US2488759A - Plywood core machine - Google Patents

Description

Nov. 22, 1949 o. s. BOLLING 2,488,759

PLYWOOD CORE MACHINE Filed Dec. 22, 1945 8 Sheets-Sheet 1 Nov. 22, 1949 '0. S. BOLLING PLYWOOD CORE MACHINE Filed Dec. 22, 17945 8 Sheets-Sheet 2 java/z i024 O. S. BOLLING PLYwooD CORE MACHINE Nov. 22, 1949 8 Sheets-Sheet 3 Filed Dec, 22, 1945 no Sno bus s 8 Sheets-#Sheet 4 HIM O. S. BOLLING PLYwooD GORE MACHINE Nov. 22, 1949 Filed Deo.

Nov. 22, 1949 o. s. BOLLING 2,488,759

PLYWOOD CORE MACHINE Nov. 22, 1949 o. s. BOLLING *2,488,759

PLYWOOD CORE MACHINE Filed pee. 22, 1945 v 8 sheets-sheet e Nov. 22, 1949 o. s. BoLLlNG PLYwooD CORE MACHINE a sheets-sheet '7 Filed Dec. 22, 1945 Nov. 22, 1949 o. s. BoLLlNG 2,488,759

PLYWOOD CORE MACHINE Filed Dec. 22, 1945 8 Sheets-Sheet 8 l hva/2202 01m/4 df oZZZ/y Patented Nov. 22, 14949 PLYWOOD CORE MACHINE scar S. Bolling, Minneapolis, Minn., assigner to Meinen-Johnson Machine Company, Minneapolis, Minn., a corporation of Minnesota Application December 22, 1945, Serial No. 637,085

,6 Claims.

My present invention provides an improved and highly efficient machine for making sheets from relatively narrow strips, slats or blocks of wood, or similar material.

Machines of the present invention are used primarily for gluing together wooden strips or slats to produce composite wood panels that are suitable for various commercial uses, such as for plywood cores. In this connection, it will be understood that in the production of plywood, the composite panels or sheets produced by this machine will be secured between wooden veneer sheets by subsequent and additional operations and by use of additional machines or devices.

In the use of the improved machine of the present invention for producing composite sheets from strip or slat material, slats or strips having glue applied to one edge of each strip (and before the glue is dried or set) are placed upon the receiving or input end of the machine in properly assembled relation and are fed from thence through a heating zone while being maintained in tight edge-to-edge contact. The glue on the previously edge-glued pieces thus becomes dried and set under heat and pressure while the material is subject to feeding movements through the machine, and a composite sheet is thus delivered from the output end of the machine.

In the machine of my present invention, as in the machine of my prior Patent 2,366,588, heating of the previously edge-glued and assembled slats or strips of work material to set and dry the glue is accomplished by passing the said material between opposed heated plates and, as in the case of the machine of my said prior patent, the edge-glued strips of work material are maintained in tight edge-to-edge contact during their passage through the space between the heating plates by resistance to forward feeding action set up by squeezing pressure of the opposed hot plates on the material and by further resistance to forward feeding movements of the material set up by a pressure-breaking mechanism located after the hot plates and adjacent the output end of the machine. The machine of the present invention, however, involves a number of very important improvements over the machine of said prior patent, and which include the following, to wit:

. a. The present invention provides an improved feeding mechanism for positively feeding and continuously delivering work pieces (slats, strips, or the like) to and through the space between the opposed hot plates and the subsequent pressure mechanism.

b. The present invention further provides an improved hot plate structure involving spaced walls and intervening heating units. In the preferred arrangement illustrated, the heating units are in the nature of steam-conducting heat lowing the hot plates.

transfer conduits running in zigzag fashion between opposite walls of the hot plates, and comprising relatively-straight laterally-spaced portions or sections extending between opposite longitudinal edge portions of the hot plates and connected by elbows. In the preferred arrangement, the only joints in the heat transfer conduits are between the relatively-straight portions or sections thereof and the connecting elbows. In accordance with the present invention, the said connecting elbows are located laterally outwardly of the marginal longitudinal edges of the hot plates, where they are readily accessible for the purposes of inspection, repair of the joints between the elbows and straight sections, and removal and replacement of the elbows or relatively-straight conduit sections connected thereby.

c. Still another important feature of the present invention has to do with the mounting of the feeding mechanism, hot plates, and the pressure mechanism following the hot plates, on, and the anchoring of the same to, a supporting frame structure. It will be understood that the re- .Y sistance to feeding action of the material set up by the hot plates and the pressure devices following the hot plates produces powerful forces tending to separate the feeding mechanism from the hot plates and the hot plates from the pressure mechanism following the same. l-Ieretofore, it has been the practice to anchor the several units independently to the supporting frame structure to prevent longitudinal movements thereof with respect to the frame and to one another, and in so doing the powerful forces tending to separate the feedingmechanism from the hot plates and the hot plates from the pressure mechanism following the same was absorbed entirely through the frame structure, with the result that the supporting frame structure was placed under powerful stresses and strains tending to buckle and warp the same, and tending to produce misalignment between the feed mechanism, hot plates, and pressure mechanism fol- In accordance with the present invention, I overcome this tendency of prior art machines to buckle and warp the frame structure by connecting the successive cooperating units comprising the feed mechanism, hot plates, and pressure mechanism following the hot plates, together in a tandem relationship, whereby the forces tending to separate the said successive units of the machine are absorbed within the units themselves, and independently of the supporting frame structure. This important feature of the invention will be clarified and amplified later on in the specication and under the heading Operation d. The present invention further provides a novel and improved transmission mechanism intermediate the prime mover or motor and the feed mechanism, whereby to permit free vertical movements of the upper unit of the secondary feed mechanism with respect to the lower unit thereof when both are driven through common endless belts.

e. The present invention still further provides a novel automatic work-actuated control mechanism for the work feeding mechanism, whereby the feeding mechanism is automatically disrupted whenever the rate of delivery of work pieces to the secondary or positive feed portion of the feed mechanism fails to equal the rate of feed of the said secondary or positive feed portion of the feed mechanism. This feature is highly important in that it prevents operation of the positive feed portion of the feed mechanism under conditions when the frictional contact area between said feed mechanism and the work is reduced to a point where slippage will occur between the feed mechanism and work, and which slippage, if allowed, would be apt to damage and deface the work.

f. The present invention still further provides an improved mechanism for variably adjusting the pressure of the upper hot plate on the work.

