US2651791A - Feed mechanism for nipple threading machines and the like - Google Patents

Description

Sept. 15, 1953 G, MARSDEN 2,651,791

FEED MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE Filed Sept. 27. 1950 3 Sheets-Sheet l AT T OHNE Y5.

Sept. 15, 1953 Filed Sept. 27. 1950 G. B. MARSDEN FEED MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE 5 Sheets-Sheet 2 INVENTOR.

ATTQINEYS.

B. FEED MECHANISM FOR NIPPLE THREADING Sept. 15, 1953 G. MARSDEN MACHINES AND THE LIKE 5 Sheets-Sheet 3 Filed Sept. 27. 1950 eD/VENTORI ATTORNEYS.

Patented Sept. 15, 1 953 UNITED STATES FATE T OFFICE FEED MECHANISM FOR NIPPLE THREADING MACHINES AND THE LIKE eorge l3. Marsden, Chicago, 111., assignor to chica o Nipple Manufacturing Company,

12 Claims.

This invention relates to feed mechanism for nipple threading machines and the like, and particularly to a mechanism for advancing nipple blanks and like work pieces into a rotating cutter and retracting thefinis'hed pieces therefrom.

It is one of the objects of the invention to provide a feeding mechanism in which the blank is advanced rapidly to a pointadjacent the cutting head and is then f'ed'slowly into the head at a rate synchronizedvvith the rotation of the head. According to one feature, the feed is entirely mechanical to produce a relativelysimple mechanism which can operate accurately at high speed. I

Another object is to provide feeding mechanism in which rapid movement of the blank is produced by a rotating cam intermittently driven over a predetermined angle by a single revolution clutch,

Still another object is to provide a feeding mechanism in which the carriage is detachably coupled to the slow feeding mechanism at the end of its rapid movement. In the preferred construction, the slow feed mechanism is started at the same time coupling-is effected to advance the work piece intothe cuttinghead.

A further object is to provide a feeding mechanism in which the slow feedis effected by a screw device driven in synchrorlism with the cutting head and preferably at a rate; slower than the rate of rotation of the cutting head; '7 I A still further object is toprovide a feeding mechanism in which the operation may be per formed automatically in a predetermined sequence.

lhe above and other objects of the invention will become more readily apparent from the following description when read in connection with the accompanying drawing in which Figure 1 isa side elevation of a nipple threading machine having a feeding mechanism em'- bodying the invention} I Figure 2 is a partial section on the line 2-2 of Figure 1; v, V p

Figure 3 is a section on'the line 3 3 of Figgure 1, V M v Figure 4 is a h'cnzofitn section on the line ii of Figure 3; and p o Figure 5 is a partial section taken immediately above the cam device and sho'vving' the cam device. r

The complete machine as best seen in Figure 1, comprises a frameorbase I'll-which may be a table-like membersupported at-= adesired convenient height above the floor on legs Ii. The frame It carries a pair of rotatable cutter heads or chasers i2 which may be of conventional construction, equipped with cutting tools to thread the ends of nipple blanks fed into them. The tools are preferably movable inward to a cutting position and outward to a release position for rapid removal of a finished blank by means Of a lever i3 pivoted on each of the heads. When the lever is thrown to its counterclockwise position shown in Figure Lthe cutters are moved inward to their cutting position. At the end of a cutting operation the end of a nipple blank will engage a trip lever in the head to release the cutters and move them outward, at the same time swinging the lever l3 clockwise. This construction is conventional and will not be illustrated or described in further detail.

Each of the cutting heads is carried by a horizontal rotating shaft mounted in a bearing block hi on the frame. The heads are driven through sprockets l5 secured to the shafts and engaged by sprocket chains l6 which are driven by sprockets ll on avariable speed reducer l8 mounted on supports above the frame. The reducer is driven through a sprocket 19 connected by a chain Zlto a driving sprocket carried by a main driving motor 22 supported below the reducer. Thus when the motor is running the heads will be turned at a speed determined by the adjustment of the variable reducer i8.

At its end opposite the mechanism which is described; the frame carries guideways 23 on which a carriage 25 is s'lidable toward and away from the heads. The carriage carries a pair of chucks 25 which are rotatable on vertical axes and are controlled through cam mechanism cooperating with tracks on the frame and through spring units 2% to turn between an aligned feeding position when remote from the heads to parallel cutting positions as they move toward the heads.

