US2509056A - Tapping machine - Google Patents

Description

F. GARTNE R TAPPING MACHINE May 23, 195o 2 Sheets-Sheet. l

Filed Dec. 4, 1947 .f man ma M n d m F A TTORNEY F. GARTNER TAPPING MACHINE May 23, 1950 2 Sheets-Sheet 2 Filed DeC- 4' 1947 Feerlck Gartner BY v M ATTORNEY Patented May 23, 1950 TAPPIN G MACHINE Frederick Gartner, Valley Stream, N. Y., assigner to Victor Industries Corporation, Brooklyn, N. Y., a corporation of New York Application December 4, 1947, Serial No. 789,654

6 Claims. (Cl. 10-129) This invention relates to screw thread tapping machines and particularly to that type intended to tap blind holes in thermosetting plastic articles such as bottle caps.

The invention contemplates the provision of a tapping machine wherein a conventional tapping attachment such as that disclosed for example in Patent No. 2,012,340 is automatically reciprocated through the proper stroke required for the tapping of the hole in the work, and wherein the work is automatically fed to the tapping station and there adequately held during the tapping operation, and then automatically discharged from the machine.

The invention further contemplates the provision of a machine utilizing a suitable well known tapping attachment, for automatically tapping blind holes in articles brought auto- .matically to the attachment, and for discharging the tapped articles by a blast, the machine being readily constructed by combining selected parts of a drill press with parts ofa dial press.

The invention further contemplates the combination of a drill press, a dial press and a tapping attachment into a single properly functioning tapping machine, to which the work to chine partly in section, certain of the parts being broken away.

Fig. 2 is a side elevational view of the machine. Fig. 3 is a fragmentary top plan view, partly in section, of a portion of the means for inter- `mittently rotating the dial and work holders.

Fig. 4 is a fragmentary horizontal sectional view, taken on the line 4 4 of Fig. 2, of the arm of the dial press employed for imparting the operative downward stroke to the tapping attachment and to the tap thereof.

Fig. 5 is a fragmentary enlarged top plan view vsimilar to Fig. 1 of the dial and work holders,

showing the means for closing the jaws of the work holders.

Fig. 6 is a fragmentary vertical sectional view of a work holder, taken on the line 6 6 of Fig. 5. Fig. '7 is a fragmentary vertical sectional view of the work discharge means taken on the line 1 1 of Fig. 1.

. Fig. 8 is a similar sectional View taken on the .line 8 8 of Fig. 7.

Fig. 9 is a. fragmentary vertical sectional view of the dial support and guide taken on the line 9 9 of Fig. 5.

Fig. 10 is an elevational view partly in section of a bottle cap suitable for tapping by the maf chine.

In the practical embodiment of the invention shown by way of example, the various rotating and reciprocating movements of the work-feeding, tapping and discharge mechanisms are imparted thereto by the typical drill press I0 and the typical dial press I I for purposes of economy, though it will be understood that an equivalent special machine usable only for tapping may readilybe designed having the same movements and operating in the same manner to perform and attain the same results. The mechanism of the drill press rotates the top. I2 carried by the conventional tapping attachment I3, which reverses the direction of rotation of the tapafter the screw thread has been completely formed in the hole of the article I'4. The dial press I I not only causes intermittent rotation of the dial or turntable I5 in a horizontal plane, but also reciprocates the arm I6 which controls the downward operative or feeding movement of the tapping attachment and reciprocates the work-gripping discharge lingers I1 and I8.

The attachment .I3 may be of any well known form such as that shown for example in Patent No. 2,012,340, designed for connection to therevoluble drill shaft of a drill press and to have its tap I2 rotated thereby first in one direction .to form the thread 2| in the hole '22 of the work I4 on the downward movement of the tap, and then in the opposite. direction to remove the tap from the work during the upward movement of the attachment. The vertical drill shaft 23 of the drill press is connected to the attachment I3 in the usual manner and is continuously rotated by the usual connections to the drill press motor v24, such as the motor pulley 25 (Fig. 2), the shaft pulley 26 and the belt 21, the shaft 23 being supported for vertical reciprocatory movement through the pulley 26 as by a key and slot connection thereto. Anarm 28 lixed at one end to the attachment I3 and at its other end terminating in a ring 29 slidable on the column 30 of the drill press, guides the attachment during its vertical movement.

