US1839476A - Workholding mechanism - Google Patents

Description

Jan. 5, 1932.* -A, R, GoLmCK 1,839,476

WORKHOLDING MEGHANISM Filel July 28, 1928 2 Sheets-Sheet 1 WORKHOLDING MECHANI SM Filed July 28, 1928 2 Sheets-Sheet 2 62 62j l a 37 50 Patented Jan. 5, 1932 y i y k l l l y narra, STATES PATENT cerros- ALBERT 1t. GoLRIoK, or CLEVELAND, oHIo, AssIGNoR To THE rooms-Baar coM'rANY,

` or' cLsvELaNntonIo, A CORPORATION or omo y WORKI-IOLDING MECHANISM- lApplication filed July 28, 1,928;I Serial No. 295,870. i

The object of this invention is to provide positioning mechanism comprises a blank mechanism'v for holding a blank in cooperaaligning andl advancing bar, and the securing tive relation to a tool arranged to act thereon. mechanisma plurality of yieldingly mounted A specific object is to provide an improved fingers arranged to engage the blanks at va- 5 holder for nut blanks or the like, which will rions points. Prior to beginning of the tap- 50 hold the blanks withther apertures in alignping operation lon the newlyv positioned ment with a tap, irrespective of variations in blanks, the fingers are arranged to be clamped the relation of such apertures to the outside or locked in place. A further refinement surfaces of the blanks. p consists in positively releasing the fingers to i9 Further objects and features of the invenpermit'free ejection of the tapped blanks tion will become apparentfrom the following when the tapping operation is substantially description relatingk to the` accompanying completed.. i j drawings, wliereinIshow my preferred form. In the drawings, Fig. 1, 2 and 3 are sect The essential characteristics are summarized tional views showing awork holder, atap, V in the claims. and blank feeding mechanism, each view im" In the prior patent to 4Daniel Kelleher No. showing the above elements indifferent rel,6-t5,285, there is shown an automatic taplationships.; F 4 is a cross sectional fragping machine with Which, for example,I my kmentary view taken substantially along the mechanism is adapted for use. The Kelleher line 4 4 of Fig. l3; Fig. 5 is a fragmentary im patent shows holders for cylindrical conduits sectional plan view, taken substantially along 65 and hexagonal nut' blanks to be internally the llne 5 5 on Fig. 1, the tap being omitted threaded. When such machines areoperated 'and some of the parts being shown in posiat very high speeds there is more or less likelitions different from F igfl; Figs. 6, 7l and 8 Y hood of breaking the tap, because of irreguare fragmentary cross sectionaly views 'El larities between the blank openings and the through dierent portions of the workhold- 70 outside surfaces thereof, for example, the er, as `indicated 4byvcorres'p'onding lines on hexagonal faces of a nut. This is mainly be- Y Fig. 5*; Fig. 9 is a sectionalbottom plan view cause in ordinary holders, the holding surof the mechanism for causing the fingers to faces are fairly close to the blank on all sides, be clamped in place when yin engagement with "l" and if an aperture in a blank about to be blanks, l0 is a perspective view of a tapped is unusually eccentric,the tap already clamping part associated with the finger threaded through several true centered clamping mechanism. blanks has to bend to enter the eccentric vReferring in detail to the drawings, th aperture. In the embodiment ofmy inventap T (F ig. l) isarranged to be automatical- "tion shown, provision is madeito hold the 1y engaged and rotated by suitablespindle su blanks with the apertures in true alignment mechanism, vsuch as, shown in the Kelleher `with the tap, irrespective of eccentricity of patent, a suitable chuck elementfor associathe apertures in some of the blanks. tion with such spindle mechanism being u In its preferred form, themechanism comshown at 1. 2 designates a work holder in prises a holder having alongitudinal bore which blanks, such asW, are placedV and held into which the blanks are fedendwise,fthe for tapping. The work holder has a longitap being brought up into cooperation with tudinal bore 3 parallel to the axis of movepaired blanks in agiven position in the holdment of the tap. The shape of the bore is deer. The holder, as shown, is arranged to re-` termined by the shape of the blanks, for eX- ceive two new blanks at a time.` kTheblank ample, if the blanks are hexagonal nuts, the

lo v

interior of the bore will be hexagonal to prevent rotation of the blanks, while in the holder. 5 designates a. rigid portion of the machine arrangedto support a longitudinally slidable feed bar 6, the end ofwhich carries new blanks, as from a 'position at V1, into thevwork holder. The blanks may be fed from a suitable raceway in the nature of a tube 8. As shown, theblanks are advanced two-abreast successively into the path of the member 6.

ln the prior application of Daniel Kelleher, Serial No. 227,677, filed October 21,1927, there is shown a more refined mechanism for feeding nut blanks, two ata time, but Ysince the feeding forms no part ofthe present application. it mav be stated that this, or any suitable feeding means, may be used.

