JPH0314519Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention is used for construction work of elevated roads, etc., in which the precast material has a lower flange whose both sides are vertical and whose upper surface is sloped so that it becomes lower towards both ends in the width direction. This invention relates to a jig for hanging scaffolds for precast girders, which is used to attach hanging scaffolds below the girders.

[Conventional technology]

Conventionally, hanging scaffolding was installed on precast girders such as T-type precast girders and I-type precast girders, which have vertical sides and a lower flange that slopes so that the upper surface is lower toward both ends in the width direction. It was carried out.

That is, as shown in Fig. 13, nut-shaped metal inserts c that open on the side surfaces of the lower flange b are buried in the lower flange b of the precast girder a at appropriate intervals in the longitudinal direction of the girder. A hanging fitting d was bolted to an insert metal fitting c, and a single pipe g of a hanging scaffold f was supported by the hanging fitting d.

[Problem that the invention attempts to solve]

In the case of the above conventional example, the following problems occurred. In other words, reinforcing reinforcing bars and prestressing prestressing prestressing steel are buried in the lower flange b of the precast girder a, so burying the insert hardware c in the vicinity of these will not only result in a section loss in the concrete, but also , cracks and rust may occur near the PC steel materials, and due to these,
It is conceivable that the inherent strength of the precast girder a will decrease.

For this reason, in recent years in this industry, instead of insert metal fittings c for suspended scaffolds, as shown by the imaginary lines in Figure 13, the traditional method has been adopted, that is, square timbers h are horizontally suspended between adjacent precast girders a. However, guidance is being given to adopt a method of supporting the suspended scaffold f via hanging metal fittings or chains.

However, in this method, a square beam h having a length corresponding to the distance between webs i of adjacent precast girders a is
If the webs i of the precast girders a are not tightly fitted without wobbling, there will be a safety problem, and construction (installation and removal) will be troublesome. Since each site is different, it is necessary to use square timbers h of a length suitable for each site, which is very disadvantageous in terms of cost.

In view of the above-mentioned current situation, the present invention is a precast girder that can be easily and quickly attached to and detached from the lower flange of a precast girder with a one-touch operation, and that can very safely suspend and support a suspended scaffold in the installed state. The purpose is to provide a jig for suspending girder scaffolding.

[Means for solving problems]

The technical measures taken by the present invention to achieve the above objectives are as follows.

That is, the jig for a precast girder suspended scaffold according to the present invention is a jig for attaching a suspended scaffold to a precast girder, which has a lower flange whose both sides are vertical and whose upper surface is inclined to be lower toward both ends in the width direction. A pair of left and right arms each having an engaging portion at the upper end that removably engages with the inclined upper surface of the lower flange from both sides of the precast girder is attached around a pivot shaft in the longitudinal direction of the precast girder at the middle part in the width direction of the precast girder. The two arms are pivotally connected to each other so as to be able to swing open and close, and a closed state in which the engaging portion engages with the inclined upper surface of the lower flange and an open state in which the two arms are engaged and disengaged by operating force above a certain level are provided between the two arms. In addition to configuring an elastic stopper mechanism that can be switched between the two arms, a suspension support member for the suspended scaffold is provided on the pivot shaft of both arms or in the vicinity thereof, so that the weight of the suspended scaffold acts in the direction of closing both arms. It is characterized by:

[Effect]

According to the above configuration, the lower flange of the precast girder is held between both arms in an open state, and in this state, both arms are swung in the closing direction with an operating force greater than the elastic biasing force of the elastic stopper mechanism. As a result, both arms are in a closed state in which the engaging portions are engaged with the inclined upper surface of the lower flange, and this closed state is maintained by the elastic stopper mechanism.

To remove the jig, both arms in the closed state are swung in the opening direction with an operating force greater than the elastic biasing force described above, so that both arms open and the jig is removed from the lower flange of the precast girder. It can be done.

In addition, when both arms are closed and the suspended scaffold is suspended via the suspension support member,
Since the weight of the suspended scaffold acts to pull down the pivot shafts of both arms or the vicinity thereof, it acts in the direction of closing both arms, so that they do not come off the lower flange.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a schematic cross-sectional view showing the usage state of the precast girder hanging scaffolding jig according to the present invention,
Figure 2 is an enlarged view of the main parts of Figure 1, Figure 3 is an exploded perspective view of the hanging scaffold jig, Figure 4 is a vertical cross-sectional view of the main parts,
FIG. 5 is a sectional view taken along the line -- in FIG. 4.

In the figure, 1 has both sides 2 vertical and the top 3
This is a precast girder having a lower flange 4 which is inclined so that it becomes lower towards both ends in the width direction. Reference numeral 5 denotes a suspended scaffold composed of a single pipe 6, a scaffold board 7, a safety net 8, and the like. A is a hanging scaffolding jig.