Means are provided for moving the arm I6 into pressing contactwith vthetapping attachment to lower the attachment the exact required distance to thread the hole in the work. In the form of the invention shown, said arm I6 is 3 adjustably attached to the ram 3i of the dial press, since such dial presses already are provided with means for vertically reciprocating the rams thereof. The bolt 32 passing through the slot 33 in the base 34 at one end of the arm and into the ram secures said arm' in its exact adjusted position wherein. the lowermost positions of the arm and the ram correspondto'the lowermost position of the tap in the hole 22 of the work. At its other end, the arm I is bifurcated. to form the fork 35, the rotating drill shaft 2 being received between the branches of the' forki Preferably, a suitable anti-friction bearing as 20.

is interposed between the under sidev of. the fork'.

35 and the top of the attachment I3 in order to. permit the shaft 23 to rotate freely While the fork presses downwardly upon the outer' race' of the bearing and thereby halts the rotation of said outer race without interference with the rotation of theA inner race and while adequately transmitting. downward pressure to the attachment. The ram 3'I is reciprocated in the usual manner by means of. the connecting rod lil'pivoted at one end at-3T to theram and pivotedi at, its other end to the crank' 35 onV the shaft 38, said shaft being the main shaft of the dial press and being rotat'ed continuously as byV the pulley 39' thereon through the belt llfiahdf the dial press motor After` thev tap I2 has completed they tapping operation', the'4 ram 31 begins its upward stroke and the arm I6 moving with the ram releases the downward pressure onA the tappingl attachment. The spring 42 around the drill pressY column 35, then becomes effective to raise` the arm 28 the attachment I3" and the drill'shaft 2'3 to begin the withdrawal'of the tap from the work. Such withdrawalicauses reversal ofthe direction of rotation of" the tap, dueto the operation of the clutch (not shown) which forms part of the tapping attachmentA asv is well understood. Release of the tap from. the work permits thetap` to be again rotated in the initial tapping. direction ready for the repetition of the operation.

TheV work pieces I4'4 being in the form shown, bottle caps7V are manually fed' to the work holders 3 on the dial I5. of the dial press; Each of said holders', as best seen. in Figs. 5 to 7, comprises a base 44 suitably secured to' the annular dial I5 as bythe screws 46', a fixed jawA 41 secured t'o the base and a radially slidable j'aw secured to the base as by means of the bolt 45 passing through theradial slot 5U' and into the base. The upstand'- ing; portion of the fixed iaw is lined with suitable materialV 52 shaped' to fit and to grip the article Ill. Said article being shown as a conical cap, the jaw' lining is provided with a tapered' recess 33l to receive a tapered part of the' cap thereby to assist in aligning the cap at the tapping station and to retain the cap in centered position even afterit has been released by the movable jaw of the work holder. Said movable jaw 48 has its upstanding inner end' portion lined with yieldable and re ,silient material 55 such as rubber to prevent inand' is guided, is the spring 6I urging said rod end 5T outwardly toward the cam plate 5S which may' be xed to the bed plate of the drill press. As the workv holder approaches' itsV rest position at the tapping station, the rod 58 is forced inwardly by the plate 55 against the action of the spring 6I to close the jaw 48 upon the work and to force the work into the recess 53 of the fixed jaw lining, thereby centering and aligning the work, which remains and is retained in the recess after thejawsopen. Openingof the movable jaw occurs under thev influence-of the-spring. SI when the rodV 58 passes the cam plate.

The dial I5 may be of any suitable type, but as shown, is of annular form, with its inner peripheral' portion 62 slidably resting on the ledge 63 of the dial support 64 upstanding from the bed G5 ofthe dial press. To rotate the dial intermittently enough to carry the Work holders 43 successively to the tapping station, the connecting rod-"6E (Figs. I' and 2) is provided at its upper end With apivotal connection to the crank 6'! on the shaft 38, and at its other end is pivoted to the bell crank lever 58, which isil pivotally mounted on the frame 6.9 as at l0. The lower end*v of the lever 68 is pivotedV to the slide 'II (Fig. 3)' as' by the pin 12", said slide-sliding'in a suitable fixed guideway 'i3 and carrying the dial-operating pawl 1li,l the freeV end of which isy urged bythe spring T5' into one of the notchesv 'I6 iny the outer periphery of the dial. One of said notches is provided for each Workholder, both beingspaced apart equally around the circumference of the dial. On each rotation of the shaft 38, the slide TI is reciprocated. causing the pawll 14- tol advance the dial one notch and to carryl the next work holder to the' tappingy station while thev tapping attachment is in its raised position. The work holder remains at rest while the pawl 14 is being retracted and the ram 3l completes its descent and moves upwardly enough to withdraw' the tap from the work.

