JP2020008141A - Beam clamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure capable of preventing loosening of left and right screw rods of a beam clamp. SOLUTION: A beam clamp A is composed of a pair of left and right clamp arms 1L / 1R, left / right screw rods 3 for opening / closing the clamp arms 1L / 1R, and nut members 2L / 2R to which left and right screw rods 3 are screwed. Will be done. One nut member 2R includes a member main body 20R attached to the clamp arm 1R, a nut block 22R to which the left and right screw rods 3 are screwed and provided so as to be movable in the contact separation direction with respect to the member main body 20R. A guide bolt 23 provided on the member main body 20R and engaged with the nut block 22R to limit the amount of separation of the nut block 22R, and provided between the nut block 22R and the member main body 20R, the nut block 22R is provided on the member main body 20R. It is composed of a spring 29 that presses and urges the 20R in the distance direction. [Selection diagram] Fig. 2

Description

  The present invention relates to an improvement in a beam clamp attached to a beam erected with an H-shaped steel, an I-shaped steel, a T-shaped steel, or the like so that a cargo handling device such as a chain block or a hoist can be suspended.

Conventionally, a beam clamp that attaches the above-described steel mold to a beam erected on a ceiling portion of a building and suspends a cargo handling device such as a chain block has been widely used (Patent Document 1).
The beam clamp is mounted so that a pair of left and right clamp arms can be opened and closed by an open / close shaft attached to their lower ends, and a right and left screw bar (right and left screws) provided in the middle part of the clamp arm. The clamp arm is opened and closed by rotating a threaded bar). A holding groove for holding the beam flange from both sides is provided inside the upper end of the clamp arm, and the beam flange is held from both sides by tightening left and right screw rods, and the beam clamp is fixed at the position. It has become.

  Thereafter, the hook of the cargo handling device is hung on the opening / closing shaft provided at the lower end of the clamp arm to perform the cargo handling operation. During the cargo handling operation, a large and small force is constantly applied to the beam clamp from various directions from the suspended cargo handling device, and sometimes the right and left screw rods are loosened. Since the left and right screw rods are maintained in the tightened state by the frictional force at the time of tightening, if loosened once, the looseness rapidly increases, and the beam clamp falls off the flange, leading to a falling accident of the suspended load.

JP 2001-234905 A

  However, with the conventional beam clamp, it is necessary to visually check the mounting state, such as whether the clamping groove of the clamp arm is fully fitted into the flange of the beam, and feel the hand when the handle is fully tightened. Just checked the tightening condition. However, if the left and right screw rods are rusted or malfunction, even if the right and left screw rods are intended to be sufficiently tightened, the required tightening force is actually insufficient. There is a danger of a serious accident of falling off from the flange and falling with the suspended load.

  In the case of a device for loading and unloading heavy objects such as a beam clamp, it is necessary to prevent the device from falling off the flange in any state for the above-described reason. To do so, even if the left and right screw rods become loose, it is necessary to prevent the loosening from expanding. At the same time, when the right and left screw rods are tightened to attach the beam clamp to the beam, it is necessary to be able to check the tightening state from the outside.

  The present invention has been made in view of the above-described problems of the related art, and a first problem of the present invention is to prevent the left and right threaded rods of a beam clamp from being loosened in a cargo handling operation and to prevent the loosening even if the loosening occurs. A second object of the present invention is to provide a structure capable of visually confirming that a tightening force necessary and sufficient for safely lifting a suspended load has been applied to a flange of a beam.

