KR102445552B1 - Marking Stick for Structural Safety Inspection - Google Patents

Abstract

The present invention relates to a marking rod for structural safety inspection, which comprises: a cylindrical pipe (20) having a certain length; a ring-shaped spring seat (21) installed on an inner circumferential surface of the pipe (20); a holder housing (30) which is inserted into the center of the spring seat (21) to be concentric with the pipe (20) and moves in a longitudinal direction of the pipe (20); a centering piston (31) installed on an outer circumferential surface of a lower end of the holder housing (30) at a distance from the spring seat (21) and maintaining the center of the holder housing (30) while moving with the holder housing (30) inside the pipe (20); a pen pressure spring (32) which is installed between the spring seat (21) and the centering piston (31) and applies a pen pressure to a chalk (12) toward the surface of a structure (10) by applying an elastic force in a direction in which the holder housing (30) is drawn out (32); a stop ring (33) installed on the outer circumferential surface of an upper end of the holder housing (30) and caught on an upper surface of the spring seat (21) to keep a withdrawal distance of the holder housing (30) constant; guide long holes (22) formed in the pipe (20) to penetrate in and out of the pipe (20); a button extension rod (40) installed on an upper end of a release button (34) provided in the holder housing (30); and a release shaft (41) which penetrates the button extension rod (40) in a direction perpendicular to an axis and is exposed to the outside of the pipe (20) through the guide long hole (22). The present invention can prevent breakage and excessive abrasion of the chalk.

Description

Marking Stick for Structural Safety Inspection

The present invention relates to an indicator rod for safety inspection of a structure, and more particularly, to an indicator rod for safety inspection of a structure in which pen pressure applied to chalk can be arbitrarily set.

In general, architectural structures or civil structures have a life-and-death cycle consisting of natural collapse or artificial demolition or premature collapse due to poor construction or damage according to the lapse of service life through the design stage, construction stage, and use stage.

Among these structures, the causes of collapse of concrete structures are partly natural due to the elapse of service life, but most of them are deeply related to the deformation of structures due to external forces acting on the structures during the construction or use phase.

Among these deformations of concrete structures, cracks occurring in structures are difficult to detect early due to the small width of the cracks, and the progress of cracks is generally very slow. Although it is easy to overlook this by judging it, any cracks can cause structural defects in the structure and eventually lead to the collapse of the structure. Detecting such cracks at an early stage and using a marker such as chalk to mark the defective part of the structure will help the repair work of the structure.

In addition, in the steel structure, corrosion due to the penetration of moisture or salt due to the peeling of the coating film reduces the lifespan of the steel structure. Marking the defective part of the structure using a marking tool such as chalk helps in the repair work of the structure.

A prior art for displaying a defect site generated in such a structure has been proposed as Korean Patent Registration No. 10-2234694. Such a prior art has a structure to hold chalk by using a collet chuck installed at the end of a structure inspection indicator bar that can be stretched in length in a telescopic form.

However, since this prior art has a structure in which the force transmitted to the chalk through the structure inspection bar is transmitted to the chalk as it is, there is a problem in that the chalk is easily broken or severely worn when excessive pressure is transmitted to the chalk. When the length of the inspection bar is elongated and marked on the surface of the structure, it is difficult to detect the pressure of the pen applied to the chalk. In this case, there is a problem that the breakage rate of the chalk is greatly increased.

In addition, the prior art has a very inconvenient problem in use because the force is transmitted from the cover to the collet chuck only in a state in which the elongated structure check indicator bar is briefly folded when the chalk is exchanged or the protrusion length of the chalk is adjusted.

