USRE23642E - Apparatus foe feeding cutting tools - Google Patents

Description

4 Sheets-Sheet 2 Original Filed Sept. 9, 1944 R #0 T N E V N V l a ll \\\N T T fi l E m m k a a IE 3 Q m MN H. K. BAKER APPARATUS FOR FEEDING CUTTING TOOLS 3 5 9 1 4 "m p A 4 Sheets-Sheet 3 Original Filed Sept. 9, 1944 INVENTOR H. K. BAKER APPARATUS FOR FEEDING CUTTING TOOLS April 14, 1953 Original Filed Sept. 9, 1944 4 Sheets-Sheet 4 Low Reissued Apr. 14, 1953 UNITED STATES PATENT OFFICE APPARATUS FOR FEEDING CUTTING TOOLS Herbert K. Baker, Detroit, Mich., assignor of twenty-four per cent to Harriett V. Baker and twenty-four per cent to Herbert K. Baker, Jr.

Original No. 2,516,842, dated August 1, 1950, Serial No. 553,432, September 9, 1944. Application for reissue July 28, 1951, Serial No. 239,163

10 Claims.

appears in the original patent but forms no part of this matter printed in italics indicates the additions made by reissue.

Matter enclosed in heavy brackets reissue specification;

This invention relates to apparatus for imparting travel motion to machine carriages, slides or spindle quills for co-operative feeding action with cutting tools and it has particular reference to mechanism for actuating in sequence, change in the speed of travel and reversing motion.

Among the more important objects of the invention are, the simplification of apparatus with respect to construction and maintenance; smoothness of action to enhance operating efficiency; accessibility of the pertinent mechanism for adjustment and changes to vary lengths of travel motion and rates of feed in steps of extremely fine degree.

How the foregoing objects and advantages, together with others which will occur to those skilled in the art, are obtained will be clear from the following description with accompanying drawings which illustrate the preferred embodiment of the apparatus, and inwhich- Figure l is a view taken from the bottom of the apparatus with the lower portion of the housing broken away.

Figure 2 is asectional view of the apparatus as indicated by line IIII of Figure 1.

Figure 3 is a sectional view of the apparatus as indicated by line iIII-I-II of Figure 1.

Figure 4 is an enlarged view of a portion of the apparatus.

Figure 5 is a sectional view taken as indicated by line V--V of Figure 4.

Referring now to the drawings, the reference numerals l and 2 indicate each of a pair of worms with extended shafts, having the same hand and lead of thread, which are spaced apart and arranged for revolving in opposite directions. Positioned between these worms and in mesh therewith is worm gear 3, arranged for rotating and reciprocating motion, being mounted on stud 3'! with needle bearing 39 (Figures 4 and 5). This stud is threaded in and secured to spindle slide or quill 32 whereby reciprocating motion of the worm gear is transmitted to the spindle quill.

The reciprocating motion is effected by a worm revolving, causing rotation of the worm gear, while the other worm remains stationary or is revolved at a slower speed, thus in response to this differential motion the rotating worm gear is caused to move in a direction lengthwise of the worms in mesh therewith at a rate of travel in ratio to the difference in the speed of these worms. The revolving of worm I while worm 2 is held stationary or rotated at a lower speed causes Worm gear 3 to travel in the direction indicated by arrow 44 (Figure 4). When worm I is held stationary while worm 2 is rotated, Worm gear 3 is caused to travel in the direction of arrow 45.

As clearly shown in Figure 1, adjacent ends of the two shafts la and 2a of the worms are journalled in housing 8 with ball bearing 46 and so mounted to resist longitudinal thrust in both directions. The drive of worms l and 2 is arranged thru clutch bodies 4 and 5 respectively mounted on and keyed to shafts lb and 2b of the worms. At one end of these clutch bodies for co-operative action therewith are driving clutch cups l2 and I3 respectively in which the ends of the shafts lb and 2b are journaled with needle bearing l4. These clutch cups have hubs 30 and 3| respectively and are journalled with ball hearing IS in intermediate rib l6 of housing 8.

