US2237760A

US2237760A - Broaching machine

Info

Publication number: US2237760A
Application number: US268535A
Authority: US
Inventors: Francis J Lapointe
Original assignee: American Broach & Machine Co
Current assignee: American Broach & Machine Co
Priority date: 1939-04-18
Filing date: 1939-04-18
Publication date: 1941-04-08
Anticipated expiration: 1958-04-08

Description

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BROACMNG :MACHINE:

Filed. April 18, 1939 3 ShGehs-Sheel; l

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E T m F A L JM F BROACHING Mmmm Filed April 18', mw

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Patented Apr. 8, 1941 BROACHING MACHINE Francis J. Lapointe, Ann Arbor, Mich., assigner, by mesne assignments, to American Broach & Machine Co., Ann Arbor, Mich., a corporation of Michigan Application April 18, 1939, Serial No. 268,535

(Cl. Sil- 33) 24 Claims.

More particularly, the invention relates to a machine for cutting gears and other externally toothed and splined elements by the use of breaching tools, it being the general object of the invention to provide a new and improved machine adapted to cut all the projecting porn tions of such an element by a single stroke of a plurality of breaching tools.

Another object is to provide such a machine embodying means for supporting the work blank from which the element is formed and the tools and for guiding the tools accurately with respect to the blank during the cutting operation.

Another object is to provide such a machine embodying a work blank support and tool guiding fixture provided with tool guiding surfaces supported integrally with the work support and laterally opposite the point oi cutting.

Another object of the invention is to provide a new and improved means for supplying cutter coolant to a plurality of broaches operable to cut a gear.

Another object is to provide such a machine with automatically operable means for ejecting a nished work piece from the machine.

Further objects will become readily apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. l is a front elevation of a preferred form 3' of the invention.

Fig. 2 is a vertical section approximately along the line 2-2 of Fig. 1.

Fig. 3 is an enlarged fragmentary vertical section approximately along the line 3--3 of Fig. 2.

Fig. 4 is a horizontal section approximately along the line 4-4 of Fig. 3.

Fig. 5 is a fragmentary elevation partly in section along the line 5--5 of Fig. 7.

Fig. 6 is a horizontal section approximately along the line 6 6 of Fig. 3.

, Fig. 7 is a horizontal section approximately along the line 'l--T of Figs. 3 and 5.

Fig. 8 is a plan section approximately along the line 8 8 of Fig. 1.

l Fig. 9 is a horizontal section approximately along the line 99 of Fig. 3.

, While there is disclosed in the drawings and hereinafter described in detail a preferred form of the invention, it is to be understood that the invention is not limited to the particular construction shown. It is contemplated that various changes may be made by those skilled in the art without departing from the spirit and scope of the appended claims.

In the form chosen for purposes of disclosure, the invention is embodied in an upright or vertical machine (Figs. 1, 2 and 8) having a column or frame 29 formed with a `base pan 2| at its lower end and a pair of laterally spaced parallel ways 22 which extend vertically along opposite sides of the frame. A wall 23 extends vertically within the frame so as to divide it into a rear compartment 24 and a front compartment 25 and reenforcing webs 25 are provided between the wall 23 and ways 22. Gribs 2'I are secured to the ways 22 by means of bolts 28 and cooperate therewith to form guideways for a tool supporting head 29 which has integral side ribs 30 fitted to slide therein. The head 29 is arranged to be reciprocated on the ways 22 by means including a pair of piston and cylinder devices, the pistons 3l of which are secured to the head 29 by means of piston rods 32 and the cylinders 33 of which are hung from a work plate 34. The work plate is supported on a pair of brackets 35 secured to the frame 2l). It is contemplated that the cylinders will be supplied with a fluid under pressure from a suitable pump and under the control of valves (not shown) which will cause a slow or feed movement of the head 29 upwardly and a more rapid return or traverse movement of the head downwardly. The hydraulic pump and circuit are well known in the art and form no part of the present invention.

The invention relates more particularly to the means for supporting a plurality of tools and a work blank during a broaching operation which cuts all the teeth of a gear on the work blank in a single stroke. The tool supporting means will be described first. 4

