US1454181A - Mechanism for milling blanks for cutters - Google Patents

Description

May 8, 1923. 1,454,181

F. MULLER.

MECHANISM FOR MILLING BLANKS FOR CUTTERS Original Filed July 2 1918 :5 Sheets-Sheet 1 mm Q ii dipEggi INVENTOR' W mum w 11% AT OH/VEY May 8,: 1923.- 1,454,181

F. MULLER I MECHANISM FOR-MILLING BLANKS FOR CUTTERS Original Filed July 20, 1918 3 Sheets-Sheet 2 //V [/5 IV TOR FMM MM 8rd w rr RIVEK May 8,1923. 1,454,181

F. MULLER MECHANISM FOR MILLING BLANKS FOR CUTTERS Original Filed July 20, 1918 :5 Sheets-Sheet 5 TT R/VEY Patented May 8 1923.

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FRIEDEBICH MULLER, or HARTFORD, CONNECTICUT, assIGnoR rorna'rra wn rr NEY COMPANY, or N W YORK, N. v, A CORPORATIQN or N W E sEYJ I MECHANISM FOR MILLING BLANKS FOR GUT'I ERS.

Application filed July 20, 191,'Serial No. 245,861. Renewed October 6, 1921.; SeriaLNo. 505,927.

ballwkomz't may concern."

Be it known that I, FRIEDERTCH' Mt'JLLnn, a citizen of the United Statearesiding at Hartford. in the county of Hartford and State of Connecticut, have invented certain new'and useful Improvements in Mechanism for Milling Blanks for Cutters, of

which the following is aspecification.

The invention relates particularly to a mechanism for milling helical grooves in blanks for end mills or other milling c'utters.

One of the objects'of the invention is to provide an improved a para tuswhereby helical grooves in a plurality of such blanks may be milled simultaneously. A further object of the invention is to provide an improved mechanism for the purpose set forth which is adapted to serve as an attachment for a previously or separately constructed milling machine of standard form.- Further objectsof the invention will be apparent from the following specification and claims.

In theaccompanying drawings I have shown one embodiment of the invention but it will be understood that the drawings are merely for illustrative purposes and that the invention can be embodied in other ways without departing from the spirit thereof as set forth in the claims appended to this specification. Particularlylt will be understood that, if preferred, the mechanism may be constructed as a permanent part of a millin machine instead of as an attachment t erefor.

Of the drawings:

Fig. 1 is a side view, partly in section, of a mechanism embodying the invention.

Fig. 2 is a plan view with certain parts broken away and others shown in section.

fFig. 3 is an end view taken from the le t. I

Fig. 4 is a-transverse sectional view taken alongthe line 44 of Fig. 2. i

Fig. 5 is a transverse view, partly in section, along the line 55 of Fig.1.

Figs. 6 and 7 are diagrammatic views,

onlan enlarged scale, showing the milling I of left-hand grooves in a cutter blank.

Figs. 8 and 9 are diagrammatic views, on an enlarged scale, showing the milling of right-hand grooves in a cutter blank.

Fig. 10is a fragmentary side view, similar trated.

in part to Fig. 1, but showing themechanism adjusted for the milling. ofright-hand grooves instead of left-hand grooves.

The illustrated embodiment oftheinven- .tion consists of a milling machine attachmilling machine of standard. construction.

As shown, there is a table 1 which is longitudinally movable on a saddle 2. The saddle is transversely movableion a knee 3, which is vertically adjustable with respect to the main milling machine frame 4. The longitudinal movement of'the table 1. along the saddle 2 is effected in any usual or preferred Way by suitable mechanism including a pinion 5 engaging a rack 6. The table is ordinarily moved y power, but in order that it maybe moved manually when .desired, there is provided a hand wheel 7. The usual devices areprovidedwhereby. the feed may be started-manually and then stopped automatically at any predetermined point. The saddle Qis transversely adjustable on the knee by meansof a screw 8 operable by a hand wheel 9. The knee is vertically adjustable by means of a screw 10. operable by a lever ll-v'hichis connected with the screw through bevel gearing 12. The milling machine has a horizontal driving spindle 13 and an adjustable overarm 14.

The attachment to which the invention particularly relates comprises a mainframe 15 which is adapted to be rigidly secured to the table 1. of the milling machine. Mounted on the frame 15 is a multiple headstock. l6 and a multiple tailstock 17 for holding a pluralityof blanks Ato be milled; Asillusthe headstock and tailstock' are adapted 'for holding four blanks, but it will be understood that the number may be varied.

