GB2356368A - Chuck construction - Google Patents

Abstract

A chuck has a generally cylindrical body with an annular ledge 66 which serves to retain an outer sleeve 12 of the chuck should it move forwards. The sleeve has an inward extending lip 60 to confront the ledge 66. The lip is preferably resilient to snap fit over the ledge.

Description

2356368 INTEGRAL LOCKING SLEEVE CT.UJCK

Backaround of the Invention

The present invention relates generally to chucks for use with drills or, with electric or pneumatic power drivers. 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 on such drivers, the tools may also comprise sc rew drivers, nut drivers, burrs, mounted is grinding stones, and'other cutting or abrading tools.

Since the tool shanks may be of varying diameter or of polygonal cross section, the device is usually provided with a chuck 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. I-n an oblique jawed chuck, a body member includes three passageways disposed approximately 1200 apart from each other. The passageways are configured 2S so that their center lines meet at a point along the chuck axis forward of the chuck. The passageways constrain three- jaws which are movable in the passageways to grip a cylindrical tool shank displaced approximately along the chuck center axis. The chuck includes a nu t which totates about the chuck center and which engages threads on the jaws so that rotation of the nut moves the jaws in ei.t--her direction within the passageways. The body is attached onto.the drive shaft of a driver and is configured so that rotation of the body in.one direction with respect to the nut forces the jaws into gripping relationship with 'the 2 tool shank, 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 ent-itled "Non-impact Keyless Chuck," commonly assigned to the present assignee and the entire disclosure of

4 S which -L. incorporated by reference here-in. Various configurations of keyless chucks are known in the art and are desirable for a variety of applications.

Summarv of the Invention The present invention recognizes and addresses S4 the foregoing con Lderations, 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 a chuck having a rotatable sleeve member and having a secondary retaining mechanism attached to the sleeve to prevent forward axial movement of the sleeve beyond the 'chuck body if the chuck fails.

These and other objects are achieved by providing chuck f or use with a manual or powered driver having rotatable drive shaft. The chuck,comprises a generally cylindrical body member having a forward section and a rearward section. The rearward section has an axial bore'formed therein to mate with the drive shaft of the driver. A generally cylindrical sleeve is received over the forward section of the body. A primary retaining mechanism is in engagement with the sleeve and the bcdymember to operatively prevent forward axial movement of the sleeve with respect to the body. A secondary retaining mechanism is attached to the sleeve so that 'Lf the primary ret---aining mechanism fails to prevent forward axial movement of the sleeve with resDect to the body, the 3 secondary retaining mechanism is brought to engagement th the body to prevent forward axial movement of the sleeve with respect to the body following the engagement.

in a pre flerred etbodiment, the forward sect ion of the body includes an annular ledge about its outer surface. The secondary retaining mechanism includes a I iz section extending radially inward from the sleeve to within the outer diameter of the annular ledge.

The lip is constructed so that it is resilient in one direction but ricid in another. -Thus, in a preferred embodiment, the lip extends radially inward and axially forward with respect to the chuck body. When the sleeve is mounted onto the chuck, the sloping rear f ace of the lip is pulled over the ledge, causing the lip to radially deform and pass over the ledge.

When the sleeve is in its operative position on the body, the lip is axially forward 7f, and does not engage, the ledge. The sleeve is ope-_-, - i.-rely maintained in position with respect to body member by the -primary retaining mechanism. In one preferred embodiment, the chuck includes a nut -r,intained in position on the body by a retaining. co_!-_-- pressed onto the body. The sleeve is attached to the nat, for example, by a press f it. Thus, the primary retaining mechanism include's the retaining cone and the nut While the chuck remains in an operative condition, the retaining cone and the nut maintain the sleeve in position with respect to the body. Under such conditions, the front lip does not engage the -edge. Should the chuck fail, ihowever, such that some disengagement occurs among the sleeve, the nut, the retaining cone and/or the body and such that the =Ieeve moves axially forward, the front lip engages 35:-,.e ledge to hold the sleeve in position proximate the 4 body. Thus, such construction can prevent the sleeve ,from completely separating from the chuck if the chuck fails while rotating at a high rate.