As shown in the drawings and more particularly Figs. l, 2 and 3 thereof, the tool head 29 has a horizontally extending portion 29 to which a tool holder or pull head 4l) is secured. This pull head is arranged to grasp the upper ends 4l of a plurality of broaching tools 42 and pull the tools upwardly through a proa-ching stroke when the head 29 is moved upwardly. As shown most clearly in 3 and 4, the pull head 4l] comprises a tubular member or stem 43 which has a reduced portion 44 positioned in a bore in the tool head portion 29 and is secured in place by a nut 45 threaded on the upper end thereof. The lower end of the stem is enlarged at 46 and provided with a plurality of annularly'arranged radially extending slots 4l for receiving the upper ends 4I of the tools 42. The slots 4l are intersected by an upper annular recess 48 and also by a lower annular recess 49. A split ring 5i) is secured in the upper recess 48 to serve as an abutment or stop member for the upper ends of the tools 42. A plurality of arcuate or segmental jaws 5I (herein eight in number) are positioned in the lower recess 49 and are movable radially from an outer position as shown in Figs. 3 and 4 to an inner clamping position wherein the jaws engage in recesses 52 in the outer edges of the upper ends 4I of the tools 42. The segmental jaws 5| are preferably provided with beveled cam surfaces 53 and 54 to facilitate operation thereof outwardly by beveled cam surfaces 55 and 55 on the upper tool ends respectively. The jaws are also provided with beveledcam surfaces 5'| to facilitate operation thereof inwardly to a clamping position by an annular beveled cam surface 58 on a clamping ring 59. This. ring is slidable up and down on the outer surface of the enlarged portion 46 of the chuck stem 43 between an upper position determined by the engagement of an abutment surface G on the ring with the lower surfaces of the jaws (in which instance the jaws are released and the tools withdrawable) to a lower position determined by a stop ring 6| secured to and extending outwardly from the lower end of the clamping ring 59. When the clamping ring is moved downwardly, the cam surface 58 acts-against the cam surfaces 51 to move the jaws inwardly to their clamping position. Preferably the recesses 52 in the upper tool portions 4I are of a greater dimension vertically than the jaws to insure proper interengagement.

The clamping ring 59 is arranged to be moved to its jaw unclamping position as shown in Figs. 3 and 4 by means of a pair of pins 62 upstanding from the work plate 34. When the tool head 29 and the tools are completing a downward stroke, the clamping ring 59 engages the pins 62 and moves to its upper position. The tools may then be drawn downwardly anddisengaged from the chuck by an elevator designated generally G3 in which the lower ends of the tools are supported, as` hereinafter described. In Figs. 3 and 4, the parts are in the positions assumed after a work blank W has been placed on a` splined work arbor 64 and the tools 42. have been. elevated to a position in which they are engageable by the chuck jaws 5|. As the tool head 29 starts its upward movement (with the tools following due to continued operation of the elevator 63), the clamping ring 59. is moved downwardly to its tool clamping position by means of a pair of plungers 55 slidably mounted in bores in .thehead portion 29' and pressed downwardly by coiled -springs 65.

"The elevator 63, as illustrated in. Figs. 1 to 3 and 9, comprises a member 61 slidable vertically on a pair of .laterally spaced rods vsecured at their lower ends in a base block 59 and joined at their upper ends by a cross member 1U. The elevator member 61 -is operableby means of a piston 'H (Fig. 2) which is mounted on the upper end of a piston rod 12 and is slidable in a cylinder 'I3 formed integrally with the member 61. `The piston vrod 12 Ais anchored at its lower end in the base block 53 and may be provided with two pas'- sages for supplying fluid under pressure to the opposite ends of the cylinder 'I3 in a manner well known in the art.

yThe broaching tools 42 are. secured at their lowerv ends in a retaining means comprising a .bushing 15 and a pair of split-ring clamping members 16. The bushing 'l5 has an outwardly extending lower flange 1l on which the lower ends of the tools 42 and the clamping members 15 rest, and has also an upper outwardly extending flange 'FS which is provided with a radially extending slot '|55 for each tool. An intermediate annular rib Si) on the bushing engages in notches 8| in the tools. rEhe slotted upper flange serves to locate the tools in accurately spaced relation around the bushing. The clamping members 'l5 have ears 82 secured together by screw devices 83.

When the tools are supported on the elevator 63, the retaining means l5, l5 rests on a centering block 84 which is carried on a forwardly extending shelf or bracket 85 on the elevator. The block 34 has a conically shaped upper end which fits into the lower end of the bushing l5, as shown in Fig. 1, so as to center the bushing thereon, and also has a bifurcated portion 85 into which one set of ears S2 fits so as to maintain the proper angular position of the lower ends of the tools.

' In broaching articles such as gears, it is necessary to obtain an unusually high degree of accuracy so that the teeth of the gears are uniform and properly spaced. It is an important object of this invention to provide means for insuring accuracy in the lbroaching of the gears, and this object is attained largely by the structure for supporting the work blank W and for guiding and backing up the individual teeth forming broaching tools immediately adjacent the work blank. This part of the invention will now be described.

The tool guiding and work supporting means is herein shown in the form of a fixture mounted on the work plate 34 and comprises an annular member 5G (Figs. 3, 5, 6, and '7), an arbor supporting member i Hl positioned centrally thereof, a lower ring |29 surrounding a reduced portion of the annular member 9i] and the work arbor 64.

