US2104993A - Apparatus for forming sheet metal elbows - Google Patents

Description

Jan. 11, 1938.v c. J. HOLUB APPARATUS FOR FORMING SHEET METAL ELBOWS Filed 0G13. 17, 1936 6 SheeLS-Sheel. l

Jan. 11; 1938.

J. HOLUB APIARATUS FOR FORMIG SHEET METAL ELBOWS Filed Oct. 1'7, 1936 6 Sheets-Sheet 2 Jan. 11,1938. Cl 1 HOLUB APPARATUS FOR FORMING SHEET METAL ELBOWS Filed Oct. 17, 1 936 6 Sheets-Sheet 5 INVENTOR Jan. l1, 1938.

c. J. HOLUB APPARATUS vFOR FORMING SHEET METAL ELBOWS 6 Sheets-Sheet 4 Filed Oct. 17, 1936 INVENTOR 6 Sheets-Sheet 5 Jan. 1l, 1938. c. J. HoLUB APPARATUS FOR FORMINGV SHEET METALy ELBOWS Filed oct. 17, 1936 N In Jan. 11, 1938. c. J. HoLUB Y lAPPARATUS FOR FORMING SHEET METL EILBOWS Fle'd Oct. 1'7, 1936 l 6 Sheets-Sheet 6 INVENTOR Patented Jan. 11, 1938 UNITED STATES PA'ENT @FFQE APPARATUS FOR FORD/.UNG SHEET METAL ELBO Application October 17, 1936, Serial N0. 106,206

3 Claims.

This invention relates to a method and apparatus for making sheet metal elbows and, in particular, stove pipe elbows.

Devices of this general character have been known before, and examples thereof are described and claimed in my prior Patents Nos. 1,517,678 and 1,553,817. The object of this invention is to improve upon the constructions disclosed in Ysaid patents, particularly in respect of certain automatic operations such as the clamping of the blank or workpiece in position to be operated upon, and the means applying a brake to arrest operation of the device at intervals.

The improvements in details of construction comprising the present invention are illustrated in the accompanying drawings, and will be completely described hereinafter.

In the drawings,

Fig. 1 is a side elevation;

Fig. 2 is an end view looking from the left in Fig. 1;

Fig. 2A is an elevation of a detail;

Fig. 3 is a view partly in elevation and partly in section along the line III-III of Fig. 1;

Fig. 4 is a central longitudinal section taken through the axis of a mandrel on which the workpiece is disposed for corrugating and bending operations;

Fig. 5 is a sectional View through the mandrel taken along the line V--V of Fig. 4;

Fig. G'is a side elevation of the parts shown in Fig. 5, looking from the' left in the latter;

Fig. 7 is a partial plan view of a clamping carriage movable on the mandrel which is also shown in Figs. 5 and 6;

Fig. 8 is a view partly in elevation and partly in section along the line VIII-VIII of Fig. 5;

Fig. 9 is a partial sectional view along the line VIII-VIII of Fig. 5 but looking in the direction opposite that of the arrows;

Fig. 10 is a partial section along the line X-X of Fig. 5;

Fig. 1l is a View partly in elevation and partly in section along the line XI-XI of Fig. 3;

Fig. 12 is a view partly in plan and partly in section along the line XII-XII of Fig. 3;

Fig. 13 is a partial sectional View along the line XII-XEII of Fig. l2;

Fig. 14 is an end elevation of a bending ring or head adapted to be placed over the end of the blank to receive the bending force applied thereto; and

Fig. 15 is a plan View of a detail.

Referring now in detail to the drawings, the

(Cl. 15S-69.5)

apparatus comprises essentially a supporting bed or frame I and a mandrel 2 carried thereby on a frame plate 3, the mandrel projecting toward and through an opposed frame plate 4. A carriage 5 slidable on the mandrel 2 and a bending ring 6 cooperate to support a tubular blank 'I therebetween. The carriage 5 is fed forward along the mandrel 2 in a step by step fashion by a ratchet bar 8. segmental corrugating dies 9 having overlapping ends intermittently form circumferential grooves or corrugations in the blank, and the forward end of the latter is bent upwardly by engagement of bending arms IIJ with the bending ring S. All the parts are operated by a common drive II including a clutch I2 and brake I3. Each of these parts will be described in detail under appropriate sub-titles.

