Apparatus For Forming Sheet-metal Fin-strips For Heat-exchangers

Abstract

Apparatus for the automatic transformation of thin metal-stock into fin-strips of predetermined widths and lengths with groups of associated apertures and protuberances, for use in structuring core-units for heat exchangers required for controlling temperature conditions in various kinds of enclosures. The apparatus has juxtaposed elements, including one element for forming tube-embracing apertures and intermediate protuberances in the metal-stock and another element for recurring cut-off of predetermined lengths of finished fin-strips. All elements are arranged in series with antecedent elements for hemming the metal-stock, controlling the feeding and linear travel thereof, and with subsequent series of elements for advancing, discharging and stacking the finished fin-strips subject to later use in the structuring of desired types of heat-exchanger core-units. All of the elements are powered by a series of motors under the control of a manually and automatically operated switch mechanism.

Description

This invention relates to an apparatus for the facilitated transformation of thin metal-stock into preformed, planar finstrips adapted for use in stacked arrangement on batteries of tubes to produce core-units for various types of heat exchangers.

The current-day economy constantly demands production facilities to materially reduce manufacturing and use costs. Such obtains in the industry producing any type of heat exchanger involving stacks of thin-metal, parallel-disposed, apertured fin-strips embracing a battery of tubes, connecting opposed tanks, through which flows a fluid subject to temperature change.

The main objects of this invention are: to provide an improved apparatus for the high-speed production of apertured-protuberant fin-strips of predetermined width and length from thin-metal stock; to provide an apparatus of this kind wherein thin-gage, metal-stock is drawn from a coil through a succession of metal-forming elements effecting the hemming of one or both of the lateral perimeters of the metal-stock and the formation of a predetermined succession of associated apertures and protuberances, and severed into predetermined, uniform lengths of fin-strips finally transferred onto a platform; to provide an apparatus of this kind for maintaining a constant uniform linear travel of the metal-stock through the succession of fin-strip forming-elements to the point of discharging the finished fin-strips onto a conveyor for advancing them to a position to permit the ordered removal thereof for later use in structuring heat exchangers; to provide an apparatus of this kind capable of use with varying widths and thickness of metal-stock; to provide a series of accessories for manually and/or automatically controlling the operation of the apparatus; and to provide an apparatus of this kind of such practical design and arrangement of the elements as to make the production of fin-strips reasonably facile and economical and highly practical and gratifying in use.

In the adaptation shown in the accompanying drawings:

FIG. 1 is a perspective view of the entire apparatus clearly indicating the frame-supported sequence of the several essential elements thereof;

FIG. 2 is an end view of the fin-receiving conveyor;

FIG. 3 is a perspective view of a section of a preferred form of fin-strip produced on the apparatus shown in FIG. 1;

FIG. 4 is a perspective view of a section of a fin-strip having different protuberant form from that of FIG. 3, and being possible of production on an apparatus of this kind requiring only a different set of dies;

FIG. 5 is a perspective view of a section of a heat-exchanger core-unit formed with a stack of fin-strips of the type herein illustrated and explained;

FIG. 6 is a top plan of the apparatus shown in FIG. 1, with the metal-stock omitted;

FIG. 7 is a front side elevation of the apparatus as shown in FIG. 6 with the lead end of the metal-stock inserted into a hemmer element;

FIG. 8 is a front side elevation of the metal-stock hemming and feeding elements taken on the plane of 8--8 FIG. 8;

FIG. 9 is a left-face view taken on the plane of the line 9--9 of FIG. 8;

FIG. 10 is a top plan view of FIG. 9;

FIG. 11 is an enlarged, vertical, cross-sectional view taken on the plane of the line 11--11 of FIG. 8;

FIG. 12 is a front side elevation of the aperture-protuberant forming element and the fin-strip cutoff element viewed from the plane of the line 12--12 of FIG. 6, with the housing omitted;

FIG. 13 is a left-face view shown in FIG. 12, taken on the plane of the line 13--13 of FIG. 12;

FIG. 14 is a top plan of what is shown in FIG. 12;

FIG. 14A is a diagrammatic perspective of the gear-pulley train that controls the functions of the intrinsic, core-elements that convert metal-stock into fin-strips;

FIG. 15 is a much-enlarged, cross-sectional view taken on the plane of the line 15--15 of FIG. 12;

FIG. 16 is an enlarged, transverse, cross-sectional view taken on the plane of the line 16--16 of FIG. 15;

FIG. 16A is a perspective view of one of the punch-activating lobes that form apertures in the metal-stock;

FIG. 17 is a further enlarged, cross-sectional view taken on the plane of the line 17--17 of FIG. 16;

FIG. 18 is a much-enlarged, partial face view of the upper fin-strip forming cylinder taken on the plane of the line 18--18 of FIG. 16;

FIG. 19 is a similar view of the lower fin-strip forming-cylinder as viewed from the plane of the line 19--19 of FIG. 16;

FIG. 19A is an enlarged, cross-sectional view of the punch-activating lobe as shown in FIG. 16;

FIG. 20 is an enlarged end elevation of the fin-strip cutoff element.

