Patent Publication Number: US-11027393-B2

Title: Adjustable sander pad assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This utility patent application claims the benefit of provisional patent application 62/503,245 filed May 8, 2017, which is hereby incorporated by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not Applicable. 
     APPENDIX 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to rotary floor sanders, and more particularly to an adjustable sander pad assembly for rotary floor sanders that provides adjustable stiffness of the sanding pad for improved sanding of surfaces. 
     Related Art 
     For years now professional floorers and do it yourselfers have been finishing their hardwood floors in their homes with equipment that consists of machines like industrial grade  7 ″ rotary floor sander edgers that use a sander pad. This machine performs the task of sanding the floor at the base of a wall where the larger floor sanders cannot reach. This machine will take the top layer of wood surface from the floor to expose the undamaged unvarnished wood to later refinish for a greater appearance. During the process of sanding the floor the process has multiple steps requiring different amounts of stiffness in the sander pad. 
     The first step in edging along the base of a wall is to use the 7″ floor sander edger with a rotating tool that is usually rigid enough to allow for the abrasive surface that is applied to the tool to remove greater amounts of wood when pressure is applied. This process removes the surface varnish previously applied to the floor and also deep surface abrasions in the floor. The second step is to replace the rigid sanding pad for one that is more flexible to sand finer details. The process of removing the sander pad from the rotary sander and replacing it with a different pad can be a complicated and time-consuming one. 
     The present invention allows the changing of the sander pad from a stiffer pad to a more flexible pad with a simple adjustment that is quick and easy by using the claimed adjustable sander pad assembly. 
     SUMMARY OF THE INVENTION 
     An adjustable sander pad assembly having a backer flange, multiple support fingers, multiple adjustment supports, and an adjustment ring where the multiple support fingers each has a first and a second attachment point and where the first attachment point is attached to the adjustment support and the second attachment point is attached to the adjustment ring. The support fingers, the adjustment supports and the adjustment ring are mounted on the backer flange. The adjustment ring is rotated to move the support fingers and adjustment supports radially from a retracted support position to an extended support position. 
     Preferably, the adjustable sander pad assembly also has a sander plate, a fixing ring, and a flex plate. The sander plate is mounted on the backer flange. The fixing ring attaches fixedly to the backer flange and secures the multiple support fingers, the multiple adjustment supports, and the adjustment ring. The flex plate is fixedly attached to the backer flange over the fixing ring. 
     When the adjustable sander pad assembly is in the extended position, the sander pad assembly is more rigid, and when it is in the retracted position, the sander pad assembly is more flexible. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is an expanded view of a first embodiment of the sander plate assembly of the present invention. 
         FIG. 2  is a plane view of the sander plate assembly without the flex plate in the retracted position. 
         FIG. 3  is a plane view of the sander plate assembly without the flex plate in the extended position. 
         FIG. 4  is a partial plane view of the sander plate assembly without the flex plate in the retracted position. 
         FIG. 5  is a partial plane view of the sander plate assembly without the flex plate in the extended position. 
         FIG. 6  is a perspective view of the key of the present invention. 
         FIG. 7  is a perspective view of a second embodiment of the key adjustment ring. 
         FIG. 8  is a partial plane view of the sander plate assembly without the flex plate in the extended position. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
       FIG. 1  shows and expanded view of a first embodiment of the sander plate assembly  1  of the present invention. A rotating backer flange  10  has a threaded area and multiple channels  46 . In a preferred embodiment, the number of channels  46  is six, but that number can vary from about 2 to 10. The channels extend radially from about mid-radius of the backer flange  10  to the outer edge of the flange. In a preferred embodiment, the length of the channel, d, is about half of the radius of the backer flange  10 . In a more preferred embodiment, the length of the channel, d, is greater than the radius of the backer flange  10 . 
     Adjacent the channels  46  are guide mounts  33  that have pairs of threaded screw holes  50  and  54 . As shown in  FIG. 8 , the guide mount  33  must be thicker than the support fingers  12  to provide space  56  for the fingers to move. Preferably, the backer flange is circular, essentially planar and had a center opening. 
     Support fingers  12  are essentially elongated and narrow. They have a first attachment point  41  and a second attachment point  42 , one at each end. Typically, the number of support fingers  12  is the same as the number of channels  46 . The adjustment supports  14  have an essentially planar top  43  and a bottom surface with a radial projection  44 . The radial projection  44  is sized to moveably nest inside the channel  46 . 
     As shown in  FIG. 8 , the adjustable supports are sufficiently wide that in either the extended or retracted position, the essentially planar top  43  provides support for the flex plate  26 . The depth of the adjustable supports, b, is sufficient to provide stiffening to the sander. In a preferred embodiment, the depth of the adjustable supports is 10% of the radius of the backer flange. In a more preferred embodiment, the depth of the adjustable supports is greater than 10% of the radius of the backer flange. The number of adjustable supports  14  is the same as the number of support fingers  12 . The adjustable supports  14  are rotatably attached to the support finger first attachment point  41  at openings  40 , typically by attachment pins or bearings  16 . Preferably, the openings  40  have a space  58  below the opening, allowing the support finger to be attached and move beneath the sander plate  18 . The attachment pins or bearings  16  are also used to rotatably attach the second attachment point  42  of the support fingers  12  to the adjustment ring  22  at attachment ring openings  36 . The adjustment ring  22  is used to move the adjustment supports  14  from the retracted position (see  FIG. 2 ) to the extended position (see  FIG. 3 ) and back by rotating clockwise and counterclockwise. In a preferred embodiment, the adjustment ring  22  is fixed in position using a set screw  30  at screw opening  52 . 