The bed and frame The bed I may conveniently be composed of a suitable casting mounted on supporting legs I4. 'Ihe frame plate 3 is mounted vertically thereon approximately midway between the ends thereof. The plate l is similarly mounted adjacent one end of the bed. Spacer rods 3a. extend between the plates 3 and 4 adjacent their upper ends. A driveshaft I5 is journaled in a bearing I6 mounted at the end of the bed opposite that on which the plate 4 is mounted, and a bearing I'I formed on the plate 3. A pulley I8 is mounted on the shaft I5 whereby the latter may be driven from any convenient power source. A pinion I9 secured to the shaft I5 meshes with a gear 2U which runs free on a shaft 2| journaled centrally and longitudinally of the bed I in bearings 22. A countershaft 23 is journaled along one side of the bed I in bearings 2t. The shaft 23 is adapted to be driven by the shaft 2I through a gear and pinion drive, the gear thereof being shown at 25.

The mandrel As best shown in Fig. 4, the mandrel 2 has reduced ends, one of which is firmly seated in a ring 26 pivoted to the plate 3 at 2l. A set screw 2 8 permits the ring 2l to be so tilted as to position the other end of the mandrel accurately. The other end of the mandrel extends through an opening 29 in the plate li, the reduced end thereof being rmly secured to an anvil ring 30, the function of which will appear later. The carriage 5 includes a member 3i in the form of an annular ring or block slidable on the mandrel 2, being guided therealong by a ratchet bar 8 reciprocable in a suitable slot extending longitudinally of the Y mandrel, the bar 8 serving as a feather key for the block or carriage 3l. A constant retracting force is exerted on the carriage 3l by a counterweight 33 connected thereto by a cable 34 trained around a pulley 35. The pulley is mounted on a bracket 3S secured to the plate 3|.

Semi-circular clamping jaws 31 are pivoteld to the carriage 3l on a pin 38. These jaws have shoulders 39 which enter an annular groove formed in the carriage, and are normally urged apart by a compression spring 4D, the ends of which are seated in sockets 4! formed in the abutting ends of the jaws. The jaws 31 have depending lugs 42 through which a cam shaft 43 extends. A cam 44 adjustable on the shaft 43 is adapted to cooperate with a xed cam 45 on the depending lug of one of the jaws whereby to cause the jaws to contract on rotation of the shaft. A lever 46 secured to the shaft 43 causes the latter to turn to contract or release the jaws.

A slide 41 is movable in guides 48 mounted on the side of the carriage 3l. The slide has a pin and slot connection 49 with the lever 46. The Ilever 45 is automatically operated on advance and retraction of the carriage 3l in a manner to be explained Yin greater, detail later.

As best shown in Fig. 4, an end of the tubular blank 1, which may be formed up into a cylinder from flat stock by any convenient means (not shown), is inserted in the annular space between the clamping jaws 3'5 and the reduced end of the carriage 3l indicated at 59. The bending ring 5 is slipped over the other end of the blank.

Worlcfeeding mechanism The ratchet bar 8 cooperates with a pawl 5! to advance the carriage 3i step by step from the solid line position, in which it is shown in Fig. 4, to the position shown in dot and dash lines. The bar 8 is reciprocated periodically by means to be described later through a distance equal to the pitch of the ratchet teeth thereon. The cooperation of the pawl 5I with the ratchet teeth causes the carriage 3lY to move forward with thebar The outer end of the blank 1 slides over the anvil ring 3G as the carriage 3l is advanced. The friction between the ring 3i! and the blank and between the carriage 3l andthe mandrel prevents the latter from moving back with the bar t. On backward movement of the latter, the pawl slides in a vertical slot in the carriage 3i and then engages the next tooth` The counterweight 33 exerts a restraining force on the carriagel to prevent it from being advanced more than one step at a time, and to ensure close engagement between the pawl and the ratchet teeth, to posi-v tion the work accurately for the corrugating operation.

VAlink 53 is pivotally mounted in Va bearing bracket 54carried on top of the carriage 3|. A lever 55 is pivoted to the link 53, and a detent 55 is pivoted to the lever 55. The detent 56 has a hook 51 normally engaging one end of the link 53. The detent 55 alsohas an inclined surface 58 adapted to cooperate with an abutment 5S on the plate 4 having a similar surface. A spring latch 60 is carried on the lever 55. At its lower end, this latch has a projection capable of engaging under a cooperating projection on the pawl 5l to hold the latter in elevated position. With the parts in the position illustrated in Fig. e, however, a stud 5I is engaged by the latch Si) to cause the latter to release the pawl 5 l. When the carriage 3| has been movedforward tothe position shown in dot and dash lines, engagement of the surface 58 of the detent 56 with the abutment 59 tilts the lever 55 and places the latch 54 in position to hold the pawl 5l in elevated position. Y

Ynism for the step by step feed of the carriage 3 I.