FIG. 21 is a cross-sectional view of the fin-strip cutoff element taken on the plane of the line 21--21 of FIG. 20;

FIG. 22 is a top plan view of what is shown in FIG. 20 taken on the plane of the line 22--22;

FIG. 23 is a partial vertical, sectional view taken on the plane of the line 23--23 of FIG. 20;

FIG. 24 is a top plan of the finished fin-strip advancing-element and discharge element as viewed from the plane of the line 24--24 of FIG. 7;

FIG. 25 is a cross-sectional view taken on the plane of the line 25--25 of FIG. 24;

FIG. 26 is a vertical, sectional view of what is shown in FIG. 24 taken on a transverse plane of FIG. 24;

FIG. 27 is a perspective view of the well-known "Disc-O-Torque" type of air-clutch;

FIG. 28 is a side elevational view of the fin-strip receiving conveyor;

FIG. 29 is a plan view of the fin-strip receiving conveyor;

FIG. 30 is a right-hand end view of what is shown in FIG. 29;

FIG. 31 is an exploded, much-enlarged diagrammatic perspective of the metal-stock trimmer;

FIG. 32 is a diagrammatic perspective view of the units involved in the linear-travel control-element;

FIG. 33 is a perspective view of a limit switch, several of which are incorporated into the apparatus;

FIG. 34 is a diagrammatic view of the parts which guide the metal-stock through and from the aperture-protuberant forming elements and arrest action if fin-strip jams;

FIG. 35 is a diagrammatic, plan view of the fin-strip advancing element;

FIG. 36 is a diagrammatic view of the funnel-shaped guide for directing the emerging fin-strip from the cutoff onto the fin-strip advancing element;

FIG. 37 is a much-enlarged, cross-sectional view of the fin-strip discharging-element taken on the plane of the line 37--37 of FIG. 24; and

FIG. 38 is a perspective view of the part of the fin-strip discharging-element that effects the retraction of the rails onto which each fin-strip is supported pending its discharge onto the receiving-conveyor.

The type of product formulated on this apparatus, and its general manner of use, are indicated in FIGS. 3, 4 and 5.

FIGS. 3 and 4 are perspective views of two of many forms of fin-strips that are producible of this nature. The apertures, in each case, are of elongated contour bounded by pairs of flanges disposed transverse to the plane of the strip. As these figures show, there is a preference for staggering adjacent rows of these apertures. Also, as here shown, these specimens have different forms of protuberances. In FIG. 3 these are in the nature of small, circular embossments. In FIG. 4 the protuberances are of a form commonly designated "louvers." Whatever the shape, these protuberances, preferably, are positioned between the adjacent apertures.

Although the fin-strip specimens of FIG. 3 and 4 are "two-row" type, it should be understood that fin-strips of this character can be produced, with almost any reasonable multiple rows, in an apparatus as herein illustrated and described.

A fin-strip forming apparatus, embodying the foregoing concept, comprises, a supporting framework A whereon is arranged sequentially a coil-holding element B, a peripheral hemmer element C, a fin-stock feeding element D, a linear-travel-control element E, an aperture and protuberant-forming element F, a fin-strip cutoff element G, a fin-strip advancing element H, a finished fin-strip discharging element I and a fin-strip receiving conveyor J, all operated by five motor-units M1, M2, M3, M4 and M5, subject to automatic and/or manual regulation through the medium of a circuit-control panel K.

The intrinsic and basic core-feature of this apparatus is the aperture-protuberant forming element F and the directly associated cutoff element C. It is to this basic core-feature that a thin metal-stock is directed by the controlled, sequential functioning of the elements B, C, D and E, arranged in advance (i.e., to the right of the forming and cutoff elements) and it is from this basic core-feature that the finished fin-strips are directed by the elements H and I, arranged forwardly (that is to the left of the forming and cutoff elements) for orderly stacking on the conveyor J. Since these elements F and G thusly constitute the intrinsic basic core-feature of this development, the details of that dual structure and its operation will be set forth first. The other noted fore-elements B, C, D and E and aft-elements H, I and J will be described later, in that sequence.

The aperture-protuberant forming element F, as variously illustrated on drawing sheets four through seven, comprises a pair of cylinders 21 and 22, the latter being keyed to a shaft 23 (FIG. 16) journaled on an elevated platform 20 (FIG. 12) substantially medially of the overall length of the framework A. The cylinder 22 is driven by a later described gear-pulley-train 25, subject to an air clutch 30 (FIGS. 13 and 32).

The cylinder 21 is formed with a plurality of circumferential series of axially spaced, elongated apertures 32, with adjacent series circumferentially staggered, as shown in FIG. 18. In between these openings 32 are groups of pins 33 (FIG. 17). Within this cylinder 21 are arranged axially spaced, circumferential groups of punches 26 radially reciprocable in the openings 32 during the rotation of the cylinder 21. The cylinder 22 is formed with a plurality of circumferential matching series of recesses 32a. In between these recesses 32a are arranged groups of depressions 34 (FIG. 17) matching the series of pins 33 on the cylinder 21.

The reciprocation of the punches 26 is effected by a comparable series of axially spaced concentric cam devices 27, during the relative rotation of the cylinders 21 and 22 (FIG. 16). These cam devices 27 are in the nature of rings, each of which embraces a lobe 36 reciprocable in the plane of the radii of the two cylinders 21 and 22 (FIG. 16).

The form and suspension of a lobe 36 is shown in FIGS. 16A and 17. Each is secured to the threaded end of a bolt 42 within the cam device 27 by side projections 36a (FIGS. 16A and 19A) with the offset portion of the lobe seated in a slot 41 of the respective punch. The bolt 42 is embraced in a sleeve 43 with a compression spring 45 interposed between the head 44 of the bolt 42 and the sleeve 43 intermediate the shaft 23 and the cam ring 27.

