Patent Publication Number: US-6342000-B1

Title: Sander having a vibrating mechanism

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a sander device, and more particularly to a sander device having a vibrating mechanism. 
     2. Description of the Prior Art 
     Typical sander devices comprise an endless sander belt engaged around one or more rollers so as to be driven by the rollers and in order to sand or work onto the work pieces. Both the rollers and the sander belt may not be rotated or vibrated such that the sander belt may not be adjusted or changed relative to the work pieces. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional sander devices. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a sander having a vibrating mechanism for vibrating the sander belt and for removing some of the dust from the sander belt. 
     In accordance with one aspect of the invention, there is provided a sander comprising a support, a first roller rotatably secured to the support at a pivot shaft, a bracket rotatably supported on the support at a pivot pin, a second roller rotatably secured to the bracket at a pivot axle, a sander belt engaged around the first roller and the second roller. and means for rotating the bracket about the pivot pin to twist the sander belt. 
     The rotating means includes an actuator disposed on the support, the actuator includes a rod extended therefrom and engaged with the bracket for rotating the bracket about the pivot pin. The bracket includes a pole extended therefrom and engaged with the rod for allowing the actuator to rotate the bracket about the pivot pin via the rod and the pole. The actuator includes a follower secured to the rod, the follower includes a cavity formed therein for receiving the pole. A spring biasing device may further be provided for biasing or for recovering the rod backward to the original position. 
     The rotating means includes a valve device coupling the actuator to an air source, and the valve device includes means for selectively supplying the air to the actuator. The valve device includes a first port coupled to the actuator and a second port for coupling to the air source, the selectively supplying means includes a spindle rotatably received in the valve device, the spindle includes a groove formed therein for selectively communicating the first and the second ports with each other when the spindle is rotated relative to the valve device. The valve device includes an air exit, the spindle includes a recess for selectively communicating the first port and the air exit of the valve device with each other when the spindle is rotated relative to the valve device. 
     The selectively supplying means includes a means for actuating the spindle to rotate relative to the valve device. The actuating means includes a lever secured to the spindle, and an air outlet directed toward the lever to rotate the spindle with the lever. The lever includes a disc attached thereto and facing toward the air outlet for allowing the air from the air outlet to act onto the disc of the lever. 
     Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front perspective view of a sander in accordance with the present invention; 
     FIG. 2 is a partial rear perspective view of the sander; 
     FIG. 3 is a partial rear plan view of the sander; 
     FIG. 4 is a partial exploded view of the control device for the sander; and 
     FIGS. 5 and 6 are a partial rear perspective view and a partial rear plan view of the sander respectively, similar to FIGS. 2 and 3 respectively, illustrating the operation of the sander. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and initially to FIG. 1, a sander in accordance with the present invention comprises a stand  10  including an endless sander member  11  movably or operatively provided thereon for sanding purposes, and including a wall  12  extended upward from the rear portion thereof for supporting a housing  13  thereon. The housing  13  includes a support  15  extended inward of the inner chamber  14  of the housing  13 , and includes a cover  18  pivotally secured thereto for enclosing the chamber  14  of the housing  13 . A roller  20  is rotatably secured to the support  15  at a pivot shaft  21 . Another roller  30  is rotatably secured on a bracket  31  at a pivot axle  32 . A sander belt, particularly an endless sander belt  40  is engaged over the rollers  20 ,  30  so as to be moved or actuated by the rollers  20 ,  30 . A typical motor or the like may be coupled to one of the rollers  20 ,  30  for rotating the rollers  20 ,  30  and for driving the sander belt  40  to work onto the work pieces. The bracket  31  includes a pin  33  extended downward therefrom and rotatably engaged into the support  15 , such that the pin  33  is formed as a pivot pin  33  for pivotally or rotatably securing the bracket  31  to the support  15 , and such that the bracket  31  and the roller  30  is rotatable relative to the support  15  about the pivot pin  33 . 
     Referring next to FIGS. 2-4, a seat  16  is disposed on the rear portion of the support  15  and a post  17  is secured to or extended upward from the block  16 . An air outlet  80  is disposed on the seat  16  and is coupled to a pressurized air source, such as an air pump or a pressurized air container, etc., via a hose  81 , for receiving the pressurized air from the pressurized air source. The bracket  31  includes an extension  34  secured thereto or extended therefrom. A pole  35  is secured to the extension  34  with one or more fasteners  38  or is extended from the extension  34 . An actuator  70 , such as a hydraulic or pneumatic cylinder, is secured on the support  15  and includes a spring  71  received in a casing  77  thereof and includes rod or a piston rod  72  extended outward through the casing  77 . A follower  74  is secured to the rod  72  so as to be moved and actuated by the actuator  70  via the rod  72 . The follower  74  includes a cavity  76  formed therein for receiving the pole  35  and for rotating the bracket  31  about the pivot pin  33 . The actuator  70  includes a piston or a slide  78  slidably received in the casing  77  and engaged with the spring  71  which may bias or recover the slide  78  to move in a direction away from the pole  35 . 
