US3379124A - Plural actuated press means for a press-charging system - Google Patents

Description

April 23, 1968 BRUDE'R ETAL 3,379,124

PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM Filed April 26, 1966 6 Sheets-Sheet 1 INVENTORS gwl ATTORNEY April 23, 1968 KQBRUDER ET AL 3,379,124

PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING sysmv,

Filed April 26, 1966 6 Sheets-Sheet INVENTORS A0424 52095? W41. 70 I2 HflJGJ BYGQUL je n ATTORNEY April 23, 1968 BRUDER ET AL 3,379,124

PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM Filed April 26, 1966 I 6 Sheets-Sheet 5 I I .2 Y 1 .I :l Q n; I; O 101 FIG. 6A

m y L i 5 INVENTOR s KARL B B (/05 9 BY w, 762 H 0': 6.: 90 16- ATTORNEY April 23, 1968 K. BRUDER ET AL PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM 6 Sheets-Sheet 4 Apr INVENTORS E4 0 4 8 e a 06G w r. 76a 1419'; 4 5 BY ATTORNEY A ril 23, 1968 K. BRUDER ET AL PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM -.'-e:i April 26, 1965 fi -N 6 Sheets-Shet Ill INVENTORS 42 a a E pee swan-e 14: 66:

ATTORNEY SYSTEM April 23, 1968 K. BRUDER ET AL FOR A PRESS-CHARGIN PLURAL ACTUA'IED PRESS MEANS 6 Sheets-Sheet 6 Filed April 26, 1966 m g a T NE m E 4 0 V r m m 5 BYQQarl United States Patent 3,379,124 PLURAL ACTUATED PRESS MEANS FOR A PRESS-CHARGING SYSTEM Karl Bruder, Krefcld, and Walter Hiisges, Dulken, Germany, assignors to Firrna G. Siempelkamp & Co., Krefeld, Germany, a corporation of Germany Continuation-impart of application Ser. No. 534,324,

Mar. 15, 1966. This application Apr. 26, 1966, Ser.

Claims. (Cl. 100-437) This application is a continuation-in-part of our copending application Ser. No. 534,324, filed Mar. 15, 1966 and entitled Press-Charging Apparatus.

The charging of presses and especially multiplaten presses for the production of coherent plate or sheet-like boards of a variety of compositions has become common in the art. Such presses have been used for the compaction of loosely coherent sheet material and for the compression of laminatable bodies. In general, the mats of loosely coherent material to be formed into fiberboard, pressed board, hard board or the like, and the multi-layer stacks to be laminated into a unitary structure (e.g. plywood, veneer composites, door structures) are fed to the platens of the press upon so-called charging tablets which are withdrawn from the press and the stacks or bodies stripped from the tablets during the withdrawal operation. Systems using throughgoing charging plates and trays remaining in the press are highly effective for the purposes indicated although they do have the disadvantage that, subsequent to the discharge of the finished board or sheet rom the platen press, an afterhandling of the charging plates and their return to the charging station is required. On the other hand, the use of such charging plates or trays greatly facilitates the handling of loosely coherent sheet materials prior to their introduction into the press and eliminates the need for complex equipment for withdrawing charging tablets or the like while leaving the sheets to be compressed within the press.

In press installations in which the plate-like material to be compressed into coherency are laminated from a plurality of layers of wood or wood composition, it has generally been the practice to provide a collecting station along the path of the plates at which the successive layers are stacked subsequent to the application of adhesives or glue to the previous layer or to the subsequent layer to be applied. The stacks thus comprise a plurality of layers, generally thin and wavy, with glue or other adhesive material sandwiched between them and adapted to be compressed at elevated temperatures to form coherent plywood, veneer or door structures. The charging station can then comprise a rack or support adjacent the press and provided with a corresponding number of presscharging stages each algined with a respective press platen and adapted to receive the material directly in the event the stages are provided with charging tablets, or to receive press-charging plates or trays. In either case, a mechanism including a plurality of arms has generally been required to advance the sheets upon their respective carriers into the press. This advancing operation simultaneously forces the completed board or plate out of the press for stacking at the discharge side thereof.