It is the recurrent rotation of these cylinders 21 and 22 that cause these punches 26 to penetrate the metal-stock and form the flanged openings 32 and cause the pins 33 and the depressions 34 to form the intermediate protuberances all as shown in FIGS. 3 and 4. Moreover, it is the penetration of these punches into the metal-stock that accounts for the draft of that metal-stock from the aforesaid advance elements and simultaneously directing the potential fin-strip to the cutoff element G, for discharge to the fin-strip advancing element H.

A metal-stock holddown artifice 28 is located adjacently in advance of the cylinders 21 and 22 (FIGS. 1, 12 and 14). This involves a plate 46 adjustably fixed on the platform 20. The plate 46 is so positioned that the under face thereof is just enough above the face of the platform to permit the desired travel of the metal-stock in its approach to the cylinder 21 and 22. Attached to this plate 46 is a tube 47 registering with a central hole in the plate 46. This tube 47 is connected to a regulated source of compressed air. The air discharged through the tube 47 so impacts the metal-stock as to hold it firmly against the face of that part of the platform 20 as the stock approaches the fin-strip-forming cylinders 21 and 22.

As most clearly shown in FIG. 14 this plate 46 is secured in place on the platform 20 by a series of spaced bolts 48 set in plate slots. These permit a close adjustment of the plate 46 with respect to the opposed face of the platform 20 as may be required by the nature and the approach of the metal-stock to the cylinders 21 and 22.

A metal-stock guide 29 (FIGS. 14 and 34) is arranged adjustably on this platform 20, in advance of the cylinders 21 and 22. The edge opposed to the cylinders is tapered so as to permit adjustment as closely as required to the periphery of the cylinder 21, as conditions seem to indicate. Directly forward of the cylinders 21 and 22 is positioned a fin-strip jamming switch 37. (FIG. 34)

The fin-strip cutoff element G is illustrated variously in FIGS. 12-14 14A,16 and 20-23 on sheets four and eight. Such G element involves a pair of knife-edge members 58 and 59 respectively fixed and rotatively mounted on a pair of opposed standards 60 anchored to the framework A forwardly of the aperture-protuberant forming element F.

The knife-edge member 58 is recessed in a bar 61, attached to standards 60, transversely spanning the platform 20 above the path of the fin-strips discharged from the cylinders 21, 22. The exposed face of the member 58 is obtusely tapered to form the cutting edge medially of the length of the member 58. The standards 60 are secured at their opposite ends to lateral parts of the framework A by suitable bolts not shown. Such a member 58 is suspended in the bar 61 by a series of bolts 58', embraced in a slot in the under face of the bar 61.

The knife-edge member 59 is recessed axially in a supplemental cylinder 62 journaled on the framework A directly below the path of the advancing fin-strip. That cylinder 62 is journaled, by ball-bearings 64 (FIG. 21) on a shaft 63 for rotation in the direction of the arrow shown in FIG. 23. The knife-edge member 59, with a less obtuse cutting edge, is embraced by a U-shaped part 65 recessed radially in the cylinder 62 and a slotted plate 66 bonded along the inner face of the cylinder 62 (FIG. 23). This knife-edge member 59 is adjustably supported in the U-part 65, by a series of bolts 67, to ensure the exposed edge being in light contact with the knife-edge of the member 58, as will be seen from FIGS. 23. The main portion of the face of the cylinder 62 is formed between axially spaced ribs 68 substantially equal to the radial dimension of the transverse upset aperture flanges and protuberances of the fin-strips. (See FIGS. 3 and 4)

The bar 61 is suspended on the respective standards 60 by pairs of opposed bolts 53 (FIGS. 20 and 22). These permit a needed transverse adjustment of the bar 61 to ensure the crown of the knife-edge member 58 being precisely in vertical alignment with the axis of the shaft 63 and the knife-edge of the member 59.

The shaft 63, as most clearly shown in FIGS. 20 and 21, is arranged on the standards 60, and has associated therewith a brake mechanism 69. This standard-shaft arrangement involves a key 54 set in the end of the shaft 63 and a cup-shaped disk 56 embracing the end of the shaft 63 and secured in place by screws 57. The key 54 secures the shaft 63 against any rotative action. However, an adjustment of the opposed bolts 53 permits a slight shift of the bar 61 sufficient to ensure the required contact of the cutting edges of the members 58 and 59, to make certain that the successively produced fin-strips are absolutely of the same length.

The brake mechanism 69 (FIGS. 20,22) involves a comparatively narrow, quadrant-shaped part, lined with a strip of friction material 51. It is hinged to one of the standards 60 for activation by an air-cylinder 52, as will be explained later.

It should be observed here that, as clearly indicated in these FIGS. 12, 13, and 14, the aperture-protuberant forming element F and the fin-strip cutoff element G are synchronized in their functioning through the hereinbefore-noted gear-pulley-train 25.

This gear-pulley train 25, driven by the motor M2 (FIGS. 12, 13 and 14) through the medium of a belt 122, pulleys 122A and 122B, and the presently explained group of gears, shown in FIGS. 14 and 14A, synchronizes the above-explained functioning of the fin-strip forming cylinders 21 and 22 and the cutoff cylinder 62. The pulleys 122A and 122B are keyed, respectively, to a jack-shaft 122C (middle of FIG. 12) and the shaft 24 of the fin-strip forming cylinder 22 (FIGS. 15, 16, 17). The belt 122 spans the pulleys 122A and 122B respectively keyed to the jack-shaft 122C and the shaft 24 of the fin-strip forming cylinder 22. This jack-shaft 122C is driven by a belt from a pulley, not here shown, keyed to the rear end of that shaft driven by the motor M2.

