US2880008A - Chuck key and support - Google Patents

Description

March 3l, 1959 A. M. sToNER CHUCK KEY AND 'SUPPORT Filed Feb; 5, 1957 nited States Patent() Jacobs Manufacturing Company, West Hartford, Conn., a corporation of New Jersey Application February 5, 1957-, Serial No. 638,249

7 Claims. (Cl. 279-58) This invention relates 'to chucks, particularly of the class "in which the jaws are tightened by manipulation of a key which is turned about an axis transverse to the chuck body. The invention is directed to a rotatable key assembly constructed and supported in a novel manner for convenient manipulation.

An object of the invention is the 'provision of a key having two manipulative portions, one having 'a Small 'radius for rapid turning and the other having a larger radius or moment arm for greater leverage.

Another object is to reduce the manufacturing cost of a chuck key assembly.

A further object is `to provide improved means for supporting the key and permitting it to be moved quickly :finto and 'outof operative position. Other objects and features of the invention will appear fthere lclearly trom the following description taken in connection with the accompanying drawings and appended claims.

lIn 'the accompanying drawings, which illustrate one `embodiment of this invention:

Fig. l isa longitudinal section of Aan internally geared chuck in -association with the rotatable key and its sup- I'porting means, the left side 'of the igure showing the jaws 'raised and the right side showing the jaws lowered or collapsed;

Fig. 2 is a longitudinal section through the rotatable key 'of Fig. l;

-'fthe rotatable key, on la smaller scale than Figs. l, 2 and 3; -and Fig. '5 isa plan View `of the rotatable key'holder on the "same scale as Fig. .4.

In "the illustrative embodiment of invention a pinion 42 yis provided at its inner end with a series of longitudinally Vextending teeth 42: adapted 'to 'be inserted into a `radial lbore 43 in `the body 44 of a chuck 4.5. The chuck, which 'will Ibe "described later, includes atace gear 46 vhaving lteeth which inesh with the teeth 42t 'on pinion 42. The .pinion 42 forms part 'of a rotatable key assembly confstructed fand supported i-n fa. novel manner for convenient manipulation. A's shown in Fig. i2, the pinion `has a "cylindrical body 47 coaxial with the toothed portion 42! and separated therefrom by an annular groove 48 having the shape of a half torus. The groove is adapted for the reception 'of `a brass :grommet 49 to be `described later. At its opposite end, the pinion 42 has a tapered extension 50 which has 'a press lit within a correspondingly shaped `opening 'in a Yknob 51. AAdjacent the tapered extension 50,

the pinion hasra shoulder 52 in 'abutting engagement with The `knob has `a tapered periphery provided .'with tintes V53 enabling Ait to be grasped conveniently beltw'een tlhe thumb land -foref-nger of the operator for rapidly ."tufrningthe-rotatable key assembly, including-.the pinion 42, when there is little resistance to rotation. The pinion body 47 has a diametrical hole 55 which receives, with Patented Mar. 31, 1959 d icc Va tight t, a wire handle or cross bar 56. The cross ba'r has a length considerably greater than the diameterofthe knob 51, and is adapted to be grasped between the operators fingers to enable him to turn the key assembly when the resistance to rotation is more substantial. The knob 51 may be of metal formed by die casting, or may be composed of plastic material. Since it transmits only a relatively small torque to the pinion, there is no difficulty in providing a sufficiently secure connection between the knob and the pinion 42. The Wire handle prevents excessive torque from being applied to the pinion teeth 42t and to the teeth on face gear 46 because it is designed to bend at torques considerably less than the breaking point of the teeth. The pinion 42 consists of an integral structure comprising toothed portion 42t, body 47 and extension 50. This part, like the other parts of the rotatable key assembly, is inexpensive and easy to make. In 'the manufacture of the pinion 42, the plain cylindrical diameter 47 facilitates chucking and the pinion can be passed through the gear cutter work holding spindle for automatic loading.