When in the feeding position, nipple blanks may be fed into the chucks and finished blanks ejected therefrom through a cross feed mechanism carried by a framework 27 mounted on the frame it. The carriage and cam control and cross feed mechanism are more particularly described and claimed in my co-pending applications Ser. No; 95,636, filed May 27, 1949 and Ser. No. 172,660, filed July 8, 1950. Since these mechanisms per so forth no part of the present invention, they will not be further illustrated or described herein.

According to the present invention, the carriage is advanced rapidly to a position adjacent to the heads and is retracted rapidly from the heads at the completion of a cutting operation by a cam mechanism including a rotating cam carried and driven by a central vertical shaft 28 extending upward through the frame. Above the base of the frame the shaft 28 carries a central external cam 29 which is generally spiraled and extends throughout approximately 180 and falls off sharply to its starting position. Facing and opposite to the cam 29 and also rigidly connected to the shaft 28 is an internal cam flange 3| which is spaced from the low side of the cam 29 to receive relatively closely between them a cam follower roller 32. At the high side of the cam 29 the spacing is greater as seen in Figure 4 so that the roller can move away from the cam 29 a distance corresponding to the desired thread length before engaging the flange 3|.

The cam is driven from the motor 22 through a gear reducer 33 driven by a sprocket chain 34 from the motor. The reducer 34 drives a sprocket 35 through a single revolution clutch 36, which turns through a complete revolution each time it is engaged and then automatically disengages. The sprocket 35 drives a bevel gear 31 through a sprocket chain 38 and the bevel gear meshes with a pinion at the upper end of a shaft 39 to drive the shaft. Below the frame it) the shaft 39 carries sprocket wheels driving sprocket chains 4| which in turn, mesh with sprocket wheels on the lower end of the shaft 28. As best seen in Figure 4, the sprocket wheels on the shaft 39 are smaller than the sprocket wheels on the shaft 23 so that the shaft 28 will be turned through 180 each time the clutch 36 is engaged.

Engagement of the clutch 36 is controlled by a solenoid 42 mounted on the frame and connected through suitable linkage to the clutch. The solenoid 42 is controlled by switches not shown, which can be operated manually to initiate operation of the apparatus, or which can be controlled automatically at the completion of a cycle of operations to initiate a succeeding cycle.

The cam follower roller 32 is carried by a slide 43 which is slidable longitudinally on the frame ID in guide ways 44. Thus, as the cam is turned the slide 43 will be shifted longitudinally of the frame by the cam and is connected to the carriage to move it. As shown, a rod 45 is connected to the carriage and extends between and beyond the heads where it carries a vertical cross pin 46. The cross pin fits in elongated slots 41 in the ends of a pair of levers 48 which are pivoted at their outer ends to fixed pivots adjacent the sides of the frame. The levers 48 are formed intermediate their ends, with elongated slots to receive pins 49 carried by a cross bar which is secured to the slide 43. With this mechanism as the slide moves it will provide a multiplied movement of the rod 45 and the carriage.

When the carriage is moved to its extreme forward position by the cam mechanism as described above, the chucks are adjacent to but spaced from the heads so that nipple blanks or similar work pieces carried by the chucks will not enter the heads. The final feeding movement during actual cutting is performed by a slow feed mechanism which is designed to feed the work pieces into the heads at a rate synchronized with their rotation. The slow feed mechanism as shown, comprises a screw mechanism including a hollow internally threaded nut body 52 which is formed remote from the carriage. A threaded shaft or screw 53 is threaded into the nut body and is recessed at one end to receive the end of a driving shaft 54 carried by the frame. The driving shaft and the recess in the screw shaft may be splined so that the screw shaft will be rotated and can move longitudinally in the nut body, moving the driving shaft 54 with it. The screw shaft is normally urged in one direction by a weight connected to a rack 55 meshing with elongated teeth on the shaft 54. The rack is so arranged that the weight thereon turns the screw shaft in a direction to move it way from the heads or to the left as seen in Figure l.

The screw shaft 53 is connected through a releasable coupling 56 to a shaft 51 which is swiveled in a rotatable sleeve 58. The sleeve 58 is slidably and rotatably mounted in a bearing block 59 on the frame so that it can move longitudinally as the screw mechanism operates but will not be turned by turning of the shaft 51. At its outer end'the sleeve 58 is formed with bayonet slots 61 to receive a pin carried by a reduced extension 62 on the rod 45 when the carriage is advanced toward the heads.