The annular member Si) has an upper portion 9| fitted within a bore 34 in the work plate 34, an outwardly extending flange 92 held against the lower surface of the work plate by a plurality of screw devices 93 and la plurality of downwardly and inwardly extending web portions E4 wedge shaped as shown in `the left hand half of Fig. '7 so as to form radially extending guide slots 95 for the breaching tools 42. The inner cylindrical wall 9G of the annular member 5&3 forms a guide surface for the outer edges of the breaching tools and backs up the tools so that they cannot move radially outwardly of the fixture. The tools 42 are also backed up against radial outward movement by means of the lower ring |29 which has an inner cylindrical surface |2| of the same diameter as the cylindrical surface 95. The outer edges of the tools 42 are preferably provided with curved surfaces formed on the same radius as the cylindrical surfaces 96 and |'2| so as to be backed-up and guided thereby. The ring |20 is a pressed fit and surrounds the downwardly projecting webs 94, the lower portion |22' of the ring serving to back up the tools laterally opposite the work piece W during a cutting operation.

The ring |25 is secured to the annular member Si) by a plurality of screw devices |22 which extend through suitable bores in the ring |25 and into screw-threaded engagement with tapped holes in the member 5D.

The arbor supporting member Ii has a central hub IH provided with a bore H2 in which the arbor 54 is positioned. The arbor is secured against rotary movement by means including a pin ||3 carried by the arbor and extending radially into a suitable recess in the hub The arbor is secured against longitudinal movement by means of a washer IIl and a screw device I I on the upper end of the arbor positioned` in an enlarged portion of the bore H2, rand an enlarged splined portion t4 on the lower end of the arbor'. Preferably, a ball detent llt` urged outwardly by means of a spring I |'I is provided on the splined portion of the arbor for detachably holding the work blank W thereon. The arbor supporting member Ii has a plurality of webs ||8 extendingradially and outwardly therefrom, as shown most clearly in Fig. 7. At their upper ends these webs are of sufficient length to overlie the annular member 50 so that the arbor supporting member I||l may be secured thereto by means of a plurality of screw devices H9. The inte-rmediate portions of the webs H8 which lie within the annular `member 5|] are of suflicient length to engage the inner cylindrical wall 9B thereof. The lower portions of webs ||8 are relatively short and project outwardly into abutting relation with the webs 54 of the annular member 95. As shown most clearly in Fig. 7, the inner portions li of the webs IIB are shaped somewhat in the form of gear teeth but slightly narrower to provide clearance for the teeth of the breaching tool. The intermediate portions H8 of the webs have side surfaces forming guideways for the broaching tools, whereas the outermost portions of the webs IIB are narrower so as to pro vide clearance between the webs and the broaching tools. The webs 94 on the annular member SI) are wedge shaped as shown in the left hand half of Fig. 'I and are of sufficient width so that their side surfaces provide guidcways for the broaching tools 42.

In order to provide cutter coolant to the broaching tools at the point of engagement with the work blank, a cutter coolant supply pipe |30 extends downwardly from the upper portion of the frame 20, through an opening |3| in the head 29 and into communication with the enlarged upper portion of the bore ||2 (Fig. 3) of the hub Iii. The hub is provided with a plurality of radially extending ports |32, one for each breaching tool 42, which receive coolant for the pipe |31) and discharge it into the inner portions of the guide slots formed by the web portions i i8 so that the coolant may flow downwardly onto the work blank.

