Keyless chuck

Abstract: A three-jaw (18) chuck (10) is provided with a unitary nut (48) rotatably mounted relative the body and a retaining member (46) located so as to contact a portion of the unitary nut (48) to prevent axial movement of the nut in the forward direction. The nut may include a first portion (56) of a first outside diameter and a second portion (58) extending axially outward from the first portion with an outside diameter less than the first outside diameter. A sleeve retaining snap ring (270) may be provided engaging the sleeve (212) for retaining the sleeve (212) on the body.

Description: Background of the Invention The present invention relates to a chuck as per the preamble of claim 1. An example of such a chuck is disclosed by FR 2606691A. More particularly, the present invention relates to a chuck of the keyless type which may be tightened or loosened by hand or by actuation of the driver motor. Both hand and electric or pneumatic tool drivers are well known. Although twist drills are the most common tools of such drivers, the tools may also comprise screwdrivers, nut drivers, burrs, mounted grinding stones, and other cutting or abrading tools. Since the tools may have shanks of varying diameter or the cross section of the tool shank may be polygonal, the device is usually provided with a chuck which is adjustable over a relatively wide range. The chuck may be attached to the driver by a threaded or tapered bore. A variety of chucks have been developed in the art. In the simplest form of chuck, three jaws spaced circumferentially approximately 120° apart from each other are constrained by angularly disposed passageways in a body attached onto the 5 drive shaft of a driver and configured so that rotation of the body in one direction with respect to a constrained nut engaging the jaws forces the jaws into gripping relationship with the cylindrical shank of a tool, while rotation in the opposite direction releases the gripping relationship. Such a chuck may be keyless if it is rotated by hand. One example of such a chuck is disclosed in U.S. Patent No. 5,125,673 entitled "Non-impact Keyless Chuck," commonly assigned to the present assignee. Despite the success of keyless chucks such as set forth in US Patent No. 5,125,673, varying configurations of keyless chucks are desirable for a variety of applications. FR 2606691 discloses a chuck having a body and a forward sleeve with a bearing disposed between the body and sleeve in a forward section thereof. The bearing is located between the body and the sleeve by virtue of the respective shapes thereof. Summary of the Invention The present invention recognises and addresses the foregoing considerations, and others of prior art constructions and methods. Accordingly, it is an object of the present invention to provide an improved chuck. It is another object of the present invention to provide an improved chuck utilising a unitary nut. It is another object of the present invention to provide a keyless chuck with an improved front sleeve retaining member. It is another object of the present invention to provide a keyless chuck that provides for efficient assembly. According to the present invention, there is provided a chuck for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising the features of claim 1. Other objects, features, and aspects of the present invention are discussed in greater detail below. Brief Description of the Drawings A full and enabling disclosure of the present invention, including the best mode thereof to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures in which: Figure 1 is a longitudinal view, partly in section, of a chuck; Figure 1A is a sectional view of the embodiment of Figure 1 taken along lines 1A-1A; Figure 1B is a sectional view of an alternate embodiment of the drive arrangement taken along lines 1B-1B of Figure 1; Figure 2 is an exploded view of a chuck in accordance with the embodiment in Figure 1; Figure 3 is a longitudinal cross sectional view of another chuck; Figure 4 is a longitudinal cross sectional view of a chuck in accordance with an embodiment of the present invention; Figure 5 is a longitudinal cross sectional view of another chuck; Figure 6 is a frontal view of a chuck. Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. Detailed Description of Preferred Embodiments It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary construction. Referring to Figures 1 and 2, a chuck 10 is illustrated. Chuck 10 includes a front sleeve member 12, an optional rear sleeve member 14, a body member 16 and jaws 18. Body member 16 is generally cylindrical in shape and comprises a nose or forward section 20 and a tail or rearward section 22. An axial bore 24 is formed in the nose section 20 of the body member 16. Axial bore 24 is dimensioned somewhat larger than the largest tool shank that the chuck is designed to accommodate. A threaded bore 26 is formed in tail section 22 of body 16 and is of a standard size to mate with the drive shaft of a powered or hand driver (not shown). The bores 24, 26 may communicate