# US 4,396,050 A · Log preparation for veneer peeling

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,396,050 A
- Document ID: US4396050A
- Status: Granted
- Kind: A
- Application number: 06/178,607
- Filed: 1980-08-15
- Granted: 1983-08-02
- Earliest claimed: 1980-08-15
- Inventors: Ralph L. Vandagriff
- Web page: https://patentgrep.com/patent/US4396050A

## CPC

- B27K 3/08: Impregnating by pressure {, e.g. vacuum impregnation}
- B27K 3/10: Apparatus
- B27K 5/001: {Heating}
- B27L 5/00: Manufacture of veneer (working veneer or plywood B27D ){; Preparatory processing therefor (drying F26B)}
- B27K: PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR (applying liquids or other fluent materials to surfaces in general B05; coating wood or similar material B44D); CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27L: REMOVING BARK OR VESTIGES OF BRANCHES (forestry A01G); SPLITTING WOOD; MANUFACTURE OF VENEER, WOODEN STICKS, WOOD SHAVINGS, WOOD FIBRES OR WOOD POWDER

## Abstract

In a semi-batch practice of the process, the logs are plasticized using hot, pressurized alkaline liquid in a closed chamber having a preceding charging chamber and a succeeding unloading chamber. The chambers are selectively flooded and emptied to facilitate operations. A ram is used at the charging end to advance the logs. Spacers are placed in opposed pairs between successive charges. The unloading trough is equipped with a sling to facilitate advancement of the conditioned logs to the lathe. Process may be program-controlled, with monitoring of processing temperature, pressure, time, pH, processing solution constituency, and heat input. Additional variables may be input to the automatic controller, such as species, ambient log temperature, length of time since log harvest, veneer end-product (e.g. thickness and whether decorative quality is needed), log weight and log diameter. The process may also be more simply conducted in batchwise fashion.

## Claims

### Claim 1

A method for conditioning logs for veneer peeling, comprising:
(a) introducing a first log charge including at least one log into a log conditioning chamber through a charging opening at one end of the chamber;
(b) closing and sealing the chamber;
(c) flooding the chamber with a log conditioning liquid comprising water and an alkaline chemical present in sufficient strength to maintain a pH of at least 7 in the log conditioning liquid;
(d) while maintaining said chamber in a flooded condition, circulating said log conditioning liquid into and out of said chamber;
(e) temporarily opening an unloading opening at an opposite end of the chamber and removing said first log charge from said chamber therethrough.

### Claim 2 (depends on 1)

The log conditioning method of claim 1, further comprising:
applying pressure to the circulating log conditioning liquid so that within said chamber, said at least one log is subjected to said log conditioning liquid at substantially elevated pressure.

### Claim 3 (depends on 2)

The log conditioning method of claim 2, wherein:
said substantially elevated pressure is in the range of 15-100 p.s.i.g.

### Claim 4 (depends on 1)

The log conditioning method of claim 1, further comprising:
adding heat to the circulating log conditioning liquid so that within said chamber, said at least one log is subjected to said log conditioning liquid at substantially elevated temperature.

### Claim 5 (depends on 4)

The log conditioning method of claim 4, wherein:
said substantially elevated temperature is in the range of 140-330 degrees F.

### Claim 6 (depends on 5)

The log conditioning method of claim 5, wherein:
the amount of heat added to the circulating log conditioning liquid is lowered over time, so that whereas at the beginning of said circulating said substantially elevated temperature is substantially above a preselected optimum temperature for veneer peeling of said at least one log in said first charge, and at the conclusion of said circulating said substantially elevated temperature is substantially below said preselected optimum temperature.

### Claim 7 (depends on 6)

The log conditioning method of claim 6, wherein:
said substantially elevated temperature at said beginning is in the range of 300 to 330 degrees F., and said substantially elevated temperature at said conclusion is in the range of 140 to 160 degrees F.

### Claim 8 (depends on 1)

The log conditioning method of claim 1, further comprising:
monitoring said log conditioning liquid pH while said log conditioning liquid is circulating into and out of said chamber, and adding make-up quantities of said alkaline chemical sufficient to maintain said pH in the range of 7-10.

