Shroud for an air sander

Abstract

A flexible shroud for an air sander. The flexible shroud has a sealing edge contacting a sanding member of the air sander at a rim of the shroud, wherein the sealing edge is bent inward to form a contact surface in surface contact with the sanding member.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a shroud structure for an air sander, and in particular to an air tool for performing sanding processes in the industry.

[0003] 2. Description of the Related Art

[0004] An air sander may operate and perform the sanding operation using compressed air as a source for driving a sanding member to rotate and utilizing the diflective orbital distance occurred during the rotation of the sanding member. A lot of dust may be generated with the wear-out of the workpiece surface during the sanding operation. Therefore, a newer air sander usually includes a dust collecting means for collecting and removing the dust on the workpiece surface during the sanding operation.

[0005] Please refer to FIG. 1, which shows a conventional air sander 10 having a dust-collecting function as disclosed in U.S. Pat. No. 4,531,329. The dust is generated between the sanding member 11 of the air sander 10 and the workpiece surface, so the sanding member 11 is formed with plural apertures 111 serving as suction holes for removing the dust. In order to prevent the air stream from leaking out and to collect the dust passing through the sanding member 11, a flexible shroud 12 is provided to cover the sanding member 11. A contact edge 121 is formed at a rim of the shroud 12 so as to contact the outer edge of the sanding member 11. Thus, the dust may be collected and removed from each aperture 111. There are many contact manners between the contact edge 121 of the shroud 12 and the sanding member 11. For example, the contact edge 121 may contact the inner edge of the sanding member 11, as shown in FIG. 2. Alternatively, the contact edge 121 may contact the outer edge of the sanding member 11, as shown in FIG. 3.

[0006] It is to be noted that the sanding member usually operates under rotation and vibration or reciprocating movement for a long period of time, and the contact portion of the shroud may be worn out by the sanding member after a period of time. Hence, the contact portion of the shroud may not tightly contact the sanding member and the dust collecting and removing effects may be deteriorated because the ambient air may enter the shroud through the contact portion. A significant problem for this may be found and will be described in the following. Since the contact portion of the conventional shroud contacts the sanding member in the form of a ring-shaped line (or in the form of a point in the cross-sectional view) and the sanding member operates under reciprocating vibrations, the air-tight effect or dust-suction effect is poor even if the contact portion of the shroud is slightly worn out. Consequently, the airtight structure between the contact portion of the conventional shroud and the sanding member has to be further improved in order to meet the requirement in usage.

SUMMARY OF THE INVENTION

[0007] A primary object of the invention is to provide a shroud for an air sander. Good airtight effect may be obtained by forming a contact surface, which extends from the sealing edge of the shroud and contacts the sanding member in the form of a plane.

[0008] According to one aspect of the invention, a flexible shroud has a sealing edge contacting a sanding member of an air sander at a rim of the shroud, wherein the sealing edge is bent inward to form a contact surface in tight and surface contact with the sanding member.

[0009] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a pictorial view showing a conventional air sander.

[0011] FIG. 2 is a partially cross-sectional view showing the contact relationship between the sanding member and the contact edge of a conventional shroud for the air sander.

[0012] FIG. 3 is a partially cross-sectional view showing the contact relationship between the sanding member and the contact edge of another conventional shroud for the air sander.

[0013] FIG. 4 is a cross-sectional view showing the contact relationship between the sanding member and the shroud of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0014] Please refer to FIG. 4, which shows the contact relationship between the sanding member and the shroud of the invention. The improvement of the invention resides in that the shroud 20 is formed with a contact surface 211. The shroud 20 is a flexible member made of, for example, rubber. The shroud 20 has a sealing edge 21 contacting the sanding member 30 of the air sander at a rim of the shroud 20. The sanding member 30 of the air sander is formed with plural apertures 31 for sucking and removing the dust on the workpiece surface. The apertures 31 are positioned inside the sealing edge 21 of the shroud 20.

[0015] In this embodiment of the invention, the sealing edge 21 of the shroud 20 is particularly bent inward to form the contact surface 211. Therefore, when the sealing edge 21 of the shroud 20 contacts the sanding member 30, the contact surface 211 may tightly contact the sanding member 30 in the form of a plane. In brief, the sanding member 30 is in tight and surface contact with the sealing edge 21 of the shroud 20 of the invention, as shown in FIG. 4.

[0016] When the air sander performs the sanding operation, the sanding member 30 rotates at high speed and a micro-vacuum state may occur at the bottom of the sanding member 30. Since contact surface 211 of the sealing edge 21 of the shroud 20 is in good contact with the sanding member 30, or the contact surface 211 is in tight and surface contact with the sanding member 30, the air-tight effect therebetween may not be adversely influenced by the high-speed rotation and vibration of the sanding member 30. Thus, the sealing effect between the shroud 20 and the sanding member 30 is pretty good, and a good dust-collecting effect may be obtained accordingly. Furthermore, the airtight effect is free from be influenced owing to slight wear-out of the shroud 20 after a period of time. Consequently, the shroud 20 and the sanding member 30 may always be kept in tight contact with each other and the lifetime of the tool may be extended according to the structure design of the invention.

[0017] While the preferred embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that various modifications may be made in the embodiment without departing from the spirit of the invention. Such modifications are all within the scope of the invention.

Claims

1. A flexible shroud for an air sander, the flexible shroud having a sealing edge contacting a sanding member of the air sander at a rim of the shroud, wherein the sealing edge is bent inward to form a contact surface in tight and surface contact with the sanding member.