US2838980A - Continuous broaching machines - Google Patents

Description

June 17, 1958 w. F. BABcocK CONTINUOUS BRoAcHING y MACHINES 6 Sheets-Sheet 1 Filed Ooi. 5. 1956 mn Mm,

June 17, 1958 w. F. BABcocK 2,838,980

coNTINuous BRoAcHING MACHINES Filed oct. s. 195s y e sheets-sheet 2 /6 &

INVEN TOR. Marge ff. 545606K June 17, 1958 Filed oct. 3. 195e w. F. BABcocK 2,838,980

coN'rINuous BRoAcHING MACHINES 6 Sheets-Sheet 5 fc4 ,wl mi s 32 Qu ma IN VEN TOR. 75@ A .ScacA/ June 17, 1958 w. F. BABcocK 2,838,980

CONTINUOUS BROACHING MACHINES Filed oen.. s. 195e e sheets-sheet 4 June 17, 1958 w. F. BABcocK l l 2,838,980

CONTINUOUS BROACHING MACHINES Filed Oct. 5, 1956 6 Sheets-Sheet 5 IN VEN TOR. h/Azrf/Q f.' 545606K 2,838,980 Patented June 17, 1958 ice f 2,838,980 f ,'V'CONTINUOUS BRoAcHrNG MACHINES WalterfF. Babcock, Cleveland, Ohio, assigner to T he t Foote-Burt Company, Cleveland, Ohio, a corporation of Ohio` .l

Application embers, 1956, serial N0. 613,623

`4l claims. (ci. ati-ss) of the type `in which the cutting tools are mounted on endless chains arranged to effect the translation ef the l.cutters over the surface or through the body of werk vpieces mounted on the work holder and indexing mechaf msm. l

The invention also contemplates mechanism associated jvwith4 the chain drive gearing in the machine to effect the automatic actuation of the werk holder and indexing n mechanism.

One ofv theobjects ef theV invention resides inthe provision of 4a chain having breaching cutters pivetally mounted on certain of the links therein and spacers y,pivotedson certain other of the links, the spacers being proportioned in relation te the` size and form of the work ;to accommodate the indexing movement of the work t within the period of translation of the spacers.

. Another object of 'the invention is to provide one er more series of breaching cutters on a pair of endless i chains, each ofthe cutters in the series being of a length totfacilitate `the translation thereof over the chain sprockets. i

Another object of the invention is to provide a work portion of the chain illustrating a broach spacer and the' contiguousV breaching bars;

Fig. 5 is a longitudinal sectional view of a fragmentary j portion of` the chain;

Fig. 6 is a Vertical sectional view through an upper portion ef the machine, the section being taken on a plane indicated by the line 6 6 in Fig. l;

Fig. 7 is a front elevational View of the indexing mechanism illustrated in Fig. l; l

Fig. 8 is a side elevational view ef the indexing mechanism;

Fig. 9 is a vertical sectional view taken on the lines 4 9-9 ef Fig. 7;

fholderand indexing mechanism which may be adjustably `inclined relative to the vertical axis thereof.

`Another-object of the invention is te provide a supporting-structure for the chain which will maintain-a v-tensiyestrain enV the upper4 run thereof and eliminate the 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 ef the f invention.

Referring to the drawings:

Fig. l is a side elevational view of a` breaching ma- ;chineernbedying the improved chain and werk supporting structure;

Fig. 2` is a plan view thereof;

t Fig. 3 is a rear elevational view of the machine, a f portion thereof being breken away and shown in section;

Fig-.4 is a side elevational view ef a fragmentary Fig. 10 is a fragmentary longitudinal sectional view taken en the lines 10--10 of Fig. 7;

Fig. 11 is a side elevational view of a modified ferm of the machine; and

Fig. 12 is an end view thereof.

Referring rst te Figs. l and 2, the breaching machine comprises generally, a base 10 having a meter 11 mounted thereon, a gear train 12 coupled therewith, `a chain and sprocket assembly en the base operatively connected with the gear train and a werk indexing mechanism 14 superjacent the top of the chain.

The chain and sprocket assembly embodies a pair of endless chains 15 engaged respectively with sprockets 17 and 18 mounted on shafts 19 journaled in the bed of the machine adjacent theends thereof. The sprocket 17 is driven by the gear train 12 which in turn is driven by a worm 20 en the motor armature shaft 21. The sprockets 17 and 18 are of the same diameter and are .mounted in equi-spaced transverse relation te the medial axis of the machine. The sprocket shafts 19 are disposed in a commen horizontal plane parallel a lineal ledge 22 in the bed of the machine, and steel rails 23 are mounted thereon for the support of breach blocks 24 carried on rollers on the chains 15.