Domestic Registered Patent No. 10-2234694 (Announcement Date: 2021.04.01.) Domestic Registered Patent No. 10-2327812 (Announcement Date: 2021.11.18.) Domestic Registered Patent No. 10-1792637 (Announcement Date: 2017.11.01.) Domestic Registered Patent No. 10-2030072 (Announcement Date 2019.10.08.) Domestic Registered Patent No. 10-2074434 (published on 2020.02.06.) Domestic Registered Patent No. 10-2137106 (published on July 23, 2020) Domestic Registered Patent No. 10-2116358 (Announcement date: 2020.05.28.) Domestic Registered Patent No. 10-2227861 (published on March 15, 2021) Domestic Registered Patent No. 10-2325802 (Announcement Date: 2021.11.12.) Domestic Registered Patent No. 10-2325803 (Announcement Date: 2021.11.12.) Domestic Registered Patent No. 10-2335964 (Announcement Date: 2021.12.06.) Domestic Registered Patent No. 10-1774361 (Announcement Date 2017.09.04.)

The present invention has been made to solve the above problems, and an object of the present invention is to provide an indicator bar for safety inspection of structures that can prevent breakage and excessive abrasion of chalk, and can set pen pressure applied to chalk arbitrarily .

In order to achieve the object of the present invention, the indicator for structural safety inspection includes: a cylinder-shaped pipe having a predetermined length; A ring-shaped spring seat installed on the inner circumferential surface of the pipe; The holder housing is inserted into the center of the spring sheet to form concentric with the pipe, and moves along the longitudinal direction of the pipe; A centering piston installed on the outer peripheral surface of the lower end of the holder housing at a distance from the spring seat, and moving together with the holder housing in the pipe to maintain the center of the holder housing; a pen pressure spring that is installed between the spring seat and the centering piston and applies a pen pressure to the chalk toward the surface of the structure by applying an elastic force in the direction of drawing out the holder housing; a stop ring installed on the outer circumferential surface of the upper end of the holder housing, while being caught on the upper surface of the spring seat, to make a constant withdrawal distance of the holder housing; a guide long hole formed in the pipe to penetrate in and out of the pipe; a button extension rod installed on the top of the release button provided in the holder housing; It has a feature that it includes a release shaft that penetrates the button extension bar in a direction perpendicular to the axis and is exposed to the outside of the pipe through the guide long hole.

The present invention is a pivot pin installed in a pipe parallel to the release shaft; a release lever rotating around the pivot pin; a slide inclined surface formed on the release lever and meeting the release shaft when the release lever is rotated in the release direction to move the release shaft in the release direction; an interference preventing surface formed on the release lever and spaced apart from the release shaft at a regular interval when the release lever is stopped at the return position; spring shackles installed on the pipe; a stop bar caught on the outer circumferential surface of the pipe when the release lever is returned; a return spring having both ends caught on the spring latch and the stopper, and applying an elastic force in a return direction opposite to the release of the release lever; It is formed to pass through the inside and outside of the pipe, and it is characterized by including a spring extension hole for drawing out a part of the return spring located inside the pipe.

The present invention relates to a pipe clamp having an open-loop type clamp hole into which a pipe is inserted, and having a slit of a certain width extending from the surface to the clamp hole; Clamp bolt for fixing the pipe clamp at any position on the pipe by narrowing the width of the slit; a wheel bracket installed on one side of the pipe clamp and extending toward the lower end of the pipe at a predetermined distance from the pipe; It is installed on one side of the lower end of the wheel bracket, and has a feature including a wheel that rolls along the surface of the structure.

As described above, the present invention moves the pipe clamp 60 in which the wheel 70 is installed along the pipe 20, so that the retreat length ( By adjusting L), there is an effect that the pip pressure applied to the chalk 12 from the pen pressure spring 32 can be arbitrarily set.

Since pressure is applied to the chalk 12 only by the pen pressure spring 32 while the wheel 70 is in contact with the surface of the structure 10, it is possible to block excessive pressure from being transmitted to the chalk 12. There is an effect that can prevent damage and excessive wear of the chalk 12 .

It is configured to release the bite of the collet chuck 35 holding the chalk 12 by pressing the pressing part 50p provided on the release lever 50 with your thumb while holding the pipe 20 by hand. Therefore, there is an effect that can replace the chalk 12 or adjust the protrusion length of the chalk 12 quickly and conveniently.