Extending from hub 30 of clutch cup l2 and integral therewith is shaft l! on which gears, I9, 20, and 2l are mounted and keyed thereto. On shaft l8 of clutch cup l3 gear 22 is mounted and keyed. Gear 22 is driven by and in mesh with gear 20, thus a differential pitch diameter of one in respect to the other of this pair of gears regulates the speed relation of the two worms when caused to revolve. For further co-operative action with the clutch bodies and opposite the driving clutch cups l2 and I3, stationary clutch cups 6 and 1 respectively are mounted and secured into the intermediate rib 9 of housing 8 and provided with key ll] interlocking with this intermediate rib to resist rotation. The shafts lb and 2b of the worms extend thru these stationary clutch cups and journalled with needle hearing I l slidably mounted on the clutch bodies 4 and 5 are shipper sleeves 23 and 24 respectively for co-operative and selective engagement or disengagement with either the driving clutch cups or stationary driving clutch cups to in turn revolve or hold stationary the shafts of the worms on which these clutch bodies are mounted and keyed thereto.

As clearly shown in Figure 5, for the mounting and securing of stud 31 to spindle quill 32, a collar 35 is provided thru which one end of the stud extends and is threaded into the spindle quill. Hexagon shoulder 38 of the stud is drawn down tight against one end of this collar with its other end bearing against recess 34 of the spindle quill. This collar rides in slot 36 of the housing for longitudinal travel of the spindle quill with the worm gear. A spacing washer 40 is positioned on the stud against hexagon shoulder 38 for worm gear 3 to ride in proper alignment with the worms in mesh therewith. Re-

taining washer 4I holds the worm gear on the stud to resist thrust, and is secured in place againsta shoulder of the stud by nut 42 which is locked by cotter pin 43.

With respect to the drive of the several shafts, a pulley 28 is mounted and keyed to shaft 2! for engagement with belt 29 extending to a power source (not shown) such as an electric motor.

Gear 25, mounted and keyed to shaft 21, drives gear 2| which is mounted and keyed on shaft I1 for rotating gears I9 and 20 mounted and keyed on this shaft also. Gear I9 drives gear 26 which is arranged for driving spindle 33 mounted in spindle quill 32. See Figures 1, 2, and 3.

Spindle 33 extends out from the spindle quill 32 and has a bored socket 41 with keyway 48 Fig1'1re'3) for receiving the shank, of a cutting tool, a tool holder-or a multiple spindle drill head (not shown).

The spindle quill 32 in its advancement toward work to be performed is required to first move at a comparatively fast rate of'travel, commonly known in the art as Rapid advance. Then during the performance of the work moves at a slower rate, in conformity with the cutting efficiency of the tool, called Feed. Upon completion of the work, the spindle quill is caused to reverse its travel direction to its starting position, known as Rapid return.

This Rapid advance, Feed and"Rapid return are sequence phases of a reciprocating cycle. In the actuation of the mechanism embodied in this invention to obtain, Rapid advance of the spindle quill, first, the worm I is caused to revolve, thus driving worm gear 3, while worm 2 is held stationary which forces this rotating worm gear to move in a direction indicated by arrow 44 at a comparatively fast rate to compensate for the difference as to speed of worm I relative to the negative operation of worm 2. For Feed, at a predetermined point of travel of the spindle quill, worm 2 is caused to revolve also but at a somewhat slower speed than worm I, as determined by the relative pitch diameters of gears 20 and 22, thus changing the rate 'of travel of this spindle quill in ratio to the difference in relative speed of the two worms. Upon completion of the Feed phase, worm I is caused to stop and held stationary while worm 2 continues to revolve which reverses the direction of travel motion of the'worm gear (indicated by arrow 45, Figures 4 and until the spindle quill reaches startin position thereupon worm 2 is also caused to stop revolving thereby holding worm gear 3 and consequently spindle quill 3'2 stationary until again repeating a reciprocating cycle.

To start the spindle quill travel at Rapid advance a double solenoid 50 (Figure 2) is provided anda push button switch (not shown) may be operated and thru wire 54 energize coil 50a of this solenoid, thus shifting forked lever 52 to engage shipper sleeve 23 of clutch body 4 with driving clutch cup I2 causing worm I to revolve.

A rod BI, secured to flange 49 of spindle quill 32 and movable therewith carries-dog 55 adjustable as to position on this rod and held secure by set screw 63.

