US2346996A - Commutator riveting machine - Google Patents

Description

April 1s, 1944. L, E OLE 2,346,996

COMMUT-ATOR RIVETING MACHINE nF1144 March 24, 1941 5 sheets-Sheet 1 fi., ,4 TTole/VE 11s (l, 2o l April 1s, 1944.

L. E. Pool.; I 2,346,996

GOMMUTATOR RIVETING MACHINE Filed March 24, 1941 .5 sheets-Sheet 2 /N VENTO/e April 18, .1944. L. E. POOLE COMMUTATOR RIVETING MACHINE 5 Sheets-Sheet I5v Filed March 24, 1941 April 8944. L, E, PQQLE' 2,346,996

COMMUTATOR RIVETI'NG MACHINE Filed March 24, 154;

5 Sheets-Sheet 4 BY. lm-e; /cvv'eb A IIORNE Ys April 18, 1944. 1 E. POOLE COMMUTATOR RIVETING MACHINE filed March 24, 1941 5 Sheets-*Sheet 5` Paienief Apr. 1e, 1944 COMlVIUTA'IOR RIVETING MACHINE Lora E. Poole, Anderson, Ind., assignor `to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application March 24, 1941, Serial No. 384,895

7 Claims.

This invention relates to the manufacture of commutators for dynamo electric machines and more particularly to commutators comprising an .annulus of metal segments separated by pieces -of sheet insulation, the segment and insulating kpieces having dovetail Shanks which are permanently clamped between metal V-rings held together by a hollow core of tubular rivet, the end edges of which are deformed or swaged against the outer edges of the V ring. Such a commutator is shown in Conklin 1,503,484 issued August 5, 1924.

A machine for assembling a commutator of the type disclosed in the Conklin patent is described and claimed in R. W. Baker et al., 1,979,434, granted November 6, 1934. This machine stakes the ends of the tubular rivets sufficiently to retain the commutator parts in assembled relation, but the final riveting operation is not performed by the machine of the Baker patent. The final riveting operation is performed by a separate riveting press which is sufficiently powerful to force the V-rings iirmly against the dovetail tangs of the metal segments and insulation pieces, while the ends of the tubular rivet are being upset. It is an cbj-ect of the present invention to provide a riveting press equipped with means for applying pressure to the outer or peripheral surfaces of the metal segments, thereby forcing them radially toward the axis of the commutator while at the same time preventing the skewing or twisting of the segments out of planes containing the axis of the commutator. To accomplish this object I provid-e a movable conveyor, preferably a rotary plate,v for carrying a plurality of workholders each adapted to receive a commutator as assembled by the machine of the Baker patent. Each workholder is equipped with means for locating the segments in parallelism with the commutator axis and with radially movable clamping bars for forcing the segments radially toward the commutator axis thereby causing their side surfaces to be brought firmly into engagement with each other. The conveyor brings each commutator clamped in a workholder into alignment with fluid pressure operated riveting devices which cause the V-rings to be forced against the segment tangs, while the ends of the the riveting operation the riveting devices are automatically retracted and the conveyor resumes its movement to'bring another unriveted commutator assembly into position for operation upon it by the riveting device.

A further ob-ject of the invention is to provide for a convenient manual control of each workholder to cause its aligning and clamping devices to engage the commutator after the operator places an unriveted commutator within a Workholder.

Another object is to provide for automatically releasing the aligning and clamping devices of each workholder as it progresses from the riveting station to the unloading station.

A further object is to provide for automatically ejecting a riveted commutator at the unloading station.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a plan view of a machine embodying the present invention.

Fig. 2 is a fragmentary'sectional view on the line 2 2 of Fig. 1.

Fig. 3 is a side view taken in the direction of the arrow 3 of Fig. 1.

Fig. 4 is an end view taken in the direction of the arrow 4 of Fig; 1.

Fig. 5 isa sectional view on line 5 5 of Fig. 1.