There is an effect that can prevent the release shaft 41 rising along the guide long hole 22 by the interference prevention surface 50k formed on the release lever 50 from interfering with the release lever 50 .

There is an effect that can prevent the return spring 55 from interfering with the pipe 20 by the spring pull-out hole 23 formed in the pipe 20 while the return spring 55 is expanded and contracted and rotated.

1 is an exploded perspective view according to the present invention;
2 is an enlarged perspective view of the main part according to the present invention;
3 is an enlarged cross-sectional view of the main part according to the present invention;
4 is a cross-sectional view showing that the bite of chalk is released by the release lever according to the present invention;
5 is a cross-sectional view showing a pen pressure applied to chalk by a pen pressure spring in a state in which the wheel and chalk according to the present invention are in close contact with the surface of the structure;
Figure 6 is an exploded perspective view showing the separation of the pipe clamp from the pipe according to the present invention
7 is an exploded perspective view showing a pipe clamp, a wheel bracket, a wheel and peripheral components according to the present invention;
8 is a cross-sectional view taken along line A-A' of FIG. 4;
9 is an exploded perspective view showing a button extension rod, a release shaft, a holder housing and peripheral components according to the present invention;
10 is an exploded perspective view showing a release lever, a spring latch, a stop bar, and peripheral components thereof according to the present invention;
11 is a cross-sectional view showing a holder housing, a collet chuck, and peripheral components thereof according to the present invention;
12 is a partially enlarged cross-sectional view showing another embodiment for installing a spring seat according to the present invention to a pipe
13 is a partially enlarged cross-sectional view showing the coupling of the pipe and the extension pipe according to the present invention;
14 is a perspective view showing marking on the ceiling of a structure using the present invention;

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings 1 to 14.

The present invention is a pipe 20 in the form of a cylinder having a constant length; a ring-shaped spring seat 21 installed on the inner circumferential surface of the pipe 20; It is inserted into the center of the spring sheet 21 to form concentric with the pipe 20 and includes a holder housing 30 that moves along the longitudinal direction of the pipe 20 .

The pipe 20 may be formed in a straight shape having a certain length, and may be formed of a metal such as a stainless alloy or a non-ferrous metal such as an aluminum alloy, or may be formed of plastic as a material.

The spring sheet 21 may be molded in the form of an annular ring, and may be permanently adhered to the inner circumferential surface of the pipe 20 so as not to move inside the pipe 20, as another example shown in FIG. 12 . Positioning holes 20a and 21a whose center of the hole coincides with each other are formed in the spring sheet 21 and the pipe 20 in the direction perpendicular to the axis, respectively, and then the spring sheet 21 is inserted into the pipe 20 to position The spring sheet 21 may be fixed to the pipe 20 by making the centers of the crystal holes 20a and 21a coincide with each other and press-fitting the fixing pins 27 into the positioning holes 20a and 21a.

As shown in FIG. 11 , the holder housing 30 , the collet chuck 35 and the holder spring 36 are for biting and holding the chalk 12 , and a release button 34 integrally formed on the upper end of the collet chuck 35 . ) is applied to move the collet chuck 35 downward, the holder spring 36 located inside is compressed, and the lower end of the collet chuck 35 protrudes downward.

At this time, as shown in the enlarged view of FIG. 11 , the lower end of the collet chuck 35 is spaced apart from the chalk 12 as it opens in a direction away from the center by the elastic restoring force, and the bite of the chalk 12 is released, in this state By freely moving the chalk 12 , the protruding length of the chalk 12 can be adjusted or replaced with a new chalk 12 .

After that, when the external force is removed from the release button 34 that was applying the force downward, the built-in holder spring 36 is extended by its own elastic restoring force, and the lower end of the collet chuck 35 enters the holder housing 30 . It will bite the chalk (12).