To prevent excess movement of the dial under the action of the pawl 'I4 andto insure exact positioning of the work holdersk and of the work thereinat the tapping station, a pair of pivoted spring-pressedl holding pawls are provided t'o enter spaced apart selected peripheral notches T6. One ofthe pawls as I1 (Fig. ll is pivoted to the bed plate. of theV dial. press asat 181 and is urged by the rod. 19 pressed by they spring 80 toward the periphery ofthe dial and into one of the notches 16. The other holding. pawl 8| may be pivoted to thev bed plate. of the drillV press as. at 8?. and is similarly pressed (Figs5 and 6) by the rod 83 and the spring 84 toward the periphery of thev dial and into one of theY notches, the ends of the pawls being suitably shaped to prevent overrunning of the dial and to accomplish the registration desired. The dial is maintained at its proper height and positioned by the clamps 85 ('Fi'g. 9) each removably secured to the d ial support 6'4 and' having an outer part 88 thereof overhanging the inner peripheral portion of the dial.

After the work I4 has been tapped. as above described, it is. released by the movablev jaw of the work holder and is carried while resting in the recess 53 of the movable jaw, to a discharge station where it is removed from the work holder and discharged from. the machine by a blast. For lifting the Iwork from the work holder, the pair of fingers I1, I8 are each pivoted atv the upper end thereof as at 8T', 88 respectively, to the bracket 8 9 adjustably secured to the ram 3 I` as by the bolt 98 passing through a suitable' upright slot in the end part of the bracket whereby the bracket may be raised or lowered as required. The fingersA are drawn toward each other by alight spring, as 8|, and each terminates in a slightly roughened inner edge portion as 92 which is inclined to the vertical (Fig. 8) so that said edge portions of the lingers converge upwardly.

As the ram 3| descends, the upper corner part v'of the work I4 enters the space between the inclined edges 92 of the lingers and is gripped thereby, the gripping action being aided by the spring 9|; As the ram 3| rises, the work is withdrawn from the recess 53 of the work holder into the vrange of the blast of air emerging from the pipe L93 leading to a suitable source of compressed air .(not shown) and which blows the lightly held article from between the discharge lingers l1, I8

lagainst rising excessively out of the jaws of the work holder with the rising tap l2 when the tap is removed from the work, a suitable guard as 96 perforated for the passage of the tap may Abe arranged at the tapping station, the work being stripped by the guard should it rise out of the jaws with the tap.

It will be seen that there is hereby provided a relatively simple, efficient and economical auto- `matic tapping machine for articles which require careful handling such as the relatively brittle bottle caps made of thermosetting material shown herein, that the machine may be readily and economically constructed by combining existing and readily available machines having the proper reciprocating and rotary movements, that the ac- Acuracy required for tapping blind holes in relatively brittle material may readily be attained by the invention to limit the tapping operation to the exact length required and thereby pre- "vent damage to or spoilage of the work, and that the invention is well designed to carry out its intended purposes.

While a certain specific embodiment of the invention has herein been shown and described, it will now be understood and obvious that various changes may be made therein without departing from the spirit of the invention delined in the appended claims.

I claim:

1. A machine for tapping the hole in a conical drilled article comprising the combination with a tapping attachment for a drill press, said attachment being provided with a tap rotatable in one direction to tap a hole in the article and rotatable in the other direction on withdrawal of the tap from the article, of a horizontal annular rotatable article-holding dial, a dial support slidably engaging the inner peripheral edge of the dial, article holders on the dial,'said holders having upwardly and inwardly tapering lianges to grip the conical article therebetween, the dial being intermittently rotatable to carry the holders successively to a tapping station aligned vertically with the tap, means including a reciprocating arm engaging and urging the attachment downwardly and a spring urging the attachment upwardly for reciprocating the attachment and the tap thereof toward and from the holders at the tapping station while the dial is at rest, springpressed pivoted fingers connected to and movable as a unit with the arm and having inclined downwardly diverging article-gripping edges adapted to spread apart and to grip the tapped article between the fingers on the downward movement of the lingers into engagement with the upper 'holder While the dial is at rest, and a pipe having a terminal portion arranged transversely of and adjacent the paths of the lingers and adapted to deliver a blast to the article lifted by the fingers clear of the holder to blow the article from between the fingers out of the machine.

