IL22190A - Fabricating honeycomb core - Google Patents

Description

This invention relates generally to honeycomb core and more particularly to new and improved methods and means for the fabrication of such core from metallic ribbon.

Metal sandwich panels comprising metallic honeycomb core have sheet metal skins are now being used extensively in the fabrication of aircraft and other structures requiring strong and light weight metal coverings. Metallic honeycomb used in the construction of such panels usually is fabricated layer by layer of thin corrugated stainless steel metal strips or ribbons. The ribbons usually have a thickness of the order of .001 inch and, following corrugation and assembly, successive layers of the ribbons are secured together by resistance welding at adjoining nodes.

In order to produce high quality precision metallic honeycomb core having maximum strength with regard to this type of metal used in its cellular co struction, it is neoessary that the cells be symmetrically formed with resulting uniform shape and size in the fully fabricated and completed core.

To accomplish this, undue working and handling of the metallic ribbon such as would strain and distort the same and impair the effectiveness of the resistance welding must be avoided during the corrugating, assemblylng and welding of the ribbon.

The foregoing requirements for producing satisfactory honeycomb core structures have been met to limited degree by various methods and means heretofore devised for fabricating honeycomb core from metallic ribbon. The prior art methods and machines, however, have not been found to be entirely satisfactory in service for one reason or another such as complexity and lack of precision of the machines, excessive and time consuming handling of the ribbons and core by the operator, and the inapplicability of the fabricating principles to pro- duction methods and operation, to mention a few.

In accordance with the method and machine of the present invention for fabricating honeycomb core, the prior art difficulties and limitations are largely obviated by an ' arrangement in which an uninterrupted corrugated ribbon is con inually supplied from a ribbon feed and a corrugation punch and assembled and welded into successive layers of adjacently disposed oppositely corrugated ribbon sections without limitation as to the length of the core in the ribbon direction or to the width of the core as determined by the number of layers added thereto. The core moves Intermittently forth and back over a predetermined length. of core and builds up down-wardly between two stripper bars by lowering the core with respect to the bars layer by layer.

The stripper bars provide spaced supports for twelve electrode pins which are precision spaced and affixed in a common support bar for unitary movement therewith axially of the pins. Thirteen indexing pins also having a common support bar upon and to which they are precision spaced and affixed for interfltting relationship with the electrode pins are mounted for unitary movement with their support and axially of the pins into interfltting position between two ribbon sections whose abutting nodes to be welded are aligned and resting on the electrode pins.

Six welding wheels are mounted and power driven for movement forward and backward across the ribbon sections above and' along alternately spaced electrode pins for passage of welding current through the abutting ribbon nodes interposed therebetween, the wheels being mechanically shifted sidewlse one corrugation width for welding of the remaining six nodes on the return sweep of the wheels and for restoring the wheels to their Initial position on completion of the welding cycle. The. wheels are connected in pairs with their associated pairs of electrodes and respectively energized in series circuits from separate power sources, and the wheels are separately pneuma ically loaded for optimum contact pressure.

The electrode and indexing pins are power driven to accomplish the Intermittent core movement, the sequence of pin movements for this purpose being: (1) Withdrawal of the electrode pins from the corej (2) Shuttling movement of the indexing pins with the core twelve corrugations widths in either direction longitudinally of the ribbon length; (5) Withdrawal of the indexing pins concurrently with return of the electrode pins into the core; (4) Shuttling return movement of the indexing pins in the reverse direction to a position of withdrawn alignment between the axes of the electrode pins; and (5) Re-entry of the indexing pins into interfltting position above and between the electrode fingers.

The corrugated ribbon received from the punch is passed along a guide which serves to supply the corrugated ribbon to either side of the electrode pins in position above and on the stripper bars. The guide is driven to opposite sides of the pins alternately preparatory to reversal of the direction of core movement.

In accordance with one mode of operation, the machine of the present inven ion is prepared for starting of fabrication of the core by withdrawing a length of ribbon, sufficient to provide the length of core desired, from and through the guide and thence over the indexing pins into position thereover doubling the ribbon back under the indexing pins; and finally, moving the electrode pins into position beneath the doubled back ribbon. The machine is then started, the initial ribbon portions being welded first , followed by successive indexing-and welding movements until the end of the initially withdrawn ribbon is reached, successive seotions of the ribbon having been drawn from, the guide during this serie s of indexing movements . The ribbons are then lowered. one-half cell width diagonally after which the guide is moved to the other side of the electrode pins which causes the ribbon t o be doubled back and over the indexing pins in position for welding and indexing movements in the reverse dire ction.

The method and machine of the instant invention with its concept of continuous corrugated ribbon feed to the honeycomb core being fabricated and the provision for doubling back of the ribbon over the length of the core to form the successive layers . of the core , lends itself very well for the interweave into the core of successive sections of ribbon of varying length and thickness to provide predetermined structural effects in the core in accordance with a prearranged pattern. The ribbon sections of different thickness may be supplied each from it β own source and each separately corrugated, spliced to the section of ribbon currently being fed to the core fabricating machine and then, after a measured number of corrugation widths , sheared and spliced to the succeeding ribbon section which is to follow it in the continuous process of interweave of the sections into the core being fabricated.

Since the .Le ngth of the various ribbon sections as well as the ir positions relative to the length of the fabricated core is measured in terms of multiples of a corrugation width, the process of interweave lends Itself readily to programming control in which the sequence of shearing, splicing, corrugating and fabricating of the ribbon may be timed, measured and^computed or counted by the number of corrugations formed in the ribbon from the start of operations in the fabrication of a particular core. Thus, honeycomb core of the so-called "picture frame" and "reinforced slug" types may be fabricated in which strips of core ribbon of varying thicknesses are welded together end to end so that the heavy gauge or light gauge falls into the right location on the finished piece of core to provide desired structural effects and configurations therein.

The object8, features and advantages of the present invention are those inherent in or to be implied from the combine tion, . construction and arrangement of parts as will become more fully apparent as the description proceeds, reference being, had to the accompanying drawings, wherein: Figures 1 and 2 are enlarged fragmentary views disclosing the relation of parts involved in the assembly and resistance welding of corrugated stainless steel ribbons together to form a honeycomb oore, Figure 1 disclosing the position of parts Just prior to assembly of the ribbon being added to the core and Figure 2 depicting the position of parts during the welding operation; Figure 5 is a side elevational view of the honeycomb core fabricating machine of the present Invention; Figure 4 is a front view of the machine, partly in section, as viewed along the lines 4-4 of Figure 3; Figure 4a is a view, in part schematic, of an electrical device suitable for lowering the core layer by layer; Figure 4b is a sectional view taken along the line 4b-4b of .Figure 4a; Figure 5 is a somewhat enlarged sectional view taken along the lines 5-5 of Figure 4; ' Figure 5a is a fragmentary view illustrating a sup-* ' porting arrangement for the core during Initial fabrication; .

Figure 6 is a fragmentary portion of the machine as viewed substantially along the line 6-6 of Figure 5» certain parts being shown in section to disclose details of structure; Figure 7 is a schematic view disclosing the pneumatic driving system for effecting the basic movements of the machine of the present invention and disclosing limit switches which are actuated as a result of these movements; Figure 7a is a schematic view of the welding carriage as viewed from beneath the welding wheels; Figure 8 is an electrical circuit diagram disclosing the manner in which the limit switches of Figure 7.are employed to control operation of valves which in turn control the pneumatic and hydraulic driving means disclosed in Figure 7; Figure 9 is a schematic view illustrating the pin and wheel movements Involved in a single shuttle movement of the core; Figure 10 is a schematic view illustrating the sequence of pin and core movements involved first in shuttling the core over its length in one direction and then over its length in the reverse direction; Figure 11 is a diagrammatic view illustrating a core Interweave system and method utilizing the honeycomb core fabricating machine of the present invention; Figure 12 is a somewhat enlarged fragmentary view of the machine as it appears in Figure 4 excep that the manually manipulated ribbon guide of Figure 4 is replaced by the driven guide of Figure 12; seen along the line lj-lj of Figure 12; Figure l4 is a sectional view of the ribbon guide taken along the line l4-l4 of Figure 12; Figure 15 is a schematic view of the driven ribbon guide illustrating its ooaction with the Indexing pins In doubling the ribbon back upon itself and over the pins; Figure l6 is a sohematlc view of the driven ribbon guide illustrating its relation to the doubled baok ribbon at the start of fabrication of the core; Figure 17 is a somewhat enlarged sectional view of a modified form of an indexing pin shown in relation to the ribbon which has been doubled back with respect thereto; Figure 18 Is a view of a portion of the machine as It appears in Figure 4 and modified to replace the manually manipulated stop of Figure 7 with a solenoid controlled stop and Figure 19 is a achematio diagram illustrating the manner of incorporating the circuits and controls for the driven ribbon guide and the solenoid controlled shuttle stop into the oontrol circuit of Figure 8, the circuit of Figure 19 being a modification and extension thereof to render the machine fully automatic Referring now to the drawings, and first more particularly to Figures 1 and 2, there is shown thereon a fragmentary portion of honeyoomb core 19 which is formed of a plurality of layers of adjacently disposed oppositely corrugated metallic ribbons 20 which are bonded together at their adjoining nodes 21 as by resistance welding. During the assembling and bonding of an additional ribbon section 2OA to the core, the core is supported on a plurality of electrode pine 22 which are inserted axially of the pins into the upper row of cells of the oore. Similarly, a plurality of holding pins are moved axially of the pins and inserted into the cells to be formed by addition of the section 20A of ribbon to the core. Section 20A, as shown in Figure 1 for purposes of illustration, is spaced considerably above the holding pins 25.

It will be understood, however, that in practice, the ribbon section 20A will generally be laid down onto the nodes 21 of the preceding core ribbon 20 such that the pins 25 move beneath and engage ribbon section 2OA generally in the position as seen in Figure 2.

A plurality of holding fingers 24 and welding wheels 25 are shown poised in Figure 1 in readiness to move into engagement with the ribbon section 20A as shown in Figure 2. As will appear more fully hereafter, the fingers 24 approaoh the holding pins 2 in a movement which Is, in part, axially of the pins such that rubber-like tips 26 on the holding fingers 2 position and hold the ribbon strip 20A on the holding fingers 25 just prior to engagement of the welding wheels 25 therewith.

The electrode and holding pins generally conform in cross-section to the configuration of the cell structure desired in the . fabricated core and thus insure that the honeycomb cells resulting from the corrugated ribbons assembled and welded thereon will be precisely formed. In practice, it is preferred that the undersurfaces and sides of the electrode and holding pins be cut back sufficiently to provide adequate clearance in the cells to insure against binding of the pins when inserted or withdrawn from the core, this clearance being somewhat exaggerated as shown for purposes of illustration.

Relieving of the undersurfaces and sides of the pins still leaves the upper surfaces in conformance with the desired configuration of the cell struoture and thus insures preoislon formin of the fabricated core. To this end it wil e e - stood that close form fitting of the pins within the cells formed by the corrugated ribbons is desired consistent with a degree of freedom of movement of the pins sufficient to avoid-distortion and damage of the thin ribbon which may be formed of stainless steel, for example, having a thickness of the order of .001 inch.

