US2801657A

US2801657A - Condensation preventer for veneer joining machine

Info

Publication number: US2801657A
Application number: US430810A
Authority: US
Inventors: Earle S Chrisawn
Original assignee: WILLIAMS FURNITURE CORP
Current assignee: WILLIAMS FURNITURE Corp
Priority date: 1954-05-19
Filing date: 1954-05-19
Publication date: 1957-08-06
Anticipated expiration: 1974-08-06

Description

Aug. 6, 1957 E. s. cHRlsAwN 2,801,657

' CONDENSATION PREVENTER FOR VENEER JOININQ MACHINE Filed May 19, 1954 2 Sheets-Sheet 1 INYENTORQ EARLE S. Cams/MN.

BY 5 5m K3621- 7 ATTQRNEYS.

Aug. 6, 1957 E. s. cHRIsAwN CONDENSATION PREVENTER FOR VENEER JOINING MACHINE Filed May 19, 1954 2 Sheets-Sheet 2 EARLE S. CHE ISHWN, INVENTOR.

.-BY Z L M ATTORNEYS nited States Furniture Corporation,- Sumter, S. C., a corporation of South Carolina Application May 19 1954, Serial No. 430,810 I 40mins"; (Cl. 144- 279 This invention relates to improvements in veneer join ing machines and particularly to that type of machine primarily adapted for uniting the edges of veneered sheets and like materials. e

e In gluing veneer sheets to edge; in certaincommercial practice, it is the custom to apply the glue or other adhesive to the edges of the sheets as these edges are being trimmed; The adhesive becomes dry in storageor at least prior to the gluing of the sheets together and in certain commercial practices, it is the custom to apply a liquid, generally formaldehyde, for moistening and softening the glue before the sheets are fed into the ma chine for applying heat and pressure to the veneers to cause the sheets to abut edge to edge. In a machine such as shown in Patent No. 2,305,525 of December 15, 1942, into which two pieces of veneer are fed, the edges of the pieces of veneer have previously been jointed are dressed and glue applied with the roller. Then the two sheets are carried to the splicer or joiner and they are fed in edge-to-eclge relation into this machine. The splicer has a small reservoir in front of a pair of endless chains, one overhead and one underneath, the reservoir carries a solution of formaldehyde. A thin disk revolves in this solution and moistens the two adjacent edges of the two veneer sheets as they are fed into the machine. Rollers in front of the two endless chains mentioned above are angled so as to force the two edges of the veneer sheets tightly together, and these are fed between the above mentioned chains and between a pair of electrically heated platens, which quickly sets the glue, bonding the two edges together firmly. However, in joining two edges of veneer sheets together there is one serious defect. The v,eneer carries moisture contents ranging from 6% to 12% and as the veencr sheetsfpas's between the heated platens the vapor or steam rises from the veneer just as it does from an electric iron ironing damp cloth. This moisture condenses on the cold iron of the machine and drops back .upon the veneer. In some woods this is not a serious problem but in oak wo'ods it is very objectionable because the iron rust in conjunction with a tannic acid in the oak veneer makes a' very ugly stain which is almost impossible to remove. Attempts to remove it are very expensive and troublesome.

It is an object ofthis invention; to provide means for directing a blast of heated air against the chains convey mg the pieces of veneer and against the upper heating element so as to heat the iron structure and the conveying strains and has prevent condensation a the vapor intd droplets on said chains and heating eleme t. The hot air also a great capacity for moisture and absorbs fir apo'r fro l the dry g vent i an speeds the setting of the glue joint, permitting the machine to: am ajliigher" rate of speed t an would otherwis'elb e possible, A machine with which this disparities is a ap ted to be usdis arid fhllydis cl din the above mentioned patent though it is to be ii'nderstbod that this atta hment for directing a blast of Hot at to the" point or joining the atetilf ice 2 veneer sheets can be used on any similar machine which is designed for joining two sheets of veneer together Some of the objects of the invention having been stated, other objects will appear as the description pro ceeds when taken in connection with the accompanying drawings, in which a 1 ,7

Figure 1 is an elevation of a veneer joining achine such as disclosed in said patent and showing a portio'nof thehot air duct associated therewith; A e e Figure 2 is an end elevation looking at the right hand end of Figure l and showing the heat generating and di recting means associated therewith; V V I Figure 3 is a vertical sectional view taken substantially along the line 3-3 in Figure 2; e I,

Figure 4' is a sectional plan view taken substantially along the line l -4 in Figure 1; e W