The cutting tools or breaches 27 are mounted in the blocks V24 which are pivetally supported on the cross pins 28 ef the chains. As will be seen in Figs. l and 4, one or more breaches 27 are omitted from the series of the blocks 24 te define voids or spacers 30 to accommedate the transaxial movement of the work simultaneous the continuous translation of the chain during the indexing cycle ef the machine.

The broach blocks 24 are formed for the reception of trip lugs 16 adjustably secured thereon and arranged on the broach blocks te protrude therefrom for engagement with an arm on the limit switch 113 which is electrically connected te similar switches in the indexing mechanism.

Thus, when the teeth in the last breaching bar 27, ad-

jacent a spacer 30, clears the work, the lug 16 on the contiguous breach block will trip the arm on the switch 113 and initiate the actuation of the indexing mechanism. Obviously the length of the spacer and position ef the lug are coordinated with the rate ef movement ef the indexing mechanism so the work will be revolved through the void in the series of breaches and inte positien for the succeeding cut before the first breaching bar ef the approaching breach or cutter is brought into engagement with the werk.

The work holder and indexing mechanism embodies a housing having a spindle 31 and a work supporting face plate 32 disposed above and normal to the path of movement of the breaches. Thus, during the indexing operation, the Werk will pass through the void or spacer 30 in the chain assembly and the succeeding work piece er divisional segment thereof carried by the spindle er face plate will be positioned to receive the iirst breach of the series of breaches following the spacer 30.

The form, length and number of breaches between the spacers is dictated by the shape, depth of cut and character of the material of the work to be machined. For example, if the stock is relatively soft, and/or the depth Lof the cut is shallow, the Vnumber of cutters or broaches between the spacers may be relatively small7 but if the stock is tough and hard, or a deep cut is to be taken, it may be necessary to employ a greater number of cutters and fewer spacers in the chain broach assembly. The face plate 32 is adapted to support a blank, such as a disc, to be machined with spaced slots in the edge thereof, or aiplurality of small parts, such as yoke ends, to be bifurcated, notched or faced.

The work indexing mechanism (Figs. 7 and 8) comprise a housing mounted for biased adjustment from a vertical plane and `lateral adjustment in a horizontal plane. The biased adjustment is attained by operation of a worm 51 controlled by a hand crank 52 on the end of a worm shaft journaled in a gear cage 53 which is bolted to the face of the bed of the machine. The worm is engaged with a worm wheel 54 affixed to a shaft having spur gear thereon which is entrained with a toothed quadrant 55 affixed to an arm integral with the housing 50. The quadrant is clamped to a cross bar 56 which is fulcrumed in the bed of the machine adjacent the center thereof. The lateral adjustments are controlled by a screw 57 threaded in the end of the bar 56. The outer end of the screw 57 is supported in a cage 59 having a thrust bearing 60 therein and a hand wheel 61 is keyed to the outer end of the screw for the rotative control thereof. The shaft 56 is locked in adjusted position by a second screw 62 threaded in an axial bore in the screw 57 and arranged to abut the end wall of the bore in the bar 56. The screw 62 is operatively controlled by a hand wheel 63 pinned on the end of the screw 62.

The upper portion of the housing 50 supports a motor 64 having speed reduction gearing in a housing 65 attached thereto and a single revolution clutch mechanism 66, of conventional form, coupled therewith. The clutch is controlled by a solenoid 67 electrically connected with other instrumentalities that regulate the operative cycle of the indexing mechanism.

