurement target portion so as to follow the movement of the part, it can be easily handled even when measuring the distance on the wall surface or ceiling surface, and the distance can be measured without stress.

  A procedure for measuring the length of a crack in the ceiling surface 7 using the distance measuring device 1 will be described below. FIG. 4 is an explanatory diagram showing how the distance measuring device 1 performs distance measurement. First, the measurer P presses the power switch 60 to turn on the power, holds the grip 21 and lifts the distance measuring device 1 so that the distal end side of the operation rod 2 points to the ceiling surface 7. Here, the measurement start button 62 is pressed, and the choke 23 attached to the tip of the operation rod 2 is traced from the start point (measurement start point S) to the end point (measurement end point E) of the crack C, which is the measurement target location. The distance measuring device 1 is moved.

  The crack C is not a clean straight line or curve, but it bends in the middle or changes direction greatly. In the distance measuring instrument 1 according to the present embodiment, the crack C is traced with the choke 23 of the operation rod 2. The measuring wheel 4 rolls along the crack C so as to follow the movement of the choke 23 of the operating rod 2 in a track such as a wheel track T indicated by a two-dot chain line in FIG. Here, the measuring wheel 4 is not on the extension line (on the axis line) of the operation rod 2 but is offset so as not to overlap the extension line. T does not exactly match the crack C. In other words, the moving distance of the measuring wheel 4 does not exactly match the length of the crack C, but even if some measurement error occurs, it is easy to handle in the distance measurement on the ceiling surface or wall surface. The ease of handling is often given priority, and there is no particular problem.

  After measuring the length of the crack C by tracing with the choke 23 to the measurement end point E, the measurement end button 63 is pressed, the measurement distance displayed on the upper stage of the display 61 is recorded, and the next measurement target location Are measured in the same way.

  Here, when it is desired to integrate the measurement results of a plurality of measurement target portions, the integration button 64 is pressed after the measurement. When the integration button 64 is pressed, the measurement distance displayed in the upper part of the display 61 is integrated into the integration distance displayed in the lower part.

  If the clear button 65 is pressed before starting measurement of the next measurement target location, the measurement distance once returns to zero. If it is desired to clear the accumulated distance, the clear button 65 and the accumulated button 64 are pressed simultaneously.

  When measuring the distance on the wall surface or ceiling surface, the positional relationship between the measurer P and the distance measuring device 1 changes during the measurement, and the positional relationship between the distance measuring device 1 and the measurement target location also changes. It is difficult to measure the measurement target portion while maintaining a constant angle so that both the tip of the operation rod 2 and the measurement wheel 4 are in contact with the wall surface and the ceiling surface. In the distance measuring instrument 1 according to the present embodiment, the choke 23 is movable by the coil spring 26 and is configured such that the relative position of the measuring wheel 4 with respect to the tip of the operating rod 2 varies. Therefore, even if the operation rod 2 is tilted when measuring the distance on the ceiling surface, for example, as shown in FIG. 5, the choke 23 (the tip of the operation rod 2) and the measurement wheel 4 are always connected to the ceiling surface. You can create a state that touches. Further, even when the ceiling surface is curved, for example, as shown in FIG. 6, it is possible to create a state where the choke 23 (the tip of the operation rod 2) and the measurement wheel 4 are always in contact with the ceiling surface. .

  In the present embodiment, the relative position of the measurement wheel 4 with respect to the distal end portion of the operating rod 2 is changed by the position of the distal end portion of the operating rod 2 being changed by the coil spring 26. However, the present invention is not limited to this. For example, the relative position of the measurement wheel 4 with respect to the distal end portion of the operating rod 2 may be changed by changing the position of the measurement wheel 4. The distance measuring devices 1A and 1B according to the second embodiment and the third embodiment described below are configured such that the position of the measurement wheel 4 varies.

[Second Embodiment]
Next, a distance measuring device 1A according to the second embodiment of the present invention will be described. The distance measuring instrument 1A includes a rod-shaped operation rod 2A gripped by the measurer P, a support member 3 rotatably attached to the vicinity of the distal end portion of the operation rod 2A using the operation rod 2A as a rotation shaft, and a support member 3, the rotating shaft 40 is supported, and the measuring wheel 4 is offset so as not to overlap the extended line of the operating rod 2A, the rotary encoder 5 that converts the rotational displacement of the measuring wheel 4 into an electric signal, and the distance The display / operation unit 6 displays the measurement results while performing operations such as starting and ending the measurement. Compared to the distance measuring device 1 according to the first embodiment, the distance measuring device 1A is different only in the structure in the vicinity of the distal end portion of the operation rod 2A shown in FIG. The same. In addition, about the member which has the same structure as 1st embodiment, the same code | symbol is used and the description is abbreviate | omitted.

