US1183526A - Veneer-drying apparatus. - Google Patents

Description

F. BISHOP. VENEER DRYING APPARATUS. APPLICATION men 950.19. 1914.

Patented May 16, 1916.

2 SHEETS-SHEET l F. BISHOP. VENEER DRYING APPARATUS. APPLICATION FILED Dic. 18. 1914.

Patented May16,1916.

2 SHEETS-SHEET 2.

1 IDI L WIT/VESSES:

'mE COLUMBIA PLANoaR/PH co., WASHING-run'. D. c

narran sTaTns TaTnnT oTTTea FRANK BISHOP, O-F CAIRO, ILLINOIS, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY, A CORPORATION OF NEW JERSEY.

VENEER-DRYING APPARATUS.

Specification of Letters Patent.

Patented May 16, 1916.

Application filed December 18, 1914. Serial No. 877,867.

To all fnv/tom t may concern:

Be it known-that I, FRANK BIsHor, a citizen of the United States, residing' at Cairo, in the county of Alexander and State of Illinois, have invented; certain new and useful Improvements in Veneer-Drying` Apparatus, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an improvement in drying apparatus, more particularly of that class designed for drying wood veneers, and it has for some of its objects to produce a uniform drying action throughout all parts of each veneer, to effect the drying operation with a minimum amount of heat, and to thus re-duce the cost of the drying operation. l

The present invention is designed particularly for use in connection with that class of drying apparatus-forming the subject of the United States patents to A. S. Nichols, No. 515,357, of February 27, 1894, and No. 918,581, of April 20, 1909, comprising a series of separable platens with means for applying heat thereto and means for alternately separating and closing together said platens with the veneers supported between them so as to apply to their opposite faces alternately heated surfaces and air currents designed to approximate uniform drying conditions. The improvement is, however, obviously adapted for employment in connection with other types and varieties of drying apparatus. Y

It has been customary heretofore to set up one or more of such drying apparatus in a room or compartment sufficiently large not only to contain all of the operative parts, but to permit the entrance of attendants engaged in introducing and removing the veneers for the successive drying operations.

According to the present improvement the supporting and heating means for the veneers or other objects to be dried are closely embraced by and housed within a closed casing having preferably detachable insulated wallswith means for access to its interior at one end of the veneers. By thus covering the drying means by a suitable insulated housing, the moistureaescaping from the veneer in the drying operation is retained within the same so as to prevent eX- cessively rapid Adrying and the consequent splitting of the end portions of the veneers.

The radiation of heat from the outer faces of the platens is also very materially reduced, and consequently the steam pressure can be correspondingly reduced so as to effeet equally rapid drying with much less liability to damage of the veneer and less steam consumption than with drying apparatus lacking such housing.

Where several drying4 apparatus are grouped together in the same room or compartment, the radiation from the heating elements -makes the temperature of the atmosphere in such room or compartment almost unbearable for-the attendants, especially in the summer season, for which reason it is diiiicult to maintain proper attendance to insure uniform production. By means of ythe present improvement, the attendants are protected from the drying hea-t, excepting in the intervals during which the casing is open for admission and withdrawal of the veneers or other objects. In the class of drying apparatus referred to, the separable platens have been connected with and moved into and out of Contact relation with the interposed veneers by means of reciprocally movable hydraulic presses which are disposed, according to the present improvement, exterior to the housing. By this means, the cylinders of said presses are disposed in an atmosphere at normal temperatures, and are protectedfrom the intense heat within the casing, thereby involving a material saving in packing.

The invention will be understood by reference to the accompanying drawings, in whichy Figure 1 is a front elevation of a drying apparatus embodying the present improvements, and Fig. 2 a side elevation of the same, portions of the casing being omitted to expose the veneer supporting and drying means within the same. Fig. 3 is a detail sectional view showing the construction of the side walls and doors of the casing and their manner of application to the frame work, and Fig. 4 is a similar view of adjacent portions of the upper and lower doors by which access is provided to the interior of the casing.

The main frame of the apparatus comprises the vertical columns 1, the compound crossbeams 2 connecting the upper ends of the same and the tie-bars 3 connecting the lower portions thereof. Resting upon the tops of the beams 2 are the pivotal studs 4 Vprojecting oppositely from the upper ends of the swinging link-bars 5 depending between the component members of the bea-ms 2 and pivotally connected at the lower ends by means of bolts 6 with the upper ends of the hollow platens 7 suitably constructed in practice for circulation of steam or other heating fluid by which the platens may be maintained in heated condition. Suspended by means of bolts 8 from one of the beams 2 are the stirrups 9 supporting the header 10 from which depend a series of supply pipes 11 (one only of which is shown in F ig. 1), connected at the lower ends with the steam circulation spacer within the respective platens. The header 10 is connected by means of the pipe 12 with a suitable steam supply. Connected with the steam circulating means at the lower end of each platen are the drip pipes 13 leading into the header 14 supported by the stirrups 15 depending from one of the tie-bars 3 and provided with the outlet pipe 16.