The rate of travel to "Feed" from Rapid advance is changed at a predetermined point of travel of the spindle quill by dog 55 tripping switch 56 (Figure 3) and thru wire 66 energizes coil 5Ib of double solenoid 5I, thereby actuating forked lever 53 for disengagement of shipper sleeve 24 of clutch'body 5 from stationary clutch cup 1 to engagement with driving clutch cup I3 4 to revolve worm 2 for cooperation with the revolving worm I.

As shown in Figure 2, a rod 62 is secured to flange 43 of spindle quill 32 and on this rod, adjustably mounted are dogs 51 and 53 which are held to position by set screw 63.

For reversing the travel of the spindle quill to "Rapid return, dog 51 trips switch 58 and thru wire 54 energizes coil 50b of double solenoid 50 for actuating forked lever 52 to disengage shipper sleeve 23 of clutch body 4 from driving clutch cup I2 for engagement with stationary clutch cup 6 to stop revolving and hold stationary worm I while worm 2 continues to revolve.

Upon reaching the end of the Rapid return, travel of the spindle quill, dog 53 trips switch 63 and thru wire 65 energizes coil 5Ia of double solenoid 5'I thereby actuating the forked lever 53 to shift shipper sleeve 24 of clutch body 5 from driving clutch cup I3 to engagement with stationary clutch cup I to stop revolving and hold stationary worm 2. At this point both worms are held stationary and the spindle quill unoperative until again actuating the mechanism to. repeat a reciprocating cycle.

The clutch assemblies employed in the'structure disclosed herein are preferably of the multiple disc type with an adjusting ring 61 for regulating pressure against the discs during engagement. In this manner, means are provided for adjusting the pressure of engagement to such an extent that when a specific torque load is exceeded, thru overload as might occur by breakage of a cutting tool, the clutches will then slip and the mechanism advancing the cutting tool be retarded or stopped, thus preventing serious damage to the apparatus.

Adjustment to a predetermined length of travel of any sequence phase Rapid advance, Feed and Rapid return of a reciprocating cycle is accomplished by merely loosening set screw 63 of the pertinent dog causing actuation of the mechanism for the particular sequence phase of the reciprocating cycle to be changed and moving this dog on its supporting rod to position relative to the length of travel desired and secure thereto by tightening the set screw.

During all phases of an entire reciprocating cycle, the worm gear 3 continuously rotates in the same direction, whether driven by one or the other or both worms simultaneously. This action provides a uniformity of wear to these cooperating members for prolonging their life and smooth operation with neglible amount of shock to the apparatus during actuation of the mechanism for changing the rate of travel or reversing direction of travel of the spindle quill.

Various Feed rates of travel of the spindle quill 32 are obtained by merely replacing the mating gears 20 and 22 on shafts I1 and I8 respectively with another pair of gears of a difierent pitch diameter relation corresponding to the de sired change in Feed rate. This arrangement affords a very fine adjustment, in steps by tooth progression (less in one gear and more in the other), as a single tooth change in differential of each gear only alters minutely the Feed rate of travel due to the longitudinal travel of the worm gear being at a rateresulting from the lead of the worm thread multiplied by only half the difference between the revolving speeds of the two worms.

In comparison of my improved structure as disclosed herein with another, heretofore, employing for instance thewell known feeding arrangement of a lead screw and nut, this prior arrangement does not provide as fine a feed adjustment be! cause of the rate of this longitudinal travel must necessarily result from the lead of the thread as multiplied by the total difference between the revolving speeds of the lead screw and nut, therefore, the steps of feed adjustment necessarily had to be twice as coarse as provided by the present invention.

Other prior feeding mechanisms employed cams of various types, configured or grooved in relation tothevaried sequence rates of travel and reversing motion desired for the specific cutting tool employed. However, these cam actuated mechanisms required that a new cam be made for every desired change in Feed" rate or length of travel, and further, a large portion of the apparatus had to be disassembled and reassembled for the replacement of these cams.