The above and other highly important objects and advantages of the present invention will be made apparent from the following specification, claims, and appended drawings.

In the accompanying drawings, like characters indicate like parts throughout the several views.

Referring to the drawings:

Fig. 1 is a front and side perspective view of a plywood core machine embodying the improvements of my invention;

Fig. 2 is a plan View of the machine of Fig. 1;

Fig. 3 is an enlarged longitudinal sectional view taken on the line 3 3 of Fig. 2, and having,T some partsbroken away;

Fig. 4 is a fragmentary view in side elevation taken on the line 4 4 of Fig. 2;

Fig. 5 is a fragmentary view in elevation taken on the line 5 5 of Fig. 2, and with some parts broken away;

Fig. 6 is a transverse sectional View taken on the line 6 5 of Fig. 5, and with some parts broken away;

Fig. 7 is a transverse sectional View taken on the line -I of Fig. 3, and with some parts broken away;

Fig. 8 is a fragmentary longitudinal sectional view taken on the line 8 8 of Fig. 2, with some parts being broken away and shown in section;

Fig. 9 is a fragmentary longitudinal sectional View taken on the line 9 9 of Fig. 7, with some parts broken away;

Fig. 10 is a greatly enlarged detail sectional view taken on the line Iii-II) of Fig. 3;

Fig. 11 is a detail sectional View on a greatly enlarged scale taken on the line I I I I of Fig. 4;

Fig. l2 is a detail fragmentary sectional view taken on the line I2 I2 of Fig. 2;

Fig. 13 is a fragmentary plan view taken on the line I3 3 of Fig. 5;

Fig. 14- is a fragmentary detail view, on an enlarged scale, taken on the vertical line 4 I4 of Fig. 5,;

Fig. 15 is a fragmentary perspective view on an enlarged scale illustrating the work pressure shoes and certain associated parts shown in side elevation in Fig. 5;

Fig. `15 is a fragmentary lView on an enlarged scale taken approximately on the line IB-IS of Fig. 9;

Fig. 17 is a fragmentary perspective view on an enlarged scale of one of the secondary feed chains; and

Fig. 18 is a diagrammatic View illustrating the electrical hook-up of the feed mechanism.

The supporting frame of the machine described is made up in three sections indicated by i, 2, and 3 respectively. The frame section I is at the input end of the machine and comprises laterally-spaced longitudinally-extending beams 4 and supporting legs 5 and Il. The legs 6 are rigidly tied together by cross-beams I and the inner ends of the beams 4 are rigidly anchored to the said legs 6; the outer ends of the said beams 4 being rigidly tied together by a transverse tie-plate 8. The intermediate frame section 2 comprises a laterally-spaced pair of 1ongitudinally-extending plates 9 extending between and rigidly tying together the frame sections I and 3. The frame section 3, which extends to the output end of the machine, comprises laterally-spaced longitudinally-extending beams l@ and legs II and I2; the legs I2 being connected by transversely-extending beams I ly (see Fig. 5).

Mounted on the primary frame section I is a primary feed mechanism comprising laterallyspaced endless link belts or chains I4. These link belts or chains I 4 run over wheels in the nature of pulleys I5 and wheels in the nature of sprockets I6. The several pulleys I5 are all journalled on an idler shaft I'I that is mounted fast in frame beams 4. The several sprockets EG are all mounted fast on a shaft I8 that is journalled in bearing flanges I9 that project one from each of several inverted U-shaped chain guide rails 20. The chains I4 run over and are supported by a table I4a rigidly secured to the frame beams li (see Figs. l, 2, 3, and 9).

The primary feed chains I4 feed stock to a secondary stock-feeding mechanism compris` ing a laterally-spaced series of lower endless feed belts or chains ZI and a laterally-spaced series of upper endless link feed belts or chains 22. At the input end of the secondary stockfeeding mechanism, the endless feed belts or chains 2 I run over wheels in the nature of pulleys 23, and the endless feed belts or chains 22 run over similar pulleys 24. The pulleys 23 are all iournalled on the shaft I8. The several pulleys 24 are each journalled on a different stub shaft and each of the stub shafts 25 is individually mounted fast on a different arm 26 of a floating frame structure immediately to be described. The said "ioating frame structure comprises the said arms 2@ and a tie-bar 21 (see Figs. 1, 2, and 3). The fioating frame arms 26, of which there are several, extend in laterally-spaced parallel relation longitudinally of the machine, and the said tie-bar 2l is bolted or otherwise rigidly secured to the ends of said arms closest to the input end of the machine (see particularly Fig. 2). The other ends of said floating frame arms 25 are journalled on a rotary shaft 2S (see particularly Figs. 2 and '7). The several endless feed belts or chains 22 run over the pulleys 24 and also run over wheels in the nature of sprockets 25 that are mounted fast on shaft 28. The shaft 28, as will be seen by reference particularly to Figs. 2, 3, 7, 8, and 9, besides being intermediately journalled in the end portionsof the several frame arms 26, are journalled adjacent their opposite end portions in bearing bosses 30 of draw bars 3|. The shaft 28 is anchored to the frame legs 6 by anchor links 3| that are pivotally mounted on said frame legs 6 at 3| and to radial flanges on the draw bar hubs 38 at 38. The shaft 28, intermediate its ends, is further journalled in bearing bosses 38 of additional draw bars 3|a (see particularly Fig. 2). The mounting of the other ends of the draw bars 3| and 3|a is important, and will be dealt with in detail later on. The lower endless belts or chains 2| run over the said pulleys 23 and sprockets 32, that are mounted fast on a power-driven rotary shaft 33. The power-driven rotary Shaft 33 is journalled adjacent its opposite ends in bearings 34 on the supporting frame section plates 9 described (see particularly Fig. 7). Also, this power-driven shaft 33 is journalled intermediate the bearings 34 in the free end portions of rigidly-anchored draw arms 35, the importance of which will be emphasized later on.