As will hereinafter more fully appear, welding wheels 25 sweep above and along the length of the electrode pins 22 while simultaneously passing welding current through the ad-. Joining nodes disposed therebetween, the width of the wheels in roiling line contact with the upper surface of ribbon section 20A being somewhat less than the width of the nodes in order to avoid burning of the ribbon adjacent the sides of the nodes. Each adjacent pair of welding wheels 25 and the electrode pins 22 in contact therewith through the ribbon nodes being welded constitute a series circuit across a transformer secondary winding which supplies the welding current, the current alternately passing from one wheel and returning to the other. For this purpose, the electrode pins 22 are all connected together electrically through their common support bar 27 which, like the electrode pins 22 and the welding wheels 25 is formed of highly conductive material such for example as copper. By reason f this arrangement, the relatively high resistance of the stainless steel of the adjoining nodes 21 comprises the major portion of the resistance in the welding circuit.

A finger bar 28 of nonconductive material is supported on pin support bar 2 and has fingers 29 so arranged as to be supported on holding pins 25 which have undercut surfaces 0 for this purpose. Fingers 29 serve as a back stop against which the ribbon strip 20A is urged by the resilient tips 26 'in engagement therewith, it being noted that the under-surface 51 of the tips is formed to conform generally with the corrugations of the ribbon. Holddown tips 26 assure that the ribbon section 20A is properly positioned and held with respect to the preceding ribbon 20 to which it is to be welded, and the holddown tips together with the backstop fingers 29 assure that when the ribbon section 20A is welded to the core it will form a common planar face with the rest of the core such that need for subsequent machining of this face of the core may be obviated.

The welding wheels are axlally spaced by two corrugation widths and thus operatively engage alternately spaced electrode pins. As will become more fully apparent as the description proceeds, the welding wheels are mounted for sweeping movement along the electrode pins to resistance weld the alternately spaced nodes in contact therewith. The wheels then move axially thereof one corrugation width and, on the return stroke, sweep back along the electrode pins to weld the remaining intermediate nodes. This arrangement has the advantage that half as many electrode wheels are required as there are electrode pins, and the.spacing between the wheels affords ample space for the bifurcated conductor supports 32 for the wheels as well as prevents ourrent flow directly between the wheels through the ribbons lengthwise thereof. The series circuit, Including each pair of electrode wheels, has the advantage in that no external electrical connection need be made with the electrod pins, the same merely being shorted together by heir common support bar 27. The welding wheels may be caused to move along the electrode pins at a suitable rate in relation to the frequence of the welding current which may be caused to flow 120 times per second, for example, in order to obtain a seam weld at the nodes.

Referring now more particularly to Figures 5 to 6 for a description of a machine embodying the aforedescribed pin and wheel structure, there is shown thereon a box-like base 55 havin feet J6. The base supports a frame structure comprising spaced side plates 57 and 8 attached to the base by suitable fasteners as at 59 , Figure 5. Extending between the side plates 57 and 58 and affixed thereto by any suitable known means are a bottom plate "2r3rand a back plate 42. Supported on base 55 and back plate 42 is a control box 4 , Figure 5 , which houses the transformers and other control equipment required in the operation of the machine. Terminals 44 from the transformer secondaries are connected as by conductors 45 to terminals 46 mounted on the conductor-actuator membere 47 which form part of the electrical circuit to the welding wheels 25. For this purpose each member 47, like the elongated wheel support bar 2 to which it is attached as by screw 48, Figure 5 , preferably is formed of highly conductive material such as copper. Bars are bifurcated at their lower ends to receive the welding wheels 25 and carry pins 49 upon which the wheels are rotatively mounted. The bars are slidably supported in elongated openings^1 provided therefor in a block 52 of insulation material.

Conductor-actuator members 47 are generally C-shaped and have horizontal leg portions disposed above and belo a projection 3 o block 52 in spaced relation therewith to provide upper and lower chambers for receiving flexible tubes 54 and 55 respectively. The arrangement is such, as best see in Figure 5 > that Inflation of tube 54 produces compression of tube 55 to thus move all of members 47 upwardly relative to block projection 53 · This, of course, causes wheel support bars 52 to be moved slldably upward In block 52 to thus elevate the welding wheels. Similarly, inflation of tube 55 causes compression of tube 4 with resultant lowering of members 7 and wheel support bars 5 to lower the welding wheels. This arrangement has the advantage that,, while the pneumatic actuator tubes and 55 act simultaneously on all of the members* 7, each of the members is actuated individually and yleldably, thereby to thus assure that the welding wheels will all be urged with equal pressure against the nodes to be welded notwithstanding any variations in the thickness thereof.

Block 52 has secured thereto a slide 56 which makes a dovetail connection as at 57 with a supporting plate $8.

Plate 58.extends between and is secured to a pair of side plates 59 and 6l which are maintained in spaced relation by one or more cross members 62. As best seen in Figure 4, side plates 59, 6l on their lower surfaces have affixed thereto slides 65 and 64 respectively which form dovetail connections as at 65 and 66 with track members 67, 68, respectively.

Track 67 is supported on a plate 69 and affixed thereto as by fasteners 71· Plate 69, in turn, is supported on and affixed to side plate 58 and a plurality of upstanding plates 72 which are affixed to side plate 58 and bottom plate 4l. Similarly, track 68 is supported on a plate 75 which, in turn, is supported on upstanding plates 74, Figure 4.

Sliding movements of the welding wheel support carriage along the dovetail connections 65, 66 is accomplished by means of a hydraulic cylinder motor 75» Figure 5, which is pivotally attached to rear plate 42 by means of a bracket 76 to which it makes pivotal connection as at 77· Hydraulic cylinder motor 75 has a piston 78 having the usual piston rod 79 which makes a threaded connection as at 8l Fi ure with l te of the welding wheel support carriage, a nut 82 being employed to secure the threaded connection.

Side plate 59 of the welding carriage has an arm 85 ■ suitably secured thereto as best seen in Figure 4, this arm extends into the vicinity of frame side plate 58 where it makes pivotal connection as at 84 with a link 85. As best seen in Figures 3* 5 and 6» the opposite end of link 85 carries a pivot 86 which slides in a slot 87 provided in a bell crank 88. Bell crank 88 is pivotally mounted on a pin 89, Figure 5, which is supported on and secured to side frame plate 58 as at 91, Figure 6. A pin 95» also secured to side frame plate 58 as at 94, serves as a stop against which bell crank 88 is biased as by a spring 95 which interconnects the bell crank with side frame plate 58 as at 96, Figure 5.

A crank 96, Figure , similar to the lower portion of bell crank 88 is similarly supported on a pivot pin 97 which is secured to side frame plate 58 as at 98, Figure 6. As best seen in Figure 5, similar cranks 99 and 101 are pivotally supported on pins 102 and lOJ respectively, these pins being affixed to and supported on side frame plate 57. Pivot pins 102 and 105 have the same spaced relationship therebetween as pivot pins 89 and 97 mounted on side frame plate 58, and all of these pivot pins are arranged such that they lie in the same horizontal plane. The lower ends of cranks 88, 96, 99 and 101 are pivotally secured as at 105 to a connecting beam 104. These cranks all have the same effective length such that beam 104" maintains a parallel relationship with the aforesaid horizontal plane which passes through the axes of pivot pins 89, 97» 102» and 105. By reason of this arrangement, any point on beam 104 will move in a circular path of the same radius as that of pivot pins 105 as the cranks oscillate about their respective axes.

This path of movement of beam 104 is also imparted to ribbon hold down tips 26, as indicated by the dashed line 105 in Figure 5 , by reason of the attachment of ribbon holding fingers 24 to beam 104 as at 106. By reason of this arrangement, as the hold down tips 26 move along path 105 from their dotted line position as shown in Figure 5 , they are progressive ly lowered as they approach ribbon 20A resting on holding and indexing pins 25, the path of movement being such that the tips engage the ribbon with yieldable holding force just prior to the final movement of bell crank 88 against stop 95 and such that, during this final movement, the holding tips move substantiall parallel to the axes of holding pins 25 with the result that the ribbon thereon is yleldably urged by the holding tips 26 into abutting engagement with the ends of fingers 29 of finger bar.28.

When the finger bar 28 is in this position, as best seen in Figure 5» "the ends of fingers 29 are in alignment with the face I06 of a stripper bar 107 which extends between and is secured, to side frame plates 57 and 58 as by suitable fasteners 108. Face 109 of core 19 is built up with reference to face 106 of stripper bar 107 acting as a guide surface, arid the movement of each additional ribbon layer into alignment with this surface by abutting engagement with fingers 29 of finger bar 28 assures that these edges of the successive ribbon layers will all lie in the same plane defined by face 106 of stripper bar 107· A similar stripper bar 111 also extends between the frame plates 57 and 8. and secured thereto as by fasteners 108, this stripper bar being so mounted such that its face 112 is disposed adjacent face 115 of core 19 with sufficient clearance being provided therebetween to assure freedom of sliding movement of the core downwardly between the stripper bars as the core is lowered to add successive ribbon layers thereto, as will more fully appear as the description proceeds. Side frame plates 57 and 58 are slotted as at ll4 and 115 respectively to provide for shuttling of the core beyond either side of the machine, it. being noted with particular reference to Figure 5, that the width of each of aligned opening ll4, 115 is somewhat greater than the spacing between the stripper bars 107 and 111 in order that precision forming of the opposed faces of the core 19 remains the province of the stripper bars.

With the parts of the machine positioned as shown in Figures 5> 5» and 6> welding wheels 25 are in a position to which they have been moved by the welding carriage from the retracted position indicated b the dashed line ll6. During this movement of the wheels, bell crank ^ moves from its dashed line position to the full line position shown and, like wise, the ribbon holding tips 26 move from their dashed line positions along the path 105 into their final ribbon holding positions as indicated in Figure 5. During movement of bell crank 88 there is no driving connection of the bell -crank with pin 86 on link 85. Their relative positions, however, are maintained as bell crank 88 is rocked under power of coil spring 95 to position the holding fingers relative to the core ribbon as aforementioned. As will more fully appear subsequently , .wheels 2 while in the full line position of Figure are lowered by inflating tube 55 "to t as engage the ribbon nodes to be welded. ■ As the wheels then sweep across the nodes to perform the welding operation, pin 86 on link 85 merely rides in slot 87 in bell crank 88 with the result that ribbon older 2 retain their holdin ositions durin the weldin operation. On reaching the other side of the core, the wheels are elevated to their positions indicated by the dashed line 117, this being accomplished by Inflating tube 54. The elevation" is sufficient such that the wheels clear the holding fingers 24 on shifting axially for subsequent lowering into engagement with the intermediate nodes and return sweep of the wheels back across the core. During this movement of the wheels the pin 86 again merely rides in slot 87.·, still leaving the holding tips 26 undisturbed in ribbon engaging position as shown in Figure 5· Upon completion of the welding on the return sweep and the elevation of the wheels to their full line position as seen in Figure 5, further movement of the welding carriage to move the wheels from this full line position to the dash line position ll6 causes pin 86 to drive bell crank 88 to its 'dashed line position and likewise moves the holding tips 26 from their position of . engagement with the core back along the path 105 to their retracted position, as indicated b the dash lines in Figure 5.

