US1976945A - Safety limit trip for spindle feed - Google Patents

Description

1934' D. c. KLAUSMEYER El AL 1,976,945 v SAFETY LIMIT TRIP FOR SPINDLE FEED Filed July 7, 1931 3 Sheets-Sheet 1 anomtou D. c; KLAUSMEYER ET AL S AFETY LIMIT TRIP FOR SPINDLE FEED Filed July '7, 1931 5 Sheets-Sheet 2 amiemtou Mm c. KLAUSME YER PEGEAJEP y H. HENRY s was/rm NA/ EXECUTO K Och 1934' D. c. KLAUSMEYER El AL 1,976,945

SAFETY LIMIT TRI P FOR SPINDLE FEED Filed July 7, 1951 5 Sheets-Sheet 5 4 may Mvwntou DAVID c. KLAUSH EYE/l 5115/15 0 H.HENR Y SUNDERMANN q ExEquron ROWLAND L .fllcKwoop Patented Oct. 16, 1934 1,976,945

UNITED STATES PTENT OFFERv f I -;1,e7s,9 45

SAFETY Lnhr rare Foa SP INDL E FEED David C; Klausmeyer, deceased, lateof Cincinnati, Ohio, by H. Henry,Sundermann,, executor, Cincinnati, Ohio, and Rowland L. lltickwood, Cincinnati, Ohio, assignors to The Cincinnati Bickford 'lo'ol Company, Cincinnati, Qhio, a co'rporationof Ohio 1, Application Ju1y .7,.1931,Serial Nor 549,254

' .Z aonims, (envy-3s;

This invention has to do with drilling ma-f of the spindle by either manual or power means; chines and relates more particularly to anim' and; if the inoperativeness occurs during power proved device for interrupting the power" feed feeding movements, then tosimultaneously dis [to the spindle when the' latter has reached a engage the power feed so that no damage will "5- predetermined position'in'its travel, anjd' to a be done 'to the feed train by reason of a con- 60; means for supporing the 'spindle and simulta tinued applicationof power. neously therewith interruptingthe power drive, To attain the objects of this invention it is at any point intermediate its extremesof move proposed to provide a machine tool with means I ment should therecccur a failure in'the-counfor disengaging the power drive at predeterterweighting mechanism. i 7 mined points in the travel of the driven element 6 Heretofore; it hasbeen customary "to: provide and to so, arrange the device that the drivewill limit feed dogs for throwing out-the power be suspended at any intermediate pointin cases drive at the extremes of spindle-movement'and of emergency and simultaneously lock the move to locate thefixed trip dogs on the translatable able "element against further movement, acci-.