Figure 5 is a vertical sectional view taken substantially along the line 5- 5 in Figure 3. l V V A In the embodiment of the invention illustrated; I pro} vide a suitable base 1 carrying an operating table 2 within the surface of which is adapted to travel a pair of conveyor chains 3 arranged side by side and in somewhat spaced relationship (Figures 4 and 5). These conveyor chains may, if desired, converge toward one another from the front toward the rear of the table. Disposed between the chains is a heating platen 4 beneath which is arranged aheating chamber 5 (Figure 5) through which is adapted to be passed an electric heating element, such as a calrod unit, for generating sufficient heat to heat the platen and therefore heat the adjacent edges of veneer sheets, indicated at V and V, as they are passed through the machine by the conveyor chains.

, Supported above the work table 2 is a presser head6 which is preferably vertically adjustable relatively to the table through the medium of suitable adjustable mocha nism (not shown). This presser head comprises an enf closing casing 7 preferably in the form of a casting having side openings 8 which are ordinarily closed by cover plates but which are removed to carry out this invention and arranged within the casing are the pressure chains.

The pressure chain's comprise a series of pressure blocks or pressure plates9 connected to a chain 12 through the medium of extended pivot pins which pins pass through brackets and through the links of the chain 12, as is clear 1y shown in Figure 7 of said Patent No. 2,305,525. The chain 12 is driven from the shaft upon which is mounted the driving sprocket 14 (Figure I) mounted within an end housing 6' slidably mounted on plates 6 and held in its adjusted position by set screws 6 (Figures 1 and 3). At its opposite end, the chain passes over suitable guide tracks, to be more fully hereinafter described. V

The pressure chain is held in pressure contact with the conveyor chains 3 through the rnedium of a series of pressure shoes or blocks 15, each of which is pivotally secured, through the medium of vertically extending bracket arrns lfion the top face thereof to the presser pin or rod 17, for, pivotally connecting the block to the pin 17 (Figure, 5) The rod 17 extends upwardly between a pair of

guide plates

19 and 20 which plates are heldin spaced relation by suitable hollow bushings 21 surrounding the rod 17 and at its upper end is provided with threaded bearing nut 22 held in its adjusted posi t'ion by a lock nut 23. These guide platesl9 and 20 assist in maintaining and guiding the presser pins or rods 17 in their vertical position. This lock nut 23 provides a bottom bearing for a coiled spring 24, the upper end of which surrounds a guide lug 25 carried by a laterally extending arm 26 projecting from a central longitudinally extending web 27,

.web, at suitable intervals along its length, has \lertically adjustable means assoeiated therewith which may be vertically adjusted and thus the tension of the 3 springs 24 varied'to meet varying pressure requirements. Each of the pressure shoes 15 rides a chain 35 through which the pressure from the' pressure shoes 15 is transmitted to the pressure plates 9 (Figure 5).

The upper run of the floating friction reducing chains- 35 travels on V-shaped tracks mounted upon the upper face of supporting plates 41 which, at their ends and at intermediate points, rest upon and are secured to cross webs 42 extending transversely between side walls of the casing 7.

The spaced

guide plates

19 and 20 are held in clamped together position by suitable clamping bolts not shown, but clearly shown in Figures 2 and 3 of Patent No. 2,305,525. -The

guide plates

19 and 20 are supported from cross webs 42 extending between the side walls of the casing 7 by bolts 43. These cross webs also assist in supporting the supporting plates 41. At the front end of the casing 6 there is provided arcuate guide tracks, not shown in the present application, but shown and described in Patent No. 2,305,525, for the friction reducing roller chains 35. The roller chain 35 is disposed between the presser shoes 15 and the presser chain comprising the plates 9 and the driving chain 12 there for. By this arrangement, a floating friction reducing member is interposed between the presser shoes 15 and the chain which comes in contact with the veneer to thus materially reduce the friction between the parts.

The floating friction reducing chains 35 travel over guide plates at the rear end of the machine, which guide plates are similar to the front guide plates and are biased outwardly to prevent slack in the floating chain.