In our copending application mentioned above, we describe an apparatus for the charging of multiplaten presses with the aid of charging tablets which carry the laminateble stacks into the press and are subsequently withdrawn therefrom with the stacks being stripped from the tablets to remain in the press. According to the improved system of that application, the press-charging station is provided with a plurality of vertically spaced charging tablets corresponding in number to the number of levels of the 70 press and shiftable relatively thereto between the charging station and an inserted position of the charging tablets in which they are received between the platens of the press. The plate-carrying arms co-operate with a plurality of sliders having a lost-motion connection therewith to align the edges of the laminatable bodies so that the respective layers are not askew during the compression stroke. The slider means is displaceable relatively to the plate-shifting and is provided with abutment means engageable with the rear edge of each of the laminatable bodies or stacks on the charging tablets for aligning the rear edge of each stack during a limited forward motion of the slider means prior to its entrainment of the platecarrying means. Thereafter, the slider means entrains the plate-carrying means to advance the charging tablets into the multiplaten press while concurrently shifting the previously pressed bodies therefrom, the slider means being then withdrawn to its limited play to disengage the abutment surfaces from the rear edges of the bodies and permit stripper elements to be inserted between these abutment surfaces and the bodies. Upon entrainment of the plate-carrying means with the slider means in the withdrawal direction, the stripper elements retain the bodies in the press and the tablets are redisposed at the charging station for subsequent receipt of stacks of laminatable layers.

We have also observed that during the feeding operation in which the stacks of laminatable layers are deposited upon the Charging tablets, the wrinkled or wavy characteristics of the layers frequently results in a disalignment thereof or the catching of one or more layers upon edges of the charging stages or tablets. Accordingly, in our copending application Ser. No. 534,231 filed Mar. 14, 1966 and entitled Apparatus for the Charging of Multiplaten Presses, we point out that a vertically shiftable feed plate can be disposed adjacent the presscharging station for receiving the laminatable stack to be transferred to the respective charging tablets, this plate being elevatable from a loading position in which the feed plate receives the body to be compressed and a discharge position at which the body can be advanced onto the respective charging-station stage. The improvement of this latter application resides in the combination with this feed plate of an abutment means disposed in the region of the discharge position of the feed plate and engageable therewith for defining a limiting position of the feed plate above the receiving surface of the respective stage of the charging station. Means is then provided for shifting the laminatable stack on the feed plate onto the receiving surface disposed therebelow in the discharge position of the feed means. Abutment rails are provided above the feed plate and form a stop therefor while a slide means is displaceable along these rails and engages a rearward edge of the laminatable stack for advancing the latter between the rails and the feed plate onto the respective tablets of the press-charging means.

In general, it has been found with laminatable stacks of relatively thin material and, most commonly, with such materials as are to be joined by adhesives and the like, that regardless of the speed of the press-charging operation, a preliminary drying of the glue may set in and the press-charging operation may involve a relative shifting of the layers and, consequently, disalignment thereof; the formation of protuberances or wavy portions results from the absorption of glue by the material, a tacking of the layers by the drying of the glue in an undesirable position, or may be present even before the glue is applied.

provide an improved press-charging system for obviating the disadvantages above and extend the principles originally set forth in our copending applications Ser. No. 534,324 and Ser. No. 534,231.

A further object of this invention is to provide a presscharging system for multiplaten presses and, especially for the processing of laminatable stacks of relatively thin sheet materials in which wavy formations of the sheets of laminatable material are avoided, any pre-existing irregularities and wavy formations rendered ineifective in detrimentally affecting the process, disalignment of the layers during the press-charging stroke can be obviated, and the dangers of premature drying of the glue in improper positions of the layers are precluded.

Yet a further object of this invention is to provide a press-charging system in which the laminatable stacks of thin layers can be handled positively through the feeding of these layers to the charging stages and, subsequently, during their advance into the press.

These objects and others which will become apparent hereinafter are attained, in accordance with the present invention, in a press-charging system in which a press charging station is disposed adjacent a multilevel press and is raisable and lowerable for successive alignment of the stages of the press-charging station at a feeding level whereby the stacks of laminatable sheets can be advanced onto the respective stages of the charging station and, when the latter is fully elevated, all of the stages of the charging station can be emptied simultaneously into the press. The invention resides to large measure in the provision of a hold-down unit at each of the stages of the press-charging station, such unit permitting introduction of the stacks of material during the stepwise elevation of the charging station but thereafter clamping the stack against the charging surface (i.e. conveyor, withdrawable tablet, or throughgoing plate) until the charging station is to be simultaneously emptied into the press. It has been found that this precompression of the stacks in the charging station permits a smoothing of predistorted layers (i.e. layers which have developed undulations even prior to the application of glue thereto), ensures a relative immobility of layers during the charging operation, and clamps the layers in place so that any preliminary setting of the glue occurs with the layers in their desired positions.