In order to support the rotatable key assembly 42, 51, 56 in convenient position for use, and to prevent the clisplacement or loss of the key, the grommet 49 is arranged to be supported by a flexible strap 57. The strap, which 'is shown unassembled in Figs. 4 and 5, is cut from a flat strip, preferably made from oil-resisting synthetic rubber. At its lower end, the strip 57 has an opening 58 whose normal unstressed diameter is slightly less than that of the toothed portion 42r of the pinion 42. The brass grommet 49, as seen in Figs. 2 and 3, has an annular groove or torroidal recess "at lits outer periphery which snugly receives the apertured portion 58 of vthe strap. The grommet is convex on its inside to provide a swivel support on the pinion 42 adjacent the toothed portion 42t. As seen in Fig. 3, the grommet is in the form of a split ring. It is adapted to be expanded, slipped over the toothed portion 42t, while in open condition, and then assembled within the annular groove 48 by means of a squeezing or crimping action. To assemble the strap with relation to the grommet, the area surrounding the hole 58 is stretched to the maximum di ameter of the tooth edges 42C and grommet 49 to permit it to be passed thereover. Extending upward from 'the apertured portion 58, the strap 57 has a narrowpor'tion 59 above which lies a body portion 61. The latter terminates in a head 62 having a transverse slit l63 cxtending between two holes 64. The perforated portion 63, 64 may be stretched to provide a slot or opening of substantial size. ln use, the body portion 61 is wrapped around a suitable support lsuch as the wire 65 (Fig. l) which delivers power to the portable electric drill (not shown); the apertured lower end of the strap, surrounding the hole 58 is folded and inserted through the stretched or opened slit 63, and the lower end 58 of the strapzis pulled until the narrow portion 59 and later a part of the body portion 61 have passed through the slit 63 and the upper end of the strap 57 snugly embraces the wire 65 as shown in Fig. l. The lower end 58 is then forced into position 011 the grommet 49 as described above, whereupon the rotatable key assembly comprising manipulative knob 51 and pinion A42 iS Supported for movement into and out of working position at the `will of the operator. If desired, the strap 57 may be Vshifted along the length of the wire to any desired position and then frictionally locked to its position of `support on the wire. With this end in view, the holes 64 karelso `dimensioned and spaced that the length of slit 63 Aadded t'o the combined diameter of two holes n64 is equal to the width 'of the body portion l61. To -release the :strap for shifting along the Wire,v and the lock it -intadjusted position, the body 61 is respectively pushed into, and pulled out of, the slotted head 62.

The chuck 45 comprises a nose piece 97 secured to Ythe lower end of the body 44, a resilient collet 98 supported within the nose piece and a thrust plug 100 resting atop the collet, the thrust plug having a threaded connection with a cylindrical extension 99 on the face gear 46. In order to permit vertical movement of the thrust plug 100 while preventing rotary movement, the plug is provided with a pair of tongues or splines 101 extending outwar'l and slidably mounted within grooves 102 on the inside wall of the chuck body 44. The face gear 46, with its extension 99, is rotatable in the chuck body 44 but is prevented from moving axially by a ball thrust bearing 103 resting on top of the extension 99 and a snap ring 104 supporting the bottom of the face gear 46 and supported within an annular groove of the body member 44.