Other objects, features, and aspects of the present invention are"discus'sed. in greater detail below.

Brief Descrintion of the DrawinQs 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 specif ication, which makes reference to the accompanying figures, in which:

Figure. 1 is a longitudinal view, partly in section, of a chuck in accordance with an embodiment of the present invention; Figure 2 is a longitudinal view, partly in section, of a chuck in accordance with an embodiment of the present invention; and Figure 3 is an exploded view of a chuck in accordance with the embodiment as in Figur e 1.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the 2S invention.

Detailed Descrintion of Preferred Embodiments Reference will now be made in detail to presently preferred embodiments to the invention, one or more examzles of which are illustrated in the accompanying drawings. Each exam Die is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention without departing from the scope or spi-rit thereof. For instance, features illustrated or described as part of o ne -embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modification and variations as come within the scope of the appended claims and their ecTuivalents.

Referring to a preferred embodiment illustrated in Figures 1 and 3, a chuck 10 in accordance with. the present invention is illustrated. Chuck 10 includes a sleeve member 12, 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. 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 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 a centrai region 28 of body member 16.;While a threadea 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 is separated from the adjacent jaw by an arc of approximately 1200. 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 may be const -Iruc -L ed. in any suitable type and pitch.

6 As illustrated in Figures 1 and 3, body member 16 includes a thrust ring member 36 which, in a preferred embodiment, may be integral with the body. In an alternate embodiment, thrust ring 36 may be a separate component from the body member. Thrust ring 36 may also include a ledge portion 38 to receive a bearing assembly 3-9. Thrust ring 36 includes a plurality of jaw guideways 42 formed around the circumference. to permit retraction o."Lr the jaws 18 therethrough.

In a preferred embodiment illustrated in Figure 2, body member 16 includes a rear cylindrical portion 22 with a knurled surface 26 for receipt of an 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.

Referring again to Figures 1 and 3-, chuck 10 includes a nut 48 which, in a preferred embodiment, is a one piece nut and which includes threads 50 for mating with threads 34 on jaws 18. Nut 48 is positioned about the body in engagement with the jaw threads so that when the nut is rotated with resmect to body 16, the jaws will be advanced or retracted.

The outer surface of nut 48 may be knurled so that the nut may be press fit to sleeve 12 at 52 so that when sleeve 12 is rotated, nut 48 will rotate therewith to move the jaws.

The outer circumferential surface of sleeve 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 a tear sleeve 14 (Figure 2), if employed, -35 may be knurled or ribbed if desired. The front and 7 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 com-oosite materials suc.h., as, for' example, graphite filled polymerics would also be suitable in certain environments. As would be appreciated by one skilled in the art, the materials for which the chuck of.the present inven. -ion is fabricated will depend on the end use of the chuck, and the above are provided by way of example only.

It should be appreciated that rear sleeve member 14 (Figure 2) is fixed to body 16 while front sleeve member 12 is operatively associated with nut 48 and axially secured with respect to the body to permit rotation with respect to the body. Relative movement of the f ront 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 movemen-t.

As indicated above, rear sleeve 14 (Figure 2) is secured to body 16 by the press fit at 46. Front sleeve 12, as illustrated in Figures 1 - 3, is axially secured with respect to the body by nut 48 and retaining ring '54'. As described above, sleeve 12 is pressed to nut 48 at 52. In one preferred embodiment, nut 48 includes a ribbed surface 56 which is oressed into sleeve 1.2. Retaining ring 54 is an annular cone that is pressed onto front section 20 of body!6 and that engages nut 48 at 58. Thus, cone 54 and nut 48 secure sleeve 12 in the axial direction with resiDect to the bodv. In an ooerative condition, they prevent forward axial movement: of the sleeve.