Fig. 6 is a side elevation taken in the direction of the arrow 6 of Fig. 1.

Fig. 7 is an end view taken in the direction of the arrow 'I of Fig. 1.

Fig. 8 is a fragmentary side View taken in' the direction of the arrow 8 of Fig. 1 showing a portion of the workholder conveyor and the mechanism and causing the aligning for clamping devices of a workholder to be tightened upon the work.

Fig. 9 is a fragmentary View taken in the direction of the arrow 9 of Fig. 8. vThe part in section is taken on line gaf-9a of Fig. 8.

Fig. 10 is a fragmentary view taken in the direction of the arrow Il! of Fig. 8, and

y Fig. 11 is drawn to a larger scalethan Fig. 8 shows an end view of one of the workholders disassembled frcm the conveyor, the partin section at the bottom. of Fig. 11A isy taken on the line IIai la of Fig. 12. The vsectional part on the right side of Fig. 11 is taken on the line l lb--l lb of Fig. 12.

Fig. 12 is a sectional View on the line I2--l2 of Fig. 11.

Fig. 13, which is drawn to a larger scale than Figs. 11 and 12, shows a fragment of the sectional View shown in Fig. of a workholder, a commutator and one of the riveting devices in section and the other in elevation. t will be noted that Fig. 13 shows the workholder in much greater detail than in Fig. 5 in which several details have been omitted owing to the smallness of the scale of Fig. 5.

Fig. 14 is a view on a larger scale than the other views showing the function of the blades Si] and bars 82 in retaining the commutator.

Referring to Figs. 1 to 7, which are drawn to the same scale, a base 29 (Figs. 3, 4, 5, 6) supports a frame 2! providing annular mounting bosses 22 and 23 (Fig. 5) for supporting hydraulic cylinders 24 and 25 respectively for operating the riveting devices to be described. Frame 2! supports brackets 23 and 21 providing bearings 23 and 29, respectively, within which a shaft 39 is journalled. Shaft 30 is connected by keys 3| with a hub 32 attached by screws 33 to a conveyor disc 34 and to a Geneva driven gear 35. Gear` 35 (Figs. 4 and 7) is provided with slots 36, each for receiving a roller 31 pivotally mounted on a driving arm 38 fixed to a shaft 39 (Figs. 3, 4, 6 and 7). As shown in Fig. 4 and Geneva gear operating arm 38 has a hub 38a, the contour of which is defined by a concave surface a-c and a convex surface a-b-c. This portion lies in the plane of the driven gear member 35. The concave surface a--c provides clearance for the driven member 35 while it is being vturned by the roller 31. The convex surface a-b-c is received by similarly shaped concave surfaces of the member 35 in order to lock that member in fixed position while it is not being turned by the roller 31. Shaft 39 carries sprocket 45 connected by a chain 4I with sprocket ft2 attached to shaft 43 journalled in bearings provided by a housing 44 mounted on bracket 21. Housing 44 contains a speed reducing gearing including a worm wheel 45 fixed to shaft 43 and a worm 41 fixed to the armature shaft 43 of an electric motor 49 supported by a. bracket 49a. Motor 49 drives shaft 39 clockwise as viewed in Fig. 4 in order to move the conveyor disc 34 counterclockwise in Fig. 4. As Viewed in Fig. 7 shaft 39 rotates counterclookwise in order to drive disc 34 clockwise. Referring to Figs. 4 and 7 it will be seen that the roller 31 is just entering a slot 36 so that movement of the conveyor disc is about to start. At this instant the high land 5I (Fig. 7) of a cam 59 fixed to shaft 39 has just been moved away from a roller 52 on the upper end of a rod 53 guided by a bracket 54 attached to bracket 21. Upward movement of yrod 53 is effected through upward movement of a valve stem 55 which controls a fluid control valve inta housing 55 attached to frame 2i. This housing 56 contains a spring which resists downward movement of stem 55 and causes upward movement thereof and of the rod 53 when the high land 5l releases the roller 52. When the valve stein 55 is in the position shown in Fig. 7, the valve within the housing 56 is conditioned so that the riveting devices, to be described later, will be retracted from the work so that the conveyor disc 34 is free to turn.