This group of gears, which effect the synchronized functioning of the above-noted cylinders 22 and 62, is clearly shown in FIGS. 14 and 14A. These involve a pinion 123, first pair of gears 124 and 127, a pinion 125, a second pair of gears 128 and 129 and a gear 130. As most clearly shown in FIG. 24A the first pair of gears 124 and 127 and the second pair of gears 128 and 129, with the interposed pinion 125, are driven by the pinion 123 to ensure the aforesaid synchronized functioning of the cylinders 22 and 62.

As previously observed, all the other-noted "advance" elements B, C, D and E and the "forward" elements H, I and J are structured and arranged to facilitate the best possible functioning of these just-delineated basic core-feature elements F and G. The form and functioning of these above-noted other elements now will be set forth in that order.

The coil-support element B, as herein shown (FIGS. 1, 6 and 7), is an open rack with a base 70 mounting a pair of rails 71 supported on pairs of posts 72. This element B is of a length to permit the positioning of two coils of metal-stock on these rails 71. However, FIG. 1 shows only one in-service coil of metal-stock. A supporting shaft 73 (FIG. 6), extending through the coil core-opening, is supported on a pair of journal bearings 74 (FIG. 6), at the forward extremities of the rails 71. When the apparatus is in continuous production of fin-strips, a second coil of metal-stock is set on the rails 71 further in advance of the in-service coil. This permits an operator to make an almost instant insert of the lead end of the metal-stock from the second coil to follow the trailing end of the metal-stock on the coil hereinshown on the support element B.

A removable air-brake 75 is fixed on the shaft 73 and connected to a source of compressed air (not shown) by a tube 76 (FIGS. 6 and 7). Normally the air-brake 75 is open to permit the free advance of the metal-stock as required by the continuing operation of the previously described aperture-protuberant forming element F and the associated fin-strip cutoff element G. As will be explained presently any irregular demand on the metal-stock rail will cause the air-brake to arrest any further release of the metal-stock (See "operation").

The metal-stock hemmer element C and the feeding element D are arranged juxtaposed on the top of a cabinet 77 integrated with the framework A (FIGS. 1, 6 and 7).

The nature of this hemmer element C is most clearly indicated in FIG. 31. This comprises a pair of spaced parts 78 and 79 fixed in opposition directly forward of the feeding element D. As this FIG. shows, the interior of the opposed faces 80 and 81, of these parts 78 and 79 effect a 90.degree. flange. Thereupon, contact of the advancing metal-stock with faces 82 completes a 180.degree. turnover of the very narrow lateral portions of the metal-stock as it approaches the feeding element D.

Contiguously in advance of this hemmer-element C is fixed a curved apron 83 (FIG. 13) for directing the metal-stock to this hemmer element C.

The metal-stock feeding element D is illustrated in FIGS. 8-11. As there revealed this element D comprises a pair of superimposed housing parts 85 and 86 (FIG. 11) respectively journaling rollers 87 and 88. The roller 87 has formed thereon a series of peripheral grooves 89 which accommodate the metal-stock flanges for various widths thereof. The rollers 87 and 88 are driven by gears 90 subject to the action of a later described air clutch 93.

The linear-travel control element E is a most imperative feature to ensure a requisite movement of the metal-stock to the previously explained core-feature combination of elements F and G. The structure of this linear-travel control element is illustrated in FIGS. 1, 6 and 7. The arrangement of parts and their functioning is diagrammatically indicated in FIG. 32. As shown in these several figures this element is in the nature of a rack 91 comprising a welded pair of side panels 92 and forming an elongated open-top pit 94. Through this pit 94 the metal-stock variously loops in its advance from the feeding element D to the aperture-protuberant forming element F. On and in this rack 91 are fixed a potentiometer 95, in circuit with upper- and lower-limit switches 96 and 97, and a conventional photoelectric light-system 98.

Each of the two limit switches 96 and 97, as shown in FIG. 33 comprises an arm 101 secured to a rod 102 journaled on a housing 103 wherein is arranged a conventional microswitch (not shown). Such switches are subject to closing or opening by the opposite turning of the respective rod 102, as effected by the action of the metal-stock, traversing the pit 94, contacting the arm 101, as later will be explained more fully.

The photoelectric light-system 97 involves a conventional opposed arrangement of an electric-eye component 104 and a photocell 105. The functioning of this linear-travel-control element E will be described later herein.

Adjacently above the ends of this rack 91 are oppositely arranged the arcuate-shaped aprons 99 and 100 (FIG. 7). These are fixedly positioned on the framework A juxtaposed, respectively, to the exit of the metal-stock feeding-element D and the entrance to the aperture-protuberant forming element F.

Such is the general nature of these "advance" elements B, C, D and E, that feed the metal-stock to these just-described basic core-elements F and G. Attention now will be focused on the "forward" elements H, I and J that receive, advance and stack the pre-formed fin-strips subject to later use.