A stud 62 is adapted to engage the slide 41 to contract the clamping jaws 31 when the carriage 3l is in the position shown in solid lines in Fig. 4. A stud 63 engages the slide 41 as the carriage 3l approaches the plate 4, to cause the clamping jaws to be released.

The mechanism for reciprocating the bar 8 includes a lever 32a connected to the end of the bar 8 by a link 32h. The lever 32a is pivoted at 32e on the plate 3. A cam follower 32d is also pivcted to the plate 3 at 320, and has a roller 32e at its lower end which traverses a groove in a barrel cam 32j carried on the shaft 2l. V.The link 32a has a projection 32g extending into a slot intermediate the ends of the follower 32d. Set screws 32h permit adjustment of the lever 32a relative to the follower 32d, whereby the desired movement of the ratchet bar 8 may be obtained.

The corrugatz'ng dies and dash lines in Fig. 4, the emerging end of the blank is bent upwardly to form the elbow. 'Ihe corrugations formed on the outside of the bend are slightly flattened or drawn out by the bending operation. Y i

The corrugating dies 9 are carried on slidesV 65 (Fig. 2A) which are movable ony theplate 4 radially of the circular opening 29 therein. The slides 35 are carried between segmental dovetail guides 55a formed on the outer side of the plate 4. Reciprocation ofthe slides 65 is elected by an annular rim 66. The ring 66 is rotatably carried by roller bearings 61 spaced about the plate 4, and is held against movement away from the plate by keepers 58. The keepers are secured'by screws to studs 69 mounted o'n the'plate '4. The ring 63 has hardened inserts 15 spaced therearound for engagement with the' roller bearings 61.

Cam slots 1l are formed at intervals around the ring 66. The outer sides of these slots are provided with hardened inserts 12. The slides E5 have roller bearings 13 thereon extending into the slots 1l. By reasonvof the construction described, counterclockwise rotation ofthe ring 65 will causeinward radial movement of the slides 65. Clockwise rotation of the ring 66 will cause outward radial movement of the slides. backand forth rotary movement of the ring 65 is provided by a crank arm 14 attached thereto, an adjustable link 15 and an eccentric 16 on the shaft 23. Y

The oscillation of the ring 66 and the reciprocation of the ratchet bar 8 are timed so that the corrugating diesrmove inwardly as .the ratchet bar is retracted, the corrugating dies being withdrawn when the ratchet bar is advanced to feed the Work.Y

Such l Vhub or block 90.

, Bending arms Bearing brackets 11 are carried at the working vend (the left end, as shown in Fig. 1) of the apparatus, and a shaft 18 is journaled therein. The ends of the shaft are flattened, as shown in Fig. 1. The bending arms |0 are pivoted at 19 on the flattened ends of the shaft. The holes in the "arms l0 through which the flattened ends of the shaft extend are relieved as at to permit the arms I0 to tilt on their pivots 19. Tension springs 8| extend between brackets mounted on the shaft 18 and.v brackets secured to the lower ends of the arms I0 for normally holding the arms in `the position illustrated in Fig. 2.

The .arms I0, on oscillation of the shaft 18, are adapted to engage lugs 82 formed on the bending ring 6. Such engagement causes the bending ring 6 to be deiiected upwardly as successive corrugations are formed in the blank 1, as indicated in dot and dash lines in Fig. 4.

Oscillation of the arms I0 is effected by a downwardly extending link 83 keyed tothe shaft 18. A tension spring 84 normally urges a set screw 85 at the lower end of the link 33 into engagement with a slide 86 axially movable in a guide 81 carried in the bed I. The slide 86 has a roller 81a projecting into a slot 88 formed in a barrel cam 89 on the shaft 2|. The oscillation of the arms I0 is thus co-ordinated with the reciprocation of the forming dies 9 and the feed bar 8.

Driving clutch and brake "I9 has a hub provided with driving faces 94 adapted to engage the slide 92, as indicated in Fig. 13, whereby clockwise rotation of the gear I9 drives the hub 90 on engagement of the slide 92 by one of the faces 94. Between the faces 94, the hub is provided with sloping surfaces 95. Since the slide 92 is normally forced toward the gear I9, the latter is normally in driving relation with the hub 90 through which the shaft 22 is driven.

A link 96 pivoted to the bed at 91 is so disposed that its free end may be moved into the space between the hub of the gear |9 and the The end of the link 96 is rounded as at 98 for cooperation with a similarly shaped surface 99 on the slide 92. If the link 96 occupies the position shown in Fig. 3, engagement of the surfaces 98 and 99, as the hub 90 rotates clockwise, will cause the slide 92 to be forced back vinto the recess 9 I, thereby freeing the hub from driving relation with the gear I9. Rotation of the latter continues thereafter without effect on the hub 90, until the free end of the link 96 is raised to permit the slide 92kto be moved back to the position indicated in Fig. 12. The next engagement between one of the driving faces 94 of the gear I9 and the slide 92 will cause the hub 90 to move again with the gear I9.