The conveyor disc 34 carries eight workholders, one of which will now be described with reference to 6 to 13. Eachworkholder assembly 69 is received by a counterbored opening 6I pro vided by conveyor disc 34. The workholder assembly comprises a frame block 52 including a ilange 63 provided with radially extending slots G4. Block 2 is provided with radially extending rectangular grooves 65 spaced by triangular shaped bosses 65 having arcuate peripheries 61. The peripheries G1 of all of the bosses 66 collectively provide a bearing fora ring 68 having a gear segment 69 for engaging a gear segment 19 on a lever arm 1l provided with a stud 12 and iixed to a shaft 13 (Fig. 9) journalled in a bearing bracket 14 and restricted in endwise movement by a washer 15 and a screw 13 threaded into the shaft 13. Each bracket 14 has a flange 14a by which screws 14D (Fig. 7) secure the bracket to the conveyor disc 34. Manually controlled means to be described causes the arm 1I to be moved from the full line position at the right hand position of Fig. 8 to the position 'lla in dot-dash lines. This causes the ring 68 to be rotated clockwise in Figs. 8 and 1l. This causes hard metal rollers 30 carried by the ring 53 to be wedged against camming surfaces 8i provided by radially sliding bars 82 fitted into grooves 65 thereby forcing said bars 82 inwardly so that they engage the metal commutator segments l36a as shown particularly in Fig. 13. When the ring 68 is moved counterclockwise the bars -82 are retracted from the work by the action of in parallel relation to the axis of the block 62.

The part of the blade located within the hole 92 carries two cross pins 93 which serve to limit inward movement of the blade 9U radially with respect to the block 62. Each bar 82 provides a radially extending bore 94 which cuts across the hole 92 and intercepts the slot 9i. Each bore 34 receives a spring 95 operating to urge the blade 9U outwardly of the bar 82. The workholder illustrated is intended for the reception of a commutator having 28 metal segments I3Sa (Fig. 14) and spaced by insulating segments |361). The metal segments i36a are wider radially than the insulating segments |361); therefore there will be shallow grooves provided by the setback insulating segments between the metal segments. A commutator having 28 metal segments would have 28 shallow grooves. The workholder shown in Figs. 11 and 14 provides seven blades 99; therefore every fourth commutator grove will receive a blade 93 as shown in Fig. 14. In other words, the converging faces of the wedge-shaped end of each blade Si) will be in engagement, respectively, with the adjacent .other --groups of metal segments through the inf sulating segments |3Bb. The machine attendant places a commutator partially within the opening (Fig. 1l) and rotates the commutator so that the seven blades 90 will register with seven grooves at the outer periphery of the commutator. Then the attendant pushes the commutator entirely into the opening |00. As he does this, the Seven blades 00 cause vthe segments I3Sa adjacent those blades to be located in planes containing the axis of the commutator. Since the segments of the commutator are only loosely assembled with the V-rings and tubular rivet, those metal segments placed in planes containing the axis of the commutator by engagement with the blades 90 cause the other metal segments to be likewise disposed due topressure exerted upon them by the segments contacting the blades 00, said pressure being transmitted through the intermediate insulating segments. Then by means to be described, the at` .tendant causes the lever 1| to be moved into the position 1Ia (Fig. 8) to cause the bars B2 and consequently the blades 90 to move inwardly to rmly wedge the commutator segments toward each other while they are being held in planes which. include the commutator axis (see Fig. 14).

The bars 82 and ring E3 are retained by an annular plate 96 attached to the block G2 by screws 01. Each block 62 is retained within the disc 34by the attachment thereto of the ange 14a of bracket 14 which supports the shaft 13 of the gear segment arm 1 i. The bracket flange 14a overlies theblock E2 as well as disc 34 as shown in Figs. 7 and 9 and a portion of the bracket 14 enters a notch 99 in block 62 as shown in Figs. 9 and l1.