The platens at the opposite ends of the series are connected with the plunger-rods 17 of alined hydraulic presses comprising the cylinders 18 which are in practice suitably supported upon the columns or standards 1 and provided each with water supply and discharge pipes 19 and 20, as represented more fully in the said Patent No. 918,581. By means of these hydraulic presses, pressure is applied and relieved between the end platens and the adjacent platens, Kthe series of platens being pref* erably connected together to move toward and from each other by means of lazy-tongs connections, as represented insaid patent.

:Disposed intermediate the end columns 1 of the main frame are the corner posts or standards21 of an auxiliary housing frame which are connected together at the bottoms by means of the cross-beams 22, and in the upper portions on opposite sides 4by the cross-beams 23. extending beneath the beams 2. These standards are connected at the upper ends atthe front and back by means of the cross-beams 24, which are respectively forwardly and rearwardly offset and sustainrthe grooved pulleys 25 by means of the studs-26. Thestandards 21 are also connected at the sides in Ytheir lower portions by the cross-beams `27 which are in turn connected intermediate'their ends with the upper cross-beams V23 bythe upright posts Orstandards 28.

Detachably ksecured to the sides of the auxiliary frame are `the fhollow insulated panels 29 and 30, the latter being ,provided in-.one edge with a `notch 30 to receive l'the plunger-rod 18, `and beneath `the Isame isa lower Apanel 31 formed in its opposite edges with "notches 32 .to receive the tie-bars 3. Banels .-33 ,and` 34 falte :appli-ed to the upper and'lower portions of the frame at the front and back with an intermediate opening for access to the forward and rearward edges or ends of the platens 7 and the veneer spaces between them. The top of the casing is closed by means of the panels 35 and 36 resting upon the cross-beams 23 between the main-frame beams 2.

Secured upon the outer faces of the angleiron standards 21 at the front and back of the casing by means of bolts 37 (Fig. 3) are kguide-strips 38 separated therefrom by means of the spacing strips 39 to afford channels or runways to receive the lateral ianges 40 of-the hollow upper and lower doors 41 and 42. These doors are provided respectively adjacent their ends with the straps 43 and 44 provided at their upper ends with eyes 45 in which are securedthe opposite endsof the cords or cha-ins 46 passing over the pulleys 25 affording supports for the doors which are thus counter-balanced. The upper doors are provided centrally with the handles 47, and the lower doors have secured thereon the depending straps 48 provided at their lower ends with lateral extensions 49 affording stirrups for the feet of the attendants when opening the doors for accessto the interior of the casing.

The several panels of the casing are made of hollow construction, each preferably comprising `a flat outer plate 50 and an inwardly recessed inner plate 51 having lateral flanges `extending entirely around the same and secured to the marginalrportions of the outer plate, as represented Lparticularly in Fig. 3. The doors are shown in said figure, similarly constructed, excepting that the inner plate 52 is fiat and the outer plate 53 is outwardly recessed with its marginal'flanges secured upon the marginal portions ofthe inner plate, and the end flanges beingembraced by the runways aorded between the standards 21 and guide-strips 38. The adjacent flanges of the doors are shown in F ig. 4 -strengthened by means of the angie-irons 54 secured thereon by means of rivets. The hollow walls of the casing, as thus constructed, are preferably lled with insulating substances commercially known as"asbestocel, air cell or nonpareil insulation, or combinations thereof best suited to the several parts of the apparatus.

The 1several component members of the auxiliary frame are shown provided with externally projecting stud-bolts 55 secured in position by means of lock-nuts 55. Overlapping `the `outer faces of the auxiliary frame members adjacent such stud-bolts are the flanges constituting the thin marginal portions of the several insulated panels. These marginal-portions are forcibly pressed upon Ythe respectiveframe mem-bers by means of the arched clamp members 56 h-avingone extremity resting thereon and ,the other resting upon another of such marginal portions or upon the frame member, while the intermediate portion is apertured to receive the stud-bolt, a thumb-nut 57 being applied to the threaded outer portion of the studbolt for'forcing the clamp-member upon the panel. The hollow insulated portion of each panel projects inwardly and is so proportioned as to fit loosely between the adjacent frame members by means of which it is laterally positioned suitably for receiving the clamping members 56.

The component members of the crossbeams 2 are spaced apart to afford a longitudinal slot to receive the upper portions of the platen-supporting links 5, and this opening is covered by means of the sheet-metal cap 58 which is recessed to receive the upper ends of the links 5 and secured upoh the top of the beam 2 by means of tap-bolts 59.

