US3852884A

US3852884A - Winding and tightening tool and method for manufacturing same

Info

Publication number: US3852884A
Application number: US00407419A
Authority: US
Inventors: H Lazarus
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-10-18
Filing date: 1973-10-18
Publication date: 1974-12-10
Anticipated expiration: 1991-12-10

Abstract

An angle drive manually-operated tool as for winding and tightening around a tooth, a matrix band pre-formed into a loop and having one end wound into a cylindrical coil having a central socket, the tool having a winding member engageable to said socket. Said tool comprising, in combination, a palm grip rotatably mounted on one end of an elongated rotatable driving member and on its other end a replaceably mounted flexible drive sleeve unit with a pre-angled guide shaft internally and pivotably suspended therein, thereby providing said rotatably angle drive tool with having on its terminal end a rotatable winding member, which automatically pivots and aligns with the axis of said matrix coil socket, said tool includes an internal torque-limiting means in said driving member.

Description

Unite States Patent [191 Lazarus [451 Dec. 10, 1974 WINDING AND TIGHTENING TOOL AND METHOD FOR MANUFACTURING SAME [76] Inventor: Harry J. Lazarus, 36 Knox Ln.,

Englishtown, NJ. 07726 [22] Filed: Oct. 18, 1973 [21] Appl. No.: 407,419

9/1973 Hopkins 32/59 Primary Examiner-Robert Peshock [57] ABSTRACT An angle drive manually-operated tool as for winding and tightening around a tooth, a matrix band preformed into a loop and having one end wound into a cylindrical coil having a central socket, the tool having a winding member engageable to said socket. Said tool comprising, in combination, a palm grip rotatably mounted on one end of an elongated rotatable driving member and on its other end a replaceably mounted flexible drive sleeve unit with a pre-angled guide shaft internally and pivotably suspended therein, thereby providing said rotatably angle drive tool with having on its terminal end a rotatable winding member, which automatically pivots and aligns with the axis of said matrix coil socket, said tool includes 'an' internal torque-limiting means in said driving member.

21 Claims, 21 Drawing Figures PATENTEDBEE 10 $974 SHEEI 10F 2 FIG. 6 (PRIOR ART) FIG. '12 (PRIOR ART) CROSS-REFERENCE TO RELATED APPLICATION The present invention pertains to a winding and tightening tool particularly adapted, such as for use with a pre-formed dental matrix band which is looped and hasone end wound into a coil having a central socket which receives for tightening a racheted winding memher on the tool of the present invention, said preformed dental matrix band being the subject of applicants prior matrix U.S. Pat., No. 3,411,214, issued Nov. 19, 1968, and co-pending U.S. matrix Pat. application, Ser. No. 382,833, filed July 26, 1973.

BACKGROUND OF THEINVENTION The present invention primarily comprises an improvement over the prior tool comprising the subject matterof applicants prior US. Pat, No. 3,435,905, is-

sued Apr. 1, 1969. Said prior tool was effective to acin the interim since the issuance of said prior patent for purposes of facilitating the use ofsaid tool by a dentist, especially for purposes of preventing any serious damage to said tool, or to the matrix band or the destruction thereof prior to the same being completely mounted in operative position around a tooth. Especially, when used by so-called heavy-handed dentists, particularly those who are accustomed to using conventional matrix bands and tightening tools. Such conventional matrices and tools require substantial force to complete the tightening of said conventional matrix band into desired, final position around a tooth. Likewise, said prior tool was capable of transmitting undesirable twisting forces and thereby causing damage to applicant's matrix band which is primarily designed to be used with said prior tool, The Work habit of said heavy-handed practitioner could cause destructive wrist twisting action during use'of prior tool.

In said prior tool, one of the principal causes of the transmission of destructive twisting to the matrix coil is the rigid mounting of the palm grip on one end of an elongated internal bearing member and bent guide shaft and is fixed thereto, whereby when said palm grip is held in the palm ofthe operator and the driving member is rotated, as'is intended, any wrist rotation by the operator causes undesirable twisting of the guide shaft during use ofthe' tool, which causes the axial alignment of said winding member, rotated at the terminal end of the'flexible driving sleeve unit, to be disturbed with relation to the axis of the central socketin the spirally wound end of the matrix band, thereby sometimes causing destructive damage to' the matrix band, incident to the matrix being tightened about the tooth.

Further, in said prior tool an internal malleable guide shaft which is subsequently bent, after assembly, is fixedly connectedto the end of the bearing member'on the opposite end to which thepalm grip is fixed, whereby should said palm grip thereon be undesirably pivoted, incident to an undesirable twist of the wrist during use of the tool, the axial alignment of the winding member which is rotatably carried by the outer end of said rigidly connected bent guide shaft also is thereby destructively pivoted, relative to the central socket of the spirally wound end of the matrix band, and thus, render said matrix coil twisted and damaged.

Still another need for improvement of said prior tool lies in the fact that a chuck which is rotatably sup ported adjacent the outer end of the aforementioned bent guide shaft and is rotatably carried by and fixed to the outer end of a flexible drive sleeve rotatable around said bent guide shaft, the terminal end of the guide shaft being disposed within the wires of the flexible member to which the chuck is connected, whereby there is a tendency for the flexible sleeve, which is comprised of coen'gaged flexible coiled wires to become destructively abraised and damaged by rotatable engagement with the terminal end of said rigidly supported, bent guide shaftQ Still other important improvements also were needed over said prior tool and the same are obviated by the tool comprising the present invention, the objectives of which are as follows: i

SUMMARY OF THE INVENTION It is the principal overriding objective of the invention to provide an improved winding tool, such as for use for tightening of applicants matrix band around a tooth in which the ratcheted winding member substantially automaticallydisposes itself in axial alignment within the socket of the coiled-end of the matrix band for the winding thereof without thereby impairing the winding capabilities of the tool or the matrix for purposes of tightening said matrix coil, and thereby, tightening the band around a tooth. Ancillary to the foregoing object, his a further object to provide a floating arrangement for an improved pre-angled shaft which is pivotably suspended within the flexible drive sleeve unit, said improved, pre-angled shaft having opposite angularly related end portions protruding from a segment of. flexible sleeve and supported thereby and pivotable therein, at the opposite ends of said flexible member by a dual socketed collar at one end and an improved socketed chuck, supporting the other end of said shaft with a winding member at the outer end of the tool opposite the end which is rotatably supported in the palm of an operator.

Still another object of the invention is to provide a floating palm grip or handle member, which normally is disposed in the palm of the operator and from which a rod-like, finger-rotated driving member extends, the rotatable connection between said driving member'and palm grip member permitting free rotation-of the driving member with respect to the palm grip member and vice versa, wherebytwisting of the wrist of the operator will not affect the axial alignment of the winding member of thetool with respect to the socket of the coiled end of the matrix band.

In connection with said destructive twisting forces,,a further improvement of this invention is to provide a guide shaft that is notrigidly connected to the palm grip or any other of said improved mechanisms, except being pivotably suspended within the flexible drive sleeve as will be further described.

An objective of this invention is to provide an improved pre-angled guide shaft whose one terminal end extends beyond said flexible sleeve and terminates in a protective socketed encasement in said chuck whereby the destructive forces of the terminal end of the guidev ing been bent after final assembly of said tool by the operator; said improved guide shaft is bent prior to assembly.

Still further, to provide a dual collar and chuck-encasements for the assembly and suspension of said preangled shaft within said sealed flexible drive sleeve unit which is thereby'a readily replaceable unit, with an improved chuck and winding member at the terminal endof said flexible sleeve unit which provides a socket for said suspended, pivotable, guide shaft and flexible sleeve unit.

