Abrading – Abrading process – Utilizing nonrigid tool
Reexamination Certificate
2001-03-21
2003-11-18
Nguyen, George (Department: 3723)
Abrading
Abrading process
Utilizing nonrigid tool
Reexamination Certificate
active
06648737
ABSTRACT:
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to tools for sanding or grinding. More particularly, the present invention relates to a contour sanding apparatus for use with hand-held power tools, enabling a user to abrade contoured surfaces.
II. Description of Related Art
Belt sanders have been used for abrading or sanding many different types of surfaces. Free standing or bench mounted belt sanders typically have three rollers, which control the travel of the abrading belt. One of these three rollers will be driven and the other two rollers remain idle or free spinning. Normally the work area of these belt sanders is in between the two idler rollers.
Most of today's bench top or pedestal type belt sanders will incorporate a rigid planar work plate that is secured and located within this work area. The abrading loop or belt will travel in front of the work plate, which is used as a support on the backside of the sanding belt while abrading the workpiece on the front side of the sanding belt. As the work plate is a rigid planar plate, these belt sanders are adapted primarily for abrading flat or straight surfaces and, consequently, cannot effectively sand contoured surfaces.
Power sanders having contouring capability are currently available. However, these are more costly and are generally limited to use on a specific contour. Accordingly, some of today's contour abrading is still being done by means of time consuming and tiresome efforts of physically sanding by hand.
A number of patents are directed to power sanding of contours. For example, U.S. Pat. No. 6,116,999, discloses a sander with the capability of sanding a bullnose concave surface by using sheets of abrasive materials, clamped in accordance with a flexible pad. Through capable of abrading a concave workpiece, it is limited to only that concave surface.
U.S. Pat. No. 5,725,423, discloses a back-up pad provided for supporting an abrasive article during abrading. Though capable of abrading some contours, this method is limited to abrading only slights contours.
U.S. Pat. No. 5,662,519, discloses a contour sander designed for sanding the details and curves of automobile body panels. This sander is limited to manual use and may not be adapted for use on a power sander.
U.S. Pat. No. 5,700,187, discloses a flexible device for holding abrasive materials, which can be adjusted to a variety of shapes. Though capable of conforming to a variety of curved shapes, the device has to be manually adjusted to each shape separately.
U.S. Pat. No. 3,956,858, discloses a flexible hand held abrading tool, which can easily conform to curves and contours. However, this is also limited to a manually operated hand held tool and not for use on power sanders.
In addition to traditional belt sanders, a number of hand held attachments directed at sanding and grinding have been introduced to the market. Typically, these attachments are mechanically coupled to the power tool at the site where a standard attachment, such as a drill-bit or sanding-wheel is otherwise placed. In spite of the advantages that these add-on devices may provide, they have not adequately addressed the problems associated with grinding or sanding surfaces intended to be non-flat. This is because these existing devices present either a flat or fixed-radius surface as a backing for the grind/sanding belt, which is a serious limitation for ornate work pieces incorporating curved portions. As a consequence, portions of such complex and ornate work-pieces tend to be either over-worked or under-worked during the finishing process.
A number of patents have been directed to hand held sanding attachments. For example, U.S. Pat. No. 4,551,951, discloses a detachable portable continuous-belt driving head for use in conjunction with an air driven rotatable spindle. By wrapping a sanding belt around the work-piece, this device can be used to sand or grind a significant portion of the circular contour of a cylindrical work-piece such as a pipe. However, wrapping such a belt around an uninterrupted span of pipe requires that the belt be ‘seamed,’ that is that it has seam where it can be opened and then rejoined. In other words, before this device can be used on a pipe, the ends of the grinding belt must be separated at the seam, the belt must be wrapped around the pipe, and the ends o the belt must be rejoined. This process is time consuming. Furthermore, the use of seam-containing grinding belts can be hazardous, since they are vulnerable to operator error in connecting and disconnecting the belt that can lead to the belt flying off the rollers, causing injury or damage.
U.S. Pat. Nos. 4,858,390 and 5,031,362, disclose similar endless-belt grinding attachments for use in conjunction with typical hand-held electric or pneumatic power drills. Both of these devices have a drive pulley, driven by the output of a power tool, and in idler-pulley disposed at the end, distal to the drive pulley, of an arm member. In use, a grinding belt is mounted on these pulleys. Because the grinding belt so mounted conforms to a single longitudinal axis these devices are limited to relatively small angles of contact when used with work pieces having curved contours, such as pipes or toroidal shapes. Consequently, it is difficult to use either of these devices to satisfactorily grind such curved surfaces.
U.S. Pat. No. 4,578,906 discloses another device using an endless grinding belt. This device is similar to those of U.S. Pat. Nos. 4,858,390 and 5,031,362 in that it has two pulleys, one being a drive-pulley. These pulleys are mounted at the ends of a longitudinal arm-member. An endless grinding belt fits over the pulleys and is stretched to an essentially flat configuration, so that it presents a flat grinding surface to the work piece. A spring is mounted coaxially with the arm-member and is used as a bias means for keeping the belt under tension and thus flat. However, this device has the same limitations as those described above.
Therefore, there is a need for a contour sanding device for use with standard sanding belts, which can work the surface of a variety of complex, ornate shapes, and can provide proper backing for a variety of contours or flat surfaces of a work-piece.
SUMMARY OF THE INVENTION
The present invention is a contour sanding apparatus for driving a sanding belt. For purposes of this application, the term sanding belt means an abrasive belt, such as those manufactured of sandpaper, steel wool, SCOTCHBRITEO®, or any other art recognized abrasive belts.
In one embodiment of the invention, the apparatus includes a body and a drive pulley rotatably attached to the body, the drive pulley comprising a drive-axle dimensioned for attachment to a source of rotation. A primary arm is fixedly attached to the body and includes an end portion to which a primary idler pulley is rotatably attached. A secondary arm is also provided. The secondary arm includes tensioning means for maintaining the sanding belt in tension, and a first end portion to which a secondary idler pulley is rotatably attached. The secondary idler pulley is disposed in relation to the primary idler pulley such that the sanding belt forms a sanding portion between the primary idler pulley and the secondary idler pulley. The sanding belt is dimensioned for disposal about the drive pulley, the primary idler pulley, and the secondary idler pulley such that the a sanding portion of the sanding belt, disposed between the primary idler pulley and the secondary idler pulley, may be made to conform to a plurality of contours.
In the preferred embodiment of the invention, the secondary arm extends from, and is pivotally attached to, the primary arm via a second end portion, which is disposed within a central slot in the central portion of the primary arm. The preferred secondary arm includes a non-slidable section that includes the second end portion, and a slidable section that includes the secondary idler pulley. It is preferred that a sleeve be slidably disposed about the non-slidable secti
Andrews William L.
Deware William R.
Lawson & Persson P.C.
Nguyen George
Persson Michael J.
LandOfFree
Contour sanding apparatus and kit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Contour sanding apparatus and kit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contour sanding apparatus and kit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3129252