     As shown in  FIG. 6 , in a second preferred embodiment, the adjustment key ring  31  is turned using by means of a key  60 . The key has a handle  62  and two prongs  64  and  66 . As shown in  FIG. 7 , the key is inserted into the two key openings  25  and  27  in the adjustment key ring  31 . Preferably, below at least one of key openings  25  and  27  is a spring-mounted retainer button  29 . The button engages with at least one of the openings when the adjustment supports are in the retracted position, securing it in the retracted position. When moving to the extended position, the two prongs are inserted into the two openings, thereby depressing the retainer button  29  and allowing the fixing ring and adjustment ring to be rotated to the extended position. 
     A sander plate  18  is used to fix the support fingers  12 , the adjustment supports  14  and the adjustment ring  22  in place on the backer flange  10  by attaching to the guide mounts  33 . When mounted to the backer flange  10 , a finger space  56  is created between the sander plate and the backer flange that allows the finger supports to move from the retracted to the extended positions. The sander plate is circular with a central opening and guides  39  extending outward radially. There the same number of guides as there are adjustment supports, and the guides are designed to nest between the adjustment supports when they are in either the retracted position or the extended. Preferably, the guides are tapered inward toward the center of the sander plate. In a preferred embodiment, the guides are dovetailed to hold the adjustment supports in place when the flex plate  26  is removed. Preferably, the adjustment supports are likewise dovetailed to nest in the guides. Screws  20  are mounted through the sander plate  18  at screw holes  38  into the backer flange  10  at threaded screw holes  50 . 
     In a first embodiment, fixing ring  24  has threads  48  on its perimeter that fixedly attached to the threaded portion  32  of backer flange  10 . When attached, it mounts the support fingers, adjustment supports and adjustment ring to the backer flange. 
     A flex plate  26  is fastened over the remaining components by flex plate screws  28  which pass through the sander plate at openings  37  and mount on backer flange  10  in screw holes  50 . 
     The purpose of the adjustable sander pad assembly is to remove the need to disassemble the tooling for the 7″ floor sander edger when increasing or decreasing flexibility. The adjustable sander pad assembly  1  is mounted onto the jackshaft of the 7″ floor sander edger. Sandpaper is attached to the surface of the flex plate  26 . Tipping the 7″ floor sander edger so that the backer flange  10  is facing the user, the set screw  30  is located and a hex tool is used to loosen the screw until adjustment ring  22  is able to rotate freely. There are two positions that the adjustment ring  22  can be rotated to and locked: the extended position and the retracted position. When the adjustment ring  22  is rotated the components that are retained by the sander plate  18  extend or retract the components that are tied to the adjustment ring  22 . Attached to the adjustment ring  22  are the support fingers  12  and the adjustment supports  14 . In this embodiment, there are six of these components around the circumference of the backer flange  10  and attached to the adjustment ring  22 . These components are able to pivot at the first and second attachment points  42  by use of a bearing or pin  16 . When the adjustment ring  22  is rotated to the desired position, the radial projection  44  on the bottom of the adjustment support  14  moves in the channel  46  on the backer flange  10 . The adjustment support is sandwiched between the backer flange  10  and the flex plate  26 , but is able to move freely. 
     When the user of the sander tool needs more rigidity for more aggressive sanding, the adjustment ring  22  is rotated counter clockwise to extend the adjustment supports to the outer edge of the backer flange  10 . See  FIG. 3 . The set screw  30  locks the adjustment ring  22  into place. When the flexibility adjustment supports are extended, the pressure that is applied to the flex plate  26  will be increased because of the support behind the plate  26  by the adjustment supports  14 . The tool is ready to use at this time. 
     When it is desired that the sanding tool needs to be more flexible for finer sanding, the adjustment screw is loosened and the ring  22  is rotated clockwise to retract the adjustment supports away from the outer edge of the backer flange  10 . See  FIG. 2 . The set screw  30  is used to lock the adjustment ring  22  in place. When the flexibility adjustment supports are retracted, the pressure applied to the flex plate  26  is less, because of the lack of support behind the plate  26  by the adjustment supports  14 . The tool is ready to use at this time. 
     As shown in  FIGS. 4 and 5 , the rotating of the adjustable ring  22  clockwise moves the support fingers  12  to retract the adjustment supports  14  by the radial projections  44  radially along the channel  46 . Rotating the adjustable ring  22  counterclockwise moves the support fingers  12  to extend the adjustment supports by the radial projections  44  radially along the channel  46 . 
     In the second embodiment, the key  60  is used to rotate the key adjustment ring  31  to move the adjustment supports from the retracted position to the extended position and back. The retainer button  29  locks the adjustment supports in the retracted position, and is released when the key is inserted to turn to the extended position. 
     The embodiments were chosen and described to best explain the principles of the invention and its practical application to persons who are skilled in the art. As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.