In order to provide for the sidewise shift of welding wheels 25 along their lined pivot axes, an angle bracket ll8 is secured to block 2 as by suitable fasteners 119. Angle 'bracket II8 has a beveled surface 121, Figure 3, which, as the welding carriage approaches its fully retracted position, engages a similar beveled surface 122, Figure 4, on an angle bracket 122 which is secured to side frame member 57 as by suitable fastener means 124. The cam action of the engaging beveled surfaces 121 and 122 causes block 52 to slide alon the dovetailed connection 57 with plate 58 to thus move the wheels 2 to the left to their positions as best seen in Figure 4. In similar manner, as the welding carriage approaches its foremost position, and after the wheels 2 have been ele- vated, engaging beveled surfaces on the opposite side of bracket' ll8 and on a bracket 125 supported and affixed to side frame member 58 causes block 52 to be shifted along its dove-tall . connection 57 by cam action of the engaging beveled surface to the right as viewed in Figure 4 by one corrugation width to thus position the welding wheels 25 for lowering movement Into engagement with the intermediate nodes to be welded.

Stripper bars 107 and 111 provide a bridging support for electrode pins 22 as may best be seen in Figure 5. Furthermore, it will be apparent that stripper bar 307 tends to hold the position of the core as the el&etrode pins 22 are withdrawn axially from the cells of the core 19 in which they are inserted and, similarly, upon re-entry of the electrode pins 22 into the cells of the core the stripper bar 111 likewise holds the core firmly to facilitate this, movement of the pins, it being recalled that the pins interfItt ingly engage the cells of the core with a minimum of clearance sufficiently only to insure freedom of movement of the pins into and out of the cells of the core. To facilitate entry into the core, the electrode pins 22 preferably are pointed at their tips as indicated at 128. The opposite ends of the electrode pins are reduced as at 129 ¾o provide a press fit engagement with their common support member 27, or otherwise suitably secured thereto.

To provide for axial movement of the electrode pins into and out of the core, their common support member 27 preferably is formed of angle stock and secured by suitable fasteners 151 to a plate 152 which makes a dovetailed connection as at I55 and 1^ with track members 15 and- 1÷56 respectively. Tracks 15 and I56 are secured to base plate 4l as by suitable fastening means 158, Figure 6. An upstanding plate 159, Figure 5, is supported on and suitably secured to tracks 155 and 156 and, in turn, supports an air cylinder motor 141 to which It is secured as by the opposed nuts 142. Cylinder motor l4l has a piston 143 having a piston rod 144 which makes a threaded connection with electrode pin support bar 27 as at l45 and secured thereto by the lock nut 146, as may best be seen in Figure 5.

In contrast with the electrode pins 22, the holding or indexing pins 25 are formed of relatively low conducting material such, for example, as steel, as in their common support bar l 7 to which they are secured as by making a forced fit therewith, the pins, for this purpose having a reduced diametrical end portion 148 , Figures 4 and 5 · As in the case of the electrode pins, the holding or indexing pins 2J have pointed tips l49 in order to facilitate entry into the core and beneath the ribbon section being added thereto.

Support bar l47 for the indexing pins 12J is formed of angular stock and secured to a slide plate 151 as by suitable fastening means 152. Slide 151 is movably supported by a plate 153 with which it makes dovetail connections Indicated at 15 , Figure 4. Power means for moving pin assembly 23 including slide 151 relative to plate 153 is provided by the air cylinder motor 155 which is secured as by nuts 156 presented .^ t on to a mounting plate 157, in turn, suitably '- ' :. '.. I.,,'.... ;.;« ^ι.'Λύ ' m^ o ¾5 ^i. a piston 158 having a rod 159 which makes threaded connection with the pin support bar l47 as at l6l and secured thereto by the locking nut 162 .

Plate 1 3 is supported on and suitably secured to a plate 163 , Figure 4, which, in turn, is supported on and suitably affixed to a slide 164 which is mounted for sliding movement in tracks 16 and l66 Fi ure with which it makes dove tail, connections as at 167 and 168 respectively. Tracks 165 and 166 are secured as by suitable fastening means l69 to a base plate 171 which extends between and is suitably secured to depending portions 173 and 174 of side frame members 37 and 38 respectively. Base 171 further comprises and is strengthen- ed by vertically disposed cross members 175 and 176 and vertically disposed longitudinal members 178, Figure 4, which extend between the cross members.

As may best be seen in Figure 4, power means for moving the indexing pins and its supporting structure including slide l64 to either side of the central position shown in Figure 4 arid selectively adjacent to the side frame members 37 and 38 respectively, is provided by an air cylinder motor 17 which makes a threaded connection with side frame plate 38 as at 181 and secured thereto by the lock nut l82. Cylinder motor 179 has a piston 183 having a piston rod 184 which makes threaded connection with plate 163 as at I85.

Prior to welding of the ribbon layer being added to •the core, the core portion disposed between side frame members 37 and 38 s generally supported by the electrode pins 22. After welding of all of nodes has been completed following forward and return sweeps of the welding wheels 25, the electrode pins 22 are withdrawn from the oore and the core is then supported by the indexing pins 23 by reason of the ribbon section disposed thereabove which has Just been bonded to the core. Support of the core by the indexing pins continues, as the core is shuttled thereby to the right or to the left as viewed in Figure 4. When the indexing movement is complete, the electrode pins re-enter the oore as the indexing pins withdraw therefrom. Thus, during the indexing movement of the machine along the length of the core in adding the new ribbon layer thereto, the portion of the core between the side frame members 57 and 58 is supported by either or both sets of the electrode and indexing pins. When the end of the core is reached, however, both indexing and electrode, pins must be removed therefrom in order to lower the core to proper position for addition of the new ribbon layer thereto. It is therefore necessary at such time to provide supplemental means, presently to be described, for supporting the core, this means also serving to support those portions of the core which extend laterally beyond the sides of frame members 57 and 58.

This supplemental core support simply comprises a pair of elongated members 186 and 187 disposed respectively below stripper bars 107 and 111 and, like the stripper bars are disposed substantially in face adjacency with respect to opposite faces 109 and 115 °f "^1® core. Member 186 Is connected by suitable angle brackets l88, Figure 5, to opposite side 8 of base 55, and member 187 is similarly connected by suitable angle brackets 189 to the depending portions 175 and 174 of side frame members 57 and 58 respectively, Figure 4. Members l86 and 187 may extend for considerable distance of the order of upwards of 20 feet beyond frame side plates 57 and 58 of the machine and may thus be employed to fabricate panels of honeycomb core of great length as measured along the length of the ribbons. In any event, the length of the oore will be a multiple of the length of the shuttling movement of the core in either direction. Suitable means, not shown, may be employed to support the extended end portions of members l86 and 187 when this is necessary in the fabrication of core of relatively great dimensions and weight.

A plurality of manually insertable pins 191 are em bridging across these members much in the same manner as the electrode pins bridge and rest upon stripper bars 107 and 111. When it is desired to lower the core, both electrode and indexing pins being withdrawn therefrom, it merely becomes necessary to withdraw the pins 191 to permit the core to fall vertically between bars l86 and 187 until pins 192 engage the elongated members 186 and 187 in the same manner. Thus, pins 192 may have been positioned one-half cell width above the pins 191, and, further, upon withdrawal of the pins 191, they may be Inserted into suitable cells disposed a half-cell width a-bove pins 192 to thus plaoe the oore in readiness for a subsequent lowering movement with respect te support bars 186 and 187. It will be understood that pins 191 and 192 could be operated by solenoids, for example, when it becomes desirable to make this lowering operation of the core fully automatic. · In the partially schematic arrangement disclosed in Figures 4a and 4b, pins 191 and 192 are disclosed as spring urged plungers of solenoids 195 and 1 respectively, the springs 200 being arranged such that the pins 191 and 192 are normally urged thereby into the core and in bridging relation with respect to core support members l86 and 187· It will be understood, of course, that only one of pins 191 and 192 is actually in engagement with the members l86 and 187 at any time Solenoids 195 and 194 are mounted on a heart shaped cam 195 which is supported for rocking movement as at 196 in a V-shaped block 1 7. Block 197 Is slldably supported upo member I87 which for this purpose is formed as a member of angular configuration designated 187* and having the horizontally extending le 198. The upper surface 199 of leg 198 upon which block 197 slides has a pair of spaced electrically conducting tracks 20J and 204 which are res ectivel en a ed b. slidin contacts 202 and 201 which are suitably carried by block 197. These slide contact s are respectively engaged by terminals of solenoids 195 and 19 , the other terminals of which are grounded.

It will be understood, that when it is desired to ■ lower the core 19, that the same must also be shifted eithe to the right or to the left , as the case may be , by one-half cell width, the movement effectively being diagonally downward at 450 e ither to the right or to the left as viewed in Figure 4 and as indicated by the arrows in Figure 4a. In the arrangement of the parts as shown in Figure 4a in which it is assumed that the core is supported by pins 191, when solenoid 195 is energized, pin 191 is withdrawn into the solenoid and pin 192 moves in the direction of arrow 206 by reason of the pivotal point 19β which the support 195 make s with block 197 and thus cause s the core now supported by pins 192 to be similarly rocked. As pin 192 moves to engage the surfaces; of support members 186 and 187, pin 191 moves in a direction reverse to that indicated by arrow 205 to assume a position upon de-energlzatlon of solenoid 195 which will permit pin 191 to enter into a cell of the core disposed one-half cell width above the core support members l86 and 187 and thereby be in readiness for the next or subsequent lowering of the oore after another ribbon layer has be en bonded thereto . When this operat ion is completed, and solenoid 194 energized to withdraw pin 192 , pin 191 and. the core supported thereby then move in the direction of arrow 205 to lower the core and shift the same in the reverse direction by. one-half cell width, the parts then being again in the position shown in Figure 4a. It will be understood that as many solenoid actuated pin assemblies such as disclosed in Figure s 4a and 4b may be employed along the member 187* as necessary to support a core 19 of particular length.

As may be seen in Figure 5, core 19 must be built up by several layers between the pins 22 and the support members 186 and 187 before the core can be supported thereon by pins 191 and 192 . Accordingly, an arrangement has been provided as disclosed in Figure 5a in which an elongated wood member 207, or the like, is perforated as at 208 to simulate the core. The core .itself rests on the upper surface 209 of member 207 until it has been built up sufficiently to be supported by pins 191 and 192 as before described.

When each of the ends of core 19 Is in position at the welding station comprising electrode pins 22 and welding wheels 25, two welding operations are performed before shut-tllng of the core again occurs. The first of these occurs prior to lowering of the core by one-half cell width preparatory to adding a new ribbon layer thereto, and the second occurs following lowering of the core and reverse winding of the ribbon 20a about the right end indexing pin 25 , as best seen in Figure.2. This reverse winding of the ribbon about the end pin 25 may be accomplished manually, or automatically, there being adequate clearance for this purpose and for training the ribbon 20a over the remaining index pins 25 by reason of the wheels 2 and holding fingers 24 being poised well above the ribbon and pins as best seen in Figure 1, and by reason of the wheel carriage being fully withdrawn at this time. As a result of the reverse bending of the ribbon at the ends of the core, these ends 211, Figure 4, are given a rounded configuration as best seen by the ends designated 211A and 211B in Figure 2. End 211A was moved into its position as shown in Figure 2 from a prior position in engagement with the end electrode pin 22, the movement between these two positions having occurred when the core was lowered diagonally downward to the right by one-half cell width in the manner aforede scribed. The core thus . makes a one-half cell movement in the direction opposite from that of the last shuttling movement in either direction of movement of the core along the length of the ribbon. This has the advantage in that the end face s of the core as def ined by the ends 211 lie at right angle s to the sides of the core . which lie along the length of the ribbon . Further shut- , tling of the core will move the same to the right as viewed In Figure s 2 and 4 , until the left end of the core moves into the welding station. Following welding of the alternate nodes in this end position, the core will be lowered diagonall downward to the le ft by one-half cell width and, following reversal' and re-alignment of the ribbon over the indexing pins 25 , t he series of shuttling and Welding operations . will continue until the right end of the core again re sumes it s posit ion at the welding stat ion . At this time however, end 211B will then be in engagement with electrode pin 22 at the extreme right in Figure 2.