The endless conveyor belts or chains I4, 2 I, and 22 are all driven from a suitable source of power, such as an electric motor 36, through power transmission connections comprising a chain 31 running over a sprocket 38 on the shaft of motor 36 and a speed-reducing sprocket 39 on a transverse shaft 48 journalled in suitable bearing brackets 4| on beam lIl (see particularly Figs. 3 and 4). A shaft 42 is journalled adjacent its ends in the frame plates 9 and is driven at reduced speed from the shaft 40 by a pair of endless link chains or belts 43 running over sprockets 44 fast on the shaft 48 and sprockets 45 fast on shaft 42. Shaft 33 is driven from the shaft 42 at reduced speed through pinions 46 fast on the opposite end portions of shaft 42 that mesh with gears 41 fast on opposite end portions of shaft 33 (see Figs. 4, 7, and 8). The shaft 28 is driven from the shaft 42 through chains 48 (see Figs. 4 and 7) running over sprockets 49 fast on opposite end portions of shaft 42, idler sprockets 58 journalled on a pair of stub shafts 5| that are mounted fast each on one of the plates 9, sprockets 52 mounted fast on opposite end portions of shaft 28, and yieldingly-biased pick-up sprockets 53. The pick-up sprockets 53 are idlers and. are journalled on the free end portions of arms 54 that are pivoted at 55 to opposite frame beams I8, and which are yieldingly-biased in directions to take up the slack in chains `48 by adjustable tension springs 56 (see particularly Fig. 4.) The primary feed chains I4 are driven from shaft 33 by a chain 51 running over a sprocket 58 fast on shaft 33 and a speed-increasing sprocket 59 fast on shaft |8. It will be seen that the above described transmission mechanism drives the chains 2| and 22 at like speeds and drives the chains |4 at a somewhat increased speed with respect to the chains 2| and 22. It will also be seen that the difference in speed between pulleys 23 on 'shaft4 I8 and sprockets 59 on shaft I8 is compensated for by free rotation of the pulleys 23 on the shaft I8 (see Fig. 9).

The lower portions of chains 2| run through the inverted U-shaped guide rails 20 and the upper portions of said chains 2| are supported by and run over the upper surfaces of said inverted U-shaped guide rails 20. The lower chainengaging portions of the chains 22 intermediate the pulleys 24 and sprockets 29 are yieldinglypressed downwardly by hold-down shoes 60 and coil lcompression springs 6| interposed between each hold-down shoe 60 and a longitudinally extended pressure bar 62. The springs 6| are telescoped over small bosses on the hold-down shoes 6l!` and corresponding bosses on the under surfaces of pressure bars 62. The pressure bars 62 each extend in closely-spaced parallel relation to a different floating frame arm 26, and these are held against longitudinal sliding movements by stop lugs 63 projecting from said arm 26. The hold-down shoes 68' and pressure bars 62 are confined between their respective cooperating floating frame arms 26 and retainer plates 64 that are anchored to their respective cooperating floating frame arms 26 by stud bolts 65 passed therethrough and threaded into bosses 66 on the floating frame arms 26 (see particularly Figs. 3 and 10). The bosses 66 adjacent the extreme ends of retainer plate 64 serve as stop lugs to limit 1ongitudinal movements of the several hold-down shoes 60. The pressure bars 62, which are yieldingly-pressed upwardly by coil springs 6|, bear against a pair of upwardly-extended pressure legs 61 that are channeled, as shown best in Fig. 10, to receive the upper portions of the bars 62. By reference particularly to Figs. 3, 7, and 10, it will be seen that the upwardly-extended pressure legs 61 are formed with transversely-extended passages 68 to receive the upper portions of link belts or chains 22. The pressure legs 61 are connected to the under surfaces of a pair of transversely-extended bridge beams 69 by screw-threaded pressure-adjusting studs 10. These pressure studs 1l] are provided with diametrically-reduced upper end portions that work loosely through apertures in the lower flanges of the bridge beams 69, and are provided near the lower extremities of said diametrically-reduced portions with stop shoulders 1| that engage the under surfaces of said beams 69 and limit upward movements of the studs 10 therethrough. The screw-threaded lower portions of the studs 18 are screw-threaded directly into the pressure legs 61, as shown best in Figs. 3, 7, and 10, and are locked in adjusted positions by lock nuts 12. The bridge beams 69 are vertically adjustably supported from the frame legs 6 (see Figs. 4, '1, and 8) by upstanding screw-threaded shanks 13 on legs 6, nut-acting worm gears 14 screw-threaded on the Shanks 13, and gear boxes 15. The upper ends of the shanks 13 work loosely through the lower flanges of the beams 69, and the nutacting worm gears 14 are journalled within the gear boxes 15. The nut-acting worm gears 14 are operated externally of the gear boxes 15 by operating mechanism comprising a driven shaft 16 within the gear box and journalled in the end portions thereof, worms 11 on the shafts 16 and meshing with the worm teeth of the nut-acting worm gears 14, bevel gears 18 fast on shafts 16, and intermeshing bevel gears 19 on an operating shaft 8|ll that is journalled in bearing flanges 8| (see Figs. 1, 2, 7, and 8) and is equipped with an operating wheel 82. From the above, it will be clear that the amount of yielding pressure exerted on the work, indicated by Y, through the lower runs of the chains 22, springs 6|, pressure bars 62, and pressure legs 61, may be adjustably varied by rotation of the hand wheel 82. Before going further, it is desirable to call attention to the fact that the work Y is in the nature of a plurality of strips extended transversely of the machine and brought into edge-to-edge contact, and that the receiving end portion of the floating conveyor or feed unit comprising pulleys 24,

