US2420521A - Drill press - Google Patents

Description

May 13, 1947. J. A. CUPLER ET AL DRILL PRESS 5 Sheets-Sheet l 7 Filed Jan. 16, 1943 3 mam M JA ample) d 61 lfllimxell, J2: WTM y w;

y 1947- J. A. CUPLER ET AL 2,420,521

DRILL PRESS Filed Jan. 16, 1945 5 Sheets-Sheet 2 Jwoenbau 101' Mi y 1947- J. A. CUPLER ET AL 20,521

DRILL PRESS Filed Jan. 16, 1943 5 Sheets-Sheet 5 y 13, 1947- J. A. CUPLER ET AL 2,420,521

DRILL PRESS Filed Jan. 16, 1943 5 Sheets-Sheet 5 I I/likvmxe l mm In awe/M046 wTMQz Patented May 13, 1947 DRILL PRESS John Adwin Cupler, Cumberland, Md., and Clyde W. Truxell, Jr., Detroit, Mich.

Application January 16, 1943, Serial No. 472,626 4 Claims. (01. 77-5) This invention relates to drill presses, particularly those of the type adapted for precision work and embodying automatic movements.

Drill presses of the ordinary machine shop variety are entirely unsuited for drilling such objects as Diesel nozzles and spinnerettes containing openings of exceedingly small diameters. For work of this type in fact, the drills employed are frequently so small that their operation must be observed through a microscope if satisfactory results are to be attained. Manual and semiautomatic drill presses have been built for such precision work, but their operation has required such a high degree of mechanical skill that competent operators are rare and production schedules are exceedingly slow.

In drilling openings of the size required for work of this kind, it has been found to be preferable to feed the drill into the work by a series of reciprocating strokes of progressively increasing length until the desired depth has been achieved. It is then necessary to relocate the work by an indexing mechanism or otherwise prior to each successive drilling operation. The time requirements of such operations are magnified by the very small tolerances permissible, as will be evident to any skilled mechanic.

Prior to the present invention, no satisfactory automatic machine has been proposed for this purpose and in consequence, even a limited production of such products has necessitated a serious, concentration of highly skilled workers. In accordance with the present invention, a work piece is clamped in an indexing support, a switch is thrown and the automatic operations of drilling and indexing are effected Without further attention other than observation. When the cycle of drilling the predetermined number of holes at predetermined positions is completed, the machine stops automatically, whereupon an operator merely removes the finished article, substitutes a new blank and again throws the starting switch.

According to the principles of the present invention, the drill is carried in a chuck by a rotary and reciprocatory spindle which is spring biased towards a retracted position with respect to the.

work. The rotary motion is imparted to the spindle by a drive sleeve which is in turn rotated by a driving motor. The spindle is reciprocated by a cam which is coupled with the drive sleeve through suitable gearing. The cam is provided with steep surfaces for rapidly moving the drill towards and away from the work, which surfaces are separated by nodes of progressively increasing radii which are in turn separated by depressions for permitting the drill to Withdraw from the work intermittently for the removal of chips and for protection of the drill and the work itself. As a further precaution for protection of the drill, a calibrated spring is interposed between the cam and spindle to prevent the imposition of excessive pressures upon the drill.

Also coupled with the drive sleeve is an indexing mechanism for moving the work to a new predetermined position upon the completion of a drilled opening. The indexing mechanism is maintained in a set position during the actual drilling by means of a detent which is retracted by a cam prior to an indexing movement by associated intermittent gearing. After the new position is imparted to the work, the detent is advanced to again latch the mechanism and at the same time, by the cooperation of complementary tapered surfaces, the new setting is verified and if necessary, corrected.

The drive sleeve also operates a timing switch through reduction gearing whose ratio is a function of the number of indexing operations required by a given cycle of operation. The timing switch maintains an electrical circuit for energizing the driving motor until openings have been drilled at each predetermined position in the work, whereupon it breaks the circuit to deenergize the motor. Simultaneously with the circuit breaking operation, an electromagnetically actuated brake is applied to bring the motor to a quick stop and thereby avoid coasting. When the drilled work has been removed from the indexing support and a new blank substituted, a manual switch connected in parallel with the driven switch is momentarily closed to start a new cycle of operations.

The spindle feed assembly, including the spindle reciprocating cam is supported in a' head which is rendered adjustable by suitable clamping means. Since a, pair of shafts are coupled at an angle to a camshaft journalled in this head, it is proposed that the angularly disposed shafts be provided with telescoping joints whereby their lengths are adjustable and at the same time their coupling for rotation is not affected.

