US2778647A

US2778647A - Floating tool holder

Info

Publication number: US2778647A
Application number: US418976A
Authority: US
Inventors: Milton L Benjamin; Stanley S Benjamin
Original assignee: Erickson Tool Co
Current assignee: Erickson Tool Co
Priority date: 1954-03-26
Filing date: 1954-03-26
Publication date: 1957-01-22
Anticipated expiration: 1974-01-22

Description

5 M. BENJAMIN ET AL 2,778,647

FLOATING TOOL. HOLDER Filed March 26, 1954 INVENTORJ M/L 7'0/V L. BEN/AM/Nnuo .5 T WLEY 5. BENJAMIN A TfOE YEYJ.

2,778,647 i e e-"se a e. an

The present invention relates generallyiasiindicated to a floating tool holder and more particularly to a floating f tool holder of the general type disclosed in the Milton L. Benjamin et alLPatent Nos-2,547,518, granted April 3, 1951; 1

In the aforesaid patent construction, and in the present construction as well, the fullefioating holder compensates for both angular and parallel misalignment-betweenthe tool and the work spindlesof'machine tools, for example. In other words, in both constructions, there isa ball-type joint for universal angular adjustment of'the tool supporting member, and interposed between such ball-type joint and the tool supporting member is, :ineifect, the elementsof an .Oldham coupling, the two elements 'of which are non-rotatably interfitted with-eachother, and respectively with the adjacent ball joint element, and with the; adjacent tool supporting 'member to accommodate parallel misalignment along angularly related axes.

A'principalobject of this invention is to provide a floating holder which employs ballfjoint trunnions'which are disposed radially, rather than axially as in the case-of the aforesaid patent. 1

Another object of this invention is toprovide metallic resilient means for efiecting pressure clamping to hold the parts of the assembly in adjusted position for self-aligning angular and transverse movement.

Another object of this invention is to provide a fu1lfloating holder wherein the aforesaid resilient means are located in the holder according to whether or not the holder as a whole is rotary or non-rotary and also whether or not accurate control of depth of cut made in a workpiece is 'desired or necessary.

Other objects and advantages 'of the present invention will become apparent as the "following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fullydescribed and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various waysinwhich the principle of the invention may be'employed;

In said annexed drawings: 4

Fig. 1 is a longitudinalcross-section view of one em- .bodiment of the present invention, suchcross-section having been'taken' substantially'along the line 11', Fig. 2;

Fig. 2 is a transverse cross-section taken substantially along the line 22, Fig. 1; and

Fig. 3 is a fragmentary longitudinal cross-section view of a modified form of holder.

Referring now more particularly to the drawing and first to the form of the holder illustrated in Figs. 1 and 2, the same is shown as comprising a body or housing 1 which is provided with an elongated shank 2 adapted to be secured to the tool spindle of a metal working machine.

Said housing 1 is further provided with an exteriorly threaded portion 3 within which is formed a conical seat 42 At diametrically opposite sides of said portion 3, ad'- jacentsaid. seat 4 and extending radially; are a-pair of cylindrical pins 5 press-fitted or otherwise securedin place. As s hown, said pins 5 extendradially inward to'point's adjacent the base of said conical seat 4. ski-Y 1 1 Within tubular portion 3 of said-housing '1 is a series of three

members

6, 7, and 8 respectively having'a universallytiltable, driving connection with said housingil and transversely movable, driving connections with each other alonggangularly disposed paths.

:The first of said series of members is a drive ring fi I which isformed with a spherical protuberance 9 adapted to makejline contactengagementxwith the conical seat 4 ah'dforrned with a radially extending flange 103 Said flange' '10 is'formed with. four equally"spaced-peripheral notches '11-; two of which' notches are adapted tofitrather closely over rthe sinwardly I projecting ends :of said pins 5 for: securing rapo'sitive driving engagement between housing :1 and .ring 6, while allowing' universal tilting offthe latter while-engaged with seat-4. -The center'line of' said 'pins 5 preferablycoincides with the center of the-spheric'al protuberance 9. In this way, the notches 11 may reasonably clos'ely'embrace theends of said pins 5 and yet said ring-6 may be universally'tilted. I 1 -'=The second or intermediateone of'said series of-member's is a 'ball retaine'r ring 7 carrying a plurality of circularly arranged balls 14 therein, each of'diameter greater than the thickness of said'ring 7,'the balls 14 being-held inplace'in said ring 7 as by peenin'g over of the edges of the openings iri' whicli the "balls are fitted. T \r 1 As sh'own, said retainer ring7 is forme'd with diametricallyfopposed axially extending lugs l5iwhich are adapted to fit, with some clearance, within the otherpair of notches 11 in said drive ring 6 to secure positive driving of ring 7 through ring 6 and adjustment of said ring 7 along a path transverse to its axis, that is','in a direction parallel to the opposed lugs-15. Said ring 7 is further formed with an= otherpair ofjsimilar-diametricallyopposed lugs'16 which extend axially in'the'opposite direction from and out ofphasewith said lugs 15'. The third or last oneof s'aid' series of members is a floating 'holdershankS of tubular form threaded at one end "asshown and formed with'a flange 17 at the other end, such flangehaving a pair of diametrically opposed notcheslS adapted to' fit over said 1ugs16 of said ballretaine'r' ring 7, whereby said holder shank 8 may also be adjusted transversely of its axis but along a path at right anglesto th'e path of transverse adjustment of said ballretainer ring 7. The fit of the notches 18 over the lugs 16 provides a driving connection between said ball-retainer ring 7'and said holder shank 8. It is to be understood that the holder shank 8 may be ofany of'thetypes shown in Figs. 1, 3, and 4 of the aforesaidBenjamin et aL'Patent No. '2,'547,5l8. The holder shank 8, as herein shown, is formed to accommodate a contractible collet, and for such purpose said shank 8 is provided with a bore having co-axial and axially spaced