Referring again to Figure 4 , a pin 191 at left end of core 19 is arranged to engage a switch 212 to close the same when the right end of the core shuttles into the welding station, as shown. In the following one-half cell movement of the core to the right , switch 212 is again opened. Similarly , pin 192 placed at the right end of the core is arranged to engage a switch J&13 and close the same as the left end of the core shuttle s into the welding station . Switch ¾13 again opens In response to movement of the core by one-half cell width t o the left , as aforede scribed. Switche s 212 and 212 conveniently may be mounted for attachment to member 187 in different positions along the length thereof in accordance with the length desired cuit hereinafter to be described to operate as limit switches and assure that a reversal in the shuttling direction occurs at the proper time.

The corrugated ribbon 20a is directed toward either side of the welding station by an elongated J-shaped guide 2l4 which, when in its full line position of Figure 4, directs the ribbon into the left side of the welding station and, when in the dashed line position, directs the ribbon along the line 215 into the right side of the welding station. For this purpose, guide 2l4 is mounted on a pair of spaced brackets 216, 217 which conveniently are secured to side frame 58 as by fasteners 2l8. The ribbon is directed to guide 214 by way of. a second guide 219 which is secured to and supported on a bracket 221 which forms a part of the corrugator generally, designated 222.

Corrugator 222 comprises a base 22^ to which bracket 221 is secured and upon whloh is mounted a die 224 appropriately formed in matching relation to the multi-stage punches 225, 226, and 227 to provide the desired corrugations in the ribbon disposed therebetween when the press 228 is power driven to bring the punches and die in lnterfitting relationship. In the arrangement shown, the dual-punch 225 merely seats in corruga- . tlons previously formed to thereby hold the ribbon in position on the die while two additional corrugations are formed in the ribbon by punches 226 and 227' which form their respective corrugations in successive order. Provision is also made for perforating the uncorrugated ribbon 20B by spaced pins 229 which are carried by the press 228 and therefore pierce the ribbon as the press engages the die to thus complete the cycle of operations performed by the corrugator 222. When the press 228 is elevated to clear the ribbon, the ribbon Is advanced two cor- r u ation widths by a hitch feed of known type generally designated 251.

'Hitch feed 251 comprises a base 2J2 which is supported on the base 225 of the corrugator. A feed member 255 is slidably mounted on member or base 2^2 and has a roller 2^ which engages a cam 255 carried b press 228 of the corrugator. The arrangement is such that as the press lowers, the feed member.255 is driven thereby to compress a coil spring 256 disposed between feed member 255 and a member 257 fixed to base 252. The initial spacing between members 235 and 237 is ad- usted by a rod 258 upon which coil 256 is sleeved.. Ribbon 20B is guided between each of members 255 an The operation of the machine, as thus far described, in fabricating, honeycomb core will best be understood by now making further additional reference to Figures 7 and 10. It will be understood that the core may be built up in as many layers as required and timmed or sheared below the support mem-bers 186, 187 to thereby leave a block of core in operative relation to the parts of the machine in order to facilitate subsequent fabrication of additional core or, alternatively, when it is desired to start fabrication of the core from the first ribbon layer, the aforementioned block 207 may be inserted be 186 and 187 "by uae of pin3 191 and 192. Assuming the latter case, with block 207 then generally occupying the position of core 19 in Figure 4 and with the electrode fingers 22 bridging the stripper bars 197 and 111 and disposed directly above block 207, guide 214 is then moved to its dashed line position. Following' line 215, ribbon 20A is then drawn under the welding wheels 25, over the pins 22, and thence over the length of block 207 as required to provide the desired length of core. The indexing pins 25 are next advanced over the ribbon and into bridging relation above the stripper bars and in nesting engagement with the electrode pins 22. Guide 214 is now returned to. its full line position as seen in Figure 4 and the corrugated ribbon is trained about the indexing pin at the extreme right in Figure 4, trained under the welding wheels 25 and aligned into engagement with the remaining Indexing pins such that the nodes of the upper and lower ribbon layers are aligned over the electrode pins. The^ ribbon will then extend from the indexing pins in guiding relation to the guide 2l4 in the manner as shown in Figure 4. The machine is then ready for automatic operation.

. Referring first to Figure 8, operation of the machine s started by closing switches SI, 32, and S3 manually. When push button switch SI is closed, energy from a generator G is supplied to the corrugator by way of a line 24l and a time delay relay 242 of conventional design. Energy is also applied by way of line 24l to the solenoid retained push button and to the wiper ¥1 and W2 of a conventional stepper switch comprising an actuating coil 24^ and a third wiper ¥5. The operation of the stepper switch is such that when coll 24j is energized, the wipers of the switch, which are all ganged as indicated by the dashed line therebetween, step ahead by one step into engagement with the succeeding contact in the bank of contacts individual thereto. Thus, when switches SI, S2 and S3 are closed., a circuit is completed to coll 243 of the stepper switches to advance the wipers of the switch from contact A to contact B of their respective banks, this circuit being completed from the generator G- by way of switch SI, line 24l, switch S3, parallel connected and normally closed switches S4 and S6, normally closed switch S7* contact A in contact with wiper WJ, section Rl of the full wave rectifier, switch S2 , stepper switch coil *243, and thence by way of rectifier section R2 to line 245 connected, to the other, side of generator On the reverse cycle of generator G, current passes by way of rectifier section R3, switch S2,, in the same direction through coil 243 and thence ; to rectifier section R4 and back through the circuit just traced through swi ch S3 and switch SI to the generator. Switch S3 is normally spring biased to open position but once actuated to closed position remains in this position as long as its actuating coil 244 remains energized. Coil 244 is connected between line 245 an Switches S4, S6 and S7 are best shown in Figure 7 wherein it may be seen that switches S4 and S5 and similarly, switches S26 and 327, are ganged together and closed as by support bar 27 for electrode pins 22 whenever the pins are advanced into core engaging position. Similarly, switches S6, S7, S8, and S9 are ganged together and closed as by support bar l48 for indexing pins 23 whenever the indexing pins are advanced into core engaging position as shown in Figure 7· Since it will be recalled that both sets of electrode and indexing pins were moved into this position in setting up ribbon 20a at the start of fabrication of core 19, switches S4 to S9 and switches S26 and S27 will all be closed.

When wiper ¥2 engages contact B, potential thereon is applied to coil 265 of a spring urged air valve 246. As best seen in Figure 7, valve 246 is noramlly urged by spring 2 ? into the position shown in which air under pressure supplied from line 248 is applied by way of line 249 to the liquid in. a tank 251. The air pressure in line 248 is supplied by way of valve 252 and at constant pressure as provided by regulating valve 255, the air under pressure being developed in tank 254 from the air compressor 255.

Liquid under pressure in tank 251 is applied by way of line 256 to the left end of piston 78 in hydraulic cylinder 75- Piston 8 is thus normally in its position as seen in Figures 7 and 7& in which position the welding carriage is retracted. Fluid at the head end of piston 78 is returned by way of line 257 to a tank 258 and the increase in air pressure therein is exhausted to the atmosphere by way of line 259 and valve 246.

It may also be noted that a second spring urged solenoid air valve 26l is positioned by its spring 262 such that air under pressure from line 248 is normally applied through valve 261 and line 265 therefrom to the tube 54 whereupon the tube is inflated and the welding wheels 25 are elevated in the manner aforedescribed. Air in tube 55 is exhausted by way of line 264 and thence through valve 2 to the atmosphere. Upon actuation of valve 246 by energization of its winding 265, air yrU-Av t from line 248 is applied via line 2 from the , vaivs- and then to tank 258. Air pressure on the liquid in tahk 258 applies a fluid pressure via line 2 7 to the head end of piston 78 whereupon the piston is moved to advance the welding carriage .

As movement of the welding carriage progresses, a cam 266 carried thereby engages a roller 267 and actuates a switch S10. Shortly thereafter a second cam 268 engages a roller 269 to actuate the same and close switch Sll. Cam 268 is shorter than cam 266 and hence switch Sll is the first to open as rollers 26 and 267 roll down the inclines at the trailing ends, of their respective cams 268 and 266.

When switch 310 closes, see also Figure 8, a circuit is completed by way of a generator G, conductor 271, and switch S10 to the actuating winding 272 for solenoid valve 26ΐ„ winding 272 being connected to conductor 245 and thence to the other side of generator G. On energization of winding 272 , solenoid air valve 26l is actuated to apply air pressure from line 248 through the valve and line 264 to tube 55 whereupon this tube is inflated to lower the welding wheels 2 in the manner aforede scribed and air in tube 54 simultaneously is exhausted to the atmosphere by way of line 265 and valve 26l.

When switch Sll, see also Figure 8, Is closed, potential on lines 245 and 271 is applied across primary winding 275 which is disclosed as exemplary of the transformer system of the present invention. Voltage induced in secondary winding yft bf 25 connected in series through the eleotrode pins with which they are brought into electrical contact by way of the abutting nodes of the ribbons disposed therebetween, the pins so engaged completing the series circuit by way of their shorting support bar 27 in the manner aforedescribed. It will be understood that each of the other two pairs of welding wheels 25 are similarly connected each to its own secondary winding 274 , only one of the three pairs of series circuits being shown in Figure 8 for the sake of brevity. It will be understood further that the moment of contact of cam 268 with its coacting roller 269 and the length of the cam 268. are such that current flows to the welding wheels 25 approximately at the moment that the wheels engage the nodes to be welded thereby and that the flow of the welding current is discontinued approximately at the moment that the welding wheels leave the nodes in the course of the · sweep of the welding wheels across the ribbons.

Shortly after switch Sll opens to discontinue the welding current, roller 267 leaves cam 266 whereupon switch S10 opens and winding 272 of air valve 26l becomes de-energized to thus restore the valve under power of spring 262 to the position s shown In Figure 7· I this position, of course, tube, , 54 is inflated and tube 55 deflated such that the wheels 25 are elevated. Thus, as the welding carriage approaches the end of its forward stroke and is shifted sideways by one corrugation width as cam ll8 engages cam 127, Figure 7a , the welding wheels 25 are elevated sufficiently to clear the holding fingers 24 as aforedescribed. 1 In the operation of the machine as thus far described, one-half of the welding cycle has been completed and the welding wheels 2 have advanced from their positio shown In Figure A to that of Figure 9B. It will be noted in Figure B that the welding wheels 2 are now in position to sweep back across the intermediately spaced electrode pins 22 to complete the welding cycle. This is initiated by switch" S12, Figure 7a, which is closed by cam ll8 as the same is shifted sideways upon engagement with fixed cam 127.