A more complete understanding of the present invention will be facilitated by a detailed description based upon the accompanying drawings, wherein:

Fig. 1 is a plan view, partially broken away, of a drill press illustrating the present invention;

Fig. 2 is an elevation, partially in section, taken along line 2-2 of Fig. 1;

Fig. 3 is an elevation, partially in section, taken along line 3-3 of Fig. 1;

Fig. 4 is a fragmentary sectional elevation taken along line 4-4 of Fig. 1;

Fig. 5 is a fragmentary sectional elevation taken along line 55 of Fig. 1;

Fig. 6 is an elevation taken along line 6-6 of Fig. 2;

Fig. '7 is an elevation at right angles to Fig. 6 depicting a portion of the indexing gear;

Fig. 8 is a circuit diagram;

Fig. 9 is an elevation taken along line 9-9 of Fig. 1; and

Fig. 10 is a sectional elevation of the lower end of the spindle, showing a drill mounted in a chuck. I

A base plate 20 supports a spindle feed housing 22, an indexing housing 24 and a binocular microscope mount 26, each of which is fastened in position on the base plate by means of suitable bolts.

The spindle feed housing provides a pair of spaced coaxial sleeves 28 and 30 each of which receives a pair of unit handled ball bearing assemblies, centrally of which a drive sleeve 32 is accurately supported for rotation. The bearings 34 and 36 of the upper sleeve are protected and retained at their upper end by a gear housing 38 and a gear housing cap 40, secured to the sleeve by suitable bolts M. The gear housing is counterbored to receive an oil seal 42 and the cover is counterbored to receive an oil retainer and cup 44. The lower end of the upper sleeve is closed by a seal retainer 46, counterbored to receive an oil retainer and cup 48. The lower sleeve has its upper end closed by a bearing retainer 50 counterbored to receive an oil retainer and .cup 52, and its lower end by a bearing retainer 54 counterbored to receive an oil retainer and cup 56. Bolts 51 are used to assemble the various retainers to their respective sleeves.

Intermediate the upper and lower sleeves, a pulley 58 is fastened to the drive shaft 32 and held in a centralized position by means of spacing collars 60 and 62 which extend from the inner races of the bearings in the upper and lower sleeves respectively. Near the lower end of the drive shaft, within the lower sleeve, a skirted deflector 64 is fastened to the sleeve by means of a retaining nut 66 threaded thereon to press the deflector against the inner race of the lower bearing. The drive sleeve has gear teeth 68 formed thereon near its upper end, received in the gear housing 38 for transmission of power to the feed and index mechanisms in a manner to be described.

A spindle I0, provided with a keyway I2, is received within the hollow drive shaft 32, and is rendered rotatable therewith by means of a key I4 which likewise holds the pulley 58 fast to the drive shaft itself. The keyway I2 is designed to permit relative reciprocation between the spindle and drive shaft however, to enable the spindle to be advanced towards and retracted from the work. As shown in Fig. 10, the lower end of the spindle supports a collet I4 and a chuck I6 for fastening a drill I8. The upper end of the spindle is formed with an enlarged head 80 terminating in a rounded tip 82 for engagement with the feed mechanism located thereabove. The spindle is normally biased towards its retracted position by means of a spring 84 interposed between the enlarged head 80 and the upper end of the drive shaft 32.

As shown in Fig. 4, the gear teeth 68 formed on the drive shaft are in constant mesh with the teeth of a gear 84 which is held fast to an intermediate worm drive shaft 86 by means of a key 88. The lower end of this shaft 86 is journaled in upper and lower bearings 90 and 92 respectively which are suitably held in the gear housing 38. The shaft is located longitudinally with respect to its bearings by means of a nut 94 threaded on its lower end which bears upon the inner race of the lower bearing 92 and causes a shoulder 96 formed on the shaft to engage the inner race of the upper bearing 90. The upper end of the shaft 86 is received in the hollow end of a worm shaft 98 to which it is secured for rotation by a key I00 which permits relative longitudinal or telescopic movement between the shafts. The worm shaft is journalcd in the feed head or housing I02 by means of upper and lower antifriction bearings I04 and I06 respectively, with respect to which it is located by a nut I08 threaded on its upper end to bear upon the inner race of the upper bearing and causing an enlarged shoulder I I0 to bear upon the inner race of the lower bearing I06. Intermediate its two bearings, the worm shaft has secured thereto by means of a pin I I2, a Worm II4, located by means of spacing sleeves H6 and H8 interposed between it and the upper and lower bearings respectively.