To connect the sleeve 58 to the extension 62, the sleeve is adapted to be rotated to move the pin carried by the extension 62 into the bayonet slots. For this purpose the end of the sleeve 53 is formed with elongated gear teeth meshing with a rack 63 which is adapted to be shifted transversely of the frame. The rack normally holds the sleeve 58 in the position shown in Figure 4, and is adapted to turn it to connect the extension 52 and sleeve 58 when the rack is shifted upward as seen in Figure 4. The shaft 54 and screw shaft 53 are driven through a sprocket 64 connected or splined on the shaft 54 and connected through a chain 65 to a sprocket 66. The sprocket 65 is driven through a clutch 61 which is normally disengaged and which is engaged when a control rod 68 thereon is shifted to the left as seen in Figure 4. The clutch is driven through a chain 59 and sprockets carried by the clutch input shaft and an extension II on one of the head driving shafts. In this way, when the clutch 61 is engaged the screw shaft 53 will be driven at a rate proportional to the rate of rotation of the heads in a direction to move the carriage toward the heads. Preferably, the sprockets provide a speed reduction so that the screw shaft will turn slower than the heads at a speed on the order of one-quarter to one-half of the head speed. This enables relatively coarse and strong threads to be employed in the screw feed mechanism while maintaining an accurate relationship between the movement of the carriage in response to the screw mechanism and the cutting rate of the heads.

The clutch 61 is engaged and the sleeve 58 is turned through an air cylinder I2 mounted on the frame and connected at one end to a lever 13 which is pivoted at one end on the frame. The lever is connected intermediate its ends to the clutch control rod 68 and is connected at one end through a push rod 14 to a bell crank lever 15 which is pivoted to the rack 63. When air is admitted to the air cylinder 12 which may be under the control of an electrically operated valve not shown, the lever 13 will be swung counterclockwise to engage the clutch and to shift the rack in a direction to couple the sleeve 58 to the extension 62.

In operation of the mechanism assuming that blanks have been properly supplied to the chucks, the solenoid 42 is energized to engage the single 5, revolution clutch at. "o'fi'h this clutch t cam?!) will be driven counterclockwise throu'gh 180 from its initial position :shownji'n :Figure 4 to move the carriage toward the heads to a point where the workpieces carriedbyfthe chucks are just ready to ent er the heads, 'At'thi's point the rod extension 62 will move into the sleeve 58 so that the pin carried by the rod extension isalignedwith the"bayonetslots. I I II I When the carriage reaches its 'forwar'd'position described it may operate a switch l6 mounted on the frame which admits 'airtothe cylinder 12 to engage the clutch'li'l andturn the sleeve "58. As the screw feed mechanism is driven'th'rou'gh the clutch til it will advance the'carriage f'u'rthertoward the heads to move the wbrkfpieces "into the heads at a rate syncuroriizee withtheirrotation so that threads can-be 'farmeuaocurately onthe blanks.

When thethr'ea'dihg isfcompleted, the heads will be tripped through their internal'mechanism or by engagement ofan "adjustablestop 11 carried by a trip bar l8'scuredto thecarriage with the trip lever'lil to rock the lever [3 clockwise. This movement or the lever may control switches which deenerg'ize the air cylinder 12 and energize the solenoid 'lz tofre-en'gage the single revolutionclutch 3B. When the *air cylinder 12 is lie-energized or. "reversed, it will release the clutch Bland will turn the sleeve 58 in a direction to disconnect it fromthe'extension 6 2. When the clutch ,61 is released, the rack 55 and its associatd'weight will 'turnfthe screw shaft 53 back to the ihitial'startingpositionready for a subsequent operation. 7 I I I I Engagement of the clutch 36"Wil1turn the cam shaft '28 and the c'ams carried thereby through an additional 180 counterclockwise as seen in Figure 4. "Duringfthis movementthe curved flange 3 I 'will e'n'gagethe follower roller 32 and will movethe carriage away from the heads back to its feediii'gposition. 'When the carriage is moved to it's fee'dingpositiona shoulder E9 on the trip bar willrockjthe lever l3 counterclockwise to close the head fre'adyfora subsequent operation. llssoo'n as thecompleted work piece is removed andan' additional blank is fed into the chucks themechani'smis ready for a subsequent operation which "maybe initiated automatically through the 'fee'd mechanism described in application Ser/Nol 172,660. Thus, the

I machine can be made fully automatic if desired.