Advantageously, the hold-down means includes a holddown element in the form of a plate overlying the receiving surface of each stage of the charging station and raisable and lowerable by means of a lever-linkage arrangement connecting each plate with a common actuating member of the first actuating means carried slidably upon the charging station rack and provided with fluidresponsive actuating means for shifting the actuating member with respect to the rack to swing the levers and raise and lower the holddown plates.

According to a further feature of this invention, each of the lever linkage is mounted upon or coupled with the actuating member via a lost-motion coupling operable by a second actuating means upon the positioning of each stage at the infeed :level of the feeding means for individually raising the hold-down plates to permit introduction of the stacks of laminatable sheet material upon elevation of the rack; fluid-responsive means disengages the lost-motion coupling means and permits the plates to close upon the stack previously inserted. Thus, the present invention provides actuating means common to all of the plates and designed to raise the plates and release all of the stacks of material after an initial precompression for advance into the press. In addition, each plate may be individually raised to permit introduction of the respective stack. Compressed charging plates and lever linkage may be so arranged that the plates not only are capable of vertical movement but are adapted to swing out substantially horizontally and/ or come to rest against the underside of an upper stage during discharge of the 4 press-charging station. Furthermore, the linkage means can include a shaft carried by the successively higher stage and connected with the charging plate with the aid of a lever keyed to this shaft. The actuating member can be a vertical bar while the coupling means can be slide bodies carried thereby.

The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is a side-elevational view of a system for the charging of a multiplaten press in accordance with this invention;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a side-elevational view of one charging stage of the apparatus, somewhat enlarged with respect to FIG. 1 and illustrated fragmentarily;

FIG. 4 is a plan view of a portion of the charging stage, illustrated in FIG. 3, partly broken away;

FIG. 5 is a side-elcvational view of the hold-down actuating means for the apparatus, partly in section and drawn to an enlarged scale;

FIG. 6 is a fragmentary elevation view of the means for individually operating the hold-down plates; and

FIG. 6A is a view taken in the direction of arrow VI-A of FIG. 6.

In FIGS. 1 and 2, we show somewhat schematically a system for the charging of multiplaten presses with laminatable multilayer stacks adapted to be compressed in the presence of heat and/ or bonded with the aid of adhesives into coherent and unitary sheets or boards. Such presses are wellknown in the art and can, for example, be of any of the types described and claimed in the commonly assigned US. Patents, Nos. 3,050,777, 3,209,405, and

3,241,189; in accordance with this invention, these presses are employed for the bonding of relatively thin wood layers to one another in respective stacks to form furniture veneer, door structures, plywod and the like.

General description In accordance with the principles of this invention, the multiplaten press 1 is flanked by a charging station 2 adapted to feed the individual stacks, which may be provided upon charging plates, shiftable platforms or tablets or movable conveyor hands, into the press to displace the previously compressed boards therefrom and introduce the stacks to be compressed. As set forth in our copending application Ser. No. 534,324, filed Mar. 15, 1966, and entitled, Press-Charging Apparatus, the charging station 2 comprises a vertically shiftable frame 3 carrying a plurality of vertically spaced or stacked charging stages or levels corresponding in number to the press stages or levels of the multiplaten press 1. ,The levels 4 of the press-charging station 2 are, of course, respectively alignable with the platens lat of the press 1 for the simultaneous advance ofall the stacks of the charging station.