The worm engages the teeth of a worm gear I20, Figs. 2 and 5, which is held fast on a camshaft I22 by a key I24 which likewise secures a cam I26 to the camshaft. The worm gear and cam are spaced longitudinally 0n the camshaft by means of an interposed spacing sleeve I28. The camshaft is supported in the head or housing I02 between spaced antifriction bearings I30 and I32. The bearing I30 is mounted in a counterbore provided in a bevel gear housing I34 fastened to the head by suitable bolts I36. A bearing retainer I38 is threaded into the bevel gear housing to maintain the bearing I30 in its proper position. The bearing I32 is received in a counterbore formed in a bearing and seal retainer I40, secured to the head by suitable bolts I42, there being a spacing sleeve interposed between the bearing and the worm gear and a nut I44 threaded on the camshaft to hold these parts in proper relationship. Another counterbore in the retainer I40 receives an oil seal I46 which serves to retain lubricant in the system. The end of the camshaft projecting beyond the oil seal I46 carries a gear I48, Fig. 9, fixed thereto, which engages the teeth of an idler gear I50 carried by an idler gear shaft I52 projecting from a gear retainer I54. The teeth of the idler gear mesh with those of an internal gear I56, to which is fastened by means of suitable bolts I58, a gear plate I60, which is thus driven from the camshaft through the reduction gearing just described. The gear retainer I54 and a switch housing I62 are secured to the bearing and seal retainer I40, and thus to the head or housing I02 by means of suitable bolts I64. Within the switch housing I62, an adjusting plate I66 is attached to the gear plate I60 by means of a shouldered pivot screw I68, a locking screw I'I0 penetrating an arcuate slot H2 in the adjusting plate serving to clamp the plates in any adjusted position with respect to one another. The adjusting plate I66 is recessed to provide a socket for a radially projecting switch button I'I4 which engages a sliding switch block I'IB once during each revolution of the adjusting plate to open the circuit energizing the driving motor. The sliding switch block I16, slides in a sleeve I18 mounted in the switch housing I62. The block I16 is urged towards its circuit making position by a coil spring I80 which bears upon a flange I82 provided by the housing. One end of the switch block carries a contact point I84 threaded therein, whereas its other end carries a terminal I86 for the attachment of a lead. The contact point I84 cooperates with a contact point I90 threaded into a relatively fixed, though adjustable switch block I92, which can be locked in any selected position in the housing I 62 by means of a set screw I94.

The end of the camshaft I22 which projects into the bevel gear housing I34 has a bevel gear I96 fastened thereto by means of a key I98 and a nut 200. The bevel gear I96 meshes with a similar bevel gear 202 held fast on a vertical shaft 204 by means of a key 206. The vertical shaft is journaled in an upper bearing 208 and a lower bearing 2 I 0, both illustrated as of the antifriction type, the bearings being suitably supported in the bevel gear housing. The bevel gear 202 is secured against a shoulder formed on the vertical shaft and the inner race of the upper bearing 208 through a spacing sleeve 2 I 2, the shaft being held against longitudinal movement with respect to its bearings by means of a, nut 2I4 threaded on its upper end. A bearing cap 2I6 is applied to the bevel gear housing by suitable bolts 2I8 to protect the moving parts. The lower end of the vertical shaft 204 is hollow for the reception of an intermediate indexing drive shaft 220, coupled to the vertical shaft for rotation therewith by means of a key 222, but capable of relative longitudinal movement with respect thereto by the provision of an extended keyway 224. The lower end of the indexing drive shaft 220 is provided with a universal joint 226 which is coupled with a miter gear shaft 228 through a tapered pin 230.

The miter gear shaft 228 is journaled in the indexing housing 24 by means of upper and lower bearings 232 and 234 respectively, separated by a spacing sleeve 236, the upper bearing being fitted into abearing retainer 238 which is threaded into the indexing housing. The lower bearing 234 has its inner race nicely fitted to the hub of a miter gear 240, made fast to its shaft 228 by a key 242 and a nut 244 threaded on the end of the shaft. The miter gear 240 engages a similar miter gear 246 keyed to an indexing shaft 248 at right angles to the miter gear shaft 228. The

miter gear 246 is held on its shaft by means of I a nut 250. The shaft 248 is supported in an antifriction bearing 252 fitted in a counterbore provided in the indexing housing and another bearing 254 fitted into a counterbore formed in the cover 256 for the indexing housing. The bearing 252 is secured in position by a cap 258 suitably bolted to the housing, while the cover 256 is secured to the housing by means of bolts 260. The shaft 248 is located with respect to its bearings by means of a spacing sleeve 262, a washer 264 and a nut 266 threaded on the end of the shaft.