At this time, the inner peripheral surface of the lower end of the holder housing 30 is formed as a cone-shaped hole having a constant taper angle R as shown in the enlarged view of FIG. 11, and the outer peripheral surface of the lower end of the collet chuck 35 has the same taper angle ( Since it is formed in a cone shape with R), as the collet chuck 35 rises by the holder spring 36, the lower end of the collet chuck 35 gathers at the center and strongly presses the outer peripheral surface of the chalk and chalk 12 to hold it. do.

The pipe 20 may be configured to extend the length by connecting at least one extension pipe 24 as shown in FIGS. 1, 13 and 14 .

As such, the configuration for connecting the pipe 20 and the extension pipe 24 is press-fitted into the center of the connection portion of the pipe 20 and the extension pipe 24, for example, as shown in FIGS. 1 and 13 , or An annular ring 81 ( 91) can be configured.

In addition, a centering hole 92 and a female threaded part 93 are formed in the center of the insert part 90 and the annular ring 91 inserted into the end of the pipe 20, and inserted into the end of the extension pipe 24 A centering rod 82 and a stud bolt 83 may be formed at the center of the insert portion 80 and the annular ring 81 .

When the centering rod 82 is inserted into the centering hole 92, the center of the pipe 20 and the extension pipe 24 are aligned, and when the stud bolt 83 is coupled to the female threaded part 93, it extends with the pipe 20. The pipe 24 remains coupled.

As another example, an extension pipe (not shown) that can adjust the length in a telescopic form may be connected to the end of the pipe 20 .

When the marking line 13 is marked on the ceiling of the structure 10 as shown in the accompanying drawings Fig. 14, the extension pipe 24 and the pipe 20 are turned upside down and then the wheel 70 is in close contact with the ceiling surface, While the wheel 70 faces the ceiling surface, the chalk 12 is pressurized, the upper part of the holder housing 30 enters the inside of the pipe 20, and the pen pressure spring 32 is compressed.

At this time, when the upper end of the chalk 12 and the upper apex of the wheel 70 coincide, the movement of the chalk 12 and the holder housing 30 is stopped, and a constant pen pressure is applied to the chalk 12 by the pen pressure spring 32 . applied

The present invention is installed on the outer peripheral surface of the lower end of the holder housing 30 at a distance from the spring seat 21, and moves together with the holder housing 30 inside the pipe 20. A centering to maintain the center of the holder housing 30 piston 31; A pen pressure spring installed between the spring seat 21 and the centering piston 31 and applying a pen pressure to the chalk 12 toward the surface of the structure 10 by applying an elastic force in the direction of drawing out the holder housing 30 . (32).

The centering piston 31 may be permanently bonded or adhered to the lower outer peripheral surface of the holder housing 30 as shown in FIGS. 3 to 5 , 9 and 11 .

The pen pressure spring 32 may be composed of, for example, a compression coil spring formed by winding a spring steel wire spirally, and when the chalk 12 in contact with the surface of the structure 10 receives pressure, the pen pressure spring 32 ) is compressed, and a constant pen pressure is applied to the chalk 12 by the pen pressure spring 32 while stopping when the lower end of the chalk 12 and the apex of the lower end of the wheel 70 coincide.

The present invention is a stop ring (33) installed on the outer peripheral surface of the upper end of the holder housing (30), while being caught on the upper surface of the spring seat (21) to make a constant withdrawal distance of the holder housing (30); a guide long hole 22 formed in the pipe 20 so as to penetrate into and out of the pipe 20; a button extension rod 40 installed on the upper end of the release button 34 provided in the holder housing 30; It includes a release shaft 41 that penetrates the button extension rod 40 in a direction perpendicular to the axis, and is exposed to the outside of the pipe 20 through the guide long hole 22 .

