US2157958A - Indexing mechanism for automatic screw machines - Google Patents

Description

y 1939- A. F. JELINEK ET AL 57,958

INDEXING MECHANISM FOR AUTOMATIC SCREW MACHINES Filed Feb. 7, 1938 5 Sheets-Sheet l INVENTOR ALFRED EJ'EL/A/EK. WI?! 7.51? E. 66 055.

ATTORNEY.

y 1939- A. F. JELINEK ET! AL 5 58 INDEXING MECHANISM FOR AUTOMA'QIC SCREW MACHINES Filed Feb. 7, 1938 5 Sheets-Sheet 2 y 1939- A. F. JELINEK El AL 2,157,953

INDEXING MECHANISM FOR AUTOMATIC SCREW MACHINES Filed Feb. 7, 1958 5 Sheegs-Sheet 3 1:: M-4H n H, l |H n n i i a 0 T'f a; m Ea P- I, II u g a m1 7 i m g w 1% I g n iw m INVENTORs.

' ALF/FED F. G'ZA/A/EK. BY W41 re: akosa ATTORNEYJ.

y 1939- A. F. JELINEK z-rr AL 2,157,958

INDEX 1N6 MECHANISM FOR AUTOMATIC SCREW MACHINES Filed Feb. '7, 1958' 5 Sheets-Sheet 4 INVENT FJ 1 //VA, a oss.

Alf/PE F J W41 ff E 7 [4g T/MT ATTORNEY),

y 1939- A. F. JELLINEK ET AL,

INDEXING MECHANISM FOR AUTOMATIC SCREW MACHINES Filed ,Feb. '7, 1958 5 Sheets-Sheet 5 INVENTORj. ALFRED I JfL/NZK. WflLTfk 5.647055.

ATTORNEY-5.

Patented May 9, 1939 UNITED STATES ArE'r OFFICE INDEXING MECHANISM FOR AUTOMATIC SCREW MACHINES corporation of Ohio Application February 7, 1938, Serial No. 189,130

6 Claims.

This invention relates broadly to automatic screw machines and more specifically to improvements in tool turret indexing mechanisms therefor.

In single spindle screw machines heretofore constructed it has been the practice to secure the turret in indexed position with the work by means of a throw bolt or plunger arranged for reentrant engagement in openings in the turret. Such construction has been found objectionable due to the excessive wear upon one side of the plunger consequent the altered timed order of operation of the actuating mechanism after bearing clearances had developed in the machine.

In the present invention the rotative movement of the turret is effected through a gear controlled by the reciprocative drive mechanism for the turret and organized therewith to prevent undue wear or misalignment of the operative members of the-assembly. In addition to the foregoing and as a further object of the invention the structure contemplates a design which will facilitate the operation of the machine with greater expedition and attain greater accuracy in the product made thereon.

Other objects and advantages more or less ancillary of the foregoing and the manner in which all the various objects are realized will .appear in the following description which, considered in connection with the accompanying drawings, sets forth the preferred embodiment of the invention.

' Referring to the drawings wherein the preferred embodiment of the invention is illus trated:

Fig. 1 is a front view in perspective of a portion of a screw machine embodying the present invention.

Fig. 2 is a fragmentary plan view, partially in section, of the improved indexing mechanism and appertinent coordinated parts of the machine;

Fig. 3 is a transverse sectional view of the indexing device, the section being taken on a plane indicated by the line 33 in Fig. 2;

Fig. 4 is an elevational view of the tool turret, and associated parts, certain portions thereof being broken away and shown in section in the interest of clarity;

Fig. 5 is a diagrammatic plan View, partially in section, of the improved indexing mechanism embodying the present invention;

Fig. 6 is a similar view to that of Fig. 5 showing the tool turret in its actuated position;

Fig. '7 is a front elevational view of a fragmentary portion of the tool turret, actuating cam and drive gearing therefor; and

Figs. 8, .9 and 10 are diagrammatic views of the index cam and gear shown in successive al- 5 tered positions with respect to each other.

As illustrated in Fig. 1, the screw machine embodies a base ill, a collet or work holder l l and a reciprocative tool slideor turret l2 organized for rotative adjustment to bring the cutting tools It in successive co-axial alignment with the Work holder l I.

As will be seen in Fig. 2, the tool turret head [2 is mounted in a bearing l4, being reciprocatively actuated therein through a cam drum mounted upon a rod it connected with the turret head 52. On the rearward face of the cam drum 5% there is a gear I! intermeshed with an idler pinion l8 formed with elongated teeth to afford the intermeshed engagement of the gear ll during the translation of the drum cam l5.