Between the spacing sleeve 262 and a flange 268, an integral intermittent gear 210 and face cam 212 is fastened to the shaft 248 by means of a key 214. As depicted in Figs. 2, 6 and '1, the intermittent gear is provided with a single tooth 216 which operates once during each revolution of its shaft to engage an index pin 218 and rotate an index plate 280 through a predetermined angle, depending upon the number and arrangement of the pins 218 carried thereby and the design of the intermittent gear. The face cam 212 is provided with an elevated cam surface 282, located with respect to the tooth of the intermittent gear so as to unlatch the index plate in time to permit its angular adjustment, and to permit latching in its newly adjusted position after the intermittent gear has acted. The index plate 280 is provided with tapered recesses 284 intermediate the pins 218, the recesses registering with a detent 286 having a complementary tapered end to assure absolute registration upon its entry into the tapered recesses. The detent is normally biased towards the index plate by means of a coil spring 288 which is interposed in a barrel 290 between the base of the detent and a wall of the housing. A wall of the barrel is provided with a breather opening 292 to assure free operation of the detent. The detent is provided with a guide 294, mounted by means of suitable bolts to restrain it against rotation by cooperation with a guide screw 296. The upper end of the guide screw carries an instrument bearing 298 which serves as a cam roller to ride against the face of the cam 212 under the influence of the spring 288.

The index plate 280 has secured thereto by means of suitable bolts 300, a collet guide 302, whose open end is provided with a tapered surface 304 for cooperating with a complementary external surface formed on the end of a collet 306. The collet guide is provided with an internally directed guide pin 308 which is received in an elongated slot 3I0 formed in the collet. The inner end of the collet is threaded to receive the threaded end of a draw bar 3I2 whose operating end is provided with a hand wheel 3I4 for rotation of the draw bar to produce expansion and contraction of the collet to remove and clamp the work as the case may be. A locating rod 3I6 is arranged centrally through the draw bar so that its forward end will limit the depth to which a work piece 3I8 may be inserted into the collet. The locating rod is threaded in the draw bar to permit, adjustment, and is fitted with a lock nut 320. A split bushing 322 is shown as embracing the work piece for reception within the collet.

Referring again to Fig. 5, it will be noted that the cam I26 has relatively steep surfaces 324 and 326 to facilitate rapid advancement and retraction of the spindle 10 with respect to the work. These steep surfaces are separated by cam surfaces or nodes 328 of increasingly larger radii, which nodes are in turn separated from one another by depressions 330 which permit the spindle to be retracted intermittently between advancing strokes of the drill to effect a reciprocating motion. The cam surfaces are engaged by a roller 332 which is pivoted in the bifurcated end of a substantially cylindrical follower 334 by means of a pin 336. The follower and its roller are biased towards the cam by a coil spring 338, the upper end of which bears upon a shoulder 340, and the lower end of which rests upon a follower guide 342 which is bolted to the housing. Projecting through the lower end of the follower 334 is a piston 344 whose lower surface is maintained in contact with the rounded tip of the spindle 10. The piston is retained in the follower by a screw thimble 346 which permits the piston to slide longitudinally of the follower. A calibrated spring 348 biases the piston towards its advanced position, but should an unsafe pressure be imposed upon the drill, the spring 348 will yield in order to avoid breakage of the drill or injury to the work.

As depicted in Fig. 3, the head or housing may have its height adjusted with respect to the work by operation of a feed screw 350 mounted in a column 362. A handle 354 of the customary type has been provided for the purpose. Such adjustment is made possible by telescopic coupling of the shafts 86-98 and 204220 already described. It should be noted that the housing 356 surrounding the worm drive shaft 86 and the sleeve 358 surrounding the worm shaft 98 are likewise relatively slidable or telescopic; and similarly, the housing 360 for the indexing drive shaft is relatively slidable or telescopic with respect to the annular flange 362 depending from the bevel gear housing to enclose the vertical shaft 204.