Due to the fact that rapid i1ioverrfentfor" the carriage is effected mechanically throu h the cam mechanism, the carriage can be 'moved'at a relatively high rate under; accurate control and without danger of over sh ootin'g I which might damage the heads. The final- ,f eed 'm e'chanism is accurately synchronizedwith the'rotaftion of the heads so that the threads areEn I I I I I I cutting and can be formed with ahigh degree of accuracy. For different sizes cf nipples having threads with different pitches -the machinecan lee-adjusted by changing the driving ratio between the shaft extension I I and theshaft flor by exchanging the screwmechanism- :so that a; large range of nipple sizes can 'be-accommodated.

While one embodiment of=the-- invention has been shown and described in-detail, it-wil 1 be understood that this is= i1lustrativeon1y nd is not to be taken as adefinition of the scope of the invention, reference being had for this purpose to the appended claims.

I What is claimed is: I

oaded durin Feeding mechanism for iiipinethreaaing u machines anathema eompr is'mg :a frame, 'a retatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, rotatable cam device and-a cam rol lower, one on the carriage and the other on.- the frame remove the carriage toward the head,. the cam device having inner and outer cam-sur faces 'engageable with the follower to shift the carriage positively toward and away from the head, the portions of the cam surfaces which register with the "follower when the carriage :isadjacent to the head being-spaced apart farther than the thickness of the follower "so that the carriage and follower can move farther toward the head, drive means intermittently to turn the cam through half revolutions, supplementary feed means effective when the cam has moved the carriage toward the head to move the carriage farther toward the head, and control means operable at the end of a threading operation to energize the drive means.

'2. Feeding mechanism for nipple thr'ea'ding machines and the like comprising a frame, a rotatable cutting 'h'eadon the frame, a carri'age slidable on the frame toward and "away from the head, a rotatable cam device-and a cam follower, one on the carriage and the other onithe frame to move the carriage toward the head, the cam device having inner'a'nd outer cam surfaces engageable with the follower- 1:0 shift the carriage positively toward and away from the head, the portions of the cam surfaces which register with the follower when 'thecarriage --is adjacent to the head being spaced apart farther than the thickness of the follower so that' the carriage and follower can move farther toward the head, a single revolution-clutch connected to thecam to turn it through a half revolution each time the clutch is engaged, m'eans-toen'gagetheclutch, supplementary feed means effective when the cam has moved the-carriage towa'rd theh'ea'd'to move the carriage farther toward the head, and control means operable at theend of "a' threading operation to operate the means to engage the clutch.

3. Feeding mechanism 'for nipple threading machines and the like comprising a frame,- a rotatable cutting head oh the frame, a carriage slidable on the frame-toward and awayifrom the head, a rotatable cain-"devi'ce ar1'd-a-=cam follower, one on the carriage'and"-the 'other 'onithe frame to move'the carriage toward theheadflthe cam device having inner and outer cam surfaces engageable with the follovverto shift the carriage positively toward and away from the head, the portions of thecarhsurfaces Whichregistr with the follower when the carriage is adjacent .to the head beingspaced apart farther than .the thickness or "the fo'l-lo'wer so that the carriage and 'follower can "move farther toward .the head, a single"revolution 'clutch connected 'to' th'ecam :to turn it through-a half revolution each time the clutch is engaged, *means to engage llihte :clutch, a feed' screw, drivemeans for the feedziscrew, a 'rleasable coupling to connect 'the feed screw to thecarriage to 'move the ca'rr'iage toward *the head, means operable when Ethic cam hastmoved the carriage towardthe'he'ad toenga'gethe :coupling I and energize the feed :screw drive means, and control "means eper-able at Jthe end of a threading operation to release ithe -coupling, ile- -'energize the feed screw drive' means, and engage the*clutch.

if Feeding ='mechan ism :ror f nipple threading =machines and-the likecomprisihg-sacframaw rm tatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, a positive feed device for moving the carriage relatively slowly from said point further toward the head, a coupling element on the positive feed device, a second coupling element carried by the carriage to engage said first named coupling element when the carriage is advanced to said point and means to move one of the coupling elements to interlock it with the other when the carriage reaches said point, the coupling elements including means to prevent relative longitudinal movement thereof when they are interlocked.

5. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, a positive feed device for moving the carriage relatively slowly from said point further toward the head, a coupling element on the positive feed device, a second coupling element carried by the carriage to engage said first named coupling element when the carriage is advanced to said point, drive means for the positive feed device, and control means to energize the drive means and move one of the coupling elements to interlock it with the other when the carriage reaches said point the coupling elements including means to prevent relative longitudinal movement thereof when they are interlocked.

6. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, feed screw mechanism including relatively rotatable screw and nut members to move the carriage relatively slowly from said point further toward the head, one of said members being mounted on the frame to be held against longitudinal movement thereon, a coupling element connected to the other member of the feed screw mechanism, and a second coupling element carried by the carriage to engage and interlock with said first named coupling element when the carriage is advanced to said point the coupling elements having means thereon to prevent relative axial movement thereof when they are interlocked.

7. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, feed screw mechanism including relatively rotatable screw and nut members to move the carriage relatively slowly from said point further toward the head, one of said members being mounted on the frame to be held against longitudinal movement thereon, a coupling element connected to the other member of the feed screw mechanism, a second coupling element carried by the carriage to engage and interlock with said first named coupling element when the carriage is advanced to ,said point, drive means for the feed screw mechanism, and control means to start the drive means when the carriage reaches said 1 point the'coupling elements having means there- 8 on to prevent relative "axial movement thereof when they are interlocked.

8. Feeding mechanism for nipple threading machines and the like comprising a frame, a r0- tatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, a positive feed device for moving the carriage relatively slowly from said point further toward the head and including a part which is movable 1ongitudinally on the frame at a positive rate, a rotatable coupling element connected to the feed device part, a complementary coupling element connected to the carriage, one of the coupling elements being tubular to receive the other and the elements being formed with parts to interlock to prevent relative axial movement therebetween upon relative rotation thereof, and means to rotate the first named coupling element when the carriage reaches said point to interlock the coupling elements.

9. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, a positive feed device'for moving the carriage relatively slowly from said point further toward the head and including a part which is movable longitudinally on the frame at a positive rate, a rotatable coupling element connected to the feed device part, a complementary coupling element connected to the carriage, one of the coupling elements being tubular to receive the other and the elements being formed with parts to interlock to prevent relative axial movement therebetween upon relative rotation thereof, drive means for the feed device, and control means operable when the carriage reaches said point to rotate the first named coupling element to interlock the coupling elements and energize the drive means.

10. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, feed screw mechanism including relatively rotatable screw and nut members one of which is fixed to the frame, a releasable clutch for rotating the other member, means yieldingly urging the other member in one direction when the clutch is released, coupling means to connect the other member to the carriage, and control means to engage the coupling means and engage the clutch when the carriage reaches said point.

11. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, feed screw mechanism including relatively rotatable screw and nut members one of which is fixed to the frame, a releasable clutch for rotating the other member, means yieldingly urging the other member in one direction when the clutch is released, complementary coupling elements connected to the other member and the carriage formed with parts to interlock upon relative rotation, the coupling element connected to the other member being rotatable, and control means to rotate the last named coupling element and engage the clutch when the carriage reaches said point.

12. Feeding mechanism for nipple threading machines and the like comprising a frame, a rotatable cutting head on the frame, a carriage slidable on the frame toward and away from the head, feed means to advance the carriage rapidly toward the head to a point spaced therefrom, feed screw mechanism including relatively rotatable screw and nut members one of which is fixed to the frame, a releasable clutch for rotating the other member, means yieldingly urging the other member in one direction when the clutch is released, complementary coupling elements connected to the other member and the carriage formed with parts to interlock upon relative rotation, the coupling element connected to the other member being rotatable, control means to rotate the last named coupling element and engage the clutch when the carriage reaches said 10 point, and additional control means operable at the end of a threading operation to disengage the clutch, rotate the last named coupling element in the reverse direction to release the coupling and energize the feed means to move the carriage away from the head.

GEORGE B. MARSDEN.

References Cited in the file of this patent UNITED STATES PATENTS

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