Discharge station The charging station 2 is disposed in front of or at the inlet side of the press (FIG. 2) while behind the press at its outlet side a discharge station 60 is provided, this discharge station comprising a collecting conveyor 5 and a stacking device 6 for the compressed and bonded board. As will be apparent from FIGSbl and 2, the colr lecting conveyor 5 comprises, a plurality of transversely spaced endless conveyor belts 5a carried by respective arrays of guide rollers 5b upon arms5c swingable jointly about a respective pivotal axis 5d to which the arms are keyed. The trough-shaped shaft 50? is, in turn, mounted in a support frame 5e and rotatably receives a drive shaft 5 which is carried in bearings (not shown) of the upwardly open semicylindrical pivot shaft 5d. The arms 50 are interconnected by bars 5g to which the platens 5/1 of the fluid-operated cylinders 5i are pivotally afiixed, these cylinders 5i being swivelably mounted at 5i to the frame 5e (FIG. 1). A drive pulley 5k is likewise carried by the frame 5e and is connected via a belt 5l to a driven pulley 5m on the shaft 5 to provide continuous rotations of the belts 5a. Thus, the unitary laminated board 5p deposited upon the belts 5a of the pull-out or discharge device 5 will be carried up over the shaft 5 and deposited upon the stacker 6. The pull-out unit 5 is sWinga-ble via the fluidresponsive means 511, Si, 5 as indicated in broken lines in FIG. 1.

The stacking device 6 comprises a roller platform 6a Whpse rolls 6b are transversely spaced but mutually parallel and extend transversely to the direction of movement (arrow 60) of the unitary goods out of the press; the rollers are provided with a common drive belt 6d which is operated by a motor 6e via a speed-reduction transmission 6 designed to rotate the roller 6b and thereby shift the entire stack out of the stacking device 6 in the direction of arrow 60. The rollers 6b are mounted in a frame 6g flanked by uprights 6h and 62 at opposite ends of the frame 6g. The uprights 6i are connected by a crossbar 6 and are displaceable in the direction of arrow 6k to align the corresponding edges of the stack board disposed thereon; hydraulic means (not shown) can be provided to displace the uprights 6i and the crossbar 6 in the direction of arrow 6k, the opposite edges of the board being retained by the uprights 6h.

Stripper means As described in our copending application Ser. No 534,324 entitled Press-Charging Apparatus, the press is charged by displacing the stacked laminated sheets onto the respective platens in the press upon respective pallets which are then withdrawn while stripper means retains the stacks of the various levels from being retracted with the pallets. The stripper means, generally designated 7, is disposed between the press-charging station 2 and the press 1 (FIG. 2).

The stripper means 7 can comprise a pair of inwardly extending arms 7a and 7b adapted to project into the path of the stack upon each level and shiftable in respective holders 7c, 7:! in the direction of arrow 7e and 7 respectively. For this purpose, the arms 7:: and 7b may be constituted as racks engagea'ble by pinions within the mechanisms 7c and 7d or as threaded bodies but with a nut rotatable in each mechanism 70 and 7d in opposite senses to advance and retract the stripper arms 7a and 7b. It will thus be apparent that, after the stack-carrying pallets are respectively introduced into the press and overlie the respective platens 1', 1" thereof, the stripper arms 7a and 7b are advanced inwardly and retain the rear longitudinal edge of each stack (a pair of such anms being provided for each press level) to prevent retraction of the stack with the respective pallet during the rearward movement thereof. The stacks remain in the press during the stroke thereof, the arms 7a and 7b being retracted subsequently to the withdrawal of the pallets but prior to the next advance thereof to permit a further set of stacks to be introduced into the press and to dislodge finished board therefrom.

Charging station The press-charging station, in accordance with the present invention, comprises the frame 3 which as can be seen in FIG. 1, is vertically shiftable upon guide rails 3a in a well 8a of the foundation 8 of the installation. The Well 8a is dimensioned to receive the entire vertical array of pallets and their rack 3 so that the successive pallets can be loaded with the respective stacks of laminated sheets at an infeed level represented at 9 with, for example, the aid of a charging device as is described and claimed in our copending application Ser. No. 534,231, filed Mar. 14, 1966, and entitled Apparatus for the Charging of Multiplaten Presses. As described in that application, the rack of pallets is raised in a stepwise manner and the successive stacks of laminated sheets are disposed upon successively lower pallets, the pallets being shifted jointly into the press and withdrawn concurrently only after each of the pallets has been charged. Vertical displacement of the rack 3 is effected with the aid of a counterweight 3b connected via cables 30 with the rack 3, the cables 30 passing over idler pulleys 3d. A further pulley 3e driven by a motor (not shown) rotates the pulleys 3d to raise and lower the rack 3. The pallets 3g are provided with longitudinally extending ribs 311 designed to receive the stacks of laminated sheets and to co-operate with sweeper plates 3i carried by arm 3 for straightening of the rearward edge of the plates. The straightening means is fully described in our application Ser. No. 534,324 entitled, Press-Charging Apparatus, and it will be understood that the present discussion thereof is to be taken where necessary with the disclosure of this latter application.