The electrical circuits and associated instrumentalities are diagrammatically shown in Fig. 8 of the drawings. A pair of leads 364 and 366 are connected with a suitable source to supply current to the system. The lead 364 is connected with one terminal of a, master switch 368, whose opposite terminal is connected by a lead 310 to a terminal 312 which is in turn connected by a lead 314 with the sliding switch block I16 of the driven switch. The stationary switch block I92 is connected by a lead 316 to a terminal 318, which, through a lead 380 and a lead 382 connects with a terminal 384 of a driving motor 386. The other terminal 388 of the motor is connected by a lead 390 to one of the supply leads 366. Capable of bridging the terminals 312 and 318, switch plate 392 is normally biased away from the terminals by a spring 394. From the portion of the circuit thus far described, it will be clear that when the switch plate 392 is depressed against the force of the spring 394, energy will be supplied to the motor to effect rotation. This results in rotation of the adjusting plate I66 whereby the sliding contact block I16 will assume its circuit closing position. Release of the manual switch 392 will then be in order, since the circuit will be maintained closed for the duration of a cycle when the position of the adjusting plate causes movement of the sliding block to its circuit breaking position.

As depicted in a very diagrammatic manner, the motor 386, mounted on a suitable base 361, is provided with a braking system to assure rapid stoppage when the motor circuit is broken. Brake bands 396 and 398 are arranged about a drum 400 carried by the motor shaft. Pivoted by a pin 402, the bands are urged towards a normal braking position by a spring 404. A cam 406 may be used between arms carried by the brake bands to spread the bands and thus release the brake. The cam is in turn actuated by an electromagnet having an armature 408 for rotating the cam and a winding 4 I connected in parallel circuit with the motor itself. Accordingly, when the motor is energized, the brake is simultaneously released and when the motor circuitis broken the brake is applied. A pulley M2 on the motor shaft drives a belt M4 for transmission of power to the drive shaft pulley 58.

From the foregoing description, it is believed that the operation of the apparatus as a whole will be clear to those skilled in the art. The apparatus described should not be construed as limiting the invention however beyond the scope of the appended claims.

We claim:

1. A drill press comprising a drill spindle, means for reciprocating said spindle through a plurality of strokes of sequentially increasing amplitude, means for positioning a work piece with respect to said spindle, means for indexing said positioning means, means responsive to the completion of a predetermined number of indexing operations for interrupting the operation of said reciprocating means, and driving means positively interlocked in continuous driving relationship with said spindle reciprocating means, said indexing means and said interrupting means for maintaining their operation in timed relationship.

2. A drill press comprising a drill spindle, means for reciprocating said spindle, work indexing means providing a, plurality of positions coupled to said reciprocating means, means in driving relationship with said reciprocating means and work indexing means under all conditions of reciprocation, means coupled with said indexing means for discontinuing the operation of said driving means at the conclusion of a predetermined cycle and means braking said driving means automatically at the conclusion of said cycle.

3. A drill press comprising a drill spindle, means for reciprocating said spindle through a sequence of progressively increasing strokes, work indexing means providing a plurality of positions positively coupled for synchronous operation to said reciprocating means, means for driving said reciprocating means and work indexing means, means actuated by said driving means for discontinuing operation of said reciprocating means at the conclusion of a predetermined cycle, and reduction gearing interposed between said discontinuing means and said driving means, the ratio of said gearing being a function of the number of positions provided by said indexing means.

4. A drill press for automatically drilling a plurality of openings during a cycle comprising a drill spindle, means for reciprocating said spindle, indexing means for positioning work with respect to said spindle, timing means for terminating operations upon the completion of the plurality of drilling operations constituting a cycle, means for locking said indexing means in predetermined positions during each drilling operation, means for unlocking said indexing means during an angular adjustment thereof between successive drilling operations, means for shifting the angular adjustment of said indexing means when in unlocked condition, means for relocking said indexing means upon attainment of a new angular adjustment, and driving means positively coupled with said reciprocating, timing, locking and shifting means for synchronous operation.

JOHN ADWIN CUPLER. CLYDE W. TRUXELL, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 673,533 Burwell May 7, 1901 751,062 Erickson Feb. 2, 1904 1,748,476 Hanson Feb. 25, 1930 1,838,945 Johnson Dec. 29, 1931 1,918,150 Swahnberg et a1. July 11, 1933 2,053,399 Kingsbury Sept. 8, 1936 2,175,037 Smith Oct. 3, 1939 2,278,824 Brotman Apr. 7, 1942 2,302,878 Muhl et a1 Nov. 24, 1942 2,271,717 Schwartz Feb. 3, 1942 1,403,985 Spencer Jan. 17, 1922 391,824 Taylor Oct. 30, 1888 357,398 Marsh Feb. 8, 1887 457,719 Hillman Aug. 11, 1891 2,280,115 Broders et a1 Apr. 21, 1942 2,020,868 Barnes et al Nov. 12, 1935

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