Quick change grinder bit holder

Abstract: The present invention is an expanding device (14) for supporting grinding sleeves. The device (14) has a cylindrical member 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 (50), and has a first outer diameter of D, and a height H. The interior bushing unit (18) 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 (22) extends from within the upper control unit (20) and between the outer and interior bushing (16,18) units with protrusions (28) below the outer and interior bushing (16,18) units. The locking mechanism (26) is interconnected to the upper control unit (20). And when the locking mechanism (26) is in the unlocked position, a grinding sleeve (50), which can have diamonds thereon, can be placed on or taken off the outer bushing unit (16) and the device can be placed on or taken off a rotatable shaft. Obviously, when the locking mechanism (26) is in the locked position, the grinding sleeve (50) is locked in place on the outer bushing unit (16), and the device is secured to a rotatable shaft because the locking mechanism (26) alter the position of the expanding unit (22) which expands the outer diameter and shortens the height of the outer bushing (16) unit, and simultaneously expands the interior diameter and shortens the height of the interior bushing unit (18).

Description: Field of the Invention The present invention relates to a grinding device and a method of securing a grinding sleeve to an expanding device. Background or the Invention Fiocchi in U.S. Patent No. 5,185,970 discloses a grinding device according to the preamble of claim 1, having 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. Patent 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 serial no. 09/267,175 (now published, US 6 083 086 A) 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. US 5 185 970 also discloses the method according to the preamble of claim 5. Summary of the Invention The present invention is defined by a device according to claim 1 and a method according to claim 5. Brief Description of the Drawings Figure 1 is a cross-sectional view of an expanding device in the unlocked position. Figure 2 is a cross-sectional view of an expanding device in the locked position. Figure 3 is an exploded view of Figure 1. Detailed Description of the Present Invention U.S. Patent Application serial no. 09/267,175 (now published, US 6 083 086 A), 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 Figure 1, the present invention relates to an expanding device 14 for supporting grinding sleeves 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 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, 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 22A and 22B, respectively, below the outer and interior bushing units 16, 18 to secure units 16, 18 in place. In particular, protrusion 22A extends beyond the outer diameter D to form a ledge 26 to hold the sleeve 50 in place. The locking mechanism 24 is unlocked in Figure 1, and locked in Figure 2, and requires no hand tool to alter between the two positions of locked and unlocked. Turning to Figure 3, the locking mechanism 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 Figure 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 24 is locked, as shown in Figure 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 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, 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 24 is further secured in position by a conventional eccentric cam 34, known to those skilled in the art. The eccentric cam 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.

Claims: A grinding device comprising a cylindrical member (14) 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), characterized in that : the outer bushing unit (16) receives a grinding sleeve (50) and has, when the outer locking mechanism (24) is in an unlocked position, a first outer diameter of D and a height H; the interior bushing unit (18) receives a rotatable shaft (12) and has, when the locking mechanism (24) is in an unlocked position, a second outer diameter which is less than D, and a height J which is less than H; the expanding unit extends from within the upper control unit (20) and at least portions thereof between the outer bushing unit (16) and interior bushing unit (18), and the expanding unit (22) has a first protrusion (22A) below and contacting the outer bushing unit (16) and a second protrusion (22B) below and contacting the interior bushing unit (18); the locking mechanism (24) is interconnected to the upper control unit (20) so that when the locking mechanism (24) is in the unlocked position, the grinding sleeve (50) can be placed on or taken off the outer bushing unit (16) and the device can be placed on or taken off a rotatable shaft (12); and when the locking mechanism (24) is in the locked position, the locking mechanism (24) pulls the expanding unit (22) towards the upper control unit (20) and pushes the upper control unit (20) towards the expanding unit (22) which expands the outer diameter and shortens the height of the outer bushing unit (16) and expands the interior diameter and shortens the height of the interior bushing unit (18). The device of claim 1, wherein the grinding sleeve (50) has diamonds. The device of claim 2, wherein the diamonds are electroplated onto the grinding sleeve (50). The device of claim 1, wherein the grinding sleeve (50) rests on the first protrusion (22A). A method of securing a grinding sleeve (50) to an expanding device in a grinding device according to one of the preceding claims, characterized by : placing a cylindrical member upon the rotatable shaft (12) wherein the cylindrical member has an outer bushing unit (16), an interior bushing unit (18), an upper control unit (20), an expanding unit (22) and a locking mechanism (24); wherein the outer bushing unit (16) receives a grinding sleeve (50) and has, when the outer locking mechanism (24) is in an unlocked position, a first outer diameter of D and a height H; wherein the interior bushing unit (18) receives a rotatable shaft (12) and has, when the locking mechanism (24) is in an unlocked position, a second outer diameter which is less than D, and a height J which is less than H; wherein the expanding unit extends from within the upper control unit (20) and at least portions thereof between the outer bushing unit (16) and interior bushing unit (18), and the expanding unit (22) has a first protrusion (22A) below and contacting the outer bushing unit (16) and a second protrusion (22B) below and contacting the interior bushing unit (18); wherein the locking mechanism (24) is interconnected to the upper control unit (20) so that when the locking mechanism (24) is in the unlocked position, the grinding sleeve (50) can be placed on or taken off the outer bushing unit (16) and the device can be placed on or taken off a rotatable shaft (12); sliding the grinding sleeve (50) upon the outer bushing unit (16) when the locking mechanism (24) is in the unlocked position, and placing the device onto a rotatable shaft (12); and positioning the locking mechanism (24) into the locked position so that the locking mechanism (24) pulls the expanding unit (22) towards the upper control unit (20) and pushes the upper control unit (20) towards the expanding unit (22) which expands the outer diameter and shortens the height of the outer bushing unit (16) and expands the interior diameter and shortens the height of the interior bushing unit (18), which secures the sleeve (50) to the device and the device to the rotating shaft (12). The method of claim 5, wherein the grinding sleeve (50) has diamonds. The method of claim 6, wherein the diamonds are electroplated onto the grinding sleeve (50). The method of claim 5, wherein the grinding sleeve (50) rests on the first protrusion (22A).

Inventors: HACIKYAN MICHAEL, HACIKYAN, MICHAEL
Applicants: TECHNICOR INC, TECHNICOR, INC.
Application year: 2001
Main classification: B24D9
IPC codes: B24B45, B24D9