The manually controlled mechanism for moving the arm 1I will now be described. Referring to Figs. 4, 8, 9 and 10, to the base 20 is attached a bracket IiII carrying a, pivot pin |02 supporting fluid pressure cylinder |03, the now of fluid to which is controlled by a foot operated valve not shown. The piston rod |04 is connected by clevis |05 and pin |06 with a bell crank lever |01 having a clevis |010. at the end of one of its arms and being pivoted on a stub shaft |08 carried by bracket |09 fixed to frame 2| Lever |01 is connetced by link |10 and pin ||I with ears I2 depending from a block |3 slidably guided by rods ||4 extending from tubular parts ||5 integral with bracket |09. The block ||3 carries a screw |2317l about which is pivoted a pawl IIO having a lug |I1 for engaging the half round stud 12 of lever arm 1| attached to shaft 13. When, due to actuation of the foot operated valve just referred to, air is admitted to the top of cylinder |03, piston rod |04 moves downwardly and block II3 moves to the'right and upwardly to cause the lug I|1 of lever II6 to engage stud 12' to move the arm 1| from the full line position to the dot dash line position 1la in the righthand part of Fig. 8. This causes the ring 68 to be rotated clockwise in Fig. S. Ring 08 in turn causes pins 80 (Fig. 1l) to be moved clockwise along the outer inclined faces 3| of the bars 82. The pins wedge forwardly the bars 82 thus causing the metal segments of the commutator to be engaged with .pressure by the bars 82 and the insulating and metal segments by the aligning and locating blades Sil.

The clamped commutator is carried counterclockwise in Figs. 4 and 8 by the conveyor disc 34 to the position in alignment with the riveting deviceswhich will now be described.` With ref- 75 erence to Figs. 5 'and 13the cylinders 24 andv 25 are provided respectively with'piston rods |24 and |25 attached' to sliding rods |26 and |21, respectively, supported in bearings |28 and |23, respectively, provided Y:by frame 2|. Movement ofthe bars |26 `and |21 away from the disc 34 islimited by U-washers |30 and |3I, respectively.

These washers may be removed when it is desired to remove the cylinders 24 and 25, and their associated rodsv |26 and |21.A As the riveting devices'carried by the rods |26 and I 21 are alike only one of them will be described in detail. For example, the rod I 21 (Fig.. 13) supports a centrally disposed riveting punch |32 for engaging and riveting over the adjacent edge of a tubular rivet v|33 against V-ring I 34 forming a part of the commutator assemblyv |35 which includes an annulus |35 of metal segments I36a and insulating segments |3611` (Fig. 14) Insulating V washersY |31 are locatedbetween the V rings |34 and the annulus |36. While the pressure is being applied by riveting punches |32 to the ends of the tubular sleeve or rivet |33, the two V rings |34 are resiliently forced against the dovetail tangs of the` segments |36.' This is accomplished by applying pressure through the medium of annular rings |40 integral with circular plates |4| which are slidable on headed studs |42. Pressure is transmitted from the rods |26` and |21 to the plates IilI by a plurality of springs |43 surrounding the studs |42 and housed in pockets |44 provided by rods |26 and |21. After a workholder has first been located in alignment. with the aligned riveting devices carried by the rods |26 and |21, the conveyor disc 34 remains stationary for a time. During this time, the roller 52v (Fig.

v'7) is engaged by the high land 5| of cam 50 in order to cause the valve housedwithin the valve case to open a passage-connecting a source of fluid pressure with the outer ends of the cylindersl 24 and 25 thereby causing the rods |23 and |21 to approach the work to effect the riveting` operation which has been described. After the riveting operation is performed and before the conveyor disc starts to move again, the high land 5| of cam 50 moves away from the roller 52 to permit the valve in case 5@ to disconnect the outer ends of the cylinders 24and 25 from the source of :fluid pressure and to connect the inner ends with s-aid source while venting the outer ends. The riveting devices are thus retracted from the workv and the conveyor is again 4free to move.'