     A valve device  60  is secured on the support  15  at the post  17  and includes an air exit  63  and includes a port  64  coupled to the pressurized air source, such as the air pump or the pressurized air container, etc., via another hose  81 , for receiving the pressurized air from the pressurized air source. The valve device  60  further includes another port  65  coupled to the actuator  70  with a hose  73  for selectively supplying the pressurized air to the actuator  70 . As best shown in FIG. 4, a valve spindle  66  is rotatably received in the valve device  60  and includes a groove  67  formed therein for selectively communicating the ports  64 ,  65  with each other (FIG. 3) and for supplying the pressurized from the port  64  to the actuator  70  via the port  65 . The valve spindle  66  further includes a recess  68  formed therein for selectively communicating the air exit  63  and the port  64  with each other (FIG. 6) for allowing the air from the actuator  70  to flow out of the valve device  60  via the air exit  63 . A lever  61  has one end secured to the valve spindle  66  with one or more fasteners  69  and includes a cap or a hood or a disc  62  attached to the other end thereof and directed toward the air outlet  80  so as to be actuated by the air flowing outward from the air outlet  80 . 
     In operation, as shown in FIGS. 2 and 3, at the beginning, the sander belt  40  that is engaged over the rollers  20 ,  30  has a portion, particularly an edge portion, disposed between the air outlet  80  and the disc  62  of the lever  61 , such that the lever  61  and thus the valve device  60  may not be actuated. At this moment, the ports  64 ,  65  of the valve device  60  are communicated with each other by the groove  67  of the valve spindle  66 , such that the pressurized air may be supplied to the actuator  70 . The rod  72  thus may be moved by the actuator  70  in order to rotate the bracket  31  and the roller  30  about the pivot pin  33  via the follower  74  and the pole  35  of the bracket  31 . When the roller  30  is rotated about the pivot pin  33 , the sander belt  40  may be moved or disengaged from the air outlet  80  and the disc  62 , such that the air from the air outlet  80  may blow or act onto the disc  62  of the lever  61  in order to rotate the valve spindle  66  via the lever  61 . 
     As shown in FIGS. 5 and 6, the groove  67  of the valve spindle  66  may thus be disengaged from the ports  64 ,  65 , and the recess  68  of the valve spindle  66  may thus be used for communicating the air exit  63  and the port  64  with each other (FIG. 6) for allowing the air from the actuator  70  to flow out of the valve device  60  via the air exit  63 . The pressurized air source thus may not be supplied to the actuator  70 . However, the spring  71  may bias and may recover the rod  72  backward to the original position, such that the bracket  31  and the roller  30  may be rotated about the pivot pin  33  back to the original position, and such that the sander belt  40 , particularly the edge portion of the sander belt  40 , may be moved to the position located between the air outlet  80  and the disc  62  again in order to prevent the disc  62  from being actuated by the air from the air outlet  80 . The rod  72  may be moved and biased backward to the original position by the spring  71 , because the actuator  70  is communicating with the air exit  63  of the valve device  60  and because the air in the actuator  70  may flow out through the air exit  63  of the valve device  60 . 
     When the air outlet  80  is blocked by the sander belt  40 , the disc  62  and the lever  61  may be moved or rotated downward to the downward depending position, in order to communicate the groove  67  thereof with the ports  64 ,  65 , such that the actuator  70  may be actuated to move the pole  35  and the rod  72  and to rotate the bracket  31  and the roller  30  about the pivot pin  33  again. The roller  30  thus may be rotated about the pivot pin  33  in a reciprocating action. The sander belt  40  thus may also be twisted or moved or vibrated in a reciprocating action, such that some of the dust may be removed from the sander belt  40 . When the portion of the sander belt  40  that is engaged on the roller  30  is twisted by the roller  30  in a reciprocating action, the other portion of the sander belt  40  that is engaged on the roller  20  may also be slightly twisted for allowing the sander belt  40  to act onto the work pieces at different working directions, for example. The sander of the invention may further provide a limiting wall device provided beside the sander belt  40  for preventing the sander belt  40  from being disengaged from the rollers  20 ,  30 . 
     When the sander belt  40  is located between the air outlet  80  and the disc  62  (FIGS. 2,  3 ), the air from the air outlet  80  may blow onto the inner portion of the sander belt  40  in order to vibrate the sander belt  40  and in order to indirectly blow or to remove some of the dust from the sander belt  40 . When the sander belt  40  is disengaged from the air outlet  80  and the disc  62  (FIGS. 5,  6 ), the air from the air outlet  80  may blow onto the disc  62  in order to rotate the roller  30  and the sander belt  40  via the lever  61 . At this moment, the air from the air exit  63  may flow outward into the chamber  14  of the housing  13  (FIG. 1) in order to blow or to remove some of the dust from the sander belt  40 . 
     Accordingly, the sander in accordance with the present invention includes a vibrating mechanism for vibrating the sander belt and for removing some of the dust from the sander belt. 
     Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.