The structure of the hanging scaffolding jig A is shown in FIGS. 2 to 5.
The explanation is as follows based on the figure.

The illustrated hanging scaffolding jig A has a pair of left and right arms 9a and 9b that are approximately L-shaped.
a and 9b are pivotally connected at the widthwise intermediate portion of the precast girder 1 around a pivot shaft 10 extending in the girder length direction so as to be able to swing open and close. At the upper end of each arm 9a, 9b, engaging portions 11a, 11b are provided which detachably engage with the inclined upper surface 3 of the lower flange 4 from both sides of the precast girder 1.

Between both arms 9a and 9b, both arms 9a and 9b are connected to the engaging portion 11 by operating force above a certain level.
An elastic stopper mechanism B is constructed that can be switched between a closed state in which a and 11b engage with the inclined upper surface 3 of the lower flange 4 and an open state in which they disengage.

The structure of the elastic stopper mechanism B is as follows. That is, as shown in FIGS. 4 and 5, a locking portion 1 is attached to the tip of the horizontal arm portion 9a' of one arm 9a.
2, and a cylindrical metal fitting 13 is fixed to the other arm 9b at a position opposite to the locking part 12 by welding or the like. The cylindrical hardware 13 includes a movable piece 14 that is movable in the axial direction and has a spherical protrusion that can be engaged with and disengaged from the locking portion 12.
A coil spring 15 that presses the coil spring 1 is installed inside, and the coil spring 1 is
5 is configured to adjust the spring force of the spring.

A hanging support member 17 of the hanging scaffold 5 is attached to the pivot shaft 10 of both the arms 9a, 9b.
A U-shaped metal fitting 18 is pivotably connected to the hanging support member 17 and is pivotally connected to the hanging support member 17.
In the state where the suspended scaffolding 5 is suspended and supported,
The structure is such that the weight of the hanging scaffold 5 acts in a direction to close both arms 9a, 9b. Incidentally, the illustrated pivot shaft 10 is constituted by a stepped bolt. 19 is a washer, 20 is a spring washer, and 21 is a double nut. Although not shown, a hanging chain may be used as the hanging support member 17.

The hanging scaffolding jig A having the above configuration holds the lower flange 4 of the precast girder 1 between both arms 9a and 9b with both arms 9a and 9b open.
By grasping b and swinging it in the closing direction with an operating force greater than the elastic biasing force of the elastic stopper mechanism B (the spring force of the coil spring 15), both arms 9a and 9b are brought into a closed state, and the engaging portion 11a ,1
1b engages with the inclined upper surface 3 of the lower flange 4. The elastic biasing force of the elastic stopper mechanism B is set in consideration of the weight of the jig A, the temporary load caused by rattling when sliding the jig A in the girder length direction, and the operating force of the operator. Therefore, in the above-mentioned closed state, even if the hand is removed from the jig A, the jig A will not fall due to its own weight.

Further, when the suspended scaffold 5 is suspended and supported via the suspended support member 17, the weight of the suspended scaffold 5 acts in the direction of closing both arms 9a, 9b, so that it does not come off the lower flange 4 unexpectedly.

To remove the jig A, after dismantling the suspended scaffold 5, simply swing the arms 9a and 9b in the opening direction against the elastic biasing force of the elastic stopper mechanism B, and the lower flange 4 It can be removed from

6 and 7 show another embodiment of the present invention. This embodiment is characterized in that the elastic stopper mechanism B is constructed using a leaf spring 22. 23 is the protection of the leaf spring 22 and the pivot shaft 10 of both arms 9a, 9b.
This is a cover that serves to prevent opening in the axial direction, and is fixed to the arm 9 by welding, bolting, or the like. The other configurations are the same as in the previous embodiment.

8 and 9 show another embodiment of the present invention. In this embodiment, the horizontal arm 9 of arms 9a and 9b is
A', 9b' are each formed with a plurality of holes 24 for inserting the pivot shaft 10, and by selecting the holes 24 according to the width of the lower flange 4, the horizontal width of the jig A (the engagement It is characterized in that it is configured to adjust the distance (distance between portions 11a and 11b) and to adjust the position of the elastic stopper mechanism B accordingly. In this embodiment, a cylindrical metal part 13 is fixed to the tip of the horizontal arm part 9a' of the arm 9a by welding or the like, and the other arm 9b is provided with a locking part 12 corresponding to the movable piece 14. The metal piece 25 is fixed with bolts and nuts 26, and the position of the metal piece 25 is adjusted by selecting the bolt holes 27 according to the selection of the holes 24 (width adjustment of jig A). However, the metal piece 25 may be fixed and the position of the cylindrical hardware 13 may be adjusted.