An improved shaft for the winding member which provides for a shoulder on said winding member shaft to limit the depth of the entry of said shaft into said' chuck enclosure, which thereby establishes internal dimensions to receive the suspended guide shaft, in said chuck socket, including clearances therein, for rotation on said shaft.

Onefurther object of the invention isto provide the aforementioned pre-angled shaft and flexible sleeve thereon in the form of a demountable, replaceable,

flexible drive sleeve unit, readily removable from a socketin the end of the driving member which receives one end of said flexible unit, whereby if damage of any kind occurs to said unit, as from continued use, it readily may be replaced by a substitute unit.

Still another object of the invention is to provide automatically releasable clutch means between the driving membera'nd said flexible drive sleeve unit, whereby when the coil of the matrix band has been tightened to a predetermined extent established by'the capability of the clutch means, any further attempt to tighten the coil of the matrix band will be prevented due to said clutch means permitting disengagement between the driving member of the tool and a rotatable barrel clutch member. Re-engagement of said clutch is incident to further use of the tool as will be described hereinafter. Details of the foregoing objects and of the invention, as well as other objects thereof, are set forth in the following specification and illustrated in'the accompanying drawings comprising apart thereof:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 isa perspective view of the winding tool embodying the principles of the present invention.

FIG. 2 is a fragmentary, foreshortened, partially vertically sectioned view of the tool shown in FIG. 1 and illustrating therotatable palm grip assembly and flexible sleeve assembled to the driving member. Arrows indicate normal rotary movement of components during use of tool.

FIG. 3 is a vertical sectional view, illustrated on a larger scale than in the preceding figures, showing details of a replaceable unit at the forward end of the tool comprising a pre-angled shaft, rotatably mounted by a flexible driving sleeve member with said shaft being suspended between a socketed chuck at the outer end of the unit and an insertible elongated socketed collar member disposable within a socket atone end of the driving member of the tool. 1

in the unit shown in FIG. 3.

FIG. 6 is an exploded perspective view of one section of the flexible sleeve arrangement shown in FIG. 5 to illustrate details of one section thereof in accordance with prior art structure and showing an improved small collar.

FIG. 7 is an exemplary vertical sectional view taken through the flexible sleeve means shown in FIGS. 5 and 6, and also additionally illustrating details of the prior art being utilized in present invention.

FIG. 8 is a fragmentary view illustrating prior art means for forming the flexible sleeve illustrated in FIGS. 5-7.

FIG. 9 is a side elevation showing a typical manner of employing the pre-angledwinding tool comprising the present invention and showing the same mounted in winding relationship with a coiled end of a matrix band surrounding an exemplary tooth, said view also showing directional arrows illustrating motions employed 'in operating the tool, both in regard to the prior art and the present invention.

FIG. 10 is a side elevation of the prior art winding tool, said view being principally in vertical section to show details thereof.

FIG. 11 is a side elevation of a pre-angled shaft upo'n which'the flexible sleeve. of the winding mechanism is adapted to be mounted.

- FIG. 12 is a perspective view of the one-pieceunit of the prior tool comprised of a palm grip, an internal bearing rod and guide shaft of the winding tool of the prior art, illustrating the pivoting of the tip of the bent guide shaft at the outer end of the guide, and the pivoting of said palm grip as indicated by arrows.

FIGS. 13 and 14 respectively are illustrations of a prior art winding tool shown in engagement with the coiled end ofa matrix band in FIG..l3, and in FIG. 14, showing the manner in which the prior art tool causes a positive, pivoting malfunction of the winding member when palm grip is rotated as in FIG. 12, and illustrating in FIG. 14, the destructive pivoting to the coiled end of the matrix band.

FIG. 15 is a view similar to FIG. 13, but illustrating the improved winding tool of the present invention to show how destruction, such as illustrated in FIG. 14, will not occur with said improved tool, even with similar palm grip rotation, as indicated by similar arrows on palm grips in FIGS. 14 and 15.

FIG. 16 is a perspective view of the winding tool of the present invention illustrating some of'the details of the releasable clutch means for the driving unit, and also, in vertical section, showing details of the rotatable mounting of a hand-held palm grip at the outer end of the modified rotatable driving member.

FIG. 17 is a fragmentary vertical sectional view, showing some details of the mounting for the replaceable, flexible drive sleeve unit in one end of the socketed, rotatable, modified driving member and also showing details of the releasable ball/socket clutch between the modified driving member and the flexible driving sleeve unit normally driven thereby.

FIG. 18 is a fragmentary perspective view of one end of the elongated barrel with view of the ball/spring channel seen therein as shown in FIG. 17 for reception of the barrel within the socket at one end of the modifled rotatable driving member.

DETAILED DESCRIPTION Referring generally to the drawings, this winding tool embodies improvements over applicants prior US.

Pat. No. 3,435,905, issued Apr. 1, 1969. Reference will now be made as to the function of the improved winding tool invention as provided in this application.

' While significant improvements are represented in this application, several basic principles of applicants prior patent are retained, where applicable. Where the prior art is retained, it will be so referred to and the improvements will be distinguished thereover.

As in applicants prior tool patent, the function of this improved tool of FIGS. 1, 9 and 15, is to act as a winding member, forexample, when tightening the coil off the applicants dental matrix. As in use with the applicants matrix, this hand-operated tool 10 transmits a horizontal winding force and converts said force into a near vertical winding force when its angled tool tip, winding member 14, is inserted into the coil 76 of the matrix 74 for winding and tightening the same. As in FIGS. 9 and 15, the rotation of the driving member 20,- in turn, winds a flexible drive sleeve 48, which winds the bur-like winding member 14 of chuck 16, when it is inserted into the coil 76 of matrix 74, the ratcheted teeth 15 0f winding member 14 automatically engages the ID. of the coil 76' and winds and tightens said matrix coil 76 when tool 10 is operated, as in FIGS. 9 and The principal objective is to continue the rotation of coil 76 by tool 10 until the matrix 74 is tightened about the tooth 72. Improved tool 10 of the present invention is operated by rotating the driving member 20 with the forefingers while holding the rotatable'palm grip 30 in' the palm of the same hand, as seen in FIG. 9. Arrows shownin FIG. 9 illustrate normal tool and wrist rotation. Rotation of drivingmember 20 transmits the rotatable driving force into the improved flexible drive sleeve wires 48, which, in turn, transmits said force into the ratcheted winding member 14 which winds and locks the matrix coil 76. To remove the tool 10 from its engagement in said coil 76, the winding tool member 20 is wound reversely to the coiling direction. The winding member 14, as in prior tool, is unidirectional, and thereby is disengaged from the inner windings of the coil when rotated reversely, while simultaneously withdrawing said disengaged winding member 14 axially from the coil 76. In prior tool, when tool A of FIG. 10 is used in dental matrix work, any undue wrist twisting or torque to palm grip T, couldcause destruction of the matrix 74 by twisting the coil 76 of the maxtrix 74 and additionally bring about excessive and uncomfortable force against the tooth 76. It is desirable, therefore, to automatically control the amount of twisting force that can be applied by said heavy-handed practitioner.

As shown in FIG. 9, the wrist 77 of the practitioner could be undesirably employed to create said undesirable twisting in the use of a winding tool A, as shown in FIGS. 13 and 14. Such twisting is employed in use of other tools and with other conventional matrices which necessarily require greater amounts of torque to effect the desired fit of the matrix to the tooth, and thereby resulting in discomfort to a patient.

