US2421563A - Stock gripper with removable pads - Google Patents

Description

June 3,1947. J, M ,NGALLS 2,421,563

STOCK GRIPPER WITH REMOVABLE PADS Filed Aug. .11, 1944 Patented June 3, 1947 UNITED PATENT OFFICE' Jol'nrM. Ingalls, Windsor, Vt., assignor to Gone Automatic Machine Company Inc., Windsor,

Via. ai corporation of: Ver

monti Application August 11, 1944,V SerialsNo. 549,043

1&1 Claims.v (Cl. 279-51) This inventionrelatesto -stock gripperssuch' as collets' or jzzush'ers'whi'ch are suitable for grasping lengths of stockl either while` machining opera'- tions areA 'being'performedY on those portions of the stock projecting from'the collets', or'ior.' feeding the stock endwise; and' relates'particularlyto such' grippers as are provided' with' removable pads on their inner faces, adapting such a `gripper to takeY stock of4 various sizes and cross' sections as desired, depending upon the" interior size and conguration' of thev pads:

Pin-object of the present inventionis to provide cooperating constructions` of jaws and pads and pad-retaining means suohthatthepads are' easily removed: and replaced and' whenV in position' are sol securely' retained that stock may be' rigidly held by the gripper.

A further object is to provide' pad retaining means movable to hold orY release the' pads by angular motion about'` the gripper axis.

A still-further object isto so form the retaining means that the-torque exerted` on' the stock dur'- ing machining operations tends to hold the retaining means in securing position.

Still an'otherobject" of the'inventionA isto provide means readily accessible-for moving the retaining means between securing',V and releasing' positions and for retainingthe securing means in securing position.

A furtherobjectis to'provi'dea means for securing` the retainer which' when. actuated to secure the retain'erwill also insure. that the retainer is in' tight retaining position.

A further object isto provide constructions by which the pads are interchangeable between thejawsofe'ach` gripper so that any pads of a set can be' assembled withany j aw of' the gripper for which the set is" designed to cooperate.

This: application is a continuation-impart of my application Serial No. 496,604y filed July 29, 1943; for Stock gripper with removable pads.

For' a more complete understanding of this invention, reference may be hadV to the accompanying drawings in. which Figure I is a side elevation partly broken away and in section. on line II of'liigure 2` of a' collet with pads, constructed. in accordance with this invention.

Figure 2` is a front end elevation` of! the same.

Figure 3 is a perspective view showing the forward' end of the collet, the lpads and retainers being removed; Y

Figures 4 and 5 are perspective views of a pad retaining element and a pad, respectively.

Figure 6 is a detail sectional view on line 6E 2' of` Figure 1 and' showing the pads locked' inI position.

Figure 'l is a view similar* to Figure 6', but showing the pads unlocked in condition for removal.,

Figurey 8 is a detaill sectional view on lines-8- of Figure 6.

Figure 9is a view similar l',o1*"igure8;` but` show"- ingY the securing means in fully secured position and: with theA retainer in tight retaining position;

Figure 1'0 is a view similar to Figurefl, but showing a modification.

Referring to the drawings, whichshowthe pads applied to a collet of the spring jaw type, at I is indicated the-tubular collet l'iavingv spring jaws 2`l formed thereon by the provision or longitudinali slots 3 extendingA inwardly from the forwa-rd'endA of thecoll'et toward the rear endthereof; which is continuous circumferentially and is provided wt-hinternal threads as at 4fL by whichl it maybesecuredto anl actuatingv` sleeve in the well known. manner.

The collet jaws have their spring portions provided with the inclinedl or conical surfaces 5 adjacent to their 'freeends for cooperation with mat?- ingl'ytapered surf-aces: (not shown)- on a suitable spindle within which the collet is positioned?, rela-- t-ive axial motionv orthesepartsthen serving to flexinwardly the free end'sof' the spring jaws to grip1 the worle or to permitthem' toexpan'd-V and release the workvwhich extends through the collet.