Referring again to Figure 8, when switch S12 closes, a circuit is completed to ooil 24? of the stepper switch by way of potential on wiper Wl in contact with contact B, switch S12, and wiper in contact with contact B. Accordingly, the wipers of the stepper switch are advanced to contact C. When wiper W2 moved out of contact with its contact B, the circuit to winding 265 of air solenoid 246 was broken and valve 246 moved under power of its spring 247 to thus position the valve for return of piston 78 to the head end of cylinder 75 to thus cause the .welding carriage to "begin the sweep of welding wheels 2 back across the aligned ribbons. On the return stroke, switches S10 and Sll are again operated by their respective cams 266 and 268 to again lower and subsequentl raise the welding wheels 2 and, during their period of engagement with the ribbons, to provide for passage of the welding 'current, all in the same manner as aforedescribed. As the » welding carriage nears the end of its return stroke, cam ll8 engages' and is actuated by cam 12^ to return the welding carriage to its Initial position as depicted in Figures 7a an As switch S15 again becomes closed upon full retraction of the weldin carriage, a circuit for energizing winding 245 of the stepper switch is completed by way of potential on wiper Wl in contact with its contact C, switch 315, and wiper 5 in contact with its contact C. Accordingly, the wipers of the stepper switch are advanced into engagement with their respective contacts D. In this position, potential on wiper W2 in contact with the contact D Is applied to winding 275 of a solenoid controlled air valve 276, the winding being connected between contact D and conductor 245 at t e other side of generator G.

Referring to Figure 7, it will be seen that prior to energization of winding 275» valve 276 is in such position that air pressure on line 248 is applied by way of line 277 to the head end of piston l4j in cylinder l4l whereupon piston l4j occupies the rod end of cylinder l4l to thus position the electrode . fingers 22 in their core engaging position as aforementioned. Upon energization of winding 275, air valve 276 is actuated thereby such that air pressure on line 248 is now directed by way of line 278 to the rod end of the cylinder motor l4l and thus the piston l4^ is driven toward the head end of the cylinder to withdraw the electrode fingers 22 axlal-ly from engagement within the core as depicted in Figure 9D. As support bar 27 for electrode pins 22 moves into its fully retracted position, a switoh Sl4 is olosed thereby to provide for further energization and stepping of the stepper switch, the circuit to winding 24^ of the stepper switch now being completed by way of potential on wiper Wl in engagement with its contact D, switch Sl4, and wiper W5 in engagement with its contact D. Accordingly, the wipers of the stepper switch are advanced into engagement with contacts E.

In position E of the stepper switch, potential on wiper W2 is applied by way of its contact E in engagement therewith to the pole 279 of a manually controlled double pole double throw switch generally designated 28l. In this position of switch 281 as shown in Figure 8, potential on pole 279 is applied by way of closed switch 39 to a winding 282 of a solenoid actuated air valve 285, the winding being connected on the other side to conductor 245 whereupon the same is energized from generator G-.

Upon energization of winding 282 of solenoid valve 285, see also Figure 7, the valve is moved from the spring-urged Inactive position shown into a position in which air pressure from line 248 is applied by way of line 284 to the head end of cylinder motor 179. Piston 183 then moves from a central position in cylinder 179 to which it previously had bee limited by reason of the hand manipulated block 285, see Figures 4 and 7» Interposed between side frame member 38 and slide support member 153 , to the rod end of cylinder 179. Piston rod l84, which makes connection with the indexing pin assembly including slide support 153 , accordingly moves this assembly and core 19 supported on the Indexing pins to the right as viewed in Figure 4 and as depicted graphically in Figure 9E-.·■· Referring again more particularly to Figure 7 , as piston 183 approaches the rod end of cylinder 179 , a pair of. ganged switches S15 and 3ΐβ are engaged and closed as by slide support member 15 . T*ie circuit controls effected by these switches are disclosed in Figure 8 wherein it may be seen that switch 315 connects time delay relay 242 to conductor 24 at ,Xhe other side of generator G whereupon relay 242 is operated for a predetermined interval of time to supply current by way of line 286 to corrugator 222 to operate the same, the interval of operation of the time delay relay being adjusted such that 12 additional corrugations are formed in ribbon 20B supplied by hitch feed 231 during the interval in which the time delay relay is operated "thereby to replace the 12 corrugations just previously shuttled from the welding station and added to the core 19 during the welding cycle of wheels 25 in sweeping forward and back across the ribbons aligned on the electrode pins.

When switch Sl6 closed, it completed the energising circuit to winding 24 of ^e stepper switch by way of potential on wiper Wl in contact with contact E, switch Sl6, and wiper W3 in contact with its contact E whereupon the wipers are advanced to their contacts F. In this position, wiper W2 applies potential thereon by way of its contact F to actuating winding 287 of solenoid valve 276 to thereby position the same such that air under pressure in line 248 is applied by way of valve 276 and line 277 whereupon pressure on the head end of piston l4^ moves the same toward the rod end of cylinder l4l with the result that the electrode pins 22 are moved axially to re-enter the cells of core 19. Simultaneously, with the energization- of winding 287 of solenoid valve 276, potential on wiper l is applied by way of Its contact F to an actuating winding 288 of a solenoid air control valve 28 ·· Prior to en erglzation of winding 288, solenoid valve 289 is in the position shown in Figure 7 wherein air pressure on line 248 Is applied by way of the valve and line 291 to the head end of piston 158 in cylinder 1 5 with the result that the piston occupies the rod end of cylinder 15 which Is in the position required for the indexing pins 25 to be in their core engaging position. Upon energization of winding 288, valve 289 is positioned such that air pressure on line 248 Is applied through the valve by way of line 292 to the rod end of piston 158 to thus move it toward the head end of cylinder 155 and thus withdraw the indexing pins 23 from engagement with core 19, this position being depicted graphically in Figure 9F wherein it may be seen that the electrode pins 22 have re-entered the core and, simultaneously, with such re-entry, the indexing pins 25 have withdrawn from the core .

A switch S17 is closed as by support bar 148 for the indexing pins 25 when these pins become fully withdrawn from the core. Switches S4 and S5 are also again closed as the electrode pins 22 simultaneously re-enter the core as the indexing pins 25 withdraw therefrom. When switches S5 and S17 are both closed, as is now the case, a circuit Is again completed for actuatin the ste er switch b wa of otential on wi er in- engagement with contact F^ switches S17 and S5, and wiper W5 in engagement with its contact F. Since winding 24 of the stepper switch is energized through this circuit, the wipers of the switch are advanced into engagement with their contacts G.

In position G of the stepper switch, potential on wiper W2 is applied by way of contact G connected to pole 295 of double pole double throw switch 28l and thence by wa cf switch S26 to winding 2 of solenoid control air valve 285. Upon energization of winding 294, solenoid valve 283 is moved into position thereby such that air pressure on line 248 is applied by way of the valve to line 295 in communication with the rod end of air motor cylinder 179 with the result that piston 185 is returned towards its center position as shown in Figure 7, in which position it is stopped by reason of the aforementioned hand manipulated block 285 being Interposed between the slide su'pport 155 and side frame member 58. Indexing pins 25 are thus returned by piston 185 and interconnecting rod l84 to their positions of approximate axial alignment with electrode pins 22 but still withdrawn therefrom and from the core as depicted graphically in Figure 9G. As the indexing pins return to this position, the roller 296 for actuating switch Sl8 is engaged as by the common support bar 148 for the Indexing pins 25. As switch Sl8 closes, a circuit is again completed for energizing the stepper switch by way of potential on wiper Wl in engagement with contact G, switch Sl8, and wiper W5 in engagement with its contact G whereupon winding 245 is energized and the wipers of the stepper switch are advanced into engagement with their contacts A.

In position A of the stepper switch, potential on wiper W2 in engagement with its contact A is applied to winding 2 7 of air solenoid control valve 28 with the result that the valve is positioned to apply air pressure on line 248 by way of the valve and line 291 to the head, end of piston 158 whereupon the same is moved toward the rod end of cycle 155 and the indexing pins 25 are moved to re-enter the core 19, the electrode and indexing pins now occupying the positions relative to core 19 and wheels 25 as depicted in Figure 9H. A complete cycle of operations involved in a normal shuttling movement of the core 19 has now been completed, it being noted that the position of the electrode and indexing pins and the welding wheels are the same in Figure 9H as Initially in Figure 9A, the disclosure of these partial figures differing only in that the core 19 is advanced to the right as seen in Figure 9H.

During the previously described cycle of operations involved in the shuttling movement, switch S4 opened as the electrode pins 22 withdrew from core 19. However, at this time, indexing pins 25 were in their core engaging position and hence switch S6 was closed and was still closed when the electrode pins re-enter the core to again close switch S4. Consequently, when switch S6 opened as the indexing pins 25 were withdrawn from their core engaging position, switch S4 was closed to maintain and continue energization of winding 244 for holding switch S3 in its actuated position. Thus, when switches S6 to S9 again closed as the indexing pins were returned to their core engaging position, the circuit is automatically completed through switch S3 and switches S4, S6, and S? to recycle the stepper switch through its contacts A to G- to again shuttle the core to the right, as viewed in Figures 4 and 9, by α».©¾&4 crement of corrugation widths or group of nodes corresponding to the number of the electrode pins and hence to the number of nodes welded during each cycle of the welding operations, this being 12 in number in accordance -with the arrangement disclosed This shuttling movement to the right is continued as many times as necessary to bring a pin 192 at the extreme right end of the core 19 into actuating engagement with switch 15, Figure 4. Upon actuation of switch 215, its ganged switches 319 arid S20 are closed. As ma be seen in Figure 8, switch 319 connects winding 288 of solenoid valve 289 to contact D engageable by wiper Wl of the stepper switch. However, at this stage of the cycle of operations of the stepper switch in shuttling the core into its end position for actuation of switch 215, the wipers of the stepper switch are in engagement with their contacts E which, it will be recalled, is the position in which the potential on wiper W2 actuates solenoid valve 285 such that air motor 179 shuttles the indexing pins and core supported thereon. In position E potential on wiper W2 is also applied by way of contact E to switch '321 which is ganged with switch 317. However, since the indexing pins are not withdrawn these switches are not closed at this time. Consequently, the stepper switch completes this shuttling cycle which has moved the core into its end position, and continues into its next cycle through positions A, B, and C to complete the welding cycle, as aforedescribed.

When the welding cycle is completed and the wipers of the stepping switch move into position D, potential on wiper W2 is effective, as before, in engagement with contact D to cause valve 276 to effect withdrawal of the electrode pins 25. In addition to this movement in this position, wiper Wl in contact with its contact D also applies potential by way of switch 319 to winding 288 of air valve 289 with the result that the' indexing pins 25 are also withdrawn from the core at this time. As a result of the withdrawal of all the electrode and indexing pins, all of switches S4 through S9 are now open with the result that holding winding 244 for switch is de-energized and switch SJ is opened. Switch Sl4 closes, as before, with withdrawal of electrode pins and, as a result, the wipers of the stepper switch are advanced into position E, as before-described. Wiper W2 in this position is ineffective to actuate the shuttling valve 285 by reason of switches S8 and S9 and switches S26 and S27 now being opened. Potential on wiper W2 however, is applied by way of its contact E and switch 21, which closed upon withdrawal of the indexing pins, and a circuit is thus completed to ground by way of switch S20 conductor track 205 , sliding contact 202 , and solenoid winding 194 whereupon solenoid winding 194 is energized to retract pin 192 and thus lower the core diagonally downward and to the left by one-half cell width.