The invention as vdisclosed herein is also provided with means for removing iinished work pieces from the arbor 64 and discharging them from the machine through a chute |45 (Fig. 2). This means includes@ pair of :fingers |4| (Figs. 3, 5 and 6) which extend through diametrically opposite slots |42 in the lower portion of the ring and are pivoted on. pins |43. The inner ends ofthese fingers overlie tooth portions of the work blank W, whereas the outer ends of the lingers are normally spring pressed downwardly by means of plungers M4 backed up by coil springs |45, the plungers and coil springs being mounted in blocks |46 suitably secured to the work plate 34. rI'he lingers I 4| are arranged to be pivoted to eject a finished work piece upon completion of the breaching operation by means of a pair of vertical slide rods |41 mounted in bushings |48 in a plate |43 (Figs. 1 to 3) which is mounted on a bracket |59 secured to the wall 23 of the frame Z5. The rods |41 are aligned vertically with theears t2 of the tool clamping members 15, with the result tha-t as the broaching tools approach their uppermost portion wherein the Cil cutting stroke is completed, the ears 82 engage the lower ends of the rods I 4I and move them upwardly, thus causing the inner ends of the fingers |4| to eject the finished Work blank W downwardly. The work blank then drops down through the opening in the bushing 15, which is preferably beveled at l5', to facilitate the passage of the finished gear therethrough. The gear is then directed into the chute by means of a pivoted denector which is pivotally mounted on depending portions |5| of the bracket |89 by means of a rod |52. This deflector is movable from an inoperative position, as shown in full lines in Figs. 1 and 2, to an. operative position, as shown in dotted lies in Fig. 2, in which position it functions to arrest the downward movement of the finished gear and to direct the gear into the discharge chute |451. In order to operate the deflector |5|J in properly timed `relation with the work ejecting means, the deflector is provided with an ear |53 (Fig. 2) which extends rearwardly from the upper end thereof adjacent the pivot rod |52 and .is connected to the lower end of a vertically extending rod |54 by means of a pin |55. This rod is normally held in its lower position (in which position the deflector is. inoperative) by means of a coil spring |56 which surrounds the lowermost portion of the rod and is compressed by engagement with a lower surface on the plate |49. The rod |54 extends upwardly through a suitable opening in the head 29 and at its upper end carries a collar |51 suitably secured thereto. As the breaching tools reach the upper end of their broaching stroke, at which time the head |29 is at the upper end of its stroke, the rod |54 is raised so as to pivot the deflector I to the dotted position shown in Fig. 2. The raising of rod |54 is accomplished by means of a coil spring 5B which surrounds the upper portion of the rod |54 below the collar |5'I and above the horizontally extending portion 29 of the head.

In the form shown in the drawings (Figs. 1 and 3), each cylinder 33 is in the form ofl a tubular member clamped intermediate a lower cylinder head Iii! and an upper cylinder head |'I| by means of a plurality of bolts |72 which extend through openings |73 in the heads |10 and openings Id in the heads |'II and into screw-threaded engagement with the work plate 34. The bolts |12 also serve to secure the entire cyiinder structure to the work plate. The piston rod 3L extends upwardly through an opening |l5 in the head lli and through a bushing i I'i and hasa reduced upper end 32 forming a shoulder ill' which fits against the lower surface of the tool head 29. Nuts |18 (Fig. l) are threaded on the upper -ends of the reduced portions 32 so as t-o secure the piston rods rigidly to the tool head.

In order to guide the upper ends of the tools 42, principally when they are disengaged from the tool holder iii), a split-ring or bushing (Fig. 3) is mounted in a suitable opening in the plate |45 and provided with a flange |85 overlying said plate. As shown most clearly in the left hand portion of Fig. 6, the bushing |85 is provided with radially extending slots I Si? which act as guideways for the tools 4Z. Preferably, these slots are slightly wider than the thickness of the tools so that the tools move freely therein.

The lower portion of the machine may be partly enclosed by means of shields |35 and i'oi (Figs. 2 and 8), extending inwardly from the front side edges of the frame 2li, around the cylinders 33 .and rearwardly intoengagement ,with the lwall Operation The operation of the machine will now be described. As illustrated in the drawings, and particularly in Figs. l to 3, the machine is shown with a preformed gear blank W already attached to the work arbor 54 and the elevator 63 has already moved upwardly to place the upper ends 4| of the broaching tools d2 within the tool holder 40. The tools then extend upwardly through the guide slots lS'I in the bushing |85. Upon movement of the head 29 upwardly (caused by-actuation of the pistons 3| by a suitable fluid), the elevator device continues its upward movement for a short distance until the upper ends of the tools are clamped by the segmental jaws 5| which move inwardly to clamping position by the action of cam surface 58 against cam surfaces 51. The tool head then continues its upward movement independently of the elevator and the tools, guided by the guideways on the members Sil, IIll and IEll, cut the teeth on the work blank. Upon the completion of the broaching operation, the ears 82 on the clamping members 'IIS engage the rods Iii and move them upwardly to pivot the fingers IGI and eject the iingers clear from the splined portion of the work arbor. Preferably,

the upper ends of the rods IM are provided with o adjustable screw and nut devices Ilt'l to facilitate accurate adjustment thereof. The finished gear, upon dropping through the opening in the bushing i5, strikes the deiiector |50 which has in the meanwhile been pivoted from the full line position of Fig. 2 to the dotted line position thereof. The finished gear then passes out through the chute IM.