sprockets 29, andA chains 22is limited against 7 downward movements'by hanger bolts v83 that are threaded into and project upwardly 'from ythe floating frame arms 26 Yand Work loosely through brackets 84 projecting from beams 80 (see Figs. l and 3). Downward movements of the floating upper conveyor unit comprising-chainsZZ are adjustably limited by nuts 85 on the upper ends of `hanger'bolts 83, and which normally are spaced above the brackets 81%. The object of these nutequipped hanger bolts v83 is to maintain a predetermined spacing less than the thickness of the work between the cooperating lower and upper chains 2| and 2-2 respectively in the absence of work strips Y therebetween, so that strips Y may be readily fed into the space therebetween. It is also desirable to call attention tothe fact that the feed chains Z'I and 22 are provided on their work-engaging faces with gripping teeth, as shown best in Fig. 1'7, which is a perspective View respective of both of the chains 2| and chains 22. The secondary feed mechanism comprising the chains 2| and 22 feeds strips of work material Y between upper and lower hot plates 86 and 81 respectively. These hot plates 86 and 81, as shown, are made up of three similar sections rigidly connected together as at 88 (see Figs. 2, 3, and 12), Each sectionof each of the hot plates 8B and 81 comprises a flat metallic work-engaging wall 89, a backing wall 90, and an intervening heating element 9|. of each section of each of the hot plates 86 and 81' is in the nature of a `heat transfer conduit comprising laterally-spaced parallel portions extending transversely of the hot plates and connecting elbows 92 that are located laterally outy,

wardly of the marginal edges of the walls 89 and 98 of their respective hot plate sections (see Figs. 2 and 16) Preferably, the laterally-spaced 'paralle] sections and connecting elbows of the heat transfer conduits 9| are formed of cross-sectionally square seamless tubing providing maximum heat transfer efciency between the conduits and work-engaging heat transfer plates 89. Preferably, also, the elbows 92, shown best in Fig. 16, are welded or brazed to the ends of the straight sections of the conduits 9| at points outwardly of the marginal edges of the hot plates, where the joints are readily accessible at all times for inspection and repair. Preferably, the otherwise exposed elbows 9-2` are covered by guard channels 934 suspended by brackets 94 (see Fig. 11). The work-engaging heat transfer plate 89 and the backing plate 90 of each hot plate section are rigidly, but detachably, connected together by stud bolts 95 passing through the walls 90 and screw-threaded into bosses 08 projecting from the walls 89 (see Fig. 12).

The lower hot plate 81 is slidably seated 'on transverse cross members 91 on longitudinal frame beams I0 through the medium of shoes 98v rigid on the backing walls 9| of the lower hot plate. Lower hot plate 81 is anchored Vat its receiving end 'to the sprocket shaft 33 by means of the before-mentioned draw arms 35, which draw arms are journalled on the shaft 33 and rigidly anchored t'o the work-engaging Wall 8'0 'of the lower hot plate by cap 'screws or the like 89 threaded into bosses |80 projecting from and rigid with-the wallY 89 4(see Figs. 3, 8, and 9) The lower draw arms 35 are equal in number to, and located directly below, the draw arms 3| and 3| a of the upper hot plate 86.

'I-he upper hot plate 88- normally rides on and is maintained under pressure against the work str-ipsV Y in a manner hereinafter described, but L The heating element 8 is held against bodily movements longitudinally cf the'machine'by the before-described draw links or bars 3| and 31a, which are pivotally anchored at their outer ends to the shaft 28, and which are pivotally anchored to the work-engaging wall 89 of the upper hot plate 86 at |0| through the medium of upstanding anchoring flanges or brackets |02 that are bolted or otherwise made fast to the wall 89 by cap screws or the like |03. Of course, it will be clear that the links or bars 3| and 3|a, being pivoted at both ends, permit free vertical movements of the upper hot plate 86.

Mounted on the upper hot plate 85 is a superstructure comprising a laterally-spaced pair of longitudinally-extended beams |04 that are clamped to a plurality of underlying transverse beams |05 vby clamping gibs |06, shown best in Fig. 11, whereby to permit free movements of the beams |05 with respect to the beams |04 as a result of expansion and contraction of the upper hot plate 86, to which the said beams |05 are anchored in a manner immediately to be described. With reference particularly to Fig. 11, it will be-seen that the beams |05 are provided with legs |01 having outturned feet |08, and it will be further seen that springs |09 are interposed between the feet |08 and the upper hot plate, whereby to transfer the Weight of the superstructure to the upper hot [plate 86. The superstructure is positively anchored to the upper hot plate by nut-equipped bolts ||0 screw-threaded into transverse ribs I of the upper hot plate 85 and passed upwardly through the springs |00 and feet |08 with the nuts thereof applied above said feet |08. At this point, attention is incidentally called to the fact that the supporting brackets 94 of the projecting channels 93 are anchored `directly to the legs |01, as shown best at H12 in Fig. 11. The transverse ribs may be assumed to be welded or brazed directly to the work-engaging heat transfer wall 89 of the upper hot plate 86.