10 and 11 show another embodiment of the present invention. In this embodiment, the horizontal arm portion 9a' of one arm 9a is connected to the horizontal arm portion 9a of the other arm 9b.
A feature is that the elastic stopper mechanism B is constructed by providing a leaf spring 22 that elastically engages with the lower edge of b'.
According to this embodiment, since the leaf spring 22 is configured to engage with the lower edge of the horizontal arm portion 9b', the width of the jig A is adjusted by selecting the holes 24 according to the width of the lower flange 4. When this is done, there is an advantage that the position adjustment operation of the elastic stopper mechanism B becomes unnecessary.

In addition, in each of the above embodiments, the hanging support member 17 is pivotally supported on the pivot shaft 10.
A bracket located near the pivot shaft 10 may be connected to either one of the arms 9a or 9b, and the hanging support member 17 may be pivotally supported by this bracket. That is, the suspension support member 17 can be provided at a location other than the pivot shaft 10 as long as the weight of the suspension scaffold 5 acts in a direction to close both arms 9a, 9b. Furthermore, in each of the above embodiments, the U-shaped hardware 18 at the lower end of the hanging support member 17 was configured to lock a single pipe in the longitudinal direction of the girder, but the hanging support member 17 was twisted at 90 degrees. Alternatively, as shown in FIG. 12, a turnbuckle 28 may be provided so that the direction of the U-shaped hardware 18 can be changed as necessary. It may also be carried out.

[Effect of idea]

The hanging scaffold jig according to the present invention has the above-mentioned configuration, and the jig body is attached to the precast girder by engaging the left and right engaging parts with the inclined upper surface of the lower flange from both sides of the precast girder. , there are no problems with the strength of the precast girder as would be the case when nut-shaped metal inserts are buried in the lower flange, and it can be used regardless of the spacing between adjacent precast girders, and is superior in terms of workability and economy. be.

In particular, the jig according to the present invention holds the lower flange of the precast girder with both arms open, and in this state swings both arms in the closing direction with an operating force greater than the elastic biasing force of the elastic stopper mechanism. By operating both arms, the engaging portions are brought into a closed state in which they are engaged with the inclined upper surface of the lower flange, and this closed state is maintained by the elastic stopper mechanism. By swinging both arms in the closed state in the opening direction with an operating force greater than the elastic biasing force, both arms are brought into the open state and removed from the lower flange of the precast girder.

In this way, the jig can be easily and quickly attached to and detached from the lower flange of the precast girder by a one-touch operation of grasping both arms to close or open them.

However, when both arms are closed and the suspended scaffold is suspended via the suspension support member, the weight of the suspended scaffold acts to pull down the pivot shaft of both arms or the vicinity thereof. Since it acts in the direction of closing both arms, it does not come off the lower flange, making it possible to suspend and support the suspended scaffold very safely.

[Brief explanation of drawings]

Figures 1 to 5 show one embodiment of the present invention, in which Figure 1 is a schematic cross-sectional view showing the usage state of a jig for hanging scaffolding for precast girders, and Figure 2 is the same as in Figure 1. 3 is an exploded perspective view of a jig for a suspended scaffold, FIG. 4 is a vertical cross-sectional view of a main part of a jig for a suspended scaffold, and FIG. 5 is a cross-sectional view taken along the line -- in FIG. 4. 6 and 7 are a front view of a hanging scaffolding jig showing another embodiment of the present invention and an enlarged cross-sectional view taken along the line - in FIG. 6. FIGS. 8 and 9 are a front view and a cross-sectional view of a main part of a hanging scaffolding jig showing another embodiment of the present invention. FIG. 10 and FIG. 11 are a front view and a longitudinal sectional side view of a main part of a hanging scaffolding jig showing another embodiment of the present invention. FIG. 12 is a front view of a hanging scaffolding jig showing another embodiment of the present invention. FIG. 13 is an explanatory diagram of a conventional example. A...Jig for hanging scaffold, B...Elastic stopper mechanism, 1...Precast girder, 4...Lower flange, 9a, 9b...Arm, 10...Pivot shaft, 1
1a, 11b...engaging portion, 17...hanging support member.

Claims (1)

[Scope of utility model registration request] A jig for attaching a suspended scaffold to a precast girder that has a lower flange whose both sides are vertical and whose upper surface is sloped so that it becomes lower toward both ends in the width direction, and the slanted upper surface of the lower flange is attached to the upper end from both sides of the precast girder. A pair of left and right arms each having an engaging part that releasably engages with the precast girder is pivotally connected at the middle part in the width direction of the precast girder so as to be able to swing open and close around a pivot axis in the length direction of the girder. , constitutes an elastic stopper mechanism capable of switching both arms between a closed state in which the engaging portion engages with the inclined upper surface of the lower flange and an open state in which the engagement portion disengages and disengages both arms by an operating force above a certain level; A suspension support member for a suspended scaffold is provided on the pivot axis or in the vicinity thereof, so that the weight of the suspended scaffold acts in the direction of closing both arms. Ingredients.