### Claim 9 (depends on 8)

The log conditioning method of claim 8, wherein:
said pH is maintained in the range of 9-10.

### Claim 10 (depends on 1)

The log conditioning method of claim 1, wherein:
said log conditioning chamber is an elongated cylinder with said charging and unloading openings disposed at opposite ends thereof, said at least one log of said first charge being longitudinally aligned in said chamber.

### Claim 11 (depends on 10)

The log conditioning method of claim 10, wherein:
said at least one log of said first charge is removed from said chamber following being conditioned therein by being displaced out said unloading opening by reopening said charging opening and pushing at least one log of a subsequent log charge into said chamber through said charging opening.

### Claim 12 (depends on 11)

The log conditioning method of claim 11, wherein:
the recited log displacing step is repeatingly conducted in a cycle in which steps (a)-(e) are continually repeated on continually succeeding log charges.

### Claim 13 (depends on 12)

The log conditioning method of claim 12, wherein:
said chamber, between said openings is at least as long as two log charges, so that each log charge as it is pushed into the chamber displaces a said log charge from the chamber that is longitudinally spaced from the log charge being introduced into the chamber by at least one intervening earlier-introduced log charge.

### Claim 14 (depends on 12)

The method of claim 12, further comprising:
interposing at least one foraminous spacer into said chamber effectively at the head end of each said subsequent log charge, for preventing the at least one log of each respective log charge from longitudinally overlapping with the at least one log of each respective next subsequent log charge while in said chamber.

### Claim 15 (depends on 12)

The method of claim 12, wherein:
the at least one log of each respectively subsequent log charge, as such log charge is about to be pushed into said chamber is first disposed in an antechamber shaped and sized similarly to said chamber in transverse section, and buoyed in a quantum of log conditioning liquid, such log charge being pushed into said chamber while so buoyed.

### Claim 16 (depends on 15)

The method of claim 15, wherein:
the at least one log of each log charge becomes disposed in said antechamber by first being deposited on a table surface which dips toward said antechamber, and by having a gate temporarily moved out of the way which otherwise is normally interposed between the table surface and the antechamber, so that said at least one log of such log charge rolls off said table and into said antechamber through an open top of said antechamber.

### Claim 17 (depends on 16)

The method of claim 16, wherein:
a cover normally closes said open top of said antechamber, and as a precursor to the temporary movement of said gate out of the way, said cover is temporarily raised on the opposite side of said antechamber from said table surface to act as an overshoot stop for said at least one log of such log charge as is about to roll off of said table surface and into said antechamber.

### Claim 18 (depends on 15)

The method of claim 15, wherein:
said charging opening is closed and reopened by closing and reopening a gate valve stationed at said charging opening.

### Claim 19 (depends on 12)

The method of claim 12, wherein:
the at least one log of each respectively preceeding log charge, as such log charge is pushed out of said chamber through said unloading opening issues into a post-chamber containing a quantum of log conditioning liquid which buoys such log charge.

### Claim 20 (depends on 19)

The method of claim 19, wherein:
such log charge while buoyed in said post-chamber is underlain by a sling, and in which the at least one log charge is removed from said post chamber by raising said sling.

### Claim 21 (depends on 19)

The method of claim 19, wherein:
said unloading opening is opened and reclosed by opening and reclosing a gate valve stationed at said unloading opening.

### Claim 22 (depends on 1)

The method of claim 1, further including:
continuously filtering debris from said log conditioning liquid while said log conditioning liquid is circulating in step (d).

### Claim 23 (depends on 10)

The method of claim 10, wherein:
the chamber is closed and sealed by rotating a respective blind flange hinged to said elongated cylinder into blocking relation with each said opening and dogging those blind flanges to opposite ends of said elongated cylinder.