Stack-straightening means The stack-straightening means for the individual laminated stacks of the respective pallets is generally shown at 7 0 and comprises a carriage a rollingly supported on a rail 70b and having an arm 70c depending from the carriage. The arm can be provided with a pair of outwardly open U-sectioned vertical channels and a pair of abutments spaced apart in the direction of movement of the carriage along the rail. Each of the plates 3g, 3g" constituting the respective pallet 3g can then include a respective inwardly turned projection 3k received in the channels 31 and displaceable therealong to permit the vertical movement of the rack 3 and the pallets thereof, as described above. The ribs 3h thus constitute transversely spaced longitudinally extending guide elements parallel to the rail; the stages of the rack (not shown in FIGS. 1 and 2) can then be provided with corresponding transversely spaced longitudinally extending guide elements. The rack 3 is subdivided into two laterally spaced portions 3' and 3" so as to leave a. central clearance in the plane of the rail 70b to permit the arm 70a to shift between the rack portions 3' and 3" in the direction of the press 1. The alignment plates 3i are constituted as heads whose arms 3 connect them with the arm 70c (FIGS. 1 and 2). The channels 3l from another arm 70d which is supported from a carriage 70:2 and by means of which the pallets 3g are advanced into the press 1. The carriage 70e has a drive roller 70 rotated via a belt 70g by a motor 70b. The arms 70c and 70d are thus mutually entrainable with lost-motion or play so as to permit the heads 31' to align the right-hand edges of the stacks upon the pallets 3g during an initial movement of the arm 70c and the heads 3i to the left. Further movement of this arm in the direction of arrow 70: is effected via arm 70d which carries the pallets into the press while developing a spacing between the heads 3i and the aforementioned rear edge of the respective stacks sufficient to accommodate the stripper arms 7a and 7b. The heads 3i can each be provided with recesses receiving the corresponding longitudinal elements or ribs 311 and in interleaved relationship therewith so as to ensure positive entrainment of the stacks while elastic surfaces can be disposed upon their abutment faces, as described in the last-mentioned copending application.

H old-down mechanism According to the present invention, each of the presscharging tablets is provided with a hold-down mechanism best seen in FIGS. 3-6 but designated generally at 10 in FIG. 2 on each side of the press-charging station. The hold-down mechanism comprises raisable and lowerable hold-down plates 11 extending generally parallel to each of the charging tablets and assigned to each of the presscharging stages at both sides 3', 3" of the station 2. A lever linkage 12 (FIG. 4) connects the plates with the raising and lowering device as generally designated at 13 for the simultaneous lifting of all of the hold-down plates. A hydraulic mechanism 14 is provided for lifting the hold-down plates independently of one another when the respective tablets are disposed in the region of the charging level 9 for insertion of the respective stacks of relatively thin laminatable material into the charging station and upon these tablets.

The hold-down plates 11 are composed of sheet metal with reinforcing profiles welded thereto or formed integrally thereon at the opposite edges 15 (FIGS. 3 and 4) of each rectangular plate. The lever linkage 12 of each of the plates 11 of the respective stages is provided with a pair of shafts 16 (FIGS. 3 and 4) extending transversely to the direction of movement of the tablets and the stacks of laminatable sheets carried by each of them during the press-charging action. The shafts 16 each have levers or arms 17 (FIG. 4) which are connected by bushings 20 slid axially into the shafts 16 and locked for rotation therewith by means of keys 21. A pair of such arms 17 are provided in axially spaced relationship along each of the shafts 16 so that each press-charging stage comprises a pair of such shafts 16 in laterally spaced relationship in the direction of movement of the stacks (arrow a of FIG. 4) on each of the halves 3, 3" of the charging device. The arms 17 then extend radially from their respective shafts 16 toward the opposite ends of the tablets.

The hold-down device of only a single charging stage at one side 3 of the charging station 2 can be seen in FIGS. 3 and 4. The shafts 16 are also keyed to respective actuating levers 18 via sleeves or bushings 18a and keys 18b for coupling the hold-down plates 11 with the plateelevating system 13. The shafts 16 are journalled in conventional pillow blocks 19 directly upon the respective halves 3 and 3" of the charging rack 3, the latter being constituted of truss or frame construction, as will be apparent from FIG. 1.