In contrast to the foregoing, when using the improved tool 10 of FIGS. 9 and 15, no excessive torque is required to acquire a tight fit of applicants matrix 74 on the tooth 72. This results in greater comfort to the patient and no damage to the matrix or tool. Therefore, to avoid such unrequited torque and tool twisting, several improvements were added to the prior art tool, among these being the improved palm piece 30 which was made free-floating, so that, unlike the prior art, when the driving member 20 is rotated by the fingertips of the practitioner, as in FIG. 9, the wrist 77 rotation indicated by the dashed arrow, will in no way cause any destructive twisting of the matrix coil 76. This is because the improved palm piece 30 is rotatably engaged to said tool 10 and is not fixed to any of the winding mechanisms, nor is it connected with the pre-angled internal shaft 46 which is pivotably suspended within socket 67 of the flexible sleeve assembly 12. In prior tool, the guide shaft K was rigidly fixed to the palm grip T, as in FIGS. l0, l2, l3 and 14. Inasmuch as improved palm grip 30 is disconnected and rotates freely, any twisting of the palm grip 30 will not be transmitted through the flexible sleeve assembly unit 12, nor into the ratcheted winding member 14 and, matrix coil 76. The function of this improved rotating palm piece 30 is to serve as a good holding means, to direct the pitch of tool 10 and yet prevent any rotation of the wrist'in any way from destructively affecting the operation of the tool 10 or the matrix 74. The pivotable disposition of the suspended, pre-angled shaft 46 in socket 67 comprises another improvement, and will hereinafter be described.

In applicants prior tool, the palm grip T was rigidly attached to the inner bearing Q, and the malleable guide shaft K and G, as clearly seen in FIG. 12. FIGS. 10, l2, l3 and 14, illustrate the prior art and show how any amount of rotation or twisting of the palm piece T by the wrist causes a pivoting of the end of the bent shaft G of the shaft K to G, as shown by dashed lines, as seen in FIG. 12.

Said pivoting of shaft K at tip G results in a destructive action of the matrix 74 into which it was inserted,

as in FIGS. 13-14, and will later be described. The

freely rotatable palm piece 30 and the improved, pivotable, pre-angled shaft 46, as seen in FIGS. 1-3 and 11, combine to overcome the potential destructiveness of the undue wrist action as shown in FIGS; 12, 13 and 14 of the prior art, to be later described herein.

Briefly, the novel tool of the invention shown in FIGS. l3 includes in combination a handle assembly 10 and a driving member 20 which has at one of its ends said rotatable palm grip 30, mounted thereon and at the tapered end 22 of the member 20, a flexible sleeve assembly unit 12, which is replaceably'secured to said rotatable driving member 20 which, in turn, ro-

tates at the extreme end of tool 10, a chuck 16 which one using this tool 10. Said improved palm grip 30 hasa deep socket 36 extending into it from one edge. The improved driving member 20 has near one end, a circumferential annular groove 28 thatis part of ajournal 26, which fits into the deep socket 36 of the palm grip 30. With the journal 26 inserted into the palm grip 30, a spring pin 34, as seen in FIG. 2, is inserted into hole 32 which transverses socket 36 of the palm grip 30, shown in FIGS. 1 and 2. When fully inserted, the pin 34 traverses the channel 28, and in a free-spinning, rotatable engagement, holds the palm grip 30 on the journal 26 of the driving member 20.

When-operating tool 10, the driving member 20 also is freely rotatable in the palm grip 30 with the fingers when said palm grip 30 is held in the palm of the users hand, as seen in FIG. 9. previously, in the prior art, as in FIGS. and 12, the palm grip T was rigidly connected to an inner bearing O that ran through a hollow,

tubular driving member P, with said malleable guide shaft K extending through the coreless flexible sleeve portion of tool A and terminating at end G, inside chuck D, as seen in prior art, FIG. 10. In the present invention, thedriving member is a solid metal rod and is also freely rotatable, as shown by arrows in FIG. 3. The improved driving member 20 has a socket 21, for receiving the replaceably engaged flexible drive sleeve unit 12.

The objective of said drive sleeve'is to transmit a rotational force from one angle to another as in said tool 10. In tool 10, the pre-angled guide shaft suspended within flexible sleeve 48 redirects the forces from that of the plane of the driving member 20 to the obtuse angle of said angled guide shaft 46, as seen in FIGS. 3

and 9 for intraoral use of the tool 10 in a patients mouth, as when used with applicants matrix 74 when winding coil 76.

FIG. 3 shows the improved rotatable flexible drive sleeve assembly 12 as being comprised of the following members: A non-connected, pivotable, angled shaft 46 suspended within the central passage inthe coreless flexible sleeve assembly 12 unit, which has socket enclosures affixed at each ending/At one end of assembly 12, a socketed chuck 16 is soldered to the end 54 of flexible sleeve wires 48 and to the chuck 16 is affixed the ratcheted winding member 14, with set screw 18. At the end 55 of assembly 12, opposite chuck 16, there is a deeply socketed collar 38 which is soldered to the end 55 of the flexible sleeve 48, thereby sealing, in socket 67 of collar 38, the pre-angled shaft 46, which is suspended internally within the thus obtuse-angled flexible drive sleeve assembly unit 12.

In FIG. 2, the deep socketed collar 38 of assembly 12 is fitted into hole 39 of driving member 20 and locked therein by set secrew 24 which bears against flat 42 of the deeply socketed collar 38. In FIG. 3, the pivotable, pre-angle shaft 46, with its chamfered ends 70 and 71, is sufficiently long so that the chamfered end 70 lies fully within the shaft socket 68 of socketed chuck 16,

while the opposite end of angled shaft 46 extends and is suspended deeply in the socketed hole 67 of collar 38. Shaft 46, while being long enough to reach from socket 68 of the chuck 16 through the flexible sleeve 48, and into the deep socket 67 of collar 38, is still short enough so as to leave a shaft clearance space 44 to permit unrestricted pivoting and rotation of tool 10 at the deepest portion of the socket 67 of collar 38, as shown in FIG. 3.

As in applicants prior tool patent, flexible sleeve 48 is composed of a pair of

helical springs

82 and 84, which are coaxially telescoped and oppositely wound, and are formed over an aluminum mandrel 58, of suitable stainless. steel or other suitably flexible material, such as, for example Monel metal, synthetic resins, etc. For clockwise rotation tool, as with tool 10, for

said matrix, outer spring 82 is wound with a left lay,

while inner spring 84 is wound with a right lay, as best seen in FIGS. 7 and 8, or vice versa, for tools with counterclockwise requirements.

In production of the assembly 12 unit, the inner ends of

spring windings

82 and 84 are united by

solder bands

55 and 54, as seen in FIGS. 5, 6, and as in prior art. The deep socketed chuck 16 in FIG. 3, then is soldered or brazed to end 54 of the flexible sleeve 48. The ratcheted winding member 14 then is fully inserted into the socketed chuck with the improved shoulder 64 of the winding member 14 against the tapered end of the chuck 16. A set screw 18 anchors the shaft 62 of the ratcheted winding member 14 inside socket 68 of chuck 16. Said shoulder 64 controls depth insertion of winding member 14 in socket 68 of chuck 16 of FIG. 3

To the opposite soldered band 52 of flexible sleeve 48, as seen in FIG. 3, an improved, short, smalldiametered collar 40 is soldered. Thereinafter preangled shaft 46 is inserted through the short collar 40. Said shortness of collar 40 permits axial passage of bend 66 of shaft 46 into the flexible sleeve assembly 12 until said end 70 of suspended, angled guide shaft 46 seats against the top of shaft 62 of winding member 14. The socketed extra long collar 38 is then telescoped over the projecting shaft 46 and the long collar 38 is soldered to the short collar 40 by means of solder fillet 100, as seen in FIG. 3. The affixed long collar 38 is then inserted into the deep hole 21 of the driving member 20, as seen in FIG. 2, and affixed therein with a set screw 24. Thus, when driving member 20 is rotated, the flexible sleeve assembly 12 unit is likewise rotated.