* member orin the feed controlling mechanism? dental orj'otherwise. The safety device is so Obviously, these device's"wereinoperativeto-disarranged as to befinefiective so long as there is connect the feed 1mm thespindle has travelled the counterpull oi the balancing mechanism its full' distance. Furthermore', the adjustable upon'the'translatable member. As soon as the V dog customarily employed in depthiridioating balancing means becomes inoperative as a haldevices for disc onnectin'g or suspending the feed ancing medium, the safety mechanism is thrown 7.5, at the proper depth, merel'y disconnects I the into action'and immediately suspends and pre-. feed and'thespindle stands unlockedjsupported vents further movement of the movable e1e only by the counterweightingff -mechanism. ment; v 1 g I V j Should the ,counterweighting means jail, the "Other objectsland advantages will be in 'part' spindle will, of its own" weightjdrop the-full indicated in'the following description and in distance with consequent 'jarringor' damaging part rendered apparent therefrom in connection of the parts orwork-pieces'andpossible injury with the annexed drawings. to the operator. fTofenable others. skilled in the art so fully This invention undertakes toovercorhe the to apprehend the underlying features hereof 0 undesirable features of the prior machines and that they may embody the same in the various to provide a simple, compact mechanism for ways contemplated byv this invention, drawings disconnecting the feed immediately upon a fail-" depicting a preferred typicalconstruction have ure of the'counterweighing mechanism, 5 and in been annexed as a part of this disclosure and, addition theretoto provide means for'automatiin such drawings,i li ke characters of reference cally retaining and supporting the spindle at; denote corresponding partsthroughout all the any point in its travel-in the event of suchfa views, of whi'ch:" failure; 7 n Figure lis a front elevation of a representa -Another object of, this'inve'ntion is wean-y tive type of machine tool incorporating the. struct'a device; of but few'working*partsjthat invention. Fig. 2 is a sectional ,view of the 40 will disconnect the power feed andsupportthe power feed clutch and tripping mechanism. spindle, in emergenoiessuchasfabove' explained, Fig.3'is a sectional view substantially along the and torender'both'the manual and' power trans line'3 '3 of Fig. '2. Fig. 4 is a fragmentary view I lating means inelfective so "long as the "parts of the trip bar and its associated mechanism. remain out of their normal position,'fthereby in Fig; 5 is a horizontal sectional view of the lower 5" forming the operator that someportion'of the end'of the feed. trip rod. Fig. 6' isasectional spindle counterweighting mechanism has failed view of the upper end of the trip bar. and latch and preventing him from ,using' the machine mechanism. Fig. '7 is a detail of the safety'latch while it is in an unsafe condition. member. j v Stillan'other object ofthis invention is to Although this invention is illustrated and de-, provide a mechanism for restraining untoward scribed in connection with a conventional drill downward movement 'of the spindle instantly ing machine, it will be understood, however, that upon the failureof the counterpoising"mecha-" its use in other types of machine tools nism and'which" will function' to suppdrt'th contemplated. spindle if the failure occurs "when the machine Figure -1 illustrates a drilling m c e a is standing idle or when during the'transla'ting a translatable headmember 10 in which there 119 is mounted for translation and rotation the usual spindle 11. In most machines of this type, power for driving the tool or tools is derived from a prime mover 12, which through the arm shaft 13, and through the speed and feed works located within the head passes to the drill spindle 11. Conventional reversing mechanisms such as the reversing clutches 14 (illustrated in dotted lines) are provided for reversing the direction of striking the operator, and there inevitably will the drive to the spindle. The ultimatepower drive to the spindle feeding means is shown in Figs. 2 and 3 in which a feedshaft conveys power from the feed gears located inthe head (in the interests of clarity, these have not been illustrated) to a worm 16 and worm wheel 17 which form part of the feed control head 18.

The worm wheel 17 is secured to, or formed integral with, a sleeve member 19 which is freely rotatable upon a tubular pinion shaft 20 journaled in the head 18. Near one end of the shaft 20 gear teeth are cutrforming pinion 21 which meshes withrack teeth 22 carried by the trans latable spindle sleeve 23. When the gear .17 and sleeve 19 are clutched to the shaft 20, as will later be described, androtated, the spindle sleeve 23 and spindle 11 arecaused to be translated. It will be, understood that the spindle sleeve 23 does not rotate'but is translated only and provides suitable bearings for the rotatable spindle 11 mountedtherein. The outer endof the pinion shaft carries, a clutch collar 24 to which are secured and rotata ble therewith serrated clutch arms125 that are pivoted at 26. A portion of the clutch arm 25 is providedwith serrations or teeth 2'7 which are adapted to engage similar serrations 29 formed, upon a ring29 that rotates with the feed 7 worm gear 17. Movement of the clutch arm 25,

to bring the serrated portions into engagement with the worm wheel ring serrations, is eifected by pins 28 whichare fitted within radial bores formed in the clutch collar24. An axially mov-' able spreader cam 29 provides cam surfaces 30 for moving the pins 28 outwardly and also provides teeth 31 for inter-engagementrwith teeth 32 formed on the hand levers 33. The-control levers 33 are likewise pivoted to the quick return head 24, as at 34, and when either'is' moved away from the head 18, the pin 29 is shifted inwardly thereby to move pins 28 and levers 25 outwardly against the action of springs 35. Movement of the levers 25 in this direction, engages the teeth 27 with the teeth 28 of thefeed worm wheels 1'7 and effects translation, of the spindle by, power. Adjusting screws 36 attached to the clutch levers 25 and contacting with the expanding pins 28, are provided for taking .up the wear and to adjust theparts so that proper engagement of the elements 2728 may be effected.

When the control levers 33 aremoved toward the head 18, withdrawing clutch pins 28, the; springs rock the clutch levers 25 and eifect a disengagement of the elements2'7--28 and thereby disengaging the power. drive. If the hand control. levers 33 are then rotated in a transverse'plana'the spindle may be translated in either direction by means of the rack and pinion connection previously described.