In order to achieve the above object, the present invention (claim 1)
A pair of left and right clamp arms 1L each of which has one end mounted so as to be opened and closed by an opening / closing shaft 4 and provided on opposite inner surfaces at the other end with holding grooves 5L and 5R into which a beam 80 to be mounted is fitted.・ 1R,
Left and right nut members 2L and 2R provided on each of the pair of left and right clamp arms 1L and 1R, and one of them is provided with a female screw hole 25N for a left screw and the other female screw hole 25M for a right screw.
In a beam clamp A comprising left and right screw rods 3 for opening and closing the clamp arms 1L and 1R screwed on the left and right nut members 2L and 2R with one axis,
The nut member 2R of one clamp arm 1R is
A member main body 20R attached to the clamp arm 1R,
The left and right screw rods 3 are screwed and provided so as to be movable in the axial direction of the left and right screw rods 3 in the contact and separation directions with respect to the member main body 20R. A nut block 22R provided with an abutting portion 22t to abut,
A guide bolt 23 provided on the member main body 20R so as to be parallel to the left and right screw rods 3 and along the nut block 22R, and to engage with the nut block 22R to limit a separation amount of the nut block 22R;
A spring 29 is provided between the nut block 22R and the member main body 20R and presses and biases the nut block 22R in a direction away from the member main body 20R.

By configuring the beam clamp A in this manner, when the right and left screw rods 3 are tightened and fitted into the beam 80 to the depths of the holding grooves 5L and 5R, the closing operation of the pair of right and left clamp arms 1L and 1R ends. I do. When the left and right screw rods 3 are further tightened from this state, the nut block 22R is pushed into the member main body 20R side, and the spring 29 is bent. When the left and right screw rods 3 are further tightened, the abutting portion 22t of the nut block 22R abuts on the member main body 20R, and the nut block 22R stops. When the left and right screw rods 3 are further tightened in this state, the right and left screw rods 3 are fixed by the strong frictional force between the right and left female screw holes 25M and 25N of the left and right nut blocks 22L and 22R by the tightening force. . The bent spring 29 increases the frictional force by the amount of the elastic force.
As a result, the frictional force is increased as compared with the conventional example in which the spring 29 is not present, so that it is harder to loosen. Even if the left and right screw rods 3 are loosened, the elastic force of the spring 29 is constantly applied. Acts as a lock.

According to a second aspect of the present invention, in the beam clamp A according to the first aspect,
The nut block 22R is provided with a guide bolt insertion hole 22g through which the guide bolt 23 is inserted, and the guide bolt insertion hole 22g has a counterbore 22h in which a head portion 23a of the guide bolt 23 projects. Is formed,
The axial length S from the planting surface 21 of the guide bolt 23 of the member main body 20R to the head 23a of the guide bolt 23 is larger than the distance H from the planting surface 21 to the bottom 22s of the counterbore 22h. so,
The depth D of the counterbore 22h is equal to or greater than the axial height T of the head 23a.

  As a result, when the right and left screw rods 3 are tightened as described above, the right and left screw rods 3 are fitted into the beam 80 to the depths of the holding grooves 5L and 5R of the clamp arms 1L and 1R, and the pair of right and left clamp arms 1L and 1R are closed. At this point the operation ends. A gap K exists between the member main body 20R and the contact portion 22t. When the left and right screw rods 3 are further tightened from this state, the nut block 22R is pushed into the member main body 20R side and the spring 29 is bent as described above. Then, the head 23a of the guide bolt 23 implanted in the member main body 20R is gradually exposed from the counterbore 22h of the nut block 22R. When the nut block 22R is tightened until the contact portion 22t contacts the member main body 20R, the nut block 22R stops, and the head 23a is exposed at a height sufficient for visual recognition from the outside. Thereby, the maximum bending of the spring 29 can be confirmed. Thereafter, the left and right screw rods 3 are fully tightened to complete the mounting of the beam clamp A. The elastic force of the spring 29 is added to the tightening force of the left and right screw rods 3 and exerts a locking effect.

  A third aspect of the present invention is characterized in that, in the beam clamp A of the first or second aspect, a set screw 30 reaching the female screw hole 25N is screwed on a lower surface of the nut block 22R on the opening / closing shaft 4 side.