  As shown in FIG. 7, the vicinity of the distal end portion of the operating rod 2A includes a choke 23, a holding member 24A, a cap member 25A, and a coil spring 26A. The choke 23 is connected to the operating rod main body 20A via the holding member 24A. It is mounted on the shaft center. Between the operation rod main body 20A and the cap member 25A, an attachment portion 22A having a diameter smaller than that of the operation rod main body 20A is provided to rotatably attach the support member 3. In addition to the support member 3, a coil spring 26A is also attached to the attachment portion 22A. First, the coil portion of the coil spring 26A is passed through the attachment portion 22A, and the attachment hole 301 of the support member 3 is provided above the coil spring 26A. Is fitted into the attachment portion 22A, and the cap member 25A is attached and fixed thereon.

  In the present embodiment, when a force that pushes the measurement wheel 4 toward the operation rod main body 20A acts, the support member 3 connected to the measurement wheel 4 slides in the direction of the operation rod main body 20A along the attachment portion 22A. The measurement wheel 4 also moves in the direction of the operating rod main body 20A together with the support member 3, and when the pushing force is released, the measurement wheel 4 and the support member 3 are returned to their original positions by the restoring force of the coil spring 26A. Yes. By being configured in this way, in the distance measuring instrument 1A according to the present embodiment, the measurement wheel 4 is movable by the coil spring 26A, and the measurement wheel 4 with respect to the tip of the operating rod 2A is moved. Since the relative position is configured to vary, the choke 23 (the tip of the operation rod 2A) and the measurement wheel 4 always remain even if the operation rod 2 is tilted when measuring the distance on the ceiling surface. Can create a state of touching the ceiling surface. Further, even when the ceiling surface is curved, it is possible to always create a state in which the choke 23 (the tip of the operating rod 2A) and the measurement wheel 4 are in contact with the ceiling surface.

[Third embodiment]
Next, a distance measuring device 1B according to the third embodiment of the present invention will be described. The distance measuring device 1B includes a rod-shaped operation rod 2B gripped by the measurer P, a support member 3B that is rotatably attached to the vicinity of the distal end portion of the operation rod 2B with the operation rod 2B as a rotation shaft, and a support member The rotating wheel 40 is supported by 3B and is offset so as not to overlap the extension of the axis of the operating rod 2B, the rotary encoder 5 that converts the rotational displacement of the measuring wheel 4 into an electrical signal, and the distance The display / operation unit 6 displays the measurement results while performing operations such as starting and ending the measurement. The distance measuring instrument 1B differs from the distance measuring instrument 1 according to the first embodiment and the distance measuring instrument 1A according to the second embodiment only in the structure near the tip of the operation rod 2B shown in FIG. Other configurations are the same as those in the first embodiment and the second embodiment. In addition, about the member which has the same structure as 1st embodiment or 2nd embodiment, the same code | symbol is used and the description is abbreviate | omitted.

  As shown in FIG. 8, the vicinity of the tip of the operating rod 2B is composed of a choke 23, a holding member 24B, and a cap member 25B. The choke 23 is placed on the axis of the operating rod main body 20B via the holding member 24B. It is attached. Between the operation rod main body 20B and the cap member 25B, an attachment portion 22B having a diameter smaller than that of the operation rod main body 20B is provided to rotatably attach the support member 3B.

  As shown in FIG. 9, the support member 3 </ b> B includes a cylindrical member 30 </ b> B that fits into the attachment portion 22 </ b> B of the operation rod main body 20 </ b> B, arm members 31 </ b> Ba and 31 </ b> Bb for supporting the rotating shaft 40 of the measurement wheel 4, It consists of pin members 32Ba and 32Bb for rotatably mounting 31Ba and 31Bb to the cylindrical member 30B, and torsion springs 33Ba and 33Bb. The arm members 31Ba and 31Bb are shaped like a side view, and the rotation shaft 40 of the measurement wheel 4 is passed and supported between the respective ends of the arm member 31Ba and the arm member 31Bb. The inner diameter of the cylindrical member 30B is slightly larger than the outer diameter of the mounting portion 22B of the operation rod main body 20B, and the support member 3B can freely rotate about the operation rod 2 as a rotation axis.