8 If chuck 10 fails, however, so that cone 54 and/or nut 48 fail to orevent forward axial movement of the sleeve, a secondary retaining mechanism retains sleeve 12 proximately about body 16.

in the ern'bodiments depicted in the figures, the secondary retaining mechanism comprises an annular lip croximate the oDen end 62 of sleeve 12. Lip 60 exz:ends radial'y inward from sleeve 12 and axially forward toward open end 62. As shown, 1-in 60 may be ulli_4:arily constructed with sleeve 12. The diameter of t'.-.e opening de-fined by lip 60 is.-smaller than the ou--=-r diameter of front section 20 of body 16. As the sleeve is mounted onto the body, however, the forward orientation of lip 60 allows the lip to deform as front section 20 contacts the sloped inner or rearward face of the lip. A groove 64 is formed in front section 20 to receive lip 60 when sleeve 12 is secured to the body in its operative position. Groove 64 forms a ledge 66 which opposes lip 60 when the sleeve is in its operative position.

When sleeve 12 is in its operative position, lip does not engage ledge 66. If the chuck should however, and if sleeve 12 moves axially forward wi::h resDect to the body, lip 60 engages ledge 66 to re::anri sleeve 12 in a position about the body.

Ledge 66 may'be constructed in a number.of con:f:'.gurat ions. For example, it might not necessarily ex7zend completely around the body, possibly defining __--zerm it is not necessary ittent gaps. in addition, it be constructed from a part of the body.

While an oblicrue-jawed chuck driven by a nut is ---s-rated, 4t should be understood. that the =_s:ruction o: the oresent invention nav be used in an,., suitable type of chuck. Furthermore, in another n-_::-_4_-iven design, a sml-it nut construction may be 9 employed. For example, the split nut may be received ,in a groove formed in the body and held together by 'a band about its outer circumference or by the sleeve.

The sleeve member may be pressed to the band, or secured to the nut or'otherwise-to the body by other suitable mechanisms. Moreove-r, it should be understood that all suitable mechanisms z"or securing the sleeve to the body in an operative condition.are encompassed by the present invention.

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 scone 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 spirit and scope of the present invention, which is more particularly set forth in the appended claims.

In addition, it should be understood that a-spects 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 (1)

1. Claims

   A chuck'for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising:

   a generally cylindrical body member, said body member havina a forward section and a rearward section and including an annular ledge -about an outer surface of said body member, said rearward section having an axial bore f-ormed therein. to mate with said drive shaft of said driver; and a generally cylindrical sleeve having an annular 4= Open torward end, said sleeve being received over said forward sect-Lon of said body and including a lip section extending radially inward from said sleeve proximate said annular' open forwa rd end and axially toward said annular open forward end, said lip sect:ion extending radially within the outer;diameter of said annular ledge so that at least a portion of said lin section opposes said annular ledge axially with reSpect to said body member.

   2. The chuck as in cla'im 1, wherein said annular ledge and said body are of a unitary construction.

   3. The chuck as in claim 1, wherein said annular ledge is included on said forward section of - said body member.

   4. The chuck as in claim 1, wherein said lip section forms an annular. lip.

   S. The chuck as in claim 1, wherein said lin section extends annularly entirely about an inner circumference of said sleeve to form a frustoconical JJD.

   6. The chuck as in claim 1,.wherein said lip section is resilient in a radial direction with respect to said body.

   7. The.thuck as in claim 1, wherein said lip section and said sleeve are of a unitary construction.

   S. A chuck for use with a manual or powered driver having a rotatable' drive shaft, said chuck comprising:

   a generally cylind-rical body member, said body member having a forward section and a rearward section, said rearward section havina an axial bore fo=ed therein to mate with said drive shaft of said driver and said forward sec't-ion having an axial bore formed there-in and a plurality of angularly disposed passageways formed therethrough and intersecting said axial bore; a plurality of jaws slidably positioned in each of said angularly disposed passageways, each of said jaws having a jaw face formed on one side thereof and threads formed on the opposite side thereof; a nut rotatably mounted relative to said body so as to engage said jaw threads; a generally cylindrical sleeve having an annular open forward end, said sleeve -being received over the forward section of said body for engaging said nut so that when said sleeve member is rotated, said nut will be rotated therewith to oDerate said jaws; a primary retaining mechanism in engagement with.

   said sleeve and said body member to operatively prevent forward axial movement of said sleeve with resmect to said body; and a secondary retaining mechanism attached to said sleeve so that if said primary retaining mechanism fails t o prevent forward axial movement of said sleeve with resmect to said body, said secondary retaining mechanism is brought to engagement with said body to prevent forward axial movement of said sleeve with respect to s aid body following said engagement.