The housing, as thus described, presents wall-s which effectively confine the heat within a comparatively small space surrounding the veneers, so as to not only economize heat but to retain the moisture escaping from the veneers for preventing the too rapid drying of the more exposed parts of the latter. By the employment of the clamps for securing the panels detachably in position, the latter may be readily removed from the auxiliary frame for cleaning and repairs. The counter-balanced doors at the front and back of the casing are easily and quickly forced apart by the attendants grasping the handle 17 with the hand and pressing the stirrup 49 by the foot in opening the same and as readily closing the same by drawing down the upper door by means of its handle.

In the use of the apparatus, the sheets of veneer are usually inserted through the front and rear doors of the casing at each end and between the platens, in case they are sufficiently short, and the hydraulic presses are set in action by automatic operation of alternately opening and closing hydraulic valves connected with the hydraulic presscylinders 18 by means of suitable apparatus, such for instance as that shown and described in the aforesaid United States Patent No. 918,581. The opening and closing of the platens usually takes place at intervals of ten to twenty seconds depending upon the thickness of the veneers, the principal object of this frequent opening and closing or breathing action being to allow for the contraction of the veneer and consequent prevention of splitting that would be liable if the veneer were maintained tightly clamped between the platens throughout the dryingprocess. This action is allowed to continue for a period of ten to twenty minutes, depending upon the character of the veneers.

The platens are heated with steam at preferably 80 to 100 pounds pressure, at a te1nperature somewhat exceeding 100 degrees Fahrenheit above the boiling point of water at atmospheric pressure, whereby the moisture is driven out by the force of its own expansion. As the platens recede, the opposite faces of the veneers are exposed to the inrushing air which absorbs the moisture which has been thus vaporized and also takes out some of the moisture from the wood itself. This action is greatest at the edges of the sheet of veneer, and especially at the end which is in practice substantially iush with the end of the adjacent platens.

When the driers are located in a large room surrounding the entire apparatus and the space adjacent the same for access by the attendants, the inrushing air between the platens under such condition is very dry, and the excessively rapid drying at the end causes a considerable loss through splitting. With the driers inclosed within a comparatively small space as above described, the air drawn in between the platens, especially for the initial portion of the drying action, becomes charged with moisture, and the excessive end drying is very much reduced, with a consequent material reduction in loss through splitting of the veneer, the drying action being entirely completed while the casing remains closed from the external atmosphere.

It will be observed that by the process above described, the moisture issues from the wood through its vaporization at a high degree of heat, rather than by being absorbed by the action of heated air entering its pores. The action of the moistened air in the drying casing or chamber is not so much to keep the pores of the wood open to permit the remaining moisture to escape as to prevent too rapid drying and consequent splitting of the veneer on the exposed end during the breathing movements of the heated platens.

As the amount of moisture absorbed by the air surrounding the platens and the in terposed veneers increases as the drying operation continues, it will be observed that this volume of air acts progressively in retarding the extraction of moisture as the drying operation approaches completion.

Having thus set forth the nature of the invention, what I claim herein is 1. In a veneer drying apparatus, in combination, a plurality of spaced platens having parallel fiat faces, means for heating them, a closed casing constructed with insulated walls closely embracing and aHording a housing for said platens and having a wall permanently in close proximity to edges of and unobstructed spaces between said platens, and means for affording direct acceslslto said spaces from the exterior of said wa 2, In a drying apparatus, in combination,

means for supporting and applying heat to the objects to be dried, a closed casing provided with detachable insulated Walls closely embracing and aiiording a housing for the same, and means applied to said easing and movable independently of said detachable Walls for aiording access to said objects.

3. In a veneer drying apparatus, in combination, a plurality of platens mounted for substantially rectilinear movement toward and from each other, means for heating said platens and for moving them toward and from each other, a closed casing provided with insulated walls housing said platens, and means in permanent alinement with and adapted to provide access simultaneously to said platens at unobstructed edges thereof from the exterior or said casing.

4f. In a drying apparatus, in combination, a series of platens, means for heating the same, a closed casing provided with insulated Walls housing said series of platens, means for providing access to said platens at the edges thereof, and means, including hydraulic cylinders disposed external to said casing, for moving said platens toward and from each other.

5. In a drying apparatus, in combination,

a series of platens, means for heating the same, means for moving them toward and away from each other, a frame for inclosing said series of platens, insulating plates detachably secured to said frame and together ail'ording a closed housing for said platens, and means adjacent the edges of 3 and adapted to provide access to said platens from the exterior of the casing.

6. In a drying apparatus, in combination,

a series of platens, means for heating the same, means for moving them toward and 4 from each other, a main frame embracing said platens and the means for heating and moving them, an auxiliary frame, and insulating plates detachably secured to said auxiliary iframe and together aiording a 4 closed housing closely embracing said platens and their heating means.

In testimony whereof, I have signed my name to this specification, in the presence off two subscribing Witnesses.

FRANK BISHOP. l/Vitnesses:

A. C. NIBLAGK, R. W. Hoovnn.

Copies o3.' this patent may be obtained for five cents each, by addressing the Commissioner o! Patents,

Washington, D. G."

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