Still other prior feeding arrangements employed hydraulic means for imparting reciprocating movement to the cutting tools. Although fine feeds are obtainable hydraulically, considerable space is required for installation of the necessary pump, valves, fluid reservoir and controls which is objectionable where compactness is desired. Furthermore in many instances when starting up the hydraulic system, the fluid being comparatively cold, the feed rate will change as the viscosity of the fluid changes with the heat generated from the pressures involved thru usage. Besides hydraulic systems are sensitive to foreign matter or sludge collecting in the fluid medium over a period of time, therefore these hydraulic systems usually require frequent servicing to maintain consistent Feed rates.

From the foregoing it will be apparent the present invention provides improved means for obtaining extremely fine rates of Feed to meet the most exacting requirements of metal cutting tools in respect to accuracy and finish in the work performed. Finally, other advantages, as will be observed from this specification, flow from the structure disclosed herein by the use of parts which have maximum strength and life, assembly in a compact arrangement to conserve space and to further provide smoothness of operation with ease of maintenance and adjustment.

What I claim is:

1. In combination, a spindle quill arranged for travel motion adapted to the feed of a cutting tool, two worms spaced apart in parallel relation, a worm gear operative between the worms and in mesh therewith, a stud secured to the spindle quill for mounting the worm gear in cooperative association with the worms, a spindle rotatably mounted in the spindle quill for rotating a cutting tool, a pair of gears meshed together for revolving the worms at a relative speed of one greater than the other and means for driving said pair of gears and said spindle simultaneously.

2. In combination, a spindle quill arranged for travel motion adapted to the feed of a cutting tool, a spindle rotatably mounted in the spindle quill for rotating a cutting tool, two worms spaced apart in parallel relation, a stud secured to the spindle quill, a worm gear rotatably mounted on the stud between the worms and in mesh therewith, a pair of shafts drivingly connected to said worms, a pair of gears meshed together on said shafts for revolving the worms at a relative speed of one greater than the other, an additional pair of gears drivingly connected to the spindle for rotating thespindle, and driving mechanism drivingly connected to one of said successive pairs of gears being mounted on one of said shafts.

3. In combination, a frame, two worms journalled in spaced parallel relation in said frame, a worm gear positioned between the worms and in mesh therewith, said worms having shafts extending from each end of the worm thread, stationary brake cups fixedly secured to said frame, one end of the shafts being journalled in bearings mounted in said frame to resist lengthwise thrust of the worms in both directions, and the other end of the shafts journalled in said stationary brake cups, clutch mechanism mounted for cooperative association with said stationary brake cups, and driving clutch cups selectively engageable with said clutch mechanism for revolving the worms.

4. In combination, a frame, a tool-holding slide, means for mounting and guiding said slide for reciprocation relatively to said frame, a pair of worms rotatably mounted in parallel spaced relationship in said frame, a support connected to said slide, a worm gear rotatably mounted on said support and disposed between said worms in meshing engagement therewith, a pair of worm driving shafts, mechanism drivingly interconnecting said driving shafts for rotation in opposite directions, a tool-holding spindle rotatably mounted on said slide, means for rotating said spindle, and clutch devices including a pair of stationary brake elements secured to said frame, said clutch devices also including means for con- -necting each of said worms selectively to its respective driving shaft or to its respective stationary element whereby to selectively hold either of said worms stationary while rotating the other or to rotate both of said worms simultaneously so as to provide rapid travel or feeding travel of said tool-holding slide.

5. In combination, a frame, a tool-holding slide, means for mounting and guiding said slide for reciprocation relatively to said frame, a pair of worms rotatably mounted in parallel spaced relationship in said frame, a support connected to said slide, a worm gear rotatably mounted on said support and disposed between said worms in meshing engagement therewith, a pair of worm driving shafts, mechanism drivingly interconnecting said driving shafts for rotation in opposite directions at different relative speeds, a tool-holding spindle rotatably mounted on said slide and drivingly connected to one of said worm driving shafts, and clutch devices including a pair of stationary brake elements secured to said frame, said clutch devices also including means for connecting each of said worms selectively to its respective driving shaft or to its respective stationary element whereby to selectively hold either of said worms stationary while rotating the other or to rotate both of said worms simultaneously at different relative speeds so as to provide rapid travel or feeding travel of said tool- 'holding slide.