The veneer sheets V and V, as is obvious, are fed forward on and by the conveyor chains 3, pressure being applied to the veneer sheets above the conveyor chains by the pressure plates 9, as above'described. In view of the fact that the pressure plates 9 are separated, the abutting edges of the veneer sheets do not come in contact with the pressure plates. In order to apply pressure to the abutting edges, I provide an upper ironing foot or plate 50which, at its forward end, is curved upwardly and is suitably secured to the front end of the casing 6. This ironing plate 50 extends rearwardly the full length of the pressure chains and islocated immediately above the joint of the veneer sheets and immediately beneath an electric heating chamber 53 which is disposed between the two pressure chains and contains a suitable heating element, such as a calrod unit. Heat is conducted to the ironing foot or plate through the medium of upwardly extending leaf spring members which are riveted to the top surface of the ironer and bear on the under surface of the heating chamber 53. By this arrangement, not only is suflicient pressure applied to the abutting edges to hold them smooth but the heat from the heating chamber is conveyed to the ironing foot or plate 50 through conduction by means of these springs as well as through radiation.

v For moistening the glue or adhesive, which has heretofore been applied to the edges of the veneer sheets or for applying the adhesive itself there is provided at the forward end of the machine and immediately in front of the pressure head and between the inlet ends of the conveyor chains, a liquid applying mechanism. To this end, a reservoir or pot 55 is removably secured to the lower front end of the operating table 2 (Figure 1). The reservoir 55 and a pressure applying mechanism broadly designated at 60, in Figure 1, are fully shown and described in Patent No. 2,503,551 of April 11, 1950, and therefore only a brief description of these parts will be given.

The reservoir 55 is provided to contain a supply of formaldehyde for moistening and softening the dried glue on the mating edges of the veneer so that they may be bonded together bythe joiner or splicer. The formaldehyde is applied on the edges of the veneer by a thin wheel 56 (Figure 4) passing'through a slot in the table 2 and between the edges of the veneer. The wheel 56 is driven by and feeds the formaldehyde by a grooved wheel, not shown, the lower surface of which runs in the liquid in the reservoir 55. It is thus seen that a thin coat of formaldehyde will be applied to the mating edges of the veneer to soften the dried glue previously applied.

Although formaldehyde is applied to the mating edges of the veneer in this application, it is to be understood that a thermo setting glue could be used in the reservoir 55 and applied to the mating edges of the veneer or the thermo setting glue could be applied to the edges of the veneer before insertion in the veneer joining machine, in which case the reservoir 55 would not be needed.

The pressure applying mechanism 60 comprises a pair of resiliently mounted presser rollers 62 which guide the edges of the veneer together and keep the veneer in contact with the table 2 so that the edges thereof will be engaged by the formaldehyde applying wheel 56. The rollers 62 are supported in a bracket 64 adjustably secured to the front end of the housing 6. The bracket. 64 also supports a pair of guide rolls 65 one of which engages each of the pieces of veneer to be joined and holds the same in sliding engagement with the table 2.

To provide an opening for the wheel 56 between adjacent edges of the veneer sheets, an aligning fin 69 is secured upon the table surface in front of the opening in the table (Figures 1 and 4). The wheel 56 is thus provided space to rotate between the edges of the veneer, thus insuring thorough moistening of the adjacent edges: of the veneer and preventing the escape of the-liquid between the adjacent edges of the veneer above the sheets.

In operation, a pair of veneer sheets V and V is fed to the intake end of the machine. The adjacent edges. of the sheets are maintained separated by the fin 69. As the separated edges pass adjacent the wheel 56 the edges, which have heretofore received adhesive, are moistened by the formaldehyde carried thereto by the wheel 56. After having received the moisture, the adjacent sheets pass forward until they are engaged between the bottom feed conveyors 3 and the pressure plates 9 being carried by the upper conveyor and fed toward the rear of the machine. Due to the fact that the conveyors 3 tend to converge toward the rear end of the machine, the edges of the veneers are brought into abutting relation and due to the fact that the presser feet bear down on the tops of the adjacent edges, there is no danger of the sheets becoming wrinkled. As the sheets pass through the machine, the adjacent edges are pressed upon by the ironing foot or plate 50 and as the base 4 and the foot 50 are heated, the moistened glue edges are heated and dried so that by the time the sheets emerge from the rear end of the machine, their abutting edges are firmly secured together.

