Patent Publication Number: US-RE38742-E

Title: Quick change bit holder

Description:
FIELD OF THE INVENTION 
     The present invention relates to glass grinders. 
     BACKGROUND OF THE INVENTION 
     Fiocchi in U.S. Pat. No. 5,185,970 discloses a conventional expanding device for supporting grinding sleeves. The expanding device has “a shaped shaft which concentrically supports a plurality of mutually facing disks which can slide in an axial direction and which are rigidly rotationally connected with the shaft. The disks define, between one another in cooperation, a plurality of peripheral seats for the accommodation of elastic rings which can expand radially upon the axial compression of the disks. The elastic rings are suitable for engaging the inner surface of an emery cloth sleeve.” Abstract of U.S. Pat. No. 5,185,970. 
     A hand tool must be used to adjust that shaft which in turns expands or contracts those elastic rings. For some people, hand tools are difficult to use for such small objects. 
     In U.S. patent application Ser. No. 09/267,175 (now allowed  U.S. Pat. No.  6 , 083 , 086 ) and assigned to applicant, Technicor, Inc., the inventor Hacikyan discloses “an expanding device for supporting grinding sleeves. The device has a cylindrical member with an outer surface, an interior chamber, an expanding chamber, and a locking mechanism. The outer surface receives the grinding sleeve and has a first outer diameter of D. The interior chamber receives a rotatable shaft and has a second outer diameter of I, which is less than D. The expanding chamber comprises an expanding material that expands and contracts based upon pressure applied thereon and has a third outer diameter of H and an inner diameter of J, wherein H and J are both greater than I and less than D. The locking mechanism has an open position and a closed position and requires no hand tool to alter its position. When the locking mechanism is in the open position the locking mechanism applies a pressure P to the expanding chamber so the first outer diameter is D, the second outer diameter is I, the third outer diameter is H, and the inner diameter is J. In contrast, when the locking mechanism is in the closed position the locking mechanism applies a pressure Z, which is greater than P, to the expanding material so the first outer diameter and the third outer diameter expand, and the second outer diameter and inner diameter contract.” The present invention is a preferred embodiment of this embodiment. 
     SUMMARY OF THE INVENTION 
     The present invention is an expanding device for supporting grinding sleeves. The  In an exemplary embodiment, the device has a cylindrical member with an outer bushing unit, an interior bushing unit, an upper control unit, an expanding unit, and a locking mechanism. The outer bushing unit receives the grinding sleeve, and has a first outer diameter of D, and a height H. The interior bushing unit receives a rotatable shaft, has a second outer diameter of I, which is less than D, and a height J, which is less than H. The expanding unit extends from within the upper control unit and between the outer and interior bushing units with protrusions below the outer and interior bushing units. The locking mechanism is interconnected to the upper control unit. And when the locking mechanism is in the unlocked position, a grinding sleeve, which can have diamonds thereon, can be placed on or taken off the outer bushing unit and the device can be placed on or taken off a rotatable shaft. Obviously, when the locking mechanism is in the locked position, the grinding sleeve is locked in place on the outer bushing unit, and the device is secured to a rotatable shaft because the locking mechanism alter the position of the expanding unit and the upper control unit which expands the outer diameter and shortens the height of the outer bushing unit, and simultaneously expands the interior diameter and shortens the height of the interior bushing unit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of an expanding device in the unlocked position. 
         FIG. 2  is a cross-sectional view of an expanding device in the locked position. 
         FIG. 3  is an exploded view of FIG.  1 . 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     U.S. patent application Ser. No. 09/267,175 (now allowed  U.S. Pat. No.  6 , 083 , 086 ), which is commonly assigned and incorporated by reference in this application, describes in detail a multi-purpose grinding machine  10  with a rotatable shaft  12 . (Numbers cited in this application do not correspond to the numbers used in that application.) 
     Turning to  FIG. 1 , the present invention relates to an expanding device  14  for supporting grinding sleeves  14    50 . The device  14  is cylindrical with an outer bushing unit  16 , an interior bushing unit  18 , an upper control unit  20 , an expanding unit  22 , and a locking mechanism  24 . 
     The outer bushing unit  16  receives the grinding sleeve  14    50 . The outer bushing unit  16  has a first outer diameter of D that receives the sleeve  50  and a height of H. 
     The interior bushing unit  18  receives a rotatable shaft  12 . The interior bushing unit  18  has an outer diameter of I, which is less than D and a height J, which is less than H. The outer bushing unit  16  and interior bushing unit  18  are made of materials that expand when a pressure is applied to them. Examples of these expandable materials include plastic and certain alloys known to those skilled in the art. 
     The expanding unit  22  comprises an expanding material that expands and contracts based upon pressure applied thereon. Examples of the expanding material include, and not limited to, rubber, metal, polyethylene and other known expandable polymers. The expanding unit  22  extends from within the upper control unit and between the outer and interior bushing units  16 ,  18  with protrusions  22 A and  22 B, respectively, below the outer and interior bushing units  16 ,  18  to secure units  16 ,  18  in place. In particular, protrusion  22 A extends beyond the outer diameter D to form a ledge  26  to hold the sleeve  50  in place. 
     The locking mechanism  26    24  is unlocked in  FIG. 1 , and locked in  FIG. 2 , and requires no hand tool to alter between the two positions of locked and unlocked. Turning to  FIG. 3 , the locking mechanism  26    24  has a set of protrusions  28 . The upper control unit  20  and the expanding unit  22  have corresponding sets of apertures  30 ,  32  that receive the protrusions  28 . When the locking mechanism is unlocked, as illustrated in  FIG. 1 , the outer bushing unit  16 , the interior bushing unit  18 , the upper control unit  20 , and the expanding unit  22  maintain their original shape, which allows the grinding sleeve  50  to be placed on or removed from device  14 , and/or allows the device  14  to be placed on or removed from the rotating shaft  12 . 
     In contrast, when the locking mechanism  26    24  is locked, as shown in  FIG. 2 , the upper control unit  20  and the expanding unit  22  are moved. The upper control unit  20  moves towards the outer and interior bushing units  16 ,  18 . And , and the expanding unit moves toward the upper control unit  20 . These movements result in the outer bushing unit  16  attaining a wider outer diameter D+1, greater than D, and shorter height H−1; and the interior bushing unit  18  attaining a narrower interior diameter I−1, and a shorter height J−1. By locking the device  14  in place, the sleeve  50  and the shaft  12  are securely attached to the device  14 . 
     The locking mechanism  26    24  is further secured in position by a conventional eccentric cam  32    34 , known to those skilled in the art. The eccentric cam  34  locks and unlocks the locking mechanism  26 . 
     The grinding sleeve  50  can be sandpaper, diamond, emery cloth or any conventional material that grinds metal, wood, or plastic materials. The grinding sleeve  50  is cylindrical or any other shape that fits upon one size of device  14 , in particular the outer bushing unit  16 . When diamonds are used, the diamonds are bonded to the grinding sleeve by conventional electroplating methods or other conventional methods, like adhesives. These sleeves are not screwed, or attached in other mechanical means, onto the device  14 . Instead the grinding sleeve  50  relies on the pressure provided by the outer bushing unit  16  to remain in position, even with a diamond surface. 
     Numerous variations will occur to those skilled in the art. It is intended therefore, that the foregoing descriptions be only illustrative of the present invention and that the present invention be limited only by the hereinafter appended claims.