According to this, the beam clamp A according to the present invention is attached to the beam 80 by turning the right and left screw bars 3, and when the attachment is completed, the elastic force of the spring 29 is added to the tightening force of the left and right screw bars 3. This is added to prevent the left and right screw rods 3 from loosening. Even if the left and right screw rods 3 are loosened, the elastic force of the spring 29 is constantly applied, so that the left and right screw rods 3 are less likely to be loosened than in the case without the spring 29.
In addition, when the right and left screw rods 3 are tightened, the head 23a of the guide bolt 23 as an indicator provided on the beam clamp A comes out from the counterbore 22h. Thereby, it can be visually confirmed that the right and left screw rods 3 have been tightened to the maximum tightening position of the spring 29. If the left and right screw rods 3 are further tightened from this state, it can be confirmed that the beam clamp A has been attached to the beam 80 with the required tightening force.
Further, by providing the set screw 30 on the lower surface of the nut block 22R on the opening / closing shaft 4 side, the set screw 30 can be operated from below with the beam clamp A attached to the beam 80. 3 can be fixed, and the cargo handling work can be performed safely.

It is a perspective view in the state where a beam clamp of the present invention was attached to a beam. FIG. 2 is a sectional view taken along line XX of FIG. 1. FIG. 3 is a partial sectional view when the beam clamp of the present invention is tightened. FIG. 4 is a partial cross-sectional view when the beam clamp of the present invention is loosened. FIG. 5 is a sectional view taken along the line YY in FIG. 4.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. The beam clamp A of the present invention includes a pair of left and right clamp arms 1L and 1R, an opening and closing shaft 4 attached to the lower ends of the clamp arms 1L and 1R, left and right nut members 2L and 2R, and opening and closing of the clamp arms 1L and 1R. The right and left screw rods 3 are provided.

The clamp arms 1L and 1R are provided symmetrically in a pair on the left and right. The front and rear sides of the left and right clamp arms 1L and 1R are configured by arm members 1Lf and 1Lr / 1Rf and 1Rr that have the same shape and are disposed before and after.
Each of the arm members 1Lf / 1Lr / 1Rf / 1Rr is formed of an elongated oblong plate. As can be seen from FIGS. 1 and 2, the lower ends of the arm members 1Lf / 1Lr / 1Rf / 1Rr are overlapped with the front arm members 1Lf / 1Rf and overlapped with the rear arm members 1Lr / 1Rr. The opening / closing shaft 4 is attached to.
Thus, the opening / closing shaft 4 hinges the left and right clamp arms 1L and 1R so that they can be opened and closed at the lower ends, and this portion serves as a hanging portion of the cargo handling device 90. The tip portions (upper end portions) of the arm members 1Lf / 1Lr / 1Rf / 1Rr are connected by connecting members 6L / 6R, respectively.

One right nut member 2R is provided in the middle part of the right clamp arm 1R, and the other left nut member 2L is provided in the middle part of the left clamp arm 1L.
The left nut member 2L includes a left nut block 22L and a collar 20L.
The nut block 22L is a columnar member, and has a right-threaded female screw hole 25M that penetrates an intermediate portion thereof at right angles to the center line thereof. The front and rear ends of the nut block 22L are rotatably inserted into support holes 1Ls and 1Ls formed in the left arm members 1Lf and 1Lr. A collar 20L is attached to an outer periphery of the nut block 22L, and an end surface of the collar 20L is in contact with inner surfaces of the left arm members 1Lf and 1Lr. A screw rod insertion hole 26L is formed in the collar 20L, and the left and right screw rods 3 screwed into the nut block 22L are inserted.

The right nut member 2R includes a member main body 20R, a nut block 22R, a guide bolt 23, a spring 29, and a rotation support shaft portion 24R.
The member body 20R is a rectangular parallelepiped block, and has a block mounting hole 26R at the center and a coaxial shaft hole 28R formed on both the front and back surfaces. The center line of the shaft hole 28R is orthogonal to the left and right screw rods 3 and becomes the center of rotation of the member main body 20R.
The rotation support shaft portion 24R is a columnar member, is fitted into the shaft hole 28R so as to protrude from a side surface of the member main body 20R, and is fixed to the member main body 20R by bolts. The rotation support shaft 24R may be formed integrally with the member main body 20R.

  The right nut member 2R is disposed at a middle portion of the right clamp arm 1R, and a rotation support shaft portion 24R is provided in a coaxially provided support hole 1Rs · 1Rs at a middle stage of a pair of front and rear arm members 1Rf · 1Rr. It is rotatably fitted. That is, the right nut member 2R is also supported rotatably about the support holes 1Rs and 1Rs provided coaxially in the front and rear.