The flexible sleeve assembly 12 unit may be easily removed by loosening set screw 24, as seen in FIG. 2, which renders the flexible sleeve assembly 12, a disposable unit, in the event said windings 48 become fatigued from continued use. This disposable feature is i one of the improved aspects of this invention. In the prior art, shown in FIG. 10, shaft K was bent after assembly of tool A, and due to the one-piece unit, comprised of the palm grip T bearing Q and shaft K of the prior art, it was necessary to tear down the entire tool A in order to replace a wornflexible sleeve L. Thus, if the winding became damaged in use, an entire new tool A was needed.

. The flexible sleeves per se are produced as in the prior art, and this method of making the flexible sleeve is best illustratedin FIGS. 5, 6 and 8. Preferably, a plurality of flexible sleeves is formed simultaneously. This is done by forming two continuous lengths of helically and oppositely wound spring sires 82 and 84 over an aluminum mandrel 58, as seen in FIGS. 5, 6 and 8.

In the prior art, as seen in FIG. 5, the continuous lengths of stainless steel wire are soldered at 54 and 55, and then are severed at lines 56, whereafter the nonsoldered aluminum mandel 58 is free tobe removed from the resultant series of coreless flexible sleeves 48 as seen in FIG. '6. In the present invention,

solder bands

54 and 55 are then smoothed and an improved short collar 40 is slipped thereover and bonded to the band 55 as by soldering or brazing. Similarly, chuck 16 is slipped over the solder band 54, which has likewise been smoothed and chuck 16 soldered or brazed to the solder band 54. 4

The improvement to the flexible sleeve assembly 12 of FIG. 3 lies primarily in sevenareas, namely, shoulder 64 of winding member 14, the socket 68 of chuck 16, the shortcollar 40, the deeply socketed collar 38, the pre-angled shaft, the suspended, pivotable shaft 46, the advantages of which are hereinafter described, including the flexible drive sleeve, which in the present invention is a self-contained replaceable unit., 7

In applicants priortool, shown in FIGS. 10 and 12, the shaft K or stem, as it was formerly named in applicants prior patent, was assembled into the flexible sleeve, unbent. Previously, the shaft was bent at U (FIG. 12) after all soldering and joints were completed, the fully assembled, flexible drive sleeve L was gripped externally and then the semi-malleable shaft K was bent to a desired. angle by bending the entire'assembly L.

. For'two reasons, the post-assembly bending of shaft K proved undesirable. Firstly, the bending'a'ction of the semimalleable shaft K often caused some destructive kinks in the windings of the flexible sleeve J and thus, on occasion, rendered the flexible sleeve unless prior to fulfilling its usefulness.

Secondly, experience has proven that for stability a more rigid pre-angled shaft than previously used, was required in the application of the winding tool 10 for dentistry. The former semi-malleable shaft could too easily be accidently rebent, during use, from itsdesired-angle and so a more rigid pre-angled shaft is currently employed in the invention of the present improved shaft 46 of FIGS. 2 and 3. Additionally, in the prior art, only a single long, open-ended collar M, as seen in FIG. 10, was employed. The collar M needed to be long enough so as to be able to seat deeply enough into the handle P in order to be engageable by the set screw N which needed to be located at adistance back from tapered end 22 to where wall thickness increases. Therefore, .in the prior art, a rigid, one piece, pre-angled shaft would not have been able to pass through the hollow driving member P ,or the long collar M during the assembly operation of tool A. Thus,

in the prior art, the bending had to be done after assembly as previously described, and this often caused said destructive kinking of the flexible sleeve L. This kinking is eliminated in the present invention by employing said improved, two-part collar system, namely, the short collar 40 and the long collar 38,-which, in combination, permit the assembly of the pre-angled shaft 46.

In operation of the improved tool 10 of this invention, the flexible drive sleeve 12 rotates around the pivotable, preangled, suspended guide shaft 46. Thus, said pivoting, angledshaft46 in the flexible drive sleeve assembly 12, combine to seek their own common axial alignment with the central socket of matrix coil 76. The

sleeve unit 12 pivots on'pre-angled shaft 46, whenever Further, pre-angling shaft 46 during manufacture, as

described, also eliminates the need for a dentist to become involved in re-bending the shaft to the exact required angles that are needed for intraoral'use. Said non-destructive bending is best produced under-exacting, controlled conditions, where the tool is being manufactured.

This-pre-bending of angle 66 of shaft 46 of FIGS, 3 and 11 being done previously to assembly as permitted with the use of

collars

38 and 40 is an improvement over the prior art.

Also, as in the prior art, FIG. 7 illustrates the relationship of the pre-angled shaft, 46 to the

windings

82 and 84, and shows the space between the ID. of the windings and the OD. o'f'shaft 46, except where bend 66 of pre-angled shaft 46 occurs. FIG. 3 shows the flexible sleeve 48 brushing against the preangled shaft 46 at the bend 66 in the flexible sleeve assembly 12. This frictional brushing prevents undesirable spring-back when flexible drivesleeve'windings 48 are flexed during use in too] 10. i

The improved socketed chuck 16 also adds longevity to the disposable assembly 12 unit by extending its usable life. In FIG. 4, the'chuck D, with shafts K and G,

represents the prior art, in which shaft K'te'rminates at G, within the soldered wire section H of chuck D. During rotation of the flexible s'leeve' assembly L, the spring-like forces of the flexible sleeve L create pressure of the soldered wires H against the terminal ends of the shaft K in the direction ofarrow Y. Continued pressures of X against G eventually become destructive v and prevent further rotation of the chuck D and the tool A and this willcause failure of tool A. Therefore,

the improved socket 68 of chuck 16 of the present invention is significant in preventing destruction of the terminal end-of flexible wires82 and 84 of sleeve 48, as will be described hereinafter.

Unlike prior tool A, in the present invention, as seen in FIG. 3, the shaft 46 terminates beyond the soldered wires segment 54 of the flexiblesleeve 48 with terminal end of shaft 46 extending deeply into an improved shaft socket 68 where said terminal end 70 cannot contact 'or do damage to said soldered sleeve wires 54. Chuck l6 and socket 68 preferably are made of hardened steel and therefore, when normal pressures are exerted between end 70 of shaft 46, at exemplary point 60 inside chuck socket 68, shown in FIG. 3, the smooth, hard walls of inner shaft socket 68 support all said pressure, which results in no destruction to the ends 70 and 71' of preangled shaft 46 are chamfered so as to create the least amount of destructive friction and wear between the socket 68 and the chamfered end 70 of the pre-angled shaft 46, and thereby also assure smooth rotation.