The weight of the above-described superstructure will provide a minimum operating pressure on the upper hot plate 86, but for producing additional pressure and for raising the upper hot plate and its superstructure, I provide a pressure-adjusting and lifting mechanism immediately lto be described, This adjusting and lifting mechanism comprises a pair of transversely-extended shafts H53 located adjacent opposite ends of thevsuperstructure ybeams |04 and over opposite end `por-tions of the upper hot plate 86. These shafts H3 are each journalled at one end in a bearing block H4 carried by the under surface cfone of the beams |04: (see Fig. 3) and at its other vend each of said shafts H3 is journalled in a gear caseV i i5 carried by and secured to the under surface of an opposite beam |04. At their extreme outerrends, the shafts ||3 are provided with cranks y| i6 that may be assumed to be keyed thereto for common `rotation therewith. The several cranks |18V are connected by rigid links ||1 to frame beams i0 at their respective sides of 'the machine. The links ||1 are pivotally connect-ed to their respective cranks ||6 at ||8 and are pivotally connected at their lower ends to bearing rackets H9 that are vertically adl'ustably anchored to the frame beams |8 through the medium of anchoring brackets |20 and nut-equipped bolts :521. For operating the several cranks ||6 and their' respective shafts ||3 in unison and from aicommon operating point, I provide an operasing Emechanism comprising worm gears |22, cooper-'ating worms i 2 3, a lo'ngitudinally-extended operating shaft |24, a ratchet gear |25 fast on shaft |24, an operating lever |26 having a bifurcated end` journalled on the shaft |24, and a reversible ratchet |21 (see Figs. 2, 5, and 14) The worm gears |22 are mounted fast on their re.- spective shafts ||3 each within a different gear case H5, and the worms |23 are mounted fast on shaft |24 each within one of the gear cases and meshing with a cooperating worm gear |22. The reversible ratchet mechanism described is of well-known Iconstruction, not requiring further description, particularly in view of the fact that a hand wheel or other operating means could be substituted therefor for operating the shaft |24 in two directions. It will, however, be understood that operation of the shaft |24 in one direction will result in lifting of the upper hot plate 86 free of the work strips Y and that operation thereof in the other direction will place the rigid links |1 under tension to lcompress the several springs |89 to adjustably increase the pressure exerted on the upper hot plate 86 and by said plate 85.011. the interposed work strips Y.

Before going further, it is desired to call attention to the fact that suitable heating medium, preferably steam, is introduced at the input end portions of the upper and lower hot plates 85 and 81 respectively by steam pipes 85' and 81 respectively, and which are respectively connected to the ends of heat transfer conduits 9| of the I upper and lower hot plates (see Fig. 4). Also, by reference particularly to Fig. 5, it will be seen that the steam is returned to the source or exhausted to atmosphere, as desired, through conduits 85 and 81 leading from the opposite ends of the heat transfer conduits 9| of the upper and lower hot plates respectively, and which are located at the output ends of said conduits. Now, by particular reference to Figs. 2 and 5, it will be seen that the sections of the heat transfer conduits 9| serving adjacent sections of the upper and lower hot plates 85 and 81 are connected in series by connecting elbows |28.

For the purpose of guiding the work strips Y into the space between the upper and lower hot plates 86 and 81, and which space will be somewhat less than the thickness 'of the work strips Y when the said space is free of work strips, I provide at the input ends of the hot plates outwardly and forwardly-extending cam shoes |29. There are several of these cam shoes |29 rigidly secured to and projecting forwardly from the input edge of each of the hot plates 85 and 81 (see Figs. 9 and 16 particularly), and which operate as upper and lower pairs; each cooperating upper and lower pair of cam shoes |29 being provided with a reversely-flared cam-acting end, whereby to receive the work strips Y and guide the same into the space between the upper and lower hot plates. The cam shoes |29 further act to prevent the work strips Y from buckling in the space between the output end of the secondary feed mechanism and the hot plates, particularly when the work strips are very narrow in width.

In machines of this character, it is highly desirable that the edge-glued work strips Y be maintained under relatively very great edgewise squeezing pressure during their passage through the hot plates 8S and 81, and, therefore, for further increasing the edgewise squeezing pressure on the work strips as they pass through the hot plates, I provide adjacent the output end of the machine and beyond the hot plates 36 and 81 a friction-retarding mechanism comprisingl l short longitudinally-extended skid rails |38 below the work strips Y and cooperating pressure shoes |3| above the moving work strips Y, which latter will, by the time they reach the output end of the machine, be united into a unitary sheet. There are a laterally-spaced series of the longitudinally-extending skid rails |38 that are rigidly anchored to and project from the output end of the lower hot plate 81, and these extend over and rest upon transverse beams I3, and on which beams the skid rails |30 are free for longitudinal sliding movements as a result of expansion and contraction of the lower hot plate. Pressure shoes |3|, of which there are a laterally-spaced series, are anchored to the output end portion of the upper hot plate .86 by leaf springs |32 (see particularly Figs. 5 and 15). By reference particularly to Fig. 15, it will be seen that the leaf springs |32 are each'connected at one end to the intermediate portion of a pressure shoe |3| and are each rigidly connected at the opposite end thereof by a bolt |34 and a key |35 to a transverse rib |33 that is mounted fast on the heat transfer wall 89 of the upper hot plate 86.