  The right nut block 22R is a cylindrical member in which a female screw hole 25N of a left-hand thread is formed so as to coincide with the central axis, and its outer peripheral surface has a small-diameter portion 22m, an intermediate-diameter portion 22n, and an outer flange portion 22f. Are formed in three stages. The step portion at the boundary between the small diameter portion 22m and the intermediate diameter portion 22n becomes the contact portion 22t.

The small-diameter portion 22m is movably inserted into the block mounting hole 26R of the member main body 20R in the insertion / removal direction, and when the small-diameter portion 22m is pushed all the way, the contact portion 22t of the intermediate-diameter portion 22n becomes It contacts the outer surface of 20R (planting surface 21 described later).
A guide bolt insertion hole 22g is formed in the outer flange portion 22f, and a counterbore 22h is formed in the outer flange portion 22f so as to open on the outer surface side of the outer flange portion 22f. Have been. The bottom of the counterbore 22h is indicated by 22s. The bottom 22s serves as an engaging portion of the head 23a of the guide bolt 23 as described later.

Guide bolts 23 are planted on both sides of the block mounting hole 26R on a surface of the right member main body 20R facing the outer flange portion 22f of the nut block 22R. This surface is referred to as a planting surface 21.
The shaft portion of the guide bolt 23 is inserted into a guide bolt insertion hole 22g of the outer flange 22f, and its head 23a is attached to the counterbore 22h of the outer flange 22f so as to be able to protrude and retract. That is, the height T of the head 23a is equal to or smaller than the depth D of the counterbore 22h, and the outer diameter of the head 23a is smaller than the inner diameter of the counterbore 22h (see FIG. 3).

  A spring 29 is attached to the outer peripheral portion of the intermediate diameter portion 22n of the nut block 22R, that is, between the planting surface 21 of the right member body 20R and the outer flange portion 22f of the right nut block 22R. , Is always urged in a direction away from the member main body 20R. As can be seen from FIG. 4, the nut block 22 </ b> R pressed and urged in the separating direction is a head of the guide bolt 23 in which the bottom 22 s of the counterbore 22 h of the outer flange 22 f is implanted in the member main body 20 </ b> R. 23a. At this time, a gap K is generated between the planting surface 21 and the contact portion 22t of the intermediate diameter portion 22n (FIG. 4).

  The left and right screw rods 3 for opening and closing include a screw member 3a in which a left screw and a right screw are engraved at one end and the other end, a handle portion 3b extending from the screw member 3a, and a handle portion 3b. A turning rod 3c is provided at an end thereof, which is slidably provided at right angles to the handle portion 3b. The left and right threaded portions of the left and right threaded rods 3 are screwed into the left and right nut blocks 22L and 22R of the nut members 2L and 2R in the same screw direction. Therefore, when the right and left screw rods 3 are rotated, the left and right nut blocks 22L and 22R move in the approaching direction, and move in the separating direction by being reversed. Thus, the clamp arms 1L and 1R open and close about the opening and closing shaft 4 via the left and right nut members 2L and 2R.

  As shown in FIG. 5, the set screw 30 is attached to the outer flange 22f of the right nut block 22R. The screw hole of the set screw 30 reaches the female screw hole 25N of the right nut block 22R. Since the set screw 30 is installed on the opening / closing shaft 4 side, when the beam clamp A is mounted on the beam 80, it is located on the lower surface side of the outer flange portion 22f.