conical seats

19 and 20 comparable with the seats formed iii the'like shank member disclosed in the aforesaid patent and, as well, in the Milton 'L; Benjamin et a1. Patent No. 2358300 dated September 19, 1944. i i A contractible collet 21 is fitted into the bore of said shank member 8, said collet having conical faces 22 and 23 respectively engageable with the

conical seats

19 and 20; and, as apparent, axial movement of said collet 21 into said holder shank 8 will eifect contraction of said collet so as to grip a tool or the like therein. The collet 21 is moved endwise into the holder shank 8 as by means of the nose piece 24 which is threaded onto said shank 8 and bears on the outer end of said collet through the intermediary of a nose ring 25.

The series of

members

6, 7, and 8 are clamped in the housing 1 by means of a counterbored ring 26 providing a shoulder which bears against the flange 17 of said holder shank 8, a clamp nut 27 being threaded onto said housing 1 and having an inturned flange 28 engaging the outer end of said ring 26. As shown, the bore through said ring 26 is slightly larger than the diameter of the holder shank 8 so that the latter may be angnlarly or eccentrically positioned therein.

Interposed between said drive ring 6 and housing 1 are a series of coil springs 29, and of course, instead of coil springs, a wavey spring washer or the like may be employed which bears against the flange 10 of said ring.

In the use of this form of the full floating holder, the shank of areamer R or like tool is positioned within the collet 21 and the nose piece 24 is tightened to grip the tool.

The nut 27 is tightened to cause the spherical protuberance 9 to engage the seat 4 and then is backed off a slight amount, such as a quarter turn, and locked in such position as by means of the check nut 30. In this condition of the parts, there is a few thousandths inch clearance between the spherical protuberance 9 and its conical seat 4 whereby the tool R gripped by the collet 21 may readily align itself with the hole in the workpiece which is being reamed and thus may partake of angular and also parallel movement for such purpose.

However, because the spherical protuberance 9 and seat 4 are not in engagement at this time, this construction is not preferred in instances where accurate control of depth of the reamer R or other tool into the work is required. This holder is better employedin non-rotating use rather than rotating use, because initial angular misalignment might increase owing to rotation, whereupon difliculty would be encountered in the initial entry of the end of the tool R into the work. Of course, parallel misalignment is readily accommodated by the chamfer at the end of the tool R whether the holder is rotated or not.

The modified form of full-floating holder as illustrated in Fig. 3 is of substantially the same construction as that already described, and therefore repetition is not necessary. Instead of providing springs '29v between the housing 1 and the drive ring 6, the pressure ring 31 is of resilient construction and is here shown'as made up of two

telescoped rings

32 and 34 having a plurality of springs 35 therebetween, one ring 32 having a flange 36 engaged by the inturned flange of the nut 27, and the other ring 34 being counterbored to provide a shoulder which bears against the flange 17. of said holder shank 8. As before indicated, instead of a plurality of coil springs 35, a single spring may be employed or a wavey spring washer or the like.

Thus, when the nut 27 is tightened, the series of

members

6, 7, and 8 are resiliently clamped together, the protuberance 9 being engaged with the conical seat 4 so that, even if this form of full-floating holder is employed in a rotating use, the angular misalignment is not increased owing to such rotation; and, therefore, the chamfered end of a tool R will readily enter a bore in the work as the holder is rotated and fed axially with respect to the work. During such feeding axially the tool follows the bore of the work by reason of the Oldham type coupling and the ball joint.

As a further feature of this invention, the

springs

29 or 35, as the case may be, have slightly enlarged ends, thus necessitating threading of the same into place into 4 their sockets whereby they will not fall out upon disassembly of the holder.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

'vVe therefore particularly point out and distinctly claim as our invention:

1. In a floating holder for tools and the like, the combination of a housing, a tool gripping assembly having a universally tiltable and transversely movable positive driving connection with said housing, said assembly comprising a plurality of adjacent members having such transversely movable positive driving connection with each other, one of said members and said housing having diametrically opposed, interfitting radial slots and coaxial, radial pins to provide such universally tiltable positive drive connection, and means for clamping said members together in said housing.

2. In a floating holder for tools and the like, the combination of a housing, a tool gripping assembly having a universally tiltable and transversely movable positivedriving connection with said housing, said assembly comprising a plurality of adjacent members having such transversely movable .positive driving connection with each other, one of said members and said housing having diametrically opposed, interfitting radial slots and coaxial, radial pins to provide such universally tiltable positive drive connection, and means for resiliently clamping said members together in said housing whereby a tool gripped by said assembly may shift to accommodate parallel and angular misalignment thereof with a workpiece.

3. The holder of claim 2 wherein said one member has a spherical end portion engaged in said housing and said means for resiliently clamping said members together in said housing acts through another of said members to urge said one member into engagement with said housing.

4-. The holder of claim 2 wherein said means for resiliently clamping said members together includes a nut threadedly engaged with said housing to engage an adjacentone of said members, and resilient means between said one member and said housing resiliently permitting such universal tilting.

5. In a floating holder for tools and the Ilike, the combination of a housing, a tool gripping assembly having a universally tiltable and transversely movable positive driving connection with said housing, said assembly comprising a plurality of adjacent members having such transversely movable positive driving connection with each other, one of said members and said housing having a pin I and slot universal positive driving connection with each References Cited in the file of this patent UNITED STATES PATENTS 119,173 Philippi Sept. 19, 1871 2,547,518 Benjamin et al Apr. 3, 1951 2,675,242 Olson Apr. 13, 1954