### Claim 24

Apparatus for conditioning logs for veneer peeling, comprising:
wall means defining a log conditioning chamber having two opposite ends;
means defining a charging opening in one of said ends and an unloading opening in the other of said ends;
openable closure means for sealingly closing each of said openings;
log conditioning liquid inlet means to said chamber for flooding said chamber with log conditioning liquid;
log conditioning liquid drain means for draining log conditioning liquid from said chamber;
a closed circulation loop for log conditioning liquid outside said chamber, connected between said log conditioning liquid inlet means and said log conditioning liquid drain means;
said closed circulation loop including means for adding make-up water to said log conditioning liquid, means for filtering debris from said log conditioning liquid, means for adding heat to said log conditioning liquid, means for adding pH-raising chemicals to said log conditioning liquid, and means for pressurizing the log conditioning liquid while said chamber is flooded therewith in order to provide a substantially elevated pressure within said chamber.

### Claim 25 (depends on 24)

The apparatus of claim 24, wherein:
said log conditioning chamber is an elongated cylinder with said charging and unloading openings being disposed at opposite ends thereof, said elongated cylinder being adapted to longitudinally receive at least one log charge at a time, of at least one log per charge, with all logs of each charge being substantially longitudinally aligned with said elongated cylinder.

### Claim 26 (depends on 25)

The apparatus of claim 25, wherein:
said elongated cylinder is sufficiently long as to simultaneously accommodate at least two such log charges in axially non-overlapping, generally adjoining relation.

### Claim 27 (depends on 25)

The apparatus of claim 25, further including:
trough means juxtaposed with said elongated cylinder in antechamber relation to said chamber, before said charging opening, so that a log charge may be introduced into said trough while awaiting displacement into said chamber through said charging opening; and
means for longitudinally displacing such charge from said trough into said chamber.

### Claim 28 (depends on 27)

The apparatus of claim 27, wherein:
said displacing means is constituted by an hydraulically-operated ram.

### Claim 29 (depends on 30)

The apparatus of claim 30, wherein:
said ram includes a ram head normally disposed within said trough;
said trough includes an outer end wall having a sealed bearing means therein; and
said ram head is disposed on a piston rod which passes out of said trough through said sealed bearing means, while being sealingly supported thereby.

### Claim 30 (depends on 27)

The apparatus of claim 27, wherein:
said trough is shaped and sized similarly in transverse cross-section;
said apparatus further including means for flooding said trough with log conditioning liquid while a log charge is disposed in said trough awaiting displacement into said chamber, to thereby float said at least one log of said log charge, so that said at least one log may be displaced into said chamber while so floated.

### Claim 31 (depends on 30)

The apparatus of claim 30, further including
a closeable/openable cover for said trough, and means for operating said cover.

### Claim 32 (depends on 31)

The apparatus of claim 31, wherein:
said cover is slidably mounted to the trough along a side of the trough; and
said apparatus further comprising:
a loading table ranked along the opposite side of said trough from where said cover is hinged, said loading table slanting down toward said trough;
a raiseable/lowerable gate interposed between the loading table and said trough to act as a temporarily removable barrier for logs piled onto said loading table;
said control means for coordinating movement of said cover and said gate, so that when a log charge is to be introduced into said trough, said cover may be slid open as said gate is temporarily removed as a barrier to the rolling of logs from said table into said trough.

### Claim 33 (depends on 25)

The apparatus of claim 25, wherein:
said openable closure means are constituted by respective gate valves.

### Claim 34 (depends on 25)

The apparatus of claim 25, wherein:
said openable closure means are constituted by respective blind flanges hinged to said elongated cylinder, and means for dogging said blind flanges sealingly tight against said elongated cylinder at said opposite ends thereof.

### Claim 35 (depends on 27)

The apparatus of claim 27, further including:
a trough-like post chamber juxtaposed with said elongated cylinder at said unloading opening, so that as a log charge is being displaced into the chamber a respectively earlier-introduced log charge having been conditioned with said chamber may be consequently displaced from said chamber into said post-chamber.

### Claim 36 (depends on 35)

The apparatus of claim 35, further including:
sling means normally slackly disposed in said post-chamber and means for raising said sling means for lifting from said post chamber such log charge as has been displaced thereinto from said chamber.