In the beam clamp A as described above, the relationship between one of the right member main body 20R and the right nut block 22R and the guide bolt 23 serving as an indicator will be described with reference to FIGS.
The shaft length S (the length of the shaft portion of the guide bolt 23) from the planting surface 21 of the member body 20R on which the guide bolt 23 is planted to the base end of the head 23a of the guide bolt 23 is the planting surface. In a state where the step-shaped contact portion 22t of the intermediate diameter portion 22n of the nut block 22R is brought into contact with 21, the distance H is larger than the distance H from the planting surface 21 to the bottom 22s of the counterbore 22h. This difference (shaft length S-distance H) is a gap from the bottom 22s of the counterbore 22h to the head 23a, and is equal to a gap K described later.
The depth D of the counterbore 22h is equal to or greater than the axial height T of the head 23a.
Therefore, as shown in FIG. 4, when the nut block 22R is pushed out in the direction away from the member main body 20R by the elastic force of the spring 29, and the head 23a is engaged with the bottom 22s of the counterbore 22h. The head 23a fits into the counterbore 22h and is buried, and cannot be visually recognized from the outside. At this time, a gap K is generated between the contact portion 22t, which is the step boundary between the small-diameter portion 22m and the intermediate-diameter portion 22n of the nut block 22R, and the planting surface 21 of the member main body 20R.

Conversely, as shown in FIG. 3, in the state where the tightening is completed, that is, in the state where the contact portion 22t is in contact with the planting surface 21, the middle or more of the head 23a is exposed from the counterbore 22h. This exposed portion is indicated by 23b. If the exposed portion 23b is painted in a color that is easily visible from the outside, the exposed portion 23b is easily visible from the outside. When the contact portion 22t is in contact with the planting surface 21, the total length W of the intermediate diameter portion 22n and the outer flange portion 22f of the nut block 22R is equal to the tip of the head 23a of the guide bolt 23 from the planting surface 21. Is shorter than the length Y by the exposed portion 23b.
If, for example, a thick line 23d is provided between the exposed portion 23b and the non-exposed portion of the head 23a, the exposure of the thick line 23d causes the contact portion 22t to come into contact with the planting surface 21. It can be confirmed visually. When the left and right screw rods 3 are fully tightened in this state, the beam clamp A is attached to the beam 80 with a necessary tightening force as described later.

  Next, a method of using the beam clamp A will be described. The clamp arms 1L and 1R of the beam clamp A are opened by turning the handle 3b of the left and right screw rods 3. In this state, as shown in FIG. 4, the right nut block 22R is pressed by the elastic force of the spring 29, is separated from the planting surface 21 of the member main body 20R, and the head 23a of the guide bolt 23 is It is buried in the counterbore 22h and cannot be seen from the outside. Therefore, a gap K is formed between the planting surface 21 of the member main body 20R and the contact portion 22t. In the nut block 22R on the right side, the head 23a of the guide bolt 23 is held in engagement with the bottom 22s of the counterbore 22h in a separated state, and the clamp arms 1L and 1R are kept open.

  In this state, the upper opening between the clamp arms 1L and 1R is inserted from below the beam 80, and the clamping grooves 5L and 5R of the clamp arms 1L and 1R are aligned with the flange 81 of the beam 80. Reverse. As a result, the clamp arms 1L and 1R close around the opening / closing shaft 4, and are tightened with the flange 81 fitted in the holding grooves 5L and 5R. At this time, the clamp arms 1L and 1R are closed while the gap K is held by the elastic force of the spring 29.

  When the end of the flange 81 reaches the deep ends of the holding grooves 5L and 5R, in this state, the left and right clamp arms 1L and 1R sandwich the flange 81 from both sides by the elastic force of the spring 29, and cannot be closed any more. . Therefore, the left and right nut blocks 22L and 22R also stop in this state. However, at this point, the clamping state is attained only by the elastic force of the spring 29 as described above, and the clamping force of the clamp arms 1L and 1R with respect to the flange 81 is insufficient because the gap K exists. At this time, the head 23a is not exposed.

  Then, when the left and right screw rods 3 are further turned and tightened from this state, the right nut block 22R is gradually screwed toward the right member body 20R against the spring 29, and the exposure of the head 23a is performed. Be started. Finally, the contact portion 22t of the intermediate diameter portion 22n is pressed against the planting surface 21 of the right member body 20R. At this time, with the movement of the right nut block 22R, the head 23a of the guide bolt 23 protrudes from the counterbore 22h and can be visually recognized from the outside. The amount of protrusion of the guide bolt 23 from the counterbore 22h of the head 23a is determined by a predetermined width (for example, by the mark painted surface 23c. If the thick line 23d is provided as described above, the exposed end of the painted surface 23c is clear. The left and right screw rods 3 are further tightened as much as possible after confirming that the bending of the spring 29 has been completed. This completes the tightening with the required tightening force by the left and right screw rods 3. At this time, since the spring 29 is bent, the resilient force is added to the required tightening force.

