Abstract:
A quick release system for an oscillating spindle sander comprises a linearly elongated shaft inserted and housed within a cavity of a sanding drum. A top washer comprising a central aperture and a pair of downwardly projecting prongs aligned about a circumference of the central aperture and insertable into notches formed within the top of the shaft. A pin assembly is insertable into the shaft to impinge the top washer with the sanding drum, thereby compressing an abrasive sanding sleeve placed onto said sanding drum and permitting sanding of an object. The pin assembly may be released and removed from the shaft, permitting removal of the top washer. Upon removal of the top washer, the abrasive sanding sleeve may be removed and disposed of, or inverted so as to use the unused portion of the sanding sleeve, and thus extending the useful life of the sleeve.

Description:
RELATED APPLICATIONS AND DISCLOSURES 
     The present application is a Continuation-In-Part of U.S. Ser. No. 09/909,935 filed Jul. 21, 2001, presently embodied in issued U.S. Pat. No. 6,547,654, issued on Apr. 15, 2003 which claimed the benefit of U.S. Provisional Patent Application No. 60/220,214, filed on Jul. 22, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an oscillating spindle sander, and more particularly, to an oscillating spindle sander with an automatic abrasive sleeve tightening means and a safety release for quickly extracting items or objects caught in the sander. 
     2. Description of the Related Art 
     Oscillating spindle sanders are well known in the prior art, embodied in a variety of configurations, including table models and portable, hand-held models. One example of the art is Sears Craftsman Oscillating Spindle Sander Model No. 113.225306, wherein an on and off switch engages and disengages, respectively, a motor for oscillating a cylindrical sander for sanding objects. 
     The oscillating spindle sanders that have developed require manual loosening and tightening of a nut for installation or removal of the abrasive sleeve. This is generally done by tightening or loosening the nut over the top washer above the sanding drum. This manual adjustment requires additional tools and time, as well as an estimation on the part of the user with regard to whether the abrasive sleeve is tight enough. Furthermore, there is a risk of over-tightening the nut that may result in stripping of the nut and bolt, thereby rendering the sander inoperable and requiring expensive maintenance to restore use to the sander. Consequently, a need exists for an automatic means by which the abrasive sleeve is accurately tightened and avoiding the risks and problems described above. The present invention fulfills this need. 
     In addition, if the user gets his/her hair or clothing caught in the sander, he/she is forced to try and reach either an on/off switch on the motor or to reach the power plug and disconnect the sander from its power source in order to stop the spindle shaft, the sanding drum and the abrasive sleeve from turning. The development of a quick-release mechanism permits a user to disengage the sanding drum and abrasive sleeve from the spindle shaft, momentarily, so as to extricate the object caught within the sander. 
     Further, it is recommended that users of oscillating spindle sanders, in order to reduce economic waste, remove and invert the abrasive sleeve once before discarding. Because of the hassle associated with removing and inverting the abrasive sleeve, many users simply discard the sleeve without maximizing the useful life of the sleeve. 
     Consequently, a need exists for a system that allows a user to quickly release the abrasive sleeve and drum from spinning, thereby allowing the user to extricate the object caught in the sander. A further need exists for a system that allows the abrasive sleeve to be quickly and easily removed, inverted and replaced. The present invention fulfills each of these needs. 
     SUMMARY OF THE INVENTION 
     The present invention, an oscillating spindle sander with automatic abrasive sleeve tightening means and quick release system operates as an improvement to current oscillating spindle sanders commercially available. In most oscillating spindle sanders, the abrasive sleeve must be manually tightened. The present invention incorporates an automatic tightening means consisting in part of a flyweight assembly that works to tighten the abrasive sleeve against the sanding drum of the oscillating spindle sander as soon as the motor of the sander is activated. An alternative embodiment of the flyweight assembly is devised to convert or modify existing oscillating spindle sanders into an apparatus similar to that disclosed herein. 
