Beam clamp

Abstract

This provides a beam clamp that allows for easy confirmation of the tightening process. [Solution] The beam clamp 10 comprises a first arm 21, a second arm 22, a support pin 23 that rotatably supports the first arm 21 and the second arm 22, a first nut structure 40 attached to the first arm 21, a tightening screw 60 inserted into the first nut structure 40, and a handle 70 attached to one axial side of the tightening screw 60 for rotating the tightening screw 60. The first nut structure 40 has a housing 41 fixed to the first arm 21, and a first nut 42 disposed inside the housing 41 into which the tightening screw 60 is inserted. The first nut 42 has a cylindrical base 42A, an enlarged diameter portion 42B connected to the base 42A and formed at the handle side end, and a reflector 42C disposed in the enlarged diameter portion 42B.

Description

Technical Field

[0001] This invention relates to a beam clamp.

Background Art

[0002] Patent Document 1 discloses an example of a beam clamp. This beam clamp includes a first arm, a second arm, a support pin that rotatably supports the first arm and the second arm, a nut structure attached to the first arm, a tightening screw inserted into the nut structure, and a handle for rotating the tightening screw. A tightening confirmation line for confirming the tightened state is attached to the nut structure. The tightening confirmation line is, for example, a ring-shaped colored line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The site where the beam clamp is placed may be, for example, a site with low illuminance and a site with restricted viewing directions. The visibility of the tightening confirmation line of the above beam clamp may be reduced.

[0005] An object of the present invention is to provide a beam clamp that can easily confirm the tightened state.

Means for Solving the Problems

[0006] A beam clamp according to a first aspect of the present invention comprises a first arm, a second arm, a support pin that rotatably supports the first arm and the second arm, a first nut structure attached to the first arm, a tightening screw inserted into the first nut structure, and a handle attached to one axial side of the tightening screw for rotating the tightening screw, wherein the first nut structure has a housing fixed to the first arm, and a first nut disposed inside the housing into which the tightening screw is inserted, and the first nut has a cylindrical base, an enlarged diameter portion connected to the base and formed at the handle side end, and a reflector disposed in the enlarged diameter portion.

[0007] A beam clamp according to a second aspect of the present invention is a beam clamp according to a first aspect, further comprising a second nut structure attached to the second arm, the second nut structure having a body into which the tightening screw is inserted and into which an internal female thread is formed, and a second nut positioned on the opposite side of the body from the handle, wherein the surface of the body that contacts the second nut is flat.

[0008] A beam clamp according to a third aspect of the present invention is a beam clamp according to a second aspect, wherein the tightening screw has a through hole formed on the other side in the axial direction, and further has a snap pin inserted into the through hole to prevent the second nut from coming off the tightening screw. [Effects of the Invention]

[0009] According to the beam clamp of this invention, it is possible to easily confirm that the tightening is complete. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a front view of the beam clamp according to the embodiment. [Figure 2] Figure 2 is a perspective view of the beam clamp shown in Figure 1. [Figure 3] Figure 3 is a perspective view of the beam clamp shown in Figure 1, viewed from the left. [Figure 4] Figure 4 is a partial cross-sectional view of the first nut structure provided by the beam clamp in Figure 1. [Modes for carrying out the invention]

[0011] <1. Embodiments> Hereinafter, a beam clamp 10 according to one embodiment of the present invention will be described with reference to the drawings. Figure 1 is a front view of the beam clamp 10 of the embodiment. Figure 2 is a perspective view of the beam clamp 10 of Figure 1. Figure 3 is a perspective view of the beam clamp 10 of Figure 1 viewed from the left. Figure 4 is a partial cross-sectional view of the first nut 42 provided on the beam clamp 10 of Figure 1. Hereinafter, the left-right direction in the front view of the beam clamp 10 shown in Figure 1 will be referred to as the width direction, the direction perpendicular to the width direction in the front view will be referred to as the height direction, and the direction perpendicular to both the width direction and the height direction will be referred to as the front-rear direction. In addition, in the width direction, the side on which the handle 70 is arranged may be referred to as one side, and the side opposite to one side may be referred to as the other side.

[0012] The beam clamp 10 is fixed to a beam 100 that constitutes a beam or the like at any site. Any site could be, for example, an entertainment facility such as a stage, or a factory. The beam 100 could be, for example, an H-beam or an I-beam. With the beam clamp 10 fixed to the beam or the like, a material handling device or any member is suspended from it. The beam clamp 10 can be in a tightened state, shown by the solid line in Figure 1, an open state, shown by the dashed line in Figure 1, and a clamped state. The tightened state is when the beam clamp 10 is fixed to the beam 100. The open state is when the first arm 21 and the second arm 22 of the beam clamp 10 are open. The clamped state is a state between the tightened state and the open state. In the clamped state, the first arm 21 and the second arm 22 of the beam clamp 10 are in contact with the beam 100, but the tightening force is insufficient. The beam clamp 10 comprises a clamp body 20 and a clamping portion 30.

[0013] The clamp body 20 includes a first arm 21, a second arm 22, a support pin 23, a first roller 24, and a second roller 25.