The clutch is connected to a secondaryY speed reduction get set in a housing 68 which drives a disc 69 having a crank pin 70 therein and connecting rod 71 pivoted thereon. The connecting rod 71 is connected to a rack 72 engaged with a pinion 73 on a shaft 74 journaled in a wall of a sub-frame on the housing 50. The shaft 74 carries a disc 7S having a spring pressed pawl 76 pivoted thereon (Fig. 9) which is engaged with a shoulder 77 in a cam. depression 78 machined in the inner wall of a disc 79. The outer end of the disc 79 has a spur gear 80 machined thereon entrained with an idler gear 81 and a pick-off gear 82. The idler gear is mounted on a plate 83 fulcrumed on the journal for the shaft of the gear and is provided with an arcuate slot 84 for an anchor bolt 85. The plate 83 is further provided with a lineal slot 86 to accommodate adjustment of the idler with pick-off gears of variable diameters. The shaft 87 for the pick-off gear 82 is supported in journal bearings 88 in the sub-frame, and carries a drive worm 94 which is engaged with a worm wheel 93 keyed to the work supporting spindle 31 and face plate 32. The worm wheel 93 constitutes the index rotor. A bevel pinion 89, mounted on the end of shaft 87, is intermeshed with a second bevel gear 90 carried on a stub shaft 91 mounted in anti-friction bearings in the sub-frame. The shaft 91 has an auxiliary worm 92 slidably mounted on the end thereof and engaged with the worm wheel 93. The shaft 91 is axially bored to receive a push rod 95 (Fig. 7) from an air cylinder 96 that maintains intermittent vertical pressure on the Worm 92 in order to eliminate tooth clearance or back lash between the drive worm 94 and worm wheel 93 during the operative cycle thereof. The spindle 31 is shouldered V to receive a ring 98 of frustro-conical cross section which is intermittently engaged by a shoe 99 of congruent configuration coupled with toggle linkage 100 on a rod 97. The rod is mounted for vertical reciprocative movement in the subframe and is actuated by an arm 101 having a yoke 102 on the end thereof which carries a bearing block 103 engaged with the end of the rod 97. The arm 101 is pivoted adjacent the yoked end thereof on a pin 104 seated in the housing sub-frame, and the outer end of the arm is pivotally connected to the piston rod 105 in a cylinder 106 coupled with a source of air under pressure. The arm 101 is machined tozreceive a set screw 107 disposed for abutting engagement with a limit switch 108 and a similar limit switch 109 Ais coupled with a back lash air cylinder 96 for the control""thereof. A similar limit switch 110 is mounted on the end of the rack 72 to effect the sequential operation of the index worm wheel 93 and the gearing associated therewith. The rack pinion shaft 74 has an arm 111 on the upper free end thereof adapted for engagement with the limit switch 112 in the electric circuit that controls the operation of the index worm 92, and a fifth limit switch 113 is mounted on the bed of the machine and 'connected in the electric control circuit for the machine. The switch 113 is operated by the trip lug or lugs 16 'mounted on the broach supporting blocks 24.

As the last broach 27 in each series of broaches on the chain leaves the work, the trip lug 16 will engage limit switch 113 which will energize the solenoid 67 and effect the engagement of the single revolution clutch 66, thus causing the descent of the rack 72 and consequent operation of index worm wheel 93. Priorto this event, the air cylinders 96 and 106 are de-energized and the back lash mechanism and brake are'held in their inoperative position. When the rack reaches the end of the stroke and operates the limit switch 110,'the back lash air cylinder 96 and the brake air cylinder 106 are energized. At this point, the machine will perform the broaching function. As the last broach 27, in each series of broaches, leaves the work, the 4trip lug 16 will engage limit switch 113 initiating the repetition of the operating indexing cycle.

In the modified form shown in Figs. -ll and l2, the principle and mode of operation is the-same as that'of the machine described above. However, the frame 40 in this embodiment is constructed to support-the chains in a vertical position and the indexing mechanism 41 is disposed to support the work holding arbor 42 parallel with the face of the cutter bars 43. The machine is driven by a motor 44 mounted on a pedestal 45 and is inter-geared with a power transmissionV gearing (not shown) of the form illustrated in Fig.. 3. In this embodiment, as in the former, spacers 46 are `provided between the cutters to accommodate the indexing movement of the work and lugs 47 are mounted on the broach blocks that precede the spacer blocks 46 to eiect the actuation of an electric limit switch 113 associated with the indexing mechanism in the fixture 41.

As will [be seen in Fig. 6, the broach blocks 24 are formed with subtended arms 115 engaged with the rails 23, and the upper ends of the chain guideway in the base 10 are formed with vertically disposed ribs 116 having cap rails 117 thereon. The opposed inner faces of the rails v117 are faced with hardened steel bars *118 engaged with similar bars 119 on the beveled upper faces of the broach blocks 24. The bars 118 and 119 restrain lateral movement of the broach blocks and maintain uniform contact between the arms 115 and the rails 23 during the translation of the blocks thereover. The breaches 27 are seated in grooves 120 in the blocks 24. Certain of the cross pins 28 in the chains have rollers 121 mounted on the ends thereof which ride on hardened steel rails 122 adjustably mounted in the sides of the railsv23.