at the central region 28 of body member 16. While a threaded bore 26 is illustrated, such bore could be replaced with a tapered bore of a standard size to mate with a tapered drive shaft. Passageways 30 are formed in body member 16 to accommodate each jaw 18. Three jaws 18 are employed and each jaw 18 is separated from the adjacent jaw by an arc of approximately 120 degrees. The axes of the passageways 30 and the jaws 18 are angled with respect to the chuck axis and intersect the chuck axis at a common point ahead of the chuck body 16. Each jaw 18 has a tool engaging face 32 which is generally parallel to the axis of the chuck body 16 and threads 34 on its opposite or outer surface. Threads 34 of any suitable type and pitch may be utilized within the scope of the present invention as would be readily apparent to one skilled in the art. As illustrated in Figures 1 and 2, body member 16 includes a thrust ring member 36 which, in one embodiment, may be integral therewith. In an alternate embodiment, thrust ring member 36 may be a separate component from the body member. Thrust ring member 36 may also include a ledge portion 38. Ledge portion 38 is adapted for engagement with a portion of a bearing assembly such as illustrated at 62 and as will be described in more detail below. Thrust ring member 36 includes a plurality of jaw guideways 42 formed around the circumference to permit retraction of the jaws 18 therethrough. Body member 16 includes a rear cylindrical portion 22 with a knurled surface thereon for receipt of optional rear sleeve 14 to be pressed thereon if so desired. It should be appreciated that rear sleeve 14 could also be retained in place by press fit without knurling or by use of a key. It could also be retained in place by crimping, staking, riveting, threading or any other suitable securing mechanism. Body 16 further includes a groove 44 in the forward section. Groove 44 is adapted to receive a snap ring 46 or the like for retaining a nut in place as will be described in more detail below. The chuck further includes a nut 48 which, in one embodiment, is a one piece nut and which includes threads 50 for mating with threads 34 on jaws 18 whereby when nut 48 is rotated with respect to body 16, the jaws will be advanced or retracted. Nut 48 may include drive slots 52 for mating with drive ribs 54 on front sleeve 12 so that when front sleeve 12 is rotated, nut 48 will rotate therewith and move jaws 18 as set forth above. Nut 48 includes a first portion 56 and a second portion 58 extending axially outwardly from the first portion, the second portion having an outside diameter less than the outside diameter of the first portion. Nut 48 also may include a ledge portion 60 (Figure 1) that is configured to mate with a portion of a bearing such as 62. It should be appreciated that although an antifriction bearing 62 is illustrated,a plain or coated bearing surface or friction reducing washer could be utilized in place of bearing 62. In addition, a self-contained baring assembly could also be utilized. In the embodiment as set forth above, front sleeve member 12 is adapted to be loosely fitted over nose section 20 of chuck 10. Multiple drive ribs 54 of front sleeve 12 engage drive slots 52 of nut 48 so that front sleeve 12 and nut 48 will be operatively connected, i.e., when front sleeve 12 is rotated, nut 48 will rotate therewith. Referring to Figures 1A and 1B, drive ribs 54 may extend in an arcuate manner as shown in Figure 1A at 64 or in a substantially rectangular manner from said sleeve as illustrated in Figure 1B at 66. The drive slots 52 on the nut 48 may be configured to generally conform to the configuration of the drive ribs on the sleeve. Body member 16 may include an additional groove 68 on its forward section 20. A sleeve retaining snap ring 70 may be received in groove 68 for retaining front sleeve 12 in place. Referring to Figures 1 and 2, sleeve retaining snap ring 70 consists of a circular ring that is disconnected or broken along its circumference at 72. This disconnection allows snap ring 70 to fit into groove 68 on body member 16. Snap ring 70 includes a substantially circular first axial portion 74 adapted to be received in a groove 68 on body member 16. Snap ring 70 also includes a second substantially circular portion 76 extending from said first portion in an L-shaped manner (Figure 1). Second substantially circular portion 76 includes a first portion 77 extending radially outwardly from first axial portion 74 and a second portion 79 extending axially outward from portion 77 in a cantilevered manner. Second portion 76 is flexible so that when said first portion 74 is received in groove 68 on body 16 and sleeve 12 is pressed over snap ring 70, a contact portion 78 of sleeve 12 will deflect second portion 76 to allow second portion 76 to be received in a groove 80 on sleeve 12. In this manner, sleeve 12 can be secured in place by snap ring 70. As can be appreciated, snap ring 70 is a one-way snap ring so that sleeve 12 is prevented from separating from the chuck. As illustrated in