For the purposes of lifting the pressure shoes i3! out of engagement with the Work and out of the path of travel of the work, and for applying varying degrees of downward pressure thereon, I provide a mechanism comprising transverse beams |35 and pressure rods |31. The transverse beams |36 are connected at their bottoms by a plate |38, and are vertically adjustably supported from legs I2 through the medium of screwthreaded studs |39 and nut-acting worm gears |48. The screw-threaded studs |39 have reduced diameter portions extended through the upper ends of the legs l2 and clamped thereto by nuts Mi. The nut-acting worm gears |48 are threaded on the studs |39 within gear boxes |43 attached to the under surfaces of opposite end portions of beams |35. By reference particularly to Fig. 5, it will be seen that the nut-acting worm gears |49 are provided with bearing hubs journalled in opposite walls of the gear boxes |43. The nut-acting worm gears |40 are all operated in unison from a hand wheel |44 through driving connections comprising a long transverse shaft |45 journalled in bearing bosses or brackets |46 projecting from opposite gear boxes |43, bevel gears |41 mounted fast on shaft |45, cooperating bevel gears |48 fast on shafts |49, and worm gears |58. The shafts |48 are each journalled at opposite end portions in an opposite gear box |43 and the worm gears |58 are mounted fast on their respective shafts |49 and mesh each with a different Worm gear |48 (see Figs. 2, 5 and 6). The pressure rods |31 are anchored fast at their lower ends each to a dif- .ferent pressure shoe |3| and all project upwardly through the beam-carried plate |38 (see Fig. 5). The pressure rods |31 work loosely through the plate |38 and are provided below the'plate |38 each with a `compression spring |5|. The springs i5! are compressed between the plate |38 and nuts |52 on said rods. For the purpose of limiting relative downward movements of the pressure rods |31 through the plate |38, suitable stop nuts or the like |53 are provided on the upper end portions of said rods |31. From the above, it will be clear that the amount of pressure exerted by the pressure shoes |3| on the work may be adjustably varied at will by manipulation of the hand wheel |44, which may also be manipulated to elevate the pressure shoes |3| out of the path of travel cf the work, if and when da sired. Also, it should be noted that the frictional pull of the work on the pressure shoes ISI is transmitted to the upper hot; plate in a substantially straight line throughthcir respective anchoring leaf springs |32, which relieve the pressure rods |31 entirely of strain in a horizontal direction.

In practice, it has been found` that if the feed chains 2| and 22 be permitted to operate faster than material is being delivered to the chains I4 and by the chains |4` to said chains 2| and 22, the chains 2| and 22 will start slipping on the Work after the last work piece Y has advanced to some indefinite point intermediate the ends of the chains 2| and 22 depending upon the amount of pressure applied to the work by the hot plates 86 and 81 and hold down shoes I3I. Such slippage between the chains 2| and 22 and the work pieces Y is, of course, objectionable because such slippingis apt to deface the work. It will be noted, however, that slippage occurring between the primary feed chains |4 and the work strips Y, becauseV of the greater speed of travel of said feed chains I4, is permissible because of the relatively smooth upper'surfaces of said feed chains I4 and relatively light weight of said work strips Y. To prevent such damaging slippage between the chains 2| and 22 and the work, it is highly important that work strips Y be fed by the chains I4 to the. space between the cooperating chains 2| and 22 at a rate equal to or faster than the rate of delivery by the chains 2| and 22, so as to maintain a maximum area of frictional driving contact between the chains 2| and 22 and the work during-all operating periods of saidchains 2| and 22. To this end, I provide a pair of workl stripoperated switches |54 above the chains I4 and ahead of the chains 2| and 22. These switches |54 are mounted on the transverse tie-bar 21, and each comprises a casing |55, a work-engaging arm |56 pivoted to its respective housing |55, a pair of fixed contacts |51, and' a bridge contact |58 carried by the free end ofv an arm |59 that is rigidlyanchored to the pivoted end of its cooperating lever or arm |56. The arms |56and |59 form bell cranks andmay be assumed to be gravity actuated-toward switch-open positions. By-reference particularly toFgs. 9 and 18, it will be seen that the free ends of the bellcrank arms- I53-nor mally ride on the upper surface of the work'strips beingffed to the space between thechains |2I and |22-, and by reference to Fig. 18, it will be seen that the work strips Y keep the bell cranks in switchclosed positions, and by reference to Fig. 18, it should be obvious that when' there is an absence of work strips Y under thefree ends of the bell crank arms |56, that the said bell cranks will be moved by gravity to switch-openpositions, not shown. The switches |54 operate in conjunction with a relay'switch |66 to automatically control operation of the feed mechanism driving motor 36 in the following manner: By reference now to the diagram of Fig. 18, it will be seen that the motor 36 is operated from a threephase power line |6| through leads |62, |63, andV |64, which respectively have interposed therein spacednxed switch contacts |62', |63', and |64 of the relay switch |66. The said relay switch |66 further comprises asolenoid winding |66 and a solenoid plunger |61 Carrying bridge contacts |62", |63, and 64 for coopera-tionY respectively with pairs of spaced contacts |62', |63?, and |64'. The saidY relay switch |66.. also embodies-a pair of fixed switch contacts |68` and a cooperating plunger-carried2 bridge contact,- |69, Therelay switch |66vis of the type that is yieldingly biased by gravity or otherwise toward open position, and from an examination of Fig. 18, it will be clear that when the relay switchV |66 is closed by energization of the solenoid coil |66 thereof that the leads |62, |63, and |64 to the motor 36 will be completed and the motor rendered operative. The solenoid coil |66 of the relay switch is initially energized to close switch |60 by a starting circuit comprising aY lead |16 extending from a point in lead |63 ahead of switch |66, a short lead |16, a manually-closed self -opening starting switch |1|, a lead |12, coil |66, and a lead |13 extending to lead |64. Momentary closing of the above-described starting circuit results in closing of all of the contacts of relay switch |66, thereby rendering the motor 36 operative and establishing a holding circuit for the solenoid coil |66; the latter, however, being dependent upon closing of the switches |54 by work pieces Y. This holding circuit comprises lead |16, a manually open self-closing switch |14, a lead |15, switches |54, a lead |16, now closed contacts |68and |69 of relay |66, a lead |11, part of lead |12, relay coil |66, and lead |13. The manually open self-closing switch |14 is used to break the holding circuit and render the relay switch |66 and motor 36 inoperative independently of Work strip-operated switches |54.