Finally, the set screw 30 is tightened from below, and the right and left screw bars 3 are locked to the right nut block 22R. Thereafter, the cargo handling device 90 is hung on the opening / closing shaft 4 of the beam clamp A fixed to the beam 80, and the cargo handling operation is performed.
As described above, the beam clamp A is applied with various forces of various sizes from the cargo handling device 90 in the cargo handling operation as described above. This force always acts to loosen the left and right screw rods 3. In the present invention, as described above, the elastic force is added to the tightening force of the left and right screw rods 3 by the spring 29, and the loosening of the left and right screw rods 3 is prevented. Even if looseness occurs, since the resilient force of the spring 29 always acts on the left and right threaded rods 3, unless the external force greater than the resilient force of the spring 29 acts, the beam clamp A suddenly falls off the beam 80. Can be prevented.

A: Beam clamp, D: Depth of the counterbore, H: Distance from the planting surface to the bottom of the counterbore, K: Gap, S: Shaft from the planting surface of the guide bolt to the head of the guide bolt Length, T: Height in the axial direction of the head, W: Total length of the intermediate diameter portion of the nut block and outer flange, Y: Length from the planting surface to the tip of the head of the guide bolt 1L 1R: (left and right) clamp arm, 1Lf / 1Lr / 1Rf / 1Rr: arm member, 1Ls / 1Rs: support hole, 2L / 2R: nut member, 3: left and right screw rod, 3a: screw member, 3b: handle portion, 3c: turning rod, 4: open / close shaft, 5L / 5R: holding groove, 6L / 6R: connecting member, 20L: collar, 20R: member body, 21: planting surface, 22L / 22R: nut block, 22f: outer collar Part, 22g: Guide bolt insertion hole, 22h: Counterbore hole, 22m: Diameter portion, 22n: Intermediate diameter portion, 22s: Bottom, 22t: Contact portion, 23: Guide bolt, 23a: Head portion, 23b: Exposed portion, 24R: Rotation support shaft portion, 25N: Left-handed female screw hole, 25M : Female screw hole of right-hand thread, 26L: Screw rod insertion hole, 26R: Block mounting hole, 28R: Shaft hole, 29: Spring, 30: Set screw, 80: Beam, 81: Flange, 90: Cargo handling device

Claims (3)

A pair of right and left clamp arms, each of which is attached so that one end thereof can be opened and closed by an opening and closing shaft, and a holding groove into which a beam to be attached is fitted is provided on the opposite inner surface of the other end,
Left and right nut members provided on each of the pair of left and right clamp arms, one of which has a female screw hole of a left screw, and the other has a female screw hole of a right screw,
In a beam clamp constituted by a left and right screw bar for opening and closing a clamp arm screwed on the left and right nut members uniaxially,
The nut member of one clamp arm is
A member body attached to the clamp arm,
The left and right threaded rods are screwed, and are provided so as to be movable in the contact and separation directions with respect to the member main body in the axial direction of the left and right threaded rods, and are in contact with the member main body when the left and right threaded rods are tightened. A nut block provided with
A guide bolt that is provided on the member body so as to be parallel to the left and right threaded rods and along the nut block, and engages with the nut block to limit a separation amount of the nut block;
A beam clamp, comprising: a spring provided between the nut block and the member main body; and a spring for urging the nut block in a direction away from the member main body R. The nut block is provided with a guide bolt insertion hole for inserting the guide bolt, and the guide bolt insertion hole is formed with a counterbore through which the head of the guide bolt appears and disappears,
The shaft length from the planting surface of the guide bolt of the member body to the head of the guide bolt is larger than the distance from the planting surface to the bottom of the counterbore.
The beam clamp according to claim 1, wherein the depth of the counterbore is equal to or greater than the axial height of the head. The beam clamp according to claim 1, wherein a set screw reaching the female screw hole is screwed on a lower surface of the nut block on the opening / closing shaft side.

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