When using tool with applicants matrix 74, the operator of tool '10 need do nothing in particular. to effect engagement except to insert the winding member 14 of the tool 10 into the coil 76, as shown in FIG. 9, and then rotate driving member 20 in order to effect a positive automatic engagement of the winding member 14, in the coil 76 that he desires to wind and tighten. This engagement feature of the winding member was also a feature of applicants prior tool patent. However, the present invention offers improvements thereover which overcome certain operational difficulties experienced in the prior art under certain conditions herewith referred to below. In the prior art, FIG. 13 shows tool A inserted androtating in coil 76 of matrix band 74 which is about the tooth 72. Rotation of the winding member B is performed so as to rotate the coil 76 and thereby wind the matrix surplus around the coil 76 and draw off all such surplus matrix until the matrix 74 fits tightly about the tooth-72. In FIG. 13 of the prior-art, the palm grip T is shown level, as indicated bythe directional arrow l08,'which also indicates that the operator had not twisted his wrist. The palm grip T being rigidlyattached to the inner shaftK extends into the sleeve L and chuck assembly D which is also seen in FIGS. 10 and 12. In FIG. 13, matrix coil 76 remains vertical and undistorted during rotation.

However, in FIG. 14, the palm grip T of the same tool A of the prior art, is being shown undesirably twisted as when used by said heavy-handed practitioner, with the palm grip T being pivoted and rotated as by the wrist ofv the user as shown by directional arrow 109. Such rotation of angle 109 of the palm grip T, which is directly connected to the internal shaft K and G as .in the prior art, and is disposed within the flexible sleeve assembly L, causes the flexible drive sleeve assembly L to equally pivot destructively in the same direction in which the palm grip T is being rotated and thereby causes the matrix coil 76 to be pushed away from the matrix 72 prior to fully tightening same and thus, causing destruction of the matrix band 74 prior to affecting the usefulness of it. However, in the present invention, in FIG. 15, although the freely rotatable palm grip 30 is also pivoted, the improved assembly 12 of the tool 10 of the present invention does not pivot or twist and no destructive pivoting of the palm grip '30 is transmitted through to the winding member 14, and therefore,

none occurs to the coil 76, which is successfully wound, in spite of the similarity of directional angle 109 of the palm grip 30, in both FIG. 14 of the prior tool and FIG. 15 of the present tool. Therefore, the improved floating palm grip in FIG. 15 prevents any maleffect from pushing or pivoting the coil 76 while the driving member is being rotated. The stabilizing action-of the present improved rotatable floating palm grip 30, in combination with the suspended guide shaft 46, maintains the winding member 14 in axial alignment with coil 76 of FIG. 15, in spite of strong angulation of the palm piece 30.

As many practitioners can be expected to unnecessarily over-rotate the palm grip due tothe habit they acquired when using other matrices, other than applicant's matrix 74,'and just as the floating palm grip 30 aids in preventing any destruction to either the tool or the matrix as a result of any rotary or twisting wrist action on the practitioners part, similarly, in FIG. 3, there is a floating nature to the suspended flexible drive sleeve assembly 12 unit, which completes the chain of protection as previously described.

FIGS. 16 through 21 illustrate a ball and socket force-limiting device 90, that prevents any undue finger-created torque from being undesirably transmitted to, and thereby preventing any destruction of the other mechanisms of the tool 10, such as the

flexible sleeve wires

82 and 84 of FIGS. 3 through 9, from undue torque, or to the matrixband 74 which said tool 10 is winding. Said force-limiting device operates automati-v cally whenever the practitioner employs any excess forces, such as he may be accustomed to applying with matrices of the past. Notably, the applicants matrix invention does not require such undue torque in order to effect adaptation of the matrix to the tooth, which provides increased patient comfort.

' However, applicants matrix 74 can be excessively wound by said heavyhanded practitioner. The ball- ,/socket releasable clutch of this improved invention prevents the transmission of such forces. This results in longer life for tool 10 and greaterpatient comfort.

FIG. 16 is a sectional view of the torque-limiting modified driving member 88. The freely rotatable palm grip 30 is the same palm grip as shown in FIGS. 1, 2, 9 and 15. The assembled flexible sleeve 12 unit is likewise the same as that shown in all previous figures pertaining to the present invention. Thedifference between tool 10 and tool 11 of FIGS. 16 through 21, is in the quad-socketed, dual ball and spring arrangement that comprises the torque-limiting device. The tool 11 has all of its modifications in two places. One is at the tapered end of the alternate ball-socketed, modified driving member 88. The other comprises the clutch member assembly of the ball and spring-retaining barrel clutch 90. These two features are seen in FIGS. 16 and 17.

The ball spring-retaining barrel 90 is made of small enough diameter so as to be able to be rotatably fitted into socket 94 of driving member 88, with clearances, as shown in FIGS. 17, 19, 20 and 21. Said clearances permit unrestricted rotation of barrel 90 within said channel 92 in FIGS. 17-2l. In FIG. 17, the balls 102 and spring 104 within the barrel 90 maintain the engagement of barrel 90 to driving member 88 by pressure of spring 106 forcing the balls into sockets 94 of said driving member 88. Barrel 90 is also fitted with a set screw 98 that is threaded through a suitable aperture in member 90 to anchor the collar 38 of said flex ible drive sleeve assembly 12 unit securely within the barrel 90, as shown in FIG. 17. With this arrangement, when barrel 90 rotates, so then does flexible drive I sleeve unit 12 rotate.

As shown in FIGS. 16 and 17, there are sockets comprising drilled holes 94a through 94d, of which there are 2 sets of pairs or four holes in the walls of socket 92 of modified driving member 88, as seenalso in FIGS. 19, 20 and 21. FIGS. 16 and 17 also show the steel balls 102 projecting into and engaging the socket holes 94, in driving member 88, which are of a smaller diameter than the balls 102, and are held in engaged position with the sockets 94 by the force of the compression spring 104 between the pair of the steel balls 102, especially as shown in FIG. 17. FIG. 17 also sectionally shows the ball/socket arrangement in which the spring 104 and balls 102 are disposed longitudinally in a transverse bore 106 of barrel 90, which is shown in FIGS. 18, comprising an external view of FIG. 17.

Said clutch is assembled with the balls 102 and spring 104 being forcefully assembled into bore 106 of barrel 90. Then barrel 90 is forced into socket 94. Clutch disengagement occurs whenever balls' 102 are dislodged from socket holes 94, which occurs only when excessive rotating force is being applied to modified driving member 88. Under such force, the balls 102 are depressed by the edges of sockets 94 and said clutch is then disengaged. However, continued rotation of tool 11 re-engages clutch.

The torque control setting of the tool is determined by the relative dimensions of two members, i.e., the spring-loaded balls 102, and the diameter of sockets 94. The smaller the diameter of the ball 102, the deeper said ball 102 becomes embedded in said socket hole 94, and therefore, a greater torque is required to dislodge the balls 102. Conversely, the larger the ball 102, or the smaller the socket holes'94, the less the ball becomes embedded in the socket which requires a lesser torque to release balls 102. Therefore, a greater rotational force of member 88 is'required to dislodge a deeply embedded spring-loaded ball 102. Inasmuch as the flexible drive sleeve 'unit 12 of tool shows fatigue at about 16 in. 02. of torque, and in dentistry, patient discomfort is obvious at 10 in. 02., and with about 12 in. 02. being destructive to applicants matrix 74, the desired torque-limiting device is thus best set at about 8 to 9 in. oz. By employing the correct combination of ball diameter to socket l.D. diameter, an 8 to 9 in. 02. torque is provided, while variations, in the combination of ball and socket diameters will provide any desired torque-limiting control means.