In operation, let it be assumed that the jaws 105 of the collet 98 are in the expanded condition as shown on the left side of Fig. l, that the operator has inserted a work piece such as a drill bit (not shown) within the collet and that he desires to clamp the work piece by moving the collet downward and inward toward the position shown onthe right side of Fig. l. The nose piece 97, being firmly seated against the lower end of the body 44 cannot move upward therein and therefore the only way the operator can collapse the jaws is to bring the thrust plug 100 downward. To this end, the operator first grasps the rotatable key assembly by the knob 51 thereof and inserts the pinion 42 of said key through the radial bore 43. The pinion is supported for rotation about its individual axis by the engagement between the peripheral surface of the teeth 42t with the bore 43. The operator, still grasping the small uted knob 51, 53, turns the key rapidly, thereby imparting rotation to the face gear 46. The thrust plug 100, being constrained by the tongue and groove connection 101, 102 for axial movement only, moves downward in response to the interengagement of the relatively rotating screw threads provided on the face gear member 46, 99 and thrust plug 100 respectively. As the jaws 105 of the collet 98 are pushed downward, their outer edges slide over the conical surface in the nose piece 97 to impart to the jaws, by a camming action, an inward component of motion. Such motion is opposed by the resistance of the rubber body 106 associated with the jaws. As the operator continues to turn the knob 51 on the rotatable key 51, 56, 42, downward movement of the thrust plug 100 meets with increased resistance from the rubber body 106 and Vfrom the frictional engagement between the edges of jaws 105 and the internal surface of the nose piece 97. The resistance to such downward movement increases abruptly as the jaws come into contact with the work piece (not shown). The effect of the resistance is to cause the face gear member 46, 99 to react upward, but such upward thrust is sustained effectively by the raceway 103. At the same time, a reactive force is set up in the pinion 42 at the point of engagement of the teeth 42t with the face gear 46. The entire force of such reaction is transmitted ina torsional direction through the pinion 42, back to the operator and does not have any tendency to disalign the pinion with the axis of its bearing surface 43. The operator, upon feeling such increased resistance to rotation releases the small diameter knob 51 and grasps the Wire-handle 56 between his fingers, thereby increasing the effective diameter or moment arm of the key assembly and gaining greater leverage to tighten the chuck to its final position. When this has been accomplished, as manifested by the tendency of the wire handle 56 to flex, the operator merely removes the rotatable key assembly 42, 51, 56 and the chuck remains securely locked in tightened position by the frictional engagement of the threads interposed between the face gear 46, 99 and the thrust plug 100.

When the operator desires to release the work piece from the chuck, he reinserts the key 42 and reverses the direction of rotation thereof, resulting in upward movement of the thrust plug against a very light resistance. Motion of the pinion 42 into and out of the chuck body 44 occurs without any interference between the chuck key assembly and the supporting means therefor, as the strap 57 is free to bend or ex. Rotation of the pinion 42 to tighten or loosen the chuck jaws likewise is not obstructed by the support as the grommet 48 swivels freely about the axis of the pinion. On the other hand, the supporting means, including the strap 57, holds the key assembly at all times in a position within convenient reach of the operator.

What is claimed is:

1. A rotatable key for tightening and loosening the jaws of a chuck comprising a pinion having teeth insertable into the chuck, a knob rigidly attached to the pinion and extending outward axially therefrom, the knob having a manipulative portion near the outer end of the key and adapted to be grasped between the operators thumb and forenger to initially turn the key rapidly under relatively small torque resistance, the key having intermediate its ends a manipulative portion of larger diameter adapted to be grasped by the operator to impart torque at a relatively slower rate but with increased leverage.

2. A key according to claim l, in which the pinion has an extension at its outer end adapted to tit within a recess at the inner end of the knob.

3. A key according to claim 2, in which the pinion has a body portion separated from the toothed portion by an annular groove.

4. A key according to claim 3, in which a grommet is swivelly mounted on the pinion and lies within the annular groove.

5. A key according to claim 4, in which the grommet consists of a split ring, said ring being convex on the inside and having side walls abutting against the respective ends of the body portion and pinion portion.

6. A key according to claim 5, in which the grommet is provided with a peripheral recess and supports within said recess an apertured portion of a strap for supporting the key.

7. In a key operated chuck device, a rotatable key having a body portion and a pinion separated from the body portion by an annular groove, in combination with a key support, said key support comprising an elongated tiat, exible strap, the upper end of the strap having a head provided with a transverse slit, the lower end having a bore, a grommet supported within said bore, said grommet being externally recessed and having a maximum diameter exceeding the normal diameter of the bore, whereby the bored portion of the strap must be stretched for attachment to or removal from the grommet, said grommet being positioned within the annular groove and providing a swivel mounting for the chuck key, the bored portion of the strap being adapted to be folded and inserted through the slit at the head end, the lower and intermediated portions of the strap being adapted to be pulled successively through the slit to permit the strap to be clasped at its upper end upon a fixed support such as an electric wire.

References Cited in the tile of this patent UNITED STATES PATENTS

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