The ends of the Vbed of the machine adjacent the sprockets 17 and 18 are provided with guide plates 123 to bridge the gap between the bars 118 and the arcuate faces of the sprockets. The plates 123 are formed with arcuate recesses in the outer ends thereof to clear the shafts 19, and the inner ends are anged to facilitate the securement thereof to the base of the machine. The opposed inner faces of the sprocket wheels 1'7 and 18 are undercut to provide running clearance for the plates and accommodate intimate engagement of plates with the separator collars 124 on the chain links. As the chains leave the bars 118, the separator collars 124 thereon engage the upper edges of the plates and restrain sagging movement thereof and consequent whipping or vertical vibration in the chain.

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 contining, and that various rearrangements of parts and modifications of detail may be resorted to without departing from the scope Ir spirit of the invention as herein claimed.

What is claimed is:

1. A broaching machine comprising a work holder mountedvon an axis for rotation, an endless chain, means mounting said chain for travel of one of its runs past said work holder in a direction substantially parallel to said axis, an 'indexing mechanism so constructed that when started will rotate said work holder a certain portion of a revolution and stop, trigger means adapted-to be actuated for starting said indexing mechanism, broaching blocks mounted on said chain, at least one spacer block between certain adjacent broaching blocks, means correlating the movement of said chain to said indexing mechanism so that said indexing mechanism is operated during the travel of a spacer block past said work holder, means on said broaching and spacing blocks for deattachably receiving lugs for operating said trigger means to initiate an indexing operation whereby lugs on said broaches that precede a spacer block can initiate a single indexing cycle with a single intervening spacer block and lugs on all but the last spacer blocks, when two or more are employer, can initiate a plurality of indexing cycles between broaches, and lugs in said detachable receiving means in accordance with the disposition of said intervening spacer blocks.

2. A broaching machine comprising a base, a`work holder mounted thereon for rotation about a vertical axis,

an endless chain on said base, means mounting said chain for travel of one of its runs past said workv holder in a direction substantially parallel to said axis, an indexing mechanism connected to said work holder organized to rotate said work holder a certain portion of a revolution and then stop, an electric switch on said base adapted to be actuated to start said indexing mechanism, broaching blocks mounted on said chain, spacer blocks on said chain, at least one spacer block between certain adjacent broaching blocks, means correlating the movement of said chain to said indexing mechanism so that said indexing mechanism is operated during the travel of a spacer block past said work holder, said broaching and spacing blocks having openings therein for detachably receiving lugs for operating said electric switch whereby lugs on said broaches that precede a spacer block can initiate a single indexing cycle through an intervening spacer block and lugs on all but the last spacer block, when two or more are employed, can initiate a plurality of indexing cycles between broaches, and lugs in said openings in said broaching and spacer blocks in accordance with the disposition of the intervening spacer blocks.

3. A broaching machine comprising a base, a work holder mounted for rotation on a vertical axis therein, an endless chain on said base mounted for translation of one of its runs past said work holder in a direction substantially parallel to said axis of rotation of said work holder, an indexing mechanism for said work holder constructed to initiate the rotation of said work holder a certain portion of a revolution and then stop, an electric switch on said base connected to said indexing mechanism and adapted When actuated to start said indexing mechanism, broaching cutter blocks mounted on said chain, spacer blocks on said chain, at least one spacer block between certain adjacent broaching blocks, means correlating the movement of said chain to said indexing mechanism so that said indexing mechanism is operated during the travel of a spacer block past said work holder, said broaching and spacer blocks having threaded openings therein for detachably receiving lugs for operating said electric switch to initiate an indexing operation whereby lugs on said broaching blocks that precede a spacer block can initiate a single indexing cycle with a single intervening spacer block and lugs on all but the last spacer blocks, when two or more are employed, can initiate a plurality of indexing cycles between broaches, lugs in said threaded openings -in accordance with the disposition of said intervening spacerblocks, and means on said indexing mechanism to alter the vertical and transaxial position thereof relative to said broaching cutters on said chain.

4. A broaching machine, according to claim 2, additionally including guide rails in said base parallel the run of said chain and subjacent said broach blocks, cap rails on said base, downwardly divergent horizontal second guide rails thereon, and third guide rails on said bolster blocks congruent said second rails and slidably engaged therewith to delimit vertical and lateral movement of said blocks.

References Cited in the le of this patent i UNITED STATES PATENTS Freter June 26, 1956 OTHER REFERENCES American Machinist, page 144, Aug. 1, 1955.

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