DUST COLLECTINGAPPARATUS FORA DUST-VACUUMING SANDER

Technical Field

The present disclosure relates to dust collecting apparatuses for use together with dust-vacuuming sanders.

Background

In an autobody repair shop, paint, putty, primer and the like are sanded, resulting in a dusty environment. The dust is perceived as a potential health issue. Furthermore, the dust may cause paint nibs during the painting operation. In order to reduce the amount of abrasive dust floating in the body repairing area, dust collecting apparatus is typically employed during sanding operations.

Fig. 1 is a schematic view showing the constitution of an ordinary sanding/dust-collecting apparatus. This sanding/dust-collecting apparatus is composed of a dust- vacuuming sander 1, a dust hose 2, an aspirator 3, an air-supply hose 4 and an air-permeable dust bag 5. When the air is fed to the air-supply hose 4, the air flow is sent to an exhaust port 7 through an air-supply port 6 of the aspirator 3 and, as a result, a negative pressure is produced in an intake port 8. The air is directed, by the action of this negative pressure, through a dust- vacuuming opening of the dust- vacuuming sander 1 via the dust hose 2.

During sanding operations, an abrasive sheet 9 is attached on the sanding surface of the dust- vacuuming sander 1 and abrasive dust is produced. The abrasive dust produced passes the dust hose 2 and the aspirator 3 together with the air taken through the dust- vacuuming opening, and is collected in the dust bag 5.

Conventional sanding/dust-collecting apparatus is typically noisy, creating a poor working environment. Further, dust bags are used while being uncovered and placed on the floor. In many cases, therefore, a dust bag may be torn, resulting in, abrasive dust passing through the dust bag. Moreover, after a sanding work using water, since the floor is wet, the mesh of a dust bag would be clogged by water.

Brief Description of the Drawings

Fig. 1 is a schematic view showing the constitution of an ordinary sanding/dust-collecting apparatus. Fig. 2 is a schematic view showing one embodiment of the dust collecting apparatus for a dust- vacuuming sander of the present invention.

Fig. 3 is a schematic view showing one embodiment of an exterior box having a noise suppresser.

Fig. 4 is a schematic view showing one embodiment of an exterior box having a conveyance-aiding member.

Explanation of Reference Numerals

21 — Exterior box

22 — Aspirator 23 — Dust bag

24 — Intake opening

25 — Exhaust opening

26 — Exhaust port

27 — Air-supply port 28 — Intake port

31 — Acoustic material

Disclosure of the Invention

The present disclosure is directed to a dust collecting apparatus which is less noisy and is resistant to damage during sanding operations.

The present disclosure provides a dust collecting apparatus for a dust- vacuuming sander comprising: an exterior box provided with an intake opening and an exhaust opening; an aspirator attached to the intake opening of the exterior box so that an exhaust port is located inside the exterior box and an air supply port and an intake port are located outside the exterior box; and a dust bag which is located inside the exterior box and which is attached to the exhaust port of the aspirator so that the air flow from the aspirator is introduced inside.

The dust collecting apparatus for a dust- vacuuming sander of the present disclosure is less noisy and the dust bag thereof is resistant to damage during sanding operations. In addition, when it is out of use, it is possible to put a sanding tool and the dust hose in the exterior box. Therefore, it is convenient for storing and transporting a sanding tool.

Fig. 2 is a schematic view showing one embodiment of the dust collecting apparatus for a dust- vacuuming sander of the present disclosure. This dust collecting apparatus for a dust- vacuuming sander has an exterior box 21, an aspirator 22 and a dust bag 23. The exterior box 21 is made of a material which is resistant to water, somewhat hard, and resistant to impact, such as plastic and metal. The exterior box 21 has an intake opening 24 and an exhaust opening 25. An aspirator 22 is attached to the intake opening 24. An exhaust port 26 of the aspirator 22 is located inside the exterior

box and an air supply port 27 and an intake port 28 are located outside the exterior box.