Before installing the stop ring 33 in the holder housing 30, install the pen pressure spring 32 between the spring seat 21 and the centering piston 31 in advance, and then install the stop ring 33 in the holder housing 30. install on

At this time, as shown in FIGS. 3 to 5 , 9 and 11 , an adhesive is applied to a portion of the upper outer circumferential surface of the holder housing 30 , and then the stop ring 33 is assembled to the holder housing 30 , the stop ring 33 ) is permanently attached to the holder housing (30).

The guide long hole 22 may be configured as a pair formed at the front and rear sides of the pipe 20 , and guides the release shaft 41 in the vertical direction by the guide long hole 22 .

The button extension rod 40 serves to extend the length of the release button 34 and reinforce the strength of the release button 34 at the same time. A press-fitting portion 44 press-fitted with a release button 34 may be formed at the lower end of the button extension rod 40 .

When an adhesive is applied to the outer peripheral surface of the press-in portion 44 and then press-fitted into the center of the release button 34 , the button extension rod 40 can be prevented from being separated from the release button 34 .

The release shaft 41 may be composed of a metal round bar having a constant diameter, and both ends of the release shaft 41 are exposed to the outside of the pipe 20 through the guide long hole 22 .

The release shaft 41 may be press-fitted into the press-fitting hole 40h formed in the button extension rod 40 as shown in FIGS. 3, 9 and 11 . A tap hole 40t is formed at the center of the upper end of the button extension rod 40 through the press-in hole 40h, and a chamfer 42 is formed on the outer peripheral surface of the release shaft 41, and then the release shaft 41) After press-fitting into the press-in hole 40h, the release shaft 41 can be prevented from being separated from the button extension rod 40 by coupling and tightening the set screw 43 to the tapped hole 40t.

The present invention is a pivot pin 51 installed on the pipe 20 in parallel with the release shaft 41; a release lever 50 that is rotated around the pivot pin 51; It is formed on the release lever 50, and includes a slide inclined surface 52 that meets the release shaft 41 when the release lever 50 is rotated in the release direction and moves the release shaft 41 in the release direction.

The release lever 50 may be formed using, for example, a metal plate having a certain thickness as a material, and the release lever 50 is a pivot pin 51 installed at the top as shown in FIGS. 2, 6 and 10 . A pair of pivoting arms (50a) rotated around and spaced apart from each other and having a pipe 20 positioned therebetween, and a pressing part connecting the pivoting arms (50a) across the pivoting arm (50a) (50p) and the spring driving arm 50s extending in parallel from one edge of the pivot arm 50a toward the spring extension hole 23 and transmitting the elastic restoring force transmitted from the return spring 55 to the pivot arm 50a ) can be configured.

The pivot pin 51 is inserted and supported in the pin holes 50h and 20h respectively formed in the upper portion of the pivoting arm 50a and the pipe 20, as shown in FIG. 10, and the outer peripheral surface of both ends of the pivot pin 51 It is possible to prevent separation of the pivot pin 51 by inserting the snap ring 57 into the stop groove 51g formed in the .

The present invention is formed on the release lever 50, when the release lever 50 is stopped at the return position, the release shaft 41 and the interference prevention surface (50k) spaced apart at regular intervals; a spring latch 53 installed on the pipe 20; When the release lever 50 is returned, it includes a stop bar 54 caught on the outer circumferential surface of the pipe 20 .

The anti-interference surface 50k may be formed on the pivot arm 50a formed on the release lever 50 .

The stop bar 54 may be configured as, for example, a bolt having a head, but is not limited thereto, and may be configured using a round bar-shaped metal bar.

The stop bar 54 can be inserted and supported in the through hole 59 formed in the spring driving arm 50s, and when the stop bar 54 is composed of a bolt, the lock nut 58 is coupled to the stop bar 54 . When the stop bar 54 can be prevented from being separated from the spring driving arm (50s).

The present invention is a return spring 55, both ends are caught on the spring latch 53 and the stop bar 54, applying an elastic force in the return direction opposite to the release of the release lever 50; It is formed to pass through the inside and outside of the pipe 20 and includes a spring extension hole 23 for drawing out a portion of the return spring 55 located inside the pipe 20 to the outside.