This movement of the core to the left re-opens switch 215 and pins 192 re-enter the core under power of their springs 200, the parts then being in the positions as indicated in Figures 4b and 4a . At this, time potential on wiper Wl in contact with its contact E is applied by way of closed switch Sl8 which is closed at this time by reason of the indexing pins 25 being withdrawn from the core. Switch Sl8 is connected in parallel with switches S25 and Sl6, and a circuit is completed in lieu thereof by switch Sl8 to step the stepper switch from its position E to its position F to effect return of the electrode pins into their core engaging position in the manner aforedescribed. Since the indexing pins at this time are al- , ready withdrawn, potential on wiper Wl in contact with its contact F is ineffective at this time to withdraw the indexing pins. Although switch S17 is closed by reason of the indexing pins being withdrawn, wiper Wl in contact with its contact F la not effective to move the stepper switch into its position G- until switch S closes upon return of the electrode pins into .their core engaging position. It will thus "be seen that the arrangement is such that the stepper switch cannot advance from position F to position G- unless two conditions exist; namely, that (1) the indexing pins are withdrawn and (2) the electrode pins are in core engaging position.

In position G-, wiper W2 in engagement with its contact G- is ineffective to operate the solenoid valve 285, al- ■ though switch S26 is closed, "by reason of the already retracted position of the indexing pins 2 . By the same token, switch Sl8 is closed and potential on wiper Wl in contact with its contact G^ is effective through switch Sl8 and wiper W5 in engagement with, its contact G- to complete the circuit to winding 245 of the stepper switch and thus advance the same to its position A in which a circuit is complete, as before, to effect return of the indexing pins into their core engaging position.

Although switches S4, S6, and S7 become closed as the indexing pins return to their core engaging position, it will be recalled that holding winding 244 for switch S5 became de-energized when both of switches S4 and S6 opened with withdrawal of both the electrode and indexing pins as the wipers moved into the position D during the previous switching cycle of the stepper switch. Accordingly, further automatic operation of the machine is brought to a stop to permit adjustment of ribbon guide 2l4 into its dashed line position as shown in Figure 4 and to permit reverse winding of the ribbon around the left most indexing pin and training of the ribbon under the welding wheels 25 and over the remaining indexing pins 2 such that the ribbon will now lie along the line 21 in readiness for the core 1 to be shuttled to the left as viewed in Fi ure 4. In addition to these preparations, hand manipulated block 25 must now be removed from the lef side of the machine and inserted between slide support 155 and the right side frame member 5^ into the position indicated by the dashed lines in Figure 7. With reference to Figure 8, double pole double throw sxitch 281 must now be moved into its position as Indicated by the dashed lines. With these preparations completed, the machine is now in readiness to perform the first welding cycle of the alternately aligned nodes at the extreme left end of the core.

The welding cycle is started, as before, by depressing switch S5 and the operations of the machine are the same as described before for a normal shuttling movement of the core with the exception that with switch 28l in its dashed line position, windings 282 and 2 are energized through switches S27 and S8 respectively and in reverse order from that heretobefore described in order that piston 183 will be moved from its central position to the head end of cylinder 179 to thus shuttle.' the core to the left as viewed in Figure 4. Upon withdrawal of the indexing pins from the core, the piston is returned to its central position to thus return the electrode pins into their position of axially extended alignment with the electrode pins, the return movement of the indexing pins being terminated in this' position by reason of block 285 now occupying its dashed line position as indicated in Figure 7.

As the indexing pin assembly approaches its shuttling movement to the left as viewed in Figure 4, it engages and closes a pair of ganged switches S22 and S25 which respective- . ly energize the time delay relay 242 to thus operate the cor-rugator and energize winding 24j of the stepper switch to thus by switches S15 a d Sl6 as heretofore described.

Shuttling of the core to the left in increments of 12 corrugations at a time is thus accomplished much in the same manner as the shuttling of the core to the right as afore-described. When the extreme right end of the core reaches the welding station, switch 212 is engaged by a support pin 191 and actuated thereby. When this happens, its ganged switches 325 and 324 are closed such that on the following cycle of the stepper switch both the electrode and indexing pins are withdrawn as the wipers move into position D and solenoid 193 is actuated to withdraw pins 191 as the wipers move into position E. Consequently, the core is moved diagonally downward to the right by one-half cell width to thus again open switch 212.

The stepper switch then completes its cycle, as beforedescrlbed, and stops at the end of this cycle by reason of switch S3 being open to permit winding and aligning of the ribbon into the position as shown in Figure 4. ' . , The machine has now performed a complete cycle of operations in that the core has 'first been shuttled over its length in one direction, to the right as disclosed, and then shuttled over its length in the reverse direction, this being to the left in the assumed example. By way of summary, this shuttling movement of the core first in one direction along the length thereof, and then in the reverse direction is depicted graphicall in Figure 10 wherein the electrode pins are designated by the letter e and the indexing pins are designated by the letter i. In Figure 10A the'- -core 19 is v:·.:.: 3d in readiness for welding and then shuttling to the right. In Figure 10B electrode pins are shown withdrawn from the core and the core advanced to the right with the indexing the core and the indexing pins..simultaneously therewith will withdraw from the core, after which the indexing pins will shift to the left and re-enter the core as shoxra in Figure IOC. Following the welding cycle, the electrode pins will again withdraw from the core and the core and the Indexing pins will again shuttle to the right as depicted in Figure 10D. Figure 10E depicts the electrode and indexing pins back into core engaging position to complete the final welding cycle to be performed on the core in its excursion from position A to position E. Following rewinding of the ribbon and with the electrode and indexing pins in the positions shown in Figure 10E, the first welding cycle to be performed on the newly added layer is begun. Upon completion of the welding cycle in position E of Figure 10, the core is shuttled to the left as depicted in Figure 10F and again welded in the position indicated in Figure 10G-. The core is thereafter shuttled again into its final position to the left as indicated in Figure 10H and the final welding cycle is completed in the position depicted in Figure, 101. Following lowering of the core in this position, the parts will occupy the same position as depicted in Figure 10A and a complete cycle of operations xill have been completed.

In order to make the machine as heretofore described fully automatic in operation, the aforedescribed structure, controls and circuits are modified as disclosed in Figures 12 to 19. The comparative disclosures of Figures 4 and l8, for example, indicate a modification of the machine wherein the plungers 351 -and 552 of solenoids 555 and 554 , respectively, are arranged to pass through openings 555 and 55 formed in frame plate 171 to thus engage opposite sides of the shuttling slide 164 . member 1 6 as by the brackets 557- Plungers 552· and 35-2 are respectively pivotally connected to a rocker arm 358 as by the pivot pins 5 and 560, the arm, in turn, being pivotally connected as by the pivot pin >6l ¾° a supporting plate 6? which is suitably secured to frame member 176, as shown.

Plungers 351 and 3 2 serve the purposes of the manu- . ally manipulated shuttling block 28 , Figure · In addition plunger 351 operates the shuttling control switch 28l, Figure 8, this being manually manipulated as heretofore, described.

Similarly, plunger 52, Figure 19, operates a switch 264 which, in turn, serves to energize the control solenoid 5& fo the cylinder 566 whose piston 5 7 operates through piston rod 368 to move the ribbon feed and guide mechanism ^9 alternately to opposite sides of the indexing pins, as best seen in Figure 12.

Referring again to Figure 19, guide 569 when in its two stop positions operates a pair of switches 570 and 573-whieh are connected in parallel with each other and in series with switch 37 and parallel connected switches S4 and S6. One or the other of switches 570 and 371 is closed when guide ^9 is in a position of rest, but both are open as the guide begins its shuttling movement from one side of the indexing pins to the other. During this movement, in either direction, gange •switches 7 and 575» which are normally open, are closed as guide 369 moves to engage the switch actuator roller 374. On closing, switch 37 completes a circuit for energizing winding 244 to^ thus close switch S3 tfhich, for purposes of rendering the machine fully .automatic, is provided with back contacts designated 375· °n closing of either of switches 370 and 571» a circuit is completed through sxtfitsh Sf, as before, to step the wipers of the stepping switch from positions A to positions B. Switch 575 parallels switches 315 and S22 and, on closing, thus actuates the time delay relay 242 and corrugator 222 in 'the same manner as aforede scribed. The additional corrugated ribbon thus supplied meets the demand for additional ribbon as the guide 56 moves to lay the same down over the indexing pins., all in the manner later to be described.

The comparative disclosures of Figures 4 and 12 indicate the manner in which guide 369 serves to move the otherwise manually manipulated guide 2l4 between the dashed and full lined positions, of Figures 4 and 12. To this end, guide support 216 'of Figure 4 is deleted and a second support 217 is secured to frame member 38. Supports 217, in turn, support a pair of spaced elongated rods¾ 76 upon which are slidably mounted a' bridging slide block 377 and spaced slide blocks 388.

As best seen in Figure 13, guide 2l4 has side walls 279 by which the guide is suitably secured, as by welding, to the spaced slide blocks 378, as at 380 where the guide passes between the blocks. The guide is similarly secured in the region 381 to the bridging slide block 377. The slide blocks have openings 382 for slidably receiving the rods 37 , and these openings may accommodate linear bearings, or the like, when these are desired or required.

A pair of stops 385» one o each rod 376, serve to stop the guide in its dashed line position, Figure 12. Similarly, a pair of stops 384, one on each rod 376, serve to stop the guide in its full line position.

. Drive cylinder 366 is suitably threadedly mounted as at 385 to support 217, and piston rod 68 is threadedly secured to bridging slide block 77 as at 386. The slide blocks 377 ■ and 378 support depending and spaced plates 387 and 388 to which they are secured in any suitable manner, not shown. These lates are of inverted L-sha ed confi uration of which the depending leg portions are maintained in spaced relation as by one or more bridging members 58 , and in the region of their lower extremities, by a pair of spaced shafts 390 and 391 which are pressed into openings provided therefore in plates 38? and 388.

A pair of gears 3 and 393 are rotatively carried on shafts 390 and 391, respectively, and spaced thereon, as by the rotatably supported sleeves or rollers 394 and 395· Gears 392 and have predetermined spaced relationship, being spaced by a whole number multiple of the spacing between corrugations of the ribbon 20A being fed to the core 19. Thus, as best seen in Figure 15, gears 392 and 39 are spaced by six corrugation widths or, as otherwise expressed, six indexing pins 23 lie between teeth 396 and 397, respectively, of the gears. Likewise, six core ribbon nodes to be welded to six nodes of ribbon 20A when abutted therewith, lie in supported relation on the six electrode pins 22 which appear in Figure . Rotation of the gears is synchronized, as by the toothed driving B§lt connection therebetween, to assure that the gears track smoothly in the rack gear formations of corrugated 'f 20A and the upper surfaces of the indexing pins. To this end, each gear .has a hub extension 398 which is suitably grooved and provided with teeth to mesh with those provided on the inner surface of toothed belt 399.

In the arrangement as thus far described, ribbon 20A passes alon guide 214 and thence between plates 587 and 88 which serve as a chute to protect the ribbon and more or less direct the same into meshed engagement with one or the other of gears 3 2 and 393» the teeth of the gears conforming generally to the shape of the corrugationa in the ribbon. The gears so as to provide adequate clearance for the ribbon as it passes between the core and the gear in meshed engagement therewith. As suchj the gears are also at the proper level to engage smoothly with the indexing pins which are positioned within the troughs of the upper ribbon layer of the core, as may best be seen in Figure 15 .