The dust bag 23 is a sheet-like material, fabricated into a bag, which is air-permeable but does not allow abrasive dust to pass through. Such a sheet-like material can be produced using cloth, paper or the like. The dust bag 23 is attached to the exhaust port 26 of the aspirator so that the air flow from the aspirator is introduced inside. The bag may be secured to the covering around the exhaust port of the aspirator with a clamp or the like. However, the manner of attachment is not particularly restricted.

When the dust collecting apparatus for a dust- vacuuming sander is used, a lid of the exterior box is closed and secured so as not to open unexpectedly. A dust hose and a dust- vacuuming sander are mounted to the intake port 28 of the aspirator. During the sanding operation, air is supplied to the air- supply port 27 of the aspirator. Air flow is directed to the exhaust port 26 of the aspirator and into the dust bag 23 together with abrasive dust taken through the intake port 28 of the aspirator. The dust bag 23 functions as a filter. It allows the air to pass through while retaining the abrasive dust. The air which passed through the dust bag goes outside through the exhaust port 25 of the exterior box.

In the dust collecting apparatus for a dust- vacuuming sander, the exhaust port 26 of the aspirator is enclosed in the exterior box 21. Therefore, the noise generated during operation is considerably reduced compared to existing dust collecting apparatus.

For reducing the noise more, the exterior box may be provided with a noise suppresser. Fig. 3 is a schematic view showing one embodiment of an exterior box having a noise suppresser, wherein an aspirator and a dust bag are not shown.

One example of such a noise suppresser is a layer of an sound-absorbing material 31 provided in the exterior box so as to surround the dust bag. A preferable

sound-absorbing material is a nonwoven fabric made by the melt-blowing method with micro fibers having a fiber diameter of 1-4 μm and staples having a fiber diameter of 20-30 μm. The nonwoven fabric which can be used has a basis weight of 200-400 g/m ² and a thicknes of 40 mm or less and preferably about 10-30 mm. Such nonwoven fabric is commercially available, for example, under the name "Thinsulate" from

Sumitomo 3M Ltd.

Another example of a noise suppresser is a silencer 32 which is attached to the exhaust opening of the exterior box. Commercially available silencers may be used.

For achieving easy transportation, the exterior box may have a conveyance-aiding member. Fig. 4 is a schematic view showing one embodiment of an exterior box having a conveyance-aiding members. Examples of such a conveyance-aiding members include a knob 41 and casters 42.

The present disclosure will be described in more detail below with reference to Examples, but the invention is not limited thereto.

Examples

Example 1

As an exterior case, a case made of polyethylene resin, 37 cm long, 20 cm wide and 18 cm high was prepared. As an aspirator and a dust bag, a "simple dust collecting apparatus for dust-vacuuming file #5560" manufactured by Sumitomo 3M

Ltd. was prepared. Then, a dust collecting apparatus with the structure shown in Fig. 2 was fabricated by making an intake opening and an exhaust opening in the case made of polyethylene resin.

To the intake port of the aspirator, a dust hose and a dust- vacuuming sander ("dust-vacuuming file kit #5555" manufactured by Sumitomo 3M Ltd.) were connected. An air- supply hose was connected to the air- supply port of the aspirator and the air was supplied through the air-supply hose at an air pressure of 60 Pa. The noise generated was measured at a position 50 cm away from the exhaust opening of the exterior box. The noise level was measured at 86.8 dB.

Example 2

Anonwoven fabric made by Sumitomo 3M Ltd., available under the trade designation "Thinsulate SM-300L" having a basis weight of 360 g/m ² and a thickness of 21 mm was prepared and was cut into a size of 74 cm long and 35 cm wide. The resulting nonwoven fabric mat was placed in the exterior box so as to surround the dust bag. The noise generated during the sanding operation was measured in the same manner as Example 1 except using the dust collecting apparatus. The noise level was measured at 75.8 dB.

Comparative Example

A dust collecting apparatus with the structure shown in Fig. 1 was made by detaching the exterior case from the dust collecting apparatus of Example 1. The noise generated during operation was measured at a position away from the exhaust port of the aspirator by a distance the same as that in Example 1, namely 50 cm. The noise level was measured at 97.1 dB.