In actual practice, when the torque limiting tool 11 is employed, as in FIGS. 19, 20 and 21, the followiing occurs. The rotation of the modified driving member 88 would function exactly as driving member 20 in the tool 10, now shown in FIG. 15, with the exception that after initial rotation of'tool 11 in coil 76, and the coil tightens against further rotation, then, when the resistance to continued rotation equals 9 in. oz. the torquelimiting mechanism of the tool 11 itself takes over the control of the amount oftorque is permitted to be transmitted from the practitioner's fingers to the rotating matrix coil 76 in the following manner. The matrix coil 76 requires about 6 inch-ounces of torque to tighten and lock the matrix 74 about the tooth 72, as in FIG. 15. The tool 11 would react in no new way if no more than 9 inch-ounces were applied to the modified driv'ing member 88, as in FIG. 19. However, if the torque would exceed 9 inch-ounces of rotational force,

said ball/socket clutch would disengage and as in FIG. 20, balls 102 would be depressed under and out of their engagement with

sockets

94a and 94c, thereby causing a cessation of the amount of transmitted torque due to said disengagement. If the rotational torque is continued as in FIG. 21, then a re-engagement of the balls 102 into

sockets

94b and 94d is made again. Then, if said excessive force is continued, the engagement, disengagement, and re-engagement would again occur as ball and sockets slip in and out, as shown in FIG. 20, thereby acting reliably as a force-limiting mechanism, as no force or torque is transmitted beyond 9 in. 02. to either the winding member 14 or the matrix coil 76 whenever said disengagement occurs.

The arrows 78 in FIGS. 192 1 illustrate the direction of the rotation of the modified driving member 88, while arrow 80 illustrates the movement of the barrel 90. The reverse direction of the heads of arrows 80 indicate where the barrel has ceased to rotate due to the acquired tightness of the matrix 74 on the tooth which caused the disengagement of said clutch, as shown in FIG. 20, and thereby ceased to rotate said barrel 90.

Notably, when said matrix tightness is accomplished, said member 88 is still revolvable around said barrel 90 as long as 9 in. 02. of torque is still being applied, as indicated by arrows 78, repeatedly disengaging the balls 102 and sockets 94, and then re-engaging, etc., so long as rotation of modified driving member 88' is continued. During such occurrence, the practitioner becomes aware of the acitivity of the force-limiting mechanism by the sound of the clicking of the balls 102 into the sockets 94 and ceases further rotation of member 88 with an awareness that the matrix has been fully tightened, without undue torque forces having reached and the matrix or the tooth or having damaged the windings of the winding member 88 in any way. Said sonic clicking is another improvement in this invention.

Any torque beyond the 9 inch-ounces would be destructive to the matrix 74, and any such continued excessive torque to the flexible sleeve assembly 12 could result in early fatiguing of the delicate

flexible sleeve windings

82 and 84, and thereby reduce said wires usable life span. The torque-limiting device of this invention prolongs the life off the tool and also affords patient comfort by preventing said undue torque from reaching the patients tooth 72.

While the invention has been described and illustrated in its several preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as illustrated and described.

I claim:

1. An angle drive manually operable tool to wind and tighten around a tooth a matrix band formed into a loop and having one end spirally wound to form a bandtightening coil provided with a central socket, said tool comprising in combination, an elongated driving member, a palm grip rotatably mounted upon one end of said member for movement about the axis thereof, a coreless rotatable flexible drive sleeve unit with sockets at each end thereof, with said sleeve having an internally pivotable angularly bent guide shaft therein, said shaft being bent prior to assembly and is internally suspended thereafter through the length of the core of the flexible sleeve unit, with said shafts terminations rotatably engaged with sockets to hold said shaft against axial disposition 'at each end, and with one such socketed collar being replaceably engageable with said driving member, and with the other socket being part of a chuck, having a winding member adapted for controlled depth insertion in said chuck and with said winding member engageable with the central socket of a matrix band coil for winding and tightening of said coil, and with said driving member being provided with a torque limiting means. I

2. An angle drive tool as in claim 1 in which said palm grip is circular in plan view and has opposite flat parallel faces, with a deep socket therein spaced between said flat faces and an annular groove substantially perpendicular to and transversing said socket, and with said socket receivable of said driving member. 7

3. An angle drive tool as in claim 2 in which said driving member comprised of a relatively elongated member with an annular groove on its one end for rotatable engagement in said socket of said palm grip and a locking pin disposed in said perpendicular groove of said palm grip transversely engaging the annular groove for rotation of said driving member in said palm grip but preventing relative axial movement therebetween said driving member and said palm grip, and with said driving member replaceably engageable with a flexible drive sleeve unit.

4. An angle drive tool as in claim 3 in which said driving member has a deep axial socket in its end opposite said palm grip whereby said socket which is receivable ofa complementary long collar on one end ofa flexible drive sleeve unit is replaceably inserted and secured therein to said driving member.

5. An angle drive tool as in claim 1 in which said flexible sleeve has suspended within its core, an angularly bent guide shaft which is encased within said sleeve unit by a long socketed collar on its one end that'supports said suspended preangled shaft for free pivotable movement, therein said socket while at said other end of said flexible sleeve assembly unit, a rotabably mounted socketed chuck supports said other end of preangled guide shaftwhich thereby permits said tool to automatically pivot into self-alignment with the coil it is winding.

6. An angle drive tool as in claim 1 in which a cylindrical chuck, with a tapered end has an axial hole through its length, with said hole being drilled of a smaller diameter at said chucks tapered end and a substantially larger diameter hole at said chucks opposite end and with both holes meeting intermediate the axial ends .of said chuck and with said flexible sleeve being complementary in diameter to the larger hole being inserted and fixed therein, and with said winding member shaft being fully inserted and fixed in said small diametered hole at the tapered end of the chuck and with said small hole having a space between the top of said winding member shaft and the inner terminal end of said small hole with said space being deepenough and being a complementary in diameter to provide a pivotable, ro-

tatably engaging socket for the terminal end of the preangled shaft.

7. An angle drive tool as in claim 6 in which a winding member which has a dual diametered shaft with the relatively larger of the diameters'constituting a shoulder on said shaft with said shafts terminal end having a smaller diameter than said shoulder and with said shaft's terminal end being complementary in diameter 'to the smaller'axial hole inthe tapered end of said chuck and being fixed in said smaller hole with said larger diametered shoulder pressed against the truncated end of the chuck and having said winding member shaft inserted fully and with said shaft insertion being less than the full axial length of the smaller hole in said chuck with the remaining portion of said hole being provided as a receiving socket for encasement of the terminal end of the pre-angled guide shaft.

8. An angle drive tool as inclaim l in which said guide shaft being cylindrical, has opposite end portions respectively disposed at an obtuse angle positioned intermediately between the ends of said shaft, one end portion of said pre-angled guide being mounted for pivoting in an axially extending socket on one end of a rotatable flexible drive sleeve unit to permit the winding member which .is rotatable on the opposite end portion of said pre-angled guide shaft automatically to pivot on said pre-angled guide shaft and align said winding member axially of the socket of the band-tightening coil of the matrix band.

9. An angle drive tool as in claim 8 in which a preangled guide shaft having its both ends chamfe red so as to ride smoothly and without destructive frictional contact within the encasement endings they are disposed into for pivoting and rotation.