The link 96 is operated from a rock shaft |90 through a linkage including links 0| and |62. The link 96 tends to fall by its own weight to the position shown in Fig. 3 in which it causes disengagement of the hub 90 from the gear I9 in the manner already described. It may be raised to permit resumption of the driving relation by tilting the rock shaft |00. The rock shaft |00 is journaled in suitable bearings in the plates 3 and 4, and is provided with a cam block |03. A slide |04 is mounted in bearings |05 on the plates 3 and 4 for longitudinal movement. An operating handle |06 is secured to the slide |94. A cam block |01 is adjustably mounted on the slide |04 for cooperation with the cam block |93. Movement of the slide |04 to the right as viewed in Fig. 1, by cooperation of the cam blocks |93 and |01 causes counterclockwise rotation of the rock shaft |00, as viewed in Fig. 3, to raise the link 96. This movement also operates to release the brake 3 to permit free rotation of the hub 99 with the gear I9.

The brake I3 comprises a yoke |98 embracing the hub 90. The yoke is pivoted to the bed at |09 and is split at a diametrically opposite point to permit contraction thereof for gripping the hub 90 in the manner of a friction brake. The adjacent ends of the yoke, indicated at H0, are normally urged apart by a spring IiI seated in alined bores therethrough, and backed up by a screw plug II 2. The ends |I0, however, may be caused to approach each other by a camming lever H3. A stud I|4 is threaded into the lower end II of the yoke, is freely movable through a hole in the other end I0, and has a pivotal ccnnection l5 with the lower end of the camming lever H3. The lower end of the lever ||3 is bifurcated and extended to provide toes or camming surfaces ||6 engaging the upper end I I0 of the yoke |98. When the lever ||3 is rotated about the pivot ||5 clockwise, as viewed in Fig. l1, the ends H0 of the yoke will be forced together, and the body of the yoke will be sprung sufficiently to grip the hub 90. Reverse rotation of the lever ||3 will permit the spring to release the gripping engagement of the yoke |08 on the hub 90.

The lever IIS is operated simultaneously with the rock shaft |09 from the slide |84. A link I I1 is pivotally mounted on a bracket I I8 carried on the plate 3, and is pivotally connected to the end of the slide |04 which extends therethrough. The lower end of the link II'I is pivotally connected to the lever 3 by a link ||9. Movement of the slide I |14 to the right, as viewed in Fig. l, thus causes the brake to be released and the clutch engaged. Reverse movement of the slide causes disengagement of the clutch and engagement of the brake. The connection between the link |9 and the lever II 3 is provided by a pin and slot ||9a providing a small amount of lost motion. The amount of this lost motion may be adjusted by a set screw H911 carried on a lug depending from the link H9. By reason of this lost motion, the brake I3 is not applied until an instant after the clutch has been disengaged, the sequence being, first, the disengagement of the clutch and, after a very short interval, the application of the brake to stop the shaft 2|. The inherent resilience of the yoke |08 causes the brake to be released as soon as the lever |06 has been moved to the right to cause engagement of the clutch.

The operation of the device The carriage 3| occupies the position indicated in dot and dash lines in Fig. 4, at the commencement of an operating cycle. One end of the tubular blank 1 to be corrugated and bent is rst inserted in the annular' slot in the bending ring 6. While the blank may be formed in any con- Cil venient manner, bending rolls (not shownllmay -well be driven by a shaft |20 which is driven 'by ar belt and pulley drive from the shaft 2|, as shown in Fig. .2. The shaft |20 is journaled in bearings supported on angles |2| extending laterally from the bed The blank is inserted in the ring 6 so that the lap joint is adjacent an index mark |22 on the ring 6 (see Fig. 14). The other end of the blank may then be inserted between the clamping jaws 3l, which are opened as a result of the engagement of the stud 63 With the slide 47. The ring 5 carries a guide tongue |23 adapted to cooperate with a guide plate |24 having a slot |25 therein, one end of the slot being tapered, as at |26, to guide thev tongue- |23 entering thereinto. The plate |24 is mounted on top of the bearing bracket 11, as shown in Fig. 2. As the blank is pushed back over the mandrel 2, forcing the carriage 3| to the right, as viewed in Fig. 4, the tongue |23 is guided into the slot |25` to position the lap joint in the blank accurately on the inside of the bend to be formed therein.