Normally theweight of the spindle is counterbalanced by suitable mechanism and hence but a slight application of power is required tojtranslate the same, consequently the operator need not and may not have a firm grip upon the levers 33 when translating'the spindle by hand. Now, should the spindle counterpoising mechanism occur damage to the tool or work-piece or the stripping of the teeth of the pinion 21 when the uncut portion of the spindle rack 22 is reached. v V This invention proposes to guard against such an eventuality by arranging a latch mechanism for preventing untoward downward movement of the-spindle when the spindle weight equalizing mechanism fails. For this purpose a spindle chain carrier 37 (see Figs. 2 and 4) is secured to the translatable part, preferably to the spindle sleeve, and to which the .counterweighting mechanism is attached. I I v For the purpose of this disclosure, one form of counterbalancing mechanism, indicated general 1y as av, has been illustrated and which, it is believed; will clearly illustrate the principles of this invention, but it will be understood, however, that any of the common devices adapted torelieve in whole or part the weight of the shift-, able element, will serve equally well or may be readily adjusted or adapted for use with this invention. All that is necessary is a device that tends normallyto maintain the shiftable element substantially in a position of rest or equilibrium so that the element, whether a drilling ma chine or any other type; of machine tool, if 'arranged for an up and down movement, will not fall-or move of its own weight. I

One side of the carrier 37 is provided with a slot 38 adapted to seat an L shaped latch mem-' ber 39 pivoted thereto at 40. .An arm 41 offthe latch projects away. from the spindle and over the slot provided for the counterbalancing conpetition- 42, which is pivoted to the carrier. The arm 41" is normally held away from-that slotb'y reason of theconnection 42. The counterpull of the balancing means normally maintains the link 42 in a position obstructing the path of movement of the latch arm 41. A second arm 43 of the latch 39 is arranged substantially perpendicular to the arm'41 and projects into a slot or guideway 44,1provided by the carrier member 37, and is adapted to be swung into engagement with a slide bar. 45 upon the release of vthe forces tending to maintain the connecting link 42 in the path of movement of the arm 41. Resilient means such as a spring 46, seated within a recess formed in the inter ference member 39, provides the energy necessary to. move the member 39 into engagement with the bar 45 whenever the-counter pull on the connection 42 is released and allowing the latch 'arm 41' to swing.

, The bar 45 is substantially stationary in the drill head'casing and is provided with a series of abutments 46 of a size adapted to be engaged 'It will thus be seen that the action of this safety, device is automatic and instantaneous upon thefailure of the counterbalancing means and is ready at all times to stop the travel of the spindlein cases of emergency whether the spindle is idle, feeding bypower, or by manual means. Obviously, similar mechanism may also be employed to prevent a counterweight from. falling whenever its connection with the spindle should failif such type of balancing means is employed.

Stripping of gears will occur, however, if translation of the spindleis stopped during a power feed and, therefore, to prevent damaging of the feed train, it is proposed to disconnect the power drive simultaneously with the failure or counterweighting mechanism and the locking of the spindle.

With that end in view, the hollow feed pinion shaft 20 carries a push bar 47 one end of which engages theend of clutch spreader pin29 and the other end engages a short lever 48 that is pivotally mounted at 49 upon a portion of the drill head frame. The opposite end of the lever 48. engages the end of a spring pressed push pin 50,. also mounted in the frame, and pro-,

jecting into the path of movement of cam surfaces 51 and 52 carried by thebar 45. ,Instead of being rigid with the frame, thesafety bar 45sis permitted to have a slight float in order that the cam surfaces 51 or 52 may translate the push pin '50. For this purpose, a slot 53 is formed in the trip bar, into which a stud 54 projects for securing the .bar to the frame and yet permitting a limited movement thereof. A bearing'nut 55 slidingly fitted within a recess in the trip barcooperates with the head of the bolt 54to hold the parts together.

' The cam surfaces 51 and 52 may be formed on the trip bar, or upona part secured thereto, and projects througlnand has a bearing in, a slot. 56 formed in a bushing 57 that supports the push pin 50. A coiled spring 58,urges the push pin against the came surfaces 51 and 52 and thus tends to maintain the trip bar in an intermediate position. Assuming that the power feed is engaged and the heavy spindle. is being fed into-the work at a predetermined rate and the'counterbalancing chain breaks. Immediately, the latch 39 is permitted to swing counter-clockwise and the interference arm 43 is urged against the notches in the irip bar, seats itself therein; and connects the trip rod 45 and spindle together. The spindle continues to. feed a slight distance, carrying the trip bar therewith, until cam surface 51 forces the pin 50 outwardly,which movement, through lever 48 and bar 47 moves the spreader cam pin 29 toward the left (Fig. 2) and declutohes the power drive. .As soon as the lost motion in the trip bar, 45 has been taken up, further movement is suspended and the spindle locked against falling.