The extremities of the swinging arms- 17 remote from the respective shafts 16 are provided with longitudinal slots 22 receiving pins 23 adapted to pivotally connect the arms 17 to the hold-down plates 11. For this purpose, the holddown plates 11 have trunnions 24 in the form of pairs of lugs receiving the respective pins 23 and lying on opposite sides of the respective lever 17. The lug 24 can also be longitudinally slotted.

The swinging arms or levers 18 are joined via slot andpin connections 25 (FIG. 3) With a sliding block 26 vertically shiftable along an actuating member 28 (FIGS. 1, 3 and 4) extending along each of the rack halves 3', 3" and adapted to actuate the hold-down plates. The tubular actuating member 28 is provided with radial pins 29 assigned to each of the slides 26 of the respective stages and engaging them with lost-motion. Thus, the extremities of pins 29 lying beyond the periphery of the actuating member 28 can be received in axially extending slots 30 of the slides 26 so that the upper and lower edges 27a and 27b of these slots form abutments engageable by the pin 29. The abutments 27a and 27b and the pins 29 define the stroke of the slides 26 upon the actuating member 28.

In the position of the device illustrated in FIG. 3, the hold-down plate 11 (as representative of all of the holddown plates) has been lifted against the next higher stage 4 of the charging station to provide a maximum clearance C between itself and the respective tablet whose receiving surface is represented by the dot-dash line T in FIG. 3. For this purpose, the actuating member 28 is drawn downwardly (arrow 28a) with respect to the rack 3 so that all the pins 29 engage the lower abutments 27a of the respective slides 26 and likewise draw them down wardly to raise all of the plates 11. The levers 18 on the left-hand side (FIG. 3) of the actuating member 28 are thus swung in the clockwise sense while levers 18 on the right-hand side of member 28 are swung in the counterclockwise sense to elevate the plates 11 and bring them to bear against the underside of the next-charging stage 4.

For simultaneous actuation of the plates 11, we provide a fluid-operated device, e.g. a pneumatic or hydraulic cylinder 31 whose piston rod 32 is hinged at 33 to a lever 34; the latter is fulcrumed at 38 to a bifurcated lug 37 mounted on. the channel irons 38a of the respective rack half 3'. The other extremity of lever 34 is pivotally connected via pin 35 to a bifuracted lug 35a threaded into a bushing 35!) at the lower extremity of the actuating member 28. The latter can be guided at spaced locations in slide bearing 36, only one of which can be seen in FIG. 5. The double-acting cylinder 31 is energizable via a hydraulic line 31a to shift the actuating member 23 relative to the rack frame 3' and thus raise or lower the plates 11. The hydraulic or pneumatic mechanism 31, 32 etc. can be disposed below all of the charging stages 4 and can be provided with a bifurcated head 33 for pivotal con-. nection via a pin 33a with the lever 34.

The system can be arranged as illustrated generally in FIG. 2 such that two tensionable actuating members 28 are provided, one for each half 3, 3" of the rack so that the charging plate of each stage is subdivided correspondingly into two halves whereby a space is left between them i for advance of the press-charging tablets and the arms 70c and 70d. Thus, the fluid-responsive cylinders 31 of both the actuating members 28 can be connected in parallel for joint operation or can be actuated via respective hydraulic lines for independent operation. It will be understood, moreover, that the hydraulic device 31, 32 can be coupled directly with the bifurcated lug 3511 without the aid of the lever 34, if desired. It is also possible to replace the hydraulic means 31 and 32 by a mechanical system having, for example, an actuating lever connected with the fulcrum pin 38 which can be keyed to the lever 34.

The mechanism 14 for individually raising the plates 11 is illustrated in FIG. 6 and comprises a double-acting hydraulic or pneumatic cylinder 39 whose piston rod 44 has a bifurcated head 45 receiving a lever arm 46 and is articulated thereto at 45a. The lever 46 is swingably mounted in the region of the charging level 9 upon a shaft 46a and has an extremity 46b adapted to depress the block 26 and thus raise the plate as each stage 4 is aligned with the stack-feed device. For this purpose, the slides 26 are each provided with a respective pin 26a engageable by the end 4617 of lever 46 during clockwise movement thereof upon energization of the hydraulic cylinder 39. The hydraulic cylinders 31 and 39 are provided with respective lugs 43, 43' for swingably mounting them upon the trunnions 42, 42 of the respective rack half 3 via pins 41, 41'.