Figure 1, a portion of sleeve 12 may bear against the outer surface of a section of portion 74 to provide additional rotational stability to the sleeve 12. It would be preferable in this instance for at least this portion of snap ring 70 to be constructed of a friction reducing material. In one embodiment, snap ring 70 is constructed of a polymeric material such as nylon and includes relief areas 82 to enhance the flexibility of portion 74. Of course, snap ring 70 could be constructed of any suitable single or composite material. As set forth above, rear sleeve member 14 is optional. If desired, rear sleeve member 14 may be omitted and the front sleeve member 12 extended to the tail end of body 16. This alternative is feasible when a spindle lock or the like is provided on the driver or when the driver is used to tighten or loosen the jaws. The circumferential surface of the front sleeve member 12 may be knurled or may be provided with longitudinal ribs or other protrusions to enable the operator to grip it securely. In like manner, the circumferential surface of the rear sleeve member 14, if employed, may be knurled or ribbed if desired. The front and rear sleeves may be fabricated from a structural plastic such as polycarbonate, a filled polypropylene, for example, glass filled polypropylene, or a blend of structural plastic materials. Other composite materials such as, for example, graphite filled polymerics would also be suitable in certain environments. As will be appreciated by one skilled in the art, the materials from which the chuck of the present invention is fabricated will depend on the end use of the chuck, and the above are provided by way of example only. It will be appreciated that rear sleeve member 14 is fixed to body member 16 while front sleeve member 12 is operatively associated with nut 48 and secured to body member 16 for relative rotation therewith. Relative movement of the front and rear sleeve members, 12 and 14, due to the interaction between threads 34 on jaws 18 and threads 50 on nut 48 causes jaws 18 to be advanced or retracted, depending upon the direction of relative movement. Referring to Figure 3, another embodiment of a chuck is illustrated at 110. This embodiment also includes a front sleeve 112 and an optional rear sleeve 114 both received on body member 116. The operation of the chuck as illustrated in the embodiment of Figure 3 is the same as the embodiment of Figures 1 and 2 with respect to the interaction of the nut 148 with jaws 118, as well as retention of nut 148 in place by snap ring 146. The primary difference between the chuck of Figure 1 and 2 and the chuck of Figure 3 is that sleeve 112 is press fitted onto nut 148 to maintain sleeve 112 in place. This press fit arrangement also provides the drive engagement between front sleeve 112 and nut 148. Nut 148 may include a knurled portion 185 for engagement with outer sleeve 112 to prevent slippage upon rotation between sleeve 112 and nut 148. Of course, in the embodiment illustrated in Figure 3, a sleeve retaining snap ring, such as 70 illustrated in Figure 1, would not be necessary, but it should be appreciated that such could be utilized if desired. Referring to Figure 4, an embodiment of the chuck in accordance with the present invention is illustrated generally at 210. Chuck 210 includes body member 216, a front sleeve member 212 and a rear sleeve member 214. Body member 216 is generally cylindrical in shape and comprises a nose or forward section 220 and a tail or rear section 222. An axial bore 224 is formed in the nose section 220 of the body member 216. Bore 224 is configured in the same manner as bore 24 in the embodiment illustrated in Figures 1 and 2. The threaded bore 226 is formed in tail section 222 of body 216 in the same manner as illustrated with respect to Figures 1 and 2. Passageways 230 are formed in body member 216 to accommodate each jaw 218, again in the same manner as set forth with respect to the embodiment of Figures 1 and 2. In the embodiment illustrated in Figure 4, unitary nut 248 may be received in a nut receiving portion 249 in sleeve 212. Nut receiving portion includes a ledge 250 to prevent movement of the nut in the forward direction, and a snap ring 251 is provided in a groove 252 in sleeve 212 to prevent rearward movement of nut 248. Any type interengaging mechanism between sleeve 212 and nut 248 to provide for rotational movement of nut 248 when sleeve 212 is rotated could be utilized including, for example, drive ribs and drive grooves as described with respect to the chuck of Figures 1 and 2, or press fit as described with respect to the chuck of Figure 3. Sleeve 212 further includes a rear ledge portion 254 adapted to engage a bearing member 256 which is received between ledge portion 254 and a ledge 258 on rear sleeve member 214. It should be appreciated that bearing member 256 can be any type known bearing member including, if desired, a coated or uncoated bearing surface, or a self-contained bearing assembly. On the forward portion of sleeve 212 is another bearing receiving ledge 260 