The tool head 29 is then moved downwardly through its return stroke by the reverse operation of the pistons 3| in the cylinders 33 and during this return stroke carries the broaching tools 42 downwardly until the bushing 15 engages the elevator 53. The tool head and elevator then move downwardly simultaneously for a short distance, during which time the tool head clamping ring 59 actuated by the pins 62 (Fig. 3) and raised relatively to the tool head to the position shown in Fig. 3. Continued downward movement of the elevator then disengages the broaching tools from the tool holder 10, the elevator carrying the tools downwardly until the upper ends thereof are below the splined portion of the work arbor 64 but still engaged in the slots |81 of bushing |85. Vihen the elevator reaches this lowermost position, the operator of the machine rnay place a new work blank on the work arbor, after which the cycle of operation may be repeated by causing the elevator to rise and engage the upper ends of the broaching tools with the tool holder 40.

The iiuid supply and control means for the hydraulic actuation of the tool head and elevator cylinders have not been illustrated and described, since such means are old and well known in this art and form no part of the present invention.

By providing a machine as disclosed herein with a tool guiding and work supporting xture having tool guideways laterally opposite the portions of the work blank to be cut, the invention produces a machine capable of cutting gears and other toothed elements with a high degree of accuracy. The broaching tools are effectively backed up by the ring |20 so as to prevent outward movement thereof and are accurately guided by the webs 94 so as to obtain proper angular spacing of the teeth on the gear. Furthermore, the invention provides a novel means for mounting the broaching tools in predetermined positions on the bushing 'I5 whereby the handling of the tools as a group is facilitated. The provision of means for ejecting the nished work blank and discharging it from the machine through the chute i0 (which may lead to a suitable hopper or conveyor (not shown) enables the operator to devote his entire attention to the reloading and starting of the machine. Thus, in a machine having automatic means for controlling the reciprocation of the tool head and elevator, the operator may after loading the machine start the machine and then return only after the finished gear has been discharged.

An important feature is the provision of a boaching tool assembly wherein a plurality of broaching tools are secured together in angularly spaced relation by `a clamping means associated with the tail ends thereof, the clamping means being provided with an opening therethrough which permits a nished work piece to pass out. In this way, a gear or similar element may be formed during a single stroke of the broaching tools, and it is not necessary for the tools to pass back over the iinished surfaces of the work piece.

Throughout the speciiication, the term gear has been used for purposes of illustration, and it is intended by the use of this term both in the description and claims'to include other toothed or splined elements as well.

I claim as my invention:

1. A broaching machine having, in combination, an upright frame, a horizont-al work plate secured to said frame intermediate the ends thereof, a broach supporting head slidably mounted on said frame above said work plate, a broach handling elevator device vertically movable with respect to said frame below said work plate, means on sai-d head for simultaneously chucking a plurality of bar-like broaching tools spaced angularly in position to cut the teeth of a gear, means for reciprocating said head, means for securing the lower ends of said tools together in vangularly spaced relation including an annular member having ya central opening sufciently large to permit a iinshed gear to pass therethrough, means for ejecting the work blank from said `arbor upon completion of the cutting operation comprising a yplurality of fingers pivotally mounted on said work plate with their inner ends overlying teeth on the iinished gear and means operable by the broach clamping device for pivoting said fingers upon completion of the cutting operation of the broaching tools, a gear receiving chute exten-ding laterally of said frame below said work plate, a delector device pivot- `ally mounted on said frame for engaging nished gears and deecting them into said chute, and means operable by said head as it approaches the upper end of its movement for swinging said delector device into position vertically underthe work plate for engaging a nished gear falling through said annular member and directing it into said chute.

2. A broaching machine having, in combination, an upright frame, a broach supporting head slidably mounted on the upper portion of Vsaid frame, a broach handling elevator device vertically movable opposite the lower portion of l said frame, means on said head for simultaneously chucking a plurality of bar-like breaching tools spaced angularly in position to cut the teeth of a work element, means for reciprocating said head, a clamping device for securing the lower ends oi said tools together in angularly spaced relation including an annular member having a central opening sufliciently large to permit a nished work element to pass therethrough, a downwardly projecting work element arbor supported on said frame for receiving a work element, and means for ejecting .the work element from said arbor upon completion of the cutting operation comprising a linger having a part thereof overlying a portion oi the finished element and means operable by the broach clamping device for movmg said finger upon completion of the cutting operation of the broaching tools.

3. Abroaching machine having, in combination, an upright frame, a broach supporting head siidabiy mounted on the upper portion of said trame, means on said head for simultaneously chucking a plurality of bar-like breaching tools spaced angularly in position to cut the teeth of an element, means for reciprocating said head, a .clamping device ror securing the lower ends of said tools together in angularly spaced relation including an annular member having a central opening sutficiently large to permit a finished element to pass therethrough, a work element arbor supported on said frame and in a position centrally of said tools, and means for ejecting the iinished element from said arbor upon completion of the cutting operation.