In the drawings, the cover plates for the opening 8 are shown as being removed in order to accommodate the present invention. The present invention includes a suitable framework 70 secured to the machine or to the ceiling and comprises spaced horizontal frame members 71, only one of which is shown, to which are secured suitable brackets 72 which support a housing 73. The housing 73 is connected to one side of a heater 74 which is a steam heater, or an electrical heater or any suitable source of heat. Housing 73 has connected thereto a duct 75 which extends downwardly and inwardly and has a horizontal portion 76 which has an open end in align! ment with one of the side openings 8 (Figures 2, 3 and 5). The horizontal portion 76 of the duct 75 is supported in spaced relation above the table 2 by a pair of vertically disposed frame members secured thereto and the upper ends of which are secured to the frame members 71 (Figures 1 and 2). The heater 74 has associated therewith a suitable fan 77 driven by a suitable electric motor 78 and this fan forces air through the heater 74, housing 73, the duct 75, the horizontal portion 76 and discharges :3) hot air onto the pieces of veneer, at the point they are being glued together. The hot air is also directed onto the heater element and the chains moving the veneer, thus any moisture which is excreted by the heat of the heating element on the pieces of veneer is absorbed by the warm air since warm air will absorb much more moisture than cold air. The hot air will also absorb the moisture which may tend to collect on the heating element and will tend to heat the chains and the heating element thus resulting in dissipating of the moisture as the moisture will be absorbed by the current of hot air and discharged out through the side opening 8 remote from the one into which the duct 76 is discharging the hot air.

It is thus seen, that there has been provided means for directing a continuous blast of hot air through a joining machine, at the point where a pair of pieces of veneer are being joined by being glued together, and thus dissipating the moisture which tends to form from the gluing and heating operation and thus eliminating any condensation spots on the veneer which is being joined.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms have been employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. In a machine for joining two sheets of veneer together in edge-to-edge relation and having means for feeding two sideby-si-de disposed pieces of veneer sheeting through the machine and applying pressure to move the pieces of veneer towards each other to press the proximate edges of the same against each other and said proximate edges having previously had an adhesive applied thereto and said machine having means for applying a softening agent such as formaldehyde to the proximate edges of the sheets of veneer material and said machine having heating means for heating the proximate edges of the sheets of veneer as they pass through the machine, a combination of heat generating means associated withthe machine and having a duct leading from the heat generating means to one side of the machine at the point where the heat is applied to the veneer sheets to join them together under pressure and a blower fan associated with,

said heat generating means for forcing a draft of heated air laterally through the machine at the point where the pressure and heat are applied thereto to thereby absorb moisture which is generated by the heating of the proximate edges of the sheets of veneer and thus prevent condensation of the moisture into droplets and also prevent the depositing of droplets of moisture onto the sheets of veneer as they are being adhesively secured to each other.

2. In an apparatus joining the two proximate edges of two sheets of veneer together and having means for conveying the two sheets of veneer through the machine simultaneously and applying lateral pressure to the two sheets of veneer to force their edges into intimate relation to each other, said sheets of veneer having previously had applied an adhesive to their proximate edges and said machine having means for applying a softening agent to the adhesive such as formaldehyde, and said machine also having a heater disposed therein for heating the proximate edges of the sheets of veneer as they are forced against each other, the combination of heat generating means, a duct leading from the heat generating means to one side of the machine at a point Where heat is being applied to the proximate portions of the two sheets of veneer and means for forcing air through the heat generator and through the duct andinto contact with the portions of the apparatus adjacent the heating means in a the apparatus and against the conveying means.

3. In an apparatus joining the two proximate edges of two sheets of veneer together and having means for con-. veying the two sheets of veneer through the machine simultaneously and applying lateral pressure to the two sheets of veneer to force their edges into intimate relation to each other, said sheets of veneer having previously had applied an adhesive to their proximate edges and said machine having means for applying a softening agent to the adhesive such as formaldehyde, and said machine also having a heater disposed therein for heating the proximate edges of the sheets of veneer as they are forced against each other, the combination of heat generating means, a duct leading from the heat generating means to one side of the machine at a point where heat is being applied to the proximate portions of the two sheets of veneer by the heating means in the machine and means for forcing air through the heat generator and through the duct and into contact with the portions of the apparatus adjacent the heating means in the apparatus and against the conveying means to thereby carry moisture, which is generated by the heating of the proximate edges of the sheets of veneer, out of the open side of the apparatus.

4. In a joiner for joining together the proximate edges of two sheets of veneer and having heating means for applying heat to the proximate edges of the sheets of veneer and conveying means for moving the veneer sheets through the joiner and towards each other; the combination therewith of heat generating means having a duct provided with an opening terminating adjacent and extending laterally of the conveying means and directed across the surface of the veneer sheets for directing air heated by the heat generating means across the surface of the veneer sheets and across the joints thereof to absorb moisture arising from the heating of the proximate edges of the sheets of veneer.

References Cited in the file of this patent UNITED STATES PATENTS 2,084,676 Friz June 22, 1937 2,305,525 Gustin Dec. 15, 1942 2,361,861 Masowich Oct. 31, 1944 2,378,123 Beck June 12, 1945