Operation In accordance with the principles of the present invention, the plant illustrated in FIGS. 1-6 can be considered to operate essentially as follows:

Assuming that the charging rack 3 is in its lowermost position, the respective charging pallets are successively fed with stacks of laminatable sheet material from a feeding device of the type described in the copending application Ser. No. 534,231, filed March 14, 1966 and entitled Apparatus for the Charging of Multiplaten Presses. As each stage 4 is aligned with the feed device, the hydraulic cylinder 39 adjacent the rack is energized so that the lever 46 engages the pin 26a of the respective slide 26 and lowers the latter within the most-motion stroke or play of the slide to elevate the respective plates 11 and provide the maximum clearance C, thereby'permitting the stacks of laminatable sheets to be inserted into the respective pallets. Cylinder 39 then rotates the lever 46 in a counterclockwise sense to release the stop 26a and permit elevation of the slide (dot-dash position in FIG. 6) whereby the plate 11 is clamped under its weight against the stack of material upon the respective charging stage. The rack 3 then is lifted and the process is repeated for each of the stacks until the rack 3 is filled. The stacks are then advanced into the press after straightening of their rearmost edges via the means and technique set forth in our copending application Ser. No. 534,324, filed March 15, 1966, and entitled, Press-Charging Apparatus. Prior to the advance of the pallets, however, the cylinders 31 are energized to draw members 28 downwardly and raise the plates 11 of all stages simultaneously, thereby releasing the stacks for advance into the press.

Th invention described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the appended claims.

We claim:

1. In a system for the charging of a multiplaten press, the improvement which comprises:

a vertically displaceable press-charging station disposed adjacent said multiplaten press and provided with a multiplicity of charging stages corresponding in num her to the platens of said press for delivering layers of material to be compressed from said stages to said platens in an elevated position of said press-charging station, said press-charging station being raisable for successive positioning of said stages at a feeding level for successively depositing corresponding layers of material upon said stages;

hold-down means carried by said press-charging station and including a respective vertically movable ho'd down element overlying each of said stages and actuatable for compressing the respective layers against the respective stages;

first actuating means for collectively lifting said holddown elements upon elevation of said station to shift the respective layers into said press; and

second actuating means operable to raise the holddown elements of each stage independently of the other hold-down elements for receiving the respec tive layers between the respective element and stage at said feeding level.

2. The improvement defined in claim 1, further comprising a lever linkage connecting each of said holddown elements with said fi st actuating means, said second actuating means being selectively engageable with each of said arrangements upon positioning of the respective stage at said feed level.

3. The improvement defined in claim 2 Wh6Ti1 said press-charging station includes a rack carrying said stages and said lever arrangements each comprising a respective pair of spaced-apart shafts extending perpendicularly to the direction of displacement of the layers into said press and journaled on said rack, a pair of swingable arms keyed to each of said shafts and pivotaily connected to the respective hold-down element, and a pair of actuating levers keyed to said shafts and displaceable by said actuating means for raising and lowering said hold-down elements.

4. The improvement defined in claim 3 wherein each of longitudinally extending slot and the other of said meazne s carrying a pin slidable along said slot.

5. The improvement defined in c aim 3 wherein said first actuating means includes a verticaly shiftable elongated actuating member and said lever arrangements each include a respective slide body vertically shiftable on said member and eatrainable therewith, said levers of each of said lever arrangements being pivotaily connected to the respective slide bodies, said actuating member and said bodies being mutually en ageable with lost-motion in vertical irection.

6. The improvement defined in claim 5 wherein said first actuating means includes fluid-responsive means coupled with said actuating member for displacing same in vertical direction.

7. The improvement defined in claim 5 wherein said second actuating means includes fluid-responsive means engageable with each of said slide bodies upon the positioning of the respective stage at said feed level for rotating said shafts independently of movement of said actuating member.

8. The improvement defined in claim 2 wherein each of said hold-down elements is constituted by a plate overlying the respective stage.