The return spring 55 may be composed of a tension coil spring made by winding a spring steel wire spirally, and a ring (symbol omitted) caught on the spring clasp 53 and the stop bar 54 is provided at both ends of the return spring 55 . to form

The spring extension hole 23 may be formed to have a constant width in the horizontal direction and a constant length in the vertical direction, for example, and the spring extension hole 23 may be formed in the vertical direction in the process of the return spring 55 being expanded and contracted. It serves to prevent the return spring 55 from interfering with the pipe 20 when it is rotated at a certain angle.

A washer-type spacer 56 may be installed between the pivot arm 50a provided in the release lever 50 and the pipe 20, and as shown in the enlarged view of FIG. 3 and FIG. 10, the spring latch 53 ) is formed in the pipe 20, an insertion hole 25 for installing install on foot

The present invention is a pipe clamp 60 having an open-loop type clamp hole 61 into which the pipe 20 is inserted, and having a slit 62 of a constant width leading to the clamp hole 61 from the surface; It includes a clamp bolt 63 that narrows the width of the slit 62 to fix the pipe clamp 60 to an arbitrary position of the pipe 20 .

The pipe clamp 60 may be molded from metal or plastic as a material, and is for determining the height of the wheel 70 by biting the outer circumferential surface of the pipe 20 by the pipe clamp 60, as shown in FIG. As shown, if the retreat length L of the chalk 12 corresponding to the length between the lower end of the chalk 12 and the vertex of the lower end of the wheel 70 is set, the pen pressure applied to the chalk 12 can be arbitrarily set.

As shown in FIGS. 7 and 8, the pipe clamp 60 has a counter-bore hole 60c formed on one side with a slit 62 therebetween, and a screw forming a straight line with the counter-bore hole 60c on the other side. After the hole 60n is formed, the clamp bolt 63 is coupled to the screw hole 60n through the counter bore hole 60c and tightened, so that the pipe clamp 60 is fixed by pressing the outer circumferential surface of the pipe 20 .

In addition, when the clamp bolt 63 is loosened, the pipe clamp 60 can be freely moved in the vertical direction along the outer circumferential surface of the pipe 20 , and at this time, the height of the wheel 70 can be adjusted.

That is, if the height of the wheel 70 is adjusted by moving the pipe clamp 60 as shown in FIG. 3 , the retreat length L between the lower end of the chalk 12 and the lower vertex of the wheel 70 can be arbitrarily set. be able to

The present invention is installed on one side of the pipe clamp 60, a wheel bracket 64 extending toward the lower end of the pipe 20 at a predetermined distance from the pipe 20; It is installed on one side of the lower end of the wheel bracket 64 and includes a wheel 70 that rolls along the surface of the structure 10 .

The wheel bracket 64 may be formed of a metal plate having a constant thickness as shown in FIGS. 6 and 7 . A screw hole 60t is formed in the side surface of the pipe clamp 60, a fastening hole 64h whose center is coincident with the screw hole 60t is formed in the wheel bracket 64, and then the fixing bolt 65 is fastened to the fastening hole. When coupled to the screw hole 60t through (64h), the wheel bracket 64 can be installed on the side of the pipe clamp 60 .

The wheel 70 may be supported by the wheel shaft 73 and the bearing 72 installed on the wheel bracket 64 as shown in the enlarged view of FIG. 3 and FIG. 7 .

A flange 74 forming a constant distance between the wheel bracket 64 and the wheel 70 is formed on the outer circumferential surface of the wheel shaft 73 , and the wheel bracket 64 has a shaft for supporting the wheel shaft 73 . A support hole 64s is formed, and a screw hole 73t is formed in the center of one end of the wheel shaft 73 to fix the wheel shaft 73 inserted into the shaft support hole 64s, and the wheel shaft 73 ) is inserted into the shaft support hole 64s, and then the end bolt 75 is coupled to the screw hole 73t to fix the wheel shaft 73 to the wheel bracket 64.