The fin-strip advancing-element H. As most clearly shown in FIGS. 24 and 25 the framework A mounts a platform 106 in planar alignment with the platform 20 (FIG. 12). Below this platform 106 are arranged the respective aligned pairs of rails 107 and 108 (FIGS. 24 and 26) along which travel the finished fin-strips discharged from the hereinbefore-described fin-strip cutoff element G. A highly-accelerated movement of these fin-strips along these pairs of rails 107 and 108, for discharge onto the conveyor J, is effected by sets of brushes 109 and 110, journaled on standards 111 and 112 (FIG. 25), driven by belts 113 and 114 (from the motor M3) subject to a speed-control device 138.

Intermediate the cutoff element G and these rails 107 is arranged a short, flat, funnel-shaped fin-strip guide 107A (FIG. 36). This serves to ensure the advancing end of the accelerated fin-strip which will be guided properly onto the rails 107.

The brushes 109 and 110 are driven by a pair of belts 113 and 114. The belt 113 spans a pulley 136, keyed to the forward end of the shaft 133 of the motor M3, and a pulley 139, keyed to the forward end of the shaft 135 journaled on the standard 112. It is on this shaft 135 that the pair of brushes 110 are axially fixed (FIG. 24). The belt 114 spans a pulley 134 keyed to the rear end of the shaft 135, and a pulley 134A keyed to the rear end of a shaft 137 journaled on the standard 111. It is to this shaft 137 that the pair of brushes 109 are fixed.

This speed-control device 138 involves a shaft 140 spanning a pair of posts 141 and supporting a pair of parts 142. A threaded rod 143, fixed at one end to a hand-wheel 144, is journaled on the juxtaposed post 141 and threaded to the adjacent part 142. Thus, the turning of this hand-wheel 144 effects an alteration in the rotary speed of the brushes 109 and 110. The purpose is to obtain the desired accelerated advance of the fin-strips, as cutoff from the element G, onto the rails 108 of the fin-strip discharging element I.

The fin-strip discharging element I, as shown in FIGS. 24-27, involves a continuation of the platform 106, reinforced by a tubular frame 115, and with the underset pair of rails 108 mounted for recurring transverse retraction by pairs of opposed solenoids 117 as instrumented by the approach of each fin-strip to a sensing instrument 118. These pairs of solenoids 117 are arranged in transverse opposition intermediate the opposite ends of the platform 106 (FIGS. 24, 25).

The sensing instrument 118 is located on the under face of this reinforced platform 106 between the most forward of the pair of solenoids 117 and the extremity of that section of the platform 106.

The details of an opposed pair of solenoids 117 and the sensing instrument 118 are shown in FIGS. 37 and 38. The action of these solenoids is biased by springs 119 to normally position the rails 108 in alignment with the rails 107 of the just-described fin-strip advancing-element H.

This sensing instrument 118 comprises a plate 120 and an electrical-field creating core 121 suspended in an arcuate cavity 121'. This creates a constant electronic field subject to invasion by each advancing fin-strip to activate the two pairs of solenoids 117 to retract the rails 108, against the springs 119, to drop each such fin-strip onto the receiving conveyor J.

The fin-strip receiving conveyor J is shown in FIGS. 1, 6, 7, 28, 29 and 30. This comprises a leg-supported platform 146 with the rollers 147 and 148 spanned by a belt 149 which is driven by the motor M4, as presently will be noted. A pair of conventional belt-tensioning means 150 are associated with the roller 147.

The circuit-control element K (FIGS. 1 and 7) is a conventional type of unit with a sloping front-panel mounting a series of buttons 155. These are for manual activation of various switches controlling the various circuits leading to the several motors M1, M2, M3, M4 and M5 and other operation-controlling parts as hereinbefore designated. These buttons 155 are formed of variously colored, translucent material. When any one of these buttons is depressed it becomes illuminated to indicate that the circuit to a certain part of the apparatus is ready for normal functioning.

The previously noted five primary motors M1, M2, M3, M4 and M5, respectively, account for the operation of the metal-stock feeding element C, the aperture-protuberant forming element F and coordinated fin-strip cutoff element G, the fin-strip advancing-element H, the fin-strip receiving element J, and an air-compression unit for the entire apparatus.

The M1 motor, as shown in FIGS. 8 and 9, is set within the cabinet 77 with a belt 38 connecting the motor pulley 39 with a pulley 40 which in turn is connected to drive the roller 88. How this M1 motor effects the feeding of this metal-stock will be explained presently.

The motor M2, which coordinates the functioning of the elements F and G, is set within that portion of the framework A which mounts the aperture-protuberant and cutoff elements F and G. It is connected to drive the hereinbefore-noted gear-pulley-train 25.

As indicated in FIG. 32 the motor M1, for the metal-stock feeding element D, and the motor M2, for the metal-stock aperture-protuberant forming element F, have associated with them the respective "disc-o-type" air-clutches 93 and 30. These clutches come into action, respectively, to arrest the draft on the metal-stock when the switch 96 is activated or arrest the draft of the stock by the rollers 87-88 when the metal-stock comes into contact with the switch 97. This, and the functioning of these limit switches 96 and 97 will be delineated in the subsequent "operation" section of this specification.

The motor M3, as shown in FIG. 25, is mounted on the cabinet 116 which forms a portion of the framework A of FIG. 1. This motor is connected to drive brushes 109 and 110 through the medium of belts 113 and 114 (FIGS. 24, 25).