When the carriage 3| is pushed back to the position illustrated in solid lines in Fig. 4, the stud 6| depresses the spring latch-'50 to release the pawl 5|. The stud |52 automatically causes the clamping jaws 3l to grip the end of the blank inserted between them and the end of the carriage 3|. Needless to say, the corrugating dies 9 should be retracted before it is attempted to insert the blank into the machine. As` the bending ring 6 approaches the arms |0 during the insertion of the blank into the machine, the lugs 82 engage divergent wings |27 extending outwardly from the arms. Advancement of the ring G causes the arms l to shift outwardly on their pivots 19 to permit the ring to pass therebetween. After the ring has passed t0 arms, the

vspringsl restore them to their normal position in which they cooperate with the lugs82 to bend the emerging blank.

The machine may be started by pushing the leverl to the right. This raises the lever 96 and permits the clutch kl2 to become engaged by advancement of the block 92? into such position as to be engaged by the driving surfaces M. 'Ihe brake |23 is simultaneously released as already explained. Intermittent operation of the -forming dies e, bending arms H3 and ratchet bar 8 proceeds in such co-ordinated fashion as successively toV form corrugations, bend the emerging end of the blank, compressing the corrugations on the inside of the bend and flattening or stretching those on the outside, and then notch the blank forward for repetition of these operations. When the required number of corrugations and bending impacts have been applied, the carriage 3| Vapp-roaches the plate l andthe detent 55 engages the abutment 59 to place the spring latch 607m the position to engage and hold up the pawl 5|. Engagement of the stud 63 by the slide M causes the latter to shift and release the clamping jaws 3l. The clutch may then be disengaged and the brake engaged by moving the handle |06 to the left, although failure to do so will not result in any damage, as'the feed means is rendered ineffective by the latch G. While op'- eration of the corrugating dies and the bending arms I0 continues until thehandle |06 is shifted, such operations will produce no effect in the ab arca-993 sence of a forward'feed'ofthe workpiece. The completed-elbow-may then be 'removed from 4the ,carriage-V 3| and, if desired, the flap joint riveted.

The bendingring 6-is removedfrom the blank and the Ymachine is-then ready for a repetition of the operating cycle just described. y Y

It will be apparent from the foregoing description that the invention is characterized by nu-V .mechanismforoperating the corrugating dies is simple, sturdy Vand rugged, and therefore not likely to cause difliculty in operation. The automatic clamping for Aengaging the end of the blank firstinserted in the machine is highly effectivefto. hold the blankin proper position during the fabricating operationfsince it engages the blank substantiallythroughout the circumference of the latter, and release it in ample time for quick removal. The brake operation is automatically `co-ordinated with the operation of the clutch tostop the. machine instantly when the clutch is disengaged, vpreventing continued operation by the momentum' of the rotating parts. Th adjusting means yincluded in the linkages operating.theratchetbarV and the corrugating dies permit the several steps of the operation to be timed accurately so there willbe no interference oroverlapping of operations.

Although I have illustrated and described but one preferred embodiment of the invention, it will be recognized that changes in the construction disclosed may be made withoutydeparting from the spirit of the inventionor'the scope of the vappended claims. Y Y

I claim: Y

1.-,Inan elbow forming machine, having a mandrel, :a carriage reciprocablef thereon adapted Vto receive one end of atubular yblank to be formed into anv elbow, a reciprocable ratchet bar and a pawl on said carriage cooperating therewith whereby to advance the carriage stepv by step; a lever tiltably mounted on said carriage, asecond lever .pivoted thereto, a detent pivoted on the second lever and releasablyV engageable with the rstVapawl-holding latch on said second lever andfmeans engaged by said detent on movement of the carriage to its extreme forward position,.to trip said detent and disengagev the i'lrst` menlcioned lever, -whereby to tilt both said Ylevers and thereby move said latch into pawl engaging position. 1

2. The-apparatus defined by claiml characterized by means for resetting said levers and releasingsaid latch on movement of the carriage to its extreme rearward position.

3. In anelbow corrugating and .bending machine having feed, Vcorrugating and bending means, a drivefor said means including a clutch, and a brake; a lever for operatingsaid clutch and alever for operatingV saidA brake, said levers beingpivoted onv axes at substantially right angles, and common means for actuating said levers comprising .a slide bar linked to one lever, a rock shaft parallel to said bar and having a crank thereon, means connecting the crank to the other lever and cooperating means on the slide bar and rock shaft to cause rotation of the latter on reciprocation of the former.

' CHARLES J. HOLUB.

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