9. The improvement defined in claim 8, further comprising reinforcing means formed along the periphery of said plate for stiffening same.

it The improvement defined in claim 1 wherein:

said press-charging station includes a vertically displaceable rack subdivided laterally of the direction of displacement of said layers into said press into two rack portions, each of said stages including a bipartite tablet slidable into said press and withdrawable therefrom to deposit the respective layers upon the respective platens, at least one arm depending between said portions for advancing said tablets simultaneously into said press, said tablets being en gageable by said arm but vertically movable relatively thereto, and means for raising and lowering said rack; said system further comprising strip means between said press-charging station and said multiplaten press and including a plurality of strip members respectively assigned to said said stages and operable upon insertion of said tablets into said press to retain said layers therein upon withdrawal of said tablets; Said elements are each constituted by a pair of plates overlying the tablets of the respective stages and received in the respective rack portion and adapted to clamp the respective layers against the respective tablets in a lowered condition of each of said plates; said hold-down means further comprising a respective pair of shafts assigned to each of said plates and journaled in the respective rack portion while extending transversely of the direction of displacement of said tablets to advance said layers into said press and being spaced apart in said direction, a pair of spaced-apart arms keyed to each of said shafts and hingedly connected to the respective plate for swinging movement about axes parallel to those of said shafts for generally parallel movement of said plates, actuating lever keyed to each of said shafts, and a respective slide body pivotally connected to the actuating levers of the shafts of each plate; said first actuating means includes a respective elongated actuating member vertically shiftable upon the respective rack pontions and slidably receiving said bodies, means forming a lost-motion connection between each of said bodies and a respective actuating member, a respective fluid-responsive piston-andcylinder arrangement disposed at one end of each of said actuating members, and link means including a lever fulcrumed on the respective rack portion and connecting each of said piston-and-cylinder arrangements with the respective actuating members; and

said second actuating means includes a fixedly positioned piston-and-cylinder arrangement successively engageable with said bodies for raising said plates independently of one another.

References Cited UNITED STATES PATENTS 2,704,608 3/1955 Graf et a1. 2l4l6.6 3,019,478 2/1962 Erickson et al. 21416.4 XR 3,024,721 3/1962 Brooks -l37 XR GERALD M. FORLENZA, Primary Examiner.

R. B. JOHNSON, Assistant Examiner.

Claims (1)

1. IN A SYSTEM FOR THE CHARGING OF A MULTIPLATEN PRESS, THE IMPROVEMENT WHICH COMPRISES: A VERTICALLY DISPLACEABLE PRESS-CHARGING STATION DISPOSED ADJACENT SAID MULTIPLATEN PRESS AND PROVIDED WITH A MULTIPLICITY OF CHARGING STAGES CORRESPONDING IN NUMBER TO THE PLATENS OF SAID PRESS FOR DELIVERING LAYERS OF MATERIAL TO BE COMPRESSED FROM SAID STAGES TO SAID PLATENS IN AN ELEVATED POSITION OF SAID PRESS-CHARGING STATION, SAID PRESS-CHARGING STATION BEING RAISABLE FOR SUCCESSIVE POSITIONING OF SAID STAGES AT A FEEDING LEVEL FOR SUCCESSIVELY DEPOSITING CORRESPONDING LAYERS OF MATERIAL UPON SAID STAGES; HOLD-DOWN MEANS CARRIED BY SAID PRESS-CHARGING STATION AND INCLUDING A RESPECTIVE VERTICALLY MOVABLE HOLDDOWN ELEMENT OVERLYING EACH OF SAID STAGES AND ACTUATABLE FOR COMPRESSING THE RESPECTIVE LAYERS AGAINST THE RESPECTIVE STAGES; FIRST ACTUATING MEANS FOR COLLECTIVELY LIFTING SAID HOLDDOWN ELEMENTS UPON ELEVATION OF SAID STATION TO SHIFT THE RESPECTIVE LAYERS INTO SAID PRESS; AND SECOND ACTUATING MEANS OPERABLE TO RAISE THE HOLDDOWN ELEMENTS OF EACH STAGE INDEPENDENTLY OF THE OTHER HOLD-DOWN ELEMENTS FOR RECEIVING THE RESPECTIVE LAYERS BETWEEN THE RESPECTIVE ELEMENT AND STAGE AT SAID FEEDING LEVEL.

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