     The present invention also incorporates a quick release system to be used in conjunction with a standard oscillating spindle sander or with an oscillating spindle sander with the automatic abrasive sleeve tightening means disclosed herein. The quick release system is comprised of a pin assembly that is used to lock down or release, respectively, the upper washer located at the top portion of the sanding drum. When activated, the quick release system releases said washer allows the abrasive sleeve and sanding drum to loosen, thereby allowing the user to extricate the item caught within the sander. The pin assembly also allows for quick and easy removal and replacement of the abrasive sleeve whenever necessary or desired. 
     It is an object of the present invention to provide an automatic abrasive sleeve tightening means for an oscillating spindle sander such that the user does not have to manually tighten the abrasive sleeve. 
     It is a further object of the present invention to provide an automatic abrasive sleeve tightening means for an oscillating spindle sander such that activation of the sander automatically tightens the abrasive sleeve about the sanding drum. 
     It is a further object of the present invention to provide a quick release system for an oscillating spindle sander such that if an item of a user is caught in the oscillating spindle sander, the user can quickly release the abrasive sleeve and sanding drum, thereby breaking free of the sander without having to reach the on/off switch on the motor, the electrical plug, or otherwise risking further injury to self or someone close by. 
     It is another object of the present invention to provide a quick release system that allows for quick and easy removal and replacement of the abrasive sleeve. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
     FIG. 1 is an elevational view of an oscillating spindle sander with a quick release system incorporated therein; 
     FIG. 2 is an elevational view of the automatic abrasive sleeve tightening means; 
     FIG. 3 is an elevational view of an alternative embodiment of the automatic abrasive sleeve tightening means; 
     FIG. 4 is an exploded perspective view of the tightening means, including the abrasive sleeve partially placed onto the sanding drum, and a shaft that communicates with the sanding drum; 
     FIG. 5 is an exploded perspective view of the abrasive sleeve secured to the sanding drum, with a top washer, spring and pin assembly partially extracted to indicate the spatial arrangement of the respective components; 
     FIG. 6 a  is a bottom view of the top washer illustrating the central aperture and the pair of downwardly projection prongs; 
     FIG. 6 b  is a partial cross-sectional view of the top washer taken along line VI—VI of FIG. 6 a;    
     FIG. 7 a  is an elevational view of the spindle shaft, shown in partial section view also to indicate the placement of the shaft openings to receive ball bearings impinged therein by the vertical alignment of the shaft; 
     FIG. 7 b  is a top view of the spindle shaft illustrating the notches provided to receive the prongs from the top washer; 
     FIG. 8 is a cross-sectional view of the sanding drum and the components necessary for the quick release system taken along the line VIII—VIII of FIG. 5; 
     FIG. 9 is a cross-sectional view of the sanding drum, similar to that of FIG. 8 except that the height “h” between the top washer and the sanding drum is now substantially zero, thereby indicating that as the spindle shaft rotates due to the force of the motor, the top washer will engage the shaft and spin the sanding drum and the abrasive sleeve; and 
     FIG. 10 a  and FIG. 10 b  are elevational views with the sanding drum removed for clarity, wherein FIG. 10 a  is the resting position of the apparatus, and FIG. 10 b  is a representation of the apparatus in use (with the spring removed for clarity), with the flywheels having moved outward from the shaft, and the dome plate having risen vertically above its starting position (indicated by the broken lines between the two figures). 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within the FIGS. 1 through 10 b.    
     1. Detailed Description of the Figures 
     Referring now to FIG.  1  through FIG. 3, an oscillating spindle sander  10  is shown with the present invention, a abrasive sleeve tightening means  20  and quick release system. An abrasive sleeve  30  on most oscillating spindle sanders is tightened manually by screwing on a nut. This action requires separate tools and requires the user to guess as to what the appropriate tightness of the nut should be. The oscillating spindle sander  10  with abrasive sleeve tightening means  20  and quick release system is a system that includes flyweights  22  to automatically tighten the abrasive sleeve  30  that fits over the sanding drum  40  (see FIG.  4 ). 