4. A breaching machine having, in combination, `an upright frame, a broach supporting head slidably mounted on said frame above said work plate, means on said head for simultaneously chucking the upper ends of a plurality of barlike broaching tools spaced angularly in position to cut the teeth of a gear, means for reciprocating said head, a clamping device for securing the lower ends of said tools permanently together in angularly spaced relation having a central opening suinciently large to permit a iinished gear to pass therethrough, a work blank arbor projecting downwardly from said Work plate, means for ejecting the iinished gear from said arbor upon completion of the cutting operation, a gear receiving chute extending laterally of said frame below said work plate, a deiiector device pivotally mounted on said frame for engaging finished gears and deflecting them into said chute, and means operable by said head as it approaches the upper end of its movement for swinging said delector device into ,position vertically under said clamping device for deflecting a finished gear falling through the central opening of said device.

5. A broaching machine having, in combination, a frame, a work plate secured .to said frame intermediate the ends thereof, a broach supporting head slidably mounted on said frame on one side of said work plate, means on said head for simultaneously chucking the leading ends of a plurality of bar-like broaching tools spaced angularly in position to cut the teeth of a gear, means for reciprocating said head, a clamping device for clamping the tail ends of said tools permanently in angularly spaced relation including a member having a central opening suiiiciently large to permit a finished gear to .pass therethrough, a work blank arbor projecting from said work plate for releasably holding a work blank, and means for ejecting the work blank from said arbor upon completion of the cutting iii operation so that it moves out .through the central opening of said clamping device.

o. in a machine for broaching gears having a plurality of tools spaced about a -circle each adapted to operate on a work blank to form the space between two adjoining teeth during a singie stroke or the tools, in combination, a work plate, a tooi guiding and work supporting fixture secured to said plate comprising a member having an annular rim and a plurality of webs extending radially inwardiy and downwardly from the lower portion oi said rim to. form radial guide Vslots roi said tools, a ring surrounding said downwardly projecting webs and having an inner suriace cooperating with the inner surface of said annular rim to back-up the tools as they pass through said slots and prevent movement thereor' radially outward, a hub positioned centrally oi' said annular rim having outwardly extending webs aligned with the webs of said member, means securing the webs of said hub to said member, a Work supporting arbor secured centrally of said hub and having a splined work blank receiving portion projecting downwardly therefrom and laterally opposite said ring, and a spring pressed detent device for releasably holding a work blank on said arbor.

1. In a machine for broaching gears and the like having a plurality of tools spaced about a circle each adapted to operate on a work blank to form the space between two adjoining teeth during a single stroke of the tools, in combination, a tool guiding and work supporting fixture comprising a member having a plurality of webs extending radially of the tools to form guide slots for said tools, a ring surrounding said webs and having an inner surface to back-up the tools as they pass through said slots and prevent movement thereof radially outward, a work supporting arbor positioned centrally of said webs and having a work blank receiving portion projecting therefrom and laterally opposite said ring, and means securing said work supporting arbor rigidly to said member.

8. In a machine for broaching toothed elements having a plurality of tools spaced about a circle each adapted to operate on a work blank to form the space between two adjoining teeth during a single stroke of the tools, in combination, a tool guiding and work supporting xture comprising a member having an annular rim and a plurality of webs extending inwardly and longitudinally from said rim to form guide slots for said tools, a ring surrounding said longitudinally projecting webs and having an inner surfacel to back-up the tools as they pass through said slots and prevent movement thereof radially outward, a hub positioned centrally of said member having outwardly extending webs aligned with the webs of said member, means securing the webs of said hub to said annular rim, and a work supporting arbor secured centrally of said hub and having a work blank receiving portion projecting therefrom laterally opposite said ring.

9. In a machine for breaching toothed elements having a plurality of tools spaced about a circle each adapted to operate on a work blank to form the space between two adjoining teeth during a single stroke of the tools, in combination, a tool guiding and lwork supporting iixture comprising a member having an annular rim and a plurality of webs extending radially inwardly and longitudinally from one end of said rim to form guide slots for said tools, a ring surrounding said longitudinally projecting webs and having an inner surface cooperating with the inner surface of said annular rim to back-up the tools as they pass through'said slots and'prevent movement thereof radially outward, a hub positioned centrally of said member having outwardly extending webs alignedwith the Webs of said member, said webs on the hub having portions abutting the inner endsl of said first mentioned webs and other por-v tions overlying said rst mentioned Webs, means securing the outer ends of the Webs of said hub to 'saidannular rim, anda work supportingmeans secured centrally of said hub and having a work blank receiving portion projecting therefrom laterally opposite said'ring.