·· As the core is shuttled in successive increments along its length, successive lengths of the ribbon 20A are drawn thereby into positions of alignment and abutment of its. nodes with those of the upper ribbon layer of the core, as may best be seen just to the right of gear 393, as viewed in Fig-, ure 12. As this occurs, ribbon 20A, in mesh with gear 9 , for example, rotates the same, and gear 3 operating through belt 599 rotates gear 592 . There Is no load on these gears so they rotate freely and thus avoid placing any strain or tension on the corrugated ribbon which, should this occur, might stretch or otherwise distort the ribbon and prevent the desired alignment, and abutment of the confronting nodes of the ribbon and "of the core to which it is being fed. Fortunately, however, the meshed relationship of the ribbon and its feed gear assures conformance between the nodal spacing on the core and that of the ribbon being fed thereto while at the same time the rotating feed gear not only precisely directs the ribbon into . the plane of the upper layer of the core, but does so without introducing any sliding friction in the process. The rotating friction, of course, is inappreciable, and the gears, through selection of the proper spacer rollers 594 and 395, may be made wide enough to provide adequate support for ribbons of varying widths. ' In setting up the ribbon at the start of fabrication, the electrode pins 22 are withdrawn, that is, they are backed out of the . plane of the paper as viewed in Figure 1.6, leaving only the indexing pins in the region of core fabrication. A length of ribbon such as depicted at 400 Is then drawn from guide 214 and passed under gear 595 and thence over and under the indexing pins. This length of ribbon 400 disposed beneath the indexing pins thus forms the bottom ribbon layer of the core to be fabricated, and its length determines the length of the block of core to be ultimately removed from the machine.

The configuration of the corrugations in the ribbon is such that the ribbon readily doubles back upon itself in the manner depicted at 401 in Figures 15 and 16, but best seen in Figure 17. In Figures 15 and 16, the indexing and electrode pins are simply shown as circles in order merely to show the arrangement and relationship of "the parts. These pins, however preferably are shaped in cross section as disclosed in Figure 17. These pins provide the clearance 402 in the bottom of the cell, as required to allow for tolerance variations in the ribbon thickness and to assure ease of entry and withdrawal of the pins into and out of the core. The pins, however, closely interfit the cells in the welding region 405 , as is required for forming satisfactory welding of the adjoining nodes, and also in the side regions 4θ4, as is required in order to assure continued precision alignment of the abutting nodes, as exemplified at 405, 4θβ. To further promote precision forming of the cells about the pins, the same are under out, as at 407, to accommodate any protrusions such as may result from the perforatin of the ribbon.

The side region 4θ4 also assists in the doubling back of the ribbon on itself since it supports the ribbon in the region of abutment of the doubled back and confronting same is already bent as at 4θ8, and gently yields In the side-wall regions 409 , in response to a reverse directing of the ribbon to double back the same, the net result being that the node 410 is readily displaced 90° from its normal position, and the node 4ll is displaced equally as well l80° from its normal position, all without otherwise distorting the ribbon. Whenever desired, or required, an additional indexing pin, having a cross section as enclosed by the ribbon portions 4l0 and 409 , may be employed at each side of the Indexing pins 2 in order further to facilitate the fold back of the ribbon upon itself.

Returning again to Figure 15, the ribbon section 400, thus folded around and under the indexing pins, presents a series of aligned and abutting nodes of the confronting upper and lower ribbon sections, there being a pair of such aligned and abutting nodes between each adjacent pair of Indexing pins 25, and the upper and lower ribbon sections are thus properly positioned to receive the electrode pins beneath the confronting nodes preparatory to welding the same together.

Figure 15 illustrates the manner In which the mechanized foldback of the ribbon is accomplished by the gears 59 and 5 5 · Referring first to Figure 12, and considering that guide 569 is being moved from its full line to Its dashed line position, gear ¾3 first rotates along, that is, rolls along ribbon 20A in mesh therewith as in the manner of a gear rolling along a gear track or rack, gear 59 being driven thereby through belt drive 599 and rotating freely. All the while, the ribbon 20A on the back side of gear 595 is being elevated thereby and returned in sliding movement back along the guide 214 as the same advances as a part of the moving guide 569. The core d been owere e h l e w d r r e of the guide movement, but the ribbon is being picked up by the back side of gear 595 and remains in mesh therewith as the gear engages the indexing pins and rolls therealong in mesh therewith. The ribbon depending from moving guide 2l4 and tethered to core 19 maintains a generally vertical position until after the tip of the guide passes to the right of the. point at which it is directly above the tethered point of the ribbon.' After this, the ribbon extends diagonally from the tethered point in a progressively decreasing angle as the guide 2l4 continues its movement. When gear 595 moves out of engagement with the ribbon, gear 592 shortly thereafter moves to engage the same and on further rotation assumes the position of Figure 15 in, relation to the ribbon which is then in fully meshed engagement therewith. At this time tooth 596 of gear 9 has moved the confronting nodes therebeneath into full abutting engagement, and the gear thereafter proceeds to bring succeeding pairs of confronting nodes into abutment as the gear continues to move along in meshed engagement with the indexing pins. As gear 592 thus begins its operation of laying the ribbon down onto the Indexing pins, the corrugator is operated, as will subsequently more fully appear, to supply additional corrugated ribbon for this purpose. When gear 592 moves beyond the indexing pins, it continues to rotate as it proceeds to lay down the additional supply of corrugated ribbon this being timed to cut off as guide 569 moves against stop 85 It will be apparent that the ribbon, is similarly doubled back mechanically over the indexing pins and laid there over when guide 569 moves from its dashed line position to it's rull line position as viewed in Figure 12.

The fully automatic operation of the machine will now be considered with reference to Figure 19. It will be recalled that in the aforede scribed partially manual operation of the machine, it was necessary that switch S3 open to prevent further cycling of the stepper switch through energization of its actuating winding 243. It was necessary that the machine stop so that the manually operated shuttling switch 28l could be reversed, the manually manipulated shuttling block 285 could be moved to the opposite side of the indexing pins, and so that the ribbon 20A could be doubled back and over the Indexing pins, all preparatory to initiating shuttling movement of the core in the reverse direction.

In the circuit control arrangement of Figure 19, potential on conductor 24l is applied by way of wiper Wl in engagement with its contact A, and thence by way of a switch S28, Figure 7, which closes when the indexing pins are inserted into the core, this it will be recalled, occurring as contact A of the stepper switch is engaged by wiper W2. Thus, as switch S28 closes, potential is applied via back contacts 575 of switch S3 and the. contact arm of switch 364 in engagement with its loiter contact to the winding on the right side of solenoid control valve 3 to thus complete the circuit thereto, the other side of this winding being connected to potential on conductor 245. Although this winding is thus energized, valve 365 doe B not move because it is already in the position to which it ia, normally moved by energization of the winding.

Potential on switch contacts 375 is also applied to solenoid windings 353 and 354, but winding 353 only is connected at this time by way of switch 364* to potential on conductor 2 5 and, hence only winding 353 ie energized. When this occurs, plunger 3 1 moves down to disengage from the left side of the slide 164, and plunger 352 moves upwardly to engage the op osite side of the slide. Shuttlin movement of the indexin pins to the right is thus blocked by plunger 552. Shuttling movement to the left, however, is now permitted, plunger 351 being withdrawn. As plunger 551 moved down, it reversed the position of the · shuttling switch to thus provide for shuttling movement of the core to the left.

As plunger 2 moved up, it moved the contact arm of switch & into engagement with its upper contact to thus complete the circuit to the left hand winding of solenoid valve 565, this winding being connected on its opposite side to potential on conductor 2 · Upon energization of this winding, valve 565 is moved to the left whereupon air pressure on line 248 is applied to the head end of piston 567 to move the same to the rod end o cylinder 566. ' As a result, piston rod 36Q is moved to drive guide 5&9 from left to right as viewed in Figures 12 and 19, and this, as af oredescribed, results in the ribbon 20A being doubled back over the indexing pins.

As guide 569 thus moves to the right, switch 0 opens, and upon further movement, and at the time that operation of the corrugator is required to supply additional cor-, rugated ribbon, switches 57 and 75 are closed by the guide. Switch 575 j as aforementioned, operates the corrugator, being paralleled with switches S15 and S22. The contact arm of switch 572 is connected to contact A in engagement with wiper Wl and the fixed contact of switch 572 is connected to the upper end of winding 244. Thus, potential on conductor 24l is applied to the upper end of winding 244, and since the other end thereof is connected to potential on conductor 245, winding is energized to open back contacts 575 of switch S5 and close the normally open front contacts thereof. As switch S5 is thus operated, a holding circuit therefore is completed - described. When guide 56 moves its stop position on the right switch 571 is closed thereby. Since the contact arm of this switch is connected to switch S.7 and its make contact is connected to switches S4 and S6, a circuit is completed by way of these switches in series with the make contacts of switch S3 to energize the actuating coil 24 of the stepper switch whereupon its wipers Wl and W3 are advanced to position B of the switch.

Cycling of the switch and resultant shuttling movement of the core to the left then occur in the same manner as heretofore described on the manual closing of switch S3 to initiate a cycle of operations to the left. As will be recalled in the partially manual operation, this cycle terminates on the withdrawal of both the electrode and indexing pins and resultant opening of switch S3, the lowering of the core diagonally to the right, and the return of the electrode and indexing pins into the core. When this has also occurred in the fully automatic operation of the machine, no closing of switch S28 as the indexing pins return, a circuit is completed between conductors 24l and 245 fo energizing solenoid coll 354 through the contact- arm of switch 264 ' in engagement with the right hand contact of the switch. As plungers 351 and 352 are thus returned to the ositie a. as shown in Figure 19, the shuttling switch 281 is also returned to the positioiTi s¾pjw¾ t$ thus place the machine in readiness for shuttling movements to the right.

Switch 364 is also returned to its position as shown upon lowering of plunger 32 in response to the energizing of winding 5 . When this occurs, a circuit is completed through this switch and between conductors 241 and 24 for energizing the right hand winding of solenoid valve 65 return the same sure is applied to the rod end of iston^67 to move the same to the position shown in Figure 19, and this moves guide 569 from its switch closing position of engagement with switch 571 into its position as shown wherein it is in switch closing engagement with switch 570. Before this occurs and during the movement of guide 56 from the left to the right, switches 372 and 373 are ffiomsstariiy closed thereby to energize winding 244 and close switch Sj5 and to operate the corrugator as previously described. As switch closes, cycling of the stepper switch is again initiated to start a series of welding and shuttling operations oh the core as the same is moved in increments to the right. At the termination of these movements, switch S3 is opened, as shown, and the electrode and indexing pins have been returned to core engaging position. At this time, a fully automatic cycle of core operations including movement of the core first to the left and then to the right has been completed, and these operations thereafter are repeated until the machine is stopped manually, as by opening switch SI, Figure 8.