At both ends of the hole of the hollow hub 71 formed in the center of the wheel 70, the outer ring of the bearing 72 composed of at least one pair is inserted, and the wheel 70 is inserted from the wheel shaft 73 into the inner ring of the bearing 72. ) and the bearing 72 may be coupled to the end bolt 75 to the screw hole 73t formed in the center of the other end of the wheel shaft 73 to prevent separation.

Hereinafter, the operation according to the present invention will be described in detail based on the accompanying drawings.

When biting the chalk 12 in the collet chuck 35 or releasing the bite of the chalk 12 bitten in the collet chuck 35, as shown in FIG. When the pressing part 50p provided in the release lever 50 is pressed using the 41), and the release shaft 41 is lowered along the guide long hole 22 while being pushed downward by the slide inclined surface 52.

At this time, the holder housing 30 is maintained in a stopped state by the stop ring 33 that is in close contact with the upper surface of the spring seat 21, and the button extension rod 40 connected to the release shaft 41 and the release button ( As the 34 is lowered together with the release shaft 41 , the lower end of the collet chuck 35 protrudes downward.

In this process, the holder spring 36 installed inside the holder housing 30 is compressed, the return spring 55 is extended and has a restoring force, and the lower end of the collet chuck 35 protruding downward is enlarged in FIG. 11 . As shown in the figure, the bite of the chalk 12 is released as it opens in a direction away from the center by its own elastic restoring force.

At this time, when the bite of the collet chuck 35 is released, it is possible to replace it with a new chalk 12 or to adjust the protrusion length of the chalk 12. In particular, as shown in FIG. 3, the lower end of the chalk 12 and the wheel 70 ), the pen pressure applied to the chalk 12 can be arbitrarily set by adjusting the retraction length L corresponding to the distance between the lower vertices.

In this way, when the external force is removed by replacing the chalk 12 with a new one or adjusting the protrusion length of the chalk 12 and then releasing the finger from the pressing part 50p of the release lever 50 that was being pressed, the return spring 55 is the elastic restoring force. As the release lever 50 is rotated around the pivot pin 51 while being contracted by do.

In addition, the release button 34 and the collet chuck 35 are raised while the holder spring 36 located inside the holder housing 30 is stretched by the elastic restoring force possessed, and the lower end of the collet chuck 35 is the center As it gathers, the chalk 12 is strongly bitten.

On the other hand, if the clamp bolt 63 installed in the pipe clamp 60 is loosened when adjusting the pen pressure applied to the chalk 12 , the pipe clamp 60 can be moved in the vertical direction along the pipe 20 . .

At this time, the retreat length L corresponding to the distance between the lower end of the chalk 12 and the lower vertex of the wheel 70 can be adjusted, and when the loosened clamp bolt 63 is strongly tightened again, the pipe clamp 60 becomes the pipe ( 20) is fixed.

After that, when the chalk 12 is brought into close contact with the surface of the structure 10 and pressure is applied, the chalk 12, the collet chuck 35, the holder housing 30 and the centering piston 31 are raised, and the spring seat 21 and The pen pressure spring 32 positioned between the centering piston 31 is compressed, and when the wheel 70 comes into contact with the surface of the structure 10, the rise of the chalk 12 is stopped, and by the pressure spring 32 A constant pressure is applied to the chalk 12 .

As such, when the holder housing 30 rises, the release button 34, the button extension rod 40, and the release shaft 41 located at the top of the collet chuck 35 are also raised together, at this time the release lever 50. Interference between the release shaft 41 and the release lever 50 is because the interference prevention surface 50k and the release shaft 41 formed on the won't happen

At this time, if the pipe 20 or the extension pipe 24 is held by hand and moved in a slightly inclined state, the wheel 70 rolls along the surface of the structure 10, and the structure 10 as the chalk 12 is worn. A marking line 13 is displayed on the surface of

That is, even if excessive force is applied to the chalk 12 through the pipe 20 or the extension pipe 24, it is buffered by the pen pressure spring 32 until the wheel 70 comes into contact with the surface of the structure 10, and the wheel At the moment 70 is in contact with the surface of the structure 10, the chalk 12 receives constant force only by the pen pressure spring 32, so it is possible to prevent damage to the chalk 12 and at the same time, excessive use of the chalk 12 wear can be prevented.