As a workholder containing a riveted commutator is moved away from the riveting station toward the next station, that is, toward the ejecting station a cam |50 attached to frame 2| engages the stud 12 and causes the lever 1I to be moved fromthe dot dash line position 1| to the full line position 1| as shown in the left hand position of Fig. 8. This causes gear segment 10 to rotate clockwise (Fig. 8) and gear 69 to rotate counterclockwise. Pins (Fig. 11) carried by gear (5S rotate about the axis of the commutator to the position shown in Fig. 11 thereby permitting springsS (Fig. 12) pushing on pins 34 carried by the bars 82 to retract said bars 82 from engagement with the commutator so that it may be ejected when brought into the ejecting station. During the time in which a commutator is at the riveting station another commutator will be at the ejecting station and in alignment with a plunger |50 (Fig. 2) guided by a tubular part IGI integral with frame 2|. This tubular part |6| merges with an annular boss` |62 to which is secured a hydraulic cylinder |63 cooperating with a piston rod |64 attached to rod |60. At the time that pressure uid is admitted to the outer ends of cylinders 24 and 25 pressure fluid is also admitted to the outer end of cylinder |63 to cause the rod |60 to move toward the right in Fig. 2 in order to eject a commutator assembly |35 from the workholder. At the time pressure Iiuid is admitted to the inner ends of cylinder 24 and 25, it is admitted also to the inner end of cylinder |63 to cause the rod |60 to be retracted so that the conveyor disc 34 is free to rotate. When a workholder is at the ejecting station shown in Fig. 8 near the central part thereof, its associated clamp operating arm 1| is in the full line position. As this arm moves from the position shown near the middle of Fig. 8 to the position shown at the right position of Fig.. 8 the stud 12 thereof engages a beveled camming surface ||1a of the lug ||1, thereby causing the lever ||6 to be cammed downwardly in Fig. 10 against the action of a plunger |10 urged upwardly by a spring |1|. After the stud 12 passes to the right of lug ||1, and lug ||1 will snap lupwardly just to the left of the stud 12, thereby locating said lug in position for engagementV with the stud 12 when the block ||3 is moved upwardly for the purpose of causing the clamp bars of @the workholder, then at the loading station, to engage the commutator assembly. Pivotal motion of lever H6 is limited by a screw |12 engaging the ends of a slot |13 provided in said lever.

The machine provides for holding the segments of an annulus of the commutator in planes including the commutator axis while wedging them tightly into closely tting relation. This operation is performed by the foot controlled pressure cylinder |03 operating through the mechanism which turns the lever 1| counterclockwise (right hand portion of Fig. 8) in order to actuate the commutator clamping bars 82. All other operations of the machine are performed automatically. The motor 49 operates continuously, so long as its control switch (not shown) is closed, to rotate the conveyor disc 34 intermittently. While Geneva gear drive pin 31 is out of engagement with slots 33 of the Geneva driven gear 35, the disc 34 is at rest. During this rest period the commutator in alignment with cylinder 24 (Fig. 4) is riveted, the commutator in alignment with the cylinder I 63 is ejected, and the empty workholder above the slide ||3 (Fig. 4) is led with an unriveted commutator by the operator of the machine. During the rest period the high point of cam 50 engages roller 52 to cause a downward movement of valve rod 55 to cause valve 56 to admit pressure fluid to the outer ends of cylinders 24 and 25 to cause the rods' |25 and |21 to move to the positions shown in Fig` 13 in order to upset the ends of the rivet |33. Before the rest period ends, the high point 5| of cam 5|] moves away from roller 52 to allow a spring (not shown) provided by valve 56 to move valve rod 55 upwardly to condition the valve for admitting pressure fluid to the inner ends of cylinders 24 and 25 so that the rods |26 and |21 will be retracted, thereby retracting the punches |32 and the rings |40 from the riveted commutator and from the carrier disc 34.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the vscope of the claims which follow.