The headstock 16 comprises bearings v18, 18 in which are mounted four similar parallel spindles 19. 19, the spindles preferably being arranged longitudinallywith their axes in a single horizontal plane. -Rotatably mounted in suitable . bearings 20, 20 carried by the frame 15 is a transverse shaft 21 upon which is mounted a long worm 22. Carried respectively by wheels 23,23 and 23, 23. It Wlll be noted that these worm wheels are relatively narrow and are located respectively at opposite ,sides of the central plane of the worm. The wheels are arranged alternately, the wheels 23 at one side of the said central-plane being on the first and third spindles and the wheels 23 on the other side of the central plane being on the second and fourth spindles. This staggered arrangement of the worm wheels enables-me to place the spindles much closer together than would otherwise be possible.

Each spindle 19 is hollow and has mounted within it at its outer end a 'collet chuck for engaging the shank B of the blank A to be milled. The shanks are usually tapered and I therefore provide a chuck adapted to engage a tapered shank. As illustrated, there is mounted within the spindle 19, a longitudinally slidable sleeve 24 which terminates at the rear in a rod 25. Located within the sleeve 24 is a split bushing 26 Y which is tapered at its outer end to engage with a similarly tapered portion of the sleeve 24. I This bushing 26 isadapted to receive and engage the shank B. The bushing is held against longitudinal movement by means of opposite pins 27, 27 which extend inward from the main body of the spindle. The sleeve 24 is suitably slotted so that the pins 27, 27 will not interfere with thelongitudinal movement thereof. Carried bythe bushing 26 at the inner endthereof is a stop screw 28 which is adjustable. This stop serves to limit the inward movement of the shank.

The rod 25 projects outward at the rear of the spindle and carries a grooved collar 29. The extreme outer end' portion of the rod is supported by a bearing 30. A forked lever 31 is pivotally mounted on the frame 15 andis provided with pins fitting the groove of the collar 29. The lower end of the lever 31 carries an adjustable screw 32 the end of which engages an eccentric 33.

The eccentrics 33 for all of the spindles are mounted on a transverse shaft 34 which is operable by means of a hand lever A spring 36 surrounds each rod 25 and tends to move it inward toward the right. Each spring is enclosed in a bushing 37 the outer end of which serves as an abutment for one end of the spring.

- The drawings show the chucks closed and in engagement with'the shanks B. When the blanks are to be removed and new blanks inserted. the handle-35 isturned to move the eccentrics and thus swing the levers 31 in the counter-clockwise direction. This movementserves to withdraw the rods 25 backward toward the left against the action the spindles 19, 19 are worm -wheel 43. longitudinal movement with respect to the of the springs 36. This backward movement of the rods 25 causes the withdrawal of the sleeves 24, thus permitting the bushings 26 to expand and release the shanks B. The blanks can then be removed manually and new blanks put in place with their inner ends abutting against the stops 28. When. the new blanks are all in place, the operator returns the handle 35 ..-to the position shown, thus permitting the rods 25 and sleeves 24 to move toward the right under the influence of the springs 36. This movement of the sleeves forces the bushings 26 into firm engagement with the shanks of the blanks. It will be observed that the split bushings 26 are fixed against longitudinal movement as are also the stops 28. The opening and closing of the chucks is effected solely by the sleeves 24 which do not engage the blanks.

For this reason it is impossible for any longitudinal movement of the blanks to take place as the result of the closing action of the chucks.- The chucks thus serveto accurately hold the blanks in predetermined positions.

The tailstock 17 comprises four spindles 38, 38 carrying centers 39, 39 respectively alining with the spindles 19, 19 of the headstock. Each spindle 38 is longitudinally slidable in the tailstock casting and is movable toward the left by means of a coil spring 40. A nut 41 at the rear of the spindle serves to limit the movement thereof under the action of the spring. The tailstock as a whole is longitudinally movable along suit-able ways on the frame 1.5. For moving the tailstock there is provided a longitudinal screw 42 operable by a hand The screw 42 is fixed against frame and engages a nut secured to the tailstock. It will be seen that the operator, by turning the hand. wheel, can move the tailstock forward or backward as desired. The tailstock can be locked in adjusted position by means of a gib 44 which is adapted to be tightened by means of a screw 45 and a lever 46. In practice, use is made of the tailstock'and of the centers 39, 39 thereof for moving the blanks into the chucks and for holding them in engagement with the stops 28, 28 thereof. When the finished blanks are to be removed the tailstock is loosened and is drawn back. Then the blanks are taken out manually and the new blanks inserted. After that the tailstock is returned to the position shown, the centers 39, 39 engaging the blanks and pushing them into the chucks. The blanks may varv slightly in length and the holes therein for the centers 39, 39 may vary slightly in depth. These variations are taken care of by the. springs 40. When the tailstock is moved forward toward the left the centers 3 sionthe springs, it is locked in position w-means of the gib 44 and the lever 46.