In order that work of various sizesgand configurations may be grippedby the collet, the spring jaws arev providedy with removable and replaceable-Work-engagingpads 6': As shown the interiorsurfaces 1- of thesepads, together form a cylindricalV surface which is particularly suitable for engagement with cylindrical Work, but these" inner facesA might beformedy todefine between thein asquare, hexagonal, or other shaped opening, depending upon the'particular coniiguration of the stock" which the collet may handle at any" particular time and may beof various internal" sizes to conform to` the sizeof the stock. The pads and the interior face of the collet are formed .with inter-engaging parts shown as ribs 84 on the pads and' mating longitudinal grooves 9 in. the colletV jaws,y which retain the pads and jaws against disassembly by relative radial motion, but permit disassemblyor'assernblyby` relative axial motion'. As shown each of' thev pads,. which covers' slightly71 less than one-third of" a complete circumference of the work, isprovided with two such ribs spaced apart, the remote faces' `Ill' and Il of these' ribs flaring outwardly' radially from each other so that the pads cannot be disassembled from the collets by bodily motion of the pads toward the axis of the collet. The ribs and grooves, however, do permit axial sliding motion between the pads and the collet jaws, which thus permits these parts to be assembled or disassembled by relative axial motion. Means are provided, however, by which when the pads are in fully assembled relation to the jaws, they may be held against relative axial motion so that they are locked against disassembly. As shown such means comprises a retainer I2 for each pad, these retainers being mounted to slide angularly about the axis of the collet in transverse grooves I4 in the collet and through mating transverse grooves I5 in the pads (see particularly Figures 1, 3 and 5).

Each of the retainers. as shown best in Figure 4, is provided with a full slot I6 and a partial slot I'I through which the ribs 8 of the pads may slide when the retainer is in such angular position that the slots I6 and I'I are in registry-with the ribs 8. Between the slots I6 and I'I the retainer has a retaining portion I8 and at one end a part of a similar portion I9, and when these parts I8 and I9 extend within the slots I5 of the pads in the position of Figure 6, they obstruct the relative axial motions between the pads and collet jaws and thus prevent disassembly thereof. The retainers are varranged to be held by one of the cooperating parts of the collet and as shown are retained by the collet jaws rather than by the pads.- To this end, each of the collet jaws has an arcuate slot 20 opening out through its forward face and extending through into the transverse slot, I4. A screw 2l rides in each of these slots 20 and is threaded through a hole 22 in one of the retainers. This screw riding in the slot 20 holds each of the retainers I2 against disassembly from the collet, but when loosened permits a sufcient relative angular motion between the retainers of the parts to permit the retainers to be moved between the positions shown in Figure '7 wherein their slots I6 are in registry with the ribs 8 of the pads which permits these pads to be assembled or disassembled by relative axial motion between the pads and the collet, and the positions of Figure 6V where the locking portions I3 and I9 are partly in alinement with the two portions 'of the pad ribs on either side of the slot I5, thus preventing disassembly of the pads from the collet.

By manipulation of the screws 2| so that their rear ends bear against the rear walls of the collet slots I4, as shownin Figures 1 and 8, the retainers may be pushed forwardly against the opposite walls of these slots and be thus clamped in adjusted position.

Preferably, and as shown in Figures 4, 8 and 9, the intermediate portions of the retainers are substantially thinner than the widths of the grooves Ill and I5 within which they ride and adjacent to opposite ends they are `provided with pads or thickened portions |20 on their outer faces which slidably lit within the grooves I4 and I5. This construction permits flexing of the intermediate portions of the retainers by tightening of the screw 2l which passes through its intermediate portion, as shown in Figure 9, which imparts a yielding locking pressure upon the pads and jaws. However, the retainers may beof uniform thickness throughout, as shown in Figure 10, if desired. If desired, also, a tapered 0r= conical seat 2H] may be made in the back face of the groove I4 of each jaw opposite to the screw 2l when the retainer is in its fully retaining position, the sloping side of this seat 2 I0 acting when the screw 2I is tightened to wedge the retainer into its limit of retaining position and hold it rmly against motion toward pad-releasing position. Should it be desired to remove the pads, these screws 2l are loosened so that the retainers are free to be moved in their slots, and they are then moved by pressure exerted on the sides of the screws 2I to unlocking position. The pads may then be freely removed and replaced by pads of a different set which may then be locked in position by moving the retainers to their obstructing positions and then clamping them against the slot walls by turning the screws 2| in the proper direction. The inner end of each screw 2| may, if desired, be slightly headed so as to prevent accidental disassembly of the screw from its retainer by too much loosening of the screw, though this will not prevent suicient motion of the screw to eiect clamping or releasing of the retainers. It does, however, prevent accidental entire removal of the screws 2|, which when the `pads are notl in position, would permit the retainers and screws to become detached with the possibility of becoming 10st. It will thus be seen that the retainers may be held with the collet and that the only parts which are ordinarily removable are the pads themselves. Thus no elements are likely to become lost, which if lost, would interfere with the proper functioning of the mechanism. While as shown these pads are applied to a collet, it should, of course, be understood that they might be applied to a pusher or any other tubular stock gripper arranged to permit pads to be assembled or disassembled with relation thereto.

From the foregoing description of one embodiment of this invention, it should be evident to those skilled in the art that various changes and modiications might be made without departing from the spirit or scope of this invention.