AThe Kelleher machine is governed by a master cam which has cani members operating'on a master control rod.` which not only brings the chuck up to the and @causes it toyengage the tap, but also operates in timed relation to such chucking to :cause the reciprocationrof a feed bar,`such as 6, herein shown, to cause it to draw away from a race- `way, such as 8,-to permit the workto drop4 in front of the feed bar in substantial alignment with the tap. Afterwards, the return movement of the feed'bar carries the new work into the work kholder `and simultaneously moves the tap, already threaded through previously tapped work, to a position yto start tapping. Y l

Such; master cam may also control a plunger, such as herein lshown atV l0, Figs. l to 4., the plunger beinearranged to hold two pairs of pieces of work in separated relation, while being tapped; The plunger, as shown, may be operated by a'rock shaftl, suitably supported on the machine in brackets, not shown, and connected as bv an arm 16 to the-plunger '10, there'being a spring 17 to force the end of the plunger downwardly between the pairsk of pieces. The `rock shaft may' be operated from an eccentric portion 18 of the cam, shown in broken lines at 19, as by reason vof a` camfollower arm 20. Y zv Starting with Fig. l, the operation of the machine lwill be first considered as having Vbeen brought to a period inits cycle at which Y the work blanks W are said tobe nished. As in the Kelleher mach1ne,the tap having advanced with relation to work sufficiently to have pushed back the feed bar 6, a: new'cvcle of operation will start in which the feed bar repeatedl f To hold the cocked orbodily displaced threads.

readers ring 27. Continuation of the cycle of operation now causes the return movement of the feed bar 6 (to the left as shown) to position the work in the work holder. As the bar returns the plunger 25 is inserted in the apertures of the blanks substantially fitting the same and aligning the apertures with the tap.

It will now be seen that ifthe outside surfaces of either or both of the two blanks, are not in parallel relation to the Vapertures in the blanks, or the apertures are eccentric, these blankswill be cockedon the plunger, as in Fig. 3,V or displaced bodily, as the case may be. kAs thenew pieces Aof work are thus advanced, the plunger l0 is withdrawn to allow n between/the two pairs of pieces of work, the

chuck takes hold of the tap and the cycle is pieces in alignment with the tap as the tap now advances, Ipropose to provide a plurality of slidable fingers, such .as Y30, Figs. 5, 6, V andf8. The fingers as shown, are ofi"- set outwardly in the holder member 2, as at 3l, Fig. 5 to provide space for clamping screws 33. rlhese screws may be ofthe character shown in Fig. 6 wherein one of the screws `is shown as having a head 34 above the holder and engaging thereagainst, the lower end being threaded, as at 35, for engagement with sa threaded block 8G -arrangedf to engage the lower surfaces of the two lowermost lingers simultaneously; As shown, one ofthe screws has right vhand threads and one vhas lefty hand @ne screw may be rotated tothe right and one to the left automatically, ust

as a pair of blanks reach start tapping positionk in the holder. The clamping reaction ofl the member 36 lon the lowermostiingers may be transmitted to the uppermost fingers through a loose block 37 between the upper and lower fingers at'each side, i. e. one of these blocks being associated with each screw but vertically-slidable relative thereto. Each of the fingers 30 is provided with a light spring, Vdesignated 40, bearing against the rear ends thereof and arranged to force the fingers against the blanks, while still On lthe aligning plunger 25, in substantially the position shown in Fig.` 5. The springs react against side closure plates 2 of the holder.