engage the stops 28, whereupon the springs yield to permit further movement of the tailstocktoward theleft. 1 After the tailstock has been moved far enough. to properly ten- Cutters 47 for milling the blanks A are mounted onan arbor 48 which is suitably connected with thespindle 13 of the milling machine. The outer. end of the arbor is supported by a bearing 49 carried by the overarm 14. The cutters must be quite small in diameter, and for this reason a small arbor must be provided. A small arbor such as shown would not of itself have sufficient strength and rigidity to properly support the cutters in operative relation with the blanks. I therefore provide supporting bearings 50, 50 positioned respectively between each two cutters and engaging the arbor at one side thereof. These bearings are adjustably connected with a bracket 51 which is clamped to the overarm; As shown in Fig 1, each bearing 50 engages the arbor on one side thereof only, the position of con:

tact being such as to withstand the reaction of the cutting operation.

.To effect the milling of grooves in the outer-surfaces of the blanks, the table 1, with the various parts carried thereby, is moved longitudinally by the usual power feed mechanism of the milling machine. My improved mech'a ism is primarily intended forthe milling o helical groovesand when such; grooves are to be milled it is obviously necessary to turn theh blanks as they are moved forward For turning the blanks I make use of the aforesaid worm 22 which hasbeen heretofore described as meshing with the worm wheels 23, 23 and 23, 23. Connected withthe shaft 21 at its front end. is a gear. 52which meshes with a gear 53 mounted on alstud54 ,Also mounted on the stud 54and connected with the gear 53 is a gear 55 which meshes with ahorizontal rack56. Thisrack is suitably secured to the saddle2 so as to be fixed against longitudinal movement with the tablel. It will be seen that fwhen the table 1 and the parts carried. thereby including the cutter blanks are moved toward the right, the gear 55 will roll .along the rack 56 causing the gear 53 to rotate in the clockwise direction. The gear 52 together with the worm .22will' be rotated in the counter-clockwise direction, thus causing th spindles 1 9 with the blanks A to rotate in the clockwise direction as viewed in Fig. 5. This rotative movement of the blanks is in exact proportion to the longitudinal movement thereof,'thus causing the cutting of helical grooves. The angle of inclination of the grooves can be changed by removing the gear 53 and substitutinganother gearof different diameter. The stud 54 is adjustably. held a slot in the frame different diameters. y v

When the blanks are first put in'place the table is in a position to hold the blanks with their right-hand ends near the cutters. To cut the first groove the automatic feed mechanismof the milling machine is started and this feed mechanism isjadjusted to antomatically effect stopping when a groove has been cut alon the blank for the required distance. '0 will beobserved that the rack 56 is of sufficient length'to permit of considerable'variation in the initial position of the table 1 and of the parts carried thereby.

After the feed has stopped automatically, the table is manually moved toward the left. It will be understood that during this movement of the table toward the right the blanks are turned in the opposite direction, being thus finally restored to their original posir tion. On account of lost motion and backlash, it is necessary to slightly lower the table during the backward movement in order to prevent the rotating cuttersfrom marring the finished grooves. This lowerinv is effected by means of' the'handle 11"whic serves tolower' theknee 3 and all ofthe parts carried thereby. lWh'en the table, has been moved to starting position, the handle 11 is returned to the, position shown, thus restoring the table to its operative position.

After the milling of oneigroove it isn'ecessary to index the blankslto' position them for the milling of the next groove. In order that'indexing mayb feffected, the gear 52 is desired a different plate issub'stituted: By

withdrawing the detent from one hole and moving it to the next the operator can index (ll four of the blanksto the sam extent and through the required angle.

After indexing the feed is again startcd and the, operations beforedescribed are'repeated until all of'the grooves have been milled.

In Figs. 1 to 5 the machine is shown'as adjusted for the cutting of left-hand grooves in the blanks. For the cutting so: such grooves the blanks are so positioned with respect tothe cutters that the cutters will engage, the blanks at one side thereof; that which can have line tangency or contact with helicoidal surfaces such as those of the grooves. If any of the cutting edges of either set were perpendicular to the cutter axis they would generate a plane surface which would intersect the helicoidal surface and which could not have line tangency therewith. It will be clear that the'inclined cutting edges of the cutter can conform to the shape of the groove only when the cutter is at one side of the cutter axis as shown in Vhen right-hand grooves are to be cut in the blanks, the blank and the cutter have the relationship shown in Figs. 8 and 9. The blank is indicated by A and the cutter by 47'. For cutting'such right-hand grooves, it is necessary for the blank to be turned in the opposite direction, and this is effected by the arrangement of gearing shown in Fig. 10. It will be noted that this arrangement differs from that shown in Fig. 1 by the inclusion of an intermediat idler gear 61 between the gears 52 and 53. This gear is mounted on a removable stud 62 held in a slot 63 in the frame 15. When the idler gear is used the stud 54 and the ear 53 are moved to new positions. The id er gear reverses the direction of rotation and causes the rotative' movement of the blanks to take place in the opposit direction from that shown in Fig. 5.