10: structure 12: chalk
20: pipe 21: spring seat
22: guide long hole 23: spring pull-out long hole
30: holder housing 31: centering piston
32: pen pressure spring 33: stop ring
34: release button 40: button extension bar
41: release shaft 50: release lever
50k: anti-interference surface 51: pivot pin
52: slide slope 53: spring latch
54: stop bar 55: return spring
60: pipe clamp 61: clamp hole
62: slit 63: clamp bolt
64: wheel bracket 70: wheel

Claims (3)

A pipe 20 in the form of a cylinder having a constant length;
a ring-shaped spring seat 21 installed on the inner circumferential surface of the pipe 20;
a holder housing 30 inserted into the center of the spring sheet 21 to form concentricity with the pipe 20 and moving along the longitudinal direction of the pipe 20;
It is installed on the outer peripheral surface of the lower end of the holder housing 30 at a distance from the spring seat 21, and moves together with the holder housing 30 inside the pipe 20 to maintain the center of the holder housing 30 a centering piston (31);
It is installed between the spring seat 21 and the centering piston 31, and applies a pen pressure to the chalk 12 toward the surface of the structure 10 by applying an elastic force in the direction in which the holder housing 30 is drawn out. a pen pressure spring (32);
a stop ring (33) installed on the outer circumferential surface of the upper end of the holder housing (30), while being caught on the upper surface of the spring seat (21), to make a constant withdrawal distance of the holder housing (30);
a guide long hole 22 formed in the pipe 20 so as to penetrate in and out of the pipe 20;
a button extension rod 40 installed on the upper end of the release button 34 provided in the holder housing 30;
a release shaft 41 passing through the button extension rod 40 in a direction perpendicular to the axis and exposed to the outside of the pipe 20 through the guide long hole 22;
Indicating bar for structural safety inspection, characterized in that it comprises a. The method of claim 1,
a pivot pin 51 installed on the pipe 20 parallel to the release shaft 41;
a release lever 50 which rotates around the pivot pin 51;
a slide inclined surface 52 formed on the release lever 50 and meeting the release shaft 41 when the release lever 50 is rotated in the release direction to move the release shaft 41 in the release direction;
an interference prevention surface (50k) formed on the release lever (50) and spaced apart from the release shaft (41) at regular intervals when the release lever (50) is stopped at a return position;
a spring latch 53 installed on the pipe 20;
a stop bar 54 caught on the outer circumferential surface of the pipe 20 when the release lever 50 is returned;
a return spring (55) having both ends hooked on the spring latch (53) and the stop bar (54) and applying an elastic force in a return direction opposite to the release of the release lever (50);
a spring extension hole 23 which is formed to penetrate inside and outside the pipe 20 and draws out a portion of the return spring 55 located inside the pipe 20;
Indicator bar for structural safety inspection, characterized in that it comprises a. 3. The method of claim 1 or 2,
a pipe clamp 60 having an open-loop clamp hole 61 into which the pipe 20 is inserted and having a slit 62 of a constant width extending from the surface to the clamp hole 61;
a clamp bolt 63 for fixing the pipe clamp 60 to an arbitrary position of the pipe 20 by narrowing the width of the slit 62;
a wheel bracket (64) installed on one side of the pipe clamp (60) and extending toward the lower end of the pipe (20) at a predetermined distance from the pipe (20);
a wheel 70 installed on one side of the lower end of the wheel bracket 64 and rolling along the surface of the structure 10;
Indicator bar for structural safety inspection, characterized in that it comprises a.

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