The motor M4 is associated with the fin-strip receiving conveyor J (FIGS. 28 and 29) and is driven at a much retarded speed, compared with the motors for the previously described elements D, F, H and I. This permits an overlapped stacking of the fin-strips as they are discharged by the element I onto the conveyor J. (See FIGS. 1 and 2) This motor M4 is mounted on a ledge 145 fixed at the rear of the conveyor element J, (FIG. 29) intermediate the floor and the platform 146. A belt 149 spans a sheeve 151 on the motor M4 and a sheeve 152 keyed to the rear roller 147.

The motor M5 also is set in that portion of the framework A which mounts the aperture-protuberant and cutoff elements F and G. (FIG. 12) This motor operates a compressor (not shown) to supply pressure to the herein-noted air valves.

The operation of this apparatus, for transforming metal-stock into aperture-protuberant fin-strips, involves the following:

It is pertinent to reiterate a prior assertion as to these associated elements F and G which are the intrinsic and basic core-feature of this apparatus. It is upon the coordinated action of these parts that all other elements of this apparatus inherently are dependent. Thus, the operator's first and ever-continuing concern has to do with the appropriate functioning of the cylinders 21, 22 and 62 and their associated parts which ultimately account for the production of the desired fin-strips.

The first action of the operator is to punch certain of these buttons 155 on the circuit control element K, to ascertain that the five motors and the associated major units all are in circuit readiness, as will be indicated by the illumination of the respective buttons 155. With such assurance the button to the air-clutch 30 and 93 is depressed. Thereupon the apparatus begins to function to produce fin-strips at a high acceleration.

Taken in sequence, the M1 motor, for the metal-stock feeding element D, begins to draw the metal-stock from the coil on the support element B. Thereupon the metal-stock advances through the hemming element C. As this metal-stock moves along the faces 80 of the blocks 78 and 79 (FIG. 31), one or both lateral portions contact the faces 81 whereupon narrow marginal portions are disposed transversely to the plane of the stock. As the advance of the stock continues between the faces of the parts 82 such marginal portions of the metal-stock are pressed down firmly against the face of the stock. (FIG. 31)

With its emergence from the metal-stock feeding element D this thusly hemmed portion loops downwardly into the pit 94 of the linear-travel-control element E and upwardly therefrom to the aperture-protuberant forming element F. (FIGS. 1 and 2) However, the element D feeding this hemmed stock, by the motor M1 and the coordinated pull thereon by the cylinders 21 and 22 of the element F, is subject, at times to considerable alteration as it moves through the linear-travel-control element E. (See FIGS. 1 and 32)

So long as the metal-stock, moving through the pit 94, is below the beam of the photoelectric-light system 98, and remains out of contact with either limit switches 96 and 97, the metal-stock continues its advance through the pit 94. This movement is at a predetermined rate to meet the demands of the cylinders 21 and 22 of the element F as they continue converting the metal-stock into potential fin-strips. However, in the event the loop of metal-stock in the pit 94 is such that it is so high or low as to activate the one or the other limit switches 96 or 97, respectively, there will be an automatic alteration of the advance of the metal-stock through the pit 94. For example: if the metal-stock should rise to a point of contacting the arm 101 (FIG. 33) of the upper limit switch 96 (FIG. 32) the air clutch 30 would be deactivated and the air-cylinder 52 activated. The movement of the cylinders 21, 22 and 61 would be arrested. However, the rollers 87 and 88 of the element D would continue feeding the metal-stock into the pit 94, until the stock becomes lowered to the point of contacting the arm 101 and the lower limit switch 97. This would result in the deactivation of the air-clutch 93, thereby completely arresting the functioning of the apparatus. It then becomes necessary for the operator to depress the button on the circuit control element K to re-activate the air clutches 30 and 93 and release the air cylinder 52. The apparatus thereupon will resume its normal functioning.

Otherwise, so long as the metal-stock intercepts the light beam of the photoelectric-light system 98 there is a more-or-less constant advance of the metal-stock from the stock-feeding element D to the fin-forming cylinders 21 and 22 of the element F. However, should the loop of metal-stock in the pit 94, rise above the beam of the photoelectric-light system 98, the potentiometer 95 would be instrumented to effect a slight increase in the speed of the motor M1. As soon as that effects an increased advance of the metal-stock, to the point of again intercepting the aforesaid light-beam, the potentiometer 95 would be instrumented to return the motor M1 to the intended speed to accommodate the advance of the metal-stock to the demand of the cylinders 21 and 22 of the element F.

Normally, the hemmed metal-stock advances out of the pit 94 up over the apron 100 and into the holddown artifice 28 for feeding to the basic core-feature forming-element F. A predetermined air-pressure through the air-tube 47 serves to hold the metal-stock firmly against the face of the platform 20 (FIG. 12) as the metal-stock is drawn between the cylinders 21 and 22 of this element F operating at speeds between 136 and 375 revolutions per minute. The successive activation of the annular series of punches 26, in the cylinder 21, by the lobes 36 of the respective cam devices 27, effects the forming of the continuing succession of flanged apertures 32 in the metal-stock. Concurrently, the series of pins 33 and the depressions 34 (FIG. 17) form the tuberances in between these apertures. Meanwhile these cylinders 21 and 22 are causing the continued advance of the potential fin-strip to the cutoff element G. (FIGS. 12 and 14)

Due note should be taken of how these punches 26 approach and recede from the recurring forming of the flanged openings 32 in the specimen fin-strips of FIGS. 3 and 4. It will be most obvious from FIG. 19A that as these two cylinders 21 and 22 rotate the V-tapered end of each punch 26 approaches a recess 32a of the cylinder 22. These initiate the forming of depressions in the rapidly-advancing fin stock. As each punch acquires its full depression into a recess 32a the formation of a flanged aperture is completed. The continued movement of the cylinders effects the retraction of the punch 26 that has just completed the formation of the respective flanged opening.