   12 The chuck as in claim 8, wherein said body includes an annular ledge about an outer surface of said body, and wherein said sleeve includes a lip t 4 sec.on extending radially' inward from said sleeve to within the outer diameter of said annular ledge surface so that at least a portion of said lip section opposes said annular ledge axially with respect to said body, said primary rer-aining mechanism being in engagement with said sleeve and said body to operatively prevent forward' axial movement of said sleeve with resDect to said body so that said lip section remains rearward of, and does not engage, said annular ledge.

   10. The chuck as in claim 9, wherein said lin sec--ion extends from Siaid sleeve proximaze said annular open forward end axially toward said annular open forward end.

   11. The chuck as in claim 8, wierein said.lip section forms an annular lip.

   12. The chuck as in claim 1.0, wherein said lip section extends annularly entirely about an inner circumference of said sleeve- to form a frustoconical 13. The chuck as in claim 9, wherein said lip section is resilient in a radial direction with resvect to said body. 1 14. The chuck as in claim 9, wherein said primary retaining mechanism includes said nut.

   1 S. The chuck as in claim 14, wherein said nut is disposed in engagement with said body so that forward axial movement of said nut with respect to said body is operatively prevented and wherein said sleeve is axially secured to said nut.

   13 6. The chuck as in claim 15, wherein said nut is a unitary nut and wherein said retaining mechanism includes an annular retaining member located on said bodv so as to contact a portion of said unitary nut to operatively prevent axial movement of said unitary nut in the forward direction.

   17. The chuck as in claim 1 5, wherein said sleeve member engages said nut %by a press fit.

   18. The chuck as in claim.9, wherein said lin section and said sleeve are' of a unitary construction.

   19. The chuck as in claim 16, wherein said annular retaining member is received in a groove in said forward section of said body.

   ?0. The chuck as in claim 19, including a bearing thrust ring located on said body and a-L le-=sz one anti-friction bearing disposed between said nuz and said thrust ring.

   21. A chuck for use with a manual or powered driver having a rotatable drive shaft, said chuck comprising:

   a generally cylindrical body member, said bodv member having a forward section and a rearward section, said rearward section having an axial bore formed therein to mate with said drive shaft of said driver; a generally cylindrical sleeve being received over said forward section of said body; a primary retaining mechanism in engagement with said sleeve and said body member to operatively prevent forward axial movement of said sleeve with respect to said body; and - 14 a secondary retaining mechanism attached to said sleeve so that if said primary retaining mechanism fails to prevent. forward axial movement of said sleeve with respect to said body' said secondary retaining mechanl:-sm is brought to engagement with said body to prevent forward axial movement of said sleeve with respect to said body following said.engagement.

   22. The chuck as in claimZI, wherein said body includes an annular ledge about an outer surface of said body, and'-wh!rein said sleeve includes a lip section extending radially inward from said sleeve to within the outer diameter of said annular ledge so that at least a portion of said lip section opposes said annular ledge axially with respect to said body, said primary retaining mechanism being in engagement with said sleeve and said body to operatively prevent forward axial movement of said sleeve with respect to said body so that said lip section remains rearward of, and does not engage, said annular ledge.

   23. The c1huck as in claim22, wherein said annular ledge and said body are of a unitary construction.

   24. The chuck as in claim22, wherein said annular ledge is included on said forward secz-ion of said body member.

   25. The chuck as in claim22, wherein said slee-%re has an annular open forward end and wherein said!in section extends from said sleeve proximate said annular oven forward end axially toward said annular open forward end.

   26. The chuck as in claim22, wherein said lit) section forms an annular lip.

   27. The chuck as in claim25, wherein said lip section extends annularly entirely about an inner circumference of said sleeve member to form a 5 frustoconical lip.

   28. The chuck as in claim22, wherein said lip section is resilient in a radial direction with respect to said body.

   29.- The chuck as in claim22, wherein said liz section and said sleeve are of a unitary construction.

   30. The chuck as in claim2l and further including a rear sleeve received on the rearward section of said body.