For operating the clamping screws, I preferably provide a'toggle arrangement, Fig; 9, wherein there are a pair of arms @rigidly attached to respective screws, the arms being substantially alike and having slots 43. En-

gaging thegslots is a pin 45 carried in the arms of a, bifurcated member 46 arranged to be shifted by a bar 47; Means for shifting the bart-o ,cause the screws Sto clamp, may comprisey ai pin 50l adapted to engage an abutment member 5l slidably and yieldingly1F40 mounted in the slotted end of the bar 47.y The force exerted by the movement of the pin may be transmitted to the bar through a spring 52. As shown, the pin is carried on an arm 55 Which is connected to the maincontrol rod (not shown), for advancing the plunger 6 to feed the Work. As shown, this arm operates yieldingly against the feed bar 6, in the direction to feed theblanks, by reason of a spring 57 reacting at one-end on the arm and at the other on an abutment or collar 58 rigid on the feed bar. VThis collar is arranged to engage the frame part 5 at a time When the two blanks are positioned adjacent the plunger 10, and thereafter, further movement to the left, (Fig. 3) of the arm 55 causes the pin 50 tooperate the toggle arms 42 to cause the clamping rotation of the screws 33, as above described.

With the fingers in engagement Withthe blanks at W, the oncoming tap Will be started in true alignment With the openings in each blank, and vvill therefore not be likely to be broken because of the shifting of the blanks after the threading operation has started.

In order to remove the lingers beforethe blanks are ejected, as by movement from the position at one side of the plunger 10 to the other, I may provide a device,such as shown in Fig. 7, comprising a U-shaped member 60 having downwardly extending arms 61'pr0- vided with cam surfaces 62- for Ybearing against respective shoulders 63 of the fingers. This U-shaped member may be drawn up- Wardly as by an arm 65 on the rock shaft 15 at the time when the rock shaft operates to Withdraw the plunger l() from the nuts.

It will be understood that the rock shaft l5 operates in timed relation to the reciprocation of the Work position bar 6 in a machine for tapping blanks, such as shown in the Kelleher patentmentioned.

I claim:

l. In mechanism of the class described, a Work holder recessed to receive blanks to be operated upon by a tool, and a plurality of resiliently biased rigid members arranged to approach the Work in the holder from aplurality of directions, together Withmeansfor simultaneously locking said members in Work holding position. n Y

2. In mechanism of the-kind described, a longitudinally recessed Work. holder, 'a tool adapted to enter the recess and operate on the Work by a rotational and advancing movement, a Work positioning device adapted to approach the Work holder to position Work therein endWise of the recess, yielding means n n n carried by said device and arranged to align Work With the tool, and other means arranged to engage the Work When positioned in the holder to malntain the Work in alignment l with the tool.

3. In mechanism ofthe kind described, a

longitudinally `recessed Workholder, a tool arranged to enter the holder, a Work positioning device,' including a .yielding member arrangedto'approach the holder and Lposition Work therein, at plurality of individually movable, disconnected fingers, and means to causexthe` fingers to engage the' positioned Work, ythere being clamping means arranged to'simultaneously act on a plurality of such to hold the same in tool engaging position,

there being means lactuated by said bar for lockingV the last mentioned means in work holding position.

5. In mechanism of the kind described, a Work holder, a tool arranged to act on Work held thereby, shiftable means arranged to convey Work to the holder, resiliently biased means for holding such advanced Work in cooperative relation to the tool, and means actuated by said Work advancing lmeans and arranged to lock said resiliently biased meansjio in Work holding position.

` 6. In Work performing mechanism means to initially position a pie-ce of Work, a plurality of resiliently biasedy members guided to engage the Work at a plurality of points to hold the Work, the means rendered active by the operation of the positioning means to lock such plurality of members in Work holding position.

7 In mechanism of the kind described, a Work holder, independently movable members arranged to engage a blank in said holder, yielding means to cause such engagement of the members with the blank and means to simultaneously lock all the members in various relationships as determined by variations in the blank. Y l

V8 In a Work holding device, a plurality of independentlymovable resiliently biased membersl arranged to approach the work.

from' opposite directions, and means to substantially simultaneously lock said members in Work engaging position.

9. In a tapping mechanism, a head having a Work holding recess,`means to move Work into said recess,-resiliently biased means arranged to engage the Work in said recess and capable of being rigidly locked to hold the Work in tapping'position, and means operating in timed relation to the operation ofk the first named means to rigidly lock said resiliently biased means in` Workl holding; pepsi? tion. Y l

1.0. VIn a tapping machine aheadhaWi-ngm Work holding andi'tap, reeeivingf recess ex- "i'5 tending'thereintomeans toinoweWerkv into said recess, resiliently biasedfmeans arranged to engage thework in said recess -andeapeble of rigidly holdingthework iny tapping posi.- tion, and means connected With the! v`first 'T0 named rneansa-ndoperated therebyI mioek said resiliently biased means in Week holding positin. y

In testimony whereof, I hereunto aiix my signature. Y n Y ALBERT GOLRICK;

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