[0014] The first arm 21 has a first plate 21A and a second plate 21B. The first plate 21A and the second plate 21B face each other in the front-rear direction. The material constituting the first arm 21 can be arbitrarily selected. From the viewpoint of increasing rigidity, it is preferable that the first arm 21 be made of metal. The surfaces of the first plate 21A and the second plate 21B may be colored in any color. For example, if the beam clamp 10 is used in an entertainment setting such as a stage, it is preferable that the surfaces of the first plate 21A and the second plate 21B be colored black in order to suppress the visibility of the beam clamp 10.

[0015] The second arm 22 has a first plate 22A and a second plate 22B. The first plate 22A and the second plate 22B face each other in the front-rear direction. The material constituting the second arm 22 can be arbitrarily selected. From the viewpoint of increasing rigidity, it is preferable that the second arm 22 be made of metal. The surfaces of the first plate 22A and the second plate 22B may be colored in any color. For example, if the beam clamp 10 is used in an entertainment setting such as a stage, it is preferable that the surfaces of the first plate 22A and the second plate 22B be colored black in order to suppress the visibility of the beam clamp 10.

[0016] The support pin 23 rotatably supports the first arm 21 and the second arm 22. The support pin 23 is attached to the lower ends of the first arm 21 and the second arm 22 in the height direction.

[0017] The first roller 24 engages with the flange 110 of the beam 100 when the tightening is complete. The first roller 24 is supported by the first plate 21A and the second plate 21B of the first arm 21 at approximately the upper end in the height direction.

[0018] In the state where the tightening is completed, the second roller 25 locks onto the flange 110 of the beam 100. The second roller 25 is supported by the first plate 22A and the second plate 22B of the second arm 22 at approximately the upper end in the height direction.

[0019] The tightening portion 30 includes a first nut structure 40, a second nut structure 50, a tightening screw 60, and a handle 70.

[0020] The first nut structure 40 is generally similar to the structure of the pressure nut structure disclosed in Japanese Patent No. 6979362. The first nut structure 40 includes a housing 41 and a first nut 42. In addition to the housing 41 and the first nut 42, the first nut structure 40 includes various elements included in the pressure nut structure disclosed in Japanese Patent No. 6979362.

[0021] The housing 41 is fixed to the first plate 21A and the second plate 21B of the first arm 21. The housing 41 forms a housing space for accommodating the first nut 42 and various components.

[0022] The first nut 42 is disposed inside the housing 41. The first nut 42 includes a base portion 42A, a diameter-expanded portion 42B, and a reflective material 42C. The base portion 42A is cylindrical. An internal thread that meshes with the external thread of the tightening screw 60 is formed on the inner peripheral surface of the base portion 42A.

[0023] The diameter-expanded portion 42B is connected to the base portion 42A. The diameter-expanded portion 42B is provided at the end of the base portion 42A on the handle 70 side in the width direction. The diameter-expanded portion 42B is configured in an annular shape, and the dimension in the radial direction is larger than the dimension in the radial direction of the base portion 42A.

[0024] The reflective material 42C is a material or component that reflects incident light to improve visibility. The reflective material 42C is arranged along the circumferential direction of the enlarged diameter portion 42B and on at least a portion of the enlarged diameter portion 42B. Preferably, the reflective material 42C is arranged over the entire circumferential direction of the enlarged diameter portion 42B. The specific configuration of the reflective material 42C can be arbitrarily selected as long as it is a material or component capable of reflecting light. For example, the reflective material 42C can be a retroreflective material, reflective paint, reflective sheet, reflective tape, reflective film, or a metallic reflective layer. The reflective material 42C may also be arranged in a groove formed along the circumferential direction of the enlarged diameter portion 42B. The depth of the groove can be arbitrarily selected as long as it is deep enough to attach the reflective material 42C. Preferably, the depth of the groove is, for example, about 3 mm.

[0025] In the open and closed states of the beam clamp 10, a portion of the enlarged diameter portion 42B is exposed from the housing 41. Therefore, in the open and closed states of the beam clamp 10, a portion of the reflective material 42C is visible from the outside.

[0026] When the beam clamp 10 is fully tightened, the entire enlarged diameter portion 42B is housed inside the housing 41. Therefore, when the beam clamp 10 is fully tightened, the reflective material 42C cannot be seen from the outside. In other words, the operator can determine that the clamping is complete by the fact that the reflective material 42C is not visible.

[0027] The second nut structure 50 comprises a main body 51 and a second nut 52. The main body 51 is fixed to the first plate 22A and the second plate 22B of the second arm 22. The inner circumferential surface of the main body 51 has a female thread that engages with the male thread of the tightening screw 60.

[0028] The second nut 52 is positioned in the width direction on the side of the main body 51 opposite the handle 70. A flat surface 51A is formed on the surface of the main body 51 that contacts the second nut 52. Because the main body 51 has a flat surface 51A, double nut fastening with the second nut 52 is possible. As a result, the beam clamp 10 can suppress the loosening of the nuts due to vibration, etc. Furthermore, because the beam clamp 10 has a second nut structure 50 in addition to the first nut structure 40, loosening due to vibration, etc. is further suppressed.