Operation Preparatory to feeding strips of work material Y to the upper and lower hot plates 86 and 81, steam or other suitable heating medium will be passed through the heat transfer conduits 9| of the hot plates for suiiicient time to bring the said hot plates up to the desired temperature. Before starting the feeding mechanism com-- prising feed chains |4, 2|, and 22, a plurality of work pieces Y will be assembled on the now stationary feed chains 4 of the primary feed mechanism, and this primarily-assembled unit of work pieces will be pushed forwardly over the feed chains I4 under the work-actuated switches |54, thereby closing said switches |54. The machine is now ready for operation and the feed mechanism thereof will be set in motion by momentarily closing the manually-closed, selfopening switch |1|, which may be assumed to be conveniently located on the machine. (For a detailed description of the hook-up of the e1ectric motor 36, switches |54, relay switch |66, and switches 1| and |14, see the foregoing part of the specification.) With the feed chains I4, 2|, and 22 now in operation, the work strips Y, manually placed upon the primary chains I4, will be fed to the space between lower and upper chains 2| and 22 respectively, and will be positively fed by the upper and lower secondary feed chains 2| and 22 to and through the space between the hot plates 86 and 81 and into and through the spaces between the final pressure mechanism comprising the skid rails |36 and the cooperating pressure shoes |3|. It will, of course, be understood that work strips Y will be continuously placed upon the primary feed chains I4 for continuous delivery to the feed chains 2| and 22. In this connection, it is important to bear in mind that the primary feed chains I4 are driven at a somewhat greater speed than are the feed chains 2| and 22 of the secondary feed mechanism, so as to produce a continuous, although not great, slippage between the chains E4 and.y the work strips, which will maintain the work strips or pieces' Y in compact edgetoedge contact for delivery tothe feed chains 2| and 22.

13 It will, of course, be understood, that the work strips or pieces placed upon the primary feed chains i4 will have had glue or other heatdrying adhesive previously applied to the edges thereof. As the edge-glued strips or work pieces Y are passed between the upper and lower hot plates 8S and 8i respectively, they will be subject to a relatively high temperature for a sufficient period of time to completely set and dry the glue while they are being maintained under edgewise crowding pressure one against the other as a result of the frictional resistance to forward feeding movements of the work set up by pressure exerted on the work by the hot plates themselves and by further resistance to feeding movements set up by the final pressure mechanism comprising the skids its and the cooperating shoes |35. The work strips, thus being united while passing between the hot plates, are delivered from the pressure shoes I3! at the output end of the machine in a continuous sheet which will be cut into desired lengths by a subsequent machine. As previously indicated in the body of the specification, the pressure exerted by the pressure shoes I3! and the hot plates B6 and 3l on the work may be adjusted, through mechanism described, to place the work Y under the desired edgewise pressure during its passage between the hot plates, and the pressure exerted by the chains 2l and 22 on the work may be adjusted, in the manner described, to obtain sufficient driving traction to positively overcome the resistance to feeding movements set up by the hot plates and the nal feeding mechanism involving skid rails |341 and pressure shoes IBI. f

As indicated in the introduction, a very important phase of the present invention is the manner in which the secondary or positive feed portion of the feed mechanism, upper and lower hot plates, and the pressure mechanism tt-13E, are mounted and anchored. In this connection, attention is directed to the fact that the lower unit of the secondary positive feed mechanism, and which comprises chains 2l, pulleys 23, and sprockets 32, is anchored directly to the supporting frame structure through the medium of shafts i8 and 33 and flanges i9 on U-shaped members 253 and the intermediate frame side plates 9 respectively. The upper unit of the secondary or positive feed portion of the feed mechanism, and which comprises feed chains 22, pulleys 2e, and sprockets 29, is free for vertical movements and normally rests upon the surface of the work, but is anchored against longitudinal ymovements with respect to the supporting frame by the rigid links 3 I With these facts in mind, attention is again directed to the fact that the lower hot plate 8l is free floating on the underlying,r frame structure and is connected at its input end portion to the shaft 33 of the secondary feed mechanism through the draw arms 35, so that the forces tending to push the lower hot plate 8l longitudinally with respect to the driving mechanism are transmitted directly to. the delivery end portion of the feed mechanism through a tandem, substantially straight line connection through draw bars 35 independently of the supporting frame structure. In a like manner, the upper hot plate 86, which floats`v upon the work, is connected in tandem to the output end portion of the upper unit of the secondary feed mechanism comprising chains 22 through draw bars 3! and Sla that connect directly to the shaft 28. Hence, the tendency of the upper hot plate to be moved longitudinally 14 of the machine and with respect to the chains 22, is absorbed through the draw bars 3l and 3|a independently of yand without placing k any stresses or strains upon the supporting structure. As we go to the output end of the machine, we note that the final pressure mechanism comprising the skid rails I3@ and the pressure shoes I3! also is anchored indirectly to the positive feed mechanism by being connected to the delivery end of the hot plates, whereby the tendency of the rails i! and shoes ISI to be moved longitudinally of the machine by frictional engagement with the work is transmitted back to the source of pressure independently of the frame structure and without producing any strains or stresses thereon. In other words, with the arrangement illustrated, a frictional vload of the work on the pressure plates and final pressure mechanism respectively is taken through straight line connections to the source of driving energy independently of the frame structure and without any tendency to warp or buckle the same. Obviously, this important feature permits the use of lighter framing and substantially eliminates any likelihood of the successive cooperating elements of the machine being thrown out of proper working alignment.

It will be noted by reference to Fig. l0 that the hold down shoes Si) are provided with laterallyextended flanges 60' that are contained within guide recesses 25' and 64 Aof the oating frame arms 26 and the retainer plates Ei respectively, to prevent the shoes 60 from being pushed by the springs -Bl out of engagement with the arms 26 and retainer plates 64, in the absence of work strips Y under the `chain 22.

The commercial form of the machine has been illustrated and described, but it will be understood that various modifications as to details of construction, combinations and arrangement of parts, may be made within the spirit of the invention herein disclosed and claimed.