` 10. A breaching machine having, in combinal tion', a frame, a tool guiding and work supporting fixture mounted "on said frame intermediate the ends thereof and having a Work arbor, and tool guiding and backing surfaces laterally opposite a work blank receiving portion of the work arbor,'a broach supporting head slidably mounted on said frame to eneside of said fixture, means for reciprocating said head, a breaching tool holder carried on said head and'adapted to chuck the leading ends 4of aplurality of annularly arranged'and parallel breaching tools for a pull breaching operation, means for clamping the tail ends of said tools in angularly spaced relation, a movably mounted device for handling said tools from the tail ends thereof, and guide means for said tools mounted on said frame between said fixture and movably mounted device in position to engage the tools throughout'their stroke including an annular member having'radiallyV extending slots through which the breaching tools pass.

breaching tool holdercarried'on said head and adapted to chuck the leading ends of a plurality of annularly arranged and parallel breaching tools for a pull `breaching operation, means for clamping the tail ends of said tools in angularly spaced relation, and guide means for said tools mountedon said frame in position to engage the tools throughout their stroke.

12. A breaching machine having, in combination-,wa frame, a tool guiding and work supporting xture mounted on said frame intermediate the ends thereof and having a werk arbor and tool guiding and backing surfaces laterally opposite a work blank receiving portion of the Work arbor, a broach supporting head slidably mounted on said frame to one side of said fixture, means for reciprocating said head upon said frame, a breaching tool holder carried on said head and adapted to chuck theleading ends of a plurality of annularly arranged and parallel breaching tools for a breaching operation, means for clamping the trailing ends of said tools together in angularly spaced relation, and a movably mounted device for handling said tools from the clamped ends thereof.

13. A broachingrmachine having, in combination, an upright frame, a tool guiding and work supporting fixture mounted on said frame intermediate the ends thereof and havinga dewn- Wardly projecting. Work arbor and tool guiding and, backing surfaces laterally opposite the work blank receiving portion of the work arbor, a broachsupporting head slidably mounted 4on'said frame above said fixture, means forreciprocating said head'vertically upon said frame, a broaching tool holderfcarried on said 'head yand adapted te chuck' the upper ends of a plurality of an'- nularly arranged and parallel breaching tools for a pull-up breaching operation,A and `means for clamping the lower ends of said 'tools together in angularly spaced relation.

14. Abreachingmachine having, in combination, arrupright frame, a tool guiding and Work' supporting xturemounted 'on said frame intermediate the ends thereof and having aI down--y wardly projecting work arbor and tool guiding and backing surfaces laterally opposite the work blank receiving portion ef the Work arbor, a breach supporting head slidably mounted on said frame above-said fixture, means for reciprocating said head vertically upon said frame, a breaching tool holder carried on said head and adapted to chuck the upper ends of a plurality of annularly arranged and parallel breaching tools for a pullup breaching operation, -a vertically movable elevator device for handling said tools from the lower ends thereof; and vguide means for said tools mounted on said frame below said fixture inY position to engage the tools throughoutther stroke and having radially extending slots through which the breaching tools pass:

i5.` AY breaching machine having, in combination,a frame, a tool guiding and work supporting fixture mounted on 'said frame intermediatethe ends thereof and having a work arbor and tool guiding and Abacking surfaces laterally opposite the Workv blank receiving portion ofthe work arbor, abroach supporting head slidably mounted on said frame onY one sideV of said'xture, means for reciprocating said head vertically upon said frame through' breaching and return strokes, a breaching tool' holder carried on said head andl adapted to chuck' the leading ends of a pluralityof annularly arranged and parallel broachin'g'tools for a pull 'breaching operation, and means having a central opening through which the finished work blank may pass for clamping the tail ends of said tools together in angularly spaced relation;

16.' Al breaching machine having, in combinatien, a frame, a broach supporting head slidably mounted `en said frame adjacent one end thereof,' a broach handling device slidably mounted on the other end of said frame, means on said head for simultaneously chucking a plurality of vbreaching tools spaced angularly in position to cut the teeth of an externally toothed element, means for reciprocating said head,v a clamping device for securing the tail ends of said tools together in angularly spaced relation including a member hav'- ing a central openingy sufficiently large to permit a finished element to. pass therethrough, and

means for supporting aL workblank in positionto be operated upon by said tools.

17. A vbreaching machine having, in combination7 a frame, a broach supporting head slidably mounted on said frame adjacent one end thereof, a broach handling device slidably mounted on the other end of said frame, means on said head for simultaneously lchucking a plurality of breaching tools spaced angularly in position to cut the teeth of an'externally toothed element, means for reciprecating'said head, a clamping device for securing the tail'endsof saidtools together in angularly spaced relation including amemlberhaving a central opening'siui'ciently large to permit a iinished element to pass therethrough, means for supporting a work blank in position to be operated upon by said tools, and means ier moving laterally a finished element after passing through said central opening.

i8. A breaching machine having, in combination, means for simultaneously chucking a plurality of bar-like breaching tools spaced angularly in position to cut a toothed element, means for supporting a work blank and guiding the tools including a backing ring surrounding the work blank, a plurality of breaching tools spaced angularly with cutting edges on their inner surfaces in position to cut a toothed element and having curved surfaces en their outer edges conforming te the radius of said backing ring, a clamping device for securing the tail ends of said breaching tools together as a unit in angularly spaced relation, said clamping means having a central opening through which a finished; work blank may pass, and means for causing relative feeding movement between the tools and work blank.