Similarly, when using the hand feed mecha- -nism or when the machine is standing idle, a

failure of the counterbalancing means permits the latch member 39 to swing around and engage itself with the tripbar and thereby lock the spindle. Inasmuch as, the power feed is not being used under these conditions, the slight axial movement imparted to the trip bar,

has no effect other than to take up the lost motion and when the endzof theslot. 53strikes the stud 54, further movement of the bar 45 1' and spindle connected therewith, is suspended.

' Inthis waythere is provided, a simple and highly effective means for preventing injury to operators or damage to expensive machinery, tools or work-piecesoccasioned by falling machine elements and a device that is rendered effective, in cases of'such emergencies, under any condition of restor motion of a machine tool so equipped.

'As an additional safeguard, the above-explained mechanism performs the function of disconnecting the power traverse and rendering the hand traversing means effective when the shiftable element reaches a predetermined position in its travel, as will now be explained.

Ordinarily, a feed trip dog 65, carried by an adjustable'feed dial plate 59, is adapted to engage-a pin 60 provided by one of the control levers 33, to swing the latter and to thereby automatically disconnect the. power feed when the tool reaches a predetermined depth. The feed" dial and trip dog are adapted to be clamped in an adjusted position by suitable means, such as clamp lever 61.

However, in order that no damage will be done to the feed pinion 21 or to other elements of the feed train when the spindle reaches a. predetermined position, for example the extreme low limit, which-would necessari1y;follow if the operator inadvertently sets the feed dial .and trip dog to a position beyond the permissible limit, a safety trip dog. 62 carried by the trip bar 45 is provided. This dog is adapted to be engaged by a dog carried by the translatable member, preferably the chain carrier element 37, and when engaged and moved downwardly, the bar 45 also is moved and cam 51 engages andmoves thepush pin 50 to a position disconnecting the power feed. A separate dog or dogs, independently adjustable upon the spindle sleeve, may alternatively be employed to effect this shifting if desired.

Likewise when feeding the spindle upwardly, there is danger of stripping the gears when the feed pinion reaches the uncut portion of the spindle sleeve, and, therefore, a second safety trip dog 63 is engaged by the chain carrier 37 and lifts the trip bar 45. up. This movement brings cam face 52 into engagement with the push pin-50 and tripsout the power feed in a manner previously explained. Although the safety dogs 62 and 63 are illustrated herein as short screws located at the ends of the trip rod, it is obvious that they maybe positioned anywhere thereupon or made adjustable if the peculiarities of, the tooling operationwarrant. Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by. applying current knowledge, readily adapt it for various utilizations by. retaining one or more. of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific aspects of this invention and,

therefore, such adaptations should be, and are,

intended to be, comprehended within the mean?- ing and range of equivalency of the following claims.

Having thus revealed this invention, it is spindle supported thereby; manual and power.

means for selectively imparting movements to said spindle; control means therefor; counter-;

balancing means for said spindle; and means for rendering one of said driving means ineffective upon a failure of said counterbalancing mechanism, said last mentioned means including a translatable trip bar operatively connected with the control means for said driving means, latch mechanism carried by. saidspindle and controlledv by said counterweighting mechanism adapted automatically toen'gage and translate saidtrip bar whe'nz' said counterweighting mechanism fails; and means for limiting the translatory movement of said trip bar. 7

2. A drilling machine combining a translatable toolspindle; a: member carried thereby; means (1% including a "power drive and acontrolling clutch for translating said spindle; trip mechanism including ashiftable element and means actuated thereby to throw out said clutch; an abutment, carried by: said element adapted to be engaged by 521) themember carriedeby' the spindle thereby to shift said element and throw out said clutch and discontinue the power drive when the spindle has reached a predetermined position in its travel; counterbalancing means for said spindle;

a normally inoperative latch mechanism carried element thereby throwing out'the power drive and locking the spindle against further movement'. .7" f