What I claim is:

l. VIn a machine of the kind described, a supporting frame structure, spaced hot plates supported on said frame and adapted to have work pieces passed therebetween, feeding mechanism mounted on said frame ahead of the hot plates and arranged to feed edge-glued strips in edge-toedge contact through the space between the hot plates, means biasing the hot plates toward one another to resist feeding movements of the work and thereby cause work pieces to be forced into tight edge-to-edge contact during their passage between the hot plates, means anchoring the feeding mechanism to the frame structure and against movements longitudinally of the machine, and n leans anchoring the receiving end portions of the hot plates directly to the output end portion of the feedA mechanism independently of the frame, said hot plates being not otherwise anchored against movements longitudinally of the machine, whereby the forces frictionally transmitted by the work from the feed mechanism to the hot plates will be transmitted from the hot plates directly back to the feed mechanism independently of the supporting frame structure and without'setting up stresses in the latter tending to warp the same.

2. The structure defined in claim 1 in which the means anchoring the receiving end portion of one of the hot plates directly to the output end portion of the feed mechanism comprises a drawbar pivotally connected at one end to the receiving end portion of said hot plate and at its other end to the output end portion of the feed mechanism.

3. In a machine of the kind described, a supporting frame structure, spaced lower and upper hot plates supported on said frame structure and adapted to have work pieces passed therebetween, feeding mechanism mounted on said frame structure ahead of the hot plates and adapted to feed edge-glued work pieces in edge-to-edge contact through the space between the hot plates, said feeding mechanism comprising lower and upper endless belts adapted to frictionally engage the lower and upper surfaces respectively of the work, the lower of said feed belts running over wheels journalled in the supporting frame structure, the upper of said endless belts running over wheels that are journalled in a floating frame structure that is vertically movable with respect to the supporting frame structure, means biasing the hot plates toward one another to resist feeding movements of the work and thereby cause the work pieces to be forced into tight edge-to-edge contact during their passage between the hot plates and as a result of feeding pressure exerted thereon by the feed mechanism ahead of the hot plates, means anchoring the receiving end of the lower hot plate to the supporting frame structure adjacent the receiving end of said hot plate and the delivery end portion of the lower endless feed belt, a substantially horizontally-disposed draw arm pivotally connected to the receiving end portion of the upper hot plate at one end and at its other end being journalled on the shaft carrying the upper feed belt wheel adjacent the output end of the feed mechanism, and a substantially horizontally-disposed link pivotally connected to the supporting frame structure at one end and to said draw bar at its other end, said lower and upper hot plates being not otherwise anchored against movements longitudinally of the machine.

4. The structure defined in claim 3 in which the said anchoring means for the lower hot plate is in the nature of a draw bar anchored at one end to the receiving end portion of the lower hot plate and journalled at its other end on the shaft carrying the wheel for the lower endless feed belt that is located adjacent the output end of the feed mechanism.

5. The structure defined in claim 3 in further combination with pressure mechanism adjacent the output end ofthe hot plates involving spaced lower and upper friction elements adapted to engage the lower and upper surfaces respectively of the work after the work has passed the hot plates and further resists feeding movements of the work, whereby to further increase the edgewise pressure of the work pieces one against the other during their passage between the hot plates, the lower of said friction elements being secured directly to and extending from the delivery end portion of the lower hot plate, a resilient arm anchored to and extending from the upper of said friction elements and connected to the output end of the upper hot plate, and yielding means biasing thev said upper friction element toward the lower friction element, whereby the forces frictionally transmitted by the work from the feed mechanism to the hot plates will be transmitted from the hot plates directly back to the feed mechanism 116 independently of the supporting frame structure and without setting up stresses in the latter tending to warp the same.

6. In a machine of the kind described, a supporting frame structure, spaced hot plates supported on said frame and adapted to have work pieces passed therebetween, feeding mechanism mounted on said frame ahead of the hot plates and arranged to feed edge-glued strips in edge-toedge contact through the space between the hot plates, means biasing the hot plates toward one another to resist feeding movements of the work and thereby cause work pieces to be forced into tight edge-to-edge contact during their passage between the hot plates, means anchoring the feeding mechanism to the frame structure and against movements longitudinally of the machine, means anchoring the receiving end portions of the hot plates directly to the output end portion of the feed mechanism independently of the frame, said hot plates being not otherwise anchored against movements longitudinally of the machine, whereby the forces frictionally transmitted by the work from the feed mechanism to the hot plates will be transmitted from the hot plates directly back to the feed mechanism independently of the supporting frame structure and without setting up stresses in the latter tending to warp the same, pressure mechanism adjacent the output ends of the hot plates involving spaced lower and upper friction elements adapted to engage the lower and upper surfaces respectively of the work after the work has passed the hot plates and further resists feeding movements of the work, whereby to further increase the edgewise pressure of the work pieces one against the other during their passage between the hot plates, the lower of said friction elements being secured directly to and extending from the 'delivery endy portion of the lower hot plate, a resilient arm anchored to and extending from the upper of said friction elements and connected to the output end of the upper hot plate, and yielding means biasing the said upper friction element toward the lower friction element.

OSCAR S. BOLLING.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 273,723 Goff Mar. 13, 1883 828,069 Steger Aug. 7, 1906 915,504 Sutter Mar. 16, 1909 1,693,606 Jones Dec. 4, 1923 1,702,185 Weber Feb. 12, 1929 1,859,370 King May 24, 1932 2,108,920 Humiston Feb. 22, 1938 2,305,525 Gustin Dec. 15, 1942 2,366,588 Bolling Jan. 2, 1945 2,398,353 Bolling Apr. 16, 1946 2,407,070 Frame Sept. 3, 1946 2,408,064 Hall Sept. 24, 1946 FOREIGN PATENTS Number Country Date 613,000 Germany May 10, 1935 647,018 Germany June 25, 1937

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