About the rod it there is a sleeve l9 journaled in bearing brackets formed in the bed of the machine and rotatively driven through a worm wheel 20 mounted thereon. The worm Worm wheel is driven by a worm keyed to a drive shaft 2!, connected to variable speed gearing, not shown, operated from the main drive shaft of the machine. Upon the outer end of the sleeve is there is a pinion 22 intermeshed with a gear 23 mounted on a shaft 24 constituting the driving medium for the stock feed and chuck operating mechanisms. Upon the inner end of the sleeve i9 adjacent the gear I"! there is a gear 25 intermeshed with the idler pinion I8 and with a gear 25 supported by a stub shaft in a frame bracket 21. The gear 26 is meshed with a gear 28 mounted upon a sleeve 29 journaled in bearings 33 in the outer ends of the bracket 21. The sleeve 29 is formed to provide a clearance for the shaft 24 which extends therethrough and is free to rotate therein. Upon the inner end of the sleeve 29 there is a face cam 3| comprising a central plate 32, an open ring 33 defining in conjunction with the plate 32 guide- ways 34 and 35 and a rectangular plate 36 defining in conjunction with the ring 33 guide- ways 31 and 38.

The pinion 42 is disposed for pg toothed engagement with a gear 45 mounted upon the rearward face of the tool turret head |2.

As is customary in machines of this type, the tool turret head is indexed to bring each of the tools therein into successive working engagement with the work upon each reciprocative movement of the tool slide or turret, thus the ratio between the index and reciprocative drive gearing is dependent upon the number of tools or tool stages in the turret head. For example, the turret head illustrated herein is designed to support five tools, whence the ratio between the reciprocative drive gearing and the index gear is five to one so as to effect five reciprocative' cycles of the turret to each complete revolution of the turret head.

In the operation of the index mechanism contemplated herein, the rotative drive transmitted through the shaft 2| causes the rotation of the worm wheel 20, the sleeve l9, and in turn the gear 25 mounted thereon. Operation of the gear 25 causes the rotation of the idler I8 and the "gear mounted on the cam drum |5. The cam .drum 1 5 is advanced and retracted, during the revolution thereof by the action of a' fixed roller 45 within the spiral grooves defined by the cam plates mounted on the drum. As the cam drum is reciprocated the rod I6 is carried therewith, thus causing the reciprocation of the tool turret head |2. The gear I! on the cam drum is engaged with the elongated teeth of the idler gear I 8 and is rotatively driven thereby during the translation thereof. The gear efiectuates the rotation of the idler pinion 26 and gear 28,

thus driving the sleeve 29 and'plate cam 3|.

As will be seen in Fig. 8, when the leading 'edge of the cam plate engages the roller 39 a downward and'outward pressure is exerted there on, causing the entry of the roller within the guide-way 38 and the entry of the roller 4| within the guide-way 31. (See Fig. 9.) Further move- 'ment of the cam disc 3| will cause the rollers 39 and 4| to enter the track 35 while the roller 40 is engaged within the track or guide-way 34. As the rollers 39, 40 and. 4| are mounted upon the gear 42 in equi-radial and chordal relation, the fcamplate 36 will efiect the rotative movement of the gear 42 about its axis, two of the rollers be- Iingcontinuously engaged in the outer guide-way 35 while one of the rollers is retained within the inner guide-way 34. Upon each rotative cycle of the cam plate 3| two of the rollers are retained within the outer guide-way or track 35 while the third roller is retained within the guide-way 34.

'It will be noted, however, that each of the rollers the tools are forwarded for operative engagement with the work. While the tools are performing their cutting operation upon the work the rollers 'are engaged respectively in the guide- ways 34 and 35 and thus hold the gear 42 in a stationary position so that the teeth thereof will register with the teeth in the gear 45' upon the return of the turret or tool slide |2.

As will be seen in' Fig. 4, the cam drum I5 is provided with a lift cam 48 disposed on the V periphery thereof to effect the depression of the plunger 49 prior the rotative movement of the gear 42. The plunger 49 is engaged with a lever 50 fulcrumed upon a bracket 51 aflixed to the bed of the machine. The free end of the lever 50 is formed with a yoke 52- engageable with a shouldered portion of a plunger 53 having a tapered wedge block 54 on the end thereof adapted for engagement in key ways 55 machined in the outside diameter of the tool turret l2 in radial alignment with axis of the cutting tools |3. The lower end of the plunger 53 is provided with a spring seated upon a bracket in a machine bed, the spring being adapted to normally urge the plunger 54 into seated engagement with the respective key ways 55 in the turret slide. 0am drum I5 is rotated, the lift cam 48 will cause the depression of the plunger 49, the actuation of the arm 59 and the retraction of the wedge block 54 from the key way 55 with which it has been engaged. The position and dwell of the cam 48 are suitable to permit the rotative As the I movement of the gear 42 during the indexing movement of the turret head |2. After the gear 42 has completed the index cycle thereof the plunger 49 will ride from the lifting cam 48 to the circular path or track 56 on the cam drum |5, which will permit the movement of the lever 50 and the re-entry of the wedge block 54 with the key way 55 of the operatively positioned cutting tool l3. 7

Although the foregoing description is necessarily of a detailed character, in order that the invention may be completely set forth, it is to be understood that the specific terminology is not intended to be restrictive or'confining, and that a,-

lar concentric guide-ways and chordal guide- J ways interconnecting said concentric guide-ways, a gear, three rollers mounted thereon, two of said rollers being engaged within one of said circular guide-ways while the other roller is engaged within the other circular guideway, a second gear intermeshed with the first named gear and mounted on said tool turret, said cam plates being arranged to force the rollers in successive order from one of said circular guide-ways through said chordal guide-ways and into another of said circular guide-ways, whereby said gear is partially rotated within. a portion of each 'cycle oi rotation of said disc and restrained from movement during the remaining cycle of rotation of the disc.