     The motor  42  causes the spindle shaft  44  to oscillate or rotate. Both the motor  42  and the spindle shaft  44  are of the type commonly known to one of ordinary skill in the art. Attached to the spindle shaft  44  is a spider gear  26  that is anchored to the spindle shaft  44  via a bolt, rivet or similar means  18 . One of ordinary skill in the art would recognize that the spider gear  26  can also be machined directly with the spindle shaft  44 . The spider gear  26  rotates with the spindle shaft  44 . Dome plate  24  sits atop spider gear  26 . In the preferred embodiment, the dome plate  24  does not rotate with the spindle shaft  44  and the spider gear  26 . One of ordinary skill in the art would recognize that the dome plate  24  may rotate with the spindle shaft  44  and the spider gear  26  without altering its function or the intentions of the inventor. The dome plate  24  has a top flat section  50  that operates in place of the base washer found in most oscillating spindle sanders known to one of ordinary skill in the art. 
     In the preferred embodiment, the two flyweights  22  are coupled to the two inverted “L”-shaped metal arms  28  that are in turn connected to the spider gear  26  via two posts (not shown) that are connected to the spider gear  26 . One of ordinary skill in the art would recognize that the number of flyweights  22  and thus the number of arms  28  and posts (not shown) may be increased depending on the length of the shaft  44 . It is preferred that the flyweights  22 , arms  28  and posts (not shown) are increased two at a time for even weight distribution, but it is envisioned that a flyweight  22  may be added one at a time provided that there is the appropriate balance provided to the device. It is preferred that the arms  28  be connected to the posts (not shown) by a rivet at pivot point  21 . One of ordinary skill in the art would recognize that the arms  28  could be connected to the posts (not shown) by other means, including, but not limited to a pin. In the preferred embodiment, the rollers  23  are connected to the arms  28  by a fastener  19  at the opposite end from the flyweights  22 . The rollers  23  may be of plastic, metal, or other similarly durable materials. The rollers  23  are preferably connected to the arms  28  by a rivet, although other means can be used. The rollers  23  are preferably single rollers, but they may be double rollers or ball shaped rollers, or other similarly functioning items. In the preferred embodiment, two springs  25 , one spring  25  attached via a screw, rivet, etc.  27  to the first flat side  28   a  of arms  28 , located on one side of the spindle shaft  44 , and a second spring  25  attached via a screw, rivet, etc.  27 , attached to the second flat side (not shown) of arms  28 , located on the opposite side of the spindle shaft  44 , keep the arms  28  and thus the flyweights  22  from overextending. The springs  25  also aid in the return of the flyweights  22  upon the motor  42  being turned off or the power to the motor  42  being terminated. 
     In the preferred embodiment, as the spindle shaft  44  rotates, centrifugal force causes the flyweights  22  to move away from the spindle shaft  44 . As the flyweights  22  move away from the spindle shaft  44 , the flyweights pull arms  28  out away from the spindle shaft  44  (as seen in FIG.  10 ). Consequently, the arms  28  pivot around pivot point  21  causing rollers  23  to roll in toward the spindle shaft  44 . As the arms  28  move around pivot point  21 , the rollers  23  force the dome plate  24  to move in an upward motion toward the sanding drum  40  such that the top platform  50  of the dome plate  24  pushes upward and compresses the sanding drum  40 . As seen in FIG. 8, the top washer  60  and the sanding drum  40  are separated by a height “h” when the sanding drum  40  is not engaged by the top washer  60 . As dome plate  24  pushes upwards on the sanding drum  40 , the sanding drum  40  is compressed against top washer  60  that rotates with the spindle shaft  44  on the horizontal plane, but is prevented from moving in an upward direction either by the traditional nut, the quick release system disclosed later herein or by other similar means. The sanding drum  40  is made out of rubber in the preferred embodiment. It is readily known to one of ordinary skill in the art, however, that the sanding drum  40  may be made out of other materials that have properties similar to rubber in that it is strong, durable and pliant. As the sanding drum  40  is vertically compressed against top washer  60 , it expands horizontally exerting pressure on the inside of the abrasive sleeve  30  that has been placed around the sanding drum  40 , thereby compressing the initial height “h” to substantially no height between the drum  40  and washer  60  (as seen in FIG.  9 ). Both the sanding drum  40  and the abrasive sleeve  30  rotate with the spindle shaft  44  just as in any oscillating spindle sander known to one of ordinary skill in the art. It is preferred that the sanding drum  40  exert just enough pressure on the abrasive sleeve  30  to keep it taught against the sanding drum  40  such that the abrasive sleeve  30  does not loosen or slip when the user presses the material that needs to be sanded against the abrasive sleeve  30  while it is rotating. 