What I claim is:

1. The combination of a horizontally movable frame, a plurality of blank-holding spindles longitudinally mounted on the frame, a plurality of milling cutters rotatable about a common axis and arranged to engage the respectiv blanks to'cut grooves therein, and -means for simultaneously turning the spindles and blanks as they move longitudinally with the frame, the said means comprising a rack fixed against movement with the frame and gearihg carried by the frame and including a gear meshing with '1 the rack.

2. The combination of a horizontally movable frame, a plurality of blank-holding spindles longitudinally mounted on the frame, a plurality of milling cutters each having their two sets of cutting edges oppositely inclined with respect to the cutter axis, the said cutters being rotatable about a common axis perpendicular to the spindle axes and being arranged to engage the respective blanks at the sides thereof to cut grooves therein, means for effecting relative adjustment transversely of the spindle axes and longitudinally of the cutter axis whereby the relationship between the cutters and the blanks may be changed from one side to the other, and means whereby the spindles and blanks may be turned in either direction as they move longitudinally with the frame.

3. The combination of a headstock comprising a pluralityof parallel rotatable blank-holding spindles, a tailstock comprisinga simila-r'pl'urality of blank-engaging centers alining respectively with the spindles of the headstock, the said centers being spring-pressed and independently movable longitudinally, and means for moving the tailstock as a whole longitudinally.

4. A milling machine attachment comprising a frame adapted to be mounted on the milling machine table, a headstock on the frame having a plurality of parallel horizontal blank-holding spindles, and mechanism comprising gearing on the frame and a. rack adapte'd'to be secured-to the milling machine saddle for turningall of the spindles simultaneously as the table is moved. 4 i

5. A milling machine attachment comprising a frame adapted to be mounted on the milling machine table, a'headstockon the frame having a plurality of parallel horizontal blank-holding spindles, a tailstock bodily movable with respect to the frame and having a plurality of centers respective ly alining with the spindles. and mechanism comprising gearing on the frame anda rack adapted to be secured to the milling machine saddle for turning all of the spindles simultaneously as the table is moved.

6. A milling machine attachment comprisin a frame adapted to be mounted on the m1 ling machine .table,;' a headstock on the .frame having, a plurality of parallel horizontal blank-holding spindles, mechanism for turning all of the spindles simultaneously as the table is moved, a cutter arbor adapted to be connected with the milling machine spindle, cutters on the arbor spaced to respectively engage blanks held by the spindles, bearings engaging the arbor be tween the cutters, and means for securing the bearings to the milling machine overarm.

7. The combination of a headstock comprisin blankolding spindles, a chuck mounted in each spindle, a-tailstock comprising a similar plurality of blank-engaging centers aligning respectively with the spindles of the headstock, means for moving the tailstock as a whole longitudinally to engage the centers with the blanks and to simultanea plurality of parallel rotatable.

ously force the latter into the chucks, and a single controlling means'for closing all the chucks simultaneously.

8. The cpmbination of a headst0ck complurality of parallel rotatable prisin a blankfiiolding-sp-indles, a chuck mounted in the centers with the blanks and to simultaneously force the latter into the chucks, the centers being spring-pressed and independently movable longitudinally whereby each engiages its blank with an equal pressure, an a single controlling means for closing all the chucks simultaneously.

9. The combination of a headstock comprising a plurality of parallel rotatable blank-holding spindles, a chuck mounted in each spindle, each chuck being provided with a stop adapted to limit the inward movement of a blank, a tailstock comprising a similar plurality of blank-engaging centers aligning respectively with the spindles of the headstock, each center being non-positively mounted in the tailstock whereby a limited longitudinal movement thereof is permitted when engaged. against a blank with a predetermined pressure, means for moving the tailstock as a whole longitudinally to engage the centers with the blanks and to simultaneously force the latter into the chucks against the stops, and a single controlling means for closing all the chucks simultaneously.

10. The combination of a headstock com prisingl a plurality of, parallel rotatable a lankolding spindles, a chuck mounted in each spindle, each chuck being provided with a stop adapted to-limit the inward movement of a blank, a tailstock comprising a similar plurality of blank-engaging centers ali ning respectively with the spin lesof the cadstock, each center being spring-pressed and independently movable longitudinally, means on. each center for limiting its longitudinal inward movement relative to the tailstock, means for moving the tailstock as a'whole longitudinally to-engage the centers with the blank and to simultaneously force the latter into the chucks against the stops','t'he center springs being adapted to yield to allow for any inequality in the length of the blanks, anda single controlling all the chucks simultaneously.

In testimony whereof, I hereto afli'x my signature. v

. FRIEDERICH MULLER.

means-for closing

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