2. Inan automatic screw machine embodying .a reciprocative tool turret, mechanism for indexing said turret comprising, a rotatively driven disc, cam plates thereon defining a pair of circular concentric guide-ways and a pair of chordal guide-ways interconnecting said circular guideways, a gear parallel said disc and adjacent'thereand projecting into said guide ways, said rollers being disposed in equi-radial and edui-chordal. relation and being disposed so that certain of said rollers are engaged in one of the circular guideways while certain other of the rollers are engaged within the other guide-way, said cam plates being arranged to force the=rollers in sucto, a plurality of rollers mounted on said gear 7 7 cessive order from one of the circular guide-ways through said chordal guide-ways and into the other circular guide-Way thereby effecting rotative movement of said gear during a portion of the cycle of rotation of said disc and restraining the gear from movement during the remaining cycle of rotation of the disc.

3. In an automatic screw machine embodying a reciprocative tool turret, mechanism for indexing said turret comprising a rotatively driven disc, cam plates thereon defining an inner and outer circular guide-way and a pair of chordal guideways interconnecting said circular guide-ways, a gear, three rollers mounted thereon, disposed in equi-radial and chordal relation and arranged so that two of said rollers are engaged within the outer guide-way while one of said rollers is engaged within said inner guide-way, said cam plates being formed to drive one of the rollers in the outer circular guide-way through one of the chordal guide-ways and into the inner circular guide-way and drive the roller in the inner circular guide-way through the other chordal guideway to the outer guide-way, thereby imparting rotative movement to said gear during a portion of the cycle of movement of the disc and holding the gear from rotation during the remaining cycle of the disc.

4. An indexing mechanism for a turret lathe comprising a rotatively driven disc, cam plates thereon defining a pair of concentric circular guide-ways and chordal guide-ways interconnected with the circular guide-ways, a gear adjacent said disc, a pair of rollers thereon engageable within the outer guide-way, and a third roller thereon engageable within the inner circular guide-way, said rollers being disposed in equi-lateral equi-radial relation, a cam plate formed to protrude into the path of one of the outer circular guide-ways and being arranged when engaged with the leading roller of the pair of rollers on said gear to effect the translation of the rollers in successive order from one of the circular guide-ways to the other, thereby causing a rotative movement of said gear during a partial cycle of the disc and restraining said gear from movement during the remainder of the cycle of the disc.

5. In an automatic screw machine having a reciprocating rotatable turret thereon, mechanism for indexing said turret comprising a rotatively driven disc, a pair of cam plates thereon defining a pair of concentric circular guide-ways, a third cam plate defining in conjunction with the circular cam plate a pair of convergent chordal guide-ways uniting the circular guideways at a common point, a gear adjacent said disc, three rollers thereon, spaced chordably to accommodate the engagement of any two of the rollers within one of the circular guide-ways while the third roller is engaged within the other circular guide-way, said third cam plate being formed to project into the path of the outer circular guide-way to guide one of the rollers therein into the inner guide-way upon each revolution of the disc and thereby cause a partial revolution of the gear and restrained movement thereof during the remaining cycle of rotation of the disc.

6. In a screw machine embodying a reciprocative tool turret, mechanism for indexing said turret comprising a rotatively driven disc, a pair of cam plates thereon defining inner and outer concentric circular grooves having interrupted side walls therein, a third cam plate disposed adjacent the interrupted side wall of the circular grooves and formed with a portion which protrudes in the path of the outer groove, said third cam plate defining in conjunction with the first named cam plates cross over grooves uniting the circular grooves, a protrusion in the third cam plate extending into the path of the outer groove, a pinion, three rollers thereon arranged in equilateral relation, said rollers being disposed so that two of the rollers are engaged within the outer groove while one of the rollers is disposed in the inner groove and so that two of the rollers are engaged within said cross over grooves while one of the rollers is engaged with said protrusion on said third cam plate, said protrusion on said third cam plate being formed to engage the leading roller on said pinion and drive the pinion rotatively until the roller in the inner groove is carried through the cross over groove to the outer groove where such roller in conjunction with the second roller in the outer groove and the third roller in the inner groove will restrain the pinion from further movement during the remaining cycle of operation of the disc.

ALFRED F. JELINEK. WALTER E. GROSS.

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