Operation of the honeycomb core fabricating machine of the present invention is predicated generally upon the principle of a continuously fed corrugated ribbon. In order to maintain the continuity of the ribbon, the end of one ribbon section may be joined to that of a succeeding ribbon section by means of a splicer 500 of known design as depicted in the block diagram of Figure 11, or alternatively, it has been found in practice that the sections may be welded together in the machine itself, the machine being designated as a fabricator 301 in Figure 11. In its simplest form splicer 300 could merely be a welding tool operable by hand to tack weld the succeeding sections together sufficiently for adequate feeding to and welding by the welding wheels and electrode pins of fabricator 501. Alte nat vely, the splicer JOO may make spot welding operations in response to pulses received from the program control designated 502.

The splicer may be eliminated where provision is made, either manually or by machine, to present the ends of succeeding sections to be joined in overlapping relation to a ¾relding wheel 25 and its coacting electrode pin. In this case three thicknesses of ribbon are presented for welding between the wheel and its electrode pin. It has been found in practice, however, that notwithstanding the increase in thickness of the material to be welded between the electrode, satisfactory welds are obtained and preliminary splicing of the succeeding sections is therefore not required. It will be understood, however, that the splicing of the ribbon prior to presentation at the fabrication facilitates feeding of the ribbon thereto. It has also been found in practice in the use of the machine of the present invention, that the spacing between the electrode and indexing pins is such that ribbons of variable thickness may be assembled therebetween for welding of the adjoining nodes, it being noted from Figure 2 that any added thickness at the nodes due to a splice would be accommodated below the welding wheel 25 by reason of the yield- -pressure applied thereto and would be accommodated below the indexing and electrode piiis By reasoft o the clearance pro-vidb&it at the underside of the pins as aforementioned.

A core 19A, Figure 11, may thus be fabricated, for example, from ribbons Rl, R2 and 5 of different thicknesses such that core 19A may have an outer or "picture frame" section formed on. one thickness ribbon Rl, a central or "slug" section formed of relatively thicker ribbo R^ and an intermediate section formed of relativel thinner ribbon R2. In this man- mer, various structural configurations and strength variables rnay be introduced into the core during fabrication thereof.

It may fairly be seen in Figure 11, that several layers of ribbon Rl at the bottom of core 19A are fabricated before short sections of ribbon R2 are introduced and alternated with successive short sections of ribbon R2 to form the core up to the point where short sections of ribbon R^ are introduced to form the central slug of the core. At such time the order of introduction of the ribbon sections will follow the patern RJ, R2 , Rl to the right and double back to the left R2, R5, R2, Rl to. the left and double back to the right R2, 2> etc., until the last. section of RJ has been introduced. Thereafter the sequence R2, Rl to right and double back to the left, R2, Rl to the left and double back to the right R2, Rl to the right and. double back to the left, etc., will be repeated until the last section of ribbon R2 is introduced after which ribbon Rl only will be added to complete the several layers of ribbon Rl comprising the border at the top of the core .

In order to mechanize the fabrication of core 19A, ribbons Rl, R2 and R^ may be supplied from reels ^O^, ;?04 and 505 individual thereto and each directed to its own degreaser 507 , hitch feed 2^1 and corrugator 222 . Each of the corruga- wx in turn, has its own shear 508 to which the corrugated ribbon is directed and from which Vt f«a-sse$ o splicer 500 , suitable ribbon guides 50 and '511 being employed in the cases of ribbons R2 and R3.

.Program control 502 may be of any type suitable for the purpose and may, for example, -take the form of three counters located respectively at the three corrugators 222 and each actuated thereby to make a count for each corru ation formed by its associated corrugator. Switches individual to the counters and arranged to supply energy to the corrugators ;and to their associated shears, in turn, may be actuated by the counters when the same have counted predetermined numbers of corrugations in accordance with the pattern desired in the core being fabricated.

Thus, energy may be supplied to the corrugator for ribbon Rl by way of line ^12 from program control 302 to actuate the corrugator and suppl sufficient corrugated ribbon Rl to form core 19A up to the point where ribbon section R2 must be injected. When the length of ribbon Rl required for this purpose has been counted out by the counter associated with the Rl corrugator, the switch actuated by the counter at such time will discontinue energy to the corrugator, actuate its associated shear by energy supplied by way of line 313, and direct energy by way of line 5l4 to the corrugator for ribbon R2 whereupon feeding of ribbon R2 will begin and counting of the corrugations thereof will be started. The timing and feeding of the ribbons Rl and R2 are such that the leading end of ribbon R2 will ride into the splicer 500 on the trailing end of ribbon Rl, and the splicer will be actuated by energy received by way of line 315 to bond the adjoining nodes when the same move into a bonding station located within the splicer A switch located at the splicer and responsive to the appearance of two overlapping ribbons at its welding station may be employed to energise the splicer via line 315.

After a predetermined number of corrugations of ribbon R2 have been counted ¾ associated with its co^rugA ar, switch actuated thereby will dieoontinue e nergy to the corrugator, direct energy to its shear for operation of the same by way of line 516 and direct energy via line J12 to again .effect feeding of corrugated ribbon Rl to the fabricator. This process will be repeated until the counter in the R2 channel has counted out a predetermined number of corrugations which when calls for feeding of a section of corrugated ribbon RJ to the fabricator.

When this happens, the R2 counter will actuate a switch which will stop its corrugator, operate its associated shear to terminate the section of R2 currently being supplied to splicer JOO, and direct energy via line 517 to the corrugator 222 for ribbon RJ whereupon feeding of this ribbon and counting of its corrugations will begin. After an appropriate number of corrugations have been formed, the leading edge of ribbon section ^ will move into splicer ^OO in overlapping relation to the trailing edge of ribbon section R2 and when the overlapping nodes arrive at the splicer welding station energy supplied via line 315 will bond the same together.

After the counter for ribbon RJ has counted out a predetermined number of corrugations, a switch actuated thereby will stop operation of the RJ corrugator and actuate its associated shear by energy supplied via line 518. The switch will also direct energy by way of line Jl to again effect further feed of corrugated ribbon R2 to the fabricator after which, in accordance with the pattern of core 19A, another section of ribbon Rl will be supplied thereto.

It suffices herein to state that additional opera- of the cofitrdl system of Figure 11, generally similar to those just described, will be performed':tocomplete the core liA Λ-s disclosed, or- t od ce oth& - cores having different structural con igurations and patterns through appropriate programming of the counters and their associated switches.

From the foregoin it will be apparent to those skilled in the art to which the fabrication of the present invention relates or most closely appertains, that the same also lends itself very well to an arrangement in which the machine is shuttled relative to the core which would be stationary, the indexing pins in such case performing a follow up shuttling movement relative to that of the electrode pins in contradistinction to the arrangement hereinbefore disclosed wherein the electrode pins merely move axially into and out of the core and the indexing pins move in a closed rectangular path.

This invention may be embodied in other forms or carried out in other ways without departing from the spirit or essential characteristics thereof. The present embodiments of . the invention are therefore to be considered as in all respects illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims (1)

1. Having now particularly described arid ascertained the nature of my invention in what manner the same is be declare that what I claim A core shuttling method of fabric comb core of unlimited length froa a continuous corrugated metallic tethered thereto and by layer vertically downward with to a plurality of horisontally disposed electrode and indexing pins into internesting relation with respect to cells of the core being said nethod ing the steps of successively lowering the core layer by layer with respect to said electrode and indexing pins while the same are from the doubling said ribbon back and forth upon itself by layer and over the indexing pine when the same have been returned into internesting and core engaging relation with the electrode pins following said lowering of the core thereby to form titie successive layers of cells of the indexing the core longitudinally thereof by the pins and with respec to the electrode while the electrode pins are drawn from the core and successively along and over the length of the and in opposite directions alternately froa layer to layer thereb to successive lengths of said tethered ribbon by and over the end into positions of alignment and abutment of the nodes thereof with corresponding nodes of the upper ribbon laye of the the electrode and indexing interneeting and core engaging relation following each of said indexing movements thereof supporting relation of the electrode pins with respect to said aligned and abutting and passing welding current to the electrode pins through said aligned and abutting nodes thereby to the A nethod according to claim wherein said lowering of the core respect to the electrode and indexing said of core longitudinally thereof being by cell width concurrently with said lowering of the core and in the reversed indexing and each of the successive longitudinal indexing movements in the reversed indexing direction being by an increment of cells corresponding to the number of said electrodo A method according to claim 1 or comprising the additional steps of said ribbon and feeding the ease to the core in timed relation to said indexing of the core and resultant drawing of corrugated ribbon by and over the and in relation to said doubling o the ribbon over the indexing and ore while the same are at rest in the end positions of the A shuttling method of fabricating honeycomb core of unlimited length a continuous corrugated ribbon tethered said comprising the steps of shuttling the core longitudinally thereof by increments in alternate tions while supported alternately on electrode and indexing pins which move into mutually intevuestln and core engaging relation preparatory to welding successive drawn increments of the tethered ribbon to the withdrawing both said electrode and indexing pins from the core when same is shuttled into position and following of the ribbon increment disposed over the corresponding incremental end portion of the ing the core by cell in response to said withdrawal of the electrode and indexing movin the electrode and indexing pins bac into and core engaging relation in response to said lowering of doubling said tethered A for fabricating honeycomb layer by continuous length of corrugated ribbon secured to tho including means for shuttling said said ribbon secured thereto and forth along tho length of tho aeons responsive to said shuttling of the core for assembling of corrugated ribbon on said core with each said layer doubled back upon itself and with cently disposed and opposite corrugations aligned and in abutting and operative during such assembly for bonding said aligned and abutting corrugations A to claim including ribbon feed and corrugation neons for feeding a continuous length of orrugated ribbo secured to he A machine according to 7 or shuttling aeons shuttles the ribbon into positions of alignment of corresponding nodes in increments over the length of the core and in opposite directions alternately layer to said assembling aeons operable in response to shuttling of the core into either of its positions ing said bonding of the nodes in sold end positions fo lowering the core by and simultaneously shifting the core by cell reverse means able in response to lowering of the core for folding the thereover into positions of alignmen of correspondin and means operable in to said folding of the ribbon and following the bonding of last named corresponding nodes for initiating said incremental shuttling movements of the A machine for fabricating honeycomb core layer supporting corresponding of adjacently disposed corrugated ribbon layers of core in positions of alignment on said electrode including said electrode pins for bonding said aligned and abutting nodes including said indexing pins for shuttling said core to said electrode pins and over length of the in increments of corrugation widths corresponding to the number of said electrode pins and opposite directions alternately layer to operable in response to of the core into either of its end positions for and indexing pins from in response t said retraction of the electrode and indexing pins lowering the core with respect to said retracted in response to said lowering of the core for returning and indexing pins into internesting and engaging operable in response to the return of indexing pins into engaging relatio for doubling the ribbon back upon itself the indexing pins into positions of alignment and abutment of corresponding and means responsive to said doubling of ribbon initiating said shuttling of A according to 9 or wherein the for bonding said abutting nodes together includes plurality of welding wheels with said aligned and abutted nodes for passing ing tnerethrough to said electrode pins thereby bond said operable in response to of said voiding wheels and prior to engagement of said with said aligned and nodes fo urging and individual to said wheels A machine to of the for dou ling back the ribbon comprises air of spaced gears having the ribbon passed therebetweens said gears being moved transversely the pins and positioned to there it and roil t ribbon is doubled back method o fabricating honeycosib core operate A constructed and to operate substantially herein reference to the illustrated in the Bated the day of Salomon insufficientOCRQuality