which receives a bearing member 262 which is retained therein by a retaining member 264. Again, it should be appreciated that bearing member 262 could be a coated or uncoated bearing surface or any suitable bearing member in accordance with the above discussions. Front sleeve 212 further includes a retaining ledge 266. The forward section of body member 216 includes a groove 268 therein for receipt of a retaining member such as a snap ring or the like. In operation, nut 248 is received in sleeve 212 and maintained in place by retaining member 251. Sleeve 212 is placed over the forward section of body member 216 and the rear portion of sleeve 212 engages a bearing member or bearing surface 256 which engages a portion of sleeve 214 thereon. In the forward section of sleeve 212 there is another bearing member 262 retained in place by a retaining member 264. The entire sleeve is maintained in place in the forward direction by retaining member which is received in groove 268 on the forward section of the body and in the rearward direction by ledge 258. It should be appreciated that bearing 262 may be press fitted onto the body and retaining member may be optional. Figure 5 illustrates at 310 another chuck. Chuck 310 includes a front sleeve member 312, an optional rear sleeve member 314, a body member 316 and jaws 318. Body member 316 is generally cylindrical in shape and comprises a nose or forward section 320 and a tail or rearward section 322. An axial bore 324 is formed in the nose section 32C of the body member 316, and a threaded bore 326 is formed in the tail section of body member 316 and is of a standard size to mate with the drive shaft of a power or hand driver (not shown). As discussed above with respect to the embodiments of Figures 1-4, the bores 324, 326 may communicate at a central region 328 of the body member 316. Passageways 330 are formed in body member 316 to accommodate each jaw 318 as set forth with respect to the above embodiments. Body member 316 also includes a thrust ring portion 336. A bearing member 338 is received between thrust ring member 336 and a nut 340. While the bearing member 338 is illustrated, it should be appreciated that a coated or uncoated bearing surface could be utilized in place of the bearing member or a self-contained bearing assembly could be utilized. In one embodiment, nut 340 is a one-piece nut and is prevented from forward movement by ledge 342 of sleeve 312. A bearing washer 344 is received about the nose section 320 of body member 316 and includes a ledge portion 346 which engages a forward portion of front sleeve 312. Member 344 may be plastic, nylon, teflon or any other suitable material and can, in general, be considered as a bearing washer to minimize friction when sleeve 312 is rotated. A nosepiece 348 is received on the forward section 320 of body member 316 by means of a press fit or the like. The rearward portion of nosepiece 348 contacts the forward portion of member 344 so that sleeve 312 is maintained in place through member 344 by nosepiece 348 that is pressed onto the forward section of body member 316. It should be appreciated that while a one-piece nosepiece is illustrated at 348, such could be a multiple piece nosepiece or any other suitable retaining member. In the chuck illustrated in Figure 5, nut 340 is maintained in place by nosepiece 348 through member 344 and sleeve 312. The operation of the chuck as illustrated in the embodiment of Figure 5 is essentially as set forth with respect to the embodiment of Figures 1 and 2. Sleeve member 312 may have drive ribs and nut 340 may have drive rib receiving grooves so that when sleeve 312 is rotated, nut 340 will rotate therewith. In addition, sleeve 312 could be press fitted onto nut 340 or attached in any other suitable manner. Figure 6 illustrates an alternate embodiment. As illustrated in Figure 6 at 400, the interior diameter of bore 405 in the forward section of the body may include a configuration such that a suitable tool may be utilized to rotate the body when the jaws are retracted into the chuck. Such a configuration may be such as a multi-sided star shape as illustrated in Figure 6, or a polygonal shape or any other suitable shape with which a tool could be inserted so as to rotate the body member to screw the chuck body onto a driver spindle. In addition, the wrench configuration could be adapted into the outside diameter of the forward portion of the body member so that a suitable socket or other mechanism could be received over the nose section of the body member to rotate the chuck body to thereby tighten it onto a spindle or the like. While the above description is set forth with respect to a keyless chuck, it should be appreciated that many of the principles of the present invention are equally applicable to a keyed chuck, and such is within the scope of the present invention. These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the scope of the present invention, which is set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention so further described in such appended claims.