  The torsion springs 33Ba and 33Bb pass through the pin members 32Ba and 32Bb through the respective coil portions, and one of the two linear portions extending from the coil portion is one of the locking members 311Ba provided on the inner surface of the arm members 31Ba and 31Bb. , 311Bb, and the other one is brought into contact with the locking members 301Ba and 301Bb provided on the side surface of the cylindrical member 30B, so that the arm members 31Ba and 31Bb are positioned relative to the cylindrical member 30B as shown in FIG. And become stable.

  In the present embodiment, when a force that pushes the measurement wheel 4 toward the operating rod main body 20B is applied, the arm members 31Ba and 31Bb rotate with respect to the cylindrical member 30B using the pin members 32Ba and 32Bb as rotation fulcrums. Is rotated in the direction of the operating rod main body 20B, and when the pushing force is released, the measuring wheel 4 and the arm members 31Ba, 31Bb return to their original positions by the restoring force of the torsion springs 33Ba, 33Bb. By being configured in this way, in the distance measuring instrument 1B according to the present embodiment, the measuring wheel 4 is movable by the torsion springs 33Ba and 33Bb, and the measuring wheel with respect to the tip of the operating rod 2B is measured. Since the relative position of 4 is configured to vary, the choke 23 (the tip of the operating rod 2B) and the measuring wheel always remain even if the operating rod 2B is tilted when measuring the distance on the ceiling surface. 4 can be brought into contact with the ceiling surface. Further, even when the ceiling surface is curved, it is possible to create a state in which the choke 23 (the tip of the operating rod 2B) and the measurement wheel 4 are always in contact with the ceiling surface.

  The distance measuring device according to the present invention has been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and various modifications can be made.

  For example, in each of the above embodiments, each of the distance measuring devices 1, 1 </ b> A, 1 </ b> B has a marking mechanism at the tip of the operation rod 2, but the present invention is not limited to this. The part may not have a marking mechanism, and may include an illumination mechanism instead of the marking mechanism, or may include both a marking mechanism and an illumination mechanism. If an illumination mechanism is provided at the tip of the operation rod 2, the measurer P can clearly grasp the measurement target location even in a dark work place, so that the ease of handling is improved.

  In each of the above embodiments, the distance measuring devices 1, 1 </ b> A, and 1 </ b> B are configured such that the relative position of the measuring wheel 4 with respect to the distal end portion of the operating rod 2 is changed using an elastic member such as a coil spring 26. However, the present invention is not limited to this, and an elastic member is not used, and the relative position of the measurement wheel 4 with respect to the distal end portion of the operating rod 2 may not be changed.

  Further, in each of the above embodiments, the rotary encoder 5 is used as the distance measuring means for measuring the moving distance from the rotation of the measuring wheel 4, but the moving distance can be measured from the rotating of the measuring wheel 4. For example, a gear-type mechanical counter used in a known wheel-type distance measuring device can be used. The detection method is not limited as long as the rotary angle of the measurement wheel can be detected. For example, as the contact type, an energization type rotary encoder can be used. As the non-contact type, an optical or magnetic rotary encoder can be used.

1, 1A, 1B Distance measuring instrument 2, 2A, 2B Control rod 3, 3B Support member 4 Measuring wheel 5 Rotary encoder 6 Display / operating unit 7 Ceiling surface S Measurement start point E Measurement end point C Crack

Claims (4)

A rod-shaped member having a tip that is gripped by a measurer and brought into contact with a measurement target location ;
A support member that is pivotally attached to the vicinity of the tip of the rod-shaped member with the rod-shaped member as a pivot shaft;
A measurement wheel that is biased to the rod-shaped member via the support member, and is brought into contact with a measurement target location at a position different from the tip of the rod-shaped member ;
A distance measuring means for measuring a moving distance from rotation of the measuring wheel;
The rotating shaft of the measurement wheel is supported by the support member,
The axial direction of the rotating shaft of the measuring wheel coincides with the tangential direction of a circular locus drawn by the center of the measuring wheel when the measuring wheel rotates together with the support member ;
It said distance measuring device relative positions of the measuring wheel against the tip of the rod is Ru is configured to vary with the elastic member. The distance measuring device according to claim 1 , wherein the relative position of the measurement wheel with respect to the tip end portion of the rod-shaped member varies due to the position of the measurement wheel being varied by the elastic member. 2. The distance measuring device according to claim 1 , wherein a relative position of the measurement wheel with respect to a tip end portion of the rod-like member changes due to a change in the position of the tip end portion of the rod-like member by the elastic member. . Wherein the marking mechanism is provided on the distal end portion of the rod-shaped member, the distance measuring instrument according to any one of claims 1-3.

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