I claim:

l. A work gripper comprising a tubular holder, work-engaging pads on the interior of said holder, said pads and holder having interengaging portions permitting relative axial motion between said pads and holder but preventing radial detachment thereof, and an element rockably carried by said holder for motion laterally of said interengaging portions between an angular position obstructing said relative axial motion and an angular position not obstructing such relative axial motion.

2. A work gripper comprising cooperating parts including a tubular holder and a detachable work-engaging pad on the interior of said holder, said parts having mating longitudinally extending ribs and grooves, certain walls of which flare outwardly from the central axis of said holder to prevent disassembly of said parts by relative radial motion but permitting disassembly of said parts by relative longitudinal motion, said parts having transverse grooves registering when said parts are in fully assembled relation, and a retainer positioned within and movable lengthwise of said transverse grooves, said retainer having a slot registering with said lengthwise ribs and grooves in one position of said retainer in which position said parts may be disassembled, parts of saidretainer bridging said ribs and grooves in another position of said retainer and holding said parts against disassembly.

3. A work gripper comprising cooperating parts including a tubular holder and a detachable workengaging,A pad onr thev interior of said'- holder; said parts havingV mating longitudin-a-lly` extending ribs and grooves, certain walls of,` which arefoutwardly from the central axis; of saidholder? to prevent disassembly off saidAY parts by relative radial motion but permitting disassembly of said parts by relativev longitudinal motion; said,` parts having transverse grooves registering; wheny said parts are in, fully assembled. relation,` a. retainer positioned Within andmovable lengthwise of said transverse grooves, saidretainerhaving a: slot registering with said lengthwise ribs and grooves in oneposition of said retainer in which position said parts; may be disassembled,` parts of saidirertainer bridging said ribs and? groovesfin another position-.of said retainer and holding said@ parts against disassembly, and meansffor holding said retainer Aassembledr witlr one of. said partsi 4. A-.worl{ gripper comprisingcooperating: parts including atubular holder anda detaohableworkengaging pad; on` thel interior ofl saidV holder, said parts-having mating longitudinalily extending ribs and grooves, certain wallsv of1 which: flare outwardly' from the central axis of said? holder to preventdisassemblyof saidv parts byrelativeradial motion. but permitting` disassembly of. said parts by' relativelongitudinal motion,. said*l parts having transverse grooves registering.l when said parts are. in fullyassem'bledl relation, a retainer'A posi'- tionedA 'vizithin and movable lengthwise. of. said transverse grooves, said retainer having aislotv registering with said lengthwise ribs and grooves in oner position. of: said retainer in which position't said parts may be disassembled, parts of saidi retainer bridging said. ribs and grooves in another position of said retainer and holding said parts against disassembly, andY adjustable means for holding said retainer assembledn withone of said parts, said gripper having means cooperating with said adjustable meansin one adjusted position of said adjustable means to secure saidI retainer in one position or to release said retainer for such.

movement when said adjustable means is outiof said adjusted position.

5. A Work gripper comprising cooperating parts including a tubular holder and a detachable workengaging pad on the interior of said holder, said parts having mating longitudinally extending ribs and grooves, certain walls of which ilare outwardly from the central axis of said holder to f prevent disassembly of said parts by relative radial motion but permitting disassembly of said parts by relative longitudinal motion, said parts having transverse grooves registering when said parts are in fully assembled relation, a retainer positioned within and movable lengthwise of said transverse grooves, said retainer having a slot registering with said lengthwise ribs and grooves in one position of said retainer in which position said parts may be disassembled, portions of said retainer bridging said ribs and grooves in another position of said retainer and holding said parts against disassembly, a screw projecting from said retainer through an elongated slot in one of said parts and having its opposite end adapted to contact with said one part, said screw being accessible from one end of said gripper for adjustment to hold said retainer assembled with said one part clamping said retainer in adjusted position, or to release said retainer for such movement.

6. A work gripper comprising a tubular holder, and Work-engaging pads on the interior of said holder, said pads having longitudinally extending ribs and said holder having longitudinally extending; grooves into which said ribs, may eX- tend,` mating longitudinal side facesofV said grooves and ribs; flaring outwardly fromthe axis or said-` holder to thereby hold saidA holder and pads against disassemblyby relative radial motion-.thereo1i but4 permitting disassembly by relative-axial: motion thereof, said ribs andthe stock betweenr sla-idr grooves having transverse slots therethrough registering; when said holder and pads.Y arein operativel assembled: relation, pad retainersfslidable4 within said transverse slots and having slots therethrough throughV which; said ribs may pass when said retainer slots are in alinement with said ribs to4 permit disassembly or said' pads from said holder and'movablerout: of alinement with said ribs to retain said' pads' in position, saidr work` gripper including means for holding said retainers in pad-locking position.