6. In combination, a frame, a tool-holding slide, means for mounting and guiding said slide for reciprocation relatively to said frame, a pair of worms rotatably mounted in parallel spaced relationship in said frame, a support connected to said slide, a worm gear rotatably mounted on said support and disposed between said worms in meshing engagement therewith, a pair of worm driving shafts, mechanism drivingly interconnecting said driving shafts for rotation in opposi-te directions, clutch devices including a pair of stationary brake elements secured to said frame and a pair of rotatable clutch elements drivingly secured to said worms, said clutch devices also including axially shiftable clutch bodies drivingly connected to said worm driving shafts and connecting each of said worms selectively to its respective driving shaft or to its respective stationary element whereby to selectively hold either of-said worms stationary while rotating the other or to rotate both of said worms simultaneously so as to provide rapid travel or feeding travel of said tool-holding slide, magnetically-operated clutch shifters operatively connected to said clutch bodies for shifting the same, and mechanism responsive to predetermined travel of said slide for energizing said clutch shifters.

7. In combination, a spindle carrier arranged for travel motion adapted to the feed of a cutting tool, two worms spaced apart in parallel relationship, a worm gear shaft connected to said spindle carrier to travel therewith, a worm gear mounted on said worm gear shaft to operate between the worms and in mesh therewith for imparting travel motion to the spindle carrier, a spindle rotatably mounted on said spindle carrier for rotating a cutting tool, a pair of gears meshed togather for revolving the worms at a relative speed of one greater than the other, and mechanism for driving said pair of gears and said spindle simultaneously.

8. In combination, a spindle carrier arranged for travel motion adapted to the feed of a cutting tool, two worms spaced apart in parallel relationship', a Worm gear shaft connected to said spindle carrier to travel therewith, a worm gear mounted on said worm gear shaft to operate 'between the worms and in mesh therewith for imparting travel motion to the spindle carrier, a spindle rotatably mounted on said spindle carrier for rotating a cutting tool, a pair of gears meshed together for revolving the worms at a relative speed of one greater than the other, and mechanism for driving said pair of gears and said spindle simultaneously, and a braking device selectively engageable with one of said worms to halt the same whereby to halt one of said worms sons to impart a relatively faster speed to the spindle carrier than the speed imparted thereto by the simultaneous revolving of both worms.

' -9.- In combination, a spindle carrier arranged for travel motion adapted .to the feed of a cutting tool, two" worms spaced apart'in parallel relationship, a worm gear shaft connected to said spindle carrier to'travel therewith, a worm gear mounted on said worm gear shaft to operate between vthe worms and in mesh therewith for imparting travel motion to the spindle carrier, a spindle rotatably mounted on said spindle carrier for :rotating a cutting tool, a pair of gears meshed together for revolving the worms at a relative speed of one greater than the other,'and mechanism for driving said pair of gears and said spindle simultaneously, and a braking device selectively engagea'ble with each of said worms to halt the same whereby to halt either one of said worms so as to impart a relatively faster speed to the spindle carrier than the speed imparted thereto by the simultaneous [revolution] resolving of both Worms.

10. In combination, a frame, two worms journa'llecl in spaced parallel relation in said fmme, a worm gear positioned between the worms and in mesh therewith, said worms having support and driving shaft ends extending from the operative lengths of worm thread, and shaft ends iournaled in bearings mounted in said frame to resist lengthwise thrust of the worms in both directions, clutch elements and brake elements associated with the'worms operative to halt one of said warms and to rotate the other so as to provide relatively rapid reciprocating motion between the worm gear and the worms or for rototing both worms simultaneously at difier'ent speeds to impart a lesser rate 0 1 relative reciproeating travel motion.

HERBERT K. BAKER.

References Cited-in the file of this patent or the original patent UNITED STATES PATENTS Number Name Date 487,775 Richards Dec. 13, 1892 750,370 Kammerer Jan. 26, 1904 863,966 Billeter Aug. 20, 1907 1,665,227 Smith Apr. 10, 1928 2,179,171 Boho -Nov.- 7, 1939 2,299,635 MacNeil Oct. 20, 1942 FOREIGN PATENTS Number Country Date 6,581 Great Britain of 1911 490,684 Germany Jan. 31, 1930

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