The succession of such formed fin-strips are precisely of the same length by reason of the gear mechanism between the cylinders 21 and 22, as shown in FIG. 14A. The length, for any series of fin-strips, can be altered merely by changing the gear 128.

In the event this forward movement of the potential fin-strip should fail its intended advance to the cutoff element G, the fin-strip would tend to bunch-up between these two elements F and G. The resulting contact with the arm 101 of the switch 35 (FIGS. 34 and 35) would deactivate the clutch 30 and arrest functioning of the cylinders 21 and 22. Meanwhile, the metal-stock would be lowered in the pit 94 to the point of activating the switch 97 and arrest the metal-stock feeding element D. Such a fault would emanate from either of several sources. One might be failure in the functioning of the cutoff element G. Another might be some failure in the functioning of the brushes 109 and 110. It might be the result of an air-cylinder failure or the failure of the sensing device of the fin-strip discharging element J.

Otherwise, the synchronized cylinder 62 of this cutoff element G continues the advance of this forming fin-strip emerging from the forming element F. Each revolution of the cylinder 62 brings the cutting edge of the member 59 into vertical alignment with the knife-edge of the member 58 (FIGS. 20-23). Thereupon a predetermined length of the emerging fin-strip is severed for discharge onto the fin-strip advancing element H (FIGS. 24,25 and 35).

As clearly will be evident from the juxtaposition of the cuf-off element G and the fin-strip advancing element H, the forward portion of the forming fin-strip, emerging from the element G, is traversing the rails 107 of this advancing element H. Thus, the forward pair of brushes 109--directly adjacent the cutoff element G--are in contact with the advancing end of this forming fin-strip (FIGS. 25 and 35). However, at the instant the fin-strip is severed by the knife-edges of 58 and 50, the two pairs of brushes 109 and 110, shoot the severed section of fin-strip forwardly onto the tracks 108 of the fin-strip discharging element I. (FIGS. 24-25)

As the advancing end of each finished fin-strip approaches the sensing instrument 118 it is activated to open the circuit to the pairs of air-cylinders 117 to permit the springs 119 to retract the opposed rails 108. Thereupon the finished fin-strip drops onto the belt 140 of the receiving conveyor J. Such actuation of the solenoids 117 is due to the advance of forward edge of the fin-strip into the field created in the cavity 120' by the energization of the core 121.

As hereinbefore noted, and as previously explained, and clearly indicated in FIGS. 1 and 2, the movement of this conveyor belt 149 is greatly retarded, compared with the functioning speed of the cylinders 21 and 22. Thus, as illustrated in FIG. 1, these successively discharged fin-strips stack up on the conveyor belt with only slightly less than a complete overlap of each successive fin-strip dropped onto the conveyor belt 149.

Variations and modifications in the details of structure and arrangement of the parts may be resorted to within the spirit and coverage of the appended claims.

Claims

We claim:

1. An apparatus for the transformation of metal-stock into individual, apertured, planar fin-strips for stacked use in structuring tubular heat-exchanger core-units, comprising

a. a supporting framework,

b. a pair of cylinders journaled one above the other on the framework for passage of metal-stock between the peripheries of the cylinders,

c. one cylinder having a plurality of circumferentially spaced, radially disposed, elongated openings arranged uniformly axially of the cylinder,

d. the openings of one radially disposed series being axially staggered with respect to the openings of the next adjacent series,

e. the other cylinder having a matching series of recesses formed therein,

f. an annual series of punches reciprocally embraced in the openings in the one cylinder, each punch having a slot adjacently the inner end thereof,

g. a series of flanged annuluses positioned between the respective series of punches with the flange on each extending into the slot of the adjacent punch,

h. a lobe associated with each annulus in the plane thereof extending radially toward the other cylinder for successively activating the respective series of punches during the rotation of the cylinders,

i. a bar fixed directly forward and parallel with the pair of cylinders the exposed face of which is tapered to form a knife-edge disposed longitudinally of the bar,

j. a supplemental cylinder journaled on an axis aligned with the ridge on the bar,

k. a second bar recessed inwardly of the periphery of the supplemental cylinder and having its exposed face tapered to form a knife-edge disposed longitudinally of the second bar in vertical alignment with the first bar knife-edge, and

1. a motor-driven gear-pulley-train on the framework for synchronizing the rotation of the pair of cylinders and the supplemental cylinder to sever the emerging fin-strip into predetermined uniform lengths.

2. An apparatus as set forth in claim 1 wherein each lobe is suspended on a bolt with an interposed spring that normally retracts the respective lobe when not in metal-stock aperturing position.

3. An apparatus as set forth in claim 1 wherein one of the gears of the gear-pulley-train is replaceable by a gear of a different pitch to alter the rotation speed of the cylinders to vary the uniform length of the fin-strips.

4. An apparatus as set forth in claim 1 wherein a pair of fin-strip advancing rails and associated motor-driven brushes are located forwardly of the supplemental cylinder and bar for accelerating the advance of the several fin-strips for stacking subject to use for structuring core-units.