[0029] The tightening screw 60 is inserted into the first nut 42, the body 51, and the second nut 52. The tightening screw 60 rotates in a first direction and a second direction opposite to the first direction. The first direction is the direction in which the first nut 42 and the second nut 52 move closer together in the width direction. The second direction is the direction in which the first nut 42 and the second nut 52 move further apart in the width direction. The axial direction and width direction of the tightening screw 60 coincide.

[0030] The fastening screw 60 has a through hole 61 formed on the other side in the width direction (axial direction). A snap pin 80 is inserted into the through hole 61. Because the snap pin 80 is positioned on the fastening screw 60, the second nut 52 is prevented from coming off the fastening screw 60. The snap pin 80 maintains its retaining state by elastic force, so it does not require bending the legs like a cotter pin. For this reason, the snap pin 80 can improve workability compared to a cotter pin, and deformation and breakage during repeated use can be suppressed.

[0031] The handle 70 is positioned on one side of the width direction (axial direction) of the tightening screw 60. The handle 70 rotates the tightening screw 60 in a first or second direction.

[0032] The operation of the beam clamp 10 will be described below. In the open state, the beam clamp 10 is positioned such that the flange 110 of the beam 100 is located between the first arm 21 and the second arm 22. Next, when the handle 70 is operated, the tightening screw 60 is rotated in the first direction, causing the first arm 21 and the second arm 22 to gradually close, forming a clamping state in which the beam 100 is sandwiched between the first roller 24 and the second roller 25.

[0033] When the clamped state is reached, if the tightening screw 60 is further rotated in the first direction by operating the handle 70, the entire enlarged diameter portion 42B of the first nut 42 is housed in the housing 41. As a result, the reflective material 42C placed on the enlarged diameter portion 42B becomes invisible from the outside. When the entire enlarged diameter portion 42B is housed in the housing 41, one end face 42D of the enlarged diameter portion 42B of the first nut 42 (the end face opposite to the side exposed from the housing 41) comes into contact with the rear stepped surface 43 of the housing 41, thereby restricting the movement of the first nut 42 in the width direction. As a result, even if the handle 70 is operated, the tightening screw 60 becomes difficult to rotate in the first direction. The operator can confirm that the tightening is complete when the tightening screw 60 becomes difficult to rotate in the first direction and the reflective material 42C becomes invisible.

[0034] <2. Features> The beam clamp 10 is equipped with a reflective material 42C. The reflective material 42C can reflect light from, for example, a light carried by a worker, a headlamp, or site lighting. Therefore, even in low-light conditions and in situations where visibility is limited, workers can easily confirm the presence or absence of the reflective material 42C. As a result, the beam clamp 10 can be easily confirmed to be fully tightened.

[0035] <3. Variant> The above embodiments are illustrative of possible forms of the beam clamp according to the present invention and are not intended to limit its form. The beam clamp according to the present invention may take forms different from those illustrated in the embodiments. One example is a form in which some of the configurations of the embodiments are replaced, modified, or omitted, or a form in which new configurations are added to the embodiments. Several examples of modifications of the above embodiments are shown below. Note that the following modifications can be combined with each other to the extent that they are not technically contradictory.

[0036] <3-1. First variation> In the above embodiment, the second nut 52 may be omitted. In the first modified example, the body 51 of the second nut structure 50 may have a curved surface instead of a flat surface 51A.

[0037] <3-2. Second variation> In the above embodiment, the snap pin 80 may be omitted. In the second modified example, the through hole 61 of the fastening screw 60 may be omitted. [Explanation of symbols]

[0038] 10: Beam Clamp 21: First Arm 22: Second Arm 23: Support pin 40: First nut structure 41: Housing 42: First nut 42A: Base 42B: Expanded diameter part 42C: Reflective material 42D: End face 43: Rear stepped surface 50: Second nut structure 51: Main unit 51A: Plane 52: Second nut 60: Tightening screw 61: Through hole 70: Handle 80: Snap pin

Claims

1. First arm and The second arm and Support pins that rotatably support the first arm and the second arm, A first nut structure attached to the first arm, A tightening screw inserted into the first nut structure, The device comprises a handle attached to one axial side of the tightening screw for rotating the tightening screw, The first nut structure is, A housing fixed to the first arm, It has a first nut, which is located inside the housing and into which the tightening screw is inserted, The first nut is A cylindrical base and, The base is connected to the enlarged diameter portion formed at the handle end, A reflective material is arranged in the enlarged diameter portion, Beam clamp.

2. The second nut structure is further attached to the second arm, The second nut structure is, The main body into which the aforementioned tightening screw is inserted and into which an internal female thread is formed, It has a second nut positioned on the opposite side of the handle from the main body, The surface of the main body that contacts the second nut is flat. The beam clamp according to claim 1.

3. The aforementioned fastening screw has a through hole formed in the other axial direction, The invention further comprises a snap pin inserted into the through hole to prevent the second nut from coming off the tightening screw. The beam clamp according to claim 2.

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