7. A worlrV grippercomprising a tubular holder; and: work-engaging pads on the interior' of said holden, said@ pads having: longitudinally extending ribs and' said` holder having' longitudinally eX- permitting,` 'disassembly by relative.' axiall motion thereof, said. ribs and the stock. between saidv grooves having: transverse slots therethrough regist-ering;` whensaid holder and pads are in opera:- tiver assembled rela-tiom and: pad' retainers slidable. within'said.- transverse slots and having slots therethrough through which: said ribs may pass y when? saidretainer slots are inalinement with said ribsto permit' disassembly of said pads. from' said holder and movableI out of; alinement with said {ribs tofretain saidV pads in position*` 8.. A- workgripper comprising a tubular holder, and work-engaging pads on: the interior of said tending grooves` into whichf said ribs. may' extend, mating longitudinal side faces of said grooves and ribs flaring outwardly from the axis of said holder to thereby hold said holder and pads against disassembly by relative radial motion thereof but permitting disassembly by relative axial motion thereof, said ribs and the stock between said grooves having transverse slots therethrough registering when said holder and pads are in operative assembled relation, pad retainers slidable within said transverse slots and having slots therethrough through which said ribs may pass when said retainer slots are in alinement with said ribs 4to permit disassembly of said pads from said holder and movable out of alinement with said ribs to retain said pads in position, and means for holding said retainers assembled with said holder.

9. A work gripper comprising a tubular holder, and Work-engaging pads on the interior of said holder, said pads having longitudinally extending ribs and said holder having longitudinally extending grooves into which said ribs may extend, mating longitudinal side faces of said grooves and ribs flaring outwardly from the axis of said holder to thereby hold said holder and pads against disassembly by relative radial Inotion thereof but permitting disassembly by relative axial motion thereof, said ribs and the stock between said grooves having transverse slots therethrough registering when said holder and pads are in operative assembled relation, pad retainers slidable within said transverse slots and having slots therethrough through which-said ribs may pass when said retainer slots are in alinement with said ribs to permit disassembly of said pads from said holder and movable out of alinement with said ribs to retain said pads in position, said work gripper including means for holding said retainers in pad-locking position, said retainers having screws threaded thereinto and movable in slots in said holder for holding said retainers assembled with said holder and adjustable to clamp said retainers in pad-holding adjusted positions or to release said retainers. v

10. A work gripper comprising cooperating parts including a tubular holder and a detachable work-engaging pad on the interior of said holder, said parts having mating longitudinally extending ribs and grooves, certain walls o-f which flare outwardly from the central axis of said holder to prevent disassembly of said parts by relative radial motion but permitting disassembly of said parts by relative longitudinal motion, said parts having transverse grooves registering when said parts are in fully assembled relation, a retainer positioned within and movable lengthwise of said transverse grooves, said retainer having a slot registering with said lengthwise ribs and grooves in one position of said retainer in which position-said parts may be disassembled, portions of said retainer bridging said ribs and grooves in another position of said retainer and holding said parts against disassembly, a screw projecting from said retainer through an elongated slot in one oi said parts and having its opposite end adapted to Contact with said one part, said screw being accessible from one end of said gripper for adjustment to hold said retainer assembled with said one part clamping said retainer in adjusted position, or to release said retainer for such movement, said retainer being thinner intermediate to its end portions than at said end portions and through which intermediate portion said screw extends to be exed on the tightening of said screw to thereby exert clamping pressure of said retainer against said pads and holder.

11. A Work gripper comprising cooperating parts including a tubular holder and a detachable work-engaging pad on the interior of said holder, said parts having mating longitudinally extending ribs and grooves, certain Walls of which flare outwardly from the central axis of said holder to prevent disassembly of said parts by relative radial motion but permitting disassembly of said parts by relative longitudinal motion, said parts having transverse grooves registering when said parts are in fully assembled relation, a retainer positioned within and movable lengthwise of said transverse grooves, said retainer having a slot registering with said lengthwise ribs and grooves in one position of said retainer in which position said parts may be disassembled, portions of said retainer bridging said ribs and grooves in another position of said retainer and holding said parts against disassembly, a screw projecting from said retainer through an elongated slot in one of said parts and having its opposite end adapted to Contact with said one part, said screw being accessible from one end of said gripper for adjustment to hold said retainer assembled with said one part clamping said retainer in adjusted position, or to release said retainer for such movement, said one part having a tapered socket to receive said opposite end of said screw in position to wedge said retainer laterally of the axis of said screw toward a limit of pad-retaining position.

JOHN M. INGALLS.

REFERENCES .CITED UNITED STATES PATENTS Name Date Profke Feb. 2l, 1933 Number

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