5. An apparatus as set forth in claim 4 wherein another pair of rails are aligned with the first pair of rails for receiving the fin-strips advanced by the motor-driven brushes, the second pair of rails being spring biased for normal alignment with the first pair of rails, and a sensing instrument positioned forwardly between the second pair of rails activated by each advancing fin-strip to separate the rails to successively discharge the fin-strips for stacking on an underplaced support.

6. An apparatus for effecting the transformation of thin metal-stock into predetermined length, planar fin-strips with elongated flanged apertures for use in structuring tubular heat exchanger, comprising

a. a supporting framework for mounting a supply of metal-stock,

b. a pair of opposed cylinders journaled on the framework for the passage of the metal-stock between the peripheries of the cylinders,

c. each of the cylinders having a plurality of radial series of axially spaced registering openings formed therein and spaced uniformly around and along the cylinders,

d. an equal plurality of reciprocable punches embraced in the openings of one of the cylinders,

e. cam means operatively connected in said one cylinder for successively activating the punches during the continuous and uninterrupted rotation of the cylinders to form apertures in the metal-stock advancing between the cylinders,

f. other means operatively connected with the cylinders for advancing the metal-stock to the cylinders,

g. a pair of members operatively connected with the cylinders and being located in the path of the stock discharge from the cylinders and being operable synchronically with the cylinders to sever the advancing stock into uniform-length fin-strips,

h. motor means operatively connected in the apparatus for causing the synchronized rotation of the cylinders, actuation of the cam means and the stock-severing members,

i. a guide-means arranged on the framework forwardly of the fin-strip severing members for receiving the severed fin-strips,

j. other means operatively associated with the guide means for accelerating the advance of each severed fin-strip and successively discharging them,

k. and a fin-strip stacking element operatively associated with said other means for receiving the severed fin-strips.

7. An apparatus as set forth in claim 6, wherein the other means for accelerating the advance of the cut-off fin-strips is a motor-driven brush positioned to contact the under face of each fin-strip discharged onto the guide-means.

8. An apparatus as set forth in claim 6, wherein the stacking element is a slow-moving conveyor belt disposed and arranged for movement transversely of the supporting framework.

9. An apparatus as set forth in claim 6, including a component operatively disposed aligned forwardly with the fin-strip receiving guide-means and the associated other means, for temporarily supporting each fin-strip successively advanced by the associated other means, and an electronic sensing instrument juxtaposed to the component, and subject to activation by the approach of each fin-strip, for discharge of each fin-strip onto the stacking element.

10. An apparatus as set forth in claim 9, wherein the component is in the form of a pair of spaced rails aligned with the fin-strip advancing means and is disposed above the stacking element and is transversely shiftable into and out of disposition for receiving fin-strips from the fin-strip advancing means and including spring-biased solenoids connected to the rails to normally bias the rails into position to receive the fin-strips successively advanced by the associated other means, and including a sensing device in the form of an electric-field creating-core operatively connected to the rails and activated by the approach of each fin-strip to effect the electric field to cause separation of the rails to drop each fin-strip onto the stacking element.

11. An apparatus as set forth in claim 6, including a motor-driven metal-stock feeding-element operatively positioned in advance of the cylinders, and means interposed between the metal-stock feeding-element and the cylinders for automatically controlling the linear advance of the metal-stock to the cylinders.

12. An apparatus as set forth in claim 6, wherein the supporting framework, intermediate the metal-stock feeding-element and the aperture forming element, defines an elongated pit for receiving a curved extent of the metal-stock between these means and cylinders, and upper and lower sensing devices operatively connected in the apparatus and arranged in the pit in the path of the advancing metal stock for sensing the extent of the curve and correspondingly automatically regulating any fluctuating travel of the metal-stock through the pit.

13. An apparatus as set forth in claim 12, wherein the sensing devices are switches disposed above and below the curve and are fixed on the framework-defined pit whereby the advancing metal-stock contacting one of the switches will temporarily accelerate the feeding of the metal-stock into the pit, and the metal-stock contacting the other switch will temporarily accelerate the draft of the metal-stock from the pit.

14. An apparatus as set forth in claim 12, including a photo-electric-light system arranged horizontally in the elongated pit and being operatively connected to the linear advance means to normally maintain the curve of metal-stock free of contact with the sensing devices.

15. An apparatus as set forth in claim 12, including an air-clutch operatively connected with the metal-stock advancing means, and an air-clutch operatively connected with the forming cylinders, whereby contact of the metal-stock with the upper sensing device will deactivate the air-clutch for the cylinders to permit an increased advance of the metal-stock into the pit, and whereby contact of the metal-stock with the lower sensing device will deactivate the air-clutch for the feeding rollers to permit an increased draft of the metal-stock from the pit by the forming cylinders.

16. An apparatus as set forth in claim 12, including a potentiometer operatively connected to the photoelectric system whereby when the draft on the metal-stock rises above the beam of the photo-electric-light system the potentiometer will slightly accelerate the drive of the motor for the metal-stock advancing means to increase the curve thereof in the pit, and when the curve of the metal-stock again intercepts the beam from the photo-electric-light system the potentiometer will be activated to decrease the speed of the motor to the metal-stock advancing means to restore the normal advance of the metal-stock to the forming cylinders.

17. An apparatus as set forth in claim 6, wherein said pair of members are rotatable cutting cylinders, and including a gear train for the operative connection of said cutting cylinders with said other cylinders, and one of the gears of said gear train being replaceable by a gear of different size to alter the rotation speed of said cutting cylinders to vary the length of the cut fin-strips.