What is claimed is as follows:

l. A machine for riveting the central tubular sleeve or rivet of a commutator assembly including an annulus of metal and insulating segments havin-g dove-tail tangs and including V- rings and a central rivet, said machine comprising a conveyor for supporting a plurality of Workholders each adapted to receive a commutator assembly and having means for exerting pressure radially upon the annulus, a manually controlled mechanism interconnected with said means when the workholder is at the loading station and operable to cause said means to become eiective, apparatus at the riveting station for riveting the ends of the central rivet against thev V-rings. a stationary cam engaged by said means after passing the riveting station for rendering said means non-effective, and a device for ejecting the .riveted commutator when located at the delivery station.

2. A machine according to claim 1 having fluid pressure operated riveting apparatus and a uid pressure operated ejector and having power driven means for effecting intermittent movement of the conveyor and for controlling the advancement of the riveting apparatus and the ejector toward the work and then the retraction thereof while the conveyor is at rest.

3. A machine according to claim 1, in which each work holder is equipped with a rotary cam ring having a gear segment, with a lever having a gear segment engaging the gear segment of the cam ring and with sliding bars movable radially against the commutator annulus, the ring and the bars having cooperating camming provisions whereby rotation of the cam ring by the lever causes the bars to move against the annulus, and in which the lever is rotated to annulus clamping position by said manually controlled apparatus with which the lever is operatively connected at the loading station, and in which the lever is actuated by the stationary cam to annulus releasing position.

4. A machine according to claim l in which the Imeans for exerting radial pressure upon the annulus is equipped with devices for causing the segments of the annulus to be located parallel with the commutator axis.

5.` A machine` for riveting the central tubular sleeve or rivet of a commutator assembly including an annulus of metal and insulating segments having dove-tail tangs and including V- rings and a central rivet, the outermost edges of the insulating segments being located nearer 'to the rivet than the outermost edges of the metal segments whereby the outer corner edges of the metal segments vare exposed, said machine comprising a workholder providing for the reception of a loosely assembled commutator by axial movement thereof, means provided by the work holder and having surfaces extending parallel to the commutator axis for engaging the exposed corner edges of certain segments as the commutator is inserted within the Work holder in order to cause the segments of the commutator to be located in planes rcontaining the axis of the commutator, means provided by the work liold'erior exerting radial pressure upon the metal segments while they are thus located; and means operable while radial pressure is being exerted upon the metal segments for exerting axial pressure upon the V-rings and for riveting the central rivet -against the V-rin'gs.

'6. A machine for riveting the central tubular sleeve or rivet of a commutator assembly including an annulus of metal and insulating segments having dove-tail tangs and including V- rings and a central rivet, the outermost edges of the insulating segments being located nearer to the rivet than the outermost edges of the metal segments whereby shallow grooves are provided between the metal segments, said machine comprising a work-holder having a cylindrical recess for receiving a loosely assembled commutator'inserted axially into the recess, blades located in planes containing the axis of the commutator and each movable edgewise radially of the commutator and providing an edge portion extending a short distance within the recess, said edge portion including surfaces engageable with the corner edges of the metal segments adjacent the groove which receives the blade whereby the insertion of the commutator within the recess causes certain grooves to receive the edges of the blades in consequence whereof the segments are caused to be located in planes containing the axis of the commutator, clamping bars for engaging the outer surfaces of the metal segments and means operable rst to cause the blades and then the bars to be forced radially against the metal segments; and means operable while radial pressure is being exerted upon the metal segments for exerting axial pressure upon the V-rings and for riveting the central rivet against the V-rings.

7. A machine according to claim 6 in which the locating blades are supported by the clamping bars and in which springs are provided for yieldingly transmitting movement to the blades from the bars.

LORA E. POOLE.

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