10. An angle drive tool as in claim 1 in which a small collar is affixed to the terminal end of said flexible drive sleeve with said small collar being of such diameter and length so as to telescope over and encase the terminal end of the flexible sleeve wires with sufficient length so that an application of solder thereto will effect retention. of said collar on said flexible sleeve, yet said collar being axially short enough so as to permit the entry of said pre-angled guide shaft through said short collar and then through said flexible sleeve and seating against the top of said winding member shaft in said chuck encasement hole and with said long socketed collar adaptable to be telescoped over and affixed to said shorter collar i 11. An angle drive tool as in claim 10 in which an as: sembled, pre-angled guide shaft with an overall length substantially equal in length to the overall inner core between the ends of said flexible sleeve unit with flexible drive sleeve wire endings that are'somewhat shorter than the overall flexible sleeve unit which includes a long socketed collar and a socketed chuck respectively assembled to each end of said unit and with said cylindrical pre-angled guide shaft having an overall diameter equal to the diameter of the small encasement hole of said chuck with sufficient difference in the relative dimensions of the guide shaft and said chuck hole so as to permit smooth rotational engagement when chuck rotates on said shaft.

12. An angle drive tool as in claim 11 in which a small collar having been soldered over the free end of the coreless flexible sleeve opposite the end to which the chuck is soldered is of such length so as to permit the passage, for assembly, of said pre-angled portion of the guide shaft which is assembled into said socket encasement hole of said chuck which is soldered onto said flexible sleeve whereupon the chuck is rotatable on said guide shaft and with said opposite end of said shaft protruding from the opposite end of said flexible sleeve, which is comprised of wound wires forming a coreless sleeve, the ends of said sleeve being severed from a sleeve longer than required, thereby resulting in severed, exposed wire endings.

13. An angle drive tool as in claim 11 in which a long cylindrical socketed collar with said socket serving as an encasement for one end of said guide shaft to pivot in and be rotated thereon, with said long collar embodying dual socketed bores which terminate short of the opposite axial end of said collar, said bores being of a shorter and deeper length with the outer bore of a diameter and depth compatible with said smaller collar and with said deep bore being equal in diameter and depth so as to rotatably engage said guide shafts terminal end which projects from said small collar affixed to the flexible drive sleeve with the depth of such sockets being sufficient to enable said long collar to telescope over said guide shaft and said smaller collar and be affixed to said smaller and shorter collar and with a flat provided on an outer portion of said collar for use in replaceable engagement of said long collar with a set screw in said driving member.

14. An angle drive tool as in claim 13 in which said long collar with its deep axial bore is telescoped over the guide shaft thatprotrudes from the flexible sleeve, whereafter said long socketed collar is telescoped over the shorter collar and soldered thereto, thereby sealing said pre-angled guide shaft suspended and encased within the flexible sleeve assembly unit with the socketed chuck on one end and said long socketed collar on the other end of said flexible sleeve unit, wherein said I shaft terminatesbeyond said flexible drive sleeve wires and ending deep in the socket of the rotatable chuck, thereby avoiding destructive interference between the projecting terminal end of the guide shaft and said flexible sleeve wire endings.

15. An angle drive tool as in claim 13 in which said long socketed collar of said assembled flexible sleeve unit is replaceably mounted in the socketed end of said driving member with both being complementary in dimensions for being so fixed together with a set screw that traverses the socket of the driving member and bearing against the flat on said cylindrical collar to fixture said long collar in said replaceable engagement until said set screw is loosened for replacement of said flexible sleeve.

16. An angle drive too] as in claim 13 in which when said rotatable palm grip is in an operators palm and said driving member is rotated with the fingers, said flexible sleeve unit rotates and is axially pivotable on its prebent guide shaft which is pivotable in said shaft socket of the long collar, which, in turn, permits the rotating winding member at the terminal end of the flexible sleeve assembly to equally pivot while rotating and when said winding member is inserted and is rotating said matrix coil, said winding member thereby will pivot and maintain automatic self-alignment of said winding member to axis of the central socket of the matrix coil it is winding.

-l7. An angle drive tool as in claiml6 in which with said freely, non-fixed rotatable palm grip in the operators palm, no amount of twisting or rotation of operators wrist will be transmitted beyond said freely rotatable palm grip and neither'the winding member of the pre-angled tool or the matrixcoil will, be twisted during the winding action of said tool.' 7

18. An angle drive tool as in claim 1 in which said driving member embodies-a releasable clutch means between said elongated collar-and the' socket in said elongated driving member which receives said clutch comprised, of an automatically releasable ball/socket pair of similar balls, mounted in each opposite end of said bore and a compression spring extending between said balls within said channel, and engaging said balls respectively at its opposite ends, and the walls of the recess in said driving member which receive said elongated barrel clutch having holes formed therein of a smaller diameter than that of the balls for purposes of providing sockets within which said balls are received when said clutch means are disposed in driving relationship.

20. An angle drive tool as in claim 19 in which said holes are small enough for said balls to enter sufficiently to develop needed sidewall engagement of said socket with said balls for rotation of said tool while said balls being large enough, diametrically, to be disengageable by said sockets depressing said balls downwardly and out from said sockets when said socket edges bear against said balls when said barrel clutch resists further rotation due to the tightness of the matrix coil and therefore said ball depression constitutes a clutch disengagement, caused by continued rotation of said driving member beyond said predetermined tightness of said coil, which repeatedly engages and disen- I gages said clutch whenever said predetermined torque limit of said ball and socket is exceeded by the amount of torque being applied by excessive rotation of the driving member by said operators fingers.

21. An angle drive tool as in claim 20 having a ball- /socket clutch in which, when the angle tool is winding said coil beyond the predetermined extent established by the relationship of the ball diameter, to that of the socket diameter, said barrel driving said balls ,will resist further rotation of said driving socket member and thereafter said balls will be depressed by said sidewalls of said sockets and said barrel clutch will thereby be disengaged and cease rotation while said modified driving member continues to rotate, causing a audible click to resonatefrom the repeated ball and socket engagements, which serves as a sonic signal to the operator that the tool has reached maximum torque transmission to said matrix coil, whereby operator ceases to rotate said tool and by reverse winding of said driving member removes said winding member and tool from said tightened matrix coil.

Claims

1. An angle drive manually operable tool to wind and tighten around a tooth a matrix band formed into a loop and having one end spirally wound to form a band-tightening coil provided with a central socket, said tool comprising in combination, an elongated driving member, a palm grip rotatably mounted upon one end of said member for movement about the axis thereof, a coreless rotatable flexible drive sleeve unit with sockets at each end thereof, with said sleeve having an internally pivotable angularly bent guide shaft therein, said shaft being bent prior to assembly and is internally suspended thereafter through the length of the core of the flexible sleeve unit, with said shaft''s terminations rotatably engaged with sockets to hold said shaft against axial disposition at each end, and with one such socketed collar being replaceably engageable with said driving member, and with the other socket being part of a chuck, having a winding member adapted for controlled depth insertion in said chuck and with said winding member engageable with the central socket of a matrix band coil for winding and tightening of said coil, and with said driving member being provided with a torque limiting means.

2. An angle drive tool as in claim 1 in which said palm grip is circular in plan view and has opposite flat parallel faces, with a deep socket therein spaced between said flat faces and an annular groove substantially perpendicular to and transversing said socket, and with said socket receivable of said driving member.

4. An angle drive tool as in claim 3 in which said driving member has a deep axial socket in its end opposite said palm grip whereby said socket which is receivable of a complementary long collar on one end of a flexible drive sleeve unit is replaceably inserted and secured therein to said driving member.

5. An angle drive tool as in claim 1 in which said flexible sleeve has suspended within its core, an angularly bent guide shaft which is encased within said sleeve unit by a long socketed collar on its one end that supports said suspended preangled shaft for free pivotable movement, therein said socket while at said other end of said flexible sleeve assembly unit, a rotabably mounted socketed chuck supports said other end of preangled guide shaft which thereby permits said tool to automatically pivot into self-alignment with the coil it is winding.