Claims: A chuck (210) for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising: a generally cylindrical body member (216), said body member (216) having a forward section (220) and a rearward section (222), said rearward section (222) having an axial bore (226) formed therein to mate with said drive shaft of said driver and said forward section (220) having an axial bore (224) formed therein and a plurality of angularly disposed passageways (230) formed therethrough and intersecting said axial bore (224); a plurality of jaws (218) slidably positioned in respective angularly disposed passageways (230), each of said jaws (218) having a jaw face (32) formed on one side thereof and threads (34) formed on the opposite side thereof; a unitary nut (248) rotatably mounted relative to said body (216) so as to engage said jaw threads (34); and a generally cylindrical sleeve member (212) received over the forward section of said body member (216) for engaging said nut (248) so that when said sleeve member (212) is rotated, said nut (248) will be rotated therewith to operate said jaws (218), said sleeve member (212) further including a bearing member (262) disposed between said sleeve member (212) and said body member (216) and adapted to engage the forward section (220) of said body member (216), said bearing member (262) serving as a thrust bearing, characterised in that said bearing member (262) being retained in said forward section of the sleeve member (212) by a retaining member (264) secured on the forward section of the sleeve member (212). A chuck (210) for use with a manual or powered driver as in claim 1, wherein said bearing member (262) is pressed onto the forward portion (220) of said body member (216) to retain said front sleeve member (212) on the body member (216) during operation of the chuck. A chuck (210) for use with a manual or powered driver as in claim 2 wherein said retaining member (264) is suitable for axially retaining said sleeve member (212) on said body member (216) through said bearing member (262). A chuck for use with a manual or powered driver as in claim 1, wherein said front sleeve (212) is retained on said body member (216) by a retaining member received in a groove (268) on the forward section of the body member (216) and engaging a portion of the front sleeve (212). A chuck for use with a manual or powered driver as in any preceding claim, wherein said unitary nut (248) is retained in said sleeve (212) by a locking ring (251) received in a groove (252) in said sleeve (212) and abutting a portion of said nut (248). A chuck for use with a manual or powered driver as in any of claims 1 to 4, wherein said sleeve is polymeric and said nut is co-moulded into said sleeve. A chuck for use with a manual or powered driver as in any preceding claim, and further including a rear sleeve (214) fixed to the rearward section (222) of the body member (216). A chuck for use with a manual or powered driver as in claim 2, and further including a bearing member (256) received between a rearward portion of said front sleeve (212) and a forward portion of said rear sleeve (214). A chuck for use with a manual or powered driver as claimed in any preceding claim, said forward section being configured to receive a tool for tightening said body to said drive shaft.

Inventors: MULLINAX WILLIE C, OWENS VALERIE D, SALPAKA GLENN L, MULLINAX, WILLIE C., OWENS, VALERIE D., SALPAKA, GLENN L.
Applicants: POWER TOOL HOLDERS INC, POWER TOOL HOLDERS, INC.
Application year: 1995
Main classification: B23B31
IPC codes: B23B31