2. The combination of a tapping attachment provided with a, tap and a drive shaft, of means in operative engagement with the shaft for rotating the tap, an intermittently rotatable horizontal work-holding dial, work holders on the dial each comprising an inner fixed jaw and a slotted outer movable jaw, a bolt passing through the slot of the movable jaw and into the dial and an extension on the outer end of the movable jaw, means for closing the movable jaw on an article of work as the work holder approaches the tap comprising a lixed cam arranged to engage the extension and to move the extension inwardly, means for reciprocating the attachment to tap the work comprising a reciprocating member having a bifurcated end straddling the drive shaft, work-lifting lingers above the dial each pivotally mounted at one end and having an inclined workgripping edge at the other end, a spring secured to the lingers and urging the lingers toward each other, a connection between the lingers and the reciprocating member to reciprocate the lingers t-oward and from the workholders thereby to receive the work between the inclined edges and to lift the work out of the jaws on the upward movement of the fingers, the upper corner edge of the work being relatively lightly gripped by the lingers, and a blast delivery pipe arranged transversely of the inclined edges and terminating adjacent a selected point in the path thereof.

3. The combination with a device having a tap rotatable in one direction to tap an internal screw thread in the wall of a hole in an article of work and rotatable in the other direction to withdraw the tap from the work, the work having a substantially conical lateral surface, of a horizontally rotatable work-supporting table below and in the path of the tap and in position to carry the work articles successively to a tapping station under the lower end of and in vertical alignment with the tap, said table comprising a rotatable ring, an inner l'lxed member having an outer ledge engaging and supporting the ring and ratchet means engaging the periphery of and intermittently rotating the ring around the lixed member, an upright rotatable and vertically reciprocable shaft operatively secured to the attachment and adapted to rotate the tap, work holders on the ring each adapted to engage the lateral surface of the work and to secure the work to the ring in position for tapping, Work-lifting mechanism above the work holders and in circumferential spaced relation to the tap, said mechanism comprising a pair of transversely spaced similar fingers each having the lower part of the inner edge thereof inclined downwardly and outwardly, a pivot for the upper end of each linger, a transverse spring across the lingers and secured at the respective ends thereof to the respective ngers thereby to urge the tapering lower edges of the lingers toward each other, said lower edges being suliiciently divergent and spaced apart at the lowermost points thereof to receive and to grip the uppermost part of the lateral conical surface of the work therebetween when the lingers are lowered on to the work held by an aligned work holder, the lingers spreading apart against the action of the spring as said edges engage and move downwardly past the uppermost corner edge of the work., and a recinroeabie member having a partcarrying thepivots ofthe fingers and having another part engaging the, shaft to lower the shaft4 and thereby to cause the fingers to grin lightly and to lift the work oil' the table while the tap is removed'y from another article. of Work, and a compressed-air-carryingpipe having a. terminal portion arranged laterally of the iingers and provided with a discharge opening adiacent the path of the tapered lower edges of the lingers to direct a blastof compressed air toward and laterally past the area between said tapered edges when the fingers approach the uppermost positions thereof, thereby toremove the work from between the lingers andy ta forward the work out of,k the. machine.y

4. The combination of claim 3, each of the work holders comprising a base secured tothe ring, a fixed jaw secured tothe base and having an` upstanding flange at its outer edge, a lining onthe lBange provided with a tapered recess, a slotted jaw slidable on the basel radially of the fixed jaw and' having an upstanding inclined inner ange, a resilient and yieldable lining on and inwardly of the inner flange, a bolt passing through the slot of the slotted j aw andinto the base, an extension projecting from the slotted jaw radially and outwardly, a. spring on the extension urging the slotted jaw away from the fixed jaw,y and a fixed cam in the path of the extensionY adapted to engage the extension and to.y close the jaws upon a alignmentwith the tap and for holding the article against movement when so. aligned, tap-holding and operating means for reciprocating the tap into and outof thearticle to tap the article, means reciprocating vertically above the feeding and holding means for lifting the tapped article out of the feeding and holding means comprising a pair of spaced apartv fingers in spaced. relation. to the tap each of the ngers being pivotally mounted at its upper end and having an inclined work gripping edge at its lower end, the inclined edges of the fingers diverging downwardly, a. spring extending across the fingers and secured thereto intermediate the ends thereof to, permit the fingers to. spread as the inclined edges are forced downwardly over the upper corner edge of an article to. grip the article lightly, and an operative connection between the tap reciprocating means and the fingers to reciprocate the fingers vertically and bodily as a unit, and a pipe having aY substantially horizontal terminal portion terminating adjacent the paths of the inclined edges and conducting air under pressure to direct. aV blast at the article lifted by the. fingers to blow the article out of the machine.

FREDERICK GARTNER.

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

UNITED STATES PATENTS Number Name Date,

1,146,374 Veith July 13, l 91 5 1,679,529 Johnson Aug.k '1,192.8 1,685,319 Erdman sept. 25, 192s 1,847,342 Hughes Mar. 1,119,3 2 1,976,991 Hersam Oct. 16,1934 2,347,585 Wainman Apr. 25, 1944 2,361,091' Edelmann Oct. 24, 19.44

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