     In the preferred embodiment, when the oscillating sander  10  is turned off or the power to the oscillating sander  10  is removed, the motor  42  will begin to turn the spindle shaft  44  slower until it eventually stops. It is preferred that as the spindle shaft  44  turns slower, the flyweights  22  will move towards the spindle shaft  44  causing the rollers  23  to move away from the spindle shaft  44  and allowing the dome plate  24  to lower, thus releasing the compression on the sanding drum  40  and loosening the abrasive sleeve  30  so that it can be removed and replaced when necessary. 
     In an alternative embodiment, the abrasive sleeve tightening means  20  is adapted such that it can be fitted onto a standard oscillating spindle sander already in existence. In this alternative embodiment  20 A, shown in FIG. 3, the spider gear  26  and posts (not shown) are replaced by a sheathe  16  that wraps around the spindle shaft  44 . It is preferred that the sheathe  16  is fastened directly to the spindle shaft  44  via two rivets, although other fastening means could be used, and that the sheathe  16  has posts machined to connect the arms  28  thereto. To apply this alternative embodiment  20 A to an existing oscillating spindle sander, one simply removes the sanding drum and the washers from the sander, sliding the automatic abrasive sleeve tightening means  20 A over the shaft, tightening the rivets or other fasteners to set the abrasive sleeve tightening means in place and replacing the sanding drum  40  and top washer  60 . The bottom washer is operatively replaced by the top platform  50  of the dome plate  24 . 
     As previously disclosed, the same compression concept is used in the quick release system mechanism as shown in FIG.  4  through FIG.  10 . In most oscillating sanders known to one of ordinary skill in the art, the top washer  60  rotates with the spindle shaft  44  on the horizontal plane, but has a retaining nut, pin, etc. to limit its vertical movement. In an oscillating spindle sander having a quick release system, the top washer  60  is held in place by a pin assembly  110 . The top washer  60  includes a pair of prongs  62  and  64  that project downward and a centralized aperture  65  through which the pin assembly  110  is inserted into the cavity  70  of the sanding drum  40 . When the top washer  60  is compressed to the sanding drum  40 , the prongs  62  and  64  insert into a pair of corresponding notches  66  and  68  within the shaft  44 . The insertion of the prongs  62  and  64  into the notches  66  and  68  synchronizes the spinning of the shaft  44  to the spinning of the sanding drum  40  (and the attached abrasive sleeve  30 ). In the preferred embodiment, the spindle shaft  44  has a core section thereof removed creating a cavity  70 . The cavity  70  must be large enough to allow the pin assembly  110  to slide down into the spindle shaft  44 , but not too large as to compromise the strength of the spindle shaft  44 . In the preferred embodiment, the quick release system mechanism is comprised of the pin assembly  110 , having an inner pin  120 , a housing  130 , bearings  140 , a spring  150  and an optional lock  160 . The pin assembly  110  may be referred to as a ball locking pin, similar to locking pins currently on the market and known to one of ordinary skill in the art. 
     Within the cavity  70 , in the preferred embodiment, is an opening, referred to herein as a shaft opening  45 , cut out of the spindle shaft  44  into the internal sides of the cavity  70 , sized to accommodate a portion of the bearings  140 . The shaft opening  45  circumscribes an internal circumference of said shaft  44  and cavity  70 . It is also envisioned that the shaft opening(s)  45  may be two independent openings cut out of the internal walls of the shaft  44  and cavity  70  and sized to accommodate the ball bearings  140 . Similarly, in the pin assembly  110 , two portions of the inner pin  120  are removed. These removed portions are referred to herein as pin openings  124 . These pin openings  124  are sized to accommodate the bearings  140  such that only a small portion of the bearings  140  is allowed to exit the pin openings  124 . 