6. An angle drive tool as in claim 1 in which a cylindrical chuck, with a tapered end has an axial hole through its length, with said hole being drilled of a smaller diameter at said chuck''s tapered end and a substantially larger diameter hole at said chuck''s opposite end and with both holes meeting intermediate the axial ends of said chuck and with said flexible sleeve being complementary in diameter to the larger hole being inserted and fixed therein, and With said winding member shaft being fully inserted and fixed in said small diametered hole at the tapered end of the chuck and with said small hole having a space between the top of said winding member shaft and the inner terminal end of said small hole with said space being deep enough and being complementary in diameter to provide a pivotable, rotatably engaging socket for the terminal end of the pre-angled shaft.

7. An angle drive tool as in claim 6 in which a winding member which has a dual diametered shaft with the relatively larger of the diameters constituting a shoulder on said shaft with said shaft''s terminal end having a smaller diameter than said shoulder and with said shaft''s terminal end being complementary in diameter to the smaller axial hole in the tapered end of said chuck and being fixed in said smaller hole with said larger diametered shoulder pressed against the truncated end of the chuck and having said winding member shaft inserted fully and with said shaft insertion being less than the full axial length of the smaller hole in said chuck with the remaining portion of said hole being provided as a receiving socket for encasement of the terminal end of the pre-angled guide shaft.

8. An angle drive tool as in claim 1 in which said guide shaft being cylindrical, has opposite end portions respectively disposed at an obtuse angle positioned intermediately between the ends of said shaft, one end portion of said pre-angled guide being mounted for pivoting in an axially extending socket on one end of a rotatable flexible drive sleeve unit to permit the winding member which is rotatable on the opposite end portion of said pre-angled guide shaft automatically to pivot on said pre-angled guide shaft and align said winding member axially of the socket of the band-tightening coil of the matrix band.

9. An angle drive tool as in claim 8 in which a pre-angled guide shaft having its both ends chamfered so as to ride smoothly and without destructive frictional contact within the encasement endings they are disposed into for pivoting and rotation.

10. An angle drive tool as in claim 1 in which a small collar is affixed to the terminal end of said flexible drive sleeve with said small collar being of such diameter and length so as to telescope over and encase the terminal end of the flexible sleeve wires with sufficient length so that an application of solder thereto will effect retention of said collar on said flexible sleeve, yet said collar being axially short enough so as to permit the entry of said pre-angled guide shaft through said short collar and then through said flexible sleeve and seating against the top of said winding member shaft in said chuck encasement hole and with said long socketed collar adaptable to be telescoped over and affixed to said shorter collar.

11. An angle drive tool as in claim 10 in which an assembled, pre-angled guide shaft with an overall length substantially equal in length to the overall inner core between the ends of said flexible sleeve unit with flexible drive sleeve wire endings that are somewhat shorter than the overall flexible sleeve unit which includes a long socketed collar and a socketed chuck respectively assembled to each end of said unit and with said cylindrical pre-angled guide shaft having an overall diameter equal to the diameter of the small encasement hole of said chuck with sufficient difference in the relative dimensions of the guide shaft and said chuck hole so as to permit smooth rotational engagement when chuck rotates on said shaft.

13. An angle drive tool as in claim 11 in which a long cylindrical socketed collar with said socket serving as an encasement for one end of said guide shaft to pivot in and be rotated thereon, with said long collar embodying dual socketed bores which terminate short of the opposite axial end of said collar, said bores being of a shorter and deeper length with the outer bore of a diameter and depth compatible with said smaller collar and with said deep bore being equal in diameter and depth so as to rotatably engage said guide shaft''s terminal end which projects from said small collar affixed to the flexible drive sleeve with the depth of such sockets being sufficient to enable said long collar to telescope over said guide shaft and said smaller collar and be affixed to said smaller and shorter collar and with a flat provided on an outer portion of said collar for use in replaceable engagement of said long collar with a set screw in said driving member.

14. An angle drive tool as in claim 13 in which said long collar with its deep axial bore is telescoped over the guide shaft that protrudes from the flexible sleeve, whereafter said long socketed collar is telescoped over the shorter collar and soldered thereto, thereby sealing said pre-angled guide shaft suspended and encased within the flexible sleeve assembly unit with the socketed chuck on one end and said long socketed collar on the other end of said flexible sleeve unit, wherein said shaft terminates beyond said flexible drive sleeve wires and ending deep in the socket of the rotatable chuck, thereby avoiding destructive interference between the projecting terminal end of the guide shaft and said flexible sleeve wire endings.

16. An angle drive tool as in claim 13 in which when said rotatable palm grip is in an operator''s palm and said driving member is rotated with the fingers, said flexible sleeve unit rotates and is axially pivotable on its prebent guide shaft which is pivotable in said shaft socket of the long collar, which, in turn, permits the rotating winding member at the terminal end of the flexible sleeve assembly to equally pivot while rotating and when said winding member is inserted and is rotating said matrix coil, said winding member thereby will pivot and maintain automatic self-alignment of said winding member to axis of the central socket of the matrix coil it is winding.

17. An angle drive tool as in claim 16 in which with said freely, non-fixed rotatable palm grip in the operator''s palm, no amount of twisting or rotation of operator''s wrist will be transmitted beyond said freely rotatable palm grip and neither the winding member of the pre-angled tool or the matrix coil will be twisted during the winding action of said tool.

18. An angle drive tool as in claim 1 in which said driving member embodies a releasable clutch means between said elongated collar and the socket in said elongated driving member which receives said clutch comprised of an automatically releasable ball/socket hole barrel clutch means operable to permit repeated engagement and disengagement between said driving member and the barrel clutch of said tool after a winding coil on the matrix band has been tightened to a predetermined extent.

19. An anGle drive tool as in claim 18 in which said releasable clutch means comprises a bore extending transversely through said elongated barrel clutch between the opposite ends thereof with one ball from a pair of similar balls, mounted in each opposite end of said bore and a compression spring extending between said balls within said channel, and engaging said balls respectively at its opposite ends, and the walls of the recess in said driving member which receive said elongated barrel clutch having holes formed therein of a smaller diameter than that of the balls for purposes of providing sockets within which said balls are received when said clutch means are disposed in driving relationship.

20. An angle drive tool as in claim 19 in which said holes are small enough for said balls to enter sufficiently to develop needed sidewall engagement of said socket with said balls for rotation of said tool while said balls being large enough, diametrically, to be disengageable by said sockets depressing said balls downwardly and out from said sockets when said socket edges bear against said balls when said barrel clutch resists further rotation due to the tightness of the matrix coil and therefore said ball depression constitutes a clutch disengagement, caused by continued rotation of said driving member beyond said predetermined tightness of said coil, which repeatedly engages and disengages said clutch whenever said predetermined torque limit of said ball and socket is exceeded by the amount of torque being applied by excessive rotation of the driving member by said operator''s fingers.

21. An angle drive tool as in claim 20 having a ball/socket clutch in which, when the angle tool is winding said coil beyond the predetermined extent established by the relationship of the ball diameter, to that of the socket diameter, said barrel driving said balls will resist further rotation of said driving socket member and thereafter said balls will be depressed by said sidewalls of said sockets and said barrel clutch will thereby be disengaged and cease rotation while said modified driving member continues to rotate, causing a audible click to resonate from the repeated ball and socket engagements, which serves as a sonic signal to the operator that the tool has reached maximum torque transmission to said matrix coil, whereby operator ceases to rotate said tool and by reverse winding of said driving member removes said winding member and tool from said tightened matrix coil.