- '3. A drilling machine' combining a toolhead; a tool spindle translatable therein; means in- 13522 cluding a power drive for translating: said spindle; clutch means for controlling said power drive; a clutch throw out mechanism including an element'having a limited shifting movement insaid tool head; counterbalancing mechanism @031 for said spindle; means rendered effective .im-

mediately upon the failure :of said counterbalancing "mechanism for shifting said element thereby to throw out said clutch and discontinue the power drive; and means carried by said 452 spindle adapted upon'failure of said counterbalancing means to engage saidrelement thereby to prevent thespindlefr om dropping from said tool head. I

' 4; A drilling machine combining a translatable tool spindle; means including a power drive for translating said spindle; clutch means for controlling said power drive; a clutch throw out mechanism including a shiftable element; counterbalancing mechanism for said spindle;

555; means rendered efiective immediately upon the failure of said counterbalancing mechanism for shifting said element thereby to throw out said clutch and discontinue the power drive; and means also rendered effective by the failure of 69; said counterbalancing mechanism to lock the spindle against movement in eithe'r direction.

'5; In 'a drilling machine, a head; a spindle translatable in 'saidhead; power means including a controlling clutch for translating said spindle;

655; meansconnected with saidspindle to counterbalance the weight thereof; a member having a; limited sliding movement in said head; a latch device carried byisaid spindle and normally maintained out, ofengagement with said slid-V 7o; ablemember; means rendieredeffective by the failure of said counterbalance to cause said latch device. to iengagesa'id member thereby: to lock said member to'said spindle .whereby'the member has-a slightkmovement with the spindle; a

' cam' 'on said slidablemember; and means ineluding an element engaging said cam and actuated by the movement thereof for throwing out said clutch and rendering the power means ineffective.

6. In a drilling machine, a head; a spindle translatable in said head; power means including a controlling clutch for translating said spindle; means connected withsaid spindle to counterbalance the weight thereof; a member having a limited sliding movement in said head; a latch device carried by said spindle and normally maintained out of engagement with said slidable member; means rendered effective by the failure of said counterbalance to cause said latch device to engage said member thereby to lock said member to said spindle whereby the member has a slight movement with the spindle; a cam on said slidable member; means including an element engaging said cam and actuated by the movement thereof for throwing out said clutch and rendering the power means ineffective; and means to prevent re-engagement of said clutch.

7. In a drilling machine, a head; a spindle translatably mounted therein; a counterbalance for said spindle; power means for translating said spindle; a member mounted in said head substantially parallel with the spindle and having a limited sliding movement in said head; means carried by said spindle and adapted immediately upon failure of said counterbalance to engage said member to cause it to be moved a limited distance, with said spindle and then to lock said spindle against dropping; a cam on said member; and means actuated by said cam during the sliding movement of said member to render ineffectivesaid power means.

3. In a drilling machine, a head; a spindle translatably mounted therein; power means for translating said spindle; means connected with the spindle to counterbalance the weight thereof; a barslidably mounted in said head substantially parallel with the spindle and provided with a plurality of shoulders; a normally inoperative latch device carried by said spindle and adapted, upon failure of said counterbalance, to engage one of the shoulders on said bar thereby to lock said bar to said spindle,

said bar thereafter having a limited sliding movement with said spindle; a cam on said bar; and means actuated by said cam during said limited sliding movement to render said power means ineffective.

9. A drilling machine combining a vertically translatable spindle; power means including a clutch for translating said spindle; means operatively connected with said spindle normally tending to' counterbalance the weight thereof; means operable immediately by the failure of said last mentioned means to stop the translation of said spindle and to lock same against further movement; and means to release said clutch simultaneously with the operation of the spindle stopping means.

10. A drilling machine combining a vertically translatable spindle; counterbalancing mechanism for said spindle including an operative connection with said spindle; power means including-a clutch for translating said spindle; means operable'immediately by failure of said connection to release said clutch thereby to suspend the action of said translating means and simultaneously to lock said spindle against further movement.

i 11. A machine tool combining a frame; a vertically arranged translatable tool spindle supported thereby; selectively operable manual and power means for translating said spindle, said power means including a clutch; counterbalancing means for said spindle; means to release said clutch immediately by failure of said counterbalancing means; and means for automatically locking said spindle against further movement.

12. A machine tool combining a vertically arranged translatable spindle; power means in-

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