     The pin assembly  110  is inserted into the cavity  70 . If the user gets an item (such as hair, clothing, an appendage or other items) caught in the spinning sander, the user need only press down on the inner pin head  122  far enough to allow the widest portion of pin openings  124  to align with the shaft openings  45  so that the small portion of the bearings  140  that is being held in the shaft openings  45  can slip out of the shaft openings  45  and into the pin openings  124  allowing the housing  130  to move in a very slight upward direction, away from the motor  42 , slightly releasing the top washer  60 , allowing the sanding drum  40  to expand vertically, thus creating a very slight release of compressive pressure from the sanding drum  40  on the abrasive sleeve  30 . This process releases just enough pressure for the abrasive sleeve  30  to come loose along with the item caught within the sander. This method does not cut power to the oscillating spindle sander  10 , but instead acts as a quick release for the user to get away from the oscillating spindle sander  10  before the user is seriously hurt. When the oscillating spindle sander  10  is off, the pin assembly  110  allows the user to quickly release and change the abrasive sleeve  30 . 
     In the preferred embodiment, the lock  160  is used to keep the inner pin  120  down so that the pin openings  124  remain in line with the shaft openings  45 . When the inner pin  120  is compressed, the lock  160  is flipped up to cover the inner pin head  122  and hold the pin head  122  down. To release the inner pin  120  simply push down on the inner pin head  122 , flip the lock  160  down, and release the inner pin  122 . It is envisioned that one embodiment of the lock  160  may be a pivoting ring (as shown), that may be pivoted between an engaged position (FIG. 10 a ) And a disengaged position (FIG. 10 b ). 
     2. Operation of the Preferred Embodiment 
     To use the present invention, a user will place the quick release pin assembly  110  into the cavity  70 . To lock the pin assembly  110  so as not to engage the sanding drum  40  with the shaft  44 , the pin assembly  110  is compressed downward so as to release the ball bearings  140  from the shaft openings  45  via the pin openings  124 . The pin assembly  110  may be secured in this position by pivoting of the ring  160  so that a horizontal cross member of the ring  160  rests across the diameter of the pin head  122 , thereby impinging the outward movement of the pin assembly  110  that is urged by the spring  150 . 
     To engage the sanding drum  40  with the shaft  44 , a user simply will release the pin assembly  110  by pivoting the ring  160  from impinging the pin assembly  110 . The spring  150  will urge the pin assembly  110  upward, and the shaft walls will urge the ball bearings  140  into the shaft openings  45 , thereby impinging the pin assembly  110  into a fixed and engaged position. When the motor  42  is actuated, the shaft  44  will turn, causing the flywheels  28  to move outward and force the dome plate  24  upward. The upward force of the dome plate  24  causes the flat section  50  to engage the lower portion of the sanding drum  40 , compressing the sanding drum  40  toward the engaged top washer  60 . The pin assembly  110  prevents the top washer  60  from popping out, thus, the sanding drum  40  is compressed therebetween, causing the abrasive sleeve  30  (attached to the exterior of the drum  40 ) to rotate and allow for sanding. 
     If an item or object becomes caught in the sander, the user may simply apply sufficient force to the pin assembly  110  to cause a downward shift of the pin assembly  110  so that the ball bearings  140  release from the shaft openings  45 , thereby momentarily disengaging the sanding drum  40  from the shaft  44 , thus allowing for extraction of the item or object. To re-engage, the user will stop the motor  42  and re-position the top washer  60  and the prongs  62  and  64  into the notches  66  and  68 . Then, the motor  42  may be switched on again, thereby restarting the oscillation of the sander. 
     The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. Therefore, the scope of the invention is to be limited only by the following claims.