19. A breaching machine having, in combination, a frame, a breach supporting head slidably mounted thereon, means en said head for simultaneously chucking a plurality of bar-like breaching tools spaced angularly in position to cut a toothed element, means for supporting a Work blank and guiding the tools including a backing ring laterally opposite the work blank and a plurality oi breaching tools spaced angularly with cutting edges on their inner surfaces in position to cut a toothed element and having curved surfaces on their outer edges conforming to the radius of said backing ring.

20. A breaching machine having, in combination, a frame, a breach supporting head slidably mounted on said frame, means en said head for detachably and simultaneously vchucking the leading ends of a plurality of breaching tools spaced -annularly and in substantially parallel relation to cut the teeth of a toothed element, means for supporting said tools in such annularly spaced and substantially parallel relation when `detached and separated from said chucking means to enable a work blank to be inserted into the space between the chucking means and the detached ends oi the tools, means for supporting the Work blank in operative relation to the tools, and means for moving said head when the tools are engaged :by the chucking means .to perform a pull breaching operation on the work blank.

21. A breaching machine having, in combination, a frame, a breach supporting head slidably mounted on said frame, means on said head for simultaneously chucking the leading ends of a plurality of bar-like breaching tools arranged in annularly spaced and substantially parallel relation te cut the teeth of a toothed element, means for reciprocating said head, means for supporting said breaching `tools in such annularly spaced and substantially parallel relation when released and separated from said chucking means to permit the insertion of a werk blank intermediate the leading ends of the tools and the chucking means, a work element support on said frame in a position to receive the work element when the tools are separated from the chucking means, and means adjacent the work element support forming guides for the sides and back of each tool during the cutting operation.

22. A breaching machine having, in combinalil) tion, an upright frame, a horizontal work plate secured to said frame intermediate the ends thereof, la breach supporting head slidably mounted on said frame above said work plate, means on said head for simultaneously chucking the leadingr ends oi a plurality of bar-like breaching tools arranged in annularly spaced and substantially parallel relation to cut the teeth of a toothed element, said means being releasable to permit separation of .the breaching tools therefrom, means including a breach handling elevator device vertically movable with respect to said frame below the work plate for separating the tools from the chu-cking means and withdrawing them below the work plate to permit a werk blank to be positioned between .the work plate and the breaches, and means for actuating said breach supporting head through a pull breaching operation with the breaches engaged by the chucking means.

23. A breaching machine having, in combination, an upright frame, a horizontal work plate secured te said frame intermediate the ends thereof, a breach supporting head slidably mounted on said frame :above said work plate, means on said head for simultaneously chucking a plurality of bar-like breaching tools arranged in annularly spaced and substantial-ly parallel relation in position to cut the teeth of a toothed element, said means being releasable to permit separation of the breaching tools therefrom, means including a breach handling elevator device vertically movable with respect to said frame below the work plate for separating 'the tools from the chucking means and withdrawing them be =low the, werk plate to permit a werk Ablank to be positioned centrally of the branch annulus, means en said work plate for supporting the work Iblank and for backing up the tools during a breaching operation, and means for actuating said breach supporting head through a pull breaching operati-on with the breaches engaged by lthe chucking means.

24. A breaching machine having, in combinatien, a frame, a iirst breach supporting head slidably mounted on said frame, means en said head for simultaneously chucking a plurality of bar-like breaching tools arranged in annularly spaced and substantially parallel relation in pesition to cut teeth on a toothed element including lmeans for releasing said tools, a second breach supporting head slidably mounted on said frame including means for holding said breaching tools in annularly spaced and substantially parallel relation when separated from said chucking means, a work blank support `on said frame positioned to mount a work blank between the leading ends of said tools and said first head when Ithe tools are separated from the chucking means, means for actuating said second breach supporting head to move the breaches into engagement with said chucking means for a breaching operation and lto withdraw the breaches from the chucking means upon completion of a breaching operation, and means for actuating said first mentioned supporting head in one direction through a breaching operation and te separate the trailing ends of the breaches from said second supporting head whereupon the nished work blank may